Advancing

Stem Cell Science

Without Destroying

Human Life

Domestic Policy Council

January 2007
Advancing Stem Cell Science 

Without Destroying Human Life 

Domestic Policy Council 

The White House 

January 9, 2007 

http://www.whitehouse.gov/stemcell 
Table of Contents 

Executive Summary...................................................................................2

1. Current Federal Law and Policy on Stem Cell Research..............................5

The History: From Clinton to Bush.....................................................5 

Embryonic Stem Cell Lines Available for Federal Funding....................6

Non-Federally Funded Embryonic Stem Cell Research.........................7

The Ethical Debate............................................................................8

2. Recent Developments in Non-Embryo-Destructive Stem Cell Research and 

Therapy............................................................................................................10

Advances in Adult Stem Cell Research.............................................11 

Advances in Alternative Sources of Pluripotent Cells.........................13

Pluripotent stem cells derived from dead embryos..........................17 

Pluripotent stem cells via blastomere extraction from living 

embryos.............................................................................18 

Pluripotent stem cells derived from biological artifacts.....................19 

Pluripotent stem cells via somatic cell de-differentiation..................20 

3. Conclusion.........................................................................................22

Appendix 1: Embryo Adoption as an Alternative to Embryo Destruction.......23

 

Appendix 2: What is the Connection to Human Cloning?............................24

 Appendix 3: Significant Studies on Alternative Sources of Stem Cells 

Produced Since 2005, as Highlighted by the President’s 

Bioethics Council.................................................................26 

1
Executive Summary

In 2001, President Bush established a policy on stem cell research that promotes 

scientific progress while respecting ethical boundaries. This policy is based on the 

President’s firm belief that science and ethics need not be at odds, and that a 

balance can be struck between the natural desire for rapid scientific progress and 

the demands of conscience. Drawing careful distinctions between practices that 

avoid ongoing destruction of nascent human life and those that do not, the 

President’s policy has allowed stem cell research to advance in rapid and promising 

ways—as the pages that follow will illustrate—without sacrificing the inherent dignity 

and matchless value of every human life. 

Before President Bush took office, there was no federal funding for human 

embryonic stem cell research. Then on August 9, 2001, the President announced his 

decision to allow federal funds to be used for experiments on the embryonic stem 

cell lines that existed at the date of his announcement. To avoid encouraging further 

destruction of human embryos, no taxpayer funding could be expended on research 

using cell lines from embryos destroyed from that point forward. 

The President’s policy and new funding has produced considerable scientific 

investigation and progress. Over the past six years, more than $130 million of 

federal money has been devoted to human embryonic stem cell research consistent 

with the President’s policy. Overall, nearly $3 billion has gone to innovative research 

on all forms of stem cells, contributing to dozens of proven medical treatments. 

 

In May of 2005, the President’s Council on Bioethics issued a “White Paper”1

reviewing possible non-destructive sources for additional stem cell lines in the future. 

Alternative Sources of Human Pluripotent Stem Cells examined the ethical, 

scientific, and practical prospects for a range of different approaches, and 

recommended specific investigations that could advance these techniques. The goal 

 

1

 President’s Council of Bioethics, White Paper: Alternative Sources of Human Pluripotent Stem 

Cells. (Washington, DC: President’s Council of Bioethics, May 2005). 

http://www.bioethics.gov/reports/white_paper/index.html 

2
of all of these alternative approaches is to produce the functional equivalent of 

embryonic stem cells, without harming embryos. 

In the 20 months since the Council’s report, peer-reviewed studies on each of the 

approaches have been published in leading scientific journals, suggesting many 

opportunities for ethical creation of new stem cell lines. One of the most promising 

possibilities is adult-cell reprogramming. Recent work by two research teams—Kevin 

Eggan and Chad Cowan of the Harvard Stem Cell Institute, and Shinya Yamanaka 

and Kazutoshi Takahashi at Japan’s Institute for Frontier Medical—suggests that it 

may be possible to use chemical and genetic factors to reprogram an adult cell to 

function like an embryonic stem cell. This approach could prove capable of creating 

cell lines for the study and treatment of disease without the many ethical dilemmas 

associated with the creation and destruction of embryos. 

In the first week of 2007, another very promising approach was outlined in the 

journal Nature Biotechnology. Dr. Anthony Atala of the Institute for Regenerative 

Medicine at Wake Forest University School of Medicine reported2

 that he and his 

colleagues had discovered a new and readily available source of stem cells in the 

amniotic fluid that cushions babies in the womb.3

 While the research is still 

developing, Dr. Atala and his team believe that these amniotic stem cells may be 

fully as flexible as embryonic stem cells, while having additional medical 

advantages: they are easier to grow than human embryonic stem cells, and they do 

not form tumors (a problem that has plagued embryonic stem cell use).4

 And since 

 

2

 Atala, A et al., Isolation of amniotic stem cell lines with potential for therapy, Nat Biotechnology. 

2007 Jan 7; [Epub ahead of print]. 

3

 Mary Carmichael, New Stem-Cell Source Could Alter Debate, Newsweek.com, January, 7, 

2007. 

4

 Mary Carmichael, New Stem-Cell Source Could Alter Debate, Newsweek, Web Exclusive, 

January 8, 2007; Maggie Fox, Human stem cells found in amniotic fluid, Reuters, January 8, 

2007; Breakthrough To Report In Stem Cell Research, The Discovery Of A New Source Of Stem 

Cells, NBC's Nightly News, January 7, 2007; Dan Harris, These Cells Can Be Gathered Without 

Hurting The Mother Or The Fetus, And Would Prove Much Less Controversial Than Research 

Done With Embryos,”ABC's World News Sunday, January 7, 2007.

3
amniotic stem cells can be collected without destroying human life, they avoid the 

ethical dilemmas.5

In sum, it increasingly appears that the qualities researchers value in embryonic 

cells may also exist in other stem cells that are easier to procure, more stable to 

grow, safer to use in therapies, and free of the ethical violations of embryo 

destruction. There is a gathering consensus among experts, thanks to technical 

advances, that today’s heated controversies over research that harms embryos 

could fade in the future.6 

The dramatic advances in stem cell research since 2001 are evidence that the 

President’s balanced policy is working. Scientists have shown they have the 

ingenuity and skill to pursue the potential benefits of embryonic stem cell research 

without endangering nascent human life in the process. In supporting these 

alternative approaches while maintaining longstanding bioethical guardrails which 

protect life and dignity, federal science-research funding can stay true to the ideals 

of a humane society.

 

5

 Dan Harris, These Cells Can Be Gathered Without Hurting The Mother Or The Fetus, And 

Would Prove Much Less Controversial Than Research Done With Embryos, ABC's World News 

Sunday, January 7, 2007. 

6

 Rick Weiss, Scientists See Potential in Amniotic Stem Cells, Washington Post, January 8, 2007; 

Rick Weiss, Stem Cell Advances May Make Moral Issues Moot, Washington Post , June 6, 2005. 

4
1. Current Federal Law and Policy on Stem Cell Research

The History: From Clinton to Bush 

Private-sector human embryonic stem cell research has been and continues to be 

permissible without restriction in the U.S. The national discussion over embryonic 

stem cells has largely taken the form of a debate over federal funding of this kind of 

research. Every year since 1995, the annual HHS appropriations bill has contained 

language (known as the Dickey-Wicker Amendment) that prohibits federal funding of 

research in which human embryos are destroyed or subjected to risk of injury or 

death.7

 In 1999 (a year after human embryonic stem cells were first derived in the 

lab), the Clinton Administration argued that as long as the actual destruction of 

embryos is performed with private dollars, research on the immediately resulting 

lines of stem cells could qualify for federal funding, since it technically would not be 

research in which embryos were directly destroyed with federal funding. That 

technical reading contradicted the intent of the law, and would have meant that 

taxpayer dollars would incentivize the destruction of embryos, since knowledge that 

federal funding would be available once the embryos were destroyed could provide 

a direct encouragement to engage in that destruction. 

The Clinton Administration drafted rules along the lines described above, but their 

term ended before they could be put into effect. No federal dollars ever went to 

support human embryonic stem cell research. Upon entering office, President Bush 

examined the issue closely, seeking a way to advance potentially significant 

research without using taxpayer funds to support or encourage the destruction of 

nascent human lives. 

 

7

 The full text of the Dickey Amendment can be found in each year’s Labor/HHS Appropriations 

Bill. The law states that “None of the funds made available in this Act may be used for—(1) the 

creation of a human embryo or embryos for research purposes; or(2) research in which a human 

embryo or embryos are destroyed, discarded, or knowingly subjected to risk of injury or death 

greater than that allowed for research on fetuses in utero under 45 CFR 46.204 and 46.207, and 

subsection 498(b) of the Public Health Service Act (42 U.S.C. 289g(b)). (b) For purposes of this 

section, the term ‘human embryo or embryos’ includes any organism, not protected as a human 

subject under 45 CFR 46 as of the date of the enactment of the governing appropriations act, that 

is derived by fertilization, parthenogenesis, cloning, or any other means from one or more human 

gametes or human diploid cells.” 

5
On August 9, 2001, President Bush announced his new policy: research on lines of 

human embryonic stem cells that already existed could qualify for funding, since 

those lines were created without any taxpayer-funded incentive, and the life-anddeath decision on the embryos had already been made. Lines created subsequently 

would not be eligible, so that federal dollars would not further ongoing embryo 

destruction. The President’s policy marked the first time the federal government ever 

made funding available for human embryonic stem cell research. 

Embryonic Stem Cell Lines Available for Federal Funding 

For more than half a century, the federal government has funded biomedical 

research through the National Institutes of Health. This support reflects the great 

value Americans place on the development of treatments and cures for those who 

suffer afflictions of health. But such support has never been offered indiscriminately 

or without ethical and moral restrictions. Researchers and institutions that accept 

federal funds must abide by many ethical strictures, including regulations governing 

the use of human subjects in research. 

Controversies surrounding the morality of certain scientific undertakings have given 

rise to disputes over federal funding. When making decisions that involve moral and 

ethical issues plus taxpayer dollars, responsible public policy dictates caution. The 

debate about whether the federal government should support research that involves 

the creation or destruction of human embryos naturally falls into this category of 

policy. 

This Administration is the first to provide federal funds for human embryonic stem 

cell research. And it has established this new funding within a careful framework that 

avoids encouraging the destruction of human embryos. Scientists can explore 

potential applications using existing cell lines—21 separate lines have been made 

available to researchers, in more than 700 shipments of cells, with over 3,000 more 

shipments available upon request from the NIH. To date, over 85% of human 

6
embryonic stem cell research projects leading to publication worldwide have used 

these approved lines.8

Federal Funding Devoted to Embryonic Stem Cell Research through NIH

0

20

40

60

80

100

120

140

before 2001 since 2001

Federal $ in millions

U.S. Federally Approved Lines Used in Global Human Embryonic Stem Research (HESCR)

Non-Federally Funded Embryonic Stem Cell Research 

Contrary to common misperceptions, there is no Presidential ban on human 

embryonic stem cell research. No federal mandates constrain private or stategovernment funding of any element of this science. In fact, funding by individual 

states is expected to add up to several billion dollars in the next few years. 

The President’s policy has been built on the proposition that stem cell research is 

proceeding rapidly and will continue to make progress in the future without requiring 

ethical shortcuts that use taxpayer dollars in ways that tread on established 

protections for human life. There is no reason to sacrifice longstanding moral 

concerns in a shortsighted rush for therapeutic payoffs. The wisdom of a careful 

approach would seem to be underscored by the growing likelihood (based on the 

last year’s research) that alternative sources of pluripotent stem cells may be 

available in the future without requiring the embryo destruction that has engendered 

so much controversy. 

 

8

 Jason Woen-Smith and Jennifer McCormick, An International gap in Human ES Cell Research, 

Nature Biotechnology, 2006 Apr;24(4):391-2

7
Rather than providing taxpayer dollars for methods that raise ethical concerns, the 

Administration has promoted intensified research into techniques to develop stem 

cells with the characteristics of those derived from embryos but without doing harm 

to embryos. And the ethical direction encouraged by the President in 2001 has 

begun to bear fruit. Scientists are now exploring a range of non-destructive 

techniques, with numerous articles in leading scientific journals reporting 

encouraging progress. Some examples are described in the second section of this 

report. 

The Ethical Debate 

Our nation has a long history of pioneering medical advances that improve life span 

and quality. We also have a deep tradition of protecting human life and dignity during 

scientific investigation. 

Research on embryonic stem cells raises profound ethical quandaries. Most 

fundamentally, is an embryo a human life, and something therefore to be protected? 

This topic forces us to confront fundamental questions about the beginnings of life 

and the ends of science. These issues lie at a difficult moral intersection, where the 

desire to extend and improve life crosses the need to respect all human beings 

equally. 

Embryos are humans in their earliest developmental stage. We do not have to think 

that human embryos are exactly the same in all ways as older humans to believe 

that they are entitled to respect and protection. Each of us originated as a singlecelled embryo, and from that moment have developed along a continuous biological 

trajectory throughout our existence. To speak of “an embryo” is to designate a 

human being at a particular stage. 

Our nation was founded on the principle that all of us are created equal, and 

endowed with a right to exist that is shared fully by all humans. There is no such 

thing as an excess life. And the fact that a human lacks some particular capacity, or 

8
even is going to die, does not justify experimenting on that individual, or exploiting 

him or her as a natural resource. That has long been the standard in medical 

ethics—as encoded in the Hippocratic Oath, as well as more modern codes like the 

Physician’s Oath in the 1948 Declaration of Geneva, which states: “I will maintain 

the utmost respect for human life from the time of conception.” 

To think of other human beings (and especially the weakest and most vulnerable of 

us at the beginning or end of life) as potential spare parts for use by others is a 

profound threat to human dignity and our society’s broader respect for its citizens. It 

is something the U.S. government has scrupulously avoided to this point. 

The destruction of embryos for experimental purposes could also open the way to 

more general and profound manipulations and reengineerings of human life. Without 

an understanding that life begins at conception, and that an embryo is a nascent 

human being, there will always be arguments that other uses, takeovers, and 

makeovers of embryos are justified by potential scientific and medical benefits. 

Crossing this line would needlessly encourage a conflict between science and ethics 

that can only do damage to both, and to our nation as a whole. 

This potentially dangerous opening would establish exactly the wrong tone as the 

era of biotechnology dawns. This emerging age has golden promise. But we must 

pursue its great hope in ways consistent with our principles. That will sometimes 

require saying no. To find the right paths for medical research, we must be willing to 

reject paths that are morally wrong. 

A policy that defends the inviolability of human life does not preclude the hopeful 

possibilities of new findings and new therapies. It simply means we must harness 

the creative powers of our advancing knowledge only to humane and morally 

balanced means and ends. Amidst today’s dizzying pace of technological innovation, 

it is worth taking care to make sure that our moral and ethical policies keep up. The 

biotechnology revolution will bring sound and wholesome human results over the 

long run only if it is sensibly governed. 

9
The stem cell debate is only the first in what will be an onrushing train of 

biotechnology challenges in our future. We must establish a constructive precedent 

here for taking the moral dimensions of these issues seriously. We must make 

certain we don’t force ourselves into a false choice between science and ethics—

because we need both. 

And there is good reason, and growing scientific evidence, to believe that we can 

have both. 

2. Recent Developments in Non-Embryo-Destructive Stem Cell Research and 

Therapy

In January 2004, the President’s Council on Bioethics published a report entitled 

“Monitoring Stem Cell Research.” In the introduction, the report made the following 

comment: 

Monitoring stem cell research can be a bit like watching Niagara Falls. Not 

only do scientific reports pour forth daily, as they do in many other areas of 

research, but a kind of mist rises up from the torrent of news flashes and 

editorials, making it difficult to separate knowledge from opinion and hope 

from hype. The underlying biology—whether viewed at the level of the gene, 

cell, tissue, organ, or organism—is dauntingly complex, as is all cell biology. 

At any of these levels, in this new and dynamic field, it is frequently difficult for 

even the most knowledgeable scientist to be truly certain of “what really 

causes what.”9

The emotional appeal of stem cell research places further strains of exaggeration 

and misinterpretation on scientific claims. The cumulative effect is often a very foggy 

 

9

 President’s Council of Bioethics, Monitoring Stem Cell Research, Pg. 15 (Washington, DC: 

President’s Council of Bioethics, January 2004). 

www.bioethics.gov/reports/stemcell/pcbe_final_version_monitoring_stem_cell_research.pdf 

10
glass. In the two sections below—on developments in adult stem cell research, and 

on alternative sources of pluripotent stem cells—we offer a brief overview 

summarizing some significant recent research. Our aim is to build clearer public and 

legislative understanding that there are alternative scientific approaches which may 

be able to produce the functional equivalent of embryonic stem cells, but without 

harming embryos. 

Advances in Adult Stem Cell Research 

While research on adult stem cells began decades ago, important new discoveries 

have been made in just the past few years. Scientists have found adult stem cells in 

many more tissues than they once thought likely, including the brain, bone marrow, 

blood, blood vessels, skeletal muscle, skin, liver, and other body parts.10 Given the 

right conditions, certain kinds of adult stem cells now seem to have the ability to 

differentiate into a number of different cell types. If this differentiation of adult stem 

cells can be controlled and sustained in the laboratory, these cells could become the 

basis of therapies for many serious common diseases and injuries. As examples of 

potential treatments, an NIH list includes replacing the dopamine-producing cells in 

the brains of Parkinson's patients, developing insulin-producing cells for type I 

diabetes, and repairing damaged heart muscle with new cardiac muscle cells 

following a heart attack.11

Scientists have also reported that adult stem cells may, in some cases, exhibit the 

ability to form specialized cell types of other tissues, a characteristic known as 

transdifferentiation, or plasticity. Some experiments have even suggested that 

certain adult stem cell types may be pluripotent.12 Over the past few years, several 

examples of adult stem cell plasticity have been reported.13 Most evidence indicates 

that while embryonic stem cells are capable of becoming all of the cell types of the 

 

10 http://stemcells.nih.gov/info/basics/basics4.asp 11 http://stemcells.nih.gov/info/basics/basics4.asp 12 http://stemcells.nih.gov/info/basics/basics4.asp 13 http://stemcells.nih.gov/info/basics/basics4.asp

11
body, adult stem cells may be more limited. Adult stem cells can also be difficult to 

isolate, and methods of growing them in culture are still a work in progress. 

Adult stem cells, however, do have some important scientific advantages as 

potential therapies. For one, since adult stem cells can be taken from the patient’s 

own tissue, they are genetically matched, and would not be rejected by that patient’s 

own immune system. This is one reason they have already been successful in 

treating many patients, while there are not yet any successful therapies derived from 

embryonic stem cells. As of January 9, 2007, there are currently 1,229 publicly 

available clinical trials related to adult stem cells, including 614 that are currently 

recruiting patients.14 There are no known publicly available clinical trials related to 

human embryonic stem cells.15 Over the last couple of years, clinical trials using 

adult stem cells have produced encouraging improvements in patients suffering a 

range of diseases and disorders, including leukemia, lymphoma, diabetes, advanced 

kidney cancer, and several inherited blood disorders.16 

Clinical Trials Related to Adult Stem Cells vs. Embryonic Stem Cells

0

200

400

600

800

1000

1200

1400

 

14 http://www.clinicaltrials.gov/ct/search?term=stem+cell&submit=Search 15 http://www.clinicaltrials.gov/ct/search?term=stem+cell&submit=Search 16 http://stemcells.nih.gov/info/health.asp 

12
It is important to note that in comparison to adult stem cell research, embryonic stem 

cell research is still in its infancy, and its potential should be understood in this 

context. Human embryonic stem cell studies are in early stages, and are currently 

being used to help understand the differentiation and functions of many human 

tissues, including neural, cardiac, vascular, pancreatic, hepatic, and bone. 

Embryonic stem cells have two properties that make them promising for research 

and cell therapy. First, they can be grown in tissue culture, and therefore provide an 

abundant, renewable source of cells. Second, they are pluripotent and can 

(theoretically) be directed to become virtually any cell type of the adult body. 

But while much has been postulated about the ability of embryonic stem cells to 

generate transplantable cells for medical applications, many scientific hurdles 

remain before they could be used clinically in the United States. One of the 

difficulties specific to embryonic stem cells is their propensity to form tumors. This 

dangerous property is the corollary to their extensive growth potential. Other issues 

needing solutions include questions of how to generate functional differentiated 

cells, and how to solve immune rejection issues. Although there is high potential for 

treatment of degenerative disease with human embryonic stem cells, development 

of practical applications lags behind adult stem cells, and indeed has been limited to 

animal studies thus far.17

Advances in Alternative Sources of Pluripotent Cells 

Recent biological advances have raised encouraging possibilities for producing 

powerful stem cells without harming human embryos. What scientists value most 

about embryonic stem cells is their pluripotency and expandability—that they have 

the potential to be teased into many, and perhaps all, of the different cell types in the 

body. But scientists have begun to find that this potential may also exist in certain 

cells derived without embryos. New ways of producing pluripotent cells that don’t 

require the destruction (or even endangerment) of human embryos are now being 

investigated. 

 

17 http://stemcells.nih.gov/staticresources/info/scireport/PDFs/C.%20Chapter%201.pdf (Pg. 8) 

13
In May 2005, the President's Council on Bioethics published Alternative Sources of 

Human Pluripotent Stem Cells, a White Paper which suggested four possible 

approaches for alternative sources: (1) by extracting viable cells from embryos 

already dead; (2) by non-harmful biopsy of living embryos; (3) by extracting cells 

from artificially created non-embryonic cellular systems or entities (engineered to 

lack the essential elements of an embryo); (4) by reprogramming (or dedifferentiation) of adult cells back to pluripotency. Each of these methods carries its 

own scientific and ethical uncertainties, but one or more may ultimately offer a path 

toward an ethically responsible source of pluripotent stem cells. 

Very recently, landmark research from Wake Forest University has suggested yet 

another alternative: Amniotic fluid, investigators discovered, contains highly flexible 

stem cells shed by the fetus. These appear to have all the valuable qualities of 

embryonic stem cells, plus some advantages of their own—like greater ease and 

speed of culture, and no tendency to produce tumors. Meanwhile, they are 

comparatively easy to collect without harming human life. 

We begin our review with the four methods identified by the Bioethics Council. Just 

in the short period since they were sketched out in May 2005, significant progress 

has been made on each of these techniques, as reported in a number of new, peerreviewed research studies published in leading scientific journals. At this point, one 

of the most promising avenues appears to be somatic cell reprogramming, which 

uses chemical and genetic factors to reprogram an adult cell to function like an 

embryonic stem cell. 

Each cell in an individual’s body has the same DNA as every other cell. But in the 

course of developing into specialized adult tissues, different cells undergo different 

patterns of gene activation. Somatic cell reprogramming seeks to switch on or off the 

appropriate genes to transform an adult cell back into the equivalent of an embryonic 

stem cell. This might be accomplished by stimulating the adult cell with the right 

combination of chemicals and genes, or by exposing it to the cytoplasm of an 

14
existing line of stem cells. This method could, in theory, create stem cells in bulk 

while bypassing entirely the problem of creating and destroying embryos. 

Two research teams that have demonstrated significant progress toward this sort of 

cell reprogramming are Kevin Eggan and Chad Cowan from the Harvard Stem Cell 

Institute, and Shinya Yamanaka and Kazutoshi Takahashi from the Department of 

Stem Cell Biology at Japan’s Institute for Frontier Medical Science. In August of 

2005 and August of 2006, respectively, each team published impressive results 

which seemed to produce pluripotent stem cells by reprogramming ordinary adult 

cells. 

The project18 conducted at the Harvard Stem Cell Institute fused a human adult cell 

with an embryonic stem cell. (These could come from one of the embryonic stem cell 

lines that President Bush has approved for use with federal funds.) That effectively 

turned back the clock on the adult cell such that it was reprogrammed to a 

pluripotent state. Eggan and Cowan believe that their research could lead to “an 

alternative route for creating genetically tailored human embryonic stem cells for use 

in the study and treatment of disease.”19 

Drs. Yamanaka and Takahashi published research based on mouse cells.20 Their 

complex study produced stunningly simple results: They reprogrammed adult cells 

into a pluripotent state simply by bathing them in four genetic factors. “The finding is 

an important step in controlling pluripotency, which may eventually allow the creation 

of pluripotent cells directly from somatic cells of patients,”21 comments Dr. 

Yamanaka. If successful, this could offer all the benefits of embryonic stem cells and 

more—these cells could be genetically matched to any prospective patient—without 

the ethical dilemmas of embryonic destruction. 

 

18 Cowan, C.A., Eggan, Kevin, et al., Nuclear reprogramming of somatic cells after fusion with 

human embryonic stem cells, Science, 2005 Aug 26;309(5739):1369-73. 19 Cowan, C.A., Eggan, Kevin, et al., Nuclear reprogramming of somatic cells after fusion with 

human embryonic stem cells, Science, 2005 Aug 26;309(5739):1369-73. 20 Takahashi, K. and S. Yamanaka, Induction of Pluripotent Stem Cells from Mouse Embryonic 

and Adult Fibroblast Cultures by Defined Factors, Cell, 2006 Aug 25;126(4):663-76. Epub 2006 

Aug 10. 21 http://www.eurekalert.org/pub_releases/2006-08cp-wff080906.php 

15
Other promising avenues are likely to open in the future. The latest alternative, 

published22 on January 7, 2007, in Nature Biotechnology, involves amniotic-fluid 

stem cells. Dr. Anthony Atala and a team from the Institute for Regenerative 

Medicine at Wake Forest University School of Medicine and the Harvard Medical 

School reported on a new category of readily available stem cells extractable from 

the waters cushioning babies in utero, as well as the placenta. While this very new 

research will need to be replicated and confirmed, Dr. Atala and colleagues have 

already managed to grow useful brain, bone, liver, muscle, and other replacement 

tissues using these stem cells.23

This discovery suggests that if all U.S. newborns had their amniotic stem cells 

frozen, they could be available for future tissue replacement without fear of immune 

rejection. Moreover, a bank of amniotic stem cells from the waters of 100,000 

pregnancies could supply 99 percent of the U.S. population with genetically 

compatible stem cells for possible transplantation. More studies will be needed to 

confirm that amniotic stem cells can generate all other cell types, but so far every 

culture attempted has succeeded. It must also be determined that tests conducted in 

mice will translate to humans. 

Meantime, that is but one of several promising glimmers in the latest research. What 

follows is a summary of the preliminary analysis from the Bioethics Council on the 

four alternative approaches they discussed in their May 2005 White Paper, 

supplemented by fresh additional findings from the most significant peer-reviewed 

studies published in each area since May 2005. It is important to note that while 

many of these alternative approaches show great promise, all of them are still being 

tested in animals and are thus in the early stages of development. The Bioethics 

Council has conducted only a preliminary analysis of the approaches, as used in 

animals. The Administration does not endorse any of these specific avenues of 

research in humans at this time. All new approaches will have to be carefully 

 

22 Atala, A et al., Isolation of amniotic stem cell lines with potential for therapy, Nat Biotechnology. 

2007 Jan 7; [Epub ahead of print].

23 http://www.eurekalert.org/pub_releases/2007-01/wfub-sdn010207.php 

16
considered by scientists, regulators, and others as appropriate on a case-by-case 

basis, as further information and research becomes available. It may be that some of 

these research proposals could prove inconsistent with the Dickey-Wicker 

Amendment protections against creating, destroying, or harming human embryos, or 

they may fail some other test of ethical or scientific viability. But the cumulative 

weight of this emerging science is, as a Washington Post science journalist recently 

summarized, “adding credence to an emerging consensus among experts that the 

popular distinction between embryonic and ‘adult’ stem cells...is artificial.”24

a. Pluripotent Stem Cells Derived from Dead Embryos 

Under this proposal, viable cells would be derived from early in vitro fertilization (IVF) 

embryos (of roughly 4-8 cells) that have spontaneously died (as large percentages 

of early embryos do). Crucial to this approach is defining and verifying what 

represents organismic death in an early embryo, which represents an ongoing 

challenge for ethics and science. This would be a determining factor in whether this 

approach could ever be used in humans. Drs. Donald Landry and Howard Zucker of 

the Columbia University College of Physicians and Surgeons presented this 

proposal to the Council. 

The preliminary evaluation from the Council in 2005 was that while it raised “some 

serious ethical questions,” the Council found the proposal “to be ethically acceptable 

for basic investigation in humans” as long as “stringent guidelines like those 

proposed by Drs. Landry and Zucker were strictly observed.” At the time, the 

proposal had not been tested, even in animals. The Council suggested that certain 

non-invasive studies to explore and define organismic death could be pursued 

immediately. 

In June 2006, Dr. Landry published a peer-reviewed study25 that proposed applying 

“the ethical framework currently used for obtaining essential organs from deceased 

 

24 Rick Weiss, Scientists See Potential in Amniotic Stem Cells, Washington Post, January 8, 2007 25 Don Landry et al., Hypocellularity and Absence of Compaction as Criteria for Embryo Death, 

Regenerative Medicine. Published in June 2006. 

17
persons for transplantation” to the harvesting of stem cells from dead human 

embryos. The study presented a history of the concept of embryonic death and 

compared the function of viable embryos with non-viable embryos. Dr. Landry’s 

research suggested that an irreversible loss of function could be documented and 

thus used as criteria that would permit a determination of embryonic death. Using 

this criteria, Dr. Landry made the case that approximately a fifth of all embryos 

generated for in vitro fertilization could be re-classified as dead. This would enable 

thousands of new embryonic stem cell lines to be created without destroying a single 

living embryo. 

In September 2006, scientists from the Centre for Stem Cell Biology and 

Developmental Genetics at the University of Newcastle in Britain published a peerreviewed study26 that described how embryos lacking essential function could be 

used as a source for the derivation of human embryonic stem cells. 

Despite the promising work of Dr. Landry and the scientists at Newcastle, more work 

is required to address the concern that stem cells from dead embryos might not 

have the same pluripotent capacity as stem cells obtained from living embryos. In 

addition, more research is required on the concept and criteria that would permit 

determination of embryonic death in a way that is ethically unassailable for use in 

human embryos. 

b. Pluripotent Stem Cells via Blastomere Extraction from Living Embryos

Under this proposal, pluripotent stem cells would be obtained through biopsy of an 

early human embryo. Crucial to this approach is finding a stage of early embryonic 

development at which one or a few cells can be removed without harming the 

embryo, with the removed cells being useable as a source of pluripotent stem cells. 

 

26 Zhang, X., P. Stojkovic, et al., Derivation of human embryonic stem cells from developing and 

arrested embryos, Stem Cells Express, 2006 Dec;24(12):2669-76. Epub 2006 Sep 21.. 

18
The preliminary evaluation from the Council in 2005 was that this proposal was 

ethically unacceptable for humans. The Council stated that imposing “risks on living 

embryos destined to become children, for the sake of acquiring stem cells for 

research” could not be justified. While the approach could be attempted in animals, 

the Council did not anticipate that results from animal experimentation could alter its 

assessment that this method would be ethically unacceptable for humans. 

 

In August 2006, Dr. Robert Lanza and a team at the firm Advanced Cell Technology 

(ACT) made widely reported27 claims that human embryonic stem cells could be 

derived from blastomeres without requiring the blastomeres’ destruction. However, 

once the details of the study’s methodology were reported, it became clear that the 

techniques used by the researchers did in fact destroy every one of the human 

embryos used, a fact ACT did not make clear in its initial press releases. This work 

thus neither proved nor disproved that human embryonic stem cells could be derived 

from individual cells extracted from an embryo without harming it. 

c. Pluripotent Stem Cells Derived from Biological Artifacts

Under this proposal, pluripotent stem cells lines would be derived from an 

engineered “biological artifact” that lacks the organismal character of a human 

embryo. Crucial to this approach is demonstrating both that the developing entity is 

truly not a human embryo and that the cells derived from it are normal human 

pluripotent cells. In addition, one must show that creating such biological artifacts 

does not itself introduce other ethical problems. One such proposal, Altered Nuclear 

Transfer (ANT), was presented to the Council by member Dr. William Hurlbut of 

Stanford University. 

The preliminary evaluation from the Council in 2005 was that this proposal would 

need to be carefully tested in animals before human trials could be considered, but 

that there were no insuperable ethical objections that would preclude pursuing it. 

 

27 Klimanskya, I., Y. Chung, S. Becker, et al., Human embryonic stem cell lines derived from 

single blastomeres, Nature, Advance online publication, August 23, 2006.

19
The possibility of any future endorsement for trying this approach in humans would 

depend upon a more thorough ethical analysis made possible in part by the animal 

experiments. 

In October 2005, Rudolf Jaenisch and Alex Meissner, scientists at the Whitehead 

Institute for Biomedical Research at MIT, conducted a peer-reviewed study28 of ANT 

in mice. “To assess the validity” of ANT, the researchers conducted a study that 

used a process of gene silencing and nuclear transfer to generate a laboratoryconstructed biological entity that could not implant in a uterus and was 

morphologically unlike a natural embryo. This non-embryonic entity nonetheless 

yielded fully functional pluripotent stem cells with the same characteristics as those 

obtained from embryos. The study in mice noted that this approach could produce 

pluripotent stem cells genetically matched to patients (because the nucleus 

transferred could be from one of their own cells). 

More recently, in November 2006 testimony29 to the Bioethics Council, Dr. Hans 

Scholer, Director of Cell and Developmental Biology at the Max Planck Institute in 

Muenster, Germany, discussed further advances that support the scientific feasibility 

and moral acceptability of ANT. Dr. Scholer used ANT techniques to preemptively 

silence a key factor essential for defining an embryonic organism. Using this 

technique he was able to obtain pluripotent stem cell lines at an earlier stage and at 

a rate 50% higher than from direct destruction of IVF-created embryos. 

d. Pluripotent Stem Cells via Somatic Cell De-differentiation

Under this proposal, adult cells would be reprogrammed to “de-differentiate” back 

into pluripotent stem cells. Crucial to this approach is discovering a way to reverse 

cell differentiation all the way to pluripotency, but without creating an organism 

capable of developing as nascent life. 

 

28 Meissner, A. and R. Jaenisch, Generation of nuclear transfer-derived pluripotent ES cells from 

cloned Cdx2-deficient blastocyst, Nature, 239: 212-5 (2006). 29 http://www.bioethics.gov/transcripts/nov06/session1.html 

20
The preliminary evaluation from the Council in 2005 was that this approach was 

ethically acceptable for use in humans, if and when it becomes scientifically 

practical, provided the line between pluripotent cell and living organism can be 

maintained. The Council noted that while this approach was scientifically and 

technically uncertain, there were encouraging results appearing in the scientific 

literature.30

In 2005, scientists from the Harvard Stem Cell Institute published a peer-reviewed 

study31 in which a fusion of human embryonic stem cells with adult cells suggested 

that adult cells could be reprogrammed. If the remaining technical barriers are 

overcome—and some of them are significant—the approaches discussed in this 

study could circumvent societal concerns over cloning or the destruction of human 

embryos. A year later, Drs. Takahashi and Yamanaka of Japan published their peerreviewed mouse study32 examining 24 genes as candidates for conveying 

pluripotency.33 They discovered that altering just four genetic factors proved 

sufficient to change adult cells into pluripotent stem cells. Scientists will now try to 

determine if human adult cells can be similarly reprogrammed using this method. 

In November 2006, scientists from the School of Biosciences and Institute of 

Genetics, University of Nottingham, Loughborough, reviewed34 the recent scientific 

advancements in reprogramming and concluded there is sufficient evidence 

 

30 Guan K et al., Pluripotency of spermatogonial stem cells from adult mouse testis, Nature 440, 

1199-1203, 27 April 2006; Kanatsu-Shinohara M & Shinohara T, The germ of pluripotency, 

Nature Biotechnology 24, 663-664, June 2006; Cyranoski D, Stem cells from testes: could it 

work? Nature 440, 586-587, March 30, 2006; Carlin R et al., Reproductive Biology and 

Endocrinology 4:8, doi:10.1186/1477-7827-4-8, 6 February 2006. 31 Cowan, C.A., Eggan, Kevin, et al., Nuclear reprogramming of somatic cells after fusion with 

human embryonic stem cells, Science, 309: 1369-1373, 2005 Aug 26;309(5739):1369-73. 32 Takahashi, K. and S. Yamanaka, Induction of Pluripotent Stem Cells from Mouse Embryonic 

and Adult Fibroblast Cultures by Defined Factors, Cell, 2006 Aug 25;126(4):663-76. Epub 2006 

Aug 10.

33 http://www.eurekalert.org/pub_releases/2006-08cp-wff080906.php 34 Andrew Johnson et al., Reprogramming Somatic Cells into Stem Cells, Reproduction, 

November 2006. 

21
demonstrating that adult cells can be reprogrammed and that cell-based approaches 

for therapeutics may be a realistic expectation in the future. The study reviewed nine 

reprogramming approaches that are commonly used today and commented on their 

respective advantages and limitations. While it is too early to tell which approaches 

may or may not work, the sheer number of methods makes clear that there may be 

several different ways to induce reprogramming of adult cells in the future. 

3. Conclusion

 

As this report shows, there has been tremendous scientific progress of late in 

exploring methods of deriving pluripotent stem cells without destroying embryos. 

This groundbreaking alternative research has developed under President Bush’s 

insistence on advancing stem cell research within clear ethical guidelines. With 

continued support for non-destructive alternatives, new developments will continue 

to unfold in this field in the years to come, holding the potential for innovative 

progress toward new medical cures, while at the same time upholding human dignity 

and the sanctity of innocent life.

22
Appendix 1

Embryo adoption as an alternative to embryo destruction 

In the complex debate over human embryonic stem cell research, it is important to 

remember that real lives are involved—both the lives of those with diseases who 

might find therapies or cures from this research, and the lives of embryos who will be 

destroyed or harmed in the process. 

President Bush strongly supports embryo adoption as a life-affirming alternative to 

embryo destruction. Embryo adoption provides an option for the survival and 

development of embryos frozen in fertility clinics, giving them a chance at life and 

giving infertile couples the opportunity to build a family. 

The value in frozen embryos can be seen in each child who began his or her life as 

a product of in vitro fertilization, remained unused and frozen after the fertility 

treatments were complete, but now breathes and burgeons in an adopted family. 

These “snowflake” children remind us of what is lost when embryos are destroyed in 

the name of research. They remind us that all human life begins as but a tiny 

collection of cells. And, they remind us that in our zeal for new treatments and cures 

it is important for society not to abandon moral fundamentals. 

Embryo adoption shows that frozen embryos do not have to be destroyed. The 

Administration has worked to inform doctors and infertile couples of embryo adoption 

programs, and the President signed a bill in 2002 granting $1 million per year for 

HHS grants to publicize embryo adoption opportunities. To date, the Nightlight 

Christian Adoptions agency has matched 289 placing families with 192 adopting 

families. The resulting new lives are not raw materials to be exploited, but rather gifts 

to be cherished. 

Embryo adoptions programs have led to the birth of 118 babies, with 25 

families currently expecting. These children are reminders that embryos are 

not raw materials to be exploited, but rather gifts to be cherished. 

23
Appendix 2

What is the connection to human cloning? 

Human cloning would involve creating a new human being who is genetically 

identical to an existing human. It would be done by replacing the nucleus of an egg 

with the nucleus of a cell taken from the body of a donor. The result would be a 

developing human embryo carrying the genetic identity of the nucleus donor. This is 

the same technique that was used to create Dolly the sheep. 

A cloned embryo is produced in the lab, and so exists at first outside the body of a 

mother, like an IVF embryo. The question of what is done with that embryo is the 

same as what is done with IVF embryos. It could be implanted in a woman, to 

potentially produce a cloned child. Or it could be experimented on or destroyed for 

its stem cells. Neither of these options is morally acceptable. We do not want to 

produce cloned children, for a wide variety of ethical reasons with which nearly 

everyone agrees. Likewise, we should not create human life merely to use it for 

research. As the President has said, “We recoil at the idea of growing human beings 

for spare body parts, or creating life for our convenience.” 

Since neither possible use of cloned embryos is morally acceptable, the President 

has consistently argued that the only appropriate, effective, and responsible policy 

toward human cloning is to prohibit it. To prevent either the creation of life for 

experimental destruction or the production of cloned children, he believes, cloned 

human embryos should never be created. 

Advocates of cloning for research (often referred to by its technical name—somatic 

cell nuclear transfer, or SCNT) try to assuage concerns by assuring us that they do 

not plan to transfer the cloned embryos into the womb of a woman. But whether or 

not the embryo is implanted in a woman for gestation and birth is not the action that 

defines human cloning, and makes it repugnant to most observers. That is simply a 

transfer, something accomplished with IVF embryos routinely. The morally 

significant act in human cloning occurs before the transfer—at the point when the 

24
25

embryo is manufactured. Intentionally creating human life to destroy it for laboratory 

research is itself a violation of an important moral principle. Moreover, the 

development of the cloning techniques involved will inevitably hasten the day when 

some practitioner oblivious to public recoil will arrange for embryos to be implanted, 

and cloned humans to be born. 
Appendix 3

This referenced collection of studies can be found on the website of the President’s Bioethics Council as of January 9, 2007. The Council did not participate in the development of any other section or appendix of this report. This appendix includes the studies from the following three sections of the Council’s site: Advances in NonEmbryonic Stem Cell Research Since 2005, Recent Studies Suggesting that Some Adult Cells Have Pluripotent Characteristics, and Update of New Research on Alternative Sources of Pluripotent Stem Cells Since May 2005. The studies cited below are a 

sampling of the published and peer-reviewed material available on the subject. The list will be updated on a regular basis.

http://www.bioethics.gov/stemcells/index.html

Significant Studies on Alternative Sources of Stem Cells Produced Since 2005 as Highlighted by the President’s Bioethics Council as of January 9, 2007 Advances in Non-Embryonic Stem Cell Research Since 2005 2007 Isolation of amniotic stem cell lines with potential for therapy, Published online: 7 January 2007; | doi:10.1038/nbt1274 Paolo De Coppi1, 3, Georg Bartsch Jr1, 3, M Minhaj Siddiqui1, Tao Xu1, Cesar C Santos1, Laura Perin1, Gustavo Mostoslavsky2, Angéline C Serre2, Evan Y Snyder2, James J Yoo1, Mark E Furth1, Shay Soker1 & Anthony Atala11 Wake Forest Institute for Regenerative Medicine, Wake Forest University School of Medicine, Medical Center Boulevard, Winston-Salem, NC, 27157-1094, USA. 2 Children's Hospital and Harvard Medical School, 300 Longwood Avenue, Boston, Massachusetts, 02115, USA. 3 These authors contributed equally to this work. Abstract: Stem cells capable of differentiating to multiple lineages may be valuable for 

therapy. We report the isolation of human and rodent amniotic fluid–derived stem (AFS) cells that express embryonic and adult stem cell markers. Undifferentiated AFS cells expand extensively without feeders, double in 36 h and are not tumorigenic. Lines maintained for over 250 population doublings retained long telomeres and a normal karyotype. AFS cells are broadly multipotent. Clonal human lines verified by retroviral 

marking were induced to differentiate into cell types representing each embryonic germ 

layer, including cells of adipogenic, osteogenic, myogenic, hepatic lineages. Examples of differentiated cells derived frdisplaying specialized functions include neuronal lineage cneurotransmitter L-glutamate or expressing G-protein-gatepotassium channels, hepatic lineage cells producing urea, 

forming tissue-engineered bone. 

Isolation and functional characterization of murine proDevon A. Lawson et al., Proc Natl Acad Sci U S A. 2007 JaDec 21.Abstract: The ability to isolate prostate stem cells is essenprostate development and disease. In vitro prostate colonywere used to quantitatively measure murine prostate stem/and self-renewal. Cell surface markers were screened for tnegatively enrich for cells with enhanced growth potential in Immunohistochemical and FACS analyses demonstrate thamarkers can be used to discriminate prostate stromal (CD3(CD24(+)CD49f(-)), basal epithelial (CD24(+)CD49f(+)), heTer119(+)), and endothelial (CD31(+)) lineages. Sorting for )Ter119(-)Sca-1(+)CD49f(+) antigenic profile results in a 60and sphere-forming cells. These cells can self-renew and emany generations and can differentiate to produce prostatiboth basal and luminal cells in vivo. These cells also localizthe region of the gland that is proximal to the urethra, which prostate stem cell niche. Prostate stem cells can be isolateby using this antigenic profile. The remarkable similarity in prostate and mammary gland stem cells suggests these mamong epithelial stem cell populations. 2006 Ex Vivo Large-Scale Generation of Human Platelets froTakuya Matsunaga et al., Stem Cells. 2006 2006 Dec;24(1Abstract: In the present investigation, we generated platel(CB) CD34(+) cells using a three-phase culture system. We CD34(+) cells on telomerase gene-transduced human stromserum-free medium supplemented with stem cell factor (SCand thrombopoietin (TPO) for 14 days. We then transferred and cultured for another 14 days with fresh medium contain
addition to the original cytokine cocktail. Subsequently, we cultured the cells in a liquid 

culture medium containing SCF, FL, TPO, and IL-11 for another 5 days to recover PLT fractions from the supernatant, which were then gel-filtered to purify the PLTs. The calculated yield of PLTs from 1.0 unit of CB (5 x 10(6) CD34(+) cells) was 1.26 x 10(11)-1.68 x 10(11) PLTs. These numbers of PLTs are equivalent to 2.5-3.4 units of random donor-derived PLTs or 2/5-6/10 of single-apheresis PLTs. The CB-derived PLTs exhibited features quite similar to those from peripheral blood in morphology, as revealed by electron micrographs, and in function, as revealed by fibrinogen/ADP aggregation, with the appearance of P-selectin and activated glycoprotein IIb-IIIa antigens. Thus, this culture system may be applicable for large-scale generation of PLTs for future clinical use. Functional Neuronal Differentiation of Bone Marrow-Derived Mesenchymal Stem Cells Philippe Tropel et al., Stem Cells. 2006 Dec;24(12):2868-76. Epub 2006 Aug 10.Abstract: Recent results have shown the ability of bone marrow cells to migrate in the brain and to acquire neuronal or glial characteristics. In vitro, bone marrow-derived MSCs can be induced by chemical compounds to express markers of these lineages. In an effort to set up a mouse model of such differentiation, we addressed the neuronal potentiality of mouse MSCs (mMSCs) that we recently purified. These cells expressed 

nestin, a specific marker of neural progenitors. Under differentiating conditions, mMSCs 

display a distinct neuronal shape and express neuronal markers NF-L (neurofilamentlight, or neurofilament 70 kDa) and class III beta-tubulin. Moreover, differentiated mMSCs acquire neuron-like functions characterized by a cytosolic calcium rise in 

response to various specific neuronal activators. Finally, we further demonstrated for the first time that clonal mMSCs and their progeny are competent to differentiate along the neuronal pathway, demonstrating that these bone marrow-derived stem cells share characteristics of widely multipotent stem cells unrestricted to mesenchymal differentiation pathways. 

Bone Marrow Transplantation Attenuates the Myopathic Phenotype of a Muscular Mouse Model of Spinal Muscular AtrophyNouzha Salah-Mohellibi et al., Stem Cells. 2006 Dec;24(12):2723-32. Epub 2006 Aug 3. Abstract: Bone marrow (BM) transplantation was performed on a muscular mouse model of spinal muscular atrophy that had been created by mutating the survival of motor neuron gene (Smn) in myofibers only. This model is characterized by a severe myopathy and progressive loss of muscle fibers leading to paralysis. Transplantation of wild-type BM cells following irradiation at a low dose (6 Gy) improved motor capacity (+85%). This correlated with a normalization of myofiber number associated with a higher number of regenerating myofibers (1.6-fold increase) and an activation of CD34 

and Pax7 satellite cells. However, BM cells had a very limitto mutant myofibers (2%). These data suggest that BM tranattenuate the myopathic phenotype through an improvemeregeneration of recipient mutant mice, a process likely med

BM-derived cells. This hypothesis was further supported by protein extracts from transplanted mutant mice to promote (1.6-fold increase). In addition, a tremendous upregulation (HGF), which activates quiescent satellite cells, was found transplanted mutants compared with nontransplanted mutaCre-loxP system, we show that BM-derived muscle cells weharboring this biological activity. Taken together, our data sactivity is likely involved in muscle regeneration improvemetransplantation. HGF may represent an attractive paracrine activity. Increased generation of neuronal progenitors after ischadult human forebrain.Macas J, et al., J Neurosci. 2006 Dec 13;26(50):13114-9.Abstract: The adult human brain retains the capacity to gehippocampal formation (Eriksson et al., 1998) and neuronathe forebrain (Bernier et al., 2000), but to what extent it is csuch as ischemia, is not known. We analyzed postmortem pathological human brain tissue (n = 54) to study the cellulain the forebrain. We observed that cells expressing the NPC adhesion cell molecule (PSA-NCAM) are continuously genesubventricular zone (SVZ) and migrate along the olfactory torganized in migrating chains as in the adult rodent rostral number was lower in the olfactory tracts of brains from old compared with young (29 + 36 years of age) individuals. Mbrains of patients of advanced age (60-87 years of age), isnumber of Ki-67-positive cells in the ipsilateral SVZ without death. Additionally, ischemia led to an increased number oclose to the lateral ventricular walls, compared with brains oobvious neuropathologic changes. These results suggest thretains a capacity to respond to ischemic injuries and that teven in old age. 

A neurovascular niche for neurogenesis after stroke.Ohab JJ, et al., J Neurosci. 2006 Dec 13;26(50):13007-16.Abstract: Stroke causes cell death but also birth and migra
sites of ischemic damage. The cellular environment that induces neuronal regeneration 

and migration after stroke has not been defined. We have used a model of long-distance migration of newly born neurons from the subventricular zone to cortex after stroke to define the cellular cues that induce neuronal regeneration after CNS injury. Mitotic, genetic, and viral labeling and chemokine/growth factor gain- and loss-of-function studies show that stroke induces neurogenesis from a GFAP-expressing progenitor cell in the subventricular zone and migration of newly born neurons into a unique neurovascular niche in peri-infarct cortex. Within this neurovascular niche, newly born, immature neurons closely associate with the remodeling vasculature. Neurogenesis and angiogenesis are causally linked through vascular production of stromal-derived factor 1 (SDF1) and angiopoietin 1 (Ang1). Furthermore, SDF1 and Ang1 promote post-stroke neuroblast migration and behavioral recovery. These experiments define a novel brain environment for neuronal regeneration after stroke and identify molecular mechanisms that are shared between angiogenesis and neurogenesis during functional recovery from brain injury. Spontaneous Fusion and Non-clonal Growth of Adult Neural Stem CellsSebastian Jessberger et al., Stem Cells, published online December 21, 2006; doi:10.1634/stemcells.2006-0620.Abstract: Multipotent neural stem cells (NSCs) can be isolated from various regions of 

the adult brain and propagated in vitro. Recent reports have suggested spontaneous fusion events among NSCs when grown as free-floating neurospheres that may affect the genetic composition of NSC cultures. We used adult NSCs expressing either red fluorescent protein (RFP) or green fluorescent protein (GFP) to analyze the fusion frequency of rat and mouse NSCs. Fluorescence activated cell sorting (FACS) revealed, that under proliferating conditions approximately 0.2% of rat and mouse NSCs coexpressed RFP and GFP, irrespective of whether the cells were grown as neurospheres (mouse NSCs) or as attached monolayers (rat and mouse NSCs). Fused cells did not proliferate and could not be propagated, suggesting that aberrantly fused cells are not viable. Furthermore, we found that neither neurospheres nor monolayers grew clonally, as even very low-density cultures had spheres containing both GFP- and RFP-expressing cells and monolayer patches with GFP- and RFP-expressing cells in close proximity. The non-clonal growth between distinct NSC populations strongly suggests the use of careful and precise culture conditions, such as single cell assays, to characterize potency and growth of NSCs in vitro. 

Designer Self-Assembling Peptide Nanofiber Scaffolds for Adult Mouse Neural Stem Cell 3-Dimensional Cultures Fabrizio Gelain et al., PLoS ONE 1. e119., i:10.1371/journal.pone.0000119, December 2006. 

Abstract: Biomedical researchers have become increasing

conventional 2-dimensional tissue cell culture systems, incmulti-well plates and slides, to fully address many critical isbiology and neurobiology, such as the 3-D microenvironmecell migration and 3-D cell-cell contact interactions. In ordebehave in the 3-D body, it is important to develop a well-cosystem where every single ingredient is known. Here we re

cell culture system using a designer peptide nanofiber scafstem cells. We attached several functional motifs, including 

and bone marrow homing motifs, to a self-assembling peptRADARADARADARADA-COHN2). These functionalized passembly into a nanofiber structure similar to Matrigel. Durfully embedded in the 3-D environment of the scaffold. Two containing bone marrow homing motifs significantly enhancwithout extra soluble growth and neurotrophic factors to the these designer scaffolds, the cell populations with b-Tubulimarkers are similar to those found in cell populations culturexpression profiling array experiments showed selective ge

involved in neural stem cell adhesion and differentiation. Beare intrinsically pure and a number of desired function celluincorporate, these designer peptide nanofiber scaffolds proD culture system for diverse tissue cells, and are useful as and cell biology. 

Mesenchymal Stem Cell-Mediated Functional Tooth ReWataru Sonoyama et al., PLoS ONE 2006 Dec 20;1:e79. Abstract: Mesenchymal stem cell-mediated tissue regenerfor regenerative medicine for a wide range of applications. population of stem cells isolated from the root apical papilla cells from apical papilla). Using a minipig model, we transpperiodontal ligament stem cells (PDLSCs) to generate a roocapable of supporting a porcelain crown, resulting in normaintegrates a stem cell-mediated tissue regeneration strategstructure, and current dental crown technologies. This hybr

approach led to recovery of tooth strength and appearance

Transplantation of Mesenchymal Stem Cells is an OptimSurgery Dianji Fang et al., Stem Cells, published online December doi:10.1634/stemcells.2006-0576.
Abstract: Mesenchymal stem cells (MSCs) are able to differentiate into a variety of cell 

types, offering promising approaches for stem-cell-mediated tissue regeneration. Here we explored the potential of utilizing MSCs to reconstruct orofacial tissue, thereby, altering the orofacial appearance. We demonstrated that bone marrow MSCs were capable of generating bone structures and bone-associated marrow elements on the surfaces of the orofacial bone. This resulted in significant re-contouring of the facial appearance in mouse and swine. Notably, the newly formed bone/marrow tissues integrated with the surfaces of the recipient bones and re-established a functional bone marrow organ-like system. These data suggested that MSC-mediated tissue regeneration led to a body structure extension, with the re-establishment of all functional components necessary for maintaining the bone/marrow organ. In addition, we found that the subcutaneous transplantation of another population of MSCs, the human periodontal ligament stem cells (PDLSCs) could form substantial amounts of collagen fibers and improve facial wrinkles in mouse. By contrast, bone marrow MSCs failed to survive at 8 weeks post-transplantation under the conditions used for the PDLSC transplantation. This study suggested that the mutual interactions between donor MSCs and recipient microenvironment determine long-term outcome of the functional tissue regeneration. 

Granulocyte-Colony–Stimulating Factor Mobilizes Bone Marrow Stem Cells in Patients With Subacute Ischemic Stroke The Stem Cell Trial of Recovery EnhanceMent After Stroke (STEMS) Pilot Randomized, Controlled Trial (ISRCTN 16784092) Nikola Sprigg et al., Stroke. 2006 Dec; 37(12):2979-83. Epub 2006 Nov 2.Background and Purpose: Loss of motor function is common after stroke and leads to significant chronic disability. Stem cells are capable of self-renewal and of differentiating into multiple cell types, including neurones, glia, and vascular cells. We assessed the safety of granulocyte-colony-stimulating factor (G-CSF) after stroke and its effect on circulating CD34+ stem cells. METHODS: We performed a 2-center, dose-escalation, 

double-blind, randomized, placebo-controlled pilot trial (ISRCTN 16784092) of G-CSF (6 blocks of 1 to 10 microg/kg SC, 1 or 5 daily doses) in 36 patients with recent ischemic stroke. Circulating CD34+ stem cells were measured by flow cytometry; blood counts and measures of safety and functional outcome were also monitored. All measures were made blinded to treatment. RESULTS: Thirty-six patients, whose mean+/-SD age was 76+/-8 years and of whom 50% were male, were recruited. G-CSF (5 days of 10 microg/kg) increased CD34+ count in a dose-dependent manner, from 2.5 to 37.7 at day 5 (area under curve, P=0.005). A dose-dependent rise in white cell count (P<0.001) was also seen. There was no difference between treatment groups in the number of patients with serious adverse events: G-CSF, 7/24 (29%) versus placebo 3/12 (25%), or in their dependence (modified Rankin Scale, median 4, interquartile range, 3 to 5) at 90 days. CONCLUSIONS: G-CSF is effective at mobilizing bone marrow CD34+ stem cells in 

patients with recent ischemic stroke. Administration is feas

and well tolerated. The fate of mobilized cells and their efferemain to be determined. 

Successful treatment of AL amyloidosis with high-dose stem cell transplantation in patients over age 65David C. Seldin et al., Blood. 2006 Dec 1;108(12):3945-7. EAbstract: Recently, protocols using high-dose melphalan cperipheral blood stem cell transplantation (HDM/SCT) have treatment of patients with immunoglobulin light chain (AL) aperitransplantation mortality is greater than for other hematleads to durable hematologic complete responses, improvequality of life, and extended survival in a substantial proporwhether this treatment can be applied to older patients, we treatment outcomes for 65 patients (aged 65 years or oldercompared with outcomes for 280 younger patients. For patmeet the same eligibility criteria as younger patients, toxicitand survival were not significantly different from those obseindicating that older patients should not be excluded a priorHDM/SCT treatment. 

Isolation of an adult blood-derived progenitor cell popudifferentiation into angiogenic, myocardial and neural lYael Porat et al., British Journal of Haematology. 2006 Dec

Abstract: Blood-derived adult stem cells were previously c

therapeutic use because of their small numbers. This repornovel human cell population derived from the peripheral blopopulation (SCP), and defined by the expression of CD31BCD34Bright, but not lineage-specific features. The SCP wainto a variety of cell lineages upon exposure to defined cultcells exhibited morphological, immunocytochemical and funangiogenic, neural or myocardial lineages. Angiogenic cell CD34, CD133, KDR, Tie-2, CD144, von Willebrand factor, binding of Ulex-Lectin and uptake of acetylated low density secreted interleukin-8, vascular endothelial growth factor atube-like structures in vitro. The majority of CD31Bright ACuptake. Neural cell precursors (NCPs) expressed the neuroTubulin, and Neu-N, the glial markers GFAP and O4, and rstimulation. Myocardial cell precursors (MCPs) expressed DConnexin 43. In conclusion, the simple and rapid method o
resulting considerable quantities of lineage-specific precursor cells makes it a potential 

source of autologous treatment for a variety of diseases. Myeloid progenitors differentiate intomicroglia and promote vascular repair in a model of ischemic retinopathyMatthew R. Ritter et al., J. Clin. Invest. 2006 Dec;116(12):3266-76. Epub 2006 Nov 16.Abstract: Vision loss associated with ischemic diseases such as retinopathy of 

prematurity and diabetic retinopathy are often due to retinal neovascularization. While significant progress has been made in the development of compounds useful for the treatment of abnormal vascular permeability and proliferation, such therapies do not address the underlying hypoxia that stimulates the observed vascular growth. Using a model of oxygen-induced retinopathy, we demonstrate that a population of adult BMderived myeloid progenitor cells migrated to avascular regions of the retina, differentiated into microglia, and facilitated normalization of the vasculature. Myeloid-specific hypoxiainducible factor 1alpha (HIF-1alpha) expression was required for this function, and we also demonstrate that endogenous microglia participated in retinal vascularization. These findings suggest what we believe to be a novel therapeutic approach for the treatment of ischemic retinopathies that promotes vascular repair rather than destruction. 

Cytokine-induced differentiation of multipotent adult progenitor cells into functional smooth muscle cells J. Ross et al. J. Clin. Invest. 2006 Dec;116(12):3139-49. Epub 2006 Nov 9.Abstract: Smooth muscle formation and function are critical in development and postnatal life. Hence, studies aimed at better understanding SMC differentiation are of great importance. Here, we report that multipotent adult progenitor cells (MAPCs) isolated from rat, murine, porcine, and human bone marrow demonstrate the potential to differentiate into cells with an SMC-like phenotype and function. TGF-beta1 alone or combined with PDGF-BB in serum-free medium induces a temporally correct expression of transcripts and proteins consistent with smooth muscle development. Furthermore, SMCs derived from MAPCs (MAPC-SMCs) demonstrated functional L-type calcium channels. MAPC-SMCs entrapped in fibrin vascular molds became circumferentially aligned and generated force in response to KCl, the L-type channel opener FPL64176, or the SMC agonists 5-HT and ET-1, and exhibited complete relaxation in response to the Rho-kinase inhibitor Y-27632. Cyclic distention (5% circumferential strain) for 3 weeks increased responses by 2- to 3-fold, consistent with what occurred in neonatal SMCs. These results provide evidence that MAPC-SMCs are phenotypically and functionally similar to neonatal SMCs and that the in vitro MAPC-SMC differentiation system may be an ideal model for the study of SMC development. Moreover, MAPCSMCs may lend themselves to tissue engineering applications. 

Human stem/progenitor cells from bone marrow promoendogenous neural stem cells in the hippocampus of mMunoz JR, et al. Proc Natl Acad Sci U S A. 2005 Dec 13;10Dec 5.Abstract: Stem/progenitor cells from bone marrow and othto repair injured tissues by differentiating into tissue-specifichemokines, and, in part, by cell fusion. Here we prepared human bone marrow (MSCs) and implanted athem into the hippocampus of immunodeficient mice. The implanted humthe proliferation of endogenous neural stem cells that expreSox2. Labeling of the mice with BrdUrd demonstrated that, the human MSCs, BrdUrd-labeled endogenous cells migrathippocampus (positive for doublecortin) and expressed maneural or oligodendrocyte progenitors. Subpopulations of Bshort cytoplasmic processes immunoreactive for nerve growdays after implantation, the newly generated cells expresseneurons and astrocytes. Also, subpopulations of BrdUrd-la

processes immunoreactive for ciliary neurotrophic factor, nfactor, or VEGF. Therefore, implantation of human MSCs smigration, and differentiation of the endogenous neural stedifferentiated neural cells. The results provide a paradigm tin which MSCs or related stem/progenitor cells were found disease models even though a limited number of the cells e

Autologous serum-derived cultivated oral epithelial trasurface disease.Ang LP, et al. Arch Ophthalmol. 2006 Nov;124(11):1543-51OBJECTIVE: To evaluate the use of autologous serum (AS

epithelial transplants for the treatment of severe ocular surfMETHODS: We used AS from 10 patients with severe oculimbal stem cell deficiency to develop autologous cultivated These were compared with epithelial equivalents derived frserum-supplemented medium. Surgery involved removal osurrounding diseased tissue and transplantation of the AS-The oral equivalents were analyzed by review of histologic findings. RESULTS: Oral epithelial sheets cultivated in AS- and feta

media were similar in morphology, and both formed basemproteins important for maintaining graft integrity. Complete 
achieved within 2 to 5 days postoperatively. The ocular surface remained stable without 

major complications in all eyes during a mean +/- SD follow-up of 12.6 +/- 3.9 months. The visual acuity improved by more than 2 lines in 9 of 10 eyes, with transplanted oral epithelium surviving up to 19 months. CONCLUSION: The successful use of an AS-derived oral epithelial equivalent to treat severe ocular surface disease represents an important advance in the pursuit of completely autologous xenobiotic-free bioengineered ocular equivalents for clinical transplantation. Tracking Neural Stem Cells in Patients with Brain TraumaJianhong Zhu, et al. N Engl J Med. 2006 Nov 30;355(22):2376-8.To the Editor: Regeneration of damaged brain tissue with neural stem cells is a 

promising strategy for reversing neurologic deficits.1 Superparamagnetic iron oxide nanoparticles have been used to label and track dendritic cells in the experimental treatment of melanoma2 and in experiments in animals. We report the feasibility of labeling neural stem cells from humans (two patients for whom written informed consent was provided by next of kin) with superparamagnetic iron oxide nanoparticles and tracking them with the use of magnetic resonance imaging (MRI). 

Antibody Targeting of Stem Cells to Infarcted Myocardium Randall J. Lee et al. Stem Cells, published online November 30, 2006; doi:10.1634/stemcells.2005-0602.Abstract: Hematopoietic stem cell therapy for myocardial repair is limited by the number of stem cells that migrate to, engraft in and proliferate at sites of injured myocardium. To alleviate this limitation, we studied whether a strategy using a bispecific antibody could target human stem cells specifically to injuredmyocardium and preserve myocardial function. Using a xenogeneic rat model whereby ischemic injury was induced by transient ligation of the left anterior descending artery (LAD), we determined the ability of a bispecific antibody to target human CD34+ cells to specific antigens expressed in ischemic injured myocardium. A bispecific antibody comprised of an anti-CD45 antibody recognizing the common leukocyte antigen found on hematopoietic stem cells (HSC) and an antibody recognizing myosin light chain, an organ-specific injury antigen expressed by infarcted myocardium was prepared by chemical conjugation. CD34+ cells armed and 

unarmed with this BiAb were injected intravenously in rats 2 days post-myocardial injury. Immunohistochemistry studies showed that the armed CD34+ cells specifically localized to the infracted region of the heart, co-localized with troponin T stained cells and colocalized with vascular structures. Compared to unarmed CD34+ cells, the bispecific antibody improved delivery of the stem cells to injured myocardium and such targeted delivery was correlated with improved myocardial function five weeksfollowing infarction 

(p<0.01). Bispecific antibody targeting offers a unique meastem cells to facilitate organ repair and a tool to study stem 

Stem Cells, Myocardial Regeneration and MethodologicPiero Anversa et al. Stem Cells, published online Novembedoi:10.1634/stemcells.2006-0623.Abstract: This review discusses the controversy that has pmyocardial regeneration in the last three decades. The notdifferentiated postmitotic organ has been so strong that obsopposite paradigm have been questioned technically and cmisinterpretation of results collected with cellular, moleculamethodologies has been the prevailing position in the scienregeneration mediated by activation of endogenous progenand differentiation of primitive cells from the bone marrow han attempt to defend an unrealistic view of the heart. This asupport of the notion that the heart is an organ regulated by responsible for cardiac homeostasis and repair. 

Improved clinical outcome after intracoronary administderived progenitor cells in acute myocardial infarction: REPAIR-AMI trial.Schachinger V, et al. Eur Heart J. 2006 Dec;27(23):2775-8AIMS: To investigate the clinical outcome after intracorona

autologous progenitor cells in patients with acute myocardiMETHODS AND RESULTS: Using a double-blind, placebodesign, we randomized 204 patients with successfully repeintracoronary infusion of bone-marrow-derived progenitor cmedium into the infarct artery 3-7 days after successful infamonths, the pre-specified cumulative endpoint of death, mynecessity for revascularization was significantly reduced in with placebo (P=0.009). Likewise, the combined endpoint dmyocardial infarction, and rehospitalization for heart failure reduced in patients receiving intracoronary BMC administraadministration of BMC remained a significant predictor of a by Cox regression analysis, adjusting for classical predictoCONCLUSION: Intracoronary administration of BMCs is as

reduction of the occurrence of major adverse cardiovasculascale studies are warranted to confirm the effects of BMC amorbidity in patients with AMIs. 
In Vitro and in Vivo Arterial Differentiation of Human Multipotent Adult Progenitor 

CellsXabier L. Aranguren et al. Blood First Edition Paper. prepublished online November 7, 2006; DOI 10.1182/blood-2006-06-030411.Abstract: Many stem cell types have been shown to differentiate into endothelial cells 

(ECs), however, their specification to arterial or venous endothelium remains unexplored. We tested whether a specific arterial or venous EC fate could be induced in human Multipotent Adult Progenitor Cells (hMAPCs) and AC133+ cells (hAC133+). In vitro, in the presence of VEGF165, hAC133+ cells only adopted a venous and microvascular EC phenotype, while hMAPCs differentiated into both arterial and venous ECs, possibly because hMAPCs expressed significantly more sonic hedgehog (Shh) and its receptors, as well as Notch 1 and 3 receptors and some of their ligands. Accordingly, blocking either of those pathways attenuated in vitro arterial EC differentiation from hMAPCs. Complementarily, stimulating these pathways by addition of Delta-like 4 (Dll-4), a Notch ligand, and Shh to VEGF165 further boosted arterial differentiation in hMAPCs both in vitro and in an in vivo matrigel model. These results represent the first demonstration of adult stem cells with the potential to be differentiated into different types of ECs in vitro and in vivo and provide a useful human model to study arterio-venous specification. 

Therapeutic strategies for Parkinson.s disease based on the modulation of adult neurogenesisMartine Geraerts et al. Stem Cells, published online November 2, 2006; doi:10.1634/stemcells.2006-0364.Abstract: Parkinson.s disease (PD) is a progressive neurodegenerative disorder, 

affecting millions of people world-wide. To date, treatment strategies are mainly symptomatic and aimed at increasing dopamine levels in the degenerating nigrostriatal system. Hope rests upon the development of effective neurorestorative or neuroregenerative therapies based on gene and stem cell therapy or a combination of both. The results of experimental therapies based on transplanting exogenous dopamine-rich fetal cells or growth factor (GDNF) overexpression into the brain of Parkinson.s disease patients encourage future cell- and gene-based strategies. The endogenous neural stem cells of the adult brain provide an alternative and attractive cell source for neuroregeneration. Prior to designing endogenous stem cell therapies, one has to investigate the possible impact of PD on adult neuronal stem cell pools and their neurogenic potential. We review the experimental data obtained in animal models or based on analysis of patients. brain prior to describing different treatment strategies. Strategies aiming to enhance neuronal stem cell proliferation and/or differentiation in the striatum or the substantia nigra will have to be compared in animal models and selected prior to clinical studies. 

Mesoangioblast stem cells ameliorate muscle function Sampaolesi M et al. Nature. 2006 Nov 30;444(7119):574-9Abstract: Duchenne muscular dystrophy remains an untreseverely limits motility and life expectancy in affected childrspecifically reproducing the alterations in the dystrophin gehuman pathology is the golden retriever dog model. Affectemutation in intron 6, resulting in complete absence of the dand severe muscle degeneration with nearly complete loss Death usually occurs at about 1 year of age as a result of fHere we report that intra-arterial delivery of wild-type caninassociated stem cells) results in an extensive recovery of dmuscle morphology and function (confirmed by measuremesingle fibres). The outcome is a remarkable clinical amelioractive motility. These data qualify mesoangioblasts as candtherapy for Duchenne patients. Transplantation of human neural stem cells exerts neuof Parkinson's disease.Yasuhara T et al. J Neurosci. 2006 Nov 29;26(48):12497-5Abstract: Neural stem cells (NSCs) possess high potencie

neuronal differentiation. We explored here whether transplacloned by v-myc gene transfer, HB1.F3 cells, is a feasible tParkinson's disease. In vivo, green fluorescent protein-labeviable cells in 3 microl of PBS) when stereotaxically transpltransplant paradigm) into the 6-hydroxydopamine-lesioned ameliorated parkinsonian behavioral symptoms compared bolus, or continuous minipump infusion of trophic factor, or derived functional effects were accompanied by preservatio(TH) immunoreactivity along the nigrostriatal pathway. Grafthe lesioned brain with some labeled with neuronal marker and decorated with synaptophysin-positive terminals. Furthneurogenesis was activated in the subventricular zone of trexplore the neuroprotective mechanisms underlying HB1.Fperformed cell culture studies and found that a modest numand dopamine and cAMP-regulated phosphoprotein 32 poswere nestin positive, suggesting a mixed population of matAdministration of the HB1.F3 supernatant to human derived cells and fetal rat ventral mesencephalic dopaminergic neuhydroxydopamine neurotoxicity by suppressing apoptosis twhich was blocked by anti-stem cell factor antibody alone, 
kinase/Akt inhibitor LY294002 [2-(4-morpholinyl)-8-phenyl-1(4H)-benzopyran-4-one] 

alone, or a combination of both. These results suggest that HB1.F3 cell transplantation exerts neuroprotective effects against dopaminergic depletion in vitro and in vivo because of trophic factor secretion and neuronal differentiation. Adipose Tissue-Derived Mesenchymal Stem Cells Have In Vivo Immunosuppressive Properties Applicable for the Control of the Graft-VersusHost DiseaseRosa Yanez et al. Stem Cells. 2006 Nov;24(11):2582-91. Epub 2006 Jul 27.Abstract: Previous studies have shown the relevance of bone marrow- derived MSCs (BM-MSCs) in controlling graft-versus- host disease (GVHD) after allogeneic transplantation. Since adipose tissue-derived MSCs (Ad-MSCs) may constitute a good alternative to BM-MSCs, we have expanded MSCs derived from human adipose tissue (hAd-MSCs) and mouse adipose tissue (mAd-MSCs), investigated the immunoregulatory properties of these cells, and evaluated their capacity to control GVHD in mice. The phenotype and immunoregulatory properties of expanded hAd-MSCs were similar to those of human BM-MSCs. Moreover, hAd-MSCs inhibited the proliferation and cytokine secretion of human primary T cells in response to mitogens and allogeneic T cells. Similarly, ex vivo expanded mAd-MSCs had an equivalent immunophenotype and exerted immunoregulatory properties similar to those of hAd-MSCs. Moreover, the infusion of mAd-MSCs in mice transplanted with haploidentical hematopoietic grafts controlled the lethal GVHD that occurred in control recipient mice. These findings 

constitute the first experimental proof that Ad-MSCs can efficiently control the GVHD associated with allogeneic hematopoietic transplantation, opening new perspectives for the clinical use of Ad-MSCs. 

Side Population Cells Isolated from Porcine Dental Pulp Tissue with Self-Renewal and Multipotency for Dentinogenesis, Chondrogenesis, Adipogenesis, and NeurogenesisKoichiro Iohara et al. Stem Cells. 2006 Nov;24(11):2493-503. Epub 2006 Jul 27.Abstract: Dental pulp has the potential to form dentin as a regenerative response to caries. This regeneration is mediated by stem/progenitor cells. Thus, stem cell therapy might be of potential utility in induction of reparative dentin. We isolated side population (SP) cells from dental pulp based on the exclusion of the DNA binding dye Hoechst 33342 by flow cytometry and compared its self-renewal capacities and multipotency with non-SP cells and primary pulp cells. The cumulative cell number of the SP cells was greater than the non-SP cells and primary pulp cells. Bmi1 was continuously expressed in SP cells, suggesting longer proliferative lifespan and self-renewal capacity of SP cells. Next, the maintenance of the multilineage differentiation potential of pulp SP cells was investigated. Expression of type II collagen and aggrecan confirmed chondrogenic 

conversion (30%) of SP cells. SP cells expressed peroxiso

receptor _ and adaptor protein 2, showing adipogenic convand proteins of neurofilament and neuromodulin confirmed (90%). These results demonstrate that pulp SP cells maintapotential. We further examined whether bone morphogenetinduce differentiation of pulp SP cells into odontoblasts. BMof dentin sialophosphoprotein (Dspp) and enamelysin in thrcultures. Autogenous transplantation of the Bmp2-supplemamputated pulp stimulated the reparative dentin formation. 

cells, which are enriched for stem cell properties and usefu

for dentin regeneration. 

Bone Marrow-Derived Cells Contribute to Podocyte ReAmelioration of Renal Disease in a Mouse Model of AlpEvangelia I. Prodromidi et al. Stem Cells. 2006 Nov;24(11)Abstract: In a model of autosomally recessive Alport syndalpha3 chain of collagen IV (Col4alpha3(-/-)) develop progrleading to renal failure. The proposed mechanism is that ponormal glomerular basement membrane, so the collagen IV easily degraded. We used this model to study whether bontransplantation can rectify this podocyte defect by correctinCol4alpha3. Female C57BL/6 Col4alpha3(-/-) (-/-) mice wefrom male wild-type (+/+) mice. Control female -/- mice recelittermates. Serum urea and creatinine levels were significaBM compared with those of -/- BM 20 weeks post-transplaninterstitial fibrosis were also significantly decreased. Donorby in situ hybridization (ISH) for the Y chromosome, and flumicroscopy indicated that some showed an apparent podoctransplanted with +/+ BM. Glomeruli of these mice showed alpha3(IV) protein by immunofluorescence. alpha3(IV) mRNtranscription-polymerase chain reaction and ISH in some mbut not -/- BM. However, a single injection of mesenchymairradiated -/- recipients did not improve renal disease. Our dfunction in Col4alpha3(-/-) mice results from BM transplantaand the mechanism by which this occurs may in part involvwithout the gene defect. 

Leukemia inhibitory factor promotes neural stem cell sbrain.Bauer S, Patterson PH. J Neurosci. 2006 Nov 15;26(46):12
Abstract: Although neural stem cells (NSCs) persist in various areas of the adult brain, 

their contribution to brain repair after injury is very limited. Treatment with exogenous growth factors can mitigate this limitation, suggesting that the brain environment is normally deficient in permissive cues and that it may be possible to stimulate the latent regenerative potential of endogenous progenitors with appropriate signals. We analyzed the effects of overexpressing the cytokine leukemia inhibitory factor (LIF) on adult neurogenesis in the normal brain. We found that LIF reduces neurogenesis in the olfactory bulb and subventricular zone by acting directly on NSCs. LIF appears to promote NSC self-renewal, preventing the emergence of more differentiated cell types. This ultimately leads to an expansion of the NSC pool. Our results have implications for the development of therapeutic strategies for brain repair and suggest that LIF may be useful, in combination with other factors, in promoting regeneration in the adult brain. 

Thymosin beta4 induces adult epicardial progenitor mobilization and neovascularization.Smart N, et al. Nature. 2006 Nov 15; [Epub ahead of print]Abstract: Cardiac failure has a principal underlying aetiology of ischaemic damage arising from vascular insufficiency. Molecules that regulate collateral growth in the ischaemic heart also regulate coronary vasculature formation during embryogenesis. Here we identify thymosin beta4 (Tbeta4) as essential for all aspects of coronary vessel development in mice, and demonstrate that Tbeta4 stimulates significant outgrowth from quiescent adult epicardial explants, restoring pluripotency and triggering differentiation of fibroblasts, smooth muscle cells and endothelial cells. Tbeta4 knockdown in the heart is accompanied by significant reduction in the pro-angiogenic cleavage product N-acetylseryl-aspartyl-lysyl-proline (AcSDKP). Although injection of AcSDKP was unable to rescue Tbeta4 mutant hearts, it significantly enhanced endothelial cell differentiation from adult epicardially derived precursor cells. This study identifies Tbeta4 and AcSDKP as potent stimulators of coronary vasculogenesis and angiogenesis, and reveals Tbeta4-induced adult epicardial cells as a viable source of vascular progenitors for continued renewal of regressed vessels at low basal level or sustained neovascularization following cardiac injury. Multipotent flk-1+ cardiovascular progenitor cells give rise to the cardiomyocyte, endothelial, and vascular smooth muscle lineages.Kattman SJ, et al. Dev Cell. 2006 Nov;11(5):723-32. Abstract: Cell-tracing studies in the mouse indicate that the cardiac lineage arises from 

a population that expresses the vascular endothelial growth factor receptor 2 (VEGFR2, Flk-1), suggesting that it may develop from a progenitor with vascular potential. Using the embryonic stem (ES) cell differentiation model, we have identified a cardiovascular progenitor based on the temporal expression of the primitive streak (PS) marker 

brachyury and Flk-1. Comparable progenitors could also be stage embryos. When cultured with cytokines known to funindividual cardiovascular progenitors generated colonies thendothelial, and vascular smooth muscle (VSM) potential. of this previously unidentified population suggests that the system develops from multipotential progenitors. 

Multipotent stromal cells from human marrow home to pancreatic islets and renal glomeruli in diabetic NOD/sLee RH, et al. Proc Natl Acad Sci U S A. 2006 Nov 14;103Nov 6.Abstract: We tested the hypothesis that multipotent stromamarrow (hMSCs) can provide a potential therapy for human but nonlethal hyperglycemia was produced in NOD/scid mistreptozotocin on days 1-4, and hMSCs were delivered via 10 and 17. The hMSCs lowered blood glucose levels in the relative to untreated controls (18.34 mM +/- 1.12 SE vs. 270.0019). ELISAs demonstrated that blood levels of mouse hMSC-treated as compared with untreated diabetic mice, bdetected. PCR assays detected human Alu sequences in Don day 17 or 32 but not in other tissues, except heart, into wIn the hMSC-treated diabetic mice, there was an increase icells producing mouse insulin. Rare islets contained human human insulin or PDX-1. Most of the beta cells in the islets expressed mouse insulin. In kidneys of hMSC-treated diabfound in the glomeruli. There was a decrease in mesangial macrophage infiltration. A few of the human cells appeared glomerular endothelial cells. Therefore, the results raised thbe useful in enhancing insulin secretion and perhaps improdevelop in patients with diabetes mellitus. 

Engraftment of Donor-Derived Epithelial Cells in MultipMarrow Transplantation into Newborn MiceEmanuela M. Bruscia et al. Stem Cells. 2006 Oct;24(10):22Abstract: Bone marrow-derived cells (BMDCs) can engrafthe body, including in the lung, liver, and gastrointestinal (Gtransplantation into lethally irradiated adult recipients. Excewhich marrow-derived epithelial cells have a survival advanthe currently attained levels of epithelial engraftment of BMtherapeutic benefit. Here we tested whether the degree of b
engraftment would be higher if bone marrow transplantation (BMT) were performed on 1-

day-old mice, when tissues are undergoing rapid growth and remodeling. BMT into newborn mice after multiple different regimens allowed for robust hematopoietic engraftment, as well as the development of rare donor-derived epithelial cells in the GI tract and lung but not in the liver. The highest epithelial engraftment (0.02%) was obtained in mice that received a preparative regimen of two doses of busulfan in utero. When BMDCs were transplanted into myelosuppressed newborn mice that lacked expression of the cystic fibrosis transmembrane conductance regulator (CFTR) protein, the chloride channel that is not functional in patients with cystic fibrosis, the engrafted mice showed partial restoration of CFTR channel activity, suggesting that marrowderived epithelial cells in the GI tract were functional. However, BMT into newborn mice, regardless of the myeloablative regimen used, did not increase the number of bone marrow-derived epithelial cells over that which occurs after BMT into lethally irradiated adult mice. Improved Liver Function in Patients with Liver Cirrhosis After Autologous Bone Marrow Cell Infusion TherapyShuji Terai et al. Stem Cells. 2006 Oct;24(10):2292-8. Epub 2006 Jun 15.Abstract: Supplementation of mesenchymal stem cells (MSCs) during hematopoietic 

stem cell (HSC) transplantation alleviates complications such as graft-versus-host 

disease, leading to a speedy recovery of hematopoiesis. To meet this clinical demand, a fast MSC expansion method is required. In the present study, we examined the feasibility of using a rotary bioreactor system to expand MSCs from isolated bone marrow mononuclear cells. The cells were cultured in a rotary bioreactor with Myelocult medium containing a combination of supplementary factors, including stem cell factor and interleukin-3 and -6. After 8 days of culture, total cell numbers, Stro-1(+)CD44(+)CD34(-) MSCs, and CD34(+)CD44(+)Stro-1(-) HSCs were increased 9-, 29-, and 8-fold, respectively. Colony-forming efficiency-fibroblast per day of the bioreactor-treated cells was 1.44-fold higher than that of the cells without bioreactor treatment. The bioreactorexpanded MSCs showed expression of primitive MSC markers endoglin (SH2) and vimentin, whereas markers associated with lineage differentiation, including osteocalcin (osteogenesis), type II collagen (chondrogenesis), and C/EBP-alpha (CCAAT/enhancerbinding protein-alpha) (adipogenesis), were not detected. Upon induction, the bioreactorexpanded MSCs were able to differentiate into osteoblasts, chondrocytes, and adipocytes. We conclude that the rotary bioreactor with the modified Myelocult medium 

reported in this study may be used to rapidly expand MSCs. 

Transforming growth factor alpha promotes sequential conversion of mature astrocytes into neural progenitors and stem cells.Sharif A, et al. Oncogene. 2006 Oct 23; [Epub ahead of print]

Abstract: An instability of the mature cell phenotype is thoformation of gliomas, primary brain tumors deriving from ascells. Transforming growth factor alpha (TGFalpha) is an e

the earliest stages of gliomas, and exerts trophic effects on Here, we questioned whether prolonged TGFalpha exposunormal mature astrocyte phenotype. We first developed as

residual neural stem cells or progenitors. We demonstrate 

treatment result in the functional conversion of a population radial glial cells, a population of neural progenitors. TGFalpsupport embryonic neurons migration, and give birth to cellexpressing neuronal markers and the electrophysiological pLengthening TGFalpha treatment to months results in the dwith neural stem cells properties: they form floating cellular renewing, can be clonally derived from a single cell and diffneuronal lineage. This study uncovers a novel population oin response to a single epigenetic factor, to regress progres

cell stage via an intermediate progenitor stage.Oncogene aOctober 2006; doi:10.1038/sj.onc.1210071. 

Risk-adapted craniospinal radiotherapy followed by higstem-cell rescue in children with newly diagnosed medMedulloblastoma-96): long-term results from a prospecGajjar A, et al. Lancet Oncol. 2006 Oct;7(10):813-20.BACKGROUND: Current treatment for medulloblastoma, wradiotherapy and 1 year of chemotherapy, does not cure mdisease. We aimed to investigate the effectiveness of risk-aby a shortened period of dose-intense chemotherapy in chiMETHODS: After resection, patients were classified as havmedulloblastoma (< or = 1.5 cm2 residual tumour and no mmedulloblastoma (> 1.5 cm2 residual disease or metastatic neuraxis) medulloblastoma. All patients received risk-adapt(23.4 Gy for average-risk disease and 36.0-39.6 Gy for higfour cycles of cyclophosphamide-based, dose-intensive chassessed regularly for disease status and treatment side-ewas 5-year event-free survival; we also measured overall sregistered with ClinicalTrials.gov, number NCT00003211. FINDINGS: Of 134 children with medulloblastoma who undaverage-risk, 48 high-risk), 119 (89%) completed the plannrelated deaths occurred. 5-year overall survival was 85% (9the average-risk group and 70% (54-84) in those in the higevent-free survival was 83% (73-93) and 70% (55-85), resp116 patients whose histology was reviewed centrally, histo
5-year event-free survival (p=0.04): 84% (74-95) for classic histology, 77% (49-100) for 

desmoplastic tumours, and 57% (33-80) for large-cell anaplastic tumours. INTERPRETATION: Risk-adapted radiotherapy followed by a shortened schedule of dose-intensive chemotherapy can be used to improve the outcome of patients with highrisk medulloblastoma. Embryonic-like stem cells from umbilical cord blood and potential for neural modelingMcGuckin C et al. Acta Neurobiol. Exp (2006) 66: 321-329.Abstract: Stem cells offer the distinct prospect of changing the face of human medicine. 

However, although they have potential to form different tissues, are still in the early stages of development as therapeutic interventions. The three most used stem cell sources are umbilical cord blood, bone marrow and human embryos. Whilst, cord blood is now used to treat over 70 disorders, at the time of writing this manuscript, not a single disease has been overcome or ameliorated using human embryonic stem cells. Advancing stem cell medicine requires ethically sound and scientifically robust models to develop tomorrow’s medicines. Media attention, however, distracts from this reality; it is important to remember that stem cells are a new visitor to the medical world and require more research. Here we describe the utility of human cord blood to develop neural models that are necessary to take stem cells to the next level – into human therapies. 

Aging does not alter the number or phenotype of putative stem/progenitor cells in the neurogenic region of the hippocampusBharathi Hattiangady, Ashok K. Shetty Neurobiol Aging (2006). doi:10.1016/j.neurobiolaging.2006.09.015.Abstract: To investigate whether dramatically waned dentate neurogenesis during aging is linked to diminution in neural stem/progenitor cell (NSC) number, we counted cells immunopositive for Sox-2 (a putative marker of NSCs) in the subgranular zone (SGZ) of young, middle-aged and aged F344 rats. The young SGZ comprised ~50,000 Sox-2+ cells and this amount did not diminish with aging. Quantity of GFAP+ cells and vimentin+ radial glia also remained stable during aging in this region. Besides, in all age groups, analogous fractions of Sox-2+ cells expressed GFAP (astrocytes/NSCs), NG-2 (oligodendrocyte-progenitors/NSCs), vimentin (radial glia), S-100_ (astrocytes) and doublecortin (new neurons). Nevertheless, analyses of Sox-2+ cells with proliferative markers insinuated an increased quiescence of NSCs with aging. Moreover, the volume of rat-endothelial-cell-antigen-1+ capillaries (vascular-niches) within the SGZ exhibited 

an age-related decline, resulting in an increased expanse between NSCs and capillaries. Thus, decreased dentate neurogenesis during aging is not attributable to altered number or phenotype of NSCs. Instead, it appears to be an outcome of increased quiescence of NSCs due to changes in NSC milieu. 

MCP-3 is a myocardial mesenchymal stem cell homing Soren Schenk, et al. Stem Cells, published online October doi:10.1634/stemcells.2006-0293.Abstract: Mesenchymal stem cells (MSC) have received a

potential in a number of disease states including bone formengraftment following marrow transplantation, graft verse hDespite this diverse interest the molecular signals regulatininjury are unclear. MSC are known to transiently home to thmyocardium. To identify MSC homing factors, we determinpattern as a function of time after MI. We merged these proreceptors expressed on MSC but not cardiac fibroblasts, wMI. This analysis identified MCP-3 as a potential MSC homMCP-3 1 month after MI restored MSC homing to the heartMSC cardiac function improved in MCP-3 expressing heartcontrol hearts (8.6%, p=0.47). MSC engraftment was not ainto cardiac myocytes. Rather MSC engraftment appeared myofibroblasts and remodeling of the collagen matrix. Thesan MSC homing factor; local over-expression of MCP-3 rectissue and improves cardiac remodeling independent of ca

Cells isolated from umbilical cord tissue rescue photorfunctions in a rodent model of retinal disease R. D. Lund et al. Stem Cells, published online October 19, doi:10.1634/stemcells.2006-0308.Abstract: Progressive photoreceptor degeneration resultinfactors is a leading and largely untreatable cause of blindnethis study was to find a cell type that is effective in slowing degeneration in an animal model of human retinal disease, generated in sufficient numbers for clinical application. We four human derived cell types in preserving photoreceptor iafter injection into the subretinal space of the Royal College progress of degeneration. Umbilical tissue-derived cells, plmesenchymal stem cells were studied; dermal fibroblasts svarious ages up to 100 days, electroretinogram responses, threshold were measured. Both umbilical-derived and mesereduced the degree of functional deterioration in each test. was little better than controls. Umbilical tissue-derived cells photoreceptor rescue; mesenchymal stem cells gave only lgave sham levels of rescue. Donor cells were confined to twas no evidence of cell differentiation into neurons, of tumo
pathology. Since the umbilical tissue-derived cells demonstrated the best photoreceptor 

rescue and unlike mesenchymal stem cells were capable of sustained population doublings without karyotypic changes, it is proposed that they may provide utility as a cell source for the treatment of retinal degenerative diseases such as retinitis pigmentosa. Sarcoma Derived from Cultured Mesenchymal Stem CellsJakub Tolar et al. Stem Cells, published online October 12, 2006; doi:10.1634/stemcells.2005-0620.Abstract: To study the biodistribution of Mesenchymal Stem Cells (MSCs), we labeled adult murine C57BL/6 MSCs with firefly luciferase and DsRed2 fluorescent protein using non-viral Sleeping Beauty transposons, and co-infused labeled MSCs with bone marrow into irradiated allogeneic recipients. Using in vivo whole body imaging, luciferase signals were shown to be increased between weeks 3 and 12. Unexpectedly, some mice with the highest luciferase signals died and all surviving mice developed foci of sarcoma in lungs. Two mice also developed sarcomas in their extremities. Common cytogenetic abnormalities were identified in tumor cells isolated from different animals. Original MSC cultures not labeled with transposons, as well as independently isolated cultured MSCs were found to be cytogenetically abnormal. Moreover, primary MSC.s derived from the bone marrow of both BALB/c and C57BL/6 mice showed cytogenetic aberrations after several passages in vitro, showing that transformation was not a strain specific nor rare event. Clonal evolution was observed in vivo suggesting that the critical transformation event(s) occurred before infusion. Mapping of the transposition insertion sites did not identify an obvious transposon related genetic abnormality and p53 was not overexpressed. Infusion of MSC-derived sarcoma cells resulted in malignant lesions in secondary recipients. This new sarcoma cell line, S1, is unique in having a cytogenetic profile similar to human sarcoma and contains bioluminescent and fluorescent genes 

making it useful for investigations of cellular biodistribution and tumor response to therapy in vivo. More importantly, our study indicates that sarcoma can evolve from MSC cultures. 

Transcoronary transplantation of progenitor cells after myocardial infarction.Assmus B, et al. N Engl J Med. 2006 Sep 21;355(12):1222-32.BACKGROUND: Pilot studies suggest that intracoronary transplantation of progenitor 

cells derived from bone marrow (BMC) or circulating blood (CPC) may improve left ventricular function after acute myocardial infarction. The effects of cell transplantation in patients with healed myocardial infarction are unknown. METHODS: After an initial pilot trial involving 17 patients, we randomly assigned, in a controlled crossover study, 75 patients with stable ischemic heart disease who had had a myocardial infarction at least 3 months previously to receive either no cell infusion (23 

patients) or infusion of CPC (24 patients) or BMC (28 patieartery supplying the most dyskinetic left ventricular area. Thgroup were subsequently randomly assigned to receive CPwho initially received BMC or CPC crossed over to receive 3 months' follow-up. RESULTS: The absolute change in left ventricular ejection 

greater among patients receiving BMC (+2.9 percentage poreceiving CPC (-0.4 percentage point, P=0.003) or no infusP<0.001). The increase in global cardiac function was relat

regional contractility in the area targeted by intracoronary incrossover phase of the study revealed that intracoronary inassociated with a significant increase in global and regiona

regardless of whether patients crossed over from control to 

CONCLUSIONS: Intracoronary infusion of progenitor cells patients with healed myocardial infarction. Transplantation moderate but significant improvement in the left ventricular months. 2006 Massachusetts Medical Society 

Intracoronary bone marrow-derived progenitor cells in infarction.Schachinger V, et al. N Engl J Med. 2006 Sep 21;355(12):BACKGROUND: Pilot trials suggest that the intracoronary 

progenitor cells may improve left ventricular function after a

METHODS: In a multicenter trial, we randomly assigned 20myocardial infarction to receive an intracoronary infusion of bone marrow (BMC) or placebo medium into the infarct artesuccessful reperfusion therapy. RESULTS: At 4 months, the absolute improvement in the g

fraction (LVEF) was significantly greater in the BMC group (mean [+/-SD] increase, 5.5+/-7.3% vs. 3.0+/-6.5%; P=0.01LVEF at or below the median value of 48.9% derived the mimprovement in LVEF, 5.0%; 95% confidence interval, 2.0 tintracoronary infusion of BMC was associated with a reduccombined clinical end point of death, recurrence of myocarrevascularization procedure (P=0.01). CONCLUSIONS: Intracoronary administration of BMC is as

recovery of left ventricular contractile function in patients winfarction. Large-scale studies are warranted to examine thprogenitor-cell administration on morbidity and mortality. 20Society 
Intracoronary injection of mononuclear bone marrow cells in acute myocardial 

infarction.Lunde K, et al. N Engl J Med. 2006 Sep 21;355(12):1199-209.BACKGROUND: Previous studies have shown improvement in left ventricular function 

after intracoronary injection of autologous cells derived from bone marrow (BMC) in the acute phase of myocardial infarction. We designed a randomized, controlled trial to further investigate the effects of this treatment. METHODS: Patients with acute ST-elevation myocardial infarction of the anterior wall treated with percutaneous coronary intervention were randomly assigned to the group that underwent intracoronary injection of autologous mononuclear BMC or to the control group, in which neither aspiration nor sham injection was performed. Left ventricular function was assessed with the use of electrocardiogram-gated single-photon-emission 

computed tomography (SPECT) and echocardiography at baseline and magnetic resonance imaging (MRI) 2 to 3 weeks after the infarction. These procedures were repeated 6 months after the infarction. End points were changes in the left ventricular ejection fraction (LVEF), end-diastolic volume, and infarct size. RESULTS: Of the 50 patients assigned to treatment with mononuclear BMC, 47 underwent intracoronary injection of the cells at a median of 6 days after myocardial infarction. There were 50 patients in the control group. The mean (+/-SD) change in LVEF, measured with the use of SPECT, between baseline and 6 months after infarction for all patients was 7.6+/-10.4 percentage points. The effect of BMC treatment on the change in LVEF was an increase of 0.6 percentage point (95% confidence interval [CI], -3.4 to 4.6; P=0.77) on SPECT, an increase of 0.6 percentage point (95% CI, -2.6 to 3.8; P=0.70) on echocardiography, and a decrease of 3.0 percentage points (95% CI, 0.1 to -6.1; P=0.054) on MRI. The two groups did not differ significantly in changes in left ventricular end-diastolic volume or infarct size and had similar rates of adverse events. CONCLUSIONS: With the methods used, we found no effects of intracoronary injection of autologous mononuclear BMC on global left ventricular function. 2006 Massachusetts Medical Society 

Integrins Are Markers of Human Neural Stem CellsPeter E. Hall et al. Stem Cells. 2006 Sep;24(9):2078-84. Epub 2006 May 11.Abstract: The identification of markers for the isolation of human neural stem cells 

(hNSCs) is essential for studies of their biology and therapeutic applications. This study investigated expression of the integrin receptor family by hNSCs as potential markers. Selection of alpha6(hi) or beta1(hi) cells by fluorescence-activated cell sorting led to an enrichment of human neural precursors, as shown by both neurosphere forming assays and increased expression of prominin-1, sox2, sox3, nestin, bmi1, and musashi1 in the beta1(hi) population. Cells expressing high levels of beta1 integrin also expressed prominin-1 (CD133), a marker previously used to isolate hNSCs, and selection using 

integrin beta1(hi) cells or prominin-1(hi) cells was found to enriching for hNSCs from neurospheres. Therefore, integrin 

are highly expressed by human neural precursors and reprtheir prospective isolation. 

High Yield of Cells Committed to the Photoreceptor FatRetinal Stem CellsFaten Merhi-Soussi et al. Stem Cells. 2006 Sep;24(9):2060Abstract: The purpose of the present work was to generat(RSCs), a large number of cells committed toward the photprovide an unlimited cell source for neurogenesis and transexpanded RSCs (at least 34 passages) sharing characterisprimed the cells in vitro with fibroblast growth factor (FGF)-were treated with the B27 supplement to induce cell differedifferentiation, cells expressed cell type-specific markers coglia. We show by immunocytochemistry analysis that a subcells was committed to the photoreceptor lineage given thaphotoreceptor proteins recoverin, peripherin, and rhodopsin Furthermore, cells infected during the differentiation procedexpressing green fluorescent protein (GFP) under the contpromoter or the interphotoreceptor retinoidbinding protein (GFP. FGF-2 priming increased neuronal differentiation whiReverse transcription-polymerase chain reaction analyses differentiated cells expressed photoreceptor-specific genes peripherin, IRBP, and phosphodiesterase-_. Quantification showed a robust differentiation into the photoreceptor lineaof the total cells harbored photoreceptor markers. The geneof nondifferentiated RSCs as well as differentiated photoreresearchers to determine via transplantation studies which to integrate a degenerating retina. 

Bioreactor Expansion of Human Adult Bone Marrow-DeCellsXi Chen et al. Stem Cells. 2006 Sep;24(9):2052-9. Epub 20Abstract: Supplementation of mesenchymal stem cells (Mstem cell (HSC) transplantation alleviates complications sudisease, leading to a speedy recovery of hematopoiesis. To fast MSC expansion method is required. In the present studof using a rotary bioreactor system to expand MSCs from ismononuclear cells. The cells were cultured in a rotary biore
containing a combination of supplementary factors, including stem cell factor and 

interleukin-3 and -6. After 8 days of culture, total cell numbers, Stro-1(+)CD44(+)CD34(-) MSCs, and CD34(+)CD44(+)Stro-1(-) HSCs were increased 9-, 29-, and 8-fold, respectively. Colony-forming efficiency-fibroblast per day of the bioreactor-treated cells was 1.44-fold higher than that of the cells without bioreactor treatment. The bioreactorexpanded MSCs showed expression of primitive MSC markers endoglin (SH2) and vimentin, whereas markers associated with lineage differentiation, including osteocalcin (osteogenesis), type II collagen (chondrogenesis), and C/EBP-alpha (CCAAT/enhancerbinding protein-alpha) (adipogenesis), were not detected. Upon induction, the bioreactorexpanded MSCs were able to differentiate into osteoblasts, chondrocytes, and adipocytes. We conclude that the rotary bioreactor with the modified Myelocult medium 

reported in this study may be used to rapidly expand MSCs. 

Multi-potent mesenchymal stromal cells in bloodQiling He et al. Stem Cells. published online Sep 14, 2006; DOI: 10.1634/stemcells.2006-0335.Abstract: Peripheral blood-derived multi-potent mesenchymal stromal cells circulate in 

low number. They share, though not all, but most of the surface markers with bone marrow-derived multi-potent mesenchymal stromal cells, possess diverse and complicated gene expression characteristics, and are capable of differentiating along and even beyond mesenchymal lineages. Although their origin and physio-pathological function are still unclear, their presence in the adult peripheral blood might relate to some interesting but controversial subjects in the filed of adult stem cell biology, such as systemic migration of bone marrowderived multi-potent mesenchymal stromal cells and the existence of common hematopoietic-mesenchymal precursors. In this review, current studies /knowledge about peripheral blood-derived multi-potent mesenchymal stromal cells is summarized and the above-mentioned topics are discussed. 

Effective cell and gene therapy in a murine model of Gaucher disease.Enquist IB, et al. Proc Natl Acad Sci U S A. 2006 Sep 12;103(37):13819-24. Epub 2006 Sep 5.Abstract: Gaucher disease (GD) is a lysosomal storage disorder due to an inherited deficiency in the enzyme glucosylceramidase (GCase) that causes hepatosplenomegaly, cytopenias, and bone disease as key clinical symptoms. Previous mouse models with GCase deficiency have been lethal in the perinatal period or viable without displaying the clinical features of GD. We have generated viable mice with characteristic clinical symptoms of type 1 GD by conditionally deleting GCase exons 9-11 upon postnatal induction. Both transplantation of WT bone marrow (BM) and gene therapy through retroviral transduction of BM from GD mice prevented development of disease and corrected an already established GD phenotype. The gene therapy approach generated 

considerably higher GCase activity than transplantation of W

therapeutic modalities normalized glucosylceramide levels of Gaucher cells could be observed in BM, spleen, and live5-6 months after treatment. The findings demonstrate the ftype 1 GD in vivo. Our type 1 GD mice will serve as an excefforts toward development of safe and efficient cell and ge

Isolation and characterization of multipotent progenitocapsule of adult human kidneys.Sagrinati C, et al. J Am Soc Nephrol. 2006 Sep;17(9):2443Abstract: Regenerative medicine represents a critical cliniESRD, but the identification of renal adult multipotent progeelusive. It is demonstrated that in human adult kidneys, a scells (PEC) in the Bowman's capsule exhibit coexpression and CD133 and of the stem cell-specific transcription factoabsence of lineage-specific markers. This CD24+CD133+ Pbe purified from cultured capsulated glomeruli, revealed secloning efficiency. Under appropriate culture conditions, indCD24+CD133+ PEC could be induced to generate mature, phenotypic features of proximal and/or distal tubules, osteocells that exhibited phenotypic and functional features of neCD24+CD133+ PEC but not of CD24-CD133- renal cells inrenal failure resulted in the regeneration of tubular structurenephron. More important, treatment of acute renal failure wsignificantly ameliorated the morphologic and functional kiddemonstrates the existence and provides the characterizatmultipotent progenitor cells in adult human glomeruli, potenfor the development of regenerative medicine in patients w

Human neural stem cells target experimental intracrandeliver a therapeutic gene leading to tumor regressionKim SK, et al. Clin Cancer Res. 2006 Sep 15;12(18):5550-PURPOSE: Medulloblastoma, a malignant pediatric brain tone third of patients despite multimodal treatments. In addilead to long-term disabilities. Based on studies of the extencells (NSC) toward malignant gliomas and the secretion of glioma and medulloblastoma, we hypothesized that NSCs and be used as a cellular therapeutic delivery system. Experimental Design: The migratory ability of HB1.F3 cells human NSC line) to medulloblastoma was studied both in v
concept, we used HB1.F3 cells engineered to secrete the prodrug activating enzyme 

cytosine deaminase. We investigated the potential of human NSCs to deliver a therapeutic gene and reduce tumor growth. RESULTS: The migratory capacity of HB1.F3 cells was confirmed by an in vitro migration assay, and corroborated in vivo by injecting chloromethylbenzamido-Dillabeled HB1.F3 cells into the hemisphere contralateral to established medulloblastoma in nude mice. In vitro studies showed the therapeutic efficacy of HB1.F3-CD on Daoy cells in coculture experiments. In vitro therapeutic studies were conducted in which animals bearing intracranial medulloblastoma were injected ipsilaterally with HB1.F3-CD cells followed by systemic 5-flourocytosine treatment. Histologic analyses showed that human NSCs migrate to the tumor bed and its boundary, resulting in a 76% reduction of tumor volume in the treatment group (P<0.01). CONCLUSION: These studies show for the first time the potential of human NSCs as an effective delivery system to target and disseminate therapeutic agents to medulloblastoma. 

A phase 2 study of high-activity( 186)Re-HEDP with autologous peripheral blood stem cell transplant in progressive hormone-refractory prostate cancer metastatic to bone.O'Sullivan JM, et al. Eur J Nucl Med Mol Imaging. 2006 Sep;33(9):1055-1061. Epub 2006 Mar 30.PURPOSE: We investigated the potential for improvement in disease control by use of autologous peripheral blood stem cell transplant (PBSCT) to permit administration of high activities of (186)Re-hydroxyethylidene diphosphonate (HEDP) in patients with progressive hormone-refractory prostate cancer (HRPC). METHODS: Eligible patients had progressive HRPC metastatic to bone, good performance status and minimal soft tissue disease. Patients received 5,000 MBq of (186)Re-HEDP i.v., followed 14 days later by PBSCT. Response was assessed using PSA, survival, pain scores and quality of life. RESULTS: Thirty-eight patients with a median age of 67 years (range 50-77) and a median PSA of 57 ng/ml (range 4-3,628) received a median activity of 4,978 MBq (186)Re-HEDP (range 4,770-5,100 MBq). The most serious toxicity was short-lived grade 3 thrombocytopenia in 8 (21%) patients. The median survival of the group is 21 months (95%CI 18-24 months) with Kaplan-Meier estimated 1- and 2-year survival rates of 83% and 40% respectively. Thirty-one patients (81%, 95% CI 66-90%) had stable or reduced PSA levels 3 months post therapy while 11 (29%, 95% CI 15-49%) had PSA reductions of >50% lasting >4 weeks. Quality of life measures were stable or improved in 27 (66%) at 3 months. CONCLUSION: We have shown that it is feasible and safe to deliver high-activity 

radioisotope therapy with PBSCT to men with metastatic HRPC. Response rates and survival data are encouraging; however, further research is needed to define optimal role of this treatment approach. 

Adipose-derived stem and progenitor cells as fillers in surgery.Moseley TA, et al. Plast Reconstr Surg. 2006 Sep;118(3 SuAbstract: Plastic surgeons are keenly aware of the principprinciple underlies much of the rationale behind the clinical transplantation, despite the procedure's drawbacks. Autolofrequently used for a variety of cosmetic and reconstructive posttraumatic defects of the face and body, involutional disatrophy, sequelae of radiation therapy, and many aesthetic augmentation and wrinkle therapy. However, the limitations known, particularly the long-term unpredictability of volume cell-based strategies such as those encompassing the use tremendous promise for augmentation of the soft-tissue spearly clinical series show that adipose-derived stem cells ofulfilling the key principle of replacing like with like as an aedrawbacks of current technology. Ex Vivo Expansion Does Not Alter the Capacity of UmbCells to Generate Functional T Lymphocytes and DendLADAN KOBARI et al. Stem Cells. 2006;24:2150–2157.Abstract: We examined whether ex vivo expansion of umbcells affected their capacity to generate immune cells such dendritic cells (DCs). The capacity to generate TLs from coexpanded for 14 days (d14) was compared with that of nonusing fetal thymus organ cultures or transfer into nonobese immunodeficient mice. The cell preparations yielded compaimmature (CD4_CD8_, CD4_CD8_) TLs and functional maCD3_CD8_) TLs with an analogous TCR (T-cell receptor)-Vregards DCs, d0 and d14 CD34_ cells also yielded similar with the same expression levels of HLA-DR, costimulatory chemokine receptors. DCs derived from either d14 or d0 CTLs to the same extent, and the cytokine pattern production similar with no shift toward a predominant Th1 or Th2 respointrinsic capacity of d14 CD34_ cells to generate DCs was CD34_ cells, this reduction was offset by the prior amplificaresulting in the overall production of 15-fold more DCs. Theexpansion of CD34_ cells does not impair T lymphopoiesis capacity. 
In Vivo Bone Formation by Human Bone Marrow Stromal Cells: Reconstruction of 

the Mouse Calvarium and MandibleMAHESH H. MANKANI et al. Stem Cells. 2006 Sep;24(9):2140-9. Epub 2006 Jun 8.Abstract: Bone marrow stromal cells (BMSCs) contain a subset of multipotent cells with 

the potential to repair hard-tissue defects. Mouse BMSCs, combined with a collagen carrier, can close critical-sized homologous mouse calvarial defects, but this new bone has a poor union with the adjacent calvarium. When human BMSCs are transplanted for the purpose of engineering new bone, best results can be achieved if the cells are combined with hydroxyapatite/tricalcium phosphate (HA/TCP) particles. Here, we demonstrate that transplantation of cultured human BMSCs in conjunction with HA/TCP particles can be used successfully to close mouse craniofacial bone defects and that removal of the periosteum from the calvarium significantly enhances union with the transplant. Transplants were followed for up to 96 weeks and were found to change in morphology but not bone content after 8 weeks; this constitutes the first description of human BMSCs placed long-term to heal bone defects. New bone formation continued to occur in the oldest transplants, confirmed by tetracycline labeling. Additionally, the elastic modulus of this engineered bone resembled that of the normal mouse calvarium, and our use of atomic force microscopy (AFM)-based nanoindentation offered us the first opportunity to compare these small transplants against equally minute mouse bones. Our results provide insights into the long-term behavior of newly engineered orthotopic bone from human cells and have powerful implications for therapeutic human BMSC transplantation. 

Growth factor-stimulated generation of new cortical tissue and functional recovery after stroke damage to the motor cortex of rats.Kolb B, et al. J Cereb Blood Flow Metab. 2006 Sep 20; [Epub ahead of print]Abstract: Recent studies suggest that proliferation in the adult forebrain subventricular zone increases in response to a forebrain stroke and intraventricular infusions of growth factors enhance this response. The potential for growth factor infusions to regenerate the damaged motor cortex and promote recovery of motor function after stroke has not been examined. Here, we report that intraventricular infusions of epidermal growth factor and erythropoietin together, but not individually, promote substantial regeneration of the damaged cerebral cortex and reverse impairments in spontaneous and skilled motor tasks, in a rat model of stroke. Cortical regeneration and functional recovery occurred even when growth factor administration was delayed for up to 7 days after the strokeinduced lesion. Cell tracking demonstrated the contribution of neural precursors originating in the forebrain subventricular zone to the regenerated cortex. Strikingly, removal of the regenerated cortical tissue reversed the growth factor-induced functional recovery. These findings reveal that specific combinations of growth factors can mobilize endogenous adult neural stem cells to promote cortical tissue re-growth and functional 

recovery after stroke.Journal of Cerebral Blood Flow & publiaction, 20 September 2006; doi:10.1038/sj.jcbfm.9600Synergy between immune cells and adult neural stem/pfunctional recovery from spinal cord injury.Ziv Y, et al. Proc Natl Acad Sci U S A. 2006 Aug 29;103(3522.Abstract: The well regulated activities of microglia and T csystem (CNS) antigens can contribute to the protection of Crenewal from adult neural stem/progenitor cells (aNPCs). Hbased vaccination of mice with a myelin-derived peptide, wtransplantation of aNPCs into the cerebrospinal fluid (CSF)functional recovery after spinal cord injury. The synergistic modulation of the nature and intensity of the local T cell anexpression of brain-derived neurotrophic factor and noggin newly formed neurons from endogenous precursor-cell poothe contention that the local immune response plays a crucaNPCs to the lesion site, and suggest that similar immunoloalso serve as a therapeutic means for controlled migration other acutely injured CNS sites. Derivation and large-scale expansion of multipotent asfrom adult human brain.Walton NM, et al. Development. 2006 Sep;133(18):3671-8Abstract: The isolation and expansion of human neural ceincreasingly relevant in restorative neurobiology. Although frequently envisaged as providing sufficiently primordial cedevelopmental plasticity of endogenous adult neural cells rexamine the developmental potential of adult human brain favoring the growth of neural stem cells to multiple cortical identification and selection of a population of adult human nThese nestin(+) progenitors may be derived from multiple fmaintainable in adherent conditions, co-express multiple gland are highly expandable, allowing a single progenitor to tcells for approximately 4x10(7) adult brains. AHNPs longitugenerate both glial and neuronal cell types in vivo and in vigenetic modification and transplantation. These findings sudegree of inducible plasticity is retained by cells of the adul
Isolation of mesenchymal stem cells from human vermiform appendix.

De Coppi P, et al. J Surg Res. 2006 Sep;135(1):85-91. Epub 2006 May 2.Abstract: BACKGROUND: Recent findings have shown that pluripotent stem cells exist in areas outside the bone marrow (BM). Moreover, it has been demonstrated that the appendix is important for the development of mucosal gut immunity, and hematopoietic progenitors have been isolated from animal and human appendices. MATERIALS AND METHODS: Non-inflamed appendices removed during laparotomy were processed and cultured until the appearance of adherent cells. Differentiations (performed under osteogenic, adipogenic, and myogenic conditions) were confirmed by immunohistochemistry and cytochemistry. Polymerase chain reaction and cytofluorimetric analyses were performed to evidence the presence of genes and protein specific lineages in appendix-derived mesenchymal stem cells (ADMCs). RESULTS: ADMCs were present in non-inflamed appendices. ADMCs under osteogenic conditions differentiated in osteoblasts and showed increased alkaline phosphatase expression; at the gene level, we observed the expression of Core binding factor alpha 1 (Cbfa1) and osteocalcin in osteogenic induced ADMCs. Under adipogenic conditions, lipidic drops in the cytoplasm, expression of lipoprotein lipase (LpL), and peroxisome proliferatoractivated receptor gamma were observed; under myogenic conditions, myotubes expressing muscle specific proteins like desmin were formed. Myogenic regulatory factor 4 and MyoD were selectively induced in the ADMCs under myogenic conditions. CONCLUSIONS: This study shows for the first time that mesenchymal stem cells can be isolated from normal appendices obtained from a pediatric and adult age group (0-18 years of age). This finding not only may further knowledge of the maturation of the intestinal immunesystem but also could indicate a new physiological role of the human vermiform appendix. 

Differentiation of adult stem cells derived from bone marrow stroma into Leydig or adrenocortical cells.Yazawa T, et al. Endocrinology. 2006 Sep;147(9):4104-11. Epub 2006 May 25.Abstract: Adult stem cells from bone marrow, referred to as mesenchymal stem cells or 

marrow stromal cells (MSCs), are defined as pluripotent cells and have the ability to differentiate into multiple mesodermal cells. In this study, we investigated whether MSCs from rat, mouse, and human are able to differentiate into steroidogenic cells. When transplanted into immature rat testes, adherent marrow-derived cells (including MSCs) were found to be engrafted and differentiate into steroidogenic cells that were indistinguishable from Leydig cells. Isolated murine MSCs transfected with green fluorescence protein driven by the promoter of P450 side-chain cleaving enzyme gene (CYP11A), a steroidogenic cell-specific gene, were used to detect steroidogenic cell production in vitro. During in vitro differentiation, green fluorescence protein-positive cells, which had characteristics similar to those of Leydig cells, were found. Stable 

transfection of murine MSCs with a transcription factor, steby treatment with cAMP almost recapitulated the properties production of testosterone. Transfection of human MSCs wled to their conversion to steroidogenic cells, but they apperather than testosterone-producing cells. These results indiuseful source of stem cells for producing steroidogenic celltheir use in cell and gene therapy. 

Autologous adipose tissue-derived stromal cells for treinjury.Kang SK, et al. Stem Cells Dev. 2006 Aug;15(4):583-94.Abstract: Isolated rat adipose tissue-derived stromal cells cells that can be differentiated into a variety of cell lineagesRecent work has shown that ATSCs can make neurospherinto neuron-like cells expressing neuronal markers, but the

Here we report that intravenous infusion of oligodendrocyte derived from rATSC autograft cells sources improve motor spinal cord injury (SCI). After 4-5 weeks, transplanted rATSmigrated into the injured region of SCI very efficiently (30-3partially differentiated into neurons and oligodendrocyte. Alengrafted OPCs migrated and integrated in the kidney, braintravenous system. Behavioral analysis revealed the locomautografted SCI rats were significantly restored. Efficient mengrafted rATSC-OPCs cells into SCI lesion suggests that factors facilitate migration of rATSC-OPCs. Here, we verifieSCI-induced chemotaxic factors indeed play an important rand differentiation of endogeneous spinal cord-derived neuinjured region. In transplantation paradigms, the interaction OPCs and endogeneous spinal cord-derived neuronal progin promoting healing through fate decisions, resulting in coomigration and differentiation. 

Cord blood mesenchymal stem cells: Potential use in nEl-Badri NS, et al. Stem Cells Dev. 2006 Aug;15(4):497-50Abstract: Our previous studies demonstrate enhanced neu

blood (CB) cells in comparison to stem cells from adult marwhether mesenchymal stem cells (MSCs) derived from hum(hUCB) possess optimal characteristics for neural therapy, plastic-adherent CB MSCs. These cells generated CD34-, cells in culture and failed to produce CFU-M, CFU-GEMM, 
colonies in methylcellulose. However, cultured CB MSCs possessed a remarkable ability 

to support proliferation as well as differentiation of hematopoietic cells in vitro. In addition, supernatants from cultured CB MSCs promoted survival of NT2 N neural cells and peripheral blood mononuclear cells (MNCs) cultured under conditions designed to induce cell stress and limit protein synthesis. After incubation in neural differentiation medium, CB MSCs expressed the neural cell-surface antigen A2B5, the neurofilament polypeptide NF200, the oligodendrocyte precursor marker 04, intermediate filament proteins characteristic of neural differentiation (nestin and vimentin), as well as the 

astrocyte marker glial fibrillary acidic protein (GFAP) and the neural progenitor marker TUJ-1. We examined the immunomodulatory effects of the CB MSCs after co-culture with murine splenocytes. Whereas spleen cells from normal C57Bl/6 mice exhibited a prominent immunoglobulin M (IgM) response after immunization with the T celldependent antigen sheep red blood cells, this response was significantly decreased after incubation with CB MSCs. These data indicate that CB MSCs possess multiple utilities that may contribute to their therapeutic potency in the treatment of neurological disorders. 

Threshold of lung injury required for the appearance of marrow-derived lung epithelia.Herzog EL, et al. Stem Cells. 2006 Aug;24(8):1986-92.Abstract: Bone marrow-derived cells (BMDCs) can adopt an epithelial phenotype in the lung following bone marrow transplantation (BMT). This phenomenon has been assumed to result from the lung injury that occurs with myeloablative radiation. To date, no study has related the degree of epithelial chimerism following bone marrow transplantation to the lung damage induced by preconditioning for BMT. Such a goal is crucial to understanding the local host factors that promote the engraftment of BMDCs as lung epithelia. We undertook this aim by performing sex-mismatched bone marrow transplantation using a variety of preconditioning regimens and comparing measurements of lung injury (bronchoalveolar lavage [BAL] cell count, alveolar-capillary leak assayed by BAL protein levels, and terminal deoxynucleotidyl transferase dUTP nick-end labeling analysis on epithelial cells) with rigorous methods to quantify bone marrow-derived lung epithelia (costaining for epithelial and donor markers on tissue sections and isolated lung epithelia in recipient mice). We found that only at doses that induced lung injury could marrow derived lung epithelium be identified following BMT. With irradiation doses less than 1,000 centigray (cGy), there was little to no apparent injury to the lung, and there were no marrow-derived pneumocytes despite high levels of hematopoietic chimerism. In contrast, 4 days after either split or single-dose 1,000 cGy irradiation, nearly 15% of lung epithelia were apoptotic, and with this dose, marrowderived type II pneumocytes (0.2%) were present at 28 days. These data indicate a critical relationship between lung injury and the phenotypic change from BMDCs to lung epithelial cells. 

The phenotypes of pluripotent human hepatic progenitSchmelzer E, et al. Stem Cells. 2006 Aug;24(8):1852-8. EpAbstract: Human livers contain two pluripotent hepatic proand hepatoblasts, with size, morphology, and gene expressof mature hepatocytes. Hepatic stem cells, the precursors tstable numbers throughout life, and those isolated from the fetal to adult are essentially identical in their gene and protegene expression profile of hepatic stem cells throughout life expression of cytokeratin 19 (CK19), neuronal cell adhesiocell adhesion molecule (EpCAM), and claudin-3 (CLDN-3); complete absence of expression of alpha-fetoprotein (AFP) proteins. By contrast, hepatoblasts, the dominant cell populivers, decline in numbers with age and are found as <0.1% express high levels of AFP, elevated levels of albumin, low liver-specific proteins, low levels of CK19, and a loss of NChepatocytes lack expression altogether of EpCAM, NCAM, and have acquired the well-known adult-specific profile thalevels of albumin, cytochrome P4503A4, connexins, phospcarboxykinase, and transferrin. Thus, hepatic stem cells haphenotype, whereas hepatoblasts have low levels of expreand genes expressed in high levels in mature hepatocytes. 

Clonogenic multipotent stem cells in human adipose tifunctional smooth muscle cells.Rodriguez LV, et al. Proc Natl Acad Sci U S A. 2006 Aug 82006 Jul 31.Abstract: Smooth muscle is a major component of human the normal function of a multitude of organs including the invascular system. The use of stem cells for cell-based tissue regeneration strategies represents a promising alternative fsuch strategies to succeed, a reliable source of smooth muidentified. Adipose tissue provides an abundant source of mthe capacity of processed lipoaspirate (PLA) and adipose-ddifferentiate into phenotypic and functional smooth muscle induce differentiation, PLA cells were cultured in smooth mSmooth muscle differentiation of PLA cells induced genetic muscle markers and further confirmed by increased protein cell-specific alpha actin (ASMA), calponin, caldesmon, SM2(MHC), and smoothelin. Clonal studies of adipose derived demonstrated differentiation of these cells into smooth mus
trilineage differentiation capacity. Importantly, smooth muscle-differentiated cells, but not 

their precursors, exhibit the functional ability to contract and relax in direct response to pharmacologic agents. In conclusion, adipose-derived cells have the potential to differentiate into functional smooth muscle cells and, thus, adipose tissue can be a useful source of cells for treatment of injured tissues where smooth muscle plays an important role. Differentiation of umbilical cord blood-derived multilineage progenitor cells into respiratory epithelial cells.Berger MJ, et al. Cytotherapy. 2006;8(5):480-7.BACKGROUND: Umbilical cord blood (UCB) has been examined for the presence of stem cells capable of differentiating into cell types of all three embryonic layers (i.e. endo-, ecto- and mesoderm). The few groups reporting success have typically confirmed endodermal potential using hepatic differentiation. We report differentiation of human UCB-derived multipotent stem cells, termed multilineage progenitor cells (MLPC), into respiratory epithelial cells (i.e. type II alveolar cells). METHODS: Using a cell separation medium (PrepaCyte-MLPC; BioE Inc.) and plastic adherence, MLPC were isolated from four of 16 UCB units (American Red Cross) and expanded. Cultures were grown to 80% confluence in mesenchymal stromal cell growth medium (MSCGM; Cambrex BioScience) prior to addition of small airway growth medium (SAGM; Cambrex BioScience), an airway maintenance medium. Following a 3-8-day culture, cells were characterized by light microscopy, transmission electron microscopy, immunofluorescence and reverse transcriptase (RT)-PCR. RESULTS: MLPC were successfully differentiated into type II alveolar cells (four of four 

mixed lines; two of two clonal lines). Differentiated cells were characterized by epithelioid morphology with lamellar bodies. Both immunofluorescence and RT-PCR confirmed the presence of surfactant protein C, a protein highly specific for type II cells. DISCUSSION: MLPC were isolated, expanded and then differentiated into respiratory epithelial cells using an off-the-shelf medium designed for maintenance of fully differentiated respiratory epithelial cells. To the best of our knowledge, this is the first time human non-embryonic multipotent stem cells have been differentiated into type II alveolar cells. Further studies to evaluate the possibilities for both research and therapeutic applications are necessary. 

Complete repair of dystrophic skeletal muscle by mesoangioblasts with enhanced migration ability.Galvez BG, et al. J Cell Biol. 2006 Jul 17;174(2):231-43. Epub 2006 Jul 10.Abstract: Efficient delivery of cells to target tissues is a major problem in cell therapy. We report that enhancing delivery of mesoangioblasts leads to a complete reconstitution of downstream skeletal muscles in a mouse model of severe muscular dystrophy (alphasarcoglycan ko). Mesoangioblasts, vessel-associated stem 

several cytokines, among which stromal- derived factor (SD(TNF) alpha were the most potent in enhancing transmigradystrophic muscle in vivo. Transient expression of alpha4 iincreased several fold migration both in vitro and in vivo. Thpretreatment with SDF-1 or TNF-alpha and expression of amassive colonization (>50%) followed by reconstitution of >expressing fibers, with a fivefold increase in efficiency in coThis study defines the requirements for efficient engraftmenoffers a new potent tool to optimize future cell therapy protodystrophies. Bone marrow stromal cells can achieve cure of chronic 

and morphological outcome one year after transplantaZurita M, Vaquero J. Neurosci Lett. 2006 Jul 10;402(1-2):5Abstract: Chronic paraplegia resulting from severe spinal 

to be an irreversible condition. Nevertheless, recent studies appear to offer promise in the treatment of this and other nwe show that progressive functional motor recovery is achiyear following the administration of bone marrow stromal ccentral spinal cord cavities of adult rats with chronic paraplrecovery is almost complete and associated with evident nethe previously injured spinal cord. Maturation of tissue engineered cartilage implanted in 

human knees. Hollander AP, et al. Tissue Eng. 2006 Jul;12(7):1787-98. Abstract: The regeneration of damaged organs requires th

when implanted at sites of injury or disease. We have used determine the extent of tissue regeneration after treatment novel cartilage tissue engineering therapy and the effect of the regeneration process. We treated 23 patients, with a mpresenting with knee articular cartilage defects 1.5 cm2 to area. Nine of the patients had X-ray evidence of osteoarthrisolated from healthy cartilage removed at arthroscopy. The days, seeded onto esterified hyaluronic acid scaffolds (Hyafurther 14 days before implantation. A second-look biopsy wafter 6 to 30 months (mean, 16 months). After standard histissue was further analyzed using a newly developed bioch

digestion with trypsin and specific, quantitative assays for t
collagen, and proteoglycan, as well as mature and immature collagen crosslinks. 

Cartilage regeneration was observed as early as 11 months after implantation and in 10 out of 23 patients. Tissue regeneration was found even when implants were placed in joints that had already progressed to osteoarthrosis. Cartilage injuries can be effectively repaired using tissue engineering, and osteoarthritis does not inhibit the regeneration process. Characterization and clinical application of human CD34+ stem/progenitor cell populations mobilized into the blood by granulocyte colony-stimulating factor.Gordon MY, et al. Stem Cells. 2006 Jul;24(7):1822-30. Epub 2006 Mar 23.Abstract: A phase I study was performed to determine the safety and tolerability of 

injecting autologous CD34(+) cells into five patients with liver insufficiency. The study was based on the hypothesis that the CD34(+) cell population in granulocyte colonystimulating factor (G-CSF)-mobilized blood contains a subpopulation of cells with the potential for regenerating damaged tissue. We separated a candidate CD34(+) stem cell population from the majority of the CD34(+) cells (99%) by adherence to tissue culture plastic. The adherent and nonadherent CD34(+) cells were distinct in morphology, immunophenotype, and gene expression profile. Reverse transcription-polymerase chain reaction-based gene expression analysis indicated that the adherent CD34(+) cells had the potential to express determinants consistent with liver, pancreas, heart, muscle, and nerve cell differentiation as well as hematopoiesis. Overall, the characteristics of the adherent CD34(+) cells identify them as a separate putative stem/progenitor cell population. In culture, they produced a population of cells exhibiting diverse morphologies and expressing genes corresponding to multiple tissue types. Encouraged by this evidence that the CD34(+) cell population contains cells with the potential to form hepatocyte-like cells, we gave G-CSF to five patients with liver insufficiency to mobilize their stem cells for collection by leukapheresis. Between 1 x 10(6) and 2 x 10(8) CD34(+) cells were injected into the portal vein (three patients) or hepatic artery (two patients). No complications or specific side effects related to the procedure were observed. Three of the five patients showed improvement in serum bilirubin and four of five in serum albumin. These observations warrant further clinical trials. 

Regeneration and transdifferentiation potential of muscle-derived stem cells propagated as myospheres.Sarig R, et al. Stem Cells. 2006 Jul;24(7):1769-78. Epub 2006 Mar 30.Abstract: We have isolated from mouse skeletal muscle a subpopulation of slow adherent myogenic cells that can proliferate for at least several months as suspended clusters of cells (myospheres). In the appropriate conditions, the myospheres adhere to the plate, spread out, and form a monolayer of MyoD(+) cells. Unlike previously described myogenic cell lines, most of the myosphere cells differentiate, without cell 

fusion, into thin mononucleated contractile fibers, which exmuscle myosin heavy chain. The presence of Pax-7 in a sigcells suggests that they originate from satellite cells. The adfactor to the growth medium of the myospheres enhances pincreases the proportion of cells expressing Sca-1, which is 

of stem cells. The capacity of myosphere cells to transdiffe

cell lineages was examined. Exposure of cloned myospherprotein resulted in suppression of myogenic differentiation markers such as alkaline phosphatase and osteocalcin. Thdifferentiated to adipocytes. Myosphere cells could not, so transdifferentiate to hematopoietic cells. When inoculated imyosphere-derived cells participated in regeneration, formistriated mature fibers. This suggests a potential medical ap

In vitro differentiation of human placenta-derived multihepatocyte-like cells.Chien CC, et al. Stem Cells. 2006 Jul;24(7):1759-68. Abstract: Multipotent cells isolated from human term place

multipotent cells [PDMCs]) have been known to be able to lineage cells, including adipocytes and osteoclasts. The low of placenta compared with other tissue origins of adult stem attractive target for cell-based therapy. However, the differetoward hepatic cells has not been evaluated yet. In this stuhepatic differentiation medium to evaluate the ability of thestoward hepatic cells. After treatment, the morphologies of dto polygonal epithelial cell-like. The differentiated cells not omorphologies but also express hepatocyte-specific markerscytokeratin 18. The bioactivity assays revealed that these huptake lipoprotein and store glycogen. Furthermore, the adthe gene expression of CYP3A4, which is similar with the aAccording to our previous results, PDMCs were capable of mesodermal and ectodermal lineage cells. Our results indicdifferentiate into three germ layer cells, which is similar to econclusion, placenta might be an easily accessible source capable of differentiating toward hepatocyte-like cells in vitr

The defined combination of growth factors controls gereplicating islet progenitor-like cells from cultures of adTa M, et al. Stem Cells. 2006 Jul;24(7):1738-49. Epub 200Abstract: Application of pancreatic islet transplantation to t
severely hampered by the inadequate islet supply. This problem could in principle be 

overcome by generating islet cells from adult pancreas in vitro. Although it is possible to obtain replicating cells from cultures of adult pancreas, these cells, when significantly 

expanded in vitro, progressively lose pancreatic-specific gene expression, including that of a "master" homeobox transcription factor Pdx1. Here we show for the first time that long-term proliferating islet progenitor-like cells (IPLCs) stably expressing high levels of Pdx1 and other genes that control early pancreatic development can be derived from cultures of adult mouse pancreas under serum-free defined culture conditions. Moreover, we show that cells derived thus can be maintained in continuous culture for at least 6 months without any substantial loss of early pancreatic phenotype. Upon growth factor withdrawal, the IPLCs organize into cell clusters and undergo endocrine differentiation of various degrees in a line-dependent manner. We propose that our experimental strategy will provide a framework for developing efficient approaches for ex vivo expansion of islet cell mass. 

Allogeneic haematopoietic stem cell transplantation for metastatic renal carcinoma in Europe.Barkholt L, et al. Ann Oncol. 2006 Jul;17(7):1134-40. Epub 2006 Apr 28.BACKGROUND: An allogeneic antitumour effect has been reported for various cancers. We evaluated the experience of allogeneic haematopoietic stem cell transplantation (HSCT) for renal cell carcinoma (RCC) in 124 patients from 21 European centres. PATIENTS AND METHODS: Reduced intensity conditioning and peripheral blood stem cells from an HLA-identical sibling (n = 106), a mismatched related (n = 5), or an unrelated (n = 13) donor were used. Immunosuppression was cyclosporine alone, or combined with methotrexate or mycophenolate mofetil. Donor lymphocyte infusions (DLI) were given to 42 patients. The median follow-up was 15 (range 3-41) months. RESULTS: All but three patients engrafted. The cumulative incidence of moderate to severe, grades II-IV acute GVHD was 40% and for chronic GVHD it was 33%. Transplant-related mortality was 16% at one year. Complete (n = 4) or partial (n = 24) responses, median 150 (range 42-600) days post-transplant, were associated with time from diagnosis to HSCT, mismatched donor and acute GVHD II-IV. Factors associated with survival included chronic GVHD (hazards ratio, HR 4.12, P < 0.001), DLI (HR 3.39, P < 0.001), <3 metastatic sites (HR 2.61, P = 0.002) and a Karnofsky score >70 (HR 2.33, P = 0.03). Patients (n = 17) with chronic GVHD and given DLI had a 2-year survival of 70%. CONCLUSION: Patients with metastatic RCC, less than three metastatic locations and a Karnofsky score >70% can be considered for HSCT. Posttransplant DLI and limited chronic GVHD improved the patient survival. 

Derivation of male germ cells from bone marrow stem cells.Nayernia K, et al. Lab Invest. 2006 Jul;86(7):654-63. Epub 2006 May 1.

Abstract: Recent studies have demonstrated that somatic 

flexible potential than expected, whether put into tissue or cconditions. Bone marrow (BM)-derived stem cells can transcells, such as muscle of mesoderm, lung and liver of endodectoderm origin. Here we show that BM stem cells are able germ cells. For derivation of male germ cells from adult BM the Stra8-enhanced green fluoresence protein (EGFP) tranEGFP specifically in male germ cells. BMS cell-derived germolecular markers of primordial germ cells, such as fragilisas well as molecular markers of spermatogonial stem cells Rbm, c-Kit, Tex18, Stra8, Piwil2, Dazl, Hsp90alpha, beta1- ability to derive male germ cells from BMS cells reveals novdevelopment and opens the possibilities for use of these ce

Living autologous heart valves engineered from human progenitors.Schmidt D, et al. Circulation. 2006 Jul 4;114(1 Suppl):I125-BACKGROUND: Heart valve tissue engineering is a promilack of autologous growing replacements, particularly for thmalformations. Here, we present a novel concept using humas new and exclusive cell source to generate autologous im

METHODS AND RESULTS: Human fetal mesenchymal prroutinely sampled prenatal chorionic villus specimens and ewas cryopreserved. After phenotyping and genotyping, cellbiodegradable leaflet scaffolds (n=12) and conditioned in a leaflets were endothelialized with umbilical cord blood-derivcells and conditioned for additional 7 days. Resulting tissueimmunohistochemistry, biochemistry (amounts of extracellutesting, and scanning electron microscopy (SEM) and were neonatal heart valve leaflets. Fresh and cryopreserved cellmyofibroblast-like phenotypes. Genotyping confirmed their exhibited organization, cell phenotypes, extracellular matrix comparable to their native counterparts. Leaflet surfaces wendothelia. SEM showed cellular distribution throughout the surfaces. Mechanical profiles approximated those of native CONCLUSIONS: Prenatal fetal progenitors obtained from sampling were successfully used as an exclusive, new cell living heart valve leaflets. This concept may enable autologpotential ready for use at birth. Combined with the use of capproach may be applied also for postnatal applications. 
Autologous human tissue-engineered heart valves: prospects for systemic 

application.Mol A, et al. Circulation. 2006 Jul 4;114(1 Suppl):I152-8.BACKGROUND: Tissue engineering represents a promising approach for the development of living heart valve replacements. In vivo animal studies of tissueengineered autologous heart valves have focused on pulmonary valve replacements, leaving the challenge to tissue engineer heart valves suitable for systemic application using human cells. METHODS AND RESULTS: Tissue-engineered human heart valves were analyzed up 

to 4 weeks and conditioning using bioreactors was compared with static culturing. Tissue formation and mechanical properties increased with time and when using conditioning. 

Organization of the tissue, in terms of anisotropic properties, increased when conditioning was dynamic in nature. Exposure of the valves to physiological aortic valve flow demonstrated proper opening motion. Closure dynamics were suboptimal, most likely caused by the lower degree of anisotropy when compared with native aortic valve leaflets. CONCLUSIONS: This study presents autologous tissue-engineered heart valves based 

on human saphenous vein cells and a rapid degrading synthetic scaffold. Tissue properties and mechanical behavior might allow for use as living aortic valve replacements. 

Autologous hematopoietic stem cell transplantation for older patients with relapsed non-Hodgkin's lymphoma.Buadi FK, et al. Bone Marrow Transplant. 2006 Jun;37(11):1017-22.

Abstract: To evaluate autologous stem cell transplant (ASCT) in older patients with intermediate grade non-Hodgkin's lymphoma (NHL), the Mayo Clinic Rochester BMT database was reviewed for all patients 60 years of age and older who received ASCT for NHL between September 1995 and February 2003. Factors evaluated included treatment-related mortality (TRM), event-free survival (EFS) and overall survival (OS). 

Ninety-three patients were identified, including twenty-four (26%) over the age of 70 years. Treatment-related mortality (5.4%) was not significantly different when compared to a younger cohort (2.2%). At a median follow-up of 14 months (0.6-87.6 months), the estimated median survival is 25 months (95% confidence interval (CI) 12-38) in the older 

group compared to 56 months (95% CI 37-75) (P=0.037) in the younger group. The estimated 4-year EFS was 38% for the older group compared to 42% in the younger cohort (P=0.1). By multivariate analysis, the only factor found to influence survival in the older group was age-adjusted International Prognostic Index at relapse, 0-1 better than 2-3 (P=0.03). Autologous stem-cell transplant can be safely performed in patients 60 years or older with chemotherapy sensitive relapsed or first partial remission NHL. The outcome may not be different from that of younger patients in terms of TRM and EFS. 

Isolation of a novel population of multipotent adult stem follicles.Yu H, et al. Am J Pathol. 2006 Jun;168(6):1879-88.Abstract: Hair follicles are known to contain a well-charact

cells: the bulge, which contains epithelial and melanocytic sembryonic stem cell culture conditions, we isolated a populhuman hair follicles that are distinctively different from knowstem cells. These cells do not express squamous or melanneural crest and neuron stem cell markers as well as the etranscription factors Nanog and Oct4. These precursor cellcapable of self-renewal, and can differentiate into multiple lnot only acquire lineage-specific markers but also demonstex vivo conditions. Most of the Oct4-positive cells in human highlighted by cytokeratin 15 staining in vivo. Our data sugstem cell medium can be used to isolate and expand humamethod, we isolated a novel population of multipotent adult follicles, and these cells appear to be located in the bulge aprovide an accessible, autologous source of adult stem cel

Successful stem cell therapy using umbilical cord bloocells for Buerger's disease and ischemic limb disease Kim SW, et al. Stem Cells. 2006 Jun;24(6):1620-6. Epub 2Abstract: Buerger's disease, also known as thromboangiitnonatherosclerotic, inflammatory, vasoocclusive disease. It pathologically as a panangiitis of medium and small blood varteries and adjacent veins, especially the distal extremities There is no curative medication or surgery for this disease. transplanted human leukocyte antigen-matched human umderived mesenchymal stem cells (MSCs) into four men with already received medical treatment and surgical therapies. transplantation, ischemic rest pain suddenly disappeared frThe necrotic skin lesions were healed within 4 weeks. In thdigital capillaries were increased in number and size. In adthe affected extremities, compared with the preoperative exdecreased due to improvement of the peripheral circulationBuerger's disease is absent and also to understand human human UCB-derived MSCs to athymic nude mice with hind artery ligation. Up to 60% of the hind limbs were salvaged ianimals. By in situ hybridization, the human UCB-derived Marterial walls of the ischemic hind limb in the treated group. 
that human UCB-derived MSC transplantation may be a new and useful therapeutic 

armament for Buerger's disease and similar ischemic diseases. Formation of a functional thymus initiated by a postnatal epithelial progenitor cell.Bleul CC, et al. Nature. 2006 Jun 22;441(7096):992-6.Abstract: The thymus is essential for the generation of self-tolerant effector and regulatory T cells. Intrathymic T-cell development requires an intact stromal microenvironment, of which thymic epithelial cells (TECs) constitute a major part. For instance, cell-autonomous genetic defects of forkhead box N1 (Foxn1) and autoimmune regulator (Aire) in thymic epithelial cells cause primary immunodeficiency and autoimmunity, respectively. During development, the thymic epithelial rudiment gives rise to two major compartments, the cortex and medulla. Cortical TECs positively select T cells, whereas medullary TECs are involved in negative selection of potentially autoreactive T cells. It has long been unclear whether these two morphologically and functionally distinct types of epithelial cells arise from a common bi-potent progenitor cell and whether such progenitors are still present in the postnatal period. Here, using in vivo cell lineage analysis in mice, we demonstrate the presence of a common progenitor of cortical and medullary TECs after birth. To probe the function of postnatal progenitors, a conditional mutant allele of Foxn1 was reverted to wild-type function in single epithelial cells in vivo. This led to the formation of small thymic lobules containing both cortical and medullary areas that supported normal thymopoiesis. Thus, single epithelial progenitor cells can give rise to a complete and functional thymic microenvironment, suggesting that cell-based therapies could be developed for thymus disorders. Stem cell niches in the adult mouse heart.Urbanek K, et al. Proc Natl Acad Sci U S A. 2006 Jun 13;103(24):9226-31. Epub 2006 Jun 5.Abstract: Cardiac stem cells (CSCs) have been identified in the adult heart, but the microenvironment that protects the slow-cycling, undifferentiated, and self-renewing CSCs remains to be determined. We report that the myocardium possesses interstitial structures with the architectural organization of stem cell niches that harbor long-term BrdU-retaining cells. The recognition of long-term label-retaining cells provides functional 

evidence of resident CSCs in the myocardium, indicating that the heart is an organ regulated by a stem cell compartment. Cardiac niches contain CSCs and lineagecommitted cells, which are connected to supporting cells represented by myocytes and fibroblasts. Connexins and cadherins form gap and adherens junctions at the interface of CSCs-lineage-committed cells and supporting cells. The undifferentiated state of CSCs is coupled with the expression of alpha(4)-integrin, which colocalizes with the alpha(2)-chain of laminin and fibronectin. CSCs divide symmetrically and asymmetrically, but asymmetric division predominates, and the replicating CSC gives rise to one daughter 

CSC and one daughter committed cell. By this mechanism primitive CSCs is preserved, and a myocyte progeny is genendothelial and smooth muscle cells. Thus, CSCs regulate heterogeneous across the heart, faster at the apex and atrimidregion of the ventricle. 

Skin-derived precursors generate myelinating Schwandysmyelinated nervous system.McKenzie IA, et al. J Neurosci. 2006 Jun 14;26(24):6651-6Abstract: Although neural stem cells hold considerable pro

injured or degenerating nervous system, their current humastem cells and fetally derived neural tissue. Here, we asked skin-derived precursors (SKPs), neural crest-related precurdermis, represent a source of functional, myelinating Schwcultured SKPs responded to neural crest cues such as neucells, and these Schwann cells proliferated and induced mywith sensory neuron axons in culture. Similar results were otransplantation of naive SKPs or SKP-derived Schwann cenerve of wild-type or shiverer mutant mice (which are geneprotein), the majority of SKP-derived cells had associated wNaive rodent or human SKPs also generated Schwann cellwhen transplanted into the dysmyelinated brain of neonataneonatal SKPs generate functional neural progeny in respocrest cues and, in so doing, provide a highly accessible soutreatment of nervous system injury, congenital leukodystropdisorders. 

Angiogenesis facilitated by autologous whole bone matransplantation for Buerger's disease.Kim DI, et al. Stem Cells. 2006 May;24(5):1194-200. Epub Abstract: We hypothesized that angiogenesis can be triggbone marrow stem cell transplantation. Twenty-seven patieBuerger's disease, who were not candidates for surgical reintervention, were enrolled in this study. Six sites of the tibia 2.5-mm-diameter screw under fluoroscopic guidance. Clidetermined using the "Recommended Standards for Reporprogenitor cells (EPCs) from bone marrow, recombinant hustimulating factor (r-HuG-CSF) was injected subcutaneouspreoperatively. During the follow-up period (19.1 +/- 3.5 momarkedly improved outcome (+3), and 26 limbs showed a m
(+2). Thirteen limbs among 17 limbs with nonhealing ulcers healed. Postoperative 

angiograms were obtained for 22 limbs. Two limbs showed marked (+3), five limbs moderate (+2), and nine limbs slight (+1) collateral development. However, six limbs showed no collateral development (0). Peripheral blood and bone marrow samples were analyzed for CD34 and CD133 molecules to enumerate potential EPCs, and EPC numbers were found to be increased in peripheral blood and in bone marrow after rHuG-CSF injection. In conclusion, the transplantation of autologous whole BMCs by fenestration of the tibia bone represents a simple, safe, and effective means of inducing therapeutic angiogenesis in patients with Buerger's disease. Transplantation of human hematopoietic stem cells into ischemic and growing kidneys suggests a role in vasculogenesis but not tubulogenesis.Dekel B, et al. Stem Cells. 2006 May;24(5):1185-93. Epub 2006 Jan 12.Abstract: Transplantation of murine bone marrow-derived stem cells has been reported recently to promote regeneration of the injured kidney. We investigated the potential of human adult CD34(+) progenitor cells to undergo renal differentiation once xenotransplanted into ischemic and developing kidneys. Immunostaining with humanspecific antibodies for tubular cells (broad-spectrum cytokeratin), endothelial cells (CD31, PECAM), stromal cells (vimentin), and hematopoietic cells (pan-leukocyte CD45) demonstrated that although kidney ischemia enhanced engraftment of human cells, they were mostly hematopoietic cells (CD45(+)) residing in the interstitial spaces. Few other engrafted cells demonstrated an endothelial phenotype (human CD31(+)in morphologically appearing peritubular capillaries), but no evidence of tubular or stromal cells of human origin was found. Upregulation of SDF1 and HIF1 transcript levels in the ischemic kidneys might explain the diffuse engraftment of CD45(+)cells following injury. Similarly, when embryonic kidneys rudiments were co-transplanted with human CD34(+)cells in mice, we found both human CD45(+)and CD31(+)cells in the periphery of the developing renal grafts, whereas parenchymal elements failed to stain. In addition, human CD34(+)cells had no effect on kidney growth and differentiation. This first demonstration of human CD34(+)stem cell transplantation into injured and developing kidneys indicates that these cells do not readily acquire a tubular phenotype and are restricted mainly to hematopoietic and, to a lesser extent, to endothelial lineages. Efforts should be made to identify additional stem cell sources applicable for kidney growth and regeneration. Bone marrow-derived cells home to and regenerate retinal pigment epithelium after injury.Harris JR, et al. Invest Ophthalmol Vis Sci. 2006 May;47(5):2108-13.PURPOSE: To determine whether hematopoietic stem and progenitor cells (HSCs/HPCs) can home to and regenerate the retinal pigment epithelium (RPE) after 

induced injury. METHODS: Enriched HSCs/HPCs from green fluorescent 

were transplanted into irradiated recipient mice to track bonPhysical damage was induced by breaching Bruch's membendothelial growth factor A (VEGFa) expression to promote damage was also induced by sodium iodate injection (40 mC57Bl/6 mice. Cell morphology, gfp expression, the presenthe presence of melanosomes were used to determine whebeing repaired by the donor bone marrow. RESULTS: Injury to the RPE recruits HSC/HPC-derived ce

layer and differentiate into an RPE phenotype. A portion of morphology, express melanosomes, and integrate into the CONCLUSIONS: HSCs/HPCs can migrate to the RPE layeinjury and regenerate a portion of the damaged cell layer. 

Unilateral intraputaminal glial cell line-derived neurotroParkinson disease: response to 1 year each of treatmeSlevin JT, et al. Neurosurg Focus. 2006 May 15;20(5):E1.OBJECT: Glial cell line-derived neurotrophic factor (GDNFputamen for 6 months was previously shown to improve molife measures significantly in 10 patients with Parkinson disthis study the authors report the safety and efficacy of contmore. After the trial was halted by the sponsor, the patients additional year to evaluate the effects of drug withdrawal. METHODS: During the extended study, patients received uinfusion of 30 mg/day GDNF at a basal infusion rate suppleevery 6 hours at a convection-enhanced delivery rate to incthe protein. When the study was stopped, the delivery systedeliver sterile saline at the basal infusion rate of 2 ml/hour. (UPDRS) total scores after 1 year of therapy were improverespectively, in the "off" and "on" states. Motor UPDRS scoand 39% in the off and on conditions, respectively. Benefits 9 to 12 months after GDNF infusion was halted. At that timtheir baseline UPDRS scores and required higher levels of drugs to treat symptoms. After 11 months of treatment, the removed in one patient because of the risk of infection. In sGDNF developed, with no evidence of clinical sequelae. ThGDNF-induced cerebellar toxicity, as evaluated using magnanalysis and clinical testing. CONCLUSIONS: Unilateral administration of GDNF results bilateral benefits. These improvements are lost within 9 moSafety concerns with GDNF therapy can be closely monito
Targeting of melanoma brain metastases using engineered neural stem/progenitor 

cells.Aboody KS, et al. Neuro-oncol. 2006 Apr;8(2):119-26. Epub 2006 Mar 8.Abstract: Brain metastases are an increasingly frequent and serious clinical problem for cancer patients, especially those with advanced melanoma. Given the extensive tropism of neural stem/progenitor cells (NSPCs) for pathological areas in the central nervous system, we expanded investigations to determine whether NSPCs could also target multiple sites of brain metastases in a syngeneic experimental melanoma model. Using cytosine deaminase-expressing NSPCs (CD-NSPCs) and systemic 5-fluorocytosine (5-FC) pro-drug administration, we explored their potential as a cell-based targeted drug delivery system to disseminated brain metastases. Our results indicate a strong tropism of NSPCs for intracerebral melanoma metastases. Furthermore, in our therapeutic paradigm, animals with established melanoma brain metastasis received intracranial implantation of CD-NSPCs followed by systemic 5-FC treatment, resulting in a significant (71%) reduction in tumor burden. These data provide proof of principle for the use of NSPCs for targeted delivery of therapeutic gene products to melanoma brain metastases. 

Tissue-engineered autologous bladders for patients needing cystoplasty.Atala A, et al. Lancet. 2006 Apr 15;367(9518):1241-6.BACKGROUND: Patients with end-stage bladder disease can be treated with cystoplasty using gastrointestinal segments. The presence of such segments in the urinary tract has been associated with many complications. We explored an alternative approach using autologous engineered bladder tissues for reconstruction. 

METHODS: Seven patients with myelomeningocele, aged 4-19 years, with highpressure or poorly compliant bladders, were identified as candidates for cystoplasty. A bladder biopsy was obtained from each patient. Urothelial and muscle cells were grown in culture, and seeded on a biodegradable bladder-shaped scaffold made of collagen, or a composite of collagen and polyglycolic acid. About 7 weeks after the biopsy, the autologous engineered bladder constructs were used for reconstruction and implanted either with or without an omental wrap. Serial urodynamics, cystograms, ultrasounds, bladder biopsies, and serum analyses were done. RESULTS: Follow-up range was 22-61 months (mean 46 months). Post-operatively, the mean bladder leak point pressure decrease at capacity, and the volume and compliance increase was greatest in the composite engineered bladders with an omental wrap (56%, 1.58-fold, and 2.79-fold, respectively). Bowel function returned promptly after surgery. No metabolic consequences were noted, urinary calculi did not form, mucus production was normal, and renal function was preserved. The engineered bladder biopsies showed an adequate structural architecture and phenotype. CONCLUSIONS: Engineered bladder tissues, created with autologous cells seeded on 

collagen-polyglycolic acid scaffolds, and wrapped in omentused in patients who need cystoplasty. 

Granulocyte colony-stimulating factor for acute ischemcontrolled trial.Shyu WC, et al. CMAJ. 2006 Mar 28;174(7):927-33. Epub 2BACKGROUND: Because granulocyte colony-stimulating finflammatory and neuroprotective properties and is known be useful in the treatment of acute ischemic stroke. We sousafety and efficacy of using G-CSF to treat acute stroke. METHODS: We conducted a randomized, blinded controlle

with acute cerebral infarction (middle cerebral artery territoadmission MRI) who presented within 7 days of onset and Institutes of Health Stroke Scale (NIHSS) were between 9 aassigned to either G-CSF therapy or usual care. The G-CSsubcutaneous G-CSF injections (15 microg/kg per day) for was percentage changes between baseline and 12-month scores on 4 clinical scales: the NIHSS, European Stroke SSubscale (EMS) and Barthel Index (BI). We also assessed 

PET to measure cerebral uptake of fluorodeoxyglucose in tthe ischemic core. RESULTS: All of the patients completed the 5-day course olost to follow-up. No severe adverse effects were seen in pThere was greater improvement in neurologic functioning bmonth follow-up in the G-CSF group than in the control grothe mean G-CSF group score v. 36% in the mean control g20%, EMS: 106% v. 58%, BI: 120% v. 60%). Although at 1difference between the 2 groups in cerebral uptake of fluoroischemic core, uptake in the area surrounding the core was G-CSF group compared with the control group. There was metabolic activity and EMS score following simple linear coINTERPRETATION: Our preliminary evidence suggests th

acute stroke is safe and feasible and leads to improved neu

Delayed transplantation of adult neural precursor cells and functional neurological recovery after spinal cord Karimi-Abdolrezaee S, et al. J Neurosci. 2006 Mar 29;26(1Abstract: Spinal cord injury (SCI) results in loss of oligodesurviving axons and severe functional impairment. SpontanThus, cell replacement therapy is an attractive approach fo
we transplanted adult brain-derived neural precursor cells (NPCs) isolated from yellow 

fluorescent protein-expressing transgenic mice into the injured spinal cord of adult rats at 2 and 8 weeks after injury, which represents the subacute and chronic phases of SCI. A combination of growth factors, the anti-inflammatory drug minocycline, and cyclosporine A immunosuppression was used to enhance the survival of transplanted adult NPCs. Our results show the presence of a substantial number of surviving NPCs in the injured spinal cord up to 10 weeks after transplantation at the subacute stage of SCI. In contrast, cell survival was poor after transplantation into chronic lesions. After subacute transplantation, grafted cells migrated >5 mm rostrally and caudally. The surviving NPCs integrated principally along white-matter tracts and displayed close contact with the host axons and glial cells. Approximately 50% of grafted cells formed either oligodendroglial precursor cells or mature oligodendrocytes. NPC-derived oligodendrocytes expressed myelin basic protein and ensheathed the axons. We also observed that injured rats receiving NPC transplants had improved functional recovery as assessed by the Basso, Beattie, and Bresnahan Locomotor Rating Scale and grid-walk and footprint analyses. Our data provide strong evidence in support of the feasibility of adult NPCs for cell-based remyelination after SCI. Human umbilical cord matrix stem cells: preliminary characterization and effect of transplantation in a rodent model of Parkinson's disease.Weiss ML, et al. Stem Cells. 2006 Mar;24(3):781-92. Epub 2005 Oct 13.Abstract: The umbilical cord contains an inexhaustible, noncontroversial source of stem cells for therapy. In the U.S., stem cells found in the umbilical cord are routinely placed into bio-hazardous waste after birth. Here, stem cells derived from human umbilical cord Wharton's Jelly, called umbilical cord matrix stem (UCMS) cells, are characterized. UCMS cells have several properties that make them of interest as a source of cells for therapeutic use. For example, they 1) can be isolated in large numbers, 2) are negative for CD34 and CD45, 3) grow robustly and can be frozen/thawed, 4) can be clonally expanded, and 5) can easily be engineered to express exogenous proteins. UCMS cells have genetic and surface markers of mesenchymal stem cells (positive for CD10, CD13, CD29, CD44, and CD90 and negative for CD14, CD33, CD56, CD31, CD34, CD45, and HLA-DR) and appear to be stable in terms of their surface marker expression in early passage (passages 4-8). Unlike traditional mesenchymal stem cells derived from adult bone marrow stromal cells, small populations of UCMS cells express endoglin (SH2, CD105) and CD49e at passage 8. UCMS cells express growth factors and angiogenic factors, suggesting that they may be used to treat neurodegenerative disease. To test the therapeutic value of UCMS cells, undifferentiated human UCMS cells were transplanted into the brains of hemiparkinsonian rats that were not immune-suppressed. UCMS cells ameliorated apomorphine-induced rotations in the pilot test. UCMS cells transplanted into normal rats did not produce brain tumors, rotational behavior, or a frank host immune rejection response. In summary, the umbilical cord matrix appears to be a rich, noncontroversial, and inexhaustible source of primitive mesenchymal stem cells. 

Olfactory mucosa autografts in human spinal cord injuLima C, et al. J Spinal Cord Med. 2006;29(3):191-203; discBACKGROUND/OBJECTIVE: Olfactory mucosa is a readiolfactory ensheathing and stem-like progenitor cells for neusafety and feasibility of transplanting olfactory mucosa autotraumatically injured spinal cords, a human pilot clinical stuMETHODS: Seven patients ranging from 18 to 32 years of Association [ASIA] class A) were treated at 6 months to 6.5 mucosa autografts were transplanted into lesions ranging fpresent at C4-T6 neurological levels. Operations were perfMarch 2003. Magnetic resonance imaging (MRI), electromyneurological and otolaryngological evaluations were performRESULTS: MRI studies revealed moderate to complete fillpatients reported return of sensation in their bladders, and regained voluntary contraction of anal sphincter. Two of the ASIA C. Every patient had improvement in ASIA motor scothe 3 subjects with tetraplegia in the upper extremities was mean increase for the 4 subjects with paraplegia in the lowAmong the patients who improved in their ASIA sensory neone patient), the mean increase was 20.3 +/- 5.0 for light topinprick. Most of the recovered sensation below the initial lAdverse events included sensory decrease in one patient tdifficulty in locating the lesion, and there were a few instancrelieved by medication. EMG revealed motor unit potential to perform movement. CONCLUSION: This study shows that olfactory mucosa authe human injured spinal cord is feasible, relatively safe, anprocedure involves risks generally associated with any surgpatient monitoring is necessary to rule out any delayed side further improvements. 

Induction of neuronal differentiation of adult human olfderived progenitors.Zhang X, et al. Brain Res. 2006 Feb 16;1073-1074:109-19. Abstract: Neurosphere forming cells (NSFCs) have been eadult olfactory neuroepithelium obtained from patients and previously. They remained undifferentiated in serum or defneurotrophic factors. Many factors affect the differentiation pathway. Retinoic acid (RA), forskolin (FN), and sonic hedgreported to act as growth promoters during neurogenesis o
effect of RA, FN, and Shh on NSFCs' neuronal lineage restriction has not been 

described. The application of RA, FN, and Shh to NSFCs induced the expression of motoneuronal transcription factors, tyrosine hydroxylase, an indicator of dopamine production, and neurite formation. These studies further heighten the potential for using olfactory neuroepithelial progenitors for future autologous cell replacement strategies in neurodegenerative conditions and trauma as well as for use in diagnostic evaluation. Role of transcription factors in motoneuron differentiation of adult human olfactory neuroepithelial-derived progenitors.Zhang X, et al. Stem Cells. 2006 Feb;24(2):434-42. Epub 2005 Sep 1.Abstract: Neurosphereforming cell (NSFC) lines have been established from cultures of human adult olfactory neuroepithelium. Few of these cells ever express mature neuronal or glial markers in minimal essential medium supplemented with 10% fetal bovine serum or defined medium. However, these neural progenitors have the potential to differentiate along glial or neuronal lineages. To evaluate the potential of NSFCs to form motoneurons, transcription factors Olig2, Ngn2, and HB9 were introduced into NSFCs to determine if their expression is sufficient for motoneuron specification and differentiation, as has been shown in the early development of the avian and murine central nervous systems in vivo. NSFCs transfected with Olig2, Ngn2, and HB9 alone exhibited no phenotypic lineage restriction. In contrast, simultaneous transfection of Ngn2 and HB9 cDNA increased the expression of Isl1/2, a motoneuron marker, when the cells were maintained in medium supplemented with retinoic acid, forskolin, and sonic hedgehog. Furthermore, a population of Olig2-expressing NSFCs also expressed Ngn2. Cotransfection of NSFCs with Olig2 and HB9, but not Olig2 and Ngn2, increased Isl1/2 expression. Coculture of NSFCs trans-fected with Ngn2-HB92 or Olig2 and HB9 with purified chicken skeletal muscle demonstrated frequent contacts that resembled neuromuscular junctions. These studies demonstrate that transcription factors governing the early development of chick and mouse motoneuron formation are able to drive human adult olfactory neuroepithelial progenitors to differentiate into motoneurons in vitro. Our long-term goal is to develop cell populations for future studies of the therapeutic utility of these olfactory-derived NSFCs for autologous cell replacement strategies for central nervous system trauma and neurodegenerative diseases. Bone marrow production of lung cells: the impact of G-CSF, cardiotoxin, graded doses of irradiation, and subpopulation phenotype.Aliotta JM, et al. Exp Hematol. 2006 Feb;34(2):230-41.OBJECTIVE: Previous studies have demonstrated the production of various types of 

lung cells from marrow cells under diverse experimental conditions. Our aim was to identify some of the variables that influence conversion in the lung. METHODS: In separate experiments, mice received various doses of total-body 

irradiation followed by transplantation with whole bone mar

of marrow cells (Lin(-/+), c-kit(-/+), Sca-1(-/+)) from GFP(+) TgN[ACTbEGFP]1Osb) mice. Some were given intramuscumobilized with granulocyte colony-stimulating factor (G-CSRESULTS: The production of pulmonary epithelial cells frowas established utilizing green fluorescent protein (GFP) a

autofluorescence and deconvolution microscopy to establisand cytokeratin and the absence of CD45 in lung samples donor-derived lung cells (GFP(+)/CD45(-)) were seen with 

(5.43% of all lung cells, 1200 cGy). In the 900-cGy group, 6cells were also cytokeratin(+). Mobilization further increase7.88% in radiation-injured mice. Up to 1.67% of lung cells wradiation-injured mice transplanted with Lin(-), c-kit(+), or Sc-kit(-), and Sca-1(-) subpopulations did not significantly enCONCLUSIONS: We have established that marrow cells apulmonary epithelial cells and identified radiation dose and variables influencing the production of lung cells from marroputative lung cell-producing marrow cell has the phenotype 

Results of the cord blood transplantation study (COBLdonor umbilical cord blood transplantation in pediatric and peroxisomal storage diseases.Martin PL, et al. Biol Blood Marrow Transplant. 2006 Feb;1Abstract: The Cord Blood Transplantation Study (COBLT)Heart, Lung, and Blood Institute, is a phase II multicenter suse of cord blood in allogeneic transplantation. In this repoof cord blood transplantation in 69 patients with lysosomal diseases. Patients with mucopolysaccharidoses I to III, muadrenoleukodystrophy (n = 8), metachromatic leukodystrop= 16), and Tay-Sachs disease (n = 3) were enrolled betwee2004. All patients received the same preparative regimen, (GVHD) prophylaxis, and supportive care. End points incluGVHD, and toxicity. Sixty-nine patients (64% men; 81% whyears underwent transplantation with a median cell dose of survival was 72% (95% confidence interval, 61%-83%). Thneutrophil engraftment by day 42 was 78% (95% confidencmedian of 25 days. Grade II to IV acute GVHD occurred in donors are readily available for rapid transplantation. Cord be considered as frontline therapy for young patients with lystorage diseases. 
Nonmyeloablative hematopoietic stem cell transplantation for systemic lupus 

erythematosus.Burt RK, et al. JAMA. 2006 Feb 1;295(5):527-35.CONTEXT: Manifestations of systemic lupus erythematosus (SLE) may in most patients be ameliorated with medications that suppress the immune system. Nevertheless, there remains a subset of SLE patients for whom current strategies are insufficient to control disease. OBJECTIVE: To assess the safety of intense immunosuppression and autologous hematopoietic stem cell support in patients with severe and treatment-refractory SLE. DESIGN, SETTING, AND PARTICIPANTS: A single-arm trial of 50 patients with SLE refractory to standard immunosuppressive therapies and either organ- or life-threatening visceral involvement. Patients were enrolled from April 1997 through January 2005 in an autologous nonmyeloablative hematopoietic stem cell transplantation (HSCT) study at a single US medical center. INTERVENTIONS: Peripheral blood stem cells were mobilized with cyclophosphamide (2.0 g/m2) and granulocyte colony-stimulating factor (5 microg/kg per day), enriched ex vivo by CD34+ immunoselection, cryopreserved, and reinfused after treatment with cyclophosphamide (200 mg/kg) and equine antithymocyte globulin (90 mg/kg). MAIN OUTCOME MEASURES: The primary end point was survival, both overall and disease-free. Secondary end points included SLE Disease Activity Index (SLEDAI), 

serology (antinuclear antibody [ANA] and anti-double-stranded (ds) DNA), complement C3 and C4, and changes in renal and pulmonary organ function assessed before treatment and at 6 months, 12 months, and then yearly for 5 years. RESULTS: Fifty patients were enrolled and underwent stem cell mobilization. Two patients died after mobilization, one from disseminated mucormycosis and another from active lupus after postponing the transplantation for 4 months. Forty-eight patients underwent nonmyeloablative HSCT. Treatment-related mortality was 2% (1/50). By intention to treat, treatment-related mortality was 4% (2/50). With a mean follow-up of 29 months (range, 6 months to 7.5 years) for patients undergoing HSCT, overall 5-year survival was 84%, and probability of disease-free survival at 5 years following HSCT was 50%. Secondary analysis demonstrated stabilization of renal function and significant improvement in SLEDAI score, ANA, anti-ds DNA, complement, and carbon monoxide diffusion lung capacity adjusted for hemoglobin. CONCLUSIONS: In treatment-refractory SLE, autologous nonmyeloablative HSCT results in amelioration of disease activity, improvement in serologic markers, and either stabilization or reversal of organ dysfunction. These data are nonrandomized and thus preliminary, providing the foundation and justification for a definitive randomized trial. Clinical Trial Registration ClinicalTrials.gov Identifier: NCT00271934. 

Autologous bone marrow-derived stem-cell transfer in patients with ST-segment elevation myocardial infarction: double-blind, randomised controlled trial.

Janssens S, et al. Lancet. 2006 Jan 14;367(9505):113-21.BACKGROUND: The benefit of reperfusion therapies for S

infarction (STEMI) is limited by post-infarction left-ventriculawas to investigate the effect of autologous bone marrow-detransfer in the infarct-related artery on LV function and struMETHODS: We did a randomised, double-blind, placebo-c

from whom we harvested bone marrow 1 day after successintervention for STEMI. We assigned patients optimum medplacebo (n=34) or BMSC (n=33). Our primary endpoint was fraction and our secondary endpoints were change in infarcfunction at 4 months' follow-up, all assessed by MRI. We amyocardial perfusion and oxidative metabolism with serial were per protocol. This study is registered with , number NCFINDINGS: Mean global LV ejection fraction 4 days after pintervention was 46.9% (SD 8.2) in controls and 48.5% (7.2increased after 4 months to 49.1% (10.7) and 51.8% (8.8; O95% CI 0.961-1.118, p=0.36). Compared with placebo infusassociated with a significant reduction in myocardial infarct 28%, p=0.036) and a better recovery of regional systolic fuand metabolism increased similarly in both groups. We notassociated with BMSC transfer and all but one patient in th4 months' follow-up. INTERPRETATION: Intracoronary transfer of autologous bof optimum reperfusion therapy does not augment recovery 

myocardial infarction, but could favourably affect infarct rem

2005

Clonal analysis of adult human olfactory neurosphere fOthman M, et al. Biotech Histochem. 2005 Sep-Dec;80(5-6Abstract: Olfactory neuroepithelium (ONe) is unique becau

capable of mitotic division that replace damaged or lost neuisolated populations of ONe progenitors from adult cadavernasal sinus surgery that were heterogeneous and consisteprogenitors. Progenitor lines have been obtained from thesdivide and form nestin positive neurospheres. In the presenpopulation analyses to probe the self-renewal and multipotforming cells (NSFCs). NSFCs plated at the single cell leveneurospheres; dissociation of these spheres resulted in mitcontinued to divide and produce spheres as long as they wactivity of clonal NSFCs was assessed using bromodeoxyu
Lineage restriction of the clonal cultures was determined using a variety of antibodies 

that were characteristic of different levels of neuronal commitment: ss-tubulin isotype III, neural cell adhesion molecule (NCAM) and microtubule associated protein (MAP2), or glial restriction: astrocytes, glial fibrillary acidic protein (GFAP); and oligodendrocytes, galactocerebroside (GalC). Furthermore, nestin expression, a marker indicative of progenitor nature, decreased in defined medium compared to serum-containing medium. Therefore, adult human ONe-derived neural progenitors retain their capacity for selfrenewal, can be clonally expanded, and offer multipotent lineage restriction. Therefore, they are a unique source of progenitors for future cell replacement strategies in the treatment of neurotrauma and neurodegenerative diseases. Administered mesenchymal stem cells protect against ischemic acute renal failure through differentiation-independent mechanismsFlorian Togel, et al. Am J Physiol Renal Physiol 2005 Jul;289(1):F31-42. Epub 2005 Feb 15.Abstract: Severe acute renal failure (ARF) remains a common, largely treatmentresistant clinical problem with disturbingly high mortality rates. Therefore, we tested whether administration of multipotent mesenchymal stem cells (MSC) to anesthetized rats with ischemia-reperfusion-induced ARF (40-min bilateral renal pedicle clamping) could improve the outcome through amelioration of inflammatory, vascular, and apoptotic/necrotic manifestations of ischemic kidney injury. Accordingly, intracarotid administration of MSC (approximately 10(6)/animal) either immediately or 24 h after renal ischemia resulted in significantly improved renal function, higher proliferative and lower apoptotic indexes, as well as lower renal injury and unchanged leukocyte infiltration scores. Such renoprotection was not obtained with syngeneic fibroblasts. Using in vivo two-photon laser confocal microscopy, fluorescence-labeled MSC were detected early after injection in glomeruli, and low numbers attached at microvasculature sites. However, within 3 days of administration, none of the administered MSC had differentiated into a tubular or endothelial cell phenotype. At 24 h after injury, expression of proinflammatory cytokines IL-1beta, TNF-alpha, IFN-gamma, and inducible nitric oxide synthase was significantly reduced and that of anti-inflammatory IL-10 and bFGF, TGFalpha, and Bcl-2 was highly upregulated in treated kidneys. We conclude that the early, highly significant renoprotection obtained with MSC is of considerable therapeutic promise for the cell-based management of clinical ARF. The beneficial effects of MSC are primarily mediated via complex paracrine actions and not by their differentiation into target cells, which, as such, appears to be a more protracted response that may become important in late-stage organ repair. Human adult olfactory neural progenitors rescue axotomized rodent rubrospinal neurons and promote functional recovery.Xiao M, et al. Exp Neurol. 2005 Jul;194(1):12-30.

Abstract: Previously, our lab reported the isolation of patieforming progenitor lines from human adult olfactory epithelipatients undergoing nasal sinus surgery. RT-PCR and ELISneurosphere-forming cells (NSFCs) produced BDNF. Since neurons have been shown to respond to exogenous BNDFthe NSFCs remained viable following engraftment into trauwould rescue axotomized RS neurons from retrograde cell functional recovery. One week after a partial cervical hemissuspended in Matrigel matrix or Matrigel matrix alone was 

GFP-labeled cells survived up to 12 weeks in the lesion cav

ipsilateral white matter; the apparent number and mean solabeled axotomized RST neurons were greater in the NSFCcontrols. Twelve weeks after engraftment, retrograde tracinRST neurons regenerated axons 4-5 segments caudal to thanterograde tracing with biotinylated dextran amine confirmaxons through the transplants within the white matter for 3-grafts. A few RST axons terminated in gray matter close to did not elicit regeneration. Behavioral analysis revealed thadisplayed better performance during spontaneous vertical erope walking than lesion Matrigel only controls 11 weeks poresults emphasize the unique potential of human olfactory progenitors as an autologous source of stem cells for spina

Generation of islet-like hormone-producing cells in vitrpancreas.Atouf F, et al. Cell Transplant. 2005;14(10):735-48.Abstract: Transplantation of pancreatic islets can provide independence for diabetic patients, but the current islet supdescribe a new in vitro system that utilizes adult human pafractions to generate hormone-producing cells over 3-4 weproliferating cells with a retrovirus-expressing green fluoresthis system hormone-producing cells are generated de novcells aggregate to form islet-like cell clusters. The cell clustrelease insulin in response to glucose and other secretagointo immunodeficient, nondiabetic mice, the islet-like cell clhuman insulin. We propose that this system will be useful ainvestigating mechanisms for generating new islet cells from for designing strategies to generate physiologically competvivo. 
Human bone marrow-derived mesenchymal stem cells in the treatment of gliomas.

Nakamizo A, et al. Cancer Res. 2005 Apr 15;65(8):3307-18.Abstract: The poor survival of patients with human malignant gliomas relates partly to the inability to deliver therapeutic agents to the tumor. Because it has been suggested that circulating bone marrow-derived stem cells can be recruited into solid organs in response to tissue stresses, we hypothesized that human bone marrow-derived mesenchymal stem cells (hMSC) may have a tropism for brain tumors and thus could be used as delivery vehicles for glioma therapy. To test this, we isolated hMSCs from bone marrow of normal volunteers, fluorescently labeled the cells, and injected them into the carotid artery of mice bearing human glioma intracranial xenografts (U87, U251, and LN229). hMSCs were seen exclusively within the brain tumors regardless of whether the cells were injected into the ipsilateral or contralateral carotid artery. In contrast, intracarotid injections of fibroblasts or U87 glioma cells resulted in widespread distribution of delivered cells without tumor specificity. To assess the potential of hMSCs to track human gliomas, we injected hMSCs directly into the cerebral hemisphere opposite an established human glioma and showed that the hMSCs were capable of migrating into the xenograft in vivo. Likewise, in vitro Matrigel invasion assays showed that conditioned medium from gliomas, but not from fibroblasts or astrocytes, supported the migration of hMSCs and that platelet-derived growth factor, epidermal growth factor, or stromal cell-derived factor-1alpha, but not basic fibroblast growth factor or vascular endothelial growth factor, enhanced hMSC migration. To test the potential of hMSCs to deliver a therapeutic agent, hMSCs were engineered to release IFN-beta (hMSC-IFNbeta). In vitro coculture and Transwell experiments showed the efficacy of hMSC-IFNbeta against human gliomas. In vivo experiments showed that treatment of human U87 intracranial glioma xenografts with hMSC-IFN-beta significantly increase animal survival compared with controls (P < 0.05). We conclude that hMSCs can integrate into human gliomas after intravascular or local delivery, that this engraftment may be mediated by growth factors, and that this tropism of hMSCs for human gliomas can be exploited to therapeutic advantage. Preservation from left ventricular remodeling by front-integrated revascularization and stem cell liberation in evolving acute myocardial infarction by use of granulocyte-colony-stimulating factor (FIRSTLINE-AMI).Ince H, et al. Circulation. 2005 Nov 15;112(20):3097-106. Epub 2005 Nov 7.BACKGROUND: Considering experimental evidence that stem cells enhance 

myocardial regeneration and granulocyte colony-stimulating factor (G-CSF) mediates mobilization of CD34+ mononuclear blood stem cells (MNCCD34+), we tested the impact of G-CSF integrated into primary percutaneous coronary intervention (PCI) management of acute myocardial infarction in man. METHODS AND RESULTS: Fifty consecutive patients with ST-segment elevation 

myocardial infarction were subjected to primary PCI stentinup for 6 months; 89+/-35 minutes after successful PCI, 25 passigned in this pilot study (PROBE design) to receive sub

microg/kg body weight for 6 days in addition to standard caclopidogrel, an ACE inhibitor, beta-blocking agents, and stasoftware on peripheral blood samples incubated with CD45 MNCCD34+ were quantified on a daily basis. With homogeclinical and infarct-related characteristics, G-CSF stimulatioMNCCD34+ to between 3.17+/-2.93 MNCCD34+/microL at MNCCD34+/microL on day 6 (P<0.001 versus control); theleukocytoclastic effects, significant pain, impaired rheologyaccelerated restenosis at 6 months. Within 35 days, G-CSF led to enhanced resting wall thickening in the infarct zone o0.99+/-0.32 mm versus 0.49+/-0.29 mm in control subjects challenge with dobutamine (10 microg.kg(-1).min(-1)), wall improvement from 1.66+/-0.23 to 1.41+/-0.21 (P<0.004 ver0.24 after 4 months (P<0.001 versus control), respectively, recovery of wall thickening to 1.24+/-0.31 mm (P<0.001 veAccordingly, resting wall motion score index improved with (P<0.001 versus control), left ventricular end-diastolic diamversus control), and ejection fraction to 54+/-8% (P<0.001 vMorphological and functional improvement with G-CSF was metabolic activity and 18F-deoxyglucose uptake in the infacontrol). CONCLUSIONS: G-CSF and mobilization of MNC(CD34+) myocardium may offer a pragmatic strategy for preservatioprevention of remodeling without evidence of aggravated re

Improvement of bilateral motor functions in patients wthrough the unilateral intraputaminal infusion of glial cneurotrophic factor.Slevin JT, et al. J Neurosurg. 2005 Feb;102(2):216-22.OBJECT: Glial cell line-derived neurotrophic factor (GDNFantiparkinsonian actions in several animal models and in a in which four of five patients received bilateral putaminal dethe authors report on a 6-month unilateral intraputaminal Gwith advanced Parkinson disease (PD). METHODS: Patients with PD in a functionally defined on aweek before and 1 and 4 weeks after intraputaminal cathetcontralateral to the most affected side. Each patient was plregimen of GDNF: 3, 10, and 30 microg/day at successive a 1-month wash-out period. The Unified Parkinson's Diseas
total scores in the on and off states significantly improved 34 and 33%, respectively, at 

24 weeks compared with baseline scores (95% confidence interval [CI] 18-47% for off scores and 16-51% for on scores). In addition, UPDRS motor scores in both the on and off states significantly improved by 30% at 24 weeks compared with baseline scores (95% CI 15-48% for off scores and 5-61% for on scores). Improvements occurred bilaterally, as measured by balance and gait and increased speed of hand movements. All significant improvements of motor function continued through the wash-out period. The only observed side effects were transient Lhermitte symptoms in two patients. CONCLUSIONS: Analysis of the data in this open-label study demonstrates the safety and potential efficacy of unilateral intraputaminal GDNF infusion. Unilateral administration of the protein resulted in significant, sustained bilateral effects. Regeneration of human infarcted heart muscle by intracoronary autologous bone marrow cell transplantation in chronic coronary artery disease: the IACT Study.Strauer BE, et al. J Am Coll Cardiol. 2005 Nov 1;46(9):1651-8.OBJECTIVES: Stem cell therapy may be useful in chronic myocardial infarction (MI); this is conceivable, but not yet demonstrated in humans. BACKGROUND: After acute MI, bone marrow-derived cells improve cardiac function. METHODS: We treated 18 consecutive patients with chronic MI (5 months to 8.5 years old) by the intracoronary transplantation of autologous bone marrow mononuclear cells and compared them with a representative control group without cell therapy. RESULTS: After three months, in the transplantation group, infarct size was reduced by 30% and global left ventricular ejection fraction (+15%) and infarction wall movement velocity (+57%) increased significantly, whereas in the control group no significant changes were observed in infarct size, left ventricular ejection fraction, or wall movement velocity of infarcted area. Percutaneous transluminal coronary angioplasty alone had no effect on left ventricular function. After bone marrow cell transplantation, there was an improvement of maximum oxygen uptake (VO2max, +11%) and of regional 18F-fluordesoxy-glucose uptake into infarct tissue (+15%). CONCLUSIONS: These results demonstrate that functional and metabolic regeneration of infarcted and chronically avital tissue can be realized in humans by bone marrow mononuclear cell transplantation. Surgical ventricular remodeling for patients with clinically advanced congestive heart failure and severe left ventricular dysfunction.Patel ND, et al. J Heart Lung Transplant. 2005 Dec;24(12):2202-10. Epub 2005 Sep 15.BACKGROUND: Surgical ventricular remodeling (SVR) is an accepted therapy for postinfarction ventricular remodeling. Current literature on SVR outcomes has focused on 

heterogeneous populations with regard to left ventricular function and New York Heart Association (NYHA) class. We assessed outcomes after SVR in patients with advanced 

congestive heart failure (CHF) (NYHA Class III/IV) and a pr(EF) < or =20%. METHODS: Data were analyzed for 51 consecutive SVR pJune 2004. Cardiac catheterization, echocardiography and (MRI) identified 62.7% (32 of 51) of patients with an EF < ohaving an EF < or =15% (65.6%; 21 of 32). Cox regression determine predictors of mortality in patients with an EF < o(32 of 32) complete. RESULTS: Mean age was 61.9 +/- 10.3 (range 40 to 80) yof 27:5. Operative mortality was 6.3% (2 of 32). Twenty-two concomitant mitral valve procedures. Follow-up demonstraimprovement in left ventricular volumes and EF in survivorsidentified the following to be significant predictors of mortalventricular end-systolic volume index >130 ml/m2; pre-opeaortic balloon pump usage. Pre-operatively, all patients (32 NYHA Class III/IV, with 69% (22 of 32) improving to NYHA 0.01). Survival did not differ statistically between patients wEF >20% (n = 19). CONCLUSIONS: Our results indicate that SVR improves lefunctional status for patients with advanced CHF and a preTherefore, SVR is a viable surgical alternative for patients wdysfunction. 

Transplantation of umbilical-cord blood in babies with Escolar ML, et al. N Engl J Med. 2005 May 19;352(20):206BACKGROUND: Infantile Krabbe's disease produces progdeterioration and death in early childhood. We hypothesizeumbilical-cord blood from unrelated donors before the devefavorably alter the natural history of the disease among newwas diagnosed because of a family history. We compared tnewborns with the outcomes among infants who underwendevelopment of symptoms and with the outcomes in an untchildren. METHODS: Eleven asymptomatic newborns (age range, 1symptomatic infants (age range, 142 to 352 days) with infaunderwent transplantation of umbilical-cord blood from unremyeloablative chemotherapy. Engraftment, survival, and newere evaluated longitudinally for four months to six years. RESULTS: The rates of donor-cell engraftment and survivapercent, respectively, among the asymptomatic newborns (and 100 percent and 43 percent, respectively, among the sfollow-up, 3.4 years). Surviving patients showed durable en
hematopoietic cells with restoration of normal blood galactocerebrosidase levels. Infants 

who underwent transplantation before the development of symptoms showed progressive central myelination and continued gains in developmental skills, and most had age-appropriate cognitive function and receptive language skills, but a few had mildto-moderate delays in expressive language and mild-to-severe delays in gross motor function. Children who underwent transplantation after the onset of symptoms had minimal neurologic improvement. CONCLUSIONS: Transplantation of umbilical-cord blood from unrelated donors in 

newborns with infantile Krabbe's disease favorably altered the natural history of the disease. Transplantation in babies after symptoms had developed did not result in substantive neurologic improvement. Copyright 2005 Massachusetts Medical Society. 

Cell-replacement therapy for diabetes: Generating functional insulin-producing tissue from adult human liver cells.Sapir T, et al. Proc Natl Acad Sci U S A. 2005 May 31;102(22):7964-9. Epub 2005 May 17.Abstract: Shortage in tissue availability from cadaver donors and the need for life-long 

immunosuppression severely restrict the large-scale application of cell-replacement therapy for diabetic patients. This study suggests the potential use of adult human liver as alternate tissue for autologous beta-cell-replacement therapy. By using pancreatic and duodenal homeobox gene 1 (PDX-1) and soluble factors, we induced a comprehensive developmental shift of adult human liver cells into functional insulinproducing cells. PDX-1-treated human liver cells express insulin, store it in defined granules, and secrete the hormone in a glucose-regulated manner. When transplanted under the renal capsule of diabetic, immunodeficient mice, the cells ameliorated hyperglycemia for prolonged periods of time. Inducing developmental redirection of adult liver offers the potential of a cell-replacement therapy for diabetics by allowing the patient to be the donor of his own insulin-producing tissue. 

New Research On Adult Cells with Pluripotent Characteristics The studies cited below are a sampling of the published and peer-reviewed material available on the subject. The list will be updated on a regular basis. Identification of stem cells from human umbilical cord blood with embryonic and hematopoietic characteristics Zhao Y et al., Exp Cell Res. 2006 Aug 1;312(13):2454-64. Epub 2006 Apr 26. 

Abstract: We identified stem cells from the umbilical cord bstem cells (CB-SC). CB-SC displayed important embryonic including expression of ES-cell-specific molecular markers OCT-4 and Nanog, along with stage-specific embryonic anCB-SC also expressed hematopoietic cell antigens includinwere negative for CD34. CB-SC displayed very low immunexpression of a very low level of major histocompatibility cofailure to stimulate the proliferation of allogeneic lymphocytcells with endothelial-like and neuronal-like characteristics expression of lineage-associated markers. Notably, CB-SC differentiate into functional insulin-producing cells in vivo anafter transplantation into a streptozotocin-induced diabetic may have significant potential to advance stem-cell-based Identification of pulmonary Oct-4+ stem/progenitor celltheir susceptibility to SARS coronavirus (SARS-CoV) inLing T-Y et al., Proc Natl Acad Sci U S A. 2006 Jun 20;10313Abstract: In this study, we report a serum-free culture systpulmonary cells that can support the growth of octamer-bin(Oct-4+) epithelial colonies with a surrounding mesenchym4, these cells also express other stem cell markers such as antigen 1 (SSEA-1), stem cell antigen 1 (Sca-1), and Clara but not c-Kit, CD34, and p63, indicating that they represent cells that have been implicated as lung stem/progenitor celThese colony cells can be kept for weeks in primary culturedifferentiation to alveolar type-2- and type-1-like pneumocyremoved from the stroma. In addition, we have demonstratlong-term BrdU label-retaining cells at the bronchoalveolar providing a link between the Oct-4+ cells in vivo and in vitro identity as putative neonatal lung stem/progenitor cells. Lascolony cells, which also express angiotensin-converting ensevere acute respiratory syndrome coronavirus infection in active virus replication leading to their own destruction. Thepossible involvement of lung stem/progenitor cells, in additacute respiratory syndrome coronavirus infection, accountideterioration of lung tissues and apparent loss of capacity f

Derivation of male germ cells from bone marrow stem cNayernial K et al., Lab Invest. 2006 Jul;86(7):654-63. Epub 
Abstract: Recent studies have demonstrated that somatic stem cells have a more flexible 

potential than expected, whether put into tissue or cultured under different conditions. Bone marrow (BM)-derived stem cells can transdifferentiate into multilineage cells, such as muscle of mesoderm, lung and liver of endoderm, and brain and skin of ectoderm origin. Here we show that BM stem cells are able to transdifferentiate into male germ cells. For derivation of male germ cells from adult BM stem (BMS) cells, we used the Stra8-enhanced green fluoresence protein (EGFP) transgenic mouse line expressing EGFP specifically in male germ cells. BMS cell-derived germ cells expressed the known molecular markers of primordial germ cells, such as fragilis, stella, Rnf17, Mvh and Oct4; as well as molecular markers of spermatogonial stem cells and spermatogonia including Rbm, c-Kit, Tex18, Stra8, Piwil2, Dazl, Hsp90alpha, beta1- and alpha6-integrins. Our ability to derive male germ cells from BMS cells reveals novel aspects of germ cell development and opens the possibilities for use of these cells in reproductive medicine. A population of very small embryonic-like (VSEL) CXCR4+SSEA-1+Oct-4+ stem cells identified in adult bone marrowKucia M et al., Leukemia. 2006 May;20(5):857-69http://www.nature.com/leu/journal/v20/n5/abs/2404171a.html Abstract: By employing multiparameter sorting, we identified in murine bone marrow (BM) a homogenous population of rare (approximately 0.02% of BMMNC) Sca-1(+)lin(-)CD45- cells that express by RQ-PCR and immunohistochemistry markers of pluripotent stem cells (PSC) such as SSEA-1, Oct-4, Nanog and Rex-1. The direct electronmicroscopical analysis revealed that these cells are small (approximately 2-4 microm), posses large nuclei surrounded by a narrow rim of cytoplasm, and contain open-type chromatin (euchromatin) that is typical for embryonic stem cells. In vitro cultures these cells are able to differentiate into all three germ-layer lineages. The number of these cells is highest in BM from young (approximately 1-month-old) mice and decreases with age. It is also significantly diminished in short living DBA/2J mice as 

compared to long living B6 animals. These cells in vitro respond strongly to SDF-1, HGF/SF and LIF and express CXCR4, c-met and LIF-R, respectively, and since they adhere to fibroblasts they may be coisolated with BM adherent cells. We hypothesize that this population of Sca-1(+)lin(-)CD45- very small embryonic-like (VSEL) stem cells is deposited early during development in BM and could be a source of pluripotent stem cells for tissue/organ regeneration. 

Pluripotency of spermatogonial stem cells from adult mouse testisGuan K et al. , Nature. 2006 Apr 27;440(7088):1199-203. Epub 2006 Mar 24Abstract: Embryonic germ cells as well as germline stem cells from neonatal mouse 

testis are pluripotent and have differentiation potential similsuggesting that the germline lineage may retain the ability tHowever, until now there has been no evidence for the plur

adult spermatogonial stem cells (SSCs), which are respons

spermatogenesis throughout life in the male. Here we show adult mouse testis using genetic selection, with a success rSSCs respond to culture conditions and acquire embryonic name these cells multipotent adult germline stem cells (maspontaneously differentiate into derivatives of the three emand generate teratomas in immunodeficient mice. When injSSCs contribute to the development of various organs and Thus, the capacity to form multipotent cells persists in adulof human maGSCs from testicular biopsies may allow indivwithout the ethical and immunological problems associated cells. Furthermore, these cells may provide new opportunitin various cell lineages. Expression of early transcription factors Oct-4, Sox-2 aumbilical cord (PUC) matrix cellsCarlin R et al. , Reprod Biol Endocrinol. 2006 Feb 6;4(1):8 Abstract: Three transcription factors that are expressed at cells (ESCs) are Nanog, Oct-4 and Sox-2. These transcriptexpression of other genes during development and are foupluripotent cells of the inner cell mass. The downregulation factors correlates with the loss of pluripotency and self-renesubsequent differentiation steps. The roles of Nanog, Oct-4 fully elucidated. They are important in embryonic developmpluripotency in ESCs. We studied the expression of these tumbilical cord (PUC) matrix cells. METHODS: Cells were isporcine umbilical cords (PUC) and histochemically assayed phosphatase and the presence of Nanog, Oct-4 and Sox-2 amplicons were sequenced and compared with known seq4 and Nanog protein was analyzed using immunocytochemutilized to evaluate Hoechst 33342 dye-stained cells. RESUmaintained in culture and formed colonies that express alkaanalysis revealed a side population of Hoechst dye-excludiexclusion was verapamil sensitive. Quantitative and non-qurevealed expression of Nanog, Oct-4 and Sox-2 in day 15 eisolates and porcine fibroblasts. Immunocytochemical analyimmunoreactivity in PUC cell nuclei, and faint labeling in fibimmunoreactivity was detected in the nuclei of some PUC cCONCLUSIONS: Cells isolated from PUC matrix express t
found in pluripotent stem cell markers both at the mRNA and protein level. The presence 

of these transcription factors, along with the other characteristics of PUC cells such as their colony-forming ability, Hoechst dye-excluding side population and alkaline phosphatase expression, suggests that PUC cells have properties of primitive pluripotent stem cells. Furthermore, PUC cells are an easily and inexpensively obtained source of stem cells that are not hampered by the ethical or legal issues associated with ESCs. In addition, these cells can be cryogenically stored and expanded. Transplantation of a novel cell line population of umbilical cord blood stem cells ameliorates neurological deficits associated with ischemic brain injury Xiao J et al., Stem Cells Dev. 2005 Dec;14(6):722-33Abstract: Umbilical cord blood (UCB) is a rich source of hematopoetic stem cells (HSCs). We have isolated a novel cell line population of stem cells from human UCB that exhibit properties of self-renewal, but do not have cell-surface markers that are typically found on HSCs. Analysis of transcripts revealed that these cells express transcription factors 

Oct-4, Rex-1, and Sox-2 that are typically expressed by stem cells. We refer to these novel cells as nonhematopoietic umbilical cord blood stem cells (nh-UCBSCs). Previous studies have shown that the intravenous infusion of UCBCs can ameliorate neurological deficits arising from ischemic brain injury. The identity of the cells that mediate this restorative effect, however, has yet to be determined. We postulate that nh-UCBSCs may be a source of the UCB cells that can mediate these effects. To test this hypothesis, we intravenously injected one million human nh-UCBSCs into rats 48 h after transient unilateral middle cerebral artery occlusion. Animals in other experimental groups received either saline injections or injections of RN33b neural stem cells. Animals were tested for neurological function before the infusion of nh-UCBSCs and at various time periods afterwards using a battery of behavioral tests. In limb placement tests, animals treated with nh-UCBSCs exhibited mean scores that were significantly better than animals treated with RN33b neural stem cells or saline. Similarly, in stepping tests, nhUCBSC-treated animals again exhibited significantly better performance than the other experimental groups of animals. Analysis of infarct volume revealed that ischemic animals treated with nh-UCBSCs exhibited a 50% reduction in lesion volume in comparison to saline-treated controls. Histological analysis of brain tissue further revealed the presence of cells that stained for human nuclei. Some human nucleipositive cells were also co-labeled for NeuN, indicating that the transplanted cells expressed markers of a neuronal phenotype. Cells expressing the human nuclei marker within the brain, however, were rather scant, suggesting that the restorative effects of nhUCBSCs may be mediated by mechanisms other than cell replacement. To test this hypothesis, nh-UCBSCs were directly transplanted into the brain parenchyma after ischemic brain injury. Sprouting of nerve fibers from the nondamaged hemisphere into the ischemically damaged side of the brain was assessed by anterograde tracing using biotinylated dextran amine (BDA). Animals with nh-UCBSC transplants exhibited significantly greater densities of BDA-positive cells in the damaged side of the brain 

compared to animals with intraparenchymal saline injectionrestorative effects observed with nh-UCBSC treatment follomay be mediated by trophic actions that result in the reorgaconnections within the injured brain. 

Human fibroblast-derived cell lines have characteristicand cells of neuro-ectodermal originRieske P et al., Differentiation. 2005 Dec;73(9-10):474-83Abstract: Fibroblasts are the most ubiquitous cells in compmain cells of stromal tissue and play an important role in reorgans. Here we report new data-initially serendipitous find

cell line (human fetal lung derived cells, MRC-5) have the mgene expression pattern characteristic of embryonic stem cectodermal origin. We have developed a serum-free culture cells in proliferative state. We discovered that, at proliferativtranscription factors of pluripotent cells, OCT-3/4 and REX-antigens SSEA-1, SSEA-3, and SSEA-4, as well as TRA-1to embryonic cell markers, the fibroblasts expressed neuronestin, medium neurofilament, and beta-III tubulin. RT-PCR mesencephalic transcription factors, Nurr-1 and PTX-3, wecells, and that these cells could be induced to express tyroExpression of TH followed down-regulation of genes assocOCT-3/4, REX-1, and beta-catenin. These data indicate thaas fibroblasts have some of the characteristics of stem cellsbecome neuroectodermal cells and perhaps even mature n

Mesenchymal stem cells derived from CD133-positive cblood and cord blood: proliferation, Oct4 expression, aTondreau T et al., Stem Cells. 2005 Sep;23(8):1105-12. EpAbstract: In this study, we used a common procedure to amobilized peripheral blood (MPB) and umbilical cord blood mesenchymal stem cells (MSCs) in comparison with bone methods: plastic adhesion supplemented with 5% of BM-Munsupplemented plastic adhesion, and selection of CD133-from MPB or UCB are identified by their positive expression and negative expression of hematopoietic markers (CD14, observed that the CD133-positive cell fraction contains moproliferative potential. Placed in appropriate conditions, theto differentiate into adipocytes, osteocytes, chondrocytes, aand UCB-MSCs express Oct4, a transcriptional binding fac
cells with high proliferative capacity. The selection of CD133-positive cells enabled us to 

obtain a homogeneous population of MSCs from UCB and MPB. These sources may have a major clinical importance thanks to their easy accessibility. Stem cell characteristics of amniotic epithelial cellsMiki T et al., Stem Cells. 2005 Nov-Dec;23(10):1549-59. Epub 2005 Aug 4Abstract: Amniotic epithelial cells develop from the epiblast by 8 days after fertilization 

and before gastrulation, opening the possibility that they might maintain the plasticity of pregastrulation embryo cells. Here we show that amniotic epithelial cells isolated from human term placenta express surface markers normally present on embryonic stem and germ cells. In addition, amniotic epithelial cells express the pluripotent stem cell-specific 

transcription factors octamer-binding protein 4 (Oct-4) and nanog. Under certain culture conditions, amniotic epithelial cells form spheroid structures that retain stem cell characteristics. Amniotic epithelial cells do not require other cell-derived feeder layers to maintain Oct-4 expression, do not express telomerase, and are nontumorigenic upon transplantation. Based on immunohistochemical and genetic analysis, amniotic epithelial cells have the potential to differentiate to all three germ layers--endoderm (liver, pancreas), mesoderm (cardiomyocyte), and ectoderm (neural cells) in vitro. Amnion derived from term placenta after live birth may be a useful and noncontroversial source of stem cells for cell transplantation and regenerative medicine. 

Production of stem cells with embryonic characteristics from human umbilical cord blood McGuckin CP et al., Cell Prolif. 2005 Aug;38(4):245-55.Abstract: When will embryonic stem cells reach the clinic? The answer is simple -- not 

soon! To produce large quantities of homogeneous tissue for transplantation, without feeder layers, and with the appropriate recipient's immunological phenotype, is a significant scientific hindrance, although adult stem (ADS) cells provide an alternative, 

more ethically acceptable, source. The annual global 100 million human birth rate proposes umbilical cord blood (UCB) as the largest untouched stem cell source, with advantages of naive immune status and relatively unshortened telomere length. Here, we report the world's first reproducible production of cells expressing embryonic stem cell markers, - cord-blood-derived embryonic-like stem cells (CBEs). UCB, after elective birth by Caesarean section, has been separated by sequential immunomagnetic removal of nucleate granulocytes, erythrocytes and haemopoietic myeloid/lymphoid progenitors. After 7 days of high density culture in microflasks, (10(5) cells/ml, IMDM, FCS 10%, thrombopoietin 10 ng/ml, flt3-ligand 50 ng/ml, c-kit ligand 20 ng/ml). CBE colonies formed adherent to the substrata; these were maintained for 6 weeks, then were subcultured and continued for a minimum 13 weeks. CBEs were positive for TRA-1-60, TRA-1-81, SSEA-4, SSEA-3 and Oct-4, but not SSEA-1, indicative of restriction in the 

human stem cell compartment. The CBEs were also microgwith hepatocyte growth medium (IMDM, FCS 10%, HGF 20 10 ng/ml, c-kit ligand 10 ng/ml). After 4 weeks the cells wercharacteristic hepatic markers, cytokeratin-18, alpha-foetopsuch CBEs are a viable human alternative from embryonic research, without ethical constraint and with potential for cl

Characterization of multipotent mesenchymal stem celrhesus macaquesIzadpanah R et al., Stem Cells Dev. 2005 Aug;14(4):440-5Abstract: The isolation and characterization of embryonic higher-order mammalian species will enhance the understatherapeutic application of stem cells. The aim of this study mesenchymal stem cells (MSCs) from adult bone marrow afunctionally their abilities to differentiate along diverse linearhesus macaque bone marrow were characterized for their lineage differentiation, cell-surface antigen expression, telocontent, and transcription factor gene expression. Rhesus are very heterogeneous, composed of primarily long, thin ccells. The cells are capable of differentiating along osteogeadipogenic lineages in vitro. The cell morphology and multicapabilities are maintained throughout extended culture. Th(Thy-1), CD105, and HLA-1 and were negative for hematopCD4, CD8, CD11b, CD13, CD34, and platelet endothelial c(CD31). BMSCs were also demonstrated to express the mRrelated transcription factors such as Oct-4, Sox-2, Rex-1, ahave a normal chromosome content, and the shortening of early passages. These data demonstrate that BMSCs isolahave a high degree of commonality with MSCs isolated from isolation of these cells provides an effective and convenienof pluripotent rhesus MSCs. 

Oocyte generation in adult mammalian ovaries by putamarrow and peripheral bloodJohnson J et al., Cell. 2005 Jul 29;122(2):303-15Abstract: It has been suggested that germline stem cells mpostnatal mouse ovaries. Here we show that adult mouse ohundreds of oocytes, despite a small premeiotic germ cell ppossibility of an extragonadal source of germ cells, we show markers in bone marrow (BM). Further, BM transplantation 
wild-type mice sterilized by chemotherapy, as well as in ataxia telangiectasia-mutated 

gene-deficient mice, which are otherwise incapable of making oocytes. Donor-derived oocytes are also observed in female mice following peripheral blood transplantation. Although the fertilizability and developmental competency of the BM and peripheral blood-derived oocytes remain to be established, their morphology, enclosure within follicles, and expression of germ-cell- and oocyte-specific markers collectively support that these cells are bona fide oocytes. These results identify BM as a potential source of germ cells that could sustain oocyte production in adulthood. Multipotent stem cells from adult olfactory mucosaMurrell W et al., Dev Dyn. 2005 Jun;233(2):496-515Abstract: Multipotent stem cells are thought to be responsible for the generation of new neurons in the adult brain. Neurogenesis also occurs in an accessible part of the nervous system, the olfactory mucosa. We show here that cells from human olfactory mucosa generate neurospheres that are multipotent in vitro and when transplanted into the chicken embryo. Cloned neurosphere cells show this multipotency. Multipotency was evident without prior culture in vitro: cells dissociated from adult rat olfactory mucosa generate leukocytes when transplanted into bone marrow-irradiated hosts, and cells dissociated from adult mouse olfactory epithelium generated numerous cell types when transplanted into the chicken embryo. It is unlikely that these results can be attributed to hematopoietic precursor contamination or cell fusion. These results demonstrate the existence of a multipotent stem-like cell in the olfactory mucosa useful for autologous transplantation therapies and for cellular studies of disease. Copyright 2005 Wiley-Liss, Inc Transplanted human bone marrow cells generate new brain cells Crain BJ et al., Proc Natl Acad Sci U S A. 2003 Feb 4;100(3):1364-9. Epub 2003 Jan 21 Abstract: Adult bone marrow stem cells seem to differentiate into muscle, skin, liver, 

lung, and neuronal cells in rodents and have been shown to regenerate myocardium, hepatocytes, and skin and gastrointestinal epithelium in humans. Because we have demonstrated previously that transplanted bone marrow cells can enter the brain of mice and differentiate into neurons there, we decided to examine postmortem brain samples from females who had received bone marrow transplants from male donors. The underlying diseases of the patients were lymphocytic leukemia and genetic deficiency of the immune system, and they survived between 1 and 9 months after transplant. We used a combination of immunocytochemistry (utilizing neuron-specific antibodies) and fluorescent in situ hybridization histochemistry to search for Y chromosome-positive cells. In all four patients studied we found cells containing Y chromosomes in several brain regions. Most of them were nonneuronal (endothelial cells and cells in the white matter), but neurons were certainly labeled, especially in the hippocampus and cerebral 

cortex. The youngest patient (2 years old), who also lived ttransplantation, had the greatest number of donor-derived distribution of the labeled cells was not homogeneous. Thecells, suggesting that single progenitor cells underwent clondifferentiation. We conclude that adult human bone marrow generate neurons just as rodent cells do. Perhaps this pheto prevent the development or progression of neurodegenetissue damaged by infarction or trauma. 

Clonal multilineage differentiation of murine common pisolated from skeletal muscle and adipose stromal cellCase J et al., Ann N Y Acad Sci. 2005 Jun;1044:183-200Abstract: Pluripotent stem cells (PSCs) with transdifferentuseful therapeutic modalities in the areas of cellular restoramedicine. The utility of PSCs depends on their ability to resto adapt to tissue-specific differentiation conditions. Given tpossessing characteristics of PSCs have been identified anmurine tissues, we hypothesized that a common PSC may tissues and that these cells may either reside permanently circulate and colonize tissues as needed. Previous data froPSCs exhibiting an immunophenotype of CD45(-)Sca-1(+)cisolated from multiple murine tissues and may represent pu(CoPSCs). To investigate whether the multiple tissue differwith these cells resulted from the presence of different tissuwithin CD45(-)Sca-1(+)c-kit(-)Thy-1(+) cells or was the prodCoPSCs, clonality studies were performed. Single skeletal were expanded for 10 days, and progeny cells were split indesigned to stimulate myogenic, adipogenic, and neurogen600 clones indicated that 2.16%, 0.83%, and 0.33% of the cells were capable of unipotent, bipotent, and tripotent diffecombinations of myocytes, adipocytes, and neuronal cells. CoPSCs represent 4.78% of the total cells analyzed, tripoteof the total muscle cells. Similar results were obtained in clstromal cell (ASC)-derived CoPSCs, suggesting that both SCoPSCs may be phenotypically and functionally identical. Tdemonstrate that a common PSC can be identified in differsuggest that a small fraction of these cells are capable of cmultiple cell types. 

Clonally expanded novel multipotent stem cells from hregenerate myocardium after myocardial infarction
Yoon Y-s et al., J Clin Invest. 2005 Feb;115(2):326-38

Abstract: We have identified a subpopulation of stem cells within adult human BM, isolated at the single-cell level, that self-renew without loss of multipotency for more than 140 population doublings and exhibit the capacity for differentiation into cells of all 3 germ layers. Based on surface marker expression, these clonally expanded human BMderived multipotent stem cells (hBMSCs) do not appear to belong to any previously described BM-derived stem cell population. Intramyocardial transplantation of hBMSCs after myocardial infarction resulted in robust engraftment of transplanted cells, which exhibited colocalization with markers of cardiomyocyte (CMC), EC, and smooth muscle cell (SMC) identity, consistent with differentiation of hBMSCs into multiple lineages in vivo. Furthermore, upregulation of paracrine factors including angiogenic cytokines and antiapoptotic factors, and proliferation of host ECs and CMCs, were observed in the hBMSC-transplanted hearts. Coculture of hBMSCs with CMCs, ECs, or SMCs revealed that phenotypic changes of hBMSCs result from both differentiation and fusion. Collectively, the favorable effect of hBMSC transplantation after myocardial infarction 

appears to be due to augmentation of proliferation and preservation of host myocardial tissues as well as differentiation of hBMSCs for tissue regeneration and repair. To our knowledge, this is the first demonstration that a specific population of multipotent human BM-derived stem cells can induce both therapeutic neovascularization and endogenous and exogenous cardiomyogenesis. 

Human bone marrow mesenchymal stem cells can express insulin and key transcription factors of the endocrine pancreas developmental pathway upon genetic and/or microenvironmental manipulation in vitroMoriscot C et al., Stem Cells. 2005 Apr;23(4):594-603Abstract: Multipotential stem cells can be selected from the bone marrow by plastic adhesion, expanded, and cultured. They are able to differentiate not only into multiple cell types, including cartilage, bone, adipose and fibrous tissues, and myelosupportive 

stroma, but also into mesodermal (endothelium), neuroectodermal, or endodermal (hepatocytes) lineages. Our goal was to characterize the multipotential capacities of human mesenchymal stem cells (hMSCs) and to evaluate their ability to differentiate into insulin-secreting cells in vitro. hMSCs were obtained from healthy donors, selected by plastic adhesion, and phenotyped by fluorescence-activated cell sorter and reverse transcription-polymerase chain reaction analysis before and after infection with adenoviruses coding for mouse IPF1, HLXB9, and FOXA2 transcription factors involved early in the endocrine developmental pathway. We found that native hMSCs have a pluripotent phenotype (OCT4 expression and high telomere length) and constitutively express NKX6-1 at a low level but lack all other transcription factors implicated in betacell differentiation. In all hMSCs, we detected mRNA of cytokeratin 18 and 19, epithelial markers present in pancreatic ductal cells, whereas proconvertase 1/3 mRNA expression was detected only in some hMSCs. Ectopic expression of IPF1, HLXB9, and FOXA2 with 

or without islet coculture or islet-conditioned medium resultIn conclusion, our results demonstrated that in vitro human able to differentiate into insulin-expressing cells by a mechtranscription factors of the beta-cell developmental pathway 

appropriate microenvironment. 

A new human somatic stem cell from placental cord blopluripotent differentiation potentialKögler G et al., J Exp Med. 2004 Jul 19;200(2):123-35Abstract: Here a new, intrinsically pluripotent, CD45-negatcord blood, termed unrestricted somatic stem cells (USSCspopulation grows adherently and can be expanded to 10(15pluripotency. In vitro USSCs showed homogeneous differechondroblasts, adipocytes, and hematopoietic and neural cneurons that express neurofilament, sodium channel proteineurotransmitter phenotypes. Stereotactic implantation of Ubrain revealed that human Tau-positive cells persisted for umigratory activity and a typical neuron-like morphology. In valong mesodermal and endodermal pathways was demonsreconstitution was observed after transplantation of USSC-cylinders in nude rat femurs. Chondrogenesis occurred aftegelfoam sponges into nude mice. Transplantation of USSCpreimmune fetal sheep, resulted in up to 5% human hematthan 20% albumin-producing human parenchymal hepatic fusion and substantial numbers of human cardiomyocytes ithe sheep heart were detected many months after USSC trformation was observed in any of these animals. 

New Research on Alternative Sources of Pluripotent StThe material below was presented to the Council at its NovRichard Roblin, Ph.D., the Council's Scientific Director.

A. Pluripotent stem cells derived from Organism

(Landry-Zucker proposal). 

Council preliminary evaluations in 2005: Not Natural history studies proposed could be undertethical manner. “Ethically acceptable for basic in
Update: Recently demonstrated for “arrested” human embryos. Zhang, X., P. 

Stojkovic, et al., Derivation of human embryonic stem cells from developing and arrested embryos, Stem Cells Express, published online September 21, 2006. Abstract: Human embryonic stem cells (hESC) hold huge promise in modern regenerative medicine, drug discovery, and as a model for studying early human development. However, usage of embryos and derivation of hESC for research and potential medical application has resulted in polarised ethical debates since the process involves destruction of viable developing human 

embryos. Here we describe that not only developing embryos (morulae and blastocysts) of both good and poor quality but also arrested embryos could be used for the derivation of hESC. Analysis of arrested embryos demonstrated that these embryos express pluripotency marker genes such OCT4, NANOG and REX1. Derived hESC lines also expressed specific pluripotency markers (TRA-1-60, TRA-1-81, SSEA4, alkaline phosphatase, OCT4, NANOG, TERT and REX1) and differentiated under in vitro and in vivo conditions into derivates of all three germ layers. All the new lines including line derived from late arrested embryo have normal karyotype. These results demonstrate that arrested embryos are additional valuable resources to surplus and donated developing embryos and should be used to study early human development or derive pluripotent hESC. 

B. Pluripotent Stem Cells via Blastomere Extraction from Living Embryos 

Council preliminary evaluations in 2005: Now technically feasible, though large ethical difficulties remain. Ethically unacceptable in humans. Update: Demonstration that hESC cultures could be derived from single blastomeres, even though in these experiments, all the human embryos were destroyed. Klimanskya, I., Y. Chung, S. Becker, et al., Human embryonic stem cell lines derived from single blastomeres, Nature. 2006 Nov 23; 444 (7118): 481-5. Epub 2006 Aug 23. Abstract: The derivation of human embryonic stem (hES) cells currently requires the destruction of ex utero embryos. A previous study in mice indicates that it might be possible to generate embryonic stem (ES) cells using a single-cell biopsy similar to that used in preimplantation genetic diagnosis (PGD), which does not interfere with the embryo's developmental potential. By growing the single blastomere overnight, the resulting cells could be used for both genetic testing and stem cell derivation without affecting the clinical outcome of the procedure. Here we report a series of ten separate 

experiments demonstrating that hES cells can be 

blastomeres. Nineteen ES-cell-like outgrowths anwere obtained. The latter hES cell lines maintainproliferation for more than eight months, and shoexpression of markers of pluripotency, including TRA-1-60, TRA-1-81, nanog and alkaline phosphthe potential to form derivatives of all three embrand in teratomas. The ability to create new stem without destroying embryos would address the eallow the generation of matched tissue for childretransferred PGD embryos. 

C. Pluripotent Stem Cells derived from Biologica

Council preliminary evaluations in 2005: Tecand ethically the most complex and puzzling. It wtested in animals before any thought of human trNot at this time ethically acceptable for trials with Update: One possible approach appears to work Meissner, A. and R. Jaenisch, Generation of nucpluripotent ES cells from cloned Cdx2-deficient b(2006) 

Abstract: The derivation of embryonic stem (ESholds great promise for research and therapy but cloned human blastocysts. Proof of principle exp'customized' ES cells derived by nuclear transfer correct immunodeficiency in mice. Importantly, thhas been demonstrated recently in humans, brinNT-ESCs within reach. Altered nuclear transfer (variation of nuclear transfer because it would creblastocysts that are inherently unable to implant capable of generating customized ES cells. To avalidity of this concept we have used nuclear tranblastocysts from donor fibroblasts that carried a stargeting Cdx2. Cloned blastocysts were morphofunctional trophoblast and failed to implant into thefficiently generated pluripotent embryonic stem culture. 

D. Pluripotent Stem Cells via Somatic Cell Dedif
Council preliminary evaluations in 2005: ethically the most 

unobjectionable, but for now scientifically and technologically uncertain. Ethically unproblematic and acceptable for use in humans. Update: Adding four genetic factors to mouse fibroblasts changes them into pluripotent stem cells. Takahashi, K. and S. Yamanaka, Induction of Pluripotent Stem Cells from Mouse Embryonic and Adult Fibroblast Cultures by Defined Factors , Cell, 126: 1-14 (2006) [Note that what was produced in these experiments were “genetically engineered” mouse pluripotent stem cells, which may or may not be the functional equivalent of mouse ESCs isolated from the inner cell mass of early mouse embryos.] Abstract: Differentiated cells can be reprogrammed to an embryonic-like state by transfer of nuclear contents into oocytes or by fusion with embryonic stem (ES) cells. Little is known about factors that induce this reprogramming. Here, we demonstrate induction of pluripotent stem cells from mouse embryonic or adult fibroblasts by introducing four factors, Oct3/4, Sox2, c-Myc, and Klf4, under ES cell culture conditions. Unexpectedly, Nanog was dispensable. These cells, which we designated iPS (induced pluripotent stem) cells, exhibit the morphology and growth properties of ES cells and express ES cell marker genes. Subcutaneous transplantation of iPS cells into nude mice resulted in tumors containing a variety of tissues from all three germ layers. Following injection into blastocysts, iPS cells contributed to mouse embryonic development. These data demonstrate that pluripotent stem cells can be directly generated from fibroblast cultures by the addition of only a few defined factors. 

Another recent publication points to the existence multipotent stem cells in human cord blood. Zhao, Y., et al., Identification of stem cells from hwith embryonic and hematopoietic characteristics

Research, 312: 2454-2464 (2006) 

Abstract: We identified stem cells from the umbcord blood-stem cells (CB-SC). CB-SC displayed (ES) cell characteristics including expression of Emarkers including transcription factors OCT-4 anspecific embryonic antigen (SSEA)-3 and SSEA-hematopoietic cell antigens including CD9, CD45 negative for CD34. CB-SC displayed very low imexpression of a very low level of major histocompantigens and failure to stimulate the proliferation CB-SC could give rise to cells with endothelial-likcharacteristics in vitro, as demonstrated by expremarkers. Notably, CB-SC could be stimulated to insulin-producing cells in vivo and eliminated hyptransplantation into a streptozotocin-induced diabfindings may have significant potential to advanctherapeutics. Thus, small numbers of multipotent, if not pluripoexist in a readily available, ethically unproblematany exotic genetic engineering or cell biology. 

Initial work with human materials using cell fusion rather than genetic factors: Cowan, C.A., et al., Nuclear reprogramming of somatic cells after fusion with human  embryonic stem cells , Science, 309: 1369-1373 (2005) 

Also noteworthy is the following publication reporting isolation of rare cells with embryonic stem cell-like characteristics from the bone marrow of young mice . Kucia, M., et al., A population of very small embryonic-like (VESL) CDCR+ SSEA-1+ Oct-4+ stem cells identified in adult [mouse] bone marrow, 

Leukemia, 20: 857-869 (2006). When I inquired of Professor Mariusz Ratajczak (University of Louisville) whether his lab or anyone else that he knew about had found similar cells in human material he replied: 

“Recently we isolated a similar population of cells from the human cord blood”.