bluuebunny/crossref_metadata_2025_split huggingface dataset:
Human Müller Glia with Stem Cell Characteristics Differentiate into Retinal Ganglion Cell (RGC) Precursors In Vitro and Partially Restore RGC Function In Vivo Following Transplantation
Authors: Singhal Shweta , Bhatia Bhairavi , Jayaram Hari , Becker Silke , Jones Megan F. , Cottrill Phillippa B. , Khaw Peng T. , Salt Thomas E. , Limb G. Astrid 
Published: May 2012

Abstract
Müller glia with stem cell characteristics have been identified in the adult human eye, and although there is no evidence that they regenerate retina in vivo, they can be induced to grow and differentiate into retinal neurons in vitro. We differentiated human Müller stem cells into retinal ganglion cell (RGC) precursors by stimulation with fibroblast growth factor 2 together with NOTCH inhibition using the γ-secretase inhibitor N-[N-(3,5-difluorophenacetyl)-l-alanyl]-S-phenylglycine t-butyl ester (DAPT). Differentiation into RGC precursors was confirmed by gene and protein expression analysis, changes in cytosolic [Ca2+] in response to neurotransmitters, and green fluorescent protein (GFP) expression by cells transduced with a transcriptional BRN3b-GFP reporter vector. RGC precursors transplanted onto the inner retinal surface of Lister hooded rats depleted of RGCs by N-methyl-d-aspartate aligned onto the host RGC layer at the site of transplantation but did not extend long processes toward the optic nerve. Cells were observed extending processes into the RGC layer and expressing RGC markers in vivo. This migration was observed only when adjuvant anti-inflammatory and matrix degradation therapy was used for transplantation. RGC precursors induced a significant recovery of RGC function in the transplanted eyes as determined by improvement of the negative scotopic threshold response of the electroretinogram (indicative of RGC function). The results suggest that transplanted RGC precursors may be capable of establishing local interneuron synapses and possibly release neurotrophic factors that facilitate recovery of RGC function. These cells constitute a promising source of cells for cell-based therapies to treat retinal degenerative disease caused by RGC dysfunction.
Concise Review: Immunomodulatory Properties of Mesenchymal Stem Cells in Cellular Transplantation: Update, Controversies, and Unknowns
Authors: Atoui Rony , Chiu Ray C.J. 
Published: May 2012

Abstract
Stem cell transplantation is a promising approach for improving cardiac function after severe myocardial damage, for which the use of autologous donor cells has been preferred to avoid immune rejection. Recently, however, rodent as well as human mesenchymal stem cells have been reported to be uniquely immune-tolerant, in both in vitro and in vivo transplant models. In this review, we explore in detail the current understanding of the underlying immunologic mechanisms, which can facilitate the use of such cells as “universal donor cells” with fascinating clinical implications.
Functional Impairment of Human Resident Cardiac Stem Cells by the Cardiotoxic Antineoplastic Agent Trastuzumab
Authors: Barth Andreas S. , Zhang Yiqiang , Li Taosheng , Smith Rachel R. , Chimenti Isotta , Terrovitis Ioannis , Davis Darryl R. , Kizana Eddy , Ho Alice S. , O'Rourke Brian , Wolff Antonio C. , Gerstenblith Gary , Marbán Eduardo 
Published: May 2012

Abstract
Trastuzumab (TZM), a monoclonal antibody against the ERBB2 protein, increases survival in ERBB2-positive breast cancer patients. Its clinical use, however, is limited by cardiotoxicity. We sought to evaluate whether TZM cardiotoxicity involves inhibition of human adult cardiac-derived stem cells, in addition to previously reported direct adverse effects on cardiomyocytes. To test this idea, we exposed human cardiosphere-derived cells (hCDCs), a natural mixture of cardiac stem cells and supporting cells that has been shown to exert potent regenerative effects, to TZM and tested the effects in vitro and in vivo. We found that ERBB2 mRNA and protein are expressed in hCDCs at levels comparable to those in human myocardium. Although clinically relevant concentrations of TZM had no effect on proliferation, apoptosis, or size of the c-kit-positive hCDC subpopulation, in vitro assays demonstrated diminished potential for cardiogenic differentiation and impaired ability to form microvascular networks in TZM-treated cells. The functional benefit of hCDCs injected into the border zone of acutely infarcted mouse hearts was abrogated by TZM: infarcted animals treated with TZM + hCDCs had a lower ejection fraction, thinner infarct scar, and reduced capillary density in the infarct border zone compared with animals that received hCDCs alone (n = 12 per group). Collectively, these results indicate that TZM inhibits the cardiomyogenic and angiogenic capacities of hCDCs in vitro and abrogates the morphological and functional benefits of hCDC transplantation in vivo. Thus, TZM impairs the function of human resident cardiac stem cells, potentially contributing to TZM cardiotoxicity.
Concise Review: Mesenchymal Stem Cells and Translational Medicine: Emerging Issues
Authors: Ren Guangwen , Chen Xiaodong , Dong Fengping , Li Wenzhao , Ren Xiaohui , Zhang Yanyun , Shi Yufang 
Published: May 2012

Abstract
Mesenchymal stem cells (MSCs) are emerging as a promising therapeutic approach of cell-based therapy for a wide range of autoimmune disorders and degenerative diseases. In preclinical and clinical studies, MSCs have been shown to be highly efficient in treating graft-versus-host disease, systemic lupus erythematosus, multiple sclerosis, type 1 diabetes, myocardial infarction, liver cirrhosis, inflammatory bowel disease, and other disorders. The underlying therapeutic mechanisms of MSCs include their homing efficiency to the tissue injury sites, their differentiation potential, their capability to produce a large amount of trophic factors, and their immunomodulatory effect. Because tissue damage sites are complicated milieus with distinct types of inflammatory cells and factors, available data have demonstrated that the properties of MSCs could be fundamentally influenced by the inflammatory elements. Thus, an understanding of the interaction between MSCs and the inflammatory microenvironment will provide critical information in revealing the precise in vivo mechanisms of MSC-mediated therapeutic effects and designing more practical protocols for clinical use of these cells.
Small Molecule Mesengenic Induction of Human Induced Pluripotent Stem Cells to Generate Mesenchymal Stem/Stromal Cells
Authors: Chen Yen Shun , Pelekanos Rebecca A. , Ellis Rebecca L. , Horne Rachel , Wolvetang Ernst J. , Fisk Nicholas M. 
Published: May 2012

Abstract
The translational potential of mesenchymal stem/stromal cells (MSCs) is limited by their rarity in somatic organs, heterogeneity, and need for harvest by invasive procedures. Induced pluripotent stem cells (iPSCs) could be an advantageous source of MSCs, but attempts to derive MSCs from pluripotent cells have required cumbersome or untranslatable techniques, such as coculture, physical manipulation, sorting, or viral transduction. We devised a single-step method to direct mesengenic differentiation of human embryonic stem cells (ESCs) and iPSCs using a small molecule inhibitor. First, epithelial-like monolayer cells were generated by culturing ESCs/iPSCs in serum-free medium containing the transforming growth factor-β pathway inhibitor SB431542. After 10 days, iPSCs showed upregulation of mesodermal genes (MSX2, NCAM, HOXA2) and downregulation of pluripotency genes (OCT4, LEFTY1/2). Differentiation was then completed by transferring cells into conventional MSC medium. The resultant development of MSC-like morphology was associated with increased expression of genes, reflecting epithelial-to-mesenchymal transition. Both ESC- and iPSC-derived MSCs exhibited a typical MSC immunophenotype, expressed high levels of vimentin and N-cadherin, and lacked expression of pluripotency markers at the protein level. Robust osteogenic and chondrogenic differentiation was induced in vitro in ES-MSCs and iPS-MSCs, whereas adipogenic differentiation was limited, as reported for primitive fetal MSCs and ES-MSCs derived by other methods. We conclude that treatment with SB431542 in two-dimensional cultures followed by culture-induced epithelial-to-mesenchymal transition leads to rapid and uniform MSC conversion of human pluripotent cells without the need for embryoid body formation or feeder cell coculture, providing a robust, clinically applicable, and efficient system for generating MSCs from human iPSCs.
Development of Serum-Free Quality and Quantity Control Culture of Colony-Forming Endothelial Progenitor Cell for Vasculogenesis
Authors: Masuda Haruchika , Iwasaki Hiroto , Kawamoto Atsuhiko , Akimaru Hiroshi , Ishikawa Masakazu , Ii Masaaki , Shizuno Tomoko , Sato Atsuko , Ito Rie , Horii Miki , Ishida Hideyuki , Kato Shunichi , Asahara Takayuki 
Published: May 2012

Abstract
Quantitative and qualitative impairment of endothelial progenitor cells (EPCs) limits the efficacy of autologous cell therapy in patients with cardiovascular diseases. Here, we developed a serum-free quality and quantity control culture system for colony-forming EPCs to enhance their regenerative potential. A culture with serum-free medium containing stem cell factor, thrombopoietin, vascular endothelial growth factor, interleukin-6, and Flt-3 ligand was determined as optimal quality and quantity culture (QQc) in terms of the most vasculogenic colony-forming EPC expansion, evaluated by the newly established EPC colony formation assay. The QQc of umbilical cord blood-CD133+ cells for 7 days produced a 52.9-fold increase in total cell number and 3.28-fold frequency in definitive EPC colony development, resulting in a 203.9-fold increase in estimated total definitive EPC colony number in vitro. Pre- or post-QQc cells were intramyocardially transplanted into nude rats with myocardial infarction (MI). Echocardiographic and micromanometer-tipped conductance catheter examinations 28 days post-MI revealed significant preservation of left ventricular (LV) function in rats receiving pre- or post-QQc cells compared with those receiving phosphate-buffered saline. Assessments of global LV contractility indicated a dose-dependent effect of pre- or post-QQc cells and the superior potency of post-QQc cells over pre-QQc cells. Furthermore, immunohistochemistry showed more abundant formation of both human and rat endothelial cells and cardiomyocytes in the infarcted myocardium following transplantation of post-QQc cells compared with pre-QQc cells. Our optimal serum-free quality and quantity culture may enhance the therapeutic potential of EPCs in both quantitative and qualitative aspects for cardiovascular regeneration.
Steering a New Course for Stem Cell Research: NIH's Intramural Center for Regenerative Medicine
Authors: Rao Mahendra S. , Collins Francis S. 
Published: May 2012

Summary
The phenomenal progress made in stem cell biology in the past few years has infused the field of regenerative medicine with a great deal of scientific enthusiasm. However, along with the excitement of discovery comes a new sense of translational urgency. The prospect of using embryonic and induced pluripotent stem cell tools and technologies to produce cell-based therapies and other treatments is no longer a distant dream; it is a very real opportunity that demands our attention today. As with most new fields, regenerative medicine has experienced some significant growing pains, and we have identified a number of key obstacles to progress. Given our role as the lead U.S. biomedical research agency and the world's largest supporter of medical research, the National Institutes of Health (NIH) has a responsibility to find ways to reduce or remove many of these obstacles and, consequently, has—and continues—to respond to these challenges in a variety of ways. In this brief essay, we will review our progress and highlight a new development: the founding of a Center for Regenerative Medicine on the NIH campus.
Wnt Signaling Orchestration with a Small Molecule DYRK Inhibitor Provides Long-Term Xeno-Free Human Pluripotent Cell Expansion
Authors: Hasegawa Kouichi , Yasuda Shin-ya , Teo Jia-Ling , Nguyen Cu , McMillan Michael , Hsieh Chih-Lin , Suemori Hirofumi , Nakatsuji Norio , Yamamoto Masashi , Miyabayashi Tomoyuki , Lutzko Carolyn , Pera Martin F. , Kahn Michael 
Published: May 2012

Abstract
An optimal culture system for human pluripotent stem cells should be fully defined and free of animal components. To date, most xeno-free culture systems require human feeder cells and/or highly complicated culture media that contain activators of the fibroblast growth factor (FGF) and transforming growth factor-β (TGFβ) signaling pathways, and none provide for replacement of FGF/TGFβ ligands with chemical compounds. The Wnt/β-catenin signaling pathway plays an important role in mouse embryonic stem cells in leukemia inhibitory factor-independent culture; however, the role of Wnt/β-catenin signaling in human pluripotent stem cell is still poorly understood and controversial because of the dual role of Wnts in proliferation and differentiation. Building on our previous investigations of small molecules modulating Wnt/β-catenin signaling in mouse embryonic stem cells, we identified a compound, ID-8, that could support Wnt-induced human embryonic stem cell proliferation and survival without differentiation. Dual-specificity tyrosine phosphorylation-regulated kinase (DYRK) is the target of the small molecule ID-8. Its role in human pluripotent cell renewal was confirmed by DYRK knockdown in human embryonic stem cells. Using Wnt and the DYRK inhibitor ID-8, we have developed a novel and simple chemically defined xeno-free culture system that allows for long-term expansion of human pluripotent stem cells without FGF or TGFβ activation. These culture conditions do not include xenobiotic supplements, serum, serum replacement, or albumin. Using this culture system, we have shown that several human pluripotent cell lines maintained pluripotency (&gt;20 passages) and a normal karyotype and still retained the ability to differentiate into derivatives of all three germ layers. This Wnt-dependent culture system should provide a platform for complete replacement of growth factors with chemical compounds.
Oncolytic Herpes Simplex Virus Counteracts the Hypoxia-Induced Modulation of Glioblastoma Stem-Like Cells
Authors: Sgubin Donatella , Wakimoto Hiroaki , Kanai Ryuichi , Rabkin Samuel D. , Martuza Robert L. 
Published: May 2012

Abstract
Glioblastoma (GBM), a fatal malignant brain tumor, contains abundant hypoxic regions that provide a “niche” to promote both the maintenance and enrichment of glioblastoma stem-like cells (GSCs) and confer resistance to chemo- and radiotherapy. Since GSCs, with an ability to resist conventional therapies, may be responsible for tumor recurrence, targeting GSCs located in such a hypoxic environment may be critical to improving the therapeutic outcome for GBM patients. Oncolytic viral therapies have been tested in the clinic as a promising therapeutic approach for GBM. In this study, we analyzed and compared the therapeutic effects of oncolytic herpes simplex virus (oHSV) type 1 G47Δ (γ34.5−ICP6−LacZ+α47−) in patient-derived GSCs under normoxia (21% oxygen) and hypoxia (1% oxygen). GSCs cultured in hypoxia showed an increased ability to form neurospheres and expressed higher levels of the putative stem cell marker CD133 compared with GSCs cultured in normoxia. G47Δ exhibited a comparable ability to infect, replicate, and kill GSCs in normoxia and hypoxia in vitro. Importantly, G47Δ could counteract hypoxia-mediated enhancement of the stem-like properties of GSCs, inhibiting their self-renewal and stem cell marker expression. Using orthotopic human GSC xenografts in mice, we demonstrated that intratumoral injection of G47ΔUs11fluc, a newly developed G47Δ derivative that expresses firefly luciferase driven by a true late viral promoter, led to an equivalent frequency of viral infection and replication in hypoxic and nonhypoxic tumor areas. These findings suggest that oHSV G47Δ represents a promising therapeutic strategy to target and kill GSCs, not only in normoxic areas of GBM but also within the hypoxic niche.
Concise Review: The Clinical Application of Mesenchymal Stem Cells for Musculoskeletal Regeneration: Current Status and Perspectives
Authors: Steinert Andre F. , Rackwitz Lars , Gilbert Fabian , Nöth Ulrich , Tuan Rocky S. 
Published: May 2012

AbstractRegenerative therapies in the musculoskeletal system are based on the suitable application of cells, biomaterials, and/or factors. For an effective approach, numerous aspects have to be taken into consideration, including age, disease, target tissue, and several environmental factors. Significant research efforts have been undertaken in the last decade to develop specific cell-based therapies, and in particular adult multipotent mesenchymal stem cells hold great promise for such regenerative strategies. Clinical translation of such therapies, however, remains a work in progress. In the clinical arena, autologous cells have been harvested, processed, and readministered according to protocols distinct for the target application. As outlined in this review, such applications range from simple single-step approaches, such as direct injection of unprocessed or concentrated blood or bone marrow aspirates, to fabrication of engineered constructs by seeding of natural or synthetic scaffolds with cells, which were released from autologous tissues and propagated under good manufacturing practice conditions (for example, autologous chondrocyte implantation). However, only relatively few of these cell-based approaches have entered the clinic, and none of these treatments has become a “standard of care” treatment for an orthopaedic disease to date. The multifaceted reasons for the current status from the medical, research, and regulatory perspectives are discussed here. In summary, this review presents the scientific background, current state, and implications of clinical mesenchymal stem cell application in the musculoskeletal system and provides perspectives for future developments.
Human Neural Crest Stem Cells Derived from Human ESCs and Induced Pluripotent Stem Cells: Induction, Maintenance, and Differentiation into Functional Schwann Cells
Authors: Liu Qiuyue , Spusta Steven C. , Mi Ruifa , Lassiter Rhonda N.T. , Stark Michael R. , Höke Ahmet , Rao Mahendra S. , Zeng Xianmin 
Published: May 2012

Abstract
The neural crest (NC) is a transient, multipotent, migratory cell population unique to vertebrates that gives rise to diverse cell lineages. Much of our knowledge of NC development comes from studies of organisms such as chicken and zebrafish because human NC is difficult to obtain because of its transient nature and the limited availability of human fetal cells. Here we examined the process of NC induction from human pluripotent stem cells, including human embryonic stem cells (hESCs) and induced pluripotent stem cells (iPSCs). We showed that NC cells could be efficiently induced from hESCs by a combination of growth factors in medium conditioned on stromal cells and that NC stem cells (NCSCs) could be purified by p75 using fluorescence-activated cell sorting (FACS). FACS-isolated NCSCs could be propagated in vitro in five passages and cryopreserved while maintaining NCSC identity characterized by the expression of a panel of NC markers such as p75, Sox9, Sox10, CD44, and HNK1. In vitro-expanded NCSCs were able to differentiate into neurons and glia (Schwann cells) of the peripheral nervous system, as well as mesenchymal derivatives. hESC-derived NCSCs appeared to behave similarly to endogenous embryonic NC cells when injected in chicken embryos. Using a defined medium, we were able to generate and propagate a nearly pure population of Schwann cells that uniformly expressed glial fibrillary acidic protein, S100, and p75. Schwann cells generated by our protocol myelinated rat dorsal root ganglia neurons in vitro. To our knowledge, this is the first report on myelination by hESC- or iPSC-derived Schwann cells.
Platelet-Rich Plasma Greatly Potentiates Insulin-Induced Adipogenic Differentiation of Human Adipose-Derived Stem Cells Through a Serine/Threonine Kinase Akt-Dependent Mechanism and Promotes Clinical Fat Graft Maintenance
Authors: Cervelli Valerio , Scioli Maria G. , Gentile Pietro , Doldo Elena , Bonanno Elena , Spagnoli Luigi G. , Orlandi Augusto 
Published: May 2012

Abstract
The potential plasticity and therapeutic utility in tissue regeneration of human adipose-derived stem cells (ASCs) isolated from adult adipose tissue have recently been highlighted. The use of autologous platelet-rich plasma (PRP) represents an alternative strategy in regenerative medicine for the local release of multiple endogenous growth factors. Here we investigated the signaling pathways and effects of PRP and human recombinant insulin on proliferation and adipogenic differentiation of ASCs in vitro. PRP stimulated proliferation (EC50 = 15.3 ± 1.3% vol/vol), whereas insulin's effect was the opposite (IC50 = 3.0 ± 0.5 μM). Although PRP alone did not increase adipogenesis, in association with insulin it prevented ASC proliferative arrest, greatly enhanced intracytoplasmic lipid accumulation, strongly increased serine/threonine kinase Akt phosphorylation and mouse monoclonal anti-sterol regulatory element binding protein-1 accumulation, and downregulated Erk-1 activity; adipogenic effects were markedly prevented by the Akt inhibitor wortmannin. PRP with insulin synergistically upregulated fibroblast growth factor receptor (FGFR) and downregulated epidermal growth factor receptor (ErbB) expression; moreover, PRP in association prevented insulin-induced insulin-like growth factor-1 receptor and insulin receptor downregulation. The inhibition of FGFR-1, epidermal growth factor receptor (EGFR), and epidermal growth factor receptor-2 (ErbB2) activity reduced ASC proliferation, but only that of FGFR-1 reduced adipogenesis and Akt phosphorylation, whereas the ErbB2 inhibition effects were the opposite. However, EGFR activity was needed for ErbB2-mediated inhibition of ASC adipogenesis. Clinically, the injection of insulin further ameliorated patients' 1-year PRP-induced fat graft volume maintenance and contour restoring. Our results ascertain that PRP in association with insulin greatly potentiates adipogenesis in human ASCs through a FGFR-1 and ErbB2-regulated Akt mechanism. The ameliorated clinical fat graft maintenance suggests additional useful translational applications of combined PRP-insulin treatment in regenerative medicine.
Os(II) Based Green to Red Phosphors: A Great Prospect for Solution‐Processed, Highly Efficient Organic Light‐Emitting Diodes
Authors: Du Bo‐Sian , Liao Jia‐Ling , Huang Ming‐Hong , Lin Cheng‐Huei , Lin Hao‐Wu , Chi Yun , Pan Hsiao‐An , Fan Gang‐Lun , Wong Ken‐Tsung , Lee Gene‐Hsiang , Chou Pi‐Tai 
Published: May 2012

AbstractPreparation and characterization of a new class of emissive Os(II) complexes (1–5) have been achieved using 3‐(thiazol‐2‐yl), 3‐(benzothiazol‐2‐yl), 3‐(imidazol‐2‐yl) and 3‐(benzimidazol‐2‐yl) azole chelates, together with the incorporation of one diphosphine ancillary for satisfying the octahedral coordination arrangement. The resulting Os(II) complexes, except for 5, all show bright emission spanning visible region from green to saturated red, and their structural versus spectroscopic properties have been comprehended by absorption/emission together with computational approaches. Subsequently, a series of solution‐processed OLEDs using 1–4 as the dopant were successfully fabricated, demonstrating excellent device performances with external quantum efficiency (EQE) of 15%, current efficiency exceeding 48 cd/A, and power conversion efficiency up to 50 lm/W. Complex 4 is the only Os(II) based phosphor so far suitable for the fabrication of highly efficient green‐emitting OLEDs.