bluuebunny/crossref_metadata_2025_split huggingface dataset:
Targeted Gene Deletion Demonstrates That Adhesion Molecule ICAM-4 Is Critical for Erythroblastic Island Formation.
Authors: Lee Gloria , Lo Annie , Short Sarah , Mankelow Tosti , Parsons Stephen , Spring Frances , Mohandas Narla , Anstee David , Chasis Joel Anne 
Published: April 2020

Abstract
Erythroid progenitors proliferate, differentiate and enucleate within specialized bone marrow subcompartments, termed erythroblastic islands, which are comprised of developing erythroblasts surrounding a central macrophage. Growing evidence suggests that within erythroblastic islands adhesion events, in concert with cytokines, play critical roles in regulating erythropoiesis and apoptosis. We are exploring the potential function of erythroid ICAM-4, a recently characterized member of the immunoglobulin superfamily, in erythroblastic island formation. We earlier identified α4β1 and αV integrins as ICAM-4 binding partners. Since erythroblasts express α4β1 and ICAM-4 and macrophages exhibit αV, ICAM-4 is an attractive candidate for mediating erythroblast-erythroblast and erythroblast-macrophage attachments. Indeed, two synthetic peptides that block ICAM-4/αV adhesion caused a marked decrease in the percentage of islands formed. To more definitively test whether ICAM-4 attachments are active in erythroblastic islands we generated ICAM-4 knockout mice and compared the capacity of single cell suspensions from freshly harvested ICAM-4 null and wild type bone marrow to form erythroblastic islands in vitro, using a reproducible live cell island reconstitution assay that we have established. Islands and their cellular components were identified and quantitated by three-color immunofluorescent microscopy employing fluoresceinated erythroid-specific TER119 antibody, macrophage-specific F4/80 antibody and a DNA probe. Strikingly, we observed a 47% decrease in the percentage of islands formed from bone marrow of ICAM-4 null mice compared to wild type littermates (n=10 and n=10, respectively). We also studied the ability of ICAM-4 null erythroblasts to form islands in vivo by analyzing intact islands freshly harvested from mouse bone marrow. Similar to the in vitro data we found a marked decrease in the percentage of islands formed in the bone marrow of ICAM-4 null mice compared to wild type littermates. The null mice had 44% fewer islands than wild type mice. Taken together, the results of this phenotypic analysis provide convincing evidence that ICAM-4 is one of the adhesion molecules critical for erythroblastic island formation. We postulate that this newly identified erythroblast receptor may be important not only for adhesive integrity of the island structure but also for initiating intracellular signaling essential for normal erythroid terminal differentiation.
Outcomes in CCG-2961, a Children’s Cancer Group Phase III Trial for Untreated Acute Myeloid Leukemia (AML).
Authors: Lange Beverly J. , Smith Franklin O. , Dinndorf Patricia A. , Arndt Carola A.S. , Barnard Dorothy R. , Dusenbery Kathryn , Feig Steven A. , Feusner James H. , Luna-Fineman Sandra , Neglia Joseph , Seibel Nita L. , Sender Leonard , Shannon Kevin M. , Weiman Margie , Gerbing Robert B. , Alonzo Todd A. 
Published: April 2020

Abstract
CCG-2961 tested an intensively timed induction therapy consisting of cytarabine (AC), etoposide, thioguanine, dexamethasone, idarubicin and daunorubicin. Patients in remission after induction were randomized to a second induction course (Arm A) or a 3-drug combination of fludarabine, AC, and idarubicin (Arm B). Course 3 for patients with related donors was bone marrow transplantation (BMT); for those without donors, high dose AC/l-asparaginase. After Course 3 patients without donors were randomized to 14 infusions of Interleukin 2 (IL2) over 18 days or follow-up. CNS prophylaxis was intrathecal AC. Eligibility included all subtypes of de novo AML except acute promyelocytic leukemia and AML in patients with Down syndrome. CCG-2961 opened in Oct.1996 and closed in Dec. 2002. The DSMC suspended the study between Oct. 1999 and May 2000 while the 2961 Committee developed supportive care policies to reduce treatment-related mortality (TRM). CCG-2961 enrolled 900 de novo patients aged 3 days to 21 years, with 495 and 405 patients accruing pre-and post suspension respectively. Remission induction rate is 88.5%. With median follow-up of 3.6 years (range: 0 – 8.1 years), event-free survival (EFS) at 3 years is 44±3% and survival (OS) 57±3%. Disease-free survival (DFS) following Course 2 Arms A and B are not different, although relapse is significantly higher in Arm A (7.3% .vs. 3.1% P=0.018) and TRM more common in Arm B (7.9% vs.4.2% P=0.059), despite 7 less days of neutropenia in Arm B (P&lt;0.001). DFS is 65±9% for patients with a donor versus 50±5% for patients without a donor (P=0.005); respective OS, 74±8% and 66±5% (P=0.221). However, among 98 patients in CR1 with t(8;21) or inv(16) cytogenetics, outcomes in those without and with a donor were no different: DFS (61±12% vs. 72±18%, P = 0.49) and OS (78±10% vs. 77±17%, l P= 0.85). DFS with and without IL2 is 55±9% and 60±8%(P=0.606). Outcomes improved progressively over time. EFS pre- and post-suspension are 41±4% and 47±5%(P=0.038); OS, 52±5% and 63±5%(P=0.005); TRM is 17±3% pre- and 12±3% post-suspension (P=0.039). Factors predictive of inferior EFS are age &gt;17 years, Afro-American and Hispanic ethnicity, body mass index &lt;10th or &gt;95th percentile for age, absence of related marrow donor, WBC &gt; 50,000/mm3, karyotype with −7/7q, −5/5q- or &gt; cytogenetic 5 abnormalities, FLT3/ITD, &gt;15 % morphologic blasts on day 14 or &gt;0.5% immunologically detectable blasts at the end of induction. CCG-2961 confirms the efficacy and high TRM of intensively timed therapy. Neither fludarabine nor IL2 increases DFS or OS, and availability of a donor does not improve outcomes in those with favorable cytogenetics.
Purified Murine Hematopoietic Stem Cells Contribute to the Generation of Cardiomyocytes Via Cell Fusion.
Authors: Fukata Mitsuhiro , Ishikawa Fumihiko , Shimazu Hideki , Ito Hiroyuki , Shimoda Kazuya , Akashi Koichi , Shultz Leonard D. , Harada Mine 
Published: April 2020

Abstract
Background and aim: It has been reported that donor-maker+ cardiomyocytes appear following the transplantation of total bone marrow (BM) cells or enriched hematopoietic stem/progenitor cells. However, recent reports suggested that highly purified hematopoietic stem cells (HSCs) might not adapt the fate of cardiomyocytes. We aimed to identify the cell populations in BM that possess the capacity to give rise to caridomyocytes. Additionally, we aimed to clarify whether cardiomyogenic potential of the hematopoietic tissue-derived cells require cell fusion with host-derived cardiomyocytes.
Method: To examine the developmental plasticity of hematopoietic tissue-derived cells, we employed the newborn transplantation model, in which age-related decline of regenerative capacity can be restored by environment factors (Conboy et al., Nature 2005). We first separated Lineage antigen−CD45+ (Lin−CD45+) cells and Lineage antigen−CD45− (Lin−CD45−) cells from BM of mice constitutively expressing GFP. Each cell population was intravenously injected into irradiated syngeneic newborn C57BL/6 mice within 48hours after the birth. The cardiac tissue of recipients was analyzed for the presence of donor GFP+ cardiomyocytes at 1 month post-transplantation. 37.0±23.9 GFP+ cardiomyocytes were detected per 40 sections in the myocardium of recipients transplanted with Lin−CD45+ (n=6), while no GFP+ cardiomyocytes were detected in recipients transplanted with Lin−CD45− (n=4). As judged by the expression of CD29 on Lin−CD45− cells and osteogenic and adipogenic potential in vitro, Lin−CD45− likely contained mesenchymal stem cells (MSCs). We further purified c-Kit+Lin−Sca-1+ cells (KLS) HSCs and c-Kit+Lin−Sca-1− progenitors by cell sorting, and transplanted limiting numbers of each population into syngeneic recipients. The number of GFP+ cardiomyocytes was compatible with the injected cell dose both in the transplantation of HSCs and progenitors, suggesting that both HSC and progenitors can give rise to cardiomyocytes in vivo. Finally, to determine the mechanism of cardiomyogenic potential of HSCs, we transplanted GFP+ KLS BM cells into CFP transgenic newborn mouse. Linear unmixing analysis using laser-scanning confocal microscopy revealed that donor-derived GFP+ cardiomyocytes coexpressed CFP. These results indicated that HSCs require cell fusion for generating cardiomyocytes.
Conclusion: Highly purified BM-derived hematopoietic stem/progenitor cells can contribute to the post-natal generation of cardiomyocytes through cell fusion, not through transdifferentiation.
Myogenic Developmental Potential of Hemangioblasts Derived from Mouse Embryonic Stem Cells.
Authors: Burke Michael J. , Kennedy Patrick , Wang Lei , Bhatt Devang , Tse William T. 
Published: April 2020

Abstract
The hemangioblast, the progenitor common to hematopoetic and endothelial lineages, expresses the vascular endothelial growth factor (VEGF) receptor flk-1 on its surface. Based on lineage-tracking studies indicating that skeletal muscle cells are derived from flk-1-expressing precursors (Sato et al. Genesis35:153–159, 2003), we tested the hypothesis that the hemangioblast is also a progenitor to the muscle lineage. We studied the development of skeletal muscle progentiors from mouse embryonic stem cells cultured in suspension to form embryoid bodies (EB). These EB were harvested at different time points, disaggregated into single cells and analyzed by flow cytometry. After 10–18 days of culture, the EB contained abundant cells that expressed α7-integrin, a skeletal muscle-specific cell surface antigen. Immunofluorescence microscopic study of sorted and cytospun α7-integrin-positive cells from EB revealed positive staining with MyoD, sarcomeric α-actinin and desmin antibodies, indicating that they were bona fide muscle cells. To test if these muscle cells were derived from hemangioblasts, green fluorescent protein (GFP)-expressing EB were collected at day 4 of development, disaggregated into single cells and replated in methylcellulose medium with the addition of VEGF, stem cell factor and thrombopoietin. After 5 days in methylcellulose culture, clusters of loosely aggregated cells appeared. These cells have features characteristic of hemangioblasts and exhibit large nuclear-to-cytoplasmic ratios. The hemangioblast colonies were individually picked, diaggregated into single cells and plated with a myoblastic cell line (C2C12 cells) in media containing 10% fetal calf serum. Co-culturing of the hemangioblasts with a myoblastic feeder layer was designed to provide the environmental signals necessary for myogenic development. After 48 hours, the co-culture medium was changed to 2% serum to promote muscle differentiation. Three days later, the plates were fixed and analyzed. A small number of GFP-expressing cells assumed an elongated, multinucleated, myofiber-like appearance and stained positiviely for skeletal muscle markers α7-integrin and desmin. We next tested the myogenic potential of hemangioblasts in vivo. The tibialis anterior muscles of C57BL/6 mice were injected with cardiotoxin, a protein kinase inhibitor that depolarizes muscle fibers and induces muscle regeneration. After two days, hemangioblast colonies were picked from methylcellulose culture and injected into the regenerating muscles. Occasional GFP-expressing fibers that stained positive for desmin were seen when analyzed several weeks post-injection. These results indicate that the hemangioblast may be a progenitor not only to hematopoetic and endothelial lineages, but also to skeletal muscle. Future experiments include investigating the significance and mechanism of the hemangioblast’s development into muscle and explore the role of cell-cell fusion in this phenomenon.
Multi-Potent Adult Progenitor Cells from Swine Bone Marrow.
Authors: Zeng Lepeng , Rahrmann Eric , Hu Qingsong , Wang Xiaohong , Zhang Jianyi , Verfaillie Catherine M. 
Published: April 2020

Abstract
Here, we show that Multi-potent Adult Progenitor Cells (MAPCs) can be derived from adult and fetal swine bone marrow. Swine MAPC (swMAPC) contain initially multiple different progenitors and mature cells; however, cultures are homogenous by 50 population doublings and can grow past 150 population doublings. SwMAPCs are CD44, CD45, and MHC-I, II negative, express Oct3a/4 at levels close to those seen in embryonic stem cells, and have telomerase activity leading to no telomere shortening with expansion. We also have very solid evidence that swMAPCs differentiate into most mesoderm, neuroectoderm, and endoderm lineages as demonstrated by a significant up-regulation of transcription factors and other lineage specific proteins in a time dependent fashion similar to development, measured by Q-RT-PCR as well as immunohistology. In addition, swMAPCs induced to the endothelial lineage form vascular tubes, to the hepatic lineage produce albumin and urea, and to the smooth muscle lineage display significant calcium flux in response to smooth muscle agonists. In addition, we are investigating the swMAPC differentiation into cardiomyocytes. Preliminary data indicates swMAPCs express TBX5, Nkx2.5, and GATA6 by day 7 at significant levels. As we have seen for rodent MAPCs, when swMAPCs are allowed to grow at high density, Oct3a/4 levels drop to undetectable ranges, the cells take on a mesenchymal stem cell (MSC) phenotype, and the differentiation potential is lost. When replated under low density conditions, oct3a/4 expression or differentiation capacity can not be re-induced, and cells remain MSC like. Therefore, we suggest that Oct3a/4 is not an in vitro culture phenomena but is already present in swMAPCs and cannot be recovered once lost with standard culturing techniques.
Human Cord Blood Cells Are Capable of Generating Amylase-Producing Pancreatic Acinar Cells without Cell Fusion.
Authors: Minamiguchi Hitoshi , Ishikawa Fumihiko , Fleming Paul A. , Yang Su , Drake Christopher J. , Ogawa Makio 
Published: April 2020

Abstract
Pancreatic acinar cells and hepatocytes arise from the same cell population located within the embryonic endoderm during embryogenesis. It has been reported that a multi-potent population of liver cells is capable of differentiating into pancreatic cells. Thus, pancreatic acinar cells and hepatocytes may share a common precursor. Recent studies revealed that murine and human hematopoietic cells have the ability to generate hepatocytes in vivo. To determine whether human cord blood cells can generate pancreatic cells, we carried out in vivo xenograft experiments. We transplanted 105 CD34+ cord blood cells into conditioned newborn NOD/SCID/beta-2 microglobulin-null mice via facial vein injection and, 2–4 months later, examined pancreata from recipient mice showing high level (16–52%, n=9) human multilineage hematopoietic engraftment in the bone marrow. RT-PCR and immunohistochemical analyses revealed human amylase mRNA and human amylase protein, respectively, in the pancreata of recipient mice. Using fluorescence in-situ hybridization (FISH), we also identified human alpha-satellite DNA positive cells with a morphology characteristic of pancreatic acinar cells. Recently, a number of investigators have reported that the apparent reconstitution of tissue cells such as hepatocytes by hematopoietic stem cells is the result of spontaneous cell fusion between donor hematopoietic cells and recipient tissue cells. To negate this possibility, we used FISH for human and mouse DNA and examined the pancreas for the evidence of fusion between human hematopoietic cells and recipient pancreatic cells. We performed four-color analysis using FISH with human pan-centromere probe, mouse pan-centromere probe, and species non-specific probes for pancreatic amylase mRNA, combined with Hoechst nuclear counter staining on paraffin-embedded sections of pancreata from recipient mice. We identified cells that were amylase mRNA-positive expressed human-specific alpha-satellite DNA and exhibited morphological characteristics of pancreatic acinar cells but did not express mouse-specific gamma-satellite DNA. These findings establish that human umbilical cord blood cells are capable of generating pancreatic acinar cells via a non-fusion mechanism.
NOD/SCID Repopulating Cells Contribute Only to Short-Term Repopulation in the Baboon.
Authors: Beard Brian C. , Mezquita Pau , Kiem Hans-Peter 
Published: April 2020

Abstract
The nonobese diabetic/severe combined immune deficiency (NOD/SCID) xenotransplantation model is widely used as an assay to study human candidate stem cells. However, in contrast to large animal or human studies, the NOD/SCID model is limited by the short life span of the recipient and the limited proliferative demand placed on transplanted cells and the inability to support differentiation into all hematopoietic lineages. We have previously performed a direct comparison in the repopulation ability of gene modified baboon CD34+ cells in an autologous transplantation versus a xenotransplant model in irradiated NOD/SCID mice. Baboon CD34-selected marrow cells were transduced with a gammaretrovirus vector and infused into irradiated baboons and NOD/SCID mice. Our results showed a significant decline in the percentage of transduced cells in the baboon 2–3 months following transplant, while the levels in the NOD/SCID mice remained high and stable up to 12 weeks. A limited integration site analysis could only detect 2 common retrovirus integration sites (RIS) in the NOD/SCID and monkey. Here we have extended this analysis and performed LAM-PCR and locus-specific PCR on 30 clones recovered from 12-week old NOD/SCID b2M mice reconstituted with transduced baboon CD34+ cells. We cloned the sequences of these RIS and generated specific primers for these sequences. We then performed PCR analysis on samples in the baboon to determine whether the clones were present in the baboon peripheral blood at different time points after transplantation. We analyzed samples early (2 to 6 weeks) and late (6 to 12 months) after transplantation. We were able to identify five common integrants in the baboon early after transplant (2 weeks), two of which could still be detected at 6 weeks. None of the clones present in the NOD/SCID b2M mice, however, was found in the baboon during the long-term follow-up (6 and 12 months post-transplant). These results confirm that repopulating cells in the NOD/SCID mouse model contribute only to short-term repopulation in a clinically relevant large animal model and suggest that distinct hematopoietic stem/progenitor cell populations are responsible for the hematopoietic reconstitution in NOD/SCID mice versus nonhuman primates.
Role of Consolidation Therapy in the Treatment of Patients up to 60 Years with High Risk AML.
Authors: Krauter Jürgen , Heil Gerhard , Hoelzer Dieter , Ottmann Oliver , Martin Hans , Lübbert Michael , Finke Jürgen , Heit Wolf , Fiedler Walter , Kanz Lothar , Brossart Peter , Schlimok Günter , Kirchner Hartmut , Raghavachar Aruna , Brugger Wolfram , Ganser Arnold 
Published: April 2020

Abstract
In the prospective multicenter AML 01/99 trial, 484 patients with acute myeloid leukemia up to 60 years (385 with de novo and 99 with secondary AML) were treated with risk-adapted therapy. Patients with CBF-leukemias [t(8;21) or inv(16)] or normal karyotype and good response (GR) to induction I (≤5% blasts in day 15 BM) were considered standard risk (SR), all other patients as high risk (HR). Patients with t(15;17) were excluded. Induction course I consisted of standard dose araC, idarubicine and etoposide (IVA-I). Patients with GR to IVA-I continued with IVA-II on day 21 as double induction. In patients with bad response (&gt;5% bone marrow blasts on day 15), the second cycle consisted of FlAG/Ida. Double induction was followed by an early consolidation with intermediate dose araC. As late consolidation, HR patients with an HLA-matched sibling were scheduled for a matched related donor (MRD) transplantation whereas patients without a family donor should undergo autologous peripheral blood stem cell transplantation (autoPBSCT). PBSC were mobilized after early consolidation. A pilot study within the 01/99 trial showed superior results for matched unrelated donor (MUD) transplantation compared to patients who had undergone autoPBSCT. Therefore, since 2003 all HR patients without a sibling donor were scheduled for MUD transplantation. 234 patients were classified as HR, of whom 137 (58%) achieved complete remission. 31 (13%) of the HR patients died during induction. After 70 months, overall survival (OS) was significantly worse for HR patients (28%) than for SR patients (51%). For HR patients, there was no difference in OS and relapse-free survival (RFS) between those patients classified as HR because of bad response to IVA-1 (n = 76), unfavourable karyotype (n = 83) or both characteristics (n = 75). Moreover, RFS was neither different between HR patients with de novo or secondary AML nor between HR patients with normal karyotype, complex karyotype or other high risk cytogenetics. Regarding the different regimens for late consolidation, the “as treated” analysis of the HR patients revealed that OS and RFS was significantly better after an MRD transplantation (n=34, OS 68%, RFS 65%) than after autoPBSCT (n=26, OS 23%, RFS 7%). OS and RFS for the 29 patients who received MUD transplantation was also significantly better than after autoPBSCT with 56% and 52% respectively. In conclusion, HR patients as defined in our study do not benefit from an autologous PBSCT even after intensive double induction and early consolidation. Therefore, an allogeneic transplantation from a related or unrelated donor should be performed.