Home About us Contact
|
Home About us Contact | ||
|
|
||
Marrow Stem Cells (marrow + stem_cell)
Kinds of Marrow Stem Cells Selected AbstractsPeriodically Discontinuous Induction of Bone Marrow Stem Cells toward Osteogenic Differentiation in VitroBIOTECHNOLOGY PROGRESS, Issue 3 2008Zhen Wang This paper reveals that a discontinuous in vitro induction, namely, the periodic presence and absence of foreign induction factors, might be, under a certain condition, more effective to stimulate stem cells' differentiation than a continuous induction. Bone marrow stem cells (BMSCs) derived from Sprague Dawley rats were employed to examine the effects of discontinuous additions of osteogenic supplements with a series of alternate frequency in contrast to those with continuous induction or no induction. The results demonstrated that a suitable discontinuous induction was more able to achieve osteogenesis than not only no induction but also the associated continuous induction. Additionally, the osteogenic supplements were confirmed to enhance cell differentiation but suppress cell proliferation. So, the combination of differentiation extent per cell and cell number accounts for the "unexpected" good osteogenic effect of the discontinuous induction. The induction effect was found to be dependent upon alternate frequency, and the optimum alternate period in our experimental systems was determined to be around 4 days. Since it is very common to change culture medium every 2,4 days, such a strategy of discontinuous induction does not bring any extra manual work but reduces the consumption of foreign induction factors and significantly enhances the global differentiation efficacy. Our work thus affords a convenient and practical approach to achieve differentiation of BMSCs, which might be useful for potential large-scale culture and differentiation of stem cells. Meanwhile, the existence of optimum frequency implies some unknown inherent rhythms of cell proliferation and differentiation. [source] c-Kit+ Bone Marrow Stem Cells Differentiate into Functional Cardiac MyocytesCLINICAL AND TRANSLATIONAL SCIENCE, Issue 1 2009Hajime Kubo Ph.D. Abstract The utility of bone marrow cells (BMCs) to regenerate cardiac myocytes is controversial. The present study examined the capacity of different types of BMCs to generate functional cardiac myocytes. Isolated c-kit+ BMCs (BMSCs), c-kit+ and crude BMCs from the adult feline femur were membrane stained with PKH26 dye or infected with a control enhanced green fluorescence protein transcript (EGFP)-adenovirus prior to co-culture upon neonatal rat ventricular myocytes (NRVM). Co-cultured cells were immuno-stained for c-kit, ,-tropomyosin, ,-actinin, connexin 43 (C×43) and Ki67 and analyzed with confocal microscopy. Electrophysiology of BMSC derived myocytes were compared to NRVMs within the same culture dish. Gap junction function was analyzed by fluorescence recovery after photo-bleaching (FRAP). BMCs proliferated and differentiated into cardiac myocytes during the first 48 hours of co-culturing. These newly formed cardiac myocytes were able to contract spontaneously or synchronously with neighboring NRVMs. The myogenic rate of c-kit+ BMSCs was significantly greater than c-kit+ and crude BMCs (41.2 ± 2.1, 6.1 ± 1.2, and 17.1 ± 1.5%, respectively). The newly formed cardiac myocytes exhibited an immature electrophysiological phenotype until they became electrically coupled to NRVMs through functional gap junctions. BMSCs did not become functional myocytes in the absence of NRVMs. In conclusion, c-kit+ BMSCs have the ability to transdifferentiate into functional cardiac myocytes. [source] BMP-2 and FGF-2 Synergistically Facilitate Adoption of a Cardiac Phenotype in Somatic Bone Marrow c-kit+/Sca-1+ Stem CellsCLINICAL AND TRANSLATIONAL SCIENCE, Issue 2 2008Brent R. DeGeorge, Jr. B.S. Abstract The aim of this study was to explore the effect of bone morphogenetic protein-2 (BMP-2) and fibroblast growth factor-2 (FGF-2), paracrine factors implicated in both cardiac embryogenesis and cardiac repair following myocardial infarction (MI),on murine bone marrow stem cell (mBMSC) differentiation in an ex vivo cardiac microenvironment. For this purpose, green fluorescent protein (GFP) expressing hematopoietic lineage negative (lin-) c-kit ligand (c-kit) and stem cell antigen-1 (Sca-1) positive (GFP-lin-/c-kit+/sca+) mBMSC were co-cultured with neonatal rat ventricular cardiomyocytes (NVCMs). GFP+ mBMSC significantly induced the expression of BMP-2 and FGF-2 in NVCMs, and approximately 4% GFP+ mBMSCs could be recovered from the co-culture at day 10. The addition of BMP-2 in concert with FGF-2 significantly enhanced the amount of integrated GFP+ mBMSCs by 5-fold (,20%), whereas the addition of anti-BMP-2 and/or anti-FGF-2 antibodies completely abolished this effect. An analysis of calcium cycling revealed robust calcium transients in GFP+ mBMSCs treated with BMP-2/FGF-2 compared to untreated co-cultures. BMP-2 and FGF-2 addition led to a significant induction of early (NK2 transcription factor related, locus 5; Nkx2.5, GATA binding protein 4; GATA-4) and late (myosin light chain kinase [MLC-2v], connexin 43 [Cx43]) cardiac marker mRNA expression in mBMSCs following co-culture. In addition, re-cultured fluorescence-activated cell sorting (FACS)-purified BMP-2/FGF-2-treated mBMSCs revealed robust calcium transients in response to electrical field stimulation which were inhibited by the L-type calcium channel (LTCC) inhibitor, nifedipine, and displayed caffeine-sensitive intracellular calcium stores. In summary, our results show that mBMSCs can adopt a functional cardiac phenotype through treatment with factors essential to embryonic cardiogenesis that are induced after cardiac ischemia. This study provides the first evidence that mBMSCs with long-term self-renewal potential possess the capability to serve as a functional cardiomyocyte precursor through the appropriate paracrine input and cross-talk within an appropriate cardiac microenvironment. [source] Adhesion molecule expression by bone marrow CD34-positive cells in aplastic anemia before and after immunosuppressive therapyINTERNATIONAL JOURNAL OF LABORATORY HEMATOLOGY, Issue 6 2003K. Kaito Summary Appropriate adhesion between bone marrow stem cells and the marrow microenvironment is necessary for hematopoiesis, since signals that promote maturation or apoptosis are transmitted from stromal cells to stem cells. In aplastic anemia (AA), interferon- , produced by stromal cells has more influence on the pathogenesis of marrow failure than interferon- , produced by lymphocytes. We evaluated the expression of cell adhesion molecules, such as very late antigen-4 (CD49d), and -5 (CD49e) or c-kit receptor (CD117), by CD34-positive bone marrow cells in patients with AA who achieved hematological complete remission after immunosuppressive therapy. Before treatment, CD34-positive cells showed markedly higher expression of CD49d and CD49e than cells from healthy controls, indicating the strong adhesion of stem cells to the bone marrow stroma. Expression of CD49d and CD49e was significantly decreased, reaching normal levels, after hematological recovery. These findings suggest that changes in adhesion molecule expression by stem cells are important in the pathology of AA. [source] Morphological characterization of GFP stably transfected adult mesenchymal bone marrow stem cellsJOURNAL OF ANATOMY, Issue 1 2006Stefania Raimondo Abstract Increasing attention is being given to the use of adult rather than embryonic stem cells, both for research and for the development of transplantation treatments for human disease. In particular, mesenchymal bone marrow stem cells have been studied extensively because of their ability to self-renew and to give rise to various differentiated cell types, and because of the relative ease with which they can be obtained and cultured. In addition, the possibility of labelling stem cells with green fluorescent protein before transplantation has opened new and promising perspectives for their use in basic research. Because no structural or ultrastructural description of adult mesenchymal stem cells is available in the literature, this paper describes their morphology as revealed by light, confocal and electron microscopy, focusing on cells that are particularly suitable for transplantation studies, i.e. those derived from rat bone marrow transfected with green fluorescent protein. The results provide a basis for experimental studies of the differentiation of these cells in normal and pathological tissues. [source] Comparison of various kinds of bone marrow stem cells for the repair of infarcted myocardium: Single clonally purified non-hematopoietic mesenchymal stem cells serve as a superior source,JOURNAL OF CELLULAR BIOCHEMISTRY, Issue 4 2006Shaoheng Zhang Abstract A variety of adult stem cells have been used to transplant into the infarcted (MI) heart, however, comparative studies are lacking to show more suitable source of cells for transplantation. We have identified a single non-hematopoietic mesenchymal stem cell subpopulation (snMSCs) isolated from human bone marrow and clonally purified, that over 99% of them expressed MSC marker proteins and cardiomyocyte marker proteins when induction in vitro. We also compared the effects of the snMSCs with unpurified MSC (uMSCs), mononuclear cells (BMMNCs), or peripheral blood mononuclear cells (PBMNCs) on myocardial repair after induction of MI in rats. Ninety days later, we observed a better cardiac function assessed by ejection fraction, fraction of shortening and lung wet/dry weight ratios, less remodeling of left ventricle (LV), lower collagen density in the LV, and more vessels in the ischemic wall in the snMSCs transplantation group than in other cell-transplanted groups. Furthermore, the transplanted cells expressing cardiomyocyte specific proteins or vascular endothelial cell marker proteins were more in the snMSCs group than in other ones. We conclude that transplantation with single clonally purified MSCs seems to be more beneficial to the cardiac repair than with other stem cells after MI. J. Cell. Biochem. 99: 1132,1147, 2006. © 2006 Wiley-Liss, Inc. [source] Studies on BrdU labeling of hematopoietic cells: Stem cells and cell linesJOURNAL OF CELLULAR PHYSIOLOGY, Issue 2 2003Lizhen Pang Studies using chronic in vivo BrdU exposure, isolating primitive stem cells, and determining BrdU labeling, indicate that stem cells cycle. BrdU is also incorporated into DNA during damage/repair. DNA, which has incorporated BrdU due to cycle transit is heavier than normal, while the density of DNA with damage/repair incorporation is intermediate. DNA density of purified lineage,rhodamine low (rholow) Hoechst low (Holow) stem cells or FDC-P1 cell line cells,was assessed in vitro, after exposure to cytokines and BrdU (cycling model) or cytokines and BrdU with bleomycin to induce strand breaks and hydroxyurea to halt cycle progression (damage/repair model). We determined DNA density using cesium chloride (CsCl) gradients and either fluorometry or dot blot chemiluminesence. DNA from BrdU labeled cycling Lin-rholoHolo or FDC-P1 cells was heavier than normal DNA, while damage repair DNA had an intermediate density. We then assessed BrdU labeling of Lin-rholoHolo cells in vivo. We found that 70.9% of lin-rholoHolo cells labeled at 5 weeks. DNA density of these cells was low, in the damage/repair range, but similar results were obtained with stem cells, which had proliferated in vivo. Dilution of BrdU in in vitro culture of proliferating FDC-P1 cells also resulted in damage/repair density. We conclude that in vitro BrdU labeling models can distinguish between proliferation and damage/repair, but that we cannot obtain high enough in vivo levels to address this issue. All together, while we cannot absolutely exclude damage/repair as contributing to stem cell BrdU labeling, the data indicate that primitive bone marrow stem cells are probably a cycling population. J. Cell. Physiol. 197: 251,260, 2003© 2003 Wiley-Liss, Inc. [source] Stem Cell Review Series: Regulating highly potent stem cells in aging: environmental influences on plasticityAGING CELL, Issue 4 2008Jay M. Edelberg Summary Significant advances in the past decade have revealed that a large number of highly plastic stem cells are maintained in humans through adulthood and are present even in older adults. These findings are notable in light of the reduced capacity for repair and regeneration in older tissues. The apparent dichotomy can be reconciled through an appreciation of the age-associated changes in the microenvironmental pathways that govern adult stem cell plasticity and differentiation patterns. Specifically, the recent identification of the age-related loss of the local platelet-derived growth factor signals that promote the induction of cardiac myocytes from Oct-3/4+ bone marrow stem cells, rather than impairment in the stem cells themselves, provides a template for understanding and targeting the environmental pathways underlying the regenerative capacity of older tissues and organs. It is projected that this paradigm extends to the overall regulation of adult stem cell biology, shifting the balance from tissue generation during development and maturation to the prevention of untoward stem cell differentiation with aging. [source] Aging and cancer cell biology, 2007AGING CELL, Issue 3 2007Judith Campisi Summary This Hot Topics review, the second in a new Aging Cell series, discusses articles published in the last year that have stimulated new ideas about the tangled relationship of aging to cancer cell biology. The year's highlights include reports on the ability of Mdm2 mutations to diminish risks of cancer in aging mice, on proliferative competition between oncogenic cells and bone marrow stem cells, and on the role of metalloproteinases in overcoming age-associated barriers to tumor invasion. Of particular interest were three articles showing that diminished activity of the tumor-suppressor gene p16/INK4a, while increasing the risk of cancer mortality, can lead to improved function in several varieties of age-sensitive stem cells. [source] Bone marrow-derived stem cells in liver repair: 10 years down the lineLIVER TRANSPLANTATION, Issue 2 2010Eleanor S. Gilchrist Hematopoietic stem cells have potential in the field of regenerative medicine because of their capacity to form cells of different lineages. Bone marrow stem cells have been shown to contribute to parenchymal liver cell populations, and although this may not be functionally significant, it has sparked interest in the field of autologous stem cell infusion as a possible treatment for cirrhosis. In this review, we will examine the evidence for the contribution of bone marrow-derived cells to populations of liver cells and for the functional contribution of bone marrow-derived cells to both liver fibrosis and repair. The mechanisms by which cells are trafficked from the bone marrow to the liver are complex; the stromal derived factor-1/CXC receptor 4 axis is central to this process. There are limited data in liver injury, but we will examine findings from the bone marrow transplantation literature and discuss their relevance to liver disease. Stromal derived factor-1 also has a role in endogenous liver stem cell accumulation. Some groups have already started infusing autologous bone marrow cells into patients with cirrhosis. We will review these trials in the context of the basic science that we have discussed, and we will consider targets for investigation in the future. Liver Transpl 16:118,129, 2010. © 2010 AASLD. [source] Cells from bone marrow that evolve into oral tissues and their clinical applicationsORAL DISEASES, Issue 1 2007OM Maria There are two major well-characterized populations of post-natal (adult) stem cells in bone marrow: hematopoietic stem cells which give rise to blood cells of all lineages, and mesenchymal stem cells which give rise to osteoblasts, adipocytes, and fibroblasts. For the past 50 years, strict rules were taught governing developmental biology. However, recently, numerous studies have emerged from researchers in different fields suggesting the unthinkable , that stem cells isolated from a variety of organs are capable of ignoring their cell lineage boundaries and exhibiting more plasticity in their fates. Plasticity is defined as the ability of post-natal (tissue-specific adult) stem cells to differentiate into mature and functional cells of the same or of a different germ layer of origin. There are reports that bone marrow stem cells can evolve into cells of all dermal lineages, such as hepatocytes, skeletal myocytes, cardiomyocytes, neural, endothelial, epithelial, and even endocrine cells. These findings promise significant therapeutic implications for regenerative medicine. This article will review recent reports of bone marrow cells that have the ability to evolve or differentiate into oral and craniofacial tissues, such as the periodontal ligament, alveolar bone, condyle, tooth, bone around dental and facial implants, and oral mucosa. [source] Bone marrow stem cells do not repopulate the healthy upper respiratory tract,PEDIATRIC PULMONOLOGY, Issue 4 2002Jane C. Davies MD Abstract Recent studies reported differentiation of both bone marrow and tissue-specific stem cells into cells of other organs. The demonstration that bone marrow stem cells differentiate into human hepatocytes in vivo has raised the possibility of new therapeutic approaches for liver disease. For diseases such as cystic fibrosis (CF), correction of the respiratory epithelium is being attempted by gene therapy. Differentiation of bone marrow stem cells into epithelium of the lung and airway was recently reported in an animal model, and would provide an alternative approach. We examined the nasal epithelium of female patients up to 15 years after gender-mismatched bone marrow transplantation. Donor-derived epithelial cells were sought with a combination of Y-chromosome fluorescence in situ hybridization and anti-cytokeratin antibody. In nasal brushing samples from 6 transplant-recipients, a median of 2.5% (range, 0.7,18.1%) of nuclei was male and identified as being of donor-origin. However, a complete absence of staining with anti-cytokeratin antibodies confirmed that these were not epithelial cells, but were likely to be either intraepithelial lymphocytes or mesenchymal cells. Following whole bone marrow transplantation, bone marrow progenitor cells do not differentiate into respiratory epithelium of the healthy upper airway. The differences between this and other studies could relate to the cells transplanted, to differential rates of turnover, or to the requirement for specific triggers to stimulate migration and differentiation. In the absence of such conditions, whole bone marrow transplantation is unlikely to provide a route for correction of the CF airway. Pediatr Pulmonol. 2002; 34:251,256. © 2002 Wiley-Liss, Inc. [source] Bone marrow stem cells regenerate infarcted myocardiumPEDIATRIC TRANSPLANTATION, Issue 2003Donald Orlic Abstract: Heart disease is the leading cause of death in the United States for both men and women. Nearly 50% of all cardiovascular deaths result from coronary artery disease. Occlusion of the left coronary artery leads to ischemia, infarction, necrosis of the affected myocardial tissue followed by scar formation and loss of function. Although myocytes in the surviving myocardium undergo hypertrophy and cell division occurs in the border area of the dead tissue, myocardial infarcts do not regenerate and eventually result in the death of the individual. Numerous attempts have been made to repair damaged myocardium in animal models and in humans. Bone marrow stem cells (BMSC) retain the ability throughout adult life to self-renew and differentiate into cells of all blood lineages. These adult BMSC have recently been shown to have the capacity to differentiate into multiple specific cell types in tissues other than bone marrow. Our research is focused on the capacity of BMSC to form new cardiac myocytes and coronary vessels following an induced myocardial infarct in adult mice. In this paper we will review the data we have previously published from studies on the regenerative capacity of BMSC in acute ischemic myocardial injury. In one experiment donor BMSC were injected directly into the healthy myocardium adjacent to the injured area of the left ventricle. In the second experiment, mice were treated with cytokines to mobilize their BMSC into the circulation on the theory that the stem cells would traffic to the myocardial infarct. In both experimental protocols, the BMSC gave rise to new cardiac myocytes and coronary blood vessels. This BMSC-derived myocardial regeneration resulted in improved cardiac function and survival. [source] Deficiency of oncoretrovirally transduced hematopoietic stem cells and correction through ex vivo expansionTHE JOURNAL OF GENE MEDICINE, Issue 2 2005David Bryder Abstract Background Extensive efforts to develop hematopoietic stem cell (HSC) based gene therapy have been hampered by low gene marking. Major emphasis has so far been directed at improving gene transfer efficiency, but low gene marking in transplanted recipients might equally well reflect compromised repopulating activity of transduced cells, competing for reconstitution with endogenous and unmanipulated stem cells. Methods The autologous settings of clinical gene therapy protocols preclude evaluation of changes in repopulating ability following transduction; however, using a congenic mouse model, allowing for direct evaluation of gene marking of lympho-myeloid progeny, we show here that these issues can be accurately addressed. Results We demonstrate that conditions supporting in vitro stem cell self-renewal efficiently promote oncoretroviral-mediated gene transfer to multipotent adult bone marrow stem cells, without prior in vivo conditioning. Despite using optimized culture conditions, transduction resulted in striking losses of repopulating activity, translating into low numbers of gene marked cells in competitively repopulated mice. Subjecting transduced HSCs to an ex vivo expansion protocol following the transduction procedure could partially reverse this loss. Conclusions These studies suggest that loss of repopulating ability of transduced HSCs rather than low gene transfer efficiency might be the main problem in clinical gene therapy protocols, and that a clinically feasible ex vivo expansion approach post-transduction can markedly improve reconstitution with gene marked stem cells. Copyright © 2004 John Wiley & Sons, Ltd. [source] Homing of transplanted bone marrow cells in livers of Schistosoma mansoni -infected miceAPMIS, Issue 4 2010NAGWA ELKHAFIF Elkhafif N, Voss B, Hammam O, Yehia H, Mansy S, Akl M, Boehm S, Mahmoud S, El Bendary O, El Fandy G. Homing of transplanted bone marrow cells in livers of Schistosoma mansoni -infected mice. APMIS 2010; 118: 277,87. The efficiency of differentiation of bone marrow cells (BMCs) into hepatocytes in vivo and its importance in physiopathological processes is still debated. Murine schistosomiasis was used as a liver injury model and unfractionated male mice BMCs were transplanted through intrahepatic injection into non-irradiated Schistosoma mansoni -infected female mice on their 16th week post-infection. Two weeks after bone marrow transplantation, mice were sacrificed on a weekly basis until 10 weeks. Tracing of male donor-derived cells in female recipient mice livers was carried out by the detection of Y chromosome expression by fluorescent in situ hybridization (FISH) and also of chromodomain Y-linked (CDYL) protein by indirect immunofluorescence (IF). Their transformation into hepatocytes was studied by double labelling indirect IF using antibodies directed against CDYL and mouse albumin. Histopathological and electron microscopic examinations revealed the presence of small hepatocyte-like cells in the periportal tracts and in between the hepatocytes facing the sinusoids. Donor-derived cells showing Y chromosome by FISH and expressing CDYL protein by IF were recovered in the infected transplanted livers. The initial number of these cells increased with increased post-transplantation time. Cells were mainly localized in the periphery of schistosoma granuloma. Few donor-derived cells appeared within the hepatic parenchymal tissue and showed positivity for albumin secretion by double labelling with IF. We suggest that transplanted bone marrow stem cells can repopulate the Schistosoma -infected liver of immunocompetent mice. Their differentiation is a complex event controlled by many factors and needs to be further characterized extensively. The extent and type of liver injury and the number of transplanted cells are important variables in the process of stem cell engraftment and differentiation into functioning hepatic cells that still need to be defined. [source] Periodically Discontinuous Induction of Bone Marrow Stem Cells toward Osteogenic Differentiation in VitroBIOTECHNOLOGY PROGRESS, Issue 3 2008Zhen Wang This paper reveals that a discontinuous in vitro induction, namely, the periodic presence and absence of foreign induction factors, might be, under a certain condition, more effective to stimulate stem cells' differentiation than a continuous induction. Bone marrow stem cells (BMSCs) derived from Sprague Dawley rats were employed to examine the effects of discontinuous additions of osteogenic supplements with a series of alternate frequency in contrast to those with continuous induction or no induction. The results demonstrated that a suitable discontinuous induction was more able to achieve osteogenesis than not only no induction but also the associated continuous induction. Additionally, the osteogenic supplements were confirmed to enhance cell differentiation but suppress cell proliferation. So, the combination of differentiation extent per cell and cell number accounts for the "unexpected" good osteogenic effect of the discontinuous induction. The induction effect was found to be dependent upon alternate frequency, and the optimum alternate period in our experimental systems was determined to be around 4 days. Since it is very common to change culture medium every 2,4 days, such a strategy of discontinuous induction does not bring any extra manual work but reduces the consumption of foreign induction factors and significantly enhances the global differentiation efficacy. Our work thus affords a convenient and practical approach to achieve differentiation of BMSCs, which might be useful for potential large-scale culture and differentiation of stem cells. Meanwhile, the existence of optimum frequency implies some unknown inherent rhythms of cell proliferation and differentiation. [source] Exogenous bone marrow cells do not rescue non-irradiated mice from acute renal tubular damage caused by HgCl2, despite establishment of chimaerism and cell proliferation in bone marrow and spleenCELL PROLIFERATION, Issue 4 2008T.-C. Fang Objective: Various studies have shown that bone marrow stem cells can rescue mice from acute renal tubular damage under a conditioning advantage (irradiation or cisplatin treatment) favouring donor cell engraftment and regeneration; however, it is not known whether bone marrow cells (BMCs) can contribute to repair of acute tubular damage in the absence of a selection pressure for the donor cells. The aim of this study was to examine this possibility. Materials and methods: Ten-week-old female mice were assigned into control non-irradiated animals having only vehicle treatment, HgCl2 -treated non-irradiated mice, HgCl2 -treated non-irradiated mice infused with male BMCs 1 day after HgCl2, and vehicle-treated mice with male BMCs. Tritiated thymidine was given 1 h before animal killing. Results: Donor BMCs could not alleviate non-irradiated mice from acute tubular damage caused by HgCl2, deduced by no reduction in serum urea nitrogen combined with negligible cell engraftment. However, donor BMCs could home to the bone marrow and spleen and display proliferative activity. This is the first report to show that despite no preparative myeloablation of recipients, engrafted donor BMCs can synthesize DNA in the bone marrow and spleen. Conclusions: Exogenous BMCs do not rescue non-irradiated mice from acute renal tubular damage caused by HgCl2, despite establishment of chimerism and cell proliferation in bone marrow and spleen. [source] | |||||||||||||