Purified Murine Hematopoietic Stem Cells Contribute to the Generation of Cardiomyocytes Via Cell Fusion.

Blood ◽  
2005 ◽  
Vol 106 (11) ◽  
pp. 1700-1700
Author(s):  
Mitsuhiro Fukata ◽  
Fumihiko Ishikawa ◽  
Hideki Shimazu ◽  
Hiroyuki Ito ◽  
Kazuya Shimoda ◽  
...  

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.

BMC Biology ◽  
2021 ◽  
Vol 19 (1) ◽  
Author(s):  
Léonard Hérault ◽  
Mathilde Poplineau ◽  
Adrien Mazuel ◽  
Nadine Platet ◽  
Élisabeth Remy ◽  
...  

Abstract Background Hematopoietic stem cells (HSCs) are the guarantor of the proper functioning of hematopoiesis due to their incredible diversity of potential. During aging, heterogeneity of HSCs changes, contributing to the deterioration of the immune system. In this study, we revisited mouse HSC compartment and its transcriptional plasticity during aging at unicellular scale. Results Through the analysis of 15,000 young and aged transcriptomes, we identified 15 groups of HSCs revealing rare and new specific HSC abilities that change with age. The implantation of new trajectories complemented with the analysis of transcription factor activities pointed consecutive states of HSC differentiation that were delayed by aging and explained the bias in differentiation of older HSCs. Moreover, reassigning cell cycle phases for each HSC clearly highlighted an imbalance of the cell cycle regulators of very immature aged HSCs that may contribute to their accumulation in an undifferentiated state. Conclusions Our results establish a new reference map of HSC differentiation in young and aged mice and reveal a potential mechanism that delays the differentiation of aged HSCs and could promote the emergence of age-related hematologic diseases.


2005 ◽  
Vol 67 (1) ◽  
Author(s):  
Hideo Ema ◽  
Yohei Morita ◽  
Hiromitsu Nakauchi ◽  
Yumi Matsuzaki

2018 ◽  
Vol 19 (7) ◽  
pp. 2122 ◽  
Author(s):  
Geoffrey Brown ◽  
Rhodri Ceredig ◽  
Panagiotis Tsapogas

Evidence from studies of the behaviour of stem and progenitor cells and of the influence of cytokines on their fate determination, has recently led to a revised view of the process by which hematopoietic stem cells and their progeny give rise to the many different types of blood and immune cells. The new scenario abandons the classical view of a rigidly demarcated lineage tree and replaces it with a much more continuum-like view of the spectrum of fate options open to hematopoietic stem cells and their progeny. This is in contrast to previous lineage diagrams, which envisaged stem cells progressing stepwise through a series of fairly-precisely described intermediate progenitors in order to close down alternative developmental options. Instead, stem and progenitor cells retain some capacity to step sideways and adopt alternative, closely related, fates, even after they have “made a lineage choice.” The stem and progenitor cells are more inherently versatile than previously thought and perhaps sensitive to lineage guidance by environmental cues. Here we examine the evidence that supports these views and reconsider the meaning of cell lineages in the context of a continuum model of stem cell fate determination and environmental modulation.


Blood ◽  
2009 ◽  
Vol 114 (18) ◽  
pp. 3783-3792 ◽  
Author(s):  
Xiaoxia Hu ◽  
Hongmei Shen ◽  
Chen Tian ◽  
Hui Yu ◽  
Guoguang Zheng ◽  
...  

Abstract The predominant outgrowth of malignant cells over their normal counterparts in a given tissue is a shared feature for all types of cancer. However, the impact of a cancer environment on normal tissue stem and progenitor cells has not been thoroughly investigated. We began to address this important issue by studying the kinetics and functions of hematopoietic stem and progenitor cells in mice with Notch1-induced leukemia. Although hematopoiesis was progressively suppressed during leukemia development, the leukemic environment imposed distinct effects on hematopoietic stem and progenitor cells, thereby resulting in different outcomes. The normal hematopoietic stem cells in leukemic mice were kept in a more quiescent state but remained highly functional on transplantation to nonleukemic recipients. In contrast, the normal hematopoietic progenitor cells in leukemic mice demonstrated accelerated proliferation and exhaustion. Subsequent analyses on multiple cell-cycle parameters and known regulators (such as p21, p27, and p18) further support this paradigm. Therefore, our current study provides definitive evidence and plausible underlying mechanisms for hematopoietic disruption but reversible inhibition of normal hematopoietic stem cells in a leukemic environment. It may also have important implications for cancer prevention and treatment in general.


1999 ◽  
Vol 189 (7) ◽  
pp. 1139-1148 ◽  
Author(s):  
Mickie Bhatia ◽  
Dominique Bonnet ◽  
Dongmei Wu ◽  
Barbara Murdoch ◽  
Jeff Wrana ◽  
...  

The identification of molecules that regulate human hematopoietic stem cells has focused mainly on cytokines, of which very few are known to act directly on stem cells. Recent studies in lower organisms and the mouse have suggested that bone morphogenetic proteins (BMPs) may play a critical role in the specification of hematopoietic tissue from the mesodermal germ layer. Here we report that BMPs regulate the proliferation and differentiation of highly purified primitive human hematopoietic cells from adult and neonatal sources. Populations of rare CD34+CD38−Lin− stem cells were isolated from human hematopoietic tissue and were found to express the BMP type I receptors activin-like kinase (ALK)-3 and ALK-6, and their downstream transducers SMAD-1, -4, and -5. Treatment of isolated stem cell populations with soluble BMP-2, -4, and -7 induced dose-dependent changes in proliferation, clonogenicity, cell surface phenotype, and multilineage repopulation capacity after transplantation in nonobese diabetic/severe combined immunodeficient (NOD/SCID) mice. Similar to transforming growth factor β, treatment of purified cells with BMP-2 or -7 at high concentrations inhibited proliferation yet maintained the primitive CD34+CD38− phenotype and repopulation capacity. In contrast, low concentrations of BMP-4 induced proliferation and differentiation of CD34+ CD38−Lin− cells, whereas at higher concentrations BMP-4 extended the length of time that repopulation capacity could be maintained in ex vivo culture, indicating a direct effect on stem cell survival. The discovery that BMPs are capable of regulating repopulating cells provides a new pathway for controlling human stem cell development and a powerful model system for studying the biological mechanism of BMP action using primary human cells.


Blood ◽  
2004 ◽  
Vol 104 (11) ◽  
pp. 1694-1694
Author(s):  
Soichi Nakata ◽  
Itaru Matsumura ◽  
Hirokazu Tanaka ◽  
Yusuke Satoh ◽  
Takumi Era ◽  
...  

Abstract NF-kB family proteins have been reported to induce the expression of over 150 target genes, thereby crucially regulating immune responses, stress responses, and inflammation. These proteins also play important roles in cell growth and survival in various cell types. However, the precise roles of NF-kB in hematopoiesis and their mechanisms remain undetermined. To examine the roles for NF-kB family proteins in the growth and survival of hematopoietic cells, we expressed dominant negative NF-kB (IkBSR) in a murine IL-3-dependent cell line Ba/F3 using a Lac-inducible system, in which IkBSR was inducibly expressed by the IPTG treatment; this clone was designated Ba/F3/IkBSR. Furthermore, we introduced EPO receptor (R), TPOR, and G-CSFR/gp130 consisting of the extracelluar domain of G-CSFR and cytoplasmic domain of gp130 into this clone. At first, we confirmed that these clones could survive and proliferate under the cultures with IL-3, EPO, TPO, G-CSF, respectively. Although IPTG-induced IkBSR slightly suppressed IL-3- and EPO-dependent growth at low concentrations, it did not affect TPO- or gp130L-dependent growth, suggesting that NF-kB might not be so important for cytokine-dependent growth of hematopoietic cells. In contrast, IkBSR prominently enhanced factor-deprived apoptosis, which was accompanied by the ROS accumulation. To access the roles of ROS in IkBSR-enhanced apoptosis, we overexpressed ROS scavenger enzymes MnSOD and thioredoxin X (TRX) in Ba/F3/IkBSR, respectively. As a result, MnSOD and TRX significantly canceled IkB-SR-enhanced apoptosis, suggesting that ROS would be responsible for this apoptosis. We next analyzed the effects of IkBSR on the growth and survival of normal hematopoietic cells. When IkBSR was introduced into murine Lin−Sca-1+ hematopoietic stem/progenitor cells with the retrovirus system, it induced apoptosis even in the presence of appropriate cytokines. This apoptosis was also accompanied by the ROS accumulation due to the downregulated expression of anti-oxidants such as glutathione, MnSOD, glutathione peroxidase, and TRX. In addition, the expression of antiapoptotic BCl-2 family members, Bcl-XL, Bcl-2, and A1 was found to be repressed by IkBSR. However, since antioxidants such as MCI (3-methyl-1-phenyl-2-pyrazolin-5-one), N-acetylecysteine and TRX cancelled this apoptosis, ROS were supposed to be more important for IkBSR-induced apoptosis in normal hematopoietic stem/progenitor cells. To further analyze the roles for NF-kB proteins in the development of hematopoietic cells, we expressed IkBSR in an inducible fashion at various stages of hematopoiesis using the OP9 system, in which hematopoietic cells are induced to develop from ES cells. When IkBSR was expressed at the stage of hemangioblasts, IkBSR induced apoptosis and inhibited the development of hematopoietic stem cells, which was also cancelled by MCI. Furthermore, when IkBSR was expressed after the development of hematopoietic stem cells, it also inhibited terminal differentiation towards granulocytes, erythrocytes, and megakaryocytes through ROS-mediated apoptosis; IkBSR inhibited granulopoiesis before the development of myeloblasts, erythropoiesis after the development of proerythroblasts, and megakaryopoiesis during polyploidization of megakaryocytes. These results indicate that NF-kB family proteins play essential roles to prevent apoptosis at multiple steps of hematopoiesis by eliminating ROS.


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