Human induced pluripotent stem （iPS） cells are similar to embryonic stem （ES） cells, and can proliferate intensively and differentiate into a variety of cell types. However, the hepatic differentiation of human iP...Human induced pluripotent stem （iPS） cells are similar to embryonic stem （ES） cells, and can proliferate intensively and differentiate into a variety of cell types. However, the hepatic differentiation of human iPS cells has not yet been reported. In this report, human iPS cells were induced to differentiate into hepatic cells by a stepwise protocol. The expression of liver cell markers and liver-related functions of the human iPS cell-derived cells were monitored and compared with that of differentiated human ES cells and primary human hepatocytes. Approximately 60% of the differentiated human iPS cells at day 7 expressed hepatic markers alpha fetoprotein and Alb. The differentiated cells at day 21 exhibited liver cell functions including albumin Asecretion, glycogen synthesis, urea production and inducible cytochrome P450 activity. The expression of hepatic markers and fiver-related functions of the iPS cellderived hepatic ceils were comparable to that of the human ES cell-derived hepatic cells. These results show that human iPS cells, which are similar to human ES cells, can be efficiently induced to differentiate into hepatocyte-like cells.展开更多
CD4^(+)T helper cells are key regulators of host health and disease.In the original model,specialized subsets of T helper cells are generated following activation through lineage-specifying cytokines and transcription...CD4^(+)T helper cells are key regulators of host health and disease.In the original model,specialized subsets of T helper cells are generated following activation through lineage-specifying cytokines and transcriptional programs,but recent studies have revealed increasing complexities for CD4^(+)T-cell differentiation.Here,we first discuss CD4^(+)T-cell differentiation from a historical perspective by highlighting the major studies that defined the distinct subsets of T helper cells.We next describe the mechanisms underlying CD4^(+)T-cell differentiation,including cytokine-induced signaling and transcriptional networks.We then review current and emerging topics of differentiation,including the plasticity and heterogeneity of T cells,the tissue-specific effects,and the influence of cellular metabolism on cell fate decisions.Importantly,recent advances in cutting-edge approaches,especially systems biology tools,have contributed to new concepts and mechanisms underlying T-cell differentiation and will likely continue to advance this important research area of adaptive immunity.展开更多
AIM: To compare the influence of different transplant sites in bone marrow mesenchymal stem cell (MSC)-based therapy for liver fibrosis. METHODS: MSCs isolated from Sprague Dawley (SD) rats were induced into hepatocyt...AIM: To compare the influence of different transplant sites in bone marrow mesenchymal stem cell (MSC)-based therapy for liver fibrosis. METHODS: MSCs isolated from Sprague Dawley (SD) rats were induced into hepatocyte-like cells. Liver fibrosis in SD rats was induced with carbon tetrachloride. Following hepatocyte induction in vitro, 4',6-diamidino- 2-phenylindole (DAPI)-labeled MSCs were transplanted by intravenous, intrahepatic, and intraperitoneal injection. Histopathological staining, immunohistochemistry, and biochemical analysis were used to compare the morphological and functional liver regeneration among different MSC injection modalities. The expression differences of interleukins, growth factor, extracellular matrix, matrix metalloproteinases, and tissue inhibitor of metalloproteinase were examined by real-time reverse transcription-polymerase chain reaction (RT-PCR) andenzyme linked immunosorbent assay (ELISA). RESULTS: Four days after exposure to hepatocyte differentiation medium, MSCs that did not express hepatocyte markers could express α-fetoprotein, albumin, and cytokeratin 18. The results of histopathological staining, immunohistochemistry, and biochemical analysis indicated that intravenous injection is more effective at rescuing liver failure than other injection modalities. DAPI-labeled cells were found around liver lobules in all three injection site groups, but the intravenous group had the highest number of cells. PCR and ELISA analysis indicated that interleukin-10 (IL-10) was highest in the intravenous group, whereas il1β, il6, tnfα and tgfβ, which can be regulated by IL10 and are promoters of liver fibrosis, were significantly lower than in the other groups. CONCLUSION: MSC administration is able to protect against liver fibrosis. Intravenous injection is the most favorable treatment modality through promotion of IL10 expression.展开更多
AIM： The origin of putative liver cells from distinct bone marrow stem cells, e.g. hematopoietic stem cells or multipotent adult progenitor cells was found in recent in vitro studies. Cell culture experiments reveale...AIM： The origin of putative liver cells from distinct bone marrow stem cells, e.g. hematopoietic stem cells or multipotent adult progenitor cells was found in recent in vitro studies. Cell culture experiments revealed a key role of growth factors for the induction of liver-specific genes in stern cell cultures. We investigated the potential of rat mesenchymal stem cells （MSC） from bone marrow to differentiate into hepatocytic cells in vitro. Furthermore, we assessed the influence of cocultured liver cells on induction of liver-specific gene expression. METHODS： Mesenchymal stem cells were marked with green fluorescent protein （GFP） by retroviral gene transduction. Clonal marked MSC were either cultured under liver stimulating conditions using fibronectin-coated culture dishes and medium supplemented with SCF, HGF, EGF, and FGF-4 alone, or in presence of freshly isolated rat liver cells. Cells in cocultures were harvested and GFP＋ or GFP- cells were separated using fluorescence activated cell sorting. RT-PCR analysis for the stem cell marker Thyl and the hepatocytic markers CK-18, albumin, CK-19, and AFP was performed in the different cell populations. RESULTS： Under the specified culture conditions, rat MSC cocultured with liver cells expressed albumin-, CK-18, CK-19, and AFP-RNA over 3 weeks, whereas MSC cultured alone did not show liver specific gene expression, CONCLUSION： The results indicate that （1） rat MSC from bone marrow can differentiate towards hepatocytic lineage in vitro, and （2） that the microenvironment plays a decisive role for the induction of hepatic differentiation of rMSC.展开更多
Human neurocristopathies include a number of syndromes, tumors, and dysmorphologies of neural crest （NC） stem cell derivatives. In recent years, many white spotting genes have been associated with hypopigmentary dis...Human neurocristopathies include a number of syndromes, tumors, and dysmorphologies of neural crest （NC） stem cell derivatives. In recent years, many white spotting genes have been associated with hypopigmentary disorders and deafness in neurocristopathies resulting from NC stem cell-derived melanocyte deficiency during development. These include PAX3, SOX10, MITF, SNAI2, EDNRB, EDN3, KIT, and KITL. Recent studies have revealed surprising new insights into a central role of MITF in the complex network of interacting genes in melanocyte development. In this perspective, we provide an overview of some of the current findings and explore complex functional roles of these genes during NC stem cell-derived melanocyte development.展开更多
IL-23/IL-17 axis is an important regulator in various inflammatory diseases. However, the role of IL-23 in allergic airway inflammation is not well understood. In this study, we show that in an allergen-induced asthma...IL-23/IL-17 axis is an important regulator in various inflammatory diseases. However, the role of IL-23 in allergic airway inflammation is not well understood. In this study, we show that in an allergen-induced asthma model, mice with transgenic overexpression of IL-23R exhibited increased airway infiltration of eosinophils and Th2 cytokine production, whereas those deficient in IL-23 displayed reduced airway inflammation. In vitro, IL-23-IL-23R signaling promoted GATA-3 expression and enhanced Th2 cytokine expression. Conversely, in the absence of this signal, Th2 cell differentiation was partially inhibited. Therefore, IL-23 signaling may regulate allergic asthma through modulation of Th2 cell differentiation.展开更多
Upon antigen stimulation, naive T helper cells differentiate into distinct lineages to attain specialized properties and effector functions. TH17 cells, a recently identified lineage of CD4＋ effector T cells, play a ...Upon antigen stimulation, naive T helper cells differentiate into distinct lineages to attain specialized properties and effector functions. TH17 cells, a recently identified lineage of CD4＋ effector T cells, play a key role in the immune defense against fungi and extracellular bacteria, but also contribute to the pathogenesis of many autoimmune conditions. The differentiation of TH 17 cells is orchestrated by an intricate network of signaling pathways and transcriptional regulators in T cells. While the involvement of T cell-intrinsic pathways has been described extensively, we are just beginning to appreciate how TH17 cell development is shaped by extrinsic pathways, espec- ially the innate immune signals. Dendritic cells （DCs）, the most important cell type to bridge innate and adaptive immunity, drive TH17 cell differentiation by providing antigenic, costimulatory and cytokine signals. This is mediated by the recognition of innate and inflam- matory signals by DCs via pattern recognition receptors, cytokine receptors and other immunomodulatory receptors that in turn activate the intracellular signaling network. In particular, p38a MAP kinase has emerged as a critical pathway to program DC-dependent TH17 cell differentiation by integrating multiple instructive signals in DCs. Here, we summarize the current knowledge on the mechanisms by which DC-derived innate immune signals drive TH17 cell differentiation.展开更多
Objective To study the transplantation efficacy of neural stem cells （NSCs） and Schwann cells （SC） in a rat model of spinal cord contusion injury. Methods Multipotent neural stem cells （NSCs） and Schwann cells w...Objective To study the transplantation efficacy of neural stem cells （NSCs） and Schwann cells （SC） in a rat model of spinal cord contusion injury. Methods Multipotent neural stem cells （NSCs） and Schwann cells were harvested from the spinal cords of embryonic rats at 16 days post coitus and sciatic nerves of newborn rats, respectively. The differential characteristics of NSCs in vitro induced by either serum-based culture or co-culture with SC were analyzed by immunofluorescence. NSCs and SCs were co-transplanted into adult rats having undergone spinal cord contusion at T9 level. The animals were weekly monitored using the Basso-Beattie-Bresnahan locomotor rating system to evaluate functional recovery from contusion-induced spinal cord injury. Migration and differentiation of transplanted NSCs were studied in tissue sections using immunohistochemical staining. Results Embryonic spinal cord-derived NSCs differentiated into a large number of oligodendrocytes in serum-based culture upon the withdrawal of mitogens. In cocultures with SCs, NSCs differentiated into neuron more readily. Rats with spinal cord contusion injury which had undergone transplantation of NSCs and SCs into the intraspinal cavity demonstrated a moderate improvement in motor functions. Conclusions SC may contribute to neuronal differentiation of NSCs in vitro and in vivo. Transplantation of NSCs and SCs into the affected area may be a feasible approach to promoting motor recovery in patients after spinal cord injury.展开更多
Background The existence of neurogenesis in the hippocampus of adult nonhuman primates has been confirmed in recent years, however, the biological properties of adult neural stem cells or neural progenitor cells （NPC...Background The existence of neurogenesis in the hippocampus of adult nonhuman primates has been confirmed in recent years, however, the biological properties of adult neural stem cells or neural progenitor cells （NPCs） from this region remain to be extensively explored. The present work was to investigate on the expansion of NSCs/NPCs from the hippocampus of adult cynomolgus monkeys and the examination of their characteristics in vitro. Methods NPCs isolated from the hippocampus of adult cynomolgus monkeys were expanded in vitro in serum-free media containing growth factors, and were then allowed to differentiate by removing mitotic factors. The expansion capacity of NPCs and their differentiation potential were assayed by immunohistochemical and immunocytochemical analysis. Results During primary culture, NPCs underwent cell division, proliferation and aggregation to form neurospheres that were growing in suspension. Without mitotic stimulation, most neurospheres adhered to the culture dish and started to differentiate. Eventually, nearly 12% of the differentiated cells expressed neuron specific marker-β Ⅲ-tubulin （Tuj1） and 84% expressed astrocyte specific marker-fibrillary acidic protein （GFAP）. In addition, the expression of a neural stem cell marker, nestin, was found both in NPCs and in the subgranular zone of adult monkey hippocampus, where NPCs were originally derived. Conclusions NPCs from the hippocampus of adult cynomolgus monkeys can be expanded to some extent in vitro and are capable of differentiating into neurons and astrocytes. Further experiments to promote the in vitro proliferation capacity of NPCs will be required before adult NPCs can be used as a useful cell model for studying adult neurogenesis and cell replacement therapy using adult stem cells.展开更多
Objective To explore the differentiation fates of rat neural stem cells (NSCs) in different environmental conditions. Methods NSCs derived from 16-day-old rat embryo were proliferated in vitro and implanted into the b...Objective To explore the differentiation fates of rat neural stem cells (NSCs) in different environmental conditions. Methods NSCs derived from 16-day-old rat embryo were proliferated in vitro and implanted into the brain of rats with intra-cerebral hemorrhage. At the same time some NSCs were co-cultured in vitro with Schwann cells derived from newborn rats. MAP-2, GFAP and GalC (which are the specific markers of neural cells, astrocytes and oligodendrocytes respectively), BrdU and β-tubulin were detected by immunohistochemical and immunofluorescent methods. Results BrdU positive cells that were implanted into the brain dfstributed around the hemorrhagic area. The majority of them were GFAP positive astrocytes while a few of them were β-tubulin positive neural cells or GalC positive oligodendrocytes. After being co-cultured with Schwann cells in vitro, NSCs are predominately shown β-tubulin and MAP-2 positive, and only a minority of them were GFAP or GalC positive. Conclusions The hemorrhagic environment in vivo induces NSCs to differentiate mainly into astrocytes while co-culture with Schwann cells in vitro induce the majority of NSCs to differentiate into neural cells.展开更多
基金We thank Dr Zicai Liang and Huang Huang （Institute of Molecular Medicine, Peking University） for their kind help with BioTek Multi-Detection Microplate Reader and Yizhe Zhang for technical support on real-time PCR. We also thank Chengyan Wang, Pengbo Zhang, Pingping Hou, Haisong Liu, Chun Liu and other colleagues in our laboratory for technical assistance and advice in carrying out these experiments. This study was supported by a Bill ＆ Melinda Gates Foundation Grant （37871）, a Ministry of Education grant （705001）, the National Basic Research Program of China （973 program, 2009CB522502, 2009CB941200 and 2007CB947901）, National Natural Science Foundation of China for Creative Research Groups （30421004）, the Chinese Science and Technology Key Project （2008zx10002-014, 2008zx10002- 011 and 2009ZX 10004-403） and a 111 Project to Deng H.
文摘Human induced pluripotent stem （iPS） cells are similar to embryonic stem （ES） cells, and can proliferate intensively and differentiate into a variety of cell types. However, the hepatic differentiation of human iPS cells has not yet been reported. In this report, human iPS cells were induced to differentiate into hepatic cells by a stepwise protocol. The expression of liver cell markers and liver-related functions of the human iPS cell-derived cells were monitored and compared with that of differentiated human ES cells and primary human hepatocytes. Approximately 60% of the differentiated human iPS cells at day 7 expressed hepatic markers alpha fetoprotein and Alb. The differentiated cells at day 21 exhibited liver cell functions including albumin Asecretion, glycogen synthesis, urea production and inducible cytochrome P450 activity. The expression of hepatic markers and fiver-related functions of the iPS cellderived hepatic ceils were comparable to that of the human ES cell-derived hepatic cells. These results show that human iPS cells, which are similar to human ES cells, can be efficiently induced to differentiate into hepatocyte-like cells.
基金the National Institutes of Health and the National Multiple Sclerosis Society.
文摘CD4^(+)T helper cells are key regulators of host health and disease.In the original model,specialized subsets of T helper cells are generated following activation through lineage-specifying cytokines and transcriptional programs,but recent studies have revealed increasing complexities for CD4^(+)T-cell differentiation.Here,we first discuss CD4^(+)T-cell differentiation from a historical perspective by highlighting the major studies that defined the distinct subsets of T helper cells.We next describe the mechanisms underlying CD4^(+)T-cell differentiation,including cytokine-induced signaling and transcriptional networks.We then review current and emerging topics of differentiation,including the plasticity and heterogeneity of T cells,the tissue-specific effects,and the influence of cellular metabolism on cell fate decisions.Importantly,recent advances in cutting-edge approaches,especially systems biology tools,have contributed to new concepts and mechanisms underlying T-cell differentiation and will likely continue to advance this important research area of adaptive immunity.
基金Supported by Millitary Medicine and Health Foundation of China, No. 08Z030
文摘AIM: To compare the influence of different transplant sites in bone marrow mesenchymal stem cell (MSC)-based therapy for liver fibrosis. METHODS: MSCs isolated from Sprague Dawley (SD) rats were induced into hepatocyte-like cells. Liver fibrosis in SD rats was induced with carbon tetrachloride. Following hepatocyte induction in vitro, 4',6-diamidino- 2-phenylindole (DAPI)-labeled MSCs were transplanted by intravenous, intrahepatic, and intraperitoneal injection. Histopathological staining, immunohistochemistry, and biochemical analysis were used to compare the morphological and functional liver regeneration among different MSC injection modalities. The expression differences of interleukins, growth factor, extracellular matrix, matrix metalloproteinases, and tissue inhibitor of metalloproteinase were examined by real-time reverse transcription-polymerase chain reaction (RT-PCR) andenzyme linked immunosorbent assay (ELISA). RESULTS: Four days after exposure to hepatocyte differentiation medium, MSCs that did not express hepatocyte markers could express α-fetoprotein, albumin, and cytokeratin 18. The results of histopathological staining, immunohistochemistry, and biochemical analysis indicated that intravenous injection is more effective at rescuing liver failure than other injection modalities. DAPI-labeled cells were found around liver lobules in all three injection site groups, but the intravenous group had the highest number of cells. PCR and ELISA analysis indicated that interleukin-10 (IL-10) was highest in the intravenous group, whereas il1β, il6, tnfα and tgfβ, which can be regulated by IL10 and are promoters of liver fibrosis, were significantly lower than in the other groups. CONCLUSION: MSC administration is able to protect against liver fibrosis. Intravenous injection is the most favorable treatment modality through promotion of IL10 expression.
基金Supported by the "Rudoff Bartling Foundation" and "Foerdergemeinschaft Kinder-Krebs-Zentrum Hamburg e.V."
文摘AIM： The origin of putative liver cells from distinct bone marrow stem cells, e.g. hematopoietic stem cells or multipotent adult progenitor cells was found in recent in vitro studies. Cell culture experiments revealed a key role of growth factors for the induction of liver-specific genes in stern cell cultures. We investigated the potential of rat mesenchymal stem cells （MSC） from bone marrow to differentiate into hepatocytic cells in vitro. Furthermore, we assessed the influence of cocultured liver cells on induction of liver-specific gene expression. METHODS： Mesenchymal stem cells were marked with green fluorescent protein （GFP） by retroviral gene transduction. Clonal marked MSC were either cultured under liver stimulating conditions using fibronectin-coated culture dishes and medium supplemented with SCF, HGF, EGF, and FGF-4 alone, or in presence of freshly isolated rat liver cells. Cells in cocultures were harvested and GFP＋ or GFP- cells were separated using fluorescence activated cell sorting. RT-PCR analysis for the stem cell marker Thyl and the hepatocytic markers CK-18, albumin, CK-19, and AFP was performed in the different cell populations. RESULTS： Under the specified culture conditions, rat MSC cocultured with liver cells expressed albumin-, CK-18, CK-19, and AFP-RNA over 3 weeks, whereas MSC cultured alone did not show liver specific gene expression, CONCLUSION： The results indicate that （1） rat MSC from bone marrow can differentiate towards hepatocytic lineage in vitro, and （2） that the microenvironment plays a decisive role for the induction of hepatic differentiation of rMSC.
基金We would like to thank Dr HeinzAmheiter （NIH/NINDS） for generously contributing to the images, and Dr Laura Baxter and Dr Yingzi Yang （NIH/NHGRI） for thoughtful comments on the manuscript. We also acknowledge the support by the National Natural Science Foundation of China （30771149） and the Intramural Research Program of the National Human Genome Research Institute, National Institutes of Health.
文摘Human neurocristopathies include a number of syndromes, tumors, and dysmorphologies of neural crest （NC） stem cell derivatives. In recent years, many white spotting genes have been associated with hypopigmentary disorders and deafness in neurocristopathies resulting from NC stem cell-derived melanocyte deficiency during development. These include PAX3, SOX10, MITF, SNAI2, EDNRB, EDN3, KIT, and KITL. Recent studies have revealed surprising new insights into a central role of MITF in the complex network of interacting genes in melanocyte development. In this perspective, we provide an overview of some of the current findings and explore complex functional roles of these genes during NC stem cell-derived melanocyte development.
文摘IL-23/IL-17 axis is an important regulator in various inflammatory diseases. However, the role of IL-23 in allergic airway inflammation is not well understood. In this study, we show that in an allergen-induced asthma model, mice with transgenic overexpression of IL-23R exhibited increased airway infiltration of eosinophils and Th2 cytokine production, whereas those deficient in IL-23 displayed reduced airway inflammation. In vitro, IL-23-IL-23R signaling promoted GATA-3 expression and enhanced Th2 cytokine expression. Conversely, in the absence of this signal, Th2 cell differentiation was partially inhibited. Therefore, IL-23 signaling may regulate allergic asthma through modulation of Th2 cell differentiation.
文摘Upon antigen stimulation, naive T helper cells differentiate into distinct lineages to attain specialized properties and effector functions. TH17 cells, a recently identified lineage of CD4＋ effector T cells, play a key role in the immune defense against fungi and extracellular bacteria, but also contribute to the pathogenesis of many autoimmune conditions. The differentiation of TH 17 cells is orchestrated by an intricate network of signaling pathways and transcriptional regulators in T cells. While the involvement of T cell-intrinsic pathways has been described extensively, we are just beginning to appreciate how TH17 cell development is shaped by extrinsic pathways, espec- ially the innate immune signals. Dendritic cells （DCs）, the most important cell type to bridge innate and adaptive immunity, drive TH17 cell differentiation by providing antigenic, costimulatory and cytokine signals. This is mediated by the recognition of innate and inflam- matory signals by DCs via pattern recognition receptors, cytokine receptors and other immunomodulatory receptors that in turn activate the intracellular signaling network. In particular, p38a MAP kinase has emerged as a critical pathway to program DC-dependent TH17 cell differentiation by integrating multiple instructive signals in DCs. Here, we summarize the current knowledge on the mechanisms by which DC-derived innate immune signals drive TH17 cell differentiation.
基金This research was supported by the National Natural Science Foundation of China (No. 30371452).
文摘Objective To study the transplantation efficacy of neural stem cells （NSCs） and Schwann cells （SC） in a rat model of spinal cord contusion injury. Methods Multipotent neural stem cells （NSCs） and Schwann cells were harvested from the spinal cords of embryonic rats at 16 days post coitus and sciatic nerves of newborn rats, respectively. The differential characteristics of NSCs in vitro induced by either serum-based culture or co-culture with SC were analyzed by immunofluorescence. NSCs and SCs were co-transplanted into adult rats having undergone spinal cord contusion at T9 level. The animals were weekly monitored using the Basso-Beattie-Bresnahan locomotor rating system to evaluate functional recovery from contusion-induced spinal cord injury. Migration and differentiation of transplanted NSCs were studied in tissue sections using immunohistochemical staining. Results Embryonic spinal cord-derived NSCs differentiated into a large number of oligodendrocytes in serum-based culture upon the withdrawal of mitogens. In cocultures with SCs, NSCs differentiated into neuron more readily. Rats with spinal cord contusion injury which had undergone transplantation of NSCs and SCs into the intraspinal cavity demonstrated a moderate improvement in motor functions. Conclusions SC may contribute to neuronal differentiation of NSCs in vitro and in vivo. Transplantation of NSCs and SCs into the affected area may be a feasible approach to promoting motor recovery in patients after spinal cord injury.
基金This work was supported by grants from the National Basic Research Program of China (No.973, 2001CB510104), National Natural Science Foundation of China (No. 30460141), and Program for New Century Excellent Talents in University (2005).
文摘Background The existence of neurogenesis in the hippocampus of adult nonhuman primates has been confirmed in recent years, however, the biological properties of adult neural stem cells or neural progenitor cells （NPCs） from this region remain to be extensively explored. The present work was to investigate on the expansion of NSCs/NPCs from the hippocampus of adult cynomolgus monkeys and the examination of their characteristics in vitro. Methods NPCs isolated from the hippocampus of adult cynomolgus monkeys were expanded in vitro in serum-free media containing growth factors, and were then allowed to differentiate by removing mitotic factors. The expansion capacity of NPCs and their differentiation potential were assayed by immunohistochemical and immunocytochemical analysis. Results During primary culture, NPCs underwent cell division, proliferation and aggregation to form neurospheres that were growing in suspension. Without mitotic stimulation, most neurospheres adhered to the culture dish and started to differentiate. Eventually, nearly 12% of the differentiated cells expressed neuron specific marker-β Ⅲ-tubulin （Tuj1） and 84% expressed astrocyte specific marker-fibrillary acidic protein （GFAP）. In addition, the expression of a neural stem cell marker, nestin, was found both in NPCs and in the subgranular zone of adult monkey hippocampus, where NPCs were originally derived. Conclusions NPCs from the hippocampus of adult cynomolgus monkeys can be expanded to some extent in vitro and are capable of differentiating into neurons and astrocytes. Further experiments to promote the in vitro proliferation capacity of NPCs will be required before adult NPCs can be used as a useful cell model for studying adult neurogenesis and cell replacement therapy using adult stem cells.
基金This research was supported by grants from Chinese Postdoctoral Foundation and Beijing New Scientist Culture Foundation (H020821360130).
文摘Objective To explore the differentiation fates of rat neural stem cells (NSCs) in different environmental conditions. Methods NSCs derived from 16-day-old rat embryo were proliferated in vitro and implanted into the brain of rats with intra-cerebral hemorrhage. At the same time some NSCs were co-cultured in vitro with Schwann cells derived from newborn rats. MAP-2, GFAP and GalC (which are the specific markers of neural cells, astrocytes and oligodendrocytes respectively), BrdU and β-tubulin were detected by immunohistochemical and immunofluorescent methods. Results BrdU positive cells that were implanted into the brain dfstributed around the hemorrhagic area. The majority of them were GFAP positive astrocytes while a few of them were β-tubulin positive neural cells or GalC positive oligodendrocytes. After being co-cultured with Schwann cells in vitro, NSCs are predominately shown β-tubulin and MAP-2 positive, and only a minority of them were GFAP or GalC positive. Conclusions The hemorrhagic environment in vivo induces NSCs to differentiate mainly into astrocytes while co-culture with Schwann cells in vitro induce the majority of NSCs to differentiate into neural cells.
