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  • Human stem/progenitor cells from bone marrow enhance glial differentiation of rat neural stem cells: a role for transforming growth factor β and Notch signaling. 20575640

    Multipotent stem/progenitor cells from bone marrow stroma (mesenchymal stromal cells or MSCs) were previously shown to enhance proliferation and differentiation of neural stem cells (NSCs) in vivo, but the molecular basis of the effect was not defined. Here coculturing human MSCs (hMSCs) with rat NSCs (rNSCs) was found to stimulate astrocyte and oligodendrocyte differentiation of the rNSCs. To survey the signaling pathways involved, RNA from the cocultures was analyzed by species-specific microarrays. In the hMSCs, there was an upregulation of transcripts for several secreted factors linked to differentiation: bone morphogenetic protein 1 (BMP1), hepatocyte growth factor (HGF), and transforming growth factor isoforms (TGFβ1 and TGFβ3). In both the hMSCs and the rNSCs, there was an upregulation of transcripts for Notch signaling. The role of TGFβ1 was verified by the demonstration that hMSCs in coculture increased secretion of TGFβ1, the rNSCs expressed the receptor, and an inhibitor of TGFβ signaling blocked differentiation. The role of Notch signaling was verified by the demonstration that in the cocultures hMSCs expressed a Notch ligand at sites of cell contact with rNSCs, and the rNSCs expressed the receptor, Notch 1. Increased Notch signaling in both cell types was then demonstrated by assays of transcript expression and by a reporter construct for downstream targets of Notch signaling. The results demonstrated that glial differentiation of the rNSCs in the cocultures was driven by increased secretion of soluble factors such as TGFβ1 by the hMSCs and probably through increased cell contact signaling between the hMSCs and rNSCs through the Notch pathway.
    Dokumententyp:
    Referenz
    Produkbestellnummer:
    Mehrere
    Produktbezeichnung:
    Mehrere

  • Neural stem cell differentiation is dictated by distinct actions of nuclear receptor corepressors and histone deacetylases. 25241747

    Signaling factors including retinoic acid (RA) and thyroid hormone (T3) promote neuronal, oligodendrocyte, and astrocyte differentiation of cortical neural stem cells (NSCs). However, the functional specificity of transcriptional repressor checkpoints controlling these differentiation programs remains unclear. Here, we show by genome-wide analysis that histone deacetylase (HDAC)2 and HDAC3 show overlapping and distinct promoter occupancy at neuronal and oligodendrocyte-related genes in NSCs. The absence of HDAC3, but not HDAC2, initiated a neuronal differentiation pathway in NSCs. The ablation of the corepressor NCOR or HDAC2, in conjunction with T3 treatment, resulted in increased expression of oligodendrocyte genes, revealing a direct HDAC2-mediated repression of Sox8 and Sox10 expression. Interestingly, Sox10 was required also for maintaining the more differentiated state by repression of stem cell programming factors such as Sox2 and Sox9. Distinct and nonredundant actions of NCORs and HDACs are thus critical for control of lineage progression and differentiation programs in neural progenitors.
    Dokumententyp:
    Referenz
    Produkbestellnummer:
    Mehrere
    Produktbezeichnung:
    Mehrere

  • Testing stem cell therapy in a rat model of inflammatory bowel disease: role of bone marrow stem cells and stem cell factor in mucosal regeneration. 25309991

    The gastrointestinal (GI) mucosal cells turnover regularly under physiological conditions, which may be stimulated in various pathological situations including inflammation. Local epithelial stem cells appear to play a major role in such mucosal renewal or pathological regeneration. Less is clear about the involvement of multipotent stem cells from blood in GI repair. We attempted to explore a role of bone marrow mesenchymal stromal cells (BMMSCs) and soluble stem cell factor (SCF) in GI mucosa regeneration in a rat model of inflammatory bowel diseases (IBD).BMMSCs labelled with the fluorescent dye PKH26 from donor rats were transfused into rats suffering indomethacin-induced GI injury. Experimental effects by BMMSCs transplant and SCF were determined by morphometry of intestinal mucosa, double labeling of PKH26 positive BMMSCs with endogenous proliferative and intestinal cell markers, and western blot and PCR analyses of the above molecular markers in the recipient rats relative to controls.PKH26 positive BMMSCs were found in the recipient mucosa, partially colocalizing with the proliferating cell nuclear antigen (PCNA), Lgr5, Musashi-1 and ephrin-B3. mRNA and protein levels of PCNA, Lgr5, Musashi-1 and ephrin-B3 were elevated in the intestine in BMMSCs-treated rats, most prominent in the BMMSCs-SCF co-treatment group. The mucosal layer and the crypt layer of the small intestine were thicker in BMMSCs-treated rats, more evident in the BMMSCs-SCF co-treatment group.BMMSCs and SCF participate in but may play a synergistic role in mucosal cell regeneration following experimentally induced intestinal injury. Bone marrow stem cell therapy and SCF administration may be of therapeutic value in IBD.
    Dokumententyp:
    Referenz
    Produkbestellnummer:
    MAB424R
    Produktbezeichnung:
    Anti-PCNA Antibody, clone PC10

  • Neural stem cells transplanted into intact brains as neurospheres form solid grafts composed of neurons, astrocytes and oligodendrocyte precursors. 15744380

    Neural stem cells (NSCs) are tissue-specific stem cells with self-renewal potential that can give rise to neurons and glia in vivo and in vitro. The aim of this study was to transplant NSCs as whole neurospheres into intact brain and assess the fate and phenotype of their progeny generated in vivo. We isolated NSCs from E14 foetal rat forebrains and cultured them in basic fibroblast and epidermal growth factor-supplemented serum-free medium in the form of neurospheres in vitro. Neurospheres were transplanted into the intact brains of 2 Wistar rats and after a period of 3 weeks, grafted brains were examined immunohistochemically. Neurospheres formed solid grafts that were found in the lateral ventricle and in the velum interpositum under the hippocampus. The majority of cells in the transplanted tissue were identified as beta-III-tubulin(+), NeuN(+), PanNF(+) and synaptophysin(+) neurons and were accumulated throughout the graft centre. GFAP(+) astrocytes were scattered throughout the entire graft and astrocyte processes delimited the outer and perivascular surfaces. A great number of NG2(+) oligodendrocyte precursors was detected. Nestin(+) endothelial cells were found to line capillaries growing in the transplant. These data indicate that nestin(+) NSCs prevailing in neurospheres differentiate following transplantation into nestin(-) neuronal and glial cells which confirms the multipotency of NSCs. Three weeks posttransplantation neuronal and astrocyte cells reached terminal differentiation (formation of synaptic vesicles and superficial and perivascular limiting membranes) while elements of oligodendroglial cell lineage remained immature. Grafting stem cells as non-dissociated neurospheres provide cells with favourable conditions which facilitate cell survival, proliferation and differentiation. However, in the intact brain, grafted neurosphere cells were not found to integrate with the brain parenchyma and formed a compact structure demarcated from its surroundings.
    Dokumententyp:
    Referenz
    Produkbestellnummer:
    Mehrere
    Produktbezeichnung:
    Mehrere

  • 8p12 stem cell myeloproliferative disorder: the FOP-fibroblast growth factor receptor 1 fusion protein of the t(6;8) translocation induces cell survival mediated by mitog ... 11689702

    The FOP-fibroblast growth factor receptor 1 (FGFR1) fusion protein is expressed as a consequence of a t(6;8) (q27;p12) translocation associated with a stem cell myeloproliferative disorder with lymphoma, myeloid hyperplasia and eosinophilia. In the present report, we show that the fusion of the leucine-rich N-terminal region of FOP to the catalytic domain of FGFR1 results in conversion of murine hematopoietic cell line Ba/F3 to factor-independent cell survival via an antiapoptotic effect. This survival effect is dependent upon the constitutive tyrosine phosphorylation of FOP-FGFR1. Phosphorylation of STAT1 and of STAT3, but not STAT5, is observed in cells expressing FOP-FGFR1. The survival function of FOP-FGFR1 is abrogated by mutation of the phospholipase C gamma binding site. Mitogen-activated protein kinase (MAPK) is also activated in FOP-FGFR1-expressing cells and confers cytokine-independent survival to hematopoietic cells. These results demonstrate that FOP-FGFR1 is capable of protecting cells from apoptosis by using the same effectors as the wild-type FGFR1. Furthermore, we show that FOP-FGFR1 phosphorylates phosphatidylinositol 3 (PI3)-kinase and AKT and that specific inhibitors of PI3-kinase impair its ability to promote cell survival. In addition, FOP-FGFR1-expressing cells show constitutive phosphorylation of the positive regulator of translation p70S6 kinase; this phosphorylation is inhibited by PI3-kinase and mTOR (mammalian target of rapamycin) inhibitors. These results indicate that translation control is important to mediate the cell survival effect induced by FOP-FGFR1. Finally, FOP-FGFR1 protects cells from apoptosis by survival signals including BCL2 overexpression and inactivation of caspase-9 activity. Elucidation of signaling events downstream of FOP-FGFR1 constitutive activation provides insight into the mechanism of leukemogenesis mediated by this oncogenic fusion protein.
    Dokumententyp:
    Referenz
    Produkbestellnummer:
    06-195

  • Neural stem cells confer unique pinwheel architecture to the ventricular surface in neurogenic regions of the adult brain. 18786414

    Neural stem cells (NSCs, B1 cells) are retained in the walls of the adult lateral ventricles but, unlike embryonic NSCs, are displaced from the ventricular zone (VZ) into the subventricular zone (SVZ) by ependymal cells. Apical and basal compartments, which in embryonic NSCs play essential roles in self-renewal and differentiation, are not evident in adult NSCs. Here we show that SVZ B1 cells in adult mice extend a minute apical ending to directly contact the ventricle and a long basal process ending on blood vessels. A closer look at the ventricular surface reveals a striking pinwheel organization specific to regions of adult neurogenesis. The pinwheel's core contains the apical endings of B1 cells and in its periphery two types of ependymal cells: multiciliated (E1) and a type (E2) characterized by only two cilia and extraordinarily complex basal bodies. These results reveal that adult NSCs retain fundamental epithelial properties, including apical and basal compartmentalization, significantly reshaping our understanding of this adult neurogenic niche.
    Dokumententyp:
    Referenz
    Produkbestellnummer:
    Mehrere
    Produktbezeichnung:
    Mehrere

  • Stem cell apoptosis in HIV-1 alopecia. 17026518

    BACKGROUND: Diffuse alopecia occurs in almost 7% of HIV-1-infected patients. Telogen effluvium is the main pathogenic mechanism involved. Apoptotic keratinocytes in the outer root sheath at bulge level was described as the most characteristic histopathologic finding of this kind of hair loss. METHODS: A case-control study was conducted to investigate the occurrence of apoptosis of follicular stem cells at the bulge in diffuse alopecia of HIV-1 infection. We applied a double-staining procedure to transverse scalp sections from 15 HIV-1-infected patients and 12 controls, with the monoclonal antibody anticytokeratin 19 as stem cell marker and TUNEL technique to identify apoptosis. RESULTS: Eighty percent of cases and 25% of controls presented at least one double-stained follicle. The proportion of positive follicles per section was 48% (+/-7%) for cases and 26% (+/-13%) for controls. CONCLUSION: Our study demonstrated that diffuse alopecia related to HIV-1 infection represents a hair cycle disturbance and that part of the follicular stem cell population become apoptotic in a higher proportion than normal subjects. We found no cytotoxic folliculitis. Owing to its cell-cycle interaction and caspase-induction capacities, we propose HIV-1 viral protein R as a possible follicular stem cell apoptosis inductor.
    Dokumententyp:
    Referenz
    Produkbestellnummer:
    S7101
    Produktbezeichnung:
    ApopTag® Plus Peroxidase In Situ Apoptosis Kit

  • Neural stem cell-like gene expression in a mouse ependymoma cell line transformed by human BK polyomavirus. 21073635

    Ependymomas often show characteristics similar to those of neural stem cells in vivo and in vitro. However, few ependymoma cell lines that exhibit neural stem cell-like properties have been reported. In this study, we have characterized a novel cell line, designated Vn19, established from ependymoma that arose in mice inoculated intracerebrally with human BK polyomavirus. Transplanted Vn19 cells in nude mice ubiquitously expressed viral large T antigen in the nucleus and coexpressed neuronal and glial marker proteins in vivo. Remarkably, individual Vn19 cells in dispersed cultures simultaneously expressed marker proteins of neural stem cells (nestin, Bmi1, CD133), neurons (?III tubulin, neurofilament-M) and glial cells (glial fibrillary acidic protein, A2B5, S100?, O4). Ubiquitous and homogenous expression of these multilineage marker proteins was also observed in cloned Vn19 cells. The Vn19 cells formed neurosphere-like aggregates when cultured in the presence of growth factors. Quantitative RT-PCR analysis revealed that expression of mRNA for nestin, neurofilament-H and glial fibrillary acidic protein significantly increased in Vn19 cells cultured under growth factor-deprived conditions. Among MAGE (melanoma antigen) family genes, MAGE-A (A1-8), MAGE-B (B1-3), MAGE-D1, MAGE-E1, MAGE-G1 (necdin-like 2) and MAGE-H1 were expressed in the Vn19 cells, in which neither necdin nor MAGEL2 was detectable. These results suggest that this murine ependymoma cell line recapitulates the gene expression profile in ependymal cells undergoing malignant transformation.
    Dokumententyp:
    Referenz
    Produkbestellnummer:
    MAB345
    Produktbezeichnung:
    Anti-O4 Antibody, clone 81

  • Neural stem cells reduce hippocampal tau and reelin accumulation in aged Ts65Dn Down syndrome mice. 20875225

    Tau accumulation, in the form of neurofibrillary tangles (NFT), is an early neuropathological characteristic of Alzheimer's disease (AD) and early onset AD frequently seen in Down syndrome (DS). We investigated the presence of tau accumulation in the brains of aging DS mice using the Ts65Dn mouse model. All aged mice appeared to have substantial clusters of extracellular granules that were positive for tau and reelin, but not for amyloid-? or APP. These clusters were found primarily in CA1 of the hippocampus. In addition, the aged trisomic DS mice had a significantly greater accumulation of extracellular tau/reelin granular deposits compared to disomic littermates. These granules were similar to those described by others who also found extracellular proteinous granules in the brains of non-DS mice engineered to model aging and/or AD. When neural stem cells (NSC) were implanted unilaterally into the hippocampus of the Ts65Dn mice, the tau/reelin-positive granules were significantly reduced in both trisomic and disomic mice. Our findings indicate that changes in tau/reelin-positive granules could be used as an index for neuropathological assessment in aging DS and AD. Furthermore, changes in granule density could be used to test the efficacy of novel treatments, such as NSC implantation. Lastly, it is speculated that the unique abilities of NSC to migrate and express growth factors might be a contributing factor to reducing tau/reelin accumulation in aging DS and AD.
    Dokumententyp:
    Referenz
    Produkbestellnummer:
    MAB360
    Produktbezeichnung:
    Anti-Glial Fibrillary Acidic Protein Antibody, clone GA5