Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: EC:2.7.7.49 (reverse transcriptase)
 31,746 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Recent evidence suggests that cells from bone marrow can acquire neuroectodermal phenotypes in cell culture or after transplantation in animal models and in the human brain. However, isolation of the bone marrow cell subpopulation with neuronal differentiation potential remains a challenge. To isolate and expand neural progenitors from whole murine bone marrow, bone marrow was obtained from hind limb bone of C57BL6 mice and plated in culture with neuronal medium with basic fibroblast growth factor and epidermal growth factor. After 5-7 days in culture, cellular spheres similar to brain neurospheres appeared either floating or attached to culture dishes. These spheres were collected, dissociated, and expanded. The bone marrow-derived spheres were positive for nestin as assessed by immunocytochemistry and by reverse transcriptase polymerase chain reaction. Thy-1- and Sca-1-positive bone marrow cells selected by magnetic cell sorting resulted in a higher yield of nestin-positive spheres. After exposure to neuronal differentiative medium retinoic acid with and without Sonic hedgehog, cells positive for neuronal markers tubulin III (TuJ-1) and neurofilament (NF) were detected. The mRNA profile of these cells included the expression of TuJ-1, neuronal-specific enolase (NSE), and NF-light chain. To evaluate the in vivo behavior of these cells, spheres derived from bone marrow-derived cells of transgenic green fluorescent protein (GFP) mice were transplanted into newborn mouse brain. Two months later, the mouse neural cortex contained a minor proportion of GFP(+) cells co-expressing neuronal markers (TuJ-1, NF, MAP-2, NeuN). Although cell fusion phenomena with the host cells could not be ruled out, bone marrow-derived neurosphere transplantation could be a strategy for cellular mediated gene therapy.
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PMID:Neuronal differentiation of murine bone marrow Thy-1- and Sca-1-positive cells. 1497 81

The MHB-2 cell line, established from a mouse hepatoblastoma (HB), was subjected to the reverse transcriptase-polymerase chain reaction (RT-PCR) for evaluation of gene expression related to cell differentiation. RNAs for c-kit, CD34, thy-1, albumin, cytokeratin (CK) 8, 18 and 19 could be detected, but expression of alpha-fetoprotein, glucose-6-phosphatase, tyrosine aminotransferase and CK7 was not observed. MHB-2 cells were positive for CK8/18 but negative for c-kit, CD34, thy-1 and albumin on protein level. Immunohistochemical staining of the HB in vivo revealed diffusely expressed c-kit. Thy-1-positive HB cells were sparsely observed, but the tumor was negative for CD34 and rarely positive for CK8/18. By in situ hybridization, the HB was positive for CK18 but negative for CK19. Slight expression of albumin, but the lack of immature hepatocytic marker suggested some heterogeneous hepatocyte or an undifferentiated cell from other origin. Furthermore, positive expression of CK19 as well as CK8 and CK18 in culture strongly suggested the differentiation into a biliary lineage or the bidirectional state. In conclusion, the present study indicated the mouse HB to have de-differentiated, bipotent, or biliary-like cell characteristics, and considering the histological difference between HB and biliary tumors, it suggests the mouse HB cells are closely like some sort of hepatic undifferentiated cells.
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PMID:Evaluation of gene expression related to hepatic cell maturation and differentiation in a chemically induced mouse hepatoblastoma cell line. 1763 80

Thy-1, a marker of hematopoietic stem cells, has been reported to be expressed by oval cells proliferating during stem cell-mediated regeneration in rat liver, suggesting a relationship between the two cell populations. Consequently, Thy-1 has become an accepted cell surface marker to sort hepatic oval cells. In the present study we used the well-characterized 2-acetylaminfluorene/partial hepatectomy model to induce transit-amplification of hepatic oval cells in the regenerating liver and characterized Thy-1 expression using Northern hybridization, quantitative reverse transcriptase-polymerase chain reaction analysis, immunofluorescence confocal microscopy, and immunoelectronmicroscopy. We found that Thy-1 expression was induced during transit-amplification of the oval cell population, but Thy-1 mRNA was not present in the alpha-fetoprotein-expressing oval cells. Thy-1 protein was consistently present outside the basement membrane surrounding the oval cells. It overlapped frequently with smooth muscle actin staining. A similar cellular localization of the Thy-1 protein was found on human liver specimens with ductular reactions obtained from patients with fulminant liver failure. Furthermore, Thy-1 was expressed by myofibroblasts in experimental liver fibrosis models without oval cell proliferation. We conclude that Thy-1 is not a marker of oval cells but is present on a subpopulation of myofibroblasts/stellate cells.
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PMID:Thy-1 is expressed in hepatic myofibroblasts and not oval cells in stem cell-mediated liver regeneration. 1788 67

The myelodysplastic syndromes (MDS) include a diverse groups of clonal and potentially malignant bone marrow disorders. Evidences exist that microenvironment cells from MDS marrow show functional abnormalities, which may be relevant to the incidence of such a disease. Mesenchymal stem cells (MSCs) are a very important component of hematopoietic microenvironment. This study was supposed to investigate the biological characteristics and functions of MSC derived from patients with MDS in low-risk. MSCs from bone marrow samples of 11 low-risk MDS patients were isolated, cultured and expanded. Morphology, immunophenotype and osteoblasts differentiation were analyzed. Their capacity of proliferation and hematopoietic supporting in vitro were measured. A real-time quantitative reverse transcriptase polymerase chain reaction method (RQ RT-PCR) was used for detecting the expression levels of relative cytokines and chemokines in MSC. MSCs from healthy donors were used as controls. The results showed that the culture-expanded cells from MDS patients displayed a typical fibroblast-like morphology. Cells were positive for SH2 (CD105), SH3 (CD73), Thy-1 (CD90), while negative for CD34 and CD45. After induction, these cells could differentiate into osteoblasts. The proliferative ability of MSCs in MDS patients were not different from those of MSC isolated from normal bone marrow (p > 0.05), however, their capacity of hematopoietic supporting in vitro were significantly weaker (p < 0.05). RQ RT-PCR detection indicated that the SDF-1 gene expression level in MSCs of low-risk MDS patients was significantly higher than that in MSC derived from healthy donors (p < 0.01). It is concluded that the abnormal function of MSC influences the regulation of hemotopoiesis in the bone marrow microenvironment of MDS patients. It is worthy to further investigate the new clue in etiological mechanism and therapeutic strategies for MDS.
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PMID:In vitro study of biological characteristics of mesenchymal stem cells in patients with low-risk myelodysplastic syndrome. 1871 67


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