ABSTRACT
Hippocampal neural stem/progenitor cells [hipp-NS/PCs] of the adult mammalian brain are important sources of neuronal and gial cell production. In this study, the main goal is to investigate the plasticity of these cells in neuronal/astroglial differentiations. To this end, the differentiation of the hipp-NS/PCs isolated from 3-month-old Wistar rats was investigated in response to the embryonic cerebrospinal fluid [E-CSF] including E13.5, E17-CSF and the adult cerebrospinal fluid [A-CSF], all extracted from rats. CSF samples were selected based on their effects on cell behavioral parameters. Primary cell culture was performed in the presence of either normal or high levels of KCL in a culture medium. High levels of KCL cause cell depolarization, and thus the activation of quiescent NSCs. Results from immunocytochemistry [ICC] and semi-quantitative RT-PCR [sRT-PCR] techniques showed that in ECSF-treated groups, neuronal differentiation increased [E17>E13.5]. In contrast, A-CSF decreased and increased neuronal and astroglial differentiations, respectively. Cell survivability and/or proliferation [S/P], evaluated by an MTT assay, increased by E13.5 CSF, but decreased by both E17 CSF and A-CSF. Based on the results, it is finally concluded that adult rat hippocampal proliferative cells are not restricted progenitors but rather show high plasticity in neuronal/astroglial differentiation according to the effects of CSF samples. In addition, using high concentrations of KCL in the primary cell culture led to an increase in the number of NSCs, which in turn resulted in the increase in neuronal or astroglial differentiations after CSF treatment
Subject(s)
Animals, Laboratory , Stem Cells , Hippocampus , Astrocytes , Neurons , Cerebrospinal Fluid , Rats, WistarABSTRACT
Type I diabetes mellitus is caused by autoimmune destruction of the insulin-producing beta-cells. A new potential method for curing the disease is transplantation of differentiated insulin- secreting cells from human embryonic stem cells. Human embryonic stem cell lines [Royan H1] were used to produce embryoid bodies. Differentiation carried out by growth factor-mediated selection of nestin positive cells. In final stage, these cells were expanded in the presence of bFGF, followed by addition of nicotinamide to promote differentiation of insulin- secreting cells. Cells were assayed by immunocytochemistry, RT-PCR, insulin secreting assay with Radio-immuno assay kit and Transmission Electron Microscopy. The cells were transplanted into immunosuppressed mice. Analysis of differentiation cells immunocytochemistry showed that these cells were insulin, glucagon, somatostatin and pancreatic polypeptide positive. RT-PCR reaction demonstrated the expression of pancreatic endocrine genes. Differentiation cells secreted insulin in response to glucose, but no significance difference in insulin concentration was observed with an increase in concentration of glucose. The implanted cells were vascularized and remained immunoreactive with insulin and glucagon. Transmission Electron microscopy of differentiate cells showed Golgi complexes, rough endoplasmic reticulum and a few granules but no true beta granules. The data showed that human embryonic stem cells can produce insulin secreting cells. However, more studies are needed to generate true beta cells
ABSTRACT
The tumor suppressor p53 protein can induce apoptosis in some cellular contexts. Among the apoptosis-inducing genes, p53 has received the most attention for cancer gene therapy. In this study, the role of Dendrosome and Lipofectin mediated normal cDNA of TP53 into MOLT-4, CCRF-CEM[T-lymphoma] and K562 cell lines was assessed. At first, CCRF-CEM, MOLT-4 and K562 [erythroleukemic] cell lines were transfected by Dendrosome and Lipofectin separately. Then, viability study was carried out by Trypan blue exclusion. The rate of apoptosis and necrosis in transfected cell lines was evaluated by Flow Cytometry. Trypan blue exclusion assay in K562 and CCRF-CEM revealed 55.8% and 17.97% viability reduction in the Dend+p53 in comparison to Dend+pcDNA3 [control], respectively. Flow Cytometry studies confirmed a significant enhancement of apoptosis and necrosis in TP53 transrected K562 and CCRF-CEM cells. Flow Cytometry and viability studies on transfected MOLT-4 cells showed no significant changes. The results showed that expression of normal cDNA of TP53 in K562 and CCRF-CEM cell lines could induce apoptosis in these cell lines with different levels. Transfection of MOLT-4 cell Line by Dend+p53 and Lipo+53 could not result in apoptosis