RESUMEN
To construct a lentiviral shRNA vector targeting human protein phosphatase 1D magnesium-dependent (PPM1D) gene and detect its effectiveness of gene silencing in human gliomas,specific siRNA targets with short hairpin frame were designed and synthesized.DNA oligo was cloned into the pFU-GW-iRNA lentiviral expression vector,and then PCR and sequencing analyses were conducted to verify the constructs.After the verified plasmids were transfected into 293T cells,the lentivirus was produced and the titer of virus was determined.Real-time quantitative PCR and Western blot were performed to detect the PPM1D expression level in the infected glioma cells.PCR and Western blot analyses revealed the optimal interfering target,and the virus with a titer of 6×108 TU/mL was successfully packaged.The PPM1D expression in human glioma cells was knocked down at both mRNA and protein levels by virus infection.The expression of PPM1D mRNA and protein was decreased by 76.3％ and 87.0％ respectively as compared with control group.The multiple functions of human glioma cells after PPM1D RNA interference were detected by flow cytometry and cell counting kit-8 (CCK-8).Efficient down-regulation of PPM1D resulted in significantly increased cell apoptosis and reduced cell proliferation and invasion potential in U87-MG cells.We have successfully constructed the lentiviral shRNA expression vector capable of stable PPM1D gene silencing at both mRNA and protein levels in glioma cells.And our data gave evidence that the reduced cell growth observed after PPM1D silencing in glioma cells was at least partly due to increased apoptotic cell death.
RESUMEN
The changes in the tau protein phosphorylation and expression of bcl-2,and bax in rat parietal cortex neurons after focal cerebral ischemia-reperfusion(I/R)were explored,and the relationship between the tau protein phosphorylation and the expression of bax or apoptosis was clarified in order to elucidate the relationship between cerebral infarction and Alzheimer's disease.The rat focal cerebral I/R model was induced by occlusion of the right middle cerebral artery using the intraluminal suture method.The level of tau protein phosphorylation at Ser396,Ser404,Tyr231,Ser199/202 sites and the expression of bcl-2,bax and total tau 5 in rat parietal cortex during focal cerebral ischemia/reperfusion were detected by Western blot.The relationship between the tau protein phosphorylation and the expression of bax,or apoptosis was examined by TUNEL method and double-labeling immunofluorenscence method.The results showed that the level of tau hyperphosphorylation at Ser199/202,Ser396,Ser404,Tyr231 sites and the expression levels of bcl-2,and bax were significantly higher in I/R group than in the sham group,bat the ratio of bcl-2/bax was decreased.Neuronal apoptosis,bax expression and the tau protein hyperphosphorylation were co-localized.It is suggested that Alzheimer's disease-like pathological changes occur after cerebral I/R.The highly abnormal phosphorylation of tau protein plays a key role in cerebral I/R-induced apoptosis.The cerebral infarction may contribute to Alzheimer's disease occurrence and development.
RESUMEN
This study established superparamagnetic iron oxide (SPIO)-labeled nerve growth factor-β (NGF-β) gene-modified spinal cord-derived neural stem cells (NSCs).The E14 rat embryonic spinal cord-derived NSCs were isolated and cultured.The cells of the third passage were transfected with plasmid pcDNA3-hNGFβ by using FuGENE HD transfection reagent.The expression of NGF-β was measured by immunocytochemistry and Western blotting.The positive clones were selected,allowed to proliferate and then labeled with SPIO,which was mediated by FuGENE HD transfection reagent.Prussian blue staining and transmission electron microscopy (TEM) were used to identify the SPIO particles in the cells.The distinctive markers for stem cells (nestin),neuron (β-Ⅲ-tubulin),oligodendrocyte (CNPase) and astrocyte (GFAP) were employed to evaluate the differentiation ability of the labeled cells.The immunocytochemistry and western blotting showed that NGF-β was expressed in spinal cord-derived NSCs.Prussian blue staining indicated that numerous blue-stained particles appeared in the cytoplasma of the labeled cells.TEM showed that SPIO particles were found in vacuolar structures of different sizes and the cytoplasma.The immunocytochemistry demonstrated that the labeled cells were nestin-positive.After differentiation,the cells expressed β-Ⅲ-tubulin,CNPase and GFAE It was concluded that the SPIO-labeled NGF-β gene-modified spinal cord-derived NSC were successfully established,which are multipotent and capable of self-renewal.
RESUMEN
Summary: The eukaryotic expression vector containing full-length cDNA sequence of rate nerve growth factor (NGF) β subunit was constructed and its effects on proliferation and differentiation of neural stem cells were observed. By using PCR, full-length cDNA sequence of NGF β subunit in rats was cloned and ligated into the eukaryotic expression vector pEGFP-N1-NGE The recombinant plasmid pEGFP-N1-NGF was transfected into the mesencephal neural stem cells of embryonic rats by Lipofectamin and transiently expressed. MTT method was used to determine the effects of NGF on proliferation of neural stem cells, and under phase-contrast microscopy, the effects of NGF on growth of nervous processes following differentiation of neural stem cells were observed. Sequence analysis indicated that the cloned full-length cDNA sequence of rat NGF β was identical to that of published sequence encoding NGF in gene GeneBank. The transfection of recombinant plasmid pEGFP-N1-NGF into mesencephal neural stem cells of embryonic rats could obviously promote proliferation of neural stem cells and faciliate the growth of neural stem cells-derived nerve cells. It was suggested that neural stem cells could be used as a vehicle of gene transfer, and the expression of NGF β subunit in the neural stem cells could promote the growth of nerve cells derived from neural stem cells.