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1.
AIM: To explore the effects of ephrin-A3 expression on the proliferation of astrocytes induced by lipopolysaccharide (LPS).METHODS: Astrocytes from cerebral cortex of newborn rats were cultured and purified.The cells were exposed to LPS at the concentration of 10 mg/L and divided into 6 groups at random: control group (without LPS) and the groups of exposure to LPS for 30 min, 6 h, 24 h, 48 h and 72 h.The morphological changes of the astrocytes were observed under inverted phase-contrast microscope.The survival rate and apoptotic rate of astrocytes were measured by MTT method and AO/EB staining,respectively.The expression of ephrin-A3 and glial fibrillary acidic protein (GFAP) was measured by fluorescein staining with CY3.The changes of the inflammatory factors TNF-α and IL-6 in the culture supernatant were detected by ELISA.RESULTS: Compared with control group, the survival rates were notably increased, the apoptotic rates were notably decreased, the expression of ephrin-A3 and GFAP was significantly up-regulated and the inflammatory cytokines were significantly increased in the cells exposed to LPS at the concentration of 10 mg/L for 24 h, 48 h and 72 h.CONCLUSION: LPS promotes the proliferation of astrocytes.The expression of ephrin-A3 increases during the proliferation of astrocytes induced by LPS in rats.The mechanism may be related to inflammatory stimulation by cytokines.  相似文献   

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AIM: The present study was designed to examine the changes in glial fibrillary acidic protein (GFAP) expression during cerebral ischemia and the effects of ginkgolide B on GFAP expression. METHODS: The focal thrombotic cerebral ischemia was formed by photochemistry-induced in tree shrews. GFAP stained by ABC immunohistochemistry and absorbance were measured with image analyze system. RESULTS: GFAP expression in astrocytes increased significantly (P<0.01) at 24 h and kept in higher level at 72 h (P<0.01) within penumbra after focal cerebral ischemia. GFAP expression declined when the animals were given GB at 6 h after thrombotic cerebral ischemia. CONCLUSIONS: Neuronal necrosis resulted in GFAP expression in astrocytes after local cerebral ischemia and GB protected neurons by antagonizing PAF receptor and inhibiting GFAP expression.  相似文献   

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AIM: To investigate the inhibitory effect of saikosaponin a (SSa) on pentylenetetrazole (PTZ)-induced activation of hippocampal astrocytes in mice. METHODS: Hippocampal astrocytes were isolated and cultured. The cells were randomly divided into control group, PTZ group, PTZ+0.625 mg/L SSa group and PTZ+1.25 mg/L SSa group. The cells were identified by detection of glial fibrillary acidic protein (GFAP). The cell viability was measured by MTT assay. The cell cycle was analyzed by flow cytometry. The expression of GFAP and connexin 43 (Cx43) was mea-sured by ELISA. The level of apoptosis was determined by flow cytometry and Hoechst 33258 staining. RESULTS: The primary hippocampal astrocytes grew by adherent culture, and the processes of the astrocytes were obvious. Immunofluorescence showed positive GFAP expression in the astrocytes. Compared with control group, the viability of the cells and the percentage of the cells in G2/M phase in PTZ group were significantly increased (P<0.05), and the expression of GFAP and Cx43 was also markedly increased (P<0.05). Compared with PTZ group, the viability of the cells and the percentage of the cells in G2/M phase were obviously decreased in PTZ+0.625 mg/L SSa group and PTZ+1.25 mg/L SSa group, and the expression of GFAP and Cx43 was also reduced, whereas the percentage of apoptotic cells was significantly increased (P<0.05).CONCLUSION: SSa significantly suppresses PTZ-induced activation of hippocampal astrocytes, inhibits the cell proliferation and induced apoptosis.  相似文献   

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AIM: The influence of MCMV infection on differentiation and differentiation gene expression in neural stem cells(NSCs) in vitro were investigated for studying the mechanisms of brain abnormalities caused by congenital cytomegalovirus infection.METHODS: NSCs were separated from fetal BALB/C mouse, and cultured and identified in vitro. The differentiation potency of NSCs was observed by immunofluorescence. The NSCs infected by MCMV at dosage of MOI(multiplicity of infection) equaled to 5, 1 and 0.1,respectively, were cultured in differentiation medium. The morphological changes of infected cells were observed under inverted microscope. The ratios of NSCs and its differentiated cells were detected by flow cytometry. The expressions of nestin, GFAP and NSE, markers of NSCs and its differentiated cells, were studied by immunofluorescence(MOI=1). The expression of early antigen(EA) of MCMV was detected to observe the infection process. Real-time RT-PCR method was employed to measure the expression levels of the key genes Neurog2, Myc and Ccnd1 in Wnt signal pathway of NSCs at early stage of differentiation culture.RESULTS: NSCs isolated from embryonic mouse brains proliferated to form neurospheres, strongly expressed nestin and differentiated into NF-200 positive neurons or GFAP positive astrocytes. The infected NSCs did not adhere to the wall and appeared differentiation growths, but showed swollen gradually after differentiation culture. The nestin expression in the infected cells downregulated slowly and was higher than that in control groups(P<0.05). The GFAP and NSE expressions of the infected cells were lower than those in control groups(P<0.05). The early antigen(EA) of MCMV was always detected in the cells in infected groups. The ratios of nestin positive cells in infected groups were higher than those in control groups, but the ratios of GFAP and NSE positive cells of former were lower than that of the latter from 3rd to 9th d after differentiation culture(P<0.05). The levels of Neurog2 mRNA and Myc mRNA in infected groups were markedly lower than those in normal control groups on 1st d and from 1st to 4th d after differentiation culture, respectively(P<0.05). The levels of Ccnd1 mRNA of infected groups were obviously lower than those in normal control groups from 12th h to 1st d(P<0.05). These changes in infected groups became more obvious as MCMV MOI increased.CONCLUSION: MCMV significantly inhibits differentiation of NSCs to neurons and astrocytes, and leads to the decrease in differentiated cells. MCMV inhibits or interferes with the gene expression of Neurog2, Myc and Ccnd1 in Wnt signal pathway of NSCs. The effect that MCMV inhibits the expressions of differentiation and the differentiation genes in NSCs shows dose-dependent with MCMV MOI. The inhibitory effect of MCMV on the differentiation of NSCs might be induced by interfering with the expression of differentiation gene in NSCs, which is possibly the one of primary causes of brain development disorders induced by congenital CMV infection.  相似文献   

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AIM: To observe the protective effect of 2,3,5,4’-tetrahydroxystilbene-2-O-β-D-glucoside (TSG) on lysophosphatidylcholine (LPC)-induced vascular endothelial cell injury. METHODS: The 3rd and 4th generations of human umbilical vein endothelial cells (HUVECs) were cultured in vitro and propagated. The cells were randomly divided into 3 groups: control group, model group (LPC) and experimental group (TSG+LPC). The cells in control group were not treated with any reagent. To establish endothelial cell injury model, LPC was administered to HUVECs at concentration of 10 mg/L and incubated with the cells for 24 h. In TSG+LPC group, TSG was administered to HUVECs at concentrations of 10.0, 1.0 and 0.1 μmol/L 1 h before administration of LPC, and then the cells were incubated for 24 h. The cell viability, the content of asymmetric dimethyl arginine (ADMA) and NO, and apoptotic rate were detected. RESULTS: Compared with control group, ADMA content in the cell culture supernatants and apoptotic rate of the HUVECs in LPC group were significantly increased, while the NO content and cell viability were notably decreased. Compared with LPC group, ADMA content and apoptotic rate in TSG+LPC group was significantly decreased, while the NO content and cell viability were notably increased. CONCLUSION: TSG may protect LPC-injured vascular endothelial cells by attenuating the expression of ADMA and enhancing the production of NO, thus inhibiting apoptosis and increasing cell survival rate.  相似文献   

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AIM: To study the effects of baicalin (BC) on glial fibrillary acidic protein (GFAP) and nuclear factor-κB (NF-κB) expression and neuronal apoptosis in juvenile rat hippocampus after status convulsion (SC). METHODS: One hundred and ninety five juvenile male Sprague-Dawley rats were randomly divided into 3 groups: normal saline pretreatment group (NS group), SC group and SC with BC pretreatment group (BC group). Each of these 3 groups would be subdivided into 5 subgroups sacrificed at 4 h, 12 h, 24 h, 48 h and 72 h after SC. The rat SC model was prepared by lithium-pilocarpine chemical method. The protein expression of GFAP and NF-κB was detected by the method of immunohistochemistry. The mRNA expression of GFAP was detected by RT-PCR. The neuronal apoptosis was observed by TdT-mediated dUTP nick end labeling (TUNEL). RESULTS: Compared with NS group, the GFAP positive cells was increased in SC group (P<0.05). Compared with SC group, the expression of GFAP was significantly reduced in BC group (P<0.05). Compared with NS group, the NF-κB positive cells was increased in SC group (P<0.05). Compared with SC group, the expression of NF-κB was significantly reduced in BC group. RT-PCR showed that the expression trend of GFAP mRNA was similar to that of the protein. Compared with NS group, the TUNEL positive cells in the hippocampus CA1 area in SC group increased significantly 12 h after SC (P<0.01), and reached a peak at 48 h. After the intervention with BC, the TUNEL positive cells decreased significantly between 12~48 h after SC (P<0.05 or P<0.01), but the number of TUNEL positive cells remained significantly greater than that in NS group (P<0.05). CONCLUSION: The expression of GFAP and NF-κB in the hippocampus increased after SC in rats. Baicalin decreases the expression of GFAP and NF-κB in hippocampus of rats with pilocarpine-induced seizures, and reduces the number of neuronal apoptosis, suggesting that baicalin may protect against the brain damage caused by status convulsion.  相似文献   

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AIM: To study the nutritional role of the normal conditioned medium of astrocytes (NCMA) on the injured cerebral cortex neurons induced by cerebral hypoxia and reoxygenation in vitro. METHODS: The normal and damaged neurons induced by hypoxia and reoxygenation were cultured with normal conditioned medium of astrocytes (NCMA) after the cerebral cortical astrocytes and neurons of rats were isolated. The viability and survival rate of cultured neurons were investigated by MTT method. RESULTS: NCMA increased the viability and survival rate of cultured neurons. CONCLUSION: NCMA has nutritional and supporting roles on cultured neurons.  相似文献   

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AIM: To observe the effect of ginsenoside Rb1 on the proliferation and the expression of serotonin transporter (SERT), 5-hydroxytryptamine 1B receptor (5HT1BR) in rat pulmonary artery smooth muscle cells (PASMCs) under hypoxia condition and the relationship with Rho/Rho-kinase signal pathway.METHODS: PASMCs were isolated from the adult male SD rats and primarily cultured. The subcultured cells from the 4th generation to the 6th generation were harvested and divided into normal group, and hypoxia group, different concentrations of Rb1 incubation groups treated with 50, 100 and 200 mg/L ginsenoside Rb1 under hypoxia (HR50, HR100 and HR200 groups, respectively). The viability of the PASMCs was measured by CCK-8 assay. BrdU positive cells were determined using flow cytometry. The expression of serotonin transporter and 5HT1BR at mRNA and protein levels was detected by RT-PCR and Western blot, respectively. The PASMCs were randomly divided into normal group, hypoxia group, HR200 group and hypoxia+Y-27632 incubation group (HY group). The mRNA expression of Rho-kinase and phosphorylated myosin phosphatase target subunit 1 (p-MYPT1) protein level were investigated by RT-PCR and Western blot, respectively.RESULTS: Compared with normal group, the proliferation of PASMCs in hypoxia group was significantly increased (P<0.01). The cell viability and the expression of SERT and 5HT1BR at mRNA and protein levels in all different concentrations of Rb1 groups were obviously decreased compared with hypoxia group (P<0.05). The mRNA expression of Rho-kinase and protein level of p-MYPT1 were markedly decreased in HR200 group, and no significant difference compared with HY group was observed (P<0.01).CONCLUSION: Treatment with ginsenoside Rb1 might prevent hypoxia-induced proliferation of PASMCs and over-expression of SERT and 5HT1BR through inhibiting the Rho/Rho-kinase pathway.  相似文献   

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AIM: To study the effect of platelet-activating factor(PAF) on proliferation of cultured rat airway smooth muscle cells(ASMCs).METHODS: The cells were divided into control group and PAF group. The cells in PAF group were subdivided into four small groups by concentrations of PAF 10-6, 10-7, 10-8, 10-9 mol·L-1, MTT assay was used not only to investigate the effects of PAF on proliferation of ASMC but also to confirm the optimal concentration. Flow cytometry and immuneohistochemistry for proliferating cell nuclear antigen (PCNA) were also used to analyse its function on proliferation of ASMC.RESULTS: PAF (10-6-10-9mol·L-1) stimulated the cell proliferation and 10-7mol·L-1 PAF reached the maximal effect. The cell percentage of the ASMCs of 107 mol·L-1 PAF subgroup at G0/1 phase (68.67%) was much lower than that of control group (85.57%, P<0.01), in this subgroup, the percentage of expression of PCNA at 48 h (71.05%±1.22%) was significantly increased compared with the control group (53.27%±2.56%, P<0.05).CONCLUSION: PAF can stimulate the proliferation of cultured ASMC in a time-dependent, but not dose-dependent manner.  相似文献   

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AIM: To investigate the protective effects of sodium ferulate (SF) on apoptosis in cultured hippocampal neurons induced by sodium nitroprusside (SNP), and the effect of SF on expression of bcl-2 and bax. METHODS: The primary cultured hippocampal neurons were exposed to 50 μmol SNP, a nitric oxide-donor, for 24 h after pretreatment with different concentrations of SF (10-160 μmol/mL) for 6 h. Then neuronal viability was tested by MTT assay. Fluorescent staining with Hoechst 33258 and agarose gel electrophoresis was used to analyze apoptosis. The expressions of bcl-2, bax mRNA and protein were tested by RT-PCR and Western blotting. RESULTS: Pretreatment with SF(10-160 μmol/L) for 6 h increased the survival rate of neurons. SF prevented the neuronal nuclei from shrinkage, condensation and cleavage and blocked neuronal nuclear DNA fragmentation induced by SNP. SF also increased the expressions of bcl-2 mRNA and Bcl-2 protein and decreased the expressions of bax mRNA and Bax protein. CONCLUSION: SF prevents the cultured hippocampal neurons against SNP neurotoxicity. The mechanism of protection is related to the increase in Bcl-2 level and the decrease in Bax level. As a result, the ratio of Bcl-2/Bax is changed.  相似文献   

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AIM: To investigate the role of Oct3/4 in inducing differentiation of rat bone marrow mesenchymal stem cells (MSCs) into neurons in vitro. METHODS: Lentivirus (LV) vector containing Oct3/4 gene was constructed and transfected into rat bone marrow MSCs. The MSCs were divided into non-transfection group, transfection group (transfected with Oct3/4 -LV) and negative control group (transfected with FU-PCG-NC-LV). β-mercaptoethanol (β-ME) was used to induce differentiation of MSCs into neurons. Morphological changes and the fluorescence in transfected MSCs were observed under inverted fluorescence microscope. The expression of Oct3/4 and microtubulin-associated protein 2(MAP-2) at mRNA and protein levels was detected by RT-PCR and Western blotting. The expression of Oct3/4 and the neural cell specific markers neuron-specific enolase(NSE), MAP-2 and glial fibrillary acidic protein(GFAP) were determined by immunocytochemical method. The viability of the MSCs was analyzed by MTT assay. RESULTS: The results of PCR confirmed that the Oct3/4 -LV was successfully constructed and the virus titer was 2×1011 TU/L. The best transfection efficiency and survival rate appeared when multiply of infection(MOI) was 10 and at 48 h, and the fluorescence of MSCs was mostly displayed. The efficiency of transfection was up to 83.4%±2.2%. The shape of the MSCs was changed in transfection group, and the survival rate of the MSCs in transfection group was significant lower than that in other groups (P<0.05). MSCs were induced by β-ME to differentiate into neurons and the best efficiency of induction was observed in transfection group. The typical neuronal morphology was observed in transfection group after induction and the expression levels of NSE and MAP-2 were higher than those in other groups (P<0.05). Compared with other groups, the expression of Oct3/4 in transfection group was significantly increased (P<0.01). Furthermore, the expression of Oct3/4 was time-dependently decreased and there was significant difference between before induction and 5 h after induction (P<0.05). CONCLUSION: Oct3/4 may have an important role in regulating the differentiation of rat MSCs into neurons.  相似文献   

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AIM:To study the effects of Scutellaria barbata flavonoids (SBF) on abnormal expression of nitric oxide synthase (NOS), heat-shock protein 70 (HSP70) and apolipoprotein E (apoE) induced by Aβ 25-35 in rat astrocytes. METHODS:The third generation of cultured rat astrocytes was divided into 5 groups. The cells in 3 drug treatment groups were given SBF at dose of 17.5 mg/L, 35 mg/L and 70 mg/L for 24 h, and then the cells in model group and 3 doses of SBF groups were exposed to Aβ 25-35 at concentration of 100 μmol/L for 24 h. The expression of endothelial nitric oxide synthase (eNOS), inducible nitric oxide synthase (iNOS) and neuronal nitric oxide synthase (nNOS) in the cultured cells was assayed by immunohistochemical method. The expression of HSP70 was estimated by Western blotting and the mRNA expression of apoE was assessed by RT-PCR. RESULTS:Compared with control group, the protein level of eNOS were significantly decreased and the protein level of iNOS increased (P<0.01) in model group. The protein expression of HSP70 and mRNA expression of apoE were notably increased (P<0.01) in model group. However, these disturbances were attenuated by SBF at dose of 17.5, 35 and 70 mg/L (P<0.01). CONCLUSION:SBF has an obvious protective effect on damaged astrocytes induced by Aβ 25-35, suggesting that SBF may be helpful for the treatment of Alzheimer disease.  相似文献   

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AIM: To explore the time-dependent change of Ski protein expression in normal and activated astrocytes in rats.METHODS: The astrocytes were obtained from rat cerebral cortex and cultured in vitro. The astrocytes were treated with LPS and scratch injury for activation. Western blot analysis was used to determine glial fibrillary acidic protein (GFAP) and Ski protein levels in activated astrocytes at a series of time points. The indirect immunofluorescence staining method was performed to detect the location of Ski protein in the astrocytes.RESULTS: The protein of GFAP was naturally expressed in the astrocytes, beginning to increase after treated with LPS and scratch injury. Little protein expression of Ski in the normal astrocytes was observed. The Ski protein expression began to increase after treated with 1 mg/L LPS, peaked at 4 d (P<0.05) and then deceased, but was stills higher than that in the normal cells. The protein expression level of Ski after scratch injury was highly consistent with above mentioned. Ski was mainly observed in the nucleus of the normal cells and the cells treated with LPS for 6 d, while it was observed in the cytoplasm 2 and 4 d after treated with LPS.CONCLUSION: The protein of Ski is expressed in the astrocytes, and the expression level is increased in activated astrocytes, mainly located in the nucelus. Ski may plays an essential roles in the processes of activation and proliferation of astrocytes.  相似文献   

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AIM: To observe the effects of prostaglandin E2 receptor1 (EP1) in neuronal cell death induced by hypoxia/re-oxygenation and ischemia/reperfusion. METHODS: The cortical neurocytes of neonatal Wistar rats were cultured for 12 days and exposed to hypoxia/re-oxygenation to establish a hypoxia/re-oxygenation model. Another set of cultured primary neonatal cortical neurocytes of rats were pre-treated with 17-pt (an antagonist of EP1), then underwent hypoxia for 3 h, re-oxygenated for 21 h. MTT reagent was added 1 h before measuring the cell viability. Neuron apoptosis was determined by flow cytometry. The protein expression was examined by Western blotting. RESULTS: Compared to the control cells (only underwent hypoxia /re-oxygenation and without any pretreatment), the neurons pretreated with 17-pt and then underwent hypoxia/re-oxygenation showed significantly lower survival rate (P<0.05) and increased expression level of caspase-3 and neuron apoptosis. CONCLUSION: EP1 is involved in the pathogenesis of neuron death induced by hypoxia/ischemia and may be a new target for treating ischemic stroke.  相似文献   

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AIM: To investigate the effects of dexmedetomidine on astrocytes in rats with focal cerebral ischemia-reperfusion. METHODS: Sixty female SD rats, weighing 230~250 g, were randomly divided into sham operation group, ischemia-reperfusion group, dexmedetomidine preconditioning group 1 and dexmedetomidine preconditioning group 2. The model of middle cerebral artery occlusion (MCAO) was established by thread embolism of middle cerebral artery. In sham operation group, the carotid arteries were exposed without performing MCAO. In ischemia-reperfusion group, NS was injected intraperitoneally 30 min before focal cerebral ischemia-reperfusion. The rats in dexmedetomidine preconditioning group 1 and dexmedetomidine preconditioning group 2 received intraperitoneal injection of dexmedetomidine at doses of 20 μg/kg and 40 μg/kg, respectively. The neurological scores were studied, and the pathological changes were observed under microscope with HE staining. The expression of glial fibrillary acidic protein (GFAP) and tumor necrosis factor α (TNF-α) in astrocytes was detected by the methods of immunohistochemistry and immunoblotting 24 h after cerebral ischemia-reperfusion. RESULTS: No neurological change was observed in sham operation group. The neurological deficiency scores in ischemia-reperfusion group were markedly higher than those in dexmedetomidine preconditioning group 1 and group 2 (P<0.05). Compared with sham operation group, the expression of GFAP and TNF-α in astrocytes and the level of GFAP increased significantly 24 h after focal cerebral ischemia-reperfusion. Pretreatment with dexmedetomidine significantly attenuated the expression of GFAP and reduced the infarct size and inflammation. CONCLUSION: Dexmedetomidine has a neuroprotective effect on focal cerebral ischemia-reperfusion injury by inhibiting the astrocytes.  相似文献   

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AIM: To investigate the effects of atorvastatin on the expression of pregnancy-associated plasma protein A(PAPP-A)induced by TNF-α and IL-1β in endothelial cells. METHODS: The rat aortic endothelial cells were isolated from thoracic aortas and cultured by the tissue explant method. The cells in passage 3-4 were used in the experiment and were randomly divided into 4 groups: blank control group: the cells were treated without any intervention; atorvastatin concentration groups: the cells were incubated with atorvastatin at the concentrations of 0.1, 1 and 10 μmol/L for 24 h; atorvastatin time groups: the cells were incubated with atorvastatin at the concentration of 10 μmol/L for 6 h,12 h and 24 h; atorvastatin+inflammatory factors groups: the cells were pre-incubated with 60 μg/L TNF-α or 20 μg/L IL-1β for 1 h, then different concentrations of atorvastatin (0.1, 1.0, 10 μmol/L) were added for 6 h,12 h and 24 h. MTT reduction assay was used to observe the cell proliferation. The mRNA expression of PAPP-A was detected by RT-PCR. The protein level of PAPP-A in the supernatants of cultured cells was measured by ELISA. RESULTS: Compared with blank control group, no significant change of cell proliferation was observed after the intervention of atorvastatin and TNF-α/IL-1β for 3 h, 6 h, 12 h, 24 h and 48 h, indicating that the drugs had no toxic effects on the cells. No significant difference of PAPP-A expression between atorvastatin groups and blank control groups was found. Compared with TNF-α groups and IL-1β groups, PAPP-A expressions in atorvastatin intervention groups significantly decreased. The protein level of PAPP-A was gradually decreased with the raised concentration of atorvastatin and the prolonged time in a concentration- and time-dependent manner. CONCLUSION: Atorvastatin doesn't influence the PAPP-A expression, but inhibits the expression of PAPP-A activated by inflammatory factors in a concentration- and time-dependent manner in primary cultured rat aortic endothelial cells.  相似文献   

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