目的探讨干扰素(IFN)-γ对内皮细胞上Toll样受体4(toll like receptor-4,TLR4)和髓样分化蛋白-2(myeloid differentiation protein-2,MD-2)表达的影响以及在内毒素(LPS)对内皮细胞激活中的影响。方法分离、培养人脐静脉内皮细胞,逆转录...目的探讨干扰素(IFN)-γ对内皮细胞上Toll样受体4(toll like receptor-4,TLR4)和髓样分化蛋白-2(myeloid differentiation protein-2,MD-2)表达的影响以及在内毒素(LPS)对内皮细胞激活中的影响。方法分离、培养人脐静脉内皮细胞,逆转录-聚合酶链反应(RT-PCR)和Western blot方法检测IFN-γ刺激后内皮细胞TLR4、MD-2表达的变化;TransAM法检测核因子(NF)-кB活性,酶联免疫吸附分析(ELISA)法检测IL-8水平。结果IFN-γ能明显上调内皮细胞TLR4、MD-2的表达,并且TLR4、MD-2表达的增加与IFN-γ呈一定的剂量依赖关系;IFN-γ对内皮细胞NF-кB的活性无明显影响,但用IFN-γ孵育后的内皮细胞却对LPS的反应明显增强,NF-кB活性明显增高,白细胞介素(IL)-8分泌明显增加,且与IFN-γ呈剂量依赖关系。结论IFN-γ通过上调内皮细胞上的LPS受体-TLR4、MD-2而促进LPS对内皮细胞的活化。展开更多
The phosphatidylinositol 3 kinase （PI3K）/protein kinase B （AKT） signaling pathway is considered important for cell survival and has been shown to mediate various anti-apoptotic biological effects. This study explo...The phosphatidylinositol 3 kinase （PI3K）/protein kinase B （AKT） signaling pathway is considered important for cell survival and has been shown to mediate various anti-apoptotic biological effects. This study explored the role of the Toll-like receptor 4 （TLR4）-mediated PI3K/AKT-glycogen syn-thase kinase 3β （GSK-3β） signaling pathways in lipopolysaccharide-induced apoptosis in a primary culture of hippocampal neurons. Results demonstrated that the apoptotic ratio of hippocampal neurons stimulated by lipopolysaccharide was significantly higher compared with the control group. Both the expression of P-AKTser473 and P-GSK-3βSserg in hippocampal neurons stimulated by lipopolysaccharide decreased compared with the control, while the level of active Caspase-3 and the ratio of Bax/Bcl-2 were significantly increased. The level of active Caspase-3 and the ratio of Bax/Bcl-2 in hippocampal neurons treated with TLR4 antibody or the GSK-3β inhibitor, LiCl, de-creased before intervention with lipopolysaccharide, but increased after treatment with the AKT in-hibitor, LY294002. These findings suggest that the TLR4-PI3K/AKT-GSKβ signaling pathway may be involved in lipopolysaccharide-induced apoptosis of hippocampal neurons.展开更多
基金supported by the Priority Academic Program Development of Jiangsu Higher Education Institutions and Graduate Scientific and Technological Innovation Projects of Nantong University,No.YKC12020Applied Research and Technology Plan of Nantong City,No.BK2013007
文摘The phosphatidylinositol 3 kinase （PI3K）/protein kinase B （AKT） signaling pathway is considered important for cell survival and has been shown to mediate various anti-apoptotic biological effects. This study explored the role of the Toll-like receptor 4 （TLR4）-mediated PI3K/AKT-glycogen syn-thase kinase 3β （GSK-3β） signaling pathways in lipopolysaccharide-induced apoptosis in a primary culture of hippocampal neurons. Results demonstrated that the apoptotic ratio of hippocampal neurons stimulated by lipopolysaccharide was significantly higher compared with the control group. Both the expression of P-AKTser473 and P-GSK-3βSserg in hippocampal neurons stimulated by lipopolysaccharide decreased compared with the control, while the level of active Caspase-3 and the ratio of Bax/Bcl-2 were significantly increased. The level of active Caspase-3 and the ratio of Bax/Bcl-2 in hippocampal neurons treated with TLR4 antibody or the GSK-3β inhibitor, LiCl, de-creased before intervention with lipopolysaccharide, but increased after treatment with the AKT in-hibitor, LY294002. These findings suggest that the TLR4-PI3K/AKT-GSKβ signaling pathway may be involved in lipopolysaccharide-induced apoptosis of hippocampal neurons.
