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目的探讨血管紧张素Ⅱ对大鼠胰星状细胞(PSC)核因子κB(NF-κB)信号转导通路活化的影响。方法采用电泳迁移率改变分析(electrophoretic mobility shift assay,EMSA)检测细胞NF- κB的DNA结合活性,Western印迹方法检测NF-κB抑制蛋白(IκBs)降解。单核细胞趋化蛋白-1 (MCP-1)基因和蛋白表达分别采用Northern印迹和ELISA方法检测。结果血管紧张素Ⅱ可诱导大鼠PSC内NF-κB发生双相活化,活化高峰分别出现在15 min和6 h后。NF-κB活化伴有IκBα和IκBβ联合降解。抗氧化剂吡咯烷二硫基甲酸盐(PDTC)、二碘基苯(DPI)和N-乙酰丝氨酸可明显抑制血管紧张素Ⅱ诱导的NF-κB活化,提示氧化应激反应在NF-κB活化中发挥了重要作用。NF-κB抑制剂 MG132和PDTC可显著下调血管紧张素诱导的MCP-1基因表达。结论血管紧张素Ⅱ可通过氧化应激机制活化PSC内NF-κB信号通路,诱导MCP-1表达,从而参与胰腺炎症和纤维化的发生。
Objective To investigate the effect of angiotensin Ⅱ on the activation of NF-κB signal transduction pathway in rat pancreatic stellate cells (PSC). Methods DNA binding activity of NF-κB was detected by electrophoretic mobility shift assay (EMSA). The degradation of NF-κB inhibitor (IκBs) was detected by Western blotting. Monocyte chemotactic protein-1 (MCP-1) gene and protein expression were detected by Northern blot and ELISA respectively. Results Angiotensin Ⅱ induced biphasic activation of NF-κB in PSCs of rats, with peak activation occurring at 15 min and 6 h, respectively. NF-κB activation accompanied by degradation of IκBα and IκBβ. Antioxidants pyrrolidine dithiocarbamate (PDTC), diiodo benzene (DPI) and N-acetyl-Serine could significantly inhibit the activation of NF-κB induced by angiotensin Ⅱ, suggesting that oxidative stress is involved in the activation of NF-κB Has played an important role. NF-κB inhibitors MG132 and PDTC significantly down-regulated angiotensin-induced MCP-1 gene expression. Conclusion Angiotensin Ⅱ can activate NF-κB signaling pathway in PSC through oxidative stress and induce the expression of MCP-1, which is involved in the pathogenesis of pancreatitis and fibrosis.