HSP70抑制剂PFTμ对干扰素γ诱导的iNOS表达的研究

Effects of HSP70 inhibitor on expression of iNOS induced by IFN-γ

目的观察热休克蛋白70抑制剂PFTμ对干扰素γ(IFN-γ)诱导的RAW 264.7细胞一氧化氮(NO)的生成及诱生型一氧化氮合酶(iNOS)表达的作用。方法采用IFN-γ诱导的RAW 264.7细胞株建立细胞炎症反应模型,采用Griess试剂法测定细胞NO释放量;采用Western blot法测定相应目的蛋白的表达;采用反转录聚合酶链反应(RT-PCR)分析iNOS mRNA表达的变化。建立小鼠心脏缺血/再灌注(I/R)模型,分为对照组和给药组,测定小鼠心肌梗死面积的变化。结果 PFTμ可抑制IFN-γ诱导的RAW264.7细胞NO的生成、i NOS蛋白及mRNA表达。其作用机制可能是通过部分抑制RAW264.7细胞核内的IRF-1蛋白表达。PFTμ可减少缺血/再灌注小鼠心脏梗死面积(P<0.05)。结论PFTμ可通过部分抑制细胞核内IRF-1蛋白表达而发挥抗炎症反应的作用。

Aim To research the effects of HSP70 inhibitor(PFTμ) on the expressions of i NOS induced by IFN-γ in RAW 264.7 cells.Methods The NO concentration was measured by Griess Kit.The expression of interest protein was measured by Western blot and i NOS mRNA was measured by RT-PCR.Mouse cardiac ischemia-reperfusion(I/R) model was established to set up the inflammatory response.These were divided into control and treated groups.The infarct size was monitored on myocardial I/R mice.Results We found that PFTμ significantly blocked the production of NO and the expression of i NOS protein and mRNA in RAW 264.7 cells.The mechanism may be part of the inhibition of nuclear IRF-1 protein expression.We also found that PFTμ reduced the infarct size in myocardial I/R mice(P<0.05).Conclusion These results suggest that PFTμ down-regulates the IFN-γ-induced i NOS transcription through decreasing translocated IRF-1 protein.