Objective To investigate whether peroxisome proliferator activated receptor-γ (PPARγ)is involved in oxygen-glucose deprivation (OGD)/reperfusion-induced expression of inflammatory mediators in RAW264.7 murine macrophages and their phenotype switch.Methods OGD/reperfusion-stimulated RAW264.7 murine macrophages served as a model of I/R injury.Knockdown and over expression of PPARγ in RAW264.7 cells were performed.The cells were divided into a control group,a model group,a model +PPAR γ group,and a model +si-PPAR γ group.The M1 marker inducible nitric oxide synthase (iNOS),M2 marker cluster of differentiation (CD)206,tumor necrosis factor-α (TNF-α),and interferon-γ(IFN-γ) were separately examined by ELISA,RT-PCR,Western blot analysis,and immunofluorescence staining.Results The levels of TNF-α and IFN-γ were significantly higher in the model group than in the control group (bothP ＜ 0.01).RT-PCR,Western blot analysis,and immunofluorescence staining showed that the expressions of iNOS,TNF-c,and IFN-γ were increased and that of CD206 decreased.The over-expression of PPAR-significantly attenuated OGD/reperfusioninduced alterations and increased the expressions of TNF-α,IFN-γ,and iNOS and down-regulated the expression of CD206.Conversely,the knockdown of PPARγ expression in these cells increased the OGD/reperfusion-induced expressions of iNOS,TNF-α,and IFN-γ and enhanced the OGD/reperfusion-induced downregulation of the expression of CD206.Conclusion PPARγ is involved in macrophage heterogeneity and IR-induced expression of inflammatory mediators in ischemia-reperfusion injury.%目的 探讨PPAR γ对缺氧复氧RAW264.7小鼠巨噬细胞异质性的影响.方法 体外培养小鼠巨噬细胞系(RAW264.7),制备缺氧复氧模型,用慢病毒包装进行PPARγ过表达和基因沉默,细胞分为对照组、模型组、过表达PPARγ组和PPARγ基因沉默组.用ELISA法、RT-PCR、Western印迹法和免疫荧光法检测各组细胞巨噬细胞亚型M1标志物诱导型一氧化氮合酶(iNOS)、M2标志物CD206及肿瘤坏死因子-α(TNF-α)、干扰素-γ(IFN-γ)的表达.结果 与对照组相比,ELISA法检测模型组TNF-α和IFN-γ水平明显升高(均P＜0.01),RT-PCR、Western印迹法和免疫荧光检测均显示TNF-α、IFN-γ、iNOS表达上调,CD206表达下调.与模型组相比,过表达PPARγ显著减轻了IRI导致的TNF-α、IFN-γ和iNOS表达的上调,上调了CD206表达;与此相反,PPARγ基因沉默加重IRI导致TNF-α、IFN-γ和iNOS表达上调,下调了CD206表达.结论 PPARγ在小鼠RAW264.7巨噬细胞缺氧复氧模型中参与调节巨噬细胞表型转换.
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