AIM:To investigate the molecular mechanism of Xijiao Dihuang decoction combined with Yinqiao powder (XDY) in treating viral pneumonia, and the effects of XDY on TNF-α-induced permeability in pulmonary microvascular endothelial cells (PMVEC) and the role of PKC-SSeCKS pathway involved.METHODS:The electric conductivity method was used to detect transendothelial electrical resistance (TER) of primarily cultured PMVEC on Transwell chamber at different time points to determine the permeability of PMVEC.After pretreatment for 24 h, the activity of PKC, TER, and the expression of SSeCKS at mRNA and protein levels were detected.Laser scanning confocal microscopy was used to observe the location of SSeCKS and construction of F-actin in PMVEC.RESULTS:The permeability of PMVECs induced by TNF-α reached the peak at 24 h.Compared with control group, the TER in TNF-α group was decreased, and the activity of PKC was increased.Compared with TNF-α group, the activity of PKC in TNF-α with PKC inhibitor group and TNF-α with XDY group was decreased, while the TER was increased, without difference from control group.Compared with control group, the mRNA expression of SSeCKS and phospho-SSeCKS was increased in PMVEC of TNF-α group, but decreased in TNF-α with XDY group compared with TNF-α group.In control group, F-actin was mainly located around the nucleus and at cytoplasmic borders of PMVEC, forming the dense peripheral bundle, and SSeCKS was evenly scattered in the cell.In TNF-α group, the dense peripheral bundle of F-actin surrounding the cells almost disappeared, and SSeCKS was concentrated around the nucleus.Compared with TNF-α group, the distribution and the structure of F-actin and SSeCKS nearly returned to normal in TNF-α with XDY group.CONCLUSION:XDY inhibits the activation of PKC signaling pathway in PMVEC caused by TNF-α to reduce the mRNA expression of SSeCKS and the phosphorylation of SSeCKS, thus preventing the deformation of endothelial cells and reducing the permeability of PMVEC.%目的:观察犀角地黄汤合银翘散(XDY)对TNF-α诱导的大鼠肺微血管内皮细胞(PMVEC)通透性的影响及其与PKC-SSeCKS信号通路的关系,以探究该方治疗病毒性肺炎的作用环节和分子机制.方法:原代培养大鼠PMVEC,在Transwell小室上用电导法于不同时点监测TNF-α诱导的PMVEC跨内皮细胞单层电阻(TER)测定其通透性.不同的干预因素作用24 h后,检测PMVEC的TER、PKC活性、SSeCKS mRNA水平和磷酸化SSeCKS蛋白水平,激光共聚焦显微镜观察PMVEC中SSeCKS的定位和F-actin的结构变化.结果:TNF-α作用24 h后PMVEC通透性达高峰;与对照组比较,TNF-α组TER降低,PKC活性增强;与TNF-α组比较,TNF-α加PKC抑制剂组和TNF-α加XDY含药血清组PKC活性降低,而TER升高且与对照组无差别.与对照组比较,TNF-α组SSeCKS的mRNA和蛋白表达升高;与TNF-α组比较,TNF-α加XDY含药血清组SSeCKS的mRNA水平和磷酸化SSeCKS蛋白水平降低.对照组PMVEC中F-actin主要分布在细胞周边和核周,形成致密周围束,SSeCKS均匀散在分布于细胞中;TNF-α组细胞周边的F-actin致密束基本消失,SSeCKS集中分布于核周;TNF-α加含XDY含药血清组F-actin结构及SSeCKS的分布趋于正常.结论:犀角地黄汤合银翘散可以抑制TNF-α诱导的PMVEC PKC信号通路的激活,降低PKC结合底物SSeCKS的表达,最终影响肌动蛋白的变构、阻止内皮细胞变形而降低PMVEC的通透性.
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