Aim To investigate the protective effect of paeoniflorin on TNF-α induced intestinal epithelial barrier dysfunction and its mechanisms.Methods The Caco-2 cells were cultured and the MTF assay was used to determine the effects of the paeoniflorin on Caco-2 cell activity.The Caco-2 cell intestinal epithelial barrier dysfunciton model was established through incubation of cells with TNF-α.The effects of paeoniflorin on intestinal epithelial barrier dysfunciton were studied.Results The transmembrane resistance in Caco-2 epithelial barrier was significantly reduced by TNF-α incubation;MLCK significantly increased,while tight junction protein occludin and ZO-1 significantly decreased by TNF-α.These changes were significantly reversed by paeoniflorin,which reduced MLCK expression and enhanced expression of occludin and ZO-1.The protective effects against epithelial barrier dysfunction could be abrogated by small interfering RNA(siRNA) of MLCK.Conclusions Paeoniflorin alleviates the epithelial barrier dysfunction induced by TNF-αthrough down-regulation of MLCK and enhancement of tight junction protein occludin and ZO-1.This study supplies a potential candidate drug for the clinical treatment of inflammatory bowel diseases.%目的 考察芍药苷对肿瘤坏死因子α(TNF-α)所致Caco-2模拟的肠上皮细胞屏障功能紊乱的保护作用及相关机制.方法 体外培养Caco-2细胞,采用MTT法研究芍药苷对Caco-2细胞活性的影响;建立TNF-α所致Caco-2细胞的屏障功能紊乱模型,研究芍药苷对屏障功能的影响.结果 TNF-α孵育Caco-2细胞,明显降低了Caco-2细胞屏障的跨膜电阻,肌球蛋白轻链激酶(MLCK)表达明显增加,紧密连接蛋白occludin和ZO-1表达明显下降,提示Caco-2细胞屏障功能紊乱;芍药苷明显逆转TNF-α所造成的Caco-2细胞屏障功能紊乱,即抑制MLCK的表达,促进紧密连接蛋白occludin和ZO-1的表达,芍药苷的这种保护细胞屏障的作用可被MLCK的小分子干扰RNA(small interfering RNA,siR-NA)所阻断.结论 芍药苷可明显缓解TNF-α诱导的肠上皮屏障功能紊乱,该作用与降低MLCK,促进紧密连接蛋白表达有关.
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