甘草泻心汤调控PERK-elF2α-CHOP信号通路保护应激态肠上皮细胞屏障的机制

Mechanisms of Gancao Xiexin Decoctionon protecting intestinal epithelial cell barrier understress state by regulating PERK-elF2α-CHOP signaling pathway

目的从PERK-elF2α-CHOP信号通路角度观察甘草泻心汤(GXD)对内质网应激(ERS)状态肠上皮细胞(IECs)的保护作用。方法培养Caco-2细胞,分为正常对照组(NC)、模型对照组(MC)、GXD低剂量(GXD-L)、中剂量(GXD-M)和高剂量组(GXD-H)。衣霉素(Tm)诱导建立应激态细胞模型,GXD各组造模同时予中药含药血清干预。CCK-8法检测细胞存活率,流式细胞术检测凋亡率和周期分布,跨膜电阻抗(TEER)和FITC-dextran示踪法共同明确细胞屏障通透性,Western blot法检测PERK-elF2α-CHOP通路蛋白的表达。结果与MC组相比,GXD干预后能提高细胞存活率(P<0.05),降低其凋亡率(P<0.01),缓解细胞周期阻滞(P<0.01),升高细胞TEER值(P<0.01)、降低FITC-dextran浓度(P<0.05)以改善细胞屏障通透性;GXD-M和GXD-H组中p-PERK、p-elF2α、ATF4和CHOP蛋白水平均明显降低(P<0.01)。结论GXD可通过抑制PERK-eIF2α-CHOP凋亡通路的信号转导,从而减少IECs的过度凋亡,保护肠上皮细胞屏障稳态。

Aim To observe the protective effect of Gancao Xiexin Decoction(GXD)on intestinal epithelial cells(IECs)under endoplasmic reticulum stress from the perspective of PERK-elF2α-CHOP signaling pathway.Methods Caco-2 cells were cultured and divided into normal control group(NC),model control group(MC),low-dose GXD group(GXD-L),medium-dose GXD group(GXD-M)and high-dose GXD group(GXD-H).Models of the stress epithelial cells were induced by tunicamycin(Tm),and GXD groups were treated with GXD contained serum at the same time.The cell survival rate was assessed by CCK-8 method,the cell apoptotic rate and cell cycle distribution were determined by flow cytometry,and the cell barrier permeability was determined by TEER and FITC-dextran method;the expression levels of core proteins of PERK-elF2α-CHOP signaling pathway were detected by Western blot.Results Compared with MC group,GXD intervention could improve cell survival rate(P<0.05),reduce their apoptotic rate(P<0.01),relieve cell cycle arrest(P<0.01),improve cell barrier permeability by increasing cell TEER value(P<0.01)and decreasing FITC-dextran concentration(P<0.05),and the levels of p-PERK,p-elF2α,ATF4 and CHOP in GXD-M and GXD-H groups all visibly descended(P<0.01).Conclusions GXD can reduce the excessive apoptosis of IECs and protect intestinal epithelial cell barrier homeostasis by inhibiting the signal transduction of PERK-elF2α-CHOP apoptotic pathway.