瞬时感受器电位离子通道香草素受体亚家族4调控肝星状细胞活化增殖作用研究

Regulatory effects of TRPV4 on liver fibrosis of rats

目的探讨瞬时感受器电位离子通道香草素受体亚家族4(transient receptor potential vanilloid receptor 4,TRPV4)对肝星状细胞(hepatic stelate cell,HSC)活化增殖的作用及可能的作用机制。方法以含50%CCl4的花生油溶液(1m L·kg-1)皮下注射,建立大鼠肝纤维化模型。应用蛋白印迹等方法在体观察TRPV4及肌动蛋白α(α-smooth muscle actin,α-SMA)的蛋白表达变化。以转化生长因子-β1(transforming growth factor-β1,TGF-β1)(10μg·L-1)刺激肝星状细胞株(HSC-T6),离体观察TRPV4及α-SMA的蛋白表达变化。应用TRPV4非特异性抑制剂钌红(ruthenium red,Ru)及TRPV4-siRNA特异性沉默TRPV4,观察HSC-T6增殖及α-SMA、蛋白激酶B(protein kinase B,Akt/PKB)蛋白表达变化。结果肝纤维化组织与TGF-β1活化的HSC中TRPV4及α-SMA蛋白表达明显增加。阻断TRPV4可明显抑制HSC增殖,且α-SMA、Akt蛋白表达明显降低。结论 TRPV4参与调控HSC的活化增殖,调控Akt蛋白磷酸化。

Aim To investigate the effect of TRPV4 on hepatic fibrosis of rats . Methods Liver fibrosis model of rats was induced by 50% CCl4 twice a week for 12 weeks. HE and Masson staining were used to evaluate the degree of hepatic fibrosis, and the levels of α-smooth muscle actin(α-SMA) and TRPV4 were detec-ted in fibrotic liver tissue by Western blot. HSC-T6 cells were activated by transforming growth factor β1 (TGF-β1),and the protein levels of α-SMA, TRPV4 were detected by Western blot. After using Ru and transfected with TRPV4-siRNA, HSC-T6 was stimula-ted with TGF-β1, the levels of α-SMA, TRPV4 and phosphorylation level of Akt were determined by West-ern blot. Results TRPV4 was highly expressed in model liver tissues and in activated HSC-T6 induced by TGF-β1 . The levels of α-SMA and phosphorylation of Akt decreased in TGF-β1-induced HSC, used with Ru or transfected with TRPV4-siRNA. Conclusions The expression of TRPV4 increases in fibrotic livers and ac-tivated hepatic stellate cells. Knockdown of TRPV4 can suppress the activation of hepatic stellate cells in-duced by TGF-β1 , and decrease the phosphorylation levels of Akt.