目的探讨醛固酮(Aldo)对介导大鼠肝星状细胞(HSC)收缩的非Ca^2+依赖性信号传导通路的影响。方法对HSCT6细胞给予Aldo10μmol/L处理,用聚硅酮膜法检测HSCT6细胞的收缩性;在激光共聚焦显微镜下动态观察HSC-T6细胞胞内游离钙离子浓度的变化。RTPCR检测Aldo受体阻断剂安体舒通、蛋白激酶C特异性抑制剂Stauro、Rho激酶特异性抑制剂Y27632、肌球蛋白轻链激酶特异性抑制剂ML-7对RhoRock通路中Rock2、RhoAGTP、RhoGEFmRNA表达水平的影响。对各组间数据行单因素方差分析,两两比较采用LSD法。结果Aldo可诱导HSC-T6细胞收缩;Aldo对HSC-T6细胞胞内游离钙离子浓度变化无明显影响。Aldo可诱导Rock2、RhoAGTP、RhoGEFmRNA的表达增强(0.770±0.049、0.960±0.096、0.180±0.006,P值均〈0.01),而其阻断剂安体舒通可明显抑制这三种元件mRNA的表达(0.440±0.166、0.370±0.180、0.050±0.001,尸值均〈0.01)。Aldo+Y27632组上述三种元件mRNA的表达较Aldo组减弱。Aldo+ML-7+Stauro组三种元件的mRNA表达水平(0.940±0.066、1.330±0.192、0.160±0.007)较对照组(0.140±0.023、0.540±0.111、0.110±0.012)增强(P〈0.05),Aldo+Y27632+ML-7+Stauro组RhoGEF(0.290±0.004,P〈0.01)的表达较ML-7+Stauro两者联合抑制组(0.160±0.007)增强。结论Aldo可诱导HSC的收缩,这与Rho激酶介导的非Ca^2+依赖性信号通路相关。
Objective To investigate the mechanisms of Aldosterone stimulating hepatic stellate cells(HSCs) contraction via Ca^2+independent pathways. Methods HSC-T6 cell line was pre-disposed with Aldo 10 μmol/L. The cell contraction was detected by silicone-rubber-membrane cultivation directly. The concentration variation of intracellular free calcium in rat HSC was observed by laser confocal microscopy. Besides, HSC-T6 cell line was under pre-disposal treatment with the blocking agents of Aldo receptor - antisterone, protein kinase C (PKC) special blocking agent-Stauro, Rho kinase blocking agent-Y27632 and MLCK special blocking agent-ML-7 respectively prior to stimulation with aldosterone. RT-PCR was used to detect the expression of Rock2, RhoAGTP and RhoGEF in Ca^2+ independent pathways mediated by Rho- kinase. Results Aldo could induce HSCs contraction. The concentration of intracellular free calcium in rat HSCs had no change after pre-disposal treatment with Aldo. The mRNA expressions of Rock2, RhoAGTP and RhoGEF increased significantly after treatment with Aldo (0.770± 0.049, 0.960 ±0.096, 0.180 ±0.006, P 〈 0.01).When inhibited with antisterone, the mRNA expressions of the three elements were (0.440 ±0.166, 0.370± 0.180 and 0.050± 0.001, P 〈 0.01), lower than that of Aldo group, but higher in ML-7+Stauro + Aldo groups (0.940 ±0.066, 1.330 ±0.192 and 0.160 ± 0.007, P 〈 0.05) as compared to the control group (0.140 ± 0.023, 0.540± 0.111 and 0.110 ±0.012). In the Y27632 + ML-7 + Stauro+Aldo group, the mRNA expression of RhoGEF (0.290 ±0.004, P 〈 0.01)was higher than that of the ML-7 + Stauro + Aldo group (0.160 ± 0.007). Conclusion Aldo could induce HSCs contraction via Ca^2+ independent pathways and Rho-Rock pathway involved in the process.