醛固酮对系膜细胞合成纤溶酶原激活剂抑制物-1的影响

目的 探讨醛固酮及阻断其受体后对系膜细胞生成纤溶酶原激活剂抑制物1（PAI-1）的影响。方法 醛固酮单独刺激大鼠系膜细胞24h以及采用螺内酯阻断后,用RT-PCR观察系膜细胞PA1-1mRNA的变化;用Western印迹方法检测细胞上清液中的PA1-1;采用ELISA方法测定细胞上清液中转化生长因子p1（TGF-β1）的含量;采用激光共聚焦检测系膜细胞内的活性氧（ROS）水平。观察不同浓度及不同作用时间的醛固酮刺激系膜细胞对PA1-1mRNA的影响。结果 醛固酮使系膜细胞PA1-1mRNA及蛋白表达明显升高,同时升高了TGF-β1的表达和细胞内的ROS水平。醛固酮使PA1-1mRNA表达呈剂量依赖性增加。100nmol／L醛固酮刺激系膜细胞4h后PA1-1mRNA表达才明显增加。加用螺内酯后使升高的PA1-1、TGF-β1表达以及细胞内ROS恢复到正常水平。结论醛固酮能独立促进大鼠系膜细胞分泌PA1-1的增加,同时醛固酮使TGF-β1表达以及细胞内ROS水平升高,而这些都是通过盐皮质激素受体介导的。

Effect of aldosterone on the expression of plasminogen activator inhibitor-1 in renal mesangial cells: experiment with rat renal mesangial cells

OBJECTIVE: To evaluate the effects of aldosterone (ald) on the expression of plasminogen activator inhibitor-1 (PAI-1) in renal mesangial cells (MCs) and the changes after aldosterone was blocked with spironolactone. METHODS: Rat MCs of the line HBZY-1 were cultured and divided into 5 groups: ald group, treated with aldosterone (1 micromol/L or 100 nmol/L), ald combined with spironolactone 1 nmol/L for 24 hours, and control group. Anotfher cells were cultured and treated with ald 100 nmol/L for 0, 0.5, 1, 2, 4, 6, 8, and 24 h respectively or treated with ald of the concentrations of 10(-5), 10(-6), 10(-7), 10(-8), 10(-9), 10(-10), pr 10(-11) mol/L. RT-PCR and Western blotting were used to detect the mRNA and protein expression of PAI-1. Confocal laser scanning microscopy was used to detect the ROS level in the MCs. The transforming growth factor-beta1 (TGF-beta1) level in the medium was detected by ELISA. RESULTS: The PAI-1 mRNA and protein levels of the ald 100 nmol/L and 1 micromol/L groups became 2 times and 1.8 times, and 1.7 times and 1.9 times respectively those of the control group (all P < 0.01). The PAI-1 mRNA and protein levels of the ald + spirolactone group were not significantly different from those of the control group (all P > 0.05). The TGF-beta1 levels of the 100 nmol/L and 1 micromol/L aldosterone groups were 147 pg/ml +/- 27 pg/ml and 183 pg/ml +/- 25 pg/ml respectively, both significantly higher than that of the control group (75 pg/ml +/- 23 pg/ml, both P < 0.01). The TGF-beta1 levels of the groups with spirolactone were not significantly different from that of the control group (both P > 0.05). The ROS levels of the 1 micromol/L and 100 nmol/L ald groups were 4.87 times and 4.77 times that of the control group (both P < 0.01), and the ROS levels of the groups with spirolactone were 1.95 time and 1.66 times that of the control group (both P > 0.05). 100 nmol/L ald time-dependently increased the PAI-1 level since 4 hours after exposure to ald (all P < 0.05). Aldosterone dose-dependently increased the PAI-1 level (all P < 0.05). CONCLUSION: Aldosterone upregulates the production of PAI-1 by MCs and increases the expression of TGF-beta1 and cellular ROS in the MCs significantly, which is mediated through mineralocorticoid receptor.