中文摘要：

目的探讨ERK1／2丝裂原活化蛋白激酶（MAPK）信号转导途径在醛固酮（ALDO）促进肾小管上皮细胞系（HKC）合成转化生长因子β（TGF·β1）中的作用。方法利用体外培养的HKC细胞行如下试验。（1）不同浓度MAPK三种支通路特异性阻滞剂对其分别进行阻断，以酶联免疫吸附方法（ELISA）检测外源性ALDO作用下HKC合成TGF-β1量的改变。（2）不同浓度及不同作用时间的外源性ALDO刺激HKC，以Western印迹方法检测细胞裂解物中磷酸化ERK1／2以及总ERK1／2表达，并对ERK1／2相对表达量（磷酸化ERK1／2／总ERK1／2）与相应刺激条件下TGF·β1合成量进行相关分析。（3）在不同浓度的安体舒通和糖皮质激素受体阻滞剂RU486作用细胞后，以外源性ALDO刺激HKC，同上方法检测细胞裂解物中磷酸化ERK1／2及总ERK1／2表达。结果（1）15μmol／L及25μmol／LERK1／2通路阻滞剂（U0126）分别使TGF-β1的合成量减低至（87±11）ps／ml及（75±19）pg／ml，而仅使用10^-7mol／LALDO刺激作用下HKC中TGF-β1的合成量（121±10）pg／na，与前者比较差异有统计学意义（P〈0．05），而JNK和P38两条支通路阻滞剂（SP600125、SB203580）未使TGF-β1合成量出现显著性变化（均P〉0．05）。（2）外源性ALDO可使HKC对ERK1／2相对表达量呈现剂量依赖性增加。10^-9及10^-7mol／LALDO刺激组ERK1／2相对表达量分别为0．67±0．06及0．80±0．05，显著高于0mol／LALDO组（P〈0．05或0．01）。相应浓度醛固酮刺激下ERKl／2相对表达量与TGF-β1合成量之间具有显著正相关关系（R=0．793，P〈0．01）；10μmol／LALDO刺激HKC15min后，磷酸化ERK1／2开始出现显著性增加并达到高峰（P〈0．01），其相对表达量为0．84±0．06，此后逐渐减低，至360min时其表达量为0．49±0．08，与0min比较差异无统计学意义（P〉0．05）。（3）10^-7mol／LALDO与10^-9、10^-7mol／L安体舒通共同?

英文摘要：

Objective Our previous study have demostrated that the expression of transforming growth factor-β1 （TGF-β1） by HKC could be up-regulated by aldosterone （ALDO） in vitro. The present study was designed to evaluate the role of MAPK/ERK1/2 phosphorylation in mediating the synthesis of TGF-β1 in renal tubular epithelial cells that was activated by aldosterone. Methods The following tests were performed in vitro： （1） HKC were pretreated with different concentrations of specific ERK1/2, JNK and P38 MAPK pathway inhibitors for 4h, then HKC were stimulated with 10^-7 mol/L ALDO for 48 h, finally enzyme-linked immunosorbent assay （ ELISA ） were performed to detect TGF-β1 expression; （ 2 ） HKC were stimulated with ALDO at different concentrations and times, then western blot assay was performed to detect the expression of phosphorylated and total ERK1/2 in the cell lysate of HKC. （3） HKC which were co-stimulated with 10^-7 mol/L ALDO and different concentrations of spironolactone or specific glucocorticoid hormone receptor inhibitor RU486 for 30min, then western blot assay was performed to detect the expression of phosphorylated and total ERK1/2 in the cell lysate of HKC. Results （ 1 ） the production in 15 and 25 μmol/L U0126 incubated groups was （87 ± 11） pg/ml and （75 ± 19） pg/ml respectively, which was significantly decreased compared with that in 10^-7 mol/L ALDO incubated group （ P 〈0.05 ）, however, the amount of TGF-β1 in these groups were still significant higher than that in the control group （P 〈0. 05）. The production of TGF-β1 in the groups which were incubated with SP600125 and SB203580 did not appear significant decrease compared with that in 10^-7 mol/L ALDO incubated group （ P 〉 0. 05 ）, the production of TGF-β1 in these groups was also significant higher than that in the control group （P 〈 0. 05）. （2） The Phos/Total ERK1/2 ratio was increased in a dose-dependent manner. After HKC were stimulated with 10^-9 - 10^-7 mol/L ALDO for 30 mi