【摘要】 目的:探讨内皮素-1(ET-1)是否可诱导大鼠肾小管上皮细胞转分化(TEMT)及可能的分子机制。方法:体外培养大鼠肾小管上皮细胞(NRK52E)并进行分组;倒置显微镜观察细胞的形态变化;Western印迹法检测细胞E钙黏蛋白(E-cadherin)、α平滑肌肌动蛋白(α-SMA)、p38丝裂原活化蛋白激酶(p38MAPK)及磷酸化-p38MAPK(p-p38MAPK)蛋白的表达;逆转录-聚合酶链反应(RT-PCR)法检测细胞E-cadherin及α-SMAmRNA的表达。结果:ET-1可诱导细胞由鹅卵石样变为梭形,下调E-cadherin表达,上调α-SMA、p38MAPK及p-p38MAPK表达,增强p38MAPK活性(P<0.05),而内皮素A受体拮抗剂BQ123能明显抑制这些变化(P<0.05)。p38MAPK特异性抑制剂SB203580可抑制ET-1诱导的细胞梭形性变,ET-1诱导的E-cadherin、α-SMA及p-p38MAPK表达改变及p38MAPK活性改变(P<0.05),但对p38MAPK表达无明显影响(P>0.05)。结论:ET-1可能通过激活肾小管上皮细胞p38MAPK通路,下调E-cadherin的表达,同时上调α-SMA的表达,从而诱导肾小管上皮细胞转分化。更多还原

【Abstract】 Objective: To investigate whether endothelin-1 ( ET-1) could induce tubular epithelial-mesenchymal transition ( TEMT ) and the possible molecular mechanisms. Methodology: The rat renal tubular epithelial cells ( NRK52E) were cultured in vitro and divided into several groups. The cells morphological changes were observed with inverted microscope. Western blot was used to assess the protein expression levels of E-cadherin,α-smooth muscle actin ( α-SMA) ,p38mitogen-activated protein kinase ( p38MAPK) and phosphorylated-p38MAPK ( p-p38MAPK) . RT-PCR was used to detect the mRNA expressions of E-cadherin and α-SMA. Results: The cobble-shaped renal tubular epithelial cells were induced to become fusiform by ET-1 which meanwhile down-regulated the expression of E-cadherin,whereas upregulated the expressions of α-SMA,p38MAPK and p-p38MAPK and enhanced the activity of p38MAPK ( P < 0. 05) . All of these changes induced by ET-1 were obviously inhibited by the endothelin A receptor antagonist BQ123 ( P < 0. 05) . The p38MAPK specific inhibitor SB203580 also significantly inhibited the changes of morpholog of the cells,E-cadherin,α-SMA and p-p38MAPK expressions and p38MAPK activity induced by ET-1 ( P < 0. 05 ) ,but had no significant effect on the expression of p38MAPK ( P > 0. 05) . Conclusion: ET-1 can down-regulate the expressions of E-cadherin and up-regulate the expressions of α-SMA by activating the p38MAPK pathway in renal tubular epithelial cells,which then induces tubular epithelial-mesenchymal transition.更多还原