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p38 MAPK介导高糖诱导的肾小管上皮细胞向间充质细胞转变

方开云, 石明隽, 肖瑛, 桂华珍, 郭兵, 张国忠

贵阳医学院病理生理学教研室.贵州,贵阳 550004

摘要

该文旨在观察p38 MAPK与高糖诱导的肾小管上皮细胞向间充质细胞转变之间的关系。将雄性Sprague--Dawley(SD)大鼠随机分为对照组、糖尿病组、胰岛素治疗组,用免疫组织化学、Western blot检测p38 MAPK和磷酸化p38 MAPK(p--p38MAPK)蛋白表达。采用机械分离和酶消化获取SD大鼠肾小管节段,进行肾小管上皮细胞培养,将肾小管上皮细胞分为对照组、高渗组(20mmol/L D--mannitol)、高糖组(20mmol/L D--glucose)和SB202190(p38 MAPK特异性抑制剂)+高糖组,处理72h后收集细胞,用免疫细胞化学检测#alpha#--平滑肌肌动蛋白(#alpha#--smooth muscle actin,#alpha#-SMA)、p--p38 MAPK和Snail1蛋白表达,Western blot检测p38 MAPK、p--p38 MAPK、Snail1、转化生长因子#beta#1(transforming growth factor--#beta#1,TGF--#beta#1)、#alpha#--SMA和E--cadherin的表达,RT--PCR检测#alpha#--SMA和E--cadherin mRNA的表达。体内和体外结果均显示,高糖状态激活了p38 MAPK,这种活化作用在体内可因胰岛素控制血糖而被消除,在体外可被p38 MAPK特异性抑制剂SB202190显著抑制;高糖组#alpha#--SMA蛋白和mRNA在原代培养肾小管上皮细胞的表达较对照组分别增加12倍和8倍({sl P}<0.01),SB202190处理组其表达则较高糖组分别减少67%和50%({sl P}<0.01)。SB202190不影响TGF--#beta#1蛋白表达,但下调Snail1蛋白表达,并部分恢复高糖组E-cadherin蛋白和mRNA的表达。上述结果提示,p38 MAPK可能通过转录因子Snail1介导高糖诱导的肾小管上皮细胞向间充质细胞转变。

关键词： p38 MAPK; 上皮细胞向间充细胞转变; Snail1; 糖尿病肾病; 大鼠

p38 MAPK mediates high glucose--induced renal tubular epithelial--mesenchymal transition

Fang Kaiyun, Shi Mingjuan, Xiao Ying, Gui Huazhen, Guo Bing, Zhang Guozhong

Department of Pathophysiology,Guiyang Medical College.Guiyang 550004,Guizhou

Abstract

The aim of the present study was to investigate the role of p38 MAPK in the renal tubular epithelial-mesenchymal transition(TEMT) induced by high glucose.In in vivo study,the rats were randomly divided into control(C),diabetes mellitus(DM) and insulin-treated DM groups.Immunohistochemical staining and Western blot were employed to determine the expression of p38 MAPK and p-p38 MAPK protein in renal cortex of rats.In in vitro study,primary renal tubular epithelial cells(PTECs) were cultured with normal glucose(5.5 mmol/L),high glucose(20 mmol/L D-glucose),high osmolality(20 mmol/L D-mannitol) and SB202190(a p38 MAPK inhibitor) plus high glucose respectively for 72 h.The expressions of p38 MAPK,p-p38 MAPK,Snail1,transforming growth factor-#beta#1(TGF-#beta#1),#alpha#-smooth muscle actin(#alpha#-SMA) and E-cadherin protein and mRNA were detected by immunocytochemical staining,Western blot and RT-PCR.The p38 MAPK and p-p38 MAPK were specifically upregulated by high glucose in both in vivo and in vitro studies.The p38 MAPK activation was abolished by insulin controlling hyperglycemia to normal level in DM rats and inhibited dramatically by SB202190 in high glucose-cultured PTECs.The protein and mRNA of #alpha#-SMA were markedly increased in PTECs cultured with high glucose and were 12-fold and 8-fold respectively over that in the normal glucose,which were significantly sup-pressed by SB202190.SB202190 down-regulated the high glucose-induced Snail1 protein expression in PETCs,and restored partly the depression of E-cadherin protein and mRNA.These results suggest that p38 MAPK mediates high glucose-induced TEMT via transcription factor Snail1.

Key words: p38 MAPK;epithelial-mesenchymal transition;Snail1;diabetic nephropathy;Rat

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引用本文：

方开云, 石明隽, 肖瑛, 桂华珍, 郭兵, 张国忠. p38 MAPK介导高糖诱导的肾小管上皮细胞向间充质细胞转变[J]. 生理学报 2008; 60 (6): 759-766.

Fang Kaiyun, Shi Mingjuan, Xiao Ying, Gui Huazhen, Guo Bing, Zhang Guozhong. p38 MAPK mediates high glucose--induced renal tubular epithelial--mesenchymal transition. Acta Physiol Sin 2008; 60 (6): 759-766 (in Chinese with English abstract).