内皮素-1对高糖溶液培养下肾小管上皮细胞转分化的影响

Effect of endothelin-1 on renal tubular epithelial cell transdifferentiation in high glucose

目的 探讨内皮素-1对高糖溶液培养肾小管上皮细胞转分化的影响和可能的机制.方法 采用甲基噻唑法检测0.1～1 000 nmol/L内皮素-1对肾小管上皮细胞增殖的影响.采用无小牛血清的低糖DMEM培养基（一种含各种氨基酸和葡萄糖的培养基）同步化肾小管上皮细胞24 h,分为4组,分别采用低糖DMEM、高糖DMEM、高糖DMEM加100 nmol/L内皮素-1、高糖DMEM加100 nmol/L内皮素-1和转化生长因子-β1中和抗体培养肾小管上皮细胞.分别检测肾小管上皮细胞内转化生长因子-β1、α-平滑肌肌动蛋白和E-钙黏蛋白mRNA和蛋白的表达.结果 0.1～1 000nmol/L内皮素-1对肾小管上皮细胞增殖无明显影响,内皮素-1明显上调大鼠近端肾小管上皮细胞α-平滑肌肌动蛋白mRNA和蛋白表达,下调E-钙黏蛋白mRNA和蛋白的表达；内皮素-1明显升高大鼠近端肾小管上皮细胞转化生长因子-β1 mRNA和蛋白的表达；转化生长因子-β1中和抗体干预后,大鼠近端肾小管上皮细胞表达的E-钙黏蛋白和mRNA明显高于内皮素-1组,而α-平滑肌肌动蛋白和mRNA明显低于内皮素-1组.结论 糖尿病肾脏病中,内皮素-1可促进肾小管上皮向肌成纤维细胞及间质细胞转分化,可能通过转化生长因子-β1发挥作用.

Objective To investigate the effect of endothelin-1 on transdifferentiation of tubular epithelial cells cultured in high glucose DMEM. Methods Methylthiazol assay was used to test the effect of 0. 1 - 1 000 nmol/L endothelin-1 on proliferation of renal tubular epithelial cells. Renal tubular epithelial cells were synchronized with fetal calf serum-free DMEM for 24 h, and divided into four groups：low glucose group（low glucose DMEM）,high glucose group（high glucose DMEM）, endothe- lin-1 group（high glucose DMEM plus 100 nmol/L endothelin-1）, transforming growth factor group （high glucose DMEM plus 100 nmol/L endothelin-1 and transforming growth factor-131 neutralizing antibody）. The expression of transforming growth factor-]31, a-smooth muscle actin and E-cadherin rnRNA and protein in renal tubular epithelial cells was detected by using reverse transcription-poly- merase chain reaction and Western blotting. Results 10-6 ~ 10-9 mol/L endothelin-1 had no effect on the proliferation of renal tubular epithelial cells. In endothelin-1 group, endothelin-1 significantly increased a-smooth muscle actin mRNA and protein expression, reduced E-cadherin rnRNA and protein expression, and endothelin-1 significantly increased transforming growth factor mRNA and protein expression. After intervention with transforming growth factor neutralizing antibody, the expression of E-cadherin protein and mRNA was significantly higher than endothelin-1 group, and the expression of a-smooth muscle actin protein and mRNA was significantly lower than endothelin-1 group. Conclusions Endothe- lin-1 could promote transdifferentiation of renal tubular epithelia to myofibroblasts and interstitial cells in diabetic kidney disease.