血管紧张素II上调肾小球系膜细胞TGF-β受体的表达

Up-regulation of expression of TGF-β receptors in rat mesangial cells by angiotensin II

目的 探讨血管紧张素II对肾小球系膜细胞TGF βI、II型受体表达的影响。 方法 4～ 8代系膜细胞长至亚融合状态时 ,换成无血清RPMI 16 4 0培养基培养 4 8h ,使细胞同步于静止期。然后换成含 10 -7mol/l血管紧张素II的无血清RPMI 16 4 0培养基 ,分别于血管紧张素II作用 0、2、4、8、12、2 4h时提取细胞总RNA。用半定量RT PCR检测各时间点系膜细胞I、II型TGF β受体mRNA的表达。 结果 系膜细胞I型TGF β受体mRNA于血管紧张素II作用 2、8、12h时显著升高 (P <0 .0 1) ,2 4h时又降至作用前 (0h时 )水平 (P >0 .0 5 )。系膜细胞II型TGF β受体mRNA于血管紧张素II作用 2、4、12h时显著升高 (P <0 .0 1) ,2 4h时也降至作用前 (0h时 )水平 (P >0 .0 5 )。结论 血管紧张素II上调肾小球系膜细胞TGF βI。

Objective To investigate the effects of angiotensin II on the expression of TGF β receptors in rat glomerular mesangial cells. Methods Subconfluent rat mesangial cells of 4～8 passages were made to be quiescent by placing them in serum free RPMI 1640 culture medium for 48 hours.They were continuously cultured for 0,2,4,8,12 and 24 h in serum free RPMI 1640 culture medium containing 10 -7 mol/l angiotensin II.Then total RNA in rat mesangial cells stimulated by angiotensin II at every time point was extracted.Expression of TGF β typeI(TβRI)and II(TβRII)receptor mRNA in rat glomerular mesangial cells at every time point was measured by quantitative reverse transcription polymerase chain reaction(RT PCR). Results Expression of TGF β type I and II receptor mRNA in rat glomerular mesangial cells stimulated by angiotensin II at 2,8 and 12 h(TβRI)and 2,4 and 12 h(Tβ RII) was significantly increased ( P <0.01),and then returned to the baseline at 24 h( P >0.05). Conclusion These results indicate that expression of TGF β type I and II receptors in rat mesangial cells is up regulated by angiotensin II.