血管紧张素Ⅱ及氯沙坦对小鼠足细胞葡萄糖转运蛋白4表达的影响

Influence of angiotensin Ⅱ and losartan on GLUT4 expression in cultured mouse podocyte cells

目的观察血管紧张素Ⅱ(AngiotensinⅡ,AngⅡ)对足细胞葡萄糖转运蛋白4(GLUT4)表达的影响,及血管紧张素1型受体阻断剂氯沙坦(Losartan,Lo)能否抑制Ang II对足细胞GLUT4的作用。方法将小鼠MPC5足细胞分成对照组、AngⅡ10-6mmol/L组、AngⅡ10-8mmol/L组、AngⅡ10-10mmol/L组、Lo10-6mmol/L+AngⅡ10-6mmol/L组,半定量聚合酶链反应(RT-PCR)检测足细胞GLUT4m RNA的水平,间接免疫荧光检测GLUT4蛋白的表达。结果与对照组相比,AngⅡ10-6mmol/L组能够显著抑制GLUT4的表达及蛋白合成,GLUT4m RNA的表达下降了56.1%(P=0.041),间接免疫荧光表达下降了54.9%(P<0.05)。AngⅡ10-8mmol/L组及AngⅡ10-10mmol/L组GLUT4的表达与对照组相比有所下降,但差异无统计学意义(P>0.05),AngⅡ10-8mmol/L组对GLUT4抑制强于AngⅡ10-10mmol/L组,两组间差异无统计学意义(P>0.05)。Lo 10-6mmol/L+AngⅡ10-6mmol/L组GLUT4的表达显著升高,与AngⅡ10-6组相比,m RNA升高176.3%(P=0.006),蛋白表达升高87.8%(P<0.05)。结论 AngⅡ能够显著抑制足细胞GLUT4的表达及合成,具有浓度依赖性,这种作用能被氯沙坦所阻断。

Objective To investigate the influence of angiotensinⅡ（AngⅡ） on the expression of GLUT4 and whether losartan （Lo） could depress the function of AngⅡon podocytes. Methods The mouse podocyte clone 5 （MPC5） were divided into five groups： the control group, AngⅡ at the concentration of 10^-6, 10^-8, 10^-10 mmol/L groups, and Lo 10^-6 mmol/L＋AngⅡ10^-6 mmol/L group. The GLUT4 mRNA level was detected by semi-quantitative RT-PCR and the expression of GLUT4 by indirect immunofluorescence. Results Compared to the control group, in group AngⅡ10^-6 mmol/L, the GLUT4 expression and protein synthesis were significantly decreased, GLUT4 mRNA transcription was decreased by 56.1%（P=0.041）, and indirect immunofluorescence expression was decreased by 54.9%. The GLUT4 expression of AngⅡ10^-10 mmol/L and AngⅡ10^-8 mmol/L group was decreased compared with the control group, but there were no statistically significant difference. AngⅡ10^-8 mmol/L depressed more GLUT4 expression than the AngⅡ10^-10 mmol/L did, and there were also no statistically significant difference （P〉0.05）. As for the Lo 10^-6 mmol/L＋AngⅡ10^-6 mmol/L group, the GLUT4 expression was significantly increased, when compared with the AngⅡ10^-6 group its GLUT4 mRNA transcription was increased by 176.3%（P=0.006）, and indirect immunofluorescence expres-sion increased by 87.8%（P〈0.05）. Conclusion AngⅡcould significantly decrease the GLUT4 expression and synthe-sis, and the effect was concentration dependent therefore could be hampered by Losartan.