替米沙坦对高糖刺激下大鼠近端肾小管上皮细胞脂联素受体的影响及其机制探讨

Effects and mechanisms of telmisartan on adiponectin receptors in rat renal proximal tubular epithelial cells induced by high glucose

目的观察替米沙坦对高糖刺激下大鼠近端肾小管上皮细胞脂联素受体1/2(AdipoR1/2)表达的影响并探讨其机制。方法体外培养大鼠近端肾小管上皮细胞(NRK-52E),同步化后分为6组:正常对照组(5. 5 mmol/L葡萄糖培养基培养,24h),高渗对照组(5. 5 mmol/L葡萄糖培养基+19. 5 mmol/L甘露醇处理,24h),高糖组(25 mmol/L葡萄糖培养基培养,分别作用12、24、48、72h),高糖+替米沙坦组[25 mmol/L葡萄糖+(1、10、100 nmol/L)替米沙坦处理,刺激24h],高糖+替米沙坦+GW9662组(预先用5 000 nmol/L PPARγ阻断剂GW9662处理30 min,再加入25 mmol/L葡萄糖和100 nmol/L替米沙坦刺激24h),高糖+GW9662组(预先用5 000nmol/L PPARγ阻断剂GW9662处理30 min,再用25 mmol/L葡萄糖刺激24h)。采用RT-PCR分别检测AdipoR1/2和PPAR-γmRNA的表达,采用Western blot法检测AdipoR1/2和PPAR-γ蛋白表达。结果在高糖刺激情况下,随着刺激时间的延长,AdipoR1/2和PPAR-γmRNA的表达均有先增高后降低的趋势,高糖刺激24h时升高达到最高点,和正常对照组相比有统计学意义(P <0. 05);替米沙坦可明显提高AdipoR1/2和PPAR-γ的mRNA和蛋白表达(P <0. 05),其增强作用均在替米沙坦浓度为100 nmol/L时达到最大值(P <0. 05),在替米沙坦处理的同时加入选择性不可逆性PPAR-γ阻断剂GW9662可显著降低AdipoR1/2和PPAR-γ的mRNA和蛋白表达(P <0. 05)。结论高糖环境下,替米沙坦可促进大鼠近端肾小管上皮细胞AdipoR1/2的表达,其作用可能是通过激活PPAR-γ途径来介导的。

Objective To investigate the effects and mechanisms of telmisartan on expression of adiponectin receptors 1/2 in rat renal proximal tubular epithelial cells induced by high glucose.Methods Cultured rat renal proximal tubular epithelial cells( NRK-52 E) which were synchronized in vitro were divided into 6 groups: normal control group( 5. 5 mmol/L glucose medium culture,24 h),hypertonic control group( 5. 5 mmol/L glucose medium with 19. 5 mmol/L mannitol treatment,24 h),high glucose group( 25 mmol/L glucose medium for 12 h,24 h,48 h,72 h respectively),high glucose +telmisartan group [25 mmol/L glucose medium with different concentrations of telmisartan( 1,10,100 nmol/L) for 24 h],high glucose + telmisartan + GW9662 group( pretreatment with 5 000 nmol/L PPARγ blocker GW9662 for 30 min,then 25 mmol/L glucose and 100 nmol/L telmisartan for 24 h),high glucose + GW9662 group( pretreatment with 5 000 nmol/L PPARγ blocker GW9662 for 30 min,then 25 mmol/L glucose for 24 h). The reverse transcription time-polymerase chain reaction( RT-PCR)and Western blotting were used to detect the expression of adiponectin-receptors 1/2,PPAR-γ mRNA and protein levels in each group. Results In rat renal proximal tubular epithelial cells stimulated by high glucose,telmisartan could promote adiponectin receptors 1/2 expression through the pathway of PPAR-γ. Conclusions In rat renal proximal tubular epithelial cells stimulated by high glucose,telmisartan could promote adiponectin receptor 1/2 expression through the pathway of PPAR-γ.