CAJ | 학술논문

目的通过观察替米沙坦、厄贝沙坦对PPARa转录活性的影响以探讨其改善糖脂代谢的机制.方法将构建的PPARa表达质粒、PPAR反应元件(PPRE)调控的荧光素酶表达质粒与pRL表达载体以脂质体(SuperFect)瞬时共转染COS-7细胞后,分别加入不同浓度的替米沙坦及厄贝沙坦,继续培养细胞不同时间,用双荧光索酶基因报告系统检测荧光素酶活性以反映PPARa转录活性.不同浓度的厄贝沙坦及替米沙坦孵育3T3-L1脂肪细胞,分别应用RT-PCR和Western印迹测定细胞的PPARα mRNA和蛋白表达水平.结果 (1)替米沙坦和厄贝沙坦均呈剂量和时间依赖性地增加COS-7细胞的PPARα转录活性,在60 h作用均达高峰,两者在100μmol/L浓度时PPRE调控的荧光素酶活性较对照组增高3.8倍和2.6倍(均P<0.01);(2)替米沙坦及厄贝沙坦激活PPARα的作用不能被PPARγ脚特异性抑制剂GW9662抑制;(3)替米沙坦和厄贝沙坦呈剂量依赖性增加3T3-L1脂肪细胞PPARα mRNA和蛋白表达水平.结论血管紧张素受体阻断剂替米沙坦和厄贝沙坦增加PPARα转录活性,可能通过此途径改善糖脂代谢.
목적 통과관찰체미사탄、액패사탄대PPARa전록활성적영향이탐토기개선당지대사적궤제.방법 장구건적PPARa표체질립、PPAR반응원건(PPRE)조공적형광소매표체질립여pRL표체재체이지질체(SuperFect)순시공전염COS-7세포후,분별가입불동농도적체미사탄급액패사탄,계속배양세포불동시간,용쌍형광색매기인보고계통검측형광소매활성이반영PPARa전록활성.불동농도적액패사탄급체미사탄부육3T3-L1지방세포,분별응용RT-PCR화Western인적측정세포적PPARα mRNA화단백표체수평.결과 (1)체미사탄화액패사탄균정제량화시간의뢰성지증가COS-7세포적PPARα전록활성,재60 h작용균체고봉,량자재100μmol/L농도시PPRE조공적형광소매활성교대조조증고3.8배화2.6배(균P<0.01);(2)체미사탄급액패사탄격활PPARα적작용불능피PPARγ각특이성억제제GW9662억제;(3)체미사탄화액패사탄정제량의뢰성증가3T3-L1지방세포PPARα mRNA화단백표체수평.결론 혈관긴장소수체조단제체미사탄화액패사탄증가PPARα전록활성,가능통과차도경개선당지대사.
Objective To investigate the effect of telmisartan and irbesartan on PPARα transcriptional activity, and to clarify their molecular mechanisms in improving glucose and lipid metabolism. Methods The structural expression vectors, including pCMV-PPARα, pGL3-PPRE and the internal control vector pRL-TK, were transiently eo-transfected into COS-7 cells using SuperFect, the cells were eontinously cultured with various concentrations of telmisartan and irbesartan, and then the PPRE controlled luciferase activity was determined by using a dual-luciferase reporter gene assay system. PPARα mRNA and protein expression levels were detected by RT-PCR and Western blot after 3T3-L1 adipoeytes were treated with various concentrations of telmisartan or irbesartan. Results (1) Both telmisartan and irbesartan stimulated PPARα transcriptional activity in concentration-and time-dependent manners in cultured COS-7 cells with the maximal effect at 60 h, with the results increased by 3.8 and 2.6 folds respectively at the concentration of 100 μmol/L compared with control group (both P<0.01). (2) The PPARγ antagonist GW9662 did not inhibit fenofibrate, telmisartan and irbesartan-stimulated PPARα transcriptional activities. (3) Both telmisartan and irbesartan increased PPARα mRNA and protein expression levels in a dose-dependent manner in 3T3-L1 adipocytes. Conclusion Angiotensin type 1 receptor blockers, telmisartan and irbesartan, can both increase PPARα transcriptional activity, which may contribute to their metabolic effects.