摘要:
目的 研究替米沙坦在细胞周期依赖性蛋白激酶(CDK)5介导的过氧化物酶体增殖物激活受体(PPAR)γ磷酸化水平上升、调节3T3-L1脂肪细胞脂联素表达的机制.方法 诱导至转化率达到80%的3T3-L1脂肪细胞以不同浓度肿瘤坏死因子(TNF)-α(10、50、100 ng/ml,分别为T10、T50、T100组)刺激1h,T100组以替米沙坦不同剂量(0.1、5、10 μmol/L,分别为Tel0.1、Tel5、Tel10组)干预24 h后利用Western blotting法检测CDK5、p35蛋白表达水平和PPARγ磷酸化水平;实时荧光定量聚合酶链反应检测CDK5、p35、PPARγ mRNA表达变化;酶联免疫吸附试验法(ELISA)检测培养基上清脂联素释放变化.构建并包装携带p35基因的逆转录病毒感染3T3-L1细胞,以空载体病毒为对照,同时设置CDK5抑制剂组,检测CDK5、p35/p25、磷酸化PPARγ(pPPARγ)及脂联素表达.实验数据以xˉ± s表示,多组间比较采用单因素方差分析.结果 与未处理组相比,T10、T50、T100组CDK5 mRNA及蛋白相对表达量差异无统计学意义(均P>0.05);T50、T100组p35 mRNA(2.11±0.66、2.71±0.59比1.22±0.35;q=3.77、4.91)及蛋白(0.32±0.02、0.45±0.04比0.09±0.01;q=2.19、4.55)相对表达量显著上升(均P0.05),T50、T100组pPPARγ/PPARγ显著上升(0.21±0.03、0.47±0.04比0.11±0.02;q=3.89、6.91),脂联素释放显著下降(1.56±0.34、1.07±0.12比2.36±0.55;q=6.32、6.99,均P0.05);Tel5、Tel10组pPPARγ/PPARγ显著降低(0.11±0.03、0.05±0.01比0.38±0.02;q=4.91、5.22),脂联素释放显著上升(1.71±0.26、1.92±0.17比1.11±0.05;q=5.77、6.43,均P0.05). The relative expression of p35 mRNA (2.11 ± 0.66, 2.71 ± 0.59 vs 1.22 ± 0.35, q=3.77, 4.91) and protein (0.32±0.02, 0.45±0.04 vs 0.09±0.01, q=2.19, 4.55) in the T50and T100groups were up-regulated, the differences were statistically significant (all P0.05). pPPARγ/PPARγ was increased in the T50and T100groups (0.21±0.03, 0.47±0.04 vs 0.11±0.02, q=3.89, 6.91) while adiponectin concentration was decreased (1.56 ± 0.34, 1.07 ± 0.12 vs 2.36 ± 0.55, q=6.32, 6.99, all P>0.05). After telmisartan intervention there was no significant difference in the relative mRNA and protein expression levels of CDK5 and p35 compared with the T100group (all P>0.05). Tel5and Tel10groups had significant decreases in pPPARγ/PPARγ (0.11±0.03, 0.05±0.01 vs 0.38±0.02, q=4.91, 5.22) and increase in adiponectin release (1.71±0.06, 1.92±0.27 vs 1.11±0.05, q=5.77, 6.43) (all P<0.05). Over-expression of p35 led to p25 expression, elevation of pPPARγ/PPARγ (0.87±0.12 vs 0.07±0.02, q=9.13) and down-regulation of adiponectin (1.39 ± 0.12 vs 2.21 ± 0.33, q=5.67). In the inhibitor group, pPPARγ/PPARγ significantly decreased (0.15±0.01 vs 0.87±0.12, q=3.14) and adiponectin increased (1.95±0.24 vs 1.39±0.12, q=4.99) (all P<0.05). Conclusion Telmisartan regulates 3T3-L1 adipocyte adiponectin expression by inhibiting PPARγ phosphorylation induced by CDK5 overactivation.