PPARα在瘦素诱导心肌细胞肥大中的作用

The role of PPARα in leptin-induced myocardiocyte hypertrophy

目的探讨PPARα是否参与瘦素诱导的新生大鼠心肌细胞内氧活性物质(ROS)增多和心肌细胞肥大。方法 0.01、0.1、1和10μmol/L PPARα拮抗剂GW6471与瘦素共同孵育心肌细胞,ROS敏感的荧光染料DCF-DA检测细胞内ROS的水平;分别用RNA敏感的荧光染料碘化丙叮(PI)、考马斯亮蓝检测细胞内RNA和总蛋白含量。以11、01、00和1 000 ng/mL瘦素孵育细胞,荧光定量PCR、Western blot法分别检测心肌细胞内PPARαmRNA和蛋白表达变化。结果 PPARα拮抗剂GW6471能够浓度依赖性地抑制瘦素诱导的心肌细胞内DCF-DA荧光信号强度增加(P<0.05)和心肌细胞肥大(P<0.05);瘦素浓度依赖性上调心肌细胞内PPARαmRNA和蛋白表达(P<0.05)。结论 PPARα在瘦素诱导的心肌细胞ROS堆积和心肌细胞肥大过程中发挥重要的介导作用。

Objective To investigate the role of PPARα in ROS production and leptin-induced hypertrophy of cultured neonatal rat myocardiocytes. Methods Cultured cardiomyocytes were treated with PPARα antagonist GW6471（0.01~10 μmol/L） and leptin.The level of intracellular ROS was measured by the ROS-specific probe 2,7-dichlorofluorescin dictate（DCF-DA）.The RNA content was determined by RNA-sensitive fluorescence probe propidium iodide（PI） after DNAase treatment,and the total protein of cell was measured by the methods of Coomassie Brilliant Blue.Meanwhile,the cardiomyocytes cultured with leptin（1~1 000 ng/mL） was used to assess the expression of PPARα mRNA and protein by real-time PCR and Western blot,respectively.Results PPARα mRNA and protein in cultured cardiomyocytes was signficnatly increased by leptin following a concentration-dependent manner（P〈0.05）.However,significant alleviation was produced with GW6471 in leptin-induced increase in intracellular ROS,RNA and total protein following a dose-dependent manner（P〈0.05）. Conclusion PPARα activation is involved in leptin-induced ROS generation and cardiomyocytes hypertrophy.