非诺贝特对脂多糖诱导的心肌细胞肿瘤坏死因子-α表达的影响

Effects of fenofibrate on tumor necrosis factor-a expression induced by lipopolysaccharide in neonatal rat cardiac myocytes

目的 探讨过氧化体增殖物激活型受体α(PPARα)激活剂对新生大鼠心肌细胞肿瘤坏死因子-α(TNF-α)和PPARα自身表达水平的影响。方法 体外原代培养新生Wistar大鼠心肌细胞,给予不同浓度的非诺贝特(PPARα激活剂)刺激,并辅加脂多糖诱导TNF-α表达。采用半定量逆转录-聚合酶链反应法检测TNF-α和PPARαmRNA的表达,酶联免疫吸附测定法检测TNF-α的蛋白水平,Westem印迹法检测PPARα蛋白表达。结果 与对照组相比,非诺贝特组的TNF-αmRNA及蛋白表达水平明显降低,且呈剂量依赖性。而相应的PPARα mR-NA及蛋白水平则无显著变化。结论 PPARα激活剂可显著抑制新生大鼠心肌细胞中脂多糖诱导的TNF-α表达,PPARα活化后发挥抗炎作用,但PPARα本身的表达水平可能并没有改变。

Objective To examine the effects of peroxisome proliferator activated receptor alpha (PPARα) activator on tumor necrosis factor-α(TNF-α) and PPARα expressions in neonatal rat cardiac myocytes. Methods Primary cultures of cardiac myocytes were prepared from ventricles of 3-day-old Wistar rats. Cardiac myocytes were pretreated with fenofibrate PPARa activator at different concentrations and then stimulated with lipopolysaccharide (LPS, 10μg/L). The levels of TNF-α and PPARα mRNA were measured by reverse transcription-polymerse chain reaction(RT-PCR). TNF-α and PPARa proteins were determined by ELISA and Western blotting, respectively. Results RT-PCR demonstrated that pretreatment of cardiac myocytes with fenofibrate inhibited LPS-induced TNF-α mRNA expression in concentration dependent manner. Fenofibrate also decreased LPS-induced TNF-α protein expression in medium. However, no significant changes were observed on PPARa mRNA and protein expression. Conclusions These results suggest that PPARα activator may inhibit cardiac TNF-α expression but not accompanied by changes in PPARa mRNA and protein levels. PPARα may mediate the modulation of the inflammatory reaction.