ERK1/2/PPARα/SCAD信号途径对生理性和病理性心肌肥大的调控

Effects of ERK1/2/PPARα/SCAD signal pathways on physiological cardiac hypertrophy and pathological cardiac hypertrophy

目的:研究ERK1/2/PPARα/SCAD(短链脂酰辅酶A脱氢酶)信号途径对生理性和病理性心肌肥大调控的不同机制,探索病理性心肌肥大治疗的新靶点。方法:分别以胰岛素样生长因子1(insulin-like growth factor 1,IGF-1)和苯肾上腺素(phenylephrine,PE)刺激心肌细胞,复制生理性和病理性心肌肥大模型,检测心肌细胞表面积,p-ERK1/2和PPARα蛋白表达变化,SCAD mRNA、蛋白表达和酶活性变化,心肌细胞游离脂肪酸含量变化。结果:与对照组比较,PE和IGF-1刺激后心肌细胞表面积均显著增大。与对照组相比,IGF-1刺激的心肌细胞SCAD mRNA和蛋白表达均上调,酶活性显著增高,游离脂肪酸含量明显减少,且PPARαmRNA和蛋白表达均上调,p-ERK1/2的蛋白表达显著下调;PE刺激的心肌细胞SCAD mRNA和蛋白表达均下调,酶活性显著降低,游离脂肪酸含量明显增加,且PPARαmRNA和蛋白表达均下调,p-ERK1/2蛋白表达显著上调。结论:p-ERK1/2/PPARα/SCAD在生理性和病理性心肌肥大中呈现出不一致的变化趋势,表明ERK1/2/PPARα/SCAD信号途径对2种不同肌肥大的调控作用不同。SCAD可能作为2种不同心肌肥大的分子标志物及病理性心肌肥大的潜在治疗靶点。

[ABSTRACT]AIM：ToinvestigatethedifferenteffectsofERK1/2/PPARα/SCAD（short-chainacyl-CoAdehy-drogenase） signal pathways on the cardiac hypertrophy induced by insulin-like growth factors 1 （ IGF-1） or phenylephrine （ PE） .METHODS：The neonatal rat cardiomyocytes induced by IGF-1 were used as the model of physiological cardiac hypertrophy , and those induced by PE were used as the model of pathological cardiac hypertrophy .The surface area of the cardiomyocytes, the expression of p-ERK1/2, PPARαand SCAD, the activity of SCAD and the content of free fatty acid in the cardiomyocytes were measured .RESULTS：Compared with the control cells , the surface area of the cardiomyocytes in-duced by IGF-1 and PE were both increased .Compared with the controls , the expression of SCAD and PPARα, and the activity of SCAD in the cardiomyocytes induced by IGF-1 were increased , while the expression of p-ERK1/2 was de-creased.However, the cardiomyocytes treated with PE showed decreased expression of SCAD and PPARα, decreased activ-ity of SCAD and increased expression of p-ERK1/2.Meanwhile, the decrease in free fatty acid in IGF-1-induced cardio-myocytes and the increase in PE-induced cardiomyocytes indicated that the fatty acid utilization was increased in the cardio -myocytes induced by IGF-1, but decreased in the cardiomyocytes induced by PE .CONCLUSION： The changes of p-ERK1/2, PPARαand SCAD in the cardiac hypertrophy induced by IGF-1 or PE indicate that the effects of ERK 1/2/PPARα/SCAD signal pathways are different between physiological cardiac hypertrophy and pathological cardiac hypertro -phy , and that SCAD may be a molecular marker of these 2 different cardiac hypertrophies and a potential therapeutic target for pathological cardiac hypertrophy .