【摘要】 目的研究过氧化物酶体增殖物激活受体α(PPAR-α)对内皮素1诱导的心肌肥大的作用及其对蛋白激酶B/糖原合成酶激酶3β-活化T细胞核因子(Akt/GSK3β-NFATc4)信号通路的影响。方法培养新生SD大鼠的心肌细胞,构建PPAR-α-EGFPN3质粒并转染心肌细胞,采用[3H]亮氨酸掺入法、蛋白免疫印迹(Westernblot)技术、免疫荧光技术等方法,观察PPAR-α过表达对内皮素1诱导的心肌细胞蛋白质合成的作用以及PPAR-α过表达对内皮素1诱导的Akt/GSK3β磷酸化和NFATc4核移位的影响。结果PPAR-α过表达和PPAR-α激动剂非诺贝特显著抑制了内皮素1诱导的心肌肥大;PPAR-α过表达及PPAR-α过表达联用非诺贝特可以显著抑制内皮素1诱导的Akt/GSK3β磷酸化;PPAR-α过表达防止了内皮素1诱导的NFATc4由胞浆到胞核的移位。结论PPAR-α可能通过影响Akt/GSK3β-NFATc4信号通路来抑制内皮素1诱导的心肌肥大反应。更多还原

【Abstract】 Objective To investigate the effects of peroxisome proliferator-activated receptor(PPAR)-α on Endothelin-1(ET-1) induced cardiomyocyte hypertrophy and its intracellular signal pathway.Methods PPAR-α-EGFPN3 plasmid was constructed to investigate the effects of PPAR-α on ET-1-induced phosphorylation of Akt and GSK3β and nuclear translocation of NFATc4 in cultured neonatal rat cardiomyocytes.[3H]-leucine incorporation assay was performed to examine protein synthesis of cardiomyocyte.Western-blot analysis was performed to investigate the effects of PPAR-activator and overexpression of PPAR-α on phosphorylation of protein kinase B(Akt) at Ser 473 and GSK3β at Ser 9,and the nuclear protein levels of NFATc4.Immunofluorescence and confocal microscopic assay were used to evaluate the effects of overexpressed PPAR-α on the nuclear translocation of NFATc4.Results Overexpression of PPAR-α and PPAR-activator fenofibrate inhibited ET-1-induced leucine uptake in cardiomyocytes.Either PPAR-α-EGFPN3 or the combination of PPAR-α-EGFPN3 with fenofibrate markedly inhibited ET-1-stimulated phosphorylation of Akt at Ser 473 and GSK3β at Ser 9.ET-1 stimulation markedly increased the translocation of NFATc4 from the cytoplasm to the nucleus.However,the nuclear expression of NFATc4 was inhibited by overexpressed PPAR-α.Conclusion Activation of PPAR-α interferes with the signaling pathway of ET-1-induced cardiomyocyte hypertrophy through negative regulation of nuclear translocation of NFATc4 and inhibition of the Akt/GSK3β pathway in cultured cardiomyocytes.更多还原