【摘要】 目的探讨单磷酸腺苷激活蛋白激酶(AMPK)对体外培养心肌细胞蛋白降解的影响。方法分离培养新生Spra-gue-Dawley大鼠心肌细胞,用AMPK特异性激动剂5-氨基咪唑-4-甲酰胺-1-β-D-呋喃核糖苷(AICAR)(2.0mmol/L)、抑制剂Compound C(0.5mmol/L)干预,按干预方式分为:对照组、AICAR组、Compound C组及AICAR+Compound C组。Westernblot检测心肌细胞AMPK、p-AMPK蛋白的表达水平;高效液相色谱法检测细胞培养基中3-甲基组氨酸(3-MH)的浓度。结果各组心肌细胞总AMPK蛋白水平没有明显变化,AICAR可上调心肌细胞p-AMPK蛋白水平,Compound C下调心肌细胞p-AMPK蛋白水平,并抑制AICAR对p-AMPK蛋白的上调作用。AMPK激活后心肌细胞3-MH释放增加,而AMPK活性受到抑制后,3-MH释放减少。结论 AMPK激活能促进心肌细胞的蛋白降解。更多还原

【Abstract】 Objective To investigate the effects of adenosine monophosphate-activated protein kinase(AMPK) on protein degradation in cardiomyocytes in vitro.Methods Neonatal Sprague-Dawley rat cardiomyocytes were isolated and cultured,and then treated with specific AMPK activator 5-aminoimidazole-4-carboxamide-1-β-D-ribofuranoside(AICAR)(2.0 mmol/L) and inhibitor Compound C(0.5 mmol/L).Cells were divided into Control,AMPK,Compound C and AMPK+Compound C group according to treatment manner.Western blot was employed to assay levels of AMPK and p-AMPK protein in cardiomyocytes,and high performance liquid chromatography was used to detect 3-methylhistidine(3-MH) concentration in culture medium.Results Levels of total AMPK protein of cardiomyocytes in each group showed no obvious changes.AICAR treatment up-regulated level of p-AMPK protein,whereas Compound C treatment down-regulated it and reversed the up-regulation effect of AICAR on p-AMPK protein.AMPK activation increased 3-MH releasing from cardiomyocytes,whereas AMPK suppression decreased it.Conclusion AMPK activation promotes protein degradation in cardiomyocytes.更多还原