Activation of AMPK inhibits cardiomyocyte hypertrophy by modulating of the FOXO1/MuRF1 signaling pathway in vitro
Activation of AMPK inhibits cardiomyocyte hypertrophy by modulating of the FOXO1/MuRF1 signaling pathway in vitro
复制标题
AMPK 的激活通过体外调节 FOXO1/MuRF1 信号通路抑制心肌细胞肥大
DOI：
10.1038/aps.2010.73
复制
发表时间：
2010-07-01
影响因子：
8.2
通讯作者：
Dong, Yu-gang
中科院分区：
文献类型：
--
作者：
Chen, Bao-lin;Ma, Yue-dong;Dong, Yu-gang
目的：研究腺苷单磷酸激活蛋白激酶（AMPK）激活对体外培养心肌细胞肥大的抑制作用，并探讨其分子机制。方法：用AMPK特异性激活剂5-氨基咪唑-4-甲酰胺核苷（AICAR）和AMPK特异性拮抗剂化合物C处理培养乳鼠心肌细胞，再用苯肾上腺素（PE）刺激。使用Lipofectamine 2000将Muscle RING finger 1（MuRF 1）-小干扰RNA（siRNA）转染到心肌细胞中。使用面积测量法测量培养的心肌细胞的表面积。使用高效液相色谱法（HPLC）测定蛋白质降解。结果：0.5mmol/L AICAR激活AMPK可抑制PE诱导的心肌细胞面积和β-MHC蛋白表达的增加及蛋白降解的减少。此外，AMPK激活增加转录因子FOXO 1的活性，并上调下游atrogene MuRF 1 mRNA和蛋白表达。用化合物C 1 μ mol/L处理肥大的心肌细胞减弱AMPK对心肌细胞肥大和FOXO 1/MuRF 1通路变化的影响。结论：AMPK激活可通过调节FOXO1/MuRF1信号通路抑制心肌细胞肥大。
Aim:To examine the inhibitory effects of adenosine monophosphate-activated protein kinase (AMPK) activation on cardiac hypertrophy in vitro and to investigate the underlying molecular mechanisms.Methods:Cultured neonatal rat cardiomyocytes were treated with the specific AMPK activator 5-aminoimidazole-4-carboxamide ribonucleoside (AICAR) and the specific AMPK antagonist Compound C, and then stimulated with phenylephrine (PE). The Muscle RING finger 1 (MuRF1)-small interfering RNA (siRNA) was transfected into cardiomyocytes using Lipofectamine 2000. The surface area of cultured cardiomyocytes was measured using planimetry. The protein degradation was determined using high performance liquid chromatography (HPLC). The expression of β-myosin heavy chain (β-MHC) and MuRF1, as well as the phosphorylation levels of AMPK and Forkhead box O 1 (FOXO1), were separately measured using Western blot or real-time polymerase chain reaction.Results:Activation of AMPK by AICAR 0.5 mmol/L inhibited PE-induced increase in cardiomyocyte area and β-MHC protein expression and PE-induced decrease in protein degradation. Furthermore, AMPK activation increased the activity of transcription factor FOXO1 and up-regulated downstream atrogene MuRF1 mRNA and protein expression. Treatment of hypertrophied cardiomyocytes with Compound C 1 μmol/L blunted the effects of AMPK on cardiomyocyte hypertrophy and changes to the FOXO1/MuRF1 pathway. The effects of AICAR on cardiomyocyte hypertrophy were also blocked after MuRF1 was silenced by transfection of cardiomyocytes with MuRF1-siRNA.Conclusion:The present study demonstrates that AMPK activation attenuates cardiomyocyte hypertrophy by modulating the atrophy-related FOXO1/MuRF1 signaling pathway in vitro.