目的:探讨AKT/FOXO1信号通路在心力衰竭(HF)小鼠骨骼肌萎缩中的作用.方法:采用主动脉弓横向结扎8周,复制小鼠HF动物模型.采用实时定量-聚合酶链式反应和Western blot技术检测HF小鼠胫骨前肌内,E3连接酶的2个肌肉萎缩特异性指标Atrogin-1和MuRF1,对胫骨前肌中转录因子FOXO1和激酶AKT的磷酸化水平和总蛋白水平进行测定,并比较磷酸化蛋白和总蛋白的比率.结果:与对照组小鼠相比,TAC 8周诱导HF小鼠的胫骨前肌肌纤维变小,质量减轻.RT-PCR分析结果显示,HF小鼠胫骨前肌内的Atrogin-1和MuRF1的mRNA表达明显上调(P＜0.01).Western blot分析结果显示,HF小鼠胫骨前肌组织中Atrogin-1和MuRF1的蛋白相对表达量HF组较对照组明显增加(P＜0.01).HF组小鼠胫骨前肌中p-FOXO1的表达水平较对照组增加,FOXO1的总蛋白水平显著下降;p-AKT的蛋白表达较对照组增加(P＜0.05),AKT的总蛋白水平差异无统计学意义.p-FOXO1/FOXO1和p-AKT/AKT比率HF组明显高于对照组(P＜0.01).结论:AKT/FOXOs信号通路参与HF后骨骼肌萎缩的过程并发挥重要作用.%Objective:To investigate the role of AKT/FOXO1 signaling pathway in skeletal muscle atrophy in mouse with heart failure.Methods:Transverse aortic constriction for 8 weeks was used to establish heart failure (HF) model.The mRNA expression of Atrogin-1 and MuRF1 were measured by realtime-polymerase chain reaction (realtime-PCR).The protein expression of Atrogin-1,MuRF1,phosohorylated-FOXO1,FOXO-1,phosphorylated-AKT and total AKT were measured by Western blot.Results:Compared with the control group,the mRNA expressions of Atrogin-1 and MuRF1 significantly increased in tibialis anterior (TA) muscle of the HF group (P ＜ 0.05).Meanwhile the protein expression of Atrogin-1 and MuRF1 significantly increased in the HF group (P ＜0.01).In addition,the protein expression levels of FOXO1 decreased in HF group and the protein expression levels AKT were not changed in control and HF group.The ratio of phosohorylated-FOXO1 to total FOXO1 and the ratio of phosphorylated-AKT to total AKT significantly increased in TA muscle of the HF group (P ＜ 0.05).Conclusion:The phosphorylated level of AKT/FOXO1 skeletal muscle are significantly increased in HF mouse,suggesting that AKT/FOXO1 signaling pathway plays a crucial role in skeletal muscle atrophy of HF.
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