AMP激活蛋白激酶对慢性心力衰竭进展影响的实验研究

Influence of AMPK activation on chronic heart failure

目的:探讨AMP激活蛋白激酶(AMPK)对慢性心力衰竭进展的影响及可能作用机制。方法:选择8~10周龄雄性C57BL/6J小鼠共40只,随机分为四组,其中A组为生理盐水(NS)注射+假手术(sham),B组为AICAR注射+假手术(sham),C组为NS注射+行主动脉缩窄手术,D组为AICAR注射+行主动脉缩窄手术;比较不同组超声心动图指标、免疫印迹(Western blotting)、荧光共焦显微镜及透射电子显微镜(TEM)结果。结果:①C组心脏重量/体重比(HW/BW)、肺重量/体重比(LW/BW)、心脏重量/胫骨长度比(HW/TL)、肺重量/胫骨长度比(LW/TL)、左心室舒张末期内径(LVEDd)及左心室收缩末期内径(LVESd)水平均显著高于A、B组(P<0.05);C组EF水平显著低于A、B组(P<0.05);D组HW/BW、LW/BW、HW/TL、LW/TL、LVEDd及LVESd水平均显著高于A、B组,但低于C组(P<0.05);D组射血分数(EF)水平显著低于A、B组,但高于C组(P<0.05)。②D组术后LC3B-Ⅱ/LC3B-Ⅰ和LC3B-Ⅱ/GAPDH比值显著低于C组,P62表达显著高于C组(P<0.05);C组和D组心脏LC3b蛋白表达量显著高于A组、B组(P<0.05);D组心脏LC3b蛋白表达量显著低于C组(P<0.05);同时B组心脏LC3b蛋白表达量显著高于A组(P<0.05)。③B组术后4EBP1、P70S6K及AKT磷酸化水平显著高于A组(P<0.05);D组术后4EBP1、P70S6K及AKT(thr308)磷酸化水平显著低于C组(P<0.05);D组术后AKT(Ser473)磷酸化水平显著高于C组(P<0.05)。结论:慢性心力衰竭患者体内AMPK激活可通过上调mTORC 2表达、抑制心脏自噬活性,从而达到有效改善心脏功能的作用。

Objective:To investigate the influence of AMPK activation on chronic heart failure and its possible action mechanism.Methods:A total of 40 male C57BL/6J mice aged 8-10 weeks were selected and randomly divided into 4 groups.Group A received injection of normal saline(NS)+,sham operation,and group B received AICAR injection+sham operation(sham),and group C received NS injection+aortic constriction surgery,and group D received AICAR injection+aortic constriction surgery.The echocardiogram indexes,Western blotting,fluorescence confocal microscope and transmission electron microscope(TEM)results were compared between groups.Results:The levels of HW/BW,LW/BW,HW/TL,LW/TL,LVEDd and LVESd in group C were significantly higher than those in group A and B(P<0.05).The EF level in group C was significantly lower than that in group A and B(P<0.05).The levels of HW/BW,LW/BW,HW/TL,LW/TL,LVEDd and LVESd in group D were significantly higher than those in group A and B,but lower than those in group C(P<0.05).The EF level in group D was significantly lower than that in group A and B,but higher than that in group C(P<0.05).The ratio of LC3B-Ⅱ/LC3B-Ⅰand LC3B-Ⅱ/GAPDH in group D were significantly lower than those in group C after operation,and the P62 level in group D was significantly higher than that in group C(P<0.05).The expression level of cardiac LC3b protein in group C and D was significantly higher than that in group A and B(P<0.05).The expression level of cardiac LC3b protein in group D was significantly lower than that in group C(P<0.05).The expression level of cardiac LC3b protein in group B was significantly higher than that in group A(P<0.05).The phosphorylation levels of 4EBP1,P70S6K and AKT in group B were significantly higher than those in group A(P<0.05).The phosphorylation levels of 4EBP1,P70S6K and AKT(thr308)in group D were significantly lower than those in group C(P<0.05).The phosphorylation level of AKT(Ser473)in group D was significantly higher than that in group C(P<0.05).Conclusion:AMPK activation of patients with chronic heart failure can effectively improve cardiac function by up-regulating the expression of mTORC 2 and inhibiting cardiac autophagy.