心脏收缩力调节对慢性心力衰竭兔心肌自噬的影响及可能机制  

Effects of cardiac contractility modulation on the autophagy of cardiomyocytes in rabbits with chronic heart failure and the underlying mechanisms

作　　者：郝清卿[1] 吕仕林 张静[4] 张立涛[2] 张飞飞[1] Hao Qingqing;Lv Shilin;Zhang Jing;Zhang Litao;Zhang Feifei(Department of Cardiology,Hebei General Hospital,Shijiazhuang 050051,China;Department of Emergency,Hebei General Hospital,Shijiazhuang 050051,China;School of Graduate,Hebei Medical University,Shijiazhuang 050017,China;School of Graduate,Hebei North University,Zhangjiakou 075051,China)

机构地区：[1]河北省人民医院心内科,河北石家庄050051 [2]河北省人民医院急诊科,河北石家庄050051 [3]河北医科大学研究生院,河北石家庄050017 [4]河北北方学院研究生院,河北张家口075051

出　　处：《临床荟萃》2024年第11期1026-1034,共9页Clinical Focus

基　　金：2021年度河北省“三三三人才工程”资助项目“SGLT2抑制剂对心力衰竭分子生物学机制的影响”(A202101065)。

摘　　要：目的研究心脏收缩力调节(CCM)干预对慢性心力衰竭(CHF)兔心肌自噬的影响及可能机制。方法将30只体重2.5~3.5 kg的健康大白兔随机分成假手术组(Sham组)、HF组和CCM干预组(CCM组),每组各10只。HF组通过升主动脉根部套扎法建立慢性心力衰竭模型,而CCM组在成功建立HF模型后进行为期4周的CCM干预。在实验的第12周和第16周,对各组进行心脏功能的超声心动图检测,利用免疫荧光染色技术检测自噬过程中一个关键的标记蛋白微管相关蛋白1轻链3(microtuble-associated protein 1 light chain 3,LC3)的表达情况,此外,运用western blot蛋白印迹技术,观察P62蛋白、Beclin1蛋白和LC3B(II/I)蛋白等表达水平,并测定各组动物心肌组织中蛋白激酶B(AKT)的三个亚型AKT1、AKT2、AKT3,磷脂酰肌醇-3-激酶(PI3K)的亚型PI3K(α110)、PI3K(α85)以及哺乳动物雷帕霉素靶蛋白(mTOR)的表达情况。结果实验第12周末,HF组和CCM组左室舒张末期内径(LVEDD)和收缩末期内径(LVESD)相较于假手术组增加,而左心室射血分数(LVEF)和左室短轴缩短率(LVFS)相比假手术组明显下降(P<0.05);实验第16周末,CCM组LVEF、LVFS、LVESD、LVEDD指标相较于HF组有明显改善(P<0.05)。与HF组相比,经CCM干预后的兔的心肌组织P62蛋白表达水平显著升高,LC3免疫荧光染色阳性染色减少,Beclin1蛋白和LC3B蛋白表达水平显著下降,LC3B(II/I)比值显著下降(P<0.05)。此外,经CCM干预后的心肌组织内AKT1、AKT2、AKT3、mTOR蛋白表达水平显著减少(P<0.05),而PI3K(α110)、PI3K(α85)蛋白的表达则增加(P<0.05),与HF组相比差异有统计学意义。结论CCM干预可通过调节PI3K/AKT信号通路,改善HF兔心肌自噬相关蛋白的异常表达,从而减轻心肌自噬活动,并改善心肌的舒缩功能。Objective To explore the effect of cardiac contractility modulation(CCM)on the autophagy of cardiomyocytes in rabbits with chronic heart failure(CHF)and the underlying mechanisms.Methods Thirty healthy New Zealand White rabbits weighing 2.5-3.5 kg were randomly assigned to the sham operation group,HF group,and CCM group,with 10 rabbits in each group.A CHF model was established by the ascending aortic constriction method,followed by CCM for 4 weeks.At 12 and 16 weeks,echocardiography was employed to assess the cardiac function.Expression level of the microtuble-associated protein 1 light chain 3(LC3)was detected by immunofluorescence staining.Protein levels of P62,Beclin1,light chain 3B II/I(LC3B II/I),protein kinase B(AKT)1,AKT2,AKT3,phosphatidylinositol 3-kinase(PI3K)α110,PI3Kα85 and mammalian target of rapamycin(mTOR)in myocardial tissue were detected by Western blot.Results At 12 weeks,rabbits in the HF and CCM groups had significantly larger left ventricular end-diastolic diameter(LVEDD)and left ventricular end-systolic diameter(LVESD),and lower left ventricular ejection fraction(LVEF)and left ventricular fractional shortening(LVFS)than those of sham operation group(P<0.05).At 16 weeks,significant improvements in LVEF,LVFS,LVESD and LVEDD were observed in the CCM group than HF group(P<0.05).Compared with those of the HF group,rabbits in the CCM group had significantly upregulated p62,PI3Kα110 and PI3Kα85,less LC3-positive immunofluorescence staining,downregulated Beclin1,LC3B,AKT1-3 and mTOR in myocardium and lower LC3B(II/I)ratio(all P<0.05).Conclusion CCM can improve the abnormal expression of LC3B(II/I),Beclin1 and p62 protein in myocardium of CHF rabbits,reduce the activity of autophagy in rabbit myocardium,and improve myocardial contractile and diastolic function by regulating the PI3K/AKT signaling pathway.

关 键 词：心力衰竭 自噬 心肌收缩 自噬相关蛋白 PI3K/AKT 兔 

分 类 号：R541.6[医药卫生—心血管疾病]