基于BDNF/TrkB信号通路介导的线粒体自噬对心肌缺血再灌注损伤的作用机制研究  

Mechanism of Mitochondrial Autophagy Mediated by BDNF/TrkB Signaling Pathway on Myocardial Ischemia-reperfusion Injury

作　　者：王宝莉[1] 刘文君[1] 李莹[1] 李晨辉 WANG Baoli;LIU Wenjun;LI Ying;LI Chenhui(Xi'an First Hospital(First Affiliated Hospital of Northwest University),Xi'an 710002,Shaanxi,China)

机构地区：[1]西安市第一医院(西北大学附属第一医院),西安710002

出　　处：《中西医结合心脑血管病杂志》2024年第17期3136-3142,共7页Chinese Journal of Integrative Medicine on Cardio-Cerebrovascular Disease

基　　金：陕西省卫生健康委员会科研项目(No.20210411)。

摘　　要：目的:探讨基于脑源性神经营养因子(BDNF)/原肌球蛋白受体激酶B(TrkB)信号通路介导的线粒体自噬对心肌缺血再灌注(I/R)损伤的作用。方法:将小鼠随机分为假手术(Sham)+磷酸盐缓冲液(PBS)组、Sham+7,8-二羟基黄酮(7,8-DHF)组、I/R+PBS组和I/R+7,8-DHF组,每组12只。除Sham组,其余小鼠建立心肌I/R损伤模型(心肌缺血45 min/再灌注2 h)。Sham+7,8-DHF组和I/R+7,8-DHF组小鼠在心肌I/R损伤前7 d腹腔注射7,8-DHF;Sham+PBS组和I/R+PBS组则给予相同体积的PBS。超声心动图、苏木精-伊红(HE)染色和免疫组织化学用于检测心脏功能、组织学和细胞间黏附分子-1(ICAM-1)表达。从各组小鼠心脏中分离心脏微血管内皮细胞(CMEC),通过将TrkB小干扰RNA(si-TrkB)转染到CMEC细胞中抑制TrkB活化,然后进行线粒体膜通透性转换孔(mPTP)开放率测量。结果:I/R+PBS组中红细胞在I/R损伤后聚集成块,I/R+7,8-DHF组则维持了红细胞的线性形态并阻止了其在微血管中的会聚。与I/R+PBS组相比,I/R+7,8-DHF组p-eNOS水平、室间隔厚度、左心室短轴缩短分数、左心室射血分数上调(P<0.05),内皮素-1(ET-1)、ICAM-1、心脏质量、心脏质量指数、左心室舒张末期内径、左心室收缩末期内径下调(P<0.05)。I/R+PBS组CMEC中BDNF、TrkB、FU N14结构域1(FUNDC1)蛋白表达和酸性自溶酶体形成较Sham+PBS组减少(P<0.05),而I/R+7,8-DHF组CMEC中BDNF、TrkB、FUNDC1蛋白表达和酸性自溶酶体形成较I/R+PBS组增加(P<0.05)。当在7,8-DHF存在的情况下施用si-TrkB以抑制CMEC中的TrkB活化时,FUNDC1的表达被抑制(P<0.05),并且线粒体轻链3(mito-LC3Ⅱ)的线粒体水平和酸性自溶酶体形成减少(P<0.05)。结论:激活BDNF/TrkB/FUNDC1信号通路通过恢复线粒体自噬改善I/R小鼠的内皮功能和微血管结构。Objective:To explore the mechanism of mitochondrial autophagy mediated by brain-derived neurotrophic factor(BDNF)/tropomyosin receptor kinase B(TrkB)signaling pathway on myocardial ischemia-reperfusion(I/R)injury.Methods:The mice were randomly divided into Sham+phosphate buffer(PBS)group,Sham+7,8-dihydroxyflavone(7,8-DHF)group,I/R+PBS group and I/R+7,8-DHF group,with 12 mice in each group.Myocardial I/R injury model(myocardial ischemia 45 min/reperfusion 2 h)were established in other mice except Sham group.Mice in Sham+7,8-DHF group and I/R+7,8-DHF group were intraperitoneally injected with 7,8-DHF 7 d before myocardial I/R injury.Sham+PBS group and I/R+PBS group were given the same volume of PBS.Echocardiography,hematoxylin-eosin(HE)staining and immunohistochemistry were used to detect cardiac function,histology,and intercellular adhesion molecule-1(ICAM-1)expression.Cardiac microvascular endothelial cells(CMEC)were isolated from the hearts of mice in each group.TrkB small interfering RNA(si-TrkB)was transfected into CMEC cells to inhibit TrkB activation,and then the opening rate of mitochondrial membrane permeability transition pore(mPTP)was measured.Results:In the I/R+PBS group,red blood cells clustered after I/R injury,while in the I/R+7,8-DHF group,the linear morphology of red blood cells were maintained and the convergence in microvessels was prevented.Compared with I/R+PBS group,P-ENOS level,ventricular septal thickness,left ventricular short axis shortening fraction,and left ventricular ejection fraction in I/R+7,8-DHF group increased(P<0.05).Endothelin-1(ET-1),ICAM-1,heart mass,heart mass index,left ventricular end-diastolic diameter and left ventricular end-systolic diameter were down regulated(P<0.05).The expression of BDNF,TrkB,FUN14 domain 1(FUNDC1)protein and the formation of acid autolyssome in CMEC in I/R+PBS group decreased compared with those in Sham+PBS group(P<0.05),the expression of BDNF,TrkB,FUNDC1 protein and the formation of acid autolyssome in CMEC in I/R+7,8-DHF group increased compared

关 键 词：心肌缺血再灌注 线粒体自噬 脑源性神经营养因子 原肌球蛋白受体激酶B 7 8-二羟基黄酮 实验研究 

分 类 号：R542.22[医药卫生—心血管疾病]