LncRNA MIR22HG调节miR-132-3p_TLR2轴对急性心肌梗死小鼠心肌细胞凋亡和心室重构的影响.pdf

广西医科大学学报JOURNAL OF GUANGXI MEDICAL UNIVERSITY2023Jul.40（7）LncRNA MIR22HG调节miR-132-3p/TLR2轴对急性心肌梗死小鼠心肌细胞凋亡和心室重构的影响*李延民1，冯艳2，魏燕云3，王献忠1（河北省邯郸市第一医院1.心内二科；2.检验科；3.新生儿科，邯郸056002）摘要目的:探讨长链非编码RNA miR-22宿主基因（lncRNA MIR22HG）调节miR-132-3p/Toll样受体2（TLR2）轴对急性心肌梗死（AMI）小鼠心肌细胞凋亡和心室重构的影响。方法:取C57BL/6J小鼠随机分为sham组、AMI组、AMI+sh-NC组、AMI+sh-MIR22HG组、AMI+sh-MIR22HG+antagomir-NC组、AMI+sh-MIR22HG+antagomir-132-3p组，每组10只，除去sham组外，其它组都进行冠状动脉左前降支结扎，sham组只开胸不结扎冠状动脉，其中AMI+sh-NC组、AMI+sh-MIR22HG组、AMI+sh-MIR22HG+antagomir-NC组、AMI+sh-MIR22HG+antagomir-132-3p组小鼠分别相对应的对尾静脉注射sh-NC、sh-MIR22HG、sh-MIR22HG+antagomir-NC、sh-MIR22HG+antagomir-132-3p。超声心动图评估小鼠心室重构和心脏功能；HE染色和Masson染色观察心肌组织病理学变化及纤维化；RT-qPCR检测心肌组织MIR22HG、miR-132-3p表达；TUNEL法检测心肌细胞凋亡；Western blotting检测心肌组织B细胞淋巴瘤-2（Bcl-2）、激活型半胱氨酸蛋白酶-3（cleved caspase-3）/半胱氨酸蛋白酶-3（cas-pase-3）、型胶原蛋白（collagen）、collagen和-平滑肌肌动蛋白（-SMA）表达；双荧光素酶报告基因实验分别验证MIR22HG和miR-132-3p、miR-132-3p和TLR2的关系。结果:与sham组比较，AMI组小鼠心功能显著降低，心肌组织损伤、心肌纤维化加重，心肌细胞凋亡率、MIR22HG、TLR2、cleved caspase-3/caspase-3、collagen、collagen和-SMA蛋白表达水平显著升高，miR-132-3p和Bcl-2蛋白表达降低（P0.05）；与AMI+sh-NC组比较，AMI+sh-MIR22HG组小鼠心功能改善，心肌组织损伤、心肌纤维化减轻，心肌细胞凋亡率、MIR22HG、TLR2、cleved caspase-3/caspase-3、collagen、collagen和-SMA蛋白表达水平显著降低，miR-132-3p和Bcl-2蛋白表达上升（P0.05）；下调miR-132-3p减弱了敲减MIR22HG对心肌组织的保护作用；双荧光素酶报告基因实验结果显示，MIR22HG靶向调控miR-132-3p表达，miR-132-3p靶向负调控TLR2表达。结论:抑制MIR22HG表达可通过调节miR-132-3p/TLR2轴抑制AMI小鼠心肌细胞凋亡，改善小鼠心室重构。关键词急性心肌梗死；lncRNAMIR22HG；miR-132-3p；TLR2；细胞凋亡；心室重构中图分类号：R542.2文献标志码：A文章编号：1005-930X（2023）07-1123-09DOI：10.16190/ki.45-1211/r.2023.07.007Influences of lncRNA MIR22HG on cardiomyocyte apoptosis and ventricular remodeling inmice with acute myocardial infarction by regulating miR-132-3p/TLR2 axisLi Yanmin1,Feng Yan2,Wei Yanyun3,Wang Xianzhong1.(1.Department of Cardiology;2.Clinical laboratory;3.Neonatal Department,First Hospital of Handan City,Hebei Province,Handan 056002,China)AbstractObjective:To explore the influences of long non-coding RNA miR-22 host gene(lncRNA MIR-22HG)on cardiomyocyte apoptosis and ventricular remodeling in mice with acute myocardial infarction(AMI)by regulating miR-132-3p/Toll-like receptor 2(TLR2)axis.Methods:C57BL/6J mice were randomly grouped in-to sham group,AMI group,AMI+sh-NC group,AMI+sh-MIR22HG group,AMI+sh-MIR22HG+antagomir-NCgroup,and AMI+sh-MIR22HG+antagomir-132-3p group,with 10 in each group.Except that the sham group onlyunderwent thoracotomy without coronary artery ligation,all the other groups underwent ligation of the left anteri-or descending coronary artery.Among them,mice in the AMI+sh-NC group,AMI+sh-MIR22HG group,AMI+sh-MIR22HG+antagomir-NC group,and AMI+sh-MIR22HG+antagomir-132-3p group were injected with sh-NC,sh-MIR22HG,sh-MIR22HG+antagomir-NC,and sh-MIR22HG+antagomir-132-3p corresponding to thetail vein,respectively.Echocardiography was used toassess ventricular remodeling and cardiac function in*基金项目：河北省卫生厅医学科学研究重点课题计划项目（No.20160335）；邯郸市科学技术研究与发展计划项目（No.1623208064-5）收稿日期：2022-06-22 1123广西医科大学学报2023 Jul.40（7）mice;HE staining and Masson staining were applied to observe myocardial histopathological changes and fibro-sis;real-time fluorescence quantitative polymerase chain reaction(RT-qPCR)was applied to detect the expres-sions of MIR22HG and miR-132-3p in myocardial tissue;TUNEL method was applied to detect cardiomyocyteapoptosis;western blotting was applied to detect the expressions of myocardial tissue B-cell lymphoma-2(Bcl-2),activated cysteine protease-3(cleved caspase-3)/cysteine protease-3(caspase-3),type collagen(collagen)I,collagen and-smooth muscle actin(-SMA);and dual-luciferase reporter assays were applied to verify the re-lationship between MIR22HG and miR-132-3p,miR-132-3p and TLR2,respectively.Results:Compared withthe sham group,the cardiac function of the mice in the AMI group obviously decreased,and myocardial tissuedamage and myocardial fibrosis were aggravated.The cardiomyocyte apoptosis rate,the expressions ofMIR22HG,TLR2,cleved caspase-3/caspase-3,collagen,collagen and-SMA proteins obviously increased,while the protein expressions of miR-132-3p and Bcl-2 decreased(P0.05).Compared with the AMI+sh-NCgroup,the cardiac function of the mice in the AMI+sh-MIR22HG group was obviously improved,and myocardialtissue damage and myocardial fibrosis were alleviated;the cardiomyocyte apoptosis rate,the expressions ofMIR22HG,TLR2,cleved caspase-3/caspase-3,collagen,collagen and-SMA proteins obviously decreased,while the protein expressions of miR-132-3p and Bcl-2 increased(P0.05);down-regulation of miR-132-3p at-tenuated the protective effect of knockdown of MIR22HG on myocardial tissue;the results of the dual-luciferasereporter gene assay showed that MIR22HG targeting regulated the expression of miR-132-3p,and miR-132-3ptargeting negatively regulated the expression of TLR2.Conclusion:Inhibition of MIR22HG expression can in-hibit cardiomyocyte apoptosis and improve ventricular remodeling in AMI mice by regulating the miR-132-3p/TLR2 axis.Keywordsacute myocardial infarction;long non-coding RNA miR-22 host gene;miR-132-3p;To