过表达GATA-4基因的骨髓间充质干细胞外泌体对心肌梗死后心功能的影响  

Overexpressed GATA-4 bone marrow-derived mesenchymal stem cell exosomes improve myocardial infarction via miRNA-673-5p/Tsc-1 molecular axis

作　　者：李敏 王梓豪 严丹 谢巧丽 撒亚莲 贺继刚 LI Min;WANG Zi-hao;YAN Dan;XIE Qiao-li;SA Ya-lian;HE Ji-gang(Department of Cardiovascular Surgery,the Affiliated Hospital of Kunming University of Science and Technology/the First People’s Hospital of Yunnan Province,Kunming 650032,Yunnan,China;Department of Emergency Care Unit,the Affiliated Hospital of Kunming University of Science and Technology/the First People’s Hospital of Yunnan Province,Kunming 650032,Yunnan,China;Department of Basic Medicine,the Affiliated Hospital of Kunming University of Science and Technology/the First People’s Hospital of Yunnan Province,Kunming 650032,Yunnan,China)

机构地区：[1]昆明理工大学附属医院/云南省第一人民医院心脏大血管外科,昆明650032 [2]昆明理工大学附属医院/云南省第一人民医院急诊ICU,昆明650032 [3]昆明理工大学附属医院/云南省第一人民医院基础医学部,昆明650032

出　　处：《医学研究生学报》2020年第7期678-683,共6页Journal of Medical Postgraduates

基　　金：国家自然科学基金(81460073);云南省卫生和计划生育委员会医学后备人才项目(H-201607)。

摘　　要：目的过表达GATA-4基因的骨髓间充质干细胞(BMSC)外泌体(BMSCGATA-4-外泌体)可以促进BMSC向心肌样细胞分化,但其分子机制不详。文章探讨过表达BMSCGATA-4-外泌体通过miRNA-673-5p/Tsc-1分子轴促进干细胞向心肌样细胞分化的机制。方法将BMSC-外泌体、BMSC空载体-外泌体、BMSCGATA-4-外泌体、BMSCmiR-673-5p-mimic-外泌体、BMSCmiR-673-5p-inhibitor-外泌体小鼠建模后48 h经尾静脉注入,分别作为BMSC组、空载体组、GATA-4组、模拟组、抑制组,每组3只;另设置梗死未处理组(建模,未给予任何exosome处理)及正常组(不建模)作为对照,各3只。采用心脏彩超检测各组心功能。采用RT-PCR检测梗死后心肌细胞内miRNA-673-5p表达。同时提取相同梗死部位心肌组织,采用RT-PCR检测心肌α-actin、CX43、Desmin、cTnT表达。采用Western blot检测miRNA-673-5p对应靶基因Tsc-1、Erk1/2及Mef2c蛋白表达。结果GATA-4组、模拟组心功能较BMSC组和空载体组改善(P<0.05);与GATA-4组比,模拟组改善、抑制组恶化(P<0.05)。GATA-4组、模拟组miRNA-673-5p表达较BMSC组和空载体组增多(P<0.05);与GATA-4组miRNA-673-5p表达比较,模拟组增多,抑制组减少(P<0.05);与BMSC组比较,GATA-4组、模拟组增多(P<0.05);与正常组比较,梗死未处理组心肌细胞内Tsc-1的表达增多,GATA-4组和模拟组Tsc-1、Erk1/2、Mef2c表达均减少(P<0.05);BMSC组、空载体组、GATA-4组、模拟组、抑制组心肌细胞内Tsc-1表达(0.82±0.03、0.80±0.06、0.60±0.07、0.47±0.05、0.86±0.06)较梗死未处理组(1.10±0.06)减少(P<0.05);BMSC组、空载体组、GATA-4组、模拟组、抑制组心肌细胞内Erk1/2表达(1.02±0.07、0.99±0.07、0.77±0.14、0.63±0.21、1.06±0.08)较梗死未处理组(1.31±0.15)减少(P<0.05);BMSC组、空载体组、GATA-4组、模拟组、抑制组心肌细胞内Mef2c表达(0.87±0.08、0.86±0.05、0.72±0.10、0.62±0.09、0.91±0.16)较梗死未处理组(1.12±0.09)减少(P<0.05);与BMSC组比,GATAObjective Exosomes secreted by BMSC overexpressing GATA-4 gene(BMSCGATA-4-exosome)can promote the differentiation of BMSC into cardiomyocyte-like cells,thereby improve cardiac function after myocardial infarction.However,the molecular mechanism of BMSCGATA-4-exosome in cardiomyocyte-like cell differentiation is unknown.The effect of the secretion of BMSCGATA-4 exosome from bone marrow mesenchymal stem cells(BMSC)in the differentiation of stem cells into cardiomyocytes was determined in miRNA-673-5 p/Tsc-1 axis dependent manner.Methods Mouse models of myocardial infarction were established and divided into seven groups.Simulation group(BMSCmiR-673-5 p-mimic exosome),inhibition group(BMSCmiR-673-5 p-inhibitor exosome),GATA-4 group(BMSCGATA-4 exosome),empty vector group(BMSCempty vector exosome),and BMSC group(BMSC exosome)were injected into the tail vein for 48 h,and the untreated and normal mice were used as the control group.Cardiac ultrasound was used to detect cardiac function in each group.miRNA-673-5 p expression in myocardial infarction was detected using real-time polymerase chain reaction(RT-PCR).The myocardial tissues were extracted from the same myocardial infarction site.Myocardial-specific molecules,such asα-actin,Desmin,cTnT,and Cx43,were detected using RT-PCR.Western blot was used to determine the expression of the corresponding target gene of miRNA-673-5 p,Tsc-1,Erk1/2,and Mef2 c proteins.Results The simulation group wan shown the most significantly improved myocardial function(P<0.05)with an expression peak of miRNA-673-5 p in cardiomyocytes(P<0.05).The highest content of myocardial-specific molecules includingα-actin,Desmin,cTnT,and Cx43 was found in the simulation group.The simulation group had the lowest expression of Tsc-1 in cardiomyocytes(P<0.05).Conclusion Overexpressed BMSCGATA-4 exosomes inhibit Tsc-1 expression through miRNA-673-5 p to improve cardiac function during myocardial infarction.

关 键 词：miRNA-673-5p Tsc-1蛋白 GATA-4 外泌体 小鼠骨髓间充质干细胞 

分 类 号：R284[医药卫生—中药学]