lncRNA-TUG1靶向Zeste同源物增强子2对缺氧心肌细胞的影响  

Effects of lncRNA-TUG1 targeting enhancer of Zeste homolog 2 on hy⁃poxic cardiomyocytes

作　　者：常晨 许玉莉 任艳玲 李金轶 苏强 CHANG Chen;XU Yuli;REN Yanling;LI Jinyi;SU Qiang(Guilin Medical University,Guilin 541000,China;Jiangbin Hospital of Guangxi Zhuang Autonomous Region,Nanning 530021,China)

机构地区：[1]桂林医学院,广西桂林541000 [2]广西壮族自治区江滨医院,广西南宁530021

出　　处：《中国病理生理杂志》2023年第11期1931-1937,共7页Chinese Journal of Pathophysiology

基　　金：国家自然科学基金资助项目(No.82160077);广西自然科学基金重点项目(No.2020GXNSFDA238007)。

摘　　要：目的:体外探讨长链非编码RNA(lncRNA)牛磺酸上调基因1(TUG1)靶向Zeste同源物增强子2(EZH2)对缺氧心肌细胞的影响。方法:缺氧诱导HL-1细胞建立细胞损伤模型,构建沉默质粒(siTUG1)和阴性对照(siNC)并分别转染至HL-1细胞内,随机分成常氧(normoxia)组、低氧(hypoxia)组、hypoxia+siNC组和hypoxia+si-TUG1组。采用RT-qPCR检测lncRNA-TUG1在各模型组中的表达。通过CCK-8分析细胞活力。ELISA检测心肌损伤标志物和炎症因子水平。RT-qPCR检测线粒体生物合成相关转录调节基因和炎症因子的表达。Western blot检测线粒体生物合成相关转录调节蛋白的表达。通过染色质沉淀(ChIP)检测lncRNA-TUG1、EZH2、内皮型一氧化氮合酶(eNOS)和脑源性神经营养因子(BDNF)间的互作关系。结果:与normoxia组相比,hypoxia组和hypoxia+siNC组细胞的活力、线粒体生物合成相关转录调节基因的表达均显著降低(P<0.05),而心肌损伤标志物和炎症因子水平均显著升高(P<0.05);沉默TUG1可部分逆转上述改变。ChIP结果表明沉默TUG1可能抑制EZH2对eNOS和BDNF启动子区的结合(P<0.05)。结论:lncRNA-TUG1可能通过EZH2途径参与缺氧诱导的HL-1细胞炎症反应以及线粒体功能障碍。lncRNA-TUG1表达降低可进一步影响EZH2与eNOS和BDNF启动子区的结合,这可能是沉默TUG1缓解缺氧诱导的HL-1细胞炎症反应和线粒体功能障碍的潜在机制。AIM:To investigate the effect of long noncoding RNA-taurine upregulated gene 1(lncRNATUG1)targeting enhancer of Zeste homolog 2(EZH2)on hypoxic cardiomyocytes in vitro.METHODS:Hypoxia-induced HL-1 cells were established as a cell injury model.Silencing plasmid(siTUG1)and negative control(siNC)were constructed and transfected into HL-1 cells.The cells were randomly divided into normoxia,hypoxia,hypoxia+siNC and hypoxia+siTUG1 groups.RT-qPCR was used to measure the expression of lncRNA-TUG1 in the cells.Cell viability was analyzed by CCK-8 assay.The levels of myocardial injury markers and inflammatory factors were measured by ELISA.RTqPCR was used to measure the expression of mitochondrial biosynthesis-related transcriptional regulatory genes and inflammatory factors.Western blot was used to evaluate the expression of mitochondrial biosynthesis-related transcriptional regulatory proteins.Interactions between lncRNA-TUG1,EZH2,endothelial nitric oxide synthase(eNOS)and brain-derived neurotrophic factor(BDNF)were examined by chromatin immunoprecipitation(ChIP)assay.RESULTS:Compared with normoxia group,both cell viability and the expression of genes associated with mitochondrial biosynthesis were significantly decreased in hypoxia group and hypoxia+siNC group(P<0.05),while the expression levels of myocardial injury markers and inflammatory factors were significantly increased(P<0.05).Silencing of TUG1 partially reversed these changes.The results of ChIP indicated that silencing of TUG1 inhibited the binding of EZH2 to the promoter regions of eNOS and BDNF(P<0.05).CONCLUSION:lncRNA-TUG1 is involved in hypoxia-induced inflammatory responses and mitochondrial dysfunction in HL-1 cells through the EZH2 pathway.Reduced expression of lncRNA-TUG1 could fur-ther affect the binding of EZH2 to the promoter regions of eNOS and BDNF,which may be a potential mechanism by which silencing of TUG1 alleviates hypoxia-induced inflammatory response and mitochondrial dysfunction in HL-1 cells.

关 键 词：lncRNA-TUG1 心肌细胞 缺氧 线粒体 炎症 

分 类 号：R542.22[医药卫生—心血管疾病] R363[医药卫生—内科学]