Yanbing Li1, Qiang Li1, Ou Zhang2, Xiaonan Guan1, Yajun Xue2, Siyuan Li3, Xianjing Zhuang3, Boda Zhou2, Guobin Miao2. 1. Department of Cardiology, Beijing Chao-Yang Hospital, Capital Medical University, Beijing, China. 2. Department of Cardiology, Beijing Tsinghua Chang Gung Hospital, Tsinghua University, Beijing, China. 3. School of Clinical Medicine, Tsinghua University, Beijing, China.
Abstract
BACKGROUND: This study was aimed to unveil micro RNA (miRNA) expression profiles in myocardial ischemia-reperfusion (MI/R) rats and explore whether and how dysregulated miRNAs were involved in the initiation and progression of MI/R in a calcium-dependent manner. METHOD AND RESULTS: Rat model of MI/R was established and cardiomyocytes isolated from neonatal rats cardiomyocytes were induced. Both miRNA and messenger RNA expression profiles were analyzed by Microarray. Quantitative reverse-transcription polymerase chain reaction, immunoblotting, bioinformatics analysis, dual-luciferase reporter gene assay, hematoxylin and eosin, Evans blue, and triphenyl tetrazolium chloride were also used in this study. Serum concentrations of myocardial enzymes (phosphocreatine kinase [CK], creatine kinase [CK-MB], lactate dehydrogenase [LDH]), cardiomyocytes loadage of Ca2+ , as well as the expression level of inositol 1,4,5-trisphosphate receptors (IP3R) and sarcoplasmic reticulum Ca2+ -ATPase 2a (SERCA2a) were measured, respectively. Effects of upregulation or downregulation of miR-202-5p or Trpv2 on these indicators were investigated in vivo and in vitro. In MI/R rats and hypoxia/reoxygenation-induced NCMs, miR-202-5p was downregulated, while Trpv2 was upregulated. Trpv2 was a promising target of miR-202-5p and negatively regulated by miR-202-5p. Upregulation of miR-202-5p or downregulation of Trpv2 significantly reduced the serum concentration of myocardial enzymes, as well as cardiomyocyte-produced reactive oxygen species, but inhibition of miR-202-5p or overexpression of Trpv2 brought the worsening situation for these indicators. Besides, upregulation of miR-202-5p upregulation or downregulation of Trpv2 also inhibited Ca2+ overload in cardiomyocytes, accompanied with the increase of SERCA2a and suppression of IP3R. The reduced damage degree and infarct size in myocardial tissue were contrarily worsened by miR-202-5p inhibitor. CONCLUSION: Overexpression of miR-202-5p or downregulation of its downstream Trpv2 presented the cardioprotective effects to MI/R rats.
BACKGROUND: This study was aimed to unveil micro RNA (miRNA) expression profiles in myocardial ischemia-reperfusion (MI/R) rats and explore whether and how dysregulated miRNAs were involved in the initiation and progression of MI/R in a calcium-dependent manner. METHOD AND RESULTS:Rat model of MI/R was established and cardiomyocytes isolated from neonatal rats cardiomyocytes were induced. Both miRNA and messenger RNA expression profiles were analyzed by Microarray. Quantitative reverse-transcription polymerase chain reaction, immunoblotting, bioinformatics analysis, dual-luciferase reporter gene assay, hematoxylin and eosin, Evans blue, and triphenyl tetrazolium chloride were also used in this study. Serum concentrations of myocardial enzymes (phosphocreatine kinase [CK], creatine kinase [CK-MB], lactate dehydrogenase [LDH]), cardiomyocytes loadage of Ca2+ , as well as the expression level of inositol 1,4,5-trisphosphate receptors (IP3R) and sarcoplasmic reticulum Ca2+ -ATPase 2a (SERCA2a) were measured, respectively. Effects of upregulation or downregulation of miR-202-5p or Trpv2 on these indicators were investigated in vivo and in vitro. In MI/Rrats and hypoxia/reoxygenation-induced NCMs, miR-202-5p was downregulated, while Trpv2 was upregulated. Trpv2 was a promising target of miR-202-5p and negatively regulated by miR-202-5p. Upregulation of miR-202-5p or downregulation of Trpv2 significantly reduced the serum concentration of myocardial enzymes, as well as cardiomyocyte-produced reactive oxygen species, but inhibition of miR-202-5p or overexpression of Trpv2 brought the worsening situation for these indicators. Besides, upregulation of miR-202-5p upregulation or downregulation of Trpv2 also inhibited Ca2+ overload in cardiomyocytes, accompanied with the increase of SERCA2a and suppression of IP3R. The reduced damage degree and infarct size in myocardial tissue were contrarily worsened by miR-202-5p inhibitor. CONCLUSION: Overexpression of miR-202-5p or downregulation of its downstream Trpv2 presented the cardioprotective effects to MI/Rrats.