Role of miR-1 and miR-133a in myocardial ischemic postconditioning

Journal of Biomedical Science

Research

Bin He¹  Ying-Wei Wang¹  Bing Xie²  Min Chen³  Hao Zhang⁴  Jian Xiao⁵  Yu-Feng Zhang⁵  Xiao-Gang Gao⁶  An-Jing Ren⁷ 

[1] Department of Anesthesiology, Xinhua Hospital, Shanghai Jiaotong University School of Medicine, Kongjiang Road, Shanghai, China;Department of Burn, Changhai Hospital, the Second Millitary Medical University, Changhai Road, Shanghai, China;Department of Cardiology, Shanghai Tenth People's Hospital, Tongji University, Middle Yanchang Road, Shanghai, China;Department of Cardiothoracic Surgery, Changhai Hospital, the Second Millitary Medical University, Changhai Road, Shanghai, China;Department of Cardiothoracic Surgery, Changzheng Hospital, the Second Military Medical University, Fengyang Road, Shanghai, China;Department of Organ Transplantation, Changzheng Hospital, the Second Military Medical University, Fengyang Road, Shanghai, China;Department of Pathophysiology, the Second Millitary Medical University, Xiangyin Road, Shanghai, China;

关键词: Left Anterior Descend;    Ischemia Reperfusion Injury;    Ischemia Reperfusion;    TUNEL Assay;    Cardiomyocyte Apoptosis;   

DOI  :  10.1186/1423-0127-18-22

 received in 2010-11-29, accepted in 2011-03-16,  发布年份 2011

来源: Springer

【 摘 要 】

BackgroundIschemic postconditioning (IPost) has aroused much attention since 2003 when it was firstly reported. The role of microRNAs (miRNAs or miRs) in IPost has rarely been reported. The present study was undertaken to investigate whether miRNAs were involved in the protective effect of IPost against myocardial ischemia-reperfusion (IR) injury and the probable mechanisms involved.MethodsThirty SD rats weighing 250-300 g were equally randomized to three groups: Control group, where the rats were treated with thoracotomy only; IR group, where the rats were treated with ischemia for 60 min and reperfusion for 180 min; and IPost group, where the rats were treated with 3 cycles of transient IR just before reperfusion. The extent of myocardial infarction, LDH and CK activities were measured immediately after treatment. Myocardial apoptosis was detected by TUNEL assay. The myocardial tissue was collected after IR or IPost stimulation to evaluate the miRNAs expression level by miRNA-microarray and quantitative real-time RT-PCR. Real-time PCR was conducted to identify changes in mRNA expression of apoptosis-related genes such as Bcl-2, Bax and Caspase-9 (CASP9), and Western blot was used to compare the protein expression level of CASP9 in the three groups. The miRNA mimics and anti-miRNA oligonucleotides (AMO) were transferred into the cultured neonatal cardiomyocytes and myocardium before they were treated with IR. The effect of miRNAs on apoptosis was determined by flow cytometry and TUNEL assay. CASP9, as one of the candidate target of miR-133a, was compared during IR after the miR-133a mimic or AMO-133a was transferred into the myocardium.ResultsIPost reduced the IR-induced infarct size of the left ventricle, and decreased CK and LDH levels. TUNEL assay showed that myocardial apoptosis was attenuated by IPost compared with IR. MiRNA-microarray and RT-PCR showed that myocardial-specific miR-1 and miR-133a were down-regulated by IR, and up-regulated by IPost compared with IR. Furthermore, IPost up-regulated the mRNA expression of Bcl-2, down-regulated that of Bax and CASP9. Western blot showed that IPost also down-regulated the CASP9 protein expression compared with IR. The results of flow cytometry and TUNEL assay showed that up-regulation of miR-1 and miR-133a decreased apoptosis of cardiomyocytes. MiR-133a mimic down-regulated CASP9 protein expression and attenuated IR-induced apoptosis.ConclusionMiRNAs are associated with the protective effect of IPost against myocardial IR injury. IPost can up-regulate miR-1 and miR-133a, and decrease apoptosis of cardiomyocyte. Myocardial-specific miR-1 and miR-133a may play an important role in IPost protection by regulating apoptosis-related genes. MiR-133a may attenuate apoptosis of myocardiocytes by targeting CASP9.

【 授权许可】

Unknown   
© He et al; licensee BioMed Central Ltd. 2011. This article is published under license to BioMed Central Ltd. This is an Open Access article distributed under the terms of the Creative Commons Attribution License (http://creativecommons.org/licenses/by/2.0), which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.