CircHIPK3 aggravates myocardial ischemia-reperfusion injury by binding to miRNA-124-3p
Authors: G-X Jiang
C-L Pan
Y-M Zhang
M Bai
Z Zhang
Journal: European review for medical and pharmacological sciences (2019)
Discipline: PHARMACOLOGY & TOXICOLOGY
Keywords: circHIPK3; miRNA-124-3p; cardiomyocytes; proliferation; apoptosis
Affiliations: Heart Center, The First Affiliated Hospital of Lanzhou University, Gansu Provincial Clinical Research Center for Cardiovascular Diseases, Gansu Provincial Key Laboratory of Cardiovascular Disease, National Project of Improving the Diagnosis and Treatment Ability of Cardiovascular and Cerebrovascular Diseases, The First Hospital of Lanzhou University, Lanzhou, China. .

Abstract:  Objective: To elucidate whether circHIPK3 could inhibit proliferation and induce apoptosis of cardiomyocytes via binding to miRNA-124-3p, thus aggravating myocardial ischemia/reperfusion (IR) injury. Materials and methods: CircHIPK3 expression in HCM cells simulated with myocardial I/R was determined by quantitative Real Time-Polymerase Chain Reaction (qRT-PCR). Influences of circHIPK3 on myocardial injury marker levels of lactate dehydrogenase (LDH), malondialdehyde (MDA), superoxide dismutase (SOD) and glutathione peroxidase (GSH-PX) in the in vitro model of myocardial I/R were evaluated using the relative commercial kits. The regulatory effects of circHIPK3 on proliferative ability and apoptosis of simulated HCM cells were examined by Cell Counting Kit-8 (CCK-8) assay and flow cytometry, respectively. Dual-Luciferase reporter gene assay was conducted to verify the binding of circHIPK3 to miRNA-124-3p. Finally, the roles of the circHIPK3/miRNA-124-3p axis in regulating apoptotic gene expressions and cardiomyocyte repair after myocardial I/R were explored. Results: CircHIPK3 was highly expressed in HCM cells with simulated myocardial I/R relative to those with normoxic treatment. The overexpression of circHIPK3 in simulated HCM cells decreased levels of LDH, SOD and GSH-PX, whereas increased the MDA level. Inhibited proliferation and accelerated apoptosis were observed in simulated HCM cells overexpressing circHIPK3. Western blot analyses illustrated that circHIPK3 overexpression upregulated pro-apoptotic Bax, and downregulated anti-apoptotic Bcl-2. Subsequently, we confirmed the binding between circHIPK3 and miRNA-124-3p. Rescue experiments demonstrated that circHIPK3 overexpression reversed the protective effects of miRNA-124-3p on myocardial I/R and cardiomyocyte apoptosis. Conclusions: CircHIPK3 inhibits proliferative ability and induces apoptosis of cardiomyocytes after myocardial I/R injury by binding to miRNA-124-3p, which may serve as a potential therapeutic target for I/R. 

Retracted: No

PubPeer comments:
 Figure 2A Day 1 and Day 3 S100 DAPI seem to have an overlap, except that the Day 3 S100 DAPI image lacks DAPI signal.  , 
 Dear Dr. Oeneis, Thank you for your comments. We backtracked the fluorescence images and found the mistake we made on Figure 2A. This is an unintentional error when sorting pictures. We now replace the wrong images with correct ones as follows. However, this technical error does not change the meaning of the picture or hinder the conclusion of the article. We have also contacted the editorial board to apply for an erratum. We apologize for our unintentional mistakes which causes great inconvenience. Thank you again for your interest in our presenting work. Dr. Chen Zhu , 
 #1 Dear Dr. Oeneis, Thank you for your comments. We backtracked the fluorescence images and found the mistake we made on Figure 2A. This is an unintentional error when sorting pictures. We now replace the wrong images with correct ones as follows. However, this technical error does not change the meaning of the picture or hinder the conclusion of the article. We have also contacted the editorial board to apply for an erratum. We apologize for our unintentional mistakes which causes great inconvenience. Thank you again for your interest in our presenting work. Dr. Chen Zhu ,