The lncRNA, H19 Mediates the Protective Effect of Hypoxia Postconditioning Against Hypoxia-Reoxygenation Injury to Senescent Cardiomyocytes by Targeting microRNA-29b-3p

J Cellular Molecular Medi

Jiang

Chen

et al. 2019

Myocardial infarction (MI) remains the leading cause of morbidity and mortality worldwide, and novel therapeutic targets still need to be investigated to alleviate myocardial injury and the ensuing maladaptive cardiac remodelling. Accumulating studies have indicated that lncRNA H19 might exert a crucial regulatory effect on cardiovascular disease. In this study, we aimed to explore the biological function and molecular mechanism of H19 in MI. To investigate the biological functions of H19, miRNA‐22‐3p and KDM3A, gain‐ and loss‐of‐function experiments were performed. In addition, bioinformatics analysis, dual‐luciferase reporter assays, RNA immunoprecipitation (RIP) assays, RNA pull‐down assays, quantitative RT‐PCR and Western blot analyses as well as rescue experiments were conducted to reveal an underlying competitive endogenous RNA (ceRNA) mechanism. We found that H19 was significantly down‐regulated after MI. Functionally, enforced H19 expression dramatically reduced infarct size, improved cardiac performance and alleviated cardiac fibrosis by mitigating myocardial apoptosis and decreasing inflammation. However, H19 knockdown resulted in the opposite effects. Bioinformatics analysis and dual‐luciferase assays revealed that, mechanistically, miR‐22‐3p was a direct target of H19, which was also confirmed by RIP and RNA pull‐down assays in primary cardiomyocytes. In addition, bioinformatics analysis and dual‐luciferase reporter assays also demonstrated that miRNA‐22‐3p directly targeted the KDM3A gene. Moreover, subsequent rescue experiments further verified that H19 regulated the expression of KDM3A to ameliorate MI‐induced myocardial injury in a miR‐22‐3p‐dependent manner. The present study revealed the critical role of the lncRNAH19/miR‐22‐3p/KDM3A pathway in MI. These findings suggest that H19 may act as a potential biomarker and therapeutic target for MI.

Section: Discussionsupporting

confidence: 91%

Section: Discussionsupporting

confidence: 91%

LncRNA H19 ameliorates myocardial infarction‐induced myocardial injury and maladaptive cardiac remodelling by regulating KDM3A

J Cellular Molecular Medi

Jiang

Chen

et al. 2019

“…it was found that H19 overexpression alleviated hypoxia-induced injury mediated apoptosis, cell cycle arrest and mitochondrial membrane potential depolarization; however, these processes were aggravated by H19 knockdown. These results suggested that H19 attenuated hypoxia-induced myocardial cell injury, which is consistent with previous studies (15,16). The findings of this previous report (16) and the present study are consistent with each other in regard to the molecular mechanism of H19 in protecting against myocardial i/r injury.…”

Section: Discussionsupporting

confidence: 93%

“…increased expression of H19 was detected in rats following surgically induced myocardial i/r, suggesting that H19 may have a role in the protective mechanisms against i/r injury (14). Previous studies have also indicated that H19 exerts protective effects against hypoxia-induced injury in cardiomyocytes (15,16). nevertheless, to date, the functional role of H19 in myocardial hypoxic injury has not been fully elucidated.…”

Section: Introductionmentioning

confidence: 93%

Long non‑coding RNA H19 protects H9c2 cells against hypoxia‑induced injury by activating the PI3K/AKT and ERK/p38 pathways

Yuan

et al. 2020

Mol Med Report

Myocardial ischemia/reperfusion injury often leads to adverse cardiovascular outcomes due to severe hypoxia. The present study aimed to evaluate the effects and mechanism of long non-coding rna H19 (H19) on rat H9c2 cells with hypoxia-induced injury. H9c2 cells were infected with lentiviruses to express H19 or H19-targeting short hairpin rna (shrna), or their respective controls, at a multiplicity of infection of 1:100. H19 expression was determined by reverse transcription-quantitative Pcr. Hypoxic injury was induced and assessed by analyzing the level of apoptosis, the cell cycle distribution and the mitochondrial membrane potential using flow cytometry in the different groups. The expression of the Pi3K/aKT and the erK/p38 signaling pathways were analyzed using western blotting. it was found that hypoxia stimulated apoptosis, induced G1 phase cell cycle arrest and increased the mitochondrial depolarization rate in H9c2 cells. When compared with the hypoxic model group, the H19 overexpression group had a significantly reduced rate of apoptosis (P=0.016), a smaller G1 population and a higher S phase population (P=0.018 and P=0.031, respectively), and a reduced mitochondrial depolarization rate (P=0.036). By contrast, the H19 shrna group exhibited the opposite trends, suggesting that hypoxia-induced injury was alleviated by the overexpression of H19 and was aggravated by the knockdown of H19. The present mechanistic studies revealed that H19 may decrease hypoxia-induced cell injury by activating the Pi3K/aKT and erK/p38 pathways. The results of the present study suggested that H19 may alleviate hypoxia-induced myocardial cell injury through the activation of the Pi3K/aKT and erK/p38 pathways.

“…The binding sites were verified by luciferase reporter gene assays. Indeed, the H19/miR-29b-3p/cIAP1 axis was revealed to play an important role in aged cardiomyocyte apoptosis [17]. However, whether Dex postconditioning can attenuate I/R injury by regulating H19 remains to be investigated.…”

Section: Introductionmentioning

confidence: 99%

Dexmedetomidine Postconditioning Alleviates Hypoxia/Reoxygenation Injury in Senescent Myocardial Cells by Regulating lncRNA H19 and m⁶A Modification

Oxidative Medicine and Cellular Longevity

et al. 2020

Self Cite

H19, a long noncoding RNA (lncRNA), reportedly protects myocardial cells (H9c2 cell line) against hypoxia-reoxygenation- (H/R-) induced injury. Dexmedetomidine (Dex) has an important myocardial protective effect, although its function and mechanism in cardiac ischemia/reperfusion (I/R) injury, especially for senile patients, requires further study. RNA N6-methyladenosine (m6A) is the most abundant endogenous RNA modification. However, the effect of Dex postconditioning on RNA m6A modification has rarely been reported. The aim of this study was to evaluate roles of H19 and m6A modification in Dex postconditioning of aged cardiomyocytes. Hydrogen peroxide (H2O2) was used to induce senescence of H9c2 cells. After 6 h of hypoxia, H9c2 cells were exposed to different concentrations of dexmedetomidine (0, 500 nM, 1 μM, and 2 μM) for 6 h. After knockdown or overexpression of H19 and its downstream gene miR-29b-3p and cellular inhibitor of apoptosis protein 1 (cIAP1), Dex postconditioning experiments were performed to examine effects on myocardial cell injury. Global m6A levels after H/R with or without Dex postconditioning were measured with a colorimetric m6A RNA Methylation Quantification Kit. The mechanism by which RNA m6A methylation regulated genes mediating H19 expression was verified by m6A RNA immunoprecipitation (MeRIP), and the function of Dex postconditioning of aged cardiomyocytes was investigated. Dex postconditioning protected against H/R-induced injury of aged myocardial cells through H19/miR-29b-3p/cIAP1, increased methylation of RNA m6A elicited by H/R, and attenuated H/R-induced injury by suppressing expression of the RNA m6A demethylase gene alkB homolog 5 (ALKBH5). In addition, AKLBH5 regulated the expression of H19, and Dex postconditioning attenuated H/R-induced injury via ALKBH5 in aged cardiomyocytes.