LncRNA HIF1A-AS1 contributes to ventricular remodeling after myocardial ischemia/reperfusion injury by adsorption of microRNA-204 to regulating SOCS2 expression

Objectives: Long non-coding RNAs (lncRNAs) serve pivotal roles in heart disease, while the role of lncRNA hypoxia-inducible factor 1α-antisense RNA 1 (HIF1A-AS1) is rarely mentioned. Therefore, the objective of this study was to investigate the mechanism of lncRNA HIF1A-AS1 regulating suppressor of cytokine signaling 2 (SOCS2) expression by adsorption of microRNA-204 (miR-204) on ventricular remodeling after myocardial ischemia-reperfusion (I/R) injury in mice. Methods: The mouse model of I/R was established by left coronary artery occlusion. The expression of HIF1A-AS1, miR-204 and SOCS2 was determined. The mice were injected with HIF1A-AS1-siRNA, miR-204 mimics or their controls to investigate their effects on cardiac function and ventricular remodeling of mice after I/R injury. The binding relationship between HIF1A-AS1 and miR-204 as well as between miR-204 and SOCS2 were verified. Results: HIF1A-AS1 and SOCS2 were upregulated and miR-204 was downregulated in myocardial tissues in mice after I/R injury. LVEDD, LVEDS, LVEDP, LVMI and RVMI expression reduced while LVEF, LVFS, +dp/dt max and - dp/dt max increased through knockdown HIF1A-AS1 and upregulated miR-204. The expression of BNP, cTnI, LDH, CK, TNF-α, IL-1β, IL-6 and β-MHC reduced, and the expression of α-MHC increased when HIF1A-AS1 was poorly expressed and miR-204 was highly expressed. Silencing HIF1A-AS1 and upregulating miR-204 inhibited apoptosis of cells. LncRNA HIF1A-AS1 could act as ceRNA to adsorb miR-204 to suppress miR-204 expression and elevate SOCS2 expression. Conclusion: Our study provides evidence that downregulation of HIF1A-AS1 and upregulation of miR-204 could alleviate ventricular remodeling and improve cardiac function in mice after myocardial I/R injury via regulating SOCS2.

The pro-apoptosis and pro-inflammation role of LncRNA HIF1A-AS1 in Coxsackievirus B3-induced myocarditis via targeting miR-138

Background

Cardiomyocyte apoptosis and inflammation induced by Coxsackievirus B3 (CVB3) are key pathogenetic mechanisms in viral myocarditis. Alterations in microRNAs and lncRNAs are associated with cardiac remodeling. However, whether the microRNA and lncRNA interact to regulate cardiomyocyte apoptosis and inflammation is unknown.

Methods

BALB/c mice were infected with CVB3 to generate acute viral myocarditis model. The expression levels of lncRNA HIF1A-AS1 and miR-138 were examined in mouse myocardium and primary cardiomyocytes with CVB3 infection. We then knocked down HIF1A-AS1 by siRNA and upregulated miR-138 by microRNA mimics in cardiomyocytes.

Results

The expression of lncRNA HIF1A-AS1was significantly increased in CVB3-induced myocardium and cardiomyocytes. As documented by flow cytometry, silencing of HIF1A-AS1 alleviated late apoptosis (5.1%±2.8% vs. 17.2%±4.2%, P<0.01) and ROS production (68.73%±2.78% vs. 90.40%±2.86%, P<0.01) compared to their levels in cardiomyocytes transfected with control siRNA. The content of proinflammatory cytokines was substantially decreased by HIF1A-AS1 siRNA. Furthermore, we identified that HIF1A-AS1 bound to miR-138 and significantly suppressed miR-138 expression. Blocking HIF1A-AS1 attenuated IκBα phosphorylation and NF-κB activity, while cotransfection with miR-138 mimics markedly reversed its effect.

Conclusions

In conclusion, lncRNA HIF1A-AS1 promotes NF-κB signaling and subsequently aggravates cardiomyocyte apoptosis and inflammation via targeting miR-138.