Inhibition of the lncRNA DANCR attenuates cardiomyocyte injury induced by oxygen-glucose deprivation via the miR-19a-3p/MAPK1 axis.

Long noncoding RNAs (lncRNAs) have been considered as crucial regulators of acute myocardial infarction (AMI). In this study, to analyze the effect of differentiation antagonizing nonprotein coding RNA (DANCR) of lncRNA on cardiomyocyte damage in AMI, cardiomyocyte injury was induced by oxygen-glucose deprivation (OGD). Cell counting kit-8 (CCK-8) assay and flow cytometry were used to assess cell viability and apoptosis, respectively. Quantitative real-time PCR was used to measure the expression levels of DANCR and miR-19a-3p. Bioinformatics analysis and luciferase gene reporter assay were utilized to explore the relationship among DANCR, miR-19a-3p, and mitogen-activated protein kinase 1 (MAPK1). CCK-8 and TUNEL assays were used to explore the effects of DANCR alone or plus miR-19a-3p on the viability and apoptosis of OGD/R-exposed HL-1 cells. Western blot analysis was used to detect changes in the MAPK1/ERK1/2 pathway in HL-1 cells. We found that DANCR expression and miR-19a-3p level are negatively correlated as DANCR expression is increased, while miR-19a-3p level is decreased in AMI patients' serum and OGD/R-exposed HL-1 cells. DANCR knockdown increased miR-19a-3p level, and miR-19a-3p inhibition increased DANCR expression. Moreover, DANCR directly binds to miR-19a-3p. DANCR knockdown reduced viability but induced apoptosis in OGD/R-exposed HL-1 cells, while miR-19a-3p inhibition weakens these effects. Furthermore, MAPK1 is a target of miR-19a-3p. miR-19a-3p overexpression decreases MAPK1 and ERK1/2 in HL-1 cells, while miR-19a-3p inhibition increases MAPK1 and ERK1/2 in HL-1 cells. Moreover, DANCR knockdown reduces myocardium apoptosis in mice with the left anterior descending artery ligated. DANCR knockdown effectively restores myocardial cell apoptosis by regulating the miR-19a-3p/MAPK1/ERK1/2 axis.