Abstract:
Objective To investigate the effect of long non-coding RNA Jumonji C domain containing histone demethylase 1 homolog D antisense RNA1 (lncRNA JHDM1D-AS1) targeting microRNA-421 (miR-421) on hydrogen peroxide (H2O2) induced oxidative damage in cardiomyocytes (H9C2 cells).
Methods H9C2 cells were divided into control (Con) group, H2O2 group, H2O2+pcDNA group, H2O2+pcDNA-JHDM1D-AS1 group, H2O2+anti-miR-NC group, H2O2+anti-miR-421 group, H2O2+pcDNA-JHDM1D-AS1+miR-NC group, and H2O2+pcDNA-JHDM1D-AS1+miR-421 group. The expressions of JHDM1D-AS1 and miR-421 were detected by real-time fluorescent quantitative PCR (RT-qPCR). The superoxide dismutase (SOD) activity, malondialdehyde (MDA) level, and lactate dehydrogenase (LDH) level in the culture medium of H9C2 cells were measured by colorimetry. Flow cytometry was used to evaluate the apoptosis rate of H9C2 cells. The targeting relationship between JHDM1D-AS1 and miR-421 was verified by dual luciferase reporter gene assay.
Results Compared with the Con group, the H2O2 group showed decreased levels of JHDM1D-AS1 and SOD activity, and increased levels of MDA, LDH, apoptosis rate, and miR-421 in H9C2 cells, with significant between-group differences (P < 0.05). Compared with the H2O2+pcDNA group, the H2O2+pcDNA-JHDM1D-AS1 group exhibited increased SOD activity and decreased miR-421 expression level, MDA level, LDH level, and apoptosis rate in H9C2 cells, with significant between-group differences (P < 0.05). Compared with the H2O2+anti-miR-NC group, the H2O2+anti-miR-421 group showed increased SOD activity and decreased MDA level, LDH level, and apoptosis rate in H9C2 cells, with significant between-group differences (P < 0.05). MiR-421 was identified as a target gene of JHDM1D-AS1. Compared with the H2O2+pcDNA-JHDM1D-AS1+miR-NC group, the H2O2+pcDNA-JHDM1D-AS1+miR-421 group exhibited decreased SOD activity and increased MDA level, LDH level, and apoptosis rate in H9C2 cells, with significant between-group differences (P < 0.05).
Conclusion LncRNA JHDM1D-AS1 inhibits apoptosis and oxidative stress by targeting and downregulating miR-421 expression, thereby alleviating H2O2-induced oxidative damage in cardiomyocytes.