Abstract
Long non‑coding RNA (lncRNA) ZNFX1 antisense RNA 1 (ZFAS1) is upregulated in acute myocardial infarction; however, the role of ZFAS1 in myocardial ischemia/reperfusion (I/R) injury remains unknown. The present study aimed to detect microRNA (miR)‑590‑3p expression levels in cardiomyocytes subjected to I/R, and to investigate the effects of ZFAS1 on myocardial I/R injury. An in vitro model of I/R injury was established using rat H9c2 cardiomyocytes exposed to hypoxia/reoxygenation (H/R). It was demonstrated that ZFAS1 was upregulated and miR‑590‑3p was downregulated in the in vitro model of cardiac I/R injury. Western blotting results indicated that the protein expression levels of p50, tumor necrosis factor‑α (TNF‑α), interleukin (IL)‑6, Bax and cleaved caspase‑3 were upregulated, and the expression levels of Bcl‑2 and pro‑caspase‑3 were downregulated. Flow cytometry results revealed that downregulation of ZFAS1 reduced H/R‑induced apoptosis in H9c2 cells. In addition, downregulation of ZFAS1 significantly increased the expression of miR‑590‑3p, and p50 was identified as a target gene of miR‑590‑3p. Furthermore, with 12 h of hypoxia followed by 2 h of reoxygenation in H9c2 cells, ZFAS1 knockdown increased the expression levels of miR‑590‑3p, Bax and cleaved‑caspase‑3, and decreased the expression levels of Bcl‑2 and pro‑caspase‑3. It was also found that the miR‑590‑3p‑mimic transfection increased the expression levels of Bax and cleaved‑caspase‑3, and decreased the protein expression levels of p50, TNF‑α, IL‑6, Bcl‑2 and pro‑caspase‑3. In addition, TNF‑α treatment induced apoptosis of H9c2 cells, and the changes in Bax, Bcl‑2, cleaved‑caspase‑3 and pro‑caspase‑3 expression levels in a dose‑dependent manner. Collectively, the present results suggested that ZFAS1 was upregulated in H9c2 cells subjected to I/R injury, and that ZFAS1 knockdown protected against I/R‑induced myocardial cell apoptosis by directly interacting with miR‑590‑3p, via the NF‑κB pathway.