Abstract
Hypoxia/reoxygenation (H/R) is used as an in vivo model of ischemia/reperfusion injury, and myocardial ischemia can lead to heart disease. Therefore, it is necessary to prevent myocardial H/R injury to avoid the risk of heart disease. The aim of the present study was to investigate whether inhibiting microRNA (miR)‑101a‑3p attenuated H9C2 cell H/R injury, apoptosis mechanisms and key target proteins. Cell viability and apoptosis were determined by Cell Counting Kit‑8 assays and flow cytometry using a cell apoptosis kit, respectively. The contents of creatine kinase (CK) and lactate dehydrogenase (LDH) were detected using colorimetric assays. Dual luciferase assays were carried out to determine if miR‑101a‑3p inhibited Janus kinase (JAK)2. Western blot analysis and reverse transcription‑quantitative PCR were used to determine proteins levels and mRNAs expression. It was found that the inhibition of miR‑101a‑3p increased the growth of H9C2 cells and decreased H9C2 cell apoptosis during H/R injury. The inhibition of miR‑101a‑3p reduced the amounts of CK and LDH in H/R model H9C2 cells. The inhibition of miR‑101a‑3p lowered the levels of Bax, interleukin‑6 and tumor necrosis factor‑α, but raised the levels of phosphorylated (p)‑STAT3 and p‑JAK2 in H9C2 cells subjected to H/R injury treatment. miR‑101a‑3p mimic was found to inhibit H9C2 cell viability, raise p‑JAK2 level and slightly increase p‑STAT3 during H/R injury. AG490 induced H9C2 cell apoptosis, and decreased the levels of p‑JAK2 and p‑STAT3 during H/R injury. The data indicated that inhibiting miR‑101a‑3p reduced H/R damage in H9C2 cells and decreased apoptosis via Bax/Bcl‑2 signaling during H/R injury. In addition, it was suggested that the inhibition of miR‑101a‑3p decreased H/R injury in H9C2 cell by regulating the JAK2/STAT3 signaling pathway.