Role and mechanism of the lncRNA SNHG1/miR‑450b‑5p/IGF1 axis in the regulation of myocardial ischemia reperfusion injury.

The increasing rates of morbidity and mortality caused by ischemic heart disease pose a serious threat to human health. Long non‑coding (lnc)RNA small nucleolar RNA host gene 1 (SNHG1) has a protective effect on the myocardium. In the present study, the role of lncRNA SNHG1 in myocardial ischemia reperfusion injury (MIRI) and the underlying mechanisms were investigated. After hypoxia/reoxygenation (H/R) induction, the expression levels of lncRNA SNHG1 were detected using reverse transcription‑quantitative PCR. After lncRNA SNHG1 overexpression via cell transfection, cell viability was detected using an MTT assay, apoptotic rates were detected using TUNEL staining, apoptosis‑related protein expression levels were detected using western blotting and respective kits were used to measure the oxidative stress levels. The Encyclopedia of RNA Interactomes database predicted the presence of binding sites between lncRNA SNHG1 and microRNA (miR)‑450b‑5p, and between miR‑450b‑5p and insulin‑like growth factor 1 (IGF1). These interactions were then verified using luciferase reporter assays. Subsequently, the regulatory mechanism underlying the lncRNA SNHG1/miR‑450b‑5p/IGF1 axis in MIRI was investigated by overexpressing miR‑450b‑5p and knocking down IGF1 expression in H/R‑induced cells. Finally, the expression of PI3K/Akt signaling pathway‑related proteins was detected using western blotting. lncRNA SNHG1 expression was significantly downregulated in H/R‑induced AC16 cells. lncRNA SNHG1 overexpression significantly inhibited apoptosis and decreased oxidative stress levels in H/R‑induced AC16 cells, which was mediated via regulation of the miR‑450b‑5p/IGF1 axis and activation of the PI3K/Akt signaling pathway. Therefore, the present study suggested that activation of the PI3K/Akt signaling pathway via the lncRNA SNHG1/miR‑450b‑5p/IGF1 axis inhibited the apoptosis and oxidative stress levels of H/R‑induced AC16 cells.