Recombinant human brain natriuretic peptide regulates PI3K/AKT/mTOR pathway through lncRNA EGOT to attenuate hypoxia-induced injury in H9c2 cardiomyocytes

This study aimed to investigate whether recombinant human brain natriuretic peptide (rhBNP) regulated hypoxia-induced injury in H9c2 cardiomyocytes through lncRNA EGOT. H9c2 cardiomyocytes were cultured under normoxia and hypoxia (21% and 3% O2) conditions, and whether hypoxia induced injury by assessing cell viability, apoptosis and autophagy. H9c2 cells were then treated with different doses of exogenous rhBNP (200, 600 and 900 nmol/L, respectively) and the effects of rhBNP on hypoxia-induced injury in H9c2 cells as well as the expression of EGOT were studied. In addition, the regulatory relationships between rhBNP and EGOT as well as between rhBNP and PI3K/AKT/mTOR pathway in hypoxia-treated H9c2 cells were investigated. Hypoxia significantly induced injury in H9c2 cells (inhibited cell viability and promoted cell apoptosis and autophagy) and decreased the expression of EGOT. However, administration of rhBNP alleviated hypoxia-induced injury in H9c2 cells and elevated expression of EGOT. Suppression of EGOT significantly reversed the effects of rhBNP on hypoxia-induced injury in H9c2 cells. Further studies showed that the effects of EGOT on cell viability and apoptosis were by positively regulating the expression of Cyclin D1. Moreover, rhBNP alleviated hypoxia-induced cell injury by activating PI3K/AKT/mTOR pathway in H9c2 cells. Our results reveal that rhBNP may play a protective role in attenuating hypoxia-induced injury in H9c2 cardiomyocytes via regulating lncRNA EGOT/Cyclin D1/PI3K/AKT/mTOR pathway axis. The findings will provide a new strategy for the treatment of heart failure induced by hypoxia.