LncRNA XIST knockdown reduces myocardial damage in myocarditis by targeting the miR-140-3p/RIPK1 axis

Viral myocarditis (MC) is caused by Coxsackie virus B3 (CVB3)-induced cardiomyocyte apoptosis and inflammation, and changes in miRNA and lncRNA are linked to cardiac remodeling. The long non-coding RNA XIST (XIST) has been identified as a regulator in various pathological processes in heart diseases, but its role in CVB3-induced MC is not well understood. This research aimed to evaluate the impact that XIST has on CVB3-induced MC as well as the mechanism behind this effect. XIST expression in CVB3-exposed H9c2 cells (H9c2 cells) was evaluated by qRT-PCR. In CVB3-exposed H9c2 cells, reactive oxygen species production, inflammatory mediators, and apoptosis were experimentally observed. An investigation into and confirmation of the existence of an interaction involving XIST, miR-140-3p, and RIPK1 were carried out. The findings showed that CVB3 induced upregulation of XIST in H9c2 cells. However, XIST knockdown reduced oxidative stress, inflammation, and apoptosis of CVB3-exposed H9c2 cells. XIST was specifically bound to miR-140-3p, and there was mutual negative regulation between the two. Moreover, XIST downregulated RIPK1, which was mediated by miR-140-3p. The study suggests that downregulating XIST can alleviate inflammatory injury in CVB3-exposed H9c2 cells through the miR-140-3p/RIPK1 axis. These findings provide novel insights into the underlying mechanisms of MC.