CircRbms1 fosters MST1 mRNA and protein levels to motivate myocardial ischaemia-reperfusion injury via autophagic status

Aims: Acute Myocardial Infarction (MI) is a significant contributor to death in individuals diagnosed with coronary Heart Disease on a worldwide level. The specific mechanism by which circRbms1 contributes to the damage caused by myocardial ischaemia-reperfusion (I/R) is not well understood. The primary aim of this study was to examine the role of circRbms1 and its associated mechanisms in the setting of I/R injury.

Methods and results: An in vivo MI mice model and an in vitro MI cell model was established. The expression levels were detected using quantitative Real-Time PCR (qRT-PCR) and western blot. Cellular proliferation, Apoptosis, Pyroptosis, and Autophagy were detected by immunostaining, immunohistochemistry, western blot, and transmission electron microscopy (TEM). Dual-luciferase reporter assay, RNA pull-down assay, and RIP assay were performed to validate the molecular interactions. CircRbms1 was up-regulated in A/R-induced HCMs and acted as a Sponge for miR-142-3p, thereby targeting MST1. CircRbms1 could improve stability of MST1 by recruiting IGF2BP2 (all P < 0.05). CircRbms1 knockout reduced cell Pyroptosis, improved Autophagy and proliferation level in A/R-induced HCMs (all P < 0.05). CircRbms1 knockout alleviated cardiac dysfunction and cell Pyroptosis and enhanced Autophagy and proliferation in mice through the miR-142-3p/MST1 axis.

Conclusions: CircRbms1 inhibited the miR-142-3p/MST1 axis and played a protective role in myocardial I/R injury. It may provide a new therapeutic target for I/R heart injury.