MicroRNA-122a aggravates intestinal ischemia/reperfusion injury by promoting pyroptosis via targeting EGFR-NLRP3 signaling pathway

Abstract

Multiple studies have confirmed the significance of microRNA (miR)-122a in disease regulation. However, its impact on ischaemia/reperfusion (I/R) injury is unknown. In this study, we propose that the promoting role of miR-122a exists in I/R injuries. Two models, including hypoxia/reoxygenation (H/R)-injured IEC-6 cells in vitro and ischemia/reperfusion (I/R)-injured C57BL/6 mice intestinal tissues in vivo, were used to verify our purpose. Applying dual-luciferase reporter assays and transfection tests, the regulatory impacts of miR-122a were examined by promoting pyroptosis on intestinal I/R injury via targeting epidermal growth factor receptor (EGFR)-NOD-, LRR-, and pyrin domain-containing 3 (NLRP3) signaling pathway. Both H/R-injured IEC-6 cells and I/R-injured mice intestinal tissues had elevated miR-122a expression, which targeted EGFR directly. Increased miR-122a expression significantly inhibited EGFR activity, decreased EGFR mRNA and protein expression, increased NLRP3 mRNA and protein expression, and up-regulated caspase 1, N-GSDMD, ASC, IL-1β, and IL-18 protein expression to promote pyroptosis. Furthermore, in IEC-6 cells, a miR-122a inhibitor and an EGFR-overexpression plasmid significantly reduced pyroptosis and alleviated intestinal I/R injury via activating the EGFR-NLRP3 signaling pathway, showing that miR-122a is very essential for regulating intestinal I/R injury. In brief, miR-122a promotes pyroptosis by inhibiting the EGFR-NLRP3 signaling pathway, which should be evaluated as a therapeutic target for intestinal I/R injury.