miRNA-182/Deptor/mTOR axis regulates autophagy to reduce intestinal ischaemia/reperfusion injury

Abstract

It had been reported miR-182 was down-regulated after intestinal ischaemia/reperfusion (I/R) damage. However, its role and potential mechanisms are still unknown. This study was aimed to elucidate the function of miR-182 in intestinal I/R injury and the underlying mechanisms. The model of intestinal injury was constructed in wild-type and Deptor knockout (KO) mice. Haematoxylin-eosin staining, Chiu's score and diamine oxidase were utilized to detect intestinal damage. RT-qPCR assay was used to detected miR-182 expression. Electronic microscopy was used to detect autophagosome. Western blot was applied to detect the expression of Deptor, S6/pS6, LC3-II/LC3-I and p62. Dual-luciferase reporter assay was used to verify the relationship between miR-182 and Deptor. The results showed miR-182 was down-regulated following intestinal I/R. Up-regulation of miR-182 reduced intestinal damage, autophagy, Deptor expression and enhanced mTOR activity following intestinal I/R. Moreover, suppression of autophagy reduced intestinal damage and inhibition of mTOR by rapamycin aggravated intestinal damage following intestinal I/R. Besides, damage of intestine was reduced and mTOR activity was enhanced in Deptor KO mice. In addition, Deptor was the target gene of miR-182 and was indispensable for the protection of miR-182 on intestine under I/R condition. Together, our research implicated up-regulation of miR-182 inhibited autophagy to alleviate intestinal I/R injury via mTOR by targeting Deptor.