MiR-23a-5p exacerbates intestinal ischemia-reperfusion injury by promoting oxidative stress via targeting PPAR alpha.

MiR-23a-5p is involved in the occurrence and development of some serious diseases, but its effects on intestinal ischemia-reperfusion (II/R) injury is unclear. In this research, the hypoxia/reoxygenation (H/R) model on IEC-6 cells and II/R model in mice were used. The data showed that the ROS level in model group was significantly increased compared with control group. The level of intestinal MPO was increased and serum SOD was decreased in mice compared with sham group. Moreover, the expression levels of miR-23a-5p in model groups were obviously increased in vitro and in vivo, while the expression levels of PPARα, FOXO3α, PGC-1α, Nrf2, CAT, NQO1, HO-1 and SOD2 were significantly decreased. The double luciferase reporter gene assay showed that there was binding site between miR-23a-5p and PPARα. When miR-23a-5p was inhibited or PPARα gene was overexpressed, H/R-caused cell damage was alleviated and ROS level was decreased compared with NC group. PPARα expression level was increased, accompanied by the increased levels of FOXO3α, PGC-1α, Nrf2, CAT, NQO1, HO-1 and SOD2. After enhancing miR-23a-5p expression or silencing PPARα gene, H/R-caused cell damage was further aggravated compared with NC group, and ROS level was increased associated with the decreased levels of FOXO3α, PGC-1α, Nrf2, CAT, NQO1, HO-1 and SOD2. Our study demonstrated that miR-23a-5p exacerbated II/R injury by promoting oxidative stress via targeting PPARα, which should be considered as one new drug target to treat II/R injury.