FOXO4 alleviates hippocampal neuronal damage in epileptic mice via the miR-138-5p/ROCK2 axis

Epilepsy (EP) is one of the most universal neurological disorders. This study investigated the mechanism of forkhead box protein O4 (FOXO4) on hippocampal neuronal damage in EP mice. Initially, the EP mouse model and the in vitro HT-22 cell model were established. EP seizures and neuronal damage in mice were assessed. FOXO4, microRNA (miR)-138-5p, and rho-associated coiled-coil containing protein kinase 2 (ROCK2) levels in hippocampal tissues or HT-22 cells were examined. The cell viability and apoptosis of HT-22 cells were determined. The concentrations of oxidative stress markers and the levels of inflammatory cytokines in hippocampal tissues or HT-22 cells were detected. We found that FOXO4 was poorly expressed in EP. FOXO4 overexpression alleviated hippocampal neuronal damage in EP mice and improved HT-22 cell viability and inhibited apoptosis, and decreased oxidative stress and inflammation in hippocampal tissue and HT-22 cells. The bindings of miR-138-5p to FOXO4 and ROCK2 were analyzed, which showed that FOXO4 promoted miR-138-5p via binding to the miR-138-5p promoter region, and miR-138-5p inhibited ROCK2 expression. Joint experiments showed that miR-138-5p suppression or ROCK2 overexpression reversed the alleviation of FOXO4 overexpression on hippocampal neuronal damage. FOXO4 inhibited ROCK2 expression via promoting miR-138-5p expression, thus alleviating hippocampal neuronal damage in EP mice.