Monomethyl fumarate protects cerebral hemorrhage injury in rats via activating microRNA-139/Nrf2 axis.

Abstract

Monomethyl fumarate (MF) exerts anti-inflammatory and antioxidant capacities. Whether microRNA-139 and nuclear factor (erythroid-derived 2)-like 2 (Nrf2) are involved in the pharmacological activity of MF remain unclear. We aim to elucidate the potential function of MF in intracerebral hemorrhage (ICH), and its possible mechanism. Twenty-four Sprague Dawley (SD) rats were randomly assigned into sham group, ICH group and MF group, with 8 rats in each group. Rats in ICH and MF group were subjected to ICH procedures. Rat brain tissues were harvested at 48 h after ICH procedures. Evans blue extravasation was performed to evaluate ICH-induced rat brain damage. Content of cerebral edema and neurological deficit were examined to reflect the neuronal pathological lesions. Reactive oxygen species (ROS) content in rat brain was examined by immunofluorescence. Activities of oxidative stress indexes in rat brain homogenate were detected using relative commercial kits. MicroRNA-139 expression in rat brain was quantified by quantitative Real-time polymerase chain reaction (qRT-PCR). Finally, protein levels of Nrf2, HO-1, NQO1 and nuclear factor-kappa B (NF-κB) in rat brain tissues were examined by Western blot. Compared with rats in sham group, neurological deficit scores of rats in ICH group were lower. Disruption of blood-brain barrier and brain tissue edema of rats were pronounced in ICH group. However, MF pretreatment markedly alleviated the above mentioned cerebral lesions. In addition, MF pretreatment increased activities of SOD, GSH and CAT, but decreased MDA and ROS contents in rat brain homogenate relative to those in ICH group (p<0.05). Western blot analysis found that expression levels of Nrf2, HO-1 and NQO-1 were markedly upregulated after MF pretreatment, while the expression level of NF-κB was downregulated. At the cellular level, we altered microRNA-139 expression in SH-SY5Y cells by transfection of microRNA-139 mimics or inhibitor. Overexpression of microRNA-139 remarkably increased Nrf2 expression and decreased NF-κB expression. Treatment of high-dose MF upregulated Nrf2, downregulated NF-κB and decreased ROS content in SH-SY5Y cells. MF protects ICH in rats by inhibiting oxidative stress and inflammatory response through activating microRNA-139/Nrf2 axis.