JLX001 Ameliorates Ischemia/Reperfusion Injury by Reducing Neuronal Apoptosis via Down-Regulating JNK Signaling Pathway

Abstract JLX001, a novel compound with similar structure with cyclovirobuxine D (CVB-D), has been proved to exert therapeutical effects on permanent focal cerebral ischemia. However, the protective effects of JLX001 on cerebral ischemia/reperfusion (I/R) injury and its anti-apoptotic effects have not been reported. We investigated the efficacy of JLX001 in two pharmacodynamic tests (pre-treatment test and post-treatment) with rats subjected to middle cerebral artery occlusion/reperfusion (MCAO/R). The pharmacodynamic tests demonstrated that JLX001 ameliorated I/R injury by reducing infarct sizes and brain edema. The results of Morris water maze, neurological scores, cylinder test and posture reflex test implied that JLX001 improved the learning, memory and motor ability after MCAO/R in the long term. Anti-apoptotic effects of JLX001 and its regulation of cytosolic c-Jun N-terminal Kinases (JNKs) signal pathway were confirmed in vivo by co-immunofluorescence staining and western immunoblotting. Furthermore, primary cortical neuron cultures were prepared and exposed to oxygen glucose deprivation/reoxygenation (OGD/R) for in vitro studies. Cytotoxicity test and mitochondrial membrane potential (MMP) test showed that JLX001 enhanced cell survival rate and maintained MMP. Flow cytometry and TdT-mediated dUTP-X nick end labeling (TUNEL) staining demonstrated the anti-apoptotic effects of JLX001 in vitro. Likewise, JLX001 regulated JNK signal pathway in vivo, which was also confirmed by western immunoblotting. Collectively, this study presents the first evidence that JLX001 exerted protective effects against I/R injury by reducing neuronal apoptosis via down-regulating JNK signaling pathway.