Maraviroc, an inhibitor of chemokine receptor type 5, alleviates neuroinflammatory response after cerebral Ischemia/reperfusion injury via regulating MAPK/NF-κB signaling

Abstract

Neuroinflammation is a key factor that contributes to the secondary damage after cerebral ischemia/reperfusion (CI/R) injury. Chemokine receptor type 5 (CCR5) has shown its pro-inflammatory effects during central nervous system (CNS) diseases. However, the role of CCR5 in CI/R injury is still unclear. In this study, we administered maraviroc (MVC, APEXBIO, UK-427857), a CCR5 antagonist, to the middle cerebral artery occlusion (MCAO) mice. In vivo studies showed that MVC was successively intraperitoneally (i.p.) injected with doses (20 mg/kg body weight) for 3 days after mice MCAO. MVC showed its neuroprotective effects in alleviating neurological deficits and infarct volumes after MCAO. The level of apoptosis and inflammation were remarkably decreased by MVC treatment after CI/R injury. Subsequently, primary microglia cells were stimulated with doses of MVC (20 nM) for 12 h after oxygen-glucose deprivation/reoxygenation model (OGD/R) in vitro. MVC significantly increased the viability of primary microglia after OGD/R. The expression of pro-inflammatory cytokines (IL-1β, IL-6 and TNF-α) in microglia was down-regulated by MVC treatment. Mechanistically, MVC also inhibited the secretion of these cytokines by microglia after OGD stimulation. Furthermore, the key components of NF-κB pathway were measured in vivo and in vitro after MCAO and OGD. MVC significantly inhibited the activity of NF-κB pathway in the above pathological environments. Finally, our data indicated that MVC treatment decreased the activation of JNK signaling pathway after CI/R injury in vivo and in vitro. The JNK activator anisomycin (AN, Beyotime, SC0132) reversed the neuroprotective effects of MVC, indicating that the JNK pathway is involved in the anti-inflammatory and anti-apoptotic mechanisms of MVC in CI/R injury. Our data demonstrated that CCR5 inhibition exhibits neuroprotective effects after CI/R injury. MVC, which is widely used for HIV treatment by its anti-virus effect, is a potential drug for the treatment of ischemic stroke in the future clinical trials. MVC has been widely used in HIV treatment which showed its safety. Based on its anti-inflammatory and anti-apoptotic mechanisms, we speculate that MVC may be a potential drug for treating ischemic stroke in future clinical trials.

Keywords: Cerebral ischemia/reperfusion; Inflammation; JNK signal pathway; Maraviroc; Microglia.