Potential role of BAY11-7082, a NF-κB blocker inhibiting experimental autoimmune encephalomyelitis in C57BL/6J mice via declining NLRP3 inflammasomes

Multiple sclerosis (MS) is an inflammatory autoimmune demyelinating disease of the central nervous system. NOD-like receptor pyrin domain-containing 3 (NLRP3) inflammasome is implicated in the pathogenesis of MS and its animal model, experimental autoimmune encephalomyelitis (EAE). However, the exact mechanism by which NLRP3 inflammasome is involved in the development of MS and EAE is not clear. NF-kappaB (NF-κB) is associated with the activity of NLRP3 inflammasomes, but the role of NF-κB is controversial. We sought to demonstrate that both NF-κB and NLRP3 contribute to development of MS and EAE, and NF-κB pathway is positively correlated with NLRP3 activation in EAE. The inhibitor of NF-κB and NLRP3, BAY11-7082, can prevent and treat EAE. BAY11-7082 (5 and 20 mg/kg/i.p.) was intraperitoneally administered to EAE mice at the time of second injection of pertussis toxin (BAY11-7082 prevention group) or at the onset of symptoms (BAY11-7082 treatment group). mRNA expressions of NLRP3 were determined by qPCR. Protein expressions of NLRP3, NF-κB p65, and phosphorylated p65 were determined by western blotting. Serum levels of inflammatory cytokines were measured by cytometric bead array. Mice treated with BAY11-7082 (both prevention and treatment groups) showed lower clinical scores and attenuated pathological changes. NLRP3 inflammasome and activity of NF-κB in spinal cord of EAE mice was higher than that in control group. However, the level of NLRP3 inflammasome decreased in BAY11-7082 prevention and treatment groups. BAY11-7082 is a promising therapeutic agent for MS. NLRP3 activation in EAE maybe related with NF-κB pathway.