The Therapeutic Potential of Rho Kinase Inhibitor Fasudil Derivative FaD-1 in Experimental Autoimmune Encephalomyelitis

Although therapeutic potential of fasudil in EAE is promising, action mechanism and clinical limitations are still not fully understood and resolved. In this study, we observed the therapeutic potential of a novel Rho kinase (ROCK) inhibitor FaD-1, a fasudil derivative, and explored possible mechanism in MOG35–55-induced EAE. Experimental autoimmune encephalomyelitis (EAE) was induced by myelin oligodendrocyte glycoprotein (MOG35–55) immunization. The pathology of spinal cord was measured by immunohistochemistry and neurological impairment was evaluated using clinical scores. FaD-1, as a novel ROCK inhibitor, inhibited the expression of ROCK II that is mainly expressed in the CNS. We show here that FaD-1 ameliorates the neurological defects and the severity of MOG-induced EAE in mice, accompanied by the protection of demyelination and the inhibition of neuroinflammation in spinal cord of EAE. In addition, FaD-1 dampened TLR2 and TLR4 signaling as well as Th1 (IFN-γ) and Th17 (IL-17) responses in spinal cord of EAE. FaD-1 also prevented the expression of iNOS and production of inflammatory cytokine IL-1β, IL-6, and TNF-α which are specific markers for M1 inflammatory microglia/macrophages. This study highlights the therapeutic potential of FaD-1 as a ROCK inhibitor for the treatment of human autoimmune diseases with both inflammatory and autoimmune components.