A novel fatty acid-binding protein 5 and 7 inhibitor ameliorates oligodendrocyte injury in multiple sclerosis mouse models

Background: Multiple sclerosis (MS) is an autoimmune disease characterised by the demyelination of mature oligodendrocytes in the central nervous system. Recently, several studies have indicated the vital roles of fatty acid-binding proteins (FABPs) 5 and 7 in regulating the immune response. Methods: We assessed a novel FABP5/FABP7 inhibitor, FABP ligand 6 (MF 6), as a potential therapeutic for MS therapy. In vivo, we established MOG35-55-administered experimental autoimmune encephalomyelitis (EAE) mice as an MS mouse model, followed by prophylactic and symptomatic treatment with MF 6. The therapeutic effect of MF 6 was determined using behavioural and biochemical analyses. In vitro, MF 6 effects on astrocytes and oligodendrocytes were examined using both astrocyte primary culture and KG-1C cell lines. Findings: Prophylactic and symptomatic MF 6 therapy reduced myelin loss and clinical EAE symptoms. Furthermore, oxidative stress levels and GFAP-positive and ionised calcium-binding adaptor protein-1-positive cells were reduced in the spinal cord of MF 6-treated mice. In addition, MF 6 attenuated lipopolysaccharide-stimulated interleukin-1β and tumour necrosis factor-α accumulation in primary astrocyte culture. Moreover, MF 6 indicated a powerful protective function for the mitochondria in the oligodendrocytes of EAE mice via FABP5 inhibition. Interpretations: MF 6 is a potent inhibitor of FABP5 and FABP7; targeted inhibition of the two proteins may confer potential therapeutic effects in MS via immune inhibition and oligodendrocyte protection. Funding: This work was supported by the Strategic Research Program for Brain Sciences from the Japan Agency for Medical Research and Development (JP17dm0107071, JP18dm0107071, JP19dm0107071, and JP20dm0107071)