Functions and mechanisms of chondroitin disaccharide-induced miRNAs in the regulation of CD44 expression involved in the development of experimental autoimmune encephalomyelitis

Abstract

Abstract Multiple sclerosis (MS) is a chronic demyelinating neurodegenerative disease of the central nervous system (CNS). In this study, we investigated the effects of chondroitin disaccharide and its induced miR-29b and miR-199b on CD44 expression in mouse lymphocytes, as well as the effects of miR-29b and miR-199b on the development and progression of experimental autoimmune encephalomyelitis (EAE) in mice, an animal model of MS. The effects of chondroitin sulfate disaccharide on the changes in cellular immunity were investigated in EAE induced in mice by MOG and PTX. Real-time PCR and flow cytometry were used to investigate the effects of the anti-miRs and mimics of miR-29b and miR-199b on CD44 expression in mouse splenocytes after electroporation. After the transduction of antai-miRs and mimics of miR-29b and miR-199b into splenocytes, they were adoptively transferred into mice intravenously and the changes in immune cells and cytokines were analyzed by flow cytometry and ELISA. Our studies revealed that chondroitin disaccharide significantly up-regulated several specific miRNAs such as miR-29b and miR-199b, and thus dramatically inhibited EAE in mice. In vitro and in vivo studies demonstrated that miR-29b and miR-199b could down-regulate the expression of CD44 and modulate the expression of IL-17 and IL-4 in the lymphocytes from EAE mice. Therefore, miR-29b and miR-199b could inhibit the expression of CD44, modulate the expression of IL-4 and IL-17, and thus suppress lymphocyte proliferation and migration, leading to significant inhibition of EAE development. Thus, miR-29b and miR-199b could also be used as therapeutic targets for EAE and MS.