MSCs ameliorate clinical course in rats with experimental autoimmune encephalomyelitis

Multiple sclerosis (MS) is a chronic immuno-mediated inflammatory and demyelinating disease characterised by both demyelinating lesions and axonal degeneration, leading to the reduction of nerve conduction velocity and the development of neurological deficits. Recently, some in vivo studies have proposed Mesenchymal Stem Cells (MSCs) as promising therapeutic treatment for MS mainly for their capacity to modulate the immune response, although it is not yet known if other mechanisms, different from immune modulation, are involved in MSCs positive. We investigate the therapeutic potential and the clinical effects of MSCs by using an animal model of multiple sclerosis, represented by Lewis rats affected by acute experimental autoimmune encephalomyelitis (EAE). MSCs were intravenously administered immediately after EAE induction (T0) or one week later (T7), in both the cases before disease onset. The clinical course of acute EAE was ameliorated only in EAE animals in which MSCs were injected one week after disease induction, while EAE rats and EAE rats with MSCs injected at T0 showed similar clinical scores. Moreover, the EAE rats which received MSCs at T7 displayed a cytokines pattern expression comparable to untreated control rats, while both EAE group and EAE+MSCs (T0) group showed an increased expression of pro-inflammatory cytokines. These results evidenced that the intravenous administration of MSCs one week after EAE induction (and before disease onset) induces the amelioration of the clinical scores of EAE-rats, thus supporting the potential role for MSCs in cell therapy in multiple sclerosis. We are now investigating the molecular mechanisms of this positive effect, focusing our attention on the Metalloproteinases pathway, involved in multiple sclerosis and modulated by MSCs.