Figure 1: Mediators involved in different stages of MS lesions remyelination (activation, recruitment and differentiation of oligodendricyte precursor cells). Those followed by a downward arrow play an inhibitory role. Circular arrows represent the interconnectedness of all steps for a successful remyelination. PDGF: platelet-derived growth factor; FGF: fibroblast growth factor; BDNF: brain-derived neurotrophic factor; IGF-1: insulin-like growth factor-1; Shh: sonic hedgehog; RXRγ: retinoid X receptor-γ; LINGO-1: leucine-rich repeat and Ig domain containing NOGO receptor interacting protein 1; BMP: bone morphogenic protein; PSA-NCAM: polysialylated-neural cell adhesion molecule.