The role of galectin-3: From oligodendroglial differentiation and myelination to demyelination and remyelination processes in a cuprizone-induced demyelination model

Abstract

The aim of this work was to combine our previously published results with our new data to show how galectin-3 (Gal-3) controls myelin integrity and function, promotes oligodendroglial cell differentiation, and regulates microglial responses to limit cuprizone- (CPZ)-induced demyelination and foster remyelination. In this study, 8-week-old Gal-3-deficient (Lgals3−/−) and wild type (WT) mice were fed a diet containing 0.2 % CPZ w/w for 6 weeks, after which CPZ was withdrawn in order to allow remyelination. Our results show that remyelination was less efficient in Lgals3−/− than in WT mice. Electron microscopic images from remyelinated sections in Lgals3−/− mice revealed collapsed axons with a defective myelin wrap, while remyelinated WT mice had normal axons without relevant myelin wrap disruption. MMP-3 expression increased during remyelination in WT but not in Lgals3−/− mice. The number of CD45+, TNFa+ and TREM-2b+ cells decreased only in WT mice only, with no alterations in Lgals3−/− mice during demyelination and remyelination. Therefore, Gal-3 influences remyelination by mechanisms involving the tuning of microglial cells, modulation of MMP activity, and changes in myelin architecture.