Extracellular galectin-3 induces oligodendroglial differentiation through the modulation of cytoskeleton dynamics

LAURA THOMAS AND LAURA A. PASQUINI

Buenos Aires

Congreso; GLIA Meeting; 2017

GLIA-Polo Científico y Tecnológico

Galectin-3 (Gal-3) isa chimeric protein structurally composed of unusual tandem repeats of prolineand short glycine-rich segments fused onto a carbohydrate recognition domain. Ourstudies have previously demonstrated that recombinant Gal-3 (rGal-3) treatmentaccelerates oligodendrocyte (OLG) differentiation. The cytoskeleton plays a keyrole in OLG maturation: the initial stage of OLG process extension requiresdynamic actin filament assembly, while subsequent myelin wrapping coincideswith the upregulation of actin disassembly proteins which are dependent on MPBexpression. The aim of our work is to elucidate the mechanism by which rGal3expedites OLG maturation, giving special attention to the actin cytoskeleton.Our results show that, in primary rat OLG cultured in vitro in the presence of rGal-3, the total area of polymerizedactin at 15? and 30? of treatment was greater than the area measured in OLG culturedin the absence of rGal-3. These changes were accompanied by a concomitantdecrease in pERK at all times evaluated. At day in vitro 1 (DIV1), a decrease was observed in the polymerized actinarea and in the number of PDGFRalpha+ cells in rGal-3-treated OLG, while anincrease was detected in the number of CNPase+ cells. At DIV5, a decrease wasobserved in the polymerized actin area, accompanied by an increase in thenumber of MBP+ cells at the expense of a decrease in the number of PDGFRalpha+and NG2+ cells. In addition, we observed an increase in Gelsolin (actin depolymerizingfactor) at DIV5. Results indicate that rGal-3may favor OLG maturation by mediating the necessary changes in the actincytoskeleton.