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

PASQUINI, LAURA A.; THOMAS, LAURA

Congreso; ISN-ESM meeting; 2017

Galectin-3 (Gal-3) is a chimeric protein structurally composed of unusual tandem repeats of proline and short glycine-rich segments fused onto a carbohydrate recognition domain. Our studies have previously demonstrated that recombinant Gal-3 (rGal-3) treatment accelerates oligodendrocyte (OLG) differentiation. The cytoskeleton plays a key role in OLG maturation: the initial stage of OLG process extension requires dynamic actin filament assembly, while subsequent myelin wrapping coincides with the upregulation of actin disassembly proteins which are dependent on MPB expression. The aim of our work is to elucidate the mechanism by which rGal3 expedites 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 polymerized actin at 15? and 30? of treatment was greater than the area measured in OLG cultured in the absence of rGal-3. These changes were accompanied by a concomitant decrease in pERK at all times evaluated. At day in vitro 1 (DIV1), a decrease was observed in the polymerized actin area and in the number of PDGFRalpha+ cells in rGal-3-treated OLG, while an increase was detected in the number of CNPase+ cells. At DIV5, a decrease was observed in the polymerized actin area, accompanied by an increase in the number 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 depolymerizing factor) at DIV5. Results indicate that rGal-3 may favor OLG maturation by mediating the necessary changes in the actin cytoskeleton.