Notch ligand-selective activation in CNS demyelination-remyelination

ALMEIRA GUBIANI, M.F.; GÓMEZ PINTO, L.; MATHIEU, P.; ADAMO, A. M.

Mar del Plata

Congreso; XXX Congreso Anual de la Sociedad Argentina de Investigación en Neurociencias; 2015

Sociedad Argentina de Investigación en Neurociencias

CNS demyelination is a pathological process characterized by myelin loss around axons, while subsequent remyelination solves functional deficits.This work studies Notch1 ligands differential roles in demyelination-remyelination in a cuprizone (CPZ)-induced demyelination model. Adult Wistar rats were fed a CPZ or control diet for 2 weeks and sacrificed 7d before (-7d), upon (0d), and 7, 14 and 21d (+7d, +14d and +21d) after CPZ withdrawal. For each survival time, F3/contactin (F3) and Jagged1 levels were assessed by Western blot in the subventricular zone (SVZ) and corpus callosum (CC) and ligand-expressing cells were immunohistochemically characterized. Primary neurosphere cultures (NC) from SVZ were carried out to evaluate SVZ participation in CC remyelination. Cultured cell populations were characterized by specific markers and Notch activation, F3 and Jagged1 expression were determined.An increase in F3 expression was detected at -7d, +7d and +21d in CC and at +14d in SVZ of CPZ animals as compared to controls. Cells expressing F3 were NG2+ and Olig2+. Also, an increase in Jagged1 expression was observed at -7d in GFAP+ cells. NC showed higher OPC proliferation in response to injury at 0d and +7d. Notch activation was found in NG2+ OPC, together with a larger percentage of Jagged1-expressing cells. F3 was found in NG2+ but went undetected in GFAP+ cells. Finally, co-immunoprecipitation assays proved F3 binding to Notch, thus confirming its role as a non-canonical ligand.