The effect of pleiotrophin signaling on adipogenesis

Pleiotrophin (PTN) plays diverse roles in cell growth and differentiation. In this investigation, we demonstrate that PTN plays a negative role in adipogensis and that glycogen synthase kinase 3β (GSK-3β) and β-catenin are involved in the regulation of PTN-mediated preadipocyte differentiation. Knocking down the expression of PTN using siRNA resulted in an increase in phospho-GSK-3β expression, and the accumulation of nuclear β-catenin, which are critical downstream signaling proteins for both the PTN and Wnt signaling pathways. Our investigation suggests that there is a PTN/PI3K/AKT/GSK-3β/β-catenin signaling pathway, which cross-talks with the Wnt/Fz/GSK-3β/β-catenin pathway and negatively regulates adipogenesis.