PLATELET-DERIVED GROWTH-FACTOR INDUCES APOPTOSIS IN VASCULAR SMOOTH-MUSCLE CELLS - ROLES OF THE BCL-2 FAMILY

Apoptosis (programmed cell death) is observed in vascular smooth muscl e cells (VSMC) in atherosclerotic lesions and stenotic lesions after i njury, and modulates the cellularity of these lesions. It is recognize d that cell growth and apoptosis are two linked processes. Platelet-de rived growth factor (PDGF) induces VSMC proliferation and migration in vitro. We studied the effect of PDGF on apoptosis in VSMC. Cultured r at VSMC were treated with PDGF-AA or PDGF-BB. PDGF-BB induced cell dea th in cultured VSMC in a time- and dose-dependent manner, but PDGF-AA did not. Gel electrophoresis of genomic DNA and in situ DNA labeling c onfirmed that the cell death induced by PDGF-BB is apoptosis. PDGF-BB treatment reduced bcl-2 mRNA and bcl-xl mRNA expression, in contrast, induced bcl-xs mRNA expression, linked with the induction of apoptosis in cultured VSMC. (C) 1998 Elsevier Science B.V. All rights reserved.