['Bone morphogenetic proteins (BMPs) are members of the transforming growth factor-beta superfamily of proteins that have multiple functional roles in mammalian development. A role for BMP4 in adult vascular remodeling has recently been suggested. We evaluated the expression of Bmp4 during neointimal lesion development in vivo.', 'Heterozygous Bmp4(lacZ/+) mice were used to evaluate in vivo Bmp4 expression after carotid ligation. beta-galactosidase (beta-gal) activity was evaluated in histological sections 1 to 14 d after carotid ligation and this was compared with control carotid arteries. The effects of recombinant human (rh) BMP4 on smooth muscle cell (SMC) migration and proliferation were evaluated using a rat aortic SMC line. We next assessed the effects of BMP4 signaling by over-expressing a constitutively active BMP receptor (BMPR-IA/Alk-3) using adenovirus-mediated gene transfer. SMC proliferation, migration, and apoptosis were evaluated in adenovirus transfected cells.', 'Ligated carotid arteries expressed endothelium-specific beta-gal staining after 1 d. Staining intensity increased at both 3 d and 1 wk after ligation and remained stable at 2 weeks while no beta-gal staining was observed in control vessels. Endothelial-specific expression of beta-galactosidase was confirmed through positive staining for PECAM-1. When human recombinant BMP4 was added to cultured SMCs, it inhibited migration but did not affect cultured SMC proliferation. SMCs infected with adenovirus encoding for the active BMP receptor Alk-3 demonstrated dose-dependent receptor expression. Alk-3 over-expressing cells showed a dose-dependent decrease in proliferation and migration but no effect on apoptosis.'] Is endothelial Bmp4 induced during arterial remodeling : effects on smooth muscle cell migration and proliferation?