Bone morphogenetic protein (BMP) family, SMAD signaling and Id helix–loop–helix proteins in the vasculature: The continuous mystery of BMPs pleotropic effects

Abstract

BMPs are multi-functional growth factors and form a large subgroup within the transforming growth factor β (TGF-β) superfamily. Although BMPs were originally identified as proteins inducing formation of bone and cartilage in nonskeletal tissue [1], BMPs also regulate proliferation, differentiation, migration, and apoptosis of many cell types including endothelial and vascular smooth muscle cells (VSMC) [2]. As explained below, although BMPs family appear to have significant pathophysiological relevance in angiogenesis and pulmonary hypertension, the signaling of different BMP family members remains unclear, because BMPs can exert pleotropic effects on multiple cellular constituents of the vascular wall depending on the cell type and ligands.