Type I collagen induces expression of bone morphogenetic protein receptor type II

The extracellular matrix regulates many fundamental cellular processes such as proliferation, migration, and differentiation. Among the ECM components , type I collagen induces endothelial tube formation in vitro. By analysing genes participating in this event, the hone morphogenetic protein receptor -II (BMPR-II) was detected to be upregulated in cells cultured on or within fibrillar type I collagen. Furthermore, the basement membrane type IV coll agen or amorphous type I collagen did not show an induction of BMPR-II, Add ition of the BMPR-II specific ligands, BMP2 and BMP4, in the culture medium of the endothelial cells seeded on type I collagen increased [H-3]-thymidi ne incorporation into cellular DNA, indicating that endothelial cells were able to form a functional receptor. In addition, in the chick chorioallanto ic membrane (CAM), an in vivo angiogenesis model, BMPR-II and BMPR-I were u pregulated in the growing phase and ceased in the mature CAM. (C) 2001 Acad emic Press.