Bone morphogenetic protein-2b stimulation of growth and osteogenic phenotypes in rat osteoblast-like cells: Comparison with TGF-β1

Abstract

The biologic effects of recombinant human bone morphogenetic protein‐2b (BMP‐2b = BMP‐4) were studied and compared with transforming growth factor‐β₁ (TGF‐β₁) in fetal rat osteoblast‐like (ROB) cells. Similar to the effects of TGF‐β₁, BMP‐2b stimulated DNA and collagen synthesis as well as protein accumulation. Unlike TGF‐β₁, which inhibited alkaline phosphatase activity, BMP‐2b enhanced enzyme activity eight‐to ninefold over the control level. The present study demonstrates direct actions of BMP‐2b on bone‐associated cells to stimulate osteogenic phenotypes in vitro and provides a cellular mechanism for the induction of bone formation by BMP‐2b in vivo.