Chemotaxis of human osteoblasts

The in vitro chemotactic response of human osteoblasts was investigated towards the following growth factors: TGF‐β, PDGFs, FGFs and IGFs. Human osteoblasts grown from trabecular bone after enzymatic digestion were studied. TGF‐β stimulated the migration of human osteoblasts in a dose‐dependent manner with a four‐fold increase in migrated cells at 100 pg/ml, which was the optimum concentration. PDGF‐BB also stimulated migration four‐fold in a dose‐dependent manner with a maximum response at 10 ng/ml. PDGF‐AA, IGF‐I and IGF‐II stimulated migration two‐fold at 100 ng/ml. The results show that TGF‐P and PDGF‐BB are important regulators of human osteoblast migration, but other growth factors IGF‐I, IGF‐II and PDGF‐AA may also stimulate osteoblast migration. Our results additionally suggest that TGF‐P and PDGF‐BB may participate in the recruitment of osteoblasts during bone remodeling since both TGF‐P and PDGF‐BB are found in bone matrix and could be released during osteoclastic bone resorption. They furthermore support a possible use of TGF‐P and PDGF‐BB in growth factor‐induced osteogenesis.