Osteopontin involvement in bone remodeling and its effects on in vivo osteogenic potential of bone marrow-derived osteoblasts/porous hydroxyapatite constructs

This review article will present our work regarding osteopontin (OPN) funct ion in bone remodeling and its application to tissue engineering in bone. O PN, one of the major non-collagenous bone proteins, has an important role i n bone remodeling. Our study suggested that OPN acts not only as a trigger for osteoblast early differentiation but activates osteoclast resorption. O n this point of view, we proposed a model of bone remodeling via integrin a lpha (v)beta (3)-OPN binding, in which OPN could act as a signal molecule b etween osteoblasts and osteoclasts in the process of remodeling. Moreover, OPN was shown to induce the in vivo osteogenesis of a bone marrow-derived o steoblast/porous hydroxyapatite (HA) constructs. Our application of adenovi rus-mediated gene transfer of osteopontin to primary osteoblasts is also pr esented. (C) 2001 Elsevier Science B.V. All rights reserved.