The cell and molecular biology of bone fracture repair: role of the transforming growth factor-ß1 in activation reparative osteogenesis (review)

Abstract

This paper describes the cellular and molecular mechanisms underlying in the basis of bone fractures healing. It is shown that there are two types of fracture healing. In the case of the primary type bone tissue directly form in zone of damage. In the case of instability of the bone fragments and considerable distance between them the process of restoration of the integrity of the bone goes through several stages including inflammation, migration and proliferation of cells, the formation of tissue-specific structures and the restructuring of the regenerate. At the same time at different stages certain factors affecting the proliferation, differentiation of osteogenic cells and synthesis of extracellular matrix release. Growth factors control the various stages of reparative osteogenesis. In recent years the regulatory role of transforming growth factor beta-1 (TGF-β1) and belonging to his family of bone morphogenetic protein (BMP) in the formation and development of bone regeneration was confirmed. According to modern scientific ideas BMP act as primary activators of differentiation of osteogenic progenitor cells, and mesenchymal cells, and are involved in the processes of bone remodeling and fracture healing. Initially it was thought that TGF-β1 stimulates the proliferation of undifferentiated mesenchymal cells and chondrocytes as well as the production of extracellular matrix during chondrogenesis and enchondral osteogenesis. As shown in recent studies optimizing effect of TGF-β1 on the processes of fracture healing is dose-dependent and requires its constant high concentration. In-depth understanding of the mechanisms of development reparative osteogenesis allows to develop a new strategy for optimization of the process of restoring the integrity of bone broken due to injury.