Mechanics in bone growth and development

Summary form only. Skeletal structure reflects the mechanical loads experienced. The skeletal adaptive response to mechanical forces is well described qualitatively but needs to be understood quantitatively and mechanistically, particularly for diseases such as osteoporosis. This minisymposium presents our understanding of skeletal integrity across different levels of consideration. First, the whole bone response to altered loading and contributing factors is discussed. Then the tissue level response is examined with mechanically-based simulations of bone adaptation which incorporate physiological parameters. Finally, cellular mechanotransduction mechanisms are investigated. These different approaches are combined to help better understanding of osteogenic stimuli, signal transduction pathways and response processes and enable us to quantitatively predict bone adaptation. Using experimental models of altered loading and animals with genetic alterations, we can examine potential contributing factors. By unloading and overloading the short ear mouse, deficient for bone morphogenetic protein-5 (BMP-5), we examined whether BMP-5 plays a role in load-based adaptation. Our findings suggest that BMP-5 is a component of the response pathway to increased, but not decreased, mechanical loads. These experiments show great promise for understanding skeletal functional adaptation.