Effect of mechanical load on bone formation
About the project
Load is also a subject of consideration in case of implants/prostheses and osseointegration. Should load be applied to implants post-operatively to improve attachment? What is the optimal load in order to decrease the rate of implant failure and promote osseointegration? How will endocrine stimulatory factors influence these aspects? As mechanical load is an important modulator of bone resorption, the expression and localization of a number of proteins already known to be involved in the mechano-transduction process will also be analyzed.
Bone is continuosly remodelled, and bone architecture and density constantly changes. A finely adjusted interplay between physical forces (e.g. load and stretching) and molecular mechanisms leads, via hormones, growth factors and cytokines, to homeostasis in bone metabolism. Disturbances in this process leads to osteoporosis, via increased bone resorption increased synthesis to osteopetrosis. It is well acknowledged that lack of exercise predisposes to bones with lower density.
Maintenance or gain of bone mass is associated with hormone and/or heavy mechanical load, either due to obesity or physical activity. Amongst the many hormones that account for the link between energy, body weigth and bone metabolism is leptin and adiponectin. Mechanical load is one of the factors that affect bone formation. To generate 3D cell culture, or artificial trabeacular bone, we use the specialized rotating-wall vessel culture system developed at NASA-Johnson Space Center and commercially available from Synthecon, Inc. (Friendswood, TX). This very low shear culture system randomizes gravitational vectors and approximates the microgravity environment by sustaining cells in continuous free fall and thus to aggregate as they would ‘in vivo’. This renders a physiologically relevant setting for testing the effects of various candidate substances for their effects on bone growth and metabolism. This system has been successfully used to generate 3D tissue like assemblies of cartilage, pancreatic tissue, intestine and bone.
The project has received funding from UiO, The Norwegian Cancer Foundation, and from The Norwegian Research Foundation.
- Alamelu (Lalita) Sundaresan, NASA Administator's Fellow, Asst.Professor, Texas Southern University and U.Texas Med.School.