Principal investigators: H. Portier, M. Bensidhoum
Investigators: S. Pallu, C. Jaffré, C. Chappard, A. Xavier
There is evidence that physical exercise has unquestionable beneficial effects on health: for instance, regular aerobic fitness exercise reduces by 20-40% the risk of developing chronic diseases such as type 2 diabetes or colon cancer and by about 30% mortality associated with them.
Bone tissue is a dynamic tissue that is modeled and reshaped according to the constraints applied to it. In particular, the development of bone mass in the absence of exercise is estimated at only 30 to 50% of its potential. As with muscle, exercise is therefore necessary for bone strengthening. Physical exercise causes mechanical stresses (impacts on the ground, shocks, traction at muscular insertions) that directly affect bone and biochemical agents transported by blood (hormones, cytokines) favoring bone anabolism. However, not all types of exercise are as effective. Thus, repeated impacts or displacements of heavy loads would be the most favorable for bone strengthening, whereas endurance exercises would have limited effect. Moreover, the local effects of exercise on bone tissue including mesenchymal stem cells (MSCs) and the effects of exercise on bone repair are still poorly understood or unknown.
The project aims are :
- to conduct a multi-scale experimental study on bone tissue to explore the effects of different exercise protocols on: (i) structural properties (microarchitecture evaluated by microscanner, histological characteristics), (ii) biomechanical properties (by nano-indentation) and (iii) biological properties (biomarkers of remodelling, osteocyte and surrounding matrix biochemical content) and (iv) on the biological properties of bone marrox MSCs (viability, proliferation, differentiation ability, growth factor secretion);
- to determine, through the use of bone defect models, the preventive or curative effects of different exercise protocols on the speed and quality of bone repair.