Bone Abstracts

Introduction: Mesenchymal stem cells (MSCs) counteract the decline of physiologic functions but their regenerative power decreases with age. In particular osteogenic differentiation capacity of MSCs has been shown to decrease with age thereby contributing to slowed down bone formation and osteoporosis. While much is known about cellular aging of MSCs, little is known about extrinsic factors influencing their functionality. Here we set out to identify circulating factors of the...

Bone strength, hence fracture risk, is dependent on bone geometry, microstructure and bone material level properties. We have reported that microstructure and material level properties contribute independently to the increase in bone strength in rats treated with strontium ranelate for 2 years, as evaluated by μCT-based Finite Element analysis.We investigated the effects of strontium ranelate (SrRan) treatment on bone material level properties of tr...

Bone microarchitecture and material level properties independently contribute to the improvement of bone strength induced by strontium (Sr) ranelate treatment as evaluated by μCT-based finite element analysis. The influence of in vitro Sr exposure on material level properties and on bone mechanical properties is unknown.We investigated whether in vitro exposure of rat femurs to Sr is able to modify the bone mechanical properties in...

Low protein or low calcium intake are known to impair bone growth, but their combined effects on determinants of bone strength are not well understood. We investigated the influence of various protein and calcium containing diets on determinants of bone strength in growing rats.One-month-old female rats were fed isocaloric diets containing 10, 7.5 or 5% casein, with 1.1% (normal; NCa) or 0.2% calcium (low; LCa) during 8 weeks. Tibia midshaft geometry (ou...

New food strategies should be developed to fight against child malnutrition and growth retardation in developing countries. Spirulina alga, one of the richest sources of vegetable protein, contains all essential amino acids. It easily grows in tropical regions. We hypothesized that impaired peak bone mass acquisition (PBMA) caused by dietary protein deficiency could be prevented by Spirulina supplementation in growing rats.One-month old female rats were ...

We assessed whether systemic Strontium ranelate (SrRan) administration accelerates the healing of a bone defect and could modulate local bone cellular activities. Proximal tibia bone defects were created in 6-month-old female rats, which received then orally SrRan (625 mg/kg per day, 5/7 days) or vehicle (controls) for 4, 8, or 12 weeks. Bone samples were analysed by micro-computed tomography and histomorphometry in various compartments, ie metaphyseal second spongiosa (MC), a...

Low protein diet (LPD) impairs body growth, decreases serum IGF1 and increases serum FGF21, two hepatokines influencing bone growth. Low calcium-phosphate diet (LCaPiD) increases serum calcitriol. We hypothesized that LPD effects on bone growth may differ according to calcium and phosphate intakes through the hormonal modulation of calcitriol, IGF1 and FGF21. One-month old rats were fed isocaloric diets containing 10 or 5% casein (10Prot, 5Prot), with 1.0% calcium and 0.8% pho...

Tumour necrosis factor receptor associated factors (TRAFs) play a key role in signal transduction in mammalian cells. Several members of the TRAF family have been identified but only TRAF2 and TRAF6 are implicated in the regulation of osteoclastogenesis. Here we studied the role of TRAF2 and TRAF6 in breast cancer induced bone cell activity and osteolysis. We observed that TRAF2, but not TRAF6, is highly expressed in the human MDA-MB-231 (MDA-231) bone-seeking breast cancer ce...

Introduction: The matrilin-3 polymorphism T298M has been described to be associated with hand osteoarthritis in the carpometacarpal joint 1 (CMC1) and with spinal disc degeneration. In vitro studies revealed that expression levels, processing and secretion of matrilin-3 T298M were similar to the wt protein. Structural analysis indicated an impact on the formation of collagen II/IX/XI heterofibrils, whereas the binding to collagen was not affected. We have now generate...

A micro-indentation technology potentially allows in vivo investigation of intrinsic bone tissue quality, a determinant of bone fragility. Thus the signification of the parameters investigated is still unclear.Since protein malnutrition affects bone material level properties – geometry and strength – rats were fed a normal or an isocaloric low-protein diet. Both femurs were collected and measurements of geometry using micro CT, materia...