Bone Abstracts

see PP180....

Senile osteoporosis and age-related osteopenia are associated with decreased osteoblastogenesis and increased bone marrow adipogenesis. The mechanisms controlling the fate determination of osteoblast to adipocyte differentiation of bone marrow stromal cells (BMSC) during aging are not known. We and others previously showed that the cell-cell adhesion molecule N-cadherin (N-Cadh) expressed in osteoblasts controls bone formation, but little is known about its role in BMSC fate d...

Purpose: Osteoclastogenesis is enhanced in osteoarthritis (OA). We have demonstrated that cartilage breakdown is reduced when osteoclastogenesis is inhibited in murine models. Wnt activity, known to regulate the bone and chondrocyte cell function, might contribute to the mechanisms that promote cartilage catabolism. Our purpose was to evaluate whether osteoclast-secreted molecules affect the chondrocyte metabolism and assess the contribution of Wnt pathway.<p class="abstex...

see PP17....

Brittle bones have been reported in children, adolescents and adults with cystic fibrosis (CF), independently of sex; this has been termed CF-related bone disease. In CF patients with the F508del mutation in the (Cftr) gene, vertebral fractures and the subsequent dorsal kyphosis decrease pulmonary function, thus accelerating the course of the disease. Mice with the homozygous F508del mutation in CFTR develop a severe osteopenic phenotype early on, in both sexes (Le He...

see PP15....

Purpose: High osteoclastogenesis accompanies early stages of osteoarthritis (OA). Cartilage loss is reduced when osteoclasts are inhibited in mice models with bone hyperresorption. Although several evidences show that osteoclast-produced molecules affects chondrocyte metabolism, the mechanism by which inhibition of osteoclasts protects from cartilage damage is unclear. Our purpose was to investigate the role of Sphingosine 1 Phosphate, a lipid mediator secreted by osteoclasts ...

Objective: Wnt/β-catenin pathway is a main regulator of bone remodeling, but might be inhibited in cartilage in osteoarthritis (OA). We here investigated the effect of mechanical loading in Wnt activation and the expression of Wnt antagonists in the joint tissues.Methods: Topgal mice were used. Mice underwent partial meniscectomy (Mnx) and sacrificed at 4, 6, and 9 weeks. Dissected knees were scanned by microCT and then prepared for cryosectioning t...

Aim: Wnt/β-catenin pathway promotes cartilage breakdown in osteoarthritis. We have previously shown that sclerostin preserves chondrocyte maintenance in vitro by reducing chondrocyte catabolism through the inhibition of Wnt/β-catenin pathway. However, sclerostin restores partially the expression of the anabolic genes. We therefore investigated the effect of sclerostin in the activation of Wnt non canonical pathways mediated by Ca2+/CaMKII, JNK, an...

Purpose: Sclerostin, a Wnt inhibitor produced by osteocytes that regulate bone remodelling, might be involved in cartilage metabolism. Therefore, we assessed the effect of sclerostin in osteoarthritis using SOST-deficient mice.Methods: SOST-KO and wild type (WT) mice underwent partial meniscectomie (Mnx). Mice were sacrificed at 4, 6 or 9 weeks after Mnx to analyze i) bone volume (BV/TV) at the femoral condyle, ii) osteophyte volume (microCT), iii) carti...