Bone Abstracts

Irisin is a hormone-like myokine secreted from skeletal muscle in response to exercise. Considering that an intimate relationship between skeletal muscle and bone has been well established and that physical exercise physiologically stimulates the skeleton strengthening, we explored the involvement of Irisin on bone metabolism.Our findings demonstrated that the myokine Irisin improves cortical bone mass and geometry in vivo, supporting the idea t...

see PP17....

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...

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...

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...

see PP15....

Objective: Cartilage loss and subchondral bone changes are hallmarks of osteoarthritis (OA). The Wnt family is involved in the regulation of bone and cartilage. We have shown that the Wnt/β-catenin pathway is activated in bone during OA, but the effect of its inhibition in bone in cartilage remodeling is unknown. We here investigated the impact of the bone-specific inhibition of Wnt during the development of OA.Methods: Partial meniscectomy (Mnx) wa...

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 ...

Increasing bone formation is an effective approach to prevent osteoporotic fractures. Although the intermittent administration of PTH is an established osteoanabolic therapy and an anti-Sclerostin antibody (Scle-AB) is currently being tested in phase 3 clinical trials, a great need exists for additional bone anabolic agents. Thus, in the context of a bi-national consortium we aim to uncover novel epigenomic networks controlling bone formation to identify new epigenomic approac...