Bone Abstracts

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...

Bisphosphonates (BP) are powerful bone resorption inhibitors. They are used for the symptomatic treatment of malignant osteolytic bone disease (e.g. multiple myeloma and bone metastasis), as well as bone diseases associated with high bone resorption (e.g. postmenopausal osteoporosis, cortisone-induced osteoporosis). However, recent data showed that a rare, but serious, adverse effect of BP therapy is osteonecrosis of the jaw (BRONJ). Given the increasing number of persons rece...

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...

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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 ...

Atypical femoral fractures (AFF) of the subtrochanteric region are rare. Bisphosphonates account to a large extent to their occurrence, however AFF also occur without exposure to bone medication. We here assessed the genetic factors associated with AFF among subtrochanteric fractures. Cases of subtrochanteric or femoral shaft fractures were identified through ICD-10 codes in three French academic centers from 2007 to 2010. Medical records were analyzed by two investigators tha...

Objective: This work investigated the changes of bone hip structural parameters in obese adolescents enrolled in a successful weight loss program.Methods: Thirty-one obese adolescents (age 13.61±1.27) enrolled in a 8-month weight loss program combining physical activity and nutrition were compared with normal-weight (NW) matched peers (age 15.9±0.43). Investigations were performed at baseline and 8 months. Bone geometric and strength indices we...

We recruited 60 healthy volunteers ages 5 to 21 to perform scan-rescan precision tests on the XtremeCT II. Participants were positioned in a carbon fiber immobilization cast. iPad-based video content was used to facilitate motion-free compliance. Distal radius and tibia scans were acquired starting 2 mm proximal to the proximal margin of the growth plate or growth plate remnant. Diaphyseal radius and tibia scans were centered at an offset from the same landmark, corresponding ...

The impact of sex and maturation on trabecular (Tb) and cortical (Ct) microarchitecture in children and young adults has not been well established. The new second-generation high-resolution peripheral quantitative CT (HR-pQCT) scanner (XCT II, Scanco Medical) incorporates three important advances to provide greater spatial resolution, direct measures of Tb thickness and spacing and measures in the Ct midshaft. The aim of this study was to identify sex and maturation effects on...