Bone Abstracts

see PP432....

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...

Introduction: Osteocalcin (OC) is a marker of bone formation but also seems to play a hormonal role in the regulation of glucose and energy metabolism. Recently, an association of BMI with a haplotype composed of three single nucleotide polymorphisms (SNPs) in the gene for OC, located on chromosome 1q22, was observed in ethnically homogeneous European pedigrees.Aim: The aim of the study was to test the association of these three polymorphisms in the gene...

Introduction: Loss in bone mineral density may occur soon after initiation of adjuvant therapy for hormone-receptor-positive (HR+), breast cancer (BC) and correlates with changes in hormone levels. Adding zoledronic acid (ZOL) to adjuvant treatment for BC can preserve/improve bone mineral density and delay disease recurrence; however, effects of ZOL on endocrine hormone levels are currently unclear.Methods: Probone II assessed the course of endocrine hor...

Introduction: Bone mineral density (BMD) evaluations have shown that adjuvant chemotherapy or endocrine therapy (ET) for early breast cancer (BC) is associated with accelerated BMD loss and increased fracture risk. In recent studies, zoledronic acid (ZOL) increased BMD in premenopausal and postmenopausal women with BC, and improved disease-free survival in some patient subsets compared with no ZOL. The purpose of the current study was to investigate the effect of adjuvant trea...

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...

Background: Cartilage matrix breakdown in osteoarthritis (OA) is due to mechanical stress and inflammation leading to increased metalloproteinases (MMPs) production. Currently, IL1β is thought to have a major role in this process. IL1β is synthesized as an inactive precursor, which is cleaved into the secreted active form. This maturation process mainly occurs in the inflammasome complex. Inflammasome is constituted by initiators (including NALP3) and adaptor molecul...

Background and aims: Cirrhosis and chronic pancreatitis (CP) are accompanied by inflammation and malnutrition. Both conditions may affect bone metabolism negatively and facilitate bone fractures. The objective of this study was to evaluate the risk of fractures among patients with CP or cirrhosis and the impact of fat malabsorption on fracture risk among patients with CP.Methods: Using the Danish National Patient Register, we did a retrospective cohort s...

Sclerostin, a product of osteocytes, is known to inhibit Wnt signaling by binding the LRP5/6 receptor.We investigated the effects of a mutated mouse sclerostin protein (muScl, R118A/R144A) with potential sclerostin antagonistic activity. In vitro, muScl fully competed with wild type sclerostin for binding to LRP6, whereas its IC50 for Wnt3a activity was 4× higher than sclerostin (i.e. 600 nM). Moreover, serum osteocalcin increased in mice a...

Background: A 5-month-old girl was referred to our unit after a systemic screening for hip dislocation by X-rays revealed bilateral femoral bowing. She was the first child of healthy non-consanguineous parents, and her family history was unremarkable. Her parents had a normal physical examination, and normal laboratory findings. At presentation, her height was 64.0 cm (Z-score: 0.0) with a regular height velocity. Weight was 7.4 kg (Z-score: 1.0). On physical...