Bone Abstracts

Background: Besides the classic actions of vitamin D on bone metabolism and calcium homeostasis, there is evidence emphasizing its antiproliferative and proapoptotic activities. Data coming mostly from Northern regions suggest an effect of 25-hydroxyvitamin D (25(OH)D) serum concentrations on breast cancer prevention. We aimed to study the association between 25(OH)D concentrations and breast cancer risk in a Mediterranean population (Spain).Methods: We ...

Odanacatib (ODN), a selective oral inhibitor of cathepsin K, is in development for the treatment of osteoporosis. In the primary efficacy analysis of the Phase 3, Long-Term ODN Fracture Trial (LOFT; NCT00529373), ODN significantly reduced fracture risk compared with placebo in postmenopausal women with osteoporosis. Pre-specified subgroup analyses evaluated the efficacy of ODN in patient subgroups.Women aged ≥65 years, without baseline radiographic...

Osteoclasts are multinucleated giant cells derived from the monocyte/macrophage lineage in the presence of receptor activator of nuclear factor kappa-B ligand (RANKL) and colony-stimulating factor 1 (CSF1). The bone remodeling process in zebrafish is incompletely understood. Here we describe several methods to quantify bone formation and resorption using a zebrafish mutant that lacks functional colony stimulating factor 1a receptor (csf1ramh5/mh5). Mice deficient in...

Osteoclasts are myeloid-derived cells that degrade bone through the localized production of acid and proteases. The catabolic action of osteoclasts is counterbalanced by formation of new matrix by osteoblasts. In mammals, bone resorption and formation are coupled through crosstalk between osteoclasts and osteoblasts. Zebrafish are emerging as a valuable model to study bone biology, but how closely zebrafish osteoclast function parallels that of higher vertebrates is unknown. T...

The endocannabinoid system has important effects on bone mass and bone turnover. Mice with targeted inactivation of type 1 (CB1) and type 2 (CB2) cannabinoid receptors develop osteoporosis with increasing age raising the possibility that cannabinoid receptor agonists might protect against age-related bone loss. Since cannabis is the most widely used illegal drug and its main psychotropic component -Δ9-tetrahydrocannabinol (THC)- is an agonist at CB1 and CB2 receptors, we ...

The essential micronutrient Selenium (Se) plays an important role for bone formation and homeostasis. This notion is mainly derived from animal experimental studies showing impaired bone development and reduced measures of bone quality in animals on diets with low Se supply. Selenoprotein P (SePP) functions as the central Se storage and transport protein. SePP-knockout mice have a growth deficit. SePP is taken up by a receptor-mediated mechanism. We hypothesize that impaired S...

Introduction: Aim of this study was to evaluate connections between Blood Pressure values and hypovitaminosis D states in elderly women with severe osteoporosis.Design and methods: The subjects were all >80: 63 women (mean age 84+3) affected by severe osteoporosis. In 26 women we discovered a new spinal fracture after treatment. Thirty-seven women had multiple spinal fractures (>3). Among subjects with severe osteoporosis we selected 37 ...

Osteosarcoma is the most common primary bone-derived tumor. However, the pathogenic molecular mechanism(s) underpinning osteosarcoma development and metastasis remain elusive. The polycystins PC1 (polycystin-1; encoded by PKD1) and PC2 (polycystin-2) are central players in mechanotransduction, a process that can influence all steps of the invasion/metastasis cascade. Recent studies from our laboratory provided, for the first time, a direct link between mechanosensing polycysti...

Analysis of genome wide data such as transcriptomics can identify genes of potential interest to bone biology. These techniques are primarily hypothesis-generating. Determining the role of candidate factors in bone ultimately requires in vivo experiments. Gene expression analysis of mouse osteoclast differentiation identified G protein-coupled receptor 137B (GPR137b) as highly upregulated. GPR137b is an orphan seven-pass transmembrane receptor of unknown func...

Glucocorticoids are the most commonly used drugs in medical therapy, released in stress and necessary for normal development in both humans and animals.The aim of this study was to investigate the effect of prenatally administered dexamethasone (Dex), a synthetic glucocorticoid, on the histomorphometry of the femur in the offsprings of spiny mice, as a precocial species, characterized by high fertility, and the rapid development of the fetal, allowing th...