Bone Abstracts

The R-spondins are a family of four small, secreted agonists of the Wnt signaling pathway. Growing evidence from both in vitro studies and in vivo models supports the major role of these proteins in the skeletal development processes. In humans, common genetic variation in the RSPO3 gene has been associated with BMD in large scale GWAS study.This study aimed at further investigation of the genetic and functional contributions of the R-s...

Few interventions directly compare equivalent calcium and vitamin D from dairy vs supplements on the same bone outcomes.Objectives and Methods: Using 41Ca tracer techniques, determine if 4 servings/d of dairy foods reduces Ca excretion more than an equivalent amount of Ca and vitamin D from supplements. Secondary objective was to evaluate the time course for change in Ca excretion.Design: In this crossover trial, postmen...

Introduction: Langerhans cell histiocytosis (LCH) is a monoclonal disorder characterized by proliferation and accumulation of atypical Langerhans cells. Bone involvement is particularly destructive and to date, no standard of care exists. Bisphosphonates are osteoclast inhibitors that could target the multinucleated giant cells within the LCH lesions and might be used to alleviate bone pain and the progression of disease.Objective: To evaluate the effica...

: In osteoporosis, poor adherence to bisphosphonate (BP) therapy is common, and is associated with poor outcomes and increased treatment costs (Siris 2006; Recker 2005). Although compliance is improved with monthly vs weekly dosing (Reginster 2008), no evidence suggests cycling through BP agents offers therapeutic benefit, assessed by bone mineral density (BMD). In two randomized, open-label studies in postmenopausal women aged ≥55 years previously treated with, but subo...

Background: Progressive osseous heteroplasia (POH) (OMIM 166350) is a rare autosomal dominant condition, characterized by heterotopic ossification of the skin, subcutaneous fat and deep connective tissue. This condition is distinct from Albright’s hereditary osteodystrophy or Mccune–Albright syndrome (AHO) (OMIM 103580) and fibrodysplasia ossificans progressiva (FOP) (OMIM 135100).Presenting problem: We present an unu...

Background: We identified a family with early onset X-linked osteoporosis and fracturesMethods: We performed whole exome sequencing of the X chromosome in three affected members. After discovering a putative pathogenic variant we performed Sanger sequencing of all exons of this gene in other members of this family and in 95 unrelated men suspected of OI type I without COL1A1/2 mutations. We also genotyped a SNP in this gene (minor allele frequency 0.02) ...

Patients with chronic inflammatory diseases such as psoriasis are at high risk for developing osteoporosis. Psoriatic arthritis patients exhibit bone loss caused by increased bone resorption through activation of osteoclasts. However, it is not clear whether psoriasis can lead to bone loss in the absence of arthritis. Using mouse models with skin inflammation as well as psoriasis patient samples, we show that increased circulating IL-17A from the inflamed skin triggers bone lo...

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Few drugs generate bone-stimulatory effects via epigenetic mechanisms. Modulation of CpG-residues hydroxymethylation in gene-promoters of key osteoblast-related factors (e.g., DLX5) induces their expression and increases osteoblast differentiation in vitro. The chemical properties of sulforaphane (SFN), a natural compound abundantly present in cruciferous vegetables like broccoli, suggest that it may have similar molecular and biological effects. Previous stu...

Mesenchymal cells alter and retain their phenotype during skeletal development through activation or suppression of signaling pathways. For example, we have shown that Wnt3a only stimulates osteoblast differentiation in cells with intrinsic osteogenic potential (e.g., MC3T3-E1 pre-osteoblasts) and not in fat cell precursors or fibroblasts (respectively, 3T3-L1 pre-adipocytes or NIH3T3 fibroblasts). Wnt3a promotes osteogenesis in part by stimulating autocrine production of the ...