Bone Abstracts

Autosomal dominant polycystic kidney disease (ADPKD) is the most common monogenic cause of renal failure. Data from adult ADPKD population show increased fibroblast growth factor 23 (FGF23) levels while circulating Klotho levels decrease, with a low TmP/GFR even in patients with normal renal function. Moreover, in ADPKD animal models, cyst lining renal cells were demonstrated to produce FGF23, although the animals displayed FGF23 resistance. No data are available in a paediatr...

Signaling pathways crucial in bone development, including Wnt, are also upregulated in breast cancer cells to promote tumor growth in the skeleton, a process known as osteomimicry. Thus, we hypothesized that bone metastatic tumor cells also aberrantly express osteogenic miRNAs to support osteomimetic properties. We have previously shown that miR-218 is highly expressed in osteoblasts and promotes osteogenic differentiation. Interestingly, expression analysis revealed a signifi...

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...

Aim: Human gut microbiota is an important determinant of health and disease. Discoveries from recent microbiome studies have been postulated as actionable targets to treat malnutrition, diabetes, obesity among other conditions. The role of the gut microbiome on the development of the human musculoskeletal system is yet to be established. The aim of our study was to investigate the association between bacterial operational taxonomic units (OTUs) of the gut in relation to bone m...

Gene deletion or treatments with a cathepsin K (CatK) inhibitor in mature preclinical models result not only result in lower bone resorption but also in higher bone formation (BF) on both remodeling and modeling surfaces. Although increased production of clastokines and matrix-derived growth factors may explain the increased BF at remodeling surfaces, the mechanisms for greater BF at modeling surfaces, including the periosteum, remain unexplained. We hypothesized that the abse...

Objectives: XLH features renal phosphate (Pi) wasting, hypophosphatemia, rickets, and skeletal deformities from elevated circulating levels of fibroblast growth factor 23 (FGF23). KRN23, an investigational fully human monoclonal antibody, binds FGF23 and inhibits its action. Our Phase 2 study of KRN23 in XLH children (ages 5–12 years) is demonstrating improvements in serum Pi and rickets. Here we present our Phase 2 trial evaluating the efficacy and safety of KRN23 in you...

: 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...