Bone Abstracts

Since the identification of LRP5 as the causative gene for the osteoporosis pseudoglioma syndrome (OPPG) as well as the high bone mass (HBM) phenotype, LRP5 and the Wnt/β-catenin signalling have been extensively studied for their role in the differentiation and proliferation of osteoblasts, in the apoptosis of osteoblasts and osteocytes and in the response of bone to mechanical loading. However, more recently the direct effect of LRP5 on osteoblasts and bone formation has...

The musculoskeletal system experiences severe mechanical strain, with repetitive or extreme strains causing significant trauma; the result being an increase in mechanobiological studies evaluating mechanical strain on musculoskeletal cells. Currently, most stretching studies utilise fibronectin-coated cultures, as these enhance cell attachment. However, recent studies suggest that fibronectin increases cell turnover and DNA damage and affects cell differentiation. Furthermore,...

Osteoclast-poor autosomal recessive osteopetrosis is characterised by susceptibility to fracture despite high bone mineral density as a consequence of an absence of osteoclasts. One of the 12 receptor activator of NF-κB (RANK) mutations associated with this condition is a frameshift mutation encoding a protein that is truncated within the extracellular, N-terminal domain (R110Pfs). We investigated the effect of this mutation on osteoclast formation, receptor localisation ...

Shwachman Diamond syndrome (SDS; MIM 260400) is a monogenic, autosomal recessive, pancreatic condition often accompanied by low bone mass and fracture. In SDS, as in cystic fibrosis, a low bone mass may be secondary to poor nutrition or chronic low-grade infection, but it has also been suggested there may be a primary bone phenotype. Paradoxically, recent studies in cell lines and in a mouse knockout for the SBDS gene, have suggested changes in important osteoclast gr...

Twelve different mutations in TNFRSF11A (encoding the RANK receptor) have been associated with osteoclast-poor autosomal recessive osteopetrosis in patients. Two truncated RANK proteins resulting from substitution mutations (W434X and G280X), identified in two infants, cause loss of the intracellular oligomerisation motif and in the case of the G280X mutation the TRAF6 binding domain. A third mutation was identified in a 10-year-old patient and is a frameshift mutatio...

Aims: To describe different multinucleated giant cell phenotypes and their associations with synovitis in people with rheumatoid arthritis (RA) or osteoarthritis (OA), and in an experimental model of chronic arthritis.Material and methods: A cross-sectional comparative study was performed on samples of knee synovia from age-matched patients with RA, OA, or non-arthritic post mortem (PM) controls. OA synovia were stratified by histological inflammation gr...

Chronic obstructive pulmonary disease (COPD) has been found associated with low areal bone mineral density and an increase in fracture rate. Previous histomorphometric findings revealed abnormally low cancellous bone volume and thin cortices. In the present work, we studied the same transiliac bone biopsy samples from n=19 COPD patients for cancellous (Cn.) and cortical (Ct.) bone mineralization density distribution (BMDD) based on quantitative backscatter electron im...

Background: Magnetic resonance imaging (MRI) is used clinically to assess bone marrow, muscle and joints. The assessment of cortical and trabecular structure using MRI may provide further insight into the muscle–bone–bone marrow unit. Previous studies using MRI to evaluate microarchitecture are confined to research due to the need for specially adapted coils and navigator software to limit motion artifact. We present a novel statistical method using HRpQCT to determi...

Introduction: Bisphosphonate treatment in children with osteogenesis imperfecta reduces bone catabolism and relies on modelling to form new bone. An anabolic treatment, anti-sclerostin antibody (Anti-SOST Ab), is being investigated in clinical trials. We hypothesized that combined treatment may produce superior outcomes in OI.Methods: Female Col1a2 G610C mice and their wild type littermates (WT) were treated from week 5 to week 9 of life with either sali...

Fractures in infancy raise the spectre of child abuse; it has been suggested that lack of vitamin D could result in bone abnormalities that could predispose to fractures. We utilised a mouse model system to investigate whether vitamin D deficiency in utero alters early bone growth and development.C57BL/6 female mice received vitamin D deficient or replete diet for 6 weeks, then mated and continued on their respective diets until weaning. Pups were culled...