Bone Abstracts

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Osteocytes differentiate from osteoblasts, are embedded in mineralised matrix and are critical regulators of bone remodelling. In vitro osteocyte models are limited to cell lines in monolayer, which do not represent their 3D environment in vivo. We have shown that osteoblasts in 3D gels differentiate along the osteocytic pathway. Since IGF1 regulates osteoblasts, and is involved in osteocyte response to mechanical loading, we hypothesised that IGF1 modulates ...

Osteocytes make up >90% of bone cells, are embedded in mineralised matrix where they form a communication network. Osteocytes differentiate from osteoblasts, and are mechano-sensitive. They are very difficult to isolate with a dependence on cell lines for in vitro studies of osteocyte biology. Therefore new methods to study these cells are essential. Recent publications indicate that osteoblasts maintained in in vitro 3D collagen gels may differentiate to...

Introduction: Normal mechanical loading potently induces bone formation via effects on osteocytes. Current investigations of mechanical loading of bone do not reflect the interactions of the cells within it, mostly focusing on mechanical loading of osteoblasts in monolayers. Existing 3D models do not elucidate the osteoblast-osteocyte interactions that regulate mechanically-induced bone formation. We developed a novel in vitro 3D co-culture model of bone1 t...

Objectives: Synovial fluid glutamate concentrations increase in various arthritides. Activation of kainate (KA) and AMPA glutamate receptors (GluRs) increase interleukin 6 (IL6) release and cause arthritic pain respectively. GluR antagonists represent potential peripheral treatments for inflammatory arthritis and inflammatory mechanisms that contribute to osteoarthritis (OA). We hypothesised that AMPA and KA GluRs are expressed in arthritic joint tissues and that peripheral ad...

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Obesity is associated with greater risk of proximal humerus and ankle fracture, despite greater areal BMD (aBMD). We aimed to investigate whether greater risk of some fractures in obesity was due to skeletal or non-skeletal determinants. 100 individually-matched pairs of normal weight (NW) (18.5–24.9 kg/m2) and obese (OB) (BMI >30 kg/m2) individuals, aged 25–40 and 55–75 years underwent DXA to determine hip and lumbar spine aBMD, whole ...

Heritability of bone mineral density (BMD) varies at skeletal sites, possibly reflecting different relative contributions of environmental and genetic influences. To quantify shared genetic influences across different sites, we estimated the genetic correlation of BMD at the upper limb (UL), lower limb (LL) and skull (S) obtained from whole body DXA scans, using bivariate genome-wide complex trait analysis (GCTA). The study (n=9395) combined data from the Avon Longitu...

Childhood hypothyroidism results in delayed skeletal maturation and impaired growth. Thyroid hormones act via temporo-spatially regulated thyroid hormone receptors α (TRα) and (TRβ).In the skeleton, TRα is the predominant receptor and we hypothesise that the skeletal effects of hypothyroidism are mediated by TRα.To investigate this we assessed the response of wild-type (WT), TRα knockout (TRα...

Background: The presence of vascular calcification (VC) is a predictive factor for the development of cardiovascular diseases, especially in the obese population. VC has also been inversely associated with bone mineral density (BMD) but the results have been inconsistent. The main aim of this study was to evaluate the associations between VC, obesity and volumetric BMD (vBMD).Methods: We studied 148 healthy men and women, aged 55–75 years, divided i...