Bone Abstracts

Background: Recent technological ‘omics’ advances have empowered us to identify associations between genetic markers and various traits. Knowledge of serum metabolites as intermediary phenotypes can help us achieve a better understanding of the causal pathways from genes to complex diseases like osteoporosis.Methods: In the context of TwinsUK study, serum metabolomic profiles of 6055 participants were assessed using a non-targeted mass spectrom...

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Despite its importance, the resorptive surface of osteoclasts has not been directly visualised. We exploited a novel approach that enables us to inspect the substrate-apposed surface of cells. To achieve this, we incubated osteoclasts on vitronectin-coated nail varnish and, afterwards, we dissolved the substrate and visualised the cells resorbing-side up in the scanning electron microscope (SEM). We then employed confocal microscopy to correlate the SEM appearances with the di...

Extracellular nucleotides, signalling through P2 receptors, play a significant role in bone biology. ATP and ADP act via the P2Y1 or P2Y12 receptors to promote osteoclast formation and activity. Bone cells express the P2Y2 receptor and, in osteoblasts, it plays a role in regulating bone mineralisation. This investigation examined the role of the P2Y2 receptor in osteoclasts. Primary osteoclasts were isolated from the bone ma...

Bisphosphonates are widely used drugs in the fight against osteoclast-mediated bone loss, including osteoporosis and Paget’s disease of bone. The first generation of these potent drugs such as clodronate, a non nitrogen-containing bisphosphonate, has been shown to inhibit osteoclast formation and osteoclastic bone resorption both in vitro and in vivo as well as inducing apoptotic cell death. Recent interest has centred on the effects of more potent nitro...

The relationship between bone formation and blood flow is unclear. Recently, PTH was reported to activate production of nitric oxide (NO), a potent vasorelaxing agent, in endothelial cells and we and others have confirmed a strong vasorelaxing action of PTH in vivo in the mouse. Here, we tested the hypothesis that a potent NO synthase inhibitor (L-NAME: NG-nitro-L-arginine methyl ester) may alter the effect of intermittent PTH (iPTH) on b...

Receptor activity modifying proteins (RAMPs 1, 2 and 3) are a class of important accessory proteins that interact and regulate several G-protein coupled receptor (GPCR) activity by finely modulating ligand interaction and in some cases trafficking receptors to cell surface.Predominant roles of RAMPs include ligand selectivity in receptors for Calcitonin (CT) family of peptides that comprise calcitonin, calcitonin gene related peptide, amylin and Adrenome...

The in vitro culture of calvarial osteoblasts from neonatal rodents remains an important method for studying the regulation of osteoblast function. Widespread use of transgenics has created a particular need for a reliable, simple method that allows the differentiation and bone-forming activity of mouse osteoblasts to be studied directly. We have established such a method and have identified key differences in optimal culture conditions between mouse and rat osteoblas...

Strontium ranelate (SrR) is now widely used for the prevention of osteoporotic fractures. The mechanisms by which this occurs, however, remain unclear. We investigated the actions of Sr2+ salts in bone-forming cultures of primary osteoblasts from rat calvariae. Osteoblasts were treated continuously with either SrR or SrCl2 for 14 days. Abundant, discretely mineralised ‘trabecular’ bone structures formed in alizarin red-stained control cultures. ...

Allopurinol and, and its active metabolite, oxypurinol are widely used in the treatment of gout and hyperuricemia. They act by inhibiting xanthine oxidase an enzyme in the purine degradation pathway that converts xanthine to uric acid. This oxygen-dependent reaction also results in the generation of superoxide free radicals. The aim of this investigation was to examine the effect of allopurinol and oxypurinol on osteoblast differentiation and function. Rat calvarial osteoblast...