Bone Abstracts

Hip osteoarthritis is a cause of significant morbidity to people and their canine companions. Medical management is frequently insufficient, leading to surgery to relieve pain and regain mobility. Hip replacements are not without potential complications, including loosening and infection. Currently, there is a focus on uncemented implants to decrease these problems, however these rely on the biology of the femur for osseointegration and long-term stability. It has been previou...

Effects of whole bone scaling on isolated osteoblast behaviour are unknown. With two orders of magnitude range in body mass, dog breeds are well-suited to determine such relationships.Femoral heads from three canine hip replacement surgeries were collected. Bone fragments were washed in PBS+AB/AM, trypsin-digested and incubated in 0.2% collagenase. Cells from resultant supernatant were seeded in DMEM+10% FCS+AB/AM at 37 °C, 5% CO2, g...

Prolyl hydroxylase 2 (PHD2) regulates hypoxia-inducible factor α (HIFα) transcription factors and thus, erythropoietin (EPO) production. Under normoxic conditions, HIFα is constantly inactivated through hydroxylation by PHD2. Due to the embryonic lethality of PHD2 knock-out mice, its precise role in erythropoiesis and tissue homeostasis has long remained unknown. Recently, we generated a conditional knock-out (cKO) mouse lacking PHD2 in EPO-producing cells. Thes...

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...

Milk fat globule-epidermal growth factor 8 (MFG-E8) is a glycoprotein that controls the engulfment of apoptotic cells and exerts anti-inflammatory effects. It has been implicated in the pathogenesis of several diseases, but its role in the bone microenvironment is still unknown. Here we tested the hypothesis that MFG-E8 also regulates bone metabolism and the development of arthritis.MFG-E8 expression was detected in mouse bones and primary murine osteobl...

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...

Objectives: To assess the effects of short-term vitamin D supplementation on bone metabolism, glycaemic status and immune function in vitamin D deficient children.Method: Treatment with daily 5000 IU cholecalciferol supplementation for 6 weeks. At baseline and end of treatment serum 25 hydroxyvitamin D (25(OH)D), parathyroid hormone (PTH), alkaline phosphatase (ALP), serum collagen type 1 cross-linked C-telopeptide (CTX), serum calcium, HbA1c, sex hormon...