Bone Abstracts

Background: We have previously shown that MLO-Y4 osteocytes express a number of P2 receptors, respond to a broad range of nucleotides (e.g. UTP) by increasing intracellular calcium concentration and release ATP upon both mechanical and UTP stimulation. The aim of this study therefore is to investigate how the osteocytes release ATP and whether there is a difference in release pathway depending on the type of stimulus.Methods: ATP release was investigated...

Experimental studies suggested that both, oxidative stress and the Wnt pathway, are important factors in the regulation of bone remodeling. Thus, low antioxidant levels and elevated markers of Wnt pathway inhibitors (sclerostin) levels are associated with a reduced bone mineral density and increased risk of osteoporotic fracture. Whether oxidative stress and the Wnt pathway are related to fracture risk is poorly understood.M&M: Cross-sectional study ...

Introduction: To compare serum vitamin D levels in elderly patients with or without osteoporotic spinal compression fractures (OSCF) and to evaluate a correlation between serum vitamin D level and several variables such as age, and bone mineral density (BMD), bone turnover markers.Methods: The medical records of 78 patients with OSCF (fracture group) and 84 age-matched control patients who were diagnosed osteoporosis without OSCF (control group) were rev...

Introduction: To analyze clinical assessment and efficacy of once-yearly i.v. zoledronic acid for osteoporosis.Materials and methods: The subjects were 322 osteoporotic patients who received more than single infusion of zoledronic acid in our hospital from October 2008 to March 2011. On clinical assessment, the adherence was evaluated by measuring the rate of reinfusion. Adverse events were recorded for safety assessment. For efficacy assessment, the bon...

Antenatal glucocorticoid (GC) injections are not only used to enhance fetal lung maturation in preterm children but also for the treatment of maternal conditions such as autoimmune diseases or infections. Animal models and clinical studies suggest that the regulation of the hypothalamic–pituitary–adrenal axis is altered in the offspring of GC-treated mothers with increased sensitivity to stress.Objective: The aim of this study is i) to define t...

Mutations in PLEKHM1 cause bone disease in humans and animals. Truncations causedeficient bone resorption by osteoclasts leading to osteopetrosis. A gain-of-function point mutation causes increased resorption leading to osteopenia. We and others have shown that PLEKHM1, a multi-modular protein, interacts with the small GTPase rab7 and is involved in vesicle trafficking, secretion, and membrane biogenesis. To investigate other interactions of PLEKHM1 we performed tandem affinit...

Tyrosine kinase c-Src plays an important role in actin ring formation and bone resorption activity in osteoclasts. Therefore, c-Src has been targeted for the treatment of osteolytic disorders. In the present study, we investigated anti-resorptive effect of dibenzazepine (DBZ), one of the γ-secretase inhibitors (GSIs), on osteoclast-mediated excessive bone resorption. DBZ did not affect osteoclast differentiation, but disturbed actin ring formation and inhibited osteoclast...

Osteogenesis imperfect (OI) is an inheritable bone disease with low bone mass, fragility, deformity and multiple fractures in skeletal tissues. Modulation of Wnt signalling components reportedly alleviates excessive bone and joint remodelling in various skeletal disorders. This study is undertaken to explore whether loss of Wnt inhibitor Dickkopf-1 (Dkk1) action affects bone formation or skeletal homeostasis in OI. In clinical vignettes, OI patients had severe osteoporosis (<e...

Owing to their anti-inflammatory effects, steroid therapy using glucocorticoids (GCs) is still part of the treatment of rheumatoid arthritis (RA), despite several severe side effects like glucocorticoid-induced osteoporosis (GIO). Until now the molecular mechanisms underlying the beneficial and side effects of GC therapy are poorly understood. GCs exert their actions via the glucocorticoid receptor (GR) that alters gene expression by either binding as a dimer to GC response el...

Chronic stress and depression are associated with alterations in the hypothalamic–pituitary–adrenal signalling cascade and considered a risk factor for bone loss and fractures. However, the mechanisms underlying the association between stress and poor bone health are unclear. Utilising a transgenic (tg) mouse model in which glucocorticoid signalling is selectively disrupted in mature osteoblasts and osteocytes (HSD2OB-tg mice), the current study examines t...