Bone Abstracts

Interleukin-6 (IL-6) plays an important role in bone metabolism and regulates fracture healing in a presently unknown process. In the fracture callus IL-6 expression is biphasic; it peaks during the inflammatory phase and again during intramembranous and endochondral ossification (Ai-Aql et al. 2008). Few studies using IL-6 knockout mice indicate that IL-6 might be crucial for bone healing (Yang et al. 2007). However, a generalized IL-6 knockout induces multi...

Chronic calcium- and vitamin-D-deficiencies are crucial risk factors for osteoporosis. However, their significance for fracture healing is still poorly investigated, despite the clinical evidence that osteoporotic bone healing is disturbed. This study addressed the important question, whether chronic deprivation of calcium and vitamin D compromises bone repair and if this could be rescued by a supplementation post-trauma. Because clinical hints suggest that a fracture induces ...

Previous studies demonstrated a negative influence of the growth- and differentiation factor midkine (MDK) on bone formation during bone remodeling and fracture healing. Additionally, MDK-deficiency protected mice from a loss of trabecular bone mass after ovariectomy (OVX). Therefore, we hypothesized that MDK may also be involved in the pathogenesis of delayed, osteoporotic fracture healing after OVX in mice. Thus, we analyzed the expression of MDK during bone regeneration and...

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Introduction: Osteocalcin (OC) is a marker of bone formation but also seems to play a hormonal role in the regulation of glucose and energy metabolism. Recently, an association of BMI with a haplotype composed of three single nucleotide polymorphisms (SNPs) in the gene for OC, located on chromosome 1q22, was observed in ethnically homogeneous European pedigrees.Aim: The aim of the study was to test the association of these three polymorphisms in the gene...

Sclerostin, a product of osteocytes, is known to inhibit Wnt signaling by binding the LRP5/6 receptor.We investigated the effects of a mutated mouse sclerostin protein (muScl, R118A/R144A) with potential sclerostin antagonistic activity. In vitro, muScl fully competed with wild type sclerostin for binding to LRP6, whereas its IC50 for Wnt3a activity was 4× higher than sclerostin (i.e. 600 nM). Moreover, serum osteocalcin increased in mice a...

Cholestatic liver disease is often associated with increased fracture risk. We had found that circulating levels of a fibronectin isoform called oncofetal fibronectin (oFN) were elevated in patients with primary biliary cirrhosis. Indeed, injecting oFN to mice suppressed osteoblast differentiation and bone mineral density in vivo, suggesting it is responsible for bone loss in these patients. The aim of this study was to define the mechanism by which oFN affects osteob...

Defects in 24-hydroxylation caused by vitamin D-hydroxylase (CYP24A1) loss-of-function mutations lead to decreased degradation of 1,25(OH)2D and the syndrome of idiopathic infantile hypercalcemia. Affected individuals show increased sensitivity to vitamin D and may develop severe hypercalcemia and hypercalciuria, even with small doses of vitamin D.Presenting: The objective of the study was to investigate the gene expression profile in...

Introduction: Mesenchymal stem cells (MSCs) counteract the decline of physiologic functions but their regenerative power decreases with age. In particular osteogenic differentiation capacity of MSCs has been shown to decrease with age thereby contributing to slowed down bone formation and osteoporosis. While much is known about cellular aging of MSCs, little is known about extrinsic factors influencing their functionality. Here we set out to identify circulating factors of the...

Objectives: Deteriorating bone mineral density and fragility fractures are common complications of Duchenne Muscular Dystrophy (DMD). This study aims to evaluate the effects of bisphosphonate therapy and testosterone supplementation (for pubertal induction) on the bone health of children with DMD.Methods: This retrospective cohort study examined the clinical records of children with DMD managed at the Neurogenetics and Endocrine clinics at The Children&#...