Bone Abstracts

The osteoclast-associated receptor (OSCAR), primarily described as a co-stimulatory regulator of osteoclast differentiation, represents a novel link between bone metabolism and vascular biology. Previously, we identified OSCAR on endothelial cells responding to the proatherogenic factor oxidized low density lipoprotein (oxLDL). Additionally, OSCAR expression was increased in the aorta of atherogenic apoE-knock-out (apoE-KO) mice, where it was further induced by feeding a high-...

Breast cancer (BrCa) patients with metastases restricted to bone (BO) show a longer overall survival compared to BrCa patients developing bone and visceral metastases (BV). To unveil the molecular mechanisms that segregate these two BrCa patient groups, we performed microarray analyses on bone metastasis samples from BO and BV patients, finding in the latter a set of up-regulated genes involved in oxygen metabolism. We focused on Hemoglobin B (HBB) and evaluated its expression...

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In autosomal recessive osteopetrosis due to mutations of the TNFSF11 gene, deficiency of the pro-osteoclastogenic cytokine RANKL prevents osteoclast formation. RANKL is a membrane-bound protein cleaved into active soluble (s)RANKL by various enzymes, including metalloproteinase 14 (MMP14). We created a bio-device that released sRANKL and induced osteoclastogenesis in tnfsf11−/− mice. We tested various RANKL cell sources, and used mouse primary calvarial osteoblasts...

Rett (RTT) syndrome is a neurodevelopmental disorder that affects girls almost exclusively. The majority are related to mutations in the MECP2 gene.Patients with RTT syndrome have a high incidence of fractures that can occur at a young age. One of the objectives of this study was to identify clinical, radiographic and biological parameters associated to fracture incidence.89 RTT patients bearing a MECP2 mutation who had no...

ADO2 is a debilitating genetic bone disease causing multiple fractures and other severe symptoms. A mouse model of ADO2, harbouring the heterozygous Clcn7G213R gene mutation, phenocopies the human syndrome. The Clc7 gene encodes the ClC7 dimeric 2Cl−/1H+ antiporter that is almost ubiquitously expressed, although the mutations hit especially the osteoclasts impairing bone resorption. By immunofluorescence, we observed that the mutant ClC7 ...

We previously demonstrated the involvement of Lcn2 in bone loss induced by mechanical unloading. This prompted us to investigate bone phenotype of Lcn2−/− mice by μCT, which showed an osteopenic phenotype, characterized by 40% lower trabecular bone volume, 50 and 21% lesser trabecular number and thickness, respectively, and 20% higher trabecular separation, compared to WT, while cortical thickness was significantly lower (40%) only in elderly Lcn2<s...

Angiogenesis and osteogenesis are tightly linked and dependent on each other. Lipocalin 2 (LCN2) is a mechanoresponding adipokine, strongly upregulated in osteogenic cells subjected to microgravity (0.08–0.008 g), in which it impairs osteogenesis and upregulates the osteoclastogenic cytokine, RANKL. We investigated the role of LCN2 in the crosstalk between angiogenesis and osteogenesis in simulated microgravity conditions as a model of mechanical unloading. Mouse and huma...

Background: Rett Syndrome (RS) is a disabling condition due to mutations in MECP2. Girls affected with RS are at risk of developing osteoporosis and fractures at a young age because of their lack of mobility and through a direct effect of MECP2 on bone mineralization. In these girls, bone fragility inflicts pain and may seriously impair the quality of life.Objective: To retrospectively assess the effect of IV bisphosphonates on fracture, bone mineral den...

Objectives: To determine the national prevalence, management and long term outcomes of patients who develop osteonecrosis after initiation of treatment for acute lymphoblastic leukaemia (ALL).Methods: The central trials unit for the leukaemia trial UKALL2003 identified patients with reported bone toxicity out of the 3126 patients recruited into the study. Questionnaires were sent to each relevant treatment centre requesting information about each patient...