Bone Abstracts

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...

Objectives: Autosomal recessive osteopetrosis (OP) is a rare metabolic bone disease characterized by impaired osteoclast function resulting in defective bone resorption and generalized high bone mineral density (BMD). Excessive bone compromises bone marrow space, leading to marrow failure. The infantile malignant form is typically fatal within the first decade of life. The intermediate form presents later during childhood. Currently, the only potential curative therapy for OP ...

Severe generalised recessive dystrophic epidermolysis bullosa (RDEB) is a rare disorder resulting from loss of function mutations in the type VII collagen gene (COL7A1). Although RDEB is characterised by severe skin blistering and erosions following minor mechanical trauma, it is a multisystem disorder with pubertal delay and low bone mass as part of the many complications.Children with RDEB have been described as having inadequate gains in bone...

Objectives: Anorexia nervosa (AN) is a life-threatening eating disorder often associated with reduced bone mass. The aim of the present study was to investigate vitamin D status and the association with BMI, fat mass and bone mineral density (BMD) during a novel intensive nutrition therapy in young AN women.Methods: Twenty-five female AN patients (20.1±2.3 years, BMI 15.5±0.9 kg/m2) admitted to a specialised inpatient eating disorder...

Objectives: Children during the intensive treatment of cancer might be exposed to vitamin D deficiency and consequently leads to, among other things, bone deficits and low bone mass. The aim of this study was: i) to assess the serum concentration of 25-hydroxyvitamin D (25-OH-D) in children diagnosed with acute lymphoblastic leukemia (ALL) at two time points (time of diagnosis and just after induction treatment), ii) to evaluate the impact of used drugs on the changes of 25-OH...

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...

The aim of the study was to evaluate relationships between morphometric, densitometric and mechanical properties of tibiotarsus in ostriches (Struthio camelus). 14-month-old males (N=15) and females (N=31) were slaughter to obtain left tibiotarsus. Using computed tomography technique (Somatom Emotion scaner, Siemens), volumetric bone mineral density (vBMD) of the trabecular (Td) and cortical bone (Cd), mean voulmetric bone mineral density (MvBMD) and...

Mast cells (MCs) are pro-inflammatory sensor and effector cells of the immune system. MCs seem to play a role in bone metabolism, because patients with systemic mastocytosis develop osteoporosis. MCs are present in the fracture callus during bone healing, however, their function has not yet been investigated. Here, we examined the role of MCs in the inflammatory and repair phase during fracture healing.Male 12-week old MC deficient mice (Mcpt5-Cre R-DTA)...