Bone Abstracts

Reduced bone mineral density (BMD) has been reported to adversely affect health related quality of life (HRQoL) also in postmenopausal women without vertebral fracture. To date no data exist in literature about any possible influences of quantitative ultrasonography (QUS) on HRQoL. This study aimed to assess whether QUS parameters at calcaneous may be associated with HRQoL.In 1812 ambulatory postmenopausal women aged 60 years or over, referred by their f...

Objectives: The Brtl mouse, a unique model for the autosomal dominant forms of osteogenesis imperfecta was used to prove the feasibility of a lentiviral-shRNA-based strategy to improve collagen quality by targeting the mutant Col1a1 allele at the point mutation responsible for the causative substitution Gly349Cys. The ability to specifically suppress the mutant allele should convert the moderate Brtl outcome to the mild one caused by quantitative defect.<p class="...

Background: Proline and hydroxyproline account for ~25% of aminoacids in collagen., Prolidase (peptidase D (EC 3.4.14.9)), cleaves iminodipeptides with a C-terminal proline or hydroxyproline, playing a major role in collagen catabolism. Mice with prolidase deficiency (PD) present with varied phenotypes including reduced size compared to wild-type littermates. We measured structural and mechanical properties of bones in PD mice.Methods: Whole femurs from ...

Strontium ranelate is a promising drug used in the treatment of osteoporosis. This drug has a unique dual effect on bone turnover, simultaneously increasing bone formation by osteoblasts (anabolic effect) and decreasing bone resorption by osteoclasts (antiresorptive effect). The goal of this study was to evaluate: i) anabolic effects of strontium ranelate on the formation of bone-like mineralized matrix in osteoblast cell cultures and ii) changes the drug could cause on the ma...

Osteoclasts resorb bone matrix through a specific adhesion structure called the sealing zone or actin ring, which is based on a belt of podosome. Much remains to be uncovered regarding the molecular mechanisms driving podosome organization into superstructures in particular the osteoclast podosome belt. Proteomic analyses in osteoclasts revealed the adaptor protein tensin 3 as a partner of Dock5, a Rac exchange factor necessary for podosome belt formation and bone resorption. ...

Dominant osteogenesis imperfecta (OI) is a bone disease mainly caused by collagen type I mutations and characterized by bone fragility and growth delay. Nowadays no definitive cure is available. A zebrafish OI model (Chihuahua) carrying an heterozygous G574D substitution in the α1 chain of collagen type I was generated by ENU mutagenesis and is available in our laboratory. Control (WT) and mutant (Chi+/−) fish growth was followed up from day 1 post fertilization to ...

Objective: Cystinosis is a rare lysosomal storage disorder caused by loss-of-function mutations of the CTNS gene, encoding for cystinosin symporter that mediates cysteine efflux from lysosome. ~95% of cystinotic patients display nephropathic Fanconi’s syndrome, short stature, osteopenia and rickets. In this study we evaluated whether the absence of cystinosin primarily affects bone remodeling activity.Methods: We analyzed bone phen...

Desbuquois dysplasia (DBQD) is a rare recessive chondrodysplasia, characterized by growth retardation, multiple dislocations and advanced carpal ossification. Two forms of DBQD have been described on the basis of the presence (type 1) or absence (type 2) of characteristic hand anomalies. DBQD type 1 is caused by mutations in the Calcium-Activated Nucleotidase 1 gene (CANT1), while DBQD type 2 is caused by mutations in the xylosiltransferase 1 gene.CANT1 ...

Bone is a complex tissue constituted by a mineral phase, hydroxyapatite, and an organic phase, mainly represented by collagen type I. Specialized cells are responsible for bone formation and remodeling. Osteoblasts represent the bone forming cells, osteocyte are the orchestrator of bone remodeling through regulation of the other bone cells activity, by functioning as endocrine cells and by acting as mechanosensor, and osteoclasts, the bone resorbing cells. Mesenchymal osteopro...

Objectives: Gorham-Stout disease (GSD) is a very rare disorder characterized by extensive angiomatous proliferation and progressive osteolysis without new bone formation. Only ~200 patients were reported. The quality of life is very poor since patients display pain, fractures, functional impairment and swelling of the affected regions. The ethiology of GSD is unknown. We aim to investigate the bone phenotype and to identify molecular and cellular defects in GSD patients.<p...