Bone Abstracts

Osteogenesis imperfecta (OI) classification has recently been broadened to include genes that primarily affect osteoblast differentiation. TMEM38B encodes TRIC-B, a ubiquitously expressed monovalent cation-specific channel protein involved in calcium release from the endoplasmic reticulum. How alterations in TMEM38B cause OI remains poorly understood and bone matrix characteristics in affected patients have not previously been described.<p class="abstext"...

Objectives: Hypophosphatasia (HPP) is a rare, inherited metabolic disorder caused by loss-of-function mutations in the ALPL gene that encodes the tissue-nonspecific alkaline phosphatase TNAP (ORPHA 436). Its clinical presentation is highly heterogeneous with a remarkably wide-ranging severity. HPP affects patients of all age. Therefor diagnosis is often difficult and delayed. To improve the understanding of HPP in children and in order to shorten the diagnostic time span in th...

Osteosarcoma is the most common primary malignant bone tumor, characterized by osteoid production and/or osteolytic lesions of bone. Despite recent improvements in chemotherapy and surgery, the problem of non-response to chemotherapy remains and constitutes a poor prognosis parameter. Consequently new therapeutic strategies aim to improve the overall rate of survival. The present work investigated the therapeutic interest of a dual phosphatidylinositol-3-kinase (PI3K)/mammalia...

Familial expansile osteolysis (FEO) is characterised by focal areas of increased bone turnover driven by bone-resorbing osteoclasts. The syndrome is caused by a heterozygous tandem insertion duplication mutation within the signal peptide region of TNFRSF11a (encoding receptor activator of NFκB; RANK). Our recent research has demonstrated that heterotrimeric receptor formation may hold the key to the disease phenotype. We have shown previously that, whilst homozygous overe...

Early-onset Paget’s disease of bone (ePDB), familial expansile osteolysis (FEO) and expansile skeletal hyperphosphatasia (ESH) are related syndromes caused by heterozygous tandem insertion duplication mutations within the signal peptide region of TNFRSF11a (encoding receptor activator of NFκB; RANK). Given that patients are always heterozygous for these mutations we have generated thirteen cell lines to investigate the molecular consequences of these mutations in...

Objectives: To evaluate the clinical outcomes of intravenous bisphosphonate treatment in children with mild-moderate osteogenesis imperfecta (OI) who had progressed from active bisphosphonate treatment to maintenance therapy for >2 years.Methods: A retrospective review was conducted on 17 patients with mild-moderate OI. Clinical data, fracture history, biochemistry, dual energy X-ray absorptiometry (DXA) parameters, vertebral measurements, bone age a...

Human mesenchymal stromal cells (hMSC) have been investigated as a clinical therapy to promote tissue repair. However, the disappearance of grafted cells soon after engraftment suggests that hMSC could principally act as initiators of repair through paracrine mechanisms.The aim of this study was to evaluate the relative contribution of grafted hMSC and host cells in promoting bone tissue repair. We isolated hMSC from three bone marrow (BM) donors, then d...

The interaction of Receptor Activator of NFkB ligand (RANKL) with its cognate receptor RANK is crucial for osteoclast formation. We studied eight point mutations within human RANK associated with rare forms of osteopetrosis to gain mechanistic insights into the regulation of RANK signalling.We investigated the role of the oligomerisation domain within the cytoplasmic region of RANK studying two mutations (W434X and G280X) identified in rare cases of oste...

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Introduction: The purpose of this study was to quantify fracture risk associated with areal bone mineral density (BMD) in older men.Methods: In this prospective analysis we followed 620 men aged 60–93 years (median 74.3 years) for a median 6.4 years, after baseline BMD assessments (performed 2001–2006) as part of the Geelong Osteoporosis Study. Based on WHO criteria, 33.5% had normal BMD at the femoral neck, 57.6% were osteopenic and 8.9% osteo...