Bone Abstracts

Reduced availability of oxygen, i.e. hypoxia, could occur during disuse, bone development, and fracture. Cartilage tissue is avascular in nature and the microenvironment of cartilage is hypoxic. Hypoxic regulation of gene expression generally involves activation of the hypoxia-inducible factor (HIF) transcription pathway. Receptor activator of nuclear factor-kappaB ligand (RANKL) is an osteoblast/stromal cell derived essential factor for osteoclastogenesis. Hypoxia-induced enh...

Purpose: The purpose of this study was to scan femoral heads from cadaveric donors and investigate the microarchitecture within each femoral head comprehensively.Material and methods: Ten proximal femora was harvested from eight human cadaveric donors and these specimens were scanned using micro-computed tomography. Reconstructed batches of images were aligned along the main trabecular direction (MTD). The upper hemisphere of each femoral head was includ...

The P2Y14 (purinergic receptor P2Y, G protein coupled, 14) receptor for UDP-glucose and other UDP-sugars has been implicated in the regulation of the stem cell compartment as well as neuroimmune function. However, the role of P2Y14 in osteoclast formation is completely unknown. We found that RANKL selectively induced P2Y14 among seven mammalian P2Y receptors when analysed at both the mRNA and protein level, but inhibitors of the MAP pathway suppressed induction of P2Y14 protei...

We sought to elucidate the effects of dietary caloric alterations on bone marrow adiposity and the effects of β-adrenergic signaling on marrow stromal cells’ adipogenic differentiation. Male 6-week-old C57BL/6 mice were assigned into three groups: an ad-libitum fed control diet (CON; 10 kcal% fat), a high calorie diet (HIGH; 60 kcal% fat) and a low calorie diet (LOW; 30% kcal restriction vs CON diet). In each diet group, mice were treated with vehicle (VEH: ...

Osteocytes may function as mechanotransducers by regulating local osteoclastogenesis. Reduced availability of oxygen, i.e. hypoxia could occur during disuse, bone development and fracture. Receptor activator of nuclear factor-κB ligand (RANKL) is an osteoblast/stromal cell derived essential factor for osteoclastogenesis. Hypoxia induced osteoclastogenesis via increased RANKL expression in osteoblasts was demonstrated. Hypoxic regulation of gene expression general...

Activation of p38 MAPK by RANKL is regulated by the scaffolding protein receptor for activated C-kinase 1 (RACK1) in osteoclast precursors, whereas it is unclear whether RACK1 can also affect in mature osteoclasts. In this study, to identify that the interaction of RACK1 with c-Src is essential for osteoclast function, we generated several mutants affecting the RACK1-c-Src association. A RACK1 mutant protein (mutations of tyrosine 228 and 246 residues to phenylalanine) disrupt...

Introduction: As Korean society have been entered to aging population, osteoporosis is considered one of the most important disease in the elderly. Osteoporotic vertebral compression fractures can affect to patient’s quality of life. But, in Korea, there is few studies about this, so we investigated.Aim: To evaluate the quality of life of patients with vertebral compression fracture.Methods: This study was performed in multice...

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...