Bone Abstracts

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...

BMPs and canonical Wnts are the representative developmental signals that enhance osteoblast differentiation and bone formation. Previously, we demonstrated that EGF inhibits BMP2-induced osteoblast differentiation through the induction of Smurf1 expression. However, the regulatory role of EGF in Wnt/β-catenin-induced osteoblast differentiation has not been elucidated. In this study, we investigated the effect of EGF on Wnt/β-catenin signaling-induced osteoblast diff...

Distal-less homeobox 5 (Dlx5) is a transcription factor that enhances osteogenic differentiation of mesenchymal stem cells via upregulating the expression of Runx2 and other osteoblast phenotypic genes. We have previously demonstrated that Dlx5 also downregulates adipogenic differentiation of mesenchymal stem cells and that insulin decreases expression levels of Dlx5 via increasing expression levels of miR-124, a microRNA targeting 3′UTR of Dlx5. However, the mechanism o...

Nutrition is a major modifiable factor that affects bone health. Dietary potassium may act as an alkaline source by neutralizing the acid load and reducing calcium loss from bone.We aimed to evaluate the association between dietary potassium intake and bone mineral density (BMD) in the Korean population. We analyzed data from the Korean National Health and Nutrition Examination Survey (KNHANES) A total of 3135 men aged >50 years and 4052 postmenopaus...

Farnesoid X receptor (FXR) is a member of the nuclear receptor superfamily, which functions as bile acid sensor controlling the bile acid homeostasis. We have investigated the role of FXR in regulating bone metabolism in vivo. We have identified expression of FXR in calvaria and bone marrow cells, which was gradually increased during osteoblastic differentiation in vitro. Deletion of FXR in vivo has resulted in significant reduction in bone mineral density by...