Bone Abstracts

Background: Bone accrual during adolescence is the main contributor to peak bone mass. Bone remodeling is a balance between bone formation and resorption as directed by osteoblast and osteoclast activity, respectively. nitric oxide (NO) is a potent regulator of bone remodeling via mediating effects of cytokines, estrogen and mechanical strain. NO is synthesized from the conversion of L-arginine to L-citrulline by the enzyme nitric oxide synthase (...

Background: Mechanical stimulation is thought to be critical for bone anabolic activity. It is unclear how quickly the growing skeleton responds to additional externally-applied mechanical stimuli. We wished to determine the acute effect of a standardised mechanical stimulus to the growing skeleton.Objectives: To determine the acute time course and magnitude of bone’s response to whole body vibration (WBV) in pre-pubertal boys.<p class="abstext"...

This study was performed to characterize the effects of calcium phosphate coated and hydroxyapatite coated zirconia compared to smooth surfaced zirconia with bone marrow-derived osteoblast culture.Bone marrow-derived osteoblasts were cultured on i) smooth zirconia, ii) zirconia coated with calcium phosphate (CaP), and iii) zirconia coated with hydroxyapatite (HA). The tetrazolium-based colorimetric assay (MTT test) was used for examining the attachment o...

Lipid raft microdomains have important role in cellular signaling. Caveolae are a specialized type of lipid rafts that are stabilized by oligomers of caveolin protein. Here we showed that caveolin-1 (Cav-1) is a critical membrane structural protein of osteoclast. In microarray analysis, we found that caveolin-1 was significantly up-regulated by RANKL. Knock-down of Cav-1 in bone marrow derived-macrophage reduced osteoclastogenesis. Consistent with the in vitro results...

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...

There are several evidences that osteocyte plays a critical role in bone remodeling. Healthy or apoptotic osteocytes can send signals to other bone surface cells like osteoblasts, osteoclasts, osteoclast precursors and bone lining cells through their networking in canaliculi. Therefore, to determine the role for osteocytes in bone remodeling, we examined the effect of healthy and apoptotic osteocytes on osteoblasts proliferation and recruitment. In addition, the effects of mec...

Background: Familial hypocalciuric hypercalcemia (FHH) is a rare autosomal dominant condition with an estimated prevalence of 1 in 78,000. The commonest cause of FHH is inactivating mutations of the calcium-sensing receptor (CASR) gene, with the rest mostly caused by missense mutations of the GNA11 and AP2S1 genes. FHH is characterized by persistent mild-to-moderate hypercalcemia, hypocalciuria with calcium-creatinine clearance ratio ⩽0.01. The disease runs a benign cou...

Bisphosphonates (BPs) are widely used for treating osteoporosis and preventing osseous metastasis or hypercalcemia in cancers. However, osteonecrosis of the jaw in patients treated with BP after dentoalveolar surgery has been increasing, especially in those treated with strong BPs such as zoledronate (ZA). The pathobiology underlying the occurrence of osteonecrosis only in the jaw bone remains unclear. The objective of this study was to compare the effects of BPs on the in...

Osteoporosis is known to be associated with metabolic diseases characterized by insulin resistance, such as central obesity, diabetes, and metabolic syndrome. Non-alcoholic fatty liver disease (NAFLD) is also increased in such insulin resistant conditions. However, little is known about whether osteoporosis and nonalcoholic fatty liver disease are etiologically related to each other or not. We investigated whether bone mineral density(BMD) is associated with NAFLD in pre- and ...

Purpose: Osteoporosis is a progressive bone disease that is characterized by a decrease in bone mass, density and destruction of microstructure, which can lead to an increased risk of fracture. Although many studies have been published about relationship between end-stage renal disease and osteoporosis, but research on the relationship between proteinuria and the prevalence of osteoporosis is still lacking.Methods: We assessed 91 postmenopausal women wit...