Bone Abstracts

Background: There have been many studies on the association between vitamin D and testosterone in the world. But it has not been fully clarified. Furthermore, data in Korean men is limited. This study aimed to determine the association between vitamin D and testosterone levels in korean men.Methods: This cross sectional study analyzed serum 25-hydroxyvitamin D (25(OH)D) and total testosterone in 365 Korean men over 25 years of age who visited a local uni...

Introduction: Percutaneous vertebroplasty is a well known surgical method to put the bone cement at osteoporotic vertebrae. There was a few report concerning about bone cement related complication such as dislodgment of injected cement. There are some contradictory study for long term reaction to bone cement in osteoporotic bone, especially injected cement features. This study is to assess the radiographic features of patients who underwent percutaneous vertebroplasty (PVP) in...

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...

The skeleton is a preferred site of metastasis in patients with advanced breast cancer, and bone loss is one of the major complications of breast cancer metastasis. Therefore, prevention of bone metastasis is clinically important. Our previous observation of an anti-osteoclastic activity of Trolox, a vitamin E analogue, led us to investigate whether Trolox could inhibit bone metastasis and bone destruction induced by breast cancer. I.P. administration of Trolox markedly inhibi...

Background and objective: Recent studies have demonstrated that higher serum 25-hydroxyvitamin D (25(OH)D) had a favorable effect on bone health. Osteocalcin, however, according to its serum concentration showed different outcomes for bone and aortic calcification. The aim of this cross-sectional study was to compare the bone mineral density (BMD) and coronary artery calcification score (CACS) according to the serum concentration of 25-hydroxyvitamin D and osteocalcin.<p c...

The receptor activator of NF-kB (RANK) and ITAM-containing adaptors have been identified as essential factors involved in osteoclast formation and bone remodeling, but their mechanisms and interacting factors have not yet been fully identified. Here we report that early estrogen-induced gene 1 (EEIG1), a novel RANK ligand (RANKL)-inducible protein, physically interacts with RANK and further associates with Gab2, PLCg2, and Tec/Btk kinases by RANKL stimulation. Overexpression o...

Tyrosine kinase c-Src plays an important role in actin ring formation and bone resorption activity in osteoclasts. Therefore, c-Src has been targeted for the treatment of osteolytic disorders. In the present study, we investigated anti-resorptive effect of dibenzazepine (DBZ), one of the γ-secretase inhibitors (GSIs), on osteoclast-mediated excessive bone resorption. DBZ did not affect osteoclast differentiation, but disturbed actin ring formation and inhibited osteoclast...

Growing body of evidence shows that microRNAs play an important role in regulating bone mass. We investigated the cooperative microRNA-mRNA regulatory mechanism of peak bone mass in inbred strain of mice with different bone density using microarray analysis. Femur and tibia of 12-week old C3H/He (high bone density) and C57BL/6 (low bone density) were harvested to extract total bone RNAs for microarray. A total of 30 miRNAs were differentially expressed between bone tissue of C...

Notch signaling plays a central role in various cell fate decisions, including skeletal development. Recently, Notch signaling was implicated in osteoclast differentiation and maturation, including the resorption activity of osteoclasts. However, the specific involvement of notch signaling in resorption activity was not fully investigated. Here, we investigated the roles of Notch signaling in the resorption activity of osteoclasts by use of the γ-secretase inhibitor diben...

Tannerella forsythia is a gram-negative, anaerobic, asaccharolytic, fusiform bacterium. The presence of the bacterium is associated with various forms of periodontal disease, including gingivitis, chronic and aggressive periodontitis. The expression of GroEL, a bacterial heat shock protein, increases in stressful conditions such as infection. GroEL is a moonlighting protein that has multiple functions. The aim of this study was to evaluate the effect of T. forsyth...