Bone Abstracts

Aim & background: Evidence from genetic studies of osteoporosis and fracture risk indicate that bone mineral density (BMD) is genetically controlled. The low-density-lipoprotein-related receptor 5 (lrp5) gene is a known co-receptor in the canonical Wnt bone formation regulatory pathway. Although mutations found in this gene have been shown to regulate BMD in humans, and Lrp5 knockout mice had reduced bone mass, its role in the bone development/bone acquis...

During the differentiation of the osteoclast, it transform from a mono-nucleated cell to multinucleated cell by fusion of its precursors. Although, cell fusion is a complicated process which likely involves many regulating proteins, only a few osteoclast fusion regulating proteins were identified. We have identified dual-specificity tyrosine-phosphorylation regulated kinase 2 (Dyrk2) as a novel regulator of the osteoclast fusion process. Dyrk2 belongs to a family of protein ki...

G-protein coupled receptors (GPCRs) are the largest family of cell surface proteins, which are important for bone development, remodeling and diseases. One of the GPCRs, called GPR39, has been found to be expressed in several osteoblastic cell lines. However, its role in bone metabolism has not been investigated yet. In order to elucidate a role for GPR39, we characterized the bone phenotype in GPR39 deficient mice. During aging, at six months old, dynamic histomorphometry dat...

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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...

Low body mass index (BMI) or body weight is a well-known risk factor for osteoporosis and fragility fractures. However, the relative contribution of lean mass and fat mass on bone health, i.e. fragility fractures is inconclusive.We elucidated the relative contribution of lean and fat mass on fracture risk by group analysis in Korean men and women. This was an ongoing prospective community-dwelling cohort study at Ansung in Korea, begun in 2001. We includ...

Objectives: Osteogenesis Imperfecta (OI) is a collagen-related disorder. Type V OI, caused by a recurrent dominant mutation in the plasma membrane protein IFITM5/BRIL, and type VI OI, caused by recessive null mutations in the anti-angiogenic factor PEDF, have distinct features. IFITM5 S40L, reported in six patients, causes severe dominant OI with phenotype and bone histology similar to type VI, rather than Type V, OI. Our objective is to understand the pathway connecting IFITM...

Objectives: A common feature of nearly all forms of osteogenesis imperfecta (OI) is a hypermineralized bone matrix. Null mutations in SERPINF1, encoding the potent antiangiogenic factor PEDF, lead to type VI OI with excessive osteoid formation, abnormal osteoblast-osteocyte development and increased matrix mineralization. Recently, atypical type VI OI has been delineated, caused by a loss-of-function mutation (p.S40L) in IFITM5 the causative gene for type V OI. The 6 cases rep...

Background: Aromatase inhibitors (AIs) increase the risk of fracture in patients with breast cancer. Therefore, we aimed to evaluate the long-term effects of AIs on bone health in postmenopausal women with primary breast cancer.Patients and methods: We performed a retrospective longitudinal observational study in patients with breast cancer who were treated by AIs for ≧3 years (baseline T-score >–2.5). Patients with previous anti-osteoporosis...

Background: Elevated plasma homocysteine levels are a risk factor for osteoporotic fractures. Supplementation with vitamin B12/folic acid lowers homocysteine levels. This study aimed to determine whether vitamin B12/folic acid supplementation reduces osteoporotic fracture incidence in hyperhomocysteinemic elderly.Methods: B-PROOF is a double-blind, randomized, placebo-controlled trial including 2 919 participants aged ≧65 years with elevated homocyste...