Bone Abstracts

Although EGF has been known to inhibit osteoblast differentiation, its molecular mechanism has not been clearly elucidated. Smurf1 acts as a negative regulator of BMP signaling by inducing ubiquitination and proteasomal degradation of BMP type I receptor and R-Smads. In this study, we investigated the effect of EGF on the expression of Smurf1 and the role of Smurf1 in EGF-induced inhibition of BMP2-induced osteogenesis. EGF increased Smurf1 expression which was blocked by trea...

Children with 21-hydroxylase deficiency (21-OHD) need chronic glucocorticoid (cGC) therapy to replace congenital deficit of cortisol synthesis, and this therapy is the most frequent and severe form of drug-induced osteoporosis. In the study we enrolled 18 patients (9 females) and 18 sex- and age-matched controls. We found in 21-OHD patients high serum and leukocyte levels of dickkopf-1 (DKK1), a secreted antagonist of the Wnt/β-catenin signaling pathway, known to be a key...

The childhood and adolescent years represent a critical period for bone acquisition. Extrinsic factors such as diet and physical activity represent modifiable variables that may have a significant impact on a young adult’s peak bone mass. This lecture will consider dietary supplementation with specific nutrients as a strategy to augment bone density during the childhood and teenage years. An overview will be provided, as well as data reviewed from supplementation trials i...

Bone metastasis is a frequent occurrence in cancer patients, with severe complications such as fracture, bone pain, and hypercalcemia. The pathogenesis of osteolyitc bone metastasis depends on cross-communications between tumor cells and various stromal cells residing in the bone microenvironment. Many of these interactions are mediated by tumor derived growth factors, cytokines, proteases, and other secreted and exosomal proteins. Using gene expression profiling and proteomic...

Giant cell tumour of bone (GCTb) is an osteolytic neoplasia with tendency to local recurrence (10–25%), while metastases or malignant transformation are described in 1–4% of cases.It is composed by three distinct populations that cross-talk each other generating unbalance in bone remodeling and activation of NF-kB signaling pathway.To identify new candidate biological markers useful for improving clinical management of GC...

Periostin (osteoblast-specific factor OSF-2) is a glycoprotein that in humans is encoded by the POSTN gene. It is a component of the extracellular matrix and is thought to be involved in osteoblast recruitment, attachment and spreading.The N-terminus part of periostin is conserved, while the C-terminal region gives rise to different splice isoforms upon alternative splicing. The isoforms have a molecular weight range from 83 to 93 kDa.<p class="abste...

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...

Osteoclasts are bone-resorbing multinucleated cells that differentiate from monocyte/macrophage-lineage precursors. Bone destruction and osteoporosis are attributed to excessively activated osteoclasts. Osteoclast differentiation is governed by diverse regulatory processes including nuclear factor-activated T cells c1 (NFATc1) activation in response to RANKL. The mechanism of epigenetic regulation of NFATc1 in osteoclastogenesis not investigated yet. Here we test a hypothesis ...

Pseudovitamin D-deficiency rickets (PDDR) is a rare autosomal recessive disorder resulting from a defect in renal 25-hydroxyvitamin D 1α-hydroxylase, which is encoded by the CYP27B1 gene. To our best knowledge, 48 mutations of the CYP27B1 gene have been identified so far. In the present study, we investigated CYP27B1 mutations in seven individuals from six separate families and identified nine different mutations: two novel missense mutations (G194R, R259L), three novel a...