Bone Abstracts

see PP474....

Extreme high bone mass (HBM) may be monogenic (e.g. due to mutations in SOST or LRP5) or polygenic, due to variants in the same genes determining bone mineral density (BMD) as found in the general population. We aimed to determine the genetic cause underlying HBM in an extreme HBM population.258 unexplained HBM cases (defined as L1 Z-score ≥+3.2 plus total hip Z-score ≥+1.2, or total hip Z-score ≥+3.2 and L1 <...

Autosomal dominant osteopetrosis type II (ADO2) is a rare osteosclerotic disease due heterozygous missense mutations of the CLC7 gene encoding the type seven chloride channel. Our two labs independently generated the first C57 black 6 (B6) mouse model of ADO2 by inserting the pG213R-clc7 mutation. Homozygous mice showed lack of tooth eruption and died within 30 days of age with severe osteopetrosis and central nervous system degenera...

Autosomal dominant type II osteopetrosis (ADO2) is a rare osteosclerotic disorder due to heterozygous missense mutations of CLC7 gene encoding the type 7 chloride channel. Our two labs (L’Aquila and Indianapolis) independently generated the first C57 black 6 (B6) mouse model of ADO2 by inserting the pG213R-clc7 mutation. We created pG213R-clc7 KI mice using a gene targeting approach. Homozygous mice showed lack of tooth eruption and died within ...

The chronic use of glucocorticoids in patients with congenital adrenal hyperplasia (CAH) may result in decreased bone mass. Therefore, using simple and accurate methods for assessing bone status in these patients could facilitate the treatment of disease. The purpose of this study was to verify the association between parameters of bone mass measured by dual energy X-ray absorptiometry (DXA) and quantitative ultrasound (QUS) of proximal phalanges in children adolescents with c...

The childhood obesity is a global epidemic. Some studies with pre-pubertal children reported a positive relationship between fat mass and bone. However, there are no available data on the influence of the nutritional status on parameters of quantitative ultrasound (QUS). The aim of this study was to evaluate the influence of nutritional status in bone mass assessed by QUS of proximal phalanges in girls. The bone mass parameter, amplitude dependent speed sound (AD-SoS) in meter...

Objective: Evidence for further reduction of nonvertebral fracture (NVFX) beyond 3 years of antiresorptive therapy is limited. Since long-term denosumab (DMAb) treatment is associated with continuous increases in BMD and sustained fracture reduction, we analyzed the influence of femoral neck (FN) BMD after 3 years on NVFX rates.Methods: Long-term subjects received 7 continuous years of DMAb; cross-over subjects received 3 years of placebo (FREEDOM) and 4...

see PP356....

Few drugs generate bone-stimulatory effects via epigenetic mechanisms. Modulation of CpG-residues hydroxymethylation in gene-promoters of key osteoblast-related factors (e.g., DLX5) induces their expression and increases osteoblast differentiation in vitro. The chemical properties of sulforaphane (SFN), a natural compound abundantly present in cruciferous vegetables like broccoli, suggest that it may have similar molecular and biological effects. Previous stu...

Mesenchymal cells alter and retain their phenotype during skeletal development through activation or suppression of signaling pathways. For example, we have shown that Wnt3a only stimulates osteoblast differentiation in cells with intrinsic osteogenic potential (e.g., MC3T3-E1 pre-osteoblasts) and not in fat cell precursors or fibroblasts (respectively, 3T3-L1 pre-adipocytes or NIH3T3 fibroblasts). Wnt3a promotes osteogenesis in part by stimulating autocrine production of the ...