Bone Abstracts

Using a CyPB-null mouse model, we previously demonstrated delayed folding, abnormal post-translational modification and altered crosslinking of type I collagen synthesized by osteoblasts. However, intracellular folding of collagen molecules was further delayed by CsA treatment of CyPB-null cells, suggesting involvement of additional PPIases in collagen folding. Since studies of CyPA functions in osteoblasts have not been reported, we investigated the role of this cytoplasmic P...

Poor bone mineralization remains a major health problem in patients with Thal and has been linked to functional zinc deficiency despite adequate dietary intake. The global etiology of poor bone mineralization includes inadequate dietary intake of calcium and vitamin D, endocrinopathies leading to disturbed calcium homeostasis, dysregulation of the GH–IGF1 axis, and delayed puberty, all resulting in limited growth, decreased bone formation and increased bone resorption. Th...

Osteoclasts are multinucleated giant cells derived from the monocyte/macrophage lineage in the presence of receptor activator of nuclear factor kappa-B ligand (RANKL) and colony-stimulating factor 1 (CSF1). The bone remodeling process in zebrafish is incompletely understood. Here we describe several methods to quantify bone formation and resorption using a zebrafish mutant that lacks functional colony stimulating factor 1a receptor (csf1ramh5/mh5). Mice deficient in...

Osteoclasts are myeloid-derived cells that degrade bone through the localized production of acid and proteases. The catabolic action of osteoclasts is counterbalanced by formation of new matrix by osteoblasts. In mammals, bone resorption and formation are coupled through crosstalk between osteoclasts and osteoblasts. Zebrafish are emerging as a valuable model to study bone biology, but how closely zebrafish osteoclast function parallels that of higher vertebrates is unknown. T...

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...

Objective: We investigated the effect of creatine administered in the diet for 10 weeks on bone turnover and bone quality in male Wistar rats.Methods: Rats were divided (after approval of Ethical committee 9814/2008–30 and 30793/2010–30) into four groups, ten animals in each group. G1 SLD-A group were fed a standard laboratory diet (SLD). G2 SLD-B group were fed SLD and 12 h before rats were sacrificed diet was removed. G3...

Objective: We investigated the effect of arginine administered for 10 weeks in diet on bone metabolism in male Wistar rats.Methods: Rats were divided (after approval of Ethical Committee 9814/2008-30 and 30793/2010-30) into four groups, ten animals in each group: G1 SLD-S group were fed a standard laboratory diet (SLD). G2 SLD-H group were fed SLD and 12 h before rats were sacrificed diet was removed. G3 ARG-S group was fed wit...

Breast cancer cells that escape primary tumors disseminate to bone with high affinity at late-stage disease. Circulating breast tumor cells that invade the bone marrow (BM) express sets of deregulated genes and/or microRNAs (miRNAs) that facilitate their bone tropism and enhance engraftment of disseminated tumor cell (DTC) in BM which may subsequently induce osteolytic lesions. MiRNA transcriptomic profiling of the human breast cancer DTC cell line, BC-M1, and of the osteotrop...

Analysis of genome wide data such as transcriptomics can identify genes of potential interest to bone biology. These techniques are primarily hypothesis-generating. Determining the role of candidate factors in bone ultimately requires in vivo experiments. Gene expression analysis of mouse osteoclast differentiation identified G protein-coupled receptor 137B (GPR137b) as highly upregulated. GPR137b is an orphan seven-pass transmembrane receptor of unknown func...

Objective: To compare whether interval BMD changes in adolescent females that can be detected using conventional dual energy X-ray absorptiometry (DXA) can also be detected using quantitative peripheral quantitative computerized tomography scans (pQCT) and quantitative ultrasound (QUS)of the os calcis.Methods: Two groups of adolescent females were recruited for assessment of BMD changes over an interval of 22–24 months. These included full time coll...