Bone Abstracts

Objectives: Congenital adrenal hyperplasia (CAH) is a rare condition characterized by the inability of the adrenal gland to produce cortisol. The classical form is due to the deficit of 21-hydroxylase activity (21-OHD) and it accounts for 90–95% of all CAH cases. Treatment of CAH patients consists of life-long glucocorticoid therapy, which must be dosed carefully to avoid excessive or insufficient adrenal suppression. There are data showing low bone mineral density (BMD) ...

Objectives: Impairment of bone mass accrual and alterations of bone metabolism is a common finding in HIV-infected youths. In particular, previous studies demonstrated higher bone formation and bone resorption rates in HIV-infected children and adolescents. Wnt ligands promote bone formation by stimulating osteoblast differentiation and their survival. Recent studies demonstrated that sclerostin (Scl) and dickkopf factor 1 (DKK-1), Wnt antagonists, are important negative regul...

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...

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...