The EphB4 receptor and ephrin B2 ligand were recently reported to influence the coupling between osteoclasts and osteoblasts in bone biology, but their downstream signaling pathways remain unclear. This study focuses on the preliminary identification of downstream PDZ-domain proteins involved in EphB4/ephrin B2 reverse signaling in osteoclasts. Similarly to primary osteoclast precursors isolate...

Androgen deficiency in males leads to an increase in osteoclastic bone resorption and a progressive decrease in bone mineral density. In the current studies, we examined the ability of 5 alpha-dihydrotestosterone to suppress osteoclast formation induced by receptor activator of NF-kB ligand (RANKL) and macrophage-colony stimulating factor in vitro. 5 alpha-Dihydrotestosterone suppressed the dif...

Osteoclasts are multinucleated cells that resorb bones, and are derived from hematopoietic cells of the monocyte/macrophage lineage. The receptor activator of NF-kappaB ligand (RANKL, also called ODF/TRANCE/OPGL) stimulates both osteoclast differentiation from osteoclast progenitors and activation of mature osteoclasts. To identify genes responsible for osteoclast differentiation, we used a mol...

Podosomes are dynamic actin-based structures found constitutively in cells of monocytic origin such as macrophages, dendritic cells and osteoclasts. They have been involved in osteoclast cell adhesion, motility and matrix degradation, and all these functions rely on the ability of podosomes to form supra-molecular structures called podosome belts or sealing zones on mineralized substrates. Podo...

Osteoclasts are multinucleate giant cells responsible for bone resorption. Osteoclast precursors are hematopoietic mononucleate cells, which give rise to osteoclasts after fusion. Nevertheless, the precise stage of differentiation where osteoclast precursors diverge from other hematopoietic lineages is still debated. We describe here both in vitro and in vivo approaches to the study of the oste...

BACKGROUND Rumex crispus root has traditionally been used in Asian medicine for the treatment of hemorrhage and dermatolosis. The aim of this study was to explore the pharmaceutical effects of water extract of Rumex crispus (WERC) on osteoblast and osteoclast differentiation. We also studied the effect of WERC on the receptor activator of nuclear factor kappa-B ligand (RANKL)-induced trabecular...

Osteoclast differentiation is dependent on the activities of receptor activator NF-kB ligand (RANKL) and macrophage colony-stimulating factor (M-CSF). Given that RANKL plays a critical role in osteoclast formation and bone resorption, any new compounds found to alter its activity would be predicted to have therapeutic potential for disorders associated with bone loss. Methylsulfonylmethane (MSM...

Regulation of osteoclast differentiation is key to understanding the pathogenesis and to developing treatments for bone diseases such as osteoporosis. To gain insight into the mechanism of the receptor activator of nuclear factor (NF)-kappaB ligand (RANKL)-specific induction of the osteoclast differentiation program, we took a suppression-subtractive hybridization screening approach to identify...

The rhizome of Atractylodes macrocephala has been used mainly in Traditional Chinese Medicine for invigorating the functions of the stomach and spleen. In the present study, we investigated the inhibitory effect of the 70% ethanol extract of the rhizome of Atractylodes macrocephala (AMEE) on osteoclast differentiation. We found that AMEE inhibits osteoclast differentiation from its precursors i...

p53 is a well known tumor suppressor. We show that p53 also regulates osteoblast differentiation, bone formation, and osteoblast-dependent osteoclast differentiation. Indeed, p53(-/-) mice display a high bone mass phenotype, and p53(-/-) osteoblasts show accelerated differentiation, secondary to an increase in expression of the osteoblast differentiation factor osterix, as a result. Reporter as...