Receptor activator of NF-kappaB ligand (RANKL) plays an essential role in osteoclast formation and bone resorption. Although genetic and biochemical studies indicate that RANKL regulates osteoclast differentiation by activating receptor activator of NF-kappaB and associated signaling molecules, the molecular mechanisms of RANKL-regulated osteoclast differentiation have not yet been fully establ...

Although it is known that mechanical stress to osteoblast and periodontal ligament cells suppresses osteoclast differentiation, little is known about the direct effect of mechanical stress on osteoclast differentiation. In this study, we examined the role of mechanical stress on osteoclast differentiation using murine pre-osteoclastic RAW264.7 cells treated with receptor activator of nuclear fa...

BACKGROUND AND PURPOSE Hypoxia, necrosis, and bone loss are hallmarks of many skeletal diseases. Hyperbaric oxygen therapy (HBO) is often used as an adjunctive therapy in these cases. However the in vivo effect of HBO on osteoclast formation has not been fully established. We therefore carried out a longitudinal study to examine the effect of HBO on osteoclast formation and bone resorptive capa...

Receptor activator of nuclear factor-kappaB ligand (RANKL)-induced signals play critical roles in osteoclast differentiation and function. SB203580, an inhibitor of p38 MAPK, blocked osteoclast formation induced by 1alpha,25-dihydroxyvitamin D(3) and prostaglandin E(2) in cocultures of mouse osteoblasts and bone marrow cells. Nevertheless, SB203580 showed no inhibitory effect on RANKL expressio...

Osteoporosis and Alzheimer's disease (AD) are common chronic degenerative disorders which are strongly associated with advanced age. We have previously demonstrated that amyloid beta peptide (Aβ), one of the pathological hallmarks of AD, accumulated abnormally in osteoporotic bone specimens in addition to having an activation effect on osteoclast (Bone 2014,61:164-75). However, the underlying m...

OBJECTIVE Rheumatoid arthritis (RA) is often complicated by generalized osteopenia due to increased bone resorption by osteoclasts. We analysed a number of cellular and humoral factors that influence osteoclast formation from circulating precursors in RA patients. METHODS Monocytes isolated from RA patients and normal controls were cultured with macrophage colony-stimulating factor (M-CSF) an...

Sickle cell disease (SCD) is a worldwide distributed hereditary red cell disorder, characterized by severe organ complication. Sickle bone disease (SBD) affects a large part of the SCD patient population, and its pathogenesis has been only partially investigated. Here, we studied bone homeostasis in a humanized mouse model for SCD. Under normoxia, SCD mice display bone loss and bone impairment,...

The recruitment of osteoclast precursors toward osteoblasts and subsequent cell-cell interactions are critical for osteoclast differentiation. Chemokines are known to regulate cell migration and adhesion. CX3CL1 (also called fractalkine) is a unique membrane-bound chemokine that has dual functions for cells expressing its receptor CX3CR1: a potent chemotactic factor in its soluble form and a ty...

Osteoclasts, the multinucleated cells that resorb bone, differentiate from hemopoietic precursors of monocyte/ macrophage lineage, which also give rise to macrophages or dendritic cells. In this study we investigated the mechanism by which interleukin-3 (IL-3) and granulocyte-macrophage colony-stimulating factor (GMCSF) inhibit tumor necrosis factor (TNF)-induced osteoclast differentiation in m...

Significant progress has been made in studies of the mechanisms by which RANKL induces terminal osteoclast differentiation. However, many crucial details in the RANKL-evoked signaling pathway for osteoclast differentiation remain to be defined. We characterized genes specifically expressed in osteoclasts by differential screening of a human osteoclastoma cDNA library, and found that the regulat...