Osteoclasts are multinucleated cells with bone resorption activity that is crucial for bone remodeling. RANK-RANKL (receptor activator of nuclear factor κB ligand) signaling has been shown as a main signal pathway for osteoclast differentiation. However, the molecular mechanism and the factors regulating osteoclastogenesis remain to be fully understood. In this study, we performed a chemical ge...

Osteoclasts, responsible for bone resorption, are multinucleated cells formed by cell-cell fusion of mononuclear pre-osteoclasts. Although osteoclast fusion is a pivotal step for osteoclastogenesis, little is known about the mechanism involved. To clarify the underlying process, we investigated dynamics of membrane phospholipids during osteoclastogenesis in vitro. We found that the cellular con...

Osteoclast over-activation and inflammation responses promote peri-implant osteolysis (PIO), which is the leading cause of aseptic artificial joint loosening. We examined the effect of lithium chloride (LiCl) on wear debris-induced osteoclastogenesis and inflammation. Fifty-Six C57BL/6J male mice were randomly distributed into four groups: sham control (sham, treated with phosphate buffered sal...

RANK and CD40 activate NF-kappaB and MAPKs to similar levels via TRAF6. Even though overexpression of TRAF6 results in osteoclast formation, RANK but not CD40 promotes osteoclastogenesis. To understand the molecular basis for RANK-specific activity in osteoclastogenesis, we created an osteoclast formation system driven by anti-human CD40 antibody-mediated stimulation of a chimeric receptor, h40...

Silicon (Si) is indispensable for many cellular processes including bone tissue metabolism. In this work, the effects of Si on human osteogenesis and osteoclastogenesis were characterized. Human mesenchymal stem cells (hMSC) and CD14+ stem cells, as osteoblast and osteoclast precursors, were treated with a wide range of Si concentrations, covering the physiological plasma levels. Si promoted a ...

Post-menopausal osteoporosis (PMOP) is a metabolic bone disorder characterized by low bone mass and micro-architectural deterioration of bone tissue. The over-activated osteoclastogenesis, which plays an important role in osteoporosis, has become an important therapeutic target. M54 was a bioactive derivative of the Chinese traditional herb matrine. We found that M54 could suppress RANKL-induce...

Osteoclastogenesis is an essential process during bone metabolism which can also be promoted by inflammatory signals. Thrombomodulin (TM), a transmembrane glycoprotein, exerts anti-inflammatory activities such as neutralization of proinflammatory high-mobility group box 1 (HMGB1) through TM lectin-like domain. This study aimed to identify the role of myeloid TM (i.e., endogenous TM expression o...

The rhizome of Davallia formosana is commonly used to treat bone disease including bone fracture, arthritis, and osteoporosis in Chinese herbal medicine. Here, we report the effects of WL1101, the ethanol extracts of fresh rhizomes of Davallia formosana on ovariectomy-induced osteoporosis. In addition, excess activated bone-resorbing osteoclasts play crucial roles in inflammation-induced bone l...

Capric acid is a second medium-chain fatty acid, and recent studies have shown that fatty acids are associated with bone density and reduce bone turnover. In this study, we investigated the effects of capric acid on lipopolysaccharide (LPS)-induced osteoclastogenesis in RAW264.7 cells. After treatment with capric acid (1 mM), the number of tartrate resistant acid phosphatase (TRAP)-positive cel...

Diseases of bone loss are a major public health problem. Here, we report the novel therapeutic action of simvastatin in osteoclastogenesis and osteoprotection, demonstrated by the ability of simvastatin to suppress osteoclast formation in vitro and in vivo. We found that in vitro, IRF4 expression is upregulated during osteoclast differentiation induced by RANKL (receptor activator of nuclear fa...