Effects of Inositol 1,4,5-triphosphate on Osteoclast Differentiation in RANKL-induced Osteoclastogenesis.
10.4196/kjpp.2012.16.1.31
- Author:
Aran SON
1
;
Min Seuk KIM
;
Hae JO
;
Hae Mi BYUN
;
Dong Min SHIN
Author Information
1. Department of Oral Biology, College of Dentistry, Yonsei University, Seoul 120-752, Korea. dmshin@yuhs.ac
- Publication Type:Original Article
- Keywords:
Inositol 1,4,5-trisphosphate;
RANKL;
Osteoclastogenesis;
Ca2+ signaling
- MeSH:
Animals;
Blood Proteins;
Boron Compounds;
Calcium-Transporting ATPases;
Cell Membrane;
Dentin;
Estrenes;
Inositol;
Inositol 1,4,5-Trisphosphate;
Inositol 1,4,5-Trisphosphate Receptors;
Macrophages;
Mice;
NF-kappa B;
Osteoclasts;
Phosphoproteins;
Proteins;
Pyrrolidinones;
Receptor Activator of Nuclear Factor-kappa B;
Reticulum;
Signal Transduction;
Tumor Necrosis Factor-alpha;
Type C Phospholipases
- From:The Korean Journal of Physiology and Pharmacology
2012;16(1):31-36
- CountryRepublic of Korea
- Language:English
-
Abstract:
The receptor activator of NF-kappaB ligand (RANKL) signal is an activator of tumor necrosis factor receptor-associated factor 6 (TRAF6), which leads to the activation of NF-kappaB and other signal transduction pathways essential for osteoclastogenesis, such as Ca2+ signaling. However, the intracellular levels of inositol 1,4,5-trisphosphate (IP3) and IP3-mediated cellular function of RANKL during osteoclastogenesis are not known. In the present study, we determined the levels of IP3 and evaluated IP3-mediated osteoclast differentiation and osteoclast activity by RANKL treatment of mouse leukemic macrophage cells (RAW 264.7) and mouse bone marrow-derived monocyte/macrophage precursor cells (BMMs). During osteoclastogenesis, the expression levels of Ca2+ signaling proteins such as IP3 receptors (IP3Rs), plasma membrane Ca2+ ATPase, and sarco/endoplasmic reticulum Ca2+ ATPase type2 did not change by RANKL treatment for up to 6 days in both cell types. At 24 h after RANKL treatment, a higher steady-state level of IP3 was observed in RAW264.7 cells transfected with green fluorescent protein (GFP)-tagged pleckstrin homology (PH) domains of phospholipase C (PLC) delta, a probe specifically detecting intracellular IP3 levels. In BMMs, the inhibition of PLC with U73122 [a specific inhibitor of phospholipase C (PLC)] and of IP3Rs with 2-aminoethoxydiphenyl borate (2APB; a non-specific inhibitor of IP3Rs) inhibited the generation of RANKL-induced multinucleated cells and decreased the bone-resorption rate in dentin slice, respectively. These results suggest that intracellular IP3 levels and the IP3-mediated signaling pathway play an important role in RANKL-induced osteoclastogenesis.
