Morichika Takita    Department   School of Medicine, School of Medicine    Position   Assistant Professor
Article types	Original article
Language	English
Peer review	Peer reviewed
Title	Capsaicin, a ligand for vanilloid receptor-1, transduces suppressive signal for osteoclast differentiation in bone.
Journal	Formal name：Journal of Health Science Abbreviation：J. Health Sci. ISSN code：13449702/13475207
Domestic / Foregin	Domestic
Publisher	Pharmaceutical Society of JAPAN
Volume, Issue, Page	53(2),pp.240-244
Author and coauthor	Takita Morichika†, Inada Masaki, Miyaura Chisato*
Authorship	Lead author
Publication date	2007/04
Summary	Vanilloid receptor-1 (VR1) has been reported to exhibit multiple functions which can transduce pain-sensitive signals in nerve systems. A VR1 ligand, capsaicin has been reported to show activities against inflammation and cancer growth, however, its role in bone metabolism is still unknown. Here we examined the effect of capsaicin on cytokine-induced inflammatory bone resorption. Capsaicin suppressed interleukin-1-induced bone resorption in mouse calvarial organ ex vivo culture in a dose-dependent manner. An assay using cocultures of osteoblast and bone marrow cells clearly showed the inhibition of osteoclast formation by treatment with capsaicin. Receptor activator of NF-kB ligandRANKL (RANKL), the sole inducer of osteoclast formation, is known to be produced by osteoblasts. In the cocultures of bone marrow cells and osteoblasts, the expression of RANKL was suppressed by capsaicin. VR1 showed expression predominantly in osteoblast, suggesting that capsaicin directly modulates osteoclast differentiation through the suppression of RANKL expression. VR1 ligands like capsaicin have the potential for use as clinical drugs targeting some bone diseases involving cytokine-induced bone resorption.
DOI	http://doi.org/10.1248/jhs.53.240