title: DC-STAMP is essential for cell-cell fusion in osteoclasts and foreign body giant cells.
abstract: Osteoclasts are bone-resorbing cells that play a pivotal role in bone remodeling. Osteoclasts form large multinuclear giant cells by fusion of mononuclear osteoclasts. How cell fusion is mediated, however, is unclear. We identify the dendritic cell-specific transmembrane protein (DC-STAMP), a putative seven-transmembrane protein, by a DNA subtraction screen between multinuclear osteoclasts and mononuclear macrophages. DC-STAMP is highly expressed in osteoclasts but not in macrophages. DC-STAMP-deficient mice were generated, and osteoclast cell fusion was completely abrogated in homozygotes despite normal expression of osteoclast markers and cytoskeletal structure. As osteoclast multinucleation was restored by retroviral introduction of DC-STAMP, loss of cell fusion was directly attributable to a lack of DC-STAMP. Defects in osteoclast multinucleation reduce bone-resorbing activity, leading to osteopetrosis. Similar to osteoclasts, foreign body giant cell formation by macrophage cell fusion was also completely abrogated in DC-STAMP-deficient mice. We have thus identified an essential regulator of osteoclast and macrophage cell fusion, DC-STAMP, and an essential role of osteoclast multinucleation in bone homeostasis.
authors.affiliation: Department of Cell Differentiation, The Sakaguchi Laboratory, 35 Shinanomachi, Shinjuku-ku, Tokyo 160-8582, Japan.
authors.forename: Mitsuru
authors.initials: M
authors.lastname: Yagi
authors.forename: Takeshi
authors.initials: T
authors.lastname: Miyamoto
authors.forename: Yumi
authors.initials: Y
authors.lastname: Sawatani
authors.forename: Katsuya
authors.initials: K
authors.lastname: Iwamoto
authors.forename: Naobumi
authors.initials: N
authors.lastname: Hosogane
authors.forename: Nobuyuki
authors.initials: N
authors.lastname: Fujita
authors.forename: Kozo
authors.initials: K
authors.lastname: Morita
authors.forename: Ken
authors.initials: K
authors.lastname: Ninomiya
authors.forename: Toru
authors.initials: T
authors.lastname: Suzuki
authors.forename: Kana
authors.initials: K
authors.lastname: Miyamoto
authors.forename: Yuichi
authors.initials: Y
authors.lastname: Oike
authors.forename: Motohiro
authors.initials: M
authors.lastname: Takeya
authors.forename: Yoshiaki
authors.initials: Y
authors.lastname: Toyama
authors.forename: Toshio
authors.initials: T
authors.lastname: Suda
mesh_terms: D000818:Animals; D001862:Bone Resorption / Q000235:genetics / Q000378:metabolism*; D001842:Bone and Bones / Q000166:cytology / Q000502:physiology; D002459:Cell Fusion; D015726:Giant Cells / Q000166:cytology / Q000502:physiology*; D006706:Homeostasis / Q000235:genetics / Q000502:physiology; D008264:Macrophages / Q000166:cytology / Q000502:physiology*; D008565:Membrane Proteins / Q000235:genetics / Q000378:metabolism*; D051379:Mice; D018345:Mice, Knockout; D009419:Nerve Tissue Proteins / Q000235:genetics / Q000378:metabolism*; D010010:Osteoclasts / Q000166:cytology / Q000502:physiology*
chemical_list: C499636:DC-STAMP protein, mouse; D008565:Membrane Proteins; D009419:Nerve Tissue Proteins