title: Tunneling nanotube formation is essential for the regulation of osteoclastogenesis.
abstract: Osteoclasts are the multinucleated giant cells formed by cell fusion of mononuclear osteoclast precursors. Despite the finding of several membrane proteins involving DC-STAMP as regulatory proteins required for fusion among osteoclast precursors, cellular and molecular events concerning this process are still ambiguous. Here we identified Tunneling Nanotubes (TNTs), long intercellular bridges with small diameters, as the essential cellular structure for intercellular communication among osteoclast precursors in prior to cell fusion. Formation of TNTs was highly associated with osteoclastogenesis and it was accompanied with the significant induction of the M-Sec gene, an essential gene for TNT formation. M-Sec gene expression was significantly upregulated by RANKL-treatment in osteoclast precursor cell line. Blockage of TNT formation by Latrunclin B or by M-Sec siRNA significantly suppressed osteoclastogenesis. We have detected the rapid intercellular transport of not only the membrane phospholipids labeled with DiI but also the DC-STAMP-GFP fusion protein through TNTs formed among osteoclast precursors during osteoclastogenesis. Transportation of such regulatory molecules through TNTs would be essential for the process of the specific cell fusion among osteoclast precursors.
authors.affiliation: Division of Oral Biological Sciences, Department of Molecular Cell Biology & Oral Anatomy, Faculty of Dental Science, Kyushu University, Fukuoka, Japan.
authors.forename: Akira
authors.initials: A
authors.lastname: Takahashi
authors.forename: Akiko
authors.initials: A
authors.lastname: Kukita
authors.forename: Yin-ji
authors.initials: YJ
authors.lastname: Li
authors.forename: Jing-qi
authors.initials: JQ
authors.lastname: Zhang
authors.forename: Hisayuki
authors.initials: H
authors.lastname: Nomiyama
authors.forename: Takayoshi
authors.initials: T
authors.lastname: Yamaza
authors.forename: Yasunori
authors.initials: Y
authors.lastname: Ayukawa
authors.forename: Kiyoshi
authors.initials: K
authors.lastname: Koyano
authors.forename: Toshio
authors.initials: T
authors.lastname: Kukita
mesh_terms: D000818:Animals; D001692:Biological Transport; D019086:Bridged Bicyclo Compounds, Heterocyclic / Q000494:pharmacology; D002454:Cell Differentiation; D022081:Cell Surface Extensions / Q000378:metabolism / Q000648:ultrastructure*; D002478:Cells, Cultured; D008565:Membrane Proteins / Q000378:metabolism; D051379:Mice; D008810:Mice, Inbred C57BL; D009419:Nerve Tissue Proteins / Q000378:metabolism; D010010:Osteoclasts / Q000502:physiology* / Q000648:ultrastructure; D010743:Phospholipids / Q000378:metabolism; D051381:Rats; D053778:Thiazolidines / Q000494:pharmacology; D048069:Tumor Necrosis Factors / Q000235:genetics / Q000378:metabolism; D015854:Up-Regulation
chemical_list: D019086:Bridged Bicyclo Compounds, Heterocyclic; C499636:DC-STAMP protein, mouse; C545682:M-sec protein, mouse; D008565:Membrane Proteins; D009419:Nerve Tissue Proteins; D010743:Phospholipids; D053778:Thiazolidines; D048069:Tumor Necrosis Factors; C037068:latrunculin B