title: Ribosome inactivating protein B-chain induces osteoclast differentiation from monocyte/macrophage lineage precursor cells.
abstract: Human osteoclast formation from mononuclear phagocyte precursors involves interactions between lectins and their receptors. A type-2 ribosome inactivating protein consists of an A chain and a B chain. The glycosylated B chain binds specifically to galactose moieties of sugar molecules. In this study we showed that the recombinant ribosome inactivating protein B-chain (rRBC) could induce osteoclast formation from human monocytes and murine RAW264.7 macrophages. Tartrate-resistant acid phosphatase (TRAP) staining and bone resorption assays demonstrated that differentiation of osteoclast-like cells was induced in the presence of rRBC in a dose-dependent manner. The rRBC-induced osteoclast differentiation was independent of caspase activation and apoptosis induction activity; however, rRBC-induced osteoclastogenesis was dependent on activation of NF-κB, ERK1/2, and p38 MAP kinase. Thus, our data demonstrated that rRBC induced osteoclast differentiation through a non-apoptotic signaling pathway. In addition to triggering apoptosis, the rRBC also induced osteoclast differentiation. According to this study, a novel role is proposed for rRBC in regulating osteoclast differentiation and in osteoimmunology.
authors.affiliation: Department of Medical Laboratory Science and Biotechnology, China Medical University, Taichung, Taiwan.
authors.forename: Yuan-Min
authors.initials: YM
authors.lastname: Wang
authors.forename: Tzu-Li
authors.initials: TL
authors.lastname: Lu
authors.forename: Ping-Ning
authors.initials: PN
authors.lastname: Hsu
authors.forename: Chih-Hsin
authors.initials: CH
authors.lastname: Tang
authors.forename: Jiunn-Horng
authors.initials: JH
authors.lastname: Chen
authors.forename: Kuo-Ching
authors.initials: KC
authors.lastname: Liu
authors.forename: Jung-Ta
authors.initials: JT
authors.lastname: Kao
authors.forename: Jason T C
authors.initials: JT
authors.lastname: Tzen
authors.forename: Yi-Ying
authors.initials: YY
authors.lastname: Wu
mesh_terms: D000818:Animals; D015153:Blotting, Western; D002454:Cell Differentiation / Q000502:physiology*; D002460:Cell Line; D019070:Cell Lineage; D004789:Enzyme Activation; D006801:Humans; D020935:MAP Kinase Signaling System; D008264:Macrophages / Q000166:cytology*; D051379:Mice; D010010:Osteoclasts / Q000166:cytology*; D020133:Reverse Transcriptase Polymerase Chain Reaction; D054788:Ribosome Inactivating Proteins / Q000502:physiology*
chemical_list: D054788:Ribosome Inactivating Proteins