title: TGF-β in dentin matrix extract induces osteoclastogenesis in vitro.
abstract: Previously, we have demonstrated that the extracellular matrix from dentin affects osteoclastic activity in co-culture between osteoclast and osteoblast-rich fraction from mouse marrow cells. In the present study, we aimed to investigate the mechanisms of dentin matrix extract-induced osteoclastogenesis in mouse bone marrow macrophages (BMMs). Dentin proteins were extracted from bovine incisor root dentin using 0.6 M HCl. BMMs were cultured in α-MEM containing macrophage colony-stimulating factor/receptor activator of nuclear factor kappa-B ligand in the presence or absence of dentin matrix extract. Tartrate-resistant acid phosphatase (TRAP)-positive cell number, total TRAP activity, and the mRNA levels of osteoclast-related genes, assayed by real-time RT-PCR, were determined as markers of osteoclastogenesis. A neutralizing antibody against transforming growth factor-β1 (TGF-β1), SB431542, a TGF-β receptor inhibitor, and ELISA were used to determine the role of TGF-β1. We observed increases in TRAP-positive cell number, TRAP activity, and the mRNA levels of osteoclast-related genes of BMMs cultured with dentin extract. The use of a neutralizing antibody against TGF-β1 or SB431542 inhibited the inductive effect of dentin extract, suggesting TGF-β1 involvement. The addition of exogenous TGF-β1, but not bone morphogenic protein-2, also increased osteoclastogenesis, corresponding to the ELISA determination of TGF-β1 in the dentin extract. In conclusion, our results indicate that proteins from dentin matrix have an inductive effect in osteoclastogenesis, which is mediated, in part, by TGF-β1.
authors.affiliation: Department of Pediatric Dentistry, Faculty of Dentistry, Chulalongkorn University, 34, Henri-Dunant Road, Pathumwan, Bangkok, 10330, Thailand, w.sriarj@gmail.com.
authors.forename: Wannakorn
authors.initials: W
authors.lastname: Sriarj
authors.forename: Kazuhiro
authors.initials: K
authors.lastname: Aoki
authors.forename: Keiichi
authors.initials: K
authors.lastname: Ohya
authors.forename: Mariko
authors.initials: M
authors.lastname: Takahashi
authors.forename: Yuzo
authors.initials: Y
authors.lastname: Takagi
authors.forename: Hitoyata
authors.initials: H
authors.lastname: Shimokawa
mesh_terms: D000818:Animals; D001549:Benzamides / Q000494:pharmacology; D001854:Bone Marrow Cells / Q000166:cytology; D002417:Cattle; D002454:Cell Differentiation / Q000187:drug effects; D003804:Dentin / Q000378:metabolism*; D004149:Dioxoles / Q000494:pharmacology; D004797:Enzyme-Linked Immunosorbent Assay; D016326:Extracellular Matrix Proteins / Q000502:physiology*; D016173:Macrophage Colony-Stimulating Factor / Q000494:pharmacology; D008264:Macrophages / Q000166:cytology; D051379:Mice; D010010:Osteoclasts / Q000166:cytology* / Q000187:drug effects; D060888:Real-Time Polymerase Chain Reaction; D000071681:Tartrate-Resistant Acid Phosphatase / Q000378:metabolism; D053773:Transforming Growth Factor beta1 / Q000494:pharmacology / Q000502:physiology*
chemical_list: C459179:4-(5-benzo(1,3)dioxol-5-yl-4-pyridin-2-yl-1H-imidazol-2-yl)benzamide; D001549:Benzamides; D004149:Dioxoles; D016326:Extracellular Matrix Proteins; D053773:Transforming Growth Factor beta1; D016173:Macrophage Colony-Stimulating Factor; D000071681:Tartrate-Resistant Acid Phosphatase