title: Methotrexate inhibits osteoclastogenesis by decreasing RANKL-induced calcium influx into osteoclast progenitors.
abstract: The increasing number of osteoporosis patients is a pressing issue worldwide. Osteoporosis frequently causes fragility fractures, limiting activities of daily life and increasing mortality. Many osteoporosis patients take numerous medicines due to other health issues; thus, it would be preferable if a single medicine could ameliorate osteoporosis and other conditions. Here, we screened 96 randomly selected drugs targeting various diseases for their ability to inhibit differentiation of osteoclasts, which play a pivotal role in development of osteoporosis, and identified methotrexate (MTX), as a potential inhibitor. MTX is currently used to treat sarcomas or leukemic malignancies or auto-inflammatory diseases such as rheumatoid arthritis (RA) through its anti-proliferative and immunosuppressive activities; however, a direct effect on osteoclast differentiation has not been shown. Here, we report that osteoclast formation and expression of osteoclastic genes such as NFATc1 and DC-STAMP, which are induced by the cytokine RANKL, are significantly inhibited by MTX. We found that RANKL-dependent calcium (Ca) influx into osteoclast progenitors was significantly inhibited by MTX. RA patients often develop osteoporosis, and osteoclasts are reportedly required for joint destruction; thus, MTX treatment could have a beneficial effect on RA patients exhibiting high osteoclast activity by preventing both osteoporosis and joint destruction.
authors.affiliation: Department of Orthopaedic Surgery, Keio University School of Medicine, 35 Shinano-machi, Shinjuku-ku, Tokyo, 160-8582, Japan.
authors.forename: Hiroya
authors.initials: H
authors.lastname: Kanagawa
authors.affiliation: Department of Molecular Bone Biology, Nagasaki University Graduate School of Biomedical Sciences, Nagasaki, 852-8588, Japan.
authors.forename: Ritsuko
authors.initials: R
authors.lastname: Masuyama
authors.affiliation: Department of Dentistry and Oral Surgery, Keio University School of Medicine, 35 Shinano-machi, Shinjuku-ku, Tokyo, 160-8582, Japan.
authors.forename: Mayu
authors.initials: M
authors.lastname: Morita
authors.affiliation: Department of Orthopaedic Surgery, Keio University School of Medicine, 35 Shinano-machi, Shinjuku-ku, Tokyo, 160-8582, Japan.|Department of Musculoskeletal Reconstruction and Regeneration Surgery, Keio University School of Medicine, 35 Shinano-machi, Shinjuku-ku, Tokyo, 160-8582, Japan.
authors.forename: Yuiko
authors.initials: Y
authors.lastname: Sato
authors.affiliation: Department of Orthopaedic Surgery, Keio University School of Medicine, 35 Shinano-machi, Shinjuku-ku, Tokyo, 160-8582, Japan.
authors.forename: Yasuo
authors.initials: Y
authors.lastname: Niki
authors.affiliation: Department of Orthopaedic Surgery, Keio University School of Medicine, 35 Shinano-machi, Shinjuku-ku, Tokyo, 160-8582, Japan.
authors.forename: Tami
authors.initials: T
authors.lastname: Kobayashi
authors.affiliation: Department of Orthopaedic Surgery, Keio University School of Medicine, 35 Shinano-machi, Shinjuku-ku, Tokyo, 160-8582, Japan.
authors.forename: Eri
authors.initials: E
authors.lastname: Katsuyama
authors.affiliation: Department of Orthopaedic Surgery, Keio University School of Medicine, 35 Shinano-machi, Shinjuku-ku, Tokyo, 160-8582, Japan.
authors.forename: Atsuhiro
authors.initials: A
authors.lastname: Fujie
authors.affiliation: Department of Orthopaedic Surgery, Keio University School of Medicine, 35 Shinano-machi, Shinjuku-ku, Tokyo, 160-8582, Japan.
authors.forename: Wu
authors.initials: W
authors.lastname: Hao
authors.affiliation: Department of Orthopaedic Surgery, Keio University School of Medicine, 35 Shinano-machi, Shinjuku-ku, Tokyo, 160-8582, Japan.
authors.forename: Toshimi
authors.initials: T
authors.lastname: Tando
authors.affiliation: Department of Orthopaedic Surgery, Keio University School of Medicine, 35 Shinano-machi, Shinjuku-ku, Tokyo, 160-8582, Japan.
authors.forename: Ryuichi
authors.initials: R
authors.lastname: Watanabe
authors.affiliation: Department of Orthopaedic Surgery, Keio University School of Medicine, 35 Shinano-machi, Shinjuku-ku, Tokyo, 160-8582, Japan.
authors.forename: Kana
authors.initials: K
authors.lastname: Miyamoto
authors.affiliation: Department of Orthopaedic Surgery, Keio University School of Medicine, 35 Shinano-machi, Shinjuku-ku, Tokyo, 160-8582, Japan.
authors.forename: Hideo
authors.initials: H
authors.lastname: Morioka
authors.affiliation: Department of Orthopaedic Surgery, Keio University School of Medicine, 35 Shinano-machi, Shinjuku-ku, Tokyo, 160-8582, Japan.
authors.forename: Morio
authors.initials: M
authors.lastname: Matsumoto
authors.affiliation: Department of Orthopaedic Surgery, Keio University School of Medicine, 35 Shinano-machi, Shinjuku-ku, Tokyo, 160-8582, Japan.
authors.forename: Yoshiaki
authors.initials: Y
authors.lastname: Toyama
authors.affiliation: Division of Gene Regulation, Institute for Advanced Medical Research, Keio University School of Medicine, 35 Shinano-machi, Shinjuku-ku, Tokyo, 160-8582, Japan.
authors.forename: Hideyuki
authors.initials: H
authors.lastname: Saya
authors.affiliation: Department of Orthopaedic Surgery, Keio University School of Medicine, 35 Shinano-machi, Shinjuku-ku, Tokyo, 160-8582, Japan. miyamoto@z5.keio.jp.|Department of Integrated Bone Metabolism and Immunology, Keio University School of Medicine, 35 Shinano-machi, Shinjuku-ku, Tokyo, 160-8582, Japan. miyamoto@z5.keio.jp.
authors.forename: Takeshi
authors.initials: T
authors.lastname: Miyamoto
mesh_terms: D000818:Animals; D002118:Calcium / Q000378:metabolism*; D002478:Cells, Cultured; D008727:Methotrexate / Q000494:pharmacology*; D008810:Mice, Inbred C57BL; D010010:Osteoclasts / Q000187:drug effects* / Q000378:metabolism; D010012:Osteogenesis / Q000187:drug effects*; D053245:RANK Ligand / Q000494:pharmacology; D013234:Stem Cells / Q000187:drug effects* / Q000378:metabolism
chemical_list: D053245:RANK Ligand; D002118:Calcium; D008727:Methotrexate
keywords: Calcium influx; Differentiation; Methotrexate; Osteoclast