title: Osteocytes up-regulate the terminal differentiation of pre-osteoblasts via gap junctions.
abstract: We examined cell-to-cell interaction between pre-osteoblasts and osteocytes using MC3T3-E1 and MLO-Y4, respectively. First, GFP expressing MC3T3-E1 (E1-GFP) cells were generated to isolate the cells from co-culture with MLO-Y4. No changes were observed in the expression of osteogenic transcription factors Runx2, Osterix, Dlx5 and Msx2, but expression of alkaline phosphatase (ALP) and bone sialoprotein (BSP) in E1-GFP co-cultured with MLO-Y4 was 300-400-fold greater than that in mono-cultured E1-GFP. In addition, mineralized nodule formation was drastically increased in co-cultured E1-GFP cells compared to mono-cultured cells. Patch clamp assay showed the presence of gap junctions between E1-GFP and MLO-Y4. Furthermore, when the gap junction inhibitor carbenoxolone (CBX) was added to the culture, increased expression of ALP and BSP in E1-GFP co-cultured with MLO-Y4 was suppressed. These results suggest that gap junction detected between pre-osteoblasts and osteocytes plays an important role on the terminal differentiation of pre-osteoblasts.
authors.affiliation: Department of Pathology, Nihon University School of Dentistry, 1-8-13 Kanda-Surugadai, Chiyoda-ku, Tokyo 101-8310, Japan.
authors.forename: Yoichi
authors.initials: Y
authors.lastname: Nishikawa
authors.affiliation: Department of Orthodontics, Nihon University School of Dentistry, 1-8-13 Kanda-Surugadai, Chiyoda-ku, Tokyo 101-8310, Japan.
authors.forename: Yuko
authors.initials: Y
authors.lastname: Akiyama
authors.affiliation: Department of Pharmacology, Nihon University School of Dentistry, 1-8-13 Kanda-Surugadai, Chiyoda-ku, Tokyo 101-8310, Japan.
authors.forename: Kiyofumi
authors.initials: K
authors.lastname: Yamamoto
authors.affiliation: Department of Pharmacology, Nihon University School of Dentistry, 1-8-13 Kanda-Surugadai, Chiyoda-ku, Tokyo 101-8310, Japan.
authors.forename: Masayuki
authors.initials: M
authors.lastname: Kobayashi
authors.affiliation: Clinical FACS Core Laboratory, The Institute of Medical Science, The University of Tokyo, 4-6-1 Shirokanedai, Minato-ku, Tokyo 108-8639, Japan.
authors.forename: Eri
authors.initials: E
authors.lastname: Watanabe
authors.affiliation: Clinical FACS Core Laboratory, The Institute of Medical Science, The University of Tokyo, 4-6-1 Shirokanedai, Minato-ku, Tokyo 108-8639, Japan.
authors.forename: Nobukazu
authors.initials: N
authors.lastname: Watanabe
authors.affiliation: Department of Orthodontics, Nihon University School of Dentistry, 1-8-13 Kanda-Surugadai, Chiyoda-ku, Tokyo 101-8310, Japan.
authors.forename: Noriyoshi
authors.initials: N
authors.lastname: Shimizu
authors.affiliation: Department of Pathology, Nihon University School of Dentistry, 1-8-13 Kanda-Surugadai, Chiyoda-ku, Tokyo 101-8310, Japan.
authors.forename: Yoshikazu
authors.initials: Y
authors.lastname: Mikami
authors.affiliation: Department of Pathology, Nihon University School of Dentistry, 1-8-13 Kanda-Surugadai, Chiyoda-ku, Tokyo 101-8310, Japan. Electronic address: komiyama.kazuo@nihon-u.ac.jp.
authors.forename: Kazuo
authors.initials: K
authors.lastname: Komiyama
mesh_terms: D016475:3T3 Cells; D000469:Alkaline Phosphatase / Q000378:metabolism; D000818:Animals; D002229:Carbenoxolone / Q000737:chemistry; D002352:Carrier Proteins / Q000378:metabolism; D002450:Cell Communication; D002453:Cell Cycle; D002454:Cell Differentiation; D018920:Coculture Techniques; D017629:Gap Junctions / Q000502:physiology*; D005786:Gene Expression Regulation; D049452:Green Fluorescent Proteins / Q000378:metabolism; D006801:Humans; D058574:Integrin-Binding Sialoprotein / Q000378:metabolism; D051379:Mice; D010006:Osteoblasts / Q000166:cytology*; D010011:Osteocytes / Q000166:cytology* / Q000378:metabolism; D018408:Patch-Clamp Techniques; D012333:RNA, Messenger / Q000378:metabolism; D000099176:Noggin Protein
chemical_list: D000469:Alkaline Phosphatase; D002229:Carbenoxolone; D002352:Carrier Proteins; D049452:Green Fluorescent Proteins; D058574:Integrin-Binding Sialoprotein; D012333:RNA, Messenger; D000099176:Noggin Protein
keywords: Alkaline phosphatase; Bone sialoprotein; Gap junction; Osteoblasts; Osteocytes