title: Characterization of a novel periodontal ligament-specific periostin isoform.
abstract: Periostin is a mesenchymal cell marker predominantly expressed in collagen-rich fibrous connective tissues, including heart valves, tendons, perichondrium, periosteum, and periodontal ligament (PDL). Knockdown of periostin expression in mice results in early-onset periodontitis and failure of cardiac healing after acute myocardial infarction, suggesting that periostin is essential for connective tissue homeostasis and regeneration. However, its role(s) in periodontal tissues has not yet been fully defined. In this study, we describe a novel human isoform of periostin (PDL-POSTN). Isoform-specific analysis by reverse-transcription polymerase chain-reaction (RT-PCR) revealed that PDL-POSTN was predominantly expressed in the PDL, with much lower expression in other tissues and organs. A PDL cell line transfected with PDL-POSTN showed enhanced alkaline phosphatase (ALPase) activity and calcified nodule formation, compared with cells transfected with the full-length periostin isoform. A neutralizing antibody against integrin-αv inhibited both ALPase activity and calcified nodule formation in cells transfected with PDL-POSTN. Furthermore, co-immunoprecipitation assays revealed that PDL-POSTN bound to integrin αvβ3 more strongly than the common isoform of periostin, resulting in strong activation of the integrin αvβ3-focal adhesion kinase (FAK) signaling pathway. These results suggest that PDL-POSTN positively regulates cytodifferentiation and mineralization in PDL cells through integrin αvβ3.
authors.affiliation: Department of Periodontology, Osaka University Graduate School of Dentistry, Suita, Osaka, Japan.
authors.forename: S
authors.initials: S
authors.lastname: Yamada
authors.affiliation: Department of Periodontology, Osaka University Graduate School of Dentistry, Suita, Osaka, Japan.
authors.forename: T
authors.initials: T
authors.lastname: Tauchi
authors.affiliation: Department of Periodontology, Osaka University Graduate School of Dentistry, Suita, Osaka, Japan.
authors.forename: T
authors.initials: T
authors.lastname: Awata
authors.affiliation: Department of Periodontology, Osaka University Graduate School of Dentistry, Suita, Osaka, Japan.
authors.forename: K
authors.initials: K
authors.lastname: Maeda
authors.affiliation: Department of Periodontology, Osaka University Graduate School of Dentistry, Suita, Osaka, Japan.
authors.forename: T
authors.initials: T
authors.lastname: Kajikawa
authors.affiliation: Department of Periodontology, Osaka University Graduate School of Dentistry, Suita, Osaka, Japan.
authors.forename: M
authors.initials: M
authors.lastname: Yanagita
authors.affiliation: Department of Periodontology, Osaka University Graduate School of Dentistry, Suita, Osaka, Japan ipshinya@dent.osaka-u.ac.jp.
authors.forename: S
authors.initials: S
authors.lastname: Murakami
mesh_terms: D000469:Alkaline Phosphatase / Q000032:analysis; D000818:Animals; D002113:Calcification, Physiologic / Q000502:physiology; D015815:Cell Adhesion Molecules / Q000032:analysis* / Q000378:metabolism / Q000502:physiology; D018929:Cell Culture Techniques; D002454:Cell Differentiation / Q000502:physiology; D002460:Cell Line; D051417:Focal Adhesion Kinase 1 / Q000378:metabolism; D005822:Genetic Vectors / Q000235:genetics; D006801:Humans; D039564:Integrin alphaV / Q000502:physiology; D039302:Integrin alphaVbeta3 / Q000378:metabolism; D051379:Mice; D008810:Mice, Inbred C57BL; D008815:Mice, Inbred Strains; D010513:Periodontal Ligament / Q000166:cytology / Q000378:metabolism*; D010957:Plasmids / Q000235:genetics; D020033:Protein Isoforms / Q000032:analysis / Q000502:physiology; D034741:RNA, Small Interfering / Q000235:genetics; D020133:Reverse Transcriptase Polymerase Chain Reaction; D015398:Signal Transduction / Q000502:physiology; D014162:Transfection
chemical_list: D015815:Cell Adhesion Molecules; D039564:Integrin alphaV; D039302:Integrin alphaVbeta3; C512835:POSTN protein, human; D020033:Protein Isoforms; D034741:RNA, Small Interfering; D051417:Focal Adhesion Kinase 1; C496050:PTK2 protein, human; D000469:Alkaline Phosphatase
keywords: cell differentiation; cementoblasts; integrin; mineralization; osteoblasts; periodontal tissues/periodontium