ヒト歯髄創傷治癒過程における細胞外基質の局在変化 : Fibrillin-1基質の動的リモデリングに関する検索  [in Japanese] Distributional Alteration of Extracellular Matrix during Wound Healing of Human Dental Pulp : Dynamic Remodeling of Fibrillin-1 Matrix  [in Japanese]

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Author(s)

    • 吉羽 永子 YOSHIBA Nagako
    • 新潟大学大学院医歯学総合研究科口腔健康科学講座う蝕学分野 Division of Cariology, Operative Dentistry and Endodontics, Department of Oral Health Science, Niigata University Graduate School of Medical and Dental Sciences
    • 吉羽 邦彦 YOSHIBA Kunihiko
    • 新潟大学大学院医歯学総合研究科口腔健康科学講座う蝕学分野 Division of Cariology, Operative Dentistry and Endodontics, Department of Oral Health Science, Niigata University Graduate School of Medical and Dental Sciences
    • 大倉 直人 OHKURA Naoto
    • 新潟大学大学院医歯学総合研究科口腔健康科学講座う蝕学分野 Division of Cariology, Operative Dentistry and Endodontics, Department of Oral Health Science, Niigata University Graduate School of Medical and Dental Sciences
    • 重谷 佳見 SHIGETANI Yoshimi
    • 新潟大学大学院医歯学総合研究科口腔健康科学講座う蝕学分野 Division of Cariology, Operative Dentistry and Endodontics, Department of Oral Health Science, Niigata University Graduate School of Medical and Dental Sciences
    • 武井 絵梨花 TAKEI Erika
    • 新潟大学大学院医歯学総合研究科口腔健康科学講座う蝕学分野 Division of Cariology, Operative Dentistry and Endodontics, Department of Oral Health Science, Niigata University Graduate School of Medical and Dental Sciences
    • 興地 隆史 OKIJI Takashi
    • 新潟大学大学院医歯学総合研究科口腔健康科学講座う蝕学分野 Division of Cariology, Operative Dentistry and Endodontics, Department of Oral Health Science, Niigata University Graduate School of Medical and Dental Sciences

Abstract

目的:細胞外基質fibrillin-1は,弾性線維の構成タンパクであると同時に,その分解によりtransforming growthfactor-β (TGF-β)を遊離させることが知られている.また,著者らはfibrillin-1がヒト歯髄直接覆髄後の創傷治癒過程で発現を消失させることを見いだしている.そこで本研究では,TGF-β制御活性を有する組胞外基質decorinとfibronectin,および創傷治癒と組織線維化に関与するtenascin-Cが,ヒト歯髄直接覆髄後の創傷治癒過程でfibrillin-1様の局在変化を示すか否かを検索した.さらに,スライス培養したヒト歯髄を用いて,fibrillin-1の発現消失へのmatrix metalloproteinase (MMP)の関与の実態を検索した.材料と方法:矯正治療により抜歯予定のヒト健全歯をmineral trioxide aggregate (MTA)で直接覆髄した後,2週および6週後に抜歯し,fibrillin-1, fibronectin, decorinおよびtenascin-Cに対する免疫組織化学的染色を行った.また,健全歯髄を組織培養し,fibrillin-1mRNA発現を定量RT-PCRで測定するとともに,MMP阻害剤であるNNGHを添加培養し,fibrillin-1タンパクの局在変化を免疫染色により解析した.結果:直接覆髄後2週および6週において,fibrillin-1に対する免疫陽性反応は,覆髄部直下の歯髄組織で局所的に消失していた.一方,fibronectin, decorinおよびtenascin-Cは同部で一様に陽性反応を示しており,明らかな局在変化は認められなかった.一方,培養歯髄組織ではfibrillin-1の染色性が減弱し,mRNAの発現も有意に低下したが,MMP-3mRNA発現は有意に亢進した.NNGHを添加培養するとfibrillin-1の染色性が向上した.結論:検索対象とした4種のタンパクのなかでfibrillin-1のみ直接覆髄後の創傷治癒過程で局在変化を示した.Fibrillin-1免疫反応性の消失には,MMPsによるタンパクの分解に加えて遺伝子発現の下方制御も関与するものと考えられた.

Purpose: Fibrillin-1 is the main structural component of extracellular microfibrils, and is known to contribute to the release of transforming growth factor-β (TGF-β) upon its degradation. We have also demonstrated that fibrillin-1 immunoreactivity disappears during the wound healing process of direct-capped human dental pulp. In this study, we extended our investigation to fibronectin and decorin (known as extracellular regulators of TGF-β) and tenascin-C (known to contribute to wound healing and tissue fibrosis), and examined whether these molecules show distributional changes similar to those observed for fibrillin-1 during the healing process of direct-capped human pulp. Human pulp slice cultures were also examined for the involvement of matrix metalloproteinases (MMPs) in the disappearance of fibrillin-1 immunoreactivity. Methods: Clinically healthy human teeth scheduled for orthodontic extraction were directly pulp-capped with mineral trioxide aggregate (MTA). After 2 or 6 weeks, the teeth were extracted and processed for immunohistochemical staining of fibrillin-1, fibronectin, decorin and tenascin-C. Cultured healthy pulp tissues were analyzed for (1) fibrillin-1 mRNA expression with quantitative RT-PCR, and (2) distributional changes of fibrillin-1 immunoreactivities after addition of an MMP inhibitor (NNGH). Results: At 2 and 6 weeks after direct pulp capping, immunoreactivity for fibrillin-1 disappeared under the exposure site of dental pulp. Immunoreactivities for fibronectin, decorin and tenascin-C were constantly detected beneath the exposed area of the pulp and no apparent distributional changes were recognized. Cultured pulp tissue slices demonstrated a decreased fibrillin-1 immunoreactivity with significant downregulation of fibrillin-1 and upregulation of MMP-3. Administration of NNGH caused an enhancement of fibrillin-1 immunoreactivity. Conclusion: Among the four proteins examined, only fibrillin-1 showed distributional alterations during the wound healing process of direct-capped human dental pulp. Degradation by MMPs, together with downregulation of fibrillin-1, may be involved in the disappearance of fibrillin-1 immunoreactivity.

Journal

  • The Japanese Journal of Conservative Dentistry

    The Japanese Journal of Conservative Dentistry 56(3), 161-168, 2013

    The Japanese Society of Conservative Dentistry

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