生体バリアとヒト疾患-細胞間隙における分子通過機構の機能分子病理学

2005 Fiscal Year Annual Research Report

• Project/Area Number: 17390117
• Research Institution: Sapporo Medical University
• Principal Investigator: 小山内 誠 札幌医科大学, 医学部, 助手 (60381266)
• Co-Investigator(Kenkyū-buntansha): 小島 隆 札幌医科大学, 医学部, 助教授 (30260764) ; 千葉 英樹 札幌医科大学, 医学部, 講師 (00295346) ; 飛岡 弘敏 札幌医科大学, 医学部, 非常勤講師 (90291559)
• Keywords: タイト結合 / occludin / アポトーシス / シグナル伝達 / フェンス機能 / 上皮細胞極性

Research Abstract

タイト結合は,生体内において上皮や内皮細胞に存在し,細胞膜のapical領域とbasolateral領域の境界を形成し,細胞膜上の蛋白質や脂質の拡散を防ぎ極性を維持するフェンス機能と,細胞間での物質の透過を制御するバリア機能がある.さらに最近の研究によりタイト結合は細胞間をシールする機能だけでなく,細胞内へのシグナル伝達の足場としての役割を有すると考えられている.今回我々は,タイト結合構成蛋白occludinに焦点を絞り,occludin欠損マウス由来の肝細胞(初代培養肝細胞,肝細胞株)およびoccludinの細胞外ドメインに対するモノクローナル抗体を用いて,occludinの詳細な機能を解析した.結果,occludin欠損マウス由来の肝細胞において,生存シグナルである活性化MAPKおよび活性化Aktの減少によるタイト結合構成膜貫通蛋白claudin-2の増加とアポトーシスの増加が見られた.以上よりoccludinは,バリア機能の調節だけではなく,生存シグナルであるMAPK/ERKおよびPI3/Akt経路の伝達にも重要な役割を果たしていると考えられた.次に,occludinの上皮細胞のフェンス機能つまり極性における役割をみるために,ヒト大腸高分化腺癌細胞株T84を用いて,occludinの細胞外ドメインに対するモノクローナル抗体を処置して,occludinの発現とapical領域マーカーであるcarcinoembryonic antigen(CEA)およびCD26(DPP-IV)の局在の変化を検索した.結果,occludin抗体処置により,occludinの発現低下がみられ,CEAおよびCD26はbasolateral領域への拡散が認められた.以上のことは,occludinの発現が上皮細胞のapical領域蛋白の局在維持に積極的に関与していることを示唆していた.

Research Products

• [Journal Article] The significance of interferon-γ-triggered internalization of tight-junction proteins in inflammatory bowel disease. (2006)
  • Author(s): Chiba H et al.
  • Journal Title: Sci STKE. 316
  • Description: 「研究成果報告書概要(和文)」より
  • Peer Reviewed
• [Journal Article] Phosphorylation of ezrin enhances microvillus length via a p38 MAP-kinase pathway in an immortalized mouse hepatic cell line. (2006)
  • Author(s): Lan MD et al.
  • Journal Title: Exp Cell Res. 312 Pages: 111-120
• [Journal Article] Hyperstimulation and a gonadotropin-releasing hormone agonist modulate ovarian vascular permeability by altering expression of the tight junction protein claudin-5. (2006)
  • Author(s): Kitajima Y et al.
  • Journal Title: Endocrinology. 147 Pages: 694-699
• [Journal Article] Abnormal β-catenin expression in oral cancer with no gene mutation : Correlation with expression of cyclin D1 and epidermal growth factor receptor, Ki-67 labeling index and clinicopathological features. (2006)
  • Author(s): Odajima T et al.
  • Journal Title: Human Pathology. 36 Pages: 234-241
• [Journal Article] ギャップ結合の病態解析法 (2005)
  • Author(s): 小島隆 他
  • Journal Title: 細胞:技術講座 37 Pages: 42-45
• [Journal Article] Ovariectomy fails to augment bone resorption and marrow B lymphopoiesis in granulocyte colony-stimulating factor transgenic mice. (2005)
  • Author(s): Oda T et al.
  • Journal Title: J Orthop Sci. 10 Pages: 70-76
• [Journal Article] Glyceraldehyde-derived advanced glycation end-products preferentially induce VEGF expression and reduce GDNF expression in human astrocytes. (2005)
  • Author(s): Miyajima H et al.
  • Journal Title: Biochem Biophys Res Commun. 330 Pages: 361-366
• [Journal Article] Glial cell line-derived neurotrophic factor in the vitreous of patients with proliferative diabetic retinopathy. (2005)
  • Author(s): Nishikiori N et al.
  • Journal Title: Diabetes Care. 10 Pages: 2588
• [Journal Article] Down-regulation of survival signaling through MAPK and Akt in occludin-deficient mouse hepatocytes in vitro. (2005)
  • Author(s): Murata M et al.
  • Journal Title: Exp Cell Res. 310 Pages: 140-151
• [Journal Article] Behavior of tight-junction, adherens-junction and cell polarity proteins during HNF-4α-induced epithelial polarization. (2005)
  • Author(s): Satohisa S et al.
  • Journal Title: Exp Cell Res. 310 Pages: 66-78
• [Journal Article] Activation of p21^<CIP1/WAF1> gene and inhibition of cell proliferation by overexpression of hepatocyte nuclear factor-4α. (2005)
  • Author(s): Chiba H et al.
  • Journal Title: Exp Cell Res. 302 Pages: 11-21
• [Journal Article] Tight junction protein MAGI-1 is up-regulated by transfection with connexin32 in an immortalized mouse hepatic cell line : cDNA microarray analysis. (2005)
  • Author(s): Murata M et al.
  • Journal Title: Cell Tissue Res. 319 Pages: 341-347
• [Journal Article] HLA-DR- and CD 11c-positive dendritic cells penetrate beyond well-developed epithelial tight junctions in human nasal mucosa of allergic rhinitis. (2005)
  • Author(s): Takano K et al.
  • Journal Title: J Histochem Cytochem. 53 Pages: 611-619
• [Journal Article] p38 MAP-kinase regulates function of gap and tight junctions during regeneration of rat hepatocytes. (2005)
  • Author(s): Yamamoto T et al.
  • Journal Title: J Hepatol. 42 Pages: 707-718
• [Journal Article] Reduced expression of claudin-7 correlates with invasion and metastasis in squamous cell carcinoma of the esophagus.
  • Author(s): Usami Y et al.
  • Journal Title: Hum Pathol. in press
• [Journal Article] Possible involvement of gap junctions in the barrier function of tight junctions of brain and lung endothelial cells.
  • Author(s): Nagasawa K et al.
  • Journal Title: J Cell Physiol. in press