title: Claudin-3 is required for modulation of paracellular permeability by TNF-α through ERK1/2/slug signaling axis in submandibular gland.
abstract: TNF-α plays an important role in the pathogenesis of salivary inflammatory diseases. Salivary dysfunction, which leads to impaired saliva secretion, can be caused by TNF-α-induced disrupted epithelial barrier. However, the signaling mechanism involved in TNF-α-modulated tight junction barrier in salivary gland remains unclear. Here, we found that TNF-α reduced transepithelial resistance (TER) and increased FITC-dextran flux in a rat submandibular cell line SMG-C6. Claudin (Cln)-3 was selectively downregulated and disrupted by TNF-α, whereas Cln-1, Cln-4, and β-catenin were not affected. Overexpression of Cln-3 retained and Cln-3 knockdown abolished the TNF-α-induced alterations. Moreover, TNF-α increased extracellular signal-regulated kinase (ERK1/2) phosphorylation and the expression of transcriptional factor slug. ERK1/2 kinase inhibitor PD98059 abrogated TNF-α-induced increase in paracellular permeability, alterations of Cln-3, and elevation of slug. Overexpression of slug decreased and slug knockdown increased Cln-3 expression. In addition, slug bind to the E-box elements of Cln-3 promoter in TNF-α-treated cells, and this response was blocked by PD98059. Furthermore, TNF-α decreased Cln-3 expression and increased slug content in cultured human submandibular gland. Taken together, our data suggest that Cln-3 plays a vital role in TNF-α-modulated paracellular permeability in submandibular epithelium and ERK1/2/slug signaling axis is involved in alteration of Cln-3 redistribution and downregulation.
authors.affiliation: Department of Oral and Maxillofacial Surgery, Peking University School and Hospital of Stomatology, Beijing 100081, China.
authors.forename: Mei
authors.initials: M
authors.lastname: Mei
authors.affiliation: Department of Physiology and Pathophysiology, Peking University Health Science Center and Key Laboratory of Molecular Cardiovascular Sciences, Ministry of Education, Beijing Key Laboratory of Cardiovascular Receptors Research, Beijing 100191, China.
authors.forename: Ruo-Lan
authors.initials: RL
authors.lastname: Xiang
authors.affiliation: Department of Physiology and Pathophysiology, Peking University Health Science Center and Key Laboratory of Molecular Cardiovascular Sciences, Ministry of Education, Beijing Key Laboratory of Cardiovascular Receptors Research, Beijing 100191, China.
authors.forename: Xin
authors.initials: X
authors.lastname: Cong
authors.affiliation: Department of Physiology and Pathophysiology, Peking University Health Science Center and Key Laboratory of Molecular Cardiovascular Sciences, Ministry of Education, Beijing Key Laboratory of Cardiovascular Receptors Research, Beijing 100191, China.
authors.forename: Yan
authors.initials: Y
authors.lastname: Zhang
authors.affiliation: Department of Oral and Maxillofacial Surgery, Peking University School and Hospital of Stomatology, Beijing 100081, China.
authors.forename: Jing
authors.initials: J
authors.lastname: Li
authors.affiliation: Department of Biochemistry and Molecular Biology, Peking University Health Science Center and Key Laboratory of Carcinogenesis and Translational Research, Ministry of Education, Beijing 100191, China.
authors.forename: Xia
authors.initials: X
authors.lastname: Yi
authors.affiliation: Department of Physiology, School of Dentistry, Seoul National University, Seoul 110-749, South Korea.
authors.forename: Kyungpyo
authors.initials: K
authors.lastname: Park
authors.affiliation: Department of Integration of Chinese and Western Medicine, Peking University Health Science Center, Beijing 100191, China.
authors.forename: Jing-Yan
authors.initials: JY
authors.lastname: Han
authors.affiliation: Department of Physiology and Pathophysiology, Peking University Health Science Center and Key Laboratory of Molecular Cardiovascular Sciences, Ministry of Education, Beijing Key Laboratory of Cardiovascular Receptors Research, Beijing 100191, China. Electronic address: pathophy@bjmu.edu.cn.
authors.forename: Li-Ling
authors.initials: LL
authors.lastname: Wu
authors.affiliation: Department of Oral and Maxillofacial Surgery, Peking University School and Hospital of Stomatology, Beijing 100081, China. Electronic address: gyyu@263.net.
authors.forename: Guang-Yan
authors.initials: GY
authors.lastname: Yu
mesh_terms: D000328:Adult; D000818:Animals; D002460:Cell Line; D002463:Cell Membrane Permeability; D062465:Claudin-3 / Q000502:physiology*; D004847:Epithelial Cells / Q000378:metabolism; D048049:Extracellular Signal-Regulated MAP Kinases / Q000378:metabolism; D015870:Gene Expression; D005786:Gene Expression Regulation; D006801:Humans; D020935:MAP Kinase Signaling System; D008297:Male; D008875:Middle Aged; D011401:Promoter Regions, Genetic; D021381:Protein Transport; D051381:Rats; D000071250:Snail Family Transcription Factors; D013363:Submandibular Gland; D019108:Tight Junctions / Q000378:metabolism; D014157:Transcription Factors / Q000378:metabolism; D014409:Tumor Necrosis Factor-alpha / Q000378:metabolism*
chemical_list: C568122:CLDN3 protein, human; D062465:Claudin-3; C000604407:SNAI1 protein, human; C000604450:Snai2 protein, rat; D000071250:Snail Family Transcription Factors; C439524:TNF protein, human; D014157:Transcription Factors; D014409:Tumor Necrosis Factor-alpha; D048049:Extracellular Signal-Regulated MAP Kinases
keywords: Claudin-3; ERK1/2; Paracellular permeability; Slug; Submandibular gland; TNF-α