title: Poly(I:C) induced microRNA-146a regulates epithelial barrier and secretion of proinflammatory cytokines in human nasal epithelial cells.
abstract: Human nasal epithelial cells (HNECs) are important in the tight junctional barrier and innate immune defense protecting against pathogens invading via Toll-like receptors (TLRs). MicroRNAs (miRNAs) regulate expression of tight junctions as direct or indirect targeting genes and maintain the barrier function. However, the roles of miRNAs in the epithelial barrier of HNECs via TLRs remain unknown. In the present study, to investigate the effects of miRNAs on the epithelial barrier of HNECs via TLRs, primary cultured HNECs transfected with human telomerase reverse transcriptase (hTERT-HNECs), were treated with the TLR3 ligand poly(I:C) and miRNA array analysis was performed. In the miRNA array of the cells treated with poly(I:C), upregulation of miR-187, -146a, -574, -4274, -4433, -4455 and -4750, and downregulation of miR-4785 by more than twofold compared to the control were observed. When control HNECs were treated with mimics and inhibitors of these miRNAs, an miR-146a mimic induced expression of tight junction proteins claudin-1, occludin and JAM-A together with an increase of the epithelial barrier function. The poly(I:C)-induced miR-146a was regulated via the distinct TLR3-mediated signal pathways PI3K, JNK and NF-κB. Furthermore, the miR-146a mimic prevented downregulation of claudin-1 and JAM-A and the secretion of proinflammatory cytokines IL-8 and TNF-α induced by poly(I:C) by targeting TRAF6. These findings indicate that, in HNECs, miRNA-146a plays crucial roles in maintenance of the tight junction barrier and innate immune defense protecting against invading pathogens.
authors.affiliation: Department of Otolaryngology, Sapporo Medical University School of Medicine, Sapporo 060-8556, Japan; Department of Cell Science, Research Institute for Frontier Medicine, Sapporo Medical University School of Medicine, Sapporo 060-8556, Japan.
authors.forename: Ryo
authors.initials: R
authors.lastname: Miyata
authors.affiliation: Department of Otolaryngology, Sapporo Medical University School of Medicine, Sapporo 060-8556, Japan; Department of Cell Science, Research Institute for Frontier Medicine, Sapporo Medical University School of Medicine, Sapporo 060-8556, Japan.
authors.forename: Takuya
authors.initials: T
authors.lastname: Kakuki
authors.affiliation: Department of Otolaryngology, Sapporo Medical University School of Medicine, Sapporo 060-8556, Japan.
authors.forename: Kazuaki
authors.initials: K
authors.lastname: Nomura
authors.affiliation: Department of Otolaryngology, Sapporo Medical University School of Medicine, Sapporo 060-8556, Japan.
authors.forename: Tsuyoshi
authors.initials: T
authors.lastname: Ohkuni
authors.affiliation: Department of Otolaryngology, Sapporo Medical University School of Medicine, Sapporo 060-8556, Japan.
authors.forename: Noriko
authors.initials: N
authors.lastname: Ogasawara
authors.affiliation: Department of Otolaryngology, Sapporo Medical University School of Medicine, Sapporo 060-8556, Japan.
authors.forename: Ken-Ichi
authors.initials: K
authors.lastname: Takano
authors.affiliation: Department of Cell Science, Research Institute for Frontier Medicine, Sapporo Medical University School of Medicine, Sapporo 060-8556, Japan.
authors.forename: Takumi
authors.initials: T
authors.lastname: Konno
authors.affiliation: Department of Cell Science, Research Institute for Frontier Medicine, Sapporo Medical University School of Medicine, Sapporo 060-8556, Japan.
authors.forename: Takayuki
authors.initials: T
authors.lastname: Kohno
authors.affiliation: Department of Pathology, Sapporo Medical University School of Medicine, Sapporo 060-8556, Japan.
authors.forename: Norimasa
authors.initials: N
authors.lastname: Sawada
authors.affiliation: Department of Otolaryngology, Sapporo Medical University School of Medicine, Sapporo 060-8556, Japan.
authors.forename: Tetsuo
authors.initials: T
authors.lastname: Himi
authors.affiliation: Department of Cell Science, Research Institute for Frontier Medicine, Sapporo Medical University School of Medicine, Sapporo 060-8556, Japan. Electronic address: ktakashi@sapmed.ac.jp.
authors.forename: Takashi
authors.initials: T
authors.lastname: Kojima
mesh_terms: D002478:Cells, Cultured; D016207:Cytokines / Q000276:immunology / Q000378:metabolism*; D017097:Electric Impedance; D004847:Epithelial Cells / Q000187:drug effects* / Q000276:immunology / Q000378:metabolism; D006801:Humans; D007113:Immunity, Innate / Q000187:drug effects; D018836:Inflammation Mediators / Q000276:immunology / Q000378:metabolism*; D048031:JNK Mitogen-Activated Protein Kinases / Q000378:metabolism; D035683:MicroRNAs / Q000235:genetics / Q000378:metabolism*; D016328:NF-kappa B / Q000378:metabolism; D009297:Nasal Mucosa / Q000187:drug effects* / Q000276:immunology / Q000378:metabolism; D010539:Permeability; D058539:Phosphatidylinositol 3-Kinase / Q000378:metabolism; D011070:Poly I-C / Q000494:pharmacology*; D015398:Signal Transduction / Q000187:drug effects; D048029:TNF Receptor-Associated Factor 6 / Q000378:metabolism; D019098:Telomerase / Q000235:genetics / Q000378:metabolism; D062725:Tight Junction Proteins / Q000378:metabolism; D019108:Tight Junctions / Q000187:drug effects / Q000276:immunology / Q000378:metabolism; D013997:Time Factors; D051196:Toll-Like Receptor 3 / Q000819:agonists / Q000378:metabolism; D014162:Transfection; D015854:Up-Regulation
chemical_list: D016207:Cytokines; D018836:Inflammation Mediators; C542542:MIRN146 microRNA, human; D035683:MicroRNAs; D016328:NF-kappa B; C495344:TLR3 protein, human; D048029:TNF Receptor-Associated Factor 6; D062725:Tight Junction Proteins; D051196:Toll-Like Receptor 3; D058539:Phosphatidylinositol 3-Kinase; D048031:JNK Mitogen-Activated Protein Kinases; C509186:TERT protein, human; D019098:Telomerase; D011070:Poly I-C
keywords: Epithelial barrier; Human nasal epithelial cells; MicroRNA-146a; Poly(I:C); Proinflammatory cytokines; TLR3; TRAF6; Tight junctions