title: Expression and localization of tricellulin in human nasal epithelial cells in vivo and in vitro.
abstract: Tricellulin was identified as the first marker of the tricellular tight junction, which forms at the meeting points of three cells, and it is required for the maintenance of the transepithelial barrier. Although it is also considered to be important for the mucosal barrier of the upper respiratory tract, little is known about its expression and localization. In the present study, we examined the expression and localization of tricellulin in normal human nasal epithelial cells in vivo and in vitro, especially using primary cultures and telomerase reverse transcriptase (hTERT)-transfected cells. In human nasal epithelial cells in vivo and in vitro, mRNA and protein of tricellulin were detected. It was localized not only at tricellular contacts but also at bicellular borders, and in part colocalized with occludin. In human nasal epithelium, by immunoelectron microscopy analysis, tricellulin-associated gold particles were observed around the junction-like structure of the uppermost region. By treatment with 10% fetal bovine serum (FBS), expression of tricellulin mRNA was weakly increased, whereas that of bicellular tight junction molecules was strongly increased, in real-time PCR. These results suggest that tricellulin is stably expressed in human nasal epithelial cells and may play an important role for the sealing of the corner at tricellular contacts to prevent infiltration by various inhaled viruses and antigens.
authors.affiliation: Department of Otolaryngology, Sapporo Medical University School of Medicine, Sapporo, Japan.
authors.forename: Tsuyoshi
authors.initials: T
authors.lastname: Ohkuni
authors.forename: Takashi
authors.initials: T
authors.lastname: Kojima
authors.forename: Noriko
authors.initials: N
authors.lastname: Ogasawara
authors.forename: Tomoyuki
authors.initials: T
authors.lastname: Masaki
authors.forename: Takafumi
authors.initials: T
authors.lastname: Ninomiya
authors.forename: Shin
authors.initials: S
authors.lastname: Kikuchi
authors.forename: Mitsuru
authors.initials: M
authors.lastname: Go
authors.forename: Ken-ichi
authors.initials: K
authors.lastname: Takano
authors.forename: Tetsuo
authors.initials: T
authors.lastname: Himi
authors.forename: Norimasa
authors.initials: N
authors.lastname: Sawada
mesh_terms: D000818:Animals; D002417:Cattle; D002478:Cells, Cultured; D004847:Epithelial Cells / Q000166:cytology / Q000378:metabolism; D006801:Humans; D062794:MARVEL Domain Containing 2 Protein; D008565:Membrane Proteins / Q000235:genetics / Q000378:metabolism*; D018613:Microscopy, Confocal; D046529:Microscopy, Electron, Transmission; D009297:Nasal Mucosa / Q000166:cytology / Q000378:metabolism; D012333:RNA, Messenger / Q000235:genetics / Q000378:metabolism; D011817:Rabbits; D019098:Telomerase / Q000235:genetics / Q000378:metabolism; D019108:Tight Junctions / Q000378:metabolism*; D014162:Transfection
chemical_list: D062794:MARVEL Domain Containing 2 Protein; C516798:MARVELD2 protein, human; D008565:Membrane Proteins; D012333:RNA, Messenger; D019098:Telomerase