title: Poly-L-arginine-Induced internalization of tight junction proteins increases the paracellular permeability of the Caco-2 cell monolayer to hydrophilic macromolecules.
abstract: We investigated whether poly-L-arginine (PLA) enhances the paracellular permeability of the Caco-2 monolayer to hydrophilic macromolecules and clarified the disposition of tight junction (TJ) proteins. The transepithelial electrical resistance (TEER) and fluorescein isothiocyanate (FITC)-dextran (FD-4) permeation were determined after treatment with PLA. TJ proteins were visualized using immunofluorescence microscopy after PLA exposure and depletion, and their expression levels were determined. The barrier function of TJs was also evaluated by measuring the alterations in the TEER and in the localization of TJ proteins. PLA induced an increase in hydrophilic macromolecule, FD-4, permeation through Caco-2 cell monolayers and a decrease in the TEER in a concentration-dependent manner, without any significant impact on the cell viability. This increased paracellular permeability induced by PLA was found to be internalized of claudin-4, ZO-1, tricellulin and mainly occludin from cell-cell junction to the subcellular space. ZO-1 appeared to play an important role in the reconstitution of TJ strand structures following PLA depletion. These results indicate that the PLA led to the internalization of TJ proteins to the subcellular space, subsequently increasing the permeability of the Caco-2 cell monolayer to FD-4 via a paracellular route.
authors.affiliation: Faculty of Pharmaceutical Sciences, Josai University, 1–1 Keyakidai, Sakado, Saitama 350–0295, Japan..
authors.forename: Tsutomu
authors.initials: T
authors.lastname: Yamaki
authors.forename: Kazuo
authors.initials: K
authors.lastname: Ohtake
authors.forename: Keiko
authors.initials: K
authors.lastname: Ichikawa
authors.forename: Masaki
authors.initials: M
authors.lastname: Uchida
authors.forename: Hiroyuki
authors.initials: H
authors.lastname: Uchida
authors.forename: Shinji
authors.initials: S
authors.lastname: Oshima
authors.forename: Shinji
authors.initials: S
authors.lastname: Ohshima
authors.forename: Kazuhiko
authors.initials: K
authors.lastname: Juni
authors.forename: Jun
authors.initials: J
authors.lastname: Kobayashi
authors.forename: Yasunori
authors.initials: Y
authors.lastname: Morimoto
authors.forename: Hideshi
authors.initials: H
authors.lastname: Natsume
mesh_terms: D018938:Caco-2 Cells; D002463:Cell Membrane Permeability / Q000187:drug effects*; D002470:Cell Survival / Q000187:drug effects; D017097:Electric Impedance; D006801:Humans; D008856:Microscopy, Fluorescence; D010455:Peptides / Q000494:pharmacology*; D062725:Tight Junction Proteins / Q000378:metabolism*
chemical_list: D010455:Peptides; D062725:Tight Junction Proteins; C015462:polyarginine