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Process of tight junction recovery in the injured vocal fold epithelium: Morphological and paracellular permeability analysis
Author(s) -
Suzuki Ryo,
Katsuno Tatsuya,
Kishimoto Yo,
Nakamura Ryosuke,
Mizuta Masanobu,
Suehiro Atsushi,
Yamashita Masaru,
Nakamura Tatsuo,
Tateya Ichiro,
Omori Koichi
Publication year - 2018
Publication title -
the laryngoscope
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.181
H-Index - 148
eISSN - 1531-4995
pISSN - 0023-852X
DOI - 10.1002/lary.26959
Subject(s) - paracellular transport , tight junction , epithelium , occludin , claudin , barrier function , microbiology and biotechnology , respiratory epithelium , biology , lamina propria , transcellular , pathology , anatomy , chemistry , permeability (electromagnetism) , medicine , biochemistry , membrane
Objectives/Hypothesis The vocal fold epithelium that includes tight junction (TJ)‐based barrier function protects underlying connective tissues from external insults. TJs play an important role to control paracellular permeability of not only solutes but also ions, and preserve the vocal fold homeostasis. However, the distribution of TJs and paracellular diffusion barrier across the entire vocal fold epithelium are still unknown. The aim of this study was to identify the distribution of TJs in the vocal fold epithelium and to characterize the recovery process of TJ‐based paracellular diffusion barrier in a rat model of vocal fold injury. Study Design Animal experiments with controls. Methods Normal and vocal fold–injured rats were used. Larynges were harvested for immunohistochemical examination of TJ proteins. For functional analysis, a tracer permeability assay was performed using EZ‐Link Sulfo‐NHS‐LC‐Biotin. Results TJ proteins occludin and zonula occludens 1 signals were localized to the junctional regions of the most luminal cell layers of the vocal fold epithelium. The injured region had been recovered with epithelium at 5 days postinjury, but the paracellular diffusion barrier assays revealed that biotinylation reagents diffused into the lamina propria at 5 days postinjury, and were blocked at the epithelium at 14 and 28 days postinjury. Conclusions It was strongly suggested that TJs in the vocal fold epithelium exist at the junctional regions of the first layer of stratified squamous epithelium. TJ‐based paracellular diffusion barrier following vocal fold injury is recovered by 14 days postinjury, and this period corresponds with the time course of structural changes in the regenerating epithelium layer. Level of Evidence NA. Laryngoscope , 128:E150–E156, 2018