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Specifically Sized Hyaluronan (35 kDa) Prevents Ethanol‐Induced Disruption of Epithelial Tight Junctions Through a layilin‐Dependent Mechanism in Caco‐2 Cells
Author(s) -
Bellos Damien A.,
Sharma Dhara,
McMullen Megan R.,
Wat Jeanette,
Saikia Paramananda,
Motte Carol A.,
Nagy Laura E.
Publication year - 2019
Publication title -
alcoholism: clinical and experimental research
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.267
H-Index - 153
eISSN - 1530-0277
pISSN - 0145-6008
DOI - 10.1111/acer.14140
Subject(s) - occludin , tight junction , microbiology and biotechnology , claudin , colocalization , caco 2 , cell junction , intestinal epithelium , chemistry , fluorescein isothiocyanate , small intestine , biochemistry , epithelium , biology , biophysics , in vitro , cell , quantum mechanics , fluorescence , genetics , physics
Background Specific‐sized species of the carbohydrate hyaluronan elicit a variety of cellular responses mediating tissue integrity and repair, as well as regulating inflammatory responses. Orally provided hyaluronan with an average molecular weight of 35 kDa (HA35) protects mice from short‐term ethanol (EtOH)‐induced liver injury. This protection was associated with maintenance of the colocalization of zonula occludens‐1 (ZO‐1) and occludin at tight junctions in the proximal colon. However, it is not known whether HA35 also protects other regions of the intestine or whether protection is due to a direct and/or indirect interaction of HA35 with the intestinal epithelium. Methods Female C57BL/6J mice were fed an EtOH containing diet or pair‐fed control diet (4 days) and treated with or without HA35 via daily gavage during the last 3 days of EtOH feeding. Intestinal morphology and tight junction integrity were assessed. Differentiated Caco‐2 cells were transfected or not with scrambled siRNA or siRNA targeting layilin, a hyaluronan receptor. Caco‐2 cells were treated with or without HA35 prior to challenge with EtOH. Localization of tight junction proteins, fluorescein isothiocyanate (FITC)‐dextran permeability, and transepithelial electrical resistance (TEER) were evaluated. Results While short‐term EtOH did not result in any apparent changes in the gross morphology of the intestine, colocalization of ZO‐1 and occludin at tight junctions was decreased in the proximal and distal colon. HA35 prevented these effects of EtOH. In differentiated Caco‐2 cells, EtOH decreased the localization of ZO‐1 and occludin at tight junctions and increased permeability of FITC‐dextran. At higher concentrations, EtOH also decreased TEER. Pretreatment with HA35 prevented these changes. When the hyaluronan receptor layilin was knocked down in Caco‐2 cells, HA35 no longer protected cells from EtOH‐induced loss of tight junctions. Conclusions Taken together, these data indicate that HA35 interacts with layilin on intestinal epithelial cells and maintains intestinal tight junction integrity during short‐term EtOH exposure.