title: Claudin-4 undergoes age-dependent change in cellular localization on pig jejunal villous epithelial cells, independent of bacterial colonization.
abstract: Newborn piglets are immunologically naïve and must receive passive immunity via colostrum within 24 hours to survive. Mechanisms by which the newborn piglet gut facilitates uptake of colostral cells, antibodies, and proteins may include FcRn and pIgR receptor-mediated endocytosis and paracellular transport between tight junctions (TJs). In the present study, FcRn gene (FCGRT) was minimally expressed in 6-week-old gut and newborn jejunum but it was expressed at significantly higher levels in the ileum of newborn piglets. pIgR was highly expressed in the jejunum and ileum of 6-week-old animals but only minimally in neonatal gut. Immunohistochemical analysis showed that Claudin-5 localized to blood vessel endothelial cells. Claudin-4 was strongly localized to the apical aspect of jejunal epithelial cells for the first 2 days of life after which it was redistributed to the lateral surface between adjacent enterocytes. Claudin-4 was localized to ileal lateral surfaces within 24 hours after birth indicating regional and temporal differences. Tissue from gnotobiotic piglets showed that commensal microbiota did not influence Claudin-4 surface localization on jejunal or ileal enterocytes. Regulation of TJs by Claudin-4 surface localization requires further investigation. Understanding the factors that regulate gut barrier maturation may yield protective strategies against infectious diseases.
authors.affiliation: Vaccine and Infectious Disease Organization (VIDO), Home of the International Vaccine Centre (InterVac), 120 Veterinary Road, University of Saskatchewan, Saskatoon, SK, Canada S7N 5E3.
authors.forename: J Alex
authors.identifier: 0000-0001-8596-3057
authors.initials: JA
authors.lastname: Pasternak
authors.affiliation: Department of Animal and Poultry Science, University of Saskatchewan, 51 Campus Drive, Saskatoon, SK, Canada S7N 5A8.
authors.forename: Coral
authors.identifier: 0000-0001-9735-577X
authors.initials: C
authors.lastname: Kent-Dennis
authors.affiliation: Department of Animal and Poultry Science, University of Saskatchewan, 51 Campus Drive, Saskatoon, SK, Canada S7N 5A8.
authors.forename: Andrew G
authors.initials: AG
authors.lastname: Van Kessel
authors.affiliation: Vaccine and Infectious Disease Organization (VIDO), Home of the International Vaccine Centre (InterVac), 120 Veterinary Road, University of Saskatchewan, Saskatoon, SK, Canada S7N 5E3.
authors.forename: Heather L
authors.initials: HL
authors.lastname: Wilson
mesh_terms: D000375:Aging; D000818:Animals; D000831:Animals, Newborn; D001424:Bacterial Infections / Q000276:immunology* / Q000378:metabolism; D062506:Claudin-4 / Q000378:metabolism*; D062507:Claudin-5 / Q000378:metabolism; D017931:DNA Primers / Q000737:chemistry; D004705:Endocytosis; D004847:Epithelial Cells / Q000276:immunology / Q000378:metabolism*; D005786:Gene Expression Regulation; D007082:Ileum / Q000378:metabolism; D007583:Jejunum / Q000276:immunology / Q000378:metabolism*; D016133:Polymerase Chain Reaction; D013552:Swine; D019108:Tight Junctions / Q000378:metabolism
chemical_list: D062506:Claudin-4; D062507:Claudin-5; D017931:DNA Primers