title: Cortisol differentially alters claudin isoforms in cultured puffer fish gill epithelia.
abstract: A primary cultured gill epithelium from the puffer fish Tetraodon nigroviridis was developed to examine the corticosteroid regulation of claudin isoform mRNA abundance in fish gills. Preparations were composed of polygonal epithelial cells exhibiting concentric apical microridges and zonula occludens-1 immunoreactivity along cell margins. No evidence was found to indicate the presence of Na(+)-K(+)-ATPase-immunoreactive or mitochondria-rich cells in cultured preparations. Therefore, epithelia appear to be composed of gill pavement cells (PVCs) only. An RT-PCR profile of 12 salinity responsive gill claudin tight junction (TJ) proteins (Tncldn3a, -3c, -6, -8d, -10d, -10e, -11a, -23b, -27a, -27c, -32a, and -33b) revealed the absence of Tncldn6, -10d and -10e in cultured epithelia, suggesting that these isoforms are not associated with gill PVCs. Cortisol treatment of cultured epithelia dose-dependently increased or decreased mRNA abundance of select claudin isoforms. Transcript abundance of several claudin isoforms was unaffected by cortisol treatment. These data provide evidence for the cell specific distribution of claudins in fish gills and suggest that heterogeneous alterations in the abundance of select claudin isoforms contribute to the corticosteroid regulation of gill permeability.
authors.affiliation: Department of Biology, York University, 4700 Keele Street, Toronto, ON, Canada M3J 1P3.
authors.forename: Phuong
authors.initials: P
authors.lastname: Bui
authors.forename: Mazdak
authors.initials: M
authors.lastname: Bagherie-Lachidan
authors.forename: Scott P
authors.initials: SP
authors.lastname: Kelly
mesh_terms: D000064:Acclimatization / Q000187:drug effects; D000818:Animals; D057167:Claudins / Q000235:genetics / Q000378:metabolism*; D004848:Epithelium / Q000187:drug effects* / Q000378:metabolism*; D005618:Fresh Water; D020869:Gene Expression Profiling; D005786:Gene Expression Regulation / Q000187:drug effects; D005880:Gills / Q000187:drug effects / Q000378:metabolism*; D006854:Hydrocortisone / Q000494:pharmacology*; D007150:Immunohistochemistry; D020033:Protein Isoforms / Q000235:genetics / Q000378:metabolism; D012333:RNA, Messenger / Q000235:genetics / Q000378:metabolism; D020133:Reverse Transcriptase Polymerase Chain Reaction; D054712:Salinity; D012623:Seawater; D023721:Tetraodontiformes / Q000235:genetics / Q000378:metabolism*; D046509:Tissue Culture Techniques
chemical_list: D057167:Claudins; D020033:Protein Isoforms; D012333:RNA, Messenger; D006854:Hydrocortisone