Voltage-gated ion channels in cultured gill epithelia of rainbow trout, Oncorhynchus mykiss, change in transcript abundance with exposure to freshwater.
Siaje Gideon, Brendan Boyd, Brandon Ramirez, Dennise Arenas, Perla Ochoa, John Eme, Dennis Kolosov
{"title":"Voltage-gated ion channels in cultured gill epithelia of rainbow trout, Oncorhynchus mykiss, change in transcript abundance with exposure to freshwater.","authors":"Siaje Gideon, Brendan Boyd, Brandon Ramirez, Dennise Arenas, Perla Ochoa, John Eme, Dennis Kolosov","doi":"10.1016/j.cbpa.2025.111835","DOIUrl":null,"url":null,"abstract":"<p><p>Salmonid fishes are well adapted to transition between salinities as part of a diadromid lifestyle, and many species are both economically and environmentally important. Ion-transporting gill epithelium helps fishes maintain ion balance during salinity transition. Recent transcriptomic surveys suggest that voltage-gated ion channels (VGICs) are present in gill epithelium of fishes. However, fish gill epithelia are architecturally complex and structurally heterogeneous (which includes layers of excitable tissues), which necessitates a model to study isolated gill epithelial cells. In the present study, we isolated gill epithelial cells, used them to reconstruct primary cultured gill epithelium model, and exposed the reconstructed epithelia to apical freshwater (FW). Using RNAseq and molecular biology we demonstrate that multiple VGICs are expressed in cultured gill epithelia of a salmonid, rainbow trout Oncorhynchus mykiss. Following apical exposure to FW, multiple subunits of voltage-gated calcium (Ca<sub>V</sub>) channels, as well as KCNE2 were upregulated in mRNA abundance. Using a custom-made antibody, we demonstrated that Ca<sub>V</sub>1.3 immunolocalized to the apical membrane of epithelia in intact trout gill, as well as in the cultured gill epithelium. Pharmacological inhibition of Ca<sub>V</sub>1 in FW-exposed cultured epithelia led to increased transepithelial resistance. Therefore, we propose that VGICs are present in gill epithelia of fishes, and may rapidly and autonomously respond to environmental salinity changes to help the fish maintain salt and water balance, where Ca<sub>V</sub>1 specifically may play a particularly important role in rapid adjustment of gill epithelia barrier properties and resistivity and potentially in responding to regulatory cell volume decrease in vitro.</p>","PeriodicalId":55237,"journal":{"name":"Comparative Biochemistry and Physiology A-Molecular & Integrative Physiology","volume":" ","pages":"111835"},"PeriodicalIF":2.1000,"publicationDate":"2025-03-10","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":"0","resultStr":null,"platform":"Semanticscholar","paperid":null,"PeriodicalName":"Comparative Biochemistry and Physiology A-Molecular & Integrative Physiology","FirstCategoryId":"99","ListUrlMain":"https://doi.org/10.1016/j.cbpa.2025.111835","RegionNum":3,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":null,"EPubDate":"","PubModel":"","JCR":"Q4","JCRName":"BIOCHEMISTRY & MOLECULAR BIOLOGY","Score":null,"Total":0}
引用次数: 0
Abstract
Salmonid fishes are well adapted to transition between salinities as part of a diadromid lifestyle, and many species are both economically and environmentally important. Ion-transporting gill epithelium helps fishes maintain ion balance during salinity transition. Recent transcriptomic surveys suggest that voltage-gated ion channels (VGICs) are present in gill epithelium of fishes. However, fish gill epithelia are architecturally complex and structurally heterogeneous (which includes layers of excitable tissues), which necessitates a model to study isolated gill epithelial cells. In the present study, we isolated gill epithelial cells, used them to reconstruct primary cultured gill epithelium model, and exposed the reconstructed epithelia to apical freshwater (FW). Using RNAseq and molecular biology we demonstrate that multiple VGICs are expressed in cultured gill epithelia of a salmonid, rainbow trout Oncorhynchus mykiss. Following apical exposure to FW, multiple subunits of voltage-gated calcium (CaV) channels, as well as KCNE2 were upregulated in mRNA abundance. Using a custom-made antibody, we demonstrated that CaV1.3 immunolocalized to the apical membrane of epithelia in intact trout gill, as well as in the cultured gill epithelium. Pharmacological inhibition of CaV1 in FW-exposed cultured epithelia led to increased transepithelial resistance. Therefore, we propose that VGICs are present in gill epithelia of fishes, and may rapidly and autonomously respond to environmental salinity changes to help the fish maintain salt and water balance, where CaV1 specifically may play a particularly important role in rapid adjustment of gill epithelia barrier properties and resistivity and potentially in responding to regulatory cell volume decrease in vitro.
期刊介绍:
Part A: Molecular & Integrative Physiology of Comparative Biochemistry and Physiology. This journal covers molecular, cellular, integrative, and ecological physiology. Topics include bioenergetics, circulation, development, excretion, ion regulation, endocrinology, neurobiology, nutrition, respiration, and thermal biology. Study on regulatory mechanisms at any level of organization such as signal transduction and cellular interaction and control of behavior are also published.