Claudin-31 contributes to corticosteroid-induced alterations in the barrier properties of the gill epithelium.
The contribution of Claudin-31 (Cldn-31) to corticosteroid-induced tightening of the trout gill epithelium was examined using a primary cultured model preparation. Cldn-31 is a ∼23 kDa protein that localizes to the periphery of gill epithelial cells and diffusely in select gill cells that are Na+-K+-ATPase-immunoreactive. Transcriptional knockdown (KD) of cldn-31 reduced Cldn-31 abundance and increased epithelium permeability. Under simulated in vivo conditions (apical freshwater), cldn-31 KD increased net ion flux rates (≡ efflux). Cortisol treatment increased Cldn-31 abundance and decreased epithelium permeability. This tightening effect was diminished, but not eliminated, by cldn-31 KD, most likely due to other cortisol-sensitive TJ proteins that were transcriptionally unperturbed or enhanced in cortisol-treated cldn-31 KD preparations. However, cldn-31 KD abolished a cortisol-induced increase in Cldn-8d abundance, which may contribute to compromised cldn-31 KD epithelium permeability. Data suggest an important barrier function for Cldn-31 and an integral role for Cldn-31 in corticosteroid-induced gill epithelium tightening.
Department of Biology, York University, Toronto, ON, M3J 1P3, Canada.
Dennis
D
Kolosov
Department of Biology, York University, Toronto, ON, M3J 1P3, Canada.
Andrew
A
Donini
Department of Biology, York University, Toronto, ON, M3J 1P3, Canada. Electronic address: spk@yorku.ca.
Scott P
SP
Kelly
D000305:Adrenal Cortex Hormones / Q000494:pharmacology*; D000595:Amino Acid Sequence; D000818:Animals; D002478:Cells, Cultured; D057167:Claudins / Q000737:chemistry / Q000378:metabolism*; D017097:Electric Impedance; D004848:Epithelium / Q000187:drug effects / Q000378:metabolism*; D055785:Gene Knockdown Techniques; D005880:Gills / Q000166:cytology / Q000378:metabolism*; D006854:Hydrocortisone / Q000494:pharmacology; D008954:Models, Biological; D017686:Oncorhynchus mykiss / Q000378:metabolism; D014158:Transcription, Genetic / Q000187:drug effects
D000305:Adrenal Cortex Hormones; D057167:Claudins; D006854:Hydrocortisone
Cortisol; Fish; Knockdown; Osmoregulation; Paracellular permeability; Tight junction