Hyposmotic activation of ICl,swell in rabbit nonpigmented ciliary epithelial cells involves increased ClC-3 trafficking to the plasma membrane.

Published

Journal Article

In mammalian nonpigmented ciliary epithelial (NPE) cells, hyposmotic stimulation leading to cell swelling activates an outwardly rectifying Cl(-) conductance (I(Cl,swell)), which, in turn, results in regulatory volume decrease. The aim of this study was to determine whether increased trafficking of intracellular ClC-3 Cl channels to the plasma membrane could contribute to the I(Cl,swell) following hyposmotic stimulation. Our results demonstrate that hyposmotic stimulation reversibly activates an outwardly rectifying Cl(-) current that is inhibited by phorbol-12-dibutyrate and niflumic acid. Transfection with ClC-3 antisense, but not sense, oligonucleotides reduced ClC-3 expression as well as I(Cl,swell). Intracellular dialysis with 2 different ClC-3 antibodies abolished activation of I(Cl,swell). Immunofluorescence microscopy showed that hyposmotic stimulation increased ClC-3 immunoreactivity at the plasma membrane. To determine whether this increased expression of ClC-3 at the plasma membrane could be due to increased vesicular trafficking, we examined membrane dynamics with the fluorescent membrane dye FM1-43. Hyposmotic stimulation rapidly increased the rate of exocytosis, which, along with ICl,swell, was inhibited by the phosphoinositide-3-kinase inhibitor wortmannin and the microtubule disrupting agent, nocodazole. These findings suggest that ClC-3 channels contribute to I(Cl,swell) following hyposmotic stimulation through increased trafficking of channels to the plasma membrane.

Full Text

Duke Authors

Cited Authors

  • Vessey, JP; Shi, C; Jollimore, CA; Stevens, KT; Coca-Prados, M; Barnes, S; Kelly, ME

Published Date

  • December 2004

Published In

Volume / Issue

  • 82 / 6

Start / End Page

  • 708 - 718

PubMed ID

  • 15674438

Pubmed Central ID

  • 15674438

International Standard Serial Number (ISSN)

  • 0829-8211

Digital Object Identifier (DOI)

  • 10.1139/o04-107

Language

  • eng

Conference Location

  • Canada