Identification of two-pore domain potassium channels as potent modulators of osmotic volume regulation in human T lymphocytes.

University of Wuerzburg, Lehrstuhl für Biotechnologie und Biophysik, Biozentrum, Am Hubland, 97074 Wuerzburg, Germany.

Biochimica et biophysica acta 2013 Feb

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Many functions of T lymphocytes are closely related to cell volume homeostasis and regulation, which utilize a complex network of membrane channels for anions and cations. Among the various potassium channels, the voltage-gated K(V)1.3 is well known to contribute greatly to the osmoregulation and particularly to the potassium release during the regulatory volume decrease (RVD) of T cells faced with hypotonic environment. Here we address a putative role of the newly identified two-pore domain (K(2P)) channels in the RVD of human CD4(+) T lymphocytes, using a series of potent well known channel blockers. In the present study, the pharmacological profiles of RVD inhibition revealed K(2P)5.1 and K(2P)18.1 as the most important K(2P) channels involved in the RVD of both naïve and stimulated T cells. The impact of chemical inhibition of K(2P)5.1 and K(2P)18.1 on the RVD was comparable to that of K(V)1.3. K(2P)9.1 also notably contributed to the RVD of T cells but the extent of this contribution and its dependence on the activation status could not be unambiguously resolved. In summary, our data provide first evidence that the RVD-related potassium efflux from human T lymphocytes relies on K(2P) channels. Copyright © 2012 Elsevier B.V. All rights reserved.

Citation

Joseph Andronic, Nicole Bobak, Stefan Bittner, Petra Ehling, Christoph Kleinschnitz, Alexander M Herrmann, Heiko Zimmermann, Markus Sauer, Heinz Wiendl, Thomas Budde, Sven G Meuth, Vladimir L Sukhorukov. Identification of two-pore domain potassium channels as potent modulators of osmotic volume regulation in human T lymphocytes. Biochimica et biophysica acta. 2013 Feb;1828(2):699-707