The Korean Journal of Physiology and Pharmacology

The Korean Society of Pharmacology (대한약리학회)
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Direct Block of Cloned $K^+$ Channels, Kv1.5 and Kv1.3, by Cyclosporin A, Independent of Calcineurin Inhibition

  • Choi, Bok-Hee (Department of Pharmacology, Chonbuk National University) ;
  • Hahn, Sang-June (Deportment of Physiology, Medical Research Center, College of Medicine, The Catholic University of Medicine, The Catholic University of Korea)
  • Published : 2005.12.21
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Abstract

The interaction of cyclosporine A (CsA), an immunosuppressant, with rat brain Kv1.5 (Kv1.5) channels, which were stably expressed in Chinese hamster ovary cells, was investigated using the whole-cell patch-clamp technique. CsA reversibly blocked Kv1.5 currents at +50 mV in a reversible concentrationdependent manner with an apparent $IC_{50}$ of 1.0μM. Other calcineurin inhibitors (cypermethrin, autoinhibitory peptide) had no effect on Kv1.5 and did not prevent the inhibitory effect of CsA. Fast application of CsA led to a rapid and reversible block of Kv1.5, and the onset time constants of the CsA-induced block were decreased in a concentration-dependent manner. The CsA-induced block of Kv1.5 channels was voltage-dependent, with a steep increase over the voltage range of channel opening. However, the block exhibited voltage independence over the voltage range in which channels were fully activated. The rate constants for association and dissociation of CsA were $7.0{\mu}M{-1}s^{-1}$ and $8.1s^{-1}$, respectively. CsA slowed the deactivation time course, resulting in a tail crossover phenomenon. Block of Kv1.5 by CsA was use-dependent. CsA also blocked Kv1.3 currents at +50 mV in a reversible concentration-dependent manner with an apparent $IC_{50}$ of $1.1{\mu}M$. The same effects of CsA on Kv1.3 were also observed in excised inside-out patches when applied to the internal surface of the membrane. The present results suggest that CsA acts directly on Kv1.5 currents as an open-channel blocker, independently of the effects of CsA on calcineurin activity.

Keywords

References

  1. Chen H, Kubo Y, Hoshi T, Heinemann SH. Cyclosporin A selectively reduces the functional expression of Kir2.1 potassium channels in Xenopus oocytes. FEBS Lett 422: 307-310, 1998 https://doi.org/10.1016/S0014-5793(98)00028-3
  2. Choi BH, Choi JS, Jeong SW, Hahn SJ, Yoon SH, Jo YH, Kim MS. Direct block by bisindolylmaleimide of rat Kv1.5 expressed in Chinese hamster ovary cells. J Pharmacol Exp Ther 293: 634- 640, 2000
  3. Choi BH, Choi JS, Rhie DJ, Yoon SH, Min DS, Jo YH, Kim MS, Hahn SJ. Direct inhibition of the cloned Kv1.5 channel by AG-1478, a tyrosine kinase inhibitor. Am J Physiol Cell Physiol 282: C1461-C1468, 2002 https://doi.org/10.1152/ajpcell.00398.2001
  4. Choi JS, Choi BH, Ahn HS, Kim MJ, Rhie DJ, Yoon SH, Min DS, Jo YH, Kim MS, Sung KW, Hahn SJ. Mechanism of block by fluoxetine of 5-hydroxytryptamine3 (5-HT3)-mediated currents in NCB-20 neuroblastoma cells. Biochem Pharmacol 66: 2125- 2132, 2003 https://doi.org/10.1016/j.bcp.2003.08.012
  5. Choi JS, Hahn SJ, Rhie DJ, Yoon SH, Jo YH, Kim MS. Mechanism of fluoxetine block of cloned voltage-activated potassium channel Kv1.3. J Pharmacol Exp Ther 291: 1-6, 1999
  6. Choi JS, Soderlund DM. Cyclosporin A and deltamethrin block the downregulation of Nav1.8 sodium channels expressed in Xenopus oocytes. Neurosci Lett 367: 389-393, 2004 https://doi.org/10.1016/j.neulet.2004.06.040
  7. Chung I, Schlichter LC. Regulation of native Kv1.3 channels by cAMP-dependent protein phosphorylation. Am J Physiol 273: C622-C633, 1997 https://doi.org/10.1152/ajpcell.1997.273.2.C622
  8. Damjanovich S, Aszalos A, Mulhern SA, Szollosi J, Balazs M, Tron L, Fulwyler MJ. Cyclosporin depolarizes human lymphocytes: earliest observed effect on cell metabolism. Eur J Immunol 17: 763-768, 1987. https://doi.org/10.1002/eji.1830170605
  9. Delpon E, Valenzuela C, Gay P, Franqueza L, Snyders DJ, Tamargo J. Block of human cardiac Kv1.5 channels by loratadine: voltage-, time- and use-dependent block at concentrations above therapeutic levels. Cardiovasc Res 35: 341-350, 1997 https://doi.org/10.1016/S0008-6363(97)00121-1
  10. Demeule M, Giroux S, Murphy GF, Beliveau R. Cyclosporin treatment alters protein phosphorylation in kidney membranes. Biochem Cell Biol 72: 143-151, 1994. https://doi.org/10.1139/o94-021
  11. Haller H, Spies K, Lindschau C, Quass P, Distler A. The effect of cyclosporine on calcium, protein kinase C, and sodium-proton exchange in platelets. Transplantation 57: 1516-1520, 1994 https://doi.org/10.1097/00007890-199405270-00021
  12. Mason HS, Latten MJ, Godoy LD, Horowitz B, Kenyon JL. Modulation of Kv1.5 currents by protein kinase A, tyrosine kinase, and protein tyrosine phosphatase requires an intact cytoskeleton. Mol Pharmacol 61: 285-293, 2002 https://doi.org/10.1124/mol.61.2.285
  13. Matsuda S, Koyasu S. Mechanisms of action of cyclosporine. Immunopharmacology 47: 119-125, 2000 https://doi.org/10.1016/S0162-3109(00)00192-2
  14. Niederberger W, Lemaire M, Maurer G, Nussbaumer K, Wagner O. Distribution and binding of cyclosporine in blood and tissues. Transplant Proc 15: 2419-2412, 1983
  15. Onuma H, Lu YF, Tomizawa K, Moriwaki A, Tokuda M, Hatase O, Matsui H. A calcineurin inhibitor, FK506, blocks voltagegated calcium channel-dependent LTP in the hippocampus. Neurosci Res 30: 313-319, 1998 https://doi.org/10.1016/S0168-0102(98)00012-1
  16. Panyi G, Gaspar R, Krasznai Z, ter Horst JJ, Ameloot M, Aszalos A, Steels P, Damjanovich S. Immunosuppressors inhibit voltagegated potassium channels in human peripheral blood lymphocytes. Biochem Biophys Res Commun 221: 254-258, 1996 https://doi.org/10.1006/bbrc.1996.0582
  17. Shiraishi S, Yanagita T, Kobayashi H, Uezono Y, Yokoo H, Minami SI, Takasaki M, Wada A. Up-regulation of cell surface sodium channels by cyclosporin A, FK506, and rapamycin in adrenal chromaffin cells. J Pharmacol Exp Ther 297: 657-665, 2001
  18. Sigal NH, Dumont FJ. Cyclosporin A, FK-506, and rapamycin: pharmacologic probes of lymphocyte signal transduction. Annu Rev Immunol 10: 519-560, 1992 https://doi.org/10.1146/annurev.iy.10.040192.002511
  19. Snyders DJ, Yeola SW. Determinants of antiarrhythmic drug action. Electrostatic and hydrophobic components of block of the human cardiac hKv1.5 channel. Circ Res 77: 575-583, 1995 https://doi.org/10.1161/01.RES.77.3.575
  20. Steiner JP, Dawson TM, Fotuhi M, Glatt CE, Snowman AM, Cohen N, Snyder SH. High brain densities of the immunophilin FKBP colocalized with calcineurin. Nature 358: 584-587, 1992 https://doi.org/10.1038/358584a0
  21. Steiner JP, Dawson TM, Fotuhi M, Snyder SH. Immunophilin regulation of neurotransmitter release. Mol Med 2: 325-333, 1996
  22. Swanson R, Marshall J, Smith JS, Williams JB, Boyle MB, Folander K, Luneau CJ, Antanavage J, Oliva C, Buhrow SA, et al. Cloning and expression of cDNA and genomic clones encoding three delayed rectifier potassium channels in rat brain. Neuron 4: 929-939, 1990 https://doi.org/10.1016/0896-6273(90)90146-7
  23. Tauboll E, Gerdts R, Gjerstad L. Cyclosporin A and brain excitability studied in vitro. Epilepsia 39: 687-691, 1998. https://doi.org/10.1111/j.1528-1157.1998.tb01152.x
  24. Tordai A, Or R, Gelfand EW. Effects of changes in membrane potential on the cyclosporin-induced inhibition of T-cell proliferation. Biochem Biophys Res Commun 185: 363-369, 1992 https://doi.org/10.1016/S0006-291X(05)80994-5
  25. Tseng-Crank JC, Tseng GN, Schwartz A, Tanouye MA. Molecular cloning and functional expression of a potassium channel cDNA isolated from a rat cardiac library. FEBS Lett 268: 63-68, 1990 https://doi.org/10.1016/0014-5793(90)80973-M
  26. Valenzuela C, Delpon E, Franqueza L, Gay P, Snyders DJ, Tamargo J. Effects of ropivacaine on a potassium channel (hKv1.5) cloned from human ventricle. Anesthesiology 86: 718-728, 1997. https://doi.org/10.1097/00000542-199703000-00025
  27. Williams CP, Hu N, Shen W, Mashburn AB, Murray KT. Modulation of the human Kv1.5 channel by protein kinase C activation: role of the Kvbeta1.2 subunit. J Pharmacol Exp Ther 302: 545- 550, 2002 https://doi.org/10.1124/jpet.102.033357
  28. Wong M, Yamada KA. Cyclosporine induces epileptiform activity in an in vitro seizure model. Epilepsia 41: 271-276, 2000 https://doi.org/10.1111/j.1528-1157.2000.tb00155.x
  29. Yakel JL. Calcineurin regulation of synaptic function: from ion channels to transmitter release and gene transcription. Trends Pharmacol Sci 18: 124-134, 1997 https://doi.org/10.1016/S0165-6147(97)01046-8