Kv7/M-type potassium channels in rat skin keratinocytes

Abstract

Skin keratinocytes fulfil important signalling and protective functions. Immunocytochemical experiments revealed the unexpected presence of immunoreactivity for the M-type potassium channel subunit Kv7.2 in the keratinocyte layer of intact rat paw skin and in keratinocytes isolated from the skin of 1-day-old rats and cultured in vitro for 3–10 days. Application of the M-channel enhancer retigabine (3–10 μM) to isolated cultured rat keratinocytes: (a) increased outward membrane currents recorded under voltage clamp, (b) produced ~3 mV hyperpolarization at rest, (c) enhanced ~3-fold the release of ATP induced by the TRPV3 agonist carvacrol (1 mM) and (d) increased the amplitude of the carvacrol-induced intracellular Ca2+ transient measured with Fura-2. The effect of retigabine on ATP release was prevented by the M-channel blocking agent XE991. We conclude that rat skin keratinocytes possess M-channels that, when activated, can modify their physiological properties, with potential significance for their sensory and other biological functions.Electronic supplementary materialThe online version of this article (doi:10.1007/s00424-013-1276-2) contains supplementary material, which is available to authorized users.

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“…TRPV3, a heat-sensitive ion channel (169), is expressed in keratinocytes and on activation, induces NO production (115). This is an interesting finding, as a number of the NO-modulated ion channels described next are also expressed in skin cells, including Kv7 (146), TRPV1 20, and TRPA1 (11) channels. Characterization of the precise details of the signaling pathways between the skin and the peripheral nervous system will provide important contributions to our understanding of the role of NO and ROS in sensory processing.…”

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