Defective cyclic guanosine monophosphate-gated calcium channels and the pathogenesis of psoriasis.

A positive association between intake of calcium channel blockers and psoriasis has been observed recently. Intake of blockers of voltage-gated calcium ion channels is associated with outbreaks of psoriasis after a latent period in patients with and without a previous family history of psoriasis. This suggests that interfering with calcium influx may trigger psoriasis. Calcium influx also occurs via cyclic guanosine monophosphate-gated channels; human keratinocytes contain functional and non-functional (splice variants) versions of these channels. We show here that keratinocytes and skin from psoriatic individuals express higher levels of mRNA encoding a non-functional cyclic guanosine monophosphate-gated calcium channel and that high expression of the splice variant by transfection of cells in culture leads to loss of protein expression for the functional cyclic guanosine monophosphate-gated Ca2+ channels.