Resveratrol inhibits K_v2.2 currents through the estrogen receptor GPR30-mediated PKC pathway

摘要

Resveratrol (REV) is a naturally occurring phytoalexin that inhibits neuronal K~+ channels; however, the molecular mechanisms behind the effects of REV and the relevant alpha-subunit are not well defined. With the use of patch-clamp technique, cultured cerebellar granule cells, and HEK-293 cells transfected with the K_v2.1 and K_v2.2 alpha-subunits, we investigated the effect of REV on K_v2.1 and K_v2.2 alpha-subunits. Our data demonstrated that REV significantly suppressed K_v2.2 but not K_v2.1 currents with a fast, reversible, and mildly concentration-dependent manner and shifted the activation or inactivation curve of K_v2.2 channels. Activating or inhibiting the cAMP/PKA pathway did not abolish the inhibition of K_v2.2 current by REV. In contrast, activation of PKC with phorbol 12-myristate 13-acetate mimicked the inhibitory effect of REV on K_v2.2 by modifying the activation or inactivation properties of K_v2.2 channels and eliminated any further inhibition by REV. PKC and PKC-a inhibitor completely eliminated the REV-induced inhibition of K_v2.2. Moreover, the effect of REV on K_v2.2 was reduced by preincubation with antagonists of GPR30 receptor and shRNA for GPR30 receptor. Western blotting results indicated that the levels of PKC-alpha and PKC-beta were significantly increased in response to REV application. Our data reveal, for the first time, that REV inhibited K_v2.2 currents through PKC-dependent pathways and a nongenomic action of the oestrogen receptor GPR30.