Allitridin Reduces IKr Current by Disrupting the Trafficking of Human Ether-a-Go-Go-Related Gene Channels

Objectives: To investigate the effects of allitridin on human ether-a-go-go-related gene (hERG) channels. Methods: We used whole-cell patch clamping and laser confocal scanning microscopy to evaluate the effects of allitridin on hERG currents and the membrane expression of the hERG protein expressed in HEK 293 cells. Results:The amplitude of l(Kr) showed a concentration-dependent decrease with increasing allitridin concentration. Additionally, alterations in the gating properties of hERG channels were also confirmed. Allitridin does not alter the voltage- and time-dependent activation of hERG channels, the gating properties of hERG channel inactivation over time or the recovery from inactivation, but allitridin does cause alterations in the steady-state inactivation and the deactivation of hERG channels. We further evaluated the influence of allitridin on membrane expression of the hERG protein. Images of allitridin-treated cells showed a reduction in hERG protein on the membrane and retention in the cytoplasm. Conclusions:To the best of our knowledge this is the first study to show that allitridin reduces the l(Kr) current by impairing the trafficking of hERG channels. The results may demonstrate that allitridin could be a promising candidate for the prevention and treatment of arrhythmia related diseases. (c) 2014 S. Karger AG, Basel