Inhibition of <i>I</i>_<i>Kr</i> by IL-6 is prevented by IL-6R and Janus Kinase blockade in HEK293 cells.

A, Voltage-clamp protocol used to generate IKr in HEK-hERG cells stably expressing hERG channel. B, Basal hERG currents. Arrows indicate hERG peak and tail currents. C, Representative IKr traces from HEK-hERG cells pretreated with IL-6+IL-6R in the presence of anti-IL-6R antibody (Ab). D, IKr currents measured in HEK-hERG cells pre-treated with IL-6+IL-6R and the JAK inhibitor-1. Plots of IKr peak current density-voltage (E) and tail current density-voltage curves (F) in the presence of anti-IL-6R antibody (n = 4) and the JAK inhibitor-1 (n = 4). IKr peak current and tail density-voltage curves for IKr measured in basal condition (Red line) and in cells pre-treated with IL-6+IL-6R (Cyan line) are shown for comparison.