Fig. 2: Increase of intracellular Ca²⁺ and activation of whole cell Cl^- currents by pore forming gasdermin D.

a, b Original recordings from each 200 experiments (a) and summary of the baseline 340/380 fluorescence ratio in Fura-2 loaded cells expressing the N-terminal pore–forming domain of gasdermin D (GD-N) or empty plasmid (mock). Tannic acid (TA; 10 µM) inhibited the baseline Ca²⁺ increase in GD-N expressing cells. c Cell morphology of cells transfected with empty plasmid (mock), full length gasdermin D (GD), or GD-N. d, e Whole cell currents and corresponding current/voltage relationships obtained in non-stimulated mock-transfected HEK293 cells and cells expressing GD, or GD-N. The whole cell current in GD-N expressing cells was enhanced, which was inhibited by removal of extracellular chloride (5Cl⁻) from the bath solution. f Current densities for all individual cells examined by patch clamping, obtained at Vc = + 100 mV. g Summaries for the 5Cl^--inhibited whole cell current indicating activation of Cl^- permeable currents in cells expressing GD-N. Cells were voltage clamped ± 100 mV (1 s) in steps of 20 mV. Mean + /− SEM (number of experiments). ^#§Significant difference when compared to mock or inhibition by tannic acid, respectively (unpaired t-test). *Significant inhibition by 5 Cl⁻ (p < 0.05; paired t-test)