Fig. 2: Synergistic effects of C16 and probenecid on rat TRPV2 currents in HEK293T cells.

Representative whole-cell current recording from HEK293T cell expressing rat TRPV2. a Inward and outward currents were elicited by voltage ramps from −100 mV to +100 mV (0.4 V/s) delivered every 1 s from a holding potential of 0 mV. Stimuli of 3 mM probenecid (white horizontal bars) and 10 µM C16 (blue horizontal bars) were individually or synergistically applied to the cell at 42 °C. b Statistical summary of the peak currents (open and blue circles) in (a), induced by probenecid (Prob) and probenecid with C16 (Prob + C16) at +100 mV and −100 mV. Control (yellow circle) indicates currents measured at 25 °C before increasing the temperature to 42 °C at which the effects of probenecid and C16 were recorded. Data are shown as means ± SEM from five separate experiments. c Representative continuous whole-cell inward current traces at a holding potential of −60 mV showing an initial exposure to probenecid alone (Prob, 10 mM) followed by a second application of probenecid (10 mM) after preincubation of either C16 at a subthreshold concentration of 10 µM (see Fig. 1c) or its vehicle (Veh). Each treatment is from a different cell. The co-application of probenecid and C16 only induced a small current in control HEK293T cells (−39 ± 11 pA, n = 4 cells). d As summarized in the graph, the peak currents (open, grey and blue circles) in (c), evoked by probenecid increased in the presence of C16 (n = 6 independent experiments) but not in the presence of vehicle (n = 9 independent experiments). e The TRPV2 inhibitor valdecoxib (100 µM) inhibited outward and inward currents evoked by the combined application of probenecid and C16 (data are from three independent experiments performed as shown by the traces). f The non-selective TRP channel antagonist ruthenium red (RR, 10 µM, n = 7 independent experiments) inhibited currents evoked by the combined application of C16 (10 µM) and probenecid (10 mM) at a holding potential of −60 mV (n = 9 independent experiments). P values are given in italics and indicate statistical significance when <0.05, Student’s two-sided paired t-test (b), Wilcoxon two-sided matched-pairs test (d) and Welch’s two-sided unpaired t-test (f). Data are shown as means ± SEM. a, b, e Experiments recorded in extra- and intracellular Ca²⁺-free solutions. c, d and f Experiments recorded in extracellular Ca²⁺-containing solution. Source data are provided as a Source Data file.