Fig. 2.

IbTX inhibits KCa1.1 channels expressed on FLSs and reduces ex vivo FLS invasion. (A) Representative whole-cell potassium currents (top) in RA-FLSs, PIA-FLSs, and CIA-FLSs before (gray) and after administration of 3 nM IbTX (black) and dose-response inhibition of potassium currents by IbTX (bottom). (B) Invasiveness of FLSs from patients with RA and rats with either PIA or CIA through Matrigel-coated Transwell inserts in the presence of 10 μM paxilline (Pax) or 10 μM IbTX. Data are the mean ± S.E.M. (n = 3 donors per group). *P < 0.05; **P < 0.01; ***P < 0.001.