Fig. 5

Silencing KCa1.1 β3 expression reduces cell surface expression of KCa1.1α. a K⁺ current density of untransfected fibroblast-like synoviocytes from patients with rheumatoid arthritis (RA-FLS) and RA-FLS transfected with control small interfering RNA (siRNA) or with siRNA against KCa1.1 β3 before (black) and after treatment with 30 μM arachidonic acid (AA) (white; top plot) or 75 μM lithocholic acid (LCA) (gray; bottom plot) and normalized to current densities before treatment. Mean ± SEM; n = 4 RA-FLS donors. b Representative flow cytometry histograms showing background staining (gray shading), expression levels of KCa1.1α in untransfected RA-FLS (dashed line) and RA-FLS transfected with siRNA against KCa1.1β3 (solid black line; left histogram) or with control siRNA (solid black line; right histogram). The bar graph below shows the percentage of cells expressing KCa1.1α calculated from the flow cytometric profiles of three RA-FLS samples. Mean ± SEM. c K⁺ current densities of RA-FLS transfected with control siRNA (open boxes) or with siRNA against KCa1.1β3 (closed circles) and pulsed stepwise from −40 to 140 mV in 20-mV increments. Mean ± SEM; n = 4 RA-FLS donors. *p ≤ 0.05, **p ≤ 0.01, ***p ≤ 0.001