FIGURE 9.

CRAC channel-mediated calcium entry is essential for NFAT nuclear translocation in HUVECs upon histamine stimulation. A, representative confocal image of HUVECs transfected with eGFP-NFATc1 (green) is shown. The eGFP-NFATc1 molecules were mainly distributed in the cytosol under the control condition (in the Ca2 solution, see supplemental Table S1, without histamine). B, after 30-min stimulation with 100 μm histamine in the Ca2 solution, the majority of eGFP-NFATc1 molecules were translocated to the nuclei. C, cells were treated with 30 μm fexofenadine for 30 min before histamine stimulation. D, cells were stimulated with 100 μm histamine in the Ca0 solution (see supplemental Table S1). E and F, cells were treated with calcineurin inhibitor, cyclosporin A (CsA, 1 μm, E), or CRAC channel blocker, Gd³⁺ (10 μm, F), for 30 min before histamine stimulation. G and H, cells were treated with siRNA targeting STIM1 (G) or Orai1 (H) before histamine stimulation. I–K, enlarged areas marked by the squares in panels A, B, and G are displayed. Scale bars, 50 μm. L, quantitative results on NFAT nuclear translocation from 40 to 140 cells for each set of experiments are shown. *: p < 0.01 compared with column B. Ctl: control.