Fig. 3.

NCLX inhibition and curcumin treatment decrease SOCE in CRC cells. A Electrophysiological recordings were performed on HEK293 ORAI1 KO cells transfected with ORAI1-CFP and STIM1-YFP. Representative time courses of whole‐cell CRAC currents activated by dialysis of 20 mM BAPTA through the patch pipette and taken at − 100 mV from control cells (black trace) or cells pre-treated with 10 µM curcumin (red trace) are shown. Representative I–V relationships are taken from traces in (A) which are indicated by color‐coded asterisks. Statistical analysis of Ca2+ CRAC currents measured at − 100 mV is shown (n = 4 independent experiments; Mann–Whitney test, *P < 0.05). B Representative traces of SOCE in HCT116 cells pre-treated with curcumin (10 µM for 1 h). The data show the effects of curcumin on SOCE in HCT116 (n = 5 independent experiments; Mann–Whitney test, **P < 0.01). C Relative mRNA levels of MCU, NCLX, MICU1, MICU2, STIM1, STIM2, ORAI1, and TRPC1 genes in HCT116 cells treated or not with 10 µM curcumin for 24 h (n = 5 independent experiments; Mann–Whitney test, *P < 0.05). D/ STIM1-dependent puncta formation a. Representative fluorescent images of HCT116 cells co-expressing STIM1 Cherry (red) showing puncta after treatment with TG (2 µM for 10 min) and pre-treated or not with curcumin for 30 min. E Representative cytosolic Ca2+ measurements in HCT116 WT and NCLX KO cells measured with Fura-2 AM in response to 2 µM TG applied first in nominally Ca2+-free external solution and subsequently with 2 mM external Ca2+. The summary data are presented as the mean ± SD (n = 5 independent experiments, 24 cells for each group; Mann–Whitney test, **P < 0.01). F SOCE was blocked after preincubation with CGP37157 (10 μM for 1 h) (right graph). Ca2+ influx in control and CGP37157-treated cells is shown. The summary data are presented as the mean ± SEM (n = 4 independent experiments, 23 cells for each group; Mann–Whitney test, ***P < 0.001)