58-F reduces the H2O2-induced [Ca2+]i increase. (a) Cells were pre-treated with 10, 50 or 100 μM 58-F for 24 h, followed by stimulation with 500 μM H2O2 in a Ca2+-free buffer and the subsequent addition of 2 mM CaCl2 into the media. (b) The quantification of intracellular Ca2+ was performed at two peaks after adding H2O2 and CaCl2. (c–f) Cells were pre-treated with 10, 50 and 100 μM 58-F for 21 h, then co-incubated with 500 μM H2O2 for 3 h (c and d) or with 50 μM 58-F for 24, 48 and 72 h. (e and f) Western blot analysis of STIM1 and Orai1 proteins. (g and h) Cells were pre-treated with 10 μM U73122 or 5 0 μM 58-F for 21 h, then co-incubated with 500 μM H2O2 for 3 h, followed by western blot analysis of p-PLCγ1 and PLCγ1 proteins. Shown are representative results from one of three independent experiments. *P<0.05, compared with the control; #P<0.05, compared with the H2O2 treatment group.