Fig. 3
KCa3.1 involved in astrocytes SOCE and ER stress. a Primary cultured astrocytes were treated with 5 μM Aβ for 12 h with or without pretreatment of the KCa3.1 blocker TRAM-34 (1 μM). Fluorescence intensities of [Ca2+]i are shown. Fluorescence intensity was measured in the presence of 1 μM Tg with or without 2 mM Ca2+. b Data are presented as the mean ± SEM (n = 10). #p < 0.05 vs. control, *p < 0.05 vs. Aβ-treated cells. c Astrocytes were treated with 5 μM Aβ for 24 h with or without 1 μM TRAM-34 pretreatment, and then subjected to western blot analysis with antibodies against GRP78 and CHOP. d Data are presented as the mean ± SEM (n = 3). #p < 0.05, ##p < 0.01 vs. controls, *p < 0.05 vs. Aβ-treated cells. One-way ANOVA followed by the Dunnett’s multiple comparison test vs. control cells. e, g Representative images of GRP78, p-PERK, and phosphorylated eIF2α (p-eIF2α) in KCa3.1−/− astrocytes, responses to 5 μM Aβ (e) or 1 μM Tg (g) vs. WT cells. f, h Mean values of GRP78, p-PERK, and p-eIF2α relative to β-actin. Data are presented as the mean ± SEM (n = 3). *p < 0.05 (unpaired, two-tailed Student’s t test). i–k Levels of the dendritic marker MAP2 were compared between neurons treated with CM from WT astrocytes (WT/CM), CM from KCa3.1−/− astrocytes (KCa3.1−/−/CM), CM from 5 μM Aβ stimulated WT astrocytes (WT/Aβ-CM), or CM from 5 μM Aβ stimulated KCa3.1−/− astrocytes (KCa3.1−/−/Aβ-CM). i Neuron dendrites were immunostained with MAP2 and nuclei were stained with DAPI (blue). Scale bars: 25 μm. Neurite length (j) and branch point counts (k) were analyzed by extended neurite outgrowth bioapplication software. Data represent mean ± SEM (n = 3). *p < 0.05, **p < 0.001 (one-way ANOVA followed by the Dunnett’s multiple comparison test). Tg thapsigargin, Con control, WT wild-type