Fig. 6

Regulation of calcium homeostasis by Sigma1R and IRE1α in atrial fibrillation. (A) Representative images of immunofluorescence staining using DAPI (nuclei) and Fura-2AM (calcium indicator) (Bar = 100 μm). (B) Quantification of Fura-2AM fluorescence intensity (n = 3). (C) Quantification of Ca²⁺ in the endoplasmic reticulum (n = 6). (D) Representative images of immunofluorescence staining using Fura-2AM (cytosolic calcium indicator) and Fura-3AM (mitochondrial calcium indicator) (Bar = 100 μm). (E) Quantification of Fura-2AM or Fura-3AM fluorescence intensity (n = 3). Data are expressed as the mean ± SD. Statistical analysis was performed using one-way ANOVA followed by Tukey’s multiple comparisons test. P^* < 0.05, P^** < 0.01, P^*** < 0.001.