Fig. 5. Cyclosporin A (CsA) increases mitochondrial depolarization induced by H₂O₂ in human kidney proximal tubule epithelial cells. HK-2 cells were treated with either 10 nM CsA or vehicle for 60 minutes and then exposed to 1 mM H₂O₂ or control for 60 minutes. (A) Percentage of mitochondrial membrane potential was measured using tetramethylrhodamine ethyl ester perchlorate dye (n=9 wells per 3 experiments per condition). The mitochondrial membrane potential in the group with control plus vehicle was taken as 100%. ^a)P<0.05 vs. control. ^b)P<0.05 vs. vehicle. (B) Expression levels of 94 kDa glucose-regulated protein (GRP94) and 78 kDa glucose-regulated protein (GRP78) were measured by western blot analysis. Antibody of β-actin (43 kDa) as a loading control was used for normalization. (C, D) Intensities of GRP94 and GRP78 protein bands were quantified using the AzureSpot software (n=6 experiments per condition). N.S., not significant.