Fig. 1. HIF stabilization aggravated SI-induced cell death in ARPE-19.

A ARPE-19 cells were treated with different concentrations of SI, DMOG or a combination of both compounds for 24 h under 3% O₂ and cell death was assessed by measuring LDH release (N = 5-6). B A subset of LDH data showing cell death in ARPE-19 cells treated with 1 mM DMOG, 5 mM SI, and co-treatment with DMOG and SI where approximately 50% of cells were dead after 24 h (B). Cell death rate was further confirmed by C MTT assay and D FACS Annexin V assay. E Histograms of FACS Annexin V-PE and 7-AAD stained cells treated with DMOG and/or SI. F Microscopic evaluation confirmed advanced cell death by co-treatment with 1 mM DMOG and 5 mM SI. G HIF-1α and -2α protein levels were increased by DMOG treatment as well as co-treatment with SI for 24 h under 3% O₂. Data are presented as means + SD. LDH, MTT, and FACS assays (5–6 independent groups) were statistically analyzed with two-way ANOVA, t-test, and one-way ANOVA, respectively. ns = not significant, ***p < 0.001, and ****p < 0.0001. Scale bar = 100 μm.