High-Salt Enhances the Inflammatory Response by Retina Pigment Epithelium Cells following Lipopolysaccharide Stimulation

Figure 1

NaCl had no influence on the apoptosis and proliferation of ARPE-19 cells. ARPE-19 cells were stimulated with LPS in the absence or presence of extra additions of NaCl (20 mM, 40 mM) to the culture medium for 24 h. Cells were stained with annexin V and PI for FACS analysis. (a) Apoptotic cells (annexin V⁺ PI⁻) are shown in the Q4 area; late apoptotic cells (annexin V⁺ PI⁺) are shown in the Q2 area; necrotic cells (annexin V⁻ PI⁺) are shown in the Q1 area. (b) The percentages of cells labeled as annexin V⁽⁺⁾ PI⁽⁻⁾ and annexin V⁽⁺⁾ PI⁽⁺⁾ were employed for analysis. The data are expressed as means ± SD of three independent experiments and there were no significant differences between the groups, . To detect the proliferation of ARPE-19, the cells were plated with medium alone or medium with extra NaCl (20 mM or 40 mM) for 24 h (c), 48 h (d), and 72 h (e) following LPS stimulation and then measured using the CCK-8 method. Data shown are the mean ± SD of the ratio for light absorbance at 450 nm. Results are representative of three separate experiments, . Paired-samples t-test (when the difference between the two tested groups conforms to normal distribution) or Wilcoxon matched-pairs test (when the difference between the two tested groups does not conform to normal distribution) was used for statistical analyses for LPS control versus LPS + 20 mM NaCl or LPS + 40 mM NaCl in each group.

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