Fig. 4
Effect of ZnONP- and UVB-triggered HaCaT cell pyroptosis. A Annexin V and PI were employed to examine ZnONP induced HaCaT cell pyroptosis via flow cytometry. C Histograms represent the percentage of Q1 + Q2 regions, indicating PI positive cells. B–F The levels of the pyroptosis proteins caspase 4, caspase 5, GSDMD and cleaved GSDMD-NT in HaCaT cells were detected by Western blotting, and GAPDH was used as a loading control. G HaCaT cell immunofluorescence staining with an anti-GSDMD antibody after a 24 h treatment with ZnONPs (10 μg/mL), UVB (68 mJ/cm2) + ZnONPs (10 μg/mL) or UVB (68 mJ/cm2) + ZnONPs (10 μg/mL) + PT (2 μM). Arrows indicate GSDMD puncta. Values are presented as the mean ± SD (n = 3). *p < 0.05, control group versus treatment groups. #p < 0.05, the UVB + ZnONPs groups versus the UVB + ZnONPs + PT groups