Fig. 4

DNase I prevents apoptosis of lung tissue and lung epithelial cells. K18-hACE2 mice (n = 6) were intranasally (i.n) inoculated with SARS-CoV-2 (2 × 10⁴ PFU) and treated with DNase I (10 mg/kg, s.c) for 5 days. a TUNEL staining (green) for detection of apoptotic cells in situ from lung tissue of mice. b Percentage of TUNEL-positive cells in lung tissue. NETs were purified from healthy neutrophils and stimulated with PMA (50 nM) for 4 h at 37 °C c Representative dot plots of FACS analysis of Annexin V + A549 cells incubated with purified NETs (10 ng/ml) pretreated, or not, with DNase I (0.5 mg/ml) for 24 h at 37 °C. d Frequency of Annexin V + A549. Data are representative of two independent experiments and are shown as mean ± SEM. P values were determined by one-way ANOVA followed by Bonferroni’s post hoc test