Fig. 5. UV-induced NETosis does not induce citrullination of histones.

a Human neutrophils were collected for western blot analysis 3 h after activation with PMA (25 nM), A23 (4 µM) or increasing doses of UV. Immunoblots show that citrullination of histones occurs in A23, but not in PMA or the UV conditions. Densitometry analysis confirm the lack of citrullination of histones following UV treatment (n = 3; error bars represent SEM; A23, A23187; *p < 0.05 for comparing to negative control). b Neutrophils were treated with PMA (25 nM), A23 (4 µM) or UV (1.92 J/cm²) and incubated for 180 min. Cells were fixed and stained for DNA (DAPI; blue) and citrullinated histones 3 (red). Imaging confirms that citrullination of histones is not found in cells undergoing UV-induced NETosis (scale bar, 10 μm). Images are representative of three independent experiments. See low-magnification images in Fig. S5