Fig. 3

UV-induced DSBs elicit a rapid NPM secretion in the absence of necrosis. a hCmPCs were treated with 50mJ/cm² of UV light for 4 h and 8 h (lower panels) or not treated (w/o UV; upper panels) in serum-free media. Representative images of γH2aX (green) immunofluorescence and DAPI (blue)-counterstained nuclei. γH2AX increases upon UV light treatment. Scale bar 10μm. b hCmPCs were treated for 1 h, 2 h, and 4h with UV light, and serum-free media were collected and analysed by ELISA assay for the presence of NPM. eNPM was induced at 2h and 4h treatment in UV-treated cells. The difference at 2h and 4h between UV treated and Ctrl was statistically significant (n = 9; ^*P < 0.05). c LDH assay, a marker of cell necrosis, showed that the release does not depend on a passive release from dead cells. A negative control and positive control were inserted in the assay, and the latter is statistically significant vs negative control (n = 4; ^*P < 0.05)