Fig. 2

Activation of DNA damage pathway in syncytia induced by SARS-CoV-2 infection and Spike-ACE2 expression. a and b Immunofluorescent images of Hela-ACE2 cells expressing exogenous SARS-CoV-2 spike glycoprotein (a) or infected by SARS-CoV-2 (b). Cells were stained with antibodies against γH2Ax protein in green. Zoomed images on the right indicate colocalization between γH2Ax and micronuclei in syncytia. Scale bars: 50 μm for the left image, 20 μm for zoomed images in the middle and 1 μm for multi-channel images on the right. c and d Quantification of micronuclei γH2Ax foci in Hela-ACE2 cells transfected by spike protein (c) or infected by SARS-CoV-2 (d). e–g Expression of γH2AX and p53 proteins in Hela-ACE2 cells 24 h post transfection by Western blot (e) and quantification (f, g). All results were normalized by the expression of β-actin. Data are mean ± SD of triple quantification. h Expression of NOXA, GADD45A, SLC7A11, PAI1 and MYC were analyzed by quantitative RT-PCR 24 h post spike transfection in Hela-ACE2 cells