Figure 2.

Progerin‐induced DNA damage is restricted to proliferating cells. (a) Schematic representation of the experimental set up. (b) Western blotting showing doxycycline‐dependent progerin expression in proliferating and confluent NDF. Progerin migrates between lamin A and C as indicated (red arrowhead). Lamin A (LA), lamin C (LC), progerin (PG), lamin B1 (LB1), LAP2α, GAPDH and actin are indicated. (c) Immunofluorescence microscopy showing progerin‐induced 53BP‐1 foci (white arrowheads) in proliferating (left panel) or confluent cells (right panel). V5‐progerin (V5 antibody) and 53BP‐1 foci (53BP‐1 antibody) are indicated. Scale bar: 20 μm. (d) Quantification of DNA damage foci (0, 1, 2, 3 or more 53BP‐1 foci), in proliferating or confluent cells in the absence or presence of progerin (***p < .001, n = 3, χ² test). (e) Immunofluorescence microscopy showing Ki‐67 staining in proliferating (left panels) and confluent cells (right panels). DAPI and Ki‐67 antibody are shown on top and bottom panels, respectively. Scale bar: 50 μm. (f) Quantification of the percentage of Ki‐67‐positive and Ki‐67‐negative cells in proliferating or confluent cultures (grey and black bars, respectively)