Figure 2

t1EK2 induces p53-dependent apoptosis in differentiated neurons. (a) Percentage of active caspase-3 positive neurons expressing LacZ (n = 150) or t1EK2 (n = 150) at 1.5 dpt (17 DIV). Three independent experiments were carried out (***p < 0.001; two-sided Fisher’s exact test). (b) Representative confocal images of active caspase-3-specific immunostaining in a LacZ control neuron and a t1EK2-expressing neuron. Note that the active caspase-3-positive nuclei is pyknotic. Arrows identify RFP positive neurons. (c) Percentage of active caspase-3 positive neurons expressing LacZ/p53DN (n = 150) or t1EK2/p53DN (n = 150) at 1.5 dpt (17 DIV). Three independent experiments were carried out (***p < 0.001; two-sided Fisher’s exact test). (d) Representative confocal images of active caspase-3-negative LacZ/p53DN (Control) and t1EK2/p53DN expressing neurons. (e) Confocal image of an active caspase-3-negative neuron presenting chromatin condensation characteristic of prophase with 3D reconstruction of the nucleus. Blue, red and green arrows represent 3D orientation. Graphs represent mean ± s.e.m. Scale bar: 25 µm.