FIGURE 2:

Loss of eIF2α-P switches cell fate away from senescence and toward apoptosis following UVB. (A) N-TERT keratinocytes were treated with 0 or 100 J/m² UVB and maintained in culture for 72 h. Cells were then fixed and stained for senescence-associated β-galactosidase activity. Quantification of senescent cells (dark blue) is indicated in B. Alternatively, cells were collected 6 h post-UVB and assayed for (C) caspase-3 specific activity or (D) trypan blue to measure loss of cells. Error bars represent mean ± SD of three separate experiments, and * indicates p < 0.05.