Induction of apoptosis by UVB irradiation in NRP1-deficient keratinocytes and epidermis.

Primary murine keratinocytes were isolated from epidermis-specific NRP1-deficient or control animals irradiated with UVB light (20 mJ/cm²) in vitro. 24 h after irradiation keratinocytes were harvested and stained with popidium iodide for cell cycle analysis by FACS (A–D). Cells in sub G1 phase were considered to be apoptotic. After UVB treatment 20.7% of NRP1-deficient keratinocytes were apoptotic, whereas only 10.9% of control cells were in subG1 phase. The figure shows one representative example out of three independent experiments.