Differential regulation of Bcl-2 in NRP1-deficient and control keratinocytes following UVB irradiation.

24 h after UVB irradition protein extracts from mouse epidermis and from primary keratinocytes cultured in vitro were prepared and analyzed by Western blotting. Prior to UVB treatment the amounts of Bcl-2 are comparable between control and NRP1-deficient samples (A). After UVB application Bcl-2 levels decrease significantly (p<0.05, indicated by an asterisk) in NRP1-deficient epidermis and cells, whereas control tissue and cell extracts show no significant changes in Bcl-2 amounts. No significant changes were observed in the levels of Mcl-1, phospho-p38 (only the induction 1 hour after UVB was significant, but present in control and NRP1-deficient cells) and phospho-Erk (B, C). All Western blots were repeated independently with extracts from tissue or cells from at least three different animals. The relative expression expresses the fold-change in comparison to the non-irradiated control lane.