Figure 2. Sensitization by LT triggers apoptotic changes. A.

: Uninduced MEFs that were not expressing LT and LT-expressing MEFs were unexposed or exposed to increasing amounts of UV (4, 40 or 400 J/m²). After one hour, cell extracts were harvested, separated by SDS PAGE, and blotted with antibodies against BAD, BclXL, Bim, LT, with p38 as a loading control. B: OBD affects localization of Bim after UV exposure. Uninduced MEFs (UN) not expressing or MEFs expressing OBD were untreated or exposed to 40 J/m² UV light. After one hour, they were stained (TRITC) with antibody to Bim and DAPI. Individual fluorescence images are shown. C: Top Panel: Morphologies of cells in which Bim has been knocked down. Stable MEF cell lines that inducibly express OBD were used to obtain cells in which Bim was stably knocked down using shRNA directed towards Bim. Morphologies of uninduced cells (UN) and cells expressing OBD are shown 16 hours after exposure to 40 J/m² UV light. Scrambled shRNA (shScr) containing uninduced (UN) MEFs and OBD expressing MEFs without shRNA were used as controls. Bottom Panel: Expression in uninduced MEFs (UN) or MEFs expressing OBD with shRNA targeting Bim. Cell extracts harvested 1 h post treatment were resolved by SDS PAGE and tested by western blotting for Bim, OBD with actin as the loading control. Scrambled shRNA (shScr) MEFs and MEFs expressing OBD were used as negative controls.