PPARδ activation prevents radiation-induced AP-1 activation and upstream activation of c-jun, MEK1/2, and ERK1/2. BV-2 cells were pretreated with 5 μM of L-165041 or vehicle control and irradiated with a single dose of 10 Gy. A, Nuclear protein was collected 30 min post-irradiation. Gel-Shift analysis was carried out by incubating 10 μg of nuclear protein with γ-ATP P32 end- labeled AP-1 consensus oligo (see Materials and methods). The samples were run on a 4% non-denaturing acrylamide gel, stained with 7% Acetic acid, and exposed to X-ray film. B, Nuclear protein was collected 30 min post-irradiation; nuclear protein was subjected to western blot analysis for p-c-jun; β-actin was used as a loading control. C & D, Protein was harvested 30 min post-irradiation and subjected to western blot analysis for C, p-MEK1/2 and total-MEK1/2 and D, p-ERK1/2 and total-ERK1/2; β-actin was used as a loading control. A–D, See SFig. 5 for densitometric analysis.