Figure 8

An irradiation-induced early p53-mediated response is associated with the activation of the pro-inflammatory gene Ccl3 . (A, B) Gene Ontology (GO) and transcription factor binding site enrichment among differentially expressed genes in the mouse embryonic brain 2 h after exposure of the E11 pregnant mother to 1.0 Gy of X-rays. (A) Top 10 GO enrichment terms among differentially expressed genes at 2 h after irradiation showed a main involvement of the classical p53-regulated DNA damage response early after irradiation. (B) A chromatin immunoprecipitation (ChIP) enrichment analysis was employed to predict transcriptional regulators of differentially expressed genes 2 h after irradiation. (C-F) Quantitative reverse transcriptase PCR experiments were applied on a set of genes to confirm microarray findings: p53 targets (Cdkn1a (C), Eda2r (D) and Tnfrsf10b (E)) and Ccl3 (F). Data are presented as mean ± SEM. *P < 0.05, **P < 0.01, ***P < 0.001 for comparison with controls. The number of animals used per test is indicated in the graphs (N/N for 2 h/24 h after irradiation).