Fig. 5

BRD4 expression in the lung of mice is synergistically induced by viral infection and CS exposure. Mice were exposed to room air (RA) or cigarette smoke (CS) for 12 weeks and then infected with influenza virus or vehicle control. They were sacrificed and evaluated on day 7 after infection. The relative mRNA levels (fold change) of BRD4 (A) in the lung are shown (n = 5 mice/group). The representative immunohistofluorescence stained lung sections (B) from mice are shown (BRD4: red, nuclear stain DAPI: blue). Original magnification, × 200. The mean fluorescence intensity values of BRD4 (C) are shown (n = 5 mice/group). RA + Flu: RA-exposed mice with influenza virus infection; CS + Flu: CS-exposed mice with influenza virus infection; *P < 0.05, **P < 0.01