Fig. 4

Exposure to DEP in conjunction with consumption of a HF diet results in increased transmembrane serine protease 2 (TMPRSS2) expression in the bronchioles of C57BL/6 mice. Representative images of TMPRSS2 expression in the bronchioles of C57Bl/6 mice on a control (LF; A-C) or high-fat (HF; G-I) diet exposed to saline (CON) or fed a LF (D-F) or HF diet (J-L) and exposed to diesel exhaust particles (DEP – 35 µg PM) twice a week for a total of 30 days. Red fluorescence indicates TMPRSS2 expression, and blue fluorescence indicates nuclear staining (Hoechst). The right panels (C, F, I, L) are overlayed figures of the left (blue; A, D, G, J) and center (red; B, E, H, K) panels. M Graph of histological analysis of lung TMPRSS2 mean fluorescence (minimum of 4 sections per slide and n = 3 per group) and N mean normalized gene expression of TMPRSS2 mRNA transcript expression within the lungs, as determined by RT-qPCR (n = 6–8 per group). 40x magnification; scale bar = 100 μm. The data are presented as mean ± SEM, with *p < 0.05 compared to LF + CON, †p < 0.05 compared to LF + DEP, ‡p < 0.05 compared with HF + CON by two-way ANOVA