Fig. 3
Probiotic treatment mitigates the DEP-mediated increase of angiotensin-converting enzyme 2 (ACE2) protein expression in the bronchioles of C57BL/6 mice. Representative images of ACE2 expression in the bronchioles of C57Bl/6 mice on a high-fat (HF) diet exposed to either (A-C) saline (CON), (D-F) DEP – 35 µg PM, (G-I) saline and probiotics (PRO) − 0.3 g/day (~ 7.5 × 107 cfu/day), or (J-L) DEP and probiotics. Red fluorescence indicates ACE2 expression, the 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 ACE2 mean fluorescence (minimum of 4 sections per slide and n = 3 per group) and N mean normalized gene expression of ACE2 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 HF + CON, †p < 0.05 compared to HF + DEP, ‡p < 0.05 compared to HF + CON + PRO by two-way ANOVA. The brightness of the nuclei image panels was increased by 40% and the overlay images were increased by 10%, as shown in this figure