Fig. 5

Mice deficient in NLRP3 display reduced silica-induced lung damage and fibrosis. (A-H) Nlrp3^−/− mice and wildtype (WT) littermates were intranasally administered 2 mg of silica. Control mice received PBS alone. On day 28, lung tissues were formalin-fixed and inflated. Histological analysis of Masson’s trichrome-stained lung tissue sections was performed. (A) Representative images at 10x magnification. Scale bar 100 μm. Lung sections were randomized, blinded, and analyzed or scored for (B) collagen deposition (Masson’s trichrome staining intensity per field of view (FOV)), (C) alveolitis (scale 0–5), and (D) lung damage (scale 0–4). (E) Representative images of H&E-stained lung tissue sections, imaged at 4x magnification. Scale bar 100 μm. The boxes on these images indicate the areas that are magnified to demonstrate silicotic nodules determined with Olympus cellSens Dimension software. Lung sections were randomized and analyzed for nodule (F) total count, average size (µm²), and cellularity (% positive pixel count per FOV). (G) Representative images at 4x magnification of TUNEL assay labeling of cell death in lung tissue sections. Scale bar 100 μm. (H) Quantification of TUNEL staining determined with ImageJ software. Data are presented as the mean percentage positive pixel count per FOV. (A-H) Data are presented as mean ± SEM, with each data point representing an individual animal. n = 5–13 per group. Data are pooled from 3 independent experiments. *P < 0.05, **P < 0.01, ***P < 0.001, ****P < 0.0001, One-way ANOVA