The effect of biomass exposure on lung inflammation, MAPK signaling and protease expression in mice.

<p>(A) Lung bronchoalveolar lavage (BAL) cellularity (left panel) was measured in C57BL/6 mice exposed to room air, biomass smoke or cigarette smoke for one week. (B) Quik-diff analysis of the lung lavage cellular pellet was used to calculate the total number of macrophages (top left panel) or neutrophils (top right panel) in the lung lavage. N = 8 in each group. (C) H&E stained lung tissue sections of control (left panels), biomass-exposed (center panels) or cigarette smoke-exposed mice (right panels). In exposed mice, biomass material (see arrows) can be seen within the airway epithelium (top center panel) and alveolar region (middle center panel). The bottom panels demonstrate that macrophages from biomass-exposed mice (bottom center panel) were larger and were full of vacuoles that were not present in the control macrophages (bottom left panel) (scale bar = 20 µM). (D) Biomass-exposed mice (center left panel) had intense, lymphocytic, perivascular inflammation. These changes were not observed in control mice (top left panel) and were less notable in cigarette smoke-exposed mice (bottom left panel) (scale bar = 20 µM). Perivascular inflammation scores were calculated for control, biomass-exposed and cigarette smoke-exposed mice (right panel). N = 8 in each group. Data is expressed as mean ± standard error of measurement.