Fig. 4

Speck immunofluorescence of NLRP3 was associated with mucus obstruction in βENaC airways. a-d Representative confocal images of NLRP3 (red). a Wild type control tissue showed mostly homogeneous NLRP3 staining and few sporadic small size specks of NLRP3 (arrowheads, inset is magnification of the boxed area). b βENaC unobstructed bronchiolar epithelium showed no significant increase in specks (arrowheads) compared to wild type control. c βENaC bronchiolar epithelium near a mucus plaque showed increased speck staining near and at the apical surface (arrowheads). d βENaC bronchiole plugged with mucus showed increased speck staining at the epithelial apex (arrowheads), and in the mucus plug which contained leucocytes (short arrow). For confirmation of mucus plaques/plugs in B-D please refer to Supplementary Data Figure S1. Nuclei counterstained with DAPI (blue), scale bars are in micrometers. e Box plot represents mean values of bronchioles’ speck numbers normalized to numbers of nuclei, measured from individual mice; βENaC animals are present with two sets of data corresponding to unobstructed (red) and obstructed (green) areas. Each dot in box plots represent the average of 10 bronchioles. Mann-Whitney, ** p < 0.01