Fig. 4: Age-dependent enrichment of inflammatory lung fibroblasts in HPS models associated with fibrosis.

a UMAP of mesenchymal compartment following isolation and re-projection in 8- and 60-week-old HPS mice. b UMAPs of select inflammatory fibroblast marker genes within alveolar fibroblasts used to identify inflammatory fibroblasts. c Proportion of alveolar fibroblasts that were identified as inflammatory fibroblasts, separated by age and genotype. d Dot plot of expression of inflammatory fibroblast marker genes in alveolar fibroblasts split by age and genotype. Arrows indicate genotypes with increased expression of inflammatory fibroblast-associated genes. e Split UMAP of inflammatory fibroblast subpopulations in alveolar fibroblasts across age and genotype. f Representative immunofluorescence images from 50 µm thick PCLS showing the enrichment of SAA3⁺ cells in lungs of HPS1, HPS2, and HPS1-2 mice compared to age-matched WT controls, HPS3 mice, and HPS2-TG mice. Imaging experiments were performed on three independent biological replicates per age and genotype. Arrows indicate regions of increased SAA3⁺ expression. Scale bar = 100 µm.