Fig. 6: Human HPS1 fibrotic lung tissue demonstrates loss of AT2 cells and increased prevalence of inflammatory fibroblasts.

a UMAP of all cells, grouped by compartment, from HPS1 patient scRNA-seq dataset merged with publicly available control and ILD patient scRNA-seq datasets^28,33,34. b UMAP of cells recovered and number of cells recovered from three separate HPS1 patient lung tissues (blue) overlaid on control tissues and ILD atlas. c Cell type proportions within the epithelial compartment of human scRNA-seq atlas, separated by disease classification. NSIP = nonspecific interstitial pneumonia, Chronic HP = chronic hypersensitivity pneumonitis. d UMAP of select inflammatory fibroblast marker genes (top panel) and fibrotic fibroblast marker genes (bottom panel) within PDGFRα⁺ fibroblasts used to identify each fibroblast subtype, respectively. e Proportion of PDGFRα⁺ fibroblasts that were classified as either normal, inflammatory, fibrotic, or both inflammatory and fibrotic in human scRNA-seq atlas by disease type. f Split UMAPs of control, HPS1, and IPF PDGFRα⁺ fibroblasts by identified fibroblast subtype. g Hematoxylin & eosin and immunofluorescent staining of tissue from control and HPS1 patient tissue. Sequential sections were used to localize SFRP2⁺ and CTHRC1⁺ fibroblasts in control and HPS1 patient tissue. Imaging experiment was performed on one HPS1 patient tissue and one control patient tissue. Arrows indicate similar regions across sequential tissue sections, which highlight the overlap of SFRP2⁺ cells with CTHRC1⁺ cells in fibrotic regions, as determined by H&E stain. Scale bars = 100 µm. h Dot plot of top 20 DEGs between control tissue and HPS1 patient PDGFRα⁺ fibroblasts. Gene expression of IL1R1 is bolded and highlighted with an arrow.