Figure 8. Postinjury β₁-deficient AT2s exhibit an AT2-AT1 mixed epithelial transcriptomic phenotype.

(A) Stacked bar graph of epithelial proportions demonstrates an expansion of the AT2 and activated AT2 populations in day 7 (D7) LPS-treated β₁^AT2-KO lungs. (B) Marker gene expression by genotype and treatment group in AT2/activated AT2 cluster, in which higher expression is represented with a darker color and the size of the dot reflects the proportion of cells expressing that marker. (C) Representative low-power images from day 7 LPS-treated lung sections immunostained for the AT1 marker AGER (purple) and AT2 marker pro–SP-C (gold) demonstrate overall decreased AGER in β₁^AT2-KO lungs. Three insets per low-power field show colocalization of AGER with pro–SP-C⁺ AT2 cells in D7 β₁^AT2-KO lungs. Scale bar = 100 μm for low-power image in C, 50 μm for middle inset, and 10 μm for high-power inset.