Figure 5.

Wnt/β-catenin signaling attenuates the impaired organoid forming capacity of distal lung epithelial progenitors in emphysema. A, Pathway enrichment analysis of genes enriched in the Wnt^low cells but downregulated in COPD. Plotted values are -Log₁₀FDR. Data shown on the right ends of bars are numbers of genes that are enriched in Wnt^low cells but downregulated in COPD/ total number of genes in each pathway. B, H&E staining of lung tissue sections shows enlargement of airspace in the PPE treated lungs compared to those of saline treated mice after 21 days. Scale bar = 100 μm. C, Representative image of organoids at day 14 from PPE and saline treated lungs treated with DMSO and CHIR99021. Yellow arrows show organoids. Scale bar = 400 μm. D, Organoid forming efficiency of whole epithelial population from PPE and saline treated TCF:GFP mice at day 14 and effects of DMSO and CHIR99021 treatments added to the organoid culture at day 0. N = 6 individual animals per treatment. Data presented as mean ± SEM. ***P < .001, *P < .05, one-way ANOVA with Holm-Sidak post-test. E, Representative fluorescence images of small alveolar organoids (SFTPC⁺/ ACT^-, left, arrows) and large bronchiolar organoids (ACT⁺/SFTCP^-, right). Scale bar = 100 μm. Nuclei stained with DAPI (blue). F, Number of alveolar (SFTPC⁺/ACT^-) and bronchiolar (SFTPC^-/ACT⁺) organoids formed from 10 000 cells of each from PPE and saline treated TCF:GFP mice at day 14 and the effects of DMSO and CHIR99021 treatments added to the organoid culture from day 0. N = 4. Data presented as mean ± SEM. **P < .01, *P < .05, one-way ANOVA with Holm-Sidak post-test. ANOVA, analysis of variance; COPD, chronic obstructive pulmonary disease; DAPI, 4′,6-diamidino-2-phenylindole; DMSO, dimethyl sulfoxide; FDR, false discovery rate; PPE, porcine pancreatic elastase