Fig 2: Validation of Hrc-activated fibroblasts and Pdgfra phosphorylation in female C57 mice.(A) p-Pdgfra (green) and Desmin (red) labeled fibroblasts in the mice heart. (B) Hrc (green) and Desmin (red) labeled activated fibroblasts in the mice heart. n = 6 mice per group for A and B; scale bar = 50 µm. (C) Acta2 mRNA expression level in the mice heart (n = 4 mice per group; mean ± standard error of mean [SEM], *p < 0.05; ***p < 0.001). (D) Col3a1 mRNA expression level in mice heart (n = 4 mice per group; mean ± SEM; **p < 0.01; ***p < 0.001).

Fig 3: Analysis of the heterogeneity of the fibroblast subpopulations.(A) t-SNE plot of the 10 cardiac fibroblast subpopulations in the high-fat diet (HFD)/streptozotocin (STZ)-treated and control mice (n = 3428 fibroblasts from healthy control and n = 2988 fibroblasts from 6 diabetic mice). (B) Correlation heatmap of the gene-expression signatures of each fibroblast subpopulation. Color differences indicate subpopulations that were resolved through multiscale bootstrapping. (C) Heatmap showing the top 5 marker genes in each fibroblast subpopulation. The red color indicates high expression, while green color indicates low expression. (D) Heatmap showing the enriched Gene Ontology (GO) terms associated with cardiac fibrosis in each fibroblast population. (E, F) Representative immunofluorescence images of Hrc (E) and Postn (F) in mouse heart (n = 6 mice per group), scale bar = 100 µm. The details of the 10 transcriptionally distinct fibroblast subpopulations are listed in Supplementary file 15. The details of distinct signatures of each fibroblast subpopulation in the heart are listed in Supplementary file 16.