Dermal αSMA+ myofibroblasts orchestrate skin wound repair 
via β1 integrin and independent of type I collagen production (2022)
Figure 4

Figure 4. Collagen I produced by αSMA+ myofibroblasts is dispensable for wound closure.

(A) IHC for collagen I on wound tissue sections at day 17 post-wounding (brown stain). Black boxes denote zoomed regions depicted in bottom panels. Scale bar: 50 μm.

(B) Quantification of collagen I positive area normalized to the average area in WT controls. WT, N=5; TK, N=5 biological replicates.

(C) Polarized light images of picrosirius red stained wound tissues at day 17 post-wounding. Red: collagen fibers. White boxes denote zoomed regions depicted in bottom panels. Scale bar, 50 µm.

(D) Quantification of collagen fiber (picrosirius red) percent area normalized to the average area in WT controls. WT, N=3; TK, N=3 biological replicates.

(E-H) Reduced collagen deposition in Col1α1cKO wounds. (E) IHC for collagen I on wound tissue sections at day 14 post-wounding (brown stain). Black boxes denote zoomed regions depicted in bottom panels. Scale bar: 25 μm. (F) Quantification of collagen I positive area normalized to the average area in WT controls. WT, N=7; Col1α1cKO, N=4 biological replicates. (G) Polarized light images of picrosirius red stained wound tissues at day 14 post-wounding. Red: collagen fibers. White boxes denote zoomed regions depicted in bottom panels. Scale bar, 50 µm. (H) Quantification of collagen fiber percent area and fiber width normalized to the average area and width, respectively, in WT controls. WT, N=4; Col1α1cKO, N=5 biological replicates.

(I) Wound area measurements in WT and Col1α1cKO mice. WT, N=7; Col1α1cKO, N=5 biological replicates. Data are from two independent experiments. Two-way ANOVA performed comparing WT and Col1α1cKO mice.

(J-M) Reepithelization and vascularization in WT and Col1α1cKO mice. (J) Representative images of keratin 5 (Krt5, red) stained wounds at day 14 post-wounding. White boxes denote zoomed regions depicted in right panels. Scale bar, 500 µm. (K) Quantification of epidermal thickness. WT, N=6; Col1α1cKO, N=5 biological replicates. (L) Immunofluorescent staining for CD31 (red) and nuclei (blue) on wound tissue sections at day 14 post-wounding. White boxes denote zoomed regions depicted in right panels. Scale bar, 20 μm. (M) Quantification of CD31+ area per visual field normalized to WT mice. WT, N=6; Col1α1cKO, N=5 biological replicates.

(N) UMAP (left panel) and violin plots (right panel) of Col1a1 expression in murine wound fibroblasts. Raw scRNA-seq data are derived from (Haensel et al., 2020, Data ref: Haensel et al 2020).

(O) Wound area measurements in Col1α1-TK and WT littermate mice. WT, N=13; Col1α1-TK, N=12 biological replicates, data are from two independent experiments. Two-way ANOVA performed comparing WT to TK mice.

(P) Granulation tissue thickness measured on digital images and normalized to the average values in the WT control. WT, N=4; TK, N=7 biological replicates.

Data information: Data are reported as mean ± s.e.m. for (B, D, F, H, I, K, M, O, and P). Data are reported as median (open circle) with interquartile range indicated with bar for violin plots (N, right panel). One sample t-test performed comparing values to WT average for (B, D, F, H, K, M, and P). Exact p-values are reported.