Fig. 3. Altered phenotypic transition of infiltrating myeloid cells in Bach1-deficient models following CTX injury.

A. Representative images of H&E stained TA skeletal muscle 8 days after CTX injury from chimeric WT BoyJ bone marrow-transplanted (BMT) animals (CD45.1 recipients) that received either WT (CD45.2) or Bach1-KO bone marrow. Scale bars in the upper left corner represent 100 μm.

B. Cumulated myofiber cross sectional area repartition and mean CSA (inset panel) at day 8 post CTX injury from WT chimeric animals transplanted with either WT (CD45.2) or Bach1-KO bone marrow (n=5 mice per group).

C. Representative images of H&E stained TA skeletal muscle 8 days after CTX injury from chimeric Bach1-KO BMT animals that received either WT (CD45.1) or Bach1-KO bone marrow. Scale bars in the upper left corner represent 100 μm.

D. Cumulated myofiber cross sectional area repartition and mean CSA (inset panel) at day 8 post CTX injury from Bach1-KO BMT animals transplanted with either WT (CD45.1) or Bach1-KO bone marrow (n=6 mice per group).

E. Number of infiltrating myeloid (CD45⁺) cells in regenerating muscle from WT-control, and Bach1-KO muscles at indicated timepoints post CTX injury (n=8 muscles per group).

F. Representative flow cytometry images of inflammatory and repair MFs from WT-control and Bach1-KO at indicated timepoints post CTX injury. Squares indicate the gating used for cell frequency quantification (black=PMNs, red=Ly6C^high inflammatory MFs, purple=Ly6C^low repair MFs). Representative frequencies for each cell population are shown adjacent to each gate.

G. H., and I. Frequency (in %) of CD45⁺ inflammatory (Ly6C^high F4/80^low) and repair (Ly6C^low F4/80^high) MFs from WT-control and Bach1-KO mice at indicated timepoints following CTX injury (n = 4 mice per group).

In all bar graphs, bars represent mean ± SEM.