Fig. 1: Identification of five distinct macrophage subsets during skeletal muscle regeneration via scRNA-seq.

a A schematic showing the experimental timeline for CTX-induced skeletal muscle injury in mice, delineating the key analyses performed at various days after injury. b Immunohistochemical detection of Cd68⁺ macrophages within injured muscle at specified time intervals after injury. Scale bar, 100 µm. c Flow cytometric analysis showed a surge in CD11b⁺ cells immediately after injury, which diminishes starting from day 3. d A graphical representation of CD11b⁺ cell percentages, corresponding to flow cytometry results depicted in c. e The transition of macrophage phenotypes from proinflammatory Ly6c^hi early post-injury to anti-inflammatory Ly6c^lo by day 4, as assessed by flow cytometry. f A UMAP plot illustrating the distribution of five identified monocyte/macrophage subsets across the time series. g A bar graph showing the relative frequencies of each monocyte–macrophage subset at the designated time points after injury. h A pseudotime analysis for five monocyte–macrophage subsets, depicting the evolution of cellular states. The arrows indicate the proposed progression order through pseudotime, an analytical construct that aligns cells to represent their developmental continuum during muscle regeneration.