Fig. 5: MerTK⁺ macrophage transfer restores cardiac repair in ATF3-CKO mice.

a, Scheme showing sorted MerTK⁻and MerTK⁺ macrophages transferred into ATF3-CKO mice via intramyocardial injection. b,c, Flow cytometry analysis (b) and immunostaining (c) of Calcein AM⁺MerTK⁻ and Calcein AM⁺MerTK⁺ macrophages in hearts of ATF3-CKO mice transferred with MerTK⁻ or MerTK⁺ macrophages (n = 6 mice per group). Scale bars, 20 μm. d–g, Immunostaining (d) and flow cytometry analysis (e) of CD31⁺ ECs, EF (f) and fibrosis (g) in the hearts of the two groups (n = 6 mice per group). h, GO enrichment analysis based on upregulated DEGs in sorted Trem2⁺, MHCII⁺ and Lyve1⁺ macrophages compared with MerTK⁻ macrophages. i, Tube formation assay in ECs cocultured with sorted MerTK⁺ and MerTK⁻ macrophages (n = 10 biologically independent samples per group). Scale bar, 100 μm. j, Predicted interactions between MerTK⁺ cardiac macrophage-derived ligands and receptors expressed on ECs using CellChat receptor–ligand interaction analysis. k, Relative mRNA expression of Igf1 in sorted MerTK⁺ and MerTK⁻ macrophages from hearts after IR (n = 6 mice per group). l, IGF1 levels in the culture supernatants of sorted MerTK⁺ and MerTK⁻ macrophages from the hearts via ELISA (n = 8 biologically independent samples per group). m, Tube formation assay in ECs transfected with siRNA-NC or siRNA-IGF1R and then cocultured with sorted MerTK⁺ macrophages (n = 10 biologically independent samples per group). Scale bars, 100 μm. n, Relative mRNA levels of Igf1 in hearts from WT mice, ATF3-CKO mice and ATF3-CKO mice injected with MerTK⁺ macrophages (n = 6 mice per group). Statistical significance was evaluated using two-tailed, unpaired Student’s t-tests (d–g,i,m), unpaired Mann–Whitney U-tests (k,l), one-way ANOVA followed by Tukey’s multiple-comparison test (n), two-way ANOVA followed by Tukey’s multiple-comparison test (b) and Fisher’s exact test (h,j). All data are presented as mean ± s.e.m.

Source data