Figure 3.

MSR1-depletion reduced the fraction of M2-like macrophages on day 7 post-surgery in the tibial monocortical defect model. (A) Immunofluorescence (IF) staining of the total macrophage biomarker, F4/80 (green), and M1-like macrophage biomarker, iNOS (purple) and M2-like macrophage biomarker, CD206 (red), in facture tissues on day 3 post-surgery in the tibial monocortical defect model. Nuclei were counterstained with DAPI (blue). Bar = 200 μm. (B and C) The infiltration of F4/80⁺ macrophages (B) and the fraction of iNOS⁺ F4/80⁺ and CD206⁺ F4/80⁺ macrophages (C) were determined on day 3 post-surgery in the tibial monocortical defect model from MSR1 WT and KO mice (Values are expressed as mean ± SD, ns indicates no significance). iNOS group indicates the samples stained with anti-F4/80 and anti-iNOS; the slides stained with anti-F4/80, and anti-CD206 denote the CD206 group. (D) Representative IF images of total macrophages (F4/80⁺), M1-like macrophages (iNOS⁺ F4/80⁺), and M2-like macrophages (CD206⁺ F4/80⁺) in facture tissues on day 7 post-surgery of the tibial monocortical defect model. Nuclei were counterstained with DAPI (blue). Bar = 200 μm. (E) The iNOS⁺ and CD206⁺ macrophage fractions were determined by the percentages of iNOS⁺ and CD206⁺ macrophages within F4/80⁺ macrophage populations in the MSR1 WT or KO fracture tissues on day 7 post-surgery in the tibial monocortical defect model (Values are expressed as mean ± SD, *p < 0.05, **p < 0.01). (F) mRNA expression levels of macrophage marker genes (M1-like: iNOS and IL-1b, M2-like: CD206 and CD163) in the fracture tissues from MSR1 WT or MSR1 KO mice on day 7 in the tibial monocortical defect model (L) (*p < 0.05, **p < 0.01, ***p < 0.001).