Fig. 3

EPC-EXOs are taken up by macrophages in the injured spinal cord region and promote macrophages’ anti-inflammatory polarization. A Diagrammatic representation of the tail vein injection of EPC-EXOs (200 μg). B Representative images of EPC-EXOs internalized by BMMs. Scale bar: 20 μm. C Western Blotting detected changes in the expression levels of iNOS and Arg-1 in macrophages in the region of injury at 7 and 14 days of spinal cord injury in Vehicle and EPC-EXOs-treated wild-type mice. D Statistical analysis of the expression levels of iNOS and Arg-1, n = 3, *P < 0.05, **P < 0.01. E Immunofluorescence images of CD11b⁺ macrophages (green), CD86⁺ (M1) /CD206⁺ (M2) (red) and DAPI (blue) staining of spinal cord injury sections of mice representative of the Vehicle group and EPC-EXOs group at 7 days post-injury (dpi) in wild-type mice. F, G Immunofluorescence results were analyzed by ImageJ, GraphPad, and SPSS, n = 3, **P < 0.01. H Immunofluorescence images of CD11b⁺ macrophages (green), CD86⁺ (M1) /CD206⁺ (M2) (red) and DAPI (blue) staining of spinal cord injury sections of mice representative of the Vehicle group and EPC-EXOs group at 14 days post-injury (dpi) in wild-type mice. I, J Immunofluorescence results were analyzed by ImageJ, GraphPad, and SPSS. n = 3, **P < 0.01. K qRT-PCR analysis of mRNA expression of pro-inflammatory markers (iNOS, CD86 and TNF-α) and anti-inflammatory markers (CD206, Arginase-1 and IL-10) in macrophages in the region of injury at 7 and 14 dpi in Vehicle and EPC-EXOs-treated wild-type mice, n = 6, *P < 0.05, **P < 0.01, ***P < 0.001