Exosomes derived from inflammatory myoblasts promote M1 polarization and break the balance of myoblast proliferation/differentiation

Figure 5 IF-C2C12-Exos induced inflammatory reactions of macrophages in vitro. A-D: iNOS, CD86, CD206, and Arg1 protein levels in macrophages were determined by western blot after culturing with different concentrations of C2C12-Exos for 24 h (1 × 10¹⁰, 2 × 10¹⁰/medium). (n = 4). Data are expressed as the mean ± SD. ^aP < 0.05, ^bP < 0.01, ^cP < 0.001, ^dP < 0.0001; E: Immunofluorescence localization and relative expression of iNOS, a marker of inflammatory level, in macrophage medium after culture with different concentrations of C2C12-Exos for 24 h. Scale bar = 90 μm; F: The concentration of cytokine interleukin (IL)-6, transforming growth factor-β, tumor necrosis factor-α, and IL-1β in supernatants of macrophage cells after culture with IF-C2C12-Exos or phosphate-buffered saline for 24 h measured by ELISA (n = 3). ^aP < 0.05, ^bP < 0.01, ^cP < 0.001. PBS: Phosphate-buffered saline. IL: Interleukin; TGF-β: Transforming growth factor-β; TNF-α: Tumor necrosis factor-α; NS: Not significant.