fig3

Figure 3. Grafted small extracellular vesicles are internalized by retinal microglia, affecting microglial morphology. (A) The staining of IBA1 (green) in the retinal section of 7 days after injection with PKH26 (red)-labeled sEVs. The rightmost orthogonal diagram of partial enlargement shows sEVs (red) located inside microglia (green). Scale bar 20 μm; (B) Representative immunofluorescence images of IBA1 (green) and DAPI (blue) showing the microglia in the retina across three retinal groups. Scale bar, 20 μm; (C and D) Statistical analysis of the number of IBA1 positive microglia in GCL (C) and IPL (D) counted in confocal images of three groups (n = 5 eyes per group); (E) Grid-crossing analysis of representative microglial images; (F-I) Statistical analysis of the average grid-crossing points of microglial cells in IPL (F) or GCL (H), respectively. Statistical analysis of the average processes of microglial cells in IPL (G) and GCL (I), respectively (n = 5 eyes per group). Using one-way ANOVA (C, D, F, G, H, and I). Data are shown as mean ± SD. Scale bar: 20 μm. ONC: Optic nerve crush; ONL: outer nuclear layer; IPL: inner plexiform layer; GCL: ganglion cell layer; sEVs: small extracellular vesicles; NS: no significant difference. ^*P < 0.05; ^**P < 0.01; ^***P < 0.001; ^****P < 0.0001.