Fig 2: BM Sca-1+ exosomes improved visual behavior after retinal ischemia–reperfusion (I/R) injuries. A Schematic illustration of the apparatus for the light/dark exploration mouse model. B, C Mice who received Sca-1+ exosomes after I/R (I/R + Sca-1+ exo) were more able to respond to light exposure, compared to those who received Sca-1− exosomes (I/R + Sca-1− exo), or untreated post-I/R. Schematic illustration (D) and photograph (E) depicting the experimental apparatus for optomotor tests. F–H Visual behaviors, in terms of head movements, under 0.1–0.3 cycles per degree (cpd) were better preserved among I/R + Sca-1+ exo mice, compared to I/R and I/R + Sca-1− exo. Data shown as mean ± SEM. n = 3 mice/group for all experiments. **P < 0.01, *P < 0.05

Fig 3: Sca-1+ exosomes protect retinal morphology by reducing I/R-induced retinal ganglion cell apoptosis. A Hematoxylin and eosin (H&E) staining of the retina to evaluate total B, ganglion cell (GCL; C), inner plexiform (IPL; D), inner nuclear (INL; E), outer plexiform (OPL; F), and outer nuclear (ONL; G) layer thicknesses, among control (Normal), I/R, I/R + Sca-1+ exo, and I/R + Sca-1− exo groups. Representative immunofluorescence images (H) and quantification I of apoptotic (TUNEL+) retinal neurons (NeuN+), both at baseline and at 3 days post-I/R. Data shown as mean ± SEM. n = 3 retinas/group for all experiments. **P < 0.01, *P < 0.05

Fig 4: Characterization of bone marrow (BM) cell-derived exosomes. A Transmission electron microscopic (TEM) images of ring-shaped BMC-Sca-1+ and BMC-Sca-1− exosomes. B Nanoparticle Tracking Analysis (NTA) histograms demonstrating the size distribution for BMC-Sca-1+ and BMC-Sca-1− exosomes. C Western blot illustrating the characteristic surface markers CD63, CD9 and CD81 being present on BMC-Sca-1+ and BMC-Sca-1− exosomes, unlike with cells

Fig 5: Increased miR-150-5p levels within Sca-1+ exosomes downregulate MEKK3/JNK signaling within post-I/R retinas in vivo. Relative expression of miR-150-5p (A) and MEKK3 (B) within the retina among the 4 treatment groups: Normal control, I/R, as well as Sca-1+ (I/R + Sca-1+ exo) or Sca-1− (I/R + Sca-1− exo) exosomes administered after I/R injury, as determined by RT-qPCR. Representative Western blot images (C) and quantification of MEKK3 (D), p-JNK/JNK (E), and p–c-Jun/c-Jun (F) protein expression levels among the 4 treatment groups, normalized to GAPDH. Data shown as mean ± SEM. n = 3/group for all experiments. **P < 0.01, *P < 0.05