Renal structure.

Top, representative images of renal sections stained with Periodic acid Schiff (PAS). Left to right, sham rats (SHAM), ischemic untreated rats (ISCH/SALINE), ischemic rats injected with kidney cells (ISCH/CELLS), and ischemic rats injected with their exosomes (ISCH/EXO). Tubular damage was widespread in untreated ischemia, including cellular attenuation and tubular dilation. These changes were improved in ISCH/CELLS, and largely prevented in ISCH/EXO. The data are summarized in the graph (right panel): (*), significantly different than sham group (SHAM; p < 0.05). (§), significantly lower than untreated ischemia rat group (ISCH/SALINE; p < 0.05. (¶), significantly lower than cell injected ischemia rat group (ISCH/CELLS, p < 0.05) (n = 27 measurements in each group). Bottom, representative images of renal sections stained with Masson’s trichrome. Interstitial renal fibrosis (blue) was extensive and replaced normal epithelia (red) in untreated ischemia (ISCH/SALINE), when compared to controls (SHAM). Treatment of renal ischemia with kidney cell injections (ISCH/CELLS) partly preserved the tubular epithelia, while injections with exosomes (ISCH/EXO) appeared to be more protective. The data are summarized in the graph (right panel): (*), significantly higher than sham controls (SHAM). (§), significantly lower than untreated ischemia rat group (ISCH/SALINE; p < 0.05). (¶), significantly lower than ischemia rat group injected with cells (ISCH/CELLS), p < 0.05. (n = 15 measurements in each group).