Fig 2: The therapeutic efficacy of 2D-exos and 3D-exos in cisplatin-induced AKI mice model. a Schematic diagram of the experimental design. In brief, mice were concurrently treated with PBS, 2D-exos (100 µg) or 3D-exos (100 µg) at 24 h and 48 h after cisplatin injection, and were sacrificed at 96 h after disease induction. b Effects of 2D-exos and 3D-exos on serum creatinine (n = 6–7). c Representative images of PAS staining of renal cortex. Scale bar, 50 µm. d The quantification of tubular injury based on PAS staining (n = 6–7). e Effects of 2D-exos and 3D-exos on the body weight (n = 6–7). f Representative confocal images of kidney injury molecular-1(Kim-1) in tubules. Scale bar, 25 µm. g The quantification of Kim-1+ tubules per HPF (n = 6). Data are presented as mean ± SD, *p < 0.05, **p < 0.01, ***p < 0.001 vs. Cis group, #p < 0.05, ###p < 0.001

Fig 3: IL-10+ EVs protect against renal I/R injury in mice.(A) Schematic diagram of the experimental design. Briefly, mice were concurrently treated with IL-10+ EVs (100 and 200 µg) or vehicle every 24 hours after renal I/R injury and were euthanized at 3 days after disease induction. (B) Effects of IL-10+ EVs on serum creatinine (n = 10). (C) The quantification of tubular injury based on H&E staining (n = 10). (D) Representative images of H&E staining of renal cortex and medulla. Scale bars, 100 µm. (E and G) Representative images of TUNEL staining and quantification of the apoptotic cells (n = 6). Scale bars, 50 µm. HFP, High power field; (F and H) Representative confocal images and quantification of KIM-1+ tubules (n = 6). Scale bars, 20 µm. (I) Western blotting analysis of caspase-3 in kidney tissues (n = 3). HPF, high power field. (J) real-time quantitative PCR analysis of inflammatory cytokine mRNA levels in kidney tissues (n = 6). Data are presented as means ± SD. *P < 0.05, **P < 0.01, and ***P < 0.001 versus IRI group, #P < 0.05, ##P < 0.01, and ###P < 0.001, one-way ANOVA.

Fig 4: Blocking exosome production using GW-4869 suppresses tubule injury in I/R-induced kidney injury. (A) The SCr and BUN levels in I/R-treated mice with GW-4869 administration. (B) Histological changes (PAS staining; scale bar 100 µm). (C and D) RT-qPCR and western blot analysis of KIM-1 expression in I/R-induced kidney injury with GW-4869 administration. (E) RT-qPCR analysis of inflammatory cytokine mRNA levels in kidney tissues (n=6). Data are presented as the means ± SEM. *P<0.05 and **P<0.01 vs. the vehicle group. I/R, ischemia/reperfusion; SCr, serum creatinine; BUN, blood urea nitrogen; PAS, periodic acid-Schiff; RT-qPCR, reverse transcription quantitative-PCR; KIM-1, kidney injury molecule-1; MCP-1, monocyte chemoattractant protein-1; TNF-a, tumor necrosis factor-a; IL-1ß, interleukin-1ß; I/RI, ischemia/reperfusion injury.

Fig 5: MSC-exos attenuate renal I/R injury in mice. (A) Schematic illustration of the experimental design. Briefly, mice were administered with MSC-exos (50 µg or 100 µg) or PBS at 0 h and 24 h after induction of renal I/R injury and euthanized at 48 h. (B) Dose-dependent effects of MSC-exos on serum creatinine (n = 10). (C) Representative images of renal I/R injuries by PAS staining. Scale bars, 50 µm. (D) The semi-quantification of tubular injury (n = 10). (E) Representative confocal images of KIM-1+ positive tubules. Scale bars, 25 µm. (F) Representative images of CD68+ macrophages in the tubulointerstitium. Scale bars, 50 µm. (G) Representative images of CD3+ T cells in the tubulointerstitium. Scale bars, 50 µm. (H) Quantification of KIM-1+ tubules per HPF (magnified 400×) (n = 7). HPF indicates high power field. (I) Quantification of CD68+ macrophages per HPF (magnified 400×) (n = 7). (J) Quantification of CD3+ T cells per HPF (magnified 400×) (n = 7). Data are presented as mean ± SD, *p < 0.05, **p < 0.01, ***p < 0.001 vs. I/R group, #p < 0.05, ###p < 0.001, one-way ANOVA.