Fig. 2

MSC-EVs ameliorated renal injury and fibrosis and promoted autophagy in STZ-induced DKD mice. (A) Schematic diagram of the animal experimental procedures. The mice were intraperitoneally administered 55 mg/kg STZ to induce a diabetic model. After 8 weeks, EVs derived from hP-MSCs (100 µg/200 µL) were administered via the tail vein for 12 weeks. (B) Relative kidney weights of the mice. n = 4 or 5. (C) Renal function of the mice was evaluated by detecting the urinary albumin-to-creatinine ratio (UACR), serum creatinine (Scr), and blood urea nitrogen (BUN). n = 4 or 5 (D, E) Representative images of periodic acid Schiff (PAS) staining and quantification of the mesangial matrix index in mouse kidneys. n = 4. Scale bar, 100 μm. (F, G) Immunohistochemical staining of PCNA in renal sections. The number of PCNA-positive cells in each glomerulus was measured. n = 4. Scale bar, 100 μm. (H, I) Representative images of Masson’s trichrome-stained mouse renal sections. The percentage of collagen area in each glomerulus was quantified. n = 3. Scale bar, 100 μm. (J, K) Immunofluorescence staining of α-SMA, fibronectin and Col IV (green) in mouse renal sections. The percentages of α-SMA-, fibronectin- and Col IV-positive areas in each glomerulus were quantified. n = 3. Scale bar, 100 μm. (L, M) Representative western blot images and quantification of the expression of LC3II/LC3I and p62 in the renal cortex of a mouse. β-actin was used as a loading control. The full-length blots are presented in Supplementary Fig. 6; n = 3. The data are expressed as the means ± SEMs. Statistical analysis was performed via one-way ANOVA with Tukey’s multiple comparison tests. ^*P < 0.05 versus NC; ^#p < 0.05 versus DKD. Abbreviations: STZ, streptavidin. Fn, fibronectin. Col IV, Collagen IV. PCNA, Proliferating Cell Nuclear Antigen