Fig. 6

miR-99b-5p delivered by MSC-EVs ameliorated renal injury in STZ-induced DKD mice by promoting mTOR-mediated autophagy. (A) 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 = 6. (B, C) Representative images of periodic acid–Schiff (PAS) staining and quantification of the mesangial matrix index in mouse kidneys. n = 4. Scale bar, 100 μm. (D, E) The percentage of PCNA-positive cells in the kidney glomeruli of the mice was quantified via immunohistochemical staining. n = 4. (F, G) Representative images of Masson staining of mouse kidney sections and quantification of the collagen deposition area in the glomerulus. Scale bar, 100 μm. (H, I) Immunofluorescence staining and quantification of α-SMA, fibronectin and Col IV (green) expression in kidney sections. n = 4. Scale bar, 100 μm. (J, K) Representative western blot images and quantification showing the expression of mTOR, p-mTOR, LC3II/LC3I and p62 in the renal cortex of mice. β-actin was used as a loading control. The full-length blots are presented in Supplementary Fig. 10; n = 4. 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. ^&p < 0.05 versus DKD + EVs-NC. Abbreviations: STZ, streptavidin. Fn, fibronectin. Col IV, Collagen IV. PCNA, Proliferating Cell Nuclear Antigen