Fig. 5

Urinary small EVs derived CCL21 mRNA increased in STZ-induced DN rats and correlated with the alteration in kidney. A, B Blood glucose and body weight of rats with or without STZ treatment at week 20 after injection. Significant increase of blood glucose (A) and body weight (B) were found in STZ-injected rats, compared with control rats. C–E Levels of albumin-to-creatinine ratio (ACR), serum creatinine (SCr) and blood urea nitrogen (BUN) in STZ-injected and control rats (n  =  8 for each group). F Representative micrographs of histological analysis (PAS staining) of renal tissue from rats with or without STZ treatment. Scale bar: 50 μm. G Western blotting analysis of protein (Alix, CD81 and CD63) in urinary small EVs fraction from Ctrl and DN rats. H Representative size distribution and particle number of urinary small EVs analyzed by nanoparticle tracking analysis (NTA). The NTA experiment has been performed for three samples in each group. Relative CCL21 mRNA expression in renal cortex (I) and urinary small EVs (J) from rats with or without STZ injection. K The correlation between renal CCL21 mRNA expression and urinary small EVs derived CCL21 mRNA expression in STZ-injected DN rats (r  =  0.6935, p  =  0.0103). *p  <  0.05, **p  <  0.01, ***p  <  0.001, ****p  <  0.0001, compared with Ctrl-rats. Ctrl control; DN diabetic nephropathy