Fig. 3
Hypoxic rat mesenchymal stem cells (HMSCs) and HMSC-conditioned medium (CM) suppressed oxidative stress, tubular injury, and renal dysfunction in ischemia-reperfusion (I/R)-injured rat kidneys. a Representative periodic acid-Schiff stained photomicrographs showed that I/R injury resulted in severe renal tubular injury such as tubular cell sloughing and flattening (arrows) as well as casts formation (yellow arrowheads) in phosphate-buffered saline (PBS)-treated groups as compared to the sham-operated (Sham) group. Scale = 100 μm. b Quantification of the tubular injury. Intra-renal arterial (IA-HMSC) or intraperitoneal (IP-HMSC) administration of HMSCs significantly reduced tubular injury. n = 6 per group. c Quantification of in vivo detection of the reactive oxygen species in the rat kidneys. I/R injury induced an increase of reactive oxygen species in the rat kidneys as compared to the Sham group. The I/R injury-induced oxidative stress was attenuated in the IA-HMSC group. n = 3–4 per group. d, e I/R injury caused a renal function decline with elevated serum blood urea nitrogen (BUN) and creatinine levels. Both intra-arterial and intraperitoneal administration of HMSCs improved the renal function decline significantly. *p < 0.05, **p < 0.01, ***p < 0.001 by one-way ANOVA with Tukey’s post hoc comparison. ns, nonsignificant; n = 6 per group. f Representative periodic acid-Schiff stained photomicrographs showed that the extent of sloughing and necrosis of the renal tubular cells due to I/R injury was gradually reduced by the HMSC-CM. CM25, CM50, and CM100 denote 25-fold, 50-fold, and 100-fold concentrated HMSC-CM, respectively. g Quantification of the tubular injury. n = 6 per group. h Quantification of in vivo detection of the reactive oxygen species in the rat kidneys. n = 3–5 per group. i, j Serum BUN and creatinine levels in the rats of renal I/R injury with treatment of PBS or HMSC-CM. Only 100-fold concentrated HMSC-CM (CM100) ameliorated oxidative stress, tubular injury and renal dysfunction. *p < 0.05 by one-way ANOVA with Tukey’s post hoc comparison, n = 6 per group