Fig. 4

Hypoxic rat mesenchymal stem cells (HMSCs) decreased oxidative damage and increased anti-oxidant response in the ischemia-reperfusion (I/R)-injured rat kidneys. a, c Immunofluorescence staining for superoxide by dihydroethidium (DHE) staining and macrophage by anti-CD68 staining in renal tissues of the sham-operated rats (Sham), I/R-injured rats with PBS administration (PBS), I/R-injured rats with intra-renal arterial administration of HMSCs (IA-HMSCs), I/R-injured rats with intraperitoneal administration of HMSCs (IP-HMSCs), and I/R-injured rats with intraperitoneal administration of 100-fold concentrated HMSCs-conditioned medium (HMSC-CM). DHE staining was predominantly at the renal tubular cells and at some macrophages (arrowheads). 4′,6-Diamidino-2-phenylindole (DAPI) represented nuclear staining. Scale bar = 50 μm. **p < 0.01, ***p < 0.001 by one-way ANOVA with Tukey’s post hoc comparison, n = 4 for the sham group; n = 5 for other groups. b, d Immunohistochemical staining for 8-hydroxy-2-deoxyguanosine (8OHdG), 4-hydroxynonenal (4-HNE), and nuclear factor erythroid 2–related factor 2 (Nrf-2) in I/R-injured rat kidneys. Renal I/R injury increased the expression of 8OHdG, 4-HNE, and Nrf-2 in tubular epithelial cells. IA and IP administration of the HMSCs as well as intraperitoneal injection of HMSC-CM decreased the numbers of 8OHdG and 4-HNE-positive tubular cells but further upregulated the number of Nrf-2-positive tubular cells. Scale = 100 μm. *p < 0.05, **p < 0.01, ***p < 0.001 by one-way ANOVA with Tukey’s post hoc comparison. ns, nonsignificant. n = 4 for the sham group; n = 5 for other groups. e–i Western blot analyses of anti-oxidant proteins in I/R-injured rat kidneys. *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