Fig 2: Evaluation of the Nrf‐2/HO‐1 pathway after hepatic I/R with/without SIN pretreatment in DM rats. The protein levels of total Nrf‐2, HO‐1, nuclear Nrf‐2 (Nu‐Nrf‐2), and cytoplasmic Nrf‐2 (Cyto‐Nrf‐2) in liver tissues were assessed by Western blot analysis. (A) Representative blots of Nrf‐2 and HO‐1 protein expression in liver tissues. Histograms showed the statistical results of Nrf‐2 (B) and HO‐1 (C). (D) Representative blots of Nu‐Nrf‐2 and Cyto‐Nrf‐2 protein expression. Histograms showed the statistical results of Nu‐Nrf‐2 (E) and Cyto‐Nrf‐2 (F). The ratio of Nu‐Nrf‐2 to Cyto‐Nrf‐2 was also calculated in (G). ANOVA was employed for multiple comparisons, followed by SNK‐q for pairwise comparisons. Bars represent means ± SD, n = 5 independent rats. *p < .05 versus DM + I/R group; # p < .05 versus DM + I/R + SIN/100 group; ns, not significant.

Fig 3: Schematic diagram showing that hUC-MSCs protect pancreatic β-cells against high glucose-induced oxidative stress via the Nrf2/HO-1 signalling pathway.

Fig 4: Nrf2 knockdown blocks the anti-oxidative effects and β-cell function restoration by hUC-MSCs under high-glucose conditions. (A) INS-1E cells were seeded into Transwell 6-well plates and treated with scrambled or Nrf2 siRNA. Then, INS-1E cells cultured with or without hUC-MSCs were exposed to high-glucose (30 mM) medium or normal medium for 24 h. (B) Nrf2 siRNA knockdown was confirmed by western blotting and quantitative real-time PCR. (C) Apoptosis of INS-1E cells was analysed by flow cytometry. (D) Intracellular ROS were assessed by flow cytometry. (E) GSIS in INS-1E cells was measured at 1 h after glucose stimulation (16.7 mM) by ELISA. (F and G) Protein levels of Nrf2, HO-1 (F), PDX-1, GLUT2, MafA, BCL-2, and cleaved Caspase-3 (G) in INS-1E cells were measured by western blotting. Protein expression levels were normalized to GAPDH. Data are presented as mean ± SEM. *P < 0.05, **P < 0.01.

Fig 5: The expression levels of Nrf2 and Nrf2-regulated genes after treatment with Nrf2 siRNA and K22. H9c2 cells were incubated with Nrf2 siRNA (50 nM), K22 (10 μM), or Nrf2 siRNA (50 nM) plus K22 (10 μM). qRT-PCR was then used to quantify the expression levels of Nrf2, HO-1 and NQO1 genes. ***p < 0.001.