Influence of heme oxygenase-1 gene transfer on the viability and function of rat islets in in vitro culture

Figure 1 Purity and viability of freshly isolated rat islets. A: Islets stained with DTZ (red staining indicates islets; islet purity was above 90%); B: Islets stained with AO/PI (green staining indicated live cells, red staining indicated dead cells; islet via bility was above 90%). Bar = 150 μm, × 200 magnification.

Figure 2 Effect of culture on glucose-stimulated insulin release. The insulin release upon either high or low glucose stimulation decreased conspicuously after seven days culture, P < 0.05

Figure 3 Ad-EGFP transduced islets. Microphotographs were taken at 48 h post-transfection (A, B). Fluorescence was intense at an MOI of 20 (B). Bar = 200 μm, × 100 magnification.

Figure 4 Western blot for hHO-1. Islets infected with Ad-HO-1, Ad-EGFP, or mock infected for 48 h were examined by Western blot. HO-1 expression was only detected in Ad-HO-1 group. A: control group; B: Ad-HO-1 group; C: Ad-EGFP group.

Figure 5 Effect of HO-1 gene transfer on the viability of cultured rat islets. At 7 d post-transfection, the control group showed the presence of numerous dead cells (red) at the center of the islets (A), while the Ad-HO-1 group showed more living cells (B). Bar = 200 Um, × 100 magnification. The islet viability was decreased greatly after 7 d culture (P < 0.05), whereas HO-1 gene transfer could reduce the loss of islet viability (P < 0.05).

Figure 6 Effect of HO-1 gene transfer on insulin release of cultured rat islets. At 7 d post-transfection, no significant difference in glucose-stimulated insulin release was detected between Ad-EGFP transfected islets and control islets, however, the insulin release upon high glucose stimulation of Ad-HO-1 transfected islets was significantly higher than that of Ad-EGFP transfected islets and control islets, P < 0.05.

Figure 7 Effect of HO-1 gene transfer on stimulation index of cultured rat islets. The SI of Ad-HO-1 transfected islets was significantly higher than that of Ad-EGFP transfected islets and control islets, P < 0.05.