FIGURE 7.

Pioglitazone reduces oxidative stress, enhances β cell mass, and suppresses β cell death in pre-diabetic NOD mice. 6-Week-old pre-diabetic NOD mice were placed on either normal chow (Control) or chow containing 0.01 wt% pioglitazone (Pio). After 4 of weeks feeding, pancreas was harvested from animals (n = 5). A, representative islet immunostaining from control and pioglitazone-treated mice for CHOP and insulin and corresponding quantitation of CHOP+insulin+ cells. Arrows indicate cells that costain for insulin and CHOP. B, representative islet immunostaining for CC3 and insulin and corresponding quantitation of CC3+insulin+ cells. The arrow indicates cells that costain for insulin and CC3. C, representative islet immunostaining for 4-HNE and insulin and corresponding 4-HNE pixel intensity. D, β cell area as a percentage of total pancreas area for animals at the start of the study (6 weeks of age) and for control and pioglitazone treated at the indicated ages. E, serum unmethylation index for control- and pioglitazone-treated mice (n = 4–5 per group). F, representative islet immunostaining from control and pioglitazone-treated mice for PCNA and insulin and corresponding quantitation of PCNA+insulin+ cells. Arrows indicate cells that costain for insulin and PCNA. * indicates that the values are significantly different (p < 0.05) by two-tailed t test.