Activation of Nrf2 Is Required for Normal and ChREBP-Augmented Glucose-Stimulated p-Cell Proliferation

摘要

Patients with both major forms of diabetes would benefit from therapies that increase p-cell mass. Glucose, a natural mitogen, drives adaptive expansion of p-cell mass by promoting p-cell proliferation. We previously demonstrated that a carbohydrate response element-binding protein (ChREBP) is required for glucose-stimulated p-cell proliferation and that overexpression of ChREBPa amplifies the proliferative effect of glucose. Here we found that ChREBPa reprogrammed anabolic metabolism to promote proliferation. ChREBPa increased mitochondrial biogenesis, oxygen consumption rates, and ATP production. Proliferation augmentation by ChREBPa required the presence of ChREBPp. ChREBPa increased the expression and activity of Nrf2, initiating antioxidant and mitochondrial biogenic programs. The induction of Nrf2 was required for ChREBPa-mediated mitochondrial biogenesis and for glucose-stimulated and ChREBPa-augmented p-cell proliferation. Overexpression of Nrf2 was sufficient to drive human p-cell proliferation in vitro; this confirms the importance of this pathway. Our results reveal a novel pathway necessary for p-cell proliferation that may be exploited for therapeutic p-cell regeneration.