Combination therapy with epidermal growth factor and gastrin increases β-cell mass and reverses hyperglycemia in diabetic NOD mice

Abstract

Combination therapy with epidermal growth factor (EGF) and gastrin induces β-cell regeneration in rodents with chemically induced diabetes. We investigated whether EGF plus gastrin could correct hyperglycemia in NOD mice with autoimmune diabetes. Combined treatment with EGF (1 μg/kg) and gastrin (3 μg/kg) for 2 weeks restored normoglycemia after diabetes onset in NOD mice, whereas EGF or gastrin alone did not. Fasting blood glucose remained normal (3.5-6.5 mmol/l) or mildly elevated (<11 mmol/l) in five of six mice (83%) for 10 weeks after EGF plus gastrin treatment was stopped, whereas all mice treated with vehicle or EGF or gastrin alone became severely hyperglycemic (12-35 mmol/l). Pancreatic β-cell mass was increased threefold and insulin content was increased eightfold in mice treated with EGF plus gastrin compared with pretreatment values. The correction of hyperglycemia correlated significantly with increases in pancreatic β-cell mass and insulin content. In addition, splenic cells from mice treated with EGF plus gastrin delayed diabetes induction by adoptive transfer of diabetogenic cells into immunodeficient NOD-scid mice, suggesting the induction of immunoregulatory cells in NOD mice treated with EGF plus gastrin. We conclude that a short course of combined EGF and gastrin therapy increases pancreatic β-cell mass and reverses hyperglycemia in acutely diabetic NOD mice; the impact of this combined therapy may result from the effects of EGF and gastrin on β-cells, immune cells, or both. © 2005 by the American Diabetes Association.