The Influence of Developmental Exposure to Maternal Overnutrition and Metformin on Offspring Mitochondrial Health and Beta Cell Function

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Project Summary/Abstract In collaboration with a non-human primate (NHP) consortium with over a decade of experience studying the developmental origins of health and disease in response to maternal overnutrition, this proposal will evaluate the effect that intrauterine exposure to metformin and overnutrition has on the development of pancreatic beta cells and islet mitochondrial health in fetal Rhesus macaques. In the United States, 31% of women of childbearing age are classified as overweight or obese. As global rates of obesity rise, the influence of developmental exposure to maternal overnutrition and the drugs prescribed to treat maternal metabolic disease on offspring metabolic outcomes is of critical interest. Metformin is typically prescribed for the treatment of Type 2 Diabetes; however, use of metformin has been expanded over the past decade to treatment for gestational diabetes, polycystic ovarian syndrome, and preeclampsia. Data suggests that metformin crosses the placental barrier and equilibrates in fetal circulation, raising concerns for unintended fetal harm. While the target of metformin is unknown, a proposed mechanism of metformin is activation of 5’ adenosine monophosphate kinase (AMPK), a nutrient sensing kinase that is central to regulation of pathways associated with cellular growth, proliferation, metabolism, and epigenetic regulation. Metformin has also been shown to inhibit complex I of the mitochondrial electron transport chain, reducing the production of ATP, which is important for glucose-stimulated insulin secretion from beta cells. The goal of the studies outlined in this proposal is to elucidate the influence that maternal consumption of a western style diet and metformin has on beta-cell mass, identity, and function at the fetal stage of development in a highly relevant NHP model. Additionally, this proposal includes studies investigating the individual and combined effects of maternal overnutrition and metformin on islet mitochondrial morphology and function in offspring. To accomplish these goals, I will use high resolution microscopy, real time metabolic analyses, and single nucleus RNA sequencing to identify programmed mechanisms that may correlate to increased propensity for beta cell failure later in the offspring’s life.