LAUSR

Introduction and Objective: More than 35% of the US population over the age of 18 has pre-diabetes, the precursor to overt type 2 diabetes (T2D). The mechanisms by which individuals progress from pre-diabetes to T2D are not well understood, but poorly controlled metabolic dysfunction during pre-diabetes is proposed to play a role. This metabolic dysfunction gives rise to reactive molecules including methylglyoxal (MG), which forms covalent adducts on DNA, RNA, and protein. Our objective is to determine the impact of MG-adducts on beta cell dysfunction and we hypothesize that MG-adducts accumulate during pre-diabetes and drive the progression to T2D by increasing double strand break formation and impairing beta cell glucose stimulated insulin secretion (GSIS). Methods: Our lab has developed a novel liquid chromatography tandem mass spectrometry method to quantitatively measure MG and MG-adducts from cells, tissue, urine, and blood. We utilize flow cytometry and a comet assay to assess the formation of DNA double strand breaks. Results: Our preliminary data shows that hyperglycemia is associated with increased accumulation of MG-adducts in INS-1 832/13 beta cells and in patients with both prediabetes and T2D compared to nondiabetic individuals. Interestingly, hyperglycemia and MG increased double strand DNA damage in INS-1 832/13 cells. We also discovered that MG-adducts decrease GSIS in INS-1 832/13 cells through activation of the receptor for advanced glycation end products (RAGE). Conclusion: MG and MG-adducts decrease GSIS through activation of RAGE and accumulation of DNA damage. This work represents the first measurement of MG and MG-adducts in prediabetes and our analytical method provides an unprecedented opportunity to determine their association with T2D progression. K. Lopez: None. E.D. Lopez Gonzalez: None. D.C. Thurmond: None. S. Shuck: None. T32 DK131943/CA/NIDDK NIH HHS/United States