Blood glucose homeostasis is maintained by a balance between insulin secretion from pancreatic islet beta cells in response to elevated glucose and insulin-stimulated glucose uptake in peripheral tissues. Defects in both of these processes cause type 2 diabetes, a disease of elevated blood glucose that eventually leads to comorbidities like blindness and increased risk for cardiovascular disease. Recent genome-wide association studies have indicated that many genes linked to type 2 diabetes have roles in the pancreatic islet beta cell. In late-stage type 2 diabetes, both beta cell function and beta cell mass are reduced. Thus, the long-term goal of this research is to understand the molecular mechanisms that regulate beta cell identity and function to advance therapeutic strategies for diabetes. Our findings show that 3, 5- substituted isoxazole compounds (ISX) exert a pro-differentiation effect in beta cells, leading to increased expression of transcription factors required for beta cell function.
Three specific aims are proposed to test the hypothesis that ISX enhances beta cell differentiation and function: 1) Determine how ISX regulates histone acetyltransferases in the beta cell, 2) Identify direct targets of ISX, and 3) Determine therapeuti effectiveness of ISX in models of diabetes. The proposed research will involve cell-based and in vitro biochemical assays to determine the direct effects of ISX on candidate target proteins. An unbiased protease resistance assay will be used to validate previously identified ISX targets and discover new targets. Studies will be carried out in mice and the clonal mouse beta cell line MIN6 and validated in human islets whenever possible. It is anticipated that the target(s) of ISX in beta cells will be identified, a mechanism of action will be found, and efficacy of ISX in diabetic mice will be determined. This research will pave the way for future studies on ISX compounds for the treatment of diabetes in humans. Given that more than 8% of the United States population has diabetes, this research is particularly relevant and timely. The proposed studies on ISX hold a wealth of potential for enhancing human islet function ex vivo for transplantation and in vivo for diabetes therapy.
Because of the prevalence of diabetes and prediabetes in United States and around the world, the development of treatments is of critical importance to public health. Therapies that prevent death and failure of the insulin-producing pancreatic beta cells, or which facilitate the production of a renewable source of new beta cells are essential for advancement of type 1 and type 2 diabetes research. The proposed research will increase our scientific understanding of how to increase beta cell function, survival, and potentially production, to treat and eventually prevent both type 1 and type 2 diabetes.