Elucidating the Nexus Between Urinary Tract Infection and Diabetes

点击翻译按钮获取中文摘要

Urinary tract infection (UTI) is among the most common bacterial infection encountered by millions of people annually. UTI is a top reason for antibiotic use, which further compounds the crisis of antimicrobial resistance in bacterial pathogens. Uropathogenic Escherichia coli (UPEC) is the predominant etiological agent of UTI. Diabetes is a metabolic disease that significantly increases the propensity for development of UTI, and dangerous complications of UTI. In the United States, ~4 in 10 people were either diabetic or prediabetic in 2018, and type 2 diabetes mellitus (T2DM) is the most common form of diabetes. Glucosuria (urinary glucose excretion) in diabetics has been presumed to increase the incidence UTI. However, roles of glucose-fueled bacterial growth in the urinary tract, changes in the host response to bacterial pathogens during UTI, and shifts in the metabolite landscape of the urinary tract in diabetic hosts continue to remain poorly understood. Mechanistic understanding of how diabetes increases the risk for UTI is critical to design effective intervention strategies, and to develop novel approaches to monitor urinary tract health in diabetics. Significant increases in bacterial burden in the urinary tract, and higher levels of bacteremia and systemic infection with UPEC during UTI were observed in non-diabetic mice with gliflozin-induced glucosuria. Gliflozins are promising tools to probe the role of glucosuria in the interaction between uropathogens and diabetic hosts. Specifically, this proposal will investigate the effect of glucosuria and other urinary metabolites on the outcomes of UTI in diabetic and healthy (control) hosts. The long-term research goal is to define the cellular and molecular determinants of health and disease in the urinary tract. The central hypothesis for this study is that glucosuria is the primary determinant of bacterial colonization in the diabetic urinary tract, and that diabetes-induced changes in urinary metabolites promote bacterial UTI. This hypothesis will be tested in a mouse model of experimental UTI, and T2DM with the following Aims: 1) Determine the impact of glucosuria on the outcomes of bacterial UTI in a mouse model of type 2 diabetes; and 2) Define the diabetic urinary metabolome, and its role in promoting UTI. This study is expected to shed light on how glucose and other metabolites affect bacterial virulence and host response during UTI in diabetic hosts. The substantial positive impact of this study will be elucidating the causal link between UTI and diabetes. The proposed study is significant because these findings are anticipated to provide mechanistic insights into factors that contribute to increased risk for UTI during diabetes. The proposed approach is innovative because it integrates gliflozin-induced glucosuria with a mouse model of T2DM, and metabolome analysis to address the nexus between UTI and diabetes. In summary, the proposed study is expected to confer a significant public health benefit against UTI, an extremely common infectious condition that often results in severe complications and long-term sequelae in diabetics.