Linking Insulin Signaling to Antimicrobial Peptide Production and the Kidney's Antibacterial Defenses

将胰岛素信号转导与抗菌肽的产生和肾脏的抗菌防御联系起来

• 批准号: 9883788
• 负责人: John David Spencer
• 金额: $ 34.2万
• 依托单位: RESEARCH INST NATIONWIDE CHILDREN'S HOSP
• 依托单位国家: 美国
• 财政年份: 2018
• 资助国家: 美国
• 起止时间: 2018-04-03 至 2022-02-28
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/9883788
• 关键词: AKT Signaling Pathway; Acute Renal Failure with Renal Papillary Necrosis; Affect; Anti-Bacterial Agents; Antibiotic Resistance; Antibiotics; Bacteremia; Caring; Cells; Cessation of life; Data; Defense Mechanisms; Diabetes Mellitus; Disease; Epithelial Cells; Foundations; Genetic Transcription; Goals; Health; Host Defense; Human; Hyperglycemia; Immune; Impairment; In Vitro; Infection; Infection prevention; Insulin; Insulin Receptor; Insulin Resistance; Insulin Signaling Pathway; Intercalated Cell; Kidney; Knowledge; Laboratories; Link; Mediating; Modeling; Mus; Non-Insulin-Dependent Diabetes Mellitus; Outcome; PI3K/AKT; Pancreatic ribonuclease; Phosphotransferases; Play; Prediabetes syndrome; Predisposition; Process; Production; Property; Publishing; Regulation; Research; Ribonucleases; Role; Site; Stream; Transgenic Mice; Transgenic Organisms; Urinary tract; Urinary tract infection; Uropathogen; Uropathogenic E. coli; Urothelium; Vertebrates; antimicrobial; antimicrobial peptide; bactericide; diabetic patient; experimental study; fighting; humanized mouse; improved; in vivo; infection risk; innate immune mechanisms; insight; insulin signaling; kidney infection; microbial; mouse model; novel; novel therapeutics; prevent; renal abscess; renal epithelium; urinary

ABSTRACT Diabetes mellitus is a systemic disorder that increases infection susceptibility. The most common site of infection is the urinary tract. Urinary tract infection (UTI) is more common, more severe, and has worse outcomes in people with diabetes. To date, the mechanisms that predispose people with diabetes to UTI have not been elucidated. This project will evaluate how insulin regulates innate immune mechanisms in the kidney’s intercalated cells. Surmounting evidence from our research group and others suggests that intercalated cells (IC) play a critical role in antibacterial defenses against uropathogenic E. coli (UPEC). Our research shows that insulin resistance and Type 2 diabetes mellitus increases UTI risk. When the insulin receptor is selectively deleted in murine ICs, UPEC susceptibility significantly increases in vivo. Also, we have demonstrated that insulin induces antimicrobial peptide (AMP) expression in primary human renal epithelial cells via the phosphatidylinositide 3-kinase (PI3K/AKT) signaling pathway. Specifically, our data show that insulin induces Ribonuclease 7 (RNase 7) production, the most potent AMP in the human urinary tract, to shield the urothelium from UPEC. Together, these data provide strong support for our hypothesis that insulin signaling plays an essential role in innate IC defenses by regulating PI3K/AKT activity and downstream AMP production. Building on these previous studies, we propose a comprehensive analysis of insulin’s ability to regulate IC defense mechanisms. Aim 1 will evaluate how insulin resistance and Type 2 diabetes mellitus affects IC antibacterial defenses. Aim 2 will identify how IC insulin receptor deletion impacts AMP transcription and whether targeted PI3K/AKT activation induces AMP expression. Aim 3 will use a novel transgenic humanized mouse model to assess how insulin resistance and insulin therapy impacts the production of RNase 7 and its antimicrobial activity in vivo. The long-term objective of this project is to improve the care of diabetic patients with UTI by identifying novel therapeutic options. By evaluating the role of insulin signaling in host defense, completion of these Aims can have profound influence on the health of people with diabetes as they may develop insulin-signaling targets, like PI3K/AKT and RNase 7, as new therapeutics that prevent UTI, extending UTI treatment options beyond the scope of antibiotics.

摘要