The Contribution of Ribonuclease 7 to Urinary Tract Anitbacterial Defense

核糖核酸酶 7 对尿路抗菌防御的贡献

• 批准号: 9897601
• 负责人: John David Spencer
• 金额: $ 40.47万
• 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: 2018-02-01 至 2023-01-31
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/9897601
• 关键词: AKT Signaling Pathway; Acute; Affect; Anti-Bacterial Agents; Antibiotic Resistance; Bacterial Infections; Biological; Bladder; Bladder Urothelium; Cells; Child; Clinical; Complementary DNA; Data; Defense Mechanisms; Development; Foundations; Genetic Polymorphism; Genetic Transcription; Genetic Variation; Genomics; Health; Host Defense; Human; Human Genetics; Immunologics; Infection; Infection prevention; Innate Immune Response; Insulin; Intercalated Cell; Invaded; Kidney; Knock-in Mouse; Knowledge; Laboratories; Laboratory mice; Lower urinary tract; Mediating; Modeling; Molecular; Morbidity - disease rate; Mus; Outcome; PI3K/AKT; Patients; Peptides; Phosphotransferases; Predisposition; Prevention; Production; Public Health; Publishing; Pyelonephritis; Recurrence; Regulation; Research; Ribonucleases; Single Nucleotide Polymorphism; Sterility; Testing; Therapeutic; Toxic effect; Transgenic Mice; Urinary tract; Urinary tract infection; Urine; Uropathogen; Uropathogenic E. coli; Urothelium; Variant; Vertebrates; antimicrobial; antimicrobial peptide; cell type; clinical practice; fighting; humanized mouse; improved; in vivo; infection risk; insight; kidney infection; microbial; mouse model; novel; novel therapeutics; pathogen; prevent; promoter; response; tissue injury; treatment strategy

ABSTRACT Urinary tract infections (UTIs), including pyelonephritis, are among the most common and serious infections encountered in clinical practice. No proven treatment options exist to prevent UTI. New strategies are needed to augment the ability of host defenses to prevent UTI and minimize UTI-associated morbidity. A growing body of evidence, from our laboratory and others suggests that antimicrobial peptides (AMP), an essential component of the innate immune response, protect the urinary tract from invasive bacterial infection. Our research team has identified Ribonuclease 7 (RNase 7) as a potent and highly abundant human AMP that shields the urothelium from uropathogenic E. coli (UPEC). Our published data suggest that RNase 7 is an ideal AMP to develop as a UTI therapeutic because: (A) it has potent antibacterial activity; (B) it is highly abundant in the urinary tract; (C) it is produced by cell types that are targeted by UPEC; and (D) it has minimal toxicity. Our emerging data suggest that RNase 7 induction shields the urothelium from UPEC, while suppressed RNase 7 production renders it susceptible to pathogens. Together, these findings provide strong support to our central hypothesis that RNase 7 is biologically necessary to maintain urine sterility and prevent UTI. Our current understanding of RNase 7's effects on innate defenses is limited in vivo because its expression is absent in the laboratory mouse and restricted to higher order vertebrates and humans. To fill this key knowledge gap, we developed two novel humanized RNase 7 mouse models. These models will be used to complete our overall objective of this application, which is to further investigate the essential contributions of RNase 7 to urine sterility. To test our central hypothesis, we will evaluate how cell-specific RNase 7 expression impacts UTI risk in vivo using a novel Rosa26 knock-in mouse (Aim 1). In Aim 2, we will investigate the molecular mechanisms that regulate RNase 7 expression using a novel humanized transgenic mouse that expresses RNase 7 under the control of its own promoter. In Aim 3, we will evaluate how human genetic polymorphisms affect RNase 7 expression and antimicrobial activity. Completion of the proposed Aims will further define the necessary contributions of RNase 7 to urine sterility and may provide the foundation to develop RNase 7 as a novel therapeutic that improves UTI outcomes. Given the clinical impact of UTI, in an era of emerging antibiotic resistant uropathogens, identifying mechanisms to develop RNase 7 as a new UTI therapy may have significant benefits to public health.

抽象的 尿路感染 (UTI)，包括肾盂肾炎，是最常见和最严重的感染之一 在临床实践中。目前还没有经过证实的治疗方案可以预防尿路感染。需要新的策略来增强能力 宿主防御以预防尿路感染并最大限度地减少尿路感染相关发病率。来自我们实验室的越来越多的证据 等人认为抗菌肽（AMP）是先天免疫反应的重要组成部分，可以保护 泌尿道免受侵袭性细菌感染。我们的研究团队已确定核糖核酸酶 7 (RNase 7) 是一种有效的、 高丰度的人类 AMP，可保护尿路上皮免受尿路致病性大肠杆菌 (UPEC) 的侵害。我们公布的数据表明 RNase 7 是开发为 UTI 治疗剂的理想 AMP，因为： (A) 它具有有效的抗菌活性； (B) 是 尿道中含量丰富； (C) 它是由 UPEC 靶向的细胞类型产生的； (D) 它有最小的 毒性。我们的新数据表明，RNase 7 感应可以保护尿路上皮免受 UPEC 的影响，同时抑制 RNase 7 生产使其容易受到病原体的影响。总之，这些发现为我们的中心假设提供了强有力的支持 RNase 7 在生物学上对于维持尿液无菌和预防 UTI 是必需的。我们目前对 RNase 的了解 7 对先天防御的影响在体内是有限的，因为它在实验室小鼠中不表达并且仅限于 高等脊椎动物和人类。为了填补这一关键知识空白，我们开发了两种新型人源化 RNase 7 小鼠 模型。这些模型将用于完成我们此应用程序的总体目标，即进一步研究 RNase 7 对尿液无菌的重要贡献。为了检验我们的中心假设，我们将评估细胞特异性如何 使用新型 Rosa26 敲入小鼠，RNase 7 表达会影响体内 UTI 风险（目标 1）。在目标 2 中，我们将调查 使用表达 RNase 7 的新型人源化转基因小鼠调节 RNase 7 表达的分子机制 RNase 7 在其自身启动子的控制下。在目标 3 中，我们将评估人类遗传多态性如何影响 RNase 7 表达和抗菌活性。完成拟议的目标将进一步确定必要的目标 RNase 7 对尿液无菌的贡献，并可能为将 RNase 7 开发为新型治疗剂奠定基础 改善尿路感染的结果。鉴于尿路感染的临床影响，在抗生素耐药性尿路病原体不断出现的时代， 确定将 RNase 7 开发为新的 UTI 疗法的机制可能会对公共健康产生重大益处。