A Novel Metabolic Pathway Regulates Urinary Tract Infections in the Bladder

项目3：项目摘要/总结 尿路感染是泌尿外科最常见的医疗问题，也是最普遍的医疗问题之一。 疾病。患者表现福尔斯沿着一系列密集的下尿路症状，以短暂的少 明确的不适和非诊断性泌尿检查结果。我们认为症状的范围 来自不同的细菌定居点和不同的毒力水平。我们的初步数据 表明细菌的嗜性和毒力与细菌获得营养物质的能力直接相关， 最令人垂涎的物质是铁。铁是细菌的“贵金属”，因为所有的代谢过程， 包括能量生产和细胞分裂，每个细菌需要10万个原子。泌尿系统是一个 特别有趣的铁获取部位，因为虽然尿液仅含有纳摩尔铁含量， 尿液中每天还含有106个红细胞，每个红细胞含有109个血红素铁原子。在这个铁的环境中 饥饿，但潜在的血红素铁丰富，细菌可以迅速部署工具，以转移铁从 哺乳动物的蛋白质，并从血红素环直接穿过他们的膜。我们建议，这一设置是 血红素铁占主导地位，血红素运输系统首先优先窃取我们的铁。这 这一假说不仅来自于对细菌基因表达的分析，而且也来自于我们对上皮细胞的研究。 对膀胱侵犯的反应。通过创造新的工具来分离新生RNA的快照， 发现泌尿系统中的尿道上皮和其他特殊细胞激活它们自己的系统 血红素捕获、血红素代谢和铁螯合。这些被激活的哺乳动物通路 感兴趣，因为他们的反应的即时性，招募新的血红素转运蛋白的网站， 细菌的攻击，并生产血红素产品，一氧化碳，一种抑菌剂。此外，本发明还提供了一种方法， 这些途径不仅净化血红素，而且是生物钟的核心复合物。我们 认识到这些发现的影响将需要大量的研究，但它们包括我们的发现 膀胱的顶膜，尿道，可以用一种新的机制运输血红素， 认识到细菌刺激这一过程作为一种先天免疫防御机制，称为营养 免疫力由于这些机制，我们发现夜间和白天UTI产生不同的 生物学成果。在哥伦比亚大学3号项目的更新建议书中，乔治M.奥布莱恩泌尿科 我们回到基本的铁生物学，我们仔细记录血红素和铁的运输， 膀胱，细胞和细菌的反应，使用新的成像工具和新的铁和CO捕获工具，小鼠 ko的和细菌携带突变的铁途径，这是至关重要的小鼠和人类感染。我们的工作与 领先的微生物学家（Uhlemann），遗传学家（Mendelsohn，Gharavi）和铁生物学的首席科学家 （哈姆扎）。总之，我们的研究将证明，尿路上皮是一个代谢活跃的细胞层， 铁的生物解毒日常显微镜血尿和免疫防御后，他们的入侵。

PROJECT 3: PROJECT ABSTRACT/SUMMARY Urinary tract infections are the most common medical problem in Urology, and one of the most pervasive medical illnesses. Patient presentation falls along a spectrum of intensive, lower urinary tract symptoms, to transient less defined discomfort and non-diagnostic urinary findings. We believe the spectrum of presenting symptoms results from different sites of colonization of bacteria and different levels of virulence at those sites. Our preliminary data indicates the bacterial tropism and virulence is directly related to the capacity of bacteria to obtain nutrients, and the most coveted substance is iron. Iron is a “precious metal” for bacteria because all metabolic processes, including energy production and cell division requires 100,000 atoms per bacteria. The urinary system is a particularly intriguing site of iron acquisition, because while the urine fluid contains only Nano-Molar iron content, the urine also contains 106 red blood cells/day, containing 109 heme iron atoms each. In this setting of iron starvation, yet potentially heme-iron abundance, bacteria can rapidly deploy tools to transfer iron from mammalian proteins, and from heme rings directly across their membrane. We propose that this setting is dominated by heme iron, and that heme transport systems take priority initially in stealing our iron. This hypothesis not only derives from analysis of bacterial gene expression, but also our study of the epithelial response to the invasion of the bladder. By creating novel tools to isolate snapshots of nascent RNA, we discovered that the urothelium and specialized cells elsewhere in the urinary system activate their own system of heme capture, heme metabolism, and iron sequestration. These activated mammalian pathways are of great interest because of the immediacy of their responses, the recruitment of novel heme transporters at the site of bacterial attack, and the production of the heme product, Carbon Monoxide, a bacteriostatic agent. In addition, these pathways not only decontaminate heme, but they are the core complex of the Circadian Clock. We are cognizant that the implications of these findings will require considerable research, but they include our finding that the apical membrane of the bladder, the urothelium, can transport heme with a novel mechanism and the realization that bacteria stimulate this process as a mechanism of innate immune defense known as nutritional immunity. As a result of these mechanisms, we found that night time and day time UTI generate different biological outcomes. In this renewal proposal for Project 3 of the Columbia University George M. O’Brien Urology Research Center we go back to basic iron biology and we carefully document heme and iron transport across the bladder, cell and bacterial responses using novel imaging tools and novel iron and CO capture tools, mouse ko’s and bacteria carrying mutations in iron pathways that are critical in mice and human infection. We work with leading microbiologists (Uhlemann), geneticists (Mendelsohn, Gharavi) and lead scientist in iron biology (Hamza). Together, our studies will demonstrate that the urothelium is a metabolically active cell layer that uses iron biology to detoxify the daily microscopic hematuria and for immune defense upon their invasion.