Kidney Cu Homeostasis and Ceruloplasmin during Infection and Inflammation

感染和炎症期间肾脏铜稳态和铜蓝蛋白

• 批准号: 9752581
• 负责人: Edward McLouth Culbertson
• 金额: $ 4.5万
• 依托单位: JOHNS HOPKINS UNIVERSITY
• 依托单位国家: 美国
• 财政年份: 2016
• 资助国家: 美国
• 起止时间: 2016-08-25 至 2020-08-24
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/9752581
• 关键词: ATP phosphohydrolase; Acute-Phase Proteins; Address; Affect; Animals; Biological Availability; Biological Markers; Candida albicans; Cells; Ceruloplasmin; Cryoultramicrotomy; Data; Disseminated candidiasis; Drops; Enzymes; Epithelial Cells; Exhibits; Goals; Homeostasis; Human; Immune response; Immunofluorescence Immunologic; Immunohistochemistry; Infection; Inflammation; Inflammatory Response; Invaded; Kidney; Knockout Mice; Lipopolysaccharides; Mammalian Cell; Mediating; Membrane; Messenger RNA; Metabolism; Micronutrients; Molecular; Monitor; Mus; Mycoses; Organ; Organism; Production; Proteins; Publishing; Regulation; Role; Serum; Severities; Signal Transduction; Site; Starvation; Superoxide Dismutase; Systemic infection; Testing; Western Blotting; Work; basolateral membrane; biological adaptation to stress; biological systems; copper oxidase; experimental study; insight; mouse model; pathogen; pathogenic fungus; pathogenic microbe; public health relevance; response; superoxide dismutase 1; uptake; virtual

Project Summary Cu is an essential micronutrient that can also be toxic to biological systems. Mammalian cells therefore need to tightly control Cu homeostasis. The kidney appears particularly effective at regulating Cu because this organ displays some of the smallest magnitude of Cu fluctuations during conditions of Cu excess or Cu limitation. However, recently published work in the Culotta lab has shown that kidney Cu levels can fluctuate during infection and inflammation. Specifically in a murine model of disseminated candidiasis, infection with the fungal pathogen Candida albicans stimulated a drop in kidney Cu and the invading pathogen responded by activating a fungal Cu starvation stress response. Concurrent to this drop in kidney Cu, serum Cu levels rose. In my preliminary studies, I discovered that the cause of this high serum Cu is a strong elevation in serum ceruloplasmin (Cp), an acute phase protein. Ceruloplasmin is a multi-copper oxidase for controlling Fe homeostasis and I observed increases in both Cp protein levels and Cp activity that can account for virtually all the elevated serum Cu. I hypothesize that during C. albicans infection, the demand for high Cu in producing ceruloplasmin triggers a loss in Cu from the kidney, and this drop in Cu is mediated through regulation of kidney Cu uptake or efflux. To investigate this hypothesis I will carry out the following aims. Aim 1: To define the host and fungal Cu responses as a function of infection severity. I will identify the level of infection required to stimulate the host Cu response (elevating serum Cp and decreasing kidney Cu) as well as the fungal Cu response (activate the Cu starvation stress response). Aim 2: To understand the mechanism for kidney Cu loss during infection. I will investigate the mechanism by which kidney Cu decrease occurs: does this involve reduced Cu uptake or enhanced Cu efflux? I will scrutinize both protein levels and localization of the Cu uptake transporter CTR1 and the Cu efflux transporter ATP7A in an effort to answer this question. Aim 3: Determine the signal for Cu loss in the kidney. To determine whether serum Cp is sufficient to induce kidney loss of Cu without fungal infection, I will inject mice with lipopolysaccharide and heat-killed C. ablicans cells, both of which will induce an inflammatory response including Cp induction without infection. Furthermore I will test if the phenomenon of kidney Cu loss occurs in Cp-/- homozygous deletion mice infected with C. albicans. Together these studies will provide insight into the mechanisms by which kidney Cu homeostasis is affected by infection and inflammation.

项目摘要 铜是一种必需的微量营养素，也可能对生物系统有毒。因此，哺乳动物细胞需要 严格控制铜稳态。肾脏似乎在调节铜方面特别有效，因为这个器官 在铜过量或铜限制的条件下，显示了一些最小的铜波动幅度。 然而，最近在Culotta实验室发表的研究表明，肾脏铜水平在治疗期间可能会波动。 感染和炎症。特别是在播散性念珠菌病的鼠模型中， 真菌病原体白色念珠菌刺激肾铜下降和入侵的病原体作出反应， 激活真菌Cu饥饿应激反应。与此同时，肾铜下降，血清铜水平上升。 在我的初步研究中，我发现这种高血清铜的原因是血清铜的强烈升高， 血浆铜蓝蛋白（Cp），一种急性时相蛋白。铜蓝蛋白是一种多铜氧化酶， 我观察到Cp蛋白水平和Cp活性的增加，这几乎可以解释所有 血清Cu升高。我假设在C.白色念珠菌感染，对高铜的需求， 产生铜蓝蛋白触发铜从肾脏的损失，这种铜的下降是通过介导的， 调节肾脏铜的吸收或流出。为了研究这个假设，我将实现以下目标。 目的1：确定宿主和真菌的Cu反应作为感染严重程度的函数。我将确定 感染需要刺激宿主Cu反应（升高血清Cp和降低肾脏Cu），以及 真菌Cu响应（激活Cu饥饿胁迫响应）。目标2：了解 感染时肾铜丢失。我将研究肾铜减少发生的机制： 这涉及减少铜吸收或增强铜流出？我将仔细检查蛋白质水平和定位 Cu摄取转运蛋白CTR 1和Cu流出转运蛋白ATP 7A，以试图回答这个问题。目的 3：确定肾脏中Cu损失的信号。为了确定血清Cp是否足以诱导肾 在没有真菌感染的情况下，我将给小鼠注射脂多糖和热灭活的C。ablicans细胞， 这两者都将诱导炎性反应，包括Cp诱导而不感染。此外，我将 检测感染C.白色念珠菌 总之，这些研究将提供深入了解肾铜稳态受影响的机制， 感染和炎症。