Combined viral and bacterial infection and zinc homeostasis in distal lung

病毒和细菌联合感染与远端肺锌稳态

• 批准号: 9043183
• 负责人: A. Murat Kaynar
• 金额: $ 38.5万
• 依托单位: UNIVERSITY OF PITTSBURGH AT PITTSBURGH
• 依托单位国家: 美国
• 财政年份: 2015
• 资助国家: 美国
• 起止时间: 2015-04-01 至 2020-03-31
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/9043183
• 关键词: Accounting; Acute; Acute Lung Injury; Adverse effects; Affect; Aging; Alveolar; Alveolar Macrophages; Apoptosis; Apoptotic; Bacterial Infections; Bacterial Pneumonia; Binding; Biological Models; Breathing; Capillary Permeability; Cell Death; Cell physiology; Cells; Child Care; Clioquinol; Coculture Techniques; Data; Dietary Zinc; Disease; Distal; Electron Microscopy; Epidemiologic Studies; Epithelial; Exposure to; Fortified Food; Granulocyte-Macrophage Colony-Stimulating Factor; Health; Homeostasis; Human; Hydration status; Immunity; In Situ; Infection; Infectious Agent; Inflammation; Inflammatory Response; Influenza; Influenza A Virus, H1N1 Subtype; Injury; Liver; Lower Respiratory Tract Infection; Lung; Mechanics; Mediating; Medical; Modeling; Molecular; Morbidity - disease rate; Mus; Natural Immunity; Nitric Oxide; Nitrites; Nutritional; Oral; Outcome; Phagocytosis; Phase; Physiological; Pneumonia; Population; Preventive; Production; Public Health; Recovery; Resolution; Role; Sepsis; Signal Transduction; Site; Source; Therapeutic; Therapeutic Agents; Therapeutic Index; Transforming Growth Factor beta; Treatment Efficacy; Uncertainty; Viral; Viral Cell Proliferation; Viral Pneumonia; Virus Diseases; Water; Zinc; Zinc deficiency; Zinc supplementation; adaptive immunity; adverse outcome; aged; airway epithelium; alveolar type II cell; burden of illness; cohort; cytokine; experience; global health; influenzavirus; insight; light microscopy; lung injury; lung repair; macrophage; methicillin resistant Staphylococcus aureus; mortality; novel; pandemic influenza; pathogen; pre-clinical; randomized trial; research study; response; transcription factor

DESCRIPTION (provided by applicant): Zinc deficiency contributes significantly to world wide burden of disease accounting for 10-15% of morbidity and mortality associated with diarrheal disorders and pneumonia. Physiological hypozincemia of aging may account for sensitivity of this population to lower respiratory tract infections. From a pragmatic point of view: a) Zn is involved in innate, adaptive and nutritional immunity; and b) Zn supplementation is inexpensive and has a relatively large therapeutic index. Nonetheless, there is a notable lack of preclinical assessment of mechanisms and therapeutic efficacy of supplemental zinc in the context of pandemic flu (H1N1) with or without secondary bacterial infection (Methicillin-resistant S. aureus, MRSA). In preliminary experiments, we noted that dietary zinc deficiency (Zn-D) did not affect the sensitivity of intact mice to either H1N1 or MRSA, but exposure to both (H1N1/MSRA) resulted in more severe acute lung injury (ALI). Further preliminary data showing that cell death (apoptosis) of distal airway epithelium and inability of alveolar macrophages to phagocytize apoptotic cells (efferocytosis) in Zn-D suggest that mechanistic insight may be obtained in co- culture model system of human alveolar type II cells (ATII) and alveolar macrophages (AM). Additional preliminary data showing that aged mice are Zn-D and sensitive to H1N1 suggest that this is a useful model to consider pharmacotherapeutic potential of Zn. Accordingly, SPECIFIC AIMS are: 1.Determine role of Zn dyshomeostasis in ALI due to H1N1/MRSA. The sensitivity of distal lung to combined infection will be assessed in mice made Zn-D and contrasted to zinc replete (Zn-R) controls. The ability of supplemental Zn to modify injury to and recovery from H1N1/MRSA will be assessed by correcting Zn deficiency prior (preventive) to or after (mitigative) exposure. 2. Determine the molecular mechanisms by which Zn modifies inflammatory response to viral and bacterial infection in cells of distal lung. We will determine: a) if Zn deficiency affects human ATII cells and AM response to H1N1/MRSA; b) the mechanism by which GM-CSF and TGFß affect Zn homeostasis and cellular function in human AM; and c) if Zn supplementation and NO affect human ATII and AM response to H1N1, MRSA or H1N1/MRSA. 3. Determine therapeutic efficacy of Zn in physiological hypozincemia of aging and sensitivity to viral and bacterial infection. Aged (18-22 months) mice will be made Zn replete and the effect of H1N1/MRSA will be assessed. A separate cohort of aged mice will be infected with H1N1/MRSA and intrapulmonary labile levels of zinc will be elevated by inhaled nitrite. Collectively, these studies will provide novel insights into the role of Zn in regulating resolutio of H1N1/MRSA-induced lung injury through modulation of alveolar epithelial apoptosis and macrophage efferocytosis. Such mechanistic insight may help guide the use of zinc in: a) preventive fashion for global health issues regarding sensitive populations to viral and bacterial pneumonia; and b) suggest combined therapies of zinc and nitrite to mitigate pneumonia in aged population.

描述（由申请人提供）：缺锌对世界范围的疾病负担有重要影响，占与呼吸道疾病和肺炎相关的发病率和死亡率的10-15%。老年人生理性低锌血症可能是该人群对下呼吸道感染敏感的原因。从实用的角度来看：a）锌参与先天性、适应性和营养性免疫;和B）锌补充剂价格低廉，治疗指数相对较大。尽管如此，在有或没有继发性细菌感染的大流行性流感（H1N1）背景下，明显缺乏对补充锌的机制和治疗效果的临床前评估（耐甲氧西林S.金黄色葡萄球菌，MRSA）。在初步实验中，我们注意到饮食锌缺乏（Zn-D）不影响完整小鼠对H1N1或MRSA的敏感性，但暴露于H1N1/MSRA导致更严重的急性肺损伤（ALI）。进一步的初步数据显示，在Zn-D中远端气道上皮的细胞死亡（细胞凋亡）和肺泡巨噬细胞不能吞噬凋亡细胞（胞饮作用），表明可以在人肺泡II型细胞（ATII）和肺泡巨噬细胞（AM）的共培养模型系统中获得机制见解。额外的初步数据显示，老年小鼠是Zn-D和敏感的H1N1表明，这是一个有用的模型，考虑锌的药理学潜力。因此，具体的目的是：1.确定锌稳态失调在H1N1/MRSA引起的ALI中的作用。将在Zn-D制备的小鼠中评估远端肺对组合感染的敏感性，并与锌充足（Zn-R）对照进行对比。将通过在暴露前（预防性）或暴露后（缓解性）纠正锌缺乏来评估补充锌改变H1N1/MRSA损伤和恢复的能力。2.确定锌改变远端肺细胞对病毒和细菌感染的炎症反应的分子机制。我们将确定：a）Zn缺乏是否影响人ATII细胞和AM对H1N1/MRSA的应答; B）GM-CSF和TGF β影响人AM中Zn稳态和细胞功能的机制;和c）Zn补充和NO是否影响人ATII和AM对H1N1、MRSA或H1N1/MRSA的应答。3.确定锌在老年生理性低锌血症中的治疗效果以及对病毒和细菌感染的敏感性。将使老年（18-22个月）小鼠充满Zn，并评估H1N1/MRSA的作用。另一组老年小鼠将感染H1N1/MRSA，吸入亚硝酸盐将提高肺内锌的不稳定水平。总的来说，这些研究将提供新的见解锌的作用，通过调节肺泡上皮细胞凋亡和巨噬细胞吞噬功能，在调节解决H1N1/MRSA诱导的肺损伤。这种机制的见解可能有助于指导锌的使用：a）预防全球健康问题的方式，对病毒性和细菌性肺炎敏感的人群;和B）建议锌和亚硝酸盐的联合治疗，以减轻老年人的肺炎。