The piRNA binding protein Miwi2 promotes cytokine expression during bacterial pneumonia

piRNA结合蛋白Miwi2促进细菌性肺炎期间细胞因子的表达

基本信息

批准号：
8908406
负责人：
Gregory Alexander Wasserman
金额：
$ 2.56万
依托单位：
BOSTON UNIVERSITY MEDICAL CAMPUS
依托单位国家：
美国
项目类别：
财政年份：
2015
资助国家：
美国
起止时间：
2015-09-01 至 2016-06-01
项目状态：
已结题

来源：
https://reporter.nih.gov/project-details/8908406
关键词：
Ablation Acute Acute Lung Injury Alveolar Alveolar Macrophages Antibiotic Resistance Antibiotics Bacterial Pneumonia Beryllium Binding Proteins CXCL1 gene CXCL2 gene Cell Line Cell physiology Cells Complement Cytokine Gene Data Defect Development Elements Enzyme-Linked Immunosorbent Assay Epithelial Epithelial Cells Exhibits Foundations Future Gene Expression Gene Expression Regulation Germ Cells Germ Lines Goals Host Defense Immune Immune response Immunohistochemistry In Vitro Infection Inflammatory Interferons Interleukin-6 Knockout Mice Laboratories Length Light Lower Respiratory Tract Infection Lung Lung diseases Malignant Neoplasms Measures Mediating Messenger RNA MicroRNAs Microarray Analysis Modeling Molecular Mus Natural Immunity Neutrophil Infiltration Northern Blotting Outcome Patients Play Pneumococcal Infections Pneumococcal Pneumonia Pneumonia Population Process Production Protein Binding Protein Family Proteins RNA RNA Interference RNA Splicing Regulation Regulator Genes Reporter Role Small RNA Somatic Cell Sorting - Cell Movement Specificity Spermatogenesis Streptococcus pneumoniae Structure Testing Testis Therapeutic Time Tissues Transcript Tumor Necrosis Factor-alpha Untranslated RNA Viral base burden of illness cell type chemokine clinically relevant cytokine fetal gene repression genetic element improved in vivo interest mRNA Expression mortality mouse model mutant neutrophil novel piRNA protein function public health relevance respiratory response small hairpin RNA therapeutic target

项目摘要

DESCRIPTION (provided by applicant): Acute lower respiratory tract infections represent the greatest burden of disease worldwide, with mortality rates that have remained virtually unchanged since the discovery of antibiotics. The effective immune response requires the tightly regulated production of cytokines and chemokines that can facilitate maximal bacterial clearance, while minimizing tissue damage. A better understanding of cytokine regulation in the lung is needed, as future therapeutics targeting the immune response may be an essential given the rising rates of antibiotic resistance. As a foundation for future therapeutics, our laboratory is interested in identifying novel regulators of cytokine elaboration. A major regulator of gene expression, PIWI proteins associate with PIWI- interacting RNAs (piRNAs) in the mammalian germ line, and function to repress ancient retroviral elements. Ablation of any of the three PIWI proteins in mice (MIWI, MILI, or MIWI2) results in defects in spermatogenesis due to aberrant expression of LINE elements. While the germ cell functions of PIWI proteins have been described, next to nothing is known about their potential role(s) in somatic cells. To our surprise microarray analysis and qRT-PCR of sorted alveolar epithelial cells demonstrated that a single PIWI protein, Miwi2 is induced in the lung during bacterial pneumonia. Both in vitro and in vivo depletion of Miwi2 indicates that it acts to promote cytokine and chemokine expression under relevant inflammatory conditions. To our knowledge, this is the first demonstration of a somatic cell function for Miwi2. Given these findings, several important questions still remain. We will test the central hypothesis that during bacterial pneumonia, the piRNA-binding protein Miwi2 is repurposed from its known function as a germ cell specific repressor of ancient viral elements and is induced in pulmonary epithelial cells to promote cytokine expression and immune defense. In Specific Aim 1 we will use a multicolor FACS strategy to identify the specific alveolar epithelial cell population where Miwi2 is induced during pneumonia. In Specific Aim 2 we begin to elucidate the molecular mechanisms of Miwi2 dependent cytokine induction. In Specific Aim 3 we test the hypothesis that Miwi2 dependent expression of cytokines and chemokines are necessary for host defense in a clinically relevant model of bacterial pneumonia. Results of these studies will shed light on the under-described somatic functions of piRNA binding proteins, as well as enhance our understanding of cytokine regulation during bacterial pneumonia. As piRNA binding protein induction has been associated with certain cancers, we anticipate that these data will extend beyond our current focus of innate immunity. Hopefully, the results gained here will serve as a basis for future immunomodulatory therapeutics that improves the outcomes of patients with pneumonia.

描述（由适用提供）：急性下呼吸道感染代表了全球疾病中最大的伯宁，自从发现抗生素以来，死亡率几乎保持不变。有效的免疫响应需要细胞因子和趋化因子的严格调节，这些因子和趋化因子可以促进最大的细菌清除率，同时最大程度地减少组织损伤。需要更好地了解肺中的细胞因子调节，因为鉴于抗生素耐药性速度的上升，针对免疫反应的未来治疗剂可能是必不可少的。作为未来治疗的基础，我们的实验室有兴趣确定细胞因子阐述的新型调节剂。主要的监管机构在基因表达中，PIWI蛋白与哺乳动物生殖系中的Piwi相互作用RNA（PIRNA）相关，并功能抑制古老的逆转录病毒元素。小鼠中三种PIWI蛋白中的任何一种（MIWI，MILI或MIWI2）的消融导致了由于线元素异常表达而导致的精子发生缺陷。虽然已经描述了PIWI蛋白的生殖细胞功能，但几乎什么都没知道它们在体细胞中的潜在作用。令我们惊讶的是，分类的肺泡上皮细胞的微阵列分析和QRT-PCR表明，单个PIWI蛋白，MIWI2在肺炎细菌期间在肺中诱导。 MIWI2的体外和体内耗竭都表明，在相关炎症条件下，它的作用是促进细胞因子和趋化因子的表达。据我们所知，这是MIWI2的躯体细胞功能的首次演示。鉴于这些发现，仍然存在一些重要问题。我们将检验一个中心假设，即在肺炎细菌肺炎中，PIRNA结合蛋白MIWI2是从已知的作用作为古代病毒元素的生殖细胞特异性复制剂中重新塑造的，并在肺上皮细胞中诱导以促进细胞因子表达和免疫防御。在特定目标1中，我们将使用多色FACS策略来识别特定的肺泡在肺炎期间诱导MIWI2的上皮细胞群。在特定目标2中，我们开始阐明MIWI2依赖性细胞因子诱导的分子机制。在特定目标3中，我们检验了以下假设：在细菌性肺炎的临床相关模型中，细胞因子和趋化因子的依赖性表达是宿主防御所必需的。这些研究的结果将揭示Pirna结合蛋白的未描述的体细胞功能，并增强我们对肺炎细菌调节的细胞因子调节的理解。由于PIRNA结合蛋白诱导与某些癌症有关，我们预计这些数据将超出我们当前先天免疫调节治疗的重点，从而改善了肺炎患者的结局。