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（由申请人提供）：急性下呼吸道感染是世界范围内最大的疾病负担，自抗生素发现以来死亡率一直保持不变有效的免疫反应需要严格调节细胞因子和趋化因子的产生，这实际上可以促进细胞因子和趋化因子的产生。需要更好地了解肺部的细胞因子调节，因为鉴于抗生素耐药率不断上升，未来针对免疫反应的治疗可能至关重要。有兴趣确定细胞因子精化的新调节因子一个主要调节因子。 PIWI 蛋白与哺乳动物种系中的 PIWI-RNA (piRNA) 相互作用，并具有抑制古老逆转录病毒元件的功能，消除小鼠体内的三种 PIWI 蛋白（MIWI、MILI 或 MIWI2）中的任何一种都会导致基因缺陷。虽然 PIWI 蛋白的生殖细胞功能已被描述，但令我们惊讶的是，对其在体细胞中的潜在作用却知之甚少。分选的肺泡上皮细胞的微阵列分析和 qRT-PCR 表明，在细菌性肺炎期间，肺部会诱导一种 PIWI 蛋白 Miwi2，Miwi2 的体外和体内耗竭表明它可以在相关炎症下促进细胞因子和趋化因子的表达。据我们所知，这是首次证明 Miwi2 的体细胞功能。鉴于这些发现，我们仍将检验细菌性肺炎期间的核心假设。 piRNA 结合蛋白 Miwi2 从其已知的古老病毒元件生殖细胞特异性阻遏物的功能中被重新利用，并在肺上皮细胞中被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 piRNA 结合蛋白 Miwi2。特定的肺泡在特定目标 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，我们测试了细胞因子和趋化因子的 Miwi2 依赖性表达对于宿主防御所必需的假设。这些研究结果将揭示 piRNA 结合蛋白的体细胞功能，并增强我们对细菌性肺炎期间细胞因子调节的理解。诱导与某些癌症有关，我们预计这些数据将超出我们目前对先天免疫的关注范围，希望这里获得的结果将成为未来改善肺炎患者预后的免疫调节疗法的基础。