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Single Immunoglobulin Interleukin-1 Related Receptor and necrotizing enterocolitis in premature infants

早产儿单一免疫球蛋白白细胞介素1相关受体与坏死性小肠结肠炎

基本信息

批准号：
10224180
负责人：
Venkatesh Sampath
金额：
$ 51.41万
依托单位：
CHILDREN'S MERCY HOSP (KANSAS CITY, MO)
依托单位国家：
美国
项目类别：
财政年份：
2018
资助国家：
美国
起止时间：
2018-09-18 至 2023-07-31
项目状态：
已结题

来源：
https://reporter.nih.gov/project-details/10224180
关键词：
Acute Address Animal Experiments Apoptosis Area Bacteria Bacteroidaceae Bioinformatics Biological Assay Biological Markers Biology CRISPR/Cas technology Clinical Data Defect Development Disease Emergency Situation Enterobacteriaceae Epithelial Cells Event Evolution Exhibits Family Future Genes Genetic Genetic Screening Genetic study Genotype Glean Goals Human Human Genetics Immune system Immunogenetics Immunoglobulin G Immunoglobulins Immunologic Receptors In Vitro Incidence Infant Inflammation Inflammatory Interleukin-1 Interleukin-1 Receptors Intestinal Diseases Intestines Knock-in Knowledge Laboratories Life Ligands Mediating Modeling Molecular Mus Mutation Necrotizing Enterocolitis Neonatal Outcome Pathogenesis Pathogenicity Pathologic Pilot Projects Play Predisposition Premature Infant Prevention Probiotics Publishing Receptor Activation Receptor Inhibition Receptor Signaling Regulation Risk Role Screening procedure Severities Signal Transduction Statistical Methods Structure TLR4 gene Testing Toll-Like Receptor Pathway Toll-like receptors Transgenic Mice Transmembrane Domain Variant base bench to bedside clinical phenotype cohort deviant dysbiosis efficacy testing extracellular fetal forward genetics gastrointestinal genetic approach genetic variant genomic locus gut microbiome gut microbiota human disease immune activation insight intestinal epithelium loss of function microbial signature microbiome microbiota microbiota profiles mortality novel personalized approach personalized screening prevent programs protein structure pup receptor receptor function response reverse genetics targeted treatment treatment strategy

项目摘要

Necrotizing enterocolitis (NEC) is the most common acute gastrointestinal emergency in premature infants with a mortality of 20-35%. Although aberrant activation of the Toll-Like Receptor (TLR) family of immune receptors by the gut microbiota is a central event in NEC pathogenesis, the mechanisms underlying TLR pathway activation selectively in infants who develop NEC remain unknown. Our laboratory used an immunogenetics approach to discover Single Immunoglobulin Interleukin-1-Related Receptor (SIGIRR), a negative regulator of TLR signaling, as a potential locus for NEC susceptibility. Pilot studies from our lab demonstrate that SIGIRR variants identified in human NEC result in a loss of inhibition of TLR and interleukin-1 receptor signaling in intestinal epithelial cells. Interestingly, unweaned mice with a knock-in of the mutation we identified in human NEC exhibit spontaneous activation of pro-inflammatory TLR signaling and intestinal dysbiosis. Based on these preliminary studies, we hypothesize that SIGIRR is a pathogenic locus for NEC susceptibility in premature infants, and deleterious SIGIRR mutations program deviant TLR4-microbiota interactions underlying NEC pathogenesis. This hypothesis will be tested by: 1) determining whether SIGIRR variants increase NEC risk in premature infants, and examining the mechanisms by which pathogenic variants disrupt molecular function, and 2) investigating the mechanisms by which SIGIRR mutations program TLR hyperresponsiveness and dysbiosis in NEC using novel mice with a knock-in of the SIGIRR mutation identified in human NEC. In Aim 1, the SIGIRR genetic locus will be sequenced in premature infants with and without NEC to determine whether rare or novel SIGIRR variants contribute to NEC susceptibility or severity. A sequence-to-structure-to-function analysis of SIGIRR combining bioinformatics analysis of SIGIRR protein structure with in vitro functional assays of genetic variants will reveal the molecular basis of altered SIGIRR function with NEC variants. For Aim 2, we created SIGIRRTIR-/- mice with a knock-in of the p.Y168X mutation identified in human NEC to elucidate the mechanisms underlying deviant microbiota-TLR4 interactions in NEC. We will characterize the molecular players and microbiota signatures that direct native TLR hyperresponsiveness and NEC vulnerability. We will also test the efficacy of probiotics and TLR4-antagonists to mitigate NEC in SIGIRRTIR-/- mice. The rationale here is to investigate the paradigm that genetically-mediated defects in SIGIRR function program deviant microbiota-TLR interactions in NEC. We have taken a translational bedside-bench approach to delineate the mechanistic role of SIGIRR mutations in NEC pathogenesis. Results of this study will significantly advance knowledge in the areas of SIGIRR biology, genetic basis of NEC susceptibility, and regulation of neonatal gut microbiome by SIGIRR. These scientific gains will positively impact the existing status quo relating to the paucity of personalized screening tools for NEC prediction, and new treatment strategies for NEC prevention in premature infants.

坏死性小肠结肠炎（NEC）是早产儿最常见的急性胃肠道急症，死亡率为20- 35%。尽管免疫受体的Toll样受体（TLR）家族的异常激活是NEC发病机制的中心事件，TLR途径激活的机制选择性地在发生NEC的婴儿中仍然未知。我们的实验室使用免疫遗传学方法，发现单一免疫球蛋白白细胞介素-1相关受体（SIGIRR），TLR信号传导的负调节因子，作为NEC易感性的潜在位点。我们实验室的初步研究表明，在人类中，NEC导致肠上皮细胞中TLR和白介素-1受体信号传导抑制丧失。有趣的是，我们在人类NEC中发现的突变基因敲入的未断奶小鼠表现出自发的促炎TLR信号传导的激活和肠道生态失调。根据这些初步研究，我们假设SIGIRR是早产儿NEC易感性致病位点， SIGIRR突变程序异常TLR 4-微生物群相互作用的NEC发病机制。这一假设将通过以下方式进行测试：1）确定SIGIRR变异是否会增加早产儿NEC的风险，并检查致病性变异破坏分子功能的机制，以及2）调查机制 SIGIRR突变程序TLR高反应性和生态失调在NEC中使用新的小鼠，在人NEC中鉴定的SIGIRR突变的敲入。在目标1中，将对SIGIRR基因座进行测序在患有和不患有NEC的早产儿中，以确定罕见或新型SIGIRR变体是否有助于NEC 易感性或严重性。结合生物信息学的SIGIRR序列-结构-功能分析 SIGIRR蛋白结构分析与遗传变异体的体外功能测定将揭示分子 NEC变异体改变SIGIRR功能的基础。对于目标2，我们创建了SIGIRRTIR-/-小鼠，其具有以下基因敲入：在人类NEC中鉴定的p.Y168X突变，以阐明异常微生物群TLR 4的潜在机制在NEC的互动。我们将描述指导天然TLR的分子参与者和微生物群特征高反应性和NEC脆弱性。我们还将测试益生菌和TLR 4拮抗剂的功效，减轻SIGIRRTIR-/-小鼠中的NEC。这里的基本原理是研究遗传介导的 NEC中SIGIRR功能程序异常微生物-TLR相互作用的缺陷。我们已经采取了一个翻译床边板凳的方法来描绘的机制作用SIGIRR NEC发病机制中的突变。这项研究的结果将显着推进知识领域的SIGIRR 生物学，NEC易感性的遗传基础，以及SIGIRR对新生儿肠道微生物组的调节。这些科学的进步将积极影响与个性化筛查工具缺乏相关的现状用于NEC预测，以及用于早产儿NEC预防的新治疗策略。