Insights into a multi-hit process in the development of necrotizing enterocolitis

深入了解坏死性小肠结肠炎发展中的多重打击过程

基本信息

批准号：
10763712
负责人：
Xiao-Di Tan
金额：
$ 65.88万
依托单位：
UNIVERSITY OF ILLINOIS AT CHICAGO
依托单位国家：
美国
项目类别：
财政年份：
2023
资助国家：
美国
起止时间：
2023-04-01 至 2026-03-31
项目状态：
未结题

来源：
https://reporter.nih.gov/project-details/10763712
关键词：
Address Affect Animal Model Bacterial Infections Bioinformatics Birth Cause of Death Cells Characteristics Coagulative necrosis Complex Data Development Disease Edema Enterobacteriaceae Enterotoxins Environmental Risk Factor Epithelial Cells Event Exhibits Exposure to Extremely Low Birth Weight Infant Family Gene Expression Genes Genetic Engineering Hemorrhage Human Human Milk Immune Immune response Immune system Immunobiology Immunologics Impairment In Vitro Infection Infiltration Inflammation Inflammation Mediators Inflammatory Inflammatory Bowel Diseases Intestinal Diseases Intestinal Mucosa Intestines Klebsiella Klebsiella oxytoca Knowledge Lesion Link Lymphocyte Macrophage Activation Microbiology Modeling Molecular Molecular Biology Molecular and Cellular Biology Mucositis Mucous Membrane Mus Natural Killer Cells Necrotizing Enterocolitis Neonatal Organoids Pathogenesis Pathologic Pathology Phenotype Premature Infant Prevention Prevention strategy Process Proteins Reporting Research Research Personnel Risk Factors Role STAT1 gene Series Signal Transduction Small Intestines TLR4 gene Techniques Testing United States Viral Virus Virus Diseases Work antimicrobial bacteriome chemokine cytokine cytotoxic dysbiosis feeding gut bacteria gut colonization gut dysbiosis gut microbiota high risk high risk population ileum in vivo insight intestinal epithelium intestinal injury microbiome mouse genetics mouse model multidisciplinary neonatal immune system neonatal mice neonate novel novel therapeutics postnatal premature preterm newborn prevent pup response transcriptome sequencing transcriptomics treatment response virome virus host interaction

项目摘要

Necrotizing enterocolitis (NEC) is a devastating intestinal inflammatory disease that primarily affects premature infants and extremely low birth weight babies. Commonly observed risk factors for NEC are prematurity, formula feeding, intestinal dysbiosis, and infection. Previous studies strongly suggest a critical role of the inappropriate microbiome colonization and activation neonatal immune system in NEC development. However, the pathogenesis of NEC is elusive. Particularly, it remains unclear how the NEC-associated risk factors contribute to the disorder. In preliminary studies, we characterized the effect of formula-feeding on intestinal flora, gene expression, and immunobiology in neonatal mice. We also examined intestinal pathology of mouse pups which were fed with formula followed by induction of a particular antimicrobial immune response. We found that formula-feeding alone resulted in a distinct type of gut dysbiosis and pre-NEC intestinal molecular changes that predispose the neonatal gut to inappropriate microbiome colonization/infection and render intestinal mucosa to be a target of cytotoxic inflammatory cells. We further revealed that formula-fed but not dam-fed mouse pups developed NEC upon activation of a cytotoxic inflammatory cell-associated antimicrobial immune response. Thus, it appears that NEC develops following inappropriate microbiome colonization in premature infants as a consequence of “multi-hit pathophysiological events”. In this project, we will study new mechanistic insights into these events and determine how the interaction of multiple-hit events contributes to the development of NEC in two complementary aims: (1) We will first characterize the series of pathophysiological events that leads to NEC development, using a novel and pathologically relevant mouse pup model of NEC and up-to-dated in vivo experimental pathological and immunological approaches. Then, we will use RNAseq and cutting-edge bioinformatic analysis to delineate the transcriptomic response of the small intestine of mouse pups to multiple- hit challenges and to unravel the relevance of this novel mouse model of NEC for human NEC. Furthermore, we will study how major NEC risk factor-induced “multi-hit events” contribute to NEC development by focusing on inflammatory cells, mucosal inflammation-associated inflammatory mediators, and a unique signal axis that protects intestinal epithelial cells against inflammatory cell attack. We will achieve this aim using in vivo experimental approaches that draw on molecular biology and mouse genetic engineering techniques. (2) We will elucidate how formula feeding causes pre-NEC molecular changes in the small intestine of premature neonates by taking a multidisciplinary in vivo and in vitro approaches that incorporate techniques of organoid culture, molecular and cellular biology, microbiology, mouse genetic engineering and gnotobiogy. Together, our work will provide a novel mouse model relevant for human NEC, advance knowledge of how the interaction between NEC risk factors and activation of the neonatal immature immune system triggers NEC development, and gain mechanistic insights that will inform the development of new strategies for the prevention and treatment of NEC.

坏死性小肠结肠炎 (NEC) 是一种破坏性肠道炎症性疾病，主要影响早产儿和极低出生体重儿是 NEC 的常见危险因素。先前的研究强烈表明，早产、配方奶喂养、肠道菌群失调和感染起着关键作用。 NEC 发育中不适当的微生物定植和激活新生儿免疫系统的研究。然而，NEC 的发病机制尚不清楚，特别是 NEC 相关风险如何仍不清楚。在初步研究中，我们描述了配方奶喂养对这种疾病的影响。我们还检查了新生小鼠的肠道菌群、基因表达和免疫生物学。给小鼠幼崽喂食配方奶，然后诱导特定的抗菌免疫反应。我们发现，单独配方奶喂养会导致一种独特类型的肠道菌群失调和 NEC 之前的肠道分子使新生儿肠道易受不适当的微生物定植/感染并使肠道粘膜是细胞毒性炎症细胞的目标，我们进一步发现配方奶喂养而非母乳喂养。细胞毒性炎症细胞相关抗菌免疫激活后，幼鼠患上 NEC 因此，NEC 似乎是在早产儿不适当的微生物组定植后发生的。在这个项目中，我们将研究新的机制。深入了解这些事件并确定多重命中事件的相互作用如何促进发展 NEC 的两个互补目标：（1）我们将首先描述一系列病理生理事件的特征，这些事件使用新颖且病理相关的 NEC 小鼠幼仔模型和最新的然后，我们将使用RNAseq和尖端的体内实验病理和免疫学方法。生物信息分析描绘小鼠幼崽小肠对多种物质的转录组反应迎接挑战并揭示这种新型 NEC 小鼠模型与人类 NEC 的相关性。将研究主要 NEC 风险因素引发的“多重打击事件”如何促进 NEC 发展，重点关注炎症细胞、粘膜炎症相关的炎症介质以及独特的信号轴保护肠上皮细胞免受炎症细胞攻击我们将在体内使用来实现这一目标。 (2) 我们将阐明配方奶喂养如何导致早产儿小肠 NEC 前分子变化通过采用结合类器官培养技术的多学科体内和体外方法，我们的工作将结合分子和细胞生物学、微生物学、小鼠基因工程和认知生物学。提供与人类 NEC 相关的新型小鼠模型，增进对 NEC 之间如何相互作用的了解危险因素和新生儿未成熟免疫系统的激活会触发 NEC 的发展和增益机制见解将为制定预防和治疗 NEC 的新策略提供信息。