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

• 批准号: 10443445
• 负责人: Xiao-Di Tan
• 金额: $ 65.65万
• 依托单位: LURIE CHILDREN'S HOSPITAL OF CHICAGO
• 依托单位国家: 美国
• 财政年份: 2022
• 资助国家: 美国
• 起止时间: 2022-04-01 至 2022-11-15
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/10443445
• 关键词: Abbreviations; 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; Immunoglobulin A; Immunologics; Impairment; In Vitro; Infection; Infiltration; Inflammation; Inflammation Mediators; Inflammatory; Inflammatory Bowel Diseases; Intestinal Diseases; Intestinal Mucosa; Intestines; Klebsiella; Klebsiella oxytoca; Knowledge; Lesion; Light; Link; Lymphocyte; Macrophage Activation; Mediator of activation protein; Microbiology; Modeling; Molecular; Molecular Biology; Molecular and Cellular Biology; Mucositis; Mucous Membrane; Mus; NK Cell Activation; Natural Killer Cells; Necrotizing Enterocolitis; Neonatal; Organoids; PPAR gamma; Pathogenesis; Pathologic; Pathology; Phenotype; Play; Postdoctoral Fellow; Premature Infant; Prevention; Prevention strategy; Process; Proteins; Reporting; Research; Research Personnel; Risk Factors; Role; STAT1 gene; STAT1 protein; Series; Signal Transduction; Small Intestines; TLR4 gene; Techniques; Testing; United States; Viral; Virus; Virus Diseases; Work; antimicrobial; bacteriome; base; cell transformation; chemokine; cytokine; cytotoxic; donor milk; 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; virome

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。 NEC 常见的危险因素是 早产、配方奶喂养、肠道菌群失调和感染。先前的研究强烈表明了关键作用 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，目前还不清楚 NEC 相关风险如何 因素导致了这种疾病。在初步研究中，我们描述了配方奶喂养对 新生小鼠的肠道菌群、基因表达和免疫生物学。我们还检查了肠道病理学 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 粘膜成为细胞毒性炎症细胞的靶标。我们进一步揭示了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，幼鼠患上了 NEC 回复。因此，NEC 似乎是在早产儿中不适当的微生物组定植后发生的。 婴儿是“多重打击病理生理事件”的结果。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 体内实验病理学和免疫学方法。然后，我们将使用RNAseq和尖端技术 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。此外，我们 将研究主要的 NEC 风险因素引发的“多重打击事件”如何通过关注 NEC 的发展来促进 NEC 的发展 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的攻击。我们将利用体内实现这一目标 利用分子生物学和小鼠基因工程技术的实验方法。 (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， 分子和细胞生物学、微生物学、小鼠基因工程和认知生物学。我们的共同努力将 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 NEC 预防和治疗新策略的制定提供信息。