Contributions of the enterocyte brush border to intestinal health and disease

肠上皮细胞刷状缘对肠道健康和疾病的贡献

基本信息

批准号：
10651348
负责人：
Kelli Lynn VanDussen
金额：
$ 48.16万
依托单位：
CINCINNATI CHILDRENS HOSP MED CTR
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：
2023-07-01 至 2027-04-30
项目状态：
未结题

来源：
https://reporter.nih.gov/project-details/10651348
关键词：
Acute Address Adherent Culture Affect Aftercare Agonist Air Anti-Inflammatory Agents Apical Area Binding Biological Biological Markers Biopsy Biopsy Specimen Body Weight decreased Brush Border Cell Culture Techniques Cell physiology Clinical Colitis Colon Colon Injury Crohn&apos s disease Crossbreeding Data Defect Development Diarrhea Digestion Disease Distal Distant Duodenum Dyslipidemias Enterocytes Environment Environmental Risk Factor Enzymes Epithelial Cells Epithelium Fatty acid glycerol esters Future Goals Health Hepatocyte High Fat Diet Histologic Homeostasis Host Defense Human Ileal Diseases In Vitro Individual Inflammation Inflammatory Injury Intestinal Diseases Intestines Knowledge Length Ligands Link Lipids Liquid substance Mediating Membrane Metabolic Methods Modeling Molecular Morphology Mouse Strains Mucin 1 protein Mucous Membrane Mus Nuclear Receptors Outcome PPAR alpha Pathologic Pathology Pathway Analysis Pathway interactions Patients Peroxisome Proliferators Phenotype Physiological Physiology Pilot Projects Poly I-C Prediction of Response to Therapy Property Refractory Disease Regulation Reporting Risk Role Signal Transduction Site Small Intestines Sodium Dextran Sulfate Structure Surface Testing Therapeutic Tissue Sample Tissues Villus antagonist cell type cellular microvillus design dextran sulfate sodium induced colitis dietary control fatty acid metabolism fatty acid oxidation feeding gain of function gene function healing ileum intestinal epithelium intestinal injury loss of function meter monolayer mouse model novel nutrient absorption overexpression prevent protein expression scaffold tissue injury tool transcriptome sequencing transcriptomics treatment risk

项目摘要

The luminal surface of each epithelial cell is covered by several thousand bristles, known individually as a microvillus and collectively as the brush border. The brush border promotes efficient digestion and absorption of nutrients by increasing intestinal surface area and by acting as a scaffold for enzymes, transporters, and host defense factors. Our proposal is significant because few studies address how microvillus structures are regulated in homeostasis or intestinal disease, despite the critical importance of the intestinal brush border to normal intestinal physiology. Monogenetic diseases with disruption of the brush border present with severe diarrhea and intestinal pathology. We have reported that abnormally short ileal microvillus length is present in a subset of histologically uninflamed Crohn’s disease (CD) ileal tissue samples. This phenotype identifies CD patients at-risk for treatment-refractory disease and future development of strictures, features associated with poor clinical outcome in CD. The major objective of this application is to define mechanisms that regulate microvillus length and brush border maturation. This knowledge could help us understand how to reverse pathological changes that occur at the brush border in Crohn’s disease and other pathologic conditions of the intestine. The key preliminary data supporting this application include 1) high fat diet feeding or acute loss of Ppara in intestinal epithelial cells of mice results in short microvillus length; 2) overexpression of Ppara in intestinal epithelial cells rescues high fat diet-induced microvillus shortening; 3) experimental injury of the duodenum or distal colon of mice cause microvillus length shortening in the ileum; and 4) altered brush border ultrastructure and protein expression are observed in Crohn’s disease vs. control patient ileal biopsy tissues. Our central hypothesis is that microvillus length and brush border maturity are suppressed following high fat diet or intestinal injury and can be restored by PPARα signaling activation within intestinal epithelial cells. In Aim 1, we will determine how high fat diet and intestinal epithelial PPARα signaling alter brush border morphology, ultrastructure, and protein expression using novel conditional mouse models with Ppara gain-of-function or loss-of-function specifically in the intestinal epithelium and air-liquid interface epithelial monolayer cultures. We will also use untargeted and targeted approaches to investigate the cellular mechanisms linking microvillus length changes to PPARα signaling. In Aim 2, we will use Ppara conditional mice to determine if intestinal epithelial PPARα signaling influences inflammatory and tissue injury outcomes and injury-associated ileal brush border changes. We anticipate that completion of the proposed studies will produce the following deliverable: identification of a biological pathway and cellular mechanism that integrates host and environmental influences to modify intestinal brush border morphology and function.

每个上皮细胞的腔表面都被数千个刷毛覆盖，单独称为微绒毛，统称为刷子边框。刷子边界通过增加肠表面积并充当酶，转运蛋白和宿主防御因素的脚手架来促进有效的营养消化和滥用营养素。我们的建议很重要，因为很少有研究涉及微绒毛结构如何在体内稳态或肠道疾病中调节，从而努力肠道边界对正常肠道生理学的重要性。单基因疾病，并破坏了严重的腹泻和肠道病理的刷子边界。我们报道说，绝对短回肠微绒毛长度在组织学上不受欢迎的克罗恩病（CD）的回肠组织样品的一部分中呈现。该表型确定了CD患者的治疗难治性疾病和未来狭窄的发育，这是与CD中临床结果不佳相关的特征。该应用的主要目的是定义调节微伏长和刷边界成熟的机制。这些知识可以帮助我们了解如何在克罗恩病和肠道其他病理状况的刷子边界发生的病理变化。支持该应用的关键初步数据包括1）小鼠肠上皮细胞中高脂饮食的高脂肪饮食喂养或PPARA急性丧失导致微绒毛长度的短； 2）肠上皮细胞中PPARA的过表达反应高脂肪饮食诱导的微绒毛缩短； 3）小鼠的十二指肠或盘状结肠的实验损伤导致微绒毛长度缩短； 4）在克罗恩病与对照患者的回肠活检组织中观察到刷边界超微结构和蛋白质表达的改变。我们的中心假设是，在高脂肪饮食或肠道损伤之后，微绒毛长度和刷子边界成熟度被抑制，并且可以通过肠上皮细胞中的PPARα信号激活来恢复。在AIM 1中，我们将使用具有PPARA功能获得的新型有条件小鼠模型在肠上皮上皮和空气界面界面上皮单层培养物中，使用具有PPARA功能获得的新型小鼠模型来确定高脂肪饮食和肠上皮PPARα信号改变刷子边界形态，超微结构和蛋白质表达。我们还将使用未靶向和靶向方法来研究将微伏长变化与PPARα信号传导联系起来的细胞机制。在AIM 2中，我们将使用PPARA条件小鼠来确定肠上皮PPARα信号传导是否影响炎症和组织损伤结果以及与损伤相关的回肠刷边界变化。我们预计，拟议研究的完成将产生以下可交付的可交付：鉴定生物学途径和细胞机制，该机制将宿主和环境影响整合起来，以修改肠道刷子边界的形态和功能。