Novel Role of DRA/SLC26A3 Downregulation in Gut Dysbiosis, Inflammation and Infection

DRA/SLC26A3 下调在肠道菌群失调、炎症和感染中的新作用

基本信息

批准号：
10909515
负责人：
Pradeep K Dudeja
金额：
$ 53.34万
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：
2011
资助国家：
美国
起止时间：
2011-09-20 至 2024-08-31
项目状态：
已结题

来源：
https://reporter.nih.gov/project-details/10909515
关键词：
Affect Age Antibiotic Therapy Bacteria Bicarbonates Butyrates CRISPR/Cas technology Cells Chlorides Citrobacter rodentium Colitis Colon Data Defect Diarrhea Disease Down-Regulation Electrolytes Epithelium Event Exhibits Feces Genes Genetic Predisposition to Disease Germ-Free Goblet Cells Human Immune Immunology Impairment Infection Inflammation Inflammatory Bowel Diseases Inflammatory Response Intervention Intestines Knock-out Knockout Mice Lymphoid Cell Metagenomics Microclimate Modeling Mucin-2 Staining Method Mucins Mucous body substance Mus Pathogenicity Phenotype Predisposition Production Regulation Role SLC26A3 gene Secondary to Sodium Bicarbonate Structure Susceptibility Gene Testing Thinness Time Transgenic Mice Tretinoin Volatile Fatty Acids Water Wild Type Mouse absorption age related design drinking water dysbiosis efficacy evaluation fecal transplantation genome wide association study gut dysbiosis gut inflammation gut microbiome insight interleukin-22 intestinal barrier loss of function mutation metabolomics microbial microbiome microbiome alteration nano-string new therapeutic target novel overexpression pathogen receptor response restoration transcriptome sequencing tributyrin

项目摘要

Down regulated in adenoma (DRA) or SLC26A3 is the key intestinal chloride transporter involved in electrolyte and water absorption in the gut. Loss of function mutations in DRA result in “Congenital Chloride Diarrhea” or CLD disease. Extensive studies from our group have now established that downregulation of DRA is one of the key events in infectious and IBD-associated diarrhea. Emerging evidence from our group and others and GWAS studies have now also established DRA gene to be an IBD susceptibility locus. DRA knockout (KO) mice exhibit a CLD phenotype, thinner mucus layer and increased susceptibility to colitis. We recently showed that DRA KO mice exhibit some of the key features of IBD, including dysbiosis and compromised barrier integrity. Our preliminary studies further showed that DRA KO mice are more susceptible to pathogen infection and exhibit immune cell dysregulation. However, the detailed mechanisms underlying dysbiosis and its role in defective mucus-epithelial barrier observed in DRAKO mice and their increased susceptibility to gut inflammation and pathogen infection have not been fully investigated. Our exciting data further showed that the dysbiosis in DRA KO mice was associated with decreased short chain fatty acid (SCFA) producing taxa, fecal SCFA levels and enrichment in mucin-degrading bacteria. Cohousing studies of DRA KO with wildtype mice showed that part of the compromised barrier integrity was secondary to microbial dysbiosis. Further, in preliminary studies, DRA KO mice showed a marked reduction in Innate Lymphoid Cells-3 and IL-22, critical for combating pathogen infection. Preliminary data also showed that the expression of key mucins (MUC2 and 4) was significantly higher in goblet cells but appeared to be trapped in cells suggesting abnormal secretion. Based upon these findings, our overall hypothesis is that “Gut dysbiosis in response to the loss of DRA function contribute to compromised mucus and epithelial barrier integrity leading to increased susceptibility to gut inflammation and pathogen infection and strategies to upregulate DRA expression may alleviate these effects”. The key component of this hypothesis for this R56 proposal will be tested by the following Specific Aims: Aim 1a: Examine the age-dependent dynamic changes in the microbiome and mucus and epithelial barrier defects in DRA KO mice; Aim 1b: Investigate if cohousing with WT mice modulates the epithelium-associated factors including TJs, mucin synthesis and secretion; Aim 1c: Examine the role of altered bacterial species and metabolites by in-depth metabolomic and metagenomic analysis in DRA KO mice; Aim 1d: Evaluate the role of altered microbiome in affecting mucus layer and epithelial integrity via fecal microbial transplant approaches from WT and DRA KO mice to GF mice. The proposed studies will provide mechanistic insights into the role of DRA induced dysbiosis in defective mucus and epithelial barrier integrity and susceptibility to inflammation and infection and may aid in unraveling novel therapeutic targets.

腺瘤 (DRA) 或 SLC26A3 的下调是参与肠道电解质和水吸收的关键肠道氯离子转运蛋白，DRA 功能突变的丧失会导致“先天性氯离子腹泻”或 CLD 疾病。我们小组和其他人的新证据表明，DRA 的下调是感染性腹泻和 IBD 相关腹泻的关键事件之一，并且 GWAS 研究现在也确定了 DRA 基因。 DRA 敲除 (KO) 小鼠表现出 CLD 表型、较薄的粘液层和对结肠炎的易感性增加，我们最近发现 DRA KO 小鼠表现出 IBD 的一些关键特征，包括生态失调和屏障完整性受损。我们的初步研究表明，DRA KO 小鼠更容易受到病原体感染，并表现出免疫细胞失调，然而，生态失调的详细机制及其在粘液上皮屏障缺陷中的作用尚未得到证实。 DRAKO 小鼠及其对肠道炎症和病原体感染的易感性增加尚未得到充分研究，我们令人兴奋的数据进一步表明，DRAKO 小鼠的生态失调与产生短链脂肪酸 (SCFA) 的分类单元、粪便 SCFA 水平和粘蛋白富集的减少有关。 DRA KO 与野生型小鼠的共存研究表明，部分屏障完整性受损是继发于微生物失调的。先天淋巴细胞 3 和 IL-22 显着减少，这对于对抗病原体感染至关重要。初步数据还表明，杯状细胞中关键粘蛋白（MUC2 和 4）的表达显着升高，但似乎被困在细胞中，表明分泌异常。基于这些发现，我们的总体假设是“DRA 功能丧失导致的肠道菌群失调导致粘液和上皮屏障完整性受损，导致肠道炎症和病原体感染的易感性增加，而上调 DRA 表达的策略可能会减轻这些影响”。该 R56 提案的这一假设的关键组成部分将通过以下具体目标进行测试：目标 1a。：检查 DRA KO 小鼠微生物组、粘液和上皮屏障缺陷的年龄依赖性动态变化；目标 1b：调查是否与 WT 小鼠共养调节上皮相关因子，包括 TJ、粘蛋白合成和分泌；目标 1c：通过 DRA KO 小鼠的深入代谢组学和宏基因组分析检查改变的细菌种类和代谢物的作用；目标 1d：评估改变的微生物组在影响中的作用；通过粪便微生物移植方法从 WT 和 DRA KO 小鼠移植到 GF 小鼠的粘液层和上皮完整性。拟议的研究将提供机制。深入了解 DRA 诱导的菌群失调在有缺陷的粘液和上皮屏障完整性以及对炎症和感染的易感性中的作用，可能有助于揭示新的治疗靶点。