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.

在腺瘤（DRA）或SLC26A3中调节的下调是参与肠道中电解质和吸水的关键肠氯化物转运蛋白。 DRA中功能突变的丧失导致“先天性氯化物腹泻”或CLD疾病。我们小组的广泛研究已经确定，DRA的下调是传染和IBD相关的腹泻的关键事件之一。我们小组以及其他GWAS研究的新兴证据现在也确立了DRA基因成为IBD易感性基因座。 DRA敲除（KO）小鼠暴露了CLD表型，粘液层较薄，对结肠炎的敏感性增加。我们最近表明，DRA KO小鼠暴露了IBD的一些关键特征，包括营养不良和障碍障碍完整性。我们的初步研究进一步表明，DRA KO小鼠更容易受到病原体感染的影响，并表现出免疫细胞失调。然而，观察到的详细机制及其在有缺陷的粘液上皮屏障中的作用 Drako小鼠及其对肠道注射和病原体感染的敏感性增加尚未得到充分研究。我们的令人兴奋的数据进一步表明，DRA KO小鼠的营养不良与产生分类群，SCFA水平和粘液降解细菌富集的短链脂肪酸（SCFA）降低有关。与野生型小鼠对DRA KO的同座研究表明，障碍的一部分屏障完整性继发于微生物营养不良。此外，在初步研究中，DRA KO小鼠显示先天淋巴样细胞-3和IL-22的显着降低，对于打击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）的表达明显更高，但似乎被困在表明异常分泌的细胞中。基于这些发现，我们的总体假设是“肠道营养不良响应DRA功能的丧失有助于为了损害粘液和上皮屏障的完整性，导致对肠道注射和病原体感染的易感性增加，以及升级DRA表达的策略可能会减轻这些影响。小鼠;目标1B：是否与WT小鼠同居，包括TJ，粘蛋白合成和分泌的上皮相关因素：检查细菌和代谢物改变的作用通过WT和DRA KO小鼠到GF小鼠的粪便微生物移植方法的完整性。