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

• 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
• 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

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.

在腺瘤中下调（DRA）或SLC26A3是参与肠道电解质和水分吸收的关键肠氯转运蛋白。DRA的功能突变丧失导致“先天性氯化物腹泻”或CLD疾病。我们小组的大量研究现已确定，DRA的下调是感染性腹泻和ibd相关腹泻的关键事件之一。来自我们小组和其他研究人员以及GWAS研究的新证据现在也确定了DRA基因是IBD的易感位点。DRA基因敲除（KO）小鼠表现出CLD表型，黏液层更薄，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。我们的初步研究进一步表明，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有缺陷的黏液上皮屏障中的作用在