Ido1 knock-out 마우스를 이용한 Dextran Sulfate Sodium 유도 대장염 모델에서의 전사체 분석

학위논문 (석사)-- 서울대학교 대학원 : 식품영양학과, 2014. 8. 신동미.Tryptophan involves in a range of biological processes including protein and biogenic nitrogen-compounds synthesis. It is metabolized to kynurenine by indoleamine 2,3-dioxygenase 1 (IDO1) that is the first rate limiting enzyme. IDO1 expresses ubiquitously in the body with heightened expressions in intestinal tissues. To examine the function of IDO1 in colon, transcriptome analysis using microarray was performed in both Ido1 knock-out (Ido1-/-) mice and wild type (Ido1+/+) mice. Differentially expressed genes in comparison of Ido1-/- and Ido1+/+ mice were categorized based upon their biological functions. Gene set enrichment analysis showed that inflammatory response was the most significant category which was modulated by IDO1 gene. This observation prompted us to study the function of IDO1 in inflammatory bowel disease mouse model. In DSS-induced ulcerative colitis model, the disease was more severely developed in Ido1+/+ mice compared with Ido1-/- mice. Total RNAs of inflamed colon tissues from both Ido1+/+ and Ido1-/- mice were applied to microarray in order to find the significant signaling pathways affected by Ido1 deficiency. TLR signaling and NF-kB signaling were turned out to be responsible for generating the difference in disease progression between those two genotypes. Dramatic changes in TLR signaling and NF-kB signaling resulted in substantial changes in expressions of many pro- and anti- inflammatory cytokines and chemokines. These findings suggest that IDO1 play roles in producing inflammatory responses and modulating transcriptional networks during colitis development.Contents Abstract ⅰ Contents ⅲ List of Figures Ⅴ List of Tables ⅶ List of Abbreviations ⅷ Ⅰ. Introduction 1 Aim of this study 5 Ⅱ. Materials and Methods 1. Animals 6 2. Induction of Colitis 7 3. Tissue Collection 9 4. Histological Analysis of Colitis 10 5. Microarray Hybridization and Scanning 11 6. Identification of Significant Genes 12 7. Functional Enrichment and Clustering Analysis 13 8. Statistical Analysis 14 Ⅲ. Results 1. Identification of Differentially Expressed Genes in Ido1-/- Mice 15 2. IDO1 Leads to Increased Susceptibility to Experimental DSS-induced Colitis 23 3. IDO1 Regulates the Expression of Multiple Inflammatory Genes in DSS-induced Colitis 31 4. Absence of IDO1 Resulted in Suppression of TLR Signaling 36 5. MUC1 Suppresses TLR Signaling 42 6. Inflammatory Cytokines and Chemokines Production in Colon is Affected by IDO1 45 7. Inflammation and Tryptophan Metabolism 49 Ⅳ. Discussion 54 Ⅴ. References 60 국문초록 69Maste