UC-supplementary_materials.doc

<b><i>Background/Aims:</i></b>Ulcerative colitis is a type of inflammatory bowel disease posing a great threat to the public health worldwide.Previously, gene expression studies of mucosal colonic biopsies have provided some insight into the pathophysiological mechanisms in ulcerative colitis; however, the exact pathogenesis is unclear. This study aimed to identify key genes and pathways associated with ulcerative colitis by bioinformatics analysis.<b><i>Methods:</i></b>Genome-wide gene expression datasets involving ulcerative colitis patients were collected from gene expression omnibus database. To identify key genes, an integrated analysis of gene expression signature was performed by employing robust rank aggregation method. We used weighted gene coexpression network analysis to explore the functional modules involved in ulcerative colitis pathogenesis. Besides, biological process and pathways analysis of co-expression modules were figured out by gene ontology enrichment analysis using metascape.<b><i>Results:</i></b>328 ulcerative colitis patients and 138 healthy controls were from fourtreen datasets. MMP1 and AQP8 were two key genes screened from the differentially genes. Seven main functional modules were identified, of which the blue modules included 1718 genes and mainly enriched in extracellular matrix organization, lymphocyte activation, blood vessel morphogenesis, leukocyte migration and inflammatory response,and the salmon module enriched in interferon signaling,defense response to virus and herpes simplex infection. There were also several other meaningful functional modules which were involved in many biological processes.<b><i>Conclusions:</i></b>The present study identifies a number of key genes and pathways involved in the progress of ulcerative colitis,which deepens the understanding of the molecular mechanism and provides theoretical foundation for molecular target therapy.