Inflammatory transcriptomic signatures and cell type compositions in inflamed and non-inflamed colonic mucosa of ulcerative colitis

Ulcerative colitis is a chronic inflammatory disorder in the lower part of the digestive system. Despite of many functional studies, the hidden mechanisms of this complex disease limit complete remission. Here, we investigated transcriptomic signature of ulcerative colitis using RNA sequencing obtained from 15 active (inflamed), 15 inactive (non-inflamed) samples of ulcerative colitis, and 15 healthy controls. The transcriptomics profiling revealed that inflammatory transcriptomic signature was highly enriched in active samples compared to inactive or healthy control samples. However, this bulk RNAseq cannot provide the cell type information, which play a key role in such a chronic inflammation. To overcome this limitation, we borrowed the power of single cell RNAseq. Deconvolution of bulk RNAseq based on the single cell expression estimated active UC enriched cell types including inflammatory fibroblast and inflammatory monocytes. This integrative approach using bulk and single cell transcriptomics provide not only target genes but also target cell types of ulcerative colitis for therapeutic purpose. We performed RNAseq on total RNA from both areas of the colonic mucosa with active inflammation and without inflammation during the colonoscopy.