P078 Inflammatory transcriptomic signatures and cell type compositions in colonic mucosa of ulcerative colitis

Abstract

Abstract Background Previous studies have explored transcriptomic profiles associated with active inflammation in patients with IBD patients, but consistent characteristics of gene expression and enriched pathways, particularly in Asian patients with UC, remain unconfirmed. Here, we aimed to assess distinctive transcriptomic changes associated with persistent active mucosal inflammation in Asian patients with UC despite of medical treatment. Methods We obtained colonic mucosa biopsies of inflamed and noninflamed tissue from 15 patients with UC and 15 healthy controls and performed RNA sequencing analysis. Utilizing publicly available single cell RNA sequencing (scRNAseq) data, we also identified cell types expressing differentially expressed genes from RNAseq data and performed data deconvolution using CIBERSORTx. Results Transcriptomics profiling revealed that the inflammatory transcriptomic signature was highly enriched in the colonic mucosa of UC-active compared to UC-inactive and controls. By incorporating scRNAseq data, the genes upregulated in UC-active were highly expressed in M cells, inflammatory monocytes, and inflammatory fibroblasts, while downregulated genes were prominent in BEST4+ enterocytes and WNT5B+ fibroblasts. Notably, a sub-cluster of enterocytes associated with SAA1, SLC6A14, and DUOXA2 genes exhibited high expression in UC-active. Deconvolution analysis using CIBERSORTx identified significant enrichment of natural killer cells, inflammatory monocytes, Tuft cells, inflammatory fibroblast, WNT2B+Fos-lo1, and pericytes in UC-active. Conclusion Our RNAseq analysis not only identified significant gene expression changes but also revealed shifts in cell type proportions associated with persistent inflammation. These findings offer valuable insights for developing novel treatment strategies for UC.