MicroARNs and hypoxia as modulators of the intestinal glycome during IB

CUTINE AM; MARIÑO KV; GARCIA PA; CAGNONI AJ; BANNOUD N; CROCI DO

Córdoba

Workshop; Advanced Course in Mucosal Immunology; 2018

Society for Mucosal Immunolog

The intestinal epithelium is placed between the anaerobic lumen and a highly metabolic lamina propria. Supported by a complex vasculature, this barrier is affected by decreased blood flow and consequent tissue hypoxia, particularly during the inflammatory process in Inflammatory Bowel Disease (IBD) patients.In spite of the fact that the cell glycome can mediate several biological processes such as cell adhesion, host-pathogen interactions and immune modulation, studies on key factors regulating glycosylation during IBD are still scarce. In this is work, we aim to evaluate microRNAs as glycome modulators in human intestinal epithelial cells during hypoxia. We started by comparing a series of curated databases to cross match published micro-interferent RNAs (miRNAs) that were dysregulated both by hypoxia and IBD, and predictive databases of putative miRNAs targets. Our results indicate dysregulation during IBD, of several miRNAs including hsa-miR-125a-5p and 140-5p that have high sequence complementarity with (2,6)-sialyltransferases (e.g. ST6GalNAc1), fucosyltransferases (such as FUT4), GlcNAc transferases (MGAT1, MGAT4) and -mannosidases (MAN1A). Using HCT 116 cells as a model of human colon carcinoma, we evaluated glycome alterations in hypoxic conditions by flow cytometry both in 2D and 3D cultures (spheroids). Interestingly, we found altered exposure of high mannose N-glycans, as well as aberrant Gal 4GlcNAc 6(GlcNAc 2Man 3)Man 3 and downregulated terminal LAcNac groups (P