Candidate microRNAs for hypoxia-driven changes in the intestinal glycome during Inflammatory Bowel Diseases (IBD).

PABLO A GARCIA; ANABELA M CUTINE; KARINA V MARIÑO; NADIA BANNOUD; ALEJANDRO J CAGNONI; JULIAN GAMBARTE; DIEGO O CROCI

BUENOS AIRES

Simposio; GlycoAR; 2019

IBYME-IHEM-FUNDACIÓN LELOIR-UNSAM-

IBD is a chronic disorder characterized by loss of barrier function in a tissue that is constantly being challenged, leading to increased antigen exposure, tolerance loss, inflammation and hypoxia. The glycome, profile of glycan structures present in a cell or tissue, is a key player in several biological processes such as cell adhesion, host-pathogen interactions, and immune modulation. However, crucial factors driving changes in intestinal glycosylation in physiopathological conditions such as intestinal inflammation, are not fully understood. The aim of this study was to evaluate the role of micro-interferent RNAs (miRNAs) as potential glycome modulators in human intestinal epithelial cells during hypoxia. We first compared several databases to cross match published dysregulated miRNAs in hypoxia and IBD and used predictive databases to find putative targets of selected miRNAs. Our in-silico analysis showed several hypoxia-modulated miRNAs with high complementarity with α-(2,6)- sialyltransferases (e.g. ST6GalNAc1), fucosyltransferases (e.g. FUT4), GlcNAc transferases (MGAT1, MGAT4) and α-mannosidases (MAN1A). To validate these results, we evaluated the glycosylation signature of monolayer and spheroid cultures of HCT 116 cells under hypoxic conditions. Flow cytometry analysis revealed an altered exposure of high mannose N-glycans, as well as an increase in fucosylated structures. Interestingly, Spheroid cultures showed a decreased exposure of β-1,6-branched complex N-glycans. In summary, hypoxia modulates the expression on specific miRNAs that can explain changes in the glycome of human intestinal epithelium.