Colonic epithelial cells and immune cells were isolated from colonic tissues, and microRNA-31 (miR-31) expression was measured. miR-31 expression was measured in colonoid cultures generated from controls and patients with CD.
Finally, using a novel statistical simulation approach applied to colonic RNA-sequencing data for patients with CD and non-IBD controls, we identified miR-31-5p and miR-203 as candidate master regulators of gene expression profiles associated with CD.
Furthermore, miR-31 is universally expressed in both ulcerative colitis and Crohn disease not only in fresh-frozen but also in formalin-fixed, paraffin-embedded tissues.
Pathway analysis indicated that ARHGEF2 and NSF participate in a molecular network, which also contains VAMP3 (previously associated to CD) and is centered around miR-31 (known to be disregulated in CD).