Micro-RNA 21 but not miR-155 is differentially expressed in the gut mucosa of patients with intestinal inflammatory conditions

EMANUEL BARBIERA ROMERO; ANAHÍ RENDÓN SORIA; MALENA FERREYRA COMPAGNUCCI; MARÍA BELEN POLO; MARÍA VIRGINIA GENTILINI; GABRIEL GONDOLESSI; GUSTAVO J. CORREA; MARTÍN YANTORNO; MARIA VICTORIA MERCADER; PAULA CHAVERO; JULIO DE MARÍA; ANDRÉS ROCCA; ALICIA SAMBUELLI; GUILLERMO DOCENA; MARTÍN RUMBO; CECILIA ISABEL MUGLIA; RENATA CURCIARELLO

Mar del Plata

Congreso; Reunión Biociencias 2022; 2022

SAIC SAI SAFIS

Mucosal myofibroblasts arekey stromal cells involved in IBD pathogenesis and in the CRC tumormicro-environment. Here, we aimed to study the expression of miR-21 and miR-155in the mucosa and intestinal fibroblasts from IBD and CRC patients, aspotential biomarkers to predict CRC outcome in patients with chronic intestinalinflammatory disorders. Target genes and proteins regulated by these miRNAswere also analyzed.Total RNA wasobtained from mucosal explants from IBD(n=25), polyp(n=8), CRC(n=7), andhealthy control (HC) patients (n=16). Intestinal fibroblast primary cultures wereestablished from colon surgical pieces (N=10). Microvesicles were obtained fromfibroblast culture supernatant by ultracentrifugation. MiR-21, miR-155, PDCD4,CBX7, KRAS transcript expression was quantified by qPCR in mucosal and cell samples.Also, TNF-α was quantified by ELISA while FAP (Fibroblast Activation Protein) expressionwas evaluated by immunofluorescence in biopsies. We found that miR-21was highly expressed in inflamed biopsies compared to uninflamed mucosa (p<0.01)and to HC (p<0.01), while PDCD4 levels were decreased in IBD biopsiescompared to HC (p<0.01). No differences were found for miR-155 expression,and KRAS was not detectable. MiR-21 was overexpressed in the stromalcompartment of the mucosa (p<0.1) compared to the epithelial layer. At theprotein level, TNF-α was increased in IBD biopsies compared to HC (21.09 vs.6.19 pg/µg of protein, p<0.1) and FAP was highly detected in inflamedintestinal biopsies from active IBD patients, polyp and CRC samples, comparedto uninflamed mucosa. Fibroblastprimary cultures from IBD patients and extracellular microvesicles overexpressedmiR-21 (p<0.1) and miR-155 (p<0.1), while PDCD4 was downregulated (p<0.001) compared to HC fibroblasts. Our results highlight the relevance of miRNAs and fibroblasts in gutinflammation and CRC development. MiRNAsexpression pattern studies would contribute to identification of CRCbiomarkers.