Comparative MiRNA Expressional Profiles and Molecular Networks in Human Small Bowel Tissues of Necrotizing Enterocolitis and Spontaneous Intestinal Perforation

Abstract

BackgroundNecrotizing enterocolitis (NEC) and spontaneous intestinal perforation (SIP) are acute intestinal conditions which could result in mortality and severe morbidity in preterm infants. Our objective was to identify dysregulated micro-RNAs (miRNAs) in small bowel tissues of NEC and SIP, and their possible roles in disease pathophysiology.MethodsWe performed differential miRNA arrays on tissues of NEC (n = 4), SIP (n = 4) and surgical-control (Surg-CTL; n = 4), and validated target miRNAs by qPCR (n = 10 each group). The association of target miRNAs with 52 dysregulated mRNAs was investigated by bioinformatics on functional and base-pair sequence algorithms, and correlation in same tissue samples.ResultsWe presented the first miRNA profiles of NEC, SIP and Surg-CTL intestinal tissues in preterm infants. Of 28 validated miRNAs, 21 were significantly different between NEC or SIP and Surg-CTL. Limited overlapping in the aberrant expression of miRNAs between NEC and SIP indicated their distinct molecular mechanisms. A proposed network of dysregulated miRNA/mRNA pairs in NEC suggested interaction at bacterial receptor TLR4 (miR-31, miR-451, miR-203, miR-4793-3p), mediated via key transcription factors NFKB2 (miR-203), AP-1/FOSL1 (miR-194-3p), FOXA1 (miR-21-3p, miR-431 and miR-1290) and HIF1A (miR-31), and extended downstream to pathways of angiogenesis, arginine metabolism, cell adhesion and chemotaxis, extracellular matrix remodeling, hypoxia/oxidative stress, inflammation and muscle contraction. In contrast, upregulation of miR-451 and miR-223 in SIP suggested modulation of G-protein-mediated muscle contraction.ConclusionsThe robust response of miRNA dysregulation in NEC and SIP, and concerted involvement of specific miRNAs in the molecular networks indicated their crucial roles in mucosa integrity and disease pathophysiology.

Necrotizing enterocolitis: Pathophysiology from a historical context

“…It is noteworthy that the clinical factors most often seen in association with NEC, including hypoxia, remote infection, and prematurity, are all associated with induced TLR4 expression in the intestine, suggesting a biologic explanation for these clinical observations. The principal findings that the LPS recognition molecule TLR4 is elevated in experimental and human NEC, and that it plays a key role in the pathogenesis of this disease, has been confirmed by a variety of investigators 40,41,42,43,44,45 .…”

Dysregulation of miR‐431 and target gene FOXA1 in intestinal tissues of infants with necrotizing enterocolitis

“…Infants with stage III NEC ( n = 10) were recruited from the Prince of Wales Hospital at The Chinese University of Hong Kong, as previously described in Ng et al (9). Surg‐ctl tissues were obtained from infants who underwent intestinal surgery because of “noninflammatory” conditions, including congenital small bowel atresia ( n = 7), intestinal obstruction ( n = 2), and elective closure of ileostomy ( n = 1).…”

“…Specific miRs have been implicated in ileal and colonic mucosal and blood specimens of Crohn's disease and ulcerative colitis patients (16, 17), suggesting that they could interfere with gut inflammation (18, 19). In our previous study, we demonstrated that the novel miR‐431 was significantly increased > 7‐fold in NEC bowel tissues compared with surgical‐control (surg‐ctl) tissues (9) and that miR‐431 could be linked to aberrant molecular signals in NEC. The objectives of the present study were to identify the target gene of miR‐431 in NEC and to investigate the role of miR‐431 in the pathophysiology of the disease.…”

The Microbiome and Biomarkers for Necrotizing Enterocolitis: Are We Any Closer to Prediction?

“…Differentiation between the two entities is of critical importance for disease categorization in clinical studies, and may contribute to the reproducibility and clinical translatability issues that have persisted. Ng, et al, used genomics to differentiate the two entities, reporting both differentially expressed mRNA as well as micro-RNAs in the small bowel tissue of NEC and SIP compared with surgical control tissue (79, 80). Shah et al used a more clinically applicable serum biomarker to distinguish NEC from SIP, called inter-alpha inhibitor proteins (IaIps) (81).…”