P0991 - Urine Extracellular Vesicle-derived miRNA Patterns in Infants with Necrotizing Enterocolitis

Background/Purpose: The purpose of this study was to identify urine extracellular vesicle-derived miRNAs that can be used as biomarkers for necrotizing enterocolitis (NEC) diagnosis and to highlight gene and molecular targets of the candidate miRNAs.

Methods: Urine samples were collected from premature infants (N=80), 24-34 weeks of age, at two neonatal intensive care units. Infants were enrolled based upon diagnosis of disease: surgical NEC, medical NEC, non-NEC sepsis, and healthy age-matched premature controls. miRNA sequencing was performed using an Illumina HiSeq 4000, and miRNA differential expression was analyzed using the R package, DESeq2. The Wald Test was used to discover potential miRNA biomarkers, using a false discovery rate adjusted p-value of 0.1. miRNAs with significantly altered expression levels in NEC infants were then passed to Ingenuity Pathway Analysis (IPA) to identify regulatory pathways that may be associated with NEC.

Results: Differential expression analysis of the miRNA transcriptome revealed multiple miRNA candidates for use in the discrimination of NEC from septic infants (e.g. miR-376a) and control infants (e.g. miR-604). IPA indicated that NEC was significantly associated with multiple disease regulatory pathways when compared to healthy premature control infants, including inflammatory disease and response, renal and urological disease, and organismal injury. Likewise, sepsis was significantly associated with disease regulatory pathways, including organismal injury, gastrointestinal disease and immunological disease. IPA also demonstrated that signal transduction molecules TP53 and HDAC5 may be associated with miRNA-mediated inflammatory mechanisms in NEC.

Conclusion: We conclude that urine extracellular vesicle-derived miRNA patterns from infants with necrotizing enterocolitis are altered in comparison to septic infants and premature healthy infants. These shifts in miRNA expression as a function of disease are associated with changes in regulatory pathways that may aid in the elucidation of necrotizing enterocolitis mechanistic progression and resolution.