P058. Increased expression of microRNA-122, microRNA-146a and microRNA-155 in intestinal mucosa of pediatric patients with Crohn's disease
N.J. Béres1, D. Szabó1, A. Arató1, A. Kiss2, G. Lendvai2, G. Veres1, 1Semmelweis University, 1st. Department of Pediatrics, Budapest, Hungary, 2Semmelweis University, 2nd. Department of Pathology, Budapest, Hungary
The pathogenesis of inflammatory bowel disease is not fully understood. In recent years, there is an increased interest in epigenetic factors, such as a specific group of small, non-coding RNAs, called microRNAs (approximately 21–24 nucleotides), which participate in the regulation of the gene expression at the posttranscriptional level. It was supposed that microRNAs play an important role in many diseases, but only a few number of studies have been done in children with Crohn's disease (CD).
Our aim was to analyze the miR-146a, miR-155 and miR-122 expressions in the colonic mucosa of pediatric patients with CD. These microRNAs has been known for their role in inflammation.
Three types of intestinal paraffin fixated biopsies were analyzed: intestinal biopsy with CD (CD: n = 22, age: 15.24±0.60), with macroscopically intact (uninflamed) (CD intact: n = 11) and inflamed (CD inflamed: n = 11) colonic mucosa, and healthy controls (C: n = 16, age: 10.13±1.37). MicroRNAs expression were measured by Real-time PCR. Statistical analysis were based on Mann–Whitney U-test.
The expression of miR-146a and miR-155 were significantly higher in the intestinal mucosa of children with CD compared to the control group. This increment was observed in macroscopically inflamed intestinal biopsies in comparison to controls and intact colonic mucosa (C vs. CD, p ≤ 0.05; C vs. CD inflamed, p ≤ 0.001; CD intact vs. CD inflamed p ≤ 0.05). MiR-122 expression was significantly higher in macroscopically intact mucosal biopsies (C vs. CD intact, p ≤ 0.05).
These results suggest microRNAs play an important role in pathogenesis of CD. Further studies are required to explore the function of these microRNAs regarding their role in the pathomechanism and possible usage as therapeutic targets.