Differential expression of microRNA related to irritable bowel syndrome in a rabbit model

OBJECTIVE: This study aimed to evaluate the differential expressions of microRNAs (miRNAs) in white hair black eye (WHBE) rabbits of irritable bowel syndrome (IBS). METHODS: WHBE and Japanese white (JW) rabbits were divided into the control and IBS groups. The IBS groups were exposed to moist heat, stress and low-dose laxatives. Their intestinal movement rate was measured. Blood samples were taken to detect serum 5-hydroxytryptamine (5-HT) and dopamine levels and colonic tissues were obtained to detect c-Fos expression by immunohistochemistry. Deep sequencing technology was used to obtain miRNA sequences in the intestinal tissues of WHBE and JW control groups. Expressions of 14 miRNAs were measured by real-time polymerase chain reaction in both the control and the IBS model groups. RESULTS: Serum 5-HT and dopamine levels, intestinal movement rate and c-Fos expressions in the WHBE rabbits were significantly increased compared with the control group. MiR-29a-3p, miR-24-3p, miR-221- 3p, let-7f-5p, let-7g-5p, let-7i-5p, miR-192-5p, miR126- 3p and miR-130b-3p expressions in WHBE IBS rabbits at day 14 were significantly higher than those in the control group while miR-324-3p and miR-132 were downregulated. MiR-29a-3p, let-7i-5p, miR-1925p and miR-126-3p were significantly upregulated only in JW IBS rabbits at day 14 and miR-324-3p, miR223- 3p and miR-132 were significantly downregulated in JW IBS group. MiR-24-3p, miR-221-3p, let-7f-5p, miR-126-3p and miR-130b-3p expressions in WHBE IBS rabbits were higher than that in JW IBS rabbits. CONCLUSIONS: Twelve miRNAs were differentially expressed in IBS rabbits. Five are specific in WHBE IBS rabbits, suggesting that they play a role in increased sensitivity to IBS.