MicroRNA-24 inhibits serotonin reuptake transporter expression and aggravates irritable bowel syndrome.

Irritable bowel syndrome (IBS) is a common chronic functional gastrointestinal disorder. MicroRNAs (miRNAs) have been widely demonstrated to take part in various physiological and pathological processes. In the present study, the role of miR-24 in the pathogenesis of IBS and the potential mechanism in this process were evaluated. Human intestinal mucosa epithelial cells of colon from IBS patients and healthy subjects were collected. An IBS mouse model was established with the induction of trinitro-benzene-sulfonic acid (TNBS). The expression levels of miR-24 and serotonin reuptake transporter (SERT) were analyzed using Real-time PCR and western blot in both human specimen and mice. miR-24 was upregulated in IBS patients and mice intestinal mucosa epithelial cells. Luciferase reporter assay showed that SERT was a potential target gene of miR-24. The treatment of miR-24 inhibitor increased pain threshold and nociceptive threshold levels and reduced MPO activity in proximal colon of IBS mice, and up-regulated the mRNA and protein expression levels of SERT in intestinal mucosa epithelial cells. miR-24 played a role in the pathogenesis of IBS probably through regulating SERT expression.