J Neurogastroenterol Motil.  2016 Apr;22(2):272-281. 10.5056/jnm15138.

Association of the Serotonin Receptor 3E Gene as a Functional Variant in the MicroRNA-510 Target Site with Diarrhea Predominant Irritable Bowel Syndrome in Chinese Women

• Zhang Y
• Li Y
• Hao Z
• Li X
• Bo P
• Gong W

• KMID: 2203581
• DOI: http://doi.org/10.5056/jnm15138

Abstract

BACKGROUND/AIMS
The functional variant (rs56109847) in the 3'-untranslated regions (3'-UTR) of the serotonin receptor 3E (HTR3E) gene is associated with female diarrhea predominant irritable bowel syndrome (IBS-D) in British populations. However, the relationship of the polymorphism both to HTR3E expression in the intestine and to the occurrence of Chinese functional gastrointestinal disorders has yet to be examined.
METHODS
Polymerase chain reaction amplification and restriction fragment length polymorphism analyses were employed to detect polymorphisms among Chinese Han women, particularly 107 patients with IBS-D, 99 patients with functional dyspepsia (FD), 115 patients with mixed IBS and 69 patients with IBS-D + FD. We also assessed microRNA-510 (miR-510) and HTR3E expression in human colonic mucosal tissues with immunohistochemistry and other methods. Dual-luciferase reporter assays were conducted to examine the binding ability of miR-510 and HTR3E 3'-UTR.
RESULTS
Genotyping data showed the variant rs56109847 was significantly associated with IBS-D, but not with FD, mixed-IBS, or FD + IBS-D. HTR3E was abundantly expressed around the colonic mucosal glands but less expressed in the stroma. miR-510 expression decreased, whereas HTR3E expression increased in the colonic mucosal tissue of patients with IBS-D compared with those in controls. HTR3E expression was significantly higher in patients with the GA genotype than that in patients with the GG genotype. The single-nucleotide polymorphisms disrupted the binding site of miR-510 and significantly upregulated luciferase expression in HEK293 and HT-29 cells.
CONCLUSIONS
The single-nucleotide polymorphisms rs56109847 led to reduced microRNA binding and overexpression of the target gene in intestinal cells, thereby increasing IBS-D risk in the Chinese Han population. The decreased expression of miR-510 might contribute to IBS-D.

Keyword

Female; Functional gastrointestinal disorders; MicroRNA-510; Receptors; Serotonin; 5-HT3

MeSH Terms

Asian Continental Ancestry Group*
Binding Sites
Colon
Diarrhea*
Dyspepsia
Female
Gastrointestinal Diseases
Genotype
HT29 Cells
Humans
Immunohistochemistry
Intestines
Irritable Bowel Syndrome*
Luciferases
MicroRNAs
Mucous Membrane
Polymerase Chain Reaction
Polymorphism, Restriction Fragment Length
Serotonin*
Luciferases
MicroRNAs
Serotonin