Regulation of serum microRNA expression by acupuncture in patients with diarrhea-predominant irritable bowel syndrome

Objective: To screen for differentially expressed serum microRNAs (miRNAs) in patients with diarrhea-predominant irritable bowel syndrome (IBS-D) compared with healthy participants and explore the mechanism of acupuncture in the treatment of IBS-D based on miRNAs. Methods: IBS-D patients that met the Rome III diagnostic criteria and age- and sex-matched healthy participants were enrolled between April 2017 and December 2017. Serum miRNA levels were initially determined using a TaqMan low-density array (TLDA) in pooled samples. Markedly altered miRNAs in IBS-D patients were subsequently validated using quantitative real-time polymerase chain reaction (qRT-PCR) on individual samples. All IBS-D patients accepted the acupuncture therapy for 6 weeks. The disease severity was assessed using the IBS symptom severity scale (IBS-SSS) questionnaire before and after treatment. After acupuncture, the patients' serum was re-analyzed for altered expression of the miRNAs by qRT-PCR. Results: TLDA and qRT-PCR analysis revealed six upregulated miRNAs (miR-1305, miR-575, miR-149-5p, miR-190a-5p, miR-135a-5p, and miR-148a-3p; P < 0.05) and two downregulated miRNAs (miR-194-5p, miR-127-5p; P < 0.05) in IBS-D patients compared with healthy controls. Post acupuncture treatment, total IBS-SSS scores, severity of abdominal pain, duration of abdominal pain, severity of abdominal distention, dissatisfaction with bowel habits and disruption in quality of life decreased significantly (P < 0.001). Furthermore, the upregulated miR-148a-3p levels in IBS-D patients also decreased significantly after acupuncture (P < 0.05). Conclusions: The over-expression or reduced expression of several miRNAs may contribute to IBS-D pathogenesis. Acupuncture might downregulate miR-148a-3p through multiple pathways to alleviate or relieve IBS-D symptoms.