Hsa-miR-374b-5p and hsa-miR-106a-5p are associated with inflammatory bowel disease through targeting IL-10/STAT3 axis

Abstract Purpose Inflammatory bowel disease (IBD), mainly including ulcerative colitis (UC) and Crohn’s disease (CD), is a common gastrointestinal disorder worldwide. Recent studies revealed that there is a strong connection between the regulatory mechanism of miRNA and IBD etiology. In the current study, we aim to investigate the potential role of hsa-miR-374b-5p(miR-374b-5p) and hsa-miR-106a-5p (miR-106a-5p)in regulating IBD development. Methods Serum was obtained from vein blood of IBD patients and healthy controls ,qRT-PCR was performed to study the expression of miR-374b-5p and miR-106a-5p. Furthermore ,we investigate the effects of overexpression or inhibition of miR-374b-5p on naïve CD4 + T cell subsets differentiation from vein blood of healthy controls by qRT-PCR, flow cytometry and western blot. And more the prediction and confirmation of the targeting genes of miR-374b-5p and miR-106a-5p were performed by bioinformatics softwares and dual-luciferase reporter assay. Results We found that miR-106a-5p and miR-374b-5p were markedly upregulated in the serum of IBD patients, and hsa-miR-374b-5p was able to facilitate the Th1 and Th17 differentiation and is associated with IBD pathogenicity. Overexpression of miR-374b-5p increased IFN-γ, IL-17A mRNA levels, and decreased IL-10 mRNA levels in CD4+T cells by qRT-PCR. Moreover, inhibition of miR-374b-5p decreased IFN-γ, IL-17A, and increased IL-10 mRNA levels in CD4+ T cells; these were further confirmed at protein level by flow cytometry and western blot. Additionally, we confirmed IL-10 as a novel target gene of miR-374b-5p by dual-luciferase reporter assay, which has been identified as anti-inflammatory cytokine to negatively regulate the development of IBD. Otherside, we identified STAT3 as a target gene of miR-106a-5p by dual-luciferase reporter assay. Our subsequent study observed that the JAK1/STAT3 pathway were regulated by miR-374b-5p through IL-10/STAT3 axis in CD4+T cells. Overexpression of miR-374b-5p could significantly decrease STAT3 mRNA levels and serine phosphorylation(ser-727) of STAT3 protein levels and inhibition of miR-374b-5p could significantly increase STAT3 mRNA levels and serine phosphorylation(ser-727) of STAT3 protein levels respectively. Conclusion MiR-374b-5p and miR-106a-5p may play an important role in IBD pathogenesis through targeting IL-10/STAT3 axis.