Identification of a Novel Substance P-Neurokinin-1 Receptor MicroRNA-221-5p Inflammatory Network in Human Colonic Epithelial Cells
- Author(s): Fang, K
- Sideri, A
- Law, IKM
- Bakirtzi, K
- Polytarchou, C
- Iliopoulos, D
- Pothoulakis, C
- et al.
Published Web Locationhttps://www.ncbi.nlm.nih.gov/pubmed/?term=PMC4669978
© 2015 The Authors. Background & Aims: Substance P (SP), a neuropeptide member of the tachykinin family, plays a critical role in colitis. MicroRNAs (miRNAs) are small noncoding RNAs that negatively regulate gene expression. We examined whether SP modulates expression of microRNAs in human colonic epithelial cells. Methods: We performed microRNA profiling analysis of SP-stimulated human colonic epithelial NCM460 cells overexpressing neurokinin-1 receptor (NCM460-NK-1R). Targets of SP-regulated microRNAs were validated by real-time polymerase chain reaction (RT-PCR). Functions of miRNAs were tested in NCM460-NK-1R cells and the trinitrobenzene sulfonic acid (TNBS) and dextran sulfate sodium (DSS) models of colitis. Results: SP stimulated differential expression of 29 microRNAs, including miR-221-5p, the highest up-regulated miR (by12.6-fold) upon SP stimulation. Bioinformatic and luciferase reporter analyses identified interleukin-6 receptor (IL-6R) mRNA as a direct target of miR-221-5p in NCM460 cells. Accordingly, SP exposure of NCM460-NK-1R cells increased IL-6R mRNA expression, and overexpression of miR-221-5p reduced IL-6R expression. Nuclear factor κB and c-Jun N-terminal kinase inhibition decreased SP-induced miR-221-5p expression. MiR-221-5p expression was increased in both TNBS- and DSS-induced colitis and in colonic biopsy samples from ulcerative colitis butnot Crohn's disease patients compared with controls. In mice, intracolonic administration ofa miR-221-5p chemical inhibitor exacerbated TNBS- and DSS-induced colitis and increased colonic tumor necrosis factor-α, C-X-C motif chemokine 10 (Cxcl10), and collagen, type II, α 1 (Col2α1) mRNA expression. In situ hybridization in TNBS- and DSS-exposed colons revealed increased miR-221-5p expression primarily in colonocytes. Conclusions: Our results reveal a novel NK-1R-miR-221-5p-IL-6R network that protects from colitis. The use of miR-221-5p mimics may be a promising approach for colitis treatment.
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