Neurotensin--regulated miR-133α is involved in proinflammatory signalling in human colonic epithelial cells and in experimental colitis.

Abstract

OBJECTIVE:

Neurotensin (NT) mediates colonic inflammation through its receptor neurotensin receptor 1 (NTR1). NT stimulates miR-133α expression in colonic epithelial cells. We investigated the role of miR-133α in NT-associated colonic inflammation in vitro and in vivo.

DESIGN:

miR-133α and aftiphilin (AFTPH) levels were measured by quantitative PCR. Antisense (as)-miR-133α was administrated intracolonicaly prior to induction of 2, 4, 6-trinitrobenzene sulfonic acid (TNBS)-induced colitis and dextran sodium sulfate (DSS)-induced colitis. The effect of AFTPH was examined by gene silencing in vitro.

RESULTS:

NT increased miR-133α levels in NCM-460 overexpressing NTR1 (NCM460-NTR1) and HCT-116 cells. NT-induced p38, ERK1/2, c-Jun, and NF-κB activation, as well as IL-6, IL-8 and IL-1β messenger RNA (mRNA) expression in NCM-460-NTR1 cells were reduced in miR-133α-silenced cells, while overexpression of miR-133α reversed these effects. MiR-133α levels were increased in TNBS (2 day) and DSS (5 day) colitis, while NTR1 deficient DSS-exposed mice had reduced miR-133α levels, compared to wild-type colitic mice. Intracolonic as-miR-133α attenuated several parameters of colitis as well expression of proinflammatory mediators in the colonic mucosa. In silico search coupled with qPCR identified AFTPH as a downstream target of miR-133α, while NT decreased AFTPH expression in NCM-460-NTR1 colonocytes. Gene silencing of AFTPH enhanced NT-induced proinflammatory responses and AFTPH levels were downregulated in experimental colitis. Levels of miR-133α were significantly upregulated, while AFTPH levels were downregulated in colonic biopsies of patients with ulcerative colitis compared to controls.

CONCLUSIONS:

NT-associated colitis and inflammatory signalling are regulated by miR-133α-AFTPH interactions. Targeting of miR-133α or AFTPH may represent a novel therapeutic approach in inflammatory bowel disease.

• Authors: Ivy Ka Man Law, Kyriaki Bakirtzi, Christos Polytarchou, Angelos Oikonomopoulos, Daniel Hommes, Dimitrios Iliopoulos, Charalabos Pothoulakis
• Journal: Gut (Gut) Vol. 64 Issue 7 Pg. 1095-104 (Jul 2015) ISSN: 1468-3288 [Electronic] England
• PMID: 25112884 (Publication Type: Journal Article, Research Support, N.I.H., Extramural, Research Support, Non-U.S. Gov't)
• Copyright: Published by the BMJ Publishing Group Limited. For permission to use (where not already granted under a licence) please go to http://group.bmj.com/group/rights-licensing/permissions.

Chemical References

• MicroRNAs
• Mirn133 microRNA, mouse
• NF-kappa B
• Nerve Tissue Proteins
• Receptors, Neurotensin
• neurotensin type 1 receptor

Topics

• Animals
• Colitis (physiopathology)
• Colon (cytology, physiology)
• Epithelial Cells (physiology)
• HCT116 Cells
• Humans
• Mice
• Mice, Knockout
• MicroRNAs
• NF-kappa B (physiology)
• Nerve Tissue Proteins (physiology)
• Receptors, Neurotensin (genetics)
• Signal Transduction (physiology)
• Up-Regulation (physiology)