Neurotensin promotes the development of colitis and intestinal angiogenesis via HIF-1α-miR-210 signaling

Abstract

Neurotensin (NT) via its receptor 1 (NTR1) modulates development of colitis, decreases HIF-1α/PHD2 interaction, stabilizes and increases HIF-1α transcriptional activity and promotes intestinal angiogenesis. HIF-1α induces miR-210 expression while miR-210 is strongly up-regulated in response to NT in NCM460 human colonic epithelial cells overexpressing NTR1 (NCM460-NTR1). Here we examined whether NT activates a NTR1-HIF-1α-miR-210 cascade using in vitro (NCM460-NTR1 cells) and in vivo [transgenic mice overexpressing (HIF-1α-OE) or lacking HIF-1α (HIF-1α-KO) in intestinal epithelial cells and mice lacking NTR1 (NTR1-KO)] models. Pre-treatment of NCM460-NTR1 cells with the HIF-1α inhibitor PX-478 or silencing of HIF-1α (si-HIF-1α) attenuated miR-210 expression in response to NT. Intracolonic 2,4,6-trinitrobenzenesulfonic acid (TNBS) administration (2-day model) increased colonic miR-210 expression that was significantly reduced in NTR1-KO, HIF-1α-KO mice, and in wild-type (WT) mice pre-treated intracolonicaly with locked nucleic acid anti-miR-210 (LNA-anti-miR-210). In contrast, HIF-1α-OE mice showed increased miR-210 expression at baseline that was further increased following TNBS administration. HIF-1α-OE mice had also exacerbated TNBS-induced neovascularization compared to TNBS-exposed WT mice. TNBS-induced neovascularization was attenuated in HIF-1α-KO mice, or mice pre-treated intracolonicaly with anti-miR-210. Intracolonic anti-miR-210 also reduced colitis in response to TNBS (2 days). Importantly, miR-210 expression was increased in tissue samples from ulcerative colitis patients (UC). We conclude that NT exerts its proinflammatory and proangiogenic effects during acute colitis via an NTR1-PHD2/HIF-1α-miR-210 signaling pathway. Our results also demonstrate that miR-210 plays a proinflammatory role in the development of colitis.