Cinacalcet Targets the Neurokinin-1 Receptor and Inhibits PKCδ/ERK/P65 Signaling to Alleviate Dextran Sulfate Sodium-Induced Colitis.

Yuehong Chen,Qiuping Zhang,Liang Wu,Yubin Luo,Yutong Zhong,Yaoyu Pu,Geng Yin,Huan Liu,Chenyang Lu,Qibing Xie,Zhigang Tang

doi:10.3389/fphar.2021.735194

Abstract

Objective: Inflammatory bowel disease is an immune-mediated chronic inflammatory disease of the gastrointestinal tract for which curative drugs are currently not available. This study was performed to assess the therapeutic effects of cinacalcet on dextran sulfate sodium (DSS)-induced colitis. Methods: Primary macrophages obtained from bone marrow and the macrophage cell line RAW264.7 were used to examine the inhibitory effect of cinacalcet on cytokine production, the PKCδ/ERK/P65 signaling pathway, and NF-κB P65 translocation. Colitis was induced using DSS to assess the treatment effect of cinacalcet. Bioinformatics approaches were adopted to predict potential targets of cinacalcet, and a drug affinity responsive target stability (DARTs) assay was performed to confirm binding between cinacalcet and potential target. Results: In vivo analysis showed that cinacalcet reduced the disease activity score, prevented shortening of the colon, diminished inflammatory cell infiltration, and protected the structural integrity of the intestinal wall. Cinacalcet also reduced production of the inflammatory cytokines TNFα, IL-1β, and IL-6 in the colon and sera of mice with DSS-induced colitis. In vitro studies revealed that cinacalcet suppressed the translocation of P65 and inhibited production of the inflammatory cytokines IL-1β and IL-6. Mechanistic studies revealed that the target of cinacalcet was neurokinin-1 receptor (NK1R) and their binding was confirmed by a DARTs assay. Furthermore, the inhibition of NK-κB P65 activation was found to occur via the suppression of PKCδ/ERK/P65 signaling mediated by cinacalcet. Conclusion: Cinacalcet inhibits the activation of NF-κB and reduces the production of inflammatory cytokines by suppressing the PKCδ/ERK/P65 signaling pathway via targeting NK1R, suggesting that it can be used to treat inflammatory diseases, particularly colitis.

Highlights

Inflammatory bowel disease (IBD) is an immune-mediated chronic inflammatory disease of the gastrointestinal tract and includes ulcerative colitis and Crohn’s disease
To test whether cinacalcet has an inhibitory effect on the production of inflammatory cytokines induced by Tumor necrosis factor α (TNFα), we used both the primary macrophages Bone marrow-derived macrophages (BMDMs) and the macrophage cell line RAW264.7
The secretion levels of IL-1β and IL-6 in the cell culture supernatants induced by TNFα were dosedependently decreased by cinacalcet (Figures 1C,D)

Summary

Introduction

Inflammatory bowel disease (IBD) is an immune-mediated chronic inflammatory disease of the gastrointestinal tract and includes ulcerative colitis and Crohn’s disease. The pathogenesis of IBD is unclear but it is considered to be associated with the genetic susceptibility of individuals, external environment, and intestinal mucosal immune system (Khor et al, 2011; Zhang and Li, 2014; de Souza and Fiocchi, 2016; Ramos and Papadakis, 2019). Tumor necrosis factor α (TNFα), which is at the top of the cytokine cascade, can be released by macrophages and stimulates the nuclear factor (NF)κB signaling pathway which plays a crucial role in the pathogenesis of IBD (Neurath, 2014; de Souza and Fiocchi, 2016; Park and Jeen, 2018). Inhibition of TNFα-induced NF-κB activation shows therapeutic effects against IBD

Methods

Results

Conclusion