炎症"程序性消退"介质RvE1在银屑病治疗中作用机制研究

Emerging evidence now suggests that an active, coordinated program of resolution initiates in the first few hours after an inflammatory response begins. It shows a highly ordering process named "programmed resolution" of inflammation. Among the new classes of specialized pro-resolving lipid mediators, RvE1 shows the same effects as Lipoxin A4 (LXA4) which can prevent excessive inflammation and promote removal of microbes and apoptotic cells. It can shorten the period of neutrophil infiltration by initiating apoptosis. Consequently, apoptotic neutrophils undergo phagocytosis by macrophages, leading to neutrophil clearance and release of anti-inflammatory cytokines. More over, it has special features of the highest efficiency on diminishing inflammation by nano level dose; at the same time, it does not increasse the inflammatory cytokines for it is come from ω-3 unsaturated fatty acid. Thus we make a hypothesis that RvE1 could inhibit the occurrence of inflammation and also promote the resolution of inflammation. Upregulation and inhibition the funciton of RvE1 were adopted to analyse anti-inflammation effectiveness of RvE1 on Th17 cells, TNF-α-NF-κB and RIP3 pathways. We aim to study the regulatory efficacy of RvE1 on keratinocytes,Th17 cells, neutrophils and macrophages though cell culture and animal experiments. The aim of this project is to go further study in clarifying the mechanism how RvE1 can promote the resolution of the inflammation in psoriasis which may lead to a novel therapeutic strategy for treating skin inflammatory diseases such as psoriasis.

炎症反应在启动同时就已经规划了炎症消退，通常呈现出一个高度有序化过程- - 炎症"程序性消退"(Programmed Resolution)。新近发现的内源性促炎症消退介质中，消退素RvE1不仅具有我们前期银屑病研究中脂氧素A4抗中性粒细胞趋化、促其凋亡和促巨噬细胞吞噬三大作用；而且具有在纳克级即发挥迄今为止最强大抗炎作用、不反馈性引起炎性因子增高（因来源于ω-3不饱和脂肪酸）等独特优势。本课题拟通过给予外源性的RvE1或阻断其受体ChemR23或/和BTL1作用，探讨RvE1对Th17细胞、TNF-α-NF-κB和RIP3通路的影响。通过细胞和动物实验，研究RvE1对角质形成细胞、Th17细胞、中性粒细胞、巨噬细胞功能的调节。从炎症"消退障碍"这一新角度阐述银屑病的发病机制，从"堵疏"兼顾的"抗炎与促进炎症消退"相结合这一新策略入手进行干预，期望对银屑病发病机制产生新认识，为治疗开辟新思路。

促炎症介质推动炎症的产生，但机体同时存在内源性促炎症消退介质调控炎症的“程序性消退”。在银屑病中，机体的炎症自限机制异常可引发炎症消退障碍，导致银屑病的迁延不愈和复发。我们的合作者Serhan教授发现了一系列“促炎症消退”介质，包括脂氧素、消退素及神经保护素等，外源性给予内源性促炎症消退介质可以在纳克水平即发挥强大的抗炎作用，且不反馈性引起炎症因子的增高。. 我们在前期研究脂氧素A4（LXA4）的基础上，进一步研究消退素E系列和D系列在银屑病发病机制中的作用。消退素E1（RvE1）来源于EPA,三年前Serhan教授进行了RvE1治疗干眼病和疼痛的II期和III期临床试验，但在试验期间停止了全球市场上RvE1的供应。Serhan教授建议我们，继续研究底物为DHA 的消退素D1（RvD1），两者抗炎效应非常类似，在目前“促炎症消退”介质中效果最理想，并且RvD1抗炎时结合受体与LXA4基本吻合，研究LXA4作用机制对研究RvD1抗炎机制有重要参考价值。 . 项目通过外源性给予RvD1和LXA4及其受体拮抗剂，应用咪喹莫特诱导的银屑病样皮损动物模型和角质形成细胞，研究银屑病发病过程中RvD1、LXA4及其受体的表达情况，调节MAPKs、SOCS2/TRAF6、ERK/NF-kB信号通路和HMGB1、IL-23, IL-17及TNF-α等炎症因子的作用机制。. 结果显示，原代角质形成细胞和Hacat细胞均可以表达消退素RvE1、RvD1受体；RvD1和LXA4能明显减轻咪喹莫特诱导的小鼠银屑病样炎症反应；RvD1能抑制MAPKs及NF-κB-p65信号转导通路的激活，降低NF-κB-p65蛋白结合活性，且这种对炎症的消退作用在外源性给予ALX受体拮抗剂Boc时被阻断，提示ALX可能是RvD1在银屑病中促炎症消退的下游作用因子；LPS可诱导HaCat细胞中ICAM-1表达的增加，RvD1呈剂量依赖抑制LPS诱导的ICAM-1的表达；LXA4通过调控SOCS2/TRAF6、ERK/NF-kB、调节HMGB1转位和表达等作用，抑制人角质形成细胞炎性因子的释放。. 通过这些研究，“促炎症消退”介质RvD1和LXA4在促进银屑病炎症消退中发挥重要作用，提示“抗炎与促炎症消退”相结合是治疗银屑病的有效策略。