5-去甲川陈皮素上调肠道Muc2表达对溃疡性结肠炎的防治作用及分子机制研究

Ulcerative colitis (UC) is characterized by protracted course of disease, repeated outbreak, and the risk of cancerization. But so far, there are no drugs on the market to completely cure UC. Besides, there are some significant problems in drugs currently available to treat UC, including more and worse untoward reaction and a high recurrence rate. UC was thereby ranked as one of the modern cureless diseases by World Health Organization. Aged-tangerine peels (chenpi), a kind of plant resource using as both medicine and food, has advantages of combination of prevention and cure, little toxicity, low cost, plentiful supply, and so on. Our previous study found that 5-demethylnobiletin (5-DN) purified from chenpi exhibited significantly therapeutic effects on colitis model in mice induced by dextran sulphate sodium (DSS). Furthermore, the results of high-throughout sequencing technology indicated this effectiveness conferred by 5-DN seemed to related to upregulation of intestinal Muc2 expression. Based on these works, we will evaluate the protection function of 5-DN against UC, and will attempt to identify whether the protection effect of 5-DN is achieved by directly activating the nuclear receptor NR2F6 and then upregulating the transcription level of Muc2. The ultimate goal of this study is to fully disclose the molecular mechanisms of protection function afforded by 5-DN against colitis, and provide scientific basis for chenpi and its active component 5-DN used as natural drugs for treatment of UC in the future.

溃疡性结肠炎（Ulcerative colitis，UC）病程长、易反复、且伴有癌变风险。目前尚没有完全治愈UC的药物上市，且现有UC治疗药物存在不良反应多、复发率高等多种弊端。因此，UC被WHO列为现代难治病之一。传统中药材陈皮具有防治结合、毒性极低、价廉易得等优势。我们前期研究发现，陈皮黄酮5-去甲川陈皮素（5-DN）对DSS诱导的小鼠结肠炎具有良好的防治功效，高通量测序显示该功效与其上调肠粘膜上皮黏蛋白Muc2表达有关。在已有工作基础之上，本项目拟利用已建立的天然产物生物活性发现平台，评价5-DN对UC的防治功效，探究该作用是否由5-DN激活核受体NR2F6进而上调Muc2表达实现，并深入分析5-DN与关键节点分子NR2F6之间的药物-蛋白相互作用位点与作用类型，期望在分子水平上全面揭示5-DN对UC防治作用的机制，为陈皮黄酮5-DN作为防治UC的天然药物的开发提供科学依据。

溃疡性结肠炎（Ulcerative colitis，UC）病程长、易反复且伴有癌变风险，现有UC治疗药物存在不良反应多、复发率高等多种弊端，UC也因此被WHO列为现代难治病之一。传统中药材陈皮具有防治结合、毒性极低、价廉易得等优势，在UC防治中具有一定应用前景。本项目前期通过动物模型研究发现，陈皮中5-去甲川陈皮素（5-DN，陈皮中一种多甲氧基黄酮类成分）对DSS诱导的小鼠结肠炎具有良好的防治功效。在前期工作基础上，本项目利用实验室已建立的天然产物生物活性发现平台，证实5-DN对UC小鼠具有确切疗效并首次发掘该作用的分子机制。高通量测序结合RT-qPCR与免疫组化等技术证实5-DN对UC的治疗作用是通过上调肠粘膜上皮黏蛋白Muc2表达实现，且RNAi特异性敲降实验与荧光报告载体实验表明该作用是5-DN通过激活核受体NR2F6而介导实现。利用有机合成手段构建Cy3-5-DN与Biotin-5-DN两个化学探针，在保留5-DN生物活性的基础上，结合蛋白质组学相关实验深入分析5-DN与关键节点分子NR2F6之间的药物-蛋白相互作用位点与作用类型，期望在分子水平上全面揭示5-DN对UC防治作用的机制，为陈皮及其多甲氧基黄酮成分5-DN作为防治UC的天然药物的开发提供科学依据，为UC患者提供毒副作用小、成本低、可长期用药的药物选择。