中草药来源的MiR-5368对溃疡性结肠炎的治疗作用与机制研究

Traditional Chinese herbs have been used to treat ulcerative colitis [UC] for thousands of years, while little was known about the specific mechanism. MicroRNAs have been widely found in animals and plants, which play an important role in post transcriptional regulation. Our previous study scanned several traditional Chinese herds used for UC treatment and found stable microRNAs in Chinese herbal decoctions, among which small RNAs extracted from Scutellaria Decoction were proved useful in alleviating the inflammation of dextran sulfate sodium [DSS]-induced experimental colitis in mice，both systematically and locally. MiR-5368, detected in several herbs, was evaluated and confirmed to lead to down-regulated expression of the vital inflammatory cytokine TNF-alpha in vitro. . Based on our previous study, further details need to be studied: firstly, further evaluation of other inflammatory-associated indexes to improve the overall assessment; secondly, the direct target cells and direct target genes of MiR-5368 by using primary cell culture, RNA pull down, high-throughput sequencing, bioinformatics, qRT-PCR, Western Blot and ELISA; next, pharmacokinetics to delve the route——the absorption，distribution and the localization——of MiR-5368 in situ of inflammatory colon by means of immunofluorescence and tracer technique; finally, more Chinese herbs will be enrolled and tested to analyze the universality of such a phenomenon that small RNAs derived from hers could be effective on the treatment of UC. . By studying the influence of herb-derived MiR-5368 on inflammatory colon mucosa, this project is proposed to provide more experimental evidence for the application of traditional Chinese hers in treatment of UC, with an attempt to bring new ideas for clinical treatment of this disease.

中医药治疗溃疡性结肠炎(ulcerative colitis,UC)疗效确切，但有关作用机制研究仍十分匮乏。我们前期筛选了多种用于治疗UC的中草药，发现中药汤中存在稳定的小RNA，证实黄芩汤小RNA灌肠可减轻实验性结肠炎小鼠全身及局部炎症，其中，MiR-5368可下调UC疾病过程中关键炎症因子TNF-alpha的表达。在此基础上，本研究设计为：在巨噬细胞及结肠上皮细胞中检测中草药来源的MiR-5368对TNF-alpha、IL-6等炎症相关基因表达的调控作用；利用DSS实验性结肠炎小鼠模型验证MiR-5368灌肠的治疗效果；采用荧光示踪技术研究MiR-5368在野生型及SIDT1基因敲除小鼠体内的吸收、分布及定位；同时，增加UC相关中草药的研究种类，以论证中草药来源的小RNA产生抗炎作用的普遍性和意义，旨在为中草药治疗UC提供新的理论基础与实验依据，以期为炎症性肠病的临床治疗带来新思路。

中医中药治疗溃疡性结肠炎(ulcerative colitis,UC)有明显疗效，但确切机制未明。本研究证实了用于治疗UC的中草药存在稳定的小RNA。中草药来源的miR5368灌肠直接或通过血液循环进入巨噬细胞，作用于TNF-alpha及IL-6的mRNA，抑制其翻译，使得巨噬细胞分泌的TNF-alpha、IL-6减少，阻断结肠上皮细胞内炎症通路，进而减轻肠道炎症与组织损伤，并正反馈减少对巨噬细胞的刺激与招募，最终改善实验性结肠炎小鼠全身及局部炎症。本研究为传统中草药治疗溃疡性结肠炎提供了新的理论基础与实验证据，同时为炎症性肠病的临床治疗带来新的思路。