基于肠道菌群调整和TLR/MYD88/NF-κb信号通路探讨大黄素延缓尿毒症动脉粥样硬化机制的研究

Emodin is an important component of traditional Chinese medicine in treatment of uremia which helps alleviate atherosclerosis, but the mechanism is still unknown . Studies have confirmed the disorder of intestinal microflora in uremia can accelerated atherosclerosis by the metabolites of intestinal flora,and the intestinal flora disturbance may activate TLR4 signaling pathway promotes atherosclerosis.We assume that the structure of intestinal flora and TLR4/MYD88 signaling pathway is important way which uremic accelerated atherosclerosis and.also the target of emodin in the uremic atherosclerosis. We use animal and cell models, uremia, or in vitro uremic serum . Firstly, expounds the intestinal bacteria colony disorder and TLRs signaling pathway leads to the artery atherosclerosis; then illustrates the emodin byadjusting the intestinal flora and the regulation of the inflammatory pathway to improve the atherosclerosis; finally through gene engineering cell model,clarify emodin regulate of the inflammatory pathways then improve atherosclerosis promote the transformation and application of traditional Chinese medicine clinical.

心血管疾病是尿毒症患者重要的并发症和主要死因，而尿毒症动脉粥样硬化(AS)备受关 注，大黄素是临床治疗尿毒症重要组分中药有助于缓解动脉粥样硬化，但机制不明。研究证实 尿毒症肠道菌群紊乱可通过菌群代谢产物氧化三甲胺加速动脉粥样硬化的发生发展，而且肠道 菌群紊乱可能激活TLRs信号传导通路促进动脉粥样硬化。假设肠道菌群结构和TLR4/MYD88信号 通路既是尿毒症加速动脉粥样硬化的途径也是大黄素干预尿毒症动脉粥样硬化的靶点。在尿毒 症或体外尿毒症血清培养下，我们借助动物和细胞模型，首先阐明肠道菌群紊乱和TLR4信号通 路导致的动脉动脉粥样硬化;其次探讨大黄素通过调整肠道菌群和调控该炎症通路而改善动脉 粥样硬化的效果和机制;最后通过基因工程细胞模型，揭露大黄素调控该炎症通路关键上游信 号而改善动脉粥样硬化，提示大黄素治疗尿毒症动脉粥样硬化的靶点，促进其在中医临床的转 化应用。

目的:研究大黄素对ApoE-/-尿毒症动脉粥样硬化模型肠道菌群和动脉粥样硬化的影响。方法:建立ApoE-/-尿毒症动脉粥样硬化模型，分为对照组，模型组和大黄素组TLR4抑制剂组，检测大鼠肌酐(SCr)、尿素氮(BUN)、⽢油三酯(TG)、⾎脂总胆固醇(Tc)水平。取各组粪便，检测各组肠菌群情况。免疫组化检测各组主动脉TLR4/MYD88信号通路，主动脉的油红O染色病变评价动脉粥样情况，并建立细胞模型，分别检测大黄素和TLR4抑制剂对内皮细胞、巨噬细胞TLR4、MYD88、NF-κB巨噬细胞和内⽪细胞中TLR4、MYD88、NF-κB、巨噬细胞中 PCSK9、LDLR、内⽪细胞中TP-结合盒转运⼦A1(ABCA1)、单核细胞趋化因⼦-1(MCP-1)基因的蛋⽩表达⽔平。结果:模型组大鼠肌酐(SCr)、尿素氮(BUN)、⽢油三酯(TG)、⾎脂总胆固醇(Tc)水平明显增高，大黄素和TLR4抑制剂可以控制SCr、BUN、TG、Tc，TLR4抑制剂组最明显，油红O染色病变进行量化显示，大黄素组和TLR4抑制剂组的病变百分比明显低于模型组，TLR4抑制剂组病变缓解最明显，TLR4抑制剂组和大黄素组均有效提高了小鼠有益肠道菌群的丰度，其中大黄素组厚壁菌门丰度降低了30.96%，拟杆菌门丰度提高了 27.9%。结论:大黄素能有效的改善尿毒症动脉粥样硬化模型的肠道菌群，抑制TLR4信号同路改善动脉粥样硬化。