基于肠道菌群研究中药组分复方GC方调节非酒精性脂肪肝GLP-1合成与分泌的机制

Our previous reaserch has proved that the optimized prescription composed of Geniposide and Chlorogenic acid (the“GC” prescription) had an ideal effect on resisting fatty-liver and significantly increased the glucagon-like peptide-1 (GLP-1) content in non-alcoholic fatty liver (NAFL) experimental animal, and it also had remarkable influence on gut microbiota of NAFL rat. Based our previous work and the theory that the gut microbiota/short-chain fatty acids (SCFAs)/ GPR41(also known as FFAR3)＆GPR43(also known as FFAR2) signaling pathways play important roles on triggering synthesis and secretion of GLP-1 through regulating intestinal endocrine L cell, we propose the hypothesis that the GC prescription may regulate L cell causing synthesis and secretion of GLP-1 through Gut microbiota /SCFAs/ GPR41＆GPR43 signaling pathways, which can impove the liver lipid metabolism to treat fatty liver disease .In this research, we use two kinds of mouse models (NAFL mice model induced by high-fat diet and germ-free mice model) and a cellular model (SCFAs induce intestinal endocrine STC-1cell strain secreting GLP-1 in vitro). Arounding the key components of Gut microbiota ,SCFAs, GPR41＆GPR43 signaling pathways, synthesis and secretion of GLP-1 and the hepatic lipid metabolism, we verify from both positive and negative aspects whether the “GC” prescription has the pharmacological effects on glucose and lipid metabolism through regulating gut microbiota. The study is to reveal the mechanism of the “GC” prescription in treating fatty liver disease which may lay the scientific basis for the future development of new drugs.

本项目在前期证实GC方对非酒精性脂肪肝(NAFLD)有显著疗效,可显著升高NAFLD大鼠胰高血糖素样肽-1(GLP-1)含量，并显著调节肠道菌群紊乱基础上，结合“肠道菌群可通过其发酵产物短链脂肪酸（SCFAs）调节肠道内分泌L细胞合成与分泌GLP-1”的理论认识，提出“GC方可能通过影响肠道菌群/SCFAs/ GPR41＆GPR43通路调节肠道L细胞GLP-1的合成与分泌，进而改善肝脏脂肪代谢治疗NAFLD”的假说。拟采用两种整体模型（高脂饮食诱导的小鼠NAFL模型、无菌小鼠模型）及SCFAs诱导肠道内分泌细胞株STC-1分泌GLP-1体外细胞模型，围绕肠道菌群、SCFAs、GPR41＆GPR43、GLP-1合成与分泌及肝脂肪代谢等关键环节，正反两方面验证GC方是否通过影响肠道菌群，调节GLP-1合成与分泌而影响糖脂代谢，以阐释该方治疗NAFLD的机制，为今后研发新药奠定基础。

课题围绕“中药成分复方GC方可能通过影响肠道菌群/SCFAs/ GPR41＆GPR43通路调节肠道L细胞合成与分泌GLP-1，进而改善肝脏脂肪代谢治疗NAFLD”假说，采用高脂饮食诱导的小鼠NAFLD模型、db/db小鼠脂肪肝模型、无菌小鼠以及肠道内分泌细胞株细胞模型，探讨该方治疗NAFLD的作用机制。.课题实施进展顺利，获得以下主要研究结果：① GC方可显著改善高脂饮食诱导的NAFLD小鼠及db/db小鼠肝脂肪变性、炎症以及气球样变性，降低肝组织脂肪含量、血清转氨酶活性及血糖血脂；②GC方显著升高两种模型小鼠结肠GLP-1蛋白表达、血清总GLP-1及活性GLP-1蛋白含量；③GC方显著升高NAFLD小鼠结肠内容物中SCFAs含量及结肠组织GPR41的表达；④GC方可显著升高NAFLD模型小鼠与产SCFAs相关的普雷沃菌、乳酸菌、乳酸双歧杆菌、Akkermansia及Allobaculum、的丰度；⑤GC方对无菌小鼠结肠GLP-1蛋白表达、血清总GLP-1及活性GLP-1蛋白含量无明显影响；⑥GC方对人结直肠腺癌细胞株NCI-H716合成及分泌GLP-1无影响。.综合体内外实验结果，研究获得以下主要结论：①GC方对实验性脂肪肝疗效显著；②增加NAFLD模型小鼠普雷沃菌、乳酸菌、乳酸双歧杆菌、Akkermansia及Allobaculum等肠道菌丰度，升高结肠内SCFAs产量，进而促进结肠GLP-1的合成与分泌是GC方治疗实验性NAFLD的主要作用机制。.项目研究工作顺利完成，达到预期目标。已发表标注论文9篇（其中SCI收录5篇），国际会议口头汇报交流论文1篇，美肝会壁报交流论文1篇，国内会议特邀报告2次，获专利授权1项，培养研究生3名。研究为探索成分明确、并可进一步提高疗效的抗脂肪肝中药成分复方制剂提供坚实理论依据。