通过cAMP/PKA/Epac2途径探讨降糖三黄片改善2型糖尿病小鼠SCFAs—β细胞调控胰岛素分泌的机制研究

肠道微生物群与2型糖尿病（T2DM）密切相关，其代谢产物短链脂肪酸（SCFAs）可刺激肠L细胞分泌胰高血糖素样肽-1（GLP-1），再通过“cAMP/PKA/Epac2”通路促进β细胞胰岛素分泌。预实验中发现降糖三黄片组与T2DM模型组小鼠相比存在菌群差异，并能提高 SCFAs及血清GLP-1浓度，但具体靶点不明，故本项目在前期工作基础上，利用db/db 2型糖尿病小鼠模型、采用16S rDNA测序、GC-MS、ELISA、免疫荧光等多种先进方法，研究降糖三黄片对SCFAs与 GLP-1作用；再从胰岛β细胞轴角度分析GLP-1在β细胞上通过PKA/cAMP/EPAC2通路调节胰岛素分泌，研究包括通路相关分子检测、原代胰岛β细胞胰岛素分泌等；最后验证性实验：抗生素复合物干预、菌群移植、SCFAs回补，再次验证降糖三黄片通过调节菌群生态平衡，调控T2DM血糖、胰岛素分泌。

The gut microbiota is closely related to T2DM. SCFAs can stimulate the secretion of glucagon like peptide-1 (GLP-1) by intestinal L cells, and then promote insulin secretion of β cells through camp/pka/epac2 pathway. In the pre experiment, it was found that there were different bacteria groups between JiangTang Sanhuang tablets group and model group, and the concentration of SCFAs and serum GLP-1 was increased. However, the specific target was unknown. Therefore, based on the previous work, the project used db/db 2 diabetic mice model, 16S rDNA sequencing, GC-MS, ELISA, immunofluorescence and other advanced methods to study the effect of Jiangtang Sanhuang tablets on SCFAs and GLP-1. The effect of GLP-1 was analyzed From the perspective of β cell axis of intestine islet. The study content includes the detection of pathway related molecules and insulin secretion of primary islet β cells. Finally, the confirmatory experiment: antibiotic complex intervention, flora transplantation, SCFAs supplement was used to verify that Jiangtang Sanhuang tablets can regulate T2DM blood glucose and insulin secretion by regulating the ecological balance of flora. This project not only discusses the hypoglycemic mechanism of Jiangtang Sanhuang tablets, but also can be used as the evidence to support the close relationship between SCFAs - β cells.