LGG上清液上调pax6促进肠道L细胞分泌glp1治疗腹泻型肠易激综合征的机制研究

益生菌治疗腹泻型肠易激综合征(D-IBS)效果肯定但机制不详。我们研究发现粪菌移植可上调肠道L细胞胰高血糖素样肽1(GLP-1)转录因子Pax6及GLP-1表达，减缓胃肠蠕动；研究发现GLP-1类似物可改善D-IBS患者腹泻症状；我们还发现鼠李糖乳杆菌GG(LGG)可上调小鼠肠上皮L细胞Pax6及GLP-1表达；细胞实验亦证明LGG上清可上调其表达但机制尚不明。本研究拟①运用肠道内分泌细胞系STC-1及GLUTag进一步验证LGG上清液对Pax6/GLP-1通路的影响及分子机制；②运用LGG干预本实验室已建立的空肠弯曲菌诱导D-IBS动物模型验证LGG上调GLP-1的作用，体内验证可能分子机制；③SDS-PAGE、MALDI-TOF等方法筛选关键作用蛋白，D-IBS模型上运用所筛选关键蛋白进一步验证其对D-IBS的治疗作用。本课题旨在发现基于Pax6/GLP-1途径治疗D-IBS的新药研究

Lactobacillus rhamnosus GG (LGG) can improve the diarrhea predominant irritable bowel syndrome (D-IBS) patients’ symptoms, including abdominal pain and diarrhea,but the mechanism is unclear. PAX6 is the key factor for the transcription of glucagon like peptide 1 (GLP-1). GLP-1 can slow the gastrointestinal motility, and GLP-1 analogues can effectively improve the clinical symptoms of patients with D-IBS. In our previous work, the results showed that the GLP-1 and PAX6 expression in intestinal epithelial L cells could be increased by fecal bacteria transplantation and LGG supernatant. So whether LGG supernatant can active PAX6 then increase the synthesis of GLP-1 plays a pivotal role in the treatment of D-IBS and its mechanism is worthy to study. This study intends to ①Analyze that after treatment of LGG supernatant in STC-1 and GLUTag cell lines，MAPK/ERK signaling pathway activation and the expression of transcription factor Pax6 and GLP-1.Using MAPK/ERK signal pathway blocker before or after LGG supernatant treated, detect the expression changes of the above factors. Clarify the molecular mechanism of LGG supernatant increase the synthesis level of GLP-1. ②The application of LGG supernatant intervention animal model of D-IBS, the expression level in general were compared before and after the intervention of key molecules in MAPK/ERK/PAX6 signaling pathway, secretion of serum GLP-1, to further verify the effect and mechanism of LGG supernatant up-regulated the expression of GLP-1 in vivo. ③Analysis and scream the probiotics which can activate the Pax6/GLP-1 signaling that search the differential proteins that increase the serum GLP-1 level, the molecular changes and clinical manifestations of animals with D-IBS before and after treatment. The purpose of this study is to provide theoretical basis for the clinical application of probiotics in the treatment of D-IBS based on GLP-1.