基于GLP-2信号通路研究高直链淀粉日粮促进羔羊小肠上皮生长的分子机制

幼龄反刍动物小肠的生长发育状况对保证动物健康及提高动物生产性能至关重要。前期研究发现，高直链淀粉日粮可促进羔羊小肠上皮生长，但其确切机制尚不清楚。本项目拟在此基础上，利用流式细胞计数、实时定量PCR、western blot及免疫荧光等技术手段，研究高直链淀粉日粮对羔羊小肠上皮细胞增殖及增殖相关基因和蛋白表达的影响，解析高直链淀粉日粮对小肠组织中GLP-2及GLP-2R的mRNA及蛋白表达水平的影响，探讨小肠上皮细胞增殖与GLP-2生成间的内在关联。在此基础上，采用肠原代细胞培养，研究IGF-1/PI3K/AKT信号通路在GLP-2调节小肠上皮细胞增殖中的作用机制。项目结果有助于揭示高直链淀粉日粮促进羔羊小肠上皮生长的分子机制，并可为羔羊营养调控策略的制订提供新思路。

The intestinal growth and development of young ruminant is critical for their health and performance. Previous studies found that high-amylose diet promoted the growth of intestinal epithelium in lamb, but the exact molecular mechanism is unclear. Thus, through the use of flow cytometry, real-time quantitative PCR, western blot and immunofluorescence technology, this project was to (1) study the effect of the high-amylose diet on small intestinal epithelial cell proliferation and proliferation-related genes and protein expression in lamb; (2) investigate the effect of the high-amylose diet on mRNA and protein expression levels of GLP-2 and GLP-2R in small intestinal tissue of lamb; and (3) explore the relationship between intestinal epithelial cell proliferation and secretion of endogenous GLP-2. Furthermore, an intestinal primary cell culture experiment was designed to explore the role of IGF-1/PI3K/AKT signaling pathway in GLP-2 promoting intestinal epithelial cell proliferation. These results will help reveal the molecular mechanism of high-amylose diet promoting growth of intestinal epithelium and provide new insight into the development of nutritional regulation strategy of lamb.