GC-C通过Wnt/beta-Catenin通路诱导回肠干细胞向潘氏细胞分化的机制研究

The interaction of intestinal microflora, Paneth cells and immune cells is essential for the physiological function of the intestine. Guanylyl cyclase C (GC-C) is expressed in intestinal epithelial cells. Activation of GC-C by its ligands elevates intracellular cyclic GMP (cGMP) levels and regulates the fluid secretion, mechanical sensitivity and mucosal inflammation, which are the essential regulations of intestinal flora. The proliferation and differentiation to Paneth cells of intestinal stem cells are under the control of the Wnt/β-catenin signaling pathway. In the current project, we will combine the in vivo study, enteroids platform and single stem cells study. The methods include immunofluorescence, flow cytometry, western blot, qPCR and etc. The aims are the effects of GC-C on the number and function of Paneth cells, the regulation of GC-C on Paneth cells through Wnt/β-catenin signaling pathway and the mechanism of increased cGMP activating Wnt/β-catenin signaling pathway. The current project will help to further understand the function of GCC signaling in intestinal function under the physiological and pathphysiological conditions. The information could offer new therapeutic targets of intestinal mucosal inflammation and functional disorders.

肠道菌群、潘氏细胞与免疫细胞之间的相互作用对肠道的生理功能至关重要。GC-C表达于肠道上皮细胞，激活后通过升高胞内cGMP诱导下游反应，对回肠的液体分泌、机械感受和黏膜炎症有调节作用，从而影响肠道菌群。回肠干细胞的增殖和向潘氏细胞的分化受Wnt/β-catenin信号通路调控。本研究拟通过在体干预、enteroids平台和单个干细胞3个层次，利用免疫荧光、流式细胞技术、western blot和qPCR等技术观察干预GC-C对潘氏细胞数量和功能的影响及对肠道功能的整体影响，揭示GC-C通过Wnt/β-catenin通路调控潘氏细胞分化的途径，探索GC-C对cGMP的影响和Wnt途径的激活机制。本研究将有助于对GC-C在肠道生理和病理状态下的功能的全面认识，为多种肠道黏膜炎症和功能性疾病的诊疗提供治疗靶点。

鸟苷酸环化酶C（Guanylyl cyclase C，GC-C）表达于肠道上皮细胞，激活后通过升高胞内cGMP诱导下游反应，对回肠的液体分泌、机械感受和粘膜炎症有调节作用。GC-C-cGMP信号轴失调导致包括肠易激综合症（Irritable Bowel Syndrome，IBS）等在内的多种胃肠道疾病。为进一步了解GC-C 在肠道生理和病理状态下的功能，本研究通过在体干预、enteroids平台和单个细胞3个层次，利用免疫荧光、单细胞测序、western blot和qPCR等技术观察干预GC-C对肠干细胞增殖分化的影响及对肠道功能的整体影响。研究结果显示在体激活GC-C信号通路可增加小鼠体重、降低回肠黏膜通透性、增加绒毛/隐窝比值，而对小鼠回肠微生物群落的影响并不显著。体外干预培养的小肠类器官模型，发现激活GC-C信号通路可抑制肠干细胞增殖，并促进其向肠吸收细胞谱系分化。下一步将通过单细胞测序技术发现GC-C信号调控肠干细胞增殖分化的具体机制。本研究将有助于为多种肠道粘膜炎症和功能性疾病的诊疗提供治疗靶点以及用药指导。