The role of lsc/p115-RhoGEF-regulated pathways for development and function of the enteric nervous system in the upper gastrointestinal tract.

胃肠道（GIT）的传输部分受口咽和食道管控制，但在胃、小肠和大肠中完全自主。贲门失弛缓症、肠假性梗阻和胃轻瘫患者胃肠道运动在胃肠道不同部位受到影响。在我们之前的研究中，我们报道了缺乏lsc/p115- rhogef蛋白的小鼠的贲门失弛缓样表型，该蛋白介导g蛋白依赖的细胞内通路，对rhogtpase的激活至关重要。特别是lsc/p115-KO小鼠在食管管和食管下括约肌（LES）中表现出明显的胶质细胞减少和神经衰弱，而在其他git切片中则没有。在本项目中，我们将评估lsc/p115- rhogef依赖通路在胃肠道上段（食管和LES）肠神经系统（ENS）中的作用。我们打算分析胚胎期和出生后ENS中神经胶质细胞和神经元的发育。将分别评估lsc/p115-KO胶质细胞和神经元的基础和诱导增殖和凋亡率、神经营养因子的表达以及两种细胞类型之间的相互作用。作为补充，我们将研究lsc/p115-RhoGEF在特定增殖和分化因子（Sox10, Mash1, phox2b）表达中的作用。我们认为lsc/p115-RhoGEF调节了这些蛋白的表达。我们研究的另一部分包括功能分析（食管压力测量和体外收缩测量）：我们将评估lsc/p115缺陷小鼠上消化道运动的改变，以便我们能够确定上消化道ENS的形态学改变何时导致功能改变。通过这些研究，我们打算阐明胃肠运动在生理和病理生理条件下的复杂调节。

The transit through the gastrointestinal tract (GIT) is partially controlled in the oropharynx and the esophagus tube, however completely autonomous in the stomach, the small and large intestines. Gastrointestinal motility is affected in different sections of the GIT in achalasia, intestinal pseudoobstruction and gastroparesis. In our previous studies we reported an achalasia-like phenotype in the mice lacking the lsc/p115-RhoGEF-protein, which mediates G-protein dependent intracellular pathways and is essential for the activation of RhoGTPases. In particular the lsc/p115-KO mice showed a significant hypogliosis and hypoinnervation in the esophagus tube and the lower esophagus sphincter (LES), but not in the other GIT-sections. In this project, we are going to evaluate the role of lsc/p115-RhoGEF-dependent pathways in the enteric nervous system (ENS) of the upper GIT-sections (esophagus and LES). We intend to analyse the development of the glial cells and neurons in the ENS at the embryonic stage and after birth. lsc/p115-KO glial cells and neurons will be evaluated for the basal and induced proliferation and apoptosis rates, the expression of neurotrophic factors and the interactions between both cell types, respectively. Complementary, we are going to investigate the role of lsc/p115-RhoGEF in the expression of particular proliferation- and differentiation-factors (Sox10, Mash1, phox2b). Here we believe that lsc/p115-RhoGEF is regulating the expression of these proteins. The other part of our investigations include the functional analysis (esophageal manometry and in-vitro contractions measurements): the alterations of the gastrointestinal motility in the upper GIT in lsc/p115-deficient mice will be evaluated so we will be able to determine when the morphological changes in the ENS of the upper GIT result in the functional alterations. By these investigations we intend to clarify the complicated regulation of gastrointestinal motility at physiological and pathophysiological conditions.