鸡肠神经胶质细胞的细胞学特征与功能研究

Enteric glial cells (EGCs) basically as support cells for the ganglia and/or utritive elements for enteric neurons. In fact, EGC display mechanical support, neurotransmitter, immune and homeostatic functions in the gut. Some intriguing experimental evidences have demonstrated that EGC may have a role in intestinal inflammatory processes，only a few studies have been published in which the role of EGC has specifically investigated in human gastrointestinal motor disorders. EGC had become one of the hot spots of digestive physiology and pathology research. However, it’s mechanism was unclear that EGC maintain the integrity of the mucous membrane of the intestinal epithelial. The project selected Xinjiang chicken as a test object. the digestion of chicken was a significant difference between mammalian. Cell biology and molecular biology methods were used to study the EGC characteristics and its associated cell specific markers (glial fibrillary acidic protein of GFAP, the S-100, neurotrophic factor), so that we knowed EGC of the chicken gastrointestinal distribution pattern and structural characteristics. On the cellular and molecular level, revealing the three-dimensional structure of the network and the cell types of spatial distribution of EGC in chicken digestive tract.Further more,not only may clarify the occurrence and outcome of physiological characteristics and inflammatory diseases of poultry digest, but also provide morphological reference for research on a digestive tract-related diseases.

肠神经胶质细胞(EGC)是给予肠神经元支持和营养成分的细胞，具有维持肠神经系统(ENS)和上皮黏膜的完整性以及调节神经活动的功能。诸多研究表明哺乳动物EGC与肠道炎症的发生发展有密切关系，EGC已经成为消化生理与病理研究的热点之一。但肠神经胶质细胞如何保持肠上皮黏膜的完整性机制目前尚不清楚。本项目选择与哺乳动物消化有明显区别的新疆肉杂鸡为试验对象，采用细胞生物学和分子生物学方法，以EGC特性和与其相联系细胞的特异标记(胶质纤维酸性蛋白GFAP,S-100,神经营养因子)为切入点，进行鸡消化道各段EGC分布规律和结构特征的研究。在细胞水平和分子水平上，揭示鸡消化道EGC与肠神经系统(ENS)网络的立体构造和细胞种类的立体空间分布规律，为阐明家禽消化生理特征和炎症性疾病的发生与转归提供新的思路，亦可为人消化道相关疾病的研究提供形态学参考。

鸡肠神经系统又称胃肠道的“肠脑”，是调控胃肠道诸多生理功能的的中枢，神经胶质细胞（EGCs）数量居多，与神经元一起发挥重要功能。超微结构显示鸡肠神经胶质细胞在小肠各段均呈星形，形态上属于星形胶质细胞，构成肠神经系统的无髓神经纤维组分。光镜结果显示肠神经胶质细胞广泛分布在肠道管壁中，其中黏膜层数量最多，主要位于黏膜固有层，其次是肌层，黏膜下层最少，按照细胞形态可以分为4种类型，其数量多少不一。进一步根据EGCs标记物S-100β蛋白、胶质纤维酸性蛋白(GFAP)、波形蛋白的分布表达确定其主要分布于黏膜层、粘膜下神经丛和肌间神经丛。形态学研究结果表明EGCs参与构成肠黏膜屏障的机械屏障，是机械屏障的重要组成部分。另外，其分泌物分布于小血管和腺体周围，参与调节血流量和腺体分泌。利用MRM方法的靶向代谢组学分析鸡肠道神经递质相对含量并进行了比较，表明不同程度部位神经递质含量不同；同时利用Western blot技术比较了GFAP、GDNF、SOX9和 S-100β蛋白在肠道不同部位的表达存在差异性；利用核酸分子原位杂交技术比较了GFAP和S100βmRNA信号的差异表达，GFAP在肠道各层均有阳性表达，而S-100β仅在空肠和回肠有阳性表达。从细胞和分子水平分析和探究了鸡EGCs 的生物学特性及神经信号传导的分子机制。