山羊复胃Cajal间质细胞生后发育的特性研究

The interstitial cells of Cajal (ICC) are a special class of cells located between the autonomic nerve endings and smooth muscle cells in the digestive tract and plays an important role in the gastrointestinal motility. In the present project, the venter ruminantia of goat were selected as research object, which was considered the main representative animal containing the characteristics of ruminant digestion. The entry point of the study is the characteristics and the spatial association between ICC and their associated cells. The aim is to explore the distribution and structural features of ICC and the structural basis of the generation of slow wave and the regulation of nerve signals in the venter ruminantia of goat at different digestive stages during postnatal development. At the same time, the difference of protein and mRNA expression of markers of ICC and its associated cells were also explored by RT-PCR and western blot, such as c-kit, NSE,AChE, NOS and Cx43, and compare and validate with their structural basis. Those researches explore the spatial network structure and effective mechanism between ICC and the regulation of nerve signals on the levels of cells and protein and molecule. And then clarify the cytological features and developmental characteristics of ICC. This study provide a new ideas for the occurrence and treatment of motility disorders in the venter ruminantia of goat.

Cajal间质细胞（ICC）是位于自主神经末梢和消化道平滑肌细胞之间一类特殊间质细胞，在胃肠道动力中发挥着重要作用。本项目选择具有反刍现象的山羊复胃作为研究对象，以ICC的特性和与其关联细胞的空间联系为切入点，运用细胞和分子生物学技术，探究其生后发育过程中复胃各区域ICC分布规律、结构特征以及ICC在慢波起搏和神经信号调控中的结构基础。同时利用荧光定量PCR和Western blot技术，检测ICC及其在复胃神经调控中相关的细胞标记物c-kit、NSE、AChE、NOS和Cx43的蛋白和mRNA表达变化，并与结构基础进行比照和互为验证。在细胞、蛋白和分子水平上，从不同角度揭示山羊复胃生后发育过程中ICC网络构筑及其在神经调控中的作用机理，进而阐明山羊复胃ICC细胞学特征和发育特点，为反刍动物复胃动力障碍性疾病的发生与治疗提供新的思路。

Cajal间质细胞（ICC）是位于消化道自主神经末梢和平滑肌细胞之间一类特殊间质细胞，在胃肠道动力中发挥着重要作用。本项目选择具有反刍现象的山羊复胃作为研究对象，以ICC的特性和与其关联细胞的空间联系为切入点，运用透射电镜技术、免疫组织化学、RT-PCR和western blot技术对山羊复胃的ICC、telocyte和神经分布进行了鉴定和关联研究，探究了其生后发育过程中复胃各区域ICC分布规律、结构特征以及ICC在慢波起搏和神经信号调控中的结构基础。结果发现ICC在山羊复胃的不同部位均有存在，数目不等。根据超微结构特征，可归纳出ICC的鉴定标准：肌间和肌内ICC主要呈梭形或星形，而粘膜下及固有层ICC主要呈梭型；它们均有数量不等的胞质突起，这些突起与周边的平滑肌细胞和神经形成密切联系，如缝隙连接；胞质内含有大量的线粒体，丰富的中间丝，不等的胞膜小凹和基底膜；细胞核呈椭圆形，内有大量异染色质。telocyte相较于ICC有着更长的突起和更小的胞体，而且其突起自胞体突然发出，突起上可见数量不等的膨大。免疫组化结果进一步验证了ICC具有四种亚型，且常伴行或环绕于神经周围，综上显示ICC在复胃蠕动中发挥着积极作用，另外ICC和telocyte常围绕在血管，可能与血供有关。结合电镜进行免疫组化单标及双标结果发现，ICC在山羊瘤胃和网胃中的表达较高，而瓣胃和皱胃次之。结合Western blot结果表明ICC分布模式随着年龄的增长而增多，这与复胃神经发育分布趋势相反，且随着年龄的增长，ICC与神经的连接逐渐增多，这种关系可能与复胃的功能发育完善有关。通过对复胃的总神经元和氮能神经元的定性定量分析，显示山羊前胃神经系统中神经元主要分布于肌间神经丛。结合对复胃ICC和神经的功能组织学研究发现，肌间神经丛以及肌内的神经均与ICC联系密切，彼此交错，共同分布于整个胃壁内。从胚后神经的发育来看，随着复胃功能的形成，复胃神经系统也在不断成熟和功能健全，提示在发育过程中复胃神经系统的正常成熟对其消化和反刍功能维持至关重要。