牛源犬新孢子虫感染致孕鼠胎盘的损伤作用及其机制研究

Neospora caninum is one of the improtant harmful diseases to the cattle industry. This disease mainly causes the miscarriage of dams, stillbirth, neonatal movement disorders and neurological diseases. However, the mechanism of the injury function is not clear. To determine this, the models of N. caninum infected pregnant rats were established in this project. Transmission electron microscopy, RNA in situ hybridization, Flow cytometry, SABC and RT2 Profiler PCR Array etc. were carried out to observe the pathology of the placentas of pregnant rats, the process of the invasion of N. caninum, cell apoptosis and detect related cytokines and the expression levels of cellular oxidative and apoptopsis related proteins to describe injury function of bovine N. caninum infection to the placentas cell of pregnant rats. By RIA, ELISA and IHC etc. placental hormones, growth factors and enzymes affected material transportion, blood flow of placental and fetal growth and development to define the affection of N. caninum to the regulatory function of placental hormones and thus reveal the injury mechanism of the placentas of pregnant rats infected by N. caninum. This project will settle the solid foundation for the pathogenic role of N. caninum.

犬新孢子虫是危害养牛业生产的重要病原之一，作为引起孕畜流产、死胎及新生儿运动和神经系统障碍的一种细胞内寄生原虫，对胎盘的损伤机制目前尚不清楚。为确定犬新孢子虫对胎盘的损伤作用，本项目拟以BABL/c小鼠为实验动物，建立牛源犬新孢子虫孕鼠感染模型，应用透射电镜、RNA原位杂交、流式细胞术、SABC及RT2 Profiler PCR Array等技术方法，对孕鼠胎盘组织进行病理学损伤观察、虫体入侵动态观察、细胞凋亡检测、相关细胞因子检测及细胞氧化、凋亡相关蛋白和酶等表达水平检测，以此阐明犬新孢子虫对胎盘组织细胞的损伤作用；采用RIA、ELISA及IHC等方法，检测影响胎盘物质转运、胎盘血流及胎儿生长发育的胎盘激素、生长因子及酶类等各项指标，明确犬新孢子虫对胎盘激素调节功能的影响，进而揭示牛源犬新孢子虫感染致孕鼠胎盘的损伤机制。以期为犬新孢子虫致病作用的研究奠定基础。

犬新孢子虫是危害养牛业生产的重要病原之一，可引起孕畜流产、死胎及新生儿运动和神经系统障碍。为阐明牛源犬新孢子虫对孕鼠胎盘的损伤机制，本研究在建立牛源犬新孢子虫BABL/c孕鼠感染模型的基础上，对模型孕鼠胎盘重量、胎盘系数及活胎数等指标进行了检测，对孕鼠胎盘组织进行了病理学损伤观察、虫体入侵动态观察、细胞凋亡检测、相关细胞因子检测及细胞氧化凋亡相关蛋白表达等检测，对影响胎盘物质转运、胎盘血流及胎儿生长发育的各项胎盘激素、生长因子等指标进行了测定。结果表明，牛源犬新孢子虫感染孕鼠胎盘重量和胎盘系数变化显著，胎盘组织滋养层细胞凋亡、胎盘细胞DNA损伤严重，导致胎盘组织细胞病理性损伤；IFN-γ、TGF-β等细胞因子水平变化整体倾向不利于胎儿生长发育的方向发展，降低机体免疫力，增加虫体入侵几率；Bax、TNF-α等氧化凋亡蛋白表达上调激活内、外源性细胞凋亡途径，致使胎盘细胞过氧化损伤严重；CG、CRH等激素水平下调严重影响胎盘对胚胎所需营养物质的转运、胎盘激素的合成、胎盘血流以及胎儿的生长发育，致使胎盘缺氧、缺血，胎儿营养不良和宫内发育迟缓，最终导致胎儿流产、早产等不良妊娠的发生。本研究为犬新孢子虫致病作用的研究奠定了基础。