APC-Cdh1在中枢神经系统中的表达分布特点

Characteristics of APC-Cdh1 expression in central nervous system

目的:探讨细胞周期末期促进复合物(APC)-Cdh1在中枢神经系统中的表达分布特点.方法:取健康成年雄性SD大鼠脑组织制作冰冻切片,免疫组化染色检测Cdh1的表达部位;免疫荧光双标检测Cdh1表达的细胞定位情况.取出生24h内乳鼠,原代培养神经元及神经干细胞,免疫组化检测NeuN进行神经元鉴定;Nestin染色进行神经干细胞初步鉴定;采用GFAP,MAP2免疫组化染色鉴定NSC分化特性.分别提取神经干细胞与神经元总RNA,采用实时定量PCR检测APC2个调节亚基Cdh1与CDC20的表达.结果:大鼠脑片免疫组化DAB染色显示Cdh1在海马、皮层均有大量表达,免疫荧光双标显示Cdh1表达主要定位于神经元中,星形胶质细胞表达较少.与神经干细胞相比,神经元中Cdh1 mRNA表达升高[(1.00±0.05)vs(2.10±0.07),P<0.05],但CDC20 mRNA几乎没有表达(1.00±0.04,0.02±0.01,P<0.05).结论:APC-Cdh1在大鼠脑组织中有大量表达,主要定位于神经元,且神经元中Cdh1表达高于神经干细胞.

AIM： To investigate the characteristics of APC-Cdh1 expression in the central nervous system. METHODS： Fresh frozen sections were prepared from the brain tissue of health adult male SD rats and the expression of Cdhl was detected by immunohistochemistry. The subtypes of Cdhl positive cells were determined by double immunofluorescent labeling technique with Cdhl ＋ NeuN or Cdhl ＋ GFAP antibody. Primary neurons and neural stem cells from the hippocampus of postnatal 24 h rat pups were cultured. Neurons were identified by NeuN immunocytochemical staining, neural stem cells were examined by Nestin immunocytochemical staining and their differentiation characteristics were identified by GFAP and MAP2 immunocytochemical staining. The mRNA of neuron and neural stein cells was extracted by Trizol method and the expression of Cdhl and CDC20 was examined by quantitive real-time PCR. RESULTS： The immuno-staining showed that Cdhl was highly expressed in the cerebral cortex and hippocampus, which was mainly located in neurons. Compared with that in neural stem cells, the expression of Cdhl mRNA significantly increased in neurons [ （ 1. 00 ± 0.05） vs （2.10±0.07）, P〈0.05], but CDC20 mRNA was hardly expressed （1.00 ±0.04, 0.02 ±0.01, P 〈0.05）. CONCLUSION： APC-Cdh1 is highly expressed in the brain tissue and it is mainly located in neurons. The expression of Cdh1 in neurons is higher than that in neural stem cells in vitro.