核受体相关因子1在大鼠脑发育过程中的表达研究

Expression of nuclear receptor related factor 1 in the developing rat brain

目的观察孤儿核受体相关因子1(Nurr1)在大鼠脑发育过程中蛋白表达的动态变化及其与增殖细胞核抗原(PCNA)的相关关系,探讨Nurr1表达在神经细胞分化迁移中的意义。方法采用石蜡包埋组织切片,免疫组织化学染色及免疫组织化学双重染色。结果 Nurr1从胚胎12d开始在侧脑室周围出现少量表达,随着发育阳性细胞数目明显增多,而且呈现向脑室远侧分化、迁移的趋势;生后侧脑室周围的阳性细胞明显减少,高量表达出现在生后1～5d的大脑皮层,随着细胞的分化成熟阳性表达又明显减少,成熟的大脑皮层仅见少量阳性表达,与PCNA的对比观察表明,两者表达在不同的部位和不同的细胞中,Nurr1主要表达在分化、迁移的幼稚神经细胞中,在增殖细胞中不表达。结论 Nurr1可能在大鼠脑神经细胞从幼稚到成熟的分化、迁移过程中有调控作用。

Objective To observe the dynamic changes in protein expression of the orphan nuclear receptor related factor 1 （Nurrl） as well as its correlation with proliferating cell nuclear antigen（PCNA） in the developing rat brain, and to investigate the significance of Nurrl in the differentiation and migration of neural cells. Methods Paraffin-embedded sections, immunohistochemistry, double labeling immunohistochemical methods were adopted. Results Nurrl was expressed in small quantities in the cells surrounding the lateral ventricle. Along with the maturing of the cells, the positive expression increased apparently and differentiated and migrated to the distant sites from the lateral ventricle. In postnatal rats, the positive cells surrounding the lateral ventricle decreased remarkably. High levels of the expression was found in the cerebral eortex on the postnatal day 1-5, then along with the maturing of the cells, the positive expression decreased obviously. Positive cells were rare in matured cerebral cortex. The comparative observation against PCNA showed that the two were expressed at different sites and in different cells. Nurrl was mainly expressed in differentiated and migrated immature cells, but not in proliferating cells. Conclusion It implies that Nurrl may play a regulatory role in the differentiation, migration and maturation of the rat neural cells.