增殖细胞核抗原在实验性脑出血大鼠脑组织中的表达及其意义

研究实验性脑出血时大鼠脑组织中增殖细胞核抗原(proliferating cell nuclear antigen,PCNA)的表达及其意义。将成年SD大鼠随机分为正常组、假手术组和脑出血组;脑出血组大鼠通过立体定向术向脑内注入自体动脉血制成脑尾壳核出血模型,并按不同的再喂养时间(1、3、7、14及30d)分为5个亚组。运用RT-PCR检测PCNA mRNA表达水平,采用免疫组化单标和双标染色观察PCNA阳性细胞的分布,增殖水平及分化情况。RT-PCR结果显示,PCNA mRNA表达在脑出血后14d达高峰。免疫组化单标结果表明,PCNA阳性细胞主要分布于出血灶边缘、脉络丛、室管膜下层、胼胝体和额顶皮质等处。PCNA阳性细胞数在脑出血后1d开始增加,14d达高峰,随后渐下降,但30d时仍明显高于正常组和假手术组。免疫组化双标结果显示在脑出血侧纹状体和额顶皮质可见PCNA/GFAP双标阳性细胞,在额顶皮质可见PCNA/NF-200双标阳性细胞。以上结果提示,脑出血可诱导PCNA阳性细胞增殖、分化,并向出血灶周边区聚集,这可能是脑出血后神经功能恢复的重要物质基础。

The expression and significance of proliferating cell nuclear antigen in brain tissue of rats following experimental intracerebral hemorrhage

To study the expression and significance of the proliferating cell nuclear antigen in brain tissue of rats following experimental intracerebral hemorrhage, the adult SD rats were randomly divided into three groups: normal group, sham group and intracerebral hemorrhage group. The rats of intracerebral hemorrhage group were stereotaxically injected with autologous arterial blood into the caudate-putamen nucleus. Then the rats were subdivided into 5 subgroups according to the various refeeding time (1, 3, 7, 14 and 30 d). RT-PCR was used to investigate the expression level of PCNA mRNA. Immunohistochemical single-or double-labeling methods were introduced to observe the distribution, proliferation and differentiation level of the PCNA-positive cells. The results of RT-PCR showed the expression of PCNA mRNA reached the peak at 14th d after intracerebral hemorrhage. PCNA-positive cells were mainly located in the margin of the hemorrhagic focus, choroid plexus, subependymal ventricular zone, corpus callosum and cortex. The number of PCNA-positive cells increased at 1st d after intracerebral hemorrhage, and reached the peak at 14th d. From then on, it decreased gradually, although the numbers of PCNA-positive cells in intracerebral hemorrhage group at 30th d was still significantly larger than those of the normal group and sham group. Immunocytochemistry showed that the PCNA and GFAP double-labeled cells were detected in the striatum and frontoparietal cortex in the ipsilateral hemisphere of intracerebral hemorrhage, and the PCNA and NF-200 double-labeled cells were observed in the frontoparietal cortex. Totally, our data indicate that PCNA-positive cells should proliferate, differentiate and migrate to the hemorrhage perifocal area after intracerebral hemorrhage stimulation, and these cells may play an important role for neural functional recovery after intracerebral hemorrhage.