脑梗死后神经干细胞的原位增殖及其可塑性

Experimental Study on the Proliferation and Plasticity of Neural Stem Cells In Situ in Adult Rats after Cerebral Infarction

目的研究成年大鼠脑梗死后自体神经干细胞的原位增殖,并探讨其可塑性。方法雄性Wistar大鼠共68只,分对照组(n=8),脑梗死后1、3、7、14、28d组,每组12只。免疫组织化学方法动态检测大鼠脑内5-溴脱氧尿苷嘧啶(BrdU)、Brdu/多唾液酸神经细胞黏附分子(PSA-NCAM)的表达。结果与对照组相比,室下区和海马BrdU阳性细胞在脑梗死后1d开始增加(P<0.05),7d达到高峰,14d后开始下降,但仍高于对照组(P<0.05),28d后接近正常水平;室下区和海马BrdU/PSA-NCAM阳性细胞在脑梗死后7d开始增加(P<0.05),14d达到高峰,28d后开始下降,但仍高于对照组(P<0.05),大约占同期BrdU阳性细胞数60%。结论脑梗死可激活自体神经干细胞原位增殖,并且大多数增殖的神经干细胞具有可塑性。

Objective To investigate the proliferation and plasticity of neural stem cells in situ in adult rats after cerebral infarction.Methods Cerebral infarction models of rats were made and the dynamic ex-pression of bromodeoxyuridine (BrdU)and BrdU/polysialylated neural cell adhesion molecule(PSA-NCAM)were determined by immunohistochemistry and immunofluorescence staining.Results Compared with the controls,the number of BrdU-positive cells in the subventricular zone(SVZ)and hippocampus increased strikingly at day1(P<0.05),reached maximum at day7,and decreased markedly at day14,but it was still elevated compared with that of the controls(P<0.05);The number of BrdU-labeled with PSA-NCAM-positive cells increased strikingly at day7(P<0.05),reached maximum at day14,and markedly decreased at day28,but it was still elevated compared with that of the controls(P<0.05),and was equal to60%of the number of BrdU-positive cells in the same period.Conclusions Our results indicate that cerebral infarction stimulate the proliferation of inherent neural stem cells in situ and most proliferated neural stem cells represent neural plasticity.