颈椎稳定性异常老龄小鼠脑海马神经细胞中Bcl-2和Bax的表达

Expressions of Bcl-2 and Bax in hippocampal neurons of senile mice with cervical vertebral instability

目的:探讨颈椎失稳老龄小鼠脑海马神经细胞凋亡相关基因Bcl-2和Bax的表达,阐明颈椎失稳所致老龄小鼠记忆和学习能力下降的机制。方法:选取ICR小鼠20只,随机分为模型组和对照组,每组10只,分组后模型组采用颈椎乳酸堆积法制备小鼠颈椎稳定性异常病理模型,对照组未经任何处理。水迷宫实验检测小鼠学习和记忆能力;HE染色观察脑海马神经细胞形态学变化;TUNEL染色观察脑海马神经细胞凋亡情况;RT-PCR和免疫组织化学法检测小鼠脑海马组织Bcl-2、Bax mRNA和蛋白的表达情况。结果:与对照组比较,模型组小鼠水迷宫实验游全程时间和错误次数显著增加(P<0.01);HE染色,与对照组比较,模型组小鼠脑海马神经细胞排列稀疏,死亡细胞明显增多;TUNEL染色,与对照组(7.52%±0.99%)比较,模型组脑海马凋亡细胞数(29.63%±1.63%)明显增多(P<0.01);RT-PCR和免疫组织化学染色,模型组小鼠脑海马神经细胞Bcl-2表达明显减弱,Bax表达明显增强。结论:颈椎稳定性异常导致的小鼠脑海马神经细胞Bcl-2表达下调,Bax表达上调,可能是促进其细胞凋亡的主要机制之一。

Objective To discuss the expressions of the senile mice with cervical vertebral instability on Bcl-2and Bax which related to neural apoptosis in hippocampal neurons,and to clarify the mechanism of reducing of learning and memory abilities induced by cervical vertebral instability in the senile mice.Methods 20ICR mice were selected and randomly divided into two groups.The cervical vertebral instability model was established by lactic acid accumulation for long time;the changes of learning and memory abilities of the mice were observed with Watermaze test;the changes of morphology in hippocampal neurons were observed by HE straining;the apoptosis of hippocampal neurons was observed by Tunel staining.The expression levels of mRNA and protein of Bax and Bcl-2 were detected by RT-PCR and immunohistochemical staining.Results Compared with control group,the escape latency and wrong times of Watermaze test in model group were increased（P0.01）.The neuron in hippocampus in model group was found scatteredly and the dead cells were increased obviously observed with HE staining compared with control group.The Tunel staining results showed that there were more buffy cells in model group（29.63%±1.63%）than control group（7.52%±0.99%）（P0.01）.The expression of Bcl-2was decreased and the Bax was increased in the brain tissue in model group compared with control group detected by RT-PCR and immunohistochemical staining.Conclusion The cervical vertebral instability could lead to Bcl-2decreasing and Bax increasing,and it might be one of the main mechanisms to promote the apoptosis.