大鼠淋巴滞留性脑病bcl-2、bax表达和细胞凋亡的动态变化

Changes of bcl-2, bax expression and neuron apoptosis in lymphostatic encephalopathy of rats

目的:研究大鼠淋巴滞留性脑病模型中大脑皮层bcl-2、bax基因表达和细胞凋亡的动态变化。方法:用阻断颈部淋巴引流的方法复制大鼠淋巴滞留性脑病模型,术后1、2、3、5、7和14d处死动物,HE染色观察脑组织结构变化,TUNEL荧光标记检测原位细胞凋亡,RT-PCR检测大脑皮层凋亡相关基因bcl-2和bax的表达。结果:显微镜下见脑组织有水肿的结构变化,第5d最明显。大脑皮层TUNEL阳性细胞数和bax表达从术后2d开始增多,5d达最高峰,14d降至对照组水平。bcl-2表达于术后1d开始增高,5d达最高值,第7d下降至对照组水平。bax表达增高的程度大于bcl-2。结论:阻断颈部淋巴引流可导致淋巴滞留性脑病,大脑皮层神经细胞死亡以凋亡为主并与bcl-2和bax的表达增加有关。

AIM： To investigate the changes of bcl - 2, bax expression and neuron apoptesis of cerebral cortex in lymphostatic encephalopathy of mrs, METHODS： The model of lymphostatic encephalopathy was established by occluding and removing both the shallow and deep cervical lymph nodes in rats. The animals were sacrificed at 1, 2, 3, 5, 7 and 14 days after operation. HE staining was used to observe the structure of brain tissues and TUNEL staining was used to detect in situ cell apoptosis. The expressions of bcl - 2 and bax were examined by RT - PCR. RESULTS： Cerebroedema appeared at the second day and was the most serious at the 5th day after blockage of cervical lymphatics. The number of TUNEL positive cells and the expression of bax began to increase at the 2nd day, reached a peak at the 5th day and dropped to control level at the 14th day. The expression of bcl - 2 began to increase at the 1st day, reached a peak at the 5th day and dropped to control level at the 7th day. The increasing extent of bax was higher than that of bcl - 2. CONCLUSION： The blockage of cervical lymphatics can lead to lymphostatic encephalopathy. Apoptosis is the main form of neuron death in the cortex and has relation to the increasing expression of bcl - 2 and bax.