脑淋巴引流阻滞加重蛛网膜下腔出血后大鼠皮层神经细胞的凋亡

Cerebral lymphatic blockage aggravates apoptosis of cortical neurons after subarachnoid hemorrhage in rats in vivo

本文旨在探讨在体脑淋巴引流阻滞(cerebral lymphatic blockage,CLB)对蛛网膜下腔出血(subarachnoid hemorrhage,SAH)后大鼠皮层神经细胞凋亡的影响及机制。选用健康成年Wistar大鼠,随机分为正常对照组、SAH组、SAH+CLB组。采用枕大池二次注血法建立SAH模型。于第二次注血3d后,采用HE染色法及碘化丙啶(PI)染色法观察各组大鼠皮层神经细胞形态结构变化;TUNEL荧光标记法检测原位凋亡情况;免疫组织化学激光共聚焦检测大鼠皮层神经细胞Caspase-3和Bcl-2的蛋白表达。结果显示:(1)HE染色和PI染色可见SAH组大鼠部分皮层神经细胞皱缩,细胞核呈波纹状或折缝样,部分呈新月形;SAH+CLB组神经细胞分布稀疏,核碎裂,可见凋亡小体,周围有空泡形成;(2)SAH组和SAH+CLB组TUNEL阳性细胞的数量均高于正常对照组,而SAH+CLB组又显著高于SAH组;(3)SAH组和SAH+CLB组Caspase-3的表达量均高于正常对照组,而SAH+CLB组又显著高于SAH组;(4)SAH组和SAH+CLB组Bcl-2蛋白表达量均高于正常对照组,而SAH+CLB组显著低于SAH组。以上结果表明,CLB可以通过Caspase-3高表达和Bcl-2低表达加重SAH后大鼠皮层神经细胞的凋亡。

This present study was performed to investigate the influence of cerebral lymphatic blockage （CLB） on apoptosis of cortical neurons after subarachnoid hemorrhage （SAH） in rats in vivo.Healthy adult Wistar rats were randomly divided into normal control group,SAH group and SAH ＋ CLB group.SAH model was made by double injection of autologous blood into the cisterna magna.On the third day after the second cisternal injection,morphological changes of cortical cells were observed by hematoxylin-eosin （HE） combined with propidium iodide （PI） staining.Terminal deoxynucleotidyl transferase-mediated dUTP nick end labeling （TUNEL） method was applied to determine in situ apoptosis in the cerebral cortex.Immunohistochemistry was conducted to detect the expres- sion of Caspase-3 and Bcl-2 in cortical neurons.HE and PI staining showed that cortical neurons of SAH rats were partly shrinkable;the nuclei showed wavy,folded or wrinkled appearance,and some nuclei had the shape of crescent.The cortical neurons in SAH ＋ CLB group distributed sparsely and the nuclear fragmentation,apoptotic bodies were found,surrounded by the formation of vacuoles.The numbers of TUNEL-positive cells in SAH group and SAH ＋ CLB group were higher than that in the normal control group,while the number in SAH ＋ CLB group was significantly higher than that in the SAH group.Caspase-3 expressions in SAH group and SAH ＋ CLB group were higher than that in the normal control group,while the expression in SAH ＋ CLB group was significantly higher than that in the SAH group.Bcl-2 expressions in SAH group and SAH ＋ CLB group were higher than that in the normal control group,while the expression in the SAH ＋ CLB group was significantly lower than that in SAH group.The results obtained suggest that CLB exacerbates the apoptosis of cortical neurons in rats after SAH by up-regulating Caspase-3 expression and down-regulating Bcl-2 expression.