地黄寡糖对血管性痴呆大鼠海马区神经细胞凋亡及相关蛋白表达的影响

目的:探讨中药提取物地黄寡糖(rehmannia glutinosa oligosaccharides,ROS)对血管性痴呆大鼠海马CA1区神经细胞凋亡及相关蛋白表达的影响.方法:选用SD成年大鼠,随机分为伪手术组、模型组和地黄寡糖高、低剂量组(9.0,45 g·kg-1·d-1).采用双侧颈总动脉缺血再灌注法制作血管性痴呆大鼠模型,采用行为学评分法评价大鼠的行为学障碍程度,HE染色法观察大鼠海马CA1区病理组织形态学变化,TUNEL法检测大鼠海马CA1区的神经元细胞凋亡情况,免疫组化法检测大鼠海马区凋亡相关蛋白B细胞淋巴瘤/白血病-2(Bcl-2),Bcl-相关x蛋白(Bax)的表达含量的变化,并检测大鼠海马组织匀浆中神经毒性氨基酸谷氨酸及海马组织和血清中超氧化物歧化酶(SOD)活性、丙二醛(MDA)含量.结果:ROS能够显著改善缺血再灌注型血管性痴呆的大鼠的行为学障碍,降低其行为学评分(P＜0.01),减轻海马CA1区神经组织的病理性改变,降低神经元凋亡细胞比例(P＜0.01),并显著升高血管性痴呆大鼠海马CA1区神经元细胞中Bcl-2蛋白表达(P＜0.01)、降低Bax蛋白表达(P＜0.01),Bcl-2/Bax显著升高,从而抑制了该区域神经元细胞的凋亡.此外,ROS给药能够显著减少血管性痴呆大鼠血清及海马组织中MDA的积累(P＜0.01),提高SOD的活性(P＜0.01),降低海马组织中谷氨酸的水平(P＜0.01).结论:ROS能够显著减少脑缺血再灌注损伤所致的大鼠海马CA1区神经元凋亡,其作用机制可能是通过调控Bcl-2/Bax相关蛋白的表达来实现的.此外与ROS减少组织中谷氨酸的水平和MDA的含量,提高SOD活性等,也提示ROS对血管性痴呆有一定的治疗作用.

Effects of Rehmannia glutinosa Oligosaccharides on Neural Apoptosis and Expression of Apoptosis-Related Proteins in Hippocampus Region of Vascular Dementia Rats

Objective:To investigate the protective effective of Rehmannia glutinosa oligosaccharides (ROS) on neural apoptosis and expression of apoptosis-related proteins in hippocampus CA1 region of vascular dementia rats. Method: SD rats were randomly and evenly divided into sham-operation group, model group, high and low dose of ROS treated groups. Vascular dementia model was established by repetitively blocking bilateral common carotid arteries and refilling. Behavioral score was used to evaluate the behavioral disorders of rats. HE staining was used to observe the pathological morphological changes in the neural cells of hippocampus CA1 region. The apoptosis of nerve cells in hippocampus CA1 region were detected with TUNEL method. The expression of B cell lymphoma/leukmia-2(Bcl-2) and Bcl-2 assaciated x protein (Bax) protein in the neural cells of hippocampus CA1 region were detected by immunohistochemical staining. The contents of glutamic acid in hippocampal tissue were detected by spectrophotometry, and superoxide dismutase(SOD) activity and malondialdehyde(MDA) contents in hippocampal tissue and serum were detected by the same method. Result: ROS could significantly reverse the ischemia-reperfusion induced increasing in behavioral score. It prevented the pathological morphological changes in hippocampus CA1 region. And it decreased the percentage of apoptotic cells in this area. Through ROS treated, the expression of Bcl-2 protein was significantly increased, while the Bax protein was decreased in this area. The Bcl-2/Bax was increasing. In addition, ROS could slow down the accumulation of MDA. It increased the activity of SOD in the serum and hippocampal tissue, while the production of glutamic acid decreased. Conclusion: ROS significantly alleviated the apoptosis of neuron in hippocampus CA1 region of vascular dementia rats, which was associated with influencing the expression of apoptotic proteins. In addition, the reducing of glutamic acid and MDA content, and the increasing of SOD activity indicated that ROS had protected effect to vascular dementia rats.