原花青素对β淀粉样蛋白25-35诱导的小鼠海马神经细胞毒性的影响

摘要

目的观察原花青素对β淀粉样蛋白25-35(Aβ25-35)诱导的小鼠学习记忆损伤的早期影响及其影响途径。方法30只成年C57bl/6小鼠，随机分为5组(n=6)：原花青素低浓度组、原花青素中浓度组和原花青素高浓度组(侧脑室注射Aβ25-35制作学习记忆损伤模型，分别给予原花青素50、100、150 mg/10 mL/kg，灌胃)，模型组(侧脑室注射Aβ25-35+无菌双蒸水10 mL·kg-1，灌胃)；对照组(侧脑室注射生理盐水+无菌双蒸水10 mL·kg-1，灌胃)。采用Hochest染色观察小鼠海马神经元凋亡情况，免疫组化学染色观察小鼠海马突触重塑及胶质炎性反应。结果与对照组比较，模型组海马CA1区神经元凋亡比例显著增加(4.03±0.26，0.85±0.20，t=9.816，P=0.000)，突触素(SYN)平均密度明显降低(0.0785±0.0009，0.0848±0.0007，t=-5.753，P=0.005)，星形胶质细胞(Ast)活化数(0.1127±0.0017，0.1015±0.0018，t=4.459，P=0.011)和小胶质细胞(Mic)活化数明显增加(8.14±0.75，4.64±0.20，t=4.48， P=0.002)。与模型组比较，各原花青素组小鼠海马CA1区神经细胞凋亡明显减少(3.72±0.90，2.47±0.12，1.03±0.17，4.03±0.26，F=4.45，P=0.019)，SYN平均密度增加(0.0935±0.0025，0.0862±0.0010，0.0802±0.0029，0.0785±0.0009，F=9.413，P=0.004)，Ast活化数量减少(0.1035±0.0017，0.0993±0.0029，0.1001±0.0023，0.1127±0.0017，F=5.484，P=0.015)，Mic活化数量减少(8.98±0.26，5.81±0.24，3.74±0.69，8.14±0.75， F=20.795，P=0.000)，且呈剂量依赖性。结论原花青素可以通过减轻Aβ25-35小鼠海马区神经胶质增生，从而减少小鼠海马区神经元及突触丢失，改善小鼠学习记忆损伤。%ABSTRACTAim To investigate the early inlfuence of procyanidins on the impairment of memory and its inlfuence pathway.MethodsThirty male c57bl/6 mice were randomly divided into ifve groups: a low concentration treatment group, a middle concentration treatment group, a high concentration treatment group, a model group, a control group. Intracerebroventricular injection of β-amyloid25-35 in C57bl/6 mice caused impairment of learning and memory. The three impairment models were made by intragastric administration of procyanidins into the treatment group mice: lower concentration group (50 mg·kg-1, 10 mL·kg-1), middle concentration group (100 mg·kg-1, 10 mL·kg-1), high concentration group (150 mg·kg-1, 10 mL·kg-1). Apoptosis of neuronal nuclei in hippocampus was observed by Hochest straining. Synaptic remodeling reaction and the expression level of glial inflammatory response were quantitatively determined by immunohistochemistry.ResultsCompared with the control group, the proportion of neuronal apoptosis increased significantly in hippocampal CA1 region of the model group (4.03±0.26, 0.85±0.20,t=9.816,P=0.000), SYN density reduced (0.078 5±0.000 9, 0.084 8± 0.000 7,t=-5.753,P=0.005) and the level of activated astrocytes (0.112 7±0.001 7, 0.101 5±0.001 8,t=4.459,P= 0.011) and microglia expression (8.14±0.75, 4.64±0.20,t=4.48,P=0.002) in hippocampus increased. Compared with the model group, the proportion of neuronal apoptosis decreased in hippocampal CA1 region of the treatment group (3.72±0.90, 2.47±0.12, 1.03±0.17, 4.03±0.26,F=4.45, P=0.01 9), SYN density increased (0.093 5±0.002 5, 0.086 2±0.001 0, 0.080 2±0.002 9, 0.078 5±0.000 9,F=9.413, P=0.004) and the level of activated astrocytes (0.103 5±0.001 7, 0.099 3±0.002 9, 0.100 1±0.002 3, 0.112 7±0.001 7, F=5.484,P=0.015) and microglia expression (8.98±0.26, 5.81±0.24, 3.74±0.69, 8.14±0.75,F=20.795, P=0.000) in hippocampus decreased.ConclusionProcyanidins have a protective influence on Aβ25-35 mice hippocampus neuron, reducing nerve cell damage and alleviatting learning and memory deficit.