脑苷肌肽对APPswe/PS1dE9双转基因小鼠脑内β-淀粉样蛋白42和钙结合蛋白-D28K表达的影响

摘要

Objective To observe the effect of cattle encephalon glycoside and ignotin injection (CEGI) on expression of amyloidβ-peptide (Aβ42) and calbindin-D28k (CB) in brain of APPswe/PS1dE9 double transgenic mice, and investigate its prevention and treatment for Alzheimer's disease. Methods A total of 48 male homozygous APPswe/PS1dE9 double transgenic mice were randomly divided into four groups, 12 in each group:low-dose CEGI group (Tg+CEGI-L;intraperitoneal injection of 6.6 ml/(kg · d) CEGI), high-dose CEGI group (Tg+CEGI-H;intraperitoneal injection of 13.2 ml/(kg · d) CEGI), positive control Donepezil group (Tg+Donepezil; intragastric administration of 2 mg/ (kg · d) Donepezil), Tg group (intraperitoneal injection of equal volume of 0.9% saline). Another 12 non-transgenic (nTg) wild-type littermates were served as normal control group (nTg, intraperitoneal injection of equal volume of 0.9%saline). After one month of drug administration, Morris water maze test was used to assess the ability of learning and memory of the mice, and the changes of expression of Aβ42 in cortex were detected by Thioflavin-S and immunohistochemistry, respectively, and the changes of expression of CB in CA1 and CA3 hippocampal region were detected by immunohistochemistry. Results Compared with Tg group, the ability of learning and memory of mice in Tg+CEGI-L group improved significantly (P < 0. 05). The expression of Aβ42 in the cortex in Tg+CEGI-L group and Tg+CEGI-H group was significantly lower than that of Tg group (43.00±10.03 vs 24.63±10.61, 24.89± 6.81, all P < 0.05). The expression of CB in CA1 and CA3 hippocampal region was higher in Tg+CEGI-L group than in Tg group (0.056±0.023 vs 0.031±0.001, P<0.05). Conclusion CEGI can reduce the expression of Aβ42 in the cortex and increase the expression of CB in CA1 hippocampal regionin APPswe/PS1dE9 double transgenic mice and improve their ability of learning and memory.%目的：观察脑苷肌肽(cattle encephalon glycoside and ignotin injection，CEGI)对APPswe/PS1dE9双转基因痴呆模型小鼠脑内β-淀粉样蛋白42(amyloidβ-peptide，Aβ42)和钙结合蛋白-D28K(calbindin-D28K，CB)表达的影响，探讨CEGI对阿茨海默病(Alzheimer's disease，AD)的防治作用。方法 APPswe/PS1dE9双转基因AD模型小鼠共48只，随机分为脑苷肌肽低剂量组[Tg+CEGI-L组，腹腔注射CEGI 6.6 ml/(kg·d)]、高剂量组[Tg+CEGI-H组，腹腔注射CEGI 13.2 ml/(kg·d)]、阳性药盐酸多奈哌齐组[Tg+Donepezil组，Donepezil灌胃2 mg/(kg·d)]，模型组(Tg组，腹腔注射等体积0.9%氯化钠注射液)，每组12只；同月龄同背景非转基因野生型C57BL/6J小鼠12只作为正常对照组(nTg组，腹腔注射等体积0.9%氯化钠注射液)。小鼠自5月龄开始腹腔注射给药1个月，然后进行Morris水迷宫实验检测小鼠的学习记忆能力，硫黄素S荧光染色和免疫组织化学染色检测皮质区Aβ42表达，免疫组织化学染色检测海马CA1区及CA3区CB表达的变化。结果行为学实验，与Tg组比较，Tg+CEGI-L组小鼠空间学习和记忆能力有明显改善(P＜0.05)；小鼠大脑皮质Aβ42的表达数目在Tg组显著高于Tg+CEGI-L组和Tg+CEGI-H组(43.00±10.03 vs 24.63±10.61/24.89±6.81，P＜0.05)；小鼠海马CA1区神经元保护性蛋白CB在Tg+CEGI-L组显著高于Tg组(0.056±0.023 vs 0.031±0.001，P＜0.05)。结论 CEGI能抑制Aβ42在大脑中的聚集沉积、CB过表达来降低神经元损伤，进而改善APPswe/PS1dE9双转基因痴呆模型小鼠的学习记忆能力。