银杏内酯B对阿尔茨海默病大鼠海马Synapsin-1、Beclin1和LC3表达的影响

目的:探讨银杏内酯B(ginkgolide B,GB)对阿尔茨海默病(alzheimer's disease,AD)大鼠海马Synapsin-1、Beclin1和LC3的影响.方法:将大鼠按随机数字表法分为假手术组、模型组、银杏内酯B低剂量组、中剂量组和高剂量组,采用Morris水迷宫检测学习记忆,透射电镜观察自噬,免疫组织化学分析海马Synapsin-1、Beclin1和LC3阳性神经元光密度值,荧光定量PCR检测海马Synapsin-1、Beclin1和LC3-Ⅱ的mRNA水平.结果:中、高剂量银杏内酯B可缩短AD大鼠逃避潜伏期,增加穿越平台次数,减少自噬体,提高海马组织Synapsin-1,降低Beclin1 mRNA和蛋白表达,同时下调LC3-ⅡmRNA水平.结论:银杏内酯B可改善AD大鼠学习记忆能力,可能与海马突触相关蛋白Synapsin-1上调、自噬相关基因Beclin1和LC3水平下降有关.

3β-Hydroxysteroid-Δ24 reductase (DHCR24) is a multifunctional enzyme that localizes to the endoplasmic reticulum and has neuroprotective and cholesterol-synthesizing activities. DHCR24 overexpression confers neuroprotection against apoptosis caused by amyloidβdeposition. hTe present study aimed to construct two recombinant adenoviruses driving DHCR24 expression specifically in neurons. Two SYN1 promoter DNA fragments were obtained from human (h) and rat (r). Recombinant Ad-r(h)SYN1-DHCR24 was transfected into AD-293, N2A (mouse neuroblastoma), and MIN6 (mouse pancreatic carcinoma) cells. Western blot analysis showed DHCR24 was specially expressed in 293 and N2A cells, but no speciifc band was found in MIN6 cells. hTis demonstrates that the recombinant adenoviruses successfully express DHCR24, and no expression is observed in non-neuronal cells. TUNEL assay results showed apoptosis was inhibited in adenovirus-transfected neurons. Detecting reactive oxygen species by immunolfu-orescence, we found that adenovirus transfection inhibits apoptosis through scavenging excess reactive oxygen species. Our ifndings show that the recombinant DHCR24 adenoviruses induce neuron-specific DHCR24 expression, and thereby lay the foundation for further studies on DHCR24 gene therapy for Alzheimer’s disease.