2-(α-羟基戊基)苯甲酸钾盐抗阿尔茨海默氏病作用机理研究

Potassium 2-(1-hydroxypentyl)-benzoate (dl-PHPB, with PCT global patents) is a candidate of prodrug of dl-NBP (anti-ischemic stroke). The phase I clinic trial of dl-PHPB was complete and the phase II clinic trial will be started soon. Recently it was found that dl-PHPB could improve cognition in several animal models, such as SAMP8 mice and vascular dementia rats. In APP 695 transgenic SK-N-SH cells and APP/PS1 transgenic mice PHPB were demonstrated to reduce ?-amyloid1-42 level and tau phosphorylation. The parent drug NBP was also demonstrated to inhibit ?-amyloid and tau phosphorylation. Dl-PHPB might be used for treatment of Alzheimer's disease (AD) as a new indication in future. Therefore, studying the mechanisms and the targets of PHPB for AD is important. In the present project we want to investigate the anti-dementia effect of PHPB on APP/PS1 mice (12 month) and study on the signal pathway for ?-amyloid generation and accumulation as well as the activity of the kinases for tau phosphorylation in the animal brain tissues and in APP transgenic cell lines. The NMDA dependent and acetylcholine related LTP will be also investigated in APP/PS1 mice after PHPB treatment. The proteomic study of APP/PS1 mice brain is planted to study to find differentially expressed proteins before and after PHPB treatment in transgenic animals and in control animals. It may help to find the new biomarkers of AD and to discover the targets of PHPB for treatment of AD. We possess the all techniques and equipment for above studies in our lab.

2-(α-羟基戊基)苯甲酸钾盐-dl-PHPB是抗脑缺血新药丁基苯酞(NBP)的前药，已完成Ⅰ期临床研究，并申请Ⅱ、Ⅲ期临床。最近的研究发现其在多种动物和细胞模型中具有明显的抗痴呆和调节相关信号通路作用。如血管性痴呆大鼠和SAMP8小鼠，PHPB都可明显提高认知能力。在APP695 SK-N-SH细胞及APP/PS1转基因小鼠中，dl-PHPB可减少Aβ和tau蛋白磷酸化。课题拟解决的关键问题是：阐明dl-PHPB抗AD的作用机制，寻找该药的靶点及用于AD治疗的可行性。研究内容包括，在APP/PS1小鼠及APP转基因细胞上，研究dl-PHPB对Aβ生成，降解及tau蛋白磷酸化相关信号通路的影响以及对胆碱能系统和NMDA受体相关的LTP的影响，并应用蛋白组学的方法，发现AD转基因小鼠脑中与AD发生发展相关的蛋白及信号系统的改变，dl-PHPB对它们的逆转作用，以期发展新的AD药物靶点。

该课题的主要目标是2-(α-羟基戊基)苯甲酸钾盐（PHPB）抗老年性痴呆的作用机理研究和探索治疗老年痴呆的药物靶点。PHPB是抗缺血性脑卒中候选新药。该课题的实施对扩大PHPB的临床适应症，发现新靶点，开发新型抗AD药物具有重要意义。.经过4年的研究，已完成了预期的研究目标，结果总结如下：.1.在APP/PS1转基因（Tg）小鼠上进行了系统的AD病理生理改变与PHPB的逆转作用研究，证明dl-PHPB显著减少转基因小鼠海马Thio-S阳性的Aβ斑块，给予dl-PHPB处理后可明显降低P-APP（T668）位点的蛋白表达并上调ADAM17和PKCα的表达，提示dl-PHPB可调节APP的加工过程，朝非淀粉样肽合成的方向发展。此外，15月龄Tg小鼠皮层、海马中p-Tau（S396）、p-Tau（T205）位点的蛋白表达明显增高，PHPB可显著降低。PHPB还可显著降低Tg小鼠皮层、海马中平p-GSK-3β（Y216）和p-CDK5(S159)的蛋白表达。电生理研究显示，dl-PHPB可使Tg小鼠海马降低的LTP水平明显升高，PHPB的作用与改善NMDAR磷酸化NR2B（Tyr1472）蛋白表达有关。.2．在Aβ侧脑室注射大鼠模型，除了上述机理外，证明PHPB具有抗神经氧化损伤和提高胆碱系统功能的作用。在LPS模型上还进一步证明，dl-PHPB能剂量依赖性的降低小鼠皮层中TNF-α的含量，降低皮层及海马中IL-1β，IL-6和IL-10的含量，dl-PHPB还能显著降低血浆及海马中iNOS的含量，上述作用与降低小胶质细胞的活化，调节p-ERK、p-JNK、p-P38信号通路蛋白有关。.3. 12月龄Tg小鼠的皮层和海马药物蛋白组学研究共发现21个差异蛋白，其中6个经Western验证，3个蛋白在AD病人血清中与动物模型变化一致，他们是Cat B, Cofilin2和VDAC1，有望成为AD生物标志物，可能辅助早期临床诊断，促进抗AD新药研发，结果已发表。.课题已发表相关研究论文10篇，另3-4篇在撰写和投稿中。参加国内外会议10余次，均做大会或专题报告。