Yang Hongna, Yang Hongling, Xie Zhaohong, Wang Ping, Bi Jianzhong
Neurol Res. 2015 Jan;37(1):84-91. doi: 10.1179/1743132814Y.0000000417. Epub 2014 Jul 9.
Alzheimer's disease (AD) is one of the most common dementia, which is not effectively cured to date. Amyloid-beta (Abeta) deposition cascade and disintegrity of brain extracellular matrix (ECM) scaffold attribute to the progress of AD. Thus, it maybe an effective way to treat AD by altering the processing of amyloid precursor protein (APP) and regaining the integrity of ECM. The peptide amphiphile (PA) with a laminin epitope isoleucine-lysine-valine-alanine-valine (IKVAV) (IKVAV-PA) can be trigged into ECM in vivo. In addition, IKVAV-PA could significantly improve cognitive impairment with remarkable increase of endoneurogensis in the hippocampus, as well as reduction of burden of amyloid plaque in the brain.
We used heterozygous AbetaPPswe/PS1dE9 double transgenic mice as the animal model of AD. After 1 week of initial stereotaxic administration into bilateral hippocampus, the mice were subjected to the Morris Water Maze (MWM) test. At the end of MWM test, immunohistochemical staining, Western blot and real-time polymerase chain reaction (PCR) were performed in mice.
Here we showed that IKVAV-PA significantly improved cognitive impairment accompanying with reducing the burden of Abeta plaques, as well as the levels of soluble Abeta1-40 and Abeta1-42 in the cortex and hippocampus after 2 weeks of initial administration into bilateral hippocampus. Further examination demonstrated that IKVAV-PA also altered the processing of APP via inhibiting the gene expression of beta-secretase (BACE1), as well as improving the gene expression of insulin-degrading enzyme (IDE) and neprilysin (NEP).
Our data suggest that IKVAV-PA may serve as an alternative therapeutic intervention for treating the learning and memory losses in AD.
阿尔茨海默病(AD)是最常见的痴呆症之一,迄今为止尚无有效治愈方法。淀粉样β蛋白(Aβ)沉积级联反应和脑细胞外基质(ECM)支架的完整性破坏是AD进展的原因。因此,通过改变淀粉样前体蛋白(APP)的加工过程和恢复ECM的完整性可能是治疗AD的有效方法。带有层粘连蛋白表位异亮氨酸 - 赖氨酸 - 缬氨酸 - 丙氨酸 - 缬氨酸(IKVAV)的肽两亲分子(PA)(IKVAV - PA)可在体内触发形成ECM。此外,IKVAV - PA可显著改善认知障碍,使海马体中的神经发生显著增加,并减轻大脑中淀粉样斑块的负担。
我们使用杂合AβPPswe/PS1dE9双转基因小鼠作为AD动物模型。在双侧海马进行初次立体定向给药1周后,对小鼠进行莫里斯水迷宫(MWM)测试。在MWM测试结束时,对小鼠进行免疫组织化学染色、蛋白质印迹和实时聚合酶链反应(PCR)。
我们发现,在双侧海马初次给药2周后,IKVAV - PA显著改善了认知障碍,同时减轻了Aβ斑块的负担,以及皮质和海马体中可溶性Aβ1 - 40和Aβ1 - 42的水平。进一步检查表明,IKVAV - PA还通过抑制β - 分泌酶(BACE1)的基因表达来改变APP的加工过程,并提高胰岛素降解酶(IDE)和中性内肽酶(NEP)的基因表达。
我们的数据表明,IKVAV - PA可能作为治疗AD学习和记忆丧失的替代治疗干预措施。