Liu Kai, Chojnacki Jeremy E, Wade Emily E, Saathoff John M, Lesnefsky Edward J, Chen Qun, Zhang Shijun
Department of Medicinal Chemistry, Virginia Commonwealth University, Richmond, VA, USA.
Department of Medicine, Pauley Heart Center, Division of Cardiology, Virginia Commonwealth University, Richmond, VA, USA.
J Alzheimers Dis. 2015;47(4):1021-33. doi: 10.3233/JAD-150242.
Multiple pathogenic factors have been suggested to play a role in the development of Alzheimer's disease (AD). The multifactorial nature of AD also suggests the potential use of compounds with polypharmacology as effective disease-modifying agents. Recently, we have developed a bivalent strategy to include cell membrane anchorage into the molecular design. Our results demonstrated that the bivalent compounds exhibited multifunctional properties and potent neuroprotection in a cellular AD model. Herein, we report the mechanistic exploration of one of the representative bivalent compounds, 17MN, in MC65 cells. Our results established that MC65 cells die through a necroptotic mechanism upon the removal of tetracycline (TC). Furthermore, we have shown that mitochondrial membrane potential and cytosolic Ca2+ levels are increased upon removal of TC. Our bivalent compound 17MN can reverse such changes and protect MC65 cells from TC removal induced cytotoxicity. The results also suggest that 17MN may function between the Aβ species and RIPK1 in producing its neuroprotection. Colocalization studies employing a fluorescent analog of 17MN and confocal microscopy demonstrated the interactions of 17MN with both mitochondria and endoplasmic reticulum, thus suggesting that 17MN exerts its neuroprotection via a multiple-site mechanism in MC65 cells. Collectively, these results strongly support our original design rationale of bivalent compounds and encourage further optimization of this bivalent strategy to develop more potent analogs as novel disease-modifying agents for AD.
多种致病因素被认为在阿尔茨海默病（AD）的发展中起作用。AD的多因素性质也表明具有多药理学特性的化合物有可能作为有效的疾病修饰剂。最近，我们开发了一种二价策略，将细胞膜锚定纳入分子设计中。我们的结果表明，二价化合物在细胞AD模型中表现出多功能特性和强大的神经保护作用。在此，我们报告了对一种代表性二价化合物17MN在MC65细胞中的作用机制探索。我们的结果表明，去除四环素（TC）后，MC65细胞通过坏死性凋亡机制死亡。此外，我们还表明，去除TC后线粒体膜电位和胞质Ca2+水平会升高。我们的二价化合物17MN可以逆转这些变化，并保护MC65细胞免受TC去除诱导的细胞毒性。结果还表明，17MN可能在Aβ物种和RIPK1之间发挥作用以产生其神经保护作用。使用17MN的荧光类似物和共聚焦显微镜进行的共定位研究表明，17MN与线粒体和内质网均有相互作用，因此表明17MN在MC65细胞中通过多位点机制发挥其神经保护作用。总的来说，这些结果有力地支持了我们对二价化合物的原始设计理念，并鼓励进一步优化这种二价策略，以开发更有效的类似物作为AD的新型疾病修饰剂。
