Establishment of new detection methods for the discovery and development of novel ABCA1 and ABCA7 modulators as Alzheimer’s disease (AD) therapeutics and diagnostics

AD是一种难以控制、无法治愈的神经退行性疾病，给西方社会带来了巨大的经济和情感负担。不溶性脑淀粉样蛋白(A-β，A-β)被认为是阿尔茨海默病最重要的生物标志物，可导致神经细胞死亡和临床症状。虽然Aβ聚集的最初原因尚不清楚，但在Aβ蛋白的(过度)生产、降解和清除方面的病理变化已经被提出。在过去的大约20年里，已经很好地证实了几个ABC转运蛋白在血脑屏障上的β分布和清除中起关键作用。在这个蛋白质超家族中，ABCA亚类在AD病理中最为明显。特别是ABCA1和ABCA7基因的缺陷--导致ABCA1和ABCA7功能缺失或不起作用--从统计学上讲，遗传变异和全基因组关联研究表明，发生AD的风险更高。由于这些转运蛋白不直接运输Aβ蛋白，因此认为它们对AD发生和发展的影响与它们影响细胞胆固醇和磷脂分布的能力有关，从而影响膜的组成、组成和流动性。尤其是它们在脂筏和囊泡室中的细胞内组织被认为影响β持久性的方方面面--即产生、降解和清除。不幸的是，与其他研究良好的ABC转运体亚类相反，直接相互作用的小分子转运体-尽管已知20多年-几乎没有报道。事实上，只有12种化合物已知能抑制ABCA1，而对ABCA7一无所知。这主要归因于缺乏短期高通量筛选(HTS)分析来发现新的铅结构。然而，ABCA1和ABCA7的抑制剂和激活剂不仅有助于我们理解这些转运蛋白的机制，而且还可以作为诊断工具和开发新的AD疗法的模板。这项研究将集中于开发新的检测方法来监测ABCA1和ABCA7的功能，特别是追踪直接转运和ATPase活性。这些分析方法将用于筛选大型化合物文库，为随后的AD治疗和诊断开发发现新的先导分子，并用于开发包括基本支架和模式分析的计算模型，以筛选虚拟化合物文库，以扩大已知的ABCA1和ABCA7调节子的资金。

AD is a barely manageable, uncurable neurodegenerative disorder that poses a huge financial and emotional burden to western society. Insoluble cerebral amyloid-β (Aβ) proteins are both pathologically and diagnostically considered as the most important biomarker in AD, leading to neuronal cell death and clinical symptoms. While the initial causes of Aβ aggregation are yet unknown, pathological changes in (over)production, degradation, and clearance of Aβ proteins have been proposed. It has been well established within then last approximately 20 years that several ABC transporters are key players in Aβ distribution and clearance over the blood-brain-barrier (BBB). Amongst this protein superfamily, the ABCA subclass is most pronounced in AD pathology. Especially defects in the Abca1 and Abca7 genes – leading to less or un-functional ABCA1 and ABCA7 – showed statistically a higher risk to develop AD as revealed by genetic variant and genome-wide association studies. As these transporters do not directly transport Aβ proteins, it is believed that their impact on AD development and progression is associated with their ability to influence cellular cholesterol as well as phospholipid distribution, and thus, membrane constitution, composition, and fluidity. Especially their (intracellular) organization in lipid rafts and vesicular compartments are considered to impact all aspects of Aβ persistence – namely production, degradation, and clearance.Unfortunately, in contrast to other well-studied ABC transporter subclasses, directly interacting small-molecule modulators of ABCA transporters – although known for over 20 years – have barely been reported. In fact, only 12 compounds are known to inhibit ABCA1, while nothing is known regarding ABCA7. This can mainly be attributed to the lack of short-term high- throughput-screening (HTS) assays for the discovery of novel lead structures. However, inhibitors and activators of ABCA1 and ABCA7 would not only contribute to our understanding of the mechanistic aspects of these transporters, but may also be used as diagnostic tools and templates for the development of novel AD therapeutics. The study will focus on the development of novel detection methodologies to monitor ABCA1 and ABCA7 function, specifically tracing direct transport and ATPase activity. These assays will be used for both, the screening of large compound libraries to discover novel lead molecules for subsequent AD therapeutics and diagnostics development, and for the development of a computational model including basic scaffold and pattern analysis for screening of virtual compound libraries to extend the fund of known modulators of ABCA1 and ABCA7.