Ramirez Eduardo, Min Sehong, Ganegamage Susantha K, Shimanaka Kazuma, Sosa Magaly Guzman, Dettmer Ulf, Rochet Jean-Christophe, Fortin Jessica S
Department of Basic Medical Sciences, College of Veterinary Medicine, Purdue University.
Department of Medicinal Chemistry and Molecular Pharmacology, College of Pharmacy, Purdue University.
Results Chem. 2023 Jan;5. doi: 10.1016/j.rechem.2023.100938. Epub 2023 Apr 28.
Alzheimer's disease (AD) is a multifactorial, chronic neurodegenerative disease characterized by the presence of extracellular β-amyloid (Aβ) plaques, intraneuronal neurofibrillary tangles (NFTs), activated microglial cells, and an inflammatory state (involving reactive oxygen species production) in the brain. NFTs are comprised of misfolded and hyperphosphorylated forms of the microtubule-binding protein tau. Interestingly, the trimeric form of the 2N4R splice isoform of tau has been found to be more toxic than the trimeric 1N4R isoform in neuron precursor cells. Few drug discovery programs have focused on specific tau isoforms. The present drug discovery project is centered on the anti-aggregation effect of a series of seventeen 4- or 5-aminoindole carboxamides on the 2N4R isoform of tau. The selection of the best compounds was performed using α-synuclein (α-syn). The anti-oligomer and -fibril activities of newly synthesized aminoindole carboxamide derivatives were evaluated with biophysical methods, such as thioflavin T fluorescence assays, photo-induced cross-linking of unmodified proteins, and transmission electron microscopy. To evaluate the reduction of inclusions and cytoprotective effects, M17D neuroblastoma cells expressing inclusion-forming α-syn were treated with the best amide representatives. The 4-aminoindole carboxamide derivatives exhibited a better anti-fibrillar activity compared to their 5-aminoindole counterparts. The amide derivatives , , and exerted anti-oligomer and anti-fibril activities on α-syn and the 2N4R isoform of tau. At a concentration of 40 μM, compound reduced inclusion formation in M17D neuroblastoma cells expressing inclusion-prone αSynuclein3K::YFP. Our results demonstrate the potential of 4-aminoindole carboxamide derivatives with regard to inhibiting the oligomer formation of α-syn and tau (2N4R isoform) for further optimization prior to pre-clinical studies.
阿尔茨海默病（AD）是一种多因素慢性神经退行性疾病，其特征是大脑中存在细胞外β淀粉样蛋白（Aβ）斑块、神经元内神经原纤维缠结（NFTs）、活化的小胶质细胞以及炎症状态（涉及活性氧的产生）。NFTs由微管结合蛋白tau的错误折叠和过度磷酸化形式组成。有趣的是，已发现tau的2N4R剪接异构体的三聚体形式在神经元前体细胞中比三聚体1N4R异构体毒性更大。很少有药物研发项目专注于特定的tau异构体。目前的药物研发项目集中于一系列17种4-或5-氨基吲哚羧酰胺对tau的2N4R异构体的抗聚集作用。使用α-突触核蛋白（α-syn）进行最佳化合物的筛选。通过生物物理方法，如硫黄素T荧光测定、未修饰蛋白质的光诱导交联和透射电子显微镜，评估新合成的氨基吲哚羧酰胺衍生物的抗寡聚体和抗纤维活性。为了评估包涵体的减少和细胞保护作用，用最佳酰胺代表物处理表达形成包涵体的α-syn的M17D神经母细胞瘤细胞。与5-氨基吲哚对应物相比，4-氨基吲哚羧酰胺衍生物表现出更好的抗纤维活性。酰胺衍生物、和对α-syn和tau的2N4R异构体具有抗寡聚体和抗纤维活性。在40μM浓度下，化合物减少了表达易形成包涵体的α-突触核蛋白3K::YFP的M17D神经母细胞瘤细胞中的包涵体形成。我们的结果证明了4-氨基吲哚羧酰胺衍生物在抑制α-syn和tau（2N4R异构体）的寡聚体形成方面的潜力，以便在临床前研究之前进行进一步优化。
