Department of Medical Biology, Faculty of Medicine, Atatürk University, 25240 Erzurum, Turkey.
Department of Pharmacy, University "G. d'Annunzio" of Chieti-Pescara, via dei Vestini 31, 66100 Chieti Scalo (CH), Italy.
Biomolecules. 2020 May 9;10(5):737. doi: 10.3390/biom10050737.
Cyclic dipeptides administered by both parenteral and oral routes are suggested as promising candidates for the treatment of neurodegeneration-related pathologies. In this study, we tested Cyclo (His-Pro) isomers (cHP1-4) for their anti-Alzheimer potential using a differentiated human neuroblastoma cell line (SH-SY5Y) as an Alzheimer's disease (AD) experimental model. The SH-SY5Y cell line was differentiated by the application of retinoic acid (RA) to obtain mature neuron-like cells. Amyloid-beta 1-42 () peptides, the main effector in AD, were administered to the differentiated cell cultures to constitute the in vitro disease model. Next, we performed cell viability analyses 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) and lactate dehydrogenase (LDH) release assays) to investigate the neuroprotective concentrations of cyclodipeptides using the in vitro AD model. We evaluated acetylcholinesterase (AChE), α- and β-secretase activities (TACE and BACE1), antioxidant potency, and apoptotic/necrotic properties and performed global gene expression analysis to understand the main mechanism behind the neuroprotective features of cHP1-4. Moreover, we conducted sister chromatid exchange (SCE), micronucleus (MN), and 8-hydroxy-2'-deoxyguanosine (8-OHdG) analyses to evaluate the genotoxic damage potential after applications with cHP1-4 on cultured human lymphocytes. Our results revealed that cHP1-4 isomers provide a different degree of neuroprotection against -induced cell death on the in vitro AD model. The applications with cHP1-4 isomers altered the activity of AChE but not the activity of TACE and BACE1. Our analysis indicated that the cHP1-4 increased the total antioxidant capacity without altering total oxidative status levels in the cellular AD model and that cHP1-4 modulated the alterations of gene expressions by exposure. We also observed that cHP1-4 exhibited noncytotoxic and non-genotoxic features in cultured human whole blood cells. In conclusion, cHP1-4 isomers, especially cHP4, have been explored as novel promising therapeutics against AD.
通过肠内和口服途径给予环二肽被认为是治疗神经退行性相关疾病的有前途的候选药物。在这项研究中，我们使用分化的人神经母细胞瘤细胞系（SH-SY5Y）作为阿尔茨海默病（AD）实验模型，测试了环（组-脯）异构体（cHP1-4）的抗阿尔茨海默病潜力。通过应用视黄酸（RA）使 SH-SY5Y 细胞系分化，获得成熟的神经元样细胞。β淀粉样蛋白 1-42（Aβ1-42）肽，AD 的主要效应物，被给予分化的细胞培养物以构成体外疾病模型。接下来，我们进行了细胞活力分析（3-（4,5-二甲基噻唑-2-基）-2,5-二苯基四唑溴盐（MTT）和乳酸脱氢酶（LDH）释放测定），以使用体外 AD 模型研究环二肽的神经保护浓度。我们评估了乙酰胆碱酯酶（AChE）、α-和β-分泌酶活性（TACE 和 BACE1）、抗氧化能力、凋亡/坏死特性，并进行了全基因表达分析，以了解 cHP1-4 的神经保护特性背后的主要机制。此外，我们进行了姐妹染色单体交换（SCE）、微核（MN）和 8-羟基-2'-脱氧鸟苷（8-OHdG）分析，以评估在培养的人淋巴细胞上应用 cHP1-4 后的遗传毒性损伤潜力。我们的结果表明，cHP1-4 异构体在体外 AD 模型中对 Aβ1-42 诱导的细胞死亡提供了不同程度的神经保护作用。cHP1-4 异构体的应用改变了 AChE 的活性，但不改变 TACE 和 BACE1 的活性。我们的分析表明，cHP1-4 在细胞 AD 模型中增加了总抗氧化能力，而不改变总氧化状态水平，并且 cHP1-4 调节了 Aβ1-42 暴露引起的基因表达的改变。我们还观察到 cHP1-4 在培养的人全血细胞中表现出非细胞毒性和非遗传毒性特征。总之，cHP1-4 异构体，特别是 cHP4，已被探索为治疗 AD 的新型有前途的治疗药物。
