Department of Chemistry and Biomolecular Sciences , University of Ottawa , 10 Marie Curie Street , Ottawa , Ontario K1N 6N5 , Canada.
Department of Biochemistry, Microbiology, and Immunology , Ottawa Institute for Systems Biology , 451 Smyth Road , Ottawa , Ontario K1H 8M5 , Canada.
ACS Chem Neurosci. 2019 Sep 18;10(9):4068-4075. doi: 10.1021/acschemneuro.9b00301. Epub 2019 Aug 8.
Protein disulfide isomerase (PDI) is a multifunctional enzyme located in the endoplasmic reticulum (ER) contributing to redox homeostasis and oxidative protein folding. PDI is associated with many diseases including neurodegenerative disorders like Alzheimer's disease and, hence, is considered a promising drug target. In this study, we investigate the abscisic acid (ABA)-derived PDI inhibitor origamicin for its neuropharmacological potential. First, we validated the function of origamicin by monitoring the inhibition of PDI's oxidoreductase activity using an in vitro enzyme activity assay. We also applied Huisgen cycloaddition chemistry (or "click chemistry") to interrogate the interaction of origamicin and PDI. Then, we evaluated the impact of origamicin on the viability of the neuroblastoma cell line SH-SY5Y. Next, we analyzed the gene expression profile of SH-SY5Y cells upon treatment with origamicin. We found 207 differentially expressed genes, including MYC. Computational analysis revealed an enrichment of genes involved in the oxidative stress response and the p53 signaling pathway. Induction of the p53 signaling pathway and downregulation of MYC are known to affect processes such as cell cycle, cellular repair, and apoptosis. Our study reveals the molecular mechanism of PDI inhibition by origamicin. Furthermore, this study provides important gene expression profiles that offer insights into the underlying mechanism of PDI inhibition and creates a valuable starting point for neuropharmacological applications of origamicin and other PDI inhibitors.
蛋白质二硫键异构酶（PDI）是一种多功能酶，位于内质网（ER）中，有助于氧化还原平衡和氧化蛋白折叠。PDI 与许多疾病有关，包括阿尔茨海默病等神经退行性疾病，因此被认为是一个有前途的药物靶点。在这项研究中，我们研究了脱落酸（ABA）衍生的 PDI 抑制剂 origamicin 的神经药理学潜力。首先，我们通过监测体外酶活性测定中 PDI 的氧化还原酶活性抑制来验证 origamicin 的功能。我们还应用了 Huisgen 环加成化学（或“点击化学”）来研究 origamicin 和 PDI 的相互作用。然后，我们评估了 origamicin 对神经母细胞瘤细胞系 SH-SY5Y 活力的影响。接下来，我们分析了 origamicin 处理后 SH-SY5Y 细胞的基因表达谱。我们发现了 207 个差异表达的基因，包括 MYC。计算分析显示，与氧化应激反应和 p53 信号通路相关的基因富集。p53 信号通路的诱导和 MYC 的下调已知会影响细胞周期、细胞修复和细胞凋亡等过程。我们的研究揭示了 origamicin 抑制 PDI 的分子机制。此外，这项研究提供了重要的基因表达谱，为 PDI 抑制的潜在机制提供了深入的见解，并为 origamicin 和其他 PDI 抑制剂的神经药理学应用创造了有价值的起点。
