Falanga Andrea Patrizia, Piccialli Ilaria, Greco Francesca, D'Errico Stefano, Nolli Maria Grazia, Borbone Nicola, Oliviero Giorgia, Roviello Giovanni N
Department of Pharmacy, University of Naples Federico II, Naples, Italy.
Division of Pharmacology, Department of Neuroscience, Reproductive and Dentistry Sciences, School of Medicine, University of Naples Federico II, Naples, Italy.
J Neurochem. 2025 Jan;169(1):e16296. doi: 10.1111/jnc.16296.
The natural compound orotic acid and its anionic form, orotate, play a pivotal role in various biological processes, serving as essential intermediates in pyrimidine de novo synthesis, with demonstrated connections to dietary, supplement, and neurodrug applications. A novel perspective on biomolecular aggregation at the nanoscale, particularly pertinent to neurodegeneration, challenges the established paradigm positing that peptide (amyloid beta) and protein (tau) aggregation mainly govern the molecular events underlying prevalent neuropathologies. Emerging biological evidence indicates a notable role for G-quadruplex (G4) DNA aggregation in neurodegenerative processes affecting neuronal cells, particularly in the presence of extended (GC) repeats in nuclear DNA sequences. Our study concerns d[(GGGGCC)GGGG], a G4-forming DNA model featuring GC repeats that is in correlation with neurodegeneration. Through different investigations utilizing spectroscopic techniques (CD, UV, and thermal denaturations), PAGE electrophoresis, and molecular docking, the study explores the influence of orotate on the aggregation of this neurodegeneration-associated DNA. A computational approach was employed to construct an in silico model of the DNA aggregate, which involved the docking of multiple G4 units and subsequent integration of the ligand into both the DNA monomer and its in silico aggregated model. The convergence of computational analyses and empirical data collectively supports the hypothesis that orotate possesses the capability to modulate the aggregation of neurodegeneration-related DNA. Notably, the findings suggest the potential utility of orotate as a neurodrug, especially for the therapy of amyotrophic lateral sclerosis (ALS) and Frontotemporal Dementia (FTD), with its current status as a dietary supplement indicating minimal safety concerns. Additionally, orotate demonstrated a slight increase in mitochondrial dehydrogenase activity as assessed by the MTT assay, which is beneficial for a neurodrug as it suggests a potential role in enhancing mitochondrial function and supporting neuronal health.
天然化合物乳清酸及其阴离子形式乳清酸盐在各种生物过程中起着关键作用，是嘧啶从头合成的重要中间体，与饮食、补充剂和神经药物应用有着密切联系。关于纳米尺度生物分子聚集的新观点，尤其与神经退行性变相关，对既定范式提出了挑战，该范式认为肽（β-淀粉样蛋白）和蛋白质（tau）聚集主要控制着常见神经病理学的分子事件。新出现的生物学证据表明，G-四链体（G4）DNA聚集在影响神经元细胞的神经退行性过程中起着显著作用，特别是在核DNA序列中存在延伸的（GC）重复序列时。我们的研究涉及d[(GGGGCC)GGGG]，这是一种形成G4的DNA模型，具有与神经退行性变相关的GC重复序列。通过利用光谱技术（圆二色性、紫外和热变性）、聚丙烯酰胺凝胶电泳和分子对接等不同研究方法，该研究探讨了乳清酸盐对这种与神经退行性变相关的DNA聚集的影响。采用了一种计算方法来构建DNA聚集体的计算机模型，该模型涉及多个G4单元的对接以及随后将配体整合到DNA单体及其计算机聚集模型中。计算分析和实验数据的结合共同支持了这样一个假设，即乳清酸盐具有调节与神经退行性变相关的DNA聚集的能力。值得注意的是，研究结果表明乳清酸盐作为一种神经药物具有潜在的应用价值，特别是对于肌萎缩侧索硬化症（ALS）和额颞叶痴呆（FTD）的治疗，其作为膳食补充剂的现状表明安全性问题极小。此外，通过MTT法评估，乳清酸盐显示出线粒体脱氢酶活性略有增加，这对神经药物来说是有益的，因为这表明它在增强线粒体功能和支持神经元健康方面可能发挥作用。
