Fatokun A A, Liu J O, Dawson V L, Dawson T M
Neuroregeneration and Stem Cell Programs, Institute for Cell Engineering, Johns Hopkins University School of Medicine, Baltimore, MD 21205, USA.
Br J Pharmacol. 2013 Jul;169(6):1263-78. doi: 10.1111/bph.12201.
The current lack of disease-modifying therapeutics to manage neurological and neurodegenerative conditions justifies the development of more efficacious agents. One distinct pathway leading to neuronal death in these conditions and which represents a very promising and attractive therapeutic target is parthanatos, involving overactivation of PARP-1. We therefore sought to identify small molecules that could be neuroprotective by targeting the pathway.
Using HeLa cells, we developed and optimized an assay for high-throughput screening of about 5120 small molecules. Structure-activity relationship (SAR) study was carried out in HeLa and SH-SY5Y cells for molecules related to the initial active compound. The neuroprotective ability of each active compound was tested in cortical neuronal cultures.
4'-Methoxyflavone (4MF) showed activity by preventing the decrease in cell viability of HeLa and SH-SY5Y cells caused by the DNA-alkylating agent, N-methyl-N'-nitro-N-nitrosoguanidine (MNNG), which induces parthanatos. A similar compound from the SAR study, 3',4'-dimethoxyflavone (DMF), also showed significant activity. Both compounds reduced the synthesis and accumulation of poly (ADP-ribose) polymer and protected cortical neurones against cell death induced by NMDA.
Our data reveal additional neuroprotective members of the flavone class of flavonoids and show that methoxylation of the parent flavone structure at position 4' confers parthanatos-inhibiting activity while additional methoxylation at position 3', reported by others to improve metabolic stability, does not destroy the activity. These molecules may therefore serve as leads for the development of novel neurotherapeutics for the management of neurological and neurodegenerative conditions.
目前缺乏用于治疗神经和神经退行性疾病的疾病修饰疗法，这使得开发更有效的药物成为必要。在这些疾病中，一条导致神经元死亡的独特途径——细胞焦亡，涉及PARP-1的过度激活，这是一个非常有前景且有吸引力的治疗靶点。因此，我们试图鉴定能够通过靶向该途径发挥神经保护作用的小分子。
我们利用HeLa细胞开发并优化了一种用于高通量筛选约5120种小分子的检测方法。对与初始活性化合物相关的分子在HeLa和SH-SY5Y细胞中进行了构效关系（SAR）研究。在皮质神经元培养物中测试了每种活性化合物的神经保护能力。
4'-甲氧基黄酮（4MF）通过防止DNA烷化剂N-甲基-N'-硝基-N-亚硝基胍（MNNG）诱导的HeLa和SH-SY5Y细胞活力下降而表现出活性，MNNG可诱导细胞焦亡。SAR研究中的一种类似化合物3',4'-二甲氧基黄酮（DMF）也表现出显著活性。这两种化合物均减少了聚（ADP-核糖）聚合物的合成和积累，并保护皮质神经元免受NMDA诱导的细胞死亡。
我们的数据揭示了黄酮类黄酮的其他神经保护成员，并表明黄酮母核结构在4'位的甲氧基化赋予了抑制细胞焦亡的活性，而其他人报道的在3'位的额外甲氧基化虽可提高代谢稳定性，但并未破坏活性。因此，这些分子可能成为开发用于治疗神经和神经退行性疾病的新型神经治疗药物的先导化合物。
