Aguirre Pabla, Mena Natalia P, Carrasco Carlos M, Muñoz Yorka, Pérez-Henríquez Patricio, Morales Rodrigo A, Cassels Bruce K, Méndez-Gálvez Carolina, García-Beltrán Olimpo, González-Billault Christian, Núñez Marco T
Iron and Biology of Aging Laboratory, Biology Department, Faculty of Sciences, Universidad de Chile, Santiago, Chile.
Research Ring on Oxidative Stress in the Nervous System, Santiago, Chile.
PLoS One. 2015 Dec 14;10(12):e0144848. doi: 10.1371/journal.pone.0144848. eCollection 2015.
Neuronal death in Parkinson's disease (PD) is often preceded by axodendritic tree retraction and loss of neuronal functionality. The presence of non-functional but live neurons opens therapeutic possibilities to recover functionality before clinical symptoms develop. Considering that iron accumulation and oxidative damage are conditions commonly found in PD, we tested the possible neuritogenic effects of iron chelators and antioxidant agents. We used three commercial chelators: DFO, deferiprone and 2.2'-dypyridyl, and three 8-hydroxyquinoline-based iron chelators: M30, 7MH and 7DH, and we evaluated their effects in vitro using a mesencephalic cell culture treated with the Parkinsonian toxin MPP+ and in vivo using the MPTP mouse model. All chelators tested promoted the emergence of new tyrosine hydroxylase (TH)-positive processes, increased axodendritic tree length and protected cells against lipoperoxidation. Chelator treatment resulted in the generation of processes containing the presynaptic marker synaptophysin. The antioxidants N-acetylcysteine and dymetylthiourea also enhanced axodendritic tree recovery in vitro, an indication that reducing oxidative tone fosters neuritogenesis in MPP+-damaged neurons. Oral administration to mice of the M30 chelator for 14 days after MPTP treatment resulted in increased TH- and GIRK2-positive nigra cells and nigrostriatal fibers. Our results support a role for oral iron chelators as good candidates for the early treatment of PD, at stages of the disease where there is axodendritic tree retraction without neuronal death.
帕金森病(PD)中的神经元死亡通常先于轴突树突的回缩和神经元功能丧失。存在无功能但存活的神经元为在临床症状出现之前恢复功能提供了治疗可能性。鉴于铁蓄积和氧化损伤是PD中常见的情况,我们测试了铁螯合剂和抗氧化剂可能的促神经突生长作用。我们使用了三种商业螯合剂:去铁胺(DFO)、地拉罗司和2,2'-联吡啶,以及三种基于8-羟基喹啉的铁螯合剂:M30、7-甲氧基-8-羟基喹啉(7MH)和7-二乙氨基-8-羟基喹啉(7DH),并使用经帕金森毒素1-甲基-4-苯基-1,2,3,6-四氢吡啶(MPP+)处理的中脑细胞培养物在体外评估了它们的作用,以及使用MPTP小鼠模型在体内评估了它们的作用。所有测试的螯合剂均促进了新的酪氨酸羟化酶(TH)阳性突起的出现,增加了轴突树突的长度,并保护细胞免受脂质过氧化。螯合剂治疗导致产生含有突触前标志物突触素的突起。抗氧化剂N-乙酰半胱氨酸和二甲基硫脲在体外也增强了轴突树突的恢复,这表明降低氧化应激可促进MPP+损伤神经元的神经突生长。在MPTP处理后给小鼠口服M30螯合剂持续14天,导致TH和G蛋白偶联内向整流钾通道2(GIRK2)阳性的黑质细胞和黑质纹状体纤维增加。我们的结果支持口服铁螯合剂作为PD早期治疗的良好候选药物,在疾病的轴突树突回缩但无神经元死亡的阶段发挥作用。