6-Hydroxydopamine disrupts cellular copper homeostasis in human neuroblastoma SH-SY5Y cells
6-Hydroxydopamine disrupts cellular copper homeostasis in human neuroblastoma SH-SY5Y cells
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DOI：
10.1093/mtomcs/mfab041
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发表时间：
2021-06-29
期刊：
影响因子：
3.4
通讯作者：
Adachi, Tetsuo
中科院分区：
文献类型：
--
作者：
Kondo, Mao;Hara, Hirokazu;Adachi, Tetsuo
铜是一种必需的微量元素，在维持神经功能方面发挥着重要作用，如神经递质的生物合成。相反，暴露在过量的铜中会导致细胞损伤。因此，细胞内的铜水平受到包括ATP7A在内的铜运输相关蛋白的严格调控。帕金森病(PD)是一种以黑质多巴胺能神经元丢失为特征的神经退行性疾病。近年来，铜稳态的异常被证实与帕金森病的发病机制有关。然而，铜代谢紊乱与帕金森病之间的关系尚不清楚。在这项研究中，我们研究了6-羟基多巴胺(6-OHDA)对人神经母细胞瘤SH-SY5Y细胞铜转运的影响。6-OHDA可降低铜出口蛋白ATP7A和铜伴侣蛋白Atox1的蛋白水平，但不影响铜进口蛋白CTR1的表达，但不影响ATP7A和Atox1基因的表达。抗氧化剂N-乙酰半胱氨酸和溶酶体抑制剂巴菲罗星A1可恢复ATP7A和Atox1蛋白水平的下降。这表明6-OHDA诱导的氧化应激促进了这些蛋白质的降解。此外，经6-OHDA处理的细胞暴露于CuCl2后，细胞内铜的含量显著高于未处理的细胞。此外，6-OHDA降低了将多巴胺转化为去甲肾上腺素的铜酶多巴胺β-羟基酶的蛋白质水平。因此，本研究提示，6-OHDA通过细胞内铜转运的失调而破坏铜的动态平衡，导致神经细胞功能障碍。
Copper (Cu) is an essential trace element that plays an important role in maintaining neuronal functions such as the biosynthesis of neurotransmitters. In contrast, exposure to excess Cu results in cell injury. Therefore, intracellular Cu levels are strictly regulated by proteins related to Cu-trafficking, including ATP7A. Parkinson's disease (PD) is a neurodegenerative disorder and is characterized by the loss of dopaminergic neurons in the substantia nigra. Recently, the abnormality of Cu homeostasis was demonstrated to be related to the pathogenesis of PD. However, the association between Cu dyshomeostasis and PD remains unclear. In this study, we examined the effects of 6-hydroxydopamine (6-OHDA), a neurotoxin used for the production of PD model animals, on cellular Cu trafficking in human neuroblastoma SH-SY5Y cells. 6-OHDA reduced the protein levels of the Cu exporter ATP7A and the Cu chaperone Atox1, but not CTR1, a Cu importer; however, it did not affect the expression of ATP7A and Atox1 mRNAs. The decreased levels of ATP7A and Atox1 proteins were restored by the antioxidant N-acetylcysteine and the lysosomal inhibitor bafilomycin A1. This suggests that 6-OHDA-induced oxidative stress facilitates the degradation of these proteins. In addition, the amount of intracellular Cu after exposure to CuCl2 was significantly higher in cells pretreated with 6-OHDA than in untreated cells. Moreover, 6-OHDA reduced the protein levels of the cuproenzyme dopamine beta-hydroxylase that converts dopamine to noradrenaline. Thus, this study suggests that 6-OHDA disrupts Cu homeostasis through the dysregulation of cellular Cu trafficking, resulting in the dysfunction of neuronal cells.