Infectious prion protein alters manganese transport and neurotoxicity in a cell culture model of prion disease
Infectious prion protein alters manganese transport and neurotoxicity in a cell culture model of prion disease
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DOI：
10.1016/j.neuro.2011.07.008
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发表时间：
2011-10-01
期刊：
影响因子：
3.4
通讯作者：
Kanthasamy, Anumantha G.
中科院分区：
文献类型：
--
作者：
Martin, Dustin P.;Anantharam, Vellareddy;Kanthasamy, Anumantha G.
蛋白质错误折叠和聚集被认为是许多神经退行性疾病的关键特征，但蛋白质错误折叠和蛋白质聚集体繁殖的生物化学机制尚不清楚。Prion病是一种典型的神经退行性疾病，由内源性表达的正常细胞PrPC蛋白错误折叠所致。虽然PrPC的确切功能尚未完全阐明，但研究表明它可以作为一种金属结合蛋白发挥作用。有趣的是，据报道，在各种Pron疾病中，大脑中的锰(Mn)水平升高，这表明二价金属也可能在疾病过程中发挥作用。最近，我们在神经细胞培养模型中报道了PrPC对锰诱导的细胞毒性的保护作用。为了进一步了解锰在普恩病毒病中的作用，我们在普恩病毒病的感染细胞培养模型中检测了锰的神经毒性。结果表明，与未感染细胞相比，感染细胞对锰的神经毒性具有更强的抗性(感染细胞的EC50=428.8 mU M，未感染细胞的EC50为211.6 mU M)。此外，在持续感染的CADS细胞中，300亩锰处理显示与未感染的细胞相比，线粒体损伤、caspase-3激活和DNA片段化都有所减少。通过电感耦合等离子体质谱(ICPMS)检测发现，感染瘙痒病的细胞对锰的摄取显著减少，金属转运蛋白DMT1和转铁蛋白的表达也发生了改变。综上所述，我们的数据表明PrP向致病异构体的转换增强了其调节锰稳态的能力，并表明了解金属与疾病特异性蛋白的相互作用可能为进一步了解神经退行性疾病中的蛋白质聚集提供帮助。(C)2011 Elsevier Inc.保留所有权利。
Protein misfolding and aggregation are considered key features of many neurodegenerative diseases, but biochemical mechanisms underlying protein misfolding and the propagation of protein aggregates are not well understood. Prion disease is a classical neurodegenerative disorder resulting from the misfolding of endogenously expressed normal cellular prion protein (PrPC). Although the exact function of PrPC has not been fully elucidated, studies have suggested that it can function as a metal binding protein. Interestingly, increased brain manganese (Mn) levels have been reported in various prion diseases indicating divalent metals also may play a role in the disease process. Recently, we reported that PrPC protects against Mn-induced cytotoxicity in a neural cell culture model. To further understand the role of Mn in prion diseases, we examined Mn neurotoxicity in an infectious cell culture model of prion disease. Our results show CAD5 scrapie-infected cells were more resistant to Mn neurotoxicity as compared to uninfected cells (EC50 = 428.8 mu M for CAD5 infected cells vs. 211.6 mu M for uninfected cells). Additionally, treatment with 300 mu M Mn in persistently infected CADS cells showed a reduction in mitochondrial impairment, caspase-3 activation, and DNA fragmentation when compared to uninfected cells. Scrapie-infected cells also showed significantly reduced Mn uptake as measured by inductively coupled plasma-mass spectrometry (ICP-MS), and altered expression of metal transporting proteins DMT1 and transferrin. Together, our data indicate that conversion of PrP to the pathogenic isoform enhances its ability to regulate Mn homeostasis, and suggest that understanding the interaction of metals with disease-specific proteins may provide further insight to protein aggregation in neurodegenerative diseases. (C) 2011 Elsevier Inc. All rights reserved.