A Brain Aggregate Model Gives New Insights Into the Pathobiology and Treatment of Prion Diseases
A Brain Aggregate Model Gives New Insights Into the Pathobiology and Treatment of Prion Diseases
复制标题
DOI：
10.1097/nen.0b013e3182544680
复制
发表时间：
2012-05-01
影响因子：
3.2
通讯作者：
DeArmond, Stephen J.
中科院分区：
文献类型：
--
作者：
Bajsarowicz, Krystyna;Ahn, Misol;DeArmond, Stephen J.
来自胎鼠大脑的脑聚集体（BrnAggs）含有成熟的神经元和神经胶质细胞。我们确定BrnAggs持续感染落基山实验室羊瘙痒病株朊病毒，并产生越来越高水平的致病形式朊病毒蛋白（PrPSc）。它们丰富的树突在朊病毒感染后不久发生变性。用药物治疗朊病毒感染的BrnAggs，如F-分泌酶抑制剂和奎纳克林（Qa），可以阻止PrPSc形成和树突状变性，反映了啮齿动物研究的结果。由于PrPSc是通过内吞作用和自噬体在朊病毒株感染的BrnAggs的神经元中通过吞噬作用进入溶酶体的，因此我们研究了调节亚细胞运输的药物的作用。雷帕霉素（Rap），激活自噬，显着增加轻链3-II（LC 3-II）阳性自噬体和组织蛋白酶D阳性溶酶体在BrnAggs，但不能消除细胞内的PrPSc。在Rap中加入Qa显著减少了LC 3-II阳性自体溶酶体的数量。Rap + Qa在Rap增加和Qa减少的LC 3-II之间产生竞争。与单独Qa相比，雷帕霉素+ Qa使总PrPSc降低56%，相对于单独Rap，其使PrPSc降低37%。我们的结论是，减少的能力Qa减少PrPSc的形成占主导地位。因此，BrnAggs为筛选药物疗法和研究朊病毒的复杂生物学提供了有效的体外工具。
Brain aggregates (BrnAggs) derived from fetal mouse brains contain mature neurons and glial cells. We determined that BrnAggs are consistently infected with Rocky Mountain Laboratory scrapie strain prions and produce increasing levels of the pathogenic form of the prion protein (PrPSc). Their abundant dendrites undergo degeneration shortly after prion infection. Treatment of prion-infected BrnAggs with drugs, such as a F-secretase inhibitors and quinacrine (Qa), which stop PrPSc formation and dendritic degeneration, mirrors the results from rodent studies. Because PrPSc is trafficked into lysosomes by endocytosis and autophagosomes by phagocytosis in neurons of prion strain-infected BrnAggs, we studied the effects of drugs that modulate subcellular trafficking. Rapamycin (Rap), which activates autophagy, markedly increased light-chain 3-II (LC3-II)-positive autophagosomes and cathepsin D-positive lysosomes in BrnAggs but could not eliminate the intracellular PrPSc within them. Adding Qa to Rap markedly reduced the number of LC3-II-positive autolysosomes. Rap + Qa created a competition between Rap increasing and Qa decreasing LC3-II. Rapamycin + Qa decreased total PrPSc by 56% compared with that of Qa alone, which reduced PrPSc by 37% relative to Rap alone. We conclude that the decrease was dominated by the ability of Qa to decrease the formation of PrPSc. Therefore, BrnAggs provide an efficient in vitro tool for screening drug therapies and studying the complex biology of prions.