Cathepsin D expression level affects alpha-synuclein processing, aggregation, and toxicity in vivo.
Cathepsin D expression level affects alpha-synuclein processing, aggregation, and toxicity in vivo.
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DOI：
10.1186/1756-6606-2-5
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发表时间：
2009-02-09
期刊：
影响因子：
3.6
通讯作者：
Tyynela, Jaana
中科院分区：
文献类型：
--
作者：
Cullen, Valerie;Lindfors, Maria;Ng, Juliana;Paetau, Anders;Swinton, Erika;Kolodziej, Piotr;Boston, Heather;Saftig, Paul;Woulfe, John;Feany, Mel B.;Myllykangas, Liisa;Schlossmacher, Michael G.;Tyynela, Jaana
SNCA基因表达升高和α-突触核蛋白（aSyn）编码蛋白的细胞内积累与帕金森病（PD）的发展有关。迄今为止，很少有酶被检测到它们降解aSyn的能力。在这里，我们探讨了编码溶酶体蛋白酶组织蛋白酶D （CathD）的CTSD基因表达对aSyn加工的影响。在多巴胺能MES23.5细胞培养中过度表达人CTSD cDNA诱导外源表达的aSyn蛋白以剂量依赖的方式显著蛋白水解。出乎意料的是，脑提取、Western blotting和ELISA定量显示，ctsd敲除小鼠中可溶性内源性aSyn水平降低。然而，通过甲酸提取检测，这些缺乏cathd的小鼠也含有高水平的不溶性低聚aSyn。与此一致，对小鼠、绵羊和人类的ctsd突变大脑的免疫组织化学研究显示，三种物种之间的选择性突触核蛋白样变化略有不同。这些变化包括细胞内aSyn的积累和泛素阳性包涵体的形成。此外，使用已建立的人类突触核蛋白病果蝇模型，我们观察到ctsd缺失果蝇的视网膜毒性显着增强。我们从这些互补的研究中得出结论：一，CathD可以有效地降解多巴胺能细胞中过量的aSyn；第二，ctsd基因突变导致溶酶体储存障碍，包括显微镜和生化证据的aSyn错误加工；第三，缺乏CathD会促进aSyn毒性。因此，我们假设CathD促进“突触核蛋白酶”的活性，并且增强其功能可能降低体内的aSyn浓度。
Elevated SNCA gene expression and intracellular accumulation of the encoded α-synuclein (aSyn) protein are associated with the development of Parkinson disease (PD). To date, few enzymes have been examined for their ability to degrade aSyn. Here, we explore the effects of CTSD gene expression, which encodes the lysosomal protease cathepsin D (CathD), on aSyn processing. Over-expression of human CTSD cDNA in dopaminergic MES23.5 cell cultures induced the marked proteolysis of exogenously expressed aSyn proteins in a dose-dependent manner. Unexpectedly, brain extractions, Western blotting and ELISA quantification revealed evidence for reduced levels of soluble endogenous aSyn in ctsd knock-out mice. However, these CathD-deficient mice also contained elevated levels of insoluble, oligomeric aSyn species, as detected by formic acid extraction. In accordance, immunohistochemical studies of ctsd-mutant brain from mice, sheep and humans revealed selective synucleinopathy-like changes that varied slightly among the three species. These changes included intracellular aSyn accumulation and formation of ubiquitin-positive inclusions. Furthermore, using an established Drosophila model of human synucleinopathy, we observed markedly enhanced retinal toxicity in ctsd-null flies. We conclude from these complementary investigations that: one, CathD can effectively degrade excess aSyn in dopaminergic cells; two, ctsd gene mutations result in a lysosomal storage disorder that includes microscopic and biochemical evidence of aSyn misprocessing; and three, CathD deficiency facilitates aSyn toxicity. We therefore postulate that CathD promotes 'synucleinase' activity, and that enhancing its function may lower aSyn concentrations in vivo.
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影响因子：
16.2
作者：
Giasson, BI;Duda, JE;Lee, VMY
通讯作者：
Lee, VMY
影响因子：
3.8
作者：
Awano, T;Katz, ML;Johnson, GS
通讯作者：
Johnson, GS
影响因子：
21.3
作者：
Fujiwara, H;Hasegawa, M;Iwatsubo, T
通讯作者：
Iwatsubo, T
影响因子：
4.7
作者：
Jabs, Sabrina;Quitsch, Arne;Braulke, Thomas
通讯作者：
Braulke, Thomas
影响因子：
5.3
作者：
Koike, M;Nakanishi, H;Uchiyama, Y
通讯作者：
Uchiyama, Y