Stress Conditions Increase Vimentin Cleavage by Omi/HtrA2 Protease in Human Primary Neurons and Differentiated Neuroblastoma Cells
Stress Conditions Increase Vimentin Cleavage by Omi/HtrA2 Protease in Human Primary Neurons and Differentiated Neuroblastoma Cells
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DOI：
10.1007/s12035-014-8906-3
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发表时间：
2015-12-01
影响因子：
5.1
通讯作者：
Behbahani, Homira
中科院分区：
文献类型：
--
作者：
Lucotte, Berangere;Tajhizi, Mehdi;Behbahani, Homira
线粒体丝氨酸蛋白酶Omi/HtrA 2功能障碍与多种神经退行性疾病有关。尽管Omi/HtrA 2在细胞凋亡中的作用有大量的证据，但对其胞质靶点知之甚少，其裂解可以解释所观察到的形态学变化，如轴突中的细胞骨架重组。通过蛋白质组学分析，波形蛋白被鉴定为Omi/HtrA 2的底物，并且我们已经报道了在阿尔茨海默病（AD）脑中Omi/HtrA 2蛋白酶活性增加。在这里，我们研究了Omi/HtrA 2和波形蛋白裂解之间的可能联系，以及这种裂解对神经元中线粒体分布的影响。在体外蛋白酶测定表明波形蛋白被Omi/HtrA 2蛋白酶切割，邻近连接试验表明，在人原代神经元中，在应激刺激后Omi/HtrA 2和波形蛋白之间的相互作用增加。使用分化的神经母细胞瘤SH-SY 5 Y细胞，我们发现Omi/HtrA 2在几种不同的应激条件下诱导野生型以及用具有阿尔茨海默病相关瑞典突变的淀粉样前体蛋白转染的SH-SY 5 Y细胞中波形蛋白的裂解。在应激处理后，Omi/HtrA 2蛋白酶活性被Omi/HtrA 2特异性抑制剂Ucf-101抑制，减少了野生型细胞中波形蛋白的切割。在应激刺激改变波形蛋白丝的完整性后，线粒体在分化的SH-SY 5 Y细胞和人原代神经元中重新分布。总之，本文中概述的发现表明Omi/HtrA 2在神经元中波形蛋白丝状结构的调节中的作用。我们的研究结果为理解Omi/HtrA 2活性在应激条件下的生物学作用提供了重要的发现，并提供了Omi/HtrA 2和波形蛋白之间相互作用的知识，这可能会影响神经元中的线粒体分布。
Dysfunctional Omi/HtrA2, a mitochondrial serine protease, has been implicated in various neurodegenerative disorders. Despite the wealth of evidence on the roles of Omi/HtrA2 in apoptosis, little is known about its cytosolic targets, the cleavage of which could account for the observed morphological changes such as cytoskeletal reorganizations in axons. By proteomic analysis, vimentin was identified as a substrate for Omi/HtrA2 and we have reported increased Omi/HtrA2 protease activity in Alzheimer disease (AD) brain. Here, we investigated a possible link between Omi/HtrA2 and vimentin cleavage, and consequence of this cleavage on mitochondrial distribution in neurons. In vitro protease assays showed vimentin to be cleaved by Omi/HtrA2 protease, and proximity ligation assay demonstrated an increased interaction between Omi/HtrA2 and vimentin in human primary neurons upon stress stimuli. Using differentiated neuroblastoma SH-SY5Y cells, we showed that Omi/HtrA2 under several different stress conditions induces cleavage of vimentin in wild-type as well as SH-SY5Y cells transfected with amyloid precursor protein with the Alzheimer disease-associated Swedish mutation. After stress treatment, inhibition of Omi/HtrA2 protease activity by the Omi/HtrA2 specific inhibitor, Ucf-101, reduced the cleavage of vimentin in wild-type cells. Following altered vimentin filaments integrity by stress stimuli, mitochondria was redistributed in differentiated SH-SY5Y cells and human primary neurons. In summary, the findings outlined in this paper suggest a role of Omi/HtrA2 in modulation of vimentin filamentous structure in neurons. Our results provide important findings for understanding the biological role of Omi/HtrA2 activity during stress conditions, and give knowledge of interplay between Omi/HtrA2 and vimentin which might affect mitochondrial distribution in neurons.