α-Enolase reduces cerebrovascular Aβ deposits by protecting Aβ amyloid formation
α-Enolase reduces cerebrovascular Aβ deposits by protecting Aβ amyloid formation
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DOI：
10.1007/s00018-022-04493-x
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发表时间：
2022-08-01
影响因子：
8
通讯作者：
Ueda，Mitsuharu
中科院分区：
文献类型：
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作者：
Inoue，Yasuteru;Tasaki，Masayoshi;Ueda，Mitsuharu
脑淀粉样血管病（Cerebral amyloid angiopathy，CAA）是以脑血管淀粉样蛋白β（amyloid β，Aβ）沉积为特征的疾病，可引起痴呆和脑出血。虽然α-烯醇化酶（ENO 1）具有多种功能，但其在CAA发病机制中的确切作用尚不清楚。在这项研究中，我们专注于ENO 1，这是一种众所周知的糖酵解酶，以前通过蛋白质组学方法鉴定为阿尔茨海默病（AD）患者脑样本中的上调蛋白质。我们利用硫磺素T荧光分析和透射电子显微镜来监测ENO 1对Aβ肽形成淀粉样蛋白的影响。我们还培养了小鼠原代脑血管平滑肌细胞，以确定ENO 1对Aβ细胞毒性的影响。为了研究ENO 1在体内的作用，我们使用连续输注系统将ENO 1或载体对照输注到AD/CAA转基因模型APP 23小鼠的脑中，随后进行认知测试和病理学和生化分析。我们发现ENO 1的新功能包括与Aβ相互作用并抑制其纤维形成，破坏Aβ纤维，并通过蛋白水解降解Aβ肽来减弱这些纤维的细胞毒性作用。我们还证明，向APP 23小鼠脑中输注ENO 1可减少脑血管Aβ沉积并改善认知障碍。此外，我们发现酶失活的ENO 1不能抑制Aβ原纤维的形成和原纤维的破坏。因此，ENO 1的蛋白水解活性可能是该酶的细胞保护作用和从脑中清除Aβ的基础，并且ENO 1可能是CAA的治疗靶点。
Cerebral amyloid angiopathy (CAA) is characterized by cerebrovascular amyloid β (Aβ) deposits and causes dementia and cerebral hemorrhage. Although α-enolase (ENO1) was shown to possess multifunctional roles, its exact functions in CAA pathogenesis have not been determined. In this study, we focused on ENO1, a well-known glycolytic enzyme, which was previously identified via a proteomic approach as an upregulated protein in brain samples from patients with Alzheimer's disease (AD). We utilized the thioflavin T fluorescence assay and transmission electron microscopy to monitor the effects of ENO1 on amyloid formation by Aβ peptides. We also cultured murine primary cerebrovascular smooth muscle cells to determine the effects of ENO1 on Aβ cytotoxicity. To investigate the effects of ENO1 in vivo, we infused ENO1 or a vehicle control into the brains of APP23 mice, a transgenic model of AD/CAA, using a continuous infusion system, followed by a cognitive test and pathological and biochemical analyses. We found that novel functions of ENO1 included interacting with Aβ and inhibiting its fibril formation, disrupting Aβ fibrils, and weakening the cytotoxic effects of these fibrils via proteolytic degradation of Aβ peptide. We also demonstrated that infusion of ENO1 into APP23 mouse brains reduced cerebrovascular Aβ deposits and improved cognitive impairment. In addition, we found that enzymatically inactivated ENO1 failed to inhibit Aβ fibril formation and fibril disruption. The proteolytic activity of ENO1 may thus underlie the enzyme’s cytoprotective effect and clearance of Aβ from the brain, and ENO1 may be a therapeutic target in CAA.