CADASIL brain vessels show a HTRA1 loss-of-function profile
CADASIL brain vessels show a HTRA1 loss-of-function profile
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DOI：
10.1007/s00401-018-1853-8
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发表时间：
2018-07-01
影响因子：
12.7
通讯作者：
Haffner, Christof
中科院分区：
文献类型：
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作者：
Zellner, Andreas;Scharrer, Eva;Haffner, Christof
常染色体显性遗传性脑动脉病伴皮质下梗死和白质脑病（CADASIL）和表型相似的隐性遗传病（CARASIL）已成为研究脑小血管病（SVD）分子病理机制的重要遗传模型疾病。CADASIL是最常见和最深入研究的单基因SVD，其特征在于脑血管系统中的严重病理学，包括突变诱导的Notch 3胞外结构域（Notch 3（ECD））聚集和血管壁中组成不充分的蛋白质沉积物的形成。为了确定参与这一过程的关键分子和途径，我们定量测定了CADASIL患者和对照尸检样本（每组n = 6）的脑血管蛋白质组，获得了95种丰度显著增加的蛋白质。有趣的是，高温需要蛋白A1（HTRA 1），在CARASIL中突变的细胞外蛋白酶，被发现强烈富集（4.9倍，p = 1.6 x 10（-3）），并与Notch 3（ECD）沉积物共定位在患者血管中，这表明了隔离过程。此外，CADASIL蛋白质组中几种HTRA 1底物水平增加的存在与HTRA 1活性丧失导致的降解减少是相容的。事实上，与HTRA 1敲除小鼠（n = 5）的脑血管蛋白质组的比较显示了18种富集蛋白质的高度显著重叠（p = 2.2 × 10（-16）），主要代表分泌和细胞外基质因子。其中几个被证明是由HTRA 1在体外蛋白水解试验，确定它们作为新的底物处理。我们的研究提供了HTRA 1功能丧失的证据，作为CADASIL病理学发展的关键步骤，将两种不同SVD形式的分子机制联系起来。
Cerebral autosomal dominant arteriopathy with subcortical infarcts and leukoencephalopathy (CADASIL) and a phenotypically similar recessive condition (CARASIL) have emerged as important genetic model diseases for studying the molecular pathomechanisms of cerebral small vessel disease (SVD). CADASIL, the most frequent and intensely explored monogenic SVD, is characterized by a severe pathology in the cerebral vasculature including the mutation-induced aggregation of the Notch3 extracellular domain (Notch3(ECD)) and the formation of protein deposits of insufficiently determined composition in vessel walls. To identify key molecules and pathways involved in this process, we quantitatively determined the brain vessel proteome from CADASIL patient and control autopsy samples (n = 6 for each group), obtaining 95 proteins with significantly increased abundance. Intriguingly, high-temperature requirement protein A1 (HTRA1), the extracellular protease mutated in CARASIL, was found to be strongly enriched (4.9-fold, p = 1.6 x 10(-3)) and to colocalize with Notch3(ECD) deposits in patient vessels suggesting a sequestration process. Furthermore, the presence of increased levels of several HTRA1 substrates in the CADASIL proteome was compatible with their reduced degradation as consequence of a loss of HTRA1 activity. Indeed, a comparison with the brain vessel proteome of HTRA1 knockout mice (n = 5) revealed a highly significant overlap of 18 enriched proteins (p = 2.2 x 10(-16)), primarily representing secreted and extracellular matrix factors. Several of them were shown to be processed by HTRA1 in an in vitro proteolysis assay identifying them as novel substrates. Our study provides evidence for a loss of HTRA1 function as a critical step in the development of CADASIL pathology linking the molecular mechanisms of two distinct SVD forms.