Pathological protein generation in cerebral small vessel disease

摘要 脑小血管病（SVD）是痴呆的重要原因， 神经退行性疾病，如阿尔茨海默氏症和帕金森氏症。 伴有皮质下梗死的常染色体显性遗传性脑动脉病 白质脑病（CADASIL）是SVD最常见的遗传性原因。临床 CADASIL的特征包括痴呆、复发性中风和精神障碍。 了解CADASIL的病理可能会导致治疗SVD的策略。 CADASIL是由NOTCH 3中的半胱氨酸改变突变引起的，这表明氧化还原 这种蛋白质的改变可能导致SVD。NOTCH 3的改变形式可能导致 大量的蛋白质积累，细胞分离，平滑肌细胞死亡， CADASIL。特异性细胞丢失、蛋白质构象改变和蛋白质 CADASIL中观察到的蓄积表明与退行性疾病相似， 阿尔茨海默氏症和帕金森氏症。在初步研究中，我们发现了一种新的后- NOTCH 3的非特异性产生的片段，称为NTF（NOTCH 3 N-末端 片段）。我们证明NTF能够跨- 将NOTCH 3还原成具有多个还原半胱氨酸的病理形式的NOTCH 3 （mrc-N3）。此外，NTF引起小鼠大脑的急性和慢性变化 通常不容易受到SVD的影响。NTF的酶促释放发生在细胞中， 我们鉴定了一种在CADASIL组织中增加的潜在蛋白酶。目标1： 将定义NTF促进NOTCH 3蛋白还原为mrc-N3的特征。在 目的二，探讨NTF介导的蛋白质减少程度。在Aim 3，我们将确定是否在CADASIL中富集的脑蛋白酶参与 NTF世代。这些实验探索了一种新的，自我永存的分子 病理蛋白质在人脑中产生的机制。 该项目产生的信息可以改进SVD的当前平移模型 并在发现治疗靶点方面取得进展。

ABSTRACT Cerebral small vessel disease (SVD) is an important cause of dementia and contributes to neurodegenerative disorders such as Alzheimer's and Parkinson's diseases. Cerebral autosomal dominant arteriopathy with subcortical infarcts and leukoencephalopathy (CADASIL) is the most common inherited cause of SVD. Clinical features of CADASIL include dementia, recurrent stroke, and psychiatric disorders. Understanding the pathology of CADASIL may lead to strategies to treat SVD. CADASIL is caused by cysteine-altering mutations in NOTCH3, suggesting that redox alteration of this protein could contribute to SVD. Altered forms of NOTCH3 may lead to massive protein accumulation, cell separation, and smooth muscle cell death seen in CADASIL. Specific cell loss, protein conformational alterations, and protein accumulation seen in CADASIL suggest similarities to degenerative disorders such as Alzheimer's and Parkinson's diseases. In preliminary studies, we identify a novel post- translationally generated fragment of NOTCH3, called NTF (NOTCH3 N-terminal fragment) from human CADASIL tissues. We show that NTF is capable of trans- reducing NOTCH3 into a pathological form of NOTCH3 with multiple reduced cysteines (mrc-N3). Moreover, NTF causes both acute and chronic changes in the brains of mice which are not normally susceptible to SVD. Enzymatic liberation of NTF occurs in cells, and we identify a potential protease that is increased in CADASIL tissues. In Aim 1, we will define the features of NTF that promote NOTCH3 protein reduction to mrc-N3. In Aim 2, we will we explore the extent of protein reduction mediated by NTF. And in Aim 3, we will determine whether a brain protease that is enriched in CADASIL participates in NTF generation. These experiments explore a novel, self-perpetuating molecular mechanism by which pathological proteins are produced in the human brain. Information generated by this project could improve current translational models of SVD and enable progress in the discovery of therapeutic targets.