使用外泌體蛋白檢測阿茲海默症之研究

Abstract

阿茲海默症是一種病程緩慢卻會隨時間不斷惡化的神經退化性疾病，主要的疾病成因為腦中折疊的β類澱粉蛋白質（Aβ）大量堆積成不正常的斑塊，與過度磷酸化的tau蛋白造成神經原纖維纏結的病理特徵。目前阿茲海默症檢測方式有許多種，主要檢測方法為正子斷層攝影以及腦脊髓液檢測，但此兩項方式除了檢測價格昂貴，以及經由腰椎間穿刺抽取腦脊髓液屬於侵入性的檢測，受試者普遍接受度不高。近年來，液態活檢是一種非侵入性的血液檢測，其中外泌體已成為液態活檢中相當熱門的標靶，有愈來愈多文獻指出血液中的外泌體與相關疾病具有其關聯性。 在本論文中，我們透過所開發的外泌體親和性晶片，捉捕血液中的外泌體，並且檢測外泌體的內源標記。從阿茲海默症臨床血液樣本中，以常見的阿茲海默症的生物標記，針對血液中的外泌體進行蛋白質檢測，進而選擇有效的標記抗體，並且從特定蛋白的表現訊號，能夠有效地區分出健康族群與阿茲海默症族群。同時，為了提升外泌體的偵測訊號，我們利用去除血液中脂蛋白的方式，有助於判斷不同族群所偵測到的訊號區別性。 此研究不僅是透過非侵入性的血液檢測方式進行阿茲海默症的相關檢測，進而證實血液中的外泌體在阿茲海默症的偵測是具有代表性，期望未來運用此外泌體檢測平台作為阿茲海默症早期診斷之檢測方式。

Alzheimer's disease is a neurodegenerative disease with a slow course but worsening over time. The main disease is caused by the accumulation of large amounts of folded beta-amyloid protein (Aβ) and the hyperphosphorylation of tau protein in the brain that causes pathological features of neurofibrillary tangles. At present, there are many assays to Alzheimer's disease diagnosis, the main detection methods are positron emission tomography and cerebrospinal fluid detection. However, these two tests are too expensive and the extraction of cerebrospinal fluid through lumbar puncture is an invasive test. The volition of the participants is not too high. In recent years, liquid biopsy is a non-invasive blood test, in which exosomes have become a very popular target in this field. Lots of studies have pointed out that the test of exosome in blood is a new strategy for treatment and prevention of diseases. In this thesis, we used the developed exosome-affinity chip to capture exosomes in the blood and detected the internal markers of exosomes. Through clinical blood samples of Alzheimer's disease, exosomes were tested for protein detection using common biomarkers of Alzheimer's disease. Promising antibodies of the specific markers can be effectively selected and distinguished between healthy donor groups and Alzheimer's disease patients groups. Furthermore, in order to evaluate the detection signal of exosomes, we used the method of removing lipoproteins in the blood. It was conducive to obtain the remarkable difference between the signals detected by different groups. In this study, we thus used the non-invasive blood test of Alzheimer's disease detection from plasma samples. It also demonstrated that the blood-based detection of exosomes in Alzheimer's disease is representative. It is expected that the exosome-detected platform will be used as a detection method for early diagnosis of Alzheimer's disease in the future.