【摘要】：阿爾茨海默癥(Alzheimer’s disease,AD),俗稱老年癡呆癥,是一類神經(jīng)退行性疾病,AD病理學(xué)上以神經(jīng)炎性斑(Neuritic Plaques,NPs)又稱老年斑(Senile Plaques,SPs)、神經(jīng)原纖維纏結(jié)(Neurofibrillary Tangles,NFTs)和腦血管淀粉樣變性(Cerebral amyloid angiopathy,CAA)為典型病理特征,腦組織內(nèi)淀粉樣蛋白質(zhì)片段異常增加或聚集是導(dǎo)致神經(jīng)元死亡的主要原因。AD發(fā)病機(jī)制復(fù)雜,由多種因素綜合導(dǎo)致,如β淀粉樣蛋白(Amyloidβ-protein,Aβ)異常沉積,Tau蛋白過(guò)度磷酸化,氧化應(yīng)激、炎癥反應(yīng)及細(xì)胞凋亡等。AD的發(fā)病進(jìn)程經(jīng)歷癥狀前AD、輕度認(rèn)知功能障礙(Mild cognitive impairment,MCI)而逐步發(fā)展為AD。鑒于AD病理的復(fù)雜性,目前尚無(wú)明確、特異、可靠的實(shí)驗(yàn)室診斷方法,難以進(jìn)行早期臨床診斷,同時(shí)也影響了AD的治療研究,故從體液(如唾液,血液及尿液等)尋找一種可用于早期阿爾茨海默病診斷的生物學(xué)標(biāo)志物便顯得尤為重要。唾液是體液生物標(biāo)志物的重要來(lái)源之一,具有易于采集和處理等優(yōu)點(diǎn)。機(jī)體內(nèi)的生物活性分子可通過(guò)主動(dòng)運(yùn)輸、被動(dòng)運(yùn)輸或細(xì)胞外超濾作用進(jìn)入到唾液,與血液類似,唾液中的成分也與人體生理和病理狀態(tài)有關(guān),并且二者在組成上具有相關(guān)性。例如,血液蛋白中30%左右的蛋白質(zhì)也存在于唾液中,大約20%總唾液蛋白在血漿中發(fā)現(xiàn)。多肽組學(xué)是以機(jī)體中內(nèi)源性多肽和低分子量蛋白質(zhì)為研究對(duì)象,研究多肽組的成份、功能、變化規(guī)律及其相關(guān)聯(lián)系。本文使用唾液多肽組學(xué)研究方法試圖尋找能夠輔助AD早期診斷的生物標(biāo)志物。我們基于納升液相色譜-高分辨串聯(lián)質(zhì)譜分析唾液多肽組學(xué),鑒定了唾液肽段的序列和其歸屬蛋白及其翻譯后修飾。首先我們研究了凍存條件對(duì)健康人唾液多肽組成份的影響,用肽段數(shù)目差異及及其歸屬蛋白異同說(shuō)明-80℃冰箱保存樣品更能維持唾液樣品組分的穩(wěn)定性。其次,考察了一天不同取樣時(shí)間是否影響唾液多肽組,MALDI-TOF MS結(jié)果表明五次不同取樣時(shí)間對(duì)唾液多肽組幾乎沒(méi)有影響。最后基于前期的研究結(jié)果,我們?cè)噲D從AD組、MCI組與對(duì)照組尋找出候選生物標(biāo)志物,通過(guò)對(duì)患者與對(duì)照組多肽組數(shù)據(jù)結(jié)果在甲硫氨酸氧化情況差異以及特異性蛋白考察,篩選出唾液差異多肽生物標(biāo)志物,包括表觀遺傳調(diào)控AD的發(fā)生的Histone H2A、Histone H3.2、Histone H1.3、Histone H3.1t、Histone H1.4等;炎癥反應(yīng)相關(guān)的Protein S100-A8、Protein S100-A9、Protein S100-A12;能量代謝相關(guān)、細(xì)胞骨架與神經(jīng)系統(tǒng)發(fā)育相關(guān):6-phosphogluconate dehydrogenase、Pyruvate kinase isozymes M1/M2、Phosphoglycerate kinase1、Phosphoglycerate mutase 1,Actin、Cofilin-1、Heterogeneous nuclear ribonucleoprotein等四大類。此外,我們另選取15例AD患者,15例MCI患者,8例老年對(duì)照對(duì)生物標(biāo)志物進(jìn)行驗(yàn)證。本研究利用唾液多肽組學(xué)的方法比較患者組與健康對(duì)照組,進(jìn)而從蛋白質(zhì)水平闡述唾液多肽組異同,篩選出AD唾液多肽潛在生物標(biāo)志物,為AD患者的早期診斷提供一定支持。
[Abstract]:Alzheimer's disease (Alzheimer's disease,AD), commonly known as Alzheimer's disease, is a kind of neurodegenerative disease. AD is characterized by Neuritic Plaques,NPs (Neuritic Plaques,NPs), Senile Plaques,SPs (neurofibrillary tangles) and (Neurofibrillary Tangles, (neurofibrillary tangles) in the pathology of AD. NFTs) and cerebrovascular amyloidosis (Cerebral amyloid angiopathy,CAA) are typical pathological features. Abnormal increase or aggregation of amyloid protein fragments in brain tissue is the main cause of neuronal death. The pathogenesis of AD is complex, which is caused by many factors. For example, abnormal deposition of Amyloid 尾-protein,A 尾, excessive phosphorylation of Tau protein, oxidative stress, inflammatory reaction and apoptosis, etc. The pathogenesis of AD experienced AD, mild cognitive impairment (Mild cognitive impairment, before symptoms. MCI) and gradually develop into AD. In view of the complexity of AD pathology, there is no clear, specific, reliable laboratory diagnosis method, it is difficult to carry out early clinical diagnosis, but also affect the treatment of AD, so from the body fluid (such as saliva, It is particularly important to find a biomarker for early diagnosis of Alzheimer's disease. Saliva is an important source of humoral biomarkers, which is easy to collect and process. Bioactive molecules in the body can be transported through active transport, passive transport or extracellular ultrafiltration into saliva, similar to the blood, saliva components are also related to the physiological and pathological state of the human body, and the two components have a correlation in composition. For example, about 30 percent of the protein in the blood is found in saliva, and about 20 percent of the total saliva protein is found in plasma. Polypeptide group is a study of endogenous peptides and low molecular weight proteins in the body to study the composition, function, changes and related relationships of polypeptide groups. This paper attempts to search for biomarkers that can assist the early diagnosis of AD by using the method of salivary polypeptide analysis. Based on the analysis of salivary polypeptides by high resolution tandem mass spectrometry, the sequence of salivary peptides and their homologous proteins and their posttranslational modifications were identified. First, we studied the effect of freezing conditions on the composition of saliva polypeptides in healthy people. The differences in number of peptide segments and their homologous proteins showed that the stability of saliva components could be maintained better when the samples were preserved in refrigerator at 80 鈩，

本文編號(hào)：2306394