阿尔茨海默症患者唾液生物标志物的多肽组学研究
发布时间：2018-11-02 16:56
【摘要】：阿尔茨海默症(Alzheimer’s disease,AD),俗称老年痴呆症,是一类神经退行性疾病,AD病理学上以神经炎性斑(Neuritic Plaques,NPs)又称老年斑(Senile Plaques,SPs)、神经原纤维缠结(Neurofibrillary Tangles,NFTs)和脑血管淀粉样变性(Cerebral amyloid angiopathy,CAA)为典型病理特征,脑组织内淀粉样蛋白质片段异常增加或聚集是导致神经元死亡的主要原因。AD发病机制复杂,由多种因素综合导致,如β淀粉样蛋白(Amyloidβ-protein,Aβ)异常沉积,Tau蛋白过度磷酸化,氧化应激、炎症反应及细胞凋亡等。AD的发病进程经历症状前AD、轻度认知功能障碍(Mild cognitive impairment,MCI)而逐步发展为AD。鉴于AD病理的复杂性,目前尚无明确、特异、可靠的实验室诊断方法,难以进行早期临床诊断,同时也影响了AD的治疗研究,故从体液(如唾液,血液及尿液等)寻找一种可用于早期阿尔茨海默病诊断的生物学标志物便显得尤为重要。唾液是体液生物标志物的重要来源之一,具有易于采集和处理等优点。机体内的生物活性分子可通过主动运输、被动运输或细胞外超滤作用进入到唾液,与血液类似,唾液中的成分也与人体生理和病理状态有关,并且二者在组成上具有相关性。例如,血液蛋白中30%左右的蛋白质也存在于唾液中,大约20%总唾液蛋白在血浆中发现。多肽组学是以机体中内源性多肽和低分子量蛋白质为研究对象,研究多肽组的成份、功能、变化规律及其相关联系。本文使用唾液多肽组学研究方法试图寻找能够辅助AD早期诊断的生物标志物。我们基于纳升液相色谱-高分辨串联质谱分析唾液多肽组学,鉴定了唾液肽段的序列和其归属蛋白及其翻译后修饰。首先我们研究了冻存条件对健康人唾液多肽组成份的影响,用肽段数目差异及及其归属蛋白异同说明-80℃冰箱保存样品更能维持唾液样品组分的稳定性。其次,考察了一天不同取样时间是否影响唾液多肽组,MALDI-TOF MS结果表明五次不同取样时间对唾液多肽组几乎没有影响。最后基于前期的研究结果,我们试图从AD组、MCI组与对照组寻找出候选生物标志物,通过对患者与对照组多肽组数据结果在甲硫氨酸氧化情况差异以及特异性蛋白考察,筛选出唾液差异多肽生物标志物,包括表观遗传调控AD的发生的Histone H2A、Histone H3.2、Histone H1.3、Histone H3.1t、Histone H1.4等;炎症反应相关的Protein S100-A8、Protein S100-A9、Protein S100-A12;能量代谢相关、细胞骨架与神经系统发育相关:6-phosphogluconate dehydrogenase、Pyruvate kinase isozymes M1/M2、Phosphoglycerate kinase1、Phosphoglycerate mutase 1,Actin、Cofilin-1、Heterogeneous nuclear ribonucleoprotein等四大类。此外,我们另选取15例AD患者,15例MCI患者,8例老年对照对生物标志物进行验证。本研究利用唾液多肽组学的方法比较患者组与健康对照组,进而从蛋白质水平阐述唾液多肽组异同,筛选出AD唾液多肽潜在生物标志物,为AD患者的早期诊断提供一定支持。
[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，
本文编号：2306394
[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，
本文编号：2306394
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