唾液Peripherin作为肌萎缩侧索硬化生物标志物的可行性及其病理机制的研究

Amyotrophic lateral sclerosis (ALS) is one of the most common fetal neurodegenerative disorders. At the present time, the key point of treatment is to make the diagnosis and initiate the supporting treatment as soon as possible to extend the early stage of the disease duration, since there is so far no totally effective drug. However, the current diagnosis is primarily dependent on the clinical manifestations and electrophysiology. Most patients get their diagnoses during the middle or late stage of disease duration. Therefore, it is of vital importance to identify the detectable biomarkers for both diagnosis and prognosis (effective measurement of clinical trials) in ALS. Peripherin is a type Ⅲ intermediate filaments expressed mainly in neurons of the peripheral nervous system, the mutations of which can cause ALS in human. It is also one of the major components of cytoplasmic inclusion in ALS pathology. Our previous findings identified for the first time the expression of peripherin in saliva of both ALS patients and healthy controls. Our aim is to compare the expression difference of salivary peripherin among ALS patients, healthy controls and diseased controls as well as among the prospective sub-cohort of fALS to identify the potential biomarkers for diagnosis and prognosis of ALS. Besides, based on salivary gland pathology, comparison of peripherin level in the saliva/plasm/CSF of the identical subject, component analysis of saliva, and ALS cell model, we are to explore the origin of salivary peripherin and the potential PNS pathology involved in ALS.

肌萎缩侧索硬化（ALS）是一种致死性神经退行性疾病，目前尚无有效治疗药物，诊断主要依靠临床表现和电生理检查，大多数患者就诊时已是中晚期，因此亟需用于诊断/病情评估的生物标志物。Peripherin 是一种分布于外周神经系统（PNS）中间丝蛋白，其基因突变可导致ALS，亦是ALS特征性病理包涵体主要成分之一。近年来研究发现ALS在早期甚至发病前即累及PNS。课题组前期已首次发现其在ALS患者唾液中较高水平表达，并与健康对照存在差异。拟通过本项目建立ALS患者及健康对照、疾病对照唾液样本库，比较三组受试者唾液peripherin表达类型和水平差异，利用已知突变的fALS前瞻队列纵向分析表达变化特点，评价其用于ALS诊断和预后判断的价值。同时通过分析唾液腺病理学、比较同一受试者唾液/血浆/CSF的peripherin水平、唾液组分分析以及相关细胞模型，探索其组织来源和参与ALS的PNS病理机制。

目前肌萎缩侧索硬化症尚无有效的治疗方案，给患者和家属带来了极大的健康负担。这一现实的深层原因是尚无法对疾病进行早期诊断，同时临床试验中尚无衡量疾病进展的精准有效工具。基于文献和本团队前期工作基础，我们认为周围神经丝（PRPH，神经微丝蛋白）可反映ALS早期的病理变化，其蛋白水平和片段大小可反应ALS发病风险和病理进展。因此我们对ALS队列患者进行了PRPH基因突变/变异进行了大样本人群评估和突变特异的细胞模型构建，结果显示：尽管以往致病性判断不一的rs57451017和rs62636520缺乏人群携带频率的支持，但携带此位点变异的细胞模型显示不同于正常细胞的骨架结构。在唾液PRPH蛋白水平的ELISA初步检测中，尚未发现统计学差别；同时，我们利用已经收集的唾液样本，检测了脂肪代谢（adiponectin）、炎症（IL-6）和食欲（Ghrelin）等相关蛋白因子的水平，发现了脂联素（adiponectin）可用于区分ALS患者和对照的作用。上述结果从人群和细胞模型的角度，进一步理解ALS发病的机制并发掘潜在的ALS生物标志物。