已经证实丝氨酸和半胱氨酸代谢对溶组织内阿米巴的生存和致病有至关重要作用，但是对棘阿米巴的相关代谢通路目前还知之甚少。我们前期的工作证实棘阿米巴丝氨酸代谢通路上的两个限速酶的存在；同时一系列的实验结果也发现虫体丝氨酸合成受到抑制后，严重影响了虫体的存活及生长。因此我们假设丝氨酸代谢是棘阿米巴代谢枢纽之一，调控下游氨基酸的合成，进而调节相关蛋白酶的表达，影响棘阿米巴的生物学特性和致病性。本课题拟在前期的研究基础上，应用蛋白质组学、质谱流式细胞术、RNA干扰或转染过表达等多种技术深入研究棘阿米巴丝氨酸代谢通路的性质和功能，证明代谢限速酶的作用及其对半胱氨酸合成代谢的调控的方式，探索丝氨酸代谢对相关蛋白酶表达的影响以及阐明其影响棘阿米巴的生存生长、抗氧化、附着乃至致病的机制。为棘阿米巴的生长机制和发病机理提供新理论依据，从而为棘阿米巴感染的早期明确诊断、有效治疗药物的筛选和高危人群的预防奠定基础。

The serine and cysteine metabolisms play an essential role in the survival and pathogenesis of Entamoeba histolytica, however little has been clarified in such metabolic pathway in Acanthamoeba at present. Our previous work demonstrated the existence of two rate-limiting enzymes in the serine metabolic pathway of Acanthamoeba, and a series of experiments illustrated serious impact on the survival and proliferation of the protozoan when its serine synthesis is inhibited. Therefore, we hypothesize that the serine metabolism is one of the core metabolism of Acanthamoeba, which first controls the synthesis of downstream amino acids, then regulates the expression related proteases, and finally affects the biological characteristics and pathogenicity of Acanthamoeba. The present proposal base on previous studies and focus on further studies of overall perspectives and functions of Acanthamoeba’s serine metabolic pathway, methods or techniques such as proteomics, latest mass cytometry, RNA interference or gene overexpression etc. will be applied. Our objectives in the proposal conclude clarifying the function of the rate-limiting enzymes in serine metabolic and their role in the regulation of cysteine metabolism, making clear the effects of serine metabolism on the expression of related proteases and their following influence on survival, growth, antioxidant, attachment to host cell, pathogenic mechanism of Acanthamoeba. The proposal aims at providing new theoretical bases in growth mechanism and pathogenesis of Acanthamoeba, which may be extremely beneficial to the early diagnosis, development of effective drug and prevention of the high-risk population during Acanthamoeba’s infection.