抑制视神经脊髓炎谱系疾病经典自身免疫反应的先导物设计

发布时间：2018-03-24 09:36

  本文选题：视神经脊髓炎谱系疾病　切入点：认知障碍　出处：《扬州大学》2017年硕士论文

【摘要】：目的:视神经脊髓炎谱系疾病(neuromyelitis optica spectrum disorders,NMOSD),是一种中枢神经系统炎性脱髓鞘性自身免疫性疾病。不及时治疗,可能会导致失明,四肢瘫痪甚至死亡。NMOSD主要侵犯目标是视神经和脊髓,但其是否对患者的认知功能造成影响,目前尚未有定论。视神经脊髓炎谱系疾病的经典发病机制为水通道蛋白4(Aquaporin 4,AQP4)抗原抗体反应,然而临床上尚未有直接针对AQP4靶标的抑制剂类药物。我们用数理统计的方法分析了视神经脊髓炎(neuromyelitis optica,NMO)对认知的影响,并且以AQP4为靶标,使用分子探针分析活性中心;使用分子动力学方法,基于对关键氨基酸的分析,探究了 AQP4的口袋特征;并采取多种方法筛选设计新药的先导化合物,为针对影响视神经脊髓炎谱系疾病的新药发现做出有益的探索。材料与方法:我们基于已有的文献报道,采用神经心理测试的方法,去除受教育程度、年龄、性别等影响因素,对24岁到60岁之间的227名NMO患者和185健康受试者以及129名多发性硬化症(multiple sclerosis,MS)患者进行认知功能的评估分析。在国家超算平台上,使用分子动力学计算的方法,模拟AQP4蛋白的生理状态,构建了 POPC双分子层和OAPs四聚体结构,并进行了关键氨基酸突变体的动态分析。分析优化了 RCSB上目前已有的AQP4晶体结构数据,研究了活性中心的关键区域。对ZINC、DrugBank和小分子肽组合库等数据库进行了基于受体的计算机辅助药物筛选。结果:我们研究结果表明,NMO患者的语言学习能力、执行能力、听觉/视觉加工能力和记忆能力等认知功能与健康人群相比,都有所下降。分子动力学计算结果显示对AQP4蛋白上与视神经脊髓炎谱系疾病经典自身免疫反应相关的关键氨基酸进行组氨酸突变,会跨越细胞外环通过多米诺效应引起细胞外环A的空间构象改变。这有可能是导致AQP4基因多态性影响视神经脊髓炎易患性的机制之一。分子探针探测到AQP4蛋白上唯一一个适合与NMOSD-IgG反应的漏斗状的活性中心,分子动力学结果提示该活性中心的核心区域位于LoopA下方。通过分析筛选结果中评分靠前的3000个化合物,发现了以双甾体类缀合物和稠杂环化合物缀合物为代表的多个先导化合物。结论:NMO患者的认知功能会有所损伤,AQP4抗原抗体反应目前是视神经脊髓炎谱系疾病重要的诊断标准,但它更是关键的治疗靶标。基于受体晶体结构的计算化学分析显示AQP4具备良好的药物靶标特征。以此为靶标筛选获得的先导化合物,可以应用于基础研究,提高我们对视神经脊髓炎谱系疾病相关发病机制的认识;也可以应用于后续的通过化合物结构优化和系统的临床前试验而获得候选药物。另外,这些先导物并非仅仅适用于视神经脊髓炎谱系疾病的研究,也适用于其他一些与水通道蛋白具有相关性的疾病的研究。
[Abstract]:Objective: neuromyelitis optica spectrum disordersNMOSD is an inflammatory demyelinating autoimmune disease of the central nervous system. If not treated in time, it may lead to blindness, quadriplegia or even death. The main targets of NMOSD are optic nerve and spinal cord. However, it has not been concluded whether it will affect the cognitive function of the patients. The classic pathogenesis of optic neuromyelitis is the antigen-antibody response of aquaporin 4(Aquaporin 4 (AQP4). However, there are no direct inhibitors for AQP4 targets in clinic. We analyzed the effects of neuromyelitis neuromyelitis on cognition by means of mathematical statistics, and used AQP4 as the target, using molecular probes to analyze the active centers. Based on the analysis of key amino acids, the pocket characteristics of AQP4 were explored using molecular dynamics, and various methods were used to screen the leading compounds for the design of new drugs. Materials and methods: based on the existing literature, we used neuropsychological tests to remove the influence factors such as education level, age, sex and so on. The cognitive function of 227 NMO patients aged 24 to 60 and 185 healthy subjects and 129 multiple sclerosis patients with multiple sclerosis were evaluated and analyzed. The structure of POPC bilayer and OAPs tetramer was constructed by simulating the physiological state of AQP4 protein, and the key amino acid mutants were dynamically analyzed. The existing AQP4 crystal structure data on RCSB were analyzed and optimized. The key regions of active centers were studied. The receptor-based computer aided drug screening was carried out on databases such as ZINCX DrugBank and small molecular peptide combination libraries. Results: our results showed that NMO patients had language learning ability and executive ability. Cognitive functions such as auditory / visual processing and memory were compared to those of healthy people. The molecular dynamics analysis showed that the key amino acids related to the classical autoimmune reaction in the AQP4 protein were mutated by histidine. It may be one of the mechanisms leading to the polymorphism of AQP4 gene affecting the susceptibility of optic neuromyelitis. The molecular probe detects the AQP4 protein. The only funnel-like active center suitable for reaction with NMOSD-IgG, Molecular dynamics results suggest that the core region of the active center lies below LoopA. Several leading compounds, represented by disteroidal conjugates and fused heterocyclic conjugates, were found. Conclusion the cognitive function of the patients with NMO may be impaired and the antigen-antibody reaction of AQP4 may be an important diagnostic criterion for optic neuromyelitis lineage diseases at present. But it is a key therapeutic target. Computational chemical analysis based on the crystal structure of the receptor shows that AQP4 has good drug targeting characteristics. To raise our awareness of the pathogenesis associated with optic neuromyelitis, and to apply it to subsequent drug candidates through compound structure optimization and systematic preclinical trials. These precursors are not only suitable for the study of optic neuromyelitis spectrum diseases, but also for other diseases related to aquaporins.
【学位授予单位】：扬州大学
【学位级别】：硕士
【学位授予年份】：2017
【分类号】：R744.52
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本文编号：1657720