虾青素调控Aβ1-42介导小胶质细胞神经炎症、氧化反应的分子机制研究

Due to the robust pathological changes like amyloid-beta (Aβ) aggregation and deposition, glial activation, pro-inflammatory factors and oxidative stress and the formation of neuroinflammation in Alzheimer's disease （AD）, we used a class of novel anti-inflammatory compound(s) to limit the oxidative stress and inflammation induced by Aβ1-42 in our previous studies. Our results showed that the anti-inflammatory compound(s) of small molecules down-regulated the neuroinflammation, oxidative stress and neuronal death in AD animal model or cellular experiments. Based on the lack of good strategies how to cure Alzheimer’s disease and the short of specific, effective drugs in the therapy of Alzheimer’s disease, there is huge space left and significantly necessary action to have drug discovery for controlling the robust events in Alzheimer’s brains. Astaxanthin, a sort of strong natural product, has the characteristics of anti-oxidative stress. A lot of experiments reported that astaxanthin inhibited lipopolysaccharide (LPS)-stimulated glial activation. However, there were not any documentation to report the application or activities of astaxanthin in activated glia, oxidative stress and neuroinflammation induced by Aβ. Based on the facts, we hypothesized that astaxanthin has great potential to modulate the inflammatory and oxidative response induced by Aβ. To test our hypothesis, the methods of molecular biology such as immunohistochemistry, confocal microscopy, flow cytometry, and PCR will be used in our investigation in this project. A couple of animal AD models will be employed to measure the inhibition of oxidative response, pro-inflammatory cytokines like interleukin and tumor necrosis factor (TNF) , and explore the acting targets of astaxanthin , working mechanisms as well as signaling pathways of its actions. Along with the further the study, we will find out and tell the fact how wide application range and good future of astaxanthin , and offer the theoretical and practical basis to dig out its potentials.

由于阿尔茨海默病脑内老年斑形成、Aβ沉积介导胶质细胞激活、产生氧化分子和前炎症因子，我们在前期研究中使用抗炎抗氧化小分子合成物，使神经炎症和氧化应激反应下调，神经元死亡减少。针对阿尔茨海默病预防治疗目前存在着无良策、缺乏特异性强或持久无耐药性药物的问题，新药研究有极大的空间和必要性。虾青素，被报导有较强抗氧化作用；实验研究中显示其有下调LPS介导的小胶质细胞激活作用。然而，未见其应用于Aβ介导的小胶质细胞激活及反应的报导。基于这些事实，我们推断和假设，虾青素有调节Aβ介导的神经炎症和过氧化反应潜能。本课题拟利用我们已建立的Aβ介导神经炎症和氧化应激模型，采用免疫组化、共聚焦、流式细胞术、PCR等手段，探索虾青素在分子、细胞及整体水平上调控氧化物、前炎症因子IL及TNF等的有效性及作用靶点，并进行作用机理和信号传导通路的研究。随着研究的深入，为拓展它的应用和开发提供理论和实践的依据。

由于阿尔茨海默病脑内老年斑形成、Aβ沉积介导胶质细胞激活、产生氧化分子和促炎症因子，我们在前期研究中使用抗炎抗氧化小分子合成物，使神经炎症和氧化应激反应下调，神经元死亡减少。针对阿尔茨海默病预防治疗目前存在着无良策、缺乏特异性强或持久无耐药性药物的问题，新药研究有极大的空间和必要性。虾青素，被报导有较强抗氧化作用；本项目实验研究中，不仅建立了人源性Aβ介导的小胶质细胞氧化应激和炎症激活模型，而且同时建立了外源性细菌内毒素脂多糖（LPS）介导的小胶质细胞氧化应激和炎症激活模型；研究证明，虾青素有下调Aβ或LPS介导小胶质细胞激活产生的氧化应激包括一氧化氮（NO）、氧合酶（iNOS）、活性氧（ROS）以及炎症反应如COX-2等靶标的作用，从而证实虾青素单用或联合应用花青素或依达拉奉均对对小胶质细胞或神经元有保护作用；其作用机制与MAPK信号传递通的抑制剂作用类似。基于这些事实，我们推断和假设，虾青素有调节Aβ介导的神经炎症和过氧化反应潜能。本课题拟利用我们已建立的Aβ介导神经炎症和氧化应激模型，采用免疫学抗原抗体反应原理、利用不同研究手段，探索虾青素在分子、细胞及整体水平上调控氧化物、前炎症因子IL及TNF等的有效性及作用靶点，并进行作用机理和信号传导通路的研究。通过四年的研究，获得的重要结果及关键数据有：虾青素下调Aβ1-42介性导小胶质细胞、神经元的神经退行性变，包括NO、iNOS、ROS、caspase-3、Bax、COX-2、IL-6等，同时，新建昆明小鼠整体动LPS氧化应激反应模型、SD大鼠或猕猴大脑皮层大脑皮层LPS介导氧化应激模型，并应用虾青素主要药理学研究，证明虾青素单用或联合使用，上述氧化应激或炎症指标的下调。研究提示，虾青素单用或与花青素联合用药，可对LPS小胶或Aβ介导的神经炎症和过氧化反应产生下调作用，对小胶质细胞或神经元有保护作用，因此，它有一定的临床应用或日常保健、国防应用的前景。