Understanding the role of aromatic amino acid derived metabolic toxins in neuroinflammation

项目摘要 多发性硬化症(MS)是年轻人最常见的神经退行性疾病。血清中的变化 代谢组已在MS中被报道，我们的初步数据表明它们也与 多发性硬化症严重程度。我们特别展示了芳香族氨基酸(AAA)衍生的代谢毒素，产生 根据肠道微生物区系，与更严重的疾病有关。我们的长期目标是改善 了解循环代谢产物在多发性硬化症病理生理中的作用并发现新的治疗方法 基于这些发现的干预措施。此R21应用程序的目标是确定AAA- 衍生的代谢毒素在体外对免疫和神经胶质细胞有直接的促炎作用，也可以 确定这些代谢物的治疗是否会加重MS小鼠模型的神经炎症。 这个项目的理论基础，得到初步数据的支持，是患有多发性硬化症的人有更高的AAA- 与健康对照组比较，这些代谢物的水平是 与临床和影像测量的疾病严重程度相关。拟议的研究性研究将 追求两个具体目标：1)确定AAA衍生的代谢毒素是否具有促炎作用 免疫和神经胶质细胞的体外培养；2)确定AAA衍生的代谢性毒素是否加重了 在多发性硬化症的动物模型中，为了达到第一个目的，我们将测试各种药物的效果。 四种AAA来源的代谢毒素浓度对适应性(T和B细胞)促炎极化的影响 和先天性(巨噬细胞)免疫细胞，以及神经胶质细胞(星形胶质细胞和小胶质细胞)。我们会比较效果 各种代谢物的载体，并识别那些具有促炎作用的代谢物(特别是那些具有 剂量-反应关系)，而不影响细胞存活率。对于第二个目标，我们将测试 补充这些AAA衍生的代谢性毒素对动物模型神经炎症严重程度的影响 MS实验性自身免疫性脑脊髓炎(EAE)。我们将利用炎症的结果 (炎性细胞浸润和脱髓鞘)和神经变性(视网膜神经节细胞计数 在EAE小鼠身上)。这将有助于为AIM 1中生成的数据提供补充。 创新之处在于它提出了一种新的假设，即循环中的代谢物与 多发性硬化症的严重程度可能直接影响免疫和神经胶质细胞功能，也可能影响 MS动物模型中的神经炎症研究具有重要意义，因为它可以提供新的 了解MS疾病的发病机制并确定新的治疗策略 治疗干预措施(如饮食变化、益生菌、抗生素和代谢物补充) 这种常见的致残性神经紊乱。

Project Summary Multiple sclerosis (MS) is the most common neurodegenerative disease in young adults. Changes in the serum metabolome have been reported in MS and our preliminary data demonstrate that they are also associated with MS disease severity. We specifically show that aromatic amino acid (AAA)-derived metabolic toxins, produced by the gut microbiota, are associated with greater disease severity. Our long-term goals are to improve the understanding of the role of circulating metabolites in the pathophysiology of MS and discover novel therapeutic interventions based on those findings. The objectives of this R21 application are to determine whether AAA- derived metabotoxins have direct pro-inflammatory effects on immune and glial cells in vitro and also to determine whether treatment with these metabolites worsens neuroinflammation in a mouse model of MS. The rationale for this project, supported by preliminary data, is that people with MS have higher levels of these AAA- derived metabotoxins in their blood compared to healthy controls and the levels of these metabotoxins are correlated with disease severity measured clinically and by imaging measures. The proposed research study will pursue two specific aims: 1) to determine whether AAA-derived metabotoxins have pro-inflammatory effects on immune and glial cells in vitro; 2) To determine whether AAA-derived metabotoxins worsen the severity of neuroinflammation in an animal model of MS. For the first aim, we will test the effects of a variety of concentrations of four AAA-derived metabotoxins on pro-inflammatory polarization of adaptive (T and B cells) and innate (macrophages) immune cells, as well as glial cells (astrocytes and microglia). We will compare effects of various metabolites to vehicle and identify those that have pro-inflammatory effects (especially those with a dose-response relationship) without affecting cell viability. For the second aim, we will test the effects of supplementation with these AAA-derived metabotoxins on the severity of neuroinflammation in an animal model of MS – experimental autoimmune encephalomyelitis (EAE). We will utilize outcomes of inflammation (inflammatory cell infiltration and demyelination) and neurodegeneration (retinal ganglion cell counts in retinal flat mounts) in EAE mice. This will help provide complementary data to those generated in Aim 1. This project is innovative in that it proposes to test a novel hypothesis that metabolites in the circulation that are associated with MS disease severity may have direct effects on immune and glial cell function and may also affect neuroinflammation in an animal model of MS. The proposed research is significant because it can provide novel understanding of the mechanisms underlying MS disease pathogenesis and identifies new strategies for therapeutic interventions (such as dietary changes, probiotics, antibiotics and metabolite supplementation) for this common disabling neurological disorder.