The Role of Microbiome Composition in Amphetamine Abuse

项目摘要/摘要：苯丙胺(AMPH)是治疗中常用的精神刺激剂。 神经精神障碍(如注意力缺陷障碍)。他们也被滥用，造成了毁灭性的后果。 AMPHs的滥用潜力与它们引起细胞质多巴胺动员的能力有关 (DA)，这导致细胞外DA水平增加。这一增长是由DA的逆转所调节的 转运体(DAT)功能，导致非囊泡性DA释放，这里定义为DA外流。值得注意的是， 抑制DA外流会降低Amph增加运动活性的能力和Amph偏好8-10。 肠道微生物群的失衡(生物失调)被认为参与了肺炎的发病。 物质使用障碍11.此外，精神刺激性药物的滥用会促进失调12-15。因此，有可能 肠道微生物组及其代谢物的变化可能不仅仅是物质使用的结果 精神障碍，但可能在调节滥用药物的行为反应中发挥作用11。 微生物产品，如短链脂肪酸(SCFA)，被认为在 调节肠道-脑轴是16。在单链脂肪酸中，丁酸盐可以穿过血脑屏障，直接作用于神经元。 和神经胶质细胞。核梭杆菌是一种厌氧、丝状、革兰氏阴性细菌。 分泌丁酸的物种18，其生长受到AMPH的刺激13-15。 我们的数据表明，在无菌(灵生)果蝇中，核盘藻的定植作用增强。 AMPH诱导的DA外流(在分离的苍蝇脑中记录)，以及AMPH行为。这种增强 核盘藻的AMPH作用与口服丁酸盐平行。要机械地理解， 核藻如何促进amph作用，重要的是要考虑DAT表达的变化调节 AMPH诱导的DA外流和精神运动动作19。此外，丁酸盐是一种有效的组蛋白抑制剂。 脱乙酰酶(HDACs)20-22；抑制HDACs显著增加DAT mRNA和 蛋白质21-23。 我们的假设是，核盘藻通过提高DAT的表达来增强amph的作用。这是经过调解的 通过分泌丁酸，抑制HDAC，增强果蝇DAT(DDAT)启动子的乙酰化。我们会 通过以下具体目标来检验这一假设： 确定核盘藻是如何调控dDAT表达的。 为了从机械上测试核藻是如何增加Amph诱导的DA外流的。 S.A.#1-2的实验将在我们实验室开发的一个模型--果蝇脑中进行 研究Amph的体外作用。此外，使用成年果蝇，我们将能够翻译分子 S.A.#1-2对特定Amph行为表型的发现。因此，SA#3将重点放在行为上。 S.A.#3.确定核藻是如何增强amph行为的。

Project Summary/Abstract: Amphetamines (AMPHs) are psychostimulants commonly used for the treatment of neuropsychiatric disorders (e.g. attention deficit disorders). They are also abused, with devastating outcomes. The abuse potential of AMPHs is associated with their ability to cause mobilization of cytoplasmic dopamine (DA), which leads to an increase in extracellular DA levels. This increase is mediated by the reversal of the DA transporter (DAT) function, which causes non-vesicular DA release, here defined as DA efflux. Notably, inhibition of DA efflux reduces both the ability of AMPH to increase motor activity and AMPH preference8-10. Imbalances in the gut microbiome (dysbiosis) have been suggested to participate in the pathogenesis of substance use disorders11. In addition, psychostimulant abuse promotes dysbiosis12-15. Therefore, it is possible that changes in the gut microbiome and its metabolites may not only be a consequence of substance use disorders, but may play a role in mediating the behavioral responses to drugs of abuse11. Microbial products, such as short-chain fatty acids (SCFAs), are thought to play a fundamental role in regulating the gut-brain axis16. Among SCFAs, butyrate is known to cross the BBB and directly act on neurons and glial cells17. Fusobacterium nucleatum (F. nucleatum) is an anaerobic, filamentous, gram-negative bacterial species that secretes butyrate18, the growth of which is stimulated by AMPH abuse13-15. Our data demonstrate that in germ-free (gnotobiotic) Drosophila, colonization with F. nucleatum enhances AMPH-induced DA effluxes (recorded in isolated fly brains), as well as AMPH behaviors. This potentiation of AMPH actions by F. nucleatum is paralleled by oral administration of butyrate. To understand, mechanistically, how F. nucleatum promotes AMPH actions, it is important to consider that changes in DAT expression regulate both AMPH-induced DA efflux and psychomotor actions19. Also, butyrate is a potent inhibitor of histone deacetylases (HDACs)20-22; inhibition of HDACs robustly increases expression of both DAT mRNA and proteins21-23. Our hypothesis is that F. nucleatum enhances AMPH actions by elevating DAT expression. This is mediated by secretion of butyrate, HDAC inhibition, and enhanced Drosophila DAT (dDAT) promotor acetylation. We will test this hypothesis through the following specific aims: S.A. #1. To determine how F. nucleatum regulates dDAT expression. S.A. #2. To test, mechanistically, how F. nucleatum increases AMPH-induced DA efflux. The experiments of S.A. #1-2 will be performed in isolated Drosophila brains, a model our laboratory developed to study AMPH actions ex vivo. Furthermore, using adult Drosophila, we will be able to translate the molecular discoveries of S.A. #1-2 to specific AMPH behavioral phenotypes. Thus, S.A. #3 focuses on behavior. S.A. #3. To define how F. nucleatum enhances AMPH behaviors.