Investigating microbiota of the gut-brain axis and the impact of cocaine

项目总结/摘要 可卡因滥用继续成为一个国家危机，在美国，非法药物成瘾的代价是 与犯罪活动、工作效率下降和医疗保健有关的损失每年总计超过7400亿美元。在 特别是，占美国人口13.4%的非洲裔美国人，不成比例地承担着 可卡因使用和过量。多项研究表明，长期使用可卡因会影响肠道微生物群， 进而改变下丘脑-垂体轴活动和情绪行为。与可卡因有关的研究 表明滥用药物会引发革兰氏阳性厚壁菌的优先增殖和革兰氏阳性厚壁菌的减少， 阴性拟杆菌，结果与微生物群与药物成瘾的关联一致。积累 证据还表明，肠道微生物影响沿着肠道的双向通信， 脑轴，这表明肠道微生物群对可卡因的关键作用。因为有证据表明 肠-脑轴微生物群、横结肠、回肠末端、基底节 神经节、垂体和肾上腺可能具有作为生物标志物的潜在作用，特别是在 过量的情况下，由于可卡因滥用造成的损害，这些组织。在本提案中，我们将解决 可卡因对肠道-大脑轴微生物群的影响。我们的方法将允许评估 使用从可卡因中提取的样本的微生物群肠-脑轴相关组织中的微生物特征 过量的尸体，这种方法以前的研究没有使用过，但可以提供信息， 确定人们对可卡因的不同反应，使研究人员能够更好地研究潜在的 微生物的不良影响。具体来说，我们将检验以下假设： 来自三个南方地区的可卡因过量病例中肠道微生物群和肠-脑轴之间的关系-亚拉巴马， 佛罗里达和田纳西。为了验证这一假设，我们将（1）确定肠道微生物组是否 与横结肠和回肠末端相关的神经系统介导可卡因使用和致死性之间的关系， 药物中毒的非洲裔美国人从美国南部地区;（2）确定是否肠道 与基底神经节、垂体和肾上腺相关的微生物组介导了 美国南部地区非裔美国人可卡因使用与致命药物中毒之间的关系 （3）在单盲研究中验证特定微生物生物标志物的数学模型 使用非裔美国人的组织来增加信心和证明可重复性。这些过程将 评估和验证，为新的诊断和治疗目标提供基础，以防止故意 和无意的可卡因过量，长期目标是恢复肠道微生物组的稳态。在 此外，还介绍了本科生进行酚-氯仿实验的实践经验， 提取，聚合酶链反应，以及德克萨斯州弗里曼牧场尸体农场的研讨会 大学在这个项目中将为他们提供洞察力，以了解是否在生物医学科学的学术生涯 可能是他们想进一步追求的途径。

PROJECT SUMMARY / ABSTRACT Cocaine abuse continues to be a national crisis, with the cost of addiction to illegal drugs in the United States related to criminal activity, lost work productivity, and medical care totaling more than $740 billion per year. In particular, African-Americans, who make up 13.4% of the U.S. population, disproportionately bear the burden of cocaine use and overdoses. Multiple studies have shown that prolonged use of cocaine affects the gut microbiota, which in turn alters hypothalamus-pituitary-axis activity and emotional behavior. Cocaine-related studies have shown that drugs of abuse trigger preferential proliferation of gram-positive Firmicutes and reduction of gram- negative Bacteroidetes, results that are consistent with microbiota associations with drug addiction. Accumulating evidence also shows that gut microorganisms influence the bidirectional communication along the gut- brain axis, which indicates the crucial role of the gut microbiota on cocaine. Since evidence exists for the influence of commonly abused drugs on the microbiota gut-brain axis, the transverse colon, the distal ileum, the basal ganglia, and the pituitary and adrenal glands may have potential roles as biomarkers, specifically in overdose cases, due to the damage to these tissues caused by cocaine abuse. In this proposal, we will address the impact that cocaine has on the microbiota of the gut-brain axis. Our approach will allow for evaluation of microbial signatures in microbiota gut-brain axis-associated tissues using specimens extracted from cocaine overdose cadavers, an approach that previous studies have not used but could provide information that helps determine how people respond differently to cocaine, allowing researchers to better examine the potential adverse effects of microbes. Specifically, we will test the hypothesis that there is a significant association between gut microbiota and the gut-brain axis in cocaine overdose cases from three Southern regions - Alabama, Florida, and Tennessee. To test this hypothesis, we will (1) determine whether the gut microbiome that is associated with the transverse colon and distal ileum mediates the relationship between cocaine use and lethal drug intoxication in African Americans from Southern regions of the United States; (2) determine whether the gut microbiome that is associated with the basal ganglia and the pituitary and adrenal glands mediates the relationship between cocaine use and lethal drug intoxication in African Americans from Southern regions of the United States;; and (3) validate a mathematical model of specific microbial biomarkers in single-blind studies using African-American tissues to increase confidence and demonstrate reproducibility. These processes will be evaluated and validated to provide a basis for new diagnostics as well as therapeutic targets to prevent intentional and unintentional cocaine overdose with the long-term objective of restoring gut microbiome homeostasis. In addition, the hands-on experience that the undergraduate students gain conducting phenol-chloroform extractions, polymerase chain reaction, and the workshop at the Freeman Ranch Body Farm at Texas State University in this project will provide them with insights into whether an academic career in biomedical sciences might be an avenue they want to further pursue.