Microcystin-LR toxicity in nonalcoholic steatohepatitis

微囊藻毒素-LR 在非酒精性脂肪性肝炎中的毒性

• 批准号: 8890996
• 负责人: John Daniel Clarke
• 金额: $ 9.14万
• 依托单位: UNIVERSITY OF ARIZONA
• 依托单位国家: 美国
• 财政年份: 2015
• 资助国家: 美国
• 起止时间: 2015-09-30 至 2017-09-29
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/8890996
• 关键词: Acute; Adult; Affect; Animals; Applications Grants; Arizona; Biliary; Carrier Proteins; Categories; Cells; Chronic; Chronic Kidney Failure; Communication; Computer software; Cyanobacterium; Cyclic Peptides; Cysteine; Data; Development; Development Plans; Diet; Disease; Dreams; Educational Activities; Educational workshop; Enterocytes; Environment; Eutrophication; Excretory function; Exhibits; Exposure to; Face; Faculty; Generations; Genetic; Glutathione; Goals; Grant; Health; Health Sciences; Hepatic; Hepatocyte; Hepatotoxicity; Human; In Vitro; Incidence; Intestines; Intravenous; Journals; Kidney; Kinetics; Knock-out; Knowledge; Lead; Liver; Liver diseases; Measures; Mediating; Membrane; Mentors; Metabolism; Methods; Mind; Modeling; Mus; National Institute of Environmental Health Sciences; OATP Transporters; Oral; Organ; Pathway interactions; Patients; Peer Review; Pharmaceutical Preparations; Pharmacology and Toxicology; Phase; Plasma; Population; Populations at Risk; Positioning Attribute; Postdoctoral Fellow; Prevalence; Proximal Kidney Tubules; Publishing; Rattus; Reporting; Research; Research Project Grants; Risk; Risk Assessment; Rodent; Route; Scientist; Series; Single Nucleotide Polymorphism; Societies; Source; System; Technical Expertise; Testing; Tissues; Toxic Environmental Substances; Toxic effect; Toxicant exposure; Toxicokinetics; Toxicology; Toxin; Training; Training Activity; Translating; United States; United States National Institutes of Health; Universities; Water; Work; Writing; Xenobiotic Metabolism; Xenobiotics; absorption; base; career; career development; climate change; cyanobacterial toxin; cyanoginosin LR; disease phenotype; drinking water; environmental stressor; exposed human population; falls; gastrointestinal; high school; improved; in vivo; nephrotoxicity; non-alcoholic fatty liver; nonalcoholic steatohepatitis; population based; post-doctoral training; public health relevance; research and development; research study; skills; symposium; undergraduate student; uptake; urinary; waterborne

DESCRIPTION (provided by applicant): This pathway to independence grant application describes the training and career development plan for Dr. John Clarke. Dr. Clarke's immediate career goal is to complete the necessary postdoctoral training in order establish a research project in toxicology that is independent from the work of his post-doctoral advisor, Dr. Nathan Cherrington. This goal is directly tied to the research proposed in the application, since this project takes the liver disease phenotype studied in Dr. Cherrington's group and applies it to exposure and toxicity of an environmental stressor. Dr. Clarke's long-term career goals are to 1) improve human health by advancing our understanding of the interaction between liver disease and environmental toxicant exposure, and 2) become a mentor to subsequent generations of scientists. These immediate and long-term career goals will be accomplished through specific aspects of the training environment and the research project. Dr. Clarke's training plan includes expanding his knowledge and recognition in the field of toxicology, developing new technical expertise, improving his mentoring and communication skills, and improving grant writing skills. In order to increase knowledge and recognition in the field of toxicology Dr. Clarke will participate in educational and training activities available through the NIEHS training grant, the Society of Toxicology, the Pharmacology and Toxicology Department, and the Arizona Health Sciences Center. These include seminars, journal clubs, colloquia, and conferences. Dr. Clarke has assembled a "dream team" of mentors and collaborators that will be an incredible asset for his career development and research plan. Dr. Clarke will develop new technical expertise in xenobiotic transport kinetics, in vivo toxicokinetics analyses, organ specific toxicity, and physiologically based toxicokinetics modeling (PBTK). An important aspect of being an independent scientist is the ability to mentor and communicate effectively. As part of the training environment Dr. Clarke will continue to present data at conferences and publish in peer-reviewed journals. He will also continue to mentor high school, graduate, and undergraduate students in Dr. Cherrington's lab. Finally, he will improve his grant writing skills by participatig in a series of grant writing workshops offered at the University of Arizona and through the NIH. By implementing each aspect of this training plan, Dr. Clarke will receive the additional training he needs to successfully transition into an independent faculty position in toxicology. This research project seeks to understand how the liver disease nonalcoholic steatohepatitis (NASH) alters the toxicokinetics and toxicity of the waterborne toxin microcystin-LR (MCLR). The prevalence of NASH, which is the most severe form of nonalcoholic fatty liver disease, continues to increase worldwide and is estimated to be present in 5% to 17% of adults in the United States. In addition to the liver problems this population faces, there is also a higher incidence of chronic kidney disease among these patients, which may be associated with MCLR exposure. MCLR-producing cyanobacteria are ubiquitous in sources of drinking water around the world, and the occurrence of blooms and MCLR contaminated drinking water are expected to increase as anthropomorphic eutrophication of water systems and global climate change continue to worsen. Unfortunately, there is a dearth of information regarding MCLR toxicokinetics in humans and how NASH-associated changes in xenobiotic transporter expression influence MCLR toxicokinetics and MCLR-induced toxicity. The objectives of this research are to 1) provide a complete picture of the xenobiotic transporters responsible for the disposition of MCLR and its main metabolites, MCLR-glutathione and MCLR-cysteine, 2) determine how altered expression of these transporters in NASH affects MCLR disposition and toxicity, and 3) move these findings towards risk assessment by constructing a PBTK model for human MCLR exposure in healthy and NASH populations. Dr. Clarke's previous work has demonstrated that NASH causes decreased expression of the liver uptake transporters important for MCLR-induced liver toxicity: organic anion transporting polypeptide-1b2 (Oatp1b2) in rodents and OATP1B1 and OATP1B3 in humans. He has also shown that this NASH-induced decrease in rodent Oatp1b2 shifted the disposition of several drugs that are substrates for OATPs away from liver exposure towards kidney exposure. In the case of MCLR, it has been shown that genetic knockout of Oatp1b2 completely protected the mice from MCLR-induced liver toxicity. In a recently completed preliminary study Dr. Clarke has shown that MCLR exposure in NASH dramatically increase kidney toxicity compared to healthy controls exposed to MCLR. These data lead to the central hypothesis that people with NASH are at increased risk of altered MCLR exposure and MCLR-induced renal toxicity due to changes in hepatic OATP transporters. To test this hypothesis and achieve the objectives of this project several methods will be employed. First, in vitro transporter kinetics experiments will be performed to identify transporters, beyond the Oatps, that contribute to MCLR disposition. Second, the effect of NASH on MCLR disposition will be determined by measuring toxicokinetics profiles after oral and intravenous MCLR administration in healthy and NASH rats. Third, acute and sub-chronic, sub-lethal toxicity studies will be performed to determine if MCLR exposure in NASH increases renal toxicity. Lastly, a PBTK model for MCLR exposure in humans will be constructed using the Simcyp software to help translate this work into exposure information for human populations. The research project outlined here is important to the development of Dr. Clarke's career but, more importantly, it is important to millions of people worldwide who have NASH and are exposed to MCLR.

描述（由申请人提供）：此独立补助金申请途径描述了约翰·克拉克博士的培训和职业发展计划。克拉克博士的近期职业目标是完成必要的博士后培训，以便建立一个独立于他的博士后顾问内森·切林顿博士的工作的毒理学研究项目。这一目标与申请中提出的研究直接相关，因为该项目采用了 Cherrington 博士小组研究的肝病表型，并将其应用于环境压力源的暴露和毒性。克拉克博士的长期职业目标是 1) 通过增进我们对肝病与环境毒物暴露之间相互作用的理解来改善人类健康，2) 成为后代科学家的导师。这些近期和长期的职业目标将通过培训环境和研究项目的具体方面来实现。克拉克博士的培训计划包括扩大他在毒理学领域的知识和认识、发展新的技术专业知识、提高他的指导和沟通技巧以及提高资助写作技巧。为了增加毒理学领域的知识和认可，Clarke 博士将参加 NIEHS 培训补助金、毒理学会、药理学和毒理学部以及亚利桑那州健康科学中心提供的教育和培训活动。其中包括研讨会、期刊俱乐部、座谈会和会议。克拉克博士组建了一支由导师和合作者组成的“梦之队”，这将成为他的职业发展和研究计划的一笔不可思议的财富。 Clarke 博士将在外源物质转运动力学、体内毒代动力学分析、器官特异性毒性和基于生理学的毒代动力学模型 (PBTK) 方面开发新技术专业知识。作为一名独立科学家的一个重要方面是有效指导和沟通的能力。作为培训的一部分 环境 克拉克博士将继续在会议上展示数据并在同行评审期刊上发表文章。他还将继续在切林顿博士的实验室指导高中生、研究生和本科生。最后，他将通过参加亚利桑那大学和美国国立卫生研究院提供的一系列资助写作研讨会来提高他的资助写作技巧。通过实施该培训计划的各个方面，克拉克博士将接受他成功过渡到毒理学独立教职职位所需的额外培训。该研究项目旨在了解肝脏疾病非酒精性脂肪性肝炎 (NASH) 如何改变水源毒素微囊藻毒素-LR (MCLR) 的毒代动力学和毒性。 NASH 是最严重的非酒精性脂肪肝疾病，其患病率在全球范围内持续增加，据估计在美国有 5% 至 17% 的成年人患有 NASH。除了该人群面临的肝脏问题外，这些患者中慢性肾脏病的发病率也较高，这可能与 MCLR 暴露有关。产生 MCLR 的蓝藻在世界各地的饮用水源中普遍存在，随着水系统的拟人化富营养化和全球气候变化的持续恶化，水华和 MCLR 污染的饮用水的发生预计将会增加。不幸的是，关于人类 MCLR 毒代动力学以及 NASH 相关的异生素转运蛋白表达变化如何影响 MCLR 毒代动力学和 MCLR 诱导的毒性的信息缺乏。本研究的目的是 1) 提供负责 MCLR 及其主要代谢物 MCLR-谷胱甘肽和 MCLR-半胱氨酸处置的外源转运蛋白的完整信息，2) 确定 NASH 中这些转运蛋白的表达改变如何影响 MCLR 处置和毒性，3) 通过构建健康和 NASH 人群中人类 MCLR 暴露的 PBTK 模型，将这些发现推向风险评估。 Clarke 博士之前的工作表明，NASH 会导致对 MCLR 诱导的肝毒性至关重要的肝脏摄取转运蛋白的表达减少：啮齿动物中的有机阴离子转运多肽-1b2 (Oatp1b2) 以及人类中的 OATP1B1 和 OATP1B3。他还表明，NASH 引起的啮齿动物 Oatp1b2 的减少使作为 OATP 底物的几种药物的处置从肝脏暴露转向肾脏暴露。就 MCLR 而言，研究表明 Oatp1b2 基因敲除可以完全保护小鼠免受 MCLR 诱导的肝毒性。在最近完成的一项初步研究中，Clarke 博士表明，与暴露于 MCLR 的健康对照相比，NASH 患者暴露于 MCLR 会显着增加肾脏毒性。这些数据得出了一个中心假设，即 NASH 患者由于肝脏 OATP 转运蛋白的变化而面临 MCLR 暴露改变和 MCLR 诱导的肾毒性的风险增加。为了检验这一假设并实现该项目的目标，将采用多种方法。首先，将进行体外转运蛋白动力学实验，以确定 Oatps 之外有助于 MCLR 处置的转运蛋白。其次，NASH 对 MCLR 处置的影响将通过测量健康大鼠和 NASH 大鼠口服和静脉注射 MCLR 后的毒代动力学曲线来确定。第三，将进行急性和亚慢性、亚致死毒性研究，以确定 NASH 中 MCLR 暴露是否会增加肾毒性。最后，将使用 Simcyp 软件构建人类 MCLR 暴露的 PBTK 模型，以帮助将这项工作转化为人群的暴露信息。这里概述的研究项目对于 Clarke 博士的职业发展很重要，但更重要的是，它对于全世界数百万患有 NASH 并接触 MCLR 的人也很重要。