Shifting paradigms to emerging toxins in freshwater cyanobacterial blooms

项目摘要 蓝藻有害藻华（cyanoHABs）和有毒化合物在这些事件中产生， 已成为淡水系统中的一个长期问题， 饮用水和对当地经济的重大负担，由于减少娱乐活动。 微囊藻毒素通常是氰基有害藻毒素中的主要毒素，主要影响肝脏（肝毒素），但 也被描述为影响肾脏、生殖系统和大脑。蓝藻在这些 已知水华事件除了产生微囊藻毒素外，还产生一系列肝毒素， 柱孢菌素和生物碱神经毒素如石房蛤毒素和类毒素。Bertin的初步结果 拟议项目中的实验室和协作行业合作伙伴Biosortia Pharmaceuticals已经表明， 在从内陆采集的蓝藻生物量的环境集合中存在着非常有效的细胞毒素， 湖泊和水体。这些新兴化合物（甾体内酯）的一套显着偏离 典型地与这些水华事件相关的有毒化合物的类型（肽和类毒素）。这些 新发现的化合物比微囊藻毒素-LR更有效，以前从未被发现过。 描述了氰藻酸盐事件。因此，有一个重大的和未满足的需要，了解生产的 这些化合物和其他细胞毒性代谢物在氰基有害生物，并开发检测，分离， 可供自然资源管理机构使用的毒理学评价工具， 卫生政策制定者。此外，初步研究结果表明，氰基赤潮藻中存在新的微囊藻毒素 比130种已知的微囊藻毒素同源物中的任何一种都具有更强的细胞毒性。这种做法的理由是， 研究项目的一个重要问题是，需要对氰基有害生物中存在的有毒化学空间进行全面核算。 此外，多种有毒化合物的多样性需要新的评估工具来确定最 有效的蓝藻毒素，它们的作用方式，它们对肝脏的潜在毒性以及它们与全身性 损伤项目目标将包括利用生物技术识别和分离新出现的有毒化合物。 代谢组学方法、微生物群落分析和新兴毒素的结构解析（目的 1）。此外，将在一项时间进程研究中调查氰基有害生物的毒素组成， 毒性代谢物组成的时间分辨率（目标1）。接下来，毒理学评估将 用于整合计算机模拟、体外和蛋白质组学研究，以确定毒性和作用机制 毒素（目标2）。仪器和专业知识是项目成功的保证。该项目将导致 分离和表征新出现的毒素，并大大偏离目前的现状， 微囊藻毒素此外，这项工作将发展这些新的机制毒性的理解， 新出现的代谢产物可能导致潜在的肝损伤，这可能是全身性疾病的早期介质。

PROJECT SUMMARY Cyanobacterial harmful algal blooms (cyanoHABs) and the toxic compounds produced during these events have become a persistent problem in freshwater systems and have affected local populations by contaminating drinking water and placing a significant burden on local economies due to diminished recreational activity. Microcystins, generally the dominant class of toxins in cyanoHABs, primarily affect the liver (hepatotoxin), but have been described to also affect the kidney, the reproductive system, and the brain. Cyanobacteria in these bloom events are known to produce a suite of hepatotoxins in addition to the microcystins such as the cylindrospermopsins, and alkaloid neurotoxins such as saxitoxin and anatoxin. Preliminary results from the Bertin Laboratory and collaborative industry partners in the proposed project, Biosortia Pharmaceuticals, have shown exquisitely potent cytotoxins exist in environmental collections of cyanobacterial biomass harvested from inland lakes and water bodies. A suite of these emerging compounds (steroidal lactones) departs significantly from the types of toxic compounds typically associated with these bloom events (peptidic and alkaloidal toxins). These newly discovered compounds are significantly more potent than microcystin-LR and have never been previously described from cyanoHAB events. Thus, there is a significant and unmet need to understand the production of these compounds and other cytotoxic metabolites during cyanoHABs and to develop detection, isolation, and toxicological evaluation tools that can be utilized by natural resource management agencies and inform public health policy makers. Furthermore, preliminary results indicate that there are new microcystins in cyanoHABs that are significantly more cytotoxic than any of the 130 known microcystin congeners. The rationale of this research project is that there needs to be a full accounting of the toxic chemical space present in cyanoHABs. Furthermore, the diversity of multiple toxic compounds requires new evaluation tools to determine the most potent cyanotoxins, their mode of action, and their potential toxicity on the liver and how that relates to systemic injury. Project goals will consist of the identification and isolation of emerging toxic compounds using metabolomics approaches, microbial community analysis, and the structure elucidation of emerging toxins (Aim 1). Furthermore, the toxin composition of cyanoHABs will be investigated in a time course study to provide temporal resolution with respect to toxic metabolite composition (Aim 1). Next, a toxicological assessment will be used that integrates in silico, in vitro, and proteomic studies to determine toxicity and the mechanism of action of toxins (Aim 2). Instrumentation and expertise are in place for project success. This project will result in the isolation and characterization of emerging toxins and significantly departs from the current status quo of focusing on microcystins. Additionally, this work will develop an understanding of the mechanistic toxicity of these novel emerging metabolites to potential liver injury, which can be an early mediator of systemic disease.