Neurotoxins from Marine Algae and Cyanobacteria

描述（由申请人提供）：天然产物在神经药理学中发挥着关键作用，因为它们对特定生化途径和受体具有强效和选择性靶向作用，并且作为探针物质和治疗先导物非常有用。海洋蓝细菌具有丰富的天然产物结构，其中许多是有毒的或具有其他生物学特性。我们建议继续天然产物化学家（Gerwick）和神经药理学家（Murray）之间富有成效的合作，扩大我们之前对这些生命形式的研究，寻找新的、具有生物学洞察力的神经活性化合物。因此，我们的长期目标是：1）开发新的化合物作为药理学和细胞生物学的新工具，2）描述新的假定环境毒素，以便在爆发时采取适当的行动，3）开发神经活性物质作为潜在的治疗先导化合物，特别是在治疗中风引起的脑损伤中。为了实现这些目标，我们有以下四个具体目标：1）收集250个蓝藻和藻类样品，并产生高质量的聚焦级分文库，用于在设计用于检测神经活性天然产物的测定中进行筛选，2）使用高通量自发Ca2+振荡和Na+流入测定在皮层神经元中评估上述不同的提取物，3）使用创新和加速的方法从筛选试验中检测阳性的海洋蓝藻中分离和结构表征新的神经活性物质，采用纳米级NMR和MSn方法，4）进一步确定在先前支持期间发现的几种蓝藻毒素的分子药理学。此外，评估新发现的蓝藻配体对新皮层神经元突起生长、棘发生和突触发生的影响。在这些体外试验中有活性的选定化合物将进入局灶性中风的小鼠模型。这将需要生产这些新发现的化合物的额外供应或类似物，包括用于放射性配体结合和分布测定的放射性同位素标记的类似物。这些目标的完成将增加我们对海洋蓝藻和藻类产生的独特的神经活性天然产物的了解。在过去的两个周期中，对这一合作计划的支持是非常富有成效的，我们现在有一个成熟的，运作良好的，高效的计划。我们将继续完善我们的方法和思想，应用于发现和利用新型海洋神经活性物质，这将使我们在新的研究方向，为拟议的未来补助金期间，如电压门控钠通道激活剂，促进神经突生长的应用在新皮层神经元中风引起的脑损伤的潜在治疗。

DESCRIPTION (provided by applicant): Natural products have played pivotal roles in neuropharmacology due to their potent and selective targeting of specific biochemical pathways and receptors, and are highly useful as probe substances and therapeutic leads. Marine cyanobacteria are exceptionally rich in diverse natural product structures, many of which are toxic or have other biological properties. We propose to continue our productive collaboration between a natural products chemist (Gerwick) and a neuropharmacologist (Murray), expanding on our previous investigations of these life forms for their new and biologically-insightful neuroactive compounds. Thus, we have the long range goals of 1) developing new compounds to serve as novel tools for pharmacology and cell biology, 2) describing new putative environmental toxins so that appropriate actions can be taken should outbreaks occur, and 3) development of neuroactive substances as potential therapeutic lead compounds, especially in the treatment of stroke-induced brain injury. To accomplish these goals we have the following four specific aims: 1) to collect 250 samples of cyanobacteria and algae, and produce high quality focused fraction libraries for screening in assays designed to detect neuroactive natural products, 2) to evaluate the above diverse extracts using high throughput spontaneous Ca2+ oscillation and Na+ influx assays in cerebrocortical neurons, 3) to use innovative and accelerated methods to isolate and structurally characterize new neuroactive substances from marine cyanobacteria testing positively in the screening assays, featuring nanoscale NMR and MSn methods, 4) to further define the molecular pharmacology of several cyanobacterial toxins discovered during prior support. Additionally, to evaluate the influence of newly discovered cyanobacterial ligands on neurite outgrowth, spinogenesis and synaptogenesis in neocortical neurons. Select compounds active in these in vitro assays will be advanced into a mouse model for focal stroke. This will require the production of additional supplies or analogs of these newly discovered compounds, including radioisotope-labeled analogs to be used in radioligand binding and distribution assays. Completion of these aims will increase our knowledge of the unique and neuroactive natural products produced by marine cyanobacteria and algae. The past two cycles of support for this collaborative program have been highly productive, and we now have a mature, well functioning, and highly effective program. We continue to refine our approaches and thinking as applied to the discovery and utility of novel marine neuroactive substances, and this leads us in new research directions for the proposed coming grant period, such as the application of voltage-gated sodium channel activators that promote neurite outgrowth in neocortical neurons to the potential treatment of stroke-induced brain injury.