Neurotoxins from Marine Algae and Cyanobacteria

描述（由申请人提供）：天然产物由于其对特定生化途径和受体的有效和选择性靶向，在神经药理学中起着关键作用，并且作为探针物质和治疗先导非常有用。海洋蓝藻具有丰富多样的天然产物结构，其中许多是有毒的或具有其他生物学特性。我们建议继续我们在天然产物化学家（Gerwick）和神经药理学家（Murray）之间的富有成效的合作，扩展我们之前对这些生命形式的研究，以寻找新的和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)描述新的假定的环境毒素，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方面。为实现这些目标，我们有以下四个具体目标：1)收集250个蓝藻和藻类样本，并建立高质量的集中部分文库，用于检测神经活性天然产物的检测；2)在脑皮质神经元中使用高通量自发Ca2+振荡和Na+内流实验来评估上述不同的提取物。3)使用创新和加速的方法从海洋蓝藻中分离和结构表征新的神经活性物质，在筛选试验中呈阳性，包括纳米级核磁共振和MSn方法；4)进一步确定先前支持过程中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神经突生长、脊髓发生和突触发生的影响。选择在这些体外试验中有活性的化合物将被推进到小鼠局灶性中风模型中。这将需要生产这些新发现化合物的额外供应物或类似物，包括放射性同位素标记类似物，用于放射性配体结合和分布分析。完成这些目标将增加我们对海洋蓝藻和藻类产生的独特和神经活性天然产品的了解。过去两个周期对这一合作项目的支持是非常富有成效的，我们现在有了一个成熟的、运转良好的、高效的项目。我们将继续完善我们的方法和思维，以应用于新型海洋神经活性物质的发现和利用，这将使我们在即将到来的拨款期内进入新的研究方向，例如应用电压门控钠通道激活剂促进新皮层神经元的神经突生长，以潜在地治疗中风引起的脑损伤。

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.