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.

Public Health Relevance

This project focuses on describing the natural neuroactive compounds present in marine algae and cyanobacteria, and this impacts human health in three areas: 1) this research will find neuroactive compounds that work by new mechanisms, thus allowing a better description of how cells communicate and react to their environment, 2) some of these neuroactive compounds may lead to new therapies for diseases such as stroke, epilepsy, pain control, schizophrenia, and cognitive disorders, and 3) by fully describing the structures and pharmacology of some of these toxic natural products, this research can help reduce human exposures and suggest treatment options in case of exposure.

National Institute of Health (NIH)
National Institute of Neurological Disorders and Stroke (NINDS)
Research Project (R01)
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Study Section
Synthetic and Biological Chemistry B Study Section (SBCB)
Program Officer
Jett, David A
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University of California San Diego
Schools of Earth Sciences/Natur
La Jolla
United States
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Kinnel, Robin B; Esquenazi, Eduardo; Leao, Tiago et al. (2017) A Maldiisotopic Approach to Discover Natural Products: Cryptomaldamide, a Hybrid Tripeptide from the Marine Cyanobacterium Moorea producens. J Nat Prod 80:1514-1521
Shao, Chang-Lun; Linington, Roger G; Balunas, Marcy J et al. (2015) Bastimolide A, a Potent Antimalarial Polyhydroxy Macrolide from the Marine Cyanobacterium Okeania hirsuta. J Org Chem 80:7849-55
Morgan, J Brian; Liu, Yang; Coothankandaswamy, Veena et al. (2015) Kalkitoxin inhibits angiogenesis, disrupts cellular hypoxic signaling, and blocks mitochondrial electron transport in tumor cells. Mar Drugs 13:1552-68
Boudreau, Paul D; Monroe, Emily A; Mehrotra, Suneet et al. (2015) Expanding the Described Metabolome of the Marine Cyanobacterium Moorea producens JHB through Orthogonal Natural Products Workflows. PLoS One 10:e0133297
Rho, Jung-Rae; Subramaniam, Gurusamy; Choi, Hyukjae et al. (2015) Gargantulide A, a complex 52-membered macrolactone showing antibacterial activity from Streptomyces sp. Org Lett 17:1377-80
Teta, Roberta; Della Sala, Gerardo; Glukhov, Evgenia et al. (2015) Combined LC-MS/MS and Molecular Networking Approach Reveals New Cyanotoxins from the 2014 Cyanobacterial Bloom in Green Lake, Seattle. Environ Sci Technol 49:14301-10
Cao, Zhengyu; Li, Xichun; Zou, Xiaohan et al. (2015) Involvement of JNK and caspase activation in hoiamide A-induced neurotoxicity in neocortical neurons. Mar Drugs 13:903-19
Cao, Zhengyu; Cui, Yanjun; Busse, Eric et al. (2014) Gambierol inhibition of voltage-gated potassium channels augments spontaneous Ca2+ oscillations in cerebrocortical neurons. J Pharmacol Exp Ther 350:615-23
Mevers, Emily; Matainaho, Teatulohi; Allara', Marco et al. (2014) Mooreamide A: a cannabinomimetic lipid from the marine cyanobacterium Moorea bouillonii. Lipids 49:1127-32
Mehrotra, Suneet; Duggan, Brendan M; Tello-Aburto, Rodolfo et al. (2014) Detailed analysis of (-)-palmyrolide a and some synthetic derivatives as voltage-gated sodium channel antagonists. J Nat Prod 77:2553-60

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