Original Paper

The c-Jun-N-Terminal Kinase is Involved in the Neurotoxic Effect of Azaspiracid-1
Carmen Vale¹, Belén Gómez-Limia¹, K.C. Nicolaou^2,3, Michael O. Frederick², Mercedes R. Vieytes⁴, Luis M. Botana<sup>1

1</sup>Departamento de Farmacología, Facultad de Veterinaria, USC, Lugo,
²Department of Chemistry and The Skaggs Institute for Chemical Biology. The Scripps Research Institute, La Jolla,
³Department of Chemistry and Biochemistry, University of California, San Diego. La Jolla,
⁴Departamento de Fisiología, Facultad de Veterinaria, USC, Lugo

Address of Corresponding Author

Cell Physiol Biochem 2007;20:957-966 (DOI: 10.1159/000110456)

  Key Words

• Azaspiracid
• MAPK
• JNK
• Cytotoxicity
• Cerebellar granule cells
• MTT

  Abstract

Aims: Azaspiracids (AZAs) are marine phycotoxins with an unknown mechanism of action, recently implicated in human intoxications. The predominant analog in nature, AZA-1 targets several organs in vivo, including the central nervous system and exhibits high neurotoxicity in vitro. Methods: We used pharmacological tools to inhibit the cytotoxic effect of the toxin in primary cultured neurons. Immunocytochemical techniques in combination with confocal microscopy were employed to examine the cellular mechanisms involved in the neurotoxic effect of AZA-1. Results: Several targets for azaspiracid-induced neurotoxicity, specifically the cAMP pathway, or protein kinase C and phosphatidylinositol 3-kinase activation were excluded. Interestingly, the specific c-Jun-N-terminal protein kinase (JNK) inhibitor SP 600125 protected cultured neurons against AZA-induced cytotoxicity. Immunocytochemistry experiments showed that AZA-1 increased the amount of phosphorylated JNK and caused nuclear translocation of the active protein that was prevented by SP 600125. Conclusion: Our data constitute the relationship between azaspiracid-induced cytotoxicity and specific modifications in cellular transduction signals, specifically we found that JNK activation is associated with the cytotoxic effect of the toxin. These results should provide the basis to identify the mechanism of action of this group of toxins.

Copyright © 2007 S. Karger AG, Basel

  Author Contacts

Luis M. Botana
Departamento de Farmacología Facultad de Veterinaria
Universidad de Santiago de Compostela
Campus Universitario s/n, 27002, Lugo, (Spain)
Tel. + 34-982 252 242, Fax: + 34-982 252 242, E-Mail Luis.Botana@lugo.usc.es

  Article Information

Accepted: August 16, 2007
Number of Print Pages : 10