Volume 15, Issue 23-24 pp. 4051-4063
Research Article

Proteomic analysis of cerebrospinal fluid in California sea lions (Zalophus californianus) with domoic acid toxicosis identifies proteins associated with neurodegeneration

Benjamin A. Neely

Benjamin A. Neely

Department of Medicine, Division of Nephrology, Medical University of South Carolina, Charleston, SC, USA

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Jennifer L. Soper

Jennifer L. Soper

The Marine Mammal Center, Sausalito, CA, USA

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Frances M. D. Gulland

Frances M. D. Gulland

The Marine Mammal Center, Sausalito, CA, USA

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P. Darwin Bell

P. Darwin Bell

Department of Medicine, Division of Nephrology, Medical University of South Carolina, Charleston, SC, USA

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Mark Kindy

Mark Kindy

Marine Biomedicine and Environmental Sciences Center, Medical University of South Carolina, Charleston, SC, USA

Department of Regenerative Medicine and Cell Biology, Medical University of South Carolina, Charleston, SC, USA

Department of Veterans’ Affairs, Research Service, Charleston, SC, USA

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John M. Arthur

John M. Arthur

Department of Internal Medicine, Division of Nephrology, University of Arkansas for Medical Sciences, Little Rock, AR, USA

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Michael G. Janech

Corresponding Author

Michael G. Janech

Department of Medicine, Division of Nephrology, Medical University of South Carolina, Charleston, SC, USA

Marine Biomedicine and Environmental Sciences Center, Medical University of South Carolina, Charleston, SC, USA

Correspondence: Dr. Michael G. Janech, Medical University of South Carolina, 96 Jonathan Lucas Street, 829 CSB - Nephrology, MSC 623, Charleston, SC 29425, USA

E-mail: [email protected]

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First published: 14 September 2015
Citations: 20

Abstract

Proteomic studies including marine mammals are rare, largely due to the lack of fully sequenced genomes. This has hampered the application of these techniques toward biomarker discovery efforts for monitoring of health and disease in these animals. We conducted a pilot label-free LC-MS/MS study to profile and compare the cerebrospinal fluid from California sea lions with domoic acid toxicosis (DAT) and without DAT. Across 11 samples, a total of 206 proteins were identified (FDR<0.1) using a composite mammalian database. Several peptide identifications were validated using stable isotope labeled peptides. Comparison of spectral counts revealed seven proteins that were elevated in the cerebrospinal fluid from sea lions with DAT: complement C3, complement factor B, dickkopf-3, malate dehydrogenase 1, neuron cell adhesion molecule 1, gelsolin, and neuronal cell adhesion molecule. Immunoblot analysis found reelin to be depressed in the cerebrospinal fluid from California sea lions with DAT. Mice administered domoic acid also had lower hippocampal reelin protein levels suggesting that domoic acid depresses reelin similar to kainic acid. In summary, proteomic analysis of cerebrospinal fluid in marine mammals is a useful tool to characterize the underlying molecular pathology of neurodegenerative disease. All MS data have been deposited in the ProteomeXchange with identifier PXD002105 (http://proteomecentral.proteomexchange.org/dataset/PXD002105).