Gilthead sea bream liver proteome altered at low temperatures by oxidative stress.
Gilthead sea bream exposed to the cold show multiple physiological alterations, particularly in liver. A typical cold-stress response was reproduced in gilthead sea bream acclimated to 20 degrees C (Warm group) when the water temperature was lowered to 8 degrees C (Cold group). After 10 days, thiobarbituric acid reactive substances in the liver had increased by 50%, and nitric oxide had increased twofold. This indicates that lipid peroxidation and oxidative stress had occurred. Protein profiles of liver from fish in warm and cold environments were obtained by 2-DE. Quantification of differential expression by matching spots showed that a total of 57 proteins were altered significantly. Many proteins were downregulated following cold exposure, including actin, the most abundant protein in the proteome; enzymes of amino acid metabolism; and enzymes with antioxidant capacity, such as betaine-homocysteine-methyl transferase, glutathione-S-transferase and catalase. Some proteins associated with protective action were upregulated at low temperatures, including peroxiredoxin, thioredoxin and lysozyme; as well as enzymes such as aldehyde dehydrogenase and adenosin-methionine synthetase. However, the upregulation of proteases, proteasome activator protein and trypsinogen-like protein indicated an increase in proteolysis. Increases in elongation factor-1alpha, the GAPDH oxidative form, tubulin and Raf-kinase inhibitor protein indicated oxidative stress and the induction of apoptosis. These data indicate that cold exposure induced oxidative damage in hepatocytes.
Xarxa de Referència i Recerca en Aqüicultura de la Generalitat de Catalunya, Dept Fisiologia (Biologia), Universitat de Barcelona, Barcelona, Spain. tibarz@ub.edu
Antoni
A
Ibarz
Miguel
M
Martín-Pérez
Josefina
J
Blasco
David
D
Bellido
Eliandre
E
de Oliveira
Jaume
J
Fernández-Borràs
D000818:Animals; D003080:Cold Temperature; D015536:Down-Regulation; D029941:Fish Proteins / Q000378:metabolism; D020869:Gene Expression Profiling; D008099:Liver / Q000378:metabolism*; D016877:Oxidants / Q000378:metabolism; D018384:Oxidative Stress; D020543:Proteome / Q000378:metabolism*; D021541:Sea Bream / Q000378:metabolism*; D012995:Solubility; D013312:Stress, Physiological; D015854:Up-Regulation
D029941:Fish Proteins; D016877:Oxidants; D020543:Proteome