Proteomic analysis of sockeye salmon serum as a tool for biomarker discovery and new insight into the sublethal toxicity of diluted bitumen.

Pipelines carrying diluted bitumen (dilbit) from Canada's oil sands traverse North America, including the freshwater habitat of Pacific salmon, posing a risk of environmental release and aquatic exposure. Swimming performance is impacted in juvenile sockeye (Oncorhynchus nerka) exposed to dilbit; therefore biomarkers of dilbit exposure will be valuable for monitoring at-risk salmon stocks. This study characterized changes in the serum proteome of sockeye exposed to a sub-lethal and environmentally relevant concentration of dilbit using isobaric tags for relative and absolute quantitation (iTRAQ), and included a range of experimental conditions to permit identification of biomarkers that are robust across time (1 and 4wk) and exercise level (at rest and following a swim test).

Novel insights into cardiac remodelling revealed by proteomic analysis of the trout heart during exercise training.

Unlabelled: The changes in the cardiac proteome of rainbow trout (Oncorhynchus mykiss) were quantified during the early phases (4, 7, and 14d) of a typical exercise-training regime to provide a comprehensive overview of the cellular changes responsible for developing a trained heart phenotype. Enhanced somatic growth during the 14d experiment was paralleled by cardiac growth to maintain relative ventricular mass. This was reflected in the cardiac proteome by the increased abundance of contractile proteins and cellular integrity proteins as early as Day 4, including a pronounced and sustained increase in blood vessel epicardial substance - an intercellular adhesion protein expressed in the vertebrate heart.

Plasma membranes as heat stress sensors: from lipid-controlled molecular switches to therapeutic applications.

The classic heat shock (stress) response (HSR) was originally attributed to protein denaturation. However, heat shock protein (Hsp) induction occurs in many circumstances where no protein denaturation is observed. Recently considerable evidence has been accumulated to the favor of the "Membrane Sensor Hypothesis" which predicts that the level of Hsps can be changed as a result of alterations to the plasma membrane.

Rapid cortisol signaling in response to acute stress involves changes in plasma membrane order in rainbow trout liver.

The activation of genomic signaling in response to stressor-mediated cortisol elevation has been studied extensively in teleosts. However, very little is known about the rapid signaling events elicited by this steroid. We tested the hypothesis that cortisol modulates key stress-related signaling pathways in response to an acute stressor in fish liver.

Novel nongenomic signaling by glucocorticoid may involve changes to liver membrane order in rainbow trout.

Stress-induced glucocorticoid elevation is a highly conserved response among vertebrates. This facilitates stress adaptation and the mode of action involves activation of the intracellular glucocorticoid receptor leading to the modulation of target gene expression. However, this genomic effect is slow acting and, therefore, a role for glucocorticoid in the rapid response to stress is unclear.