Proteomics in aquatic amphipods: Can it be used to determine mechanisms of toxicity and interspecies responses after exposure to atrazine?

Abstract

Proteomics has gained popularity in the field of ecotoxicology as a holistic tool for unraveling novel mechanisms of toxicity and elucidating subtle effects of contaminant exposure. The holoarctic amphipod Diporeia spp. is declining at precipitous rates in the Great Lakes, and we are evaluating the use of the well-studied amphipod model Hyalella azteca as a surrogate for Diporeia spp. This article presents proteomics data from both amphipod species exposed to atrazine (ATZ) and one of its metabolites, desethylatrazine (DEA; 3 and 30 µg/L for 21 and 42 d). We used a proteomics approach to determine whether these two species of amphipods responded similarly to the same chemicals and to understand better the mechanisms of toxicity of ATZ and DEA in aquatic invertebrates. We observed disruption in energy production and mitochondrial function as well as hormesis in exposed organisms. In addition, we identified a two proteins (GAPDH and HSP 90 kDa) that have been linked to hormonal disruptions, suggesting potential endocrine disruption. Finally, we found that H. azteca and Diporeia spp. responded with similar proteomic profiles after ATZ and DEA exposure, suggesting that H. azteca may be used as a surrogate model organism for Diporeia spp.

Review of the reproductive biology of amphipods and their endocrine regulation: Identification of mechanistic pathways for reproductive toxicants

“…To date, the proteomic studies with aquatic invertebrates that have not been sequenced have identified on average only 15 proteins, highlighting the problem with matching amino acid sequences across species [134]. Recently, a few studies have appeared using proteomics in ecotoxicological research on crustacean species with nonsequenced genomes, including three amphipod species [135][136][137]. Leroy et al [135] detected more than 560 protein spots on two-dimensional polyacrylamide gel electrophoresis and found a total of 21 proteins exhibiting significant expression differences in G. pulex exposed to two polychlorinated biphenyl congeners, with 14 of these proteins identified by mass spectrometry.…”

“…In a study comparing the brains of two amphipod species, G. pulex and G. insensibilis, infected with parasites using proteomic tools, Ponton et al [136] detected over 500 protein spots in each species using image analysis software and identified over 30 proteins. Ralston-Hooper et al [137] reported on the use of proteomics in an interspecies comparison and demonstrated that the amphipods H. azteca and Diporeia spp. responded with similar proteomic profiles when exposed to atrazine and its metabolite desethylatrazine.…”

Screening differentially expressed genes in an amphipod (Hyalella azteca) exposed to fungicide vinclozolin by suppression subtractive hybridization

“…Some have investigated the effect of polychlorinated biphenyls (PCBs) on Gammarus pulex and atrazine on H. azteca by proteomics. [22,11] The exposure of G. pulex to PCBs may affect the metabolism of carbohydrates, energy, amino acids and nucleotides. [22] Besides this, energy metabolism was affected in H. azteca exposed to atrazine.…”

“…Examples are G. pulex collected in rivers contaminated with polychlorinated biphenyl, polycyclic aromatic hydrocarbon and other pollutants, H. azteca exposure in atrazine and G. pulex exposure in PCBs. [11,22,23] The heatshock protein may be induced by exposure to atrazine, a known endocrine disruptor. Moreover, hormetic responses may be due to an induction of heatshock proteins or other changes at the molecular level that may stimulate growth.…”

“…[10] Furthermore, knowledge of the reproductive physiology of H. azteca is adequate, and both acute and chronic effects have been studied for many environmental contaminants. [11] In recent years, most studies of reproduction in aquatic species have focused on endocrine disruptor chemicals with estrogenic action. [12] Comparatively little is known about chemicals that might interact with androgens because the functions of androgen receptors are largely unknown.…”