Cadmium effects on DNA and protein metabolism in oyster (Crassostrea gigas) revealed by proteomic analyses

Abstract

Marine molluscs, including oysters, can concentrate high levels of cadmium (Cd) in their soft tissues, but the molecular mechanisms of Cd toxicity remain speculative. In this study, Pacific oysters (Crassostrea gigas) were exposed to Cd for 9 days and their gills were subjected to proteomic analysis, which were further confirmed with transcriptomic analysis. A total of 4,964 proteins was quantified and 515 differentially expressed proteins were identified in response to Cd exposure. Gene Ontology enrichment analysis revealed that excess Cd affected the DNA and protein metabolism. Specifically, Cd toxicity resulted in the inhibition of DNA glycosylase and gap-filling and ligation enzymes expressions in base excision repair pathway, which may have decreased DNA repair capacity. At the protein level, Cd induced the heat shock protein response, initiation of protein refolding as well as degradation by ubiquitin proteasome pathway, among other effects. Excess Cd also induced antioxidant responses, particularly glutathione metabolism, which play important roles in Cd chelation and anti-oxidation. This study provided the first molecular mechanisms of Cd toxicity on DNA and protein metabolism at protein levels, and identified molecular biomarkers for Cd toxicity in oysters.

A “Population Dynamics” Perspective on the Delayed Life-History Effects of Environmental Contaminations: An Illustration with a Preliminary Study of Cadmium Transgenerational Effects over Three Generations in the Crustacean Gammarus

“…The fertilization success of F0 was also not affected, as already observed in other invertebrates with similar Cd concentrations [49,50] or in fish [51,52]. In addition, a lack of DNA machinery repair in crustacean sperm cells has been suggested in different studies [37,53] and genotoxic effects of Cd on DNA machinery repair have been recorded [54][55][56][57].…”

Untargeted NMR-based metabolomics for field-scale monitoring: Temporal reproducibility and biomarker discovery in mosquitofish (Gambusia holbrooki) from a metal(loid)-contaminated wetland

“…Amino acids serve as the building blocks for proteins, so increased levels may reflect decreased protein biosynthesis, as has indeed been previously reported as a consequence of metal (loid) exposure (Kumar and Banerjee, 2016;Viarengo et al, 1980). Reductions in amino acids may be mechanistically linked with alterations to protein folding (Tamás et al, 2014) or repair capacity (Meng et al, 2017), or with alterations to the activity of various enzymes (Kumar and Banerjee, 2013;Mizrahi and Achituv, 1989). The latter is largely consistent with the overall trends observed in the present study, specifically in terms of a well-established relationship between metal(loid) exposure and increased aspartate amino-transferase (AST) enzymatic activity .…”

Transcriptome sequencing reveals genes involved in cadmium-triggered oxidative stress in the chicken heart

“…What is more, the myocardial ischemia-reperfusion (I/R) injury was alleviated by PGI2 via decreased oxidative stress ( Zhong et al., 2019 ), and heart protection by NGR1 was closely related to inhibition of oxidative stress ( Yu et al., 2016 ). It is reported that oxidative stress could be induced by ingestion of excessive Cd ( Meng et al., 2017 ), and oxidative stress was related to Cd-induced toxicity in both in vivo or in vitro studies ( Yu et al., 2008 ). Similarly, our results showed that the activation of major detoxification enzymes POD and SOD and the level of GSH were decreased in the Cd-induced chicken heart.…”