Proteomics reveals plasma profiles for monitoring the toxicity caused by chromium compounds

Background: Today, various heavy metals are widespread in the ecosystem and have become important environmental contaminants. Exposure to these hazardous metals such as chromium usually results in cytotoxicity and large-scale protein changes which reflect pathologic states. Methods: We used a comprehensive proteomic tool to survey changes in plasma proteins elicited by two chromium species (Cr⁶⁺ and Cr³⁺). RT-PCR was applied to evaluate levels of cytokines associated with adverse responses. Lectin blotting was used to investigate the contents of fucosylated proteins. Results: Protein profiles revealed statistically significant changes in the intensity of 12 proteins. The network analysis implied that Cr⁶⁺ application strongly induced the IL-6-stimulated inflammatory pathway. mRNA levels of specific cytokines were also correlated with inflammatory events. Increased IL-6 modulation of the fucosylation of haptoglobin was also identified in Cr⁶⁺-treated samples. Conclusions: These results suggest that Cr⁶⁺ may induce IL-6-mediated inflammatory responses which result in hepatic injury. This paper highlights the applications of functional proteomics of plasma profiles and fucosylated glycoproteins as a predictive tool to monitor human health in contact with chromium.