hsp70 AS New Cadmium Bioaccumulation Marker to prevent the risks of Mussels Consumption in Human Nutrition

The consumption of seafood has increased in recent years, especially in coastal regions. The consumption of mussels provides proteins, essential minerals and vitamins, and thus, some protection from certain diseases but the risks and benefits of their consumption are still hard to assess because of the metals bioaccumulated from the marine environment, with their toxicity. Mussels accumulate a wide range of metals, included cadmium, in their soft tissue. Cadmium is a heavy metal particularly hazardous for human health and is an important pollutant in estuarine and coastal environments. Thus, the determination of the concentrations of cadmium in mussels is essential because of their usage as seafood and the potential adverse effects of their consumption on human health. In order to identify a quick cadmium bioaccumulation marker usable in monitoring programs, we analyzed the metal content in Mytilus galloprovincialis gill tissues and its relationship with hsp70 expression levels after a laboratory exposure for 24 h to 1,5; 5 and 10 μM CdCl2 in artificial sea water. Inductively coupled plasma-mass spectrometry showed that cadmium content increased in gills tissues in an exposure dose-dependent fashion. RT-qPCR, showed that Cd exposure induced hsp70 increase resulting in 3,1;10 and 12 fold at 1,5; 5, 10 μM, respectively in comparison with unexposed mussels. Finally, hsp70 expression levels correlated with the amount of bioaccumulated cadmium in gill tissue, indicating hsp70 as a potential marker, even if not univocally, of significative cadmium bioaccumulation usable in environmental monitoring programs and for seafood safety.