title: Oxidative stress parameters induced by exposure to either cadmium or 17β-estradiol on Mytilus galloprovincialis hemocytes. The role of signaling molecules.
abstract: The aim of the present study was to determine and compare the possible effects of exposure to an estrogen, 17β-estradiol and to a metal, cadmium on oxidative parameters of Mytilus galloprovincialis hemocytes and to elucidate the signaling pathways that probably mediate the studied effects exerted by these two chemicals. In addition, it was of interest to investigate if the studied parameters could constitute biomarkers for aquatic pollution monitoring. Our results suggest that micromolar concentrations of either cadmium or 17β-estradiol affected the redox status of mussels by modulating oxidative parameters and antioxidant enzymes gene expression in mussel M. galloprovincialis hemocytes. In particular, our results showed that treatment of hemocytes with either 5 μM of cadmium chloride or with 25 nM of 17β-estradiol for 30 min caused significant increased ROS production; this led to oxidative damage exemplified by significant increased DNA damage, protein carbonylation and lipid peroxidation, as well as increased mRNA levels of the antioxidant enzymes catalase (CAT), superoxide dismoutase (SOD) and glutathione S-transferase (GST). Furthermore, our results suggest that either cadmium or 17β-estradiol signal is mediated either through one of the already known pathways initiated by photatidyl-inositol 3-kinase (PI3K) and reaching Na(+)/H(+) exchanger (NHE) probably through protein kinase C (PKC) or a kinase-mediated signaling pathway that involves in most of the cases NHE, PKC, Ca(2+)-dependent PKC isoforms, PI3-K, NADPH oxidase, nitric oxide (NO) synthase, c-Jun N-terminal kinase (JNK) and cyclic adenosine-3'-5'-monophosphate (cAMP). Our results also attribute a protective role to cAMP, since pre-elevated intracellular cAMP levels inhibited the signal induced by each exposure. Finally, since aquatic invertebrates have been the most widely used monitoring organisms for pollution impact evaluation in marine environments and taking under consideration the positive correlation obtained between the studied parameters, we can suggest the simultaneous use of these oxidative stress parameters offering an effective early warning system in biomonitoring of aquatic environments.
authors: Laboratory of Animal Physiology, Zoology Department, School of Biology, Faculty of Science, Aristotle University of Thessaloniki, 54124 Thessaloniki, Greece.
authors: Sophia
authors: S
authors: Koutsogiannaki
authors: University of Bologna, Interdepartment Centre for Environmental Science Research, via S. Alberto 163, 48123 Ravenna, Italy.
authors: Silvia
authors: S
authors: Franzellitti
authors: University of Bologna, Interdepartment Centre for Environmental Science Research, via S. Alberto 163, 48123 Ravenna, Italy; University of Bologna, Department of Biological, Geological, and Environmental Sciences, via Selmi 3, 40100 Bologna, Italy.
authors: Elena
authors: E
authors: Fabbri
authors: Laboratory of Animal Physiology, Zoology Department, School of Biology, Faculty of Science, Aristotle University of Thessaloniki, 54124 Thessaloniki, Greece. Electronic address: kaloyian@bio.auth.gr.
authors: Martha
authors: M
authors: Kaloyianni
mesh_terms: D000818:Animals; D002104:Cadmium / Q000633:toxicity*; D000242:Cyclic AMP / Q000378:metabolism; D004249:DNA Damage / Q000187:drug effects; D004798:Enzymes / Q000235:genetics / Q000378:metabolism; D004958:Estradiol / Q000633:toxicity*; D015971:Gene Expression Regulation, Enzymologic / Q000187:drug effects; D006434:Hemocytes / Q000187:drug effects; D015227:Lipid Peroxidation / Q000187:drug effects; D049878:Mytilus / Q000187:drug effects*; D018384:Oxidative Stress / Q000187:drug effects*; D050050:Protein Carbonylation / Q000187:drug effects; D017382:Reactive Oxygen Species / Q000378:metabolism; D015398:Signal Transduction / Q000187:drug effects*; D014874:Water Pollutants, Chemical / Q000633:toxicity*
chemical_list: D004798:Enzymes; D017382:Reactive Oxygen Species; D014874:Water Pollutants, Chemical; D002104:Cadmium; D004958:Estradiol; D000242:Cyclic AMP
keywords: Biomarkers; DNA damage; Mytilus galloprovincialis; Protein carbonylation; ROS production; mRNA expression