'In vivo' effects of Bisphenol A in Mytilus hemocytes: modulation of kinase-mediated signalling pathways.
Endocrine disrupting chemicals (EDCs) include a variety of natural and synthetic estrogens, as well as estrogen-mimicking chemicals. We have previously shown that in the hemocytes of the mussel Mytilus galloprovincialis Lam. both natural and environmental estrogens in vitro can rapidly affect the phosphorylation state of components of tyrosine kinase-mediated cell signalling, in particular of mitogen activated protein kinases (MAPKs) and signal transducers and activators of transcription (STAT), that are involved in mediating the hemocyte immune response. These effects were consistent with the hypothesis that 'alternative' modes of estrogen action involving kinase-mediated pathways similar to those described in mammalian systems are also present in invertebrate cells. This possibility was investigated in vivo with Bisphenol A (BPA): mussels were injected with BPA and hemocytes sampled at 6, 12, and 24 h post-injection. The results show that BPA (25 nM nominal concentration in the hemolymph) lead to a significant lysosomal membrane destabilisation at all times post-injection, indicating BPA-induced stress conditions in the hemocytes, whereas lower concentrations were ineffective. BPA induced significant changes in the phosphorylation state of MAPK and STAT members, as evaluated by SDS-PAGE and WB of hemocyte protein extracts with specific antibodies, although to a different degree at different exposure times. In particular, BPA induced a dramatic decrease in phosphorylation of the stress-activated p38 MAPK, whose activation is crucial in mediating the bactericidal activity. Moreover, BPA decreased the phosphorylation of a CREB-like transcription factor (cAMP-responsive element binding protein). The results demonstrate that BPA can affect kinase-mediated cell signalling in mussel hemocytes also in vivo, and suggest that EDCs may affect gene expression in mussel cells through modulation of the activity of transcription factors secondary to cytosolic kinase cascades. Overall, these data address the importance of investigating full range responses to EDCs in ecologically relevant marine invertebrate species.
Canesi
Laura
L
Istituto di Scienze Fisiologiche, Università di Urbino Carlo Bo, Loc. Crocicchia, 61029 Urbino PU, Italy. canesi@uniurb.it
Betti
Michele
M
Lorusso
Lucia Cecilia
LC
Ciacci
Caterina
C
Gallo
Gabriella
G
D051697:Activating Transcription Factor 1; D000818:Animals; D001559:Benzhydryl Compounds; D049872:Bivalvia / Q000187:drug effects* / Q000378:metabolism; D015153:Blotting, Western; D004268:DNA-Binding Proteins / Q000378:metabolism; D004591:Electrophoresis, Polyacrylamide Gel; D004968:Estrogens, Non-Steroidal / Q000633:toxicity*; D048049:Extracellular Signal-Regulated MAP Kinases / Q000378:metabolism; D006434:Hemocytes / Q000187:drug effects / Q000201:enzymology / Q000378:metabolism; D008247:Lysosomes / Q000187:drug effects / Q000378:metabolism; D020935:MAP Kinase Signaling System / Q000187:drug effects*; D008894:Milk Proteins / Q000378:metabolism; D010636:Phenols / Q000633:toxicity*; D010766:Phosphorylation / Q000187:drug effects; D050796:STAT3 Transcription Factor; D050799:STAT5 Transcription Factor; D015534:Trans-Activators / Q000378:metabolism; D014157:Transcription Factors / Q000378:metabolism; D048051:p38 Mitogen-Activated Protein Kinases / Q000378:metabolism; D000098826:Bisphenol A Compounds
D051697:Activating Transcription Factor 1; D001559:Benzhydryl Compounds; D004268:DNA-Binding Proteins; D004968:Estrogens, Non-Steroidal; D048049:Extracellular Signal-Regulated MAP Kinases; D008894:Milk Proteins; D010636:Phenols; D050796:STAT3 Transcription Factor; D050799:STAT5 Transcription Factor; D015534:Trans-Activators; D014157:Transcription Factors; D048051:p38 Mitogen-Activated Protein Kinases; C006780:bisphenol A; D000098826:Bisphenol A Compounds