Evaluating bivalve cytoprotective responses and their regulatory pathways in a climate change scenario

• Published in: The Science of the total environment Vol. 720; p. 137733
• Main Authors: Franzellitti, Silvia, Prada, Fiorella, Viarengo, Aldo, Fabbri, Elena
• Format: Journal Article
• Language: English
• Published: Netherlands Elsevier B.V 10.06.2020
• Subjects: Antibiotic; Marine mussel; Metal; Stress response; Temperature; Transcriptional control; Marine mussel; Temperature; Antibiotic; Metal; Stress response; Transcriptional control
• ISSN: 0048-9697; 1879-1026
• DOI: 10.1016/j.scitotenv.2020.137733

Temperature is a relevant abiotic factor affecting physiological performance and distribution of marine animals in natural environments. The changes in global seawater temperatures make it necessary to understand how molecular mechanisms operate under the cumulative effects of global climate change and chemical pollution to promote/hamper environmental acclimatization. Marine mussels are excellent model organisms to infer the impacts of those anthropogenic threats on coastal ecosystems. In this study, Mediterranean mussels (Mytilus galloprovincialis) were exposed to different concentrations of the metal copper (Cu as CuCl2: 2.5, 5, 10, 20, 40 μg/L) or the antibiotic oxytetracycline (OTC: 0.1, 1, 10, 100, 1000 μg/L) at increasing seawater temperatures (16 °C, 20 °C, 24 °C). Transcriptional modulation of a 70-kDa heat shock protein (HSP70) and of the ABC transporter P-glycoprotein (P-gp, encoded by the ABCB gene) was assessed along with the cAMP/PKA signaling pathway regulating both gene expressions. At the physiological temperature of mussels (16 °C), Cu and OTC induced bimodal changes of cAMP levels and PKA activities in gills of exposed animals. A correlation between OTC- or Cu- induced changes of PKA activity and expression of hsp70 and ABCB was observed. Temperature increases (up to 24 °C) altered ABCB and hsp70 responses to the pollutants and disrupted their relationship with cAMP/PKA modulation, leading to loss of correlation between the biological endpoints. On the whole, the results indicate that temperature may impair the effects of inorganic and organic chemicals on the cAMP/PKA signaling pathway of mussels, in turn altering key molecular mediators of physiological plasticity and cytoprotection. [Display omitted] •Marine mussels were exposed to copper (Cu) or oxytetracycline (OTC) at increasing temperatures.•Heat shock proteins (hsp70) and P-glycoprotein (ABCB) transcription were assessed.•The cAMP/PKA signaling regulating both gene expressions was assessed.•At 16 °C, Cu/OTC induced changes of ABCB/hsp70 correlated with PKA activities.•Temperature (up to 24 °C) disrupted ABCB/hsp70 relationship with cAMP/PKA modulation.