Effects of ocean acidification and warming on apoptosis and immune response in the mussel Mytilus coruscus

Ocean acidification and warming are significant stressors impacting marine ecosystems, exerting profound effects on the physiological ecology of marine organisms. We investigated the impact of ocean acidification and warming on the immune system of mussels, focusing on the regulatory mechanisms of intrinsic and extrinsic apoptosis. The study explored the effects on the immune response ability of mussels (Mytilus coruscus) after 14 and 21 days under combined conditions of different temperatures (20 °C and 30 °C) and pH (8.1 and 7.7), as expected for the year 2100. The experimental results indicated that ocean acidification and warming have significant interactive effects on various immune parameters of M. coruscus. Specifically, ocean acidification and warming lead to an increase in ROS (Reactive Oxygen Species), apoptosis, TNF-α (Tumor Necrosis Factor-alpha), TGF-β (Transforming Growth Factor-beta), Caspase-8, and a decrease in IL-17 (Interleukin 17). These findings suggest that ocean acidification and warming trigger an immune inflammatory response in mussels. Regulating immune functions through apoptosis pathways may be a crucial coping mechanism in response to environmental variations, but its long-term impact on population health and sustainability remains uncertain. Our findings offer important insights into the complex interactions between bivalve immune responses and environmental stressors. This also underscores the need for further research into the adaptive capabilities of marine organisms facing the compounded challenges of ocean acidification and warming.