Unveiling the mechanisms of oxidative stress-mediated multi-pathway programmed cell death in Ruditapes philippinarum...

Synthetic phenolic antioxidants (SPAs), as representative emerging contaminants, have been widely detected across various environmental media and organisms, raising significant ecological and health concerns. However, the toxicological effects and underlying molecular mechanisms of SPAs in marine organisms remain poorly understood. By integrating transcriptomics, in silico simulations, and experimental validation, this study elucidates the "oxidative stress-macromolecular damage-cell death" mechanism in the Ruditapes philippinarum under BHT stress. Our results demonstrate that BHT exposure triggers significant ROS accumulation in the digestive glands. A time-dependent response was observed: an initial induction of antioxidant defenses (0-6 d) was followed by a late-stage (12-21 d) suppression of the NRF2-mediated pathway, culminating in compromised antioxidant capacity and severe macromolecular damage. Mechanistically, BHT-induced ROS disrupts the calcium pump, causing Ca^2 + homeostasis imbalance and triggering the ER-mitochondria stress axis, which ultimately initiates apoptosis. Furthermore, BHT impairs iron homeostasis, causing Fe²⁺ overload, which drives ALOX5-mediated lipid peroxidation and may ultimately lead to ferroptosis. Simultaneously, activation of the NLRP3-CASPASE1 signaling cascade may also trigger pyroptosis. Collectively, this study provides comprehensive evidence of how BHT orchestrates oxidative stress-mediated multi-pathway programmed cell death (PCD) in aquatic invertebrates, offering crucial scientific insights for the ecological risk assessment of SPA pollution in marine ecosystems.