The influence of temperature rise on the metabolic response of Ruditapes philippinarum clams to 17-?-ethinylestradiol

Untargeted Nuclear Magnetic Resonance metabolomics was employed to study the effects of warming conditions (17-21 degrees C) and exposure to 17-alpha-ethinylestradiol (EE2) on the polar metabolome of Ruditapes philippinarum clams, to identify metabolic markers for monitoring/prediction of deviant environmental conditions. Warming alone trig-gered changes in alanine/aspartate/glutamate, aromatic amino acids, taurine/hypotaurine and homarine/trigonelline pathways, as well as in energy metabolism, suggesting osmoregulatory adaptations and glycolytic/tricarboxylic acid (TCA) cycle activation, possibly accompanied to some extent by gluconeogenesis to preserve glycogen reserves. At 17 degrees C, the lowest EE2 concentration (5 ng/L) specifically engaged branched-chain and aromatic amino acids to activate the glycolysis/TCA cycle. Notably, a partial metabolic recovery was observed at 25 ng/L, whereas higher EE2 concen-trations (125 and 625 ng/L) again induced significant metabolic disturbances. These included enhanced glycogen bio-synthesis and increased lipid reserves, sustained by low-level glutathione-based antioxidative mechanisms that seemed active. At 21 degrees C, response to EE2 was notably weak at low/intermediate concentrations, becoming particularly significant at the highest EE2 concentration (625 ng/L), suggesting higher protection capacity of Ruditapes philippinarum clams under warming conditions. At 625 ng/L, disturbances in alanine/aspartate/glutamate and tau-rine/hypotaurine metabolisms were observed, with no evidence of enhanced carbohydrate/protein catabolism. This low energy function profile was accompanied by marked antioxidative mechanisms and choline compounds modula-tion for cell membrane protection/repair. These results help monitor clams ' response to temperature rise and EE2 ex-posure, paving the way for future effective guidance and prediction of environmental damaging effects.

Automated summary

Untargeted Nuclear Magnetic Resonance metabolomics was used to study the effects of warming and exposure to EE2 on the metabolome of Ruditapes philippinarum clams. The results identified metabolic markers for monitoring and predicting deviant environmental conditions. Warming alone triggered changes in various metabolic pathways, while EE2 exposure caused significant metabolic disturbances. These findings help understand clams' response to temperature rise and EE2 exposure and can guide future prediction of environmental damaging effects.