Perfluorooctanoic acid (PFOA) disrupts cardiac performance of thick-shell mussel by inserting into the binding pocket of proliferator-activated receptor gamma and thereby causing lipid metabolism disorders

Invertebrates constitute the largest group of animals on Earth, accounting for approximately 97 % of all animal species. Although the heart of invertebrates could be a sensitive target for environmental pollution, potential cardiotoxicity for most contaminants has received little attention. In this study, perfluorooctanoic acid (PFOA) and thick-shell mussels ( Mytilus coruscus ) were used to investigate the effect of PFOA on cardiac performance and the potential underlying mechanisms. Heart beat monitoring demonstrated that four-week exposure to 0.5 and 5.0 μg/L of PFOA resulted in bradycardia and arrhythmia in thick-shell mussels. Moreover, considerably more triglyceride (TG) accumulation, higher lipoprotein lipase (LPL) and lipase (LPS) activities, and disruption of lipid metabolism-related genes were observed in the hearts of PFOA-exposed mussels. In addition, comparable adverse impacts were detected in mussels treated with proliferator-activated receptor gamma (PPARγ) agonist whereas the PFOA-induced effects were fully or partially alleviated by PPARγ antagonist. Furthermore, molecular docking and molecular dynamics simulation revealed a high binding affinity of PFOA to the PPARγ of 12 invertebrates, including thick-shell mussels. In general, our data suggest that PFOA may pose a severe threat to cardiac performance of invertebrate species by inserting into the binding pocket of PPARγ, and thereby causing cardiac lipid metabolism disorders.