Concomitant exposure to benzo[a]pyrene and triclosan at environmentally relevant concentrations induces metabolic syndrome with multigenerational consequences in Silurana (Xenopus) tropicalis

Marie Usal (1) , Christophe Regnault (1) , Sylvie Veyrenc (1) , Karine Couturier (2) , Cécile Batandier (2) , Anne-Laure Bulteau (3) , David Lejon (4) , Bruno Combourieu (4) , Thomas Lafond (5) , Muriel Raveton (1) , Stéphane Reynaud (1)

1 LECA - Laboratoire d'Ecologie Alpine
2 LBFA - Laboratory of Fundamental and Applied Bioenergetics = Laboratoire de bioénergétique fondamentale et appliquée
3 IGFL - Institut de Génomique Fonctionnelle de Lyon
4 Fondation de Coopération Scientifique ROVALTAIN
5 Centre de Ressources Biologiques Xénopes

Numerous studies suggest that amphibians are highly sensitive to endocrine disruptors (ED) but their precise role in population decline remains unknown. This study shows that frogs exposed to a mixture of ED throughout their life cycle, at environmentally relevant concentrations, developed an unexpected metabolic syndrome. Female Silurana (Xenopus) tropicalis exposed to a mixture of benzo[a]pyrene and triclosan (50 ng·L-1 each) from the tadpole stage developed liver steatosis and transcriptomic signature associated with glucose intolerance syndrome, and pancreatic insulin hyper secretion typical of pre-diabetes. These metabolic disorders were associated with delayed metamorphosis and developmental mortality in their progeny, both of which have been linked to reduced adult recruitment and reproductive success. Indeed, F1 females were smaller and lighter and presented reduced reproductive capacities, demonstrating a reduced fitness of ED-exposed Xenopus. Our results confirm that amphibians are highly sensitive to ED even at concentrations considered to be safe for other animals. This study demonstrates that ED might be considered as direct contributing factors to amphibian population decline, due to their disruption of energetic metabolism.

Keywords: endocrine disruptors; metabolic syndrome; amphibian population decline; transgenerational; Silurana (Xenopus) tropicalis

Domains: Life Sciences [q-bio]; Toxicology; Ecotoxicology; Environmental Sciences

Marie Usal, Christophe Regnault, Sylvie Veyrenc, Karine Couturier, Cécile Batandier, et al.. Concomitant exposure to benzo[a]pyrene and triclosan at environmentally relevant concentrations induces metabolic syndrome with multigenerational consequences in Silurana (Xenopus) tropicalis. Science of the Total Environment, 2019, 689, pp.149-159. ⟨10.1016/j.scitotenv.2019.06.386⟩. ⟨hal-02466552⟩