New insights on the protection of endangered aquatic species: Embryotoxicity effects of 2,2',4,4'-tetrabromodiphenyl ether (BDE-47) via integrin-mediated oxidative stress and inflammatory pathways in Siberian sturgeon, Acipenser baerii.

Polybrominated diphenyl ethers (PBDEs), are emerging pollutants ubiquitous in the environment, posing a threat to aquatic ecosystems. This study investigates the toxicological effects of PBDEs on sturgeon embryos, focusing on BDE-47, a representative PBDEs homologues. Siberian sturgeon embryos were exposed to BDE-47, revealing significant reductions in hatching and survival rates and the occurrence of developmental abnormalities. Oxidative stress induction by BDE-47 was evidenced by increased antioxidant enzyme activities and the presence of oxidative damage biomarker MDA. Besides, transcriptome analysis unveiled the activation of integrin signaling pathways, with molecular docking indicating strong binding to integrin receptors (specifically ITG-α5, ITG-α8, and ITG-α11). Moreover, qPCR and correlation analysis showed that BDE-47 significantly upregulated inflammatory cytokines and keap1/nrf2 signaling through ITGs. Furthermore, cultivation of head kidney macrophages showed that ITGs antagonist Cilengitide significantly reversed the upregulation of the above factors induced by BDE-47, including nf-κb, il-6, tnf-α, gpx, and nrf2. These findings indicate that BDE-47 induced embryotoxicity in Siberian sturgeon, which was potentially via ITGs-mediated oxidative stress and inflammatory pathways. This study providing novel insights into the protein binding of BDE-47 in animals, contributes to understanding emerging pollutant toxicity in fish embryos and offering a new perspective for the improvement of hatchability and survival rate of cultured sturgeon embryos to guarantee the sustainable development of the sturgeon aquaculture industry, as well as providing evidence for wild sturgeon populations conservation and habitat restoration.