Cellular and molecular responses of adult zebrafish after exposure to CuO nanoparticles or ionic copper

Abstract

Due to their antimicrobial, electrical and magnetic properties, copper nanoparticles (NPs) are suitable for a vast array of applications. Copper can be toxic to biota, making it necessary to assess the potential hazard of copper nanomaterials. Zebrafish (Danio rerio) were exposed to 10 µg Cu/L of CuO NPs of ≈100 nm (CuO-poly) or ionic copper to compare the effects provoked after 3 and 21 days of exposure and at 6 months post-exposure (mpe). At 21 days, significant copper accumulation was only detected in fish exposed to ionic copper. Exposure to both copper forms caused histopathological alterations that could reduce gill functionality, more markedly in the case of ionic copper. Nevertheless, at 6 mpe higher prevalences of gill lesions were detected in fish previously exposed to CuO-poly NPs. No relevant histological alterations were detected in liver, but the lysosomal membrane stability test showed significantly impaired general health status after exposure to both metal forms that lasted up to 6 mpe. 69 transcripts appeared regulated after 3 days of exposure to CuO-poly NPs, suggesting that NPs could produce oxidative stress and reduce metabolism and transport processes. Thirty transcripts were regulated after 21 days of exposure to ionic copper, indicating possible DNA damage. Genes of the circadian clock were identified as the key genes involved in time-dependent differences between the two copper forms. In conclusion, each copper form showed a distinct pattern of liver transcriptome regulation, but both caused gill histopathological alterations and long lasting impaired health status in adult zebrafish.

Mechanisms of toxic action of copper and copper nanoparticles in two Amazon fish species: Dwarf cichlid (Apistogramma agassizii) and cardinal tetra (Paracheirodon axelrodi)

“…The main histopathological alterations in the gill tissue of the dwarf cichids were lamellar epithelium lifting, hyperplasia, and hypertrophy, which were more frequent in the nCuO treatment. Similar branchial damage has been observed in rainbow trout and zebrafish after exposure to nCuO (Al-Bairuty et al, 2013;Vicario-Parés et al, 2018). Additionally, SEM images revealed some particles in the surface of the gill epithelium only in the treatment with nCuO, which may be assumed to be nanoparticle aggregations (Fig.…”

Toxicities of copper oxide nanomaterial and copper sulphate in early life stage zebrafish: Effects of pH and intermittent pulse exposure

“…The attachment of CuO ENMs to the chorion of zebrafish embryos has been demonstrated by microscopy (Böhme et al, 2017). Copper oxide ENMs have also recently been shown not to accumulate in adult zebrafish (Vicario-Parés et al, 2018). Secondly, the present study also showed greater sub-lethal effects of early exposure to CuO ENMs than CuSO 4 .…”

Interaction of Copper-Based Nanoparticles to Soil, Terrestrial, and Aquatic Systems: Critical Review of the State of the Science and Future Perspectives

“…On the other hand, cellular and molecular responses of adult zebrafish after exposure to CuO-NPs or ionic Cu were tested by Vicario-Pares et al (2018). Another study performed by Bai et al (2010) was undertaken to test the toxicity of nano-Cu suspension to zebrafish embryos.…”