Using zebrafish as a model to assess the individual and combined effects of sub-lethal waterborne and dietary zinc exposure during development. (1st September 2021)

• Record Type: Journal Article
• Authors: Puar, Pankaj; Naderi, Mohammad; Niyogi, Som; Kwong, Raymond W.M.
• Is Part Of: Environmental pollution. Volume 284(2021)
• Publication Date: 2021-09-01
• Subjects: Metal regulation -- Zinc -- ZIP -- Developing fish -- Zebrafish; Pollution -- Periodicals; Pollution -- Environmental aspects -- Periodicals; Environmental Pollution -- Periodicals; Pollution -- Périodiques; Pollution -- Aspect de l'environnement -- Périodiques; Pollution -- Effets physiologiques -- Périodiques; Pollution; Pollution -- Environmental aspects; Periodicals; Electronic journals; 363.73
• DOI: 10.1016/j.envpol.2021.117377
• Languages: English
• ISSNs: 0269-7491

Abstract

Abstract: The present research used zebrafish (5–28 days post-fertilization; dpf) as a model organism to investigate the effects of chronic exposure to environmentally relevant sub-lethal concentrations of waterborne (261 μg/L) and dietary zinc (Zn) (1500 mg Zn/kg dw), either independently or simultaneously, during development. The results showed that whole body contents of Zn were increased in all Zn treatment groups, with the highest accumulation of Zn observed in larvae simultaneously exposed to elevated waterborne and dietary Zn. In addition, exposure to elevated levels of Zn, either through the water or the diet, led to a decrease in whole body calcium (Ca) contents at 28 dpf. The findings also suggested that exposure to elevated levels of Zn resulted in a significant reduction in whole body manganese (Mn) contents. More importantly, the magnitude of decrease in Mn contents by Zn exposure was markedly higher than that in Ca and appeared to mirror the increases in whole body Zn accumulation. These results indicate that Mn regulation is more sensitive than Ca to disruption by Zn exposure in developing fish. Further examination of the Zrt-Irt-Like Protein (ZIP) family of transporters using droplet digital PCR technologies revealed that several zip transporters exhibited temporal and exposure route-specific changes following Zn exposure. In particular, the level of zip4 was influenced by Zn exposure regardless of the exposure routes, while changes in zip7 and zip8 levels were predominantly driven by waterborne exposure. Overall, our findings demonstrated that zebrafish during the developmental periods are sensitive to elevated levels of Zn seen in the environment, particularly following co-exposures to waterborne and dietary Zn. Future toxicological assessment of elevated Zn exposure should consider both the exposure routes and the life stages of fish. Graphical abstract: Image 1 Highlights: Developing fish are sensitive to both waterborne and dietary Zn exposure. Co-exposure via both routes results in the highest mortality. Homeostasis of Ca and Mn are disrupted by Zn exposure. Several Zn transporters exhibit exposure-route specific changes by Zn exposure. Abstract : Larval fish are susceptible to the effects of dietary zinc exposure, particularly when they are also co-exposed to waterborne zinc, leading to Ca and Mn dysregulation.