Chemicals, Toxicity Assessment, Human Health, and Zebrafish

Kitae Kim

Department of Environmental Engineering, Seoul National University of Science and Technology

The embryonic zebrafish model has emerged as the best choice for a rapid and efficient in vivo animal toxicity testing, offering marked advantages over developmental rodent model in quicker identification of the toxicity mechanism. A fast track to identifying developmental toxicity mechanisms is possible using zebrafish because an induced phenotype, whether morphological, physicological or behavioral, can quickly be dissected using molecular approaches. Zebrafish are resource-efficient due to their small size, high fecundity and relative inexpensive husbandry. The versatility of the zebrafish model is further bolstered by the availability of many mutant lines, diverse and robust transgenic lines, the simplicity of performing transient antisense RNA knockdowns, and the applicability to next generation sequencing technologies like RNA-seq. The near complete annotation of the genome has enabled the integration of zebrafish toxicology, genomics and toxicogenomics. As a consequence of these advantages, toxicity mechanisms of nanoparticles (NPs) can be pursed more systematically in zebrafish than any other vertebrate model. Only small quantities of NPs are required for developmental exposure of zebrafish, a big advantage for compounds under development, for which sample quantity available for testing may be limited to only a few milligrams. Research investigating how NPs affect zebrafish development is more translatable to human biological an in vitro approaches. This study addresses how the experimental power and flexibility of embryonic zebrafish model are utilized to solve unclear toxicity mechanisms of silver and gold NPs. We investigated size- and surface-coating dependent toxicity of silver NPs and that how gold NPs disrupt the progression of eye development and pigmentation that continues to behavioral and neuronal damage in the developing zebrafish. Additionally, we provided the new insight on how the quality of NP synthesis and characterization significantly contribute to the nanotoxicology field by demonstrating subtle differences in NP surface ligands drive biological compatibility of gold NPs. Lastly, zebrafish have been utilized as promising human disease model to identify biomarker, pathway, and therapy. We introduced the current project that demonstrates diabetes incidence by POPs(persistent organic pollutants) exposure using zebrafish model.