Polystyrene microplastic exposure disturbs hepatic glycolipid metabolism at the physiological, biochemical, and transcriptomic levels in adult zebrafish

Microplastics (MPs), which are new types of environmental pollutants, have recently received widespread attention worldwide. MPs can accumulate in the bodies of animals and in plants, and they can also enter the human body through the food chain. However, knowledge of the effects of MPs on the health of animals is still limited. In this experiment, adult male zebrafish were exposed to 20 or 100 μg/L of 5 μm polystyrene MP for 21 days in an attempt to determine the hepatic effects related to glycolipid metabolism at the biochemical and transcriptomic levels. It was found that body weight and condition factor decreased significantly in zebrafish after exposure to 20 and 100 μg/L polystyrene MP for 21 days. The transcription levels of major genes related to glycolipid metabolism decreased significantly in the liver. Correspondingly, the levels of major biochemical parameters, including Glu, pyruvic acid, α-ketoglutaric acid and IDH, were also decreased in the livers of exposed zebrafish, especially those in the 100 μg/L polystyrene MP-treated group. Moreover, the data on the hepatic transcriptome also confirmed that some genes related to fatty acid metabolism, amino acid metabolism and carbon metabolism tended to be decreased in the livers of exposed zebrafish. Taken together, our data confirmed that polystyrene PS-MP can induce hepatic glycolipid metabolism disorder at the physiological, biochemical, and transcriptomic levels in adult zebrafish after 21 days of exposure.