Toxic effects of nanoplastics and microcystin-LR coexposure on the liver-gut axis of Hypophthalmichthys molitrix

• Published in: The Science of the total environment 2024-03, Vol.916, p.170011-170011, Article 170011
• Main Authors: Zhang, Chaonan, Bao, Feifan, Wang, Fei, Xue, Zhihao, Lin, Daohui
• Format: Article
• Language: English
• Subjects: Hypophthalmichthys molitrix; Intestinal microorganism; Metabolome; Microcystin-LR; Nanoplastics
• ISSN: 0048-9697; 1879-1026
• DOI: 10.1016/j.scitotenv.2024.170011

Plastic products and nutrients are widely used in aquaculture facilities, resulting in copresence of nanoplastics (NPs) released from plastics and microcystins (MCs) from toxic cyanobacteria. The potential effects of NPs-MCs coexposure on aquatic products require investigation. This study investigated the toxic effects of polystyrene (PS) NPs and MC-LR on the gut-liver axis of silver carp Hypophthalmichthys molitrix, a representative commercial fish, and explored the effects of the coexposure on intestinal microorganism structure and liver metabolic function using traditional toxicology and multi-omics association analysis. The results showed that the PS-NPs and MC-LR coexposure significantly shortened villi length, and the higher the concentration of PS-NPs, the more obvious the villi shortening. The coexposure of high concentrations of PS-NPs and MC-LR increased the hepatocyte space in fish, and caused obvious loss of gill filaments. The diversity and richness of the fish gut microbes significantly increased after the PS-NPs exposure, and this trend was amplified in the copresence of MC-LR. In the coexposure, MC-LR contributed more to the alteration of fish liver metabolism, which affected the enrichment pathway in glycerophospholipid metabolism and folic acid biosynthesis, and there was a correlation between the differential glycerophospholipid metabolites and affected bacteria. These results suggested that the toxic mechanism of PS-NPs and MC-LR coexposure may be pathological changes of the liver, gut, and gill tissues, intestinal microbiota disturbance, and glycerophospholipid metabolism imbalance. The findings not only improve the understanding of environmental risks of NPs combined with other pollutants, but also provide potential microbiota and glycerophospholipid biomarkers in silver carp. [Display omitted] •PS-NPs and MC-LR coexposure caused pathological damages of silver carp liver, gut, and gill.•The coexposure aggravated the changes in intestinal microbial community structure.•The coexposure triggered metabolic pattern variation of the fish liver.•There was a correlation between the affected liver metabolites and intestinal microbes.