Perfluorobutanesulfonate (PFBS) is a ubiquitous pollutant in the aquatic environment, but its toxic effects andmechanisms on amphibian species remain largely unknown. In the present study, tadpoles (Lithobates catesbe...Perfluorobutanesulfonate (PFBS) is a ubiquitous pollutant in the aquatic environment, but its toxic effects andmechanisms on amphibian species remain largely unknown. In the present study, tadpoles (Lithobates catesbeianus) were exposed to various concentrations of PFBS (0, 1, 3, 10, and 30 μg/L) for 14 days, with the goal ofunveiling the impairment of intestinal health. Histopathological examination showed that sub-lethal exposure oftadpoles to PFBS at concentrations as low as 3 μg/L could result in the injury of intestinal structures. In a clearconcentration-dependent manner, the expressions of epithelial barrier components (i.e., Claudin 1 gene and tightjunction protein 2) were significantly decreased in PFBS-exposed intestines, while the intestinal content oflipopolysaccharide (LPS) and transcriptions of downstream responsive genes (e.g., TLR4, MyD88, and NF-κB) wereconcurrently significantly increased by exposure to 3, 10, and 30 μg/L of PFBS. As a consequence, the number ofeosinophils and expression of pro-inflammatory cytokines (e.g., IL-1β and TNF-α) were increased therein.Furthermore, PFBS exposure induced oxidative stress in intestinal tissues by increasing the level of reactive oxygen species (ROS) and suppressing antioxidant capacity. The transcriptional levels of CytoC and Bax genes aswell as activities of caspase 9 and caspase 3 enzymes were remarkably increased, while the transcript abundanceof Bcl-2 was down-regulated significantly after PFBS exposure, thereby favoring apoptosis in tadpole intestines.PFBS sub-lethal exposure also drove the composition of intestinal microbiota to a dysbiosis status. Correlationanalysis further revealed that the relative abundance of members of the genus Bosea was positively related withthe contents of LPS and IL-1β. Overall, the present study provides the first evidence for pronounced impacts ofPFBS on amphibian intestinal ecology, highlighting the susceptibility of tadpoles to the environmental risks ofPFBS.展开更多
基金supported by the National Natural Science Foundation of China(No.31971236 and 32071498).
文摘Perfluorobutanesulfonate (PFBS) is a ubiquitous pollutant in the aquatic environment, but its toxic effects andmechanisms on amphibian species remain largely unknown. In the present study, tadpoles (Lithobates catesbeianus) were exposed to various concentrations of PFBS (0, 1, 3, 10, and 30 μg/L) for 14 days, with the goal ofunveiling the impairment of intestinal health. Histopathological examination showed that sub-lethal exposure oftadpoles to PFBS at concentrations as low as 3 μg/L could result in the injury of intestinal structures. In a clearconcentration-dependent manner, the expressions of epithelial barrier components (i.e., Claudin 1 gene and tightjunction protein 2) were significantly decreased in PFBS-exposed intestines, while the intestinal content oflipopolysaccharide (LPS) and transcriptions of downstream responsive genes (e.g., TLR4, MyD88, and NF-κB) wereconcurrently significantly increased by exposure to 3, 10, and 30 μg/L of PFBS. As a consequence, the number ofeosinophils and expression of pro-inflammatory cytokines (e.g., IL-1β and TNF-α) were increased therein.Furthermore, PFBS exposure induced oxidative stress in intestinal tissues by increasing the level of reactive oxygen species (ROS) and suppressing antioxidant capacity. The transcriptional levels of CytoC and Bax genes aswell as activities of caspase 9 and caspase 3 enzymes were remarkably increased, while the transcript abundanceof Bcl-2 was down-regulated significantly after PFBS exposure, thereby favoring apoptosis in tadpole intestines.PFBS sub-lethal exposure also drove the composition of intestinal microbiota to a dysbiosis status. Correlationanalysis further revealed that the relative abundance of members of the genus Bosea was positively related withthe contents of LPS and IL-1β. Overall, the present study provides the first evidence for pronounced impacts ofPFBS on amphibian intestinal ecology, highlighting the susceptibility of tadpoles to the environmental risks ofPFBS.
