| Ökotoxizitätsauszüge | /AQUATIC SPECIES/ Benzotriazole (BT) and its associated derivatives are used ubiquitously in industrial processes, and can be detected in indoor temperature coolants and in chemicals designed to inhibit corrosion. This chemical has been widely detected in aquatic environments and shows some degree of environmental persistence. Evidence has shown that BT exposure can negatively affect endocrine systems and can result in neurotoxicity in fish. However, no study has examined whether this chemical exhibits hepatotoxicity in fish, and if so, what are the underlying mechanism associated with the damage. To address this knowledge gap, we measured the liver proteome of adult male Chinese rare minnow (Gobiocypris rarus) exposed to either 0.05, 0.5, or 5 mg/L BT for 28 days. Overall, 17 proteins were induced and 9 were reduced in abundance following BT treatment (ratio > 1.5, p < 0.05). Pathway analysis revealed that cellular processes affected by BT included xenobiotic clearance, oxidative stress response, apoptosis, and translation. Moreover, transcripts related to these toxic pathways were also significantly affected by BT. In addition, rare minnows exposed to BT showed signs of hypertrophy of hepatocytes, nuclei pyknosis, and higher levels of cellular vacuolization compared to the controls, thus these early proteomic responses in the liver may be related to pathology (i.e. adverse outcome pathway). Our data demonstrate that BT dysregulates molecular responses in the liver and tissue pathology indicative of damage. This study provides new insight into BT hepatotoxicity in Chinese rare minnow./AQUATIC SPECIES/ Benzotriazoles (BZTs) are ubiquitous aquatic contaminants used in a wide range of industrial and domestic applications from aircraft deicers to dishwasher tablets. Acute toxicity has been reported in aquatic organisms for some of the BZTs but their mode of action remains unknown. The objectives of this study were to evaluate the transcriptomic response of D. magna exposed to sublethal doses of 1H-benzotriazole (BTR), 5-methyl-1H-benzotriazole (5MeBTR) and 5-chloro-1H-benzotriazole (5ClBTR) using RNA-sequencing and quantitative real-time PCR. Cellular and life-history endpoints (survival, number of neonates, growth) were also investigated. Significant effects on the molting frequency were observed after 21-day exposure to 5MeBTR and 5ClBTR. No effects on molting frequency were observed for BTR but RNA-seq results indicated that this BZT induced the up-regulation of genes coding for cuticular proteins, which could have compensated the molting disruption. Molting in cladocerans is actively controlled by ecdysteroid hormones. Complementary short-term temporal analysis (4- and 8-day exposure) of the transcription of genes related to molting and hormone-mediated processes indicated that the three compounds had specific modes of action. BTR induced the transcription of genes involved in 20-hydroxyecdysone synthesis, which suggests pro-ecdysteroid properties. 5ClBTR exposure induced protein activity and transcriptional levels of chitinase enzymes, associated with an impact on ecdysteroid signaling pathways, which could explain the decrease in molt frequency. Finally, 5MeBTR seemed to increase molt frequency through epigenetic processes. Overall, results suggested that molting effects observed at the physiological level could be linked to endocrine regulation impacts of BZTs at the molecular level./AQUATIC SPECIES/ As an emerging contaminant, 1-H-benzotriazole (1H-BTR) has been detected in the engineered and natural aquatic environments, which usually coexists with heavy metals and causes combined pollution. In the present study, wild-type and transgenic zebrafish Danio rerio were used to explore the acute toxicity as well as the single and joint hepatotoxicity of cadmium (Cd) and 1H-BTR. Although the acute toxicity of 1H-BTR to zebrafish was low, increased expression of liver-specific fatty acid binding protein was observed in transgenic zebrafish when the embryos were exposed to 5.0 uM of 1H-BTR for 30 days. Besides, co-exposure to 1H-BTR not only reduced the acute toxic effects induced by Cd, but also alleviated the Cd-induced liver atrophy in transgenic fish. Correspondingly, effects of combined exposure to 1H-BTR on the Cd-induced expressions of several signal pathway-related genes and superoxide dismutase and glutathione-s-transferase proteins were studied. Based on the determination of Cd bioaccumulation in fish and the complexing stability constant (beta) of Cd-BTR complex in solution, the detoxification mechanism of co-existing 1H-BTR on Cd to the zebrafish was discussed./AQUATIC SPECIES/ Benzotriazole (BT) is a high-production volume chemical which has been ubiquitously detected in aquatic environments. Although adverse effects from acute and chronic exposure to BT have been reported, the neurotoxic effect of BT and the mechanisms of toxicity are not well documented. In this study, adult female Chinese rare minnow (Gobiocypris rarus) were exposed to 0.05, 0.5, and 5 mg/L BT for 28 days. The brain proteome showed that BT exposure mainly involved in metabolic process, signal transduction, stress response, cytoskeleton, and transport. Pathway analysis revealed that cellular processes affected by BT included cellular respiration, G-protein signal cascades, Ca2+-dependent signaling, cell cycle and apoptosis. Moreover, data on relative mRNA levels demonstrated that genes related to these toxic pathways were also significantly affected by BT. Furthermore, proteins affected by BT such as CKBB /creatine kinase, brain b/, GS /glutamine synthetase/, HPCA /hippocalcin/, VDAC1 /voltage-dependent anion channel 1/, and FLOT1A /flotillin 1a/ are associated with neurological disorders. Therefore, our finding suggested that BT induced molecular responses in the brain and could provide new insight into BT neurotoxicity in Chinese rare minnow.For more Ecotoxicity Excerpts (Complete) data for 1,2,3-Benzotriazole (14 total), please visit the HSDB record page. |
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