Cyanobacteria are known for their ability to produce and release mixtures of up to thousands of compounds into the environment. Recently, the production of novel metabolites, retinoids, was reported for some cyanobacterial species along with teratogenic effects of samples containing these compounds. Retinoids are natural endogenous substances derived from vitamin A that play a crucial role in early vertebrate development. Disruption of retinoid signalling- especially during the early development of the nervous system- might lead to major malfunctions and malformations. In this study, the toxicity of cyanobacterial biomass samples from the field containing retinoids was characterized by in vivo and in vitro bioassays with a focus on the potential hazards towards nervous system development and function. Additionally, in order to identify the compounds responsible for the observed in vitro and in vivo effects the complex cyanobacterial extracts were fractionated (C18 column, water-methanol gradient) and the twelve obtained fractions were tested in bioassays. In all bioassays, all-trans retinoic acid (ATRA) was tested along with the environmental samples as a positive control. Retinoid-like activity (mediated via the retinoic acid receptor, RAR) was measured in the transgenic cell line p19/A15. The in vitro assay showed retinoid-like activity by specific interaction with RAR for the biomass samples. Neurotoxic effects of selected samples were studied on zebrafish (Danio rerio) embryos using the light/dark transition test (Viewpoint, ZebraLab system) with 120 hpf larvae. In the behavioural assay, the cyanobacterial extracts caused significant hyperactivity in zebrafish at 120 hpf after acute exposure (3 h prior to the measurement) at concentrations below the teratogenicity LOEC (0.2 g dw L-1). Similar effect was observed after exposure to fractions of the extracts with detected retinoid-like activity and additive effect was observed after combining the fractions. However, the effect on behaviour was not observed after exposure to ATRA only. To provide additional insight into the behavioural effects and describe the underlying mechanism gene expression of selected biomarkers was measured. We evaluated an array of 28 genes related to general toxicity, neurodevelopment, retinoid and thyroid signalling. We detected several affected genes, most notably, the Cyp26 enzymes that control endogenous ATRA concentration, which documents an effect on retinoid signalling.
- MeSH
- Biomass MeSH
- Biological Assay MeSH
- Water Pollutants, Chemical metabolism toxicity MeSH
- Behavior, Animal drug effects MeSH
- Zebrafish growth & development metabolism MeSH
- Embryo, Nonmammalian drug effects metabolism MeSH
- Gene Expression drug effects MeSH
- Mice MeSH
- Cell Line, Tumor MeSH
- Receptors, Retinoic Acid genetics metabolism MeSH
- Cyanobacteria growth & development metabolism MeSH
- Tretinoin metabolism toxicity MeSH
- Animals MeSH
- Check Tag
- Mice MeSH
- Animals MeSH
- Publication type
- Journal Article MeSH
Ziram is a broad spectrum pesticide that belongs to the class of dimethyl-dithiocarbamate (DTC) fungicides. The objectives of this study were to assess the effects of ziram in developing zebrafish. Ziram was highly toxic to zebrafish embryos, with a 96-h LC50 value of 1082.54 nM (∼0.33 mg/L). Zebrafish embryos at 6 h post-fertilization (hpf) were exposed to solvent control (0.1% DMSO), or one dose of 1, 10, 100, and 1000 nM ziram for 96 h. Ziram induced lethality in a dose-dependent manner, decreased hatching rate and heartbeat, and caused wavy deformities at 72 and 96 hpf at 100 and 1000 nM. Basal oxygen consumption rates of zebrafish at 24 hpf were decreased with 1000 nM, suggesting that ziram affects oxidative phosphorylation. We also measured the expression of transcripts associated with the oxidative stress response (sod1 and sod2) and dopamine receptor signaling at ∼96 h of exposure. There was no difference in the expression of genes related to oxidative stress, nor those related to the dopamine system. Locomotor activity was also assessed in larval zebrafish (7 dpf), and ziram increased total activity, the velocity in light zone, and total distance moved at 10 nM, while it decreased the mean time spent in the dark zone at 1 and 10 nM. Behavioral responses were dependent upon the time point and clutch examined. These data demonstrate that ziram negatively impacts embryonic development (i.e. mortality, hatching, heartbeat and notochord development) of zebrafish, decreases basal respiration of embryos, and alters behavioral responses in larvae.
- MeSH
- Behavior, Animal drug effects MeSH
- Zebrafish growth & development metabolism MeSH
- Dopamine genetics MeSH
- Embryo, Nonmammalian drug effects MeSH
- Embryonic Development drug effects MeSH
- Larva drug effects MeSH
- Locomotion drug effects MeSH
- Oxidative Stress genetics MeSH
- Fungicides, Industrial metabolism toxicity MeSH
- Oxygen Consumption drug effects MeSH
- Ziram toxicity MeSH
- Animals MeSH
- Check Tag
- Animals MeSH
- Publication type
- Journal Article MeSH
Drugs are excreted from the human body as both original substances and as metabolites and enter aquatic environment through waste water. The aim of this study was to widen the current knowledge considering the effects of waterborne antidepressants with different modes of action-amitriptyline, venlafaxine, sertraline-on embryos of non-target aquatic biota-fish (represented by Danio rerio) and amphibians (represented by Xenopus tropicalis). The tested concentrations were 0.3; 3; 30; 300 and 3000 μg/L in case of amitriptyline and venlafaxine and 0.1; 1; 10; 100 and 1000 μg/L for sertraline. Test on zebrafish embryos was carried out until 144 h post fertilization, while test on Xenopus embryos was terminated after 48 h. Lethal and sublethal effects as well as swimming alterations were observed at higher tested concentrations that are not present in the environment. In contrast, mRNA expression of genes related to heart, eye, brain and bone development (nkx2.5, otx 2, bmp4 and pax 6) seems to be impacted also at environmentally relevant concentrations. In a wider context, this study reveals several indications on the ability of antidepressants to affect non target animals occupying environments which may be contaminated by such compounds.
- MeSH
- Antidepressive Agents toxicity MeSH
- Water Pollutants, Chemical toxicity MeSH
- Zebrafish growth & development physiology MeSH
- Amphibians physiology MeSH
- Swimming MeSH
- Seafood MeSH
- Toxicity Tests MeSH
- Animals MeSH
- Check Tag
- Animals MeSH
- Publication type
- Journal Article MeSH
Synthetic polycyclic musks, widely used as additives in personal care products, are present in both biotic and abiotic matrices of the aquatic environment at concentrations of ng/l to µg/l. Although they are determined at comparatively low concentrations, these levels are biologically relevant and pose a significant growing risk as stressors to aquatic organisms. The purpose of our study was to evaluate the effects of 28-day-long exposure to polycyclic musk tonalide in zebrafish juvenile stages (Danio rerio) using selected biomarkers. Environmentally relevant concentrations of tonalide caused significant changes in selected enzyme activities in the experimental groups exposed to the highest concentrations. The activity of glutathione S-transferase and lipid peroxidation increased significantly (p < 0.05) after exposure to the highest concentration (50,000 ng/l) compared with the control. A similar trend was observed in catalase activity; there was a significant increase (p < 0.05) after exposure to two highest concentrations of tonalide (5000 and 50,000 ng/l). In addition, a statistically significant decrease (p < 0.05) in glutathione reductase activity was found in the lowest test concentration of tonalide (50 ng/l). None of the tested concentrations resulted in histopathological changes in liver, kidney, skin, or gill. Furthermore, no effects on body weight, body length, specific growth rate, and behavior were observed. Our results showed that tonalide exposure induced profound changes in the activities of antioxidant and detoxifying enzymes, such changes representing an adaptive response of the fish organism to tonalide toxicity.
- MeSH
- Antioxidants metabolism MeSH
- Environmental Biomarkers drug effects MeSH
- Water Pollutants, Chemical toxicity MeSH
- Behavior, Animal drug effects MeSH
- Zebrafish * growth & development physiology MeSH
- Glutathione Transferase metabolism MeSH
- Catalase metabolism MeSH
- Oxidative Stress drug effects MeSH
- Lipid Peroxidation drug effects MeSH
- Body Weight drug effects MeSH
- Toxicity Tests, Subchronic methods MeSH
- Tetrahydronaphthalenes toxicity MeSH
- Gills drug effects metabolism MeSH
- Animals MeSH
- Check Tag
- Animals MeSH
- Publication type
- Journal Article MeSH
Genomics methodologies have significantly improved elucidation of Mendelian disorders. The combination with high-throughput functional-omics technologies potentiates the identification and confirmation of causative genetic variants, especially in singleton families of recessive inheritance. In a cohort of 99 individuals with abnormal Golgi glycosylation, 47 of which being unsolved, glycomics profiling was performed of total plasma glycoproteins. Combination with whole-exome sequencing in 31 cases revealed a known genetic defect in 15 individuals. To identify additional genetic factors, hierarchical clustering of the plasma glycomics data was done, which indicated a subgroup of four patients that shared a unique glycomics signature of hybrid type N-glycans. In two siblings, compound heterozygous mutations were found in SLC10A7, a gene of unknown function in human. These included a missense mutation that disrupted transmembrane domain 4 and a mutation in a splice acceptor site resulting in skipping of exon 9. The two other individuals showed a complete loss of SLC10A7 mRNA. The patients' phenotype consisted of amelogenesis imperfecta, skeletal dysplasia, and decreased bone mineral density compatible with osteoporosis. The patients' phenotype was mirrored in SLC10A7 deficient zebrafish. Furthermore, alizarin red staining of calcium deposits in zebrafish morphants showed a strong reduction in bone mineralization. Cell biology studies in fibroblasts of affected individuals showed intracellular mislocalization of glycoproteins and a defect in post-Golgi transport of glycoproteins to the cell membrane. In contrast to yeast, human SLC10A7 localized to the Golgi. Our combined data indicate an important role for SLC10A7 in bone mineralization and transport of glycoproteins to the extracellular matrix.
- MeSH
- Zebrafish genetics growth & development metabolism MeSH
- Adult MeSH
- Exome MeSH
- Phenotype MeSH
- Fibroblasts metabolism pathology MeSH
- Calcification, Physiologic * MeSH
- Genomics * MeSH
- Glycomics * MeSH
- Peptide-N4-(N-acetyl-beta-glucosaminyl) Asparagine Amidase deficiency MeSH
- Glycosylation MeSH
- Golgi Apparatus metabolism pathology MeSH
- Cohort Studies MeSH
- Infant MeSH
- Cells, Cultured MeSH
- Humans MeSH
- Young Adult MeSH
- Mutation * MeSH
- Organic Anion Transporters, Sodium-Dependent genetics metabolism MeSH
- Pedigree MeSH
- Symporters genetics metabolism MeSH
- Protein Transport MeSH
- Congenital Disorders of Glycosylation complications MeSH
- Bone Diseases, Developmental etiology metabolism pathology MeSH
- Animals MeSH
- Check Tag
- Adult MeSH
- Infant MeSH
- Humans MeSH
- Young Adult MeSH
- Male MeSH
- Female MeSH
- Animals MeSH
- Publication type
- Journal Article MeSH
- Research Support, Non-U.S. Gov't MeSH
Glyphosate (N-(phosphonomethyl)glycine) is an active substance of many herbicides. According to literature studies, glyphosate residues and their metabolites have been commonly detected in surface waters and toxicological reports confirmed negative effects on living organisms. In this study, the acute embryo toxicity of glyphosate into two different fish species-common carp (Cyprinus carpio) and zebrafish (Danio rerio)-was investigated. Lethal endpoints, development disorder, and, in addition, other sublethal endpoints such as hatching rate, formation of somites, and development of eyes, spontaneous movement, heartbeat/blood circulation, pigmentation, and edema were recorded to indicate the mode of action of the toxic compound. Hatching retardation (p < 0.05) was observed in experimental groups of common carp exposed to glyphosate with significant statistical difference especially at the highest concentration after 72, 96, and 120 hpf. The significantly highest cumulative mortality at concentration of 50 mg/l was observed. In contrast, hatching stimulation was observed in embryos of zebrafish exposed to the highest concentration of glyphosate. The significantly highest cumulative mortality for zebrafish was observed only at concentration of 50 mg/l. Based on our results, early life stages of common carp are more sensitive in comparison to zebrafish to the toxic action of glyphosate.
- MeSH
- Water Pollutants, Chemical toxicity MeSH
- Zebrafish growth & development MeSH
- Species Specificity MeSH
- Embryo, Nonmammalian drug effects MeSH
- Embryonic Development drug effects MeSH
- Glycine analogs & derivatives toxicity MeSH
- Herbicides toxicity MeSH
- Carps growth & development MeSH
- Dose-Response Relationship, Drug MeSH
- Animals MeSH
- Check Tag
- Animals MeSH
- Publication type
- Journal Article MeSH
Carbendazim is a widely used broad spectrum benzimidazole fungicide; however, its effects to non-target aquatic organisms are poorly studied. The aim of this study was to investigate the toxic effects of carbendazim to zebrafish early life stages at several levels of biological organization, including developmental, biochemical and behavioural levels. The embryo assay was done following the OECD guideline 236 and using a concentration range between 1.1 and 1.8mg/L. Lethal and developmental endpoints such as hatching, edemas, malformations, heart beat rate, body growth and delays were assessed in a 96h exposure. A sub-teratogenic range (from 0.16 to 500μg/L) was then used to assess effects at biochemical and behavioural levels. Biochemical markers included cholinesterase (ChE), glutathione-S-transferase (GST), lactate dehydrogenase (LDH) and catalase (CAT) and were assessed at 96h. The locomotor behaviour was assessed using an automated video tracking system at 120h. Carbendazim (96h-LC50 of 1.75mg/L) elicited several developmental anomalies in zebrafish embryos with EC50 values ranging from 0.85 to 1.6mg/L. ChE, GST and LDH activities were increased at concentrations equal or above 4μg/L. The locomotor assay showed to be extremely sensitive, detecting effects in time that larvae spent swimming at concentrations of 0.16μg/L and thus, being several orders of magnitude more sensitive that developmental parameters or lethality. These are ecological relevant concentrations and highlight the potential of behavioural endpoints as early warning signs for environmental stress. Further studies should focus on understanding how the behavioural disturbances measured in these types of studies translate into fitness impairment at the adult stage.
- MeSH
- Benzimidazoles analysis toxicity MeSH
- Water Pollutants, Chemical analysis toxicity MeSH
- Cholinesterases metabolism MeSH
- Behavior, Animal drug effects MeSH
- Zebrafish growth & development physiology MeSH
- Embryo, Nonmammalian drug effects physiology MeSH
- Glutathione Transferase metabolism MeSH
- Carbamates analysis toxicity MeSH
- Catalase metabolism MeSH
- Larva drug effects physiology MeSH
- Locomotion drug effects MeSH
- Swimming MeSH
- Fungicides, Industrial analysis toxicity MeSH
- Tandem Mass Spectrometry MeSH
- Chromatography, High Pressure Liquid MeSH
- Animals MeSH
- Check Tag
- Animals MeSH
- Publication type
- Journal Article MeSH
- Research Support, Non-U.S. Gov't MeSH
Pharmaceuticals are emerging contaminants as their worldwide consumption increases. Fibrates such as gemfibrozil (GEM) are used in human medicine to reduce blood concentrations of cholesterol and triacylglycerol and also are some of the most frequently reported pharmaceuticals in waste waters and surface waters. Despite some studies have already demonstrated the negative impact in physiological and/or reproductive endpoints in adult fish, data on survival and behavioral effects in fish larvae are lacking. This study aimed to assess the effects of GEM on zebrafish eleutheroembryo development and locomotor behavior. A fish embryo toxicity (FET) test was undertaken to evaluate GEM acute toxicity by exposing embryos to 0, 6.58, 9.87, 14.81, 22.22, 33.33 and 50mg/L. Developmental endpoints such as hatching success, edemas and malformations were recorded. A second test was undertaken by exposing embryos to 0, 1.5, 3 and 6mg/L in order to evaluate the effects of GEM on 120 and 144h post fertilization (hpf) larvae locomotor activity by video tracking, using a Zebrabox(®) (Viewpoint, France) device. From the data recorded, several parameters such as total swimming distance (TSD) and total swimming time (TST) in each 120s integration time were calculated. Data showed that this compound has a moderate toxic effect on fish embryo development, affecting both survival and hatching success with a calculated 96h LC50 of 11.01mg/L and no effects at the developmental level at 6mg/L. GEM seems to impair locomotor activity, even at concentrations where developmental abnormalities were unperceived, at concentrations as low as 1.5mg/L. Both TSD and TST were sensitive to GEM exposure. These effects do not seem to be independent of the developmental stage as 120hpf larvae seem to present a development bias with repercussions in locomotor behavior. This study highlights the need to include behavioral endpoints in ecotoxicological assays as this seems to be a more sensitive endpoint often disregarded.
- MeSH
- Water Pollutants, Chemical toxicity MeSH
- Zebrafish growth & development physiology MeSH
- Embryonic Development drug effects MeSH
- Gemfibrozil toxicity MeSH
- Larva drug effects MeSH
- Swimming MeSH
- Motor Activity drug effects MeSH
- Toxicity Tests, Acute MeSH
- Animals MeSH
- Check Tag
- Animals MeSH
- Publication type
- Journal Article MeSH
- Research Support, Non-U.S. Gov't MeSH
The aim of this study was to perform the fish embryo acute toxicity test (FET) on zebrafish (Danio rerio) and the early-life stage toxicity test on common carp (Cyprinus carpio) with tramadol hydrochloride. The FET was performed using the method inspired by the OECD guideline 236. Newly fertilized zebrafish eggs were exposed to tramadol hydrochloride at concentrations of 10; 50; 100 and 200μg/l for a period of 144h. An embryo-larval toxicity test on C. carpio was performed according to OECD guideline 210 also with tramadol hydrochloride at concentrations 10; 50; 100 and 200μg/l for a period of 32 days. Hatching was significantly influenced in both acute and subchronic toxicity assays. Subchronic exposure also influenced early ontogeny, both morphometric and condition characteristics and caused changes in antioxidant enzyme activity. The LOEC value was found to be 10μg/l tramadol hydrochloride.
- MeSH
- Water Pollutants, Chemical toxicity MeSH
- Zebrafish embryology growth & development MeSH
- Embryo, Nonmammalian drug effects MeSH
- Embryonic Development drug effects MeSH
- Carps growth & development MeSH
- Toxicity Tests, Acute MeSH
- Tramadol toxicity MeSH
- Animals MeSH
- Check Tag
- Animals MeSH
- Publication type
- Journal Article MeSH
Omics-based methods are increasingly used in current ecotoxicology. Therefore, a large number of observations for various toxic substances and organisms are available and may be used for identifying modes of action, adverse outcome pathways, or novel biomarkers. For these purposes, good statistical analysis of toxicogenomic data is vital. In contrast to established ecotoxicological techniques, concentration-response modeling is rarely used for large datasets. Instead, statistical hypothesis testing is prevalent, which provides only a limited scope for inference. The present study therefore applied automated concentration-response modeling for 3 different ecotoxicotranscriptomic and ecotoxicometabolomic datasets. The modeling process was performed by simultaneously applying 9 different regression models, representing distinct mechanistic, toxicological, and statistical ideas that result in different curve shapes. The best-fitting models were selected by using Akaike's information criterion. The linear and exponential models represented the best data description for more than 50% of responses. Models generating U-shaped curves were frequently selected for transcriptomic signals (30%), and sigmoid models were identified as best fit for many metabolomic signals (21%). Thus, selecting the models from an array of different types seems appropriate, because concentration-response functions may vary because of the observed response type, and they also depend on the compound, the organism, and the investigated concentration and exposure duration range. The application of concentration-response models can help to further tap the potential of omics data and is a necessary step for quantitative mixture effect assessment at the molecular response level.
- MeSH
- Zebrafish growth & development metabolism MeSH
- Ecosystem * MeSH
- Embryo, Nonmammalian drug effects metabolism MeSH
- Genomics * MeSH
- Environmental Pollutants toxicity MeSH
- Linear Models MeSH
- Metabolomics * MeSH
- High-Throughput Screening Assays MeSH
- Oligonucleotide Array Sequence Analysis MeSH
- Tetrachloroethylene toxicity MeSH
- Transcriptome drug effects MeSH
- Animals MeSH
- Check Tag
- Animals MeSH
- Publication type
- Journal Article MeSH
- Research Support, Non-U.S. Gov't MeSH
