Proteomics analysis of zebrafish larvae exposed to 3,4-dichloroaniline using the fish embryo acute toxicity test

Alleviation of endothelial dysfunction of Pheretima guillemi (Michaelsen)-derived protein DPf3 in ponatinib-induced thrombotic zebrafish and mechanisms explored through ox-LDL-induced HUVECs and TMT-based proteomics

ETHNOPHARMACOLOGICAL RELEVANCE

Thrombus generation is one of the leading causes of death in human, and vascular endothelial dysfunction is a major contributor to thrombosis. Pheretima guillemi (Michaelsen), a traditional medicinal animal known as "Dilong", has been utilized to cure thrombotic disorders for many years. DPf3, a group of functional proteins extracted from P. guillemi, has been characterized and identified to possess antithrombotic bioactivity via in vitro and ex vivo experiments.

AIM OF THE STUDY

This study is aimed to investigate the vascular-protection activity and related mechanism of antithrombotic protein DPf3 purified from Pheretima guillelmi systematically.

MATERIALS AND METHODS

The antithrombotic activity and vascular endothelium protection effect of DPf3 was explored in vivo using ponatinib-induced vascular endothelial injury zebrafish thrombus model. Then, (hi) ox-LDL-induced HUVECs was applied to investigate the protection mechanism of DPf3 against the injury of vascular endothelium. In addition, TMT-based proteomics analysis was used to study the biomarkers, biological processes and signal pathways involved in the antithrombotic and vascular protective effects of DPf3 holistically.

RESULTS

DPf3 exerted robust in vivo antithrombosis and vascular endothelial protection ability. DPf3 was identified to prevent HUVECs from damage by reducing ROS production, and to reduce monocyte adhesion by decreasing the protein content of adhesion factor VCAM 1. DPf3 was also observed to weaken the migration ability of injured cells and inhibit abnormal angiogenesis. The mechanism of DPf3's antithrombotic and vascular protective activity was mainly related to the regulation of lipid metabolism, energy metabolism, complement and coagulation system, ECM receptor interaction, MAPK signal pathway, etc. CONCLUSIONS: This study demonstrates that DPf3 has strong antithrombotic and endothelial protective effects. The endothelial protective ability and related mechanisms of DPf3 provide a scientific reference for the traditional use of earthworms in the treatment of thrombosis.

Multi-omics and gut microbiome: Unveiling the pathogenic mechanisms of early-life pesticide exposure

The extensive application of pesticides in agricultural production has raised significant concerns about its impact on human health. Different pesticides, including fungicides, insecticides, and herbicides, cause environmental pollution and health problems for non-target organisms. Infants and young children are so vulnerable to the harmful effects of pesticide exposure that early-life exposure to pesticides deserves focused attention. Recent research lays emphasis on understanding the mechanism between negative health impacts and early-life exposure to various pesticides. Studies have explored the impacts of exposure to these pesticides on model organisms (zebrafish, rats, and mice), as well as the mechanism of negative health effects, based on advanced methodologies like gut microbiota and multi-omics. These methodologies help comprehend the pathogenic mechanisms associated with early-life pesticide exposure. In addition to presenting health problems stemming from early-life exposure to pesticides and their pathogenic mechanisms, this review proposes expectations for future research. These proposals include focusing on identifying biomarkers that indicate early-life pesticide exposure, investigating transgenerational effects, and seeking effective treatments for diseases arising from such exposure. This review emphasizes how to understand the pathogenic mechanisms of early-life pesticide exposure through gut microbiota and multi-omics, as well as the adverse health effects of such exposure.

Using proteomics, q-PCR and biochemical methods complementing as a multiapproach to elicit the crucial responses of zebrafish liver exposed to neonicotinoid pesticide

Pesticides enter the environment through runoff and leaching and this raises public concern about effects on non-target organisms. Imidacloprid (IMI) a synthetic pesticide, has an unstable half-life, metabolized in minutes to weeks in the water. To evaluate the effects of IMI on the zebrafish liver, we conducted proteomic, molecular and biochemical analysis in a multi-level approach, to highlight the complementary features regarding the results of each method. Adult zebrafish were exposed to 60 mg/L IMI for 48 h and were evaluated using nLC-MS/MS for proteins, q-PCR analysis for expression of cat, gpx, pxr, ache, along with CAT and AChE enzyme activities and GSH and MDA assays. Based on proteomics, the regulation of antioxidant and immune responses, as well as gene transcription were significant processes affected. Apoptosis and ER stress pathways were upregulated and there was a down-regulation of cat and gpx genes. There was also elevated CAT activity and GSH and decreased MDA. Additionally, elevated AChE activity and up regulation of ache expression was observed. The multi-approach results included regulators of antioxidant, xenobiotic response and neuro-protective related proteins (genes and enzymes), which overall reflected harmful effects of IMI. Consequently, this study highlights the effects of IMI on zebrafish liver and reveals new potential biomarkers. In this respect, evaluated outcomes reveal the complementary features emphasizing the importance of studying chemicals using several methods. Our study provides deeper insights for future work in ecotoxicological studies regarding IMI and contribute to existing toxicity literature.

An innovative insecticidal approach based on plant protease inhibitor and Bt protoxins inhibits trypsin-like activity in zebrafish

The Leucaena leucocephala trypsin inhibitor (LTI) + Bacillus thuringiensis (Bt) protoxins mix has been proposed as a novel larvicide agent in order to control the vector mosquito of dengue virus, Aedes aegypti, in their aquatic breeding sites. However, use of this insecticide formulation has raised concerns about its impacts on aquatic biota. In this context, this work aimed to assess the effects of LTI and Bt protoxins, separately or in combination, in zebrafish, in regard to the evaluation of toxicity at early life stages and to the presence of LTI inhibitory effects on intestinal proteases of this fish. Results showed that LTI and Bt concentrations (250 mg/L, and 0.13 mg/L, respectively), and LTI + Bt mix (250 mg/L + 0.13 mg/L) - 10 times superior to those with insecticidal action - did not cause death nor did it induce morphological changes during embryonic and larval development (3 to 144 h post-fertilization) of zebrafish. Molecular docking analyses highlighted a possible interaction between LTI and zebrafish trypsin, especially through hydrophobic interactions. In concentrations near to those with larvicidal action, LTI (0.1 mg/mL) was able to inhibit in vitro intestinal extracts of trypsin in female and male fish by 83 % and 85 %, respectively, while LTI + Bt mix promoted trypsin inhibition of 69 % in female and 65 % in male ones. These data show that the larvicidal mix can potentially promote deleterious effects to nutrition and survival in non-target aquatic organisms, especially those with trypsin-like dependent protein digestion.

Single-shot Mueller-matrix imaging of zebrafish tissues: In vivo analysis of developmental and pathological features

Zebrafish is a well-established animal model for developmental and disease studies. Its optical transparency at early developmental stages allows in vivo tissues visualization. Interaction of polarized light with these tissues provides information on their structure and properties. This approach is effective for muscle tissue analysis due to its birefringence. To enable real-time Mueller-matrix characterization of unanesthetized fish, we assembled a microscope for single-shot Mueller-matrix imaging. First, we performed a continuous observation of 48 species within the period of 2 to 96 hpf and measured temporal dependencies of the polarization features in different tissues. These measurements show that hatching was accompanied by a sharp change in the angle and degree of linearly polarized light after interaction with muscles. Second, we analyzed nine species with skeletal disorders and demonstrated that the spatial distribution of light depolarization features clearly indicated them. Obtained results demonstrated that real-time Mueller-matrix imaging is a powerful tool for label-free monitoring zebrafish embryos.

A battery of baseline toxicity bioassays directed evaluation of plastic leachates-Towards the establishment of bioanalytical monitoring tools for plastics

There are increasing concerns regarding the ecological risks of plastics to the natural environment, especially the potential effects of plastic leachates on organisms, which contain various toxic components. However, appropriate methods to assess the overall environmental risks of plastics are limited. In this study, five different plastic products (three conventional and two biodegradable plastics) were immersed in simulated freshwater, and their toxicity was assessed using a battery of bioassays. We evaluated the effects of plastic leachates effects on organisms from four trophic levels of species (nematodes, Caenorhabditis elegans; algae, Scenedesmus obliquus; daphnids, Daphnia magna; and fish, Danio rerio) by measuring their acute and chronic toxicity. Our results indicated that all plastic leachates exhibited poor acute and chronic toxicity to the organisms. The acute toxicity of conventional plastic leachates with EC₂₀ values <1.6 g plastic/L was higher than that of the biodegradable polydioxanone (PPDO) leachate (EC₂₀: 16.2-796.1 g plastic/L); however, the toxicity of PPDO-octane (EC₂₀: 0.04-1.9 g plastic/L) was similar to that of polyethylene or polystyrene (excluding toxicity in D. magna). Similarly, the leachates of the three conventional plastics and PPDO-octane had obvious inhibitory effects on the growth of C. elegans at exposure concentrations higher than 0.01 g plastic/L; however, the toxicity of the PPDO leachates was at least an order of magnitude lower. Therefore, the environmental related concentration of the plastic leachates did not have significant toxic effects. Considering that a single bioassay does not provide comprehensive information on biological implications, this study provided a new integrated and efficient method for the environmental risk assessment (ERA) of plastic leachates. Moreover, the toxicity sensitivity of different organisms varied following exposure to different plastics, thus demonstrating that multiple organisms from different trophic levels should be included in the ERA for plastics.

New Sorbicillinoids with Tea Pathogenic Fungus Inhibitory Effect from Marine-Derived Fungus Hypocrea jecorina H8

Four new dimeric sorbicillinoids (1–3 and 5) and a new monomeric sorbicillinoid (4) as well as six known analogs (6–11) were purified from the fungal strain Hypocrea jecorina H8, which was obtained from mangrove sediment, and showed potent inhibitory activity against the tea pathogenic fungus Pestalotiopsis theae (P. theae). The planar structures of 1–5 were assigned by analyses of their UV, IR, HR-ESI-MS, and NMR spectroscopic data. All the compounds were evaluated for growth inhibition of tea pathogenic fungus P. theae. Compounds 5, 6, 8, 9, and 10 exhibited more potent inhibitory activities compared with the positive control hexaconazole with an ED₅₀ of 24.25 ± 1.57 µg/mL. The ED₅₀ values of compounds 5, 6, 8, 9, and 10 were 9.13 ± 1.25, 2.04 ± 1.24, 18.22 ± 1.29, 1.83 ± 1.37, and 4.68 ± 1.44 µg/mL, respectively. Additionally, the effects of these compounds on zebrafish embryo development were also evaluated. Except for compounds 5 and 8, which imparted toxic effects on zebrafish even at 0.625 μM, the other isolated compounds did not exhibit significant toxicity to zebrafish eggs, embryos, or larvae. Taken together, sorbicillinoid derivatives (6, 9, and 10) from H. jecorina H8 displayed low toxicity and high anti-tea pathogenic fungus potential.

Antagonistic Effects of Enrofloxacin on Carbendazim-Induced Developmental Toxicity in Zebrafish Embryos

Carbendazim (CAR) and enrofloxacin (ENF) are frequently detected in fruits and meat products, respectively. Since most people consume fruits, vegetables, and meat products, combined exposure is possible, necessitating further evaluation of toxic interactions. In this study, the developmental toxicity of separate and combined exposure was examined in zebrafish embryos. Carbendazim exposure at 0.79 mg/L and above significantly affected developmental parameters, while enrofloxacin alone had no substantial effects on these developmental parameters within the selected concentration range (0.10-0.40 mg/L). Surprisingly, ENF antagonized the CAR-evoked reduction in the 48 hpf (hours post-fertilization) hatching rate and the increases in the 96 hpf malformation and lethality rates. The results revealed that the antagonism might be associated with reciprocal effects of these compounds on metabolism-related genes, such as cyp7a1 and apoa1a. These results reveal a complex interaction between ENF and CAR on metabolic regulation during development and highlight the importance of combined assessment for agents with the potential for simultaneous exposure.

Advantages of omics technology for evaluating cadmium toxicity in zebrafish

In the last decade, several advancements have been made in omics technologies and they have been applied extensively in diverse research areas. Especially in toxicological research, omics technology can efficiently and accurately generate relevant data on the molecular dynamics associated with adverse outcomes. Toxicomics is defined as the combination of toxicology and omics technologies and encompasses toxicogenomics, toxicoproteomics, and toxicometabolomics. This paper reviews the trend of applying omics technologies to evaluate cadmium (Cd) toxicity in zebrafish (D. rerio). Cd is a toxic heavy metal posing several environmental concerns; however, it is being used widely in everyday life. Zebrafish embryos and larvae are employed as standard models for many toxicity tests because they share 71.4% genetic homology with humans. This study summarizes the toxicity of Cd on the nerves, liver, heart, skeleton, etc. of zebrafish and introduces detailed omics techniques to understand the results of the toxicomic studies. Finally, the trend of toxicity evaluation in the zebrafish model of Cd based on omics technology is presented.

Atlantic cod (Gadus morhua) embryos are highly sensitive to short-term 3,4-dichloroaniline exposure

3,4-dichloroaniline (3,4-DCA) is one of the most widely produced anilines world-wide, used in plastic packaging, fabrics, pharmaceuticals, pesticides, dyes and paints as well as being a degradation product of several pesticides. 3,4-DCA has been detected in freshwater, brackish and marine environments. Although freshwater toxicity thresholds exist, very little toxicological information is available on marine and cold-water species. In this study, we exposed Atlantic cod (Gadus morhua) embryos (3-7 days post fertilization) to 3,4-DCA concentrations ranging from 8-747 μg/L for 4 days followed by a recovery period in clean sea water until 14 days post fertilization (dpf). The cod embryos were significantly more sensitive to acute 3,4-DCA exposure compared to other species tested and reported in the literature. At the highest concentration (747 μg/L), no embryos survived until hatch, and even at the lowest concentration (8 μg/L), a small, but significant increase in mortality was observed at 14 dpf. Delayed and concentration-dependent effects on surviving yolk-sac larvae, manifested as cardiac, developmental and morphometric alterations, more than a week after exposure suggest potential long-term effects of transient embryonic exposure to low concentrations of 3,4-DCA.

Zebrafish as the toxicant screening model: Transgenic and omics approaches

The production of large amounts of synthetic industrial and biomedical compounds, together with environmental pollutants, poses a risk to our ecosystem and induces negative effects on the health of wildlife and human beings. With the emergence of the global problem of chemical contamination, the adverse biological effects of these chemicals are gaining attention among the scientific communities, industry, governments, and the public. Among these chemicals, endocrine disrupting chemicals (EDCs) are regarded as one of the major global issues that potentially affecting our health. There is an urgent need of understanding the potential hazards of such chemicals. Zebrafish have been widely used in the aquatic toxicology. In this review, we first discuss the strategy of transgenic lines that used in the toxicological studies, followed by summarizing the current omics approaches (transcriptomics, proteomics, metabolomics, and epigenomics) on toxicities of EDCs in this model. We will also discuss the possible transgenerational effects in zebrafish and future prospective of the integrated omics approaches with customized transgenic organism. To conclude, we summarize the current findings in the field, and provide our opinions on future environmental toxicity research in the zebrafish model.

Reproductive Toxicity of 3,4-dichloroaniline (3,4-DCA) on Javanese Medaka (Oryziasjavanicus, Bleeker 1854)

Compound 3,4-dichloroaniline (3,4-DCA) is a metabolite of several urea herbicides and intermediate chemical of several industrial products. Moreover, 3,4-DCA has been frequently detected in aquatic ecosystems around the world. This aniline is more toxic than the parent chemicals, and it affects non-target organisms. This study evaluated a 21-day reproductive response of an emerging aquatic vertebrate model, Javanese medaka (Oryzias javanicus), exposed to 3,4-DCA. Fecundity and gonads histopathology were observed. The spawning rate and fertilisation reduced significantly in the highest exposed-group (250 µg/L). Gonadosomatic index (GSI) was significantly low in females exposed to 250 µg/L. No substantial structural alteration of male gonads. However, oocyte development and ovarian cell structure were disrupted in 250 µg/L exposed females. The gonadal developmental was not affected in the males; however, a significant reduction in the developmental of female gonads was observed at 250 µg/L. These results show that 3,4-DCA interfere with the reproduction of Javanese medaka through fecundity and alteration of gonadal tissues.