Developmental toxicity of procymidone to larval zebrafish based on physiological and transcriptomic analysis.

As a broad-spectrum with low toxicity, procymidone (PCM), is widely used in agriculture and frequently observed in aquatic system, which may cause some impacts on aquatic organisms. Here, to determine the developmental toxicity of PCM, embryonic and larval zebrafish were exposed to PCM at 0, 1, 10, 100 µg/L in dehydrogenated natural water containing 0.01% acetone for 7 days. The results showed that high concentration of PCM could cause the pericardial edema and increase the heart rates in larval zebrafish, suggesting that PCM had developmental toxicity to zebrafish. We also observed that PCM exposure not only changed the physiological parameters including TBA, GLU and pyruvic acid, but also changed the transcriptional levels of glycolipid metabolism related genes. In addition, after transcriptomics analysis, a total of 1065 differentially expressed genes, including 456 up-regulated genes and 609 down-regulated genes, changed significantly in 100 µg/L PCM treated larval zebrafish. Interestingly, after GO (Gene Ontology) analysis, the different expression genes (DEGs) were mainly enriched to the three different biology processes including GABA-nervous, lipid Metabolism and response to drug. We also observed that the levels of GABA receptor related genes including gabrg2, gabbr1α, gabbr1 and gabra6α were inhibited by PCM exposure. Interestingly, the swimming distance of larval zebrafish had the tendency to decrease after PCM exposure, indicating that the nervous system was affected by PCM. Taken together, the results confirmed that the fungicide PCM could cause developmental toxicity by influencing the lipid metabolism and GABA mediated nervous system and behavior in larval zebrafish. We believed that the results could provide an important data for the influence of PCM on aquatic animals.

Embryonic toxicity of epoxiconazole exposure to the early life stage of zebrafish.

Epoxiconazole (EPX), as a broad-spectrum triazole fungicide, is widely used in agriculture to resist pests and diseases, while it may have potential toxicity to non-target organisms. In the present study, early developmental stage zebrafish were used as the subject organisms to assess the toxicity of EPX, and the possible mechanism of toxicity was also discussed by biochemical and transcriptomic analysis. Through embryo toxicity test, we had made it clear that the 96 h LC50 of embryo was 7.204 mg/L, and acute exposure to EPX effected hatching rate, heartbeats, body length and even morphological defects. Then, by being exposed to EPX for 7 days at concentrations of 175 (1/40 LC50), 350 (1/20 LC50) and 700 (1/10 LC50), biochemical parameters were affected, mainly manifested as increase of the triglyceride (TG) level and decrease of glucose content. Correspondingly, the transcription of genes related of glucose metabolism, lipid metabolism and cholesterol metabolism were also affected significantly in larval zebrafish. Moreover, some pathways, including lipid metabolism, glucose metabolism and amino acid metabolism were affected through transcriptome sequencing analysis in the larval zebrafish. Further data analysis based on the sequencing, EPX exposure also affected the expression of genes related to cell apoptosis. We further conformed that the bright fluorescence on the liver and bright spots near the liver by acridine orange staining. In addition, the mRNA levels of apoptosis related genes were also significantly affected in the EPX exposed larval zebrafish. Taken together, the work could provide an insight into toxic effects of EPX on the zebrafish larvae at embryo toxicity and transcriptional levels, providing some evidences for the toxic effects of triazole fungicides on non-target organisms.

Propane-2-sulfonic acid octadec-9-enyl-amide, a novel PPARα/γ dual agonist, reverses neuroinflammation in lipopolysaccharide-induced mice.

Our previous study showed that propane-2-sulfonic acid octadec-9-enyl-amide (N15), a novel peroxisome proliferator-activated receptor α and γ (PPARα/γ) dual agonist, inhibits inflammatory responses in tumor necrosis factor alpha (TNFα)-induced vascular endothelial cells or lipopolysaccharide (LPS)-induced human myeloid leukemia mononuclear cells-1. However, little is known about whether N15 applies to other pathological or neuroinflammatory conditions. In the present study, we detected the effect of N15 on the LPS-induced neuroinflammatory response in mice and further investigated whether the effect of N15 on neuroinflammation and neuronal cells survival was related to PPARα/γ dual pathways. We found that N15 decreased the mRNA expression of the proinflammatory cytokines IL-1ß, IL-6, TNFα, inducible nitric oxide synthase and cyclooxygenase-2; inhibited microglial activation; and ameliorated neuronal apoptosis in the hippocampus and cortex of LPS-induced mice. In addition, PPARα antagonist MK886 or PPARγ antagonist T0070907 partially eliminated the effect of N15. These results demonstrate that N15 exerts an anti-inflammatory effect, at least in part, by enhancing PPARα/γ dual signaling. Our study reveals that N15 may be a promising neuronal protective drug for the treatment of neuroinflammatory diseases.

Propane-2-sulfonic acid octadec-9-enyl-amide alleviates scopolamine-induced spatial learning and memory deficits in mice.

Our previous reports demonstrated that the novel peroxisome proliferator-activated receptors α and γ (PPARα/γ) dual agonist propane-2-sulfonic acid octadec-9-enyl-amide (N15) alleviates cognitive ability in the chronic phase of ischemic stroke. However, the potential effects of N15 on Alzheimer's disease (AD) animal models have not been elucidated. In the present study, we investigated the effects of N15 on scopolamine-induced cognitive dysfunction and cholinergic system ability. N15 (50, 100 or 200 mg/kg) was administered to mice via oral gavage for 21 days, and spatial cognitive dysfunction was induced via an intraperitoneal injection of scopolamine (4 mg/kg) for 6 days. We found that N15 pretreatment markedly ameliorated scopolamine-induced spatial cognitive impairment and enhanced cholinergic system reactivity in the hippocampus. N15 pretreatment also significantly increased the expression levels of growth-associated protein-43, synaptophysin, brain-derived neurotrophic factor and neurotrophin-3 in the hippocampus. Our data demonstrate that N15 has an anti-amnesic effect, which may be mediated by enhancing cholinergic activity and synaptic plasticity. These findings support N15 as a potent neuropharmacological drug against AD.

Sub-chronic carbendazim exposure induces hepatic glycolipid metabolism disorder accompanied by gut microbiota dysbiosis in adult zebrafish (Daino rerio).

Carbendazim (CBZ) as a broad spectrum fungicide is widely used in the whole world to contorl plant diseases. With the application of CBZ in the agriculture, it has been detected in vegetables and fruits. Nowadays, it even has been detected in the watercourse and indoor dust. However, the toxic effects of CBZ on aquatic organisms have received limited attention. In this study, male adult zebrafish were exposed at 0, 30 and 100 µg/L CBZ for 21 days to assess its effects on hepatic glycolipid metabolism. After exposure, the body weight and length decreased, but the condition factor increased significantly. Some hepatic biochemical parameters including the levels of glucose, pyruvate, low density lipoprotein (LDL) and triglyceride (TG) decreased significantly in the liver of zebrafish after exposure with CBZ. Two transaminases alanine transaminase (ALT) and aspartate transaminase (AST) also increased significantly, indicating that subchronic CBZ exposure influenced the liver function. Moreover, the relative mRNA levels of some key genes related to the glycolysis and lipid metabolism in the liver also changed significantly. Furthermore, the transcriptome analysis showed that the carbon metabolism, lipid metabolism and detoxification metabolism were also affected in the liver of CBZ exposed zebrafish. Interestingly, we also found the amounts of the Firmicutes, Bacteroidetes, Actinobacteria, α-Proteobacteria, γ-Proteobacteria and Verrucomicrobia at phylum level significantly decreased in the gut. Sequencing V3-V4 region of 16S rRNA also demonstrated gut microbiota composition changed significantly according to weighted UniFrac distance analysis. Consequently, subchronic CBZ exposure induced hepatic metabolic disorder accompanied by gut microbiota dysbiosis in adult male zebrafish.