Perfluorooctanoic acid toxicity on zebrafish embryonic development and mechanism exploration with single-cell RNA sequencing
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ABSTRACT: The aquatic environment is an important site for perfluorooctanoic acid (PFOA) deposit and induced a high risk for aquatic organisms. Nevertheless, the current toxicity assessment was rarely reported the heart effect of PFOA. The exact mode of action and its resulting heterogeneity toxicological effects in aquatic organisms also remain largely unknown. In this study, the heart effects were investigated with a series of assays. The scRNA-seq showed nine cells populations were significantly altered with PFOA exposure. Heart was the mostly influenced cells and the function of cardiac muscle contraction, gas transport and oxygen binding was significantly changed. Moreover, the hatching gland cells, macrophages and lens cells were also significantly influenced with the altered function of apoptosis, endocrine and nervous and immune system. In addition, a significantly decreased swimming behavior and heart morphogenesis were verified.
Project description:Perfluorooctanoic acid (PFOA) is one of the most used perfluorinated compounds in numerous applications and can be detected in environmental samples from around the globe. The aquatic environment is an important site for PFOA deposit. Nevertheless, the exact mode of action and its resulting toxicological effects on aquatic organisms remain largely unknown. To gain a more extensive understanding of the mode of action of teleost PFOA toxicity, transcriptomics, proteomics, biochemical parameters and reproduction were integrated in the present study. Male and female zebrafish were exposed to nominal concentrations of 0.1; 0.5 and 1 mg/l PFOA for 4 and 28 days resulting in an accumulation which was higher in males compared to females. These gender-related differences were likely caused by different elimination rates due to distinct hormone levels and differences in transport activity by solute carriers. The general mode of action of PFOA was believed to be an increase of the mitochondrial membrane permeability which caused effects on the electron transport system at the biochemical level and resulted in alterations of the oxidative phosphorylation, oxidative stress and apoptosis at the gene transcript and protein level. As a consequence, evidence for the replacement of the affected cells and organelles to sustain tissue homeostasis was found at the molecular level. The higher energy demand, due to these adverse effects, was provided by lowering the glycogen stores. Despite this increase in metabolic expenditure, no effects on reproduction were found indicating that the fish seemed to cope with exposure to the tested concentrations of PFOA. Adult zebrafish (Danio rerio) were exposed to nominal concentrations of 0mg/l; 0.1mg/l; 1mg/l PFOA (perfluorooctanoic acid) for 28 days. Three different 25 litre aquaria per exposure concentration were used resulting in 3 biological replicates with each aquarium containing 8 male and 8 female zebrafish. The livers of 6 male fish and 6 female fish were pooled separately and snap frozen in liquid nitrogen. A reference sample was made by pooling equal amounts of RNA from all samples. A carriage wheel design was used in which all samples were connected to the reference sample and the main contrasts of interest were made directly on the same microarrays as frequently as possible. This design resulted in technical triplicates of each sample.
Project description:Perfluorooctanoic acid (PFOA) is one of the most used perfluorinated compounds in numerous applications and can be detected in environmental samples from around the globe. The aquatic environment is an important site for PFOA deposit. Nevertheless, the exact mode of action and its resulting toxicological effects on aquatic organisms remain largely unknown. To gain a more extensive understanding of the mode of action of teleost PFOA toxicity, transcriptomics, proteomics, biochemical parameters and reproduction were integrated in the present study. Male and female zebrafish were exposed to nominal concentrations of 0.1; 0.5 and 1 mg/l PFOA for 4 and 28 days resulting in an accumulation which was higher in males compared to females. These gender-related differences were likely caused by different elimination rates due to distinct hormone levels and differences in transport activity by solute carriers. The general mode of action of PFOA was believed to be an increase of the mitochondrial membrane permeability which caused effects on the electron transport system at the biochemical level and resulted in alterations of the oxidative phosphorylation, oxidative stress and apoptosis at the gene transcript and protein level. As a consequence, evidence for the replacement of the affected cells and organelles to sustain tissue homeostasis was found at the molecular level. The higher energy demand, due to these adverse effects, was provided by lowering the glycogen stores. Despite this increase in metabolic expenditure, no effects on reproduction were found indicating that the fish seemed to cope with exposure to the tested concentrations of PFOA.
Project description:DU145 (human prostate cancer cell line) were treated with different concentrations of Perfluorooctanoic acid (PFOA) : 10-6, 10-9 and 10-12M for 48h and modifications of gene expression were analyzed.
Project description:We reported the hepatic gene expression profiling in male Sprague-Dawley rats treated by different concentrations of perfluorooctanoic acid (PFOA) for 7, 14, and 28 days. We confirmed that PFOA induced liver tumor formation was mainly through the activation of peroxisome proliferator-activated receptor α (PPARα). We identified a panel of 7 genes (Cyp4a1, Nr1d1, Acot2, Vnn, Ehhadh, and Acot1) that might serve as the biomarkers for PPARα activation. We also meausred the apical endpoints of PPARα activation and found a good correlation with the expression level of these biomarker genes. Consitituitive androstane receptor mediated Cyp2b enzymatic activity and gene expression was also upregulated by PFOA in a dose-response manner. On the other hand, acyl hydrocarbon receptor (AhR) target gene Cyp1a2 were significantly downregulated at all time points studied. To our surprise, results of KEGG and Reactome pathway analyses suggested that PFOA did not drive the cell cycles and proliferations in the liver. While some of the DNA replication genes such as Pold2 and Mcm8 were upregulated by PFOA treatment, several key cyclin-dependent cell growth genes, including Ccnd1, Ccne2, Ccnb1, and Ccna2 were all significantly downregulated by PFOA in a dose-dependent manner, especailly at 28 days. Ingenuity Pathway Analysis also indicated that PFOA led to a suppression of liver cancer related pathways at later time points studied. These results suggest that while PFOA clearly induced PPARα activation, the increased cell growth (the second key event in the tumor mode of action), was transient and tightly regulated by feedback mechanisms. Whether such changes will eventually cause the formation of preneoplastic foci and liver tumors in rats remains unclear.
Project description:Multiple per- and polyfluoroalkyl substances (PFAS) have been associated with adverse liver outcomes in adult humans and toxicological models, but effects on the developing liver or biologic pathways involved are not known. We performed whole-transcriptome gene expression analysis to investigate the molecular mechanisms of liver toxicity in the dam and female fetuses after exposure to two different PFAS, perfluorooctanoic acid (PFOA) and its replacement, hexafluoropropylene oxide-dimer acid (HFPO-DA, commonly referred to as GenX).
Project description:The renal clearance of perfluorooctanoic acid (PFOA) increased in Abcb4 null mice compared with wild type mice, especially in male Abcb4 null mice. We evaluated the expression changes of transporters in kidney of male Abcb4 null mice by using microarray to reveal the candidate transporters of PFOA.
Project description:The renal clearance of perfluorooctanoic acid (PFOA) increased in Abcb4 null mice compared with wild type mice, especially in male Abcb4 null mice. We evaluated the expression changes of transporters in kidney of male Abcb4 null mice by using microarray to reveal the candidate transporters of PFOA. Male of Abcb4-null mice and wild-type mice (3 mice of 8 weeks old in each group) were sacrificed, collected their kidneys. Six independent experiments were performed.
Project description:Using mouse lungs from perfluorooctanoic acid (PFOA) exposed mice, we examine effects of exposure to short and long chain PFAS alone or in a mixture on NLRP3 inflammasome activation and cytokine productions.
Project description:Perfluorooctanoic acid (PFOA) exposure is linked with tumorigenesis in rats, mice, and potentially tumorigenic in humans. Here, we studied long-term PFOA exposure with an in vitro transformation model using the rat liver epithelial cell, TRL 1215. Cells were cultured in 10 µM (T10), 50 µM (T50) and 100 µM (T100) PFOA for 38 weeks and compared to passage-matched control cells. T100 cells showed morphological changes, loss of cell contact inhibition, formation of multinucleated giant and spindle-shaped cells. T10, T50, and T100 cells increased LC50 values 20%, 29% to 35% above control with acute PFOA treatment, indicating a resistance to PFOA toxicity. PFOA-treated cells showed increases in Matrix metalloproteinase-9 secretion, cell migration, and developed more and larger colonies in soft agar. Microarray data showed Myc pathway activation at T50 and T100, associating Myc upregulation with PFOA-induced morphological transformation. Western blot confirmed that PFOA produced significant increases in c-MYC protein expression in a time- and concentration-dependent manner. Tumor invasion indicators MMP-2 and MMP-9, cell cycle regulator cyclin D1, and oxidative stress protein GST were all significantly overexpressed in T100 cells. Taken together, chronic in vitro PFOA exposure produced multiple cell characteristics of malignant progression and differential gene expression changes suggestive of rat liver cell transformation.
Project description:Wistar rats were treated with either PFOA or 8:2 FTOH for 10 days with the following doses, 3, 10 or 25 mg/kg Bwt, followed by one recovery day. The treatment was given daily by i.p. injections. The rats were humanly sacrificed by decapitation, and the liver was immediatly dissected and divided, one piece of the liver was sumerged in RNALater (for use in microarray and realtime experiments) and the other piece of liver was submerged in cold buffer(for ezymatic assays). Pentadecafluorooctanoic (Perfluorooctanoic acid, PFOA) acid is an industrial surfactant. 8:2 FTOH is a fluorotelomer alcohol.