PFOA exposure induces aberrant glucose and lipid metabolism in the rat liver through the AMPK/mTOR pathway

Multi-omics analysis reveals BPF exposure causes hepatic glucose and lipid metabolism disorder in rats by disrupting energy homeostasis

Bisphenol F (BPF) is one of the main substitutes for Bisphenol A (BPA) and is widely used in the manufacture of household products. In addition, BPF threatens human health through environmental pollution and the food chain. However, the hepatotoxicity of BPF and its effects on glucose and lipid metabolism remain unclear. This study used male SD rats as an animal model to investigate the hepatotoxicity of BPF and its effects on glucose and lipid metabolism. The results of the HE staining, serum and liver biochemical indicators show that BPF can damage the basic structure of the liver, cause liver dysfunction and lead to disorders of liver glucose metabolism and lipid metabolism. Furthermore, we conducted metabolomics and proteomics analyses on the livers of the BPF exposed group at 100 mg/kg/d in comparison with the control group. The results indicated that BPF exposure had a significant effect on liver metabolism. Combined with biological analysis and the validation of changes in genes and proteins related to glucose and lipid metabolism in the liver, it was elucidated that BPF can promote fatty acid oxidation and inhibit fatty acid synthesis through the AMPK and PPAR signaling pathways, leading to a reduction in fatty acids. Furthermore, it has been demonstrated that BPF can promote glycogen synthesis and gluconeogenesis via the AKT pathway, which can result in disorders of glucose metabolism.

Age-specific associations between per- and polyfluoroalkyl substances exposure and metabolic syndrome: a cross-sectional study

BACKGROUND

The widespread presence of per-and polyfluoroalkyl substances (PFAS) has raised global health concerns. This study aims to determine the age-specific relationships of PFAS compounds with metabolic syndrome (MetS) and its components.

METHODS

We used data from the National Health and Nutrition Examination Survey (NHANES) in 2003-2018. Modified Poisson regression was employed to estimate associations between individual PFAS compounds and prevalence of MetS, as well as its components. Multiple linear regression analyses were performed to examine the associations between PFAS congeners and metabolic markers, including lipid and glucose homeostasis traits. Additionally, weighted quantile sum (WQS) regression and Bayesian kernel machine regression (BKMR) models were conducted to investigate the joint effects of PFAS mixtures on the prevalence of MetS and its components across different age groups.

RESULTS

A total of 5850 participants were included for analysis. In the Modified Poisson regression model, ln-transformed perfluorononanoic acid (PFNA) level was positively correlated with MetS prevalence in adolescents (prevalence ratio [PR] = 1.42; 95% CI: 1.01-1.99). Conversely, ln-transformed perfluorohexanesulfonic acid (PFHxS) and ln-transformed 2-(N-Methylperfluorooctane sulfonamido) acetic acid (MeFOSAA) were negatively associated with the risks of MetS in young adults (PR = 0.86, 95% CI: 0.76-0.98) and middle-aged adults (PR = 0.88, 95% CI: 0.79-0.98), respectively. Notably, individual PFAS exposure was positively associated with levels of total cholesterol, low-density lipoprotein, non-high-density lipoprotein, and high-density lipoprotein in young and middle-aged adults. However, overall effect analyses using WQS and BKMR showed no significant associations of PFAS mixture with MetS in any age group. Nonetheless, in middle-aged adults, PFAS mixture was adversely correlated with hypertriglyceridemia and positively linked to a greater risk of hypertension and increased high-density lipoprotein cholesterol levels.

CONCLUSIONS

Our study highlighted the complex relationships between PFAS exposure and the risks of MetS and its components across different age groups. Co-exposure to PFAS was particularly linked to dyslipidemia in young and middle-aged adults. Prospective studies are needed for better comprehension of the causative impact of PFAS on the risks of MetS.

A review of microbial degradation of perfluorinated and polyfluoroalkyl substances (PFAS) during waste biotransformation processes: influencing factors and alleviation measures

Per- and polyfluoroalkyl substances (PFASs) are stable synthetic compounds that pose significant risks to humans and tend to accumulate during the biotransformation of municipal waste. Although physical and chemical methods can effectively remove PFASs, their high costs and susceptibility to secondary contamination have limited broader adoption. Microbial degradation of PFASs is an environmentally friendly and cost-effective approach, making it a highly promising method for removing PFASs in municipal waste biotransformation. This paper summarizes recent advancements in the mechanisms of PFASs removal in common waste biotransformation processes, such as composting, anaerobic digestion and biological wastewater treatment. Microorganisms remove PFAS from municipal waste mainly through adsorption and biodegradation. We suggest that the type of PFAS, the coexistence of multiple emerging pollutant and PFAS, and the nutrients provided by municipal waste are the key factors influencing microbial degradation of PFAS. We consider that in situ enrichment of microorganisms capable of degrading PFAS is an effective way to mitigate the inhibitory effect of PFAS on waste biotransformation. Also, the addition of adsorbent materials, the application of voltage, and the addition of quorum-sensing signalling molecules in combination with biodegradation can improve the effectiveness of biodegradation of PFAS. In this study, we look forward to the future research direction to understand the key metabolic pathways of microbial degradation of PFAS using isotope tracer method. This review provides new insights for efficient biotransformation of municipal waste and effective removal of PFAS.

Low lipid levels caused by bisphenol S exposure trigger neuroinflammation and apoptosis in the brain of zebrafish

Bisphenol S (BPS), as an environmental pollutant, is known to reduce brain lipid levels and induce neurotoxicity. However, whether brain lipid imbalance can induce neurotoxicity has not yet been clarified. Here, wild-type zebrafish and apoEb mutant zebrafish were used to investigate the effect of BPS on the macrophages proliferation and microglia mobilization caused by the decrease of cerebral lipids and its potential neurotoxic effects. The zebrafish exposed to BPS (1, 10, or 100 μg/L) from 2 hours after fertilization (hpf) to 3 days after fertilization (dpf) displayed microglial aggregation, as well as a decrease in brain lipid content. Lipidomic analyses of the brains and plasma of 50 dpf zebrafish exposed to BPS were used to identify key lipids, including lysophosphatidylcholine and phosphatidylcholine in brain and phosphatidylcholine in plasma. The apoEb mutant zebrafish as a hyperlipidemia model was used to further demonstrate that BPS-induced lipid reduction increased the number of microglia in the brain. Our data provide new insight into the mechanism by which pollutants cause neurotoxicity.

Per- and polyfluoroalkyl substances as persistent pollutants with metabolic and endocrine-disrupting impacts

The widespread use of per- and polyfluoroalkyl substances (PFASs), and their resistance to degradation, renders human exposure to them inevitable. PFAS exposure disturbs endocrine function, potentially affecting cognitive development in newborns through thyroid dysfunction during pregnancy. Recent studies reveal varying male and female reproductive toxicity across PFAS classes, with alternative analogs affecting sperm parameters and legacy PFASs correlating with conditions like endometriosis. Metabolically, PFASs exposure is linked to metabolic disorders, including obesity, type 2 diabetes mellitus (T2DM), dyslipidemia, and liver toxicity, particularly in early childhood. This review focuses on the endocrine-disrupting impact of PFASs, particularly on fertility, thyroid, and metabolic functions. We highlight the complexity of the PFAS issue, given the large number of molecules and their extremely diverse mixed effects.

Insights into toxicological mechanisms of per-/polyfluoroalkyl substances by using omics-centered approaches

The extensive presence of per-/polyfluoroalkyl substances (PFASs) in the environment and their adverse effects on organisms have garnered increasing concern. With the shift of industrial development from legacy to emerging PFASs, expanding the understanding of molecular responses to legacy and emerging PFASs is essential to accurately assess their risks to organisms. Compared with traditional toxicological approaches, omics technologies including transcriptomics, proteomics, metabolomics/lipidomics, and microbiomics allow comprehensive analysis of the molecular changes that occur in organisms after PFAS exposure. This paper comprehensively reviews the insights of omics approaches, especially the multi-omics approach, on the toxic mechanisms of both legacy and emerging PFASs in recent five years, focusing on hepatotoxicity, developmental toxicity, immunotoxicity, reproductive toxicity, neurotoxicity, and the endocrine-disrupting effect. PFASs exert various toxic effects via lipid and amino acid metabolism disruption, perturbations in several cell signal pathways, and binding to nuclear receptors. Notably, integrating multi-omics offers a thorough insight into the mechanisms of toxicity associated with PFASs. The gut microbiota plays an essential regulatory role in the toxic mechanisms of PFAS-induced hepatotoxicity. Finally, further research directions for PFAS toxicology based on omics technologies are prospected.

Effects of perfluorooctanoic acid and nano titanium dioxide on the immune response and energy allocation in Mytilus coruscus

Perfluorooctanoic acid (PFOA) functions as a surfactant, while nano-titanium dioxide (nano-TiO2) serves as an antibacterial agent. These substances are extensively utilized in industrial production and, upon release into aquatic environments, pose significant threats to the viability and development of marine organisms. However, research into the effects of PFOA and nano-TiO2 on the immune functions and cellular energy allocation (CEA) of bivalves remains limited. To investigate the impact of PFOA and nano-TiO2 on immunity and cellular energy, we exposed Mytilus coruscus individuals to different concentrations of PFOA (2 and 200 μg/L), either alone or in combination with nano-TiO2 (0.1 mg/L, particle size: 25 nm) for 14 days. We found that the co-exposure to PFOA and nano-TiO2 had significant interactive effects on multiple immune function parameters of mussels. PFOA and nano-TiO2 notably reduced the total hemocyte count (THC), esterase activity (EST), mitochondrial number (MN), lysosomal content (LYSO), and cell viability, while concurrently elevating hemocyte mortality (HM) and reactive oxygen species (ROS) levels. Some immune-related genes, such as Tumor Necrosis Factor-alpha (TNF-α) and Myeloid Differentiation Primary Response 88 (MyD88) were downregulated, while others such as Interleukin 17 (IL-17) and Transforming Growth Factor-beta (TGF-β) were upregulated after 14-day exposure to combined pollutant exposure. Furthermore, negative effects on CEA were observed under both individual and combined pollutant stress. Therefore, PFOA and nano-TiO2 regulate cellular and humoral immunity through the regulation of immune genes as mediators, while simultaneously disrupting cellular energy metabolism. The immunotoxicity of organic and particulate pollutants, and their mixtures, thus poses a significant risk to the immune defense capabilities of mussel populations in polluted coastal environments.

Bioactivity Profiling of Chemical Mixtures for Hazard Characterization

The assessment and regulation of chemical toxicity to protect human health and the environment are done one chemical at a time and seldom at environmentally relevant concentrations. However, chemicals are found in the environment as mixtures, and their toxicity is largely unknown. Understanding the hazard posed by chemicals within the mixture is critical to enforce protective measures. Here, we demonstrate the application of bioactivity profiling of environmental water samples using the sentinel and ecotoxicology model species Daphnia to reveal the biomolecular response induced by exposure to real-world mixtures. We exposed a Daphnia strain to 30 sampled waters of the Chaobai River and measured the gene expression response profiles. Using a multiblock correlation analysis, we establish correlations between chemical mixtures identified in 30 water samples with gene expression patterns induced by these chemical mixtures. We identified 80 metabolic pathways putatively activated by mixtures of inorganic ions, heavy metals, polycyclic aromatic hydrocarbons, industrial chemicals, and a set of biocides, pesticides, and pharmacologically active substances. Our data-driven approach discovered both known bioactivity signatures with previously described modes of action and new pathways linked to undiscovered potential hazards. This study demonstrates the feasibility of reducing the complexity of real-world mixture toxicity to characterize the biomolecular effects of a defined number of chemical components based on gene expression monitoring of the sentinel species Daphnia.

Exploring the effects of perfluorooctanoic acid (PFOA) and tetrabromobisphenol A (TBBP-A) on silkworm from the insights of metabolome

Perfluorooctanoic acid (PFOA) and tetrabromobisphenol A (TBBP-A) are emerging environmental contaminants with recognized potential health and ecological risks. This study investigated the effects of PFOA and TBBP-A exposure on the global of metabolites of silkworm gut with GC-MS metabolomics. Our results revealed distinct metabolic alterations in silkworms exposed to PFOA and TBBP-A, highlighting their differential impacts on silkworm health and productivity. Exposure to these chemicals significantly altered metabolic profiles, leading to disruptions in pathways related to lipid, carbohydrate, and amino acid metabolism. These findings suggest that PFOA and TBBP-A disrupt crucial metabolic processes in silkworms, indicating potential toxicity and prompting further investigation into their effects on human health and the environment. Ongoing research is crucial to develop safer alternatives and mitigate the risks associated with these persistent contaminants.

Neurotoxicity of per- and polyfluoroalkyl substances: Evidence and future directions

Per- and polyfluoroalkyl substances (PFAS) are synthetic chemicals widely used in various products, including food packaging, textiles, and firefighting foam, owing to their unique properties such as amphiphilicity and strong CF bonds. Despite their widespread use, concerns have arisen due to their resistance to degradation and propensity for bioaccumulation in both environmental and human systems. Emerging evidence suggests a potential link between PFAS exposure and neurotoxic effects, spanning cognitive deficits, neurodevelopmental disorders, and neurodegenerative diseases. This review comprehensively synthesizes current knowledge on PFAS neurotoxicity, drawing insights from epidemiological studies, animal experiments, and mechanistic investigations. PFAS, known for their lipophilic nature, tend to accumulate in lipid-rich tissues, including the brain, breaching biological barriers such as the blood-brain barrier (BBB). The accumulation of PFAS within the central nervous system (CNS) has been implicated in a spectrum of neurological maladies. Neurotoxicity induced by PFAS manifests through a multitude of direct and indirect mechanisms. A growing body of research associated PFAS exposure with BBB disruption, calcium dysregulation, neurotransmitter alterations, neuroinflammation, oxidative stress, and mitochondrial dysfunction, all contributing to neuronal impairment. Despite notable strides in research, significant lacunae persist, necessitating further exploration to elucidate the full spectrum of PFAS-mediated neurotoxicity. Prospective research endeavors should prioritize developing biomarkers, delineating sensitive exposure windows, and exploring mitigation strategies aimed at safeguarding neurological integrity within populations vulnerable to PFAS exposure.

Identification of sanguinarine as a novel antagonist for perfluorooctanoate/perfluorooctane sulfonate-induced senescence of hepatocytes: An integrated computational and experimental analysis

Perfluorooctanoate (PFOA) and perfluorooctane sulfonate (PFOS), two prominent per- and polyfluoroalkyl substances (PFASs), are potentially harmful to many human organs. However, there only exist limited methods to mitigate their health hazards. The aim of this study is to combine a bioinformatics analysis with in vitro experiments to discover small molecules that can alleviate liver damage caused by PFOA/PFOS. We identified 192 and 82 key genes related to hepatocytes exposed to PFOA and PFOS, respectively. The functional enrichment analysis of key genes suggested cellular senescence may be important in PFOA/PFOS-induced hepatotoxicity. The in vitro models revealed that PFOA/PFOS led to hepatocyte senescence by increasing the activity of SA-β-gal, inducing mitochondrial dysfunction, impacting cell cycle arrest, and elevating the expressions of p21, p53, IL-1β, and SASP-related cytokines. The drug-target gene set enrichment analysis method was employed to compare the transcriptome data from the Gene Expression Omnibus database (GEO), Comparative Toxicogenomics Database (CTD), and the high-throughput experiment- and reference-guided database (HERB), and 21 traditional Chinese medicines (TCMs) were identified that may alleviate PFOA/PFOS-induced liver aging. The experimental results of co-exposure to PFOA/PFOS and TCMs showed that sanguinarine has particular promise in alleviating cellular senescence caused by PFOA/PFOS. Further investigations revealed that the mTOR-p53 signaling pathway was involved in PFOA/PFOS-mediated hepatic senescence and can be blocked using sanguinarine.

Sex and obesity influence the relationship between perfluoroalkyl substances and lean body mass: NHANES 2011-2018

Objective

Polyfluoroalkyl substances (PFAS) are known endocrine disruptors, that have been the subject of limited research regarding their impact on human lean body mass. The aim of this study was to investigate the effects of PFAS exposure on lean body mass.

Methods

We performed a cross-sectional data analysis involving 1022 adolescents and 3274 adults from the National Health and Nutrition Examination Survey (NHANES) 2011-2018, whose lean body mass was measured by dual-energy X-ray absorptiometry. The lean mass index (LMI) was calculated as lean body mass dividing by the square of height. The association between PFAS and LMI was examined through a multivariate-adjusted weighted generalized linear model. Moreover, weighted quantile sum (WQS) regression models were employed to futher examine the relationship between the mixture of PFAS and LMI.

Results

Regression analyses revealed an inverse correlation between PFAS exposure and LMI after adjusting for potential covariates. Adults with higher serum PFAS concentrations manifested a reduction in whole LMI ( β  = -0.193, 95 % confidence interval (CI): -0.325 to -0.06). Notably, this correlation was particularly significant in adult females and individuals with obesity, and it was observed across diverse anatomical regions, including lower limbs, right arm, trunk, and whole lean body mass. In adult females, the association between PFAS and whole LMI was statistically significant ( β  = -0.294, 95 % CI: -0.495 to -0.094), and a similar trend was found in obese individuals ( β  = -0.512, 95 % CI: -0.762 to -0.261). WQS regression analyses supported the results obtained from weighted linear regression analyses.

Conclusions

Our study suggests that exposure to PFAS, whether individually or in combination, is associated with decreased lean body mass in specific body areas, with sex and obesity serving as major influencing factors.

Transcriptome and Metabolome analysis reveal HFPO-TA induced disorders of hepatic glucose and lipid metabolism in rat by interfering with PPAR signaling pathway

PFOA is one of the most representative compounds in the family of perfluorinated organic compounds. Due to its varying toxicity, alternatives to PFOA are beginning to emerge. HFPO-TA is an alternative for PFOA. It is currently unclear whether HFPO-TA affects glucose and lipid metabolism. In this study, rats were used as an animal model to investigate the effects of HFPO-TA on liver glucose and lipid metabolism. We found that HFPO-TA can affect glucose tolerance. Through omics analysis and molecular detection, it was found that HFPO-TA mainly affects the PPAR signaling pathway in the liver of rats, inhibiting liver glycolysis while promoting glucose production. HFPO-TA not only promotes the synthesis of fatty acids in the liver, but also promotes the breakdown of fatty acids, which ultimately leads to the disruption of hepatic glucose and lipid metabolism. The effects of HFPO-TA on metabolism are discussed in this paper to provide a reference for the risk assessment of this PFOA substitute.

An Atomic and Molecular Insight into How PFOA Reduces α-Helicity, Compromises Substrate Binding, and Creates Binding Pockets in a Model Globular Protein

Per- and polyfluoroalkyl substances (PFAS) pose significant health risks due to their widespread presence in various environmental and biological matrices. However, the molecular-level mechanisms underlying the interactions between PFAS and biological constituents, including proteins, carbohydrates, lipids, and DNA, remain poorly understood. Here, we investigate the interactions between a legacy PFAS, viz. perfluorooctanoic acid (PFOA), and the milk protein β-lactoglobulin (BLG) obtained using a combination of experimental and computational techniques. Circular dichroism studies reveal that PFOA perturbs the secondary structure of BLG, by driving a dose-dependent loss of α-helicity and alterations in its β-sheet content. Furthermore, exposure of the protein to PFOA attenuates the on-rate constant for the binding of the hydrophobic probe 8-anilino-1-naphthalene sulfonic acid (ANS), suggesting potential functional impairment of BLG by PFOA. Steered molecular dynamics and umbrella sampling calculations reveal that PFOA binding leads to the formation of an energetically favorable novel binding pocket within the protein, when residues 129-142 are steered to unfold from their initial α-helical structure, wherein a host of intermolecular interactions between PFOA and BLG's residues serve to insert the PFOA into the region between the unfolded helix and beta-sheets. Together, the data provide a novel understanding of the atomic and molecular mechanism(s) by which PFAS modulates structure and function in a globular protein, leading to a beginning of our understanding of altered biological outcomes.

Environment relevant exposure of perfluorooctanoic acid accelerates the growth of hepatocellular carcinoma cells through mammalian target of rapamycin (mTOR) signal pathway

Perfluorooctanoic acid (PFOA), a synthetic alkyl chain fluorinated compound, has emerged as a persistent organic pollutant of grave concern, casting a shadow over both ecological integrity and humans. Its insidious presence raises alarms due to its capacity to bioaccumulate within the human liver, potentially paving the treacherous path toward liver cancer. Yet, the intricate mechanisms underpinning PFOA's role in promoting the growth of hepatocellular carcinoma (HCC) remain shrouded in ambiguity. Here, we determined the proliferation and transcription changes of HCC after PFOA exposure through integrated experiments including cell culture, nude mice tests, and colony-forming assays. Based on our findings, PFOA effectively promotes the proliferation of HCC cells within the experimental range of concentrations, both in vivo and in vitro. The proliferation efficiency of HCC cells was observed to increase by approximately 10% due to overexposure to PFOA. Additionally, the cancer weight of tumor-bearing nude mice increased by 87.0% (p < 0.05). We systematically evaluated the effects of PFOA on HCC cells and found that PFOA's exposure can selectively activate the PI3K/AKT/mTOR/4E-BP1 signaling pathway, thereby playing a pro-cancer effect on HCC cells Confirmation echoed through western blot assays and inhibitor combination analyses. These insights summon a response to PFOA's dual nature as both an environmental threat and a promoter of liver cancer. Our work illuminates the obscured domain of PFOA-induced hepatoxicity, shedding light on its ties to hepatocellular carcinoma progression.