Integrated transcriptomics and metabolomics reveal signatures of lipid metabolism dysregulation in HepaRG liver cells exposed to PCB 126

Bioconcentration, oxidative stress and molecular mechanism of the toxic effect of acetamiprid exposure on Xenopus laevis tadpoles

Acetamiprid is a neonicotinoid commonly detected in aquatic ecosystems, with residual concentrations of up to 0.41 mg/L in surface water, posing a threat to the health of nontarget aquatic organisms. However, studies on the potential toxicity and underlying mechanisms of action of acetamiprid on nontarget aquatic organisms are limited. This study investigated the acute and short-term toxicity of acetamiprid to Xenopus laevis tadpoles. A 96-h acute toxicity test determined the LC50 of acetamiprid to be 32.1 mg/L. After 28 days of exposure to 1/10 and 1/100 LC50 concentrations, tadpole samples were collected for bioconcentration elimination analysis, biochemical analyses, transcriptomics, and metabolomics studies to comprehensively evaluate the toxic effects of acetamiprid and its underlying mechanisms. The results, indicating bioconcentration factors (BCFs) < 1, suggest that acetamiprid has a low bioconcentration in tadpoles. Additionally, oxidative stress was observed in treated Xenopus laevis tadpoles. Transcriptomic and nontargeted metabolomic analyses identified 979 differentially expressed genes (DEGs) and 95 differentially metabolites in the 0.321 mg/L group. The integrated analysis revealed that disruption of purine and amino acid metabolic pathways potentially accounts for acetamiprid-induced toxic effects in tadpoles. The disruptive effects of acetamiprid on valine, leucine and isoleucine biosynthesis; and aminoacyl-tRNA biosynthesis metabolic pathways in tadpoles were validated through targeted metabolomics analysis. These findings are crucial for assessing the risk of acetamiprid to nontarget aquatic organisms.

Metabolic and phenotypic changes induced by PFAS exposure in two human hepatocyte cell models

PFAS are ubiquitous industrial chemicals with known adverse health effects, particularly on the liver. The liver, being a vital metabolic organ, is susceptible to PFAS-induced metabolic dysregulation, leading to conditions such as hepatotoxicity and metabolic disturbances. In this study, we investigated the phenotypic and metabolic responses of PFAS exposure using two hepatocyte models, HepG2 (male cell line) and HepaRG (female cell line), aiming to define phenotypic alterations, and metabolic disturbances at the metabolite and pathway levels. The PFAS mixture composition was selected based on epidemiological data, covering a broad concentration spectrum observed in diverse human populations. Phenotypic profiling by Cell Painting assay disclosed predominant effects of PFAS exposure on mitochondrial structure and function in both cell models as well as effects on F-actin, Golgi apparatus, and plasma membrane-associated measures. We employed comprehensive metabolic characterization using liquid chromatography combined with high-resolution mass spectrometry (LC-HRMS). We observed dose-dependent changes in the metabolic profiles, particularly in lipid, steroid, amino acid and sugar and carbohydrate metabolism in both cells as well as in cell media, with HepaRG cell line showing a stronger metabolic response. In cells, most of the bile acids, acylcarnitines and free fatty acids showed downregulation, while medium-chain fatty acids and carnosine were upregulated, while the cell media showed different response especially in relation to the bile acids in HepaRG cell media. Importantly, we observed also nonmonotonic response for several phenotypic features and metabolites. On the pathway level, PFAS exposure was also associated with pathways indicating oxidative stress and inflammatory responses. Taken together, our findings on PFAS-induced phenotypic and metabolic disruptions in hepatocytes shed light on potential mechanisms contributing to the broader comprehension of PFAS-related health risks.

Comparative Analysis of Metabolome and Transcriptome in Different Tissue Sites of Aquilaria sinensis (Lour.) Gilg

The resinous stem of Aquilaria sinensis (Lour.) Gilg is the sole legally authorized source of agarwood in China. However, whether other tissue parts can be potential substitutes for agarwood requires further investigation. In this study, we conducted metabolic analysis and transcriptome sequencing of six distinct tissues (root, stem, leaf, seed, husk, and callus) of A. sinensis to investigate the variations in metabolite distribution characteristics and transcriptome data across different tissues. A total of 331 differential metabolites were identified by chromatography-mass spectrometry (GC-MS), of which 22.96% were terpenoids. The differentially expressed genes (DEGs) in RNA sequencing were enriched in sesquiterpene synthesis via the mevalonate pathway. The present study establishes a solid foundation for exploring potential alternatives to agarwood.

Integrated analysis of multiple metabolome and transcriptome revealed the accumulation of flavonoids and associated molecular regulation mechanisms in Rubus chingii Hu at different developmental stages

The traditional Chinese herb Rubus chingii Hu (R. chingii) is widely used in clinical practice due to its beneficial effects. Flavonoids are the important class of pharmacological substances in R. chingii, however, the molecular mechanism underlying the differences in active flavonoid contents in R. chingii at different developmental stages remain poorly understood. In this experiment, we selected four developmental stages (GG, GY, YR, RR) of R. chingii as the research material. We studied the untargeted and targeted metabolic profiles of flavonoids in different periods of R. chingii, combining full-length and comparative transcriptome analyses. Functional analyses were conducted on genes implicated in flavonoid differences. GG and RR displayed relatively higher and lower contents of flavonols, flavones, flavanols, flavanones, and isoflavonoid, respectively. RNA-seq analyses showed structural genes such as RcPAL, RcC4H, Rc4CL, RcCHS, RcCHI, RcF3H, RcF3'H, and RcFLS in flavonoid biosynthesis pathway were upregulated in GG, which were essential for the accumulation flavanones, flavones, and flavonols (effective components). qRT-PCR analyses investigated that six structural genes RcCHI, RcF3H, 2 RcCHS, and 2 Rc4CL, two TFs RcMYB308 and RcMYB123 had a consistent expression pattern with which in transcriptome. Also, an interaction network showed that the RcMYB308 could positively regulate Ka3R, Qu, Qu3G, AS, Hy, Ti through RcF3H. Furthermore, Subcellular localization analysis revealed that RcMYB308 was localization to the nucleus. In tobacco, RcMYB308 was overexpressed, resulting in higher flavonoids, RcF3H, RcF3'H, RcCHI, and RcFLS. RcMYB308 upregulated RcF3H in dual-luciferase assays. These results provide new insights for further understanding the molecular mechanism regulating flavonol biosynthesis in R. chingii fruit, and also provide a potential MYB regulator for molecular breeding of R. chingii.

Dietary exposure to endocrine disruptors in gut microbiota: A systematic review

Endocrine disrupting chemicals (EDCs) can interfere with hormonal actions and have been associated with a higher incidence of metabolic disorders. They affect numerous physiological, biochemical, and endocrinal activities, including reproduction, metabolism, immunity, and behavior. The purpose of this review was to elucidate the association of EDCs in food with the gut microbiota and with metabolic disorders. EDC exposure induces changes that can lead to microbial dysbiosis. Products and by-products released by the microbial metabolism of EDCs can be taken up by the host. Changes in the composition of the microbiota and production of microbial metabolites may have a major impact on the host metabolism.

BPA and its alternatives BPF and BPAF exaggerate hepatic lipid metabolism disorders in male mice fed a high fat diet

Alternatives to Bisphenol A (BPA), such as BPF and BPAF, have found increasing industrial applications. However, toxicological research on these BPA analogues remains limited. This study aimed to investigate the effects of BPA, BPF, and BPAF exposure on hepatotoxicity in mice fed with high-fat diets (HFD). Male mice were exposed to the bisphenols at a dose of 0.05 mg per kg body weight per day (mg/kg bw/day) for eight consecutive weeks, or 5 mg/kg bw/day for the first week followed by 0.05 mg/kg bw/day for seven weeks under HFD. The low dose (0.05 mg/kg bw/day) was corresponding to the tolerable daily intake (TDI) of BPA and the high dose (5 mg/kg bw/day) was corresponding to its no observed adverse effect level (NOAEL). Biochemical analysis revealed that exposure to these bisphenols resulted in liver damage. Metabolomics analysis showed disturbances of fatty acid and lipid metabolism in bisphenol-exposed mouse livers. BPF and BPAF exposure reduced lipid accumulation in HFD mouse liver by lowering glyceride and cholesterol levels. Transcriptomics analysis demonstrated that expression levels of genes related to fatty acid synthesis and metabolism were changed, which might be related to the activation of the PPAR signaling pathway. Besides, a feedback regulation mechanism might exist to maintain hepatic metabolic homeostasis. For the first time, this study demonstrated the effects of BPF and BPAF exposure in HFD-mouse liver. Considering the reality of the high prevalence of obesity nowadays and the ubiquitous environmental distribution of bisphenols, this study provides insight and highlights the adverse effects of BPA alternatives, further contributing to the consideration of the safe use of such compounds.

Metabolome-wide association study of four groups of persistent organic pollutants and abnormal blood lipids

Environmental exposure increases the risk of dyslipidemia, which affects human health. Research has shown that persistent organic pollutants (POPs), including per- and polyfluoroalkyl substances (PFASs), polychlorinated biphenyls, polybrominated diphenyl ethers, and phthalate metabolites, are associated with a higher risk of abnormal blood lipid levels in humans. However, the key molecules involved in dyslipidemia and the mechanisms are not fully understood. This study aims to investigate the biomarkers that mediate the relationships between blood lipids and four groups of POPs and revealed their potential mechanisms. Specifically, in 278 male blood samples, blood lipid and POPs levels were measured and metabolites were detected using untargeted metabolomics. Spearman's correlation analysis and binary logistic regression were employed to assess the relationship between POPs and lipid indexes. We observed that PFASs were associated with a higher risk of abnormal total cholesterol (TC) and low-density lipoprotein (LDL), while other POPs displayed little association with abnormal lipid indexes. Among all the PFASs, 6:2Cl-PFESA was associated with the fewest metabolites. A metabolome-wide association study combined with a meet-in-the-middle approach was used to identify potential biomarkers that mediate the association between POPs and abnormal blood lipids. The mediation analysis pointed to 105 significant mediators as potential biomarkers mediating the association between PFASs and TC, and 82 significant mediators were potential biomarkers that mediated the association between PFASs and LDL. 24-Hydroxycholesterol, 3alpha,7alpha-dihydroxy-5beta-cholestan-26-al, PC(18:0/0:0), PC(22:5/0:0), GPCho(18:1/18:1), LysoPC(22:2(13Z,16Z)), LysoPC(16:0), 9(S)-HODE, 9,10-DHOME, l-glutamate, 4-hydroxybutyric acid, cytosine, PC(14:1(9Z)/18:0), sphinganine, and (S)-beta-aminoisobutyrate were identified as important biomarkers. The mechanism may mainly involves glycerophospholipid metabolism, primary bile acid biosynthesis, and linoleic acid metabolism. PPARγ likely plays a role in the associations between PFASs and abnormal cholesterol metabolism. Overall, our study provides clues for the early detection of PFAS-induced dyslipidemia and brings forth a theoretical framework for further research into this mechanism.

Transcriptomics and Metabolomics for Co-Exposure to a Cocktail of Neonicotinoids and the Synergist Piperonyl Butoxide

Here, the transcriptomics and metabolomics on a model of exposure to a cocktail of neonicotinoids (Neo) containing seven commercial compounds and a synergist piperonyl butoxide (PBO) were established. The results showed that Neo and PBO disrupted mRNA and metabolite levels in a dose-dependent manner. Neo caused tryptophan pathway-related neurotoxicity, reduced lipolysis, and promoted fat mass accumulation in the liver, while PBO induced an increase in inflammatory factors and damage to intercellular membranes. Co-exposure enhanced Neo-induced liver steatosis, focal necrosis, and oxidative stress by inhibiting oxidative phosphorylation (OXPHOS). Furthermore, diglycerides and metabolic biomarkers demonstrated that the activation of insulin signaling is associated with restricted OXPHOS, which commonly leads to a high risk of non-alcoholic fatty liver disease (NAFLD) and Alzheimer's disease (AD) as the result of over-synthesis of lipids, low energy supply, and high thermogenesis. The study demonstrates that chronic disease can be induced by Neo and the synergist PBO at the molecular level.

The environmental pollutant, polychlorinated biphenyl 126, alters liver function in a rodent model of alcohol-associated liver disease

BACKGROUND

The prevalence of alcohol-associated liver disease (ALD), a subtype of fatty liver disease (FLD), continues to rise. ALD is a major cause of preventable death. Polychlorinated biphenyl (PCB) 126 is an environmentally relevant, dioxin-like pollutant whose negative metabolic effects have been well documented. In human and animal studies, PCB has been associated with the severity of nonalcoholic fatty liver disease (NAFLD). However, few studies have investigated whether exposures to environmental toxicants can worsen ALD. Thus, the objective of the current study was to develop an alcohol-plus-toxicant model to study how an environmental pollutant, PCB 126, impacts rodent ALD pathology.

METHODS

Briefly, male C57BL/6J mice were exposed to 0.2 mg/kg PCB 126 or corn oil vehicle four days prior to ethanol feeding using the chronic-binge (10-plus-one) model.

RESULTS

Concentrations of macromolecules, including hepatic lipids, carbohydrates, and protein (albumin) were impacted. Exposure to PCB 126 exacerbated hepatic steatosis and hepatomegaly in mice exposed to the chemical and fed an ethanol diet. Gene expression and the analysis of blood chemistry showed a potential net increase and retention of hepatic lipids and reductions in lipid oxidation and clearance capabilities. Depletion of glycogen and glucose was evident, which contributes to disease progression by generating systemic malnutrition. Granulocytic immune infiltrates were present but driven solely by ethanol feeding. Hepatic albumin gene expression and plasma levels were decreased by ~50% indicating a potential compromise of liver function. Finally, gene expression analyses indicated that the aryl hydrocarbon receptor and constitutive androstane receptor were activated by PCB 126 and ethanol, respectively.

CONCLUSIONS

Various environmental toxicants are known to modify or enhance FLD in high-fat diet models. Findings from the present study suggest that they interact with other lifestyle factors such as alcohol consumption to reprogram intermediary metabolism resulting in exacerbated ethanol-associated systemic malnutrition in ALD.

Early Life Polychlorinated Biphenyl 126 Exposure Disrupts Gut Microbiota and Metabolic Homeostasis in Mice Fed with High-Fat Diet in Adulthood

Evidence supports the potential influence of persistent organic pollutants (POPs) on the pathogenesis and progression of obesity and diabetes. Diet-toxicant interactions appear to be important in diet-induced obesity/diabetes; however, the factors influencing this interaction, especially the early life environmental exposure, are unclear. Herein, we investigated the metabolic effects following early life five-day exposure (24 μg/kg body weight per day) to 3,3′,4,4′,5-pentacholorobiphenyl (PCB 126) at four months after exposure in mice fed with control (CTRL) or high-fat diet (HFD). Activation of aryl hydrocarbon receptor (AHR) signaling as well as higher levels of liver nucleotides were observed at 4 months after PCB 126 exposure in mice, independent of diet status. Inflammatory responses including higher levels of serum cytokines and adipose inflammatory gene expression caused by early life PCB 126 were observed only in HFD-fed mice in adulthood. Notably, early life PCB 126 exposure worsened HFD-induced impaired glucose homeostasis characterized by glucose intolerance and elevated gluconeogenesis and tricarboxylic acid (TCA) cycle flux without worsening the effects of HFD related to adiposity in adulthood. Furthermore, early life PCB 126 exposure resulted in diet-dependent changes in bacterial community structure and function later in life, as indicated by metagenomic and metabolomic analyses. These data contribute to a more comprehensive understanding of the interactions between diet and early life environmental chemical exposure.

Environmental Toxicants and NAFLD: A Neglected yet Significant Relationship

The liver is an organ of vital importance in the body; it is the center of metabolic activities and acts as the primary line of defense against toxic compounds. Exposure to environmental toxicants is an unavoidable fallout from rapid industrialization across the world and is even higher in developing countries. Technological development and industrialization have led to the release of toxicants such as pollutant toxic gases, chemical discharge, industrial effluents, pesticides and solvents, into the environment. In the last few years, a growing body of evidence has shed light on the potential impact of environmental toxicants on liver health, in particular, on non-alcoholic fatty liver disease (NAFLD) incidence and progression. NAFLD is a multifactorial disease linked to metabolic derangement including diabetes and other complications. Environmental toxicants including xenobiotics and pollutants may have a direct or indirect steatogenic/fibrogenic impact on the liver and should be considered as risk factors associated with NAFLD. This review discusses the contribution of environmental toxicants toward the increasing disease burden of NAFLD.

L, Li H, Ba G, Cho S. Metabolomics investigation on antiobesity effects of Corydalis bungeana on high-fat high-sugar diet-induced obese rats

Objective

Corydalis bungeana (CB) is a well-used medicinal herb in Mongolian folk medicine and has been traditionally applied as an antiobesity agent. However, the evidence-based pharmacological effects of CB and its specific metabolic alterations in the obese model are not entirely understood. This study aimed to utilize untargeted metabolomic techniques to identify biomarkers and gain mechanistic insight into the serum metabolite alterations associated with weight loss and lipid metabolism in obese rats.

Methods

A high-fat high-sugar (HFHS) diet was used to induce obese models in rats. CB extract was orally gavaged at 0.18, 0.9 and 1.8 g/kg doses for six weeks, and feed intake, body weight, fat pad weight, and blood indexes were measured. Blood serum metabolites were evaluated by gas chromatography/quadrupole time-of-flight tandem mass spectrometry (GC-TOF/MS).

Results

The results showed that compared with the obese group, the administration of CB extract caused significant decreases in body weight (P < 0.05), feed intake, Lee's index, and perirenal, mesenteric, epididymal fat weight. CB extract also reduced blood triglyceride and total cholesterol levels (P < 0.05) of obese rats. Metabolomic findings showed that nine differential metabolites, including pyruvic acid, D-glucuronic acid, malic acid, dimethylglycine, oxoglutaric acid, pantothenic acid, sorbitol acid, fumaric acid and glucose 6-phosphate were identified under CB treatment and altered metabolic pathways such as TCA cycle, pantothenate and CoA biosynthesis, and glycolysis/gluconeogenesis.

Conclusion

This study demonstrated weight loss and lipid lowering effects of CB on HFHS diet-induced obese rats and identified nine metabolites as potential biomarkers for evaluating the favorable therapeutic mechanism of CB via regulation of lipid and glucose metabolism.

Metabolomics and lipidomics to identify biomarkers of effect related to exposure to non-dioxin-like polychlorinated biphenyls in pigs

Recent epidemiological studies show that current levels of exposure to polychlorinated biphenyls (PCBs) remain of great concern, as there is still a link between such exposures and the development of chronic environmental diseases. In this sense, most studies have focused on the health effects caused by exposure to dioxin-like PCBs (DL-PCBs), although chemical exposure to non-dioxin-like PCB (NDL-PCB) congeners is more significant. In addition, adverse effects of PCBs have been documented in humans after accidental and massive exposure, but little is known about the effect of chronic exposure to low-dose PCB mixtures. In this work, exposure to Aroclor 1260 (i.e. a commercially available mixture of PCBs consisting primarily of NDL-PCB congeners) in pigs is investigated as new evidence in the risk assessment of NDL-PCBs. This animal model has been selected due to the similarities with human metabolism and to support previous toxicological studies carried out with more frequently used animal models. Dietary exposure doses in the order of few ng/kg body weight (b.w.) per day were applied. As expected, exposure to Aroclor 1260 led to the bioaccumulation of NDL-PCBs in perirenal fat of pigs. Metabolomics and lipidomics have been applied to reveal biomarkers of effect related to Aroclor 1260 exposure, and by extension to NDL-PCB exposure, for 21 days. In the metabolomics analysis, 33 metabolites have been identified (level 1 and 2) as significantly altered by the Aroclor 1260 administration, while in the lipidomics analysis, 39 metabolites were putatively annotated (level 3) and associated with NDL-PCB exposure. These biomarkers are mainly related to the alteration of fatty acid metabolism, glycerophospholipid metabolism and tryptophan-kynurenine pathway.

Transcriptome sequencing of 3,3',4,4',5-Pentachlorobiphenyl (PCB126)-treated human preadipocytes demonstrates progressive changes in pathways associated with inflammation and diabetes

Polychlorinated biphenyls (PCBs) are persistent organic pollutants that accumulate in adipose tissue and have been associated with cardiometabolic disease. We have previously demonstrated that exposure of human preadipocytes to the dioxin-like PCB126 disrupts adipogenesis via the aryl hydrocarbon receptor (AhR). To further understand how PCB126 disrupts adipose tissue cells, we performed RNAseq analysis of PCB126-treated human preadipocytes over a 3-day time course. The most significant predicted upstream regulator affected by PCB126 exposure at the early time point of 9 h was the AhR. Progressive changes occurred in the number and magnitude of transcript levels of genes associated with inflammation, most closely fitting the pathways of cytokine-cytokine-receptor signaling and the AGE-RAGE diabetic complications pathway. Transcript levels of genes involved in the IL-17A, IL-1β, MAP kinase, and NF-κB signaling pathways were increasingly dysregulated by PCB126 over time. Our results illustrate the progressive time-dependent nature of transcriptional changes caused by toxicants such as PCB126, point to important pathways affected by PCB126 exposure, and provide a rich dataset for further studies to address how PCB126 and other AhR agonists disrupt preadipocyte function. These findings have implications for understanding how dioxin-like PCBs and other dioxin-like compounds are involved in the development of obesity and diabetes.

Effect of synbiotic yogurt fortified with monk fruit extract on hepatic lipid biomarkers and metabolism in rats with type 2 diabetes

Monk fruit extract (MFE) is widely used as a sweetener in foods. In this study, the effects of the consumption of MFE-sweetened synbiotic yogurt on the lipid biomarkers and metabolism in the livers of type 2 diabetic rats were evaluated. The results revealed that the MFE-sweetened symbiotic yogurt affected the phosphatidylcholines, phosphatidylethanolamines, phosphatidylglycerol, lysophosphatidic acids, lysophosphatidylcholines, lysophosphatidylethanolamines, lysophosphatidylglycerols, lysophosphatidylinositols, lysophosphatidylserines, and fatty acid-hydroxy fatty acids biomarkers in the livers of type 2 diabetic rats. In addition, the consumption of the MFE-sweetened synbiotic yogurt significantly altered 12 hepatic metabolites, which are involved in phenylalanine metabolism, sphingolipid metabolism, bile secretion, and glyoxylate and dicarboxylate metabolism in the liver. Furthermore, a multiomics (metabolomic and transcriptomic) association study revealed that there was a significant correlation between the MFE-sweetened synbiotic yogurt and the metabolites and genes involved in fatty acid biosynthesis, bile secretion, and glyoxylate and dicarboxylate metabolism. The findings of this study will provide new insights on exploring the function of sweeteners for improving type 2 diabetes mellitus liver lipid biomarkers.

Recent advances in PCB removal from historically contaminated environmental matrices

Despite being drastically restricted in the 1970s, polychlorinated biphenyls (PCBs) still belong among the most hazardous contaminants. The chemical stability and dielectric properties of PCBs made them suitable for a number of applications, which then lead to their ubiquitous presence in the environment. PCBs are highly bioaccumulative and persistent, and their teratogenic, carcinogenic, and endocrine-disrupting features have been widely reported in the literature. This review discusses recent advances in different techniques and approaches to remediate historically contaminated matrices, which are one of the most problematic in regard to decontamination feasibility and efficiency. The current knowledge published in the literature shows that PCBs are not sufficiently removed from the environment by natural processes, and thus, the suitability of some approaches (e.g., natural attenuation) is limited. Physicochemical processes are still the most effective; however, their extensive use is constrained by their high cost and often their destructiveness toward the matrices. Despite their limited reliability, biological methods and their application in combinations with other techniques could be promising. The literature reviewed in this paper documents that a combination of techniques differing in their principles should be a future research direction. Other aspects discussed in this work include the incompleteness of some studies. More attention should be given to the evaluation of toxicity during these processes, particularly in terms of monitoring different modes of toxic action. In addition, decomposition mechanisms and products need to be sufficiently clarified before combined, tailor-made approaches can be employed.

Differences in biological efficiency of one- and two-component graminicide on sugar beet crops in Tula region

One of the most urgent tasks in sugar beet production for Russia today is irregularities in cultivation technology and a low-efficiency crop protection. It leads to a high level of weed infestation of agricultural fields. Developing and identifying the most efficient, selective and accessible herbicides, which have low phytotoxicity, do not have a negative effect on soil chemical characteristics and can be used in sugar beet cultivation is relevant today. The aim of this study was to examine and compare biological efficiency of various doses and concentrations of one- and two-component graminicides on sugar beet crops against the following weeds: Cockspur grass Echinochloa crusgalli (L.) Beauv., Wild millet Setaria glauca (L.) Beauv. and Couch Grass Elytrigia repens (L.) Nevski. The experiment was conducted on the territory of the Tula region in 2020. The total field experiment area was 480 m2. Application of clethodim + quizalofop-P-ethyl (0.5 l/ha) resulted in reducing the number and weight of annual weeds by 6471 %, reducing the number and weight of perennial weeds by 5458 %, which had the same efficiency as clethodim (0.6 l/ha). The efficiency of clethodim + quizalofop-P-ethyl (1.0 l/ha) was higher than Clethodim (0.6 l/ha) and amounted to 7387 % of reduction in the number of weeds compared to the control, but was lower than Clethodim (1.8 l/ha), which resulted in 8995 % reduction in the number of weeds compared to the control. The highest sugar beet yields were obtained in the variants with clethodim (1.8 l/ha) and two-component herbicide (1 l/ha), which amounted to 28 and 25 % yield increase, in comparison with the control.

Transcriptomics and metabolomics analyses of the mechanism of flavonoid synthesis in seeds of differently colored quinoa strains

Quinoa (Chenopodium quinoa Willd.) is an herb of the genus Chenopodiaceae that is native to the Andes Mountains of South America. To understand the metabolic differences between various quinoa strains, we selected quinoa strains of four colors (black, red, yellow, and white) and we subjected seeds to extensive targeted metabolomics analysis using liquid chromatography-tandem mass spectrometry and transcriptomics analysis. In total, 90 flavonoid-related metabolites were detected in quinoa seeds of the four colors. We elucida ted the regulatory mechanisms of flavonoid biosynthesis in the different quinoa varieties, and thus identified key genes for flavonoid biosynthesis. The results showed that 18 flavone metabolites and 25 flavonoid-related genes were key contributors to flavonoid biosynthesis in quinoa seeds. The results of this study may provide a basis for the breeding and identification of new quinoa strains and for the screening of potential target genes in flavonoid biosynthesis regulation in quinoa.

Integrated metabolomics and transcriptomics reveal di(2-ethylhexyl) phthalate-induced mitochondrial dysfunction and glucose metabolism disorder through oxidative stress in rat liver

Di(2-ethylhexyl) phthalate (DEHP) is a ubiquitous pollutant that results in hepatotoxicity. However, an understanding of the systematic mechanism of hepatic injury caused by DEHP remains limited. Here, we performed a comprehensive metabolomics and transcriptomics analyses to describe hepatic responses of rats to long-term DEHP exposure and, together with pathology and functional injury of liver, systematically analyzed the pathogenesis and mechanisms of liver damage. SD rats were exposed to 0 and 600 mg/kg/day DEHP for 12 weeks. Thereafter, biochemical indicators and histopathological changes regarding liver function were detected. Metabolomics and transcriptomics profiles of rat liver samples were analyzed using a UPLC-MS/MS system and Illumina Hiseq 4000, respectively. DEHP induced hepatocyte structural alterations and edema, depressed monooxygenase activity, decreased antioxidant activities, aggravated oxidative damage, blocked the tricarboxylic acid cycle and respiratory chain, and disturbed glucose homeostasis in the liver. These findings indicate that reactive oxygen species play a major role in these events. Overall, this study systematically depicts the comprehensive mechanisms of long-term DEHP exposure to liver injury and highlights the power of metabolomics and transcriptomics platforms in the mechanistic understanding of xenobiotic hepatotoxicity.

Defining NASH from a Multi-Omics Systems Biology Perspective

Non-alcoholic steatohepatitis (NASH) is a chronic liver disease affecting up to 6.5% of the general population. There is no simple definition of NASH, and the molecular mechanism underlying disease pathogenesis remains elusive. Studies applying single omics technologies have enabled a better understanding of the molecular profiles associated with steatosis and hepatic inflammation—the commonly accepted histologic features for diagnosing NASH, as well as the discovery of novel candidate biomarkers. Multi-omics analysis holds great potential to uncover new insights into disease mechanism through integrating multiple layers of molecular information. Despite the technical and computational challenges associated with such efforts, a few pioneering studies have successfully applied multi-omics technologies to investigate NASH. Here, we review the most recent technological developments in mass spectrometry (MS)-based proteomics, metabolomics, and lipidomics. We summarize multi-omics studies and emerging omics biomarkers in NASH and highlight the biological insights gained through these integrated analyses.

Review of aquatic toxicity of pharmaceuticals and personal care products to algae

Pharmaceuticals and Personal Care Products (PPCPs) have been frequently detected in the environment around the world. Algae play a significant role in aquatic ecosystem, thus the influence on algae may affect the life of higher trophic organisms. This review provides a state-of-the-art overview of current research on the toxicity of PPCPs to algae. Nanoparticles, contained in personal care products, also have been considered as the ingredients of PPCPs. PPCPs could cause unexpected effects on algae and their communities. Chlorophyta and diatoms are more accessible and sensitive to PPCPs. Multiple algal endpoints should be considered to provide a complete evaluation on PPCPs toxicity. The toxicity of organic ingredients in PPCPs could be predicted through quantitative structure-activity relationship model, whereas the toxicity of nanoparticles could be predicted with limitations. Light irradiation can change the toxicity through affecting algae and PPCPs. pH and natural organic matter can affect the toxicity through changing the existence of PPCPs. For joint and tertiary toxicity, experiments could be conducted to reveal the toxic mechanism. For multiple compound mixture toxicity, concentration addition and independent addition models are preferred. However, there has no empirical models to study nanoparticle-contained mixture toxicity. Algae-based remediation is an emerging technology to prevent the release of PPCPs from water treatment plants. Although many individual algal species are identified for removing a few compounds from PPCPs, algal-bacterial photobioreactor is a preferable alternative, with higher chances for industrial applications.

The modulatory effect of taurine on benzo (a) pyrene-induced hepatorenal toxicity

Toxicities linked with Benzo (a) pyrene B[a]P exposure, particularly in liver and kidney have been reported in both animals and humans. Taurine (2-aminoethane sulfonic acid) is an intracellular β-amino acid reported to elicit hepatorenal protective functions. However, the modulatory effect of taurine on hepatorenal toxicity associated with exposure to B[a]P has not been reported. This study evaluated the effects of taurine on the hepatorenal toxicities induced in cohorts of rats exposed to B[a]P. Experimental rats were treated as follows: B[a]P (10 mg/kg); co-treated cohorts -B[a]P (10 mg/kg) plus taurine (100 or 200 mg/kg) for 4 successive weeks. Results show that co-dosing with taurine significantly (P < 0.05) improved B[a]P-induced distortion of oxidative stress markers (catalase, superoxide dismutase, glutathione S-transferase, glutathione peroxidase, total sulphydryl, reduced glutathione, lipid peroxidation and xanthine oxidase), renal function (urea and creatinine) and liver function marker enzymes (alkaline phosphatase, aspartate aminotransferase, alanine aminotransferase and gamma glutamyl transferase). Moreover, taurine effectively mitigated increase in myeloperoxidase activity, levels of reactive oxygen and nitrogen species, nitric oxide and interleukin-1β in kidney and liver of rats treated with B[a]P. In conclusion, taurine modulates hepatorenal toxicity in B[a]P-exposed rats by suppressing hepatic and renal damage indices, oxidative injury and inflammatory stress.

Toxicogenomics of drug induced liver injury - from mechanistic understanding to early prediction

Despite rigorous preclinical testing, clinical attrition rates in drug development remain high with drug-induced liver injury (DILI) remaining one of the most frequent causes of project failures. To understand DILI mechanisms, major efforts are put into the development of physiologically relevant cell models and culture paradigms with the aim to enhance preclinical to clinical result translation. While the majority of toxicogenomic studies have been based on cell lines, there are emerging trends toward the predominant use of stem cell-derived organoids and primary human hepatocytes in complex 3D cell models. Such studies have been successful in disentangling diverse toxicity mechanisms, including genotoxicity, mitochondrial injury, steatogenesis and cholestasis and can aid in distinguishing hepatotoxic from nontoxic structural analogs. Furthermore, by leveraging inter-individual differences of cells from different donors, these approaches can emulate the complexity of polygenic risk scores, which facilitates personalized drug-specific DILI risk analyses. In summary, toxicogenomic studies into drug-induced hepatotoxicity have majorly contributed to our mechanistic understanding of DILI and the incorporation of organotypic human 3D liver models into the preclinical testing arsenal promises to enhance biological insights during drug discovery, increase confidence in preclinical safety and minimize the translational gap.

Assessment of fibrotic pathways induced by environmental chemicals using 3D-human liver microtissue model

Exposure to environmental chemicals, particularly those with persistent and bioaccumulative properties have been linked to liver diseases. Induction of fibrotic pathways is considered as a pre-requirement of chemical induced liver fibrosis. Here, we applied 3D in vitro human liver microtissues (MTs) composed of HepaRG, THP-1 and hTERT-HSC that express relevant hepatic pathways (bile acid, sterol, and xenobiotic metabolism) and can recapitulate key events of liver fibrosis (e.g. extracellular matrix-deposition). The liver MTs were exposed to a known profibrotic chemical, thioacetamide (TAA) and three representative environmental chemicals (TCDD, benzo [a] pyrene (BaP) and PCB126). Both TAA and BaP triggered fibrotic pathway related events such as hepatocellular damage (cytotoxicity and decreased albumin release), hepatic stellate cell activation (transcriptional upregulation of α-SMA and Col1α1) and extracellular matrix remodelling. TCDD or PCB126 at measured concentrations did not elicit these responses in the 3D liver MTs system, though they caused cytotoxicity in HepaRG monoculture at high concentrations. Reduced human transcriptome (RHT) analysis captured molecular responses involved in liver fibrosis when MTs were treated with TAA and BaP. The results suggest that 3D, multicellular, human liver microtissues represent an alternative, human-relevant, in vitro liver model for assessing fibrotic pathways induced by environmental chemicals.

Oxidative Stress in NAFLD: Role of Nutrients and Food Contaminants

Non-alcoholic fatty liver disease (NAFLD) is often the hepatic expression of metabolic syndrome and its comorbidities that comprise, among others, obesity and insulin-resistance. NAFLD involves a large spectrum of clinical conditions. These range from steatosis, a benign liver disorder characterized by the accumulation of fat in hepatocytes, to non-alcoholic steatohepatitis (NASH), which is characterized by inflammation, hepatocyte damage, and liver fibrosis. NASH can further progress to cirrhosis and hepatocellular carcinoma. The etiology of NAFLD involves both genetic and environmental factors, including an unhealthy lifestyle. Of note, unhealthy eating is clearly associated with NAFLD development and progression to NASH. Both macronutrients (sugars, lipids, proteins) and micronutrients (vitamins, phytoingredients, antioxidants) affect NAFLD pathogenesis. Furthermore, some evidence indicates disruption of metabolic homeostasis by food contaminants, some of which are risk factor candidates in NAFLD. At the molecular level, several models have been proposed for the pathogenesis of NAFLD. Most importantly, oxidative stress and mitochondrial damage have been reported to be causative in NAFLD initiation and progression. The aim of this review is to provide an overview of the contribution of nutrients and food contaminants, especially pesticides, to oxidative stress and how they may influence NAFLD pathogenesis.

Quizalofop-p-Ethyl Induces Adipogenesis in 3T3-L1 Adipocytes

Exposure to endocrine disrupting chemicals is an established risk factor for obesity. The most commonly used pesticide active ingredients have never been tested in an adipogenesis assay. We tested for the first time the potential of glyphosate, 2, 4-dichlorophenoxyacetic acid, dicamba, mesotrione, isoxaflutole, and quizalofop-p-ethyl (QpE) to induce lipid accumulation in murine 3T3-L1 adipocytes. Only QpE caused a dose-dependent statistically significant triglyceride accumulation from a concentration of 5 up to 100 µM. The QpE commercial formulation Targa Super was 100 times more cytotoxic than QpE alone. Neither the estrogen receptor antagonist ICI 182, 780 nor the glucocorticoid receptor antagonist RU486 was able to block the QpE-induced lipid accumulation. RNAseq analysis of 3T3-L1 adipocytes exposed to QpE suggests that this compound exerts its lipid accumulation effects via a peroxisome proliferator-activated receptor gamma (PPARγ)-mediated pathway, a nuclear receptor whose modulation influences lipid metabolism. QpE was further shown to be active in a PPARγ reporter gene assay at 100 µM, reaching 4% of the maximal response produced by rosiglitazone, which acts as a positive control. This indicates that lipid accumulation induced by QpE is only in part caused by PPARγ activation. The lipid accumulation capability of QpE we observe suggest that this pesticide, whose use is likely to increase in coming years may have a hitherto unsuspected obesogenic property.

2,3,7,8-Tetrachlorodibenzo-p-dioxin (TCDD) Disrupts Control of Cell Proliferation and Apoptosis in a Human Model of Adult Liver Progenitors

The aryl hydrocarbon receptor (AhR) activation has been shown to alter proliferation, apoptosis, or differentiation of adult rat liver progenitors. Here, we investigated the impact of 2,3,7,8-tetrachlorodibenzo-p-dioxin (TCDD)-mediated AhR activation on a human model of bipotent liver progenitors, undifferentiated HepaRG cells. We used both intact undifferentiated HepaRG cells, and the cells with silenced Hippo pathway effectors, yes-associated protein 1 (YAP) and transcriptional coactivator with PDZ-binding motif (TAZ), which play key role(s) in tissue-specific progenitor cell self-renewal and expansion, such as in liver, cardiac, or respiratory progenitors. TCDD induced cell proliferation in confluent undifferentiated HepaRG cells; however, following YAP, and, in particular, double YAP/TAZ knockdown, TCDD promoted induction of apoptosis. These results suggested that, unlike in mature hepatocytes, or hepatocyte-like cells, activation of the AhR may sensitize undifferentiated HepaRG cells to apoptotic stimuli. Induction of apoptosis in cells with silenced YAP/TAZ was associated with upregulation of death ligand TRAIL, and seemed to involve both extrinsic and mitochondrial apoptosis pathways. Global gene expression analysis further suggested that TCDD significantly altered expression of constituents and/or transcriptional targets of signaling pathways participating in control of expansion or differentiation of liver progenitors, including EGFR, Wnt/β-catenin, or tumor growth factor-β signaling pathways. TCDD significantly upregulated cytosolic proapoptotic protein BMF (Bcl-2 modifying factor) in HepaRG cells, which could be linked with an enhanced sensitivity of TCDD-treated cells to apoptosis. Our results suggest that, in addition to promotion of cell proliferation and alteration of signaling pathways controlling expansion of human adult liver progenitors, AhR ligands may also sensitize human liver progenitor cells to apoptosis.

Exposure to 2,3,3',4,4',5-hexachlorobiphenyl promotes nonalcoholic fatty liver disease development in C57BL/6 mice

Previous in vitro studies have indicated that 2,3,3',4,4',5-hexachlorobiphenyl (PCB 156) may be a new contributor to metabolic disruption and may further cause the occurrence of nonalcoholic fatty liver disease (NAFLD). However, no study has clarified the specific contributions of PCB 156 to NAFLD progression by constructing an in vivo model. Herein, we evaluated the effects of PCB 156 treatment (55 mg/kg, i.p.) on the livers of C57BL/6 mice fed a control diet (CD) or a high-fat diet (HFD). The results showed that PCB 156 administration increased intra-abdominal fat mass, hepatic lipid levels and dyslipidemia in the CD-fed group and aggravated NAFLD in HFD-fed group. By using transcriptomics studies and biological methods, we found that the genes expression involved in lipid metabolism pathways, such as lipogenesis, lipid accumulation and lipid β-oxidation, was greatly altered in liver tissues exposed to PCB 156. In addition, the cytochrome P450 pathway, peroxisome proliferator-activated receptors (PPARs) and the glutathione metabolism pathway were significantly activated following exposure to PCB 156. Furthermore, PCB 156 exposure increased serum transaminase levels and lipid peroxidation, and the redox-related genes were significantly dysregulated in liver tissue. In conclusion, our data suggested that PCB 156 could promote NAFLD development by altering the expression of genes related to lipid metabolism and inducing oxidative stress.

Chronic Inflammation in the Context of Everyday Life: Dietary Changes as Mitigating Factors

The lifestyle adopted by most people in Western societies has an important impact on the propensity to metabolic disorders (e.g., diabetes, cancer, cardiovascular disease, neurodegenerative diseases). This is often accompanied by chronic low-grade inflammation, driven by the activation of various molecular pathways such as STAT3 (signal transducer and activator of transcription 3), IKK (IκB kinase), MMP9 (matrix metallopeptidase 9), MAPK (mitogen-activated protein kinases), COX2 (cyclooxigenase 2), and NF-Kβ (nuclear factor kappa-light-chain-enhancer of activated B cells). Multiple intervention studies have demonstrated that lifestyle changes can lead to reduced inflammation and improved health. This can be linked to the concept of real-life risk simulation, since humans are continuously exposed to dietary factors in small doses and complex combinations (e.g., polyphenols, fibers, polyunsaturated fatty acids, etc.). Inflammation biomarkers improve in patients who consume a certain amount of fiber per day; some even losing weight. Fasting in combination with calorie restriction modulates molecular mechanisms such as m-TOR, FOXO, NRF2, AMPK, and sirtuins, ultimately leads to significantly reduced inflammatory marker levels, as well as improved metabolic markers. Moving toward healthier dietary habits at the individual level and in publicly-funded institutions, such as schools or hospitals, could help improving public health, reducing healthcare costs and improving community resilience to epidemics (such as COVID-19), which predominantly affects individuals with metabolic diseases.

Metabolomic-based assessment reveals dysregulation of lipid profiles in human liver cells exposed to environmental obesogens

Significant attention has been given to the potential of environmental chemicals to disrupt lipid homeostasis at the cellular level. These chemicals, classified as obesogens, are abundantly used in a wide variety of consumer products. However, there is a significant lack of information regarding the mechanisms by which environmental exposure can contribute to the onset of obesity and non-alcoholic fatty liver disease (NAFLD). Several studies have described the interaction of potential obesogens with lipid-related peroxisome proliferator-activated receptors (PPAR). However, no studies have quantified the degree of modification to lipidomic profiles in relevant human models, making it difficult to directly link PPAR agonists to the onset of lipid-related diseases. A quantitative metabolomic approach was used to examine the dysregulation of lipid metabolism in human liver cells upon exposure to potential obesogenic compounds. The chemicals rosiglitazone, perfluorooctanoic acid, di-2-ethylexylphthalate, and tributyltin significantly increased total lipids in liver cells, being diglycerides, triglycerides and phosphatidylcholines the most prominent. Contrarily, perfluorooctane sulfonic acid and the pharmaceutical fenofibrate appeared to lower total lipid concentrations, especially those belonging to the acylcarnitine, ceramide, triglyceride, and phosphatidylcholine groups. Fluorescence microscopy analysis for cellular neutral lipids revealed significant lipid bioaccumulation upon exposure to obesogens at environmentally relevant concentrations. This integrated omics analysis provides unique mechanistic insight into the potential of these environmental pollutants to promote diseases like obesity and NAFLD. Furthermore, this study provides a significant contribution to advance the understanding of molecular signatures related to obesogenic chemicals and to the development of alternatives to in vivo experimentation.

Endocrine Disruptors in Food: Impact on Gut Microbiota and Metabolic Diseases

Endocrine disruptors (EDCs) have been associated with the increased incidence of metabolic disorders. In this work, we conducted a systematic review of the literature in order to identify the current knowledge of the interactions between EDCs in food, the gut microbiota, and metabolic disorders in order to shed light on this complex triad. Exposure to EDCs induces a series of changes including microbial dysbiosis and the induction of xenobiotic pathways and associated genes, enzymes, and metabolites involved in EDC metabolism. The products and by-products released following the microbial metabolism of EDCs can be taken up by the host; therefore, changes in the composition of the microbiota and in the production of microbial metabolites could have a major impact on host metabolism and the development of diseases. The remediation of EDC-induced changes in the gut microbiota might represent an alternative course for the treatment and prevention of metabolic diseases.

Understanding Environmental Contaminants' Direct Effects on Non-alcoholic Fatty Liver Disease Progression

PURPOSE OF REVIEW

Environmental contaminants are considered one of the major factors in the development and progression of NAFLD, the most common liver disease in the USA.

RECENT FINDINGS

The evolving knowledge of mechanisms of hepatic steatosis and steatohepatitis has recently been reviewed and characterized as ALD, NAFLD, and TAFLD. The most recent mechanistic studies on PFAS and PCBs have revealed a greater role for toxicants in the initiation of not only TAFLD but also NAFLD and the more progressive inflammatory stage of NAFLD, non-alcoholic steatohepatitis. In addition to insecticides, recent studies support a significant contribution of fungicides and herbicides to NAFLD. The mechanisms of PFAS, PCBs, and fungicides in contributing to the increased prevalence of NAFLD remain unclear. Addressing whether chronic, low-dose exposures could result in liver pathology and whether real-world exposure to mixtures of environmental contaminants pose a significant risk factor for NAFLD is paramount to understand the impact of NAFLD on populations today.

Transcriptome analysis in normal human liver cells exposed to 2, 3, 3', 4, 4', 5 - Hexachlorobiphenyl (PCB 156)

BACKGROUNDS

Polychlorinated biphenyls are persistent environmental pollutants associated with the onset of non-alcoholic fatty liver disease in humans, but there is limited information on the underlying mechanism. In the present study, we investigated the alterations in gene expression profiles in normal human liver cells L-02 following exposure to 2, 3, 3', 4, 4', 5 - hexachlorobiphenyl (PCB 156), a potent compound that may induce non-alcoholic fatty liver disease.

METHODS

The L-02 cells were exposed to PCB 156 for 72 h and the contents of intracellular triacylglyceride and total cholesterol were subsequently measured. Microarray analysis of mRNAs and long non-coding RNAs (lncRNAs) in the cells was also performed after 3.4 μM PCB 156 treatment.

RESULTS

Exposure to PCB 156 (3.4 μM, 72 h) resulted in significant increases of triacylglyceride and total cholesterol concentrations in L-02 cells. Microarray analysis identified 222 differentially expressed mRNAs and 628 differentially expressed lncRNAs. Gene Ontology and pathway analyses associated the differentially expressed mRNAs with metabolic and inflammatory processes. Moreover, lncRNA-mRNA co-expression network revealed 36 network pairs comprising 10 differentially expressed mRNAs and 34 dysregulated lncRNAs. The results of bioinformatics analysis further indicated that dysregulated lncRNA NONHSAT174696, lncRNA NONHSAT179219, and lncRNA NONHSAT161887, as the regulators of EDAR, CYP1B1, and ALDH3A1 respectively, played an important role in the PCB 156-induced lipid metabolism disorder.

CONCLUSION

Our findings provide an overview of differentially expressed mRNAs and lncRNAs in L-02 cells exposed to PCB 156, and contribute to the field of polychlorinated biphenyl-induced non-alcoholic fatty liver disease.

Aryl hydrocarbon receptor pathway: Role, regulation and intervention in atherosclerosis therapy (Review)

The aryl hydrocarbon receptor (AhR) is a ligand‑activated transcription factor originally isolated and characterized as the dioxin or xenobiotic receptor. With the discovery of endogenous ligands and studies of AhR knockout mice, AhR has been found to serve an important role in several biological processes, including immune responses and developmental and pathological regulation. In particular, it has been considered as a new major player in cardiovascular diseases. Recent studies have revealed that the development of atherosclerosis is closely associated with AhR function. However, the roles of the AhR in the pathological development of atherosclerosis and atherosclerosis‑associated diseases remain unclear. The current review presents the molecular mechanisms involved in the regulation of AhR expression during inflammation, oxidative stress and lipid deposition. Additionally, the role of the AhR in atherosclerosis and atherosclerosis‑associated diseases is reviewed.

Structure-activity relationship study: Mechanism of cyto-genotoxicity of Nitropyrazole-derived high energy density materials family

Stringent toxicological tests have to be performed prior to the industrial development of alternative chemicals particularly high energy dense materials (HEDMs) such as explosives. The properties (e.g., power, stability) of these compounds are constantly being improved, the current axis of research being the nitration of nitrogen heterocycles leading to HEDMs such as nitropyrazole-derived molecules. However, except for 3,4,5-trinitropyrazole (3,4,5-TNP), which was shown to be highly toxic in mice, the toxicological impact of these HEDMs has so far not been investigated. Furthermore, as industrials are strongly advised to develop alternative safety testing assays to in vivo experiments, we herein focused on determining the cytotoxic and genotoxic effects of seven Nitropyrazole-derived HEDMs on three rodent cell lines (mouse embryonic BALB/3T3 clone A31 cells, Chinese hamster ovary cells CHO-K1 and mouse lymphoma L5178Y TK +/- clone (3.7.2C) cells), two human fibroblast lines (CRC05, PFS04062) and on the human hepatic HepaRG model (both in proliferative and differentiated cells). A stronger cytotoxic effect was observed for 1,3-dinitropyrazole (1, 3-DNP) and 3,4,5-TNP in all cell lines, though differentiated HepaRG cells clearly displayed fewer likely due to the metabolism and elimination of these molecules by their functional biotransformation pathways. At the mechanistic level, the sub-chronic cytotoxic and genotoxic effects were linked to ROS/RNS production (experimental assays), HA2.X and to transcriptomic data highlighting the increase in DNA repair mechanisms.

The application of omics-based human liver platforms for investigating the mechanism of drug-induced hepatotoxicity in vitro

Drug-induced liver injury (DILI) complicates safety assessment for new drugs and poses major threats to both patient health and drug development in the pharmaceutical industry. A number of human liver cell-based in vitro models combined with toxicogenomics methods have been developed as an alternative to animal testing for studying human DILI mechanisms. In this review, we discuss the in vitro human liver systems and their applications in omics-based drug-induced hepatotoxicity studies. We furthermore present bioinformatic approaches that are useful for analyzing toxicogenomic data generated from these models and discuss their current and potential contributions to the understanding of mechanisms of DILI. Human pluripotent stem cells, carrying donor-specific genetic information, hold great potential for advancing the study of individual-specific toxicological responses. When co-cultured with other liver-derived non-parenchymal cells in a microfluidic device, the resulting dynamic platform enables us to study immune-mediated drug hypersensitivity and accelerates personalized drug toxicology studies. A flexible microfluidic platform would also support the assembly of a more advanced organs-on-a-chip device, further bridging gap between in vitro and in vivo conditions. The standard transcriptomic analysis of these cell systems can be complemented with causality-inferring approaches to improve the understanding of DILI mechanisms. These approaches involve statistical techniques capable of elucidating regulatory interactions in parts of these mechanisms. The use of more elaborated human liver models, in harmony with causality-inferring bioinformatic approaches will pave the way for establishing a powerful methodology to systematically assess DILI mechanisms across a wide range of conditions.

Establishment of a human embryonic stem cell-based liver differentiation model for hepatotoxicity evaluations

The liver is one of the major targets of hormones, including thyroid hormones (THs), and many industrial chemicals, such as endocrine-disrupting chemicals. Those compounds may permeate the placenta barrier and pose a risk for embryonic development. Therefore, it is necessary to assess the toxic effects of those kind of industrial chemicals during liver development. In this study, to mimic liver specification in vitro, we differentiated human embryonic stem cells (ESCs) into functional hepatocyte-like cells. We performed this differentiation process in presence of two THs, triiodothyronine (T3) and thyroxine (T4), with the purpose of identifying biomarkers for toxicity screening. TH exposure (3, 30 and 300 nM) yielded to hepatocytes with impaired glycogen storage ability and abnormal lipid droplets' accumulation. Global gene expression analysis by RNA-seq identified a number of genes responsible for hepatic differentiation and function which were affected by 30 nM T3 and T4. Those differentially expressed genes were used to assess the potential developmental liver toxicity of two famous environmental pollutants, 2, 2, 4, 4-tetrabromodiphenyl ether (BDE-47) and decabromodiphenyl ether (BDE-209), at 10 nM to 1 μM treatments. Our findings demonstrate that BDE-47 and BDE-209, dysregulated pathways such as "chemical carcinogenesis", "steroid hormone biosynthesis" and "drug metabolism-cytochrome P450". Moreover, we were able to identify a set of 17 biomarkers, very useful to predict the potential developmental hepatotoxicity of industrial chemicals.

Effects of single and combined toxic exposures on the gut microbiome: Current knowledge and future directions

Human populations are chronically exposed to mixtures of toxic chemicals. Predicting the health effects of these mixtures require a large amount of information on the mode of action of their components. Xenobiotic metabolism by bacteria inhabiting the gastrointestinal tract has a major influence on human health. Our review aims to explore the literature for studies looking to characterize the different modes of action and outcomes of major chemical pollutants, and some components of cosmetics and food additives, on gut microbial communities in order to facilitate an estimation of their potential mixture effects. We identified good evidence that exposure to heavy metals, pesticides, nanoparticles, polycyclic aromatic hydrocarbons, dioxins, furans, polychlorinated biphenyls, and non-caloric artificial sweeteners affect the gut microbiome and which is associated with the development of metabolic, malignant, inflammatory, or immune diseases. Answering the question 'Who is there?' is not sufficient to define the mode of action of a toxicant in predictive modeling of mixture effects. Therefore, we recommend that new studies focus to simulate real-life exposure to diverse chemicals (toxicants, cosmetic/food additives), including as mixtures, and which combine metagenomics, metatranscriptomics and metabolomic analytical methods achieving in that way a comprehensive evaluation of effects on human health.

Mechanistic identification of biofluid metabolite changes as markers of acetaminophen-induced liver toxicity in rats

Acetaminophen (APAP) is the most commonly used analgesic and antipyretic drug in the world. Yet, it poses a major risk of liver injury when taken in excess of the therapeutic dose. Current clinical markers do not detect the early onset of liver injury associated with excess APAP-information that is vital to reverse injury progression through available therapeutic interventions. Hence, several studies have used transcriptomics, proteomics, and metabolomics technologies, both independently and in combination, in an attempt to discover potential early markers of liver injury. However, the casual relationship between these observations and their relation to the APAP mechanism of liver toxicity are not clearly understood. Here, we used Sprague-Dawley rats orally gavaged with a single dose of 2 g/kg of APAP to collect tissue samples from the liver and kidney for transcriptomic analysis and plasma and urine samples for metabolomic analysis. We developed and used a multi-tissue, metabolism-based modeling approach to integrate these data, characterize the effect of excess APAP levels on liver metabolism, and identify a panel of plasma and urine metabolites that are associated with APAP-induced liver toxicity. Our analyses, which indicated that pathways involved in nucleotide-, lipid-, and amino acid-related metabolism in the liver were most strongly affected within 10 h following APAP treatment, identified a list of potential metabolites in these pathways that could serve as plausible markers of APAP-induced liver injury. Our approach identifies toxicant-induced changes in endogenous metabolism, is applicable to other toxicants based on transcriptomic data, and provides a mechanistic framework for interpreting metabolite alterations.

Study of the Persistence of the Phytotoxicity Induced by Graphene Oxide Quantum Dots and of the Specific Molecular Mechanisms by Integrating Omics and Regular Analyses

Although increasing attention has been paid to the nanotoxicity of graphene oxide quantum dots (GOQDs) due to their broad range of applications, the persistence and recoverability associated with GOQDs had been widely ignored. Interestingly, stress-response hormesis for algal growth was observed for Chlorella vulgaris as a single-celled model organism. Few physiological parameters, such as algal density, plasmolysis, and levels of reactive oxygen species, exhibited facile recovery. In contrast, the effects on chlorophyll a levels, permeability, and starch grain accumulation exhibited persistent toxicity. In the exposure stage, the downregulation of genes related to unsaturated fatty acid biosynthesis, carotenoid biosynthesis, phenylpropanoid biosynthesis, and binding contributed to toxic effects on photosynthesis. In the recovery stage, downregulation of genes related to the cis-Golgi network, photosystem I, photosynthetic membrane, and thylakoid was linked to the persistence of toxic effects on photosynthesis. The upregulated galactose metabolism and downregulated aminoacyl-tRNA biosynthesis also indicated toxicity persistence in the recovery stage. The downregulation and upregulation of phenylalanine metabolism in the exposure and recovery stages, respectively, reflected the tolerance of the algae to GOQDs. The present study highlights the importance of studying nanotoxicity by elucidation of stress and recovery patterns with metabolomics and transcriptomics.

Gut microbiota dysbiosis correlates with a low-dose PCB126-induced dyslipidemia and non-alcoholic fatty liver disease

There is growing evidence that polychlorinated biphenyl 126 (PCB126) not only has adverse effects on host health but also has the ability to shift gut microbiota, which is recently recognized as a crucial factor determining numerous physiological processes. However, the interplay between the gut microbiota and host health remains largely unknown. Herein, adult female C57BL/6 mice were orally exposed to environmentally relevant low-dose of PCB126, at 50 μg/kg body weight once per week for 6 weeks. This study aims to illuminate how PCB126 influences gut microbiota variations and host disorders and to further identify the correlation between the gut microbiota and metabolic markers of host disorders. Obtained results demonstrated that the PCB126 administration induced gut microbiota dysbiosis in mice, with changes both in the gut microbiota constitution and structure. PCB126 administration also simultaneously altered the physiological status of serum and liver, as evaluated by dyslipidemia, liver lipid accumulation and injury, and non-alcoholic fatty liver disease. Importantly, Spearman's correlation analysis suggested that several specific bacterial taxa were positively and significantly related to metabolic markers of the mentioned disorders. Moreover, based on the co-occurrence network map, some of the bacterial taxa may synergistically regulate host physiology. This work provides new insight into the mechanism underlying the interaction between the gut microbiota and host disorders. It is expected that gut microbiota modulation should be another novel way used for the prevention and treatment of PCB126-triggered diseases.

Comparison of transcriptome responses to glyphosate, isoxaflutole, quizalofop-p-ethyl and mesotrione in the HepaRG cell line

Use and thus exposure to quizalofop-p-ethyl, isoxaflutole, mesotrione and glyphosate, which are declared as active principles in commercial formulations of herbicides, is predicted to rapidly increase in coming years in an effort to overcome the wide-spread appearance of glyphosate-resistant weeds, especially in fields where glyphosate-tolerant genetically modified crops are cultivated in the USA. Thus, there is an urgent need for an evaluation of metabolic effects of new pesticide ingredients used to replace glyphosate. As the liver is a primary target of chemical pollutant toxicity, we have used the HepaRG human liver cell line as a model system to assess the toxicological insult from quizalofop-p-ethyl, isoxaflutole, mesotrione and glyphosate by determining alterations in the transcriptome caused by exposure to three concentrations of each of these compounds, including a low environmentally relevant dose. RNA-seq data were analysed with HISAT2, StringTie and Ballgown. Quizalofop-p-ethyl was found to be the most toxic of the pesticide ingredients tested, causing alterations in gene expression that are associated with pathways involved in fatty acid degradation and response to alcoholism. Isoxaflutole was less toxic, but caused detectable changes in retinol metabolism and in the PPAR signalling pathway at a concentration of 1 mM. ToxCast data analysis revealed that isoxaflutole activated PPAR gamma receptor and pregnane X responsive elements in reporter gene assays. Glyphosate and mesotrione caused subtle changes in transcriptome profiles, with too few genes altered in their function to allow a reliable pathway analysis. In order to explore the effects of glyphosate in greater depth and detail, we undertook a global metabolome profiling. This revealed a decrease in free long chain fatty acids and polyunsaturated fatty acid levels at the lowest concentration (0.06 μM) of glyphosate, although no effects were detected at the two higher concentrations tested, perhaps suggesting a non-linear dose response. This surprising result will need to be confirmed by additional studies. Overall, our findings contribute to filling the knowledge gap regarding metabolic toxicity that can potentially arise from exposure to these four herbicide active principles.