Identifying active xenobiotics in humans by use of a suspect screening technique coupled with lipidomic analysis

Current understanding of human bioaccumulation patterns and health effects of exposure to perfluorooctane sulfonate (PFOS)

Perfluorooctane sulfonate (PFOS) is a persistent organic pollutant of global concern due to its environmental presence,bioaccumulative potential and toxicological impacts. This review synthesizes current knowledge regarding PFOS exposure, bioaccumulation patterns and adverse health outcomes in human population. Analysis of worldwide biomonitoring data, and epidemiological studies reveals PFOS systemic effects, including immunological dysfunction (decreased vaccine response), developmental toxicity (reduced birth weight), hepatic metabolic disruption, potential carcinogenogenicity, and reproductive abnormalities. At the molecular level, PFOS induces toxicity through multiple pathways, including PI3K/AKT/mTOR pathway inhibition, PPARα activation, NF-κB signaling modulation, and oxidative stress induction. Recent advances in analytical methodologies have enhanced our understanding of PFOS distribution and fate, while evolving egulatory frameworks attempts to address its risk. This review identifies critical research gaps and emphasized the need for coordinated multidisciplinary approaches to address this persistent environmental contaminant.

Biotransformation of bis(2-chloroethyl)2-chloroethylphosphphonate, and its effects on metabolism of lipid molecules in primary mouse hepatocytes

Bis(2-chloroethyl)2-chloroethylphosphphonate (B2CE2CEPP) was recently reported as a contaminant in underground water samples, however, information regarding its biotransformation and adverse effects is relatively rare. In this study, B2CE2CEPP and tris(2-chloroethyl) phosphate (TCEP; a typical organophosphate triester with a very similar structure as compared to B2CE2CEPP) were used as target contaminants to comparatively investigate their cytotoxicity, biotransformation, and alteration of lipid metabolism by use of an in vitro primary hepatocyte assay of ICR mice. This study aims to thoroughly investigate the cytotoxicity, biotransformation, and lipid metabolism effects of B2CE2CEPP and TCEP on primary hepatocytes of ICR mice, in order to reveal the potential health risks of these two organophosphorus compounds. The results showed that both B2CE2CEPP and TCEP were cytotoxic with LC50 values of 456 μM (B2CE2CEPP) and 1250 μM (TCEP), respectively. Both compounds underwent significant metabolic transformation follow exposure to primary mouse hepatocytes (PMHs), and a total of 4 potential metabolites were identified based on high-resolution orbitrap mass spectrometry technique. Exposure to TCEP and B2CE2CEPP led to lipid metabolism disorders in PMHs. TG (16:0/16:1/18:1) showed high sensitivity to B2CE2CEPP exposure and exhibited a significant upregulation trend, making it a potential biomarker significantly influenced by B2CE2CEPP exposure. Lipidomic analysis showed that B2CE2CEPP affected lipid metabolic pathways including thiamine metabolism, one carbon pool by folate, and folatesteroid hormone biosynthesis. The present study filled a knowledge gap in the current research on the biotransformation and adverse effects of B2CE2CEPP, and emphasized the importance on consistent monitoring of B2CE2CEPP and its structure-like compounds in various environmental samples.

Novel Organophosphate Ester Tris(2,4-di-tert-butylphenyl)phosphate Alters Lipid Metabolism: Insights from Lipidomic Analysis and mRNA Expression

Tris(2,4-di-tert-butylphenyl)phosphate (TDTBPP), a novel organophosphate ester (OPE), has been extensively detected in various environmental and biological samples; however, its potential biological effects remain unexplored. In this study, we investigated biotransformation characteristics, alteration of lipid metabolism, and mRNA expression in primary mouse hepatocytes (PMHs) following exposure to TDTBPP. After 36-h exposure in PMHs, TDTBPP exhibited a high stability potential with no statistically significant degradation trend. Subsequently, we analyzed the disruption of lipid homeostasis in PMHs following exposure to 0-4.5 μM TDTBPP. Lipidomic analysis indicated that TDTBPP disrupted lipid homeostasis in PMHs, and several lipid classes were dysregulated, in particular, glycerolipids and glycerophospholipids. Additionally, three lipids were proposed as potential lipid biomarkers of TDTBPP exposure, including triglycerides (TGs) and phosphatidylcholines (PCs). These observations were further supported by transcriptional changes, with significant alteration observed in genes associated with lipid uptake, de novo lipogenesis, β-oxidation of fatty acids, glycerolipid metabolism, and lipid export. Overall, these findings highlight the detrimental effects of TDTBPP on lipid homeostasis, providing important insights for health risk assessments of this abundant OPE in the environment.

PFOS-Induced Perturbations in Trophoblast Functions through the Oip5os1/miR-155/Rnd3 Axis in PE

The widespread use of perfluorooctanesulfonic acid (PFOS) has raised concerns regarding its potential on pregnant women, particularly in relation to the development of pre-eclampsia (PE). This study investigates the impact of PFOS exposure on the LncRNA/Rnd3 axis in pregnant mice and its association with trophoblast cell functions in PE. Bioinformatics analysis revealed PFOS-related gene alterations in PE, with pathways enriched in apoptotic signaling and cytokine interactions. Experimental findings showed the downregulation of Oip5os1 and Rnd3, along with the upregulation of miR-155, affecting trophoblast behavior. Animal experiments confirmed that PFOS-induced gene expression changes are linked to PE progression. PFOS exposure impairs trophoblast proliferation and migration via the Oip5os1/miR-155/Rnd3 axis, contributing to PE development.

A proposed biomarker for human citric acid ester (CAE) exposure, and the potential disturbance on human lipid metabolism

Citric acid esters (CAEs), as one class of important alternative plasticizers, have been proven to be ubiquitous in the environments, leading to an increasing concern regarding their potential health risk to humans. However, information regarding the biomarkers for human CAE biomonitoring is currently unknown. In the present study, we investigated the metabolism characteristics of CAEs by use of in vitro rat liver microsomes (RLMs) and in vivo mice. We observed that CAEs would undergo a rapid metabolism in both in vitro and in vivo conditions, implying that parent CAEs could be not suitable for biomonitoring of human CAE exposure. By use of high-resolution Orbitrap mass spectrometry (MS), ten molecules were tentatively identified as CAE potential metabolites on the basis of their MS and MS/MS characteristics, and CAEs could be metabolized via multiple pathways, i.e. hydrolyzation, hydroxylation, O-dealkylation. Further MS screening in human serum samples demonstrated that most of parent CAEs were not detectable, whereas numerous CAE metabolites were detected in the same batch of analyzed samples. Especially, one of metabolites of tributyl citrate (named with TBC-M1), exhibited a high detection frequency of 73.3%. By use of TBC-M1 as the biomarker of human CAE exposure, alteration of lipid metabolism was further examined in human serum. Interestingly, we observed statistically significant correlations between TBC-M1 levels and population characteristics (i.e., age, BMI, and drinking). Beyond that, we also observed statistically significant correlation between levels of TBC-M1 and lipid molecules (phosphatidylinositol (18:0/20:4) and sphingomyelin (d34:1)). Collectively, this study underscored the property of rapid metabolism of CAEs in exposed organism, and proposed a potential biomarker that could be greatly helpful for further investigating the human CAE exposure and understanding their potential health risks.

Tracking chemical feature releases from plastic food packaging to humans

Humankind are being exposed to a cocktail of chemicals, such as chemicals released from plastic food packaging. It is of great importance to evaluate the prevalence of plastic food packaging-derived chemicals pollution along the flow of food-human. We developed a robust and practical database of 2101 chemical features associated with plastic food packaging that combined data from three sources, 925 of which were acquired from non-target screening of chemical extracts from eight commonly used plastic food packaging materials. In this database, 625 features, especially half of the non-targets, were potential migrants who likely entered our bodies through dietary intake. Biomonitoring analysis of plastic chemical features in foodstuffs or human serum samples showed that approximately 78 % of the 2101 features were detectable and approximately half were non-targets. Of these, 17 plastic chemicals with high detection frequencies (DFs) in the human serum were confirmed to be functional chemical additives. Together, our work indicates that the number of plastic chemicals in our bodies could be far greater than previously recognized, and human exposure to plastic chemicals might pose a potential health risk.

Phospholipidomics in Clinical Trials for Brain Disorders: Advancing our Understanding and Therapeutic Potentials

Phospholipidomics is a specialized branch of lipidomics that focuses on the characterization and quantification of phospholipids. By using sensitive analytical techniques, phospholipidomics enables researchers to better understand the metabolism and activities of phospholipids in brain disorders such as Alzheimer's and Parkinson's diseases. In the brain, identifying specific phospholipid biomarkers can offer valuable insights into the underlying molecular features and biochemistry of these diseases through a variety of sensitive analytical techniques. Phospholipidomics has emerged as a promising tool in clinical studies, with immense potential to advance our knowledge of neurological diseases and enhance diagnosis and treatment options for patients. In the present review paper, we discussed numerous applications of phospholipidomics tools in clinical studies, with a particular focus on the neurological field. By exploring phospholipids' functions in neurological diseases and the potential of phospholipidomics in clinical research, we provided valuable insights that could aid researchers and clinicians in harnessing the full prospective of this innovative practice and improve patient outcomes by providing more potent treatments for neurological diseases.

Lipid Metabolic Disorders Induced by Organophosphate Esters in Silver Carp from the Middle Reaches of the Yangtze River

The Yangtze River fishery resources have declined strongly over the past few decades. One suspected reason for the decline in fishery productivity, including silver carp (Hypophthalmichthys molitrix), has been linked to organophosphate esters (OPEs) contaminant exposure. In this study, the adverse effect of OPEs on lipid metabolism in silver carp captured from the Yangtze River was examined, and our results indicated that muscle concentrations of the OPEs were positively associated with serum cholesterol and total lipid levels. In vivo laboratory results revealed that exposure to environmental concentrations of OPEs significantly increased the concentrations of triglyceride, cholesterol, and total lipid levels. Lipidome analysis further confirmed the lipid metabolism dysfunction induced by OPEs, and glycerophospholipids and sphingolipids were the most affected lipids. Hepatic transcriptomic analysis found that OPEs caused significant alterations in the transcription of genes involved in lipid metabolism. Pathways associated with lipid homeostasis, including the peroxisome proliferator-activated receptor (PPAR) signal pathway, cholesterol metabolism, fatty acid biosynthesis, and steroid biosynthesis, were significantly changed. Furthermore, the affinities of OPEs were different, but the 11 OPEs tested could bind with PPARγ, suggesting that OPEs could disrupt lipid metabolism by interacting with PPARγ. Overall, this study highlighted the harmful effects of OPEs on wild fish and provided mechanistic insights into OPE-induced metabolic disorders.

The associations between high-levels of urine benzophenone-type UV filters (BPs) and changes in serum lipid concentrations

Little is known about the potential health impacts of benzophenone-type UV filters (BPs) exposure among the general population. In our study conducted in Wuxi, China, we investigated the associations between the concentrations of eight BP-derivatives and five target lipid molecules. We collected basic information, serum, and urine samples from 120 residents aged 9 to 80 in Wuxi. We determined BPs in urine samples and lipid levels in serum samples. Generalized linear models were used to evaluate the differences in ln-transformed serum target lipids levels (μg/L) with different urine BPs quartiles compared to the lowest quartile. Benzophenone-4 (BP-4) had the highest detection rate (95.0%) and geometric mean concentration (1.96 μg/L) among all the BP-derivatives in our study population. The exposure levels of BPs were generally higher in females than in males. Participants in the 9-17 and 18-50 age groups exhibited greater levels of exposure to BPs than those in the 51-80 age group. We observed statistically significant changes in LysoPC (18:0), LysoPE (18:0), ΣLPL, and ΣTL concentrations between the highest and lowest quartiles of BP-4. Similar changes were found in LysoPE (18:0) concentration between the highest and lowest quartiles of ΣBP-3 and ΣBPs. High urine BP concentrations were associated with variations in our target serum lipids involved in neurological and metabolic disorders, and posed a potential health risk. Future studies are warranted to further validate and elucidate our findings.

Ceramides during Pregnancy and Obstetrical Adverse Outcomes

Ceramides are a group of sphingolipids located in the external plasma membrane layer and act as messengers in cellular pathways such as inflammatory processes and apoptosis. Plasma ceramides are biomarkers of cardiovascular disease, type 2 diabetes mellitus, Alzheimer's disease, various autoimmune conditions and cancer. During pregnancy, ceramides play an important role as stress mediators, especially during implantation, delivery and lactation. Based on the current literature, plasma ceramides could be potential biomarkers of obstetrical adverse outcomes, although their role in metabolic pathways under such conditions remains unclear. This review aims to present current studies that examine the role of ceramides during pregnancy and obstetrical adverse outcomes, such as pre-eclampsia, gestational diabetes mellitus and other complications.

PFAS Exposures and the Human Metabolome: A Systematic Review of Epidemiological Studies

Purpose of Review

There is a growing interest in understanding the health effects of exposure to per- and polyfluoroalkyl substances (PFAS) through the study of the human metabolome. In this systematic review, we aimed to identify consistent findings between PFAS and metabolomic signatures. We conducted a search matching specific keywords that was independently reviewed by two authors on two databases (EMBASE and PubMed) from their inception through July 19, 2022 following PRISMA guidelines.

Recent Findings

We identified a total of 28 eligible observational studies that evaluated the associations between 31 different PFAS exposures and metabolomics in humans. The most common exposure evaluated was legacy long-chain PFAS. Population sample sizes ranged from 40 to 1,105 participants at different stages across the lifespan. A total of 19 studies used a non-targeted metabolomics approach, 7 used targeted approaches, and 2 included both. The majority of studies were cross-sectional (n = 25), including four with prospective analyses of PFAS measured prior to metabolomics.

Summary

Most frequently reported associations across studies were observed between PFAS and amino acids, fatty acids, glycerophospholipids, glycerolipids, phosphosphingolipids, bile acids, ceramides, purines, and acylcarnitines. Corresponding metabolic pathways were also altered, including lipid, amino acid, carbohydrate, nucleotide, energy metabolism, glycan biosynthesis and metabolism, and metabolism of cofactors and vitamins. We found consistent evidence across studies indicating PFAS-induced alterations in lipid and amino acid metabolites, which may be involved in energy and cell membrane disruption.

Environmental phenol exposure associates with urine metabolome alteration in young Northeast Indian females

Urinary biomonitoring delivers the most accurate environmental phenols exposure assessment. However, environmental phenol exposure-related biomarkers are required to improve risk assessment to understand the internal processes perturbed, which may link exposure to specific health outcomes. This study aimed to investigate the association between environmental phenols exposure and the metabolome of young adult females from India. Urinary metabolomics was performed using liquid chromatography-mass spectrometry. Environmental phenols-related metabolic biomarkers were investigated by comparing the low and high exposure of environmental phenols. Seven potential biomarkers, namely histidine, cysteine-s-sulfate, 12-KETE, malonic acid, p-hydroxybenzoic acid, PE (36:2), and PS (36:0), were identified, revealing that environmental phenol exposure altered the metabolic pathways such as histidine metabolism, beta-Alanine metabolism, glycerophospholipid metabolism, and other pathways. This study also conceived an innovative strategy for the early prediction of diseases by combining urinary metabolomics with machine learning (ML) algorithms. The differential metabolites predictive accuracy by ML models was >80%. This is the first mass spectrometry-based metabolomics study on young adult females from India with environmental phenols exposure. The study is valuable in demonstrating multiple urine metabolic changes linked to environmental phenol exposure and a better understanding of the mechanisms behind environmental phenol-induced effects in young female adults.

Perfluorooctanoic Acid-Disturbed Serum and Liver Lipidome in C57BL/6 Mice

Perfluorooctanoic acid is a manufactured material extensively utilized in industrial and consumer products. As a persistent organic pollutant, perfluorooctanoic acid has raised increasing public health concerns recently. Although perfluorooctanoic acid is known to induce lipid accumulation in the liver, the impact of perfluorooctanoic acid on different lipid classes has not been fully evaluated. In this study, we performed untargeted lipidomics analysis to investigate the impact of perfluorooctanoic acid on the lipid homeostasis in C57BL/6 male mice. Perfluorooctanoic acid disturbed the lipid profiles in serum and liver, with a variety of lipid classes significantly altered. Greater impacts were observed in the liver lipidome than the serum lipidome. In particular, some lipid clusters in the liver were altered by both high- and low-dose perfluorooctanoic acid exposure, including the increase of unsaturated triglycerides and the decrease of sphingomyelins, saturated phosphatidylcholines, saturated lysophosphatidylcholines, and phospholipid ethers. In parallel with an increase in the liver, a decrease of saturated phosphatidylcholines was found in the serum of high-dose perfluorooctanoic acid-treated mice. The findings from this study are helpful to improve the understanding of perfluorooctanoic acid-induced dysregulation of lipid metabolism and perfluorooctanoic acid-associated health effects in liver.

Suspect and non-targeted screening-based human biomonitoring identified 74 biomarkers of exposure in urine of Slovenian children

Human exposure to organic contaminants is widespread. Many of these contaminants show adverse health effects on human population. Human biomonitoring (HBM) follows the levels and the distribution of biomarkers of exposure (BoE), but it is usually done in a targeted manner. Suspect and non-targeted screening (SS/NTS) tend to find BoE in an agnostic way, without preselection of compounds, and include finding evidence of exposure to predicted, unpredicted known and unknown chemicals. This study describes the application of high-resolution mass spectrometry (HRMS)-based SS/NTS workflow for revealing organic contaminants in urine of a cohort of 200 children from Slovenia, aged 6-9 years. The children originated from two regions, urban and rural, and the latter were sampled in two time periods, summer and winter. We tentatively identified 74 BoE at the confidence levels of 2 and 3. These BoE belong to several classes of pharmaceuticals, personal care products, plasticizers and plastic related products, volatile organic compounds, nicotine, caffeine and pesticides. The risk of three pesticides, atrazine, amitraz and diazinon is of particular concern since their use was limited in the EU. Among BoE we tentatively identified compounds that have not yet been monitored in HBM schemes and demonstrate limited exposure data, such as bisphenol G, polyethylene glycols and their ethers. Furthermore, 7 compounds with unknown use and sources of exposure were tentatively identified, either indicating the entry of new chemicals into the market, or their metabolites and transformation products. Interestingly, several BoE showed location and time dependency. Globally, this study presents high-throughput approach to SS/NTS for HBM. The results shed a light on the exposure of Slovenian children and raise questions on potential adverse health effects of such mixtures on this vulnerable population.

Comparative study of neonicotinoid insecticides (NNIs) and NNI-Related substances (r-NNIs) in foodstuffs and indoor dust

Comparative studies of neonicotinoid insecticides (NNIs) and NNI-related substances (r-NNIs) in foodstuffs and indoor dust are rare. Herein, we investigated the feature fragmentations of nine NNIs in high-energy collision dissociation cells via high-resolution orbitrap mass spectrometry and observed that NNIs can consistently generate several feature fragments (e.g., C6H5NCl+, C4H3NSCl+, and C6H5NF3+). Consequently, NNIs and r-NNIs were comprehensively (targeted, suspect, and feature fragment-dependent) detected in 107 foodstuff and 49 indoor dust samples collected from Nanjing City (eastern China). We fully or tentatively identified 9 target NNIs and 5 r-NNIs in these samples. NNIs and r-NNIs were detected in 93.5% of the analyzed foodstuff samples, and high concentrations were detected in vegetables (mean: 409 ng/g wet weight [ww]) and fruits (127 ng/g ww). Regarding indoor dust, imidacloprid and acetamiprid exhibited extremely high detection frequencies and contamination levels, and the highest mean concentrations of NNIs and r-NNIs were detected in dormitory samples. Based on the NNI and r-NNI concentrations in the analyzed samples, the mean estimated daily intake values for Chinese adults and children via dietary intake and dust ingestion were 2080-8190 ng/kg bw/day and 378-2680 pg/kg bw/day, respectively.