Understanding the Chemical Exposome During Fetal Development and Early Childhood: A Review

The characterization of developmental toxicity in fetal offspring induced by acetaminophen exposure during pregnancy

OBJECTIVE

Acetaminophen (APAP), an antipyretic and analgesic commonly used during pregnancy, has been recognized as a novel environmental contaminant. Preliminary evidence suggests that prenatal acetaminophen exposure (PAcE) could adversely affect offspring's gonadal and neurologic development, but there is no systematic investigation on the characteristics of APAP's fetal developmental toxicity.

METHODS

Pregnant mice were treated with 100 or 400 mg/kg∙d APAP in the second-trimester, or 400 mg/kg∙d APAP in the second- or third-trimester, or different courses (single or multiple) of APAP, based on clinical regimen. The effects of PAcE on pregnancy outcomes, maternal/fetal blood phenotypes, and multi-organ morphological and functional development of fetal mice were analyzed.

RESULTS

PAcE increased the incidence of adverse pregnancy outcomes and altered blood phenotypes including aminotransferases, lipids, and sex hormones in dams and fetuses. The expression of key functional genes in fetal organs indicated that PAcE inhibited hippocampal synaptic development, sex hormone synthesis, and osteogenic and chondrogenic development, but enhanced hepatic lipid synthesis and uptake, renal inflammatory hyperplasia, and adrenal steroid hormone synthesis. PAcE also induced marked pathological alterations in the fetal hippocampus, bone, kidney, and cartilage. The sensitivity rankings of fetal organs to PAcE might be hippocampus/bone > kidney > cartilage > liver > gonad > adrenal gland. Notably, PAcE-induced multi-organ developmental toxicity was more considerable under high-dose, second-trimester, and multi-course exposure and in male fetuses.

CONCLUSION

This study confirmed PAcE-induced alterations in multi-organ development and function in fetal mice and elucidated its characteristics, which deepens the comprehensive understanding of APAP's developmental toxicity.

High lead contamination in Mother's breastmilk in Bihar (India): Health risk assessment of the feeding children

Lead poisoning in the recent times has caused serious health threats in the exposed human population. It is estimated that about 815 million people are exposed to lead poisoning worldwide and in India total 275 million children are exposed to blood lead contamination. The present study was carried outed in 6 districts of Bihar to know the extent of lead exposure in the children through their mother's breastmilk. The biological samples such as breastmilk, mother's urine, child's urine, and mother's blood samples were collected for quantitative lead estimation. Moreover, the selected household water sources (handpump) and the food consumed by the individuals-wheat, rice and potato samples were also collected for lead quantification. The study reveals that the breastmilk had high lead content in 92% of the samples (highest value 1309 μg/L), in blood presence of lead was observed in 87% studied samples (highest value 677.2 μg/L). In mother's urine the highest lead value was 4168 μg/L (62%) and in child's urine the highest value was 875.4 μg/L (62%) respectively of the studied samples. Moreover, in the studied food samples, wheat had lead content in 45% the studied samples (highest value 7910 μg/kg). In rice in 40% of the studied samples (highest value 6972 μg/kg) and in potato 90% of the studied samples (highest value = 13786 μg/kg) were found with elevated lead content respectively. The hazard quotient (HQ) and the cancer risk (CR) for lead contamination was very much higher in mothers followed by their children. The entire study indicated that lead exposure through food (wheat, rice and potato) has reached the mother's breastmilk and from their it has reached their child's body. This could cause serious hazards in the exposed children causing serious neurological damages, low IQ, low memory, and low mental growth in them. Therefore, a strategic action is required to control the present problem.

Brain structural and functional outcomes in the offspring of women experiencing psychological distress during pregnancy

In-utero exposure to maternal psychological distress is increasingly linked with disrupted fetal and neonatal brain development and long-term neurobehavioral dysfunction in children and adults. Elevated maternal psychological distress is associated with changes in fetal brain structure and function, including reduced hippocampal and cerebellar volumes, increased cerebral cortical gyrification and sulcal depth, decreased brain metabolites (e.g., choline and creatine levels), and disrupted functional connectivity. After birth, reduced cerebral and cerebellar gray matter volumes, increased cerebral cortical gyrification, altered amygdala and hippocampal volumes, and disturbed brain microstructure and functional connectivity have been reported in the offspring months or even years after exposure to maternal distress during pregnancy. Additionally, adverse child neurodevelopment outcomes such as cognitive, language, learning, memory, social-emotional problems, and neuropsychiatric dysfunction are being increasingly reported after prenatal exposure to maternal distress. The mechanisms by which prenatal maternal psychological distress influences early brain development include but are not limited to impaired placental function, disrupted fetal epigenetic regulation, altered microbiome and inflammation, dysregulated hypothalamic pituitary adrenal axis, altered distribution of the fetal cardiac output to the brain, and disrupted maternal sleep and appetite. This review will appraise the available literature on the brain structural and functional outcomes and neurodevelopmental outcomes in the offspring of pregnant women experiencing elevated psychological distress. In addition, it will also provide an overview of the mechanistic underpinnings of brain development changes in stress response and discuss current treatments for elevated maternal psychological distress, including pharmacotherapy (e.g., selective serotonin reuptake inhibitors) and non-pharmacotherapy (e.g., cognitive-behavior therapy). Finally, it will end with a consideration of future directions in the field.

Mass spectrometry analysis of environmental pollutants in breast and artificial milk for newborns

Environmental toxins, particularly liposoluble compounds that accumulate in adipose tissues, present a risk for newborns, not only through breastfeeding but also through artificial milks. These compounds pass into breast milk, potentially exposing infants to harmful substances. In a monocentric observational study carried out in the Charleroi region, we employed liquid chromatography coupled with mass spectrometry to analyze the presence of environmental toxins in milk for newborns. Out of 39 breast milk and 12 artificial milk samples analyzed, 15 and six contained at least one pesticide, respectively, with nine different pesticides identified from a panel of 54 substances tested. The study found an association between the consumption of fresh produce and a higher presence of pesticides in breast milk. This. highlights the broader issue of environmental toxin exposure for infants, regardless of the feeding method. The results underline the need for a comprehensive approach when considering the establishment of breast milk banks and the safety of artificial milk, especially in the context of potential risks to premature newborns. Our findings not only validate the analysis technique for detecting toxins in breast milk but also suggest the necessity for a larger prospective study to explore these risks in the future.

Insights into the early-life chemical exposome of Nigerian infants and potential correlations with the developing gut microbiome

Early-life exposure to natural and synthetic chemicals can impact acute and chronic health conditions. Here, a suspect screening workflow anchored on high-resolution mass spectrometry was applied to elucidate xenobiotics in breast milk and matching stool samples collected from Nigerian mother-infant pairs (n = 11) at three time points. Potential correlations between xenobiotic exposure and the developing gut microbiome, as determined by 16S rRNA gene amplicon sequencing, were subsequently explored. Overall, 12,192 and 16,461 features were acquired in the breast milk and stool samples, respectively. Following quality control and suspect screening, 562 and 864 features remained, respectively, with 149 of these features present in both matrices. Taking advantage of 242 authentic reference standards measured for confirmatory purposes of food bio-actives and toxicants, 34 features in breast milk and 68 features in stool were identified and semi-quantified. Moreover, 51 and 78 features were annotated with spectral library matching, as well as 416 and 652 by in silico fragmentation tools in breast milk and stool, respectively. The analytical workflow proved its versatility to simultaneously determine a diverse panel of chemical classes including mycotoxins, endocrine-disrupting chemicals (EDCs), antibiotics, plasticizers, perfluorinated alkylated substances (PFAS), and pesticides, although it was originally optimized for polyphenols. Spearman rank correlation of the identified features revealed significant correlations between chemicals of the same classification such as polyphenols. One-way ANOVA and differential abundance analysis of the data obtained from stool samples revealed that molecules of plant-based origin elevated as complementary foods were introduced to the infants' diets. Annotated compounds in the stool, such as tricetin, positively correlated with the genus Blautia. Moreover, vulgaxanthin negatively correlated with Escherichia-Shigella. Despite the limited sample size, this exploratory study provides high-quality exposure data of matched biospecimens obtained from mother-infant pairs in sub-Saharan Africa and shows potential correlations between the chemical exposome and the gut microbiome.

Biomonitoring of Dietary Mycotoxin Exposure and Associated Impact on the Gut Microbiome in Nigerian Infants

Mycotoxins are toxic chemicals that adversely affect human health. Here, we assessed the influence of mycotoxin exposure on the longitudinal development of early life intestinal microbiota of Nigerian neonates and infants (NIs). Human biomonitoring assays based on liquid chromatography tandem mass spectrometry were applied to quantify mycotoxins in breast milk (n = 68) consumed by the NIs, their stool (n = 82), and urine samples (n = 15), which were collected longitudinally from month 1-18 postdelivery. Microbial community composition was characterized by 16S rRNA gene amplicon sequencing of stool samples and was correlated to mycotoxin exposure patterns. Fumonisin B1 (FB1), FB2, and alternariol monomethyl ether (AME) were frequently quantified in stool samples between months 6 and 18. Aflatoxin M1 (AFM1), AME, and citrinin were quantified in breast milk samples at low concentrations. AFM1, FB1, and ochratoxin A were quantified in urine samples at relatively high concentrations. Klebsiella and Escherichia/Shigella were dominant in very early life stool samples (month 1), whereas Bifidobacterium was dominant between months 3 and 6. The total mycotoxin levels in stool were significantly associated with NIs' gut microbiome composition (PERMANOVA, p < 0.05). However, no significant correlation was observed between specific microbiota and the detection of certain mycotoxins. Albeit a small cohort, this study demonstrates that mycotoxins may influence early life gut microbiome composition.

Multi-omics and gut microbiome: Unveiling the pathogenic mechanisms of early-life pesticide exposure

The extensive application of pesticides in agricultural production has raised significant concerns about its impact on human health. Different pesticides, including fungicides, insecticides, and herbicides, cause environmental pollution and health problems for non-target organisms. Infants and young children are so vulnerable to the harmful effects of pesticide exposure that early-life exposure to pesticides deserves focused attention. Recent research lays emphasis on understanding the mechanism between negative health impacts and early-life exposure to various pesticides. Studies have explored the impacts of exposure to these pesticides on model organisms (zebrafish, rats, and mice), as well as the mechanism of negative health effects, based on advanced methodologies like gut microbiota and multi-omics. These methodologies help comprehend the pathogenic mechanisms associated with early-life pesticide exposure. In addition to presenting health problems stemming from early-life exposure to pesticides and their pathogenic mechanisms, this review proposes expectations for future research. These proposals include focusing on identifying biomarkers that indicate early-life pesticide exposure, investigating transgenerational effects, and seeking effective treatments for diseases arising from such exposure. This review emphasizes how to understand the pathogenic mechanisms of early-life pesticide exposure through gut microbiota and multi-omics, as well as the adverse health effects of such exposure.

The Austrian children's biomonitoring survey 2020 Part B: Mycotoxins, phytotoxins, phytoestrogens and food processing contaminants

This study assessed the levels of environment and food-related exposures in urine of Austrian school children aged six to ten (n = 85) focusing on mycotoxins, phytoestrogens, and food processing by-products using two multi-analyte LC-MS/MS methods. Out of the 55 biomarkers of exposure reported in this study, 22 were quantified in the first void urine samples. Mycotoxins frequently quantified included zearalenone (detection rate 100%; median 0.11 ng/mL), deoxynivalenol (99%; 15 ng/mL), alternariol monomethyl ether (75%; 0.04 ng/mL), and ochratoxin A (19%; 0.03 ng/mL). Several phytoestrogens, including genistein, daidzein, and its metabolite equol, were detected in all samples at median concentrations of 22 ng/mL, 43 ng/mL, and 14 ng/mL, respectively. The food processing by-product 2-amino-1-methyl-6-phenylimidazo[4,5-b]pyridine (PhIP), was detected in 4% of the samples (median 0.016 ng/mL). None of the investigated samples contained the tested phytotoxins that were rarely considered for human biomonitoring previously (pyrrolizidine alkaloids, tropane alkaloids, aristolochic acids). When relating estimated exposure to current health-based guidance values, 22% of the children exceeded the tolerable daily intake for deoxynivalenol, and the estimated MOE for OTA indicates possible health risks for some children. The results clearly demonstrate frequent low-level (co-)exposure and warrant further exposome-scale exposure assessments, especially in susceptible sub-populations and longitudinal settings.

A Critical Review on the Opportunity to Use Placenta and Innovative Biomonitoring Methods to Characterize the Prenatal Chemical Exposome

Adverse effects associated with chemical exposures during pregnancy include several developmental and reproductive disorders. However, considering the tens of thousands of chemicals present on the market, the effects of chemical mixtures on the developing fetus is still likely underestimated. In this critical review, we discuss the potential to apply innovative biomonitoring methods using high-resolution mass spectrometry (HRMS) on placenta to improve the monitoring of chemical exposure during pregnancy. The physiology of the placenta and its relevance as a matrix for monitoring chemical exposures and their effects on fetal health is first outlined. We then identify several key parameters that require further investigations before placenta can be used for large-scale monitoring in a robust manner. Most critical is the need for standardization of placental sampling. Placenta is a highly heterogeneous organ, and knowledge of the intraplacenta variability of chemical composition is required to ensure unbiased and robust interindividual comparisons. Other important variables include the time of collection, the sex of the fetus, and mode of delivery. Finally, we discuss the first applications of HRMS methods on the placenta to decipher the chemical exposome and describe how the use of placenta can complement biofluids collected on the mother or the fetus.

Nervonic acid improves liver inflammation in a mouse model of Parkinson's disease by inhibiting proinflammatory signaling pathways and regulating metabolic pathways

BACKGROUND

Nervonic acid (NA) - a type of bioactive fatty acid that is found in natural sources - can inhibit inflammatory reactions and regulate immune system balance. Therefore, the use of NA for the treatment of neurodegenerative diseases has received considerable attention. Our previous study found that NA inhibited inflammatory responses in the brain of Parkinson's disease (PD) mouse models. In addition to the brain, PD is also associated with visceral organ dysfunction, especially impaired liver function. Thus, studying the role of NA in PD-mediated inflammation of the liver is particularly important.

METHODS

A combined transcriptome and metabolomic approach was utilized to investigate the anti-inflammatory effects of NA on the liver of PD mice. Inflammatory signaling molecules and metabolic pathway-related genes were examined in the liver using real-time PCR and western blotting.

RESULTS

Liver transcriptome analysis revealed that NA exerted anti-inflammatory effects by controlling several pro-inflammatory signaling pathways, such as the down-regulation of the tumor necrosis factor and nuclear factor kappa B signaling pathways, both of which were essential in the development of inflammatory disease. In addition, liver metabolomic results revealed that metabolites related to steroid hormone biosynthesis, arachidonic acid metabolism, and linoleic acid metabolism were up-regulated and those related to valine, leucine, and isoleucine degradation pathways were down-regulated in NA treatment groups compared with the PD model. The integration of metabolomic and transcriptomic results showed NA significantly exerted its anti-inflammatory function by regulating the transcription and metabolic pathways of multiple genes. Particularly, linoleic acid metabolism, arachidonic acid metabolism, and steroid hormone biosynthesis were the crucial pathways of the anti-inflammatory action of NA. Key genes in these metabolic pathways and key molecules in inflammatory signaling pathways were also verified, which were consistent with transcriptomic results.

CONCLUSION

These findings provide novel insights into the liver protective effects of NA against PD mice. This study also showed that NA could be a useful dietary element for improving and treating PD-induced liver inflammation.

A review of important heavy metals toxicity with special emphasis on nephrotoxicity and its management in cattle

Toxicity with heavy metals has proven to be a significant hazard with several health problems linked to it. Heavy metals bioaccumulate in living organisms, pollute the food chain, and possibly threaten the health of animals. Many industries, fertilizers, traffic, automobile, paint, groundwater, and animal feed are sources of contamination of heavy metals. Few metals, such as aluminum (Al), may be eliminated by the elimination processes, but other metals like lead (Pb), arsenic (As), and cadmium (Ca) accumulate in the body and food chain, leading to chronic toxicity in animals. Even if these metals have no biological purpose, their toxic effects are still present in some form that is damaging to the animal body and its appropriate functioning. Cadmium (Cd) and Pb have negative impacts on a number of physiological and biochemical processes when exposed to sub-lethal doses. The nephrotoxic effects of Pb, As, and Cd are well known, and high amounts of naturally occurring environmental metals as well as occupational populations with high exposures have an adverse relationship between kidney damage and toxic metal exposure. Metal toxicity is determined by the absorbed dosage, the route of exposure, and the duration of exposure, whether acute or chronic. This can lead to numerous disorders and can also result in excessive damage due to oxidative stress generated by free radical production. Heavy metals concentration can be decreased through various procedures including bioremediation, pyrolysis, phytoremediation, rhizofiltration, biochar, and thermal process. This review discusses few heavy metals, their toxicity mechanisms, and their health impacts on cattle with special emphasis on the kidneys.

Studying the Impact of Persistent Organic Pollutants Exposure on Human Health by Proteomic Analysis: A Systematic Review

Persistent organic pollutants (POPs) are organic chemical substances that are widely distributed in environments around the globe. POPs accumulate in living organisms and are found at high concentrations in the food chain. Humans are thus continuously exposed to these chemical substances, in which they exert hepatic, reproductive, developmental, behavioral, neurologic, endocrine, cardiovascular, and immunologic adverse health effects. However, considerable information is unknown regarding the mechanism by which POPs exert their adverse effects in humans, as well as the molecular and cellular responses involved. Data are notably lacking concerning the consequences of acute and chronic POP exposure on changes in gene expression, protein profile, and metabolic pathways. We conducted a systematic review to provide a synthesis of knowledge of POPs arising from proteomics-based research. The data source used for this review was PubMed. This study was carried out following the PRISMA guidelines. Of the 742 items originally identified, 89 were considered in the review. This review presents a comprehensive overview of the most recent research and available solutions to explore proteomics datasets to identify new features relevant to human health. Future perspectives in proteomics studies are discussed.