Extending Nontargeted Discovery of Environmental Chemical Exposures during Pregnancy and Their Association with Pregnancy Complications-A Cross-Sectional Study

Application of a Non-targeted Biomonitoring Method to Characterize Occupational Chemical Exposures of Women Nurses Relative to Office Workers

We analyzed blood serum samples from two unique female occupational cohorts - 60 nurses and 40 office workers in San Francisco, CA - using liquid chromatography and high-resolution mass spectrometry (quadrupole time-of-flight). Applying a nontargeted analysis (NTA) approach, we sought to isolate occupationally related chemical exposures that were unique to nurses by flagging features that were different from office workers in abundance (mean; 95th percentile) or detection frequency. Of 9828 negative electrospray ionization (ESI-) and 6898 positive electrospray ionization (ESI+) detected chemical features, 1094 and 938, respectively, were higher in nurses, possibly due to workplace exposures. We deciphered the molecular structures of these chemical features by applying data-dependent acquisition (DDA) and targeted MS/MS approaches to pooled samples from each occupational group, and we annotated them using spectral MS/MS databases in MS-DIAL. Nurses had higher concentrations of 14 chemicals that we identified at Schymanski Level 1 (N = 6) or 2 (N = 8), as well as 20 tentatively identified chemicals without spectra. Several chemicals may be occupationally relevant for nurses, including a PFAS (6:2 fluorotelomer sulfonic acid), tridecanedioic acid, salicylic acid, and the medications acetaminophen and theophylline. To our knowledge, this study is the first to apply NTA to elucidate novel chemical exposures in nurses.

The impact of environmental and dietary exposure on gestational diabetes mellitus: a comprehensive review emphasizing the role of oxidative stress

Gestational diabetes mellitus (GDM) is a common pregnancy complication closely associated with maternal oxidative and antioxidant imbalance, known as oxidative stress. Environmental and dietary exposure plays an important role in inducing oxidative stress during pregnancy. This review aims to provide an in-depth analysis of the role of oxidative stress induced by environmental and dietary exposure in GDM while incorporating current research frontiers. Environmental pollution, smoking, excessive nutrition, and unhealthy eating habits such as a high-fat diet and vitamin deficiency, may contribute to the generation and accumulation of reactive oxygen species (ROS), leading to oxidative stress. Within the pathway of oxidative stress in GDM, the production and clearance mechanisms of ROS play a pivotal role. Relevant studies have demonstrated that ROS production is closely linked to insulin resistance, adipose tissue accumulation, inflammation, and other pathological processes. Antioxidant substances like vitamins C and E or glutathione can mitigate oxidative stress damage on pregnant women and fetuses by scavenging ROS. Currently, there remain several cutting-edge issues regarding the involvement of the oxidative stress pathway in GDM pathogenesis as well as its relationship with environmental and dietary factors, for instance: how to reduce maternal oxidative stress levels through dietary adjustments or lifestyle modifications; how antioxidant substances can be utilized for intervention treatment; and accurate assessment methods for maternal oxidative stress status along with its association with GDM risk. In conclusion, environmental and dietary factors exert significant influence on GDM pathogenesis while highlighting increasing attention toward understanding the role played by the oxidative stress pathway within this context. In-depth research endeavors within this field are anticipated to offer novel insights into prevention strategies as well as therapeutic approaches for GDM.

Chemical exposure in females of childbearing age associated with sex hormones: Evidence from an untargeted exposomic approach

Exposure to organic chemicals can cause reproductive hormones disturbance in women. However, there is very limited evidence regarding real-world chemical exposures in reproductive-aged women and their joint effects on sex hormone levels. Here, we applied non-targeted screening workflow based on High-Performance Liquid Chromatography-High-Resolution Mass Spectrometry to investigate the serum chemical exposome of 156 women of childbearing age from Jinan, China. A total of 185 exogenous chemicals from 19 categories were identified in at least 80% of serum samples with confidence levels 1-3, 84 of which have never been reported in humans, and 9 of those showed active effects on multiple biological targets in ToxCast program. A combination of grouped weighted quantile sum regression (GWQS), weighted quantile sum regression (WQS), quantile g calculation (q g-comp), and Bayesian kernel machine regression (BKMR) models indicated significant associations of chemical mixture exposure with progesterone (P4), testosterone (T), and luteinizing hormone (LH)/follicle-stimulating hormone (FSH) ratios, and 7, 4, and 8 priority contributors were identified, respectively, such as fipronil sulfone for P4, dicyclohexyl phthalate for T, and 3-hydroxybenzyl alcohol for LH/FSH. Three chemicals closely related to androgen synthesis and metabolism were proposed. Restricted cubic spline curves showed that 10 of the 28 priority compound-hormone pairs displayed significant non-monotonic exposure-response relationships. This study provides more information on the chemical exposome in Chinese women of childbearing age and has important implications for understanding the effect of chemical co-exposure on sex hormone homeostasis in women.

An Enhanced Protocol to Expand Human Exposome and Machine Learning-Based Prediction for Methodology Application

The human exposome remains limited due to the challenging analytical strategies used to reveal low-level endocrine-disrupting chemicals (EDCs) and their metabolites in serum and urine. This limits the integrity of the EDC exposure assessment and hinders understanding of their cumulative health effects. In this study, we propose an enhanced protocol based on multi-solid-phase extraction (multi-SPE) to expand human exposome with polar EDCs and metabolites and train a machine learning (ML) model for methodology prediction based on molecular descriptors. The protocol enhanced the measurement of 70 (25%) and 34 (12%) out of 295 well-acknowledged EDCs in serum and urine compared to the hydrophilic-lipophilic balance sorbent alone. In a nontarget analysis of serum and urine from 20 women of childbearing age in a cohort of 498, controlling occupational factors and daily behaviors for high chemical exposure potential, the multi-SPE protocol increased the measurement of 10 (40%) and 16 (53%) target EDCs and identification of 17 (77%) and 70 (36%) nontarget chemicals (confidence ≥ level 3) in serum and urine, respectively. Interestingly, the ML model predicted that the multi-SPE protocol could identify an additional 38% of the most bioactive chemicals. In conclusion, the multi-SPE protocol advances human exposome by expanding the measurement and identification of exposure profiles.

Liquid crystal monomers induce placental development and progesterone release dysregulation through transplacental transportation

Embryonic and fetal development can be affected during gestation by exposure to xenobiotics that cross the placenta. Liquid crystal monomers (LCMs) are emerging contaminants commonly found in indoor environments; however, whether they can cross the placenta and affect placental development remains unexplored. Here, we develop an evaluation system that integrates human biomonitoring, uterine perfusion in pregnant rats, and placental cells. We find fourteen out of the fifty-six LCMs that are detected in maternal and cord serum samples from ninety-three healthy pregnant women, at median levels of 13.9 and 18.1 ng/mL, respectively. Subsequent explorations of in utero exposure in rats indicate that aromatic amino acid transporter 1 (SLC16A10) mediates transplacental transportation of the LCMs. Placental cells exposed to LCMs exhibit delayed placental development and reduced progesterone release. These findings show that SLC16A10-mediated transplacental transportation of LCMs inhibits placental development and progesterone release, highlighting the importance of gestational exposure to emerging contaminants.

Per- and polyfluoroalkyl substances (PFAS) and hypertensive disorders of Pregnancy- integration of epidemiological and mechanistic evidence

BACKGROUND

Hypertensive disorders of pregnancy (HDP) remain a significant global health burden despite medical advancements. HDP prevalence appears to be rising, leading to increased maternal and fetal complications, mortality, and substantial healthcare costs. The etiology of HDP are complex and multifaceted, influenced by factors like nutrition, obesity, stress, metabolic disorders, and genetics. Emerging evidence suggests environmental pollutants, particularly Per- and polyfluoroalkyl substances (PFAS), may contribute to HDP development.

OBJECTIVE

This review integrates epidemiological and mechanistic data to explore the intricate relationship between PFAS exposure and HDP.

EPIDEMIOLOGICAL EVIDENCE

Studies show varying degrees of association between PFAS exposure and HDP, with some demonstrating positive correlations, particularly with preeclampsia. Meta-analyses suggest potential fetal sex-specific differences in these associations.

MECHANISTIC INSIGHTS

Mechanistically, PFAS exposure appears to disrupt vascular hemodynamics, placental development, and critical processes like angiogenesis and sex steroid regulation. Experimental studies reveal alterations in the renin-angiotensin system, trophoblast invasion, oxidative stress, inflammation, and hormonal dysregulation - all of which contribute to HDP pathogenesis. Elucidating these mechanisms is crucial for developing preventive strategies.

THERAPEUTIC POTENTIAL

Targeted interventions such as AT2R agonists, caspase inhibitors, and modulation of specific microRNAs show promise in mitigating adverse outcomes associated with PFAS exposure during pregnancy.

KNOWLEDGE GAPS AND FUTURE DIRECTIONS

Further research is needed to comprehensively understand the full spectrum of PFAS-induced placental alterations and their long-term implications for maternal and fetal health. This knowledge will be instrumental in developing effective preventive and therapeutic strategies for HDP in a changing environmental landscape.

Multi-omics evaluation of clinical-grade human umbilical cord-derived mesenchymal stem cells in synergistic improvement of aging related disorders in a senescence-accelerated mouse model

BACKGROUND

The prevalence of age-related disorders, particularly in neurological and cardiovascular systems, is an increasing global health concern. Mesenchymal stem cell (MSC) therapy, particularly using human umbilical cord-derived MSCs (HUCMSCs), has shown promise in mitigating these disorders. This study investigates the effects of HUCMSCs on aging-related conditions in a senescence-accelerated mouse model (SAMP8), with a focus on DNA damage, gut microbiota alterations, and metabolic changes.

METHODS

SAMP8 mice were treated with clinical-grade HUCMSCs via intraperitoneal injections. Behavioral and physical assessments were conducted to evaluate cognitive and motor functions. The Single-Strand Break Mapping at Nucleotide Genome Level (SSiNGLe) method was employed to assess DNA single-strand breaks (SSBs) across the genome, with particular attention to exonic regions and transcription start sites. Gut microbiota composition was analyzed using 16S rRNA sequencing, and carboxyl metabolomic profiling was performed to identify changes in circulating metabolites.

RESULTS

HUCMSC treatment significantly improved motor coordination and reduced anxiety in SAMP8 mice. SSiNGLe analysis revealed a notable reduction in DNA SSBs in MSC-treated mice, especially in critical genomic regions, suggesting that HUCMSCs may mitigate age-related DNA damage. The functional annotation of the DNA breaktome indicated a potential link between reduced DNA damage and altered metabolic pathways. Additionally, beneficial alterations in gut microbiota were observed, including an increase in short-chain fatty acid (SCFA)-producing bacteria, which correlated with improved metabolic profiles.

CONCLUSION

The administration of HUCMSCs in SAMP8 mice not only reduces DNA damage but also induces favorable changes in gut microbiota and metabolism. The observed alterations in DNA break patterns, along with specific changes in microbiota and metabolic profiles, suggest that these could serve as potential biomarkers for evaluating the efficacy of HUCMSCs in treating age-related disorders. This highlights a promising avenue for the development of new therapeutic strategies that leverage these biomarkers, to enhance the effectiveness of HUCMSC-based treatments for aging-associated diseases.

Accommodating detection limits of multiple exposures in environmental mixture analyses: an overview of statistical approaches

BACKGROUND

Identifying the impact of environmental mixtures on human health is an important topic. However, such studies face challenges when exposure measurements lie below limit of detection (LOD). While various approaches for accommodating a single exposure subject to LOD have been used, their impact on mixture analysis has not been thoroughly investigated. Our study aims to understand the impact of five popular LOD accommodation approaches on mixture analysis results with multiple exposures subject to LOD, including omitting subjects with any exposures below LOD (complete case analysis); single imputations by LOD/ 2 , and by estimates from a censored accelerated failure time (AFT) model; and multiple imputation (MI) with or without truncation based on LOD.

METHODS

In extensive simulation studies with high-dimensional and highly correlated exposures and a continuous health outcome, we examined the performance of each LOD approach on three mixture analysis methods: elastic net regression, weighted quantile sum regression (WQS) and Bayesian kernel machine regression (BKMR). We further analyzed data from the National Health and Nutrition Examination Survey (NHANES) on how persistent organic pollutants (POPs) influenced leukocyte telomere length (LTL).

RESULTS

Complete case analysis was inefficient and could result in severe bias for some mixture methods. Imputation by LOD/ 2 showed unstable performance across mixture methods. Conventional MI was associated with consistent mild biases, which can be reduced by using a truncated distribution for imputation. Estimating censored values by AFT models had a minimal impact on the results. In the NHANES analysis, imputation by LOD/ 2 , truncated MI and censored AFT models performed similarly, with a positive overall effect of POPs on LTL while PCB126, PCB169 and furan 2,3,4,7,8-pncdf being the most important exposures.

CONCLUSIONS

Our study favored using truncated MI and censored AFT models to accommodate values below LOD for the stability of downstream mixture analysis.

Exposure to DEP Modifies the Human Umbilical Artery Vascular Resistance Contributing to Hypertension in Pregnancy

Hypertensive disorders in pregnancy (HDP) are the most prevalent diseases during pregnancy. In addition to the already identified risk factors, exposure to environmental contaminants has been also considered a new one. Phthalates, which are classified as priority environmental pollutants due to their ubiquitousness and endocrine disrupting properties, have been implicated in HDP in some epidemiological studies. Nevertheless, phthalates' vascular impacts still need to be clarified. Thus, we aimed to understand the connection between phthalates exposure and the occurrence of gestational hypertension, as well as the pathway involved in the pathological vascular effects. We investigated diethyl phthalate's (DEP) effect on the vascular reactivity of the human umbilical arteries (HUAs) from normotensive and hypertensive pregnant women. Both DEP's nongenomic (within minutes effect) and genomic (24 h exposure to DEP) actions were evaluated, as well as the contribution of cyclic guanosine monophosphate and Ca2+ channel pathways. The results show that short-term exposure to DEP interferes with serotonin and histamine receptors, while after prolonged exposure, DEP seems to share the same vasorelaxant mechanism as estrogens, through the NO/sGC/cGMP/PKG signaling pathway, and to interfere with the L-type Ca2+ channels. Thus, the vascular effect induced by DEP is similar to that observed in HUA from hypertensive pregnancies, demonstrating that the development of HDP may be a consequence of DEP exposure.

Association between prenatal perfluorinated compounds exposure and risk of pregnancy complications: A meta-analysis

BACKGROUND AND OBJECTIVE

Per- and polyfluoroalkyl substances (PFASs) have been shown to be persistent and bioaccumulative. An elevated danger of pregnancy complications perhaps connected with exposure to PFASs, but the potential effects remain elusive. The objective of this study is to investigate the possible association between PFASs exposure and pregnancy complications, drawing upon existing evidence.

METHODS

Electronic databases of PubMed, Qvid Medline, Embase, and Web of Science were searched thoroughly to identify eligible research published prior to November 28, 2023, examining the relationship between PFASs and pregnancy-related complications. To evaluate the quality of observational studies incorporated into the article, the Strengthening Reporting of Observational Studies in Epidemiology (STROBE) tool was utilized. The main outcomes assessed in this study included gestational diabetes mellitus (GDM), hypertensive disorders of pregnancy (HDP), gestational hypertension (GH), and preeclampsia (PE).

RESULTS

Twenty-five relevant studies involving 30079 participants were finally selected from four databases. The combined estimates indicate that prenatal exposure to perfluorooctanoic acid (PFOA), perfluorohexane sulfonic acid (PFHxS), perfluorobutane sulfonic acid (PFBS), and perfluoroenanthic acid (PFHpA) is associated with gestational diabetes mellitus (GDM) (PFOA: OR = 1.45, 95%CI: 1.07-1.94, P = 0.015; PFHxS: OR = 1.16, 95%CI: 1.00-1.36, P = 0.055; PFBS: OR = 1.44, 95%CI: 1.16-1.79, P = 0.001; PFHpA: OR = 1.41, 95%CI: 1.10-1.82, P = 0.008). The exposure to PFBS is positively associated with HDP (OR = 1.27, 95%CI: 1.14-1.41, P < 0.001), while both PFOA and PFHpA demonstrate statistically significant positive correlations with GH (PFOA: OR = 1.09, 95%CI: 1.00-1.19, P = 0.049; PFHpA: OR = 1.43, 95%CI: 1.15-1.78, P = 0.001). Negative correlations were observed for prenatal perfluorododecanoic acid (PFDoA) exposure and GH (OR = 0.71, 95%CI: 0.57-0.87, P = 0.001). However, no compelling evidence was identified to link PFASs exposure with the risk of PE.

CONCLUSION

According to the meta-analysis findings, exposure to PFASs may be linked to GDM, HDP, and GH, but it does not significantly raise the risk of PE alone. Further research with larger sample size is required to verify this potential association and explore the biological mechanisms.