Environmental exposure to legacy and emerging per- and polyfluoroalkyl substances and endometriosis in women of childbearing age

Environmentally relevant concentrations of individual per- and polyfluoroalkyl substances (PFAS) and a PFAS mixture impact proliferation, migration, and gene transcription in a human myometrial cell line

Per- and polyfluoroalkyl substances (PFAS) are persistent environmental contaminants linked to adverse health effects. Epidemiological studies have linked PFAS with an increased risk of uterine diseases including fibroids however, the mechanisms involved remain to be elucidated. This study examined the impact of individual PFAS, such as legacy compounds [perfluorooctanoic acid (PFOA), perfluorooctanesulfonic acid (PFOS)] and alternative short-chain compounds [GENX/HFPO-DA and perfluorobutanesulfonic acid (PFBS)], along with a PFAS mixture, on the function and transcriptome of immortalized human myometrial cells (UT-TERT). Exposure to these PFAS resulted in increased cell viability and proliferation. Flow cytometry showed that PFOS and the PFAS mixture altered cell cycle progression, while migration assays indicated significant enhancement of cell migration following PFOS and mixture exposure. Moreover, PFOA, PFBS, and the PFAS mixture impaired gap junction intercellular communication (GJIC), suggesting possible disruptions in cellular communication in the uterine environment. Transcriptomic analysis identified extensive changes in gene expression after exposure to environmentally relevant PFAS levels, revealing common molecular pathways involved in cell signaling, lipid metabolism, and cell survival. These findings provide crucial insights into how PFAS may contribute to reproductive health risks, warranting further investigation into the long-term effects of PFAS on uterine function and overall reproductive health.

Prenatal PFAS exposure and outcomes related to maternal gut microbiome composition in later pregnancy

The composition of the gut microbiome is dependent on factors including diet, lifestyle, and exposure to environmental chemicals, and has implications for human health. Per- and polyfluoroalkyl substances (PFAS), a class of man-made chemicals that have nonstick and flame-retardant properties may impact on gut microbiome composition. Our objective was to elucidate links between PFAS and maternal gut microbiome composition in two geographically diverse sites of the Environmental Influences on Child Health Outcomes program. The present analysis includes participants in the Atlanta African American Maternal Child Cohort; ATL AA and a predominately non-Hispanic White subsample of the Michigan Archive for Research on Child Health Cohort; MARCH with serum or plasma PFAS concentrations measured in early or late pregnancy and 16s rRNA sequencing from maternal gut microbiome samples available primarily in later pregnancy (2nd-3rd trimester). Linear regression models tested associations between prenatal PFAS levels (separately for the 1st/3rd trimesters) and measures of alpha diversity, bacterial composition differences, and differential taxonomic abundance. Bayesian Kernel Machine Regression and Elastic net regression mixture modeling were also incorporated. In both cohorts, multiple PFAS were significantly associated with the relative abundance of specific microbiome taxa even after adjustment for covariates including maternal diet, age, race, BMI, and smoking; A total of 16 significant family-level associations were identified for ATL AA (e.g., PFOA with Clostridiaceae; natural log fold change = 0.94) and 13 significant family-level associations identified for MARCH e.g., PFOS with Desulfovibrionaceae; natural log fold change = -1.53 (pFDR<0.05), but similarities between cohorts were lacking. Mixture analyses did not identify interactive or combined effects but did provide modest evidence of inclusion of individual PFAS in beta diversity models in both cohorts. In 2 distinct cohorts, there were significant associations between prenatal PFAS and the relative abundance of several bacterial taxa, but these differences were cohort-specific. This work suggests that PFAS may modulate the gut microbiome during pregnancy.

Perfluorooctane Sulfonate (PFOS) and Related Compounds Induce Nuclear Receptor 4A1 (NR4A1)-Dependent Carcinogenesis

Polyfluoroalkyl substances (PFAS) are widely used industrial compounds that have been identified as contaminants in almost every component of the global ecosystem, and in human studies, higher levels of PFAS have been correlated with increased incidence of multiple diseases. Based on the results of human and laboratory animal studies, we hypothesize that the orphan nuclear receptor 4A1 (NR4A1) may be a critical target for some PFAS such as the legacy linear polyfluorooctanesulfonate (PFOS) and other sulfonates. We show that PFOS and related compounds bound the ligand binding domain (LBD) of NR4A1 and induced the growth of several cancer cell lines and enhanced tumor growth in an athymic nude mouse model. Using NR4A1-responsive rhabdomyosarcoma Rh30 cells as a model, PFOS induced NR4A1-dependent cell proliferation and Rh30 cell migration and invasion. Moreover, in Rh30 cells, PFOS also induces several NR4A1-regulated genes including the PAX3-FOXO1 oncogene and downstream gene products, and in a chromatin immunoprecipitation assay, PFOS does not decrease NR4A1 binding to the promoter. These results demonstrate that PFOS is an NR4A1 ligand and enhances tumorigenesis through the activation of this receptor.

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

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

Association between plasma perfluoroalkyl substances and high-grade serous ovarian cancer overall survival: A nested case-control study

BACKGROUND

Although evidence suggests that perfluoroalkyl and polyfluoroalkyl substances (PFASs) are positively correlated to several disease risks, no studies have proven if plasma PFASs are related to ovarian cancer survival.

OBJECTIVE

To explore the association between plasma PFASs and high-grade serous ovarian cancer (HGSOC) overall survival (OS) in the population who did not smoke.

METHODS

We conducted a nested case-control study within the Ovarian Cancer Follow-Up Study, matching 159 dead patients and 159 survival ones based on body mass index, sample date, and age at diagnosis. Nine plasma PFASs were extracted by solid phase extraction and measured using a liquid chromatography system coupled with tandem mass spectrometry. Baseline plasma concentrations of perfluorinated carboxylic acids (PFCAs) [perfluorooctanoic acid (PFOA), perfluorononanoic acid (PFNA), perfluorodecanoic acid (PFDA), and perfluoroheptanoic acid (PFHpA)] and perfluorinated sulfonic acids (PFSAs) [perfluorooctane sulfonic acid (PFOS) and perfluorohexane sulfonic acid (PFHxS)] were calculated. Odds ratios (ORs) and corresponding 95 % confidence intervals (CIs) were calculated via conditional logistic regression models. To elucidate the combined effects, Bayesian kernel machine (BKMR), and regression quantile g-computation (QGC) models were utilized.

RESULT

In full-adjusted model, significant differences were observed between HGSOC survival and perfluorobutane sulfonic acid, PFHpA, PFHxS, PFOS, PFCA, and PFSA. ORs and 95 %CIs were 2.74 (1.41-5.31), 1.97 (1.03-3.76), 2.13 (1.15-3.95), 2.28 (1.16-4.47), 3.74 (1.78-7.85), and 2.56 (1.31-5.01), respectively for the highest tertile compared with the lowest tertile. The QGC and BKMR models indicated that elevated concentrations of PFAS mixtures were associated with poor OS in HGSOC.

CONCLUSIONS

Both individual and mixed plasma PFASs may relate to poor OS of HGSOC. Further research is necessary to establish causality, and it is recommended to reinforce environmental risk mitigation strategies to minimize PFAS exposure.

Reproductive and Metabolic Health Following Exposure to Environmental Chemicals: Mechanistic Insights from Mammalian Models

The decline in human reproductive and metabolic health over the past 50 years is associated with exposure to complex mixtures of anthropogenic environmental chemicals (ECs). Real-life EC exposure has varied over time and differs across geographical locations. Health-related issues include declining sperm quality, advanced puberty onset, premature ovarian insufficiency, cancer, obesity, and metabolic syndrome. Prospective animal studies with individual and limited EC mixtures support these observations and provide a means to investigate underlying physiological and molecular mechanisms. The greatest impacts of EC exposure are through programming of the developing embryo and/or fetus, with additional placental effects reported in eutherian mammals. Single-chemical effects and mechanistic studies, including transgenerational epigenetic inheritance, have been undertaken in rodents. Important translational models of human exposure are provided by companion animals, due to a shared environment, and sheep exposed to anthropogenic chemical mixtures present in pastures treated with sewage sludge (biosolids). Future animal research should prioritize EC mixtures that extend beyond a single developmental stage and/or generation. This would provide a more representative platform to investigate genetic and underlying mechanisms that explain sexually dimorphic and individual effects that could facilitate mitigation strategies.

Per- and Polyfluoroalkyl Substances and Female Health Concern: Gender-based Accumulation Differences, Adverse Outcomes, and Mechanisms

The deleterious health implications of perfluoroalkyl and polyfluoroalkyl substances (PFAS) are widely recognized. Females, in contrast to males, exhibit unique pathways for PFAS exposure and excretion, leading to complex health outcomes. The health status of females is largely influenced by hormone-related processes. PFAS have been reported to be associated with various aspects of female health, including reproductive system disorders and pregnancy-related diseases. In this article, we provide insights into the correlations between PFAS and female-prevalent diseases. Current epidemiological and toxicological evidence has demonstrated that the adverse effects of PFAS on the health of the female reproductive system are primarily attributed to the disruption of the hypothalamic-pituitary-gonadal (HPG) axis and hormonal homeostasis. However, these findings do not sufficiently elucidate the intricate associations between PFAS and specific diseases. Furthermore, autoimmune disorders, another category that is more prevalent in women compared to men, require additional investigation. Immune biomarkers pertinent to autoimmune disorders have been observed to be influenced by PFAS exposure, although epidemiological evidence is insufficient to substantiate these relations. Further thorough exploration encompassing epidemiological and toxicological studies is essential to elucidating the inherent influence of PFAS on human pathologies. Additionally, comprehensive investigations into female health issues beyond their reproductive functions is essential.

Developmental exposure to perfluorooctane sulfonate(PFOS) impairs the endometrial receptivity

Perfluorooctane sulfonate (PFOS) is a widely used chemical in industrial production. It can be introduced into the environment through multiple pathways and exhibits resistance to degradation. Recent research has demonstrated a significant correlation between its exposure levels in the human body and the incidence of various diseases. The expression of genes related to endometrial receptivity and the differentiation of human endometrial stromal cells (hESCs) were assessed in this study concerning PFOS. In this study, we investigated the effect of PFOS exposure on endometrial tolerance by cell and animal experiments. The activity against endometrial mesenchymal cells was significantly reduced by PFOS intervention, and the apoptosis flow assay results showed that PFOS significantly promoted cell death in a concentration-dependent manner. Transmission electron microscopy results revealed mitochondrial damage in the PFOS-intervened group, and WB results showed that the expression levels of endometrial tolerance-related proteins Homeobox A10 (HOXA10) and integrin beta3 (ITGB3) were decreased, and the expression level of Forkhead box O1 (FOXO1) protein was increased. Animal studies have shown that PFOS exposure can change uterine morphology, cause obvious damage to pinopodes morphology, change the estrous cycle of mice, and affect endometrial receptivity In the present study, we found that PFOS may synergistically affect the viability of endometrial mesenchymal stromal cells through accumulation in vivo, and that PFOS may contribute to the failure of embryo implantation by affecting mitochondrial function and consequently endometrial permissive sites.

Prenatal exposure to per- and polyfluoroalkyl substances, genetic factors, and autistic traits: Evidence from the Shanghai birth cohort

The epidemiological evidence regarding prenatal PFAS exposure and its interaction with genetic factors on the autistic traits risk is unclear. This study included 1610 mother-child pairs from the Shanghai Birth Cohort (SBC). Ten PFAS were quantified in blood serum collected in the first trimester. Child autistic traits were evaluated at age 4 using a Chinese version of the social responsiveness scale-short form (SRS-SF). We calculated the polygenic risk score (PRS) to evaluate the cumulative genetic effects of autism. Additive interaction models were established to explore whether genetic susceptibility modified the effects of prenatal PFAS exposure. After adjusting for confounders, we found prenatal PFOA exposure was associated with an increased risk of autistic traits in children (OR, 3.05; 95 % CI, 1.14-7.58), and the increased risk associated with PFOA was mitigated among women who reported pre-pregnancy folic acid supplementation. Additionally, an increased risk of autistic traits was observed in children with higher levels of prenatal PFHxS exposure and a high PRS (p for interaction = 0.021). Our findings suggest prenatal PFAS exposure may increase the risk of autistic traits in children, especially in those with a high genetic risk. Further research is warranted to confirm this association and explore the underlying mechanisms.

The mixture of non-persistent endocrine-disrupting chemicals in relation to endometriosis

Non-persistent endocrine-disrupting chemicals (EDCs) are of significant concern due to their reproductive toxicity. Previous research reported a relationship between a single type of EDCs and endometriosis. Yet, evidence regarding mixed exposure of multiple categories of EDCs is scarce. Between 2014 and 2018, our hospital-based case-control study recruited 238 endometriosis cases diagnosed by laparoscopy and 296 normal controls in China. Seventeen non-persistent EDCs (phthalates and bisphenols) were measured in urine. The association of single EDC with endometriosis was estimated using logistic regression, while the association between EDC mixture and endometriosis was modeled by Bayesian kernel machine regression (BKMR), quantile-based g-computation (q-gcomp), and principal component analysis (PCA). Consistent results were observed in both single and mixture models where phthalates and bisphenols were associated with increased risk of endometriosis (mixture effect: adjusted odds ratio (aOR)=1.44, 1.22-1.70) and the major contributors were bisphenol A (BPA) and the metabolites of di(2-ethylhexyl) phthalate (DEHP). Interaction analysis showed that bisphenols exhibited significant synergistic interactions with phthalates. Our results suggest that non-persistent EDCs are associated with endometriosis but the underlying mechanisms remain to be elucidated. Our finding may have important public health implications in preventing endometriosis.

Per- and Polyfluoroalkyl Substances (PFASs) and Their Potential Effects on Female Reproductive Diseases

Per- and polyfluoroalkyl substances (PFASs) are a class of anthropogenic organic compounds widely present in the natural and human living environments. These emerging persistent pollutants can enter the human body through multiple channels, posing risks to human health. In particular, exposure to PFASs in women may cause a series of reproductive health hazards and infertility. Based on a review of the existing literature, this study preliminarily summarizes the effects of PFAS exposure on the occurrence and development of female reproductive endocrine diseases, such as polycystic ovary syndrome (PCOS), endometriosis, primary ovarian insufficiency (POI), and diminished ovarian reserve (DOR). Furthermore, we outline the relevant mechanisms through which PFASs interfere with the physiological function of the female ovary and finally highlight the role played by nutrients in reducing the reproductive health hazards caused by PFASs. It is worth noting that the physiological mechanisms of PFASs in the above diseases are still unclear. Therefore, it is necessary to further study the molecular mechanisms of PFASs in female reproductive diseases and the role of nutrients in this process.

Exploring the Potential Link between PFAS Exposure and Endometrial Cancer: A Review of Environmental and Sociodemographic Factors

This exploratory narrative review paper delves into the intricate interplay between per- and polyfluoroalkyl substances (PFAS) exposure, sociodemographic factors, and the influence of stressors in the context of endometrial cancer. PFAS, ubiquitous environmental contaminants notorious for their persistence in the ecosystem, have garnered attention for their potential to disrupt endocrine systems and provoke immune responses. We comprehensively examine the various sources of PFAS exposure, encompassing household items, water, air, and soil, thus shedding light on the multifaceted routes through which individuals encounter these compounds. Furthermore, we explore the influence of sociodemographic factors, such as income, education, occupation, ethnicity/race, and geographical location and their relationship to endometrial cancer risk. We also investigated the role of stress on PFAS exposure and endometrial cancer risk. The results revealed a significant impact of sociodemographic factors on both PFAS levels and endometrial cancer risk. Stress emerged as a notable contributing factor influencing PFAS exposure and the development of endometrial cancer, further emphasizing the importance of stress management practices for overall well-being. By synthesizing evidence from diverse fields, this review underscores the need for interdisciplinary research and targeted interventions to comprehensively address the complex relationship between PFAS, sociodemographic factors, stressors, and endometrial cancer.