Di (2-ethyl-hexyl) phthalate disrupts placental growth in a dual blocking mode

Simultaneous analysis of PAEs in edible oil and dietary exposure assessment in Hubei

Phthalic acid esters (PAEs), widely used in food processing, pose significant risks to food safety and human health. A rapid and accurate method to simultaneously detect 18 PAEs in edible oil was developed and applied to evaluate daily exposures in Hubei. By using ultrasound-assisted extraction and GC-MS with deuterated isotopes, we improved extraction efficiency and detection accuracy. The method exhibited excellent linearity and low limits of quantification, with average recoveries ranging from 84.32 % to 115.80 % and relative standard deviations between 2.08 % and 12.82 %. Among 30 commercial edible oils analyzed, higher average levels of DBP, DEHP, and DINP were found at 0.207, 1.767, and 0.600 mg/kg, respectively. Dietary exposure assessment indicated that daily intakes were below health guideline values, but DEHP posed a relatively higher health risk. These findings provide a simple method and reference for assessing PAEs exposure and health risk in edible oil.

Comprehensive utilization of in silico approach and in vitro experiment to unveil the molecular mechanisms of mono (2-ethylhexyl) phthalate-induced lung adenocarcinoma

Mono (2-ethylhexyl) phthalate (MEHP), the main bioactive metabolite of commonly used plasticizer Di (2-ethylhexyl) phthalate, has received increasing attention due to its carcinogenic toxicity. This study aims to systematically explore the molecular mechanisms underlying MEHP-induced lung adenocarcinoma (LUAD). Firstly, network toxicology was employed to construct the interaction network of MEHP-targeted LUAD-related proteins and identify core proteins. Subsequently, functional analyses were used to determine the key pathways of these proteins enriched. Next, expression and survival analyses of multiple public datasets were conducted to emphasize the importance of core genes, and an optimized prognostic model was constructed based on independent prognostic genes to explore the relationship of gene risk with immune infiltration and immunotherapy. Ultimately, molecular docking and dynamics simulation were used to predict the binding modes and affinities of MEHP with core proteins, and surface plasmon resonance experiments were utilized to further validate their direct interactions. The findings demonstrated that MEHP targets 167 LUAD-related proteins, including 28 core target proteins. These proteins form the critical networks that regulate cancer and immune-associated pathways to induce the occurrence and development of LUAD, and further coordinate patient prognosis and treatment by altering the immune microenvironment. Most importantly, their direct interactions (especially PTGS2) lay the structural foundation of MEHP regulating core proteins, greatly supporting its LUAD toxicity. In conclusion, this study introduces a novel approach for evaluating the safety of plasticizers and elucidates the molecular mechanisms behind MEHP-induced LUAD, thus offering new and effective targets and strategies for cancer prevention and treatment.

Effect of combined exposure to phthalates and polycyclic aromatic hydrocarbons during early pregnancy on gestational age and neonatal size: A prospective cohort study

Many studies have indicated that individual exposure to phthalates (PAEs) or polycyclic aromatic hydrocarbons (PAHs) affects pregnancy outcomes. However, combined exposure to PAEs and PAHs presents a more realistic situation, and research on the combined effects of PAEs and PAHs on gestational age and newborn size is still limited. This study aimed to assess the effects of combined exposure to PAEs and PAHs on neonatal gestational age and birth size. Levels of 9 PAE and 10 PAH metabolites were measured from the urine samples of 1030 women during early pregnancy from the Zunyi Birth Cohort in China. Various statistical models, including linear regression, restricted cubic spline, Bayesian kernel machine regression, and quantile g-computation, were used to study the individual effects, dose-response relationships, and combined effects, respectively. The results of this prospective study revealed that each ten-fold increase in the concentration of monoethyl phthalate (MEP), 2-hydroxynaphthalene (2-OHNap), 2-hydroxyphenanthrene (2-OHPhe), and 1-hydroxypyrene (1-OHPyr) decreased gestational age by 1.033 days (95 % CI: -1.748, -0.319), 0.647 days (95 % CI: -1.076, -0.219), 0.845 days (95 % CI: -1.430, -0.260), and 0.888 days (95 % CI: -1.398, -0.378), respectively. Moreover, when the concentrations of MEP, 2-OHNap, 2-OHPhe, and 1-OHPyr exceeded 0.528, 0.039, 0.012, and 0.002 µg/g Cr, respectively, gestational age decreased in a dose-response manner. Upon analyzing the selected PAE and PAH metabolites as a mixture, we found that they were significantly negatively associated with gestational age, birth weight, and the ponderal index, with 1-OHPyr being the most important contributor. These findings highlight the adverse effects of single and combined exposure to PAEs and PAHs on gestational age. Therefore, future longitudinal cohort studies with larger sample sizes should be conducted across different geographic regions and ethnic groups to confirm the impact of combined exposure to PAEs and PAHs on birth outcomes.

Defective Homologous Recombination Repair By Up-Regulating Lnc-HZ10/Ahr Loop in Human Trophoblast Cells Induced Miscarriage

Human trophoblast cells are crucial for healthy pregnancy. However, whether the defective homologous recombination (HR) repair of dsDNA break (DSB) in trophoblast cells may induce miscarriage is completely unknown. Moreover, the abundance of BRCA1 (a crucial protein for HR repair), its recruitment to DSB foci, and its epigenetic regulatory mechanisms, are also fully unexplored. In this work, it is identified that a novel lnc-HZ10, which is highly experssed in villous tissues of recurrent miscarriage (RM) vs their healthy control group, suppresses HR repair of DSB in trophoblast cell. Lnc-HZ10 and AhR (aryl hydrocarbon receptor) form a positive feedback loop. AhR acts as a transcription factor to promote lnc-HZ10 transcription. Meanwhile, lnc-HZ10 also increases AhR levels by suppressing its CUL4B-mediated ubiquitination degradation. Subsequently, AhR suppresses BRCA1 transcription; and lnc-HZ10 (mainly 1-447 nt) interacts with γ-H2AX; and thus, impairs its interactions with BRCA1. BPDE exposure may trigger this loop to suppress HR repair in trophoblast cells, possibly inducing miscarriage. Knockdown of murine Ahr efficiently recovers HR repair in placental tissues and alleviates miscarriage in a mouse miscarriage model. Therefore, it is suggested that AhR/lnc-HZ10/BRCA1 axis may be a promising target for alleviation of unexplained miscarriage.

Rice straw-derived chitosan-enhanced plasticizers as biologically and environmentally friendly alternatives for sustainable materials

Plasticizers like Bis(2-ethylhexyl)phthalate (DEHP) are commonly used to enhance plastic properties but pose environmental and health risks. This study successfully derived plasticizers X and Y from rice straws, demonstrating efficacy in chitosan polymer coatings. Chitosan-based polymers exhibit exceptional hardness, with a value of 300 MPa, due to their enriched structure and robust chitosan bonding. This surpasses the hardness of DEHP. Zebrafish exposure over 5 days revealed that X and Y had no significant behavioral impact, while DEHP caused noticeable toxic effects. Maternal DEHP exposure reduced placental cell growth, unlike X and Y, which had no adverse effects on uterine differentiation or placenta formation, suggesting their safety in human pregnancy. The successful development of X and Y represents a crucial step towards greener plasticizers, addressing environmental concerns and promoting safer alternatives in various industries.

Exposure assessment of plastics, phthalate plasticizers and their transformation products in diverse bio-based fertilizers

Bio-based fertilizers (BBFs) produced from organic waste have the potential to reduce societal dependence on limited and energy-intensive mineral fertilizers. BBFs, thereby, contribute to a circular economy for fertilizers. However, BBFs can contain plastic fragments and hazardous additives such as phthalate plasticizers, which could constitute a risk for agricultural soils and the environment. This study assessed the exposure associated with plastic and phthalates in BBFs from three types of organic wastes: agricultural and food industry waste (AgriFoodInduWaste), sewage sludge (SewSludge), and biowaste (i.e., garden, park, food and kitchen waste). The wastes were associated with various treatments like drying, anaerobic digestion, and vermicomposting. The number of microplastics (0.045-5 mm) increased from AgriFoodInduWaste-BBFs (15-258 particles g-1), to SewSludge-BBFs (59-1456 particles g-1) and then to Biowaste-BBFs (828-2912 particles g-1). Biowaste-BBFs mostly contained packaging plastics (e.g., polyethylene terephthalate), with the mass of plastic (>10 g kg-1) exceeding the EU threshold (3 g kg-1, plastics >2 mm). Other BBFs mostly contained small (< 1 mm) non-packaging plastics in amounts below the EU limit. The calculated numbers of microplastics entering agricultural soils via BBF application was high (107-1010 microplastics ha-1y-1), but the mass of plastic released from AgriFoodInduWaste-BBFs and SewSludge-BBFs was limited (< 1 and <7 kg ha-1y-1) compared to Biowaste-BBFs (95-156 kg ha-1y-1). The concentrations of di(2-ethylhexyl)phthalate (DEHP; < 2.5 mg kg-1) and phthalate transformation products (< 8 mg kg-1) were low (< benchmark of 50 mg kg-1 for DEHP), attributable to both the current phase-out of DEHP as well as phthalate degradation during waste treatment. The Biowaste-BBF exposed to vermicomposting indicated that worms accumulated phthalate transformation products (4 mg kg-1). These results are overall positive for the implementation of the studied AgriFoodInduWaste-BBFs and SewSludge-BBFs. However, the safe use of the studied Biowaste-BBFs requires reducing plastic use and improving sorting methods to minimize plastic contamination, in order to protect agricultural soils and reduce the environmental impact of Biowaste-BBFs.

PFASs in Cerebrospinal Fluids and Blood-CSF Barrier Permeability in Patients with Cognitive Impairment

Attention has been drawn to the associations between PFASs and human cognitive decline. However, knowledge on the occurrence and permeability of PFASs in the brains of patients with cognitive impairment has not been reported. Here, we determined 30 PFASs in paired sera and cerebrospinal fluids (CSFs) from patients with cognitive impairment (n = 41) and controls without cognitive decline (n = 18). We revealed similar serum PFAS levels but different CSF PFAS levels, with lower CSF PFOA (median: 0.125 vs 0.303 ng/mL, p < 0.05), yet higher CSF PFOS (0.100 vs 0.052 ng/mL, p < 0.05) in patients than in controls. Blood-brain transfer rates also showed lower RCSF/Serum values for PFOA and higher RCSF/Serum values for PFOS in patients, implying potential heterogeneous associations with cognitive function. The RCSF/Serum values for C4-C14 perfluoroalkyl carboxylates exhibited a U-shape trend with increasing chain length. Logistic regression analyses demonstrated that CSF PFOS levels were linked to the heightened risk of cognitive impairment [odds ratio: 3.22 (1.18-11.8)] but not for serum PFOS. Toxicity inference results based on the Comparative Toxicogenomics Database suggested that PFOS in CSF may have a greater potential to impair human cognition than other PFASs. Our results contribute to a better understanding of brain PFAS exposure and its potential impact on cognitive function.

Dichloroacetic acid and trichloroacetic acid as disinfection by-products in drinking water are endocrine-disrupting chemicals

Dichloroacetic acid (DCAA) and trichloroacetic acid (TCAA) are two typical non-volatile disinfection by-products (DBPs) found in drinking water. Increasing evidence has demonstrated that they show reproductive toxicity. However, whether they might have endocrine disrupting properties remains largely unknown. To discover this, we treated male mice or pregnant mice with 0, 1-, 102-, 103-, 104-, or 5 × 104-fold maximal concentration level (MCL) of DCAA or TCAA in drinking water. In male mice, the levels of testosterone in serum and androgen receptor (AR) in testis were declined with ≥ 103-fold MCL of DCAA (26.4 mg/kg/d) or TCAA (52.7 mg/kg/d). In pregnant mice, miscarriage rates were increased with ≥ 104-fold MCL of DCAA (264 mg/kg/d) or ≥ 103-fold MCL of TCAA. The levels of FSH in serum were increased and those of estradiol and progesterone were reduced with ≥ 103-fold MCL of DCAA or TCAA. The protein levels of estrogen receptors (ERα and ERβ) in ovary were reduced with ≥ 102-fold MCL of DCAA (2.64 mg/kg/d) or TCAA (5.27 mg/kg/d). Exposure to some certain fold MCL of DCAA or TCAA also altered the protein levels of ERα and ERβ in uterus and placenta. Exposure to 5 × 104-fold MCL of both DCAA and TCAA showed the combined effects. Therefore, both DCAA and TCAA could be considered as novel reproductive endocrine disrupting chemicals, which might be helpful for further assessment of the toxicological effects of DCAA and TCAA and the awareness of reproductive endocrine disrupting properties caused by DCAA and TCAA in drinking water.

Mechanisms of action of mineral fibres in a placental syncytiotrophoblast model: An in vitro toxicology study

Asbestos has been widely used due to its unique characteristics. It is known that exposure to asbestos causes serious damage to health but one species, chrysolite, is still used because it is considered less toxic and not biopersistent in some countries. The aim of our study was to investigate if cellular process underlying the proliferation, differentiation and cell death of placental tissues could be modify in presence of asbestos fibres (50 μg/ml final concentration), long chrysolite fibres (CHR-L) and short chrysolite fibres (CHR-S), using BeWo cell line, an in vitro model that mimics the syncytiotrophoblast (STB), the outer layer of placental villi. Our data demonstrated that none of the fibres analysed alter syncytiotrophoblast formation but all of them induce ROS formation and reduced cell proliferation. Moreover, we showed that only CHR-L fibre induced was able to induce irreversible DNA alterations that carried cells to apoptosis. In fact, BeWo cells exposed to CHR-L fibre showed a significant increase in cleaved CASP3 protein, a marker of apoptosis. These data suggest that CHR-L may induce death of the placental villi leading to impaired placental development. The impairment of placental development is the basis of many gestational pathologies such as preeclampsia and intrauterine growth retardation. Since these pathologies are very dangerous for foetal and maternal life, we suggest to the gynaecologists to carefully evaluate the area of maternal residence, the working environment, the food used, and the materials used daily to avoid contact with these fibres as much as possible.

The Impact of Chronic Phthalate Exposure on Rodent Anxiety and Cognition

Background

There is a growing importance for environmental contributions to psychiatric disorders and understanding the impact of the exposome (i.e., pollutants and toxins). For example, increased biomonitoring and epidemiological studies suggest that daily phthalate chemical exposure contributes to neurological and behavioral abnormalities; however, these mechanisms remain poorly understood. Therefore, the current study was aimed at examining the effects of chronic phthalate exposure on rodent anxiety behaviors and cognition and the impact on hypothalamic-pituitary-adrenal axis function.

Methods

Adult male mice (C57BL6/J) were administered MEHP via drinking water (1 mg/mL), and anxiety-like behavior and cognition combined with hypothalamic-pituitary-adrenal axis and inflammatory assays were assessed after 3 weeks of MEHP exposure.

Results

MEHP-treated mice exhibited enhanced generalized anxiety-like behaviors, as demonstrated by reduced time spent in the open-arm of the elevated plus maze and center exploration in the open field. Tests of spatial memory and cognition were unchanged. Following MEHP administration, circulating levels of corticosterone and proinflammatory cytokines were significantly increased, while at the tissue level, there were MEHP-dependent reductions in glucocorticoid metabolism genes Hsd11b1 and Hsd11b2.

Conclusions

These data suggest that chronic MEHP exposure leads to enhanced generalized anxiety behaviors independent of rodent measures of cognition and memory, which may be driven by MEHP-dependent effects on hypothalamic-pituitary-adrenal axis and peripheral glucocorticoid metabolism function.

In-depth profiling of di(2-ethylhexyl) phthalate metabolic footprints in rats using click chemistry-mass spectrometry probes

Di(2-ethylhexyl) phthalate (DEHP), the most widely used plasticizers in the world, has been regarded as an endocrine disrupting chemical with serious adverse health outcomes. Accumulating evidence strongly suggests that the undesirable biological effects of DEHP are meditated by its metabolites rather than itself. However, the metabolic footprints of DEHP in vivo are still unclear. Here we developed a click chemistry-assisted mass spectrometry (CC-MS) strategy for in-depth profiling DEHP metabolites in rats. An alkyne-modified DEHP analogue (alkyne-DEHP) was synthesized as a tracer for in vivo tracing, and a pair of MS probes (4-azido-nphenylbenzamide, 4-ANPA, and its deuterated reagent d₅-4-ANPA) were prepared to specifically label the alkyne-DEHP metabolites, and prominently improve their detection sensitivity and selectivity. Using the CC-MS strategy, we successfully screened 247 alkyne-DEHP metabolites from rat urine, feces, and serum, including many unrevealed metabolites, such as oxidized phthalate diester metabolites and glucuronides of phthalate monoester metabolites. The discovery of new DEHP metabolites provides additional insights for understanding the metabolism of DEHP, which may be beneficial in exploring the mechanism underlying DEHP induced-toxicity in the future.

Colonic mechanism of serum NAD+ depletion induced by DEHP during pregnancy

Di (2-ethylhexyl) phthalate (DEHP) is a widely used plasticizer in polyvinyl chloride products such as feed piping, packing bag, and medical consumable. Our previous studies have demonstrated that DEHP exposure reduced the concentration of nicotinamide adenine dinucleotide (NAD⁺) in pregnant mice serum, which cuts off the source of NAD⁺ to placenta and results fetal growth restriction. However, the mechanism of serum NAD⁺ depletion by DEHP remains elusive. This study investigated the intestinal mechanism of NAD⁺ shortage-induced by DEHP in pregnant mice. The transcriptome results implicated that the mRNA level of oxidative response genes Cyp1a1, Gsto2, Trpv1 and Trpv3 were upregulated in colon. These changes induced intestinal inflammation. Transmission Electron Microscopy results displayed that DEHP destroyed the tight junctions and cell polarity of colonic epithelial cells. These dysfunctions diminished the expression of NAD⁺ precursor transporters SLC12A8, SLC5A8, SLC7A5, and the NAD⁺ biosynthetic key enzymes NAMPT, NMNAT1-3, and TDO2 in colonic epithelial cells. Analysis of the gut microbiota showed that DEHP led to the dysbiosis of gut microbiota, reducing the relative abundance of Prevotella copri which possesses the VB3 biosynthetic pathway. Therefore, maternal DEHP exposure during pregnancy decreased the transportation of NAD⁺ precursors from enteric cavity to colonic epithelial cells, and inhibited the synthesis of NAD⁺ in colonic epithelial cells. Meanwhile, DEHP reduced the NAD⁺ precursors provided by gut microbiota. Eventually, serum NAD⁺ content was lowered. Taken together, our findings provide a new insight for understanding the intestinal mechanisms by which DEHP affects serum NAD⁺ levels.

The Impact of Chronic Phthalate Exposure on Rodent Anxiety and Cognition

There is a growing importance for environmental contributions to psychiatric disorders and understanding the impact of the exposome (i.e., pollutants and toxins). Increased biomonitoring and epidemiological studies, for example, suggest that daily phthalate chemical exposure contribute to neurological and behavioral abnormalities, however these mechanisms remain poorly understood. The current study therefore aimed to examine the effects of chronic phthalate exposure on rodent anxiety behaviors, cognition, and the impact on hypothalamic-pituitary- adrenal (HPA)-axis function. Adult male mice (C57BL6/J) were administered mono-2-ethylhexyl phthalate (MEHP) via drinking water (1 mg/ml), and anxiety-like behavior, cognition combined with HPA- axis and inflammatory assays were assessed after 3 weeks of MEHP exposure. MEHP-treated mice exhibited enhanced generalized anxiety-like behaviors, as demonstrated by reduced time spent in the open-arm of the elevated plus maze (EPM) and center exploration in the open field (OF). Tests of spatial, cognition and memory function were unchanged. Following MEHP administration, circulating levels of corticosterone and pro- inflammatory cytokines were significantly increased, while at the tissue level, MEHP-dependent reductions in glucocorticoid metabolism genes 11β-hydroxysteroid dehydrogenase (11β-HSD) 1 and 2. These data suggest that chronic MEHP exposure leads to enhanced generalized-anxiety behaviors independent of rodent measures of cognition and memory, which maybe driven by MEHP-dependent effects on HPA-axis and peripheral glucocorticoid metabolism function.

m6A contributes to a pro-survival state in GC-2 cells by facilitating DNA damage repair: Novel perspectives on the mechanism underlying DEHP genotoxicity in male germ cells

Di(2-ethyl-hexyl) phthalate (DEHP), an environmental endocrine disruptor, can destroy the sperm genomic integrity and impairs spermatogenesis. N6-methyladenosine (m6A) is involved in the cellular effects of DEHP. However, the genotoxic effect of DEHP on spermatocytes and the possible role of m6A in this process remain unclear. This study demonstrated that m6A alleviates DEHP genotoxicity in GC-2 cells. In DEHP-treated mice, DNA double-strand breaks (DSBs) were induced in the testis and spermatocytes. To further explore the molecular mechanism of DEHP genotoxicity on spermatocytes, GC-2 cells were exposed to DEHP. DEHP produced distinct genotoxicity and caused DSBs, which led to the inhibition of DNA synthesis and cell cycle arrest. The DNA damage response (DDR) was initiated to repair the DSBs induced by environmentally relevant levels of DEHP (100 μM and 200 μM). During this process, METTL3 upregulated m6A, which facilitated the DDR via stabilizing the DNA damage repair factors (Rad51 and Xrcc5) mRNA to maintain the pro-survival state. Moreover, Mettl3 knockdown partially inhibited DDR. Interestingly, high-dose DEHP (400 μM and 600 μM) directly induced apoptosis rather than the pro-survival state. Altogether: METTL3-mediated m6A participates in maintaining the pro-survival state by upregulating DDR, providing guidance for mitigating the genotoxicity of environment-related level DEHP exposure.

Association of phthalate exposure with low birth weight in couples conceiving naturally or via assisted reproductive technology in a prospective birth cohort

BACKGROUND

Few studies have investigated the adverse effects of preconception phthalate (PAE) exposure on birth weight in couples receiving assisted reproductive technology (ART) compared to naturally conceived newborns.

OBJECTIVES

We examined the association between parental preconception/prenatal urinary phthalate exposure and low birth weight (LBW) risk in couples who conceived using ART or naturally.

METHODS

From the Jiangsu Birth Cohort Study (China), we recruited 544 couples who conceived after infertility treatment and 940 couples who conceived naturally and gave birth to a singleton infant between November 2014 and December 2019. Seventeen metabolites of phthalate and three metabolites of phthalate alternatives were analyzed in parental spot urine samples. Clinical data were collected from medical records. We used generalized linear models, elastic net regression, Bayesian kernel machine regression, and quantile-based g-computation to examine the individual and joint effects of parental phthalate exposure on birth weight and LBW risk ratios (RR).

RESULTS

The relationship between parental phthalate exposure and birth weight was consistent between ART and natural conception. Maternal exposure to mono-ethyl phthalate and mono-carboxyisooctyl phthalate was associated with an increased risk of LBW in ART-conceived infants (RR = 1.27; 95 % confidence interval (CI): 1.03, 1.56; and RR = 1.31; 95 % CI: 1.03, 1.67, respectively). In contrast, in the spontaneously conceived infants, higher paternal prenatal concentrations of mono-benzyl phthalate and mono-carboxyisononyl phthalate were associated with a 40 % and 53 % increase in LBW risk, respectively. Exposure to PAE mixtures was associated with LBW in ART-conceived infants, with the effects primarily driven by di-ethyl phthalate, benzylbutyl phthalate, and di-isononyl phthalate metabolites. Sex-specific LBW was observed, with females appearing to be more susceptible than males.

CONCLUSIONS

Maternal preconception and paternal prenatal exposure to phthalates were associated with increased risk of LBW in infants. Compared with natural conception, ART-conceived fetuses were more sensitive to PAE mixtures, which requires further attention.

The effect of endocrine-disrupting chemicals on placental development

Endocrine-disrupting chemicals (EDCs) or endocrine disruptors are substances that are either naturally occurring or artificial and are released into the natural environment. Humans are exposed to EDCs through ingestion, inhalation, and skin contact. Many everyday household items, such as plastic bottles and containers, the liners of metal food cans, detergents, flame retardants, food, gadgets, cosmetics, and pesticides, contain endocrine disruptors. Each hormone has a unique chemical makeup and structural attributes. The way that endocrine hormones connect to receptors is described as a "lock and key" mechanism, with each hormone serving as the key (lock). This mechanism is enabled by the complementary shape of receptors to their hormone, which allows the hormone to activate the receptors. EDCs are described as exogenous chemicals or compounds that have a negative impact on organisms' health by interacting with the functioning of the endocrine system. EDCs are associated with cancer, cardiovascular risk, behavioural disorders, autoimmune abnormalities, and reproductive disorders. EDCs exposure in humans is highly harmful during critical life stages. Nonetheless, the effect of EDCs on the placenta is often underestimated. The placenta is especially sensitive to EDCs due to its abundance of hormone receptors. In this review, we evaluated the most recent data on the effects of EDCs on placental development and function, including heavy metals, plasticizers, pesticides, flame retardants, UV filters and preservatives. The EDCs under evaluation have evidence from human biomonitoring and are found in nature. Additionally, this study indicates important knowledge gaps that will direct future research on the topic.

Maternal exposure to di-2-ethylhexyl phthalate (DEHP) depresses lactation capacity in mice

Increasing evidence shows that di-2-ethylhexyl phthalate (DEHP), mostly commonly used phthalate for the production of flexible polyvinyl chloride (PVC), has the potential to induce serious health risks in humans. However, the understanding of DEHP-induced lactation performance remains largely unknown. We sought to investigate the adverse effects of DEHP on lactation and examine the underlying mechanism linking DEHP exposure with the lactation alterations. We successfully adapted a maternal DEHP exposure model in female pregnant/lactating mice. Then we determined effects of DEHP exposure on food intake, body weight and milk production as well as the alterations in endocrine factors in lactating mice. The integrated metabonomic and transcriptomic analyses of the mammary gland were performed to measure the changed metabolites and genes related to DEHP exposure-induced lactation alterations. We observed the reduced food intake with elevated blood leptin and the decreased milk yield as well as the reduced levels of serum prolactin, growth hormone, insulin-like growth factor 1 and insulin after exposed to DEHP. Furthermore, 208 metabolites and 3452 genes were separately identified as differentially expressed features associated with DEHP exposure. Integrated metabonomic and transcriptomic analyses demonstrated that DEHP caused lactation depression mainly through impairing energy generation, inducing stress responses along with the hypoactivation of inflammation, reducing the production of antioxidants, disrupting hormone homeostasis and repressing the synthesis of milk constituents (the lower glucose availability for lactose synthesis; the disruption of milk fat globule membrane for lipid droplet formation; the ribosomal dysfunction and disruption of post-modifications for milk protein synthesis). We demonstrated that DEHP disrupted several lactation-related hormone homeostasis and multiple processes like energy insufficiency, inflammation activation, oxidative stress aggravation and disturbance of milk production in the mammary gland of female lactating mice. Our results provide valuable information for the health risk of plastic additive (DEHP) on female lactation dysfunction.

Compartmentalized regulation of NAD+ by Di (2-ethyl-hexyl) phthalate induces DNA damage in placental trophoblast

Di (2-ethyl-hexyl) phthalate (DEHP) is a wildly used plasticizer. Maternal exposure to DEHP during pregnancy blocks the placental cell cycle at the G2/M phase by reducing the efficiency of the DNA repair pathways and affects the health of offsprings. However, the mechanism by which DEHP inhibits the repair of DNA damage remains unclear. In this study, we demonstrated that DEHP inhibits DNA damage repair by reducing the activity of the DNA repair factor recruitment molecule PARP1. NAD+ and ATP are two substrates necessary for PARP1 activity. DEHP abated NAD+ in the nucleus by reducing the level of NAD+ synthase NMNAT1 and elevated NAD+ in the mitochondrial by promoting synthesis. Furthermore, DEHP destroyed the mitochondrial respiratory chain, affected the structure and quantity of mitochondria, and decreased ATP production. Therefore, DEHP inhibits PARP1 activity by reducing the amount of NAD+ and ATP, which hinders the DNA damage repair pathways. The supplement of NAD+ precursor NAM can partially rescue the DNA and mitochondria damage. It provides a new idea for the prevention of health problems of offsprings caused by DEHP injury to the placenta.

Exposure to phthalates in early pregnancy and the risk of fetal growth restriction: a nested case-control study in a Zhuang Chinese population

Phthalates (PAEs) are common endocrine disrupting chemicals (EDCs) that disrupt fetal development. The present study aimed to evaluate the effects of single and coexposure to phthalates in early pregnancy on fetal growth restriction (FGR) by a nested case-control study based on the Guangxi Zhuang Birth Cohort (GZBC). Maternal serum concentrations of seven phthalates in 97 neonates with FGR and 291 matched controls were detected through gas chromatography-mass spectrometry (GC-MS). The associations between phthalates and FGR were analyzed using multiple logistic regression, weight quantile sum (WQS) regression, and Bayesian kernel machine regression (BKMR) models. We found that exposures to butyl-benzyl phthalate (BBP, OR_adj = 1.849, 95% CI: 1.080-3.177, P_adj = 0.025, P_trend = 0.046), di (2-ethyl-hexyl) phthalate (DEHP, OR_adj = 3.893, 95% CI: 1.305-11.910, P_adj = 0.015, P_trend = 0.098) and dimethyl phthalate (DMP, OR_adj = 1.722, 95% CI: 1.089-2.725, P_adj = 0.020, P_trend = 0.002) were significantly positively associated with the risk of FGR, while mono-butyl phthalate (MBP) showed a significant negative association with FGR (OR_high = 0.192, 95% CI: 0.036-0.795, P_adj = 0.033, P_trend = 0.035) only among girls. The WQS model identified that BBP, di(2-ethyl)phthalate (DEP), DMP, DEHP, di-n-butyl phthalate (DBP), and MBP were highly weighted in the association with FGR. The BKMR model supported the positive association between joint exposure to phthalates and the risk of FGR and identified no significant interaction between the seven phthalates. Overall, maternal exposure to BBP, DEHP, and DMP may cause adverse effects on FGR, especially with combined effects.

Phthalate Exposures and Placental Health in Animal Models and Humans: A Systematic Review

Phthalates are ubiquitous compounds known to leach from the plastic products that contain them. Due to their endocrine-disrupting properties, a wide range of studies have elucidated their effects on reproduction, metabolism, neurodevelopment, and growth. Additionally, their impacts during pregnancy and on the developing fetus have been extensively studied. Most recently, there has been interest in the impacts of phthalates on the placenta, a transient major endocrine organ critical to maintenance of the uterine environment and fetal development. Phthalate-induced changes in placental structure and function may have significant impacts on the course of pregnancy and ultimately, child health. Prior reviews have described the literature on phthalates and placental health; however to date, there has been no comprehensive, systematic review on this topic. Here, we review 35 papers (24 human and 11 animal studies) and summarize phthalate exposures in relation to an extensive set of placental measures. Phthalate-related alterations were reported for placental morphology, hormone production, vascularization, histopathology, and gene/protein expression. The most consistent changes were observed in vascular and morphologic endpoints, including cell composition. These changes have implications for pregnancy complications such as preterm birth and intrauterine growth restriction as well as potential ramifications for children's health. This comprehensive review of the literature, including common sources of bias, will inform the future work in this rapidly expanding field.