Vitamin D Deficiency Exacerbates Poor Sleep Outcomes with Endocrine-Disrupting Chemicals Exposure: A Large American Population Study

Phthalates and bisphenol A are recognized as the predominant endocrine-disrupting substances (EDCs) in the environment, but their impact on sleep health remains unclear. Vitamin D has often been reported to play a role in sleep health and may be affected by endocrine-disrupting compounds. The study utilized data from 5476 individuals in the NHANES project to investigate the correlation between combined exposure to environmental EDCs and sleep duration through modeling various exposures. Furthermore, it emphasizes the importance of vitamin D in the present scenario. Preliminary analyses suggested that vitamin D-deficient individuals generally slept shorter than individuals with normal vitamin D (p < 0.05). Exposure to Mono-ethyl phthalate (MEP), triclosan (TRS), and Mono-benzyl phthalate (MZP), either alone or in combination, was associated with reduced sleep duration and a greater risk of vitamin D deficiency. Individuals with low vitamin D levels exposed to TRS experienced shorter sleep duration than those with normal vitamin D levels (p < 0.05). TRS and MZP were identified as crucial factors in patient outcomes when evaluating mixed exposures (p < 0.05). The results provide new data supporting a link between exposure to EDCs and insufficient sleep length. Additionally, they imply that a vitamin D shortage may worsen the sleep problems induced by EDCs.

Assessment of five typical environmental endocrine disruptors and thyroid cancer risk: a meta-analysis

Introduction

There are conflicting reports on the association between environmental endocrine disruptors (EEDs) and thyroid cancer. This meta-analysis aimed to elucidate the relationship between EEDs and thyroid cancer.

Methods

We searched for epidemiological studies on EEDs and thyroid cancer published in PubMed and Web of Science up to December 2022. We then screened the articles that could extract data on EEDs concentration levels in both thyroid cancer patients and healthy controls. We excluded articles that could not calculate effect sizes, focused on other thyroid diseases, or lacked controls. Standardized mean difference (SMD) was calculated to analyze the association between EEDs and thyroid cancer. We measured the heterogeneity among the included studies using I2, assessed publication bias by Egger's and Begg's test, and evaluated article quality using the Newcastle-Ottawa Quality Score (NOS). In the end, fifteen eligible case-control studies were included.

Results

Our comprehensive analysis revealed that polychlorinated biphenyls (PCBs) were negatively associated with thyroid cancer{ SMD = -0.03, 95% confidence interval (CI) = (-0.05, -0.00), P = 0.03}, while polybrominated diphenyl ethers (PBDEs), phthalates (PAEs), and heavy metals were positively associated with thyroid cancer{PBDEs: SMD = 0.14, 95%CI = (0.04, 0.23), P = 0.007; PAEs: SMD = 0.30, 95%CI = (0.02, 0.58), P = 0.04; heavy metals: SMD = 0.21, 95%CI = (0.11, 0.32), P < 0.001}. We did not find a statistically significant relationship between bisphenol A (BPA) and thyroid cancer. Most of the included studies did not show publication bias, except for those on PCBs.

Discussion

Our results indicate that exposure to certain EEDs, such as PBDEs, PAEs, and heavy metals, increases the risk of thyroid cancer. However, further large-scale epidemiological studies and mechanism studies are needed to verify these potential relationships and understand the underlying biological mechanisms.

Phthalate exposure and risk of ovarian dysfunction in endometriosis: human and animal data

Objective: We aimed to explore the correlations between and possible mechanisms of common environmental endocrine disruptors, phthalates, and ovarian dysfunction in endometriosis. Methods: Subjects were included in the case group (n = 107) who were diagnosed with endometriosis by postoperative pathology in Fujian Maternal and Child Hospital from February 2018 to February 2021, and the women who were excluded from endometriosis by surgery were as the control group (n = 70). The demographic information of the subjects were evaluated by questionnaire, and the clinical characteristics were evaluated by medical records and 3-year follow-up results. Gas chromatography‒mass spectrometry was used to quantify 10 metabolites of phthalates, including dimethyl ortho-phthalate (DMP), mono-n-methyl phthalate (MMP), dioctyl ortho-phthalate (DEP), mono-ethyl phthalate (MEP), di-n-butyl ortho-phthalate (DBP), mono-butyl phthalate (MBP), benzylbutyl phthalate (BBzP), mono-benzyl; phthalate (MBzP), diethylhexyl phthalate (DEHP) and mono-ethylhexyl phthalate (MEHP), in the urine samples of the subjects. Furthermore, a total of 54 SD rats were exposed to DEHP 0, 5, 50, 100, 250, 500, 1,000, 2000, and 3,000 mg/kg/day for 2 weeks. The SD rats' body weight, oestrus cycle changes, and serum anti-mullerian hormone (AMH) levels were evaluated. After sacrifice, the mass index of the rat uterus and bilateral ovaries were calculated. Finally, bioinformatics analysis of rat ovarian tissues was performed to explore the possible mechanism. SPSS 24.0 (IBM, United States) was used for data analysis. p-value <0.05 was considered statistically significant. Results: The human urinary levels of DMP (p < 0.001), MMP (p = 0.001), DEP (p = 0.003), MEP (p = 0.002), DBP (p = 0.041), MBP (p < 0.001), BBzP (p = 0.009), DEHP (p < 0.001), and MEHP (p < 0.001) were significantly higher in women with endometriosis than in controls. Notably, DEHP was a significant risk factor for endometriosis (OR: 11.0, 95% CI: 5.4-22.6). The area under the ROC curve increased when multiple phthalates were diagnosed jointly, reaching 0.974 as the highest value, which was helpful for the diagnosis of endometriosis. In vivo experiments showed that after DEHP exposure in rats, the mass index of the ovary and uterus decreased in a dose-dependent manner; the oestrus cycle of SD rats was irregularly prolonged and disordered; and the serum AMH level was negatively correlated with the DEHP exposure dose (Rho = -0.8, p < 0.001). Bioinformatics analysis of rat ovarian tissues showed that seven genes involved in the steroid biosynthesis pathway were upregulated and may play a negative role in ovarian function. Conclusion: Exposure to phthalates, especially DEHP, is associated with the occurrence of endometriosis and affects women's reproductive prognosis and ovarian function. The steroid biosynthesis pathway may be related to ovarian dysfunction. The detection of phthalate in urine may become a new biological target for the diagnosis of endometriosis.

Quartz crystal microbalance-based method to study adsorption of endocrine disruptor compounds on zeolite

Endocrine disrupting chemicals (EDCs) can be present as trace-level organic pollutants in aquatic environments and are difficult to measure and remove. In this study, a method was developed using a modified quartz crystal microbalance (QCM) to investigate the adsorption of EDCs by zeolite filter. Bisphenol A (BPA), oestrone (E1), oestradiol (E2), and sulfamethoxazole (SMZ) were selected as four representative endocrine disruptors in a water environment and their adsorption on zeolite was measured by QCM in real-time. The adsorption results were well described by a pseudo-first-order kinetic model and by a Sips isotherms model. The adsorption of the four adsorbents is related to their molecular structure, molecular polarity, and chargeability. The removal rate of EDCs by zeolite for different initial concentrations appeared to plateau, with the removal rates of the four selected EDCs all above 80% except for the maximum initial concentration. Changes of pH and ionic strength had no effect on the adsorption capacity of the four EDCs, with a removal rate of about 90%. However, the response time at pH 5.50 was about 300 s faster than that at pH 8.50 and the addition of electrolyte shortened the mass response time of several organic compounds on QCM.

[Preparation of a two-dimensional azine-linked covalent organic framework-coated capillary and its application to the separation of nitrophenol environmental endocrine disruptors by open-tubular capillary electrochromatography]

As a class of new porous crystalline materials, covalent organic frameworks (COFs) are attracting the attention of a large number of scientists. Because of their large specific surface area, low density, high stability, and tunable pore size, COFs have been widely applied in many fields, including analytical chemistry. Open-tubular capillary electrochromatography (OT-CEC) is a mode of capillary electrochromatography. In recent years, a variety of materials such as porous organic frameworks have been used as the stationary phase for OT-CEC to overcome the disadvantages of low phase ratio and column capacity, thereby improving the separation efficiency. However, there are a few reports on the use of COFs as the stationary phase to improve the separation efficiency of OT-CEC. Environmental endocrine disruptors (EEDs) are a large class of exogenous chemicals that can disturb the effect of the normal endocrine substances and adversely affect the endocrine and reproductive systems of human beings. Considering the widespread existence of EEDs and the disadvantages of existing detection methods (e. g., gas chromatography-mass spectrometry and high performance liquid chromatography-mass spectrometry), such as complicated operation and large sample consumption, it is necessary to develop new methods for the separation and determination of EEDs in complex samples. OT-CEC is a good choice in this regard because of its low sample dosage, simple operation, and high analytical speed. Accordingly, a two-dimensional azine-linked covalent organic framework (ACOF-1) with a large surface area and small pore size was synthesized according to the reference method. Then, an ACOF-1-coated capillary was fabricated using ACOF-1 as the stationary phase, via covalent bonding, and used as the separation channel to establish a new OT-CEC method for the separation and detection of nitrophenol EEDs. X-ray powder diffraction (XRD), Fourier transform infrared spectroscopy (FT-IR), and scanning electron microscopy (SEM) were used to characterize the synthesized ACOF-1 and the ACOF-1-coated capillary. The peak pattern in the XRD spectrum confirmed the successful synthesis of ACOF-1. The absorption peaks in the FT-IR spectrum and the morphology of the inner wall seen in the SEM images also demonstrated that the ACOF-1-coated capillary was fabricated successfully. A series of experiments were carried out to investigate the effects of the organic additive (methanol) content, pH, and concentration of the borate buffer on the resolution, migration time, and peak shape. Based on the results, the optimal separation conditions for the four nitrophenol analytes were 15 mmol/L borate (pH 9.20) with 10% (v/v) methanol. Under the optimum conditions, 2-nitrophenol (2-NP), 4-nitrophenol (4-NP), 2,4-dinitrophenol (DNP), and 2,4,6-trinitrophenol (TNP) could be baseline separated within 20 min by the established OT-CEC method. The linear range for 2-NP and 4-NP was 10-500 mg/L, while that for DNP and TNP was 20-1000 mg/L. The determination coefficients (R²) were greater than 0.99. For the four analytes, the limits of detection and limits of quantitation were in the ranges of 0.13-0.23 mg/L and 0.45-0.60 mg/L, respectively. The intraday, interday, and column-to-column relative standard deviations (RSDs) of the migration time and peak area were less than 9.4%. These results revealed that the established method has good repeatability and high stability, thus being suitable for the separation and detection of nitrophenol EEDs. The mechanism studies revealed that the pore size of ACOF-1 was the main factor influencing the separation behavior of each analyte. This work demonstrated the feasibility of using capillary electrochromatography with COFs as the stationary phase for the separation and detection of EEDs. Future research will continue to focus on the preparation of COF-coated capillaries and their application to OT-CEC separation and determination of EEDs.

Effects of the prenatal environment on cryptorchidism: A narrative review

Cryptorchidism, the absence of testes from the scrotum, is the most common genital disorder in boys and a risk factor for reduced fertility and testicular cancer. The mechanism responsible for cryptorchidism involves two discrete stages: a transabdominal and an inguinoscrotal phase. These phases of testicular descent are regulated by the prenatal sex hormone environment, including levels of testosterone, insulin-like factor 3, and calcitonin gene-related peptide. Environmental endocrine disruptors, which are unfavorable environmental factors, may also affect testicular descent through prenatal sex hormones. This review examined the effects of environmental factors, particularly environmental endocrine disruptors, such as phthalates, organochlorine pesticides, diethylstilbestrol, bisphenol A, dioxins/dioxin-like compounds, and perfluoroalkyl substances, and parental lifestyles on the risk of cryptorchidism. Although some studies have shown that environmental endocrine disruptors can affect testicular descent by changing the hormonal environment during the prenatal period, no significant association has been established between exposure to environmental endocrine disruptors and the incidence of cryptorchidism. Therefore, the role played by environmental endocrine disruptor exposure (if any) in the pathogenesis of cryptorchidism remains unknown. Further studies are needed to examine these issues.

The role of epigenetics in the reproductive toxicity of environmental endocrine disruptors

Environmental endocrine disruptors (EEDs) seriously endanger human health by interfering with the normal function of reproductive systems. In males, EEDs can affect sperm formation and semen quality as well spermatogenesis, ultimately reducing fertility. In females, EEDs can affect uterine development and the expression levels of reproduction-related genes, ultimately reducing female fertility and the normal development of the fetus. There are a large number of putative mechanisms by which EEDs can induce reproductive toxicity, and many studies have shown the involvement of epigenetics. In this review, we summarize the role of DNA methylation, noncoding RNAs, genomic imprinting, chromatin remodeling and histone modification in the reproductive toxicity of EEDs.

The correlation between UDP-glucuronosyltransferase polymorphisms and environmental endocrine disruptors levels in polycystic ovary syndrome patients

BACKGROUND

In recent years, there has been an interest in whether environmental endocrine disruptors (EEDs) may contribute to the endocrine disorders in patients with polycystic ovary syndrome (PCOS). The clearance of EEDs from the human body is regulated by the glucuronidation of UDP-glucuronosyltransferases (UGT). This study aimed to analyze the relationship of UGT1A1, UGT2B7, and UGT2B15 polymorphisms with the metabolism of EEDs in patients with PCOS.

METHODS

A total of 357 Chinese women (119 PCOS cases and 238 controls) were genotyped for polymorphisms of UGT1A1, UGT2B7, and UGT2B15. The plasma concentrations of EEDs were measured by the gas chromatography-mass spectrometry method. The association between UGT polymorphisms and the serum level of EEDs in patients with PCOS was analyzed.

RESULTS

The UGT2B7 single nucleotide polymorphism was associated with an increased risk of PCOS. The homozygous polymorphism (TT) of UGT2B7 showed higher bisphenol A and PAEs concentrations in serum. However, a single nucleotide polymorphism on UGT2B15 expression was associated with a decreased risk of PCOS. Subjects homozygous for the T allele of UGT2B15 had a significant effect on phthalates in the blood. In addition, our results also showed that the homozygous polymorphism (TT) of UGT2B7 and UGT2B15 was associated with the capacity of the excretion of androgen in patients with PCOS.

CONCLUSIONS

Our study reported the novel associations between the UGT polymorphisms and EEDs concentrations in patients with PCOS, supporting the relevance of genetic differences in EEDs metabolism, which might be considered as an etiology of PCOS.

Adverse stimulation of 4-nonylphenol in abnormal reproductive organs of female chickens

4-Nonylphenol (4-NP) is a known endocrine disrupting chemical and a persistent environmental contaminant. However, the 4-NP caused mechanism of reproductive toxicity still remains largely unknown in birds. In this study, female chickens (Hy-Line Variety White) were dosed via oral gavage in the early laying period with 0, 50, 100, and 200 mg 4-NP/kg/d for 60 days. Food intake and weight increase were monitored in this organism to investigate chicken growth and development. Moreover, pathological changes of reproductive organs, serum hormone, and mRNA changes on the HPOA were detected. The results showed that gonad development and maturity were retarded in female chickens, and the circulating concentrations of sex hormones were disordered in 4-NP-treated chicken. In 4-NP exposed animals, the mRNA expressions of GnRH and PRLH in hypothalamus and FSH and LH in pituitary were significantly unregulated by 4-NP. In addition, expressions of FSHR and LHR were down-regulated in ovaries of the 4-NP-treatment group, while the levels of stAR, P450scc, P450arom, 3β-HSD, and 17β-HSD were up-regulated in ovaries. Furthermore, expression of ERα in the ovaries of chicken was up-regulated, however, no significant change was observed for ERβ expression. Our results suggest that granulosa cells were an important target and severely disturbed by 4-NP.

[Effect of maternal health and prenatal environmental exposure factors on tooth development]

Odontogenesis is a consequence of a complex series of reciprocal signal interactions between odontogenic epithelium and neural crest-derived odontotgenic mesenchyme. These interactions result from a complex interplay of genetic and environmental factors. Given that a fetus develops in the mother, maternal health and environmental exposures have a great influence on tooth development. In this review, we focused on the key issues in the developmental defects of teeth induced by various types of maternal environmental factors, including environmental endocrine disruptors, joint action of two or more chemical exposures, and maternal health status. This review also discussed the adverse effects of maternal environmental factors on tooth development. These effects include enamel developmental defects, molar incisor hypomineralization, dental fluorosis, hyperdontia and hypodontia. Overall, this review provides a theoretical basis for the prevention of tooth defects in early life, assessment of risks from developmental tooth defects, and advancement of pediatric oral health management.

Genistein inhibits estradiol- and environmental endocrine disruptor-induced growth effects on neuroblastoma cells in vitro

The aim of this study was to examine the effect of genistein on human neuroblastoma cell proliferation induced by two common environmental endocrine disruptors, bisphenol A (BPA) and Di-2-ethylhexyl phthalate (DEHP), and to investigate its underlying mechanism. SK-N-SH human neuroblastoma cells were treated with E₂ (1 ng/ml), BPA (2 μg/ml) or DEHP (100 μM), with or without genistein (12.5 μM) in vitro. The number of viable cells was detected with an absorbance reader after 0, 24, 48 or 72 h treatment. The percentage of cells in different phases, and expression of Akt and its phosphorylation levels were also assessed by flow cytometry and western blot analysis at 72 h, respectively. The BPA and DEHP groups had a 30% higher number of viable cells compared to the non-treated group at 48 h (P<0.001). However, the cell numbers did not increase significantly in the groups with additional treatment with genistein (P>0.05 vs. control) and the same trend was observed at 72 h. The expression of phospho-Akt protein was increased in the groups treated with BPA or DEHP compared to the control group at 72 h (P<0.05), while no significant elevation in the expression of phospho-Akt was observed (P>0.05) in genistein-treated groups. Cells were arrested at the G₂/M phase by genistein. Similar effects were observed in the E₂ group with or without genistein treatment. Akt protein expression had no significant change among all the groups (P>0.05). In conclusion, estradiol- or environmental endocrine disruptor-induced proliferation of human neuroblastoma cells is effectively abolished by genistein, likely in a cell cycle- and Akt pathway-dependent manner.