Mono-(2-ethylhexyl) Phthalate Research Articles

The role of estrogen receptors (ERs)-Notch pathway in thyroid toxicity induced by Di-2-ethylhexyl phthalate (DEHP) exposure: Population data and in vitro studies

BackgroundThis study aimed to assess the exposure level and risk of Di-2-ethylhexyl Phthalate (DEHP) among adults in Jilin Province, China, clarify the impact of DEHP on human thyroid function, and to explore the role of estrogen receptors (ERs)-Notch signaling pathway in the effect of DEHP metabolites on thyroid hormones based on population data and in vitro experiments. Methods312 adults participated in this study. Urinary DEHP metabolites were determined by high performance liquid chromatography coupled to a tandem mass spectrometer (HPLC-MS/MS). Two pharmacokinetic models were used to evaluate the estimated daily intake (EDI) and hazard quotient (HQ) of the adults. Multiple linear regression and mediating effect models were used to evaluate the target associations. In cell experiments, thyroid follicular epithelial (Nthy-ori3–1) cells were exposed to mono (2-ethylhexyl) phthalate (MEHP) for testing. The inhibitions of ERα and Notch pathway were conducted by siRNA and Notch pathway inhibitor DAPT. ResultsThe detection rate of five DEHP metabolites was 97.1∼100.0%. The HQ value of 0.3% of adults was higher than 1. The levels of urinary DEHP metabolites were significantly correlated with thyrotropin (TSH), thyrotropin-releasing hormone (TRH), total triiodothyronine (TT3), total thyroxine (TT4), free triiodothyronine (FT3) and free thyroxine (FT4) and gene (estrogen receptor α (ERα), Notch1, Dll4) levels. The ERα-Notch pathway played a mediating role in the association between DEHP metabolite levels and FT4. The cell results showed, the levels of FT3 and FT4 in cell supernatant decreased after MEHP exposure, and the downward trend was reversed after ERα and notch pathways were inhibited, notch pathway genes also decreased after ERα inhibition. ConclusionAdults in the Jilin Province of China were widely exposed to DEHP. ERs-Notch pathway played an important role in the effect of DEHP metabolites on thyroid hormones.

Associations between Phthalate Metabolite Concentrations in Follicular Fluid and Reproductive Outcomes among Women Undergoing in Vitro Fertilization/Intracytoplasmic Sperm Injection Treatment.

Phthalates have been reported to impair fertility in various studies. However, evidence exploring the associations between phthalate metabolites in follicular fluid (FF) and reproductive outcomes is lacking. To investigate the associations between phthalate metabolite concentrations in FF and in vitro fertilization/intracytoplasmic sperm injection (IVF/ICSI) outcomes among women recruited from a fertility clinic. We included 641 women undergoing IVF/ICSI treatment from December 2018 to January 2020. The levels of eight phthalate metabolites, including monoethyl phthalate (MEP), mono-isobutyl phthalate (MiBP), mono--butyl phthalate (MBP), monobenzyl phthalate (MBzP), mono(2-ethylhexyl) phthalate (MEHP), mono(2-ethyl-5-hydroxyhexyl) phthalate (MEHHP), mono(2-ethyl-5-oxohexyl) phthalate (MEOHP), and mono(2-ethyl-5-carboxypentyl) phthalate (MECPP), were quantified in FF collected on the oocyte retrieval day. Associations between quartiles of individual phthalate metabolite concentrations and nine IVF/ICSI outcomes, including oocyte yield, mature oocyte number, two distinct pronuclei (2PN) zygote number, fertilization rate, blastocyst formation rate, implantation, clinical pregnancy, miscarriage, and live birth, were estimated with generalized linear models. The effects of phthalate mixtures on IVF/ICSI outcomes were assessed using Bayesian kernel machine regression (BKMR) models. After adjusting for relevant confounders, elevated quartiles of MBzP, MEHHP, and MEHP in FF were inversely associated with the numbers of retrieved oocytes, mature oocytes, and 2PN zygotes (all for trends ). In comparison with the lowest quartile, the highest quartile of molar sum of di(2-ethylhexyl) phthalate metabolites () was associated with a reduction of 9.1% [95% confidence interval (CI): , ] and 10.3% (95% CI: , ) in yielded oocyte and mature oocyte numbers, respectively. Furthermore, the BKMR models revealed inverse associations between phthalate mixtures and the numbers of retrieved oocytes and mature oocytes. We generally found null results for implantation, clinical pregnancy, miscarriage, and live birth. Certain phthalate metabolites in FF are inversely associated with the numbers of retrieved oocytes, mature oocytes, and 2PN zygotes among women undergoing IVF/ICSI treatment. https://doi.org/10.1289/EHP11998.

Phthalate metabolites in urine and follicular fluid in relation to menstrual cycle characteristics in women seeking fertility assistance

BackgroundPhthalates have been shown to disrupt the estrous cycle in animal studies. However, epidemiological research investigating their associations with menstrual cycle characteristics is limited. ObjectiveTo explore the relationships between phthalate exposure and menstrual cycle characteristics among women seeking fertility assistance. MethodsWe determined the levels of eight phthalate metabolites in both follicular fluid (FF) and urine specimens collected from 441 women in the Tongji Reproductive and Environmental (TREE) cohort, using high-performance liquid chromatography and tandem mass spectrometry. Information about menstrual cycle parameters was obtained through a questionnaire. The impacts of individual and joint exposure to phthalates on menstrual cycle characteristics were assessed using multivariable linear regression, Poisson regression, and quantile g-computation approaches. ResultsAfter adjusting for relevant covariates, we found that per log10-unit increase in mono(2-ethylhexyl) phthalate (MEHP) level in urine specimens was associated with a decrease of 0.20 days (95 % CI: −0.37, −0.03) in bleeding duration. We also observed that mono(2-ethyl-5-carboxypentyl) phthalate (MECPP) and the sum of di(2-ethylhexyl) phthalate (DEHP) metabolites (∑DEHP) concentrations in FF samples were inversely related to cycle length [β = −1.92 (95 % CI: −3.10, −0.75) and −1.87 (95 % CI: −3.56, −0.19), respectively]. However, we generally observed null associations between phthalate metabolites and irregular cycle, dysmenorrhea, hypomenorrhea, or cycle length variation. Furthermore, we also found that phthalate metabolite mixtures in FF and urine were generally unrelated to menstrual cycle characteristics. ConclusionOur findings suggest that some DEHP metabolites in FF and urine are inversely associated with menstrual cycle length and menstrual bleeding duration in women attending a fertility center.

Long-term exposure to exogenous phthalate, masculinity and femininity trait, and gender identity in children: a Chinese 3-year longitudinal cohort study

BackgroundPhthalate esters (PAEs) are known to have hormone-like properties, and there is a growing trend of children expressing a gender identity different from assigned sex. However, there has been limited research in the potential links between PAEs exposure and gender identity.MethodsA total of 571 children (278 boys) completed the follow-up from Oct 2017 to Oct 2020 in Childhood Blood Pressure and Environmental Factors (CBPEF) cohort in Xiamen, China. Urinary PAE metabolites were measured at three time of visits using ultraperformance liquid chromatography-tandem mass spectrometry. The Children’s Sex Role Inventory scale was used to assess gender identity (masculinity, femininity, androgyny and undifferentiated), and Tanner definition was used to define puberty timing. Generalized linear models and log-binomial regression were used to assess the relationships between PAEs exposure, gender trait scores and gender identity.ResultsOverall, the concentration of most PAEs in more than 90% of participants was above the limit of detection values. In visit 1, there were 10.1% boys with femininity and 11.3% girls with masculinity; while these figures increased to 10.8% and 12.3% during follow-up, respectively. Early puberty onset accounted for 24.8% and 25.6% among boys and girls. Long-term exposure to mono-2-ethylhexyl phthalate (MEHP) (β = 1.20, 95%CI = 0.13, 2.28), mono-2-ethyl-5-hydroxyhexyl phthalate (MEHHP) (β = 1.25, 95%CI = 0.22, 2.28) and mono-2-ethyl-5-oxohexyl phthalate (MEOHP) (β = 1.40, 95%CI = 0.24, 2.56) was associated with the increased differences of femininity trait scores in boys who enter puberty earlier, prolonged exposure to di(2-ethylhexyl) phthalate (DEHP) might also have such a positive impact (β = 1.38, 95%CI = 0.36, 2.41). For gender identity, persistent exposure to low molecular weight phthalates (LMWP) was negatively associated with undifferentiated type among boys entering puberty earlier (RR = 0.18, 95%CI = 0.05, 0.75, P < 0.05), and most of the PAE metabolites exposures showed risk ratios > 1 for their femininity.ConclusionLong-term exposure to PAEs increase the femininity trait scores in boys with early onset of puberty. Although the mechanisms remain to be determined, environmental pollution might have subtle, yet measurable effects on childhood gender identity. Reducing these chemicals exposure has important public implications on gender development.

Dummy molecularly imprinted polymer-based solid-phase extraction method for the determination of some phthalate monoesters in urine by gas chromatography–mass spectrometry analysis

A dummy molecularly imprinted polymer-based solid-phase extraction (SPE) sorbent was used for the selective extraction of some phthalate monoesters, monoethyl phthalate (MEP), monobutyl phthalate (MnBP) and mono-(2-ethylhexyl) phthalate (MEHP) in urine prior to gas-chromatography-mass spectrometry (GC-MS) analysis. Diethyl phthalate (DEP), a phthalate ester, was successfully used as a dummy template to prepare selective sorbent for MEP, MnBP, and MEHP extraction. DEP-imprinted poly(ethylene glycol dimethacrylate N-methacryloyl-l-tryptophan methyl ester) (DPEMT) microbeads were synthesized by suspension polymerization and characterized by Fourier Transform infrared spectroscopy (FTIR), scanning electron microscopy (SEM) and Brunauer Emmet Teller (BET) analysis. The critical parameters (i.e., pH, sorbent amount, ionic strength, sample volume, elution solvent) affecting the extraction performance of the DPEMT-SPE sorbent were optimized. Under optimum conditions, good linearities were obtained in the concentration range of 4 to 60 ng/mL with determination coefficients (R2) of greater than 0.9959. The developed SPE method provided low limits of detection (LOD) of 0.05–1.20 ng/mL and limits of quantification (LOQ) of 0.18–4.01 ng/mL with relative standard deviations (RSDs) of less than 8.95 % for intra- and inter-day analyses. The proposed SPE method was used to analyze phthalate monoesters in spiked urine samples, and recoveries of 97.45–109.26 % were obtained. DPEMT-SPE sorbent was reused for 15 times without any losses of performance. Consequently, a highly selective and sensitive SPE method based on a dummy molecularly imprinted polymer combined with GC-MS was successfully developed to monitor human phthalate exposure via urine samples.

Mono-2-ethylhexylphthalate (MEHP) is a potent agonist of human TRPA1 channel

Phthalates are extensively used as plasticizers in diverse consumer care products but have been reported to cause adverse health effects in humans. A commonly used phthalate, di-2-ethylhexylphthalate (DEHP) causes developmental and reproductive toxicities in humans, but the associated molecular mechanisms are not fully understood. Mono-2-ethylhexylphthalate (MEHP), a hydrolytic product of DEHP generated by cellular esterases, is proposed to be the active toxicant. We conducted a screen for sensory irritants among compounds used in consumer care using an assay for human Transient Receptor Potential A1 (hTRPA1). We have identified MEHP as a potent agonist of hTRPA1. MEHP-induced hTRPA1 activation was blocked by the TRPA1 inhibitor A-967079. Patch clamp assays revealed that MEHP induced inward currents in cells expressing hTRPA1. In addition, the N855S mutation in hTRPA1 associated with familial episodic pain syndrome decreased MEHP-induced hTRPA1 activation. In summary, we report that MEHP is a potent agonist of hTRPA1 which generates new possible mechanisms for toxic effects of phthalates in humans.

BMI-specific inflammatory response to phthalate exposure in early pregnancy: findings from the TMCHESC study.

Studies that have evaluated associations between phthalate metabolites and inflammation have reported inconsistent results among pregnant women, and it is unclear how body mass index (BMI) affects such relationships. Therefore, the present study aimed to examine the association between urinary phthalate metabolite concentrations and the levels of inflammatory biomarkers in the general circulation among 394 pregnant women selected from the Tianjin Maternal and Child Health Education and Service Cohort (TMCHESC) and to determine the role that BMI plays in the relationship. The concentrations of eight inflammatory biomarkers and three phthalate metabolites were measured in serum and urine samples, respectively. Multivariable linear modeling was conducted to examine the association between each phthalate and inflammatory biomarker while controlling for potential confounding factors in BMI-stratified subgroups. Restricted cubic splines were also utilised to explore potential non-linear relationships. In the high-BMI group, positive associations were observed between the levels of mono-n-butyl phthalate (MBP) and interleukin 1 beta (IL-1β) (β = 0.192; 95% CI: 0.033, 0.351), monoethyl phthalate (MEP), and C-reaction protein (CRP) (β = 0.129; 95% CI 0.024, 0.233), and mono-ethylhexyl phthalate (MEHP) and interleukin 6 (IL-6) (β = 0.146; 95% CI 0.016, 0.277). Restricted cubic spline models also revealed non-linear associations between the levels of MBP and interleukins 10 and 17A (IL-10 and IL-17A) and between MEP and interleukin 8 (IL-8) and tumor necrosis factor alpha (TNF-α) in pregnant women. These results suggest that phthalate exposure plays a potential role in promoting inflammation in the high-BMI group. While the precise mechanisms underlying the proinflammatory effects of phthalates are not fully understood, these findings suggest that BMI may play a role.

Association of mono-2-ethylhexyl phthalate with adverse outcomes in chronic hemodialysis patients

Phthalate exposure is widespread and has a global impact. Growing evidence shows that mono-2-ethylhexyl phthalate (MEHP) exposure has a negative impact on human health. However, whether MEHP exposure is associated with mortality and other adverse outcomes in hemodialysis patients remains unknown. This study prospectively enrolled 217 patients on maintenance hemodialysis from June 30, 2021, to August 16, 2022. Baseline serum MEHP, di-2-ethylhexyl phthalate (DEHP), and indoxyl sulfate (IS) concentrations were measured. Primary endpoints were all-cause mortality or composite adverse outcomes, including all-cause death plus hospitalization due to cardiovascular disease, heart failure, stroke, infection, or cancer. Serum MEHP concentrations were positively associated with DEHP but not indoxyl sulfate concentrations in hemodialysis patients. Additionally, serum MEHP concentrations were significantly and independently associated with all-cause mortality and composite adverse outcomes (adjusted hazard ratios [HRs], 1.04 and 1.03 per ng/mL, 95% confidence intervals [CIs], 1.01–1.07 and 1.00–1.05; p = 0.016 and 0.015, respectively). We found a cutoff value of MEHP for predicting both endpoints. Patients with serum MEHP concentrations of ≥ 41.8 ng/mL had much higher risks for all-cause mortality and composite adverse outcomes (adjusted HRs, 39.2 and 13; 95% CIs, 2.44–65.7 and 2.74–61.4; p = 0.011 and 0.001, respectively). MEHP exposure is significantly associated with higher risks for all-cause mortality and composite adverse outcomes. Hemodialysis patients with serum MEHP concentrations above 41.8 ng/mL had much poorer prognoses regarding both outcomes.

Mono-(2-ethylhexyl) phthalate (MEHP) reversibly disrupts the blood-testis barrier (BTB) in pubertal rats.

The blood-testis barrier (BTB) is constituted by tight junctions between adjacent Sertoli cells (SC) that create a specialized adluminal microenvironment to foster the development of spermatocytes and spermatids. The BTB is a well-studied target of numerous environmental toxicants, including di-(2-ethylhexyl) phthalate (DEHP), a compound widely used in various consumer products. MEHP is the active toxic metabolite of DEHP that has long been recognized in postnatal rodents to disrupt SC function. This study evaluates the impact of MEHP on the integrity of the BTB in both pubertal and adult rats and the signal transduction pathways known to be involved in the disruption of the BTB. Treatment of prepubertal rats with 700 mg/kg MEHP for 24 hours functionally disrupted the BTB integrity. A similar treatment of adult rats with MEHP did not disrupt the integrity of the BTB. The observed disruption of the BTB integrity in the MEHP-treated prepubertal rats occurred concomitantly with a decreased expression and mislocalization of both the ZO1 and occludin tight junction-associated proteins, as well as sloughing of spermatocytes and spermatids. At this same time, MEHP treatment induced a transient surge of p44/42 mitogen-activated protein kinase (MAPK) pathway. Interestingly, after a recovery period of 5 weeks, the BTB recovered and was functionally intact. This is the first report to indicate that acute MEHP exposure of prepubertal rats, but not adult rats, disrupts the functional integrity of the BTB and that this effect on the BTB is reversible.

Phthalate metabolites in breast milk from mothers in Southern China: Occurrence, temporal trends, daily intake, and risk assessment

The extensive production and use of phthalates means that these compounds are now ubiquitous in the environment and various biota, which raises concerns about potential harmful health effects. In this study, phthalate metabolites (mPAEs) were measured in breast milk (n = 100) collected from mothers of southern China between 2014 − 2022. Of the nine target mPAEs, five were detected in all of the samples, including mono-methyl phthalate (MMP), mono-ethyl phthalate (MEP), mono-isobutyl phthalate (MiBP), mono-n-butyl phthalate (MnBP), and mono-(2-ethylhexyl) phthalate (MEHP). The total levels of mPAEs in breast milk ranged from 4.76 to 51.6 ng/mL, with MiBP and MnBP being the predominant isomers (MiBP + MnBP > 48.3%). Increasing trends were observed in MMP (5.7%/year) and MEHP (7.1%/year) levels during the study period, while a decreasing trend were observed in MiBP (−6.6%/year); no clear temporal trends were found for the other metabolites and total mPAE levels. The results indicate that exposure to phthalates is still prevalent in southern China. Breastfeeding was found to contribute to estimated daily phthalate intakes of 0.383–6.95 μg/kg-bw/day, suggesting insignificant health risks to infants based on dietary exposure. However, the increasing exposure to MMP and MEHP calls for more research into the possible sources and potential risks.

Associations between phthalate metabolites and cytokines in the follicular fluid of women undergoing in vitro fertilization

Many studies have showed that phthalates have reproductive and embryonic toxicity, while the potential mechanisms are mostly unknown. Inflammation may play a mediating part in phthalate exposure and adverse reproductive endpoints. A cross-sectional survey was conducted to investigate the associations of phthalate metabolites with inflammatory cytokines in the follicular fluid (FF) of women undergoing in vitro fertilization (IVF). We determined the levels of eight phthalate metabolites and five cytokines in the FF of 76 women, including interleukin (IL)- 6, IL-8, IL-10, monocyte chemoattractant protein-1 (MCP-1) and tumor necrosis factor-α (TNF-α). The associations of individual phthalate exposure with cytokines in FF samples were explored by multiple linear regression. We further evaluated the combined effects of multiple phthalate exposures on FF levels of cytokines by using Bayesian kernel machine regression (BKMR) models. We found that there was a positive relationship between mono-ethyl phthalate (MEP) and IL-6 in the FF (percent change:12.4%; 95% CI: 1.3%, 24.9%). In contrast, elevated mono-benzyl phthalate (MBzP), mono(2-ethylhexyl) phthalate (MEHP) and %MEHP levels were associated with decreased MCP-1. In the BKMR models, phthalate metabolite mixtures were positively associated with TNF-α when the mixtures were lower than 65th percentile compared with their medians. In the stratified analyses, MEHP was inversely associated with MCP-1 among women with BMI ≥ 23 kg/m2 (test for interaction <0.05). Our results suggest that certain phthalate metabolites or their mixtures may alter levels of inflammatory cytokines in the FF, and further research is necessary to elucidate the mechanisms underlying the relationship between phthalates exposure, ovarian dysfunction and adverse pregnancy outcomes.

Froriepia subpinnata Leaf Extract-Induced Apoptosis in the MCF-7 Breast Cancer Cell Line by Increasing Intracellular Oxidative Stress.

Froriepia subpinnata is one of the plants used in the diet of Iranian people. Previous studies have investigated the antioxidant and antibacterial effects of this plant extract, but no study has been conducted on its anticancer properties. In this study, we investigated the effect of F. subpinnata extract on MCF-7 breast cancer cells. The inhibitory effect of F. subpinnata leaf extract was determined on the growth of cancer cells by the MTT test. The ROS (reactive oxygen species) test was used to investigate the impact of the extract on intracellular oxidative stress. Flow cytometry and real-time PCR tests were used to investigate the apoptosis-related molecular processes. The GC-MS analysis was performed to determine the most abundant components. The GC-MS analysis showed that phytol, mono-ethylhexyl phthalate (MEHP), cinnamaldehyde, and neophytadiene constituted 60% of the extracted content. The MTT assay demonstrated that F. subpinnata leaf extract caused 50% lethality at a 400 μg/mL dose in MCF7 cells. The F. subpinnata extract at low doses decreased the ROS level for 24 hours in MCF-7, but by increasing the concentration, the ROS levels increased. At the IC50 dose (inhibitory concentration (IC) associated with 50% impact), the ROS level increased 3.5 times compared to the control group. Examining the effect of N-acetyl cysteine (NAC) showed that this antioxidant agent could prevent the lethal impact of the extract and eliminate the ROS increase in MCF7 cells. Flow cytometry and real-time PCR results showed that the extract specifically induced apoptosis through the internal apoptosis pathway in this cancer cell line. The F. subpinnata extract induced apoptosis by increasing ROS in MCF-7 cancer cells and can be considered for further studies.

MEHP activates JNK to inhibit the migration of human foreskin fibroblasts

This study aimed to investigate the impact of mono(2-ethylhexyl) phthalate (MEHP) on the proliferation, apoptosis, and migration of human foreskin fibroblast cells (HFF-1) and the role of the JNK signaling pathway in cell migration. HFF-1 cells were randomly assigned to the control group with 0 MEHP exposure (M0) or the experimental groups with 25, 50, 100, 200, and 400 μmol/L MEHP exposure (M25, M50, M100, M200, and M400, respectively). After 24 and 48 h of MEHP exposure, the proliferation of HFF-1 cells in any group had no significant change. However, compared with the M0 group, the M200 and M400 groups presented substantially increased apoptosis of HFF-1 cells. Moreover, cell migration ability significantly decreased in all groups (p < 0.05). Additionally, the transcription and phosphorylated protein activation of JNK kinase in HFF-1 cells were substantially upregulated with the increase in MEHP exposure. Subsequently, HFF-1 cells were randomly divided into three groups: the DMSO blank control group, the 100 μM MEHP experimental group (M100), and the 100 μM MEHP plus 10 μM SP600125 (specific JNK inhibitor) experimental group (S10). The activation of JNK protein in HFF-1 cells was substantially downregulated in the S10 group. HFF-1 cells were also divided into the blank control group (M0). They were treated with 100 μM MEHP and varying concentrations of SP600125 (5, 10, and 15 μM for S5, S10, and S15, respectively). As the concentration of the antagonist increased, the migration ability of HFF-1 cells was returned to normal. Finally, the ROS in HFF-1 cells increased under MEHP exposure. This finding indicates that the regulation of cell migration by the JNK signaling pathway may be important in the occurrence of hypospadias.

Activation of the p62-Keap1-Nrf2 pathway protects against oxidative stress and excessive autophagy in ovarian granulosa cells to attenuate DEHP-induced ovarian impairment in mice

Di-(2-ethylhexyl) phthalate (DEHP) is widely used in various plastics but has been demonstrated to cause female reproductive toxicity. However, the exact mechanism underlying the ovarian damage induced by DEHP remains unclear. In this study, DEHP was administered orally to 5-week-old female mice for 30 days at doses of 0, 250, 500, and 1000 mg/kg/day. The findings demonstrated that DEHP exposure disrupted ovarian function and follicular development as well as induced oxidative stress and autophagy in ovarian granulosa cells (GCs). Further, 200 µM mono-(2-ethylhexyl) phthalate (MEHP), the primary metabolite of DEHP in vivo, induced autophagy in both human ovarian granulosa cells line (KGN) and mouse primary GCs within 24 h in vitro. However, it did not affect the p62-dependent autophagy flux. Furthermore, MEHP-induced autophagy was inhibited by the autophagy inhibitor 3-MA and exacerbated by the autophagy activator rapamycin, indicating that MEHP induces excessive autophagy in GCs. Subsequently, we found that MEHP-induced autophagic cell death was primarily attributed to oxidative damage from elevated intracellular ROS levels. Meanwhile, MEHP exposure induced nuclear translocation of erythroid-derived factor 2-related factor (Nrf2), a key regulator of antioxidant activity resulting in activating antioxidant effects. Interestingly, we also found that MEHP-induced increase in p62 competitively binds Keap1, thereby facilitating nuclear translocation of Nrf2 and establishing a positive feedback loop in antioxidant regulation. Therefore, this study demonstrated that inhibition of Nrf2 could aggravate oxidative damage and enhance excessive autophagy caused by MEHP, while activation of Nrf2 could reverse the trend. These findings have also been reinforced in studies of cultured ovaries in vitro. Our study suggests that the p62-Keap1-Nrf2 pathway may serve as a potential protective mechanism against DEHP-induced oxidative stress and excessive autophagy in mouse GCs.

Associations of urinary di(2-ethylhexyl) phthalate metabolites with lipid profiles among US general adult population

BackgroundDi(2-ethylhexyl) phthalate (DEHP) a parent compound that is metabolized into 4 phthalate metabolites, which correlate to adverse cardio-metabolic risk factors. This study aimed to explore the links between urinary DEHP metabolites and serum lipids in the U.S. general adult population. MethodsIn this cross-sectional study, data on 11 urinary phthalate metabolites from the 2005–2018 National Health and Nutrition Examination Surveys (NHANES) were analyzed. Multivariate linear regression and restricted cubic spline (RCS) were used to examine the relationship between phthalate metabolites [specific DEHPs: mono-(2-ethyl-5-carboxy-pentyl) phthalate (MECPP), mono-(2-ethyl-5-hydroxy-hexyl) phthalate (MEHHP), mono-(2-ethylhexyl) phthalate (MEHP), mono-(2-ethyl-5-oxo-hexyl) phthalate (MEOHP)] and serum lipids (triglycerides [TG], total cholesterol [TC], low-density lipoprotein cholesterol [LDL-C], and high-density lipoprotein cholesterol [HDL-C]). To identify mixed exposure effects of phthalate metabolites, quantile g-computation (QG-C) and weighted quantile sum (WQS) regression were employed for the lipid profiles. ResultsA total of 9141 adults were included in the analysis. MECPP, MEHHP, MEHP, and MEOHP in the highest quartile had a negative relationship with HDL-C compared to the lowest quartile (All P for trend <0.05). TG showed a significant positive relation with MECPP, MEHHP, and MEOHP (All P for trend <0.05), but there was no notable association with MEHP. RCS demonstrated a linear relationship of DEHP metabolites with HDL-C, TC, TG, and LDL-C (all P for nonlinearity >0.05). The WQS index of DEHP metabolites showed independent correlations with HDL-C [β = −0.26, 95%CI (−0.43, −0.09), P = 0.002], TC [β = 0.55, 95%CI (0.13, 0.98), P = 0.011], and TG [β = 2.40, 95%CI (0.85, 3.96), P = 0.003]. ConclusionOur study suggests that environmental DEHP exposure may affect serum HDL-C and TG levels in the general adult population. Further research is warranted to confirm these findings and illuminate the underlying mechanisms of DEHP exposure on lipids.

Unraveling the contribution of dietary intake to human phthalate internal exposure

Human exposure to phthalates (PAEs) occurs primarily through diet, but the contribution of dietary exposure to the total internal exposure of PAEs has not been well studied. This work investigated the relationship between dietary exposure and human internal exposure to PAEs. Daily food samples were determined to evaluate the health risk of dietary exposure, and phthalate metabolites (mPAEs) were determined from urine samples of 360 volunteers of Guangzhou to assess their internal exposure. The total mPAEs concentration in the urine samples ranged from 8.43 to 1872 ng/mL, with mono-(2-ethylhexyl) phthalate (MEHP), mono-n-butyl phthalate (MnBP), and mono-isobutyl phthalate (MiBP) being the most predominant mPAEs. The concentration of PAEs in food ranged from n.d-40200 μg/kg, and benzyl butyl phthalate (BBzP), di-n-butyl phthalate (DnBP) and di-(2-ethylhexyl) phthalate (DEHP) were the most prevalent. PAE exposure was significantly associated with age, and children exhibited the highest concentration of mPAEs. Using Monte Carlo simulation to estimate PAE exposure's health risk eliminated uncertainties caused by single-point sampling and provided more reliable statistical results. The hazard quotient (HQ) was used to evaluate PAE exposure health risks. The results showed that 37% of the volunteers had HQ levels higher than 1 based on urinary mPAE concentrations, while 24% of the volunteers had HQ levels greater than 1 because of dietary exposure to PAEs. Dietary intake was the predominant exposure route for PAEs, and accounted for approximately 65% (24% out of 37%) of the cases where HQ levels exceeded 1.The work revealed the correlation between dietary external and internal exposure to PAEs, and further studies are needed to better understand the implications.

Testis exposure to unopposed/elevated activin A in utero affects somatic and germ cells and alters steroid levels mimicking phthalate exposure.

Correct fetal testis development underpins adult male fertility, and TGFβ superfamily ligands control key aspects of this process. Transcripts encoding one such ligand, activin A, are upregulated in testes after sex determination and remain high until after birth. Testis development requires activin signalling; mice lacking activin A (Inhba KO) display altered somatic and germ cell proliferation, disrupted cord elongation and altered steroid synthesis. In human pregnancies with pre-eclampsia, the foetus is inappropriately exposed to elevated activin A. To learn how this affects testis development, we examined mice lacking the potent activin inhibitor, inhibin, (Inha KO) at E13.5, E15.5 and PND0. At E13.5, testes appeared similar in WT and KO littermates, however E15.5 Inha KO testes displayed two germline phenotypes: (1) multinucleated germ cells within cords, and (2) germ cells outside of cords, both of which are documented following in utero exposure to endocrine disrupting phthalates in rodents. Quantitation of Sertoli and germ cells in Inha KO (modelling elevated activin A) and Inhba KO (low activin A) testes using immunofluorescence demonstrated activin A bioactivity determines the Sertoli/germ cell ratio. The 50% reduction in gonocytes in Inha KO testes at birth indicates unopposed activin A has a profound impact on embryonic germ cells. Whole testis RNAseq on Inha KO mice revealed most transcripts affected at E13.5 were present in Leydig cells and associated with steroid biosynthesis/metabolism. In agreement, androstenedione (A4), testosterone (T), and the A4:T ratio were reduced in Inha KO testes at E17.5, confirming unopposed activin A disrupts testicular steroid production. E15.5 testes cultured with either activin A and/or mono-2-ethylhexyl phthalate (MEHP) generated common histological and transcriptional outcomes affecting germline and Leydig cells, recapitulating the phenotype observed in Inha KO testes. Cultures with activin A and MEHP together provided evidence of common targets. Lastly, this study extends previous work focussed on the Inhba KO model to produce a signature of activin A bioactivity in the fetal testis. These outcomes show the potential for elevated activin A signalling to replicate some aspects of fetal phthalate exposure prior to the masculinization programming window, influencing fetal testis growth and increasing the risk of testicular dysgenesis.

Precocious puberty in patients with Pompe disease.

The life expectancy of Pompe disease patients has increased due to improved neonatal screening and enzyme replacement therapy. Nevertheless, the potential effect of frequent medical device exposure on pubertal development in these patients is not well understood, so further investigation is warranted. In this cross-sectional study, we assessed the growth and puberty of nine Pompe disease patients. In addition, to determine the effects of frequent plastic medical device exposure in these patients, we measured urinary phthalate metabolites before and one day after enzyme replacement therapy. Five out of nine patients (55%) with Pompe disease on enzyme replacement therapy had precocious puberty. Patients with precocious puberty had significantly shorter predicted adult heights compared to those with normal puberty (p = 0.014). The levels of mono-2-ethylhexyl phthalate (MEHP) and mono(2-ethyl-5-carboxypentyl) phthalate (MECPP) increased after enzyme replacement therapy, but the average levels of phthalate metabolites did not significantly differ between patients with normal and precocious puberty. Pompe disease patients on enzyme replacement therapy tend to have precocious puberty, which may reduce their adult height. There are no significant differences in urinary phthalate metabolites between normal and precocious puberty patients. Regular follow-up of growth and puberty in Pompe disease patients is important to improve their health outcomes.

Effects of postnatal exposure to phthalate, bisphenol a, triclosan, parabens, and per- and poly-fluoroalkyl substances on maternal postpartum depression and infant neurodevelopment: a korean mother-infant pair cohort study.

Exposure to endocrine-disrupting chemicals (EDCs) can promote infant neurodevelopmental impairment and maternal postpartum depression (PPD). However, the associations between lactation exposure to EDCs, maternal PPD, and infant neurodevelopment are unclear. Hence, we investigated these relationships in infants aged 36-42months. We recruited 221 Korean mothers and analyzed 29 EDCs. The Edinburgh Postnatal Depression Scale (EPDS) was used to assess maternal PPD. Bayley scales of infant development; the Swanson, Nolan, and Pelham rating scale (SNAP); and the Child Behavior Checklist (CBCL) were used to assess neurodevelopment in infants exposed to the top 30% of EDC over three years. Multiple regression analyses were adjusted for maternal age, pre-pregnancy body mass index, education, income, employment, residence, and infant age and sex. The rates of infants with clinically abnormal diagnoses on neurologic developmental tests (Balyey, SNAP, and CBCL scales) ranged from 7.7 to 38.5% in this study, with the motor and hyperactivity/impulsivity areas scoring the highest among 65 boys and girls. Mono-2-ethylhexyl phthalate (MEHP) and mono-isononyl phthalate (MiNP) levels in breast milk significantly correlated with infant inattention and hyperactivity. Perfluorononanoic acid (PFNA) and perfluorooctyl sulfonate (PFOS) levels correlated significantly with motor development of BSID-III and total CBCL score which mean infant might have lower developmental status. EDC concentrations in breast milk were not associated with maternal PPD. Overall, lactational exposure to EDCs during the postpartum period can exert a negative effect on maternal PPD and infant neurodevelopment.

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 3,000mg/kg/day for 2weeks. 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.