Endometriosis and organochlorinated environmental pollutants: a case-control study on Italian women of reproductive age

Environmental Exposure to Persistent Organic Pollutants and Its Association with Endometriosis Risk: Implications in the Epithelial-Mesenchymal Transition Process

We aimed to explore the relationship of adipose tissue concentrations of some persistent organic pollutants (POPs) with the risk of endometriosis and the endometriotic tissue expression profile of genes related to the endometriosis-related epithelial-mesenchymal transition (EMT) process. This case-control study enrolled 109 women (34 cases and 75 controls) between January 2018 and March 2020. Adipose tissue samples and endometriotic tissues were intraoperatively collected to determine concentrations of nine POPs and the gene expression profiles of 36 EMT-related genes, respectively. Associations of POPs with endometriosis risk were explored with multivariate logistic regression, while the relationship between exposure and gene expression profiles was assessed through Spearman correlation or Mann-Whitney U tests. After adjustment, increased endometriosis risk was associated with p,p'-DDT, PCB-180, and ΣPCBs. POP exposure was also associated with reduced gene expression levels of the CLDN7 epithelial marker and increased levels of the ITGB2 mesenchymal marker and a variety of EMT promoters (HMGA1, HOXA10, FOXM1, DKK1, CCR1, TNFRSF1B, RRM2, ANG, ANGPT1, and ESR1). Our findings indicate that exposure to POPs may increase the risk of endometriosis and might have a role in the endometriosis-related EMT development, contributing to the disease onset and progression. Further studies are warranted to corroborate these findings.

Advances in polychlorinated biphenyls-induced female reproductive toxicity

Polychlorinated biphenyls (PCBs) are a class of endocrine-disrupting chemicals (EDCs) widely present in the environment. PCBs have been of concern due to their anti/estrogen-like effects, which make them more toxic to the female reproductive system. However, there is still a lack of systematic reviews on the reproductive toxicity of PCBs in females, so the adverse effects and mechanisms of PCBs on the female reproductive system were summarized in this paper. Our findings showed that PCBs are positively associated with lower pregnancy rate, hormone disruption, miscarriage and various reproductive diseases in women. In animal experiments, PCBs can damage the structure and function of the ovaries, uterus and oviducts. Also, PCBs could produce epigenetic effects and be transferred to the offspring through the maternal placenta, causing development retardation, malformation and death of embryos, and damage to organs of multiple generations. Furthermore, the mechanisms of PCBs-induced female reproductive toxicity mainly include receptor-mediated hormone disorders, oxidative stress, apoptosis, autophagy, and epigenetic modifications. Finally, we also present some directions for future research on the reproductive toxicity of PCBs. This detailed information provided a valuable reference for fully understanding the reproductive toxicity of PCBs.

Polychlorinated biphenyls and the risk of endometriosis: Systematic review and meta-analysis

OBJECTIVE

We aimed to collect recent findings for a deeper understanding of the association between human exposure to polychlorinated biphenyls (PCBs) and endometriosis development.

METHODS

Web of Science, PubMed, Scopus, Google Scholar, and Embase were searched based on inclusion criteria from 2000 to the end of 2020. No filter was exerted to limit the language of publications and geographical restriction. Odds ratios (OR) using the random-effects model and the corresponding 95% confidence interval (CI) were calculated for each included study.

RESULTS

Fourteen studies were included in our analyses. The pooled OR and 95% CI for PCB was 1.96 (1.31 to 2.93). Despite being statistically significant, there was evidence of moderate heterogeneity (I² = 63%, P = 0.001, τ² = 0.32). Findings from our subgroup analyses showed a significant association between PCB exposure and endometriosis among European population (OR = 3.66, 95% CI: 2.08-6.44). Also a positive association was detected between PCB exposure and an increased odds of endometriosis in studies with laparoscopy (OR = 2.32, 95% CI: 1.16-4.63) or surgery confirm of controls (OR = 1.39, 95% CI: 1.02-1.89). Moreover, according to matched-pairs design, a significant association between PCB exposure and endometriosis development was detected (OR = 1.51, 95% CI: 1.04-2.18), also heterogeneity decreased in studies with matched-pairs design (I² = 30.4%).

CONCLUSIONS

Findings of this study confirm an association between endometriosis and exposure to PCB. However, more primary studies using proper methodology are needed to confirm this association.

Efficacy of N-Acetylcysteine on Endometriosis-Related Pain, Size Reduction of Ovarian Endometriomas, and Fertility Outcomes

BACKGROUND

Endometriosis is a chronic, estrogen-dependent, inflammatory disease, whose pivotal symptoms are dysmenorrhea, dyspareunia, and chronic pelvic pain (CPP). Besides the usual medical treatments, recent evidence suggests there are potential benefits of oral N-acetylcysteine (NAC) on endometriotic lesions and pain. The primary objective of this prospective single-cohort study was to confirm the effectiveness of NAC in reducing endometriosis-related pain and the size of ovarian endometriomas. The secondary objective was to assess if NAC may play a role in improving fertility and reducing the Ca125 serum levels.

METHODS

Patients aged between 18-45 years old with a clinical/histological diagnosis of endometriosis and no current hormonal treatment or pregnancy were included in the study. All patients received quarterly oral NAC 600 mg, 3 tablets/day for 3 consecutive days of the week for 3 months. At baseline and after 3 months, dysmenorrhea, dyspareunia and CPP were assessed using the Visual Analog Scale score (VAS), while the size of the endometriomas was estimated through a transvaginal ultrasound. Analgesics (NSAIDs) intake, the serum levels of Ca125 and the desire for pregnancy were also investigated. Finally, the pregnancy rate of patients with reproductive desire was evaluated.

RESULTS

One hundred and twenty patients were recruited. The intensity of dysmenorrhea, dyspareunia and CPP significantly improved (p < 0.0001). The use of NSAIDs (p = 0.001), the size of the endometriomas (p < 0.0001) and the serum levels of Ca125 (p < 0.0001) significantly decreased. Among the 52 patients with reproductive desire, 39 successfully achieved pregnancy within 6 months of starting therapy (p = 0.001).

CONCLUSIONS

Oral NAC improves endometriosis-related pain and the size of endometriomas. Furthermore, it decreases Ca125 serum levels and may improve fertility in patients with endometriosis.

Prenatal Origins of Endometriosis Pathology and Pain: Reviewing the Evidence of a Role for Low Testosterone

Endometriosis is a polygenic, estrogen-dependent, inflammatory disorder of uncertain aetiology associated with pain, infertility and reduced quality of life. While the positive association between endometriosis and estrogen is established, a suite of recent studies has demonstrated an inverse association between the presence of endometriosis lesions and levels of testosterone both prenatally and postnatally. The following narrative review provides new insights into the roles of testosterone in the aetiology, diagnosis, and management of endometriosis and associated symptoms, especially pain. A relatively short anogenital distance (AGD) is indicative of lower levels of testosterone during fetal development. A shorter AGD has recently been correlated with both a higher risk of developing endometriosis in adult life, and with known correlates of endometriosis including earlier onset of reproductive cycling, lower ovarian follicle number, lower postnatal testosterone, and premature ovarian insufficiency. During adult life, lower levels of testosterone are positively associated with key comorbidities of endometriosis, including days per month of pelvic pain and increased pain sensitivity. Biochemically, lower levels of testosterone are associated with higher levels of pro-inflammatory IL-1β and lower levels of β-endorphin. In rodents, prenatal administration of testosterone to females reduces their pain sensitivity in adulthood. The emerging convergent links of endometriosis with low prenatal and postnatal testosterone provide evidence of a centrally mediated effect beginning in early prenatal development, and persisting through adult life, with notable effects on pain sensitivity. They generate a novel conceptual framework for understanding, studying and treating this disorder, whereby endometriosis is mediated by a combination of high estrogen in endometrial tissue with low systemic and ovarian testosterone.

Endocrine disruptors and endometriosis

Endometriosis is a hormone-dependent inflammatory gynecological disease of reproductive-age women. It is clinically and pathologically characterized by the presence of functional endometrium as heterogeneous lesions outside the uterine cavity. The two major symptoms are chronic pelvic pain and infertility, which profoundly affect women's reproductive health and quality of life. This significant individual and public health concerns underscore the importance of understanding the pathogenesis of endometriosis. The environmental endocrine-disrupting chemicals (EDCs) are exogenous agents that interfere with the synthesis, secretion, transport, signaling, or metabolism of hormones responsible for homeostasis, reproduction, and developmental processes. Endometriosis has been potentially linked to exposure to EDCs. In this review, based on the robust literature search, we have selected four endocrine disruptors (i) polychlorinated biphenyls (PCB)s (ii) dioxins (TCDD) (iii) bisphenol A (BPA) and its analogs and (iv) phthalates to elucidate their critical role in the etiopathogenesis of endometriosis. The epidemiological and experimental data discussed in this review indicate that these four EDCs activate multiple intracellular signaling pathways associated with proinflammation, estrogen, progesterone, prostaglandins, cell survival, apoptosis, migration, invasion, and growth of endometriosis. The available information strongly indicates that environmental exposure to EDCs such as PCBs, dioxins, BPA, and phthalates individually or collectively contribute to the pathophysiology of endometriosis. Further understanding of the molecular mechanisms of how these EDCs establish endometriosis and therapeutic strategies to mitigate the effects of these EDCs in the pathogenesis of endometriosis are timely needed. Moreover, understanding the interactive roles of these EDCs in the pathogenesis of endometriosis will help regulate the exposure to these EDCs in reproductive age women.

Time trends of PCDDs, PCDFs, DL-PCBs, and NDL-PCBs in Italian women from biomonitoring studies

A number of biomonitoring investigations were carried out in Italy between 2000 and 2018 by the Unit of Human Exposure to Environmental Chemicals of the Italian National Institute of Health (Rome). The investigations were characterized by different features (case-control or cross-sectional studies, participants from impacted or no impacted areas, etc), but despite the differences, it was possible to study the time trends of Σ₇(PCDDs), Σ₁₀(PCDFs), Σ₁₂(DL-PCBs), and Σ₆(NDL-PCBs) (analytical and TEQ cumulative concentrations, as appropriate). All the chemicals considered showed clear rates of a time-dependent concentration decrease, data having previously been adjusted for the sampled Region and subject age. Σ₇(PCDDs) exhibited the fastest decrease with an average rate of -4.44 pg/g-fat year^-1 (2009-2018), whereas Σ₆(NDL-PCBs) was characterized by the slowest decrease with a rate of -0.771 ng/g-fat year^-1 (2000-2018). A clear distinction between the decreasing rates of Σ₇(PCDDs) and Σ₁₀(PCDFs) was observed, as the latter decreased at half the rate of the Σ7(PCDDs). The slower rate of the Σ₁₀(PCDFs) decline may be due to an ongoing source of PCDFs in the environment beyond those traditionally considered for this group of contaminants such as the production of PCDFs due to PCBs thermal conversion from matrices contaminated with PCBs. Production of PCDFs due to thermal conversion of matrices contaminated with PCBs could be an ongoing source which may be of concern because recent data have highlighted the diffusion of PCBs in the European environment. The decreasing rates of PCDDs + PCDFs, DL-PCBs, and PCDDs + PCDFs + DL-PCBs - original analytical data converted to "dioxin equivalents" - were respectively estimated as (pgTEQ/g-fat year^-1) -2.08, -2.06, and -2.10, values exhibiting good compatibility between one another.

A review on bismuth-based materials for the removal of organic and inorganic pollutants

Modernized lifestyle and increased industrialization threaten living organisms because of the pollutants released from industries and household wastes. The presence of even small amounts of pollutants (organic pollutants (OPs) and inorganic pollutants-heavy metals (HMs)) shows significant effects. Thus wastewater treatment is urgently needed before being subjected to use. Many methods and materials have been developed and reported for the removal of pollutants from wastewater. This review focused on the removal of both OPs and HMs using bismuth-based (Bi-based) materials because of their low toxicity and excellent properties compared to other metals. Bi-based materials as a photocatalyst for photodegradation of OPs are discussed in detail with synthesis methods. Further, since few reviews are available on the Bi-based material for the removal and sensing of HMs, this topic was intentionally summarized. About 200 published articles and reviews have been reviewed here. Additionally, the key point that needs to be focused on the development of Bi-based photocatalysts for the removal of OPs and for upgrading the Bi-based materials as adsorbents for HMs are conferred in the outlook. This will help many researchers in their upcoming work.

Endometriosis and environmental factors: a critical review

This review provides an overview of current knowledge on the relationship between various environmental factors and endometriosis. We successively searched for a given exposure factor combined with the word "endometriosis." The literature was comprehensively analyzed and summarized by quoting only the most important and recent studies on each exposition factor. The data focused primarily on endocrine disruptors, such as dioxins and polychlorinated biphenyls, that appear to have the strongest effect. Intriguing data suggest a link with night work, sun exposure and red meat consumption. For the other risk factors studied, particularly those related to lifestyle (tobacco consumption, alcohol, coffee, soy, physical exercise), the data are not sufficient to draw conclusions. In summary, the epidemiological evidence does not support a strong, scientific link between exposure to environmental factors and endometriosis. The complexity of this disease requires advanced study designs and standardized methodology. Future studies should be carefully designed to address these issues to advance our understanding of the impact of the environment and its consequences on endometriosis.

A case-control study of polychlorinated biphenyl association with metabolic and hormonal outcomes in polycystic ovary syndrome

Polychlorinated biphenyls (PCBs) are a class of environmental pollutants with a long half-life that sequester in fat. Women with polycystic ovarian syndrome (PCOS) may represent a sensitive subgroup to endogenous exposure to PCBs because of associated weight gain. Seven PCB congeners were compared in age, ethnicity, and BMI matched women with (n = 29) and without (n = 30) PCOS and related to metabolic outcomes, and steroid and thyroid hormone levels. PCB118, PCB138, PCB153, and PCB180 were detected in all serum samples but geometric mean did not differ between cases and controls. PCBs correlated with increasing concentrations of each other (p < .01), increasing age (p < .01) and decreasing lneGFR (p < .05). lnPCB118 correlated with increasing Free-T4 (p = .028). lnPCB158, lnPCB180, and ln∑PCB correlated with increasing lnSHBG (p = .044). In regression modeling, although not significant, PCB118 positively associated with lnSHBG in controls (p = .0504) but not in cases; estradiol inversely associated with PCB138 in controls (p = .055) and ∑PCB in cases (p = .051). No significant associations were observed between metabolic endpoints, and steroid and thyroid hormone levels. The results presented do not suggest the PCOS cases in this cohort are at adverse risk compared to age, ethnicity, and BMI matched controls.

Environmental pollution, a hidden culprit for health issues

The environmental and health impacts from the massive discharge of chemicals and subsequent pollution have been gaining increasing public concern. The unintended exposure to different pollutants, such as heavy metals, air pollutants and organic chemicals, may cause diverse deleterious effects on human bodies, resulting in the incidence and progression of different diseases. The article reviewed the outbreak of environmental pollution-related public health emergencies, the epidemiological evidence on certain pollution-correlated health effects, and the pathological studies on specific pollutant exposure. By recalling the notable historical life-threatening disasters incurred by local chemical pollution, the damning evidence was presented to criminate certain pollutants as the main culprit for the given health issues. The epidemiological data on the prevalence of some common diseases revealed a variety of environmental pollutants to blame, such as endocrine-disrupting chemicals (EDCs), fine particulate matters (PMs) and heavy metals. The retrospection of toxicological studies provided illustrative clues for evaluating ambient pollutant-induced health risks. Overall, environmental pollution, as the hidden culprit, should answer for the increasing public health burden, and more efforts are highly encouraged to strive to explore the cause-and-effect relationships through extensive epidemiological and pathological studies.

Chemical mixtures in human post-mortem tissues assessed by a combination of chemical analysis and in vitro bioassays after extraction with silicone

Passive equilibrium sampling of chemical mixtures from different human post-mortem tissues (liver, brain (cerebrum and cerebellum), adipose tissue) and blood was combined with instrumental analysis using direct sample introduction (DSI) GC-MS/MS and bioanalytical profiling using in vitro bioassays targeting the activation of the aryl hydrocarbon receptor (AhR-CALUX), the adaptive stress response (AREc32) and cytotoxicity. The tissues stemmed from pathology samples collected in two German cities and covered males and females aged 21 to 100 with a mean age of 67 years. Neutral organic chemicals were extracted using polydimethylsiloxane (PDMS) at mass ratios of tissue to PDMS of approximately 6 for blood, 3 for adipose tissue and 10 for liver and brain. Amounts of chemicals in PDMS were converted to lipid-associated concentrations using previously measured partition constants that were chemical-independent despite covering eight orders of magnitude in hydrophobicity. Up to 35 of 99 targeted chemicals were detected in 6 tissues of 16 individuals (88 samples in total), among them legacy persistent organic pollutants (POP) such as DDT and derivatives and polychlorinated biphenyls (PCB) but also modern pesticides and chemicals present in consumer products. POPs were highest in adipose tissue and lipid-associated concentrations increased with age, while concentrations of fragrance materials such as galaxolide were independent of age. In tissues from the same individual, chemical concentrations mostly increased from similar levels in brain and blood to higher levels in liver and highest in adipose tissue. However, easily degradable chemicals such as phenanthrene were mainly detected in blood and brain, and very hydrophilic chemicals were least abundant in adipose tissue. The passive sampling method allows a direct comparison of chemical burden between different tissues and may have forensic applications, for example to study internal distributions or to use one tissue type as a proxy for others. The sum of concentrations of the detected chemicals was positively correlated with the bioassay responses but mixture modeling showed that the detected chemicals explained less than 2% of the activation of the AhR and less than 0.5% of cytotoxicity. This means that more than 10,000 chemicals would need to be included in an analytical method to capture all the effects with many chemicals potentially being below detection limits but still contributing to mixture effects. Therefore, we propose a smart combination of chemical analysis and bioassays to quantify priority chemicals but use bioassay responses as effect-scaled concentrations to capture the entire exposome in future epidemiological studies.

Occurrence and spatial distribution of dioxin and dioxin-like compounds in topsoil of Taranto (Apulia, Italy) by GC-MS analysis and DR-CALUX® bioassay

The aim of the present study was to assess the occurrence and spatial distribution of PCDD/Fs and dioxin-like compounds in topsoils of Taranto (Apulia Region), one of the most heavily industrialized and contaminated area of Southern Italy. A combined approach of chemical analysis by GC-MS/MS and AhR reporter gene bioassay was applied in a subset of topsoil samples (n = 20) collected in 2017-18 from ten sites embracing three levels of risk (from high to low) in the framework of a large survey inside Taranto municipality. TCDD-BEQs and GC-MS/MS TEQ_WHO and TEQ_THEORETICAL revealed a decreasing trend with the distance from main industrial settings and landfill areas. A strong correlation between TCDD-BEQs and TEQ_WHO values (R² = 0.85) and TEQ_THEORETICAL (R² = 0.88) was also found. In 3 out of 10 topsoil investigated, BEQs and TEQ_{WHO/THEORETICAL} resulted above Italian National Regulatory Limits for ∑PCDD/Fs in green, private and recreational used soils (10 ng TEQ/kg d.w. D.Lgs 152/2006) and for ∑PCDD/F/dl-PCBs in agricultural and farming soil (6 ng TEQ/kg d.w. D.M. 46/2019). GC-MS/MS pattern revealed the highest prevalence of dl-PCBs in 6 out of 10 sites, followed by PCDFs and PCDDs. Those sites are all located in proximity of main industrial steel and iron ore sinter plant, steel plant's landfills and illegal dumping sites. An update on occurrence and spatial distribution of PCDD/Fs and dl-PCBs contamination of Taranto urban soils was obtained and the DR-CALUX® bioassay was further recommended as a suitable screening tool for environmental and human risk assessment.

Adipose to serum ratio and mixtures of persistent organic pollutants in relation to endometriosis: Findings from the ENDO Study

BACKGROUND

Endometriosis is an estrogen-dependent disease. Endocrine disrupting chemicals (EDCs) and their mixtures may play an etiologic role.

OBJECTIVES

We evaluated an adipose-to-serum ratio (ASR) of lipophilic EDCs and their mixtures associated with incident endometriosis.

METHODS

We quantified 13 polychlorinated biphenyl (PCB) congeners, 6 polybrominated diphenyl ether (PBDE) congeners, and 11 organochlorine pesticides (OCPs) in serum and omental fat among women from the ENDO Study (2007-2009) aged 18-44 years diagnosed with (n=190) or without (n=283) surgically-visualized incident endometriosis. Odds ratios (OR) and 95% confidence intervals (CI) between ASR and endometriosis were estimated using logistic regression models adjusted for age (years), body mass index (kg/m²), serum cotinine (ng/ml), and breastfeeding conditional on parity. Bayesian hierarchical models (BHM) compared estimated associations for adipose and ASR to serum. Bayesian kernel machine regression (BKMR) estimated change in latent health and 95% posterior intervals (PI) between chemical mixtures and endometriosis.

RESULTS

Select ASR for estrogenic PCBs and OCPs were associated with an increased odds of an endometriosis diagnosis, but not for anti-estrogenic PCBs or PBDEs. Across all chemicals, BHMs generated ORs that were on average 14% (95% PI: 6%, 22%) higher for adipose and 20% (95% PI: 12%, 29%) higher for ASR in comparison to serum. ORs from BHMs were greater for estrogenic PCBs and OCPs, with no differences for PBDEs. BKMR models comparing the 75th to 25th percentile were moderately associated with endometriosis for estrogenic PCBs [adipose 0.27 (95% PI: 0.18, 0.72) and ASR 0.37 (95% PI: 0.06, 0.80)] and OCPs [adipose 0.17 (95% PI: 0.21, 0.56) and ASR 0.26 (95% PI: 0.05, 0.57)], but not for antiestrogenic PCBs and PBDEs.

DISCUSSION

ASR added little insight beyond adipose for lipophilic chemicals. BKMR results supported associations between ASR and adipose estrogenic PCB and OCP mixtures and incident endometriosis. These findings underscore the importance of choice of biospecimen and considering mixtures when assessing exposure-disease relationships.

Environmental exposures to endocrine disrupting chemicals (EDCs) and their role in endometriosis: a systematic literature review

PURPOSE

Endocrine-related diseases and disorders are on the rise globally. Synthetically produced environmental chemicals (endocrine-disrupting chemicals (EDCs)) mimic hormones like oestrogen and alter signalling pathways. Endometriosis is an oestrogen-dependent condition, affecting 10-15% of women of the reproductive age, and has substantial impacts on the quality of life. The aetiology of endometriosis is believed to be multifactorial, ranging from genetic causes to immunologic dysfunction due to environmental exposure to EDCs. Hence, we undertook a systematic review and investigated the epidemiological evidence for an association between EDCs and the development of endometriosis. We also aimed to assess studies on the relationship between body concentration of EDCs and the severity of endometriosis.

METHOD

Following PRISMA guidelines, a structured search of PubMed, Embase and Scopus was conducted (to July 2018). The included studies analysed the association between one or more EDCs and the prevalence of endometriosis. The types of EDCs, association and outcome, participant characteristics and confounding variables were extracted and analysed. Quality assessment was performed using standard criteria.

RESULTS

In total, 29 studies were included. Phthalate esters were positively associated with the prevalence of endometriosis. The majority (71%) of studies revealed a significant association between bisphenol A, organochlorinated environmental pollutants (dioxins, dioxin-like compounds, organochlorinated pesticides, polychlorinated biphenyls) and the prevalence of endometriosis. A positive association between copper, chromium and prevalence of endometriosis was demonstrated in one study only. Cadmium, lead and mercury were not associated with the prevalence of endometriosis. There were conflicting results for the association between nickel and endometriosis. The relationship of EDCs and severity of endometriosis was not established in the studies.

CONCLUSION

We found some evidence to suggest an association between phthalate esters, bisphenol A, organochlorinated environmental pollutants and the prevalence of endometriosis. Disentangling these exposures from various other factors that affect endometriosis is complex, but an important topic for further research.

Threshold values of antibodies to estrogen, progesteron and benzo [a] pyrene as a risk factor for the development of endometriosis

OBJECTIVES

The objective of the study was to determine the level of antibodies (AB) of Ig classes A and G to estradiol (E2), progesterone (P) and benzo [a] pyrene (Bp) in patients with endometriosis of various severity and estimate their threshold values as a risk factor for the development of endometriosis.

METHODS

A retrospective case-control study was performed. The study involved 200 women. Group I: women with endometriosis (n=100), Group II: patients with tubal-peritoneal infertility (n=100). All patients underwent immunological studies of blood serum; and the levels of steroid hormones (P, E2), antibodies to them and Bp were determined. A ROC analysis was carried out to identify threshold values of antibodies levels.

RESULTS

Women with endometriosis were found to have statistically significantly higher levels of antibodies IgA and IgG to E2, P and benzo [a] pyrene compared to women of Group II. The threshold levels of IgA-Bp, IgA-E2 and IgA-P are >5 CU (conventional unit), IgG-Bp, IgG-E2>9 CU and IgG-P>8 CU. The level of IgG-P in patients with severe forms of endometriosis is statistically significantly higher than in minor forms of the disease. In case of severe forms, there is a tendency to increasing other classes of antibodies.

CONCLUSIONS

Patients with endometriosis usually have a higher level of IgA and IgG to Bp, E2, P. Their threshold values, which are risk factors for the development of the disease, are estimated.

Receptor-based in vitro activities to assess human exposure to chemical mixtures and related health impacts

Humans are exposed to a large number of chemicals from sources such as the environment, food, and consumer products. There is growing concern that human exposure to chemical mixtures, especially during critical periods of development, increases the risk of adverse health effects in newborns or later in life. Historically, the one-chemical-at-a-time approach has been applied both for exposure assessment and hazard characterisation, leading to insufficient knowledge about human health effects caused by exposure to mixtures of chemicals that have the same target. To circumvent this challenge researchers can apply in vitro assays to analyse both exposure to and human health effects of chemical mixtures in biological samples. The advantages of using in vitro assays are: (i) that an integrated effect is measured, taking combined mixture effects into account and (ii) that in vitro assays can reduce complexity in identification of Chemicals of Emerging Concern (CECs) in human tissues. We have reviewed the state-of-the-art on the use of receptor-based in vitro assays to assess human exposure to chemical mixtures and related health impacts. A total of 43 studies were identified, in which endpoints for the arylhydrocarbon receptor (AhR), the estrogen receptor (ER), and the androgen receptor (AR) were used. The majority of studies reported biological activities that could be associated with breast cancer incidence, male reproductive health effects, developmental toxicities, human demographic characteristics or lifestyle factors such as dietary patterns. A few studies used the bioactivities to check the coverage of the chemical analyses of the human samples, whereas in vitro assays have so far not regularly been used for identifying CECs in human samples, but rather in environmental matrices or food packaging materials. A huge field of novel applications using receptor-based in vitro assays for mixture toxicity assessment on human samples and effect-directed analysis (EDA) using high resolution mass spectrometry (HRMS) for identification of toxic compounds waits for exploration. In the future this could lead to a paradigm shift in the way we unravel adverse human health effects caused by chemical mixtures.

Endocrine disrupting chemicals and reproductive disorders in women, men, and animal models

This chapter covers the known effects of endocrine disrupting chemicals (EDCs) on reproductive disorders. The EDCs represented are highly studied, including plasticizers (bisphenols and phthalates), chemicals in personal care products (parabens), persistent environmental contaminants (polychlorinated biphenyls), and chemicals in pesticides or herbicides. Both female and male reproductive disorders are reviewed in the chapter. Female disorders include infertility/subfertility, irregular reproductive cycles, early menopause, premature ovarian insufficiency, polycystic ovarian syndrome, endometriosis, and uterine fibroids. Male disorders include infertility/subfertility, cryptorchidism, and hypospadias. Findings from both human and animal studies are represented.

An Integrated Genomic Approach Identifies HOXC8 as an Upstream Regulator in Ovarian Endometrioma

PURPOSE

To identify the upstream regulators (URs) involved in the onset and pathogenesis of ovarian endometrioma.

METHODS

Recently, a method called Significance-based Modules Integrating the Transcriptome and Epigenome (SMITE) that uses transcriptome data in combination with publicly available data for identifying URs of cellular processes has been developed. Here, we used SMITE with transcriptome data from ovarian endometrioma stromal cells (ovESCs) and eutopic endometrium stromal cells (euESCs) in combination with publicly available gene regulatory network data. To confirm the URs identified by SMITE, we developed a Boolean network simulation to see if correcting aberrant expressions of the identified genes could restore the entire gene expression profile of ovESCs to a profile similar to that of euESCs. We then established euESCs overexpressing the identified gene and characterized them by cell function assays and transcriptome analysis.

RESULTS

SMITE identified 12 potential URs in ovarian endometrioma that were confirmed by the Boolean simulation. One of the URs, HOXC8, was confirmed to be overexpressed in ovESCs. HOXC8 overexpression significantly enhanced cell proliferation, migration, adhesion, and fibrotic activities, and altered expression statuses of the genes involved in transforming growth factor (TGF)-β signaling. HOXC8 overexpression also increased the expression levels of phosphorylated SMAD2/SMAD3. The increased adhesion and fibrosis activities by HOXC8 were significantly inhibited by E-616452, a selective inhibitor of TGF-β receptor type I kinases.

MAIN CONCLUSIONS

Integrated genomic approaches identified HOXC8 as an UR in ovarian endometrioma. The pathological features of ovarian endometrioma including cell proliferation, adhesion, and fibrosis were induced by HOXC8 and its subsequent activation of TGF-β signaling.

Plasma levels of polychlorinated biphenyl, genetic polymorphisms, and the risk of advanced stage endometriosis

Both environmental and genetic factors interact and play a critical role in the pathogenesis of endometriosis. We analyzed the plasma levels of 12 polychlorinated biphenyl (PCB) congeners with genetic polymorphisms of glutathione-S-transferase M1 (GSTM1), glutathione-S-transferase T1 (GSTT1), and aryl hydrocarbon receptor repressor (AhRR) codon 185. Total sum of the 12 congeners was significantly higher in the controls compared with endometriosis group. Women without C/C genotype in AhRR codon 185 had a significantly increased risk of endometriosis compared with those with C/C genotype. Total sum of the 12 congeners was significantly higher in women without C/C genotype compared with those with C/C genotype. Adjusting for age and AhRR codon 185 genotype, there was no significant association between exposure to PCBs and the risk of endometriosis. These findings suggest a possible presence of gene-environment interaction, however, we could not see any clear association between exposure to PCBs and the risk of endometriosis.

TLR4 T399I Polymorphism and Endometriosis in a Cohort of Italian Women

Background: Endometriosis is a widespread multifactorial disease in which environmental, genetic, and epigenetic factors contribute to the phenotype. Single Nucleotide Polymorphisms (SNPs) in genes implicated in pivotal molecular mechanisms have been investigated as susceptible risk factors in distinct populations. Among these, Toll-like receptor 4 (TLR4) represents a good candidate due to its role in the immune/inflammatory response and endometriosis pathogenesis. Methods: The TRL4 gene T399I SNP (C/T transition, rs4986791) was investigated in 236 Italian endometriosis patients and 150 controls by using the PCR-RFLP method. One-tailed Fisher’s exact test was used to compare differences between categorical variables. T399I genotype distribution was evaluated for Hardy–Weinberg equilibrium in both groups using the Chi-squared test for given probabilities. Results: Fisher’s exact test comparing C and T allele frequencies showed a difference in the frequency of T alleles between patients and controls (OR = 1.96, 95% confidence interval 0.91–4.23; p-value = 0.0552). Genotype frequencies did not show any significant difference between patients and controls. The homozygous TT genotype was observed in 2% of endometriosis women and not in controls. Conclusions: Our results show that the TLR4 rs4986791 T variant may be considered a genetic risk factor for endometriosis in Italian women. More extensive studies in other populations are needed to confirm this result.

PCB levels in adipose tissue of dogs from illegal dumping sites in Campania region (Italy)

The aim of the study is to investigate the potential relationship between exposure to PCBs and cancer. In doing so we relied on a sample of dogs coming from a peculiar area of the Campania region (Italy), that has been suffering for illegal waste dumping and open air burning of plastic waste for many years. The latter determined the release of organic and inorganic pollutants, such as the PCBs. By comparing dogs with cancer and healthy dogs, we found much higher PCB concentrations in the former, with a significant difference (p < 0.05) for the non-indicator ∑10NDL-PCB and the DL-PCBs. A regression analysis, controlling for three potentially confounding factors, that are sex, age and weight, confirmed the higher ∑10NDL-PCB concentration in dogs with cancer. Hence, our evidence suggests a potential health hazard for animals and likewise people living in a risky area due to the presence of environmental organic pollutants.

Association of urinary metabolites of organophosphate and pyrethroid insecticides, and phenoxy herbicides with endometriosis

Endometriosis is a hormone-responsive gynecologic disease, signifying its connotations across a woman's life span. Previous studies suggested that endocrine disrupting chemicals were risk factors for endometriosis. Nevertheless, little is known on exposure to organophosphate, pyrethroid and phenoxy acid pesticides on endometriosis diagnosis. In this study, we determined the concentrations of 11 pesticides, metabolites of organophosphate and pyrethroid insecticides, and phenoxy herbicides, in urine collected from 619 reproductive-age women in Utah and California, using liquid chromatography-tandem mass spectrometry. The association of urinary concentrations of pesticides with an increase in the odds of endometriosis diagnosis was examined in 594 women who underwent laparoscopy/laparotomy (operative cohort: n = 471) or pelvic magnetic resonance imaging (population cohort: n = 123), during 2007-2009. 2-Isopropyl-4-methyl-6-hydroxypyrimidine (IMPY), malathion dicarboxylic acid (MDA), para-nitrophenol (PNP), 3,5,6-trichloro-2-pyridinol (TCPY), 3-phenoxybenzoic acid (3-PBA), and 2,4-dichlorophenoxyacetic acid (2,4-D) were detected in ≥95% of the urine samples analyzed. Urinary concentrations of IMPY, MDA, PNP, 3-PBA and 2,4-D tended to be higher in younger, non-Hispanic black, nulliparous and less affluent women. IMPY was the most dominant compound in urine followed by PNP and TCPY. When women in the 4th quartile of IMPY and the 2nd quartile of TCPY concentrations (μg/g creatinine) were compared with women in the 1st quartile, the odds ratios (ORs) for diagnosis of endometriosis increased significantly in unadjusted models (IMPY OR = 1.89, 95% confidence interval (Cl) = 1.12-3.20; TCPY OR = 1.65, 95% Cl = 1.02-2.69) for the operative (n = 471) and entire data set (n = 594), respectively. Our results suggest that exposure to elevated concentrations of diazinon (the parent compound of IMPY) and chlorpyrifos and chlorpyrifos-methyl (parent compounds of TCPY) may be associated with endometriosis.

Irritable Bowel Syndrome-Like Disorders in Endometriosis: Prevalence of Nickel Sensitivity and Effects of a Low-Nickel Diet. An Open-Label Pilot Study

Alimentary nickel (Ni) may result in allergic contact mucositis (ACM), whose prevalence is >30% and may present with IBS-like and extra-intestinal symptoms. These symptoms are also frequent in endometriosis, and Ni allergic contact dermatitis has already been observed in endometriosis. Therefore, intestinal and extra-intestinal symptoms in endometriosis may depend on a Ni ACM, and a low-Ni diet could improve symptoms. We studied the prevalence of Ni ACM in endometriosis and focused on the effects of a low-Ni diet on gastrointestinal, extra-intestinal, and gynecological symptoms. We recruited 84 women with endometriosis, symptomatic for gastrointestinal disorders. Thirty-one out of 84 patients completed the study. They underwent Ni oral mucosa patch test (omPT), questionnaire for intestinal/extra-intestinal/gynecological symptoms, and a low-Ni diet. Clinical evaluation was performed at baseline (T0) and after three months (T1). Twenty-eight out 31 (90.3%) patients showed Ni omPT positive results, with Ni ACM diagnosis, whereas three out of 31 (9.7%) patients showed negative Ni omPT. After three months of low-Ni diet, all gastrointestinal, extra-intestinal and gynecological symptoms showed a statistically significant reduction. Ni ACM has a high prevalence in endometriosis and a low-Ni diet may be recommended in this condition to reduce gastrointestinal, extra-intestinal and gynecological symptoms.

The risk of endometriosis after exposure to endocrine-disrupting chemicals: a meta-analysis of 30 epidemiology studies

Endocrine-disrupting chemicals (EDCs) are suspected to be associated with endometriosis (EMs). This study aimed to synthesize published data and evaluate the relationship between four classic EDCs exposure and the risk of EMs. A systematic literature search for original peer reviewed papers was performed in the databases PubMed, EMBASE, and Web of Science based on inclusion criteria up to January 2018. Subsequently, a total of 20 papers conducting 30 studies fulfilled the eligibility criteria and were included in this meta-analysis (four studies for bisphenol A (BPA), 12 studies for polychlorinated biphenyls (PCBs), eight studies for organochlorine pesticides (OCPs), and six studies for phthalate esters (PAEs)). The overall odds ratio (OR) across all exposures and EMs was 1.41 (95% confidence interval (CI): 1.23-1.60). When assessing four specific chemicals, respectively, consistent increases in the risk of EMs were found in PCBs group (OR = 1.58; 95% CI: 1.18-2.12), OCPs group (OR = 1.40; 95% CI: 1.02-1.92) and PAEs group (OR = 1.27; 95% CI: 1.00-1.60), while BPA showed no significant association with EMs. Besides, in the di-(2-ethylhexyl)-phthalate (DEHP) group - the most commonly used PAEs, significant risk was also found (OR = 1.42; 95% CI: 1.19-1.70). The current meta-analysis strengthens the evidence that specific EDCs or their metabolites may promote the occurrence of EMs.

Environmental toxins and the impact of other endocrine disrupting chemicals in women's reproductive health

This review aimed to look into agents and mechanisms characterized as endocrine disrupting chemicals (EDCs). These agents are known to cause several harmful effects to the reproductive system of women and wildlife. There is a wide range of chemicals, developed for commercial use mainly in agriculture, which may cause endocrine disruption. Numerous studies show evidence of environmental contamination. However, no one is being held liable for the damages. The most important potentially harmful agents are identified and described, along with the different effects they have on the female genital area. Brazil is a large consumer of pesticides and others chemicals that may interfere with a normal women's life. We analyzed and described the mode of action and the impacts of different EDCs (bisphenols, phthalates, atrazine, polychlorinated and polybrominated biphenyls, DDT-dichlorodiphenyltrichloroethane; DDE-dichlorodiphenyldichloroethylene; DDD-dichlorodiphenyldichloroethane; and DES-diethylstilbestrol) on the genital area, ovarian steroidogenesis, polycystic ovary syndrome, endometriosis, the structure of the uterus and the vagina, and on the formation of leiomyomas.

Environmental Contaminants Exposure and Preterm Birth: A Systematic Review

Preterm birth is an obstetric condition associated with a high risk of infant mortality and morbidities in both the neonatal period and later in life, which has also a significant public health impact because it carries an important societal economic burden. As in many cases the etiology is unknown, it is important to identify environmental factors that may be involved in the occurrence of this condition. In this review, we report all the studies published in PubMed and Scopus databases from January 1992 to January 2019, accessible as full-text articles, written in English, including clinical studies, original studies, and reviews. We excluded articles not written in English, duplicates, considering inappropriate populations and/or exposures or irrelevant outcomes and patients with known risk factors for preterm birth (PTB). The aim of this article is to identify and summarize the studies that examine environmental toxicants exposure associated with preterm birth. This knowledge will strengthen the possibility to develop strategies to reduce the exposure to these toxicants and apply clinical measures for preterm birth prevention.

Associations between exposure to organochlorine chemicals and endometriosis in experimental studies: A systematic review protocol

BACKGROUND

Endometriosis is a hormone-dependent gynaecological disease characterised by the presence and growth of endometrial tissues outside of the uterus. There is growing experimental evidence that suggests environmental endocrine disrupting chemicals, specifically organochlorine chemicals (OCCs), may play a role in the pathogenesis of endometriosis, but to date, there are no studies attempting to gather and synthesise the published literature systematically.

OBJECTIVES

The main objective of this SR is to evaluate the associations between the exposure to OCCs and endometriosis in experimental models (in vivo and in vitro).

METHODS

The SR framework has been developed following the guidelines established in National Toxicology Program/ Office of Health Assessment and Translation (NTP/OHAT) Handbook for Conducting a Literature-Based Health Assessment, which provides a standardised methodology to implement the Grading of Recommendations Assessment, Development and Evaluation (GRADE) approach to environmental health assessments. The review process will be managed and documented through HAWC, an open-source content management system, to guarantee transparency.

ELIGIBILITY CRITERIA

Only experimental studies, in vivo, ex vivo or in vitro, exploring associations between controlled exposures to OCCs and endometriosis and related outcomes will be included. Eligible studies will include peer reviewed articles of any publication date which are sources of primary data. Only studies published in English will be considered.

INFORMATION SOURCES

We will apply the search strings to the scientific literature databases NCBI PubMed, Web of Science and SCOPUS. Manual searches will be performed through the list of references of included articles.

DATA EXTRACTION AND SYNTHESIS OR RESULTS

Data will be extracted according to a pre-defined set of forms and synthesised in a narrative report. Given sufficient commensurate data, a meta-analysis may also be performed.

RISK OF BIAS

A quality assessment will be performed for in vivo and in vitro studies using the NTP/OHAT Risk of Bias Rating Tool for Human and Animal Studies.

LEVEL OF EVIDENCE RATING

Following a comprehensive assessment of the quality of evidence for both in vivo and in vitro studies, a confidence rating will be assigned to the body of literature and subsequently translated into a rating on the level of evidence (high, moderate, low, or inadequate) regarding the research question. Systematic review registration: PROSPERO CRD42018102618.

Human epidemiological evidence about the associations between exposure to organochlorine chemicals and endometriosis: Systematic review and meta-analysis

BACKGROUND

Endometriosis is a gynaecological disease characterized by the presence of ectopic endometrial tissue that affects women during their reproductive years, having a strong impact on their lives, fertility and healthcare costs. The aetiology remains largely unknown, but current evidence suggests that it is multi-causal and oestrogen-dependent. Many epidemiologic studies have explored associations between organochlorine chemicals (OCCs) and endometriosis, but the findings are inconsistent.

OBJECTIVES

A systematic review (SR) and meta-analysis were conducted to gather and synthesize all the available evidence from human epidemiological studies about the associations between OCCs and endometriosis.

DATA SOURCES

The searches were conducted in PubMed and Web of Science in June 2016 with a final follow-up in August 2018.

STUDY ELIGIBILITY CRITERIA

Only human epidemiological studies were considered, independent of participant age, body mass index or life-stage. Studies reporting individual measures of exposure to OCCs were included, considering but not limited to polychlorinated dibenzodioxins and dibenzofurans (PCDD/Fs), polychlorinated biphenyls (PCBs), or organochlorine pesticides (OCPs). The primary health outcome was presence of endometriosis, including all sub-types. Eligibility criteria excluded articles not written in English, conference papers, reviews and studies with overlapping information.

STUDY APPRAISAL AND SYNTHESIS METHODS

A SR protocol pre-registered at PROSPERO was applied in duplicate to gather and extract all eligible original papers from PUBMED and Web of Science databases. Odds ratios were pooled using the inverse variance method for random effects meta-analysis for each group of OCCs. Risk of bias was assessed using the National Toxicology Program/Office of Health Assessment and Translation (NTP/OHAT) Risk of Bias Rating Tool for Human and Animal Studies adapted to the review question. The confidence in the body of evidence and related level of evidence was measured by using the Grading of Recommendations Assessment, Development and Evaluation (GRADE) based NTP/OHAT framework. The results were structured and presented in accordance with the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines.

RESULTS

Of the 51 studies retained for the full-text screening, 17 provided effect sizes and metrics sufficient for pooling estimates through meta-analysis. The overall odds ratios and 95% confidence intervals were 1.65 (1.14; 2.39) for dioxins (n = 10), 1.70 (1.20; 2.39) for PCBs (n = 9), and 1.23 (1.13; 1.36) for OCPs (n = 5). Despite being statistically significant, these estimates should be considered with caution given the notable heterogeneity and small estimated effect size. Misclassification of exposure, due to varying laboratory detection rate capabilities, and disease status, due to varying definitions of endometriosis, were identified as major sources of uncertainty.

LIMITATIONS, CONCLUSIONS, AND IMPLICATIONS OF KEY FINDINGS

The level of evidence was considered to be "moderate" with "serious" risk of bias according the NTP/OHAT criteria, supporting the need for further well-designed epidemiological research to fill lingering data gaps. Given the complexity of endometriosis and lack of known biomarkers suitable for population-based research, carefully designed observational studies play an important role in better understanding the aetiology of endometriosis, as will evolving mixture modeling approaches capable of handling various environmental chemical exposures. Attention to critical windows of exposure will shed further light on the possible developmental origin of endometriosis. Considering the high economic and societal cost associated with endometriosis, further research on this field is urged.

SYSTEMATIC REVIEW REGISTRATION NUMBER

CRD42018080956.

Risk for animal and human health related to the presence of dioxins and dioxin-like PCBs in feed and food

The European Commission asked EFSA for a scientific opinion on the risks for animal and human health related to the presence of dioxins (PCDD/Fs) and DL-PCBs in feed and food. The data from experimental animal and epidemiological studies were reviewed and it was decided to base the human risk assessment on effects observed in humans and to use animal data as supportive evidence. The critical effect was on semen quality, following pre- and postnatal exposure. The critical study showed a NOAEL of 7.0 pg WHO2005-TEQ/g fat in blood sampled at age 9 years based on PCDD/F-TEQs. No association was observed when including DL-PCB-TEQs. Using toxicokinetic modelling and taking into account the exposure from breastfeeding and a twofold higher intake during childhood, it was estimated that daily exposure in adolescents and adults should be below 0.25 pg TEQ/kg bw/day. The CONTAM Panel established a TWI of 2 pg TEQ/kg bw/week. With occurrence and consumption data from European countries, the mean and P95 intake of total TEQ by Adolescents, Adults, Elderly and Very Elderly varied between, respectively, 2.1 to 10.5, and 5.3 to 30.4 pg TEQ/kg bw/week, implying a considerable exceedance of the TWI. Toddlers and Other Children showed a higher exposure than older age groups, but this was accounted for when deriving the TWI. Exposure to PCDD/F-TEQ only was on average 2.4- and 2.7-fold lower for mean and P95 exposure than for total TEQ. PCDD/Fs and DL-PCBs are transferred to milk and eggs, and accumulate in fatty tissues and liver. Transfer rates and bioconcentration factors were identified for various species. The CONTAM Panel was not able to identify reference values in most farm and companion animals with the exception of NOAELs for mink, chicken and some fish species. The estimated exposure from feed for these species does not imply a risk.

Exposure to environmental concentrations of hexachlorobenzene induces alterations associated with endometriosis progression in a rat model

Hexachlorobenzene (HCB) is a dioxin-like compound widely distributed and is a weak ligand of the aryl hydrocarbon receptor (AhR). Endometriosis is a disease characterized by growth of endometrial tissue in ectopic sites. Our aim was to investigate the impact of HCB on the endocrine, invasion and inflammatory parameters in a rat endometriosis model surgically induced. Female rats were exposed to HCB (1, 10 and 100 mg/kg b.w.) during 30 days. Results showed that HCB increases endometriotic like-lesions (L) volume in a dose-dependent manner. In L, HCB10 increases microvessel density (immunohistochemistry) and the vascular endothelial growth factor (VEGF), cyclooxygenase-2 (COX-2) and AhR levels (Western Blot), while HCB1 enhances aromatase expression (Western Blot). In addition, in eutopic endometrium (EU), HCB10/HCB100 augments microvessel density, VEGF and MMP-9 expression, while HCB1/HCB10 increases tumor necrosis factor-α (TNF-α) content in peritoneal fluid (ELISA). Interestingly, both L and EU from HCB-treated rats exhibited higher estrogen receptor α (ERα) (immunohistochemistry) and metalloproteases (MMP)-2 and -9 levels (Western Blot), as well as lower progesterone receptor (PR) expression (immunohistochemistry) than in control rats. Environmentally relevant concentrations of HCB could contribute to abnormal changes associated with endometriosis progression and development.

The challenging use and interpretation of circulating biomarkers of exposure to persistent organic pollutants in environmental health: Comparison of lipid adjustment approaches in a case study related to endometriosis

The gold-standard matrix for measuring the internal levels of persistent organic pollutants (POPs) is the adipose tissue, however in epidemiological studies the use of serum is preferred due to the low cost and higher accessibility. The interpretation of serum biomarkers is tightly related to the understanding of the underlying causal structure relating the POPs, serum lipids and the disease. Considering the extended benefits of using serum biomarkers we aimed to further examine if through statistical modelling we would be able to improve the use and interpretation of serum biomarkers in the study of endometriosis. Hence, we have conducted a systematic comparison of statistical approaches commonly used to lipid-adjust the circulating biomarkers of POPs based on existing methods, using data from a pilot case-control study focused on severe deep infiltrating endometriosis. The odds ratios (ORs) obtained from unconditional regression for those models with serum biomarkers were further compared to those obtained from adipose tissue. The results of this exploratory study did not support the use of blood biomarkers as proxy estimates of POPs in adipose tissue to implement in risk models for endometriosis with the available statistical approaches to correct for lipids. The current statistical approaches commonly used to lipid-adjust circulating POPs, do not fully represent the underlying biological complexity between POPs, lipids and disease (especially those directly or indirectly affecting or affected by lipid metabolism). Hence, further investigations are warranted to improve the use and interpretation of blood biomarkers under complex scenarios of lipid dynamics.

Association between Organochlorine Pesticide Levels in Breast Milk and Their Effects on Female Reproduction in a Taiwanese Population

Only few studies have focused on organochlorine pesticides (OCPs) in breast milk and the related health risks for women in Taiwan. Our goal is to examine breast milk OCPs and their associations with female reproductive function (infertility, gynecological diseases, and menstruation characteristics) as well as their correlation with sociodemographic parameters (age, pre-pregnant body mass index (BMI), annual incomes, population, birth year, and parity) and dietary habit. The breast milk samples were collected in southern Taiwan (n = 68) from 2013 to 2016 and the OCP residues were analyzed using high resolution gas chromatography with low resolution mass spectrometry (HRGC/LRMS). The results show that the most abundant OCP residues in the breast milk was ΣDDT with the geometric mean ± standard deviation of 9.81 ± 7.52 ng⁻¹ lipid⁻¹ followed by ΣHCH (0.539 ± 0.557 ng⁻¹·lipid⁻¹). In the principal component analysis, cis-chlordane (cis-CHL) and γ-HCH were found to be related to participants who received medical treatment for infertility, and 4,4′-DDT was associated with those who received gynecological surgery. The logistic regression showed that the odds ratio (OR) of log γ-hexachlorocyclohexane (γ-HCH) was higher for mothers who had received medical treatment for infertility than for the normal group (OR = 25.6, p = 0.035) after adjustments for age, pre-pregnant BMI, annual income, population (i.e., native-born Taiwanese), birth year, and parity. Cow milk and beef consumption as well as menstruation characteristics such as average menstrual period (>5 days), shortest menstrual period (<3 days), and women who had taken hormonal drugs were significantly associated to several OCP residues in the breast milk. In addition, ΣHCH including β-HCH and γ-HCH was correlated with annual family income and gravidity as well as cow milk and beef consumptions. Overall, γ-HCH exhibited a probable association with the infertility diseases of Taiwanese women, and dietary habit might play an important role in the female Taiwanese exposure to OCPs.

Polychlorinated biphenyl 104 promotes migration of endometrial stromal cells in endometriosis

Polychlorinated biphenyls (PCBs), as part of environmental contaminants, have been proved to be related to endometriosis. This study is to investigate the effect of PCB 104 on cell migration, invasion and resultant gene expression in endometrial stromal cells (ESCs). Fifty-three specimens of eutopic endometrial tissues were collected from twenty-four women with endometriosis (EU-EMS) and twenty-nine women without endometriosis (EU-NON). Both EU-EMS and EU-NON were divided into the PCB 104 exposure group and the control group according to whether they were exposed to PCB 104. Primary cultured ESCs were exposed to PCB 104 at the micro molar doses (2 × 10^-3, 0.2 and 1 μmol/L) and concentrations of 2, 5 and 10 μmol/L in six-well plates. Cell mobility and proliferation assay were used to evaluate the effects of PCB 104 on the migration, invasion and proliferation of ESCs, and the effect of PCB 104 on actin cytoskeleton was also examined by immunofluorescence. Subsequently, the mRNA levels of related genes including matrix metalloproteinase (MMP) -2, -3, -9, -10, E-cadherin, Snail, Slug and tissue inhibitor of metalloproteinase (TIMP) -2 in ESCs were examined by using real-time PCR, as well as protein levels of MMP-3 and MMP-10 were detected by enzyme-linked immunosorbent assay (ELISA). We explored the role of epidermal growth factor receptor (EGFR) in the expression of MMP-3 and MMP-10 induced by PCB 104. Exposure to PCB 104 significantly increased the migration and invasion of ESCs. The mRNA and protein levels of MMP-3 and MMP-10 in ESCs treated with PCB 104 were higher than that in the control, with a dose- and time-dependent manner in mRNA level, while the expression of MMP-2, MMP-9, TIMP-2, E-cadherin, Snail and Slug did not change significantly. Taken together, PCB 104 promotes migration and invasion of ESCs by inducing the expression of MMP-3 and MMP-10, which may involved the EGFR signalling pathway.

Transplacental transfer characteristics of organochlorine pesticides in paired maternal and cord sera, and placentas and possible influencing factors

Organochlorine pesticides (OCPs), including dichlorodiphenyltrichloroethane (DDT) and its metabolites [dichlorodiphenyldichloroethylene (DDE) and dichlorodiphenyldichloroethane], hexachlorocyclohexanes (HCHs), and hexachlorobenzene (HCB), are widely detected in humans despite the considerable decline in environmental concentrations. To understand the placental transfer of OCPs and the possible maternal influence on them, we measured the concentrations of DDTs, HCHs, and HCB in 102 paired samples of maternal and cord sera, and placentas collected in Shanghai, China. The median concentrations of DDTs and HCHs were the highest in maternal sera (601, 188 ng g^-1 lipid), followed by umbilical cord sera (389, 131 ng g^-1 lipid), and placentas (65, 37 ng g^-1 lipid). 4,4'-DDE, β-HCH, and HCB were the predominant contaminants in the three matrices. The ubiquitous existence of OCPs, and the significant concentration relationships of DDTs, HCHs, and OCPs in the three matrices suggested placental transfer from mother to fetus. The lipid-based concentration ratios of 4,4'-DDE, β-HCH, and HCB in umbilical cord serum to those in maternal serum (F/M), and ratios of placenta to maternal serum (P/M) ranged from 0.66 to 1.01, and 0.12 to 0.25, respectively. Maternal variables affected the levels of fetal contamination. For primiparous women, significant correlations between maternal age and maternal HCHs, and between pre-pregnancy body mass index (BMI) and maternal HCHs were found. The negative effect of parity, and the positive effect of food consumption on maternal OCP concentrations were also observed, although there were no significant differences. The possible influence of parity on F/M and P/M of 4,4'-DDE suggested borderline significant differences between primiparous and multiparous women. Also, slight group differences were observed between elder and younger women, and between overweight and normal/underweight women. Parity seems to have a potential influence on transfer ratios of some OCP pollutants.

Epigenetic Therapy: Novel Translational Implications for Arrest of Environmental Dioxin-Induced Disease in Females

Increased toxicant exposure and resultant environmentally induced diseases are a tradeoff of industrial productivity. Dioxin [2,3,7,8 tetrachlorodibenzo-p-dioxin (TCDD)], a ubiquitous byproduct, is associated with a spectrum of diseases including endometriosis, a common, chronic disease in women. TCDD activates cytochrome (CYP) p450 metabolic enzymes that alter organ function to cause disease. In contrast, the transcription factor, Krüppel-like factor (KLF) 11, represses these enzymes via epigenetic mechanisms. In this study, we characterized these opposing mechanisms in vitro and in vivo as well as determining potential translational implications of epigenetic inhibitor therapy. KLF11 antagonized TCDD-mediated activation of CYP3A4 gene expression and function in endometrial cells. The repression was pharmacologically replicated by selective use of an epigenetic histone acetyltransferase inhibitor (HATI). We further showed phenotypic relevance of this mechanism using an animal model for endometriosis. Fibrotic extent in TCDD-exposed wild-type animals was similar to that previously observed in Klf11-/- animals. When TCDD-exposed animals were treated with a HATI, Cyp3 messenger RNA levels and protein expression decreased along with disease progression. Fibrotic progression is ubiquitous in environmentally induced chronic, untreatable diseases; this report shows that relentless disease progression can be arrested through targeted epigenetic modulation of protective mechanisms.

Familial deep endometriosis: A rare monogenic disease?

Endometriosis is a frequent cause of pelvic pain and subfertility in women of reproductive age. Presence of extra-uterine endometrial-like tissue is responsible for non-specific symptoms such as chronic pelvic pain, dysmenorrhea, dyspareunia, dyschesia and sometimes infertility. Three different phenotypes according to the location of the lesions are described, namely peritoneal, ovarian and deep infiltrating endometriosis. Deep endometriosis is considered as a distinct homogeneous disease. Heritability of endometriosis has been previously demonstrated. Despite extensive efforts to characterize candidate alleles contributing to genetic basis of endometriosis, these factors relevant to endometriosis pathophysiology remain unclear. No high penetrance pathogenic variant could be identified. We report herein two families with familial aggregation of severe deep infiltrating endometriosis, providing further evidence for monogenic mendelian inheritance of this form of endometriosis.

Associations between internal exposure levels of persistent organic pollutants in adipose tissue and deep infiltrating endometriosis with or without concurrent ovarian endometrioma

Endometriosis is a gynaecological disease characterized by the presence of ectopic endometrial tissue. Histologically, it appears as different sub-types, being peritoneal endometriosis, ovarian endometrioma (OvE) and deep infiltrating endometriosis (DIE), which are of major relevance due to their varying clinical presentations. A number of persistent organic pollutants (POPs) have been associated with the onset of endometriosis, yet the overall set of existing studies remains fairly divergent. In this preliminary case-control study we aimed to assess the potential associations between the internal exposure to POPs and the presence of DIE with or without concurrent OvE. Adipose tissue and serum samples were collected from surgically confirmed cases (n=55) and controls (n=44) enrolled during 2013 and 2015 in Pays de la Loire, France. Targeted pollutants (76 historical or more emerging POPs including dioxins, polychlorobiphenyls (PCB), polybrominated diphenyl ethers (PBDEs), polybrominated biphenyls (PBBs), hexabromocyclododecanes (HBCDs) and organochlorine pesticides (OCPs) were quantified by chromatography coupled to mass spectrometry. Odds ratios (ORs) and 95% confidence intervals (CI) were estimated from unconditional logistic regression adjusted for known confounding variables. The results showed significant associations between DIE and adipose tissue levels of 1.2.3.7.8 - PeCDD, OCDF, PCB 105, 114, 118 and 123, PBDE 183, PBB 153, and several OCPs including trans‑nonachlor, cis‑heptachlor epoxide, dieldrin, β-hexachlorocyclohexane and hexachlorobenzene. The largest associations were observed for OCDF followed by cis‑heptachlor epoxide, exhibiting adjusted ORs (95% CI) of 5.42 (2.73-12.85) and 5.36 (2.44-14.84) per 1-SD increase, respectively. The stratified analysis comparing both disease sub-types suggested that adipose tissue exposure markers may be more associated with DIE concurrent with OvE, however these results need to be confirmed in a larger population.

Polychlorinated biphenyls and its potential role in endometriosis

With the progress of global industrialization and environmental deterioration, the relationship between human health and the living environment has become an increasing focus of attention. Polychlorinated biphenyls (PCBs, including dioxin-like polychlorinated biphenyls and non-dioxin-like polychlorinated biphenyls), as part of the organic chlorine contaminants, have been suspected as playing a role in the etiopathogenesis of endometriosis. Several population-based studies have proposed that exposure to PCBs may increase the risk of developing endometriosis, while some epidemiological studies have failed to find any association between PCBs and endometriosis. The purpose of this review is to discuss the potential pathophysiological relationship between endometriosis and PCBs with a focus on both dioxin-like polychlorinated biphenyls and non-dioxin-like polychlorinated biphenyls.

Glycyrrhizin inhibits LPS-induced inflammatory mediator production in endometrial epithelial cells

Endometriosis is a continuous inflammation of uterine endometrium that usually affects women of reproductive age. Glycyrrhizin, a triterpene isolated from the roots and rhizomes of licorice (Glycyrrhiza glabra), has been known to have anti-inflammatory effect. The purpose of this study was to investigate the anti-inflammatory effect of glycyrrhizin on LPS-stimulated mouse endometrial epithelial cells (MEEC). The levels of TNF-α, IL-1β, and PGE₂ were measured by ELISA. The expression of COX-2, iNOS, TLR4, and NF-ĸB were detected by western blot analysis. The results showed that glycyrrhizin significantly suppressed LPS-induced TNF-α, IL-1β, NO, and PGE₂ production. Also, LPS-induced iNOS and COX-2 expression were attenuated by glycyrrhizin. Furthermore, glycyrrhizin significantly attenuated TLR4 expression and NF-κB activation induced by LPS in MEEC. In conclusion, the present study demonstrated that glycyrrhizin inhibited LPS-induced inflammatory response by inhibiting TLR4 signaling pathway in MEEC. Glycyrrhizin may be used as a potential agent for the treatment of endometriosis.

Self-management and psychological-sexological interventions in patients with endometriosis: strategies, outcomes, and integration into clinical care

Endometriosis has a multifactorial etiology. The onset and progression of the disease are believed to be related to different pathogenic mechanisms. Among them, the environment and lifestyle may play significant roles. Diet, dietary supplements, physical exercise, osteopathy, massage, acupuncture, transcutaneous electrical nerve stimulation, and Chinese herbal medicine may represent a complementary and feasible approach in the treatment of symptoms related to the disease. In this narrative review, we aimed to examine the most updated evidence on these alternative approaches implicated in the self-management of the disease. In addition, several studies have demonstrated that endometriosis may negatively impact mental health and quality of life, suggesting that affected women may have an increased risk of developing psychological suffering as well as sexual problems due to the presence of pain. In light of these findings, we discuss the importance of integrating psychological interventions (including psychotherapy) and sexual therapy in endometriosis treatment.

Distribution of persistent organic pollutants in serum, omental, and parietal adipose tissue of French women with deep infiltrating endometriosis and circulating versus stored ratio as new marker of exposure

Several studies have assessed the potential role of environmental chemicals in the onset, growth, and/or physiopathology of endometriosis. However, their contour in terms of considered exposure markers remains limited. The present study aimed to characterize the internal exposure levels of 78 persistent organic pollutants (POPs, including dioxins, polychlorobiphenyls, brominated flame retardants and organochlorine pesticides) in a set of 113 adult French women (45 controls, 68 cases), and to characterize the distribution of these POPs within three biological compartments (omental adipose tissue, parietal adipose tissue, and serum). For all targeted substances, the correlation between the concentrations measured in omental versus parietal adipose tissue was found strongly significant (p<0.0001). An equivalence of the measures performed in parietal and omental adipose tissue was moreover observed with median levels of 6.4 vs. 7.4pg/gl.w. for WHO-TEQ₂₀₀₅ PCDD/F, 4.5 vs. 4.7pg/gl.w. for WHO-TEQ₂₀₀₅ dl-PCB, 137.1 vs. 147.9ng/gl.w. for sum of 6 ndl-PCB, and 2.1 vs. 2.0ng/gl.w. for sum of 7 i-PBDE, respectively. The same observation was made for individual targeted OCs compounds. Significant correlations were also observed between these concentrations determined in adipose tissue and those measured in serum for dioxins (WHO-TEQ₂₀₀₅ PCDD/F=6.1pg/gl.w), PCBs (WHO-TEQ₂₀₀₅ dl-PCB=3.6pg/gl.w., sum of 6 ndl-PCB=81.1ng/gl.w.), and brominated flame-retardants (sum of 7 i-PBDE=0.9ng/gl.w.). The circulating versus stored ratio of some exposure markers (Sum PCDDs, 1,2,3,6,7,8-HxCDF, slightly versus highly chlorinated PCBs ratio, PBDE 99 and PBB 153) was found statistically different for control and case individuals. These extended exposure data from deep infiltrating endometriosis patients are the first ones available for France and give a new insight about the equilibrium of chemicals between storage and circulating compartments that should be further considered as new marker of exposure in the context of exposure-health relationship studies.

EDC-2: The Endocrine Society's Second Scientific Statement on Endocrine-Disrupting Chemicals

The Endocrine Society's first Scientific Statement in 2009 provided a wake-up call to the scientific community about how environmental endocrine-disrupting chemicals (EDCs) affect health and disease. Five years later, a substantially larger body of literature has solidified our understanding of plausible mechanisms underlying EDC actions and how exposures in animals and humans-especially during development-may lay the foundations for disease later in life. At this point in history, we have much stronger knowledge about how EDCs alter gene-environment interactions via physiological, cellular, molecular, and epigenetic changes, thereby producing effects in exposed individuals as well as their descendants. Causal links between exposure and manifestation of disease are substantiated by experimental animal models and are consistent with correlative epidemiological data in humans. There are several caveats because differences in how experimental animal work is conducted can lead to difficulties in drawing broad conclusions, and we must continue to be cautious about inferring causality in humans. In this second Scientific Statement, we reviewed the literature on a subset of topics for which the translational evidence is strongest: 1) obesity and diabetes; 2) female reproduction; 3) male reproduction; 4) hormone-sensitive cancers in females; 5) prostate; 6) thyroid; and 7) neurodevelopment and neuroendocrine systems. Our inclusion criteria for studies were those conducted predominantly in the past 5 years deemed to be of high quality based on appropriate negative and positive control groups or populations, adequate sample size and experimental design, and mammalian animal studies with exposure levels in a range that was relevant to humans. We also focused on studies using the developmental origins of health and disease model. No report was excluded based on a positive or negative effect of the EDC exposure. The bulk of the results across the board strengthen the evidence for endocrine health-related actions of EDCs. Based on this much more complete understanding of the endocrine principles by which EDCs act, including nonmonotonic dose-responses, low-dose effects, and developmental vulnerability, these findings can be much better translated to human health. Armed with this information, researchers, physicians, and other healthcare providers can guide regulators and policymakers as they make responsible decisions.

Integrated Bioinformatics, Environmental Epidemiologic and Genomic Approaches to Identify Environmental and Molecular Links between Endometriosis and Breast Cancer

We present a combined environmental epidemiologic, genomic, and bioinformatics approach to identify: exposure of environmental chemicals with estrogenic activity; epidemiologic association between endocrine disrupting chemical (EDC) and health effects, such as, breast cancer or endometriosis; and gene-EDC interactions and disease associations. Human exposure measurement and modeling confirmed estrogenic activity of three selected class of environmental chemicals, polychlorinated biphenyls (PCBs), bisphenols (BPs), and phthalates. Meta-analysis showed that PCBs exposure, not Bisphenol A (BPA) and phthalates, increased the summary odds ratio for breast cancer and endometriosis. Bioinformatics analysis of gene-EDC interactions and disease associations identified several hundred genes that were altered by exposure to PCBs, phthalate or BPA. EDCs-modified genes in breast neoplasms and endometriosis are part of steroid hormone signaling and inflammation pathways. All three EDCs–PCB 153, phthalates, and BPA influenced five common genes—CYP19A1, EGFR, ESR2, FOS, and IGF1—in breast cancer as well as in endometriosis. These genes are environmentally and estrogen responsive, altered in human breast and uterine tumors and endometriosis lesions, and part of Mitogen Activated Protein Kinase (MAPK) signaling pathways in cancer. Our findings suggest that breast cancer and endometriosis share some common environmental and molecular risk factors.