In utero exposure to di-(2-ethylhexyl) phthalate decreases mineralocorticoid receptor expression in the adult testis

Confirmation of Di(2-ethylhexyl) phthalate-induced micronuclei by repeated dose liver micronucleus assay: focus on evaluation of liver micronucleus assay in young rats

BACKGROUND

Di(2-ethylhexyl) phthalate (DEHP) is a plasticizer commonly used in a wide variety of products, including medical devices. It is rapidly metabolized in the liver into various metabolites upon absorption through oral ingestion, dermal absorption, and inhalation. DEHP is classified as a non-genotoxic hepatocarcinogen in rodents, as its chronic exposure has been associated with the development of liver cancer in these animals, but most genotoxicity studies have been negative. Epidemiologic studies in humans suggest that long-term high intakes of DEHP may be a risk factor for liver dysfunction. The repeated-dose liver micronucleus (RDLMN) assay is a well-established method for assessing chromosomal changes caused by hepatic genotoxins and/or carcinogens. It is particularly valuable for detecting substances that undergo metabolic activation, especially when the metabolite has a short half-life or does not reach the bone marrow effectively. Therefore, we investigated whether the RDLMN assay could detect DEHP-induced micronucleus formation in the liver following a 14 or 28-day treatment.

RESULTS

We report that the RDLMN assay demonstrated an increased frequency of hepatic micronuclei in rats exposed to DEHP for 14 or 28 days. The increases in micronuclei correlated with hepatomegaly, an established response to phthalates in the liver. Conversely, no such increases were observed in the micronucleus assay using bone marrow from these rats.

CONCLUSION

The detection of DEHP-induced micronuclei by the RDLMN assay suggests that this assay could detect the potential genotoxicity and hepatocarcinogenicity of DEHP. It also demonstrated the utility of the RDLMN assay in identifying metabolically activated hepatic carcinogens.

Prenatal diethylhexylphthalate exposure disturbs adult Leydig cell function via epigenetic downregulation of METTL4 expression in male rats

Prenatal exposure to diethylhexyl phthalate (DEHP) has been linked with a decline in testosterone levels in adult male rats, but the underlying mechanism remains unclear. We investigated the potential epigenetic regulation, particularly focusing on N6-methyladenosine (m6A) modification, as a possible mechanism. Dams were gavaged with DEHP (0, 10, 100, and 750 mg/kg/day) from gestational day 14 to day 21. The male offspring were examined at the age of 56 days. Prenatal DEHP administration at 750 mg/kg/day caused a decline in testosterone concentrations, an elevation in follicle-stimulating hormone, a downregulated expression of CYP11A1 HSD3B2, without affecting Leydig cell numbers. Interestingly, Methyltransferase Like 4 (METTL4), an m6A methyltransferase, was downregulated, while there were no changes in METTL3 and METTL14. Moreover, CYP11A1 showed m6A reduction in response to prenatal DEHP exposure. Additionally, METTL4 expression increased postnatally, peaking in adulthood. Knockdown of METTL4 resulted in the downregulation of CYP11A1 and HSD3B2 and an increase in SCARB1 expression. Furthermore, the increase in autophagy protection in adult Leydig cells induced by prenatal DEHP exposure was not affected by 3-methyladenosine (3MA) treatment, indicating a potential protective role of autophagy in response to DEHP exposure. In conclusion, prenatal DEHP exposure reduces testosterone by downregulating CYP11A1 and HSD3B2 via m6A epigenetic regulation and induction of autophagy protection in adult Leydig cells as a response to DEHP exposure.

Endocrine Disruptors and Metabolic Changes: Impact on Puberty Control

OBJECTIVE

This study aims to explore the significant impact of environmental chemicals on disease development, focusing on their role in developing metabolic and endocrine diseases. The objective is to understand how these chemicals contribute to the increasing prevalence of precocious puberty, considering various factors, including epigenetic changes, lifestyle, and emotional disturbances.

METHODS

The study employs a comprehensive review of descriptive observational studies in both human and animal models to identify a degree of causality between exposure to environmental chemicals and disease development, specifically focusing on endocrine disruption. Due to ethical constraints, direct causation studies in human subjects are not feasible; therefore, the research relies on accumulated observational data.

RESULTS

Puberty is a crucial life period with marked physiological and psychological changes. The age at which sexual characteristics develop is changing in many regions. The findings indicate a correlation between exposure to endocrine-disrupting chemicals and the early onset of puberty. These chemicals have been shown to interfere with normal hormonal processes, particularly during critical developmental stages such as adolescence. The research also highlights the interaction of these chemical exposures with other factors, including nutritional history, social and lifestyle changes, and emotional stress, which together contribute to the prevalence of precocious puberty.

CONCLUSION

Environmental chemicals significantly contribute to the development of certain metabolic and endocrine diseases, particularly in the rising incidence of precocious puberty. Although the evidence is mainly observational, it adequately justifies regulatory actions to reduce exposure risks. Furthermore, these findings highlight the urgent need for more research on the epigenetic effects of these chemicals and their wider impact on human health, especially during vital developmental periods.

Steroid hormone signaling: multifaceted support of testicular function

Embryonic development and adult physiology are dependent on the action of steroid hormones. In particular, the reproductive system is reliant on hormonal signaling to promote gonadal function and to ensure fertility. Here we will describe hormone receptor functions and their impacts on testicular function, focusing on a specific group of essential hormones: androgens, estrogens, progesterone, cortisol, and aldosterone. In addition to focusing on hormone receptor function and localization within the testis, we will highlight the effects of altered receptor signaling, including the consequences of reduced and excess signaling activity. These hormones act through various cellular pathways and receptor types, emphasizing the need for a multifaceted research approach to understand their critical roles in testicular function. Hormones exhibit intricate interactions with each other, as evidenced, for example, by the antagonistic effects of progesterone on mineralocorticoid receptors and cortisol's impact on androgens. In light of research findings in the field demonstrating an intricate interplay between hormones, a systems biology approach is crucial for a nuanced understanding of this complex hormonal network. This review can serve as a resource for further investigation into hormonal support of male reproductive health.

The active phthalate metabolite, DHEP, induces proliferation and metastasis of prostate cancer cells via upregulation of β-catenin and downregulation of KLF7

Phthalates such as DHEP are among the widely used compounds in industry. It has been shown that DHEP can convey various biological consequences in mammalian cells, among them, the carcinogenic effects of DHEP are emphasized. The present study aimed to assess the impact of DHEP exposure on the proliferation and invasiveness of DU145 prostate cancer cells through in vitro and in vivo models. The DU145 cells were treated with increasing concentrations of DHEP and the tumorigenic parameters were analyzed. KLF7 as a probable mediator of the effect of DHEP was either overexpressed or knocked down in DU145 to evaluate the probable impact of KLF7 on the biological effects of DHEP. The effect of DHEP was also studied in a DU145 xenograft tumor model. The moderate doses of DHEP increased the proliferation and migration of DU145 cells. In the case of gene expression patterns, DHEP reduced the levels of p53 and KLF7 while elevated the expression of β-catenin. The knock-down of KLF7 conveyed comparable effects to that of DHEP to some degree and increased the proliferation of DU145 cells, while the transduction of KLF7 increased the expressions of p53 and p21 along with controlling the tumor size. The present study demonstrated the potential of DHEP in increasing the tumorigenic properties of DU145 cells along with a focus on the underlying mechanisms. Sustained exposure to DHEP can cause a dysregulation in balance between oncogenes and tumor suppressor genes which is the hallmark of malignant transformation. Thus, special considerations seem necessary for the safe exploitation of phthalates.

Cadmium exposure-induced rat testicular dysfunction and its mechanism of chronic stress

Cadmium is a common environmental pollutant in daily life, the toxic mechanisms of chronic cadmium exposure on the testes have not been fully elucidated. This study aimed to explore the effects of cadmium exposure on male reproductive health and its mechanism. The results showed that cadmium exposure led widened interstitial spaces, abnormal seminiferous tubule morphology, and decreased Leydig cell numbers. Moreover, sperm quality was significantly reduced, along with a decrease in fertility rate. And cadmium exposure could activate the hypothalamic-pituitary-adrenal (HPA) axis, elevate blood glucocorticoid levels, subsequently increase glucocorticoid receptor (GR) expression and activation in testicular Leydig cells. Then GR act on the glucocorticoid receptor element (GRE) in the DNA methyltransferase 3 A (DNMT3A) promoter region and upregulate DNMT3A expression. Consequently, this led to an increase in DNA methylation levels in the angiotensin II receptor 2 (AT2R) promoter region, resulting in reduced AT2R expression and inhibiting testicular steroidogenesis. This study systematically elucidated that cadmium exposure could lead to testicular steroidogenesis suppression and decreased fertility through the GR/DNMT3A/AT2R signaling pathway. This research further provides theoretical and experimental evidence for confirming the threat of cadmium exposure to human reproduction, and contributes to the guidance and protection of male reproductive health.

Reproductive toxicity of combined effects of endocrine disruptors on human reproduction

Confluence of environmental, genetic, and lifestyle variables is responsible for deterioration of human fecundity. Endocrine disruptors or endocrine disrupting chemicals (EDCs) may be found in a variety of foods, water, air, beverages, and tobacco smoke. It has been demonstrated in experimental investigations that a wide range of endocrine disrupting chemicals have negative effects on human reproductive function. However, evidence on the reproductive consequences of human exposure to endocrine disrupting chemicals is sparse and/or conflicting in the scientific literature. The combined toxicological assessment is a practical method for assessing the hazards of cocktails of chemicals, co-existing in the environment. The current review provides a comprehensive overview of studies emphasizing the combined toxicity of endocrine disrupting chemicals on human reproduction. Endocrine disrupting chemicals interact with each other to disrupt the different endocrine axes, resulting in severe gonadal dysfunctions. Transgenerational epigenetic effects have also been induced in germ cells, mostly through DNA methylation and epimutations. Similarly, after acute or chronic exposure to endocrine disrupting chemicals combinations, increased oxidative stress (OS), elevated antioxidant enzymatic activity, disrupted reproductive cycle, and reduced steroidogenesis are often reported consequences. The article also discusses the concentration addition (CA) and independent action (IA) prediction models, which reveal the importance of various synergistic actions of endocrine disrupting chemicals mixtures. More crucially, this evidence-based study addresses the research limitations and information gaps, as well as particularly presents the future research views on combined endocrine disrupting chemicals toxicity on human reproduction.

Temporal decline of sperm concentration: role of endocrine disruptors

INTRODUCTION

Male infertility is a widespread disease with an etiology that is not always clear. A number of studies have reported a decrease in sperm production in the last forty years. Although the reasons are still undefined, the change in environmental conditions and the higher exposure to endocrine-disrupting chemicals (EDCs), namely bisphenol A, phthalates, polychlorinated biphenyls, polybrominated diphenyl esters, dichlorodiphenyl-dichloroethylene, pesticides, and herbicides, organophosphates, and heavy metals, starting from prenatal life may represent a possible factor justifying the temporal decline in sperm count.

AIM

The aim of this study is to provide a comprehensive description of the effects of the exposure to EDCs on testicular development, spermatogenesis, the prevalence of malformations of the male genital tract (cryptorchidism, testicular dysgenesis, and hypospadias), testicular tumor, and the mechanisms of testicular EDC-mediated damage.

NARRATIVE REVIEW

Animal studies confirm the deleterious impact of EDCs on the male reproductive apparatus. EDCs can compromise male fertility by binding to hormone receptors, dysregulating the expression of receptors, disrupting steroidogenesis and hormonal metabolism, and altering the epigenetic mechanisms. In humans, exposure to EDCs has been associated with poor semen quality, increased sperm DNA fragmentation, increased gonadotropin levels, a slightly increased risk of structural abnormalities of the genital apparatus, such as cryptorchidism and hypospadias, and development of testicular tumor. Finally, maternal exposure to EDCs seems to predispose to the risk of developing testicular tumors.

CONCLUSION

EDCs negatively impact the testicular function, as suggested by evidence in both experimental animals and humans. A prenatal and postnatal increase to EDC exposure compared to the past may likely represent one of the factors leading to the temporal decline in sperm counts.

Health effects associated with phthalate activity on nuclear receptors

Phthalates are endocrine disruptors, widely used as plasticizers to impart flexibility in plastics, and as solvents in personal care products. Due to their nearly ubiquitous use in consumer products, most humans are exposed to phthalates daily. There has been extensive research on the reproductive health effects associated with phthalate exposure, but less attention has been paid to other actions. This review aims to summarize the known action of phthalates on different nuclear receptors. Some phthalates bind to and activate the estrogen receptor, making them weakly estrogenic. However, other phthalates antagonize androgen receptors. Some high molecular weight phthalates antagonize thyroid receptors, affecting metabolism. Several phthalates activate and interfere with the normal function of different peroxisome proliferator-activated receptors (PPARs), receptors that have critical roles in lipid metabolism and energy homeostasis. Some phthalates activate the aryl hydrocarbon receptor, which is critical for xenobiotic metabolism. Although phthalates have a short half-life in vivo, because people are continuously exposed, studies should examine the health effects of phthalates associated with long-term exposure. There is limited research on the effects of phthalates on health outcomes aside from reproductive function, particularly concerning are childhood adiposity, behavior, and learning. There is also limited information on actions of phthalates not mediated via nuclear receptors. Humans are exposed to multiple chemicals simultaneously, and how chemical mixtures act on nuclear receptor activity needs study. Although we know a great deal about phthalates, there is still much that remains uncertain. Future studies need to further examine their other potential health effects.

Phthalates - A family of plasticizers, their health risks, phytotoxic effects, and microbial bioaugmentation approaches

Phthalates are a family of reprotoxicant compounds, predominantly used as a plasticizer to improve the flexibility and longevity of consumable plastic goods. After their use these plastic products find their way to the waste disposal sites where they leach out the hazardous phthalates present within them, into the surrounding environment, contaminating soil, groundwater resources, and the nearby water bodies. Subsequently, phthalates move into the living system through the food chain and exhibit the well-known phenomenon of biological magnification. Phthalates as a primary pollutant have been classified as 1B reprotoxicants and teratogens by different government authorities and they have thus imposed restrictions on their use. Nevertheless, the release of these compounds in the environment is unabated. Bioremediation has been suggested as one of the ways of mitigating this menace, but studies regarding the field applications of phthalate utilizing microbes for this purpose are limited. Through this review, we endeavor to make a deeper understanding of the cause and concern of the problem and to find out a possible solution to it. The review critically emphasizes the various aspects of phthalates toxicity, including their chemical nature, human health risks, phytoaccumulation and entry into the food chain, microbial role in phthalate degradation processes, and future challenges.

Endokrine Disruptoren

Definition Eine einheitliche Definition endokriner Disruptoren gibt es noch nicht. Inzwischen wurden jedoch Schlüsselcharakteristika definiert, welche die Einordnung einer Substanz als endokrinen Disruptor vereinfachen sollen.

Bisherige Forschungsschwerpunkte Der Einfluss endokriner Disruptoren auf den menschlichen Organismus wurde bisher wenig untersucht. Die Schwerpunkte der bisherigen Forschung liegen auf Stoffwechsel-Erkrankungen und Reproduktionsmedizin.

Aktuelle Forschungsbemühungen und Ausblick Die bisherigen Erkenntnisse zu endokrinen Disruptoren beruhen auf epidemiologischen Beobachtungen und Expositionsstudien in Zellkultur und Tierexperimenten. Auch Ökologie und Ökonomie werden durch endokrine Disruptoren beeinflusst. Daher sind globale Bemühungen notwendig, um irreversible Schäden aufzuhalten.

Polystyrene nanoparticles enhance the adverse effects of di-(2-ethylhexyl) phthalate on male reproductive system in mice

Coexposure of nanoplastics (NPs) with other pollutants adsorbed from the surroundings has received extensive attention. Currently, the combined effects of NPs and plasticizers remain unclear. Di-(2-ethylhexyl) phthalate (DEHP) is a commonly used plasticizer that has raised much concern owing to its ubiquitous pollution and endocrine-disrupting potential. This study aimed to investigate the toxic effects on the male reproductive system upon coexposure to NPs and DEHP. The C57BL/6J mice were orally administrated with polystyrene nanoparticles (PSNPs), DEHP or both for 35 days to evaluate their effects on sperm quality, histology of testes and epididymides, testicular transcriptomic characteristics as well as expression of some important genes in the epididymides. The low-dose PSNPs used here did not induce significant changes in sperm quality, while DEHP alone or cotreatment with DEHP and PSNPs caused notable impairment, mainly manifesting as decreased sperm quality and aberrant structure of the testis and epididymis. Moreover, enhanced toxic effects were found in the cotreatment group when compared with the individual DEHP treatment group, as manifested by more obvious alterations in the sperm parameters as well as histological changes in the testis and epididymis. Testicular transcriptomic analysis revealed differential regulation of genes involved in immune response, cytoplasmic pattern recognition receptor signaling pathways, protein ubiquitination, oxidative stress, necrotic cell death, ATP synthesis and the cellular respiratory chain. RT-qPCR verified that the expression patterns of Cenpb, Crisp1 and Mars were changed in testes, and genes relevant to epididymal function including Aqp9 and Octn2 were downregulated in epididymides, particularly in the cotreatment group. Collectively, our results emphasize that DEHP at an environmentally relevant dose can induce male reproductive toxicity, and PSNPs may aggravate the toxic effects.

Exposure to DEHP is potential to increase the risk of overactive bladder, evidence from NHANES 2003-2008

Overactive bladder (OAB) is a group of clinical symptoms that are highly bothersome to the life and spirit of patients. However, little is known about the role of ubiquitous di-(2-ethylhexyl) phthalate (DEHP) exposure in the disorder. Hence, the study was conducted. The data were collected using the 2003-2008 National Health and Nutrition Examination Survey (NHANES) data (n = 2121), and multiple logistic regression was adapted. The concentrations of DEHP (∑DEHP) were calculated for each metabolite and split into quartiles for analysis. After adjusting for confounding factors, ∑DEHP was associated with increased odds of OAB for the highest quartile (OR = 1.15, 95% CI [1.06, 1.25], p < 0.05), and the highest quartile of metabolites showed similar results, such as mono-(2-ethyl-5-hydroxyhexyl) phthalate (OR = 1.09, 95% CI [1.01, 1.19], p < 0.05), mono-(2-ethyl-5-oxohexyl) phthalate (OR = 1.21, 95% CI [1.11, 1.32], p < 0.05) and mono-(2-ethyl-5-carboxypentyl) phthalate (OR = 1.22, 95% CI [1.12, 1.33], p < 0.05). The association remained when the analyses were stratified by age and sex. Our study adds evidence for understanding the potential role of environmental factors in OAB, and further research is needed to determine whether the status of OAB can be changed by controlling DEHP exposure.

Environmental disruption of reproductive rhythms

Reproduction is a key biological function requiring a precise synchronization with annual and daily cues to cope with environmental fluctuations. Therefore, humans and animals have developed well-conserved photoneuroendocrine pathways to integrate and process daily and seasonal light signals within the hypothalamic-pituitary-gonadal axis. However, in the past century, industrialization and the modern 24/7 human lifestyle have imposed detrimental changes in natural habitats and rhythms of life. Indeed, exposure to an excessive amount of artificial light at inappropriate timing because of shift work and nocturnal urban lighting, as well as the ubiquitous environmental contamination by endocrine-disrupting chemicals, threaten the integrity of the daily and seasonal timing of biological functions. Here, we review recent epidemiological, field and experimental studies to discuss how light and chemical pollution of the environment can disrupt reproductive rhythms by interfering with the photoneuroendocrine timing system.

The role of endocrine-disrupting phthalates and bisphenols in cardiometabolic disease: the evidence is mounting

PURPOSE OF REVIEW

There is substantive and accumulating evidence that endemic exposure to plastic-associated chemicals (PACs) contribute to the pathophysiology of metabolic conditions, like obesity, diabetes, and heart disease. The consequences of this endemic exposure in inducing a pro-inflammatory state in adipose tissues as a critical link between exposure and disease is reviewed.

RECENT FINDINGS

In general, PACs are classified as nonpersistent in vivo because of their rapid metabolism to easily excreted forms. The parental chemicals, however, are typically lipophilic, with the potential to bioaccumulate. Recent data from selected association studies suggest exposure to PACs drive predisease states like obesity and inflammation of the adipose tissues. A range of experimental studies are discussed with a focus on biological mechanisms that are susceptible to the influence of PACs and which may promote metabolic disease, the detection of PACs within susceptible tissues and biological effects that are detectable at doses that correspond to real-life exposures to these chemicals.

SUMMARY

If we hypothesize the toxic pressure from chronic exposure to PACs will progress disease processes, then individuals with comprehensively characterized indicators of premetabolic disease could undergo trials of quantifiable interventions to reduce exposure to PACs to test if the trajectory of disease-associated analytes, is altered.

In utero exposure to endocrine-disrupting chemicals, maternal factors and alterations in the epigenetic landscape underlying later-life health effects

Widespread persistence of endocrine-disrupting chemicals (EDCs) in the environment has mandated the need to study their potential effects on an individual's long-term health after both acute and chronic exposure periods. In this review article a particular focus is given on in utero exposure to EDCs in rodent models which resulted in altered epigenetic programming and transgenerational effects in the offspring causing disrupted reproductive and metabolic phenotypes. The literature to date establishes the impact of transgenerational effects of EDCs potentially associated with epigenetic mediated mechanisms. Therefore, this review aims to provide a comprehensive overview of epigenetic programming and it's regulation in mammals, primarily focusing on the epigenetic plasticity and susceptibility to exogenous hormone active chemicals during the early developmental period. Further, we have also in depth discussed the epigenetic alterations associated with the exposure to selected EDCs such as Bisphenol A (BPA), di-2-ethylhexyl phthalate (DEHP) and vinclozlin upon in utero exposure especially in rodent models.

Exposure to DEHP induces testis toxicity and injury through the ROS/mTOR/NLRP3 signaling pathway in immature rats

As the most abundantly used phthalate derivative, di-(2-ethylhexyl) phthalate (DEHP) leads to reproductive disorders, especially in males. Testicular injury can be triggered when the testis is exposed to DEHP during the immature stage. However, the potential mechanism is largely unclear. In the present study, Sprague-Dawley rats were exposed to 0, 250 and 500 mg/kg/day DEHP from postnatal day (PND) 20 to PND 30. The spermatogonia cell line GC-1 and spermatocyte cell line GC-2 were exposed to different doses of monoethylhexyl phthalate (MEHP), a metabolite of DEHP. Testicular injury was observed. Oxidative stress was evaluated both in vivo and in vitro. Our results showed that after DEHP exposure, the testicular structure was damaged and spermatogenesis was disturbed. We also found that oxidative stress was increased, as indicated by the upregulation of the important factors in the antioxidant pathway. Furthermore, the expression of autophagy-related proteins was significantly downregulated. Autophagy inhibition led to activation of the pyroptosis pathway. Nucleotide-binding and oligomerisation (NOD) domain-like receptor (NLR) family pyrin domain (PYD)-containing 3 (NLRP3), Caspase-1 and cytokine interleukin-1β (IL-1β) were significantly upregulated. Additionally, an imbalance in self-renewal and differentiation was observed in germ cells after DEHP exposure, causing the cessation of germ cell development. In summary, these data suggest that DEHP exposure enhances oxidative stress, downregulates autophagy, induces NLRP3 inflammasome activation and subsequently triggers pyroptosis in vivo and in vitro, which provides novel insight into DEHP-related injury in immature testes in the context of pyroptosis.

Perinatal DEHP exposure modulates pituitary estrogen receptor α and β expression altering lactotroph and somatotroph cell growth in prepuberal and adult male rats

Phthalates are synthetic chemicals widely used to make polyvinylchloride (PVC) soft and flexible. Of these, Di-(2-ethylhexyl) phthalate (DEHP) is the most commonly used, with high human exposure occurring as early as the fetal developmental stage and affecting the endocrine system. We focused on the perinatal DEHP effects on pituitary estrogen receptor (ER) expression in male rats, explored their impact on lactotroph and somatotroph cell growth, and evaluated the direct effects of this phthalate on pituitary cell cultures. Our results showed that DEHP perinatal exposure was unable to modify the ERα+ pituitary cell number from prepuberal rats, but increased ERβ+ cells. In adulthood, the pituitary ERα+ cells underwent a slight decrease with ERβ showing the greatest changes, and with a significant increase observed in somatotroph cells. Also, in vitro, DEHP reduced the ERα+ cells, increased the percentage of ERβ+ pituitary cells and modified the Ki67 index, as well as decreasing the lactotrophs and increasing the somatotroph cells. In conclusion, the present study showed that DEHP induced ER expression changes in normal pituitary glands from male rats in in vivo and in vitro conditions, suggesting that DEHP could differentially modulate lactotroph and somatotroph cell growth, possibly as a consequence of ER imbalance.

Risk analysis of leachables in cell and gene therapy using a CAR-T model process

With the rapidly emerging field of autologous therapies, Single-Use (SU) technologies are increasingly used in personalized medicine due to their manifold advantages. Although qualification of the starting material of autologous therapies such as the CAR-T process has been highlighted, little attention has been paid to the effect of leachables on cell-based therapies, even if recent studies indicate interactions of leachables with cells. To close this gap, this study presents a risk-analysis of SU-material on a CAR-T process and identifies hazards imposed by tubing materials and leachables thereof. In order to represent a CAR-T process in its entirety, two test systems, namely a lentivirus production process and primary T-cells, were used. While the effects on lentivirus production are comparable to those reported for antibody production processes in CHO cells, we found that PVC material and corresponding leachables, i.e. plasticizer, inhibit cell growth of primary T-cells to a great extent. Additionally, our results indicate that critical quality attributes are affected by the PVC material.

Mechanistic insight into toxicity of phthalates, the involved receptors, and the role of Nrf2, NF-κB, and PI3K/AKT signaling pathways

The wide use of phthalates, as phthalates are used in the manufacturing of not only plastics but also many others goods, has become a main concern in the current century because of their potency to induce deleterious effects on organism health. The toxic effects of phthalates such as reproductive toxicity, cardiotoxicity, hepatotoxicity, nephrotoxicity, teratogenicity, and tumor development have been widely indicated by previous experimental studies. Some of the important mechanisms of toxicity by phthalates are the induction and promotion of inflammation, oxidative stress, and apoptosis. Awareness of the involved molecular pathways of these mechanisms will permit the detection of exact molecular targets of phthalates to protect or treat their toxicity. Up to now, various transcription factors and signaling pathways have been associated with phthalate-induced toxicity which by influencing on nuclear surface and the expression of different genes can alter cell hemostasis. In different studies, the role of nuclear factor erythroid 2-related factor 2 (Nrf2), nuclear factor-κB (NF-κB), and phosphatidylinositol-3-kinase (PI3K)/AKT signaling pathways in processes of oxidative stress, inflammation, apoptosis, and cancer has been shown following exposure to phthalates. In the present review, we aim to survey experimental studies (in vitro and in vivo) in order to show firstly the most involved receptors and also the importance and the role of the mentioned signaling pathways in phthalate-induced toxicity, and with considering this point, the future studies can focus on these molecular targets as a strategic method to reduce environmental chemicals-induced toxicity especially phthalates toxic effects.

In utero exposure to dipentyl phthalate disrupts fetal and adult Leydig cell development

Phthalates as plasticizers are widely used in many consumer products. Dipentyl phthalate (DPeP) is one of phthalates. However, there are currently few data on whether DPeP exposure affects rat Leydig cell development. In this study, we investigated the effects of in utero DPeP exposure on Leydig cell development in the testes of male newborn and adult rats. From gestational days 14 to 21, Sprague-Dawley pregnant rats were gavaged vehicle (corn oil, control) or DPeP (10, 50, 100, and 500 mg/kg body weight/day). Testosterone and the expression of Leydig cell genes and proteins in the testis at birth and at postnatal day 56 were examined. DPeP dose-dependently reduced serum testosterone levels of male offspring at birth and at postnatal day 56 at 100 and 500 mg/kg and lowered serum luteinizing hormone levels at adult males at ≥10 mg/kg when compared with the control. In addition, DPeP increased number of fetal Leydig cells by inducing their proliferation but down-regulated the expression of Lhcgr, Scarb1, Star, Cyp11a1, Hsd3b1, Cyp17a1, Hsd17b3, and Insl3 in fetal Leydig cells per se. DPeP reduced number of adult Leydig cells by inducing cell apoptosis and down-regulated the expression of Lhcgr and Star in adult Leydig cells at postnatal day 56. DPeP lowered SIRT1 and BCL2 levels in the testis of adult rats. In conclusion, DPeP adversely affects both fetal and adult Leydig cell development after in utero exposure.

Impact of endocrine-disrupting chemicals on steroidogenesis and consequences on testicular function

Testicular steroidogenesis is a tightly regulated process that produces the androgens important for the development, maintenance and function of the male reproductive system. These androgens are also essential for overall health, and well-being. Disruptions in the ability of the testis to form steroids can result in developmental abnormalities, dysfunction, and infertility. Endocrine-disrupting chemicals (EDCs) can interfere with the intricate signaling and metabolizing networks that produce androgens and promote their dysfunction. These chemicals are found ubiquitously in our environment, as they are integral components of products that are used every day. The effects of EDCs, such as bisphenols, phthalates, and alkyl chemicals, have been studied independently, revealing deleterious effects; but the combined influence of these structures on steroidogenesis has yet to be completely elucidated. This manuscript presents an updated review on EDC mixtures and their impact on testicular function and fertility, highlighting new findings that illustrate the anti-androgenic capabilities of EDC mixtures.

Endocrine-Disrupting Chemicals: Introduction to the Theme

BACKGROUND

Endocrine-disrupting chemicals (EDCs) are natural or synthetic compounds deriving from different human activities and are widely spread into the environment, contributing to indoor and outdoor pollution. EDCs may be conveyed by food and water consumption and skin, airways, placental, and breastfeeding. Upon entering the circulation, they can interfere with endocrine system homeostasis by several mechanisms.

AIM

In this narrative review, the authors overviewed the leading mechanisms by which EDCs interact and disrupt the endocrine system, leading to possible human health concerns.

RESULTS

The leading mechanisms of EDCs-related toxicity have been illustrated in in vitro studies and animal models and may be summarized as follows: receptor agonism and antagonism; modulation of hormone receptor expression; interference with signal transduction in hormone-responsive cells; epigenetic modifications in hormone-producing or hormone-responsive cells; interference with hormone synthesis; interference with hormone transport across cell membranes; interference with hormone metabolism or clearance; interference with the destiny of hormone-producing or hormone-responsive cells.

DISCUSSION

Despite these well-defined mechanisms, some limitations do not allow for conclusive assumptions. Indeed, epidemiological and ecological studies are currently lacking and usually refer to a specific cluster of patients (occupational exposure). Methodological aspects could further complicate the issue since these studies could require a long time to provide useful information. The lack of a real unexposed group in environmental conditions, possible interference of EDCs mixture on biological results, and unpredictable dose-response curves for some EDCs should also be considered significant limitations.

CONCLUSION

Given these limitations, specific observational and long-term studies are needed to identify at-risk populations for adequate treatment of exposed patients and effective prevention plans against excessive exposure to EDCs.

Interaction of leachable model compounds and their impact on Chinese hamster ovary cell cultivation

The presence of leachables in biopharmaceutical processes using single-use technologies (SUT) is well known. For the detection and quantification of the latter, extractable studies of SUT are very common nowadays. Although a mixture of compounds is regularly found in extractable studies, research has only been carried out regarding the effect of individual compounds on cell culture and the cumulative effect of a mix of leachables has not been investigated yet. In this study, a set of leachable model compounds (LMCs) was chosen and the effect of the LMCs on a Chinese hamster ovary DG44 cell line producing an IgG antibody was investigated concerning cell growth, cell cycle distribution and productivity. It was shown that even if worst-case concentrations were used, the LMCs solely impact cell growth. Additionally, interaction studies revealed that the inhibiting effect of the mix is lower than the expected cumulative effect. A strong antagonism between the antioxidant butylated hydroxytoluene and the plasticizer Tris(2-ethylhexyl)trimellitate was found using an isobologram analysis.

Critical Review on the Presence of Phthalates in Food and Evidence of Their Biological Impact

Phthalates are a huge class of chemicals with a wide spectrum of industrial uses, from the manufacture of plastics to food contact applications, children's toys, and medical devices. People and animals can be exposed through different routes (i.e., ingestion, inhalation, dermal, or iatrogenic exposure), as these compounds can be easily released from plastics to water, food, soil, air, making them ubiquitous environmental contaminants. In the last decades, phthalates and their metabolites have proven to be of concern, particularly in products for pregnant women or children. Moreover, many authors reported high concentrations of phthalates in soft drinks, mineral waters, wine, oil, ready-to-eat meals, and other products, as a possible consequence of their accumulation along the food production chain and their accidental release from packaging materials. However, due to their different physical and chemical properties, phthalates do not have the same human and environmental impacts and their association to several human diseases is still under debate. In this review we provide an overview of phthalate toxicity, pointing out the health and legal issues related to their occurrence in several types of food and beverage.

In utero exposure to low doses of genistein and di-(2-ethylhexyl) phthalate (DEHP) alters innate immune cells in neonatal and adult rat testes

BACKGROUND

Although humans are exposed to mixtures of endocrine disruptor chemicals, few studies have examined their toxicity on male reproduction. We previously found that fetal exposure to a mixture of the phytoestrogen genistein (GEN) and the plasticizer di(2-ethylhexyl) phthalate (DEHP) altered gene expression in adult rat testes.

OBJECTIVES

Our goal was to investigate the effects of fetal exposure to GEN-DEHP mixtures at two doses relevant to humans on testicular function and transcriptome in neonatal and adult rats.

MATERIALS AND METHODS

Pregnant SD rats were gavaged with vehicle, GEN or DEHP, alone or mixed at 0.1 and 10 mg/kg/day, from gestation day 14 to birth. Fertility, steroid levels, and testis morphology were examined in neonatal and adult rats. Testicular transcriptomes were examined by gene array and functional pathway analyses. Cell-specific genes/proteins were determined by quantitative real-time PCR and immunohistochemistry.

RESULTS

GEN-DEHP mixtures increased the rates of infertility and abnormal testes in adult rats. Gene array analysis identified more genes exclusively altered by the mixtures than individual compounds. Altered top canonical pathways included urogenital/reproductive developmental and inflammatory processes. GEN-DEHP mixtures increased innate immune cells and macrophages markers at both doses and ages, more strongly and consistently than DEHP or GEN alone. Genes exclusively increased by the mixture in adult testis related to innate immune cells and macrophages included Kitlg, Rps6ka3 (Rsk2), Nr3c1, Nqo1, Lif, Fyn, Ptprj (Dep-1), Gpr116, Pfn2, and Ptgr1.

DISCUSSION AND CONCLUSION

These findings demonstrate that GEN-DEHP mixtures at doses relevant to human induce adverse testicular phenotypes, concurrent with age-dependent and non-monotonic changes in testicular transcriptomes. The involvement of innate immune cells such as macrophages suggests immediate and delayed inflammatory responses which may contribute to testicular dysfunction. Moreover, these effects are complex and likely involve multiple interactions between immune and non-immune testicular cell types that will entail further studies.

Phthalate Exposure and Long-Term Epigenomic Consequences: A Review

Phthalates are esters of phthalic acid which are used in cosmetics and other daily personal care products. They are also used in polyvinyl chloride (PVC) plastics to increase durability and plasticity. Phthalates are not present in plastics by covalent bonds and thus can easily leach into the environment and enter the human body by dermal absorption, ingestion, or inhalation. Several in vitro and in vivo studies suggest that phthalates can act as endocrine disruptors and cause moderate reproductive and developmental toxicities. Furthermore, phthalates can pass through the placental barrier and affect the developing fetus. Thus, phthalates have ubiquitous presence in food and environment with potential adverse health effects in humans. This review focusses on studies conducted in the field of toxicogenomics of phthalates and discusses possible transgenerational and multigenerational effects caused by phthalate exposure during any point of the life-cycle.

Di-(2-ethylhexyl) Phthalate (DEHP) and Uterine Histological Characteristics

Phthalates have a long industrial history. It is suspected that phthalates and their metabolites have detrimental effects on reproduction and development. They are well-known for their anti-androgenic effects. Several studies have indicated that phthalates and their metabolites are reprotoxic in males and endocrine disruptors. Reproduction and embryogenesis occur in the uterus of female eutherian mammals. A horizontal analytical method is preferred to elucidate the toxic effects of phthalates on human reproduction. Nevertheless, there are vast numbers of known phthalates and not all of their modes of action have been clarified. Di-(2-ethylhexyl) phthalate (DEHP) is a commonly used plasticizer and has been the subject of numerous toxicological studies. However, few of these have reported on the toxic effects of DEHP, its metabolites, other phthalates, or mixtures on female reproduction. Acute and high doses of DEHP adversely affect uterine histology. Recently, it was disclosed that chronic exposures to low doses of DEHP have endocrine disruption efficacy. DEHP induces various cellular responses including modulation of the expression and regulation of steroid hormone receptors and transcription and paracrine factors. Uteri do not respond uniformly to DEHP exposure. The phenotypic manifestations and effects on fertility in response to DEHP and its metabolites may vary with species, developmental stage, and generation. Hence, DEHP exposure may histological alter the uterus and induce endometriosis, endometriosis, hyperplasia, myoma, and developmental and reproductive toxicity.

Consensus on the key characteristics of endocrine-disrupting chemicals as a basis for hazard identification

Endocrine-disrupting chemicals (EDCs) are exogenous chemicals that interfere with hormone action, thereby increasing the risk of adverse health outcomes, including cancer, reproductive impairment, cognitive deficits and obesity. A complex literature of mechanistic studies provides evidence on the hazards of EDC exposure, yet there is no widely accepted systematic method to integrate these data to help identify EDC hazards. Inspired by work to improve hazard identification of carcinogens using key characteristics (KCs), we have developed ten KCs of EDCs based on our knowledge of hormone actions and EDC effects. In this Expert Consensus Statement, we describe the logic by which these KCs are identified and the assays that could be used to assess several of these KCs. We reflect on how these ten KCs can be used to identify, organize and utilize mechanistic data when evaluating chemicals as EDCs, and we use diethylstilbestrol, bisphenol A and perchlorate as examples to illustrate this approach.

Tissue-specific changes in Srebf1 and Srebf2 expression and DNA methylation with perinatal phthalate exposure

Perinatal exposure to endocrine disrupting chemicals negatively impacts health, but the mechanism by which such toxicants damage long-term reproductive and metabolic function is unknown. Lipid metabolism plays a pivotal role in steroid hormone synthesis as well as energy utilization and storage; thus, aberrant lipid regulation may contribute to phthalate-driven health impairments. In order to test this hypothesis, we specifically examined epigenetic disruptions in lipid metabolism pathways after perinatal phthalate exposure. During gestation and lactation, pregnant Long-Evans rat dams were fed environmentally relevant doses of phthalate mixture: 0 (CON), 200 (LO), or 1000 (HI) µg/kg body weight/day. On PND90, male offspring in the LO and HI groups had higher body weights than CON rats. Gene expression of lipid metabolism pathways was altered in testis and adipose tissue of males exposed to the HI phthalate dosage. Specifically, Srebf1 was downregulated in testis and Srebf2 was upregulated in adipose tissue. In testis of HI rats, DNA methylation was increased at two loci and reduced at one other site surrounding Srebf1 transcription start site. In adipose tissue of HI rats, we observed increased DNA methylation at one region within the first intron of Srebf2. Computational analysis revealed several potential transcriptional regulator binding sites, suggesting functional relevance of the identified differentially methylated CpGs. Overall, we show that perinatal phthalate exposure affects lipid metabolism gene expression in a tissue-specific manner possibly through altering DNA methylation of Srebf1 and Srebf2.

Risk assessment of endocrine disrupting phthalates and hormonal alterations in children and adolescents

Risk assessment and hormone evaluation were carried out for di(2-ethylhexyl) phthalate (DEHP) and dibutyl phthalate (DBP), endocrine disrupting chemicals (EDCs), in 302 Korean children (n = 223) and adolescents (n = 79) (< age 19). Urinary and serum concentrations of DEHP, MEHP (mono(2-ethylhexyl) phthalate), DBP, MBP (monobutyl phthalate), and PA (phthalic acid, a common final metabolite of phthalates) were detected in children and adolescents. Daily exposure levels were estimated to be 16.45 ± 36.50 μg/kg b.w./day for DEHP, which is one-third of the tolerable daily intake (TDI) value (50 μg/kg b.w./day), but 14 out of 302 participants had a hazard index (HI = intake/TDI) value >1. The mean daily exposure level of DBP was 1.23 ± 1.45 μg/kg b.w./day, which is one-eighth of the TDI value (10 μg/kg b.w./day), but 1 out of 302 participants had a HI value > 1. Positive correlations were observed between serum DBP or MEHP, and serum estradiol (E2) and/or luteinizing hormone (LH) in prepubescent children. In addition, serum MBP levels were found to be negatively correlated with serum triiodothyronine (T3) or thyroxine (T4) in male participants, and serum DEHP levels with serum thyroid stimulating hormone (TSH) in female adolescents. Low-density lipoprotein (LDL) levels were positively correlated with serum PA levels in children and adolescents. DEHP, DBP or its metabolites may be associated with altered hormone levels in children and adolescents. Data suggest that exposure levels of DEHP and DBP in Korean children need to be reduced to levels below TDI to protect them from EDC-mediated toxicities. Abbreviations: DBP: dibutyl phthalate; DEHP: di(2-ethylhexyl) phthalate; E2: estradiol; EDC: endocrine disrupting chemical; EFSA: European Food Safety Authority; FSH: follicle stimulating hormone; HDL: high density lipoprotein; HI: hazard index; LDL: low density lipoprotein; LH: luteinizing hormone; MEHP: mono(2-ethylhexyl) phthalate; MBP: monobutyl phthalate; PA: phthalic acid; PPAR: peroxisome proliferator-activated receptor gamma; PVC: polyvinyl chloride; T3: triiodothyronine; T4: thyroxine; TDI: tolerable daily intake; TG: triglyceride; TSH: thyroid stimulating hormone; UPLC/MS/MS: Ultra Performance Liquid Chromatography/Tandem Mass Spectrometry; WWF: World Wildlife Fund.

Postnatal exposure to di-(2-ethylhexyl)phthalate alters cardiac insulin signaling molecules and GLUT4Ser488 phosphorylation in male rat offspring

Di-(2-ethylhexyl)phthalate (DEHP), a distinctive endocrine-disrupting chemical, is widely used as a plasticizer in a variety of consumer products. It can easily cross the placenta and enter breast milk and then it is rapidly absorbed by offspring. Since it is generally accepted that individuals are more sensitive to chemical exposure during vital developmental periods, we investigated whether DEHP exposure during lactation affects cardiac insulin signaling and glucose homeostasis in the F₁ male rat offspring at postnatal day 22 (PND22). Lactating Wistar rats were administered with DEHP (1, 10, and 100 mg/kg/d) or olive oil from lactation day 1 to 21 by oral gavage. All the male pups were perfused and killed on PND22. On the day before the killing, they were kept for fasting overnight and blood was collected. The cardiac muscle was dissected out, washed in ice-cold physiological saline repeatedly and used for the assay of various parameters. DEHP-exposed offspring had significantly lower body weight than the control. DEHP-exposed offspring showed elevated blood glucose, decreased ¹⁴ C-2-deoxyglucose uptake and ¹⁴ C-glucose oxidation in cardiac muscle at PND22. The concentration of upstream insulin signaling molecules such as insulin receptor subunit β (InsRβ) and insulin receptor substrate 1 (IRS1) were downregulated in DEHP-exposed offspring. However, no significant alterations were observed in protein kinase B (Akt) and Akt substrate of 160 kDa (AS160). Surprisingly, phosphorylation of IRS1 ^Tyr632 and Akt ^Ser473 were diminished. Low levels of glucose transporter type 4 (GLUT4) protein and increased GLUT4 ^Ser488 phosphorylation which decreases its intrinsic activity and translocation towards plasma membrane were also recorded. Lactational DEHP exposure predisposes F ₁ male offspring to cardiac glucometabolic disorders at PND22, which may impair cardiac function.

Maternal exposure to di-n-butyl phthalate induces alterations of c-Myc gene, some apoptotic and growth related genes in pups’ testes

The aim of this study was to investigate the effects of maternal exposure to di-( n-butyl) phthalate (DBP) on testicular development and function in pre-pubertal and post-pubertal male rat offspring. Fourteen pregnant female rats were equally divided into two groups: a control group and a DBP-treated group. During gestation day (GD) 12 to postnatal day (PND) 14, the control group was administered 1 ml/day corn oil, and the DBP-treated group was administered DBP 500 mg/kg/day by oral gavage. On PND 25 (pre-puberty) and PND 60 (post-puberty), blood for serum and the testes were collected from five male offspring of each group. To determine the relationship between the methylation state of the c-Myc promoter and the expression of the c-Myc gene, some apoptotic-related genes, such as p53 and Bax, the anti-apoptotic Bcl-2 gene, and some growth arrest-related genes, such as BRD7 and GAS1, were examined. Compared with the control ( p < 0.05), at pre-puberty, DBP induces c-Myc hyper-methylation with significant downregulation for c-Myc, p53, Bax genes, and significant upregulation for Bcl-2, BRD7, and GAS1, while at post puberty, the methylation state and expression of c-Myc and apoptosis-related genes returned to control levels in the same sequence with the fold change in the expression of BRD7 and GAS1 genes. These findings suggest that DBP induced a transient pre-pubertal increase in c-Myc promoter methylation that may be associated with disruption of both apoptotic and growth mechanisms in the testes.

Effects of In Utero and Lactational Exposure to New Generation Green Plasticizers on Adult Male Rats: A Comparative Study With Di(2-Ethylhexyl) Phthalate

Di(2-ethylhexyl) phthalate (DEHP), a widely used plasticizer, is a ubiquitous environmental contaminant and may act as an endocrine disruptor. Early life exposures to DEHP may result in anti-androgenic effects, impairing the development of the male reproductive tract. However, data on the long-lasting consequences of such DEHP exposures on adult male reproductive function are still rare and discrepant. Previously, we identified 2 novel plasticizers, 1,4-butanediol dibenzoate (BDB) and dioctyl succinate (DOS), as potential substitutes for DEHP that did not reproduce classically described endocrine disrupting phenotypes in prepubertal male offspring after maternal exposure. Here, we investigated the consequences of in utero and lactational exposure to BDB and DOS on adult male rat reproductive function in a comparative study with DEHP and a commercially available alternative plasticizer, 1,2-cyclohexane dicarboxylic acid diisononyl ester (DINCH). Timed pregnant Sprague Dawley rats were gavaged with vehicle or a test chemical (30 or 300 mg/kg/day) from gestation day 8 to postnatal day 21. While DEHP exposure (300 mg/kg/day) significantly increased epididymal weight in the adult, exposure to DINCH, BDB, or DOS did not affect reproductive organ weights, steroid levels, or sperm quality. Using a toxicogenomic microarray approach, we found that adult testicular gene expression was affected by exposure to the higher dose of DEHP; transcripts such as Nr5a2, Ltf, or Runx2 were significantly downregulated, suggesting that DEHP was targeting estrogen signaling. Lesser effects were observed after treatment with either DINCH or BDB. DOS exposure did not produce such effects, confirming its potential as a responsible substitute for DEHP.

Prenatal Exposure to DEHP Induces Premature Reproductive Senescence in Male Mice

Di-(2-ethylhexyl) phthalate (DEHP) is the most commonly used phthalate, and it is an endocrine-disrupting chemical. This study tested a hypothesis that prenatal exposure to DEHP lays the foundation for premature gonadal dysfunction and subsequent reproductive senescence in male mice. Pregnant female CD-1 mice were orally dosed with vehicle control (tocopherol-stripped corn oil) or with 20 μg/kg/day, 200 μg/kg/day, 500 mg/kg/day, or 750 mg/kg/day of DEHP from gestational day 11 to birth. Overall, the prenatal DEHP exposure did not cause any overt physical health problems in male offspring, as no significant differences in their body nor gonadal weight were seen up to the age of 23 months. However, an age- and dose-dependent gonadal dysfunction was observed. As early as 7 months of age, the 750 mg/kg/day group of mice exhibited significantly reduced fertility. At 19 months of age, 86% of the 750 mg/kg/day mice became infertile, whereas only 25% of the control mice were infertile. At this age, all of the DEHP-exposed mice had lower serum testosterone levels, higher serum estradiol levels, and higher LH levels compared with control mice. Histological evaluations showed that mice prenatally exposed to DEHP displayed a wide array of gonadal and epididymal abnormalities such as increased germ cell apoptosis, degenerative seminiferous tubules, oligozoospermia, asthenozoospermia, and teratozoospermia in comparison to age-matching control mice. In summary, this study shows that prenatal exposure to DEHP induces premature reproductive senescence in male mice.

Toxic Effects of Di-2-ethylhexyl Phthalate: An Overview

Di-2-ethylhexyl phthalate (DEHP) is extensively used as a plasticizer in many products, especially medical devices, furniture materials, cosmetics, and personal care products. DEHP is noncovalently bound to plastics, and therefore, it will leach out of these products after repeated use, heating, and/or cleaning of the products. Due to the overuse of DEHP in many products, it enters and pollutes the environment through release from industrial settings and plastic waste disposal sites. DEHP can enter the body through inhalation, ingestion, and dermal contact on a daily basis, which has raised some concerns about its safety and its potential effects on human health. The main aim of this review is to give an overview of the endocrine, testicular, ovarian, neural, hepatotoxic, and cardiotoxic effects of DEHP on animal models and humans in vitro and in vivo.

Systems Analysis of the Liver Transcriptome in Adult Male Zebrafish Exposed to the Plasticizer (2-Ethylhexyl) Phthalate (DEHP)

The organic compound diethylhexyl phthalate (DEHP) represents a high production volume chemical found in cosmetics, personal care products, laundry detergents, and household items. DEHP, along with other phthalates causes endocrine disruption in males. Exposure to endocrine disrupting chemicals has been linked to the development of several adverse health outcomes with apical end points including Non-Alcoholic Fatty Liver Disease (NAFLD). This study examined the adult male zebrafish (Danio rerio) transcriptome after exposure to environmental levels of DEHP and 17α-ethinylestradiol (EE2) using both DNA microarray and RNA-sequencing technologies. Our results show that exposure to DEHP is associated with differentially expressed (DE) transcripts associated with the disruption of metabolic processes in the liver, including perturbation of five biological pathways: ‘FOXA2 and FOXA3 transcription factor networks’, ‘Metabolic pathways’, ‘metabolism of amino acids and derivatives’, ‘metabolism of lipids and lipoproteins’, and ‘fatty acid, triacylglycerol, and ketone body metabolism’. DE transcripts unique to DEHP exposure, not observed with EE2 (i.e. non-estrogenic effects) exhibited a signature related to the regulation of transcription and translation, and ruffle assembly and organization. Collectively our results indicate that exposure to low DEHP levels modulates the expression of liver genes related to fatty acid metabolism and the development of NAFLD.

Human exposure to endocrine disrupting chemicals: effects on the male and female reproductive systems

Endocrine disrupting chemicals (EDCs) comprise a group of chemical compounds that have been examined extensively due to the potential harmful effects in the health of human populations. During the past decades, particular focus has been given to the harmful effects of EDCs to the reproductive system. The estimation of human exposure to EDCs can be broadly categorized into occupational and environmental exposure, and has been a major challenge due to the structural diversity of the chemicals that are derived by many different sources at doses below the limit of detection used by conventional methodologies. Animal and in vitro studies have supported the conclusion that endocrine disrupting chemicals affect the hormone dependent pathways responsible for male and female gonadal development, either through direct interaction with hormone receptors or via epigenetic and cell-cycle regulatory modes of action. In human populations, the majority of the studies point towards an association between exposure to EDCs and male and/or female reproduction system disorders, such as infertility, endometriosis, breast cancer, testicular cancer, poor sperm quality and/or function. Despite promising discoveries, a causal relationship between the reproductive disorders and exposure to specific toxicants is yet to be established, due to the complexity of the clinical protocols used, the degree of occupational or environmental exposure, the determination of the variables measured and the sample size of the subjects examined. Future studies should focus on a uniform system of examining human populations with regard to the exposure to specific EDCs and the direct effect on the reproductive system.

Future of environmental research in the age of epigenomics and exposomics

Environmental research and public health in the 21st century face serious challenges such as increased air pollution and global warming, widespread use of potentially harmful chemicals including pesticides, plasticizers, and other endocrine disruptors, and radical changes in nutrition and lifestyle typical of modern societies. In particular, exposure to environmental and occupational toxicants may contribute to the occurrence of adverse birth outcomes, neurodevelopmental deficits, and increased risk of cancer and other multifactorial diseases such as diabetes and asthma. Rapidly evolving methodologies of exposure assessment and the conceptual framework of the Exposome, first introduced in 2005, are new frontiers of environmental research. Metabolomics and adductomics provide remarkable opportunities for a better understanding of exposure and prediction of potential adverse health outcomes. Metabolomics, the study of metabolism at whole-body level, involves assessment of the total repertoire of small molecules present in a biological sample, shedding light on interactions between gene expression, protein expression, and the environment. Advances in genomics, transcriptomics, and epigenomics are generating multidimensional structures of biomarkers of effect and susceptibility, increasingly important for the understanding of molecular mechanisms and the emergence of personalized medicine. Epigenetic mechanisms, particularly DNA methylation and miRNA expression, attract increasing attention as potential links between the genetic and environmental determinants of health and disease. Unlike genetics, epigenetic mechanisms could be reversible and an understanding of their role may lead to better protection of susceptible populations and improved public health.

A systematic review on the adverse health effects of di-2-ethylhexyl phthalate

Di (ethylhexyl) phthalate (DEHP) is a global environmental pollutant. This study aims to systematically review the literature on health effects of exposure to DEHP including effects on reproductive health, carcinogenesis, pregnancy outcome, and respiratory system. The literature search was done through Scopus, ISI Web of Science, Google Scholar, PubMed, Medline, and the reference lists of previous review articles to identify relevant articles published to June 2016 in each subject area. The inclusion criteria were as follows: original research, cross-sectional studies, case-control studies, cohort studies, interventional studies, and review articles. Both human and animal studies were included. The search was limited to English language papers. Conference papers, editorials, and letters were not included. The systematic review was conducted and reported in accordance with the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) statement. Overall, 152 of the 407 papers met the inclusion criteria. We provided an up-to-date comprehensive and critical assessment of both human and animal studies undertaken to explore the effects of DEHP. It revealed that in experimental studies, exposure to DEHP mainly targeted the reproductive, neurodevelopment, and respiratory systems. Human studies reported that exposure to this contaminant had carcinogenic effects and influenced neurodevelopment in early life. This systematic review underscored the adverse health effects of DEHP for pregnant women and the pediatric age group. It summarizes different response of humans and experimental animals to DEHP exposure, and some suggested underlying mechanisms.

In vitro functional screening as a means to identify new plasticizers devoid of reproductive toxicity

Plasticizers are indispensable additives providing flexibility and malleability to plastics. Among them, several phthalates, including di (2-ethylhexyl) phthalate (DEHP), have emerged as endocrine disruptors, leading to their restriction in consumer products and creating a need for new, safer plasticizers. The goal of this project was to use in vitro functional screening tools to select novel non-toxic plasticizers suitable for further in vivo evaluation. A panel of novel compounds with satisfactory plasticizer properties and biodegradability were tested, along with several commercial plasticizers, such as diisononyl-cyclohexane-1,2-dicarboxylate (DINCH®). MEHP, the monoester metabolite of DEHP was also included as reference compound. Because phthalates target mainly testicular function, including androgen production and spermatogenesis, we used the mouse MA-10 Leydig and C18-4 spermatogonial cell lines as surrogates to examine cell survival, proliferation, steroidogenesis and mitochondrial integrity. The most promising compounds were further assessed on organ cultures of rat fetal and neonatal testes, corresponding to sensitive developmental windows. Dose-response studies revealed the toxicity of most maleates and fumarates, while identifying several dibenzoate and succinate plasticizers as innocuous on Leydig and germ cells. Interestingly, DINCH®, a plasticizer marketed as a safe alternative to phthalates, exerted a biphasic effect on steroid production in MA-10 and fetal Leydig cells. MEHP was the only plasticizer inducing the formation of multinucleated germ cells (MNG) in organ culture. Overall, organ cultures corroborated the cell line data, identifying one dibenzoate and one succinate as the most promising candidates. The adoption of such collaborative approaches for developing new chemicals should help prevent the development of compounds potentially harmful to human health.

Emerging Roles of the Mineralocorticoid Receptor in Pathology: Toward New Paradigms in Clinical Pharmacology

The mineralocorticoid receptor (MR) and its ligand aldosterone are the principal modulators of hormone-regulated renal sodium reabsorption. In addition to the kidney, there are several other cells and organs expressing MR, in which its activation mediates pathologic changes, indicating potential therapeutic applications of pharmacological MR antagonism. Steroidal MR antagonists have been used for decades to fight hypertension and more recently heart failure. New therapeutic indications are now arising, and nonsteroidal MR antagonists are currently under development. This review is focused on nonclassic MR targets in cardiac, vascular, renal, metabolic, ocular, and cutaneous diseases. The MR, associated with other risk factors, is involved in organ fibrosis, inflammation, oxidative stress, and aging; for example, in the kidney and heart MR mediates hormonal tissue-specific ion channel regulation. Genetic and epigenetic modifications of MR expression/activity that have been documented in hypertension may also present significant risk factors in other diseases and be susceptible to MR antagonism. Excess mineralocorticoid signaling, mediated by aldosterone or glucocorticoids binding, now appears deleterious in the progression of pathologies that may lead to end-stage organ failure and could therefore benefit from the repositioning of pharmacological MR antagonists.

Phthalates in neonatal health: friend or foe?

Exposure to environmental chemicals has adverse effects on the health and survival of humans. Emerging evidence supports the idea that exposure to endocrine-disrupting compounds (EDCs) can perturb an individual’s physiological set point and as a result increase his/her propensity toward several diseases. The purpose of this review is to provide an update on di-(2-ethylhexyl) phthalate, the primary plasticizer found in plastic medical devices used in neonatal intensive care units, its effects on the fetus and newborn, epidemiological studies, pharmacokinetics, toxicity and epigenetic implications. We searched the PubMed databases to identify relevant studies. Phthalates are known EDCs that primarily are used to improve the flexibility of polyvinyl chloride plastic products and are called plasticizers in lay terms. Neonates and infants are particularly vulnerable to the effects of phthalates, beginning with maternal exposure and placental transfer during gestation and during infancy following birth. In line with the developmental origins of adult disease, a focus on the effects of environmental chemicals in utero or early childhood on the genesis of adult diseases through epigenome modulation is timely and important. The epigenetic effects of phthalates have not been fully elucidated, but accumulating evidence suggests that they may be associated with adverse health effects, some of which may be heritable. Phthalate exposure during pregnancy and the perinatal period is particularly worrisome in health-care settings. Although the clinical significance of phthalate exposure has been difficult to assess with epidemiologic studies, the evidence that physiological changes occur due to exposure to phthalates is growing and points toward the need for more investigation at a molecular, specifically epigenetic level.

Environmentally induced epigenetic toxicity: potential public health concerns

Throughout our lives, epigenetic processes shape our development and enable us to adapt to a constantly changing environment. Identifying and understanding environmentally induced epigenetic change(s) that may lead to adverse outcomes is vital for protecting public health. This review, therefore, examines the present understanding of epigenetic mechanisms involved in the mammalian life cycle, evaluates the current evidence for environmentally induced epigenetic toxicity in human cohorts and rodent models and highlights the research considerations and implications of this emerging knowledge for public health and regulatory toxicology. Many hundreds of studies have investigated such toxicity, yet relatively few have demonstrated a mechanistic association among specific environmental exposures, epigenetic changes and adverse health outcomes in human epidemiological cohorts and/or rodent models. While this small body of evidence is largely composed of exploratory in vivo high-dose range studies, it does set a precedent for the existence of environmentally induced epigenetic toxicity. Consequently, there is worldwide recognition of this phenomenon, and discussion on how to both guide further scientific research towards a greater mechanistic understanding of environmentally induced epigenetic toxicity in humans, and translate relevant research outcomes into appropriate regulatory policies for effective public health protection.