Genome-Wide Analysis of Low Dose Bisphenol-A (BPA) Exposure in Human Prostate Cells

Bisphenol A exposure stimulates prostatic fibrosis via exosome-triggered epithelium changes

Fibrosis is the pathological basis for the clinical progression of benign prostatic hyperplasia (BPH). Prostatic fibrosis is an important risk factor in patients with BPH who experience lower urinary tract symptoms. Bisphenol A (BPA) is an environmental endocrine disruptor (EED) that causes prostate defects. The effects of BPA on the prostate were investigated in this study using mouse and human prostate cell models. BPA-induced mouse prostatic fibrosis is characterized by collagen deposition and an increase in hydroxyproline concentration. Furthermore, BPA-exposed prostatic stromal fibroblasts exosomes promote the epithelial-mesenchymal transition of epithelial cells. High-throughput RNA sequencing and functional enrichment analyses show that substantially altered mRNAs, lncRNAs and circRNAs play roles in cellular interactions and the hypoxia-inducible factor-1 signaling pathway. The results showed that exosomes participated in the pro-fibrogenic effects of BPA on the prostate by mediating communication between stromal and epithelial cells and triggering epithelial changes.

Impact of chronic exposure of rats to bisphenol A from perinatal period to adulthood on intraprostatic levels of 5α-reductase isozymes, aromatase, and genes implicated in prostate cancer development

The synergetic effect of estrogens and androgens is known to play a crucial role in the physiopathology of the prostate gland. Bisphenol A (BPA) is an endocrine disrupting compound that can interfere with endocrine hormone functioning and thereby influence prostate development. The objective of this study was to examine the impact on prostate expression of aromatase, 5α-R isozymes, and prostate cancer-related genes of exposure to low doses of BPA from perinatal period to adulthood. Vehicle or BPA (2.5 μg/kg b.w./day) was administered to gestating Wistar rats from gestational day 12 (GD12) to parturition and then to their male pups from postnatal day 1 (PND1) until euthanization on PND90. Their prostate glands were examined by qRT-PCR, Western blot, PCR array, and morphological study. mRNA and protein levels of 5α-R2 were significantly reduced and mRNA and protein levels of aromatase were significantly increased in BPA-treated animals, which also showed modifications of 8 out of the 84 key genes implicated in the development of prostate cancer. Because BPA interferes with genes involved in intraprostatic androgen and estrogen production and others implicated in prostate cancer, research is warranted into the prostate disease risk associated with chronic low-dose BPA exposure throughout life.

Bisphenol A attenuates the therapeutic effect of the selective G protein-coupled estrogen receptor agonist G-1 on allergic rhinitis inflammation in mice

BACKGROUND

Bisphenol A (BPA) is found in many plastics widely used in everyday life and affects the immune system. Previous studies found that the selective G protein coupled estrogen receptor (GPER) agonist G-1 can reduce the inflammation associated with asthma and allergic rhinitis (AR). BPA also interferes with the protective effect of estradiol against myocardial ischemia-reperfusion injury.

OBJECTIVE

We explored whether BPA attenuates the effect of G-1 on inflammation in a mouse AR model.

METHODS

The AR model was established by sensitizing and stimulating female BALB/c mice with ovalbumin (OVA) and G-1/BPA. Eosinophils, neutrophils, and lymphocyte subsets (including T and B cells) in nasal mucosa and Th2 and Treg cells in the spleen were detected by flow cytometry. Cytokines and transcription factors characteristic of Th2 and Treg cells in nasal mucosa were detected using cytometric bead arrays and quantitative PCR, respectively.

RESULTS

G-1 reduced OVA-induced nasal mucosal inflammation in mice. The proportions of eosinophils, neutrophils, Siglec-F⁺ neutrophils, lymphocytes, and T cell subsets were reduced by G-1, and this effect was attenuated by BPA. G-1 significantly decreased the Th2 population and levels of IL-4, IL-5, IL-13 and GATA-3; these effects were attenuated by BPA. The enhanced Treg response (as evidenced by an increased Treg population and higher IL-10 and Foxp3 levels) mediated by G-1 tended to be reduced by BPA.

DISCUSSION

We found that G-1 reduced OVA-induced nasal mucosal inflammation and significantly decreased the Th2 response, while increasing the Treg response. These effects were attenuated by BPA.

Review on bisphenol A and the risk of polycystic ovarian syndrome: an insight from endocrine and gene expression

Bisphenol A (BPA) is one of the most widely studied endocrine disrupting chemicals because of its structural similarity to 17-β estradiol; its ability to bind as an agonist/antagonist to estrogen receptors elicits adverse effects on the functioning of the metabolic and endocrinal system. Therefore, BPA has been thoroughly scrutinized concerning its disruption of pathways like lipid metabolism, steroidogenesis, insulin signaling, and inflammation. This has resulted in reports of its correlation with various aspects of cardiovascular diseases, obesity, diabetes, male and female reproductive disorders, and dysfunctions. Among these, the occurrence of the polycystic ovarian syndrome (PCOS) in premenopausal women is of great concern. PCOS is a highly prevalent disorder affecting women in their reproductive age and is clinically characterized by hyperandrogenism, ovulatory dysfunction, and polycystic ovarian morphology, along with metabolism-related dysfunctions like hyperinsulinemia, obesity, and insulin resistance. In this review, we analyzed certain researched effects of BPA, while focusing on its ability to alter the expression of various significant genes like GnRH, AdipoQ, ESR1, StAR, CYP11A1, CYP19A1, and many more involved in the pathways and endocrine regulation, whose disruption is commonly associated with the clinical manifestations of PCOS.

Impacts of endocrine-disrupting chemicals on prostate function and cancer

Because of their historical mode of action, endocrine-disrupting chemicals (EDCs) are associated with sex-steroid receptors, namely the two estrogen receptors (ERα and ERβ) and the androgen receptor (AR). Broadly, EDCs can modulate sex-steroid receptor functions. They can also indirectly impact the androgen and estrogen pathways by influencing steroidogenesis, expression of AR or ERs, and their respective activity as transcription factors. Additionally, many of these chemicals have multiple cellular targets other than sex-steroid receptors, which results in a myriad of potential effects in humans. The current article reviews the association between prostate cancer and the endocrine-disrupting functions of four prominent EDC families: bisphenols, phthalates, phytoestrogens, and mycoestrogens. Results from both in vitro and in vivo models are included and discussed to better assess the molecular mechanisms by which EDCs can modify prostate biology. To overcome the heterogeneity of results published, we established common guidelines to properly study EDCs in the context of endocrine diseases. Firstly, the expression of sex-steroid receptors in the models used must be determined before testing. Then, in parallel to EDCs, pharmacological compounds acting as positive (agonists) and negative controls (antagonists) have to be employed. Finally, EDCs need to be used in a precise range of concentrations to modulate sex-steroid receptors and avoid off-target effects. By adequately integrating molecular endocrinology aspects in EDC studies and identifying their underlying molecular mechanisms, we will truly understand their impact on prostate cancer and distinguish those that favor the progression of the disease from those that slow down tumor development.

Endocrine Disruptors and Prostate Cancer

The role of endocrine disruptors (EDs) in the human prostate gland is an overlooked issue even though the prostate is essential for male fertility. From experimental models, it is known that EDs can influence several molecular mechanisms involved in prostate homeostasis and diseases, including prostate cancer (PCa), one of the most common cancers in the male, whose onset and progression is characterized by the deregulation of several cellular pathways including androgen receptor (AR) signaling. The prostate gland essentiality relies on its function to produce and secrete the prostatic fluid, a component of the seminal fluid, needed to keep alive and functional sperms upon ejaculation. In physiological condition, in the prostate epithelium the more-active androgen, the 5α-dihydrotestosterone (DHT), formed from testosterone (T) by the 5α-reductase enzyme (SRD5A), binds to AR and, upon homodimerization and nuclear translocation, recognizes the promoter of target genes modulating them. In pathological conditions, AR mutations and/or less specific AR binding by ligands modulate differently targeted genes leading to an altered regulation of cell proliferation and triggering PCa onset and development. EDs acting on the AR-dependent signaling within the prostate gland can contribute to the PCa onset and to exacerbating its development.

BPA-induced prostatic hyperplasia in vitro is correlated with the unbalanced gene expression of AR and ER in the epithelium and stroma

As a typical environmental endocrine disruptor (EED), bisphenol A (BPA) can induce pathological hyperplasia of the prostatic epithelium and stroma. This study concentrates mainly on the effect and underlying mechanisms of BPA on prostatic hyperplasia, which is based on the culture of primary human prostate epithelial cells (HPEpiC) and human prostate fibroblasts (HPrF). In an effect to screen the optimal pro-survival BPA levels, HPEpiC and HPrF were, respectively, exposed to concentration gradients of BPA (10^-12 M-10^-4 M) solution diluted with two corresponding medium and incubated for 72 h at 37°C. CCK-8 assay showed that 10^-9 M-10^-5 M BPA could facilitate the proliferation of HPEpiC, while similar proliferative effect of HPrF only needed 10^-11 M-10^-7 M BPA. HPrF were more sensitive to BPA than HPEpiC. The qualification of PCNA gene expression measured using quantitative real-time polymerase chain reaction (qRT-PCR) also mirrored the BPA-induced cell proliferation. Additionally, our results considered that androgen receptor (AR), estrogen receptor (ERα, ERβ), and NFKB1 gene expressions exhibited up-regulation in HPEpiC treated with 10^-9 M BPA for 72 h. However, in HPrF, the identical BPA treatment could activate ERα, ERβ, and NFKB1 gene expressions and down-regulated the expression of AR levels. It is further confirmed that low-dose BPA can indeed promote the proliferation of human prostate cells in vitro, and the mechanisms of BPA for prostatic epithelial and stromal hyperplasia may not be consistent.

Effect of selected bisphenol derivatives on nuclear receptor expression in ovarian cell line COV434

Objectives. Bisphenol A (BPA), as an indispensable plastic additive, has also been proven as an endocrine disruptor associated with adverse health effects including impaired ovarian function and cancer. Due to the restrictions of its usage, several analogs have been employed to replace BPA. Although many studies revealed a harmfulness in the biological effects of BPA analogs, their specific targets remain largely unknown. Nuclear receptors (NRs) may be one of the most important targets of bisphenols. Therefore, in this study, our attention was directed to explore the effect of BPA and its analogs, AF and S, on the mRNA expression of selected NRs involved in the steroidogenic and carcinogenic pathways in the human granulosa cell line COV434. The NRs investigated included: thyroid hormone receptor α (THRA), peroxisome proliferator activating receptor β/δ (PPARD), retinoid X receptor α (RXRA), chicken ovalbumin upstream promoter-transcription factor II (COUPTFII), nuclear receptor-related protein 1 (NURR1), and liver receptor homolog-1 (LRH1).Methods. COV434 cells were treated with the bisphenols at the concentrations of 10^-9 M, 10^-7 M, and 10^-5 M, and after 24 and 48 h, cell viability was monitored by the MTS assay and gene expressions were analyzed using RT-qPCR.Results. Bisphenol treatment did not alter the COV434 cell viability. After 24 h, the expression of neither of the NRs was changed. Likewise, after 48 h, the expression of the selected genes was not altered. However, both BPAF and BPS increased, at the highest concentration (10^-5 M) used, the mRNA levels of both PPARD and NURR1 NRs after 48 h of the treatment. In the BPA-treated groups, no significant upregulation was observed.Conclusions. In the present study, the effect of bisphenols on COUP-TFII, Nurr1, and LRH-1 NRs was investigated for the first time. Although generally we did not observe that BPs provoked any alterations in the expression of the selected NRs in COV434 cells, at specific concentrations and time points they might alter mRNA expression of certain NRs (NURR1, PPARD).

Early-life exposure to bisphenol A and reproductive-related outcomes in rodent models: a systematic review and meta-analysis

We performed this meta-analysis to elucidate the associations between early-life BPA exposure and reproductive-related outcome indicators. The standardized mean differences (SMDs) and its 95% confidence intervals (CIs) were measured by fixed-effects or random-effects models. The results revealed that BPA exposure at extremely-high dose (>50mg/kg/day) was significantly associated with negative reproductive-related outcomes (Prostate weight: SMD: -4.21; 95% Cl: -5.97, -2.44; Testis weight: SMD: -1.92; 95% Cl: -2.61, -1.23; Epididymis weight: SMD: -2.16; 95% Cl: -3.47, -0.86; Daily sperm production; SMD: -1.90; 95% Cl: -3.27, -0.53; Epididymal sperm count; SMD: -3.42; 95% Cl: -3.87, -2.97). Meanwhile, regardless of the dose, early-life BPA exposure could result in an adverse effect on sperm parameters of F1 generation male rodents at any period. Also, we found the non-monotonic dose response curves of BPA in specific tissues or organs, which may challenge the traditional mindset of "safe dose". This study demonstrated that bisphenol A exposure was relevant to adverse reproductive-related outcomes at specially appointed dose and period of life. Yet the assumption that no adverse effects can occur below the "safe" dose is suspected.

Potential Mechanisms of Bisphenol A (BPA) Contributing to Human Disease

Bisphenol A (BPA) is an organic synthetic compound serving as a monomer to produce polycarbonate plastic, widely used in the packaging for food and drinks, medical devices, thermal paper, and dental materials. BPA can contaminate food, beverage, air, and soil. It accumulates in several human tissues and organs and is potentially harmful to human health through different molecular mechanisms. Due to its hormone-like properties, BPA may bind to estrogen receptors, thereby affecting both body weight and tumorigenesis. BPA may also affect metabolism and cancer progression, by interacting with GPR30, and may impair male reproductive function, by binding to androgen receptors. Several transcription factors, including PPARγ, C/EBP, Nrf2, HOX, and HAND2, are involved in BPA action on fat and liver homeostasis, the cardiovascular system, and cancer. Finally, epigenetic changes, such as DNA methylation, histones modification, and changes in microRNAs expression contribute to BPA pathological effects. This review aims to provide an extensive and comprehensive analysis of the most recent evidence about the potential mechanisms by which BPA affects human health.

How microplastic components influence the immune system and impact on children health: Focus on cancer

BACKGROUND

As a result of human socioeconomic activity, industrial wastes have increased distressingly. Plastic pollution is globally distributed across the world due to its properties of buoyancy and durability. A big health hazard is the sorption of toxicants to plastic while traveling through the environment. Two broad classes of plastic-related chemicals are of critical concern for human health-bisphenols and phthalates. Bisphenol A (BPA) is an endocrine-disruptor compound (EDC) with estrogenic activity. It is used in the production of materials that are used daily. The endocrine modulating activity of BPA and its effects on reproductive health has been widely studied. BPA also has effects on the immune system; however, they are poorly investigated and the available data are inconclusive. Phthalates are also EDCs used as plasticizers in a wide array of daily-use products. Since these compounds are not covalently bound to the plastic matrix, they easily leach out from it, leading to high human exposure. These compounds exert several cell effects through modulating different endocrine pathways, such as estrogen, androgen, peroxisome proliferator-activated receptor gamma, and arylhydrocarbon receptor pathways. The exposure to both classes of plastic derivatives during critical periods has detrimental effects on human health.

METHODS

In this review, we have compiled the most important of their perinatal effects on the function of the immune system and their relationship to the development of different types of cancer.

RESULTS/CONCLUSION

The administration of bisphenols and phthalates during critical stages of development affects important immune system components, and the immune function; which might be related to the development of different diseases including cancer.

Bisphenol A-Induced Epigenetic Changes and Its Effects on the Male Reproductive System

Bisphenol A (BPA) is a widespread chemical agent which can exert detrimental effects on the male reproductive system. Exposure to BPA has been shown to induce several epigenetic modifications in both animal and human cells. Specifically, BPA could not only modify the methylation pattern of multiple genes encoding proteins related to reproductive physiology but also directly influence the genes responsible for DNA methylation. BPA effects include hormonal alterations, microscopic and macroscopic alteration of male reproductive organs, and inheritable epigenetic changes involving human reproduction. BPA exposure was also linked to prostate cancer. This review aims to show the current scenario of BPA-induced epigenetic changes and its effects on the male reproductive system. Possible strategies to counter the toxic effect of BPA were also addressed.