An estrogen (17α-ethinyl estradiol-3-sulfate) reduces mortality in a swine model of multiple injuries and hemorrhagic shock.

BACKGROUND: Although 17α-ethinyl estradiol-3-sulfate (EES) reduces mortality in animal models of controlled hemorrhage, its role in a clinically relevant injury model is unknown. We assessed the impact of EES in a swine model of multiple injuries and hemorrhage. METHODS: The study was performed under Good Laboratory Practice, with 30 male uncastrated swine (25-50 kg) subjected to tibial fracture, pulmonary contusion, and 30% controlled hemorrhage for an hour. Animals were randomized to one of five EES doses: 0 (control), 0.3, 1, 3, and 5 mg/kg, administered postinjury. Subjects received no resuscitation and were observed for 6 hours or until death. Survival data were analyzed using Cox-proportional hazard regression. Left ventricular pressure-volume loops were used to derive preload recruitable stroke work as a measure of cardiac inotropy. Immediate postinjury preload recruitable stroke work values were compared with values at 1 hour post-drug administration. RESULTS: Six-hour survival for the 0, 0.3, 1, 3, and 5 mg/kg groups was 0%, 50%, 33.3%, 16.7%, and 0%, respectively. Following Cox regression, the hazard (95% confidence interval) of death was significantly reduced in the 0.3 (0.22 [0.05-0.93]) and 1 (0.24 [0.06-0.89]) mg/kg groups but not the 3 (0.49 [0.15-1.64]) and 5 (0.46 [0.14-1.47]) mg/kg groups. Mean survival time was significantly extended in the 1 mg/kg group (246 minutes) versus the 0 mg/kg group (96 minutes) (p = 0.04, t test). At 1 hour post-drug administration, inotropy was significantly higher than postinjury values in the 0.3 and 1 mg/kg groups (p = 0.003 and p < 0.001, respectively). Inotropy was unchanged in the 3 and 5 mg/kg groups but significantly depressed in the control (p = 0.022). CONCLUSION: Administration of EES even in the absence of fluid resuscitation reduces mortality and improves cardiac inotropy in a clinically relevant swine model of multiple injuries and hemorrhage. These findings support the need for a clinical trial in human trauma patients.

Effects of Bisphenol A and Its Alternatives, Bisphenol F and Tetramethyl Bisphenol F on Osteoclast Differentiation.

Bisphenol A (BPA) is a typical environmental endocrine disruptor that exhibits estrogen-mimicking, hormone-like properties and can cause the collapse of bone homeostasis by an imbalance between osteoblasts and osteoclasts. Various BPA substitutes, structurally similar to BPA, have been used to manufacture 'BPA-free' products; however, the regulatory role of BPA alternatives in osteoclast differentiation still remains unelucidated. This study aimed to investigate the effects of these chemicals on osteoclast differentiation using the mouse osteoclast precursor cell line RAW 264.7. Results confirmed that both BPA and its alternatives, bisphenol F and tetramethyl bisphenol F (TMBPF), were nontoxic to RAW 264.7 cells. In particular, tartrate-resistant acid phosphatase (TRAP)-positive multinucleated cell staining and activity calculation assays revealed that TMBPF enhanced osteoclast differentiation upon stimulation of the receptor activator of nuclear factor-kappa B ligand (RANKL). Additionally, TMBPF activated the mRNA expression of osteoclast-related target genes, such as the nuclear factor of activated T-cells, cytoplasmic 1 (NFATc1), tartrate-resistant acid phosphatase (TRAP), and cathepsin K (CtsK). Western blotting analysis indicated activation of the mitogen-activated protein kinase signaling pathway, including phosphorylation of c-Jun N-terminal kinase and p38. Together, the results suggest that TMBPF enhances osteoclast differentiation, and it is critical for bone homeostasis and skeletal health.

Potential Estrogenic Properties of 17ß-Hydroxy-ethylimine Estradiol Derivative Targeted to Menopause Stage.

BACKGROUND/AIM: Hormone replacement therapy during menopause increases the risk of thromboembolic diseases and cancer, so safety alternative therapeutic strategies are needed. 17ß-Aminoestrogens are a synthetic estrogens group that possess mild anticoagulant activity that contrasts with the pro-coagulant effects showed by estradiol's (E2) in rodents. Being considered an alternative to conventional hormone replacement therapy during menopause without thrombogenic risks producing. The present study aimed to determine the estrogenic profile and anxiolytic activity of 17ß-[hydroxy-ethylimine]-1,3,5(10)-estratrien-3-ol (IE2), a related compound unknown until now. METHODS: IE2 was assessed in immature rats by uterotrophic assay administering IE2, E2, or vehicle. In ovariectomized adult Wistar rats (Ovx) to facilitating the lordotic behavior compared with E2, estradiol benzoate, or vehicle. The effect of IE2 on anxiety was estimated in Ovx animals treated with IE2, E2, or vehicle group and evaluated in the elevated plus-maze model. RESULTS AND CONCLUSION: IE2 produced an uterotrophic effect, lordotic behavior, and anxiolytic effect in a dose-dependent manner, similar to E2. IE2 depicted estrogenicity, indicating potential clinical use as hormone replacement therapy during menopause.

11-Oxygenated Estrogens Are a Novel Class of Human Estrogens but Do not Contribute to the Circulating Estrogen Pool.

Androgens are the obligatory precursors of estrogens. In humans, classic androgen biosynthesis yields testosterone, thought to represent the predominant circulating active androgen both in men and women. However, recent work has shown that 11-ketotestosterone, derived from the newly described 11-oxygenated androgen biosynthesis pathway, makes a substantial contribution to the active androgen pool in women. Considering that classic androgens are the obligatory substrates for estrogen biosynthesis catalyzed by cytochrome P450 aromatase, we hypothesized that 11-oxygenated androgens are aromatizable. Here we use steroid analysis by tandem mass spectrometry to demonstrate that human aromatase generates 11-oxygenated estrogens from 11-oxygenated androgens in 3 different cell-based aromatase expression systems and in human ex vivo placenta explant cultures. We also show that 11-oxygenated estrogens are generated as a byproduct of the aromatization of classic androgens. We show that 11ß-hydroxy-17ß-estradiol binds and activates estrogen receptors α and ß and that 11ß-hydroxy-17ß-estradiol and the classic androgen pathway-derived active estrogen, 17ß-estradiol, are equipotent in stimulating breast cancer cell line proliferation and expression of estrogen-responsive genes. 11-oxygenated estrogens were, however, not detectable in serum from individuals with high aromatase levels (pregnant women) and elevated 11-oxygenated androgen levels (patients with congenital adrenal hyperplasia or adrenocortical carcinoma). Our data show that while 11-oxygenated androgens are aromatizable in vitro and ex vivo, the resulting 11-oxygenated estrogens are not detectable in circulation, suggesting that 11-oxygenated androgens function primarily as androgens in vivo.

Rapid Induction of the Unfolded Protein Response and Apoptosis by Estrogen Mimic TTC-352 for the Treatment of Endocrine-Resistant Breast Cancer.

Patients with long-term estrogen-deprived breast cancer, after resistance to tamoxifen or aromatase inhibitors develops, can experience tumor regression when treated with estrogens. Estrogen's antitumor effect is attributed to apoptosis via the estrogen receptor (ER). Estrogen treatment can have unpleasant gynecologic and nongynecologic adverse events; thus, the development of safer estrogenic agents remains a clinical priority. Here, we study synthetic selective estrogen mimics (SEM) BMI-135 and TTC-352, and the naturally occurring estrogen estetrol (E4), which are proposed as safer estrogenic agents compared with 17ß-estradiol (E2), for the treatment of endocrine-resistant breast cancer. TTC-352 and E4 are being evaluated in breast cancer clinical trials. Cell viability assays, real-time PCR, immunoblotting, ERE DNA pulldowns, mass spectrometry, X-ray crystallography, docking and molecular dynamic simulations, live cell imaging, and Annexin V staining were conducted in 11 biologically different breast cancer models. Results were compared with the potent full agonist E2, less potent full agonist E4, the benchmark partial agonist triphenylethylene bisphenol (BPTPE), and antagonists 4-hydroxytamoxifen and endoxifen. We report ERα's regulation and coregulators' binding profiles with SEMs and E4 We describe TTC-352's pharmacology as a weak full agonist and antitumor molecular mechanisms. This study highlights TTC-352's benzothiophene scaffold that yields an H-bond with Glu353, which allows Asp351-to-helix 12 (H12) interaction, sealing ERα's ligand-binding domain, recruiting E2-enriched coactivators, and triggering rapid ERα-induced unfolded protein response (UPR) and apoptosis, as the basis of its anticancer properties. BPTPE's phenolic OH yields an H-Bond with Thr347, which disrupts Asp351-to-H12 interaction, delaying UPR and apoptosis and increasing clonal evolution risk.

New frontiers of developmental endocrinology opened by researchers connecting irreversible effects of sex hormones on developing organs.

In the early 1960's, at Professor Bern's laboratory, University of California, Berkeley) in the US, Takasugi discovered ovary-independent, persistent vaginal changes in mice exposed neonatally to estrogen, which resulted in vaginal cancer later in life. Reproductive abnormalities in rodents were reported as a result of perinatal exposure to various estrogenic chemicals. Ten years later, vaginal cancers were reported in young women exposed in utero to the synthetic estrogen diethylstilbestrol (DES) and this has been called the "DES syndrome". The developing organism is particularly sensitive to developmental exposure to estrogens inducing long-term changes in various organs including the reproductive organs. The molecular mechanism underlying the persistent vaginal changes induced by perinatal estrogen exposure was partly demonstrated. Persistent phosphorylation and sustained expression of EGF-like growth factors, lead to estrogen receptor α (ESR1) activation, and then persistent vaginal epithelial cell proliferation. Agents which are weakly estrogenic by postnatal criteria may have major developmental effects, especially during a critical perinatal period. The present review outlines various studies conducted by four generations of investigators all under the influence of Prof. Bern. The studies include reports of persistent changes induced by neonatal androgen exposure, analyses of estrogen responsive genes, factors determining epithelial differentiation in the Müllerian duct, ESR and growth factor signaling, and polyovular follicles in mammals. This review is then expanded to the studies on the effects of environmental estrogens on wildlife and endocrine disruption in Daphnids.

Agrochemicals with estrogenic endocrine disrupting properties: Lessons Learned?

Many agrochemicals have endocrine disrupting properties. A subset of these chemicals is characterized as "estrogenic". In this review, we describe several distinct ways that chemicals used in crop production can affect estrogen signaling. Using three agrochemicals as examples (DDT, endosulfan, and atrazine), we illustrate how screening tests such as the US EPA's EDSP Tier 1 assays can be used as a first-pass approach to evaluate agrochemicals for endocrine activity. We then apply the "Key Characteristics" approach to illustrate how chemicals like DDT can be evaluated, together with the World Health Organization's definition of an endocrine disruptor, to identify data gaps. We conclude by describing important issues that must be addressed in the evaluation and regulation of hormonally active agrochemicals including mixture effects, efforts to reduce vertebrate animal use, chemical prioritization, and improvements in hazard, exposure, and risk assessments.

Neurodevelopmental effects of natural and synthetic ligands of estrogen and progesterone receptors in zebrafish eleutheroembryos.

Natural and synthetic estrogens and progestins are widely used in human and veterinary medicine and are detected in waste and surface waters. Our previous studies have clearly shown that a number of these substances targets the brain to induce the estrogen-regulated brain aromatase expression but the consequences on brain development remain virtually unexplored. The aim of the present study was therefore to investigate the effect of estradiol (E2), progesterone (P4) and norethindrone (NOR), a 19-nortestosterone progestin, on zebrafish larval neurogenesis. We first demonstrated using real-time quantitative PCR that nuclear estrogen and progesterone receptor brain expression is impacted by E2, P4 and NOR. We brought evidence that brain proliferative and apoptotic activities were differentially affected depending on the steroidal hormone studied, the concentration of steroids and the region investigated. Our findings demonstrate for the first time that steroid compounds released in aquatic environment have the capacity to disrupt key cellular events involved in brain development in zebrafish embryos further questioning the short- and long-term consequences of this disruption on the physiology and behavior of organisms.

Design, Synthesis, Anticancer Evaluation and Molecular Modeling of Novel Estrogen Derivatives.

A series of estrone derivatives 3⁻8 was designed and synthesized using estrone arylmethylenes 2a,b as starting materials and their structures were confirmed by different spectral data and elemental analyses. All the newly synthesized compounds exhibited potent in vitro and in vivo cytotoxic activities against breast cancer cell lines. In addition, all compounds were subjected to in vitro and in vivo inhibition assays for EGFR and VEGFR-2 kinases as well as p53 ubiquitination activity to obtain more details about their mechanism of action. Based on the promising results, a molecular docking study was investigated for the most representative compound 5a against the two targets, EGFR and VEGFR-2 kinases, to assess its binding affinity, hoping to rationalize and obtain potent anticancer agents in the future.

Neuroprotective Role of Hypothermia in Hypoxic-ischemic Brain Injury: Combined Therapies using Estrogen.

Hypoxic-ischemic brain injury is a complex network of factors, which is mainly characterized by a decrease in levels of oxygen concentration and blood flow, which lead to an inefficient supply of nutrients to the brain. Hypoxic-ischemic brain injury can be found in perinatal asphyxia and ischemic-stroke, which represent one of the main causes of mortality and morbidity in children and adults worldwide. Therefore, knowledge of underlying mechanisms triggering these insults may help establish neuroprotective treatments. Selective Estrogen Receptor Modulators and Selective Tissue Estrogenic Activity Regulators exert several neuroprotective effects, including a decrease of reactive oxygen species, maintenance of cell viability, mitochondrial survival, among others. However, these strategies represent a traditional approach of targeting a single factor of pathology without satisfactory results. Hence, combined therapies, such as the administration of therapeutic hypothermia with a complementary neuroprotective agent, constitute a promising alternative. In this sense, the present review summarizes the underlying mechanisms of hypoxic-ischemic brain injury and compiles several neuroprotective strategies, including Selective Estrogen Receptor Modulators and Selective Tissue Estrogenic Activity Regulators, which represent putative agents for combined therapies with therapeutic hypothermia.

Evaluation of Estrogenic Activity of Novel Bisphenol A Alternatives, Four Bioinspired Bisguaiacol F Specimens, by in Vitro Assays.

Alternatives to bisphenol A (BPA), such as lignin-inspired bisguaiacol F (BGF), are of interest for food contact materials due to increasing evidence of estrogenic activity (EA) and exposure-correlated harmful effects of BPA and its analogues. BGF has similar thermal and mechanical properties to BPA, but contains additional methoxy substituents that may significantly reduce its endocrine disruption potential. In this study, the EA of four BGF samples with different regioisomer ratios was quantified relative to 17ß-estradiol at ten concentrations by using two in vitro assays: MCF-7 cell proliferation and VM7Luc4E2 transactivation (TA). The results suggest BGF mixtures with higher molar ratios of p, p'-BGF and o, p'-BGF regioisomers exhibited lower EA than BPA, while BGF samples containing higher molar ratios of m, p'-BGF had no detectable EA over a wide range of test concentrations. These findings suggest the potential of BGF as a viable alternative to BPA for use in more environmentally friendly materials.

Estrogen agonistic/antagonistic activity of brominated parabens.

The estrogen agonistic/antagonistic activity of 16 brominated by-products of parabens was assessed by using a yeast two-hybrid assay transfected with the human estrogen receptor α. Characterization of synthetic compounds including novel brominated parabens was performed using 1H-NMR spectroscopy and high-resolution mass spectrometry. For the agonist assay, five C3-C4 alkylparabens exhibited significant activity (P < 0.05) relative to that of 17ß-estradiol, ranging from 3.7 × 10-5 to 7.1 × 10-4. In contrast, none of the brominated alkyl parabens exhibited agonistic activity. In the antagonist assay, 12 brominated alkylparabens and butylparaben exhibited significant antagonistic activity (P < 0.05). Their antagonistic activity relative to 4-hydroxytamoxifen ranged from 0.11 to 2.5. The antagonist activity of C1-C4 alkylparabens increased with the number of bromine substitutions. Benzylparaben exhibited both agonistic and antagonistic activity, and these activities dissipated or were weakened with increased bromination. Thus, increased bromination appeared to attenuate the estrogen agonistic activity of most parabens such that it resulted in increased antagonistic activity, a feature of parabens that had not been previously described.

Sex Hormone Metabolism and Threatened Abortion.

BACKGROUND The aim of this study was to evaluate changes in sex hormone metabolism in patients with threatened miscarriage. MATERIAL AND METHODS We recruited 73 women in early pregnancy (6-8 weeks of gestation) and divided them into the following 2 groups based on whether they had vaginal bleeding: group A (n=34), the threatened abortion group; and group B (n=39), the normal pregnancy group. Human chorionic gonadotrophin (hCG), estradiol (E2), progesterone (P4), and testosterone (T) serum levels were tested and sex hormone metabolites in the urine were detected using gas chromatography-triple quadrupole mass spectrometry (GC-MS/MS). As the control, data for sex hormones and their metabolites were obtained in normal women of childbearing age without pregnancy (group C: n=23). RESULTS E2 and T serum levels were lower in women with threatened miscarriage (group A). Estrone (E1), E2, estriol (E3), 16α-hydroxyestrone (16α-OHE1), 4-methoxyestrone (4-MeOE1), 2-hydroxyestradiol (2-OHE2), and 4-methoxyestradiol (4-MeOE2) levels were significantly lower in group A (P=0.001, 0.003, 0.009, 0.001, 0.012, 0.032, and 0.047, respectively.). Urine levels of dehydroepiandrosterone (DHEA), androstenedione (A2), and the metabolite of (A2) were also significantly lower in group A (P=0.007, 0.009, and 0.011, respectively). The 2-OHE1/E1, 4-OHE1/E1, 2-MeOE1/E1, and 2-MeOE2/E2 ratios were lower in group B, whereas the 2-OHE2/E2, 4-OHE2/E2, and 4-MeOE2/E2 ratios were dramatically lower in all pregnant women (groups A and B) than in group C. CONCLUSIONS Deficiency in DHEA and abnormal levels of sex hormone metabolites may cause a reduction in the activity of estrogens in women with threatened abortion. These alterations may result in bleeding during the first trimester of pregnancy.

Local hormone therapy for genitourinary syndrome of menopause in breast cancer patients: is it safe?

The genitourinary syndrome of menopause (GSM) is a frequent complaint among breast cancer (BC) survivors that lead to an important affection of their quality of life (QoL). Lifestyle measures such as smoking cessation or regular sexual activity are usually insufficient to significantly improve GMS and although therapies such as lubricants and polycarbophil moisturized gels are considered first-line therapies to alleviate symptoms of vulvovaginal atrophy, these non-hormonal options are not able to reverse atrophy once it occurs. Instead, this complaint is corrected by local estrogens. The estrogen vaginal treatment usually used to treat GSM, is an issue of concern in this group due to the possible negative effect over the BC outcomes. On the other hand, the worsening of QoL in these patients due to symptoms related to GSM can lead to discontinuation of hormone adjuvant therapies and therefore must be addressed properly. The goal of this review is to contribute to health care professionals to make an informed decision to care for their BC patients.

Metabolism and health effects of phyto-estrogens.

Phyto-estrogens are plant-derived compounds that can exert various estrogenic and anti-estrogenic effects, and are usually used as a natural alternative to estrogen replacement due to their health benefits, including a lowered risk of osteoporosis, heart disease, breast cancer, and menopausal symptoms. Phyto-estrogens are also considered as endocrine disruptors due to their structure similar to human female hormone 17-ß oestradiol. However, the issue of whether phyto-estrogens are beneficial or harmful to human health remains unknown, as this may depend on the dose, form, level and duration of administration of phyto-estrogens, and influence by genetics, metabolism, gut physiology, age, diet, and the health status of individuals. Clarification on this issue is necessary for the sake of their two-side effects on human health and rapidly increasing global consumption of phyto-estrogens. This review mainly includes the metabolism of phyto-estrogens and weighs the evidence for and against the purported health benefits and adverse effects of phyto-estrogens.

Aluminium and the human breast.

The human population is exposed to aluminium (Al) from diet, antacids and vaccine adjuvants, but frequent application of Al-based salts to the underarm as antiperspirant adds a high additional exposure directly to the local area of the human breast. Coincidentally the upper outer quadrant of the breast is where there is also a disproportionately high incidence of breast cysts and breast cancer. Al has been measured in human breast tissues/fluids at higher levels than in blood, and experimental evidence suggests that at physiologically relevant concentrations, Al can adversely impact on human breast epithelial cell biology. Gross cystic breast disease is the most common benign disorder of the breast and evidence is presented that Al may be a causative factor in formation of breast cysts. Evidence is also reviewed that Al can enable the development of multiple hallmarks associated with cancer in breast cells, in particular that it can cause genomic instability and inappropriate proliferation in human breast epithelial cells, and can increase migration and invasion of human breast cancer cells. In addition, Al is a metalloestrogen and oestrogen is a risk factor for breast cancer known to influence multiple hallmarks. The microenvironment is established as another determinant of breast cancer development and Al has been shown to cause adverse alterations to the breast microenvironment. If current usage patterns of Al-based antiperspirant salts contribute to causation of breast cysts and breast cancer, then reduction in exposure would offer a strategy for prevention, and regulatory review is now justified.

Estrogen O-sulfamates and their analogues: Clinical steroid sulfatase inhibitors with broad potential.

Estrogen sulfamate derivatives were the first irreversible active-site-directed inhibitors of steroid sulfatase (STS), an emerging drug target for endocrine therapy of hormone dependent diseases that catalyzes inter alia the hydrolysis of estrone sulfate to estrone. In recent years this has stimulated clinical investigation of the estradiol derivative both as an oral prodrug and its currently ongoing exploration in endometriosis. 2-Substituted steroid sulfamate derivatives show considerable potential as multi-targeting agents for hormone-independent disease, but are also potent STS inhibitors. The steroidal template has spawned nonsteroidal STS inhibitors one of which, Irosustat, has been evaluated clinically in breast cancer, endometrial cancer and prostate cancer and there is potential for innovative dual-targeting approaches. This review surveys the role of estrogen sulfamates, their analogues and current status.

Lipid nanocarriers of a lipid-conjugated estrogenic derivative inhibit tumor growth and enhance cisplatin activity against triple-negative breast cancer: pharmacokinetic and efficacy evaluation.

Breast cancer is the leading cause of malignancies among women globally. The triple negative breast cancer (TNBC) subtype is the most difficult to treat and accounts for 15% of all cases. Targeted therapies have been developed for TNBC but come short of clinical translation due to acquired tumor resistance. An effective therapy against TNBC must combine properties of target specificity, efficient tumor killing, and translational relevance. The objective of this study was to formulate a nontoxic, cationic, lipid-conjugated estrogenic derivative (ESC8), with demonstrated anticancer activity, for oral delivery in mice bearing triple negative breast cancer (TNBC) as xenograft tumors. The in vitro cell viability, Caco-2 permeability, and cell cycle dynamics of ESC8-treated TNBC cells were investigated. ESC8 was formulated as liposomes, solid lipid nanoparticles (SLNs), and nanostructured lipid carriers (NLCs) and characterized for size, zeta potential, entrapment efficiency, size stability, and tumor biodistribution. Pharmacokinetic modeling of plasma concentration-time course data was carried out following intravenous and oral administration in Sprague-Dawley rats. In vivo efficacy investigation of ESC8-SLNC was carried out in Nu/Nu mice bearing MDA-MB-231 TNBC as xenograft tumors, and the molecular dynamics modulating tumor growth inhibition was analyzed by Western blot. In vitro ESC8 inhibited TNBC and non-TNBC cell viability with IC50 ranging from 1.81 to 3.33 µM. ESC8 was superior to tamoxifen and Cisplatin in inhibiting MDA-MB-231 cell viability; and at 2.0 µM ESC8 enhanced Cisplatin cytotoxicity 16-fold. Intravenous ESC8 (2.0 mg/kg) was eliminated at a rate of 0.048 ± 0.01 h(-1) with a half-life of 14.63 ± 2.95 h in rats. ESC8 was orally bioavailable (47.03%) as solid lipid nanoparticles (ESC8-SLN). ESC8-SLN (10 mg/kg/day, ×14 days, p.o.) inhibited breast tumor growth by 74% (P < 0.0001 vs control) in mice bearing MDA-MB-231 cells as xenografts; and when given in combination with Cisplatin (2.0 mg/kg/biweekly, ×2 weeks, IV), tumor growth was inhibited by 87% (P = 0.0002, vs ESC8-SLN; 10 mg/kg/day, ×14 days, p.o). ESC8-SLN tumor growth inhibition was associated with increased expression of p21 and Caspase-9; as well as by inhibition of EGFR, Slug, p-Akt1, Vimentin, NFkß, and IKKγ. These results show the promise of ESC8 as an oral adjuvant or neoadjuvant against triple negative breast cancer.

MAPK and NF-κB pathways are involved in bisphenol A-induced TNF-α and IL-6 production in BV2 microglial cells.

Microglial activation has been reported to play an important role in neurodegenerative diseases by producing pro-inflammatory cytokines. Bisphenol A (BPA, 2,2-bis (4-hydroxyphenyl) propane), known as a ubiquitous endocrine-disrupting chemical, is reported to perform both mimic- and anti-estrogen properties; however, whether it affects cytokine production or immune response in central nervous system remains unclear. The present study was aimed to explore whether BPA was involved in inflammatory action and to investigate the potential mechanisms in microglial cells. BV2, the murine microglial cell line, was used in the present work as the cell model. BPA-associated morphologic changes, cytokine responses, and signaling events were examined using immunofluorescence analysis, real-time PCR, enzyme-linked immunosorbent assay, and western blot. Our results indicated that BPA increased BV2 cells activation and simultaneously elevated tumor necrosis factor-α and interleukin 6 expression, which could be partially reversed by estrogen receptor antagonist, ICI182780. In addition, the c-Jun N-terminal protein kinase (JNK) inhibitor (SP600125), rather than ERK1/2 blocker (PD98059), displayed anti-inflammatory properties on BPA-elicited cytokine responses. Moreover, the inflammatory transcription factor NF-κB was specifically activated by BPA as well. These results, taken together, suggested that BPA may have functional effects on the response of microglial cell activation via, in part, the estrogen receptor, JNK, ERK mitogen-activated protein kinase, and NF-κB signaling pathways with its subsequent influence on pro-inflammatory action.

Estrogenic endocrine-disrupting chemicals modulate the production of inflammatory mediators and cell viability of lipopolysaccharide-stimulated macrophages.

Estrogenic endocrine-disrupting chemicals (EDCs) are exogenous substances that act as competitive inhibitors of estrogen in the endocrine system. By disrupting the endocrine system, EDCs can cause severe disabilities and diseases, including cancers and altered sexual development. Although the influence of these molecules in the endocrine system is evident, the effects of EDCs on the immune system as well as their cytotoxicity have been poorly examined. Therefore, we selected 21 EDCs that are commonly found in Korean ecosystems, such as surface waters and effluents, and studied their immunologic effects by comparing nitric oxide (NO) production and cytotoxicity in lipopolysaccharide (LPS)-stimulated RAW 264.7 cells (RAW cells), a macrophage cell line. Among the EDCs tested, fenitrothion (FTH) inhibited the messenger RNA (mRNA) expression of inducible NO synthase (iNOS), resulting in reduced NO production, while treatment with andostenedione (AD), diethyl phthalate, di-n-butyl phthalate (DBP), estriol, or molinate decreased production of NO in an iNOS-independent fashion. In contrast, benzo(a)pyrene (B(a)P) increased the production of NO in RAW cells. In addition, AD, DBP, or FTH inhibited the mRNA expression of tumor necrosis factor alpha or interleukin-1 beta. Treatment with 17-α-ethynylestradiol, 17-ß-estradiol, 4-n-butyl phenol, or alachlor induced apoptosis of RAW cells, while dicyclohexyl phthalate and B(a)P caused cell death in an apoptosis-independent manner. These data suggest that EDCs can influence the immune response to pathogens by modulating the functions of macrophages.