Estrogen receptor- but not - or GPER inhibits high glucose-induced human VSMC proliferation: potential role of ROS and ERK

The decreased incidence of cardiovascular disease in premenopausal women has been attributed, at least partially, to protective effects of estrogens. However, premenopausal women with diabetes mellitus are no longer selectively protected. High-glucose (HG) conditions have previously been shown to abolish the antimitogenic effects of 17β-estradiol (E(2)) in vascular smooth muscle cells (VSMCs).

Endogenous estrogens, through estrogen receptor , constrain autoimmune inflammation in female mice by limiting CD4(+) T-cell homing into the CNS

Sex hormones influence immune responses and the development of autoimmune diseases including MS and its animal model, EAE. Although it has been previously reported that ovariectomy could worsen EAE, the mechanisms implicated in the protective action of endogenous ovarian hormones have not been addressed. In this report, we now show that endogenous estrogens limit EAE development and CNS inflammation in adult female mice through estrogen receptor expression in the host non-hematopoietic tissues. We provide evidence that the enhancing effect of gonadectomy on EAE development was due to quantitative rather than qualitative changes in effector Th1 or Th17 cell recruitment into the CNS. Consistent with this observation, adoptive transfer of myelin oligodendrocyte glycoprotein-specific encephalitogenic CD4(+) T lymphocytes induced more severe EAE in ovariectomized mice as compared to normal female mice. Finally, we show that gonadectomy accelerated the early recruitment of inflammatory cells into the CNS upon adoptive transfer of encephalitogenic CD4(+) T cells. Altogether, these data show that endogenous estrogens, through estrogen receptor , exert a protective effect on EAE by limiting the recruitment of blood-derived inflammatory cells into the CNS.

Estrogen Receptor α Signaling in T Lymphocytes Is Required for Estradiol-Mediated Inhibition of Th1 and Th17 Cell Differentiation and Protection against Experimental Autoimmune Encephalomyelitis

Estrogen treatment exerts a protective effect on experimental autoimmune encephalomyelitis (EAE) and is under clinical trial for multiple sclerosis therapy. Estrogens have been suspected to protect from CNS autoimmunity through their capacity to exert anti-inflammatory as well as neuroprotective effects. Despite the obvious impacts of estrogens on the pathophysiology of multiple sclerosis and EAE, the dominant cellular target that orchestrates the anti-inflammatory effect of 17β-estradiol (E2) in EAE is still ill defined. Using conditional estrogen receptor (ER) α-deficient mice and bone marrow chimera experiments, we show that expression of ERα is critical in hematopoietic cells but not in endothelial ones to mediate the E2 inhibitory effect on Th1 and Th17 cell priming, resulting in EAE protection. Furthermore, using newly created cell type-specific ERα-deficient mice, we demonstrate that ERα is required in T lymphocytes, but neither in macrophages nor dendritic cells, for E2-mediated inhibition of Th1/Th17 cell differentiation and protection from EAE. Lastly, in absence of ERα in host nonhematopoietic tissues, we further show that ERα signaling in T cells is necessary and sufficient to mediate the inhibitory effect of E2 on EAE development. These data uncover T lymphocytes as a major and nonredundant cellular target responsible for the anti-inflammatory effects of E2 in Th17 cell-driven CNS autoimmunity.

PRO_10--a new tissue-based prognostic multigene marker in patients with early estrogen receptor-positive breast cancer

Clinicopathological and molecular factors determine the prognosis of breast cancer. PRO_10 is a prognostic score based on quantitative RT-PCR of 10 proliferation-associated genes obtained from formalin-fixed, paraffin-embedded breast cancer tissues. We revalidated PRO_10 in patients treated in a non-trial setting.

Estrogen receptor modulators and down regulators: optimal use in postmenopausal women with breast cancer

Endocrine treatments have been used in breast cancer since 1896, when Beatson reported on the results of oophorectomy for advanced breast cancer. In the second half of the last century, different endocrine-based compounds were developed and, in this review, the role of the selective estrogen receptor modulators (SERMs) and selective estrogen receptor down regulators (SERDs) in the postmenopausal setting are discussed. Tamoxifen is the most investigated and most widely used representative of these agents, and has been introduced in the advanced disease, in the neoadjuvant and adjuvant setting, and for the prevention of the disease. Its role has been challenged in recent years by the introduction of third-generation aromatase inhibitors that have proven higher activities than tamoxifen with different toxicity patterns. Several other SERMs have been investigated, but none have been clearly superior to tamoxifen. SERDs act as pure estrogen antagonists and should compare favourably to tamoxifen. For the time being, they have been used in the treatment of advanced breast cancers and their role in other settings still needs investigation. The increased use of aromatase inhibitors as first-line endocrine therapy has resulted in new discussions regarding the role that tamoxifen and other SERMs or SERDs may play in breast cancer. The sequencing of endocrine therapies in hormone-sensitive breast cancer remains a very important research issue.

Expression of zebra fish aromatase cyp19a and cyp19b genes in response to the ligands of estrogen receptor and aryl hydrocarbon receptor

Many endocrine-disrupting chemicals act via estrogen receptor (ER) or aryl hydrocarbon receptor (AhR). To investigate the interference between ER and AhR, we studied the effects of 17beta-estradiol (E2) and 2,3,7,8-tetrachlorodibenzo-p-dioxin (TCDD) on the expression of zebra fish cyp19a (zfcyp19a) and cyp19b (zfcyp19b) genes, encoding aromatase P450, an important steroidogenic enzyme. In vivo (mRNA quantification in exposed zebra fish larvae) and in vitro (activity of zfcyp19-luciferase reporter genes in cell cultures in response to chemicals and zebra fish transcription factors) assays were used. None of the treatments affected zfcyp19a, excluding the slight upregulation by E2 observed in vitro. Strong upregulation of zfcyp19b by E2 in both assays was downregulated by TCDD. This effect could be rescued by the addition of an AhR antagonist. Antiestrogenic effect of TCDD on the zfcyp19b expression in the brain was also observed on the protein level, assessed by immunohistochemistry. TCDD alone did not affect zfcyp19b expression in vivo or promoter activity in the presence of zebra fish AhR2 and AhR nuclear translocator 2b (ARNT2b) in vitro. However, in the presence of zebra fish ERalpha, AhR2, and ARNT2b, TCDD led to a slight upregulation of promoter activity, which was eliminated by either an ER or AhR antagonist. Studies with mutated reporter gene constructs indicated that both mechanisms of TCDD action in vitro were independent of dioxin-responsive elements (DREs) predicted in the promoter. This study shows the usefulness of in vivo zebra fish larvae and in vitro zfcyp19b reporter gene assays for evaluation of estrogenic chemical actions, provides data on the functionality of DREs predicted in zfcyp19 promoters and shows the effects of cross talk between ER and AhR on zfcyp19b expression. The antiestrogenic effect of TCDD demonstrated raises further concerns about the neuroendocrine effects of AhR ligands.

Patterns of recurrence of early breast cancer according to estrogen receptor status: a therapeutic target for a quarter of a century

The current therapeutic strategy in breast cancer is to identify a target, such as estrogen receptor (ER) status, for tailoring treatments. We investigated the patterns of recurrence with respect to ER status for patients treated in two randomized trials with 25 years' median follow-up. In the ER-negative subpopulations most breast cancer events occurred within the first 5-7 years after randomization, while in the ER-positive subpopulations breast cancer events were spread through 10 years. In the ER-positive subpopulation, 1 year endocrine treatment alone significantly prolonged disease-free survival (DFS) with no additional benefit observed by adding 1 year of chemotherapy. In the small ER-negative subpopulation chemo-endocrine therapy had a significantly better DFS than endocrine alone or no treatment. Despite small numbers of patients, "old-fashioned" treatments, and competing causes of treatment failure, the value of ER status as a target for response to adjuvant treatment is evident through prolonged follow-up.

Tamoxifen inhibits TRPV6 activity via estrogen receptor-independent pathways in TRPV6-expressing MCF-7 breast cancer cells

The epithelial calcium channel TRPV6 is upregulated in breast carcinoma compared with normal mammary gland tissue. The selective estrogen receptor modulator tamoxifen is widely used in breast cancer therapy. Previously, we showed that tamoxifen inhibits calcium uptake in TRPV6-transfected Xenopus oocytes. In this study, we examined the effect of tamoxifen on TRPV6 function and intracellular calcium homeostasis in MCF-7 breast cancer cells transiently transfected with EYFP-C1-TRPV6. TRPV6 activity was measured with fluorescence microscopy using Fura-2. The basal calcium level was higher in transfected cells compared with nontransfected cells in calcium-containing solution but not in nominally calcium-free buffer. Basal influxes of calcium and barium were also increased. In transfected cells, 10 mumol/L tamoxifen reduced the basal intracellular calcium concentration to the basal calcium level of nontransfected cells. Tamoxifen decreased the transport rates of calcium and barium in transfected cells by 50%. This inhibitory effect was not blocked by the estrogen receptor antagonist, ICI 182,720. Similarly, a tamoxifen-induced inhibitory effect was also observed in MDA-MB-231 estrogen receptor-negative cells. The effect of tamoxifen was completely blocked by activation of protein kinase C. Inhibiting protein kinase C with calphostin C decreased TRPV6 activity but did not alter the effect of tamoxifen. These findings illustrate how tamoxifen might be effective in estrogen receptor-negative breast carcinomas and suggest that the therapeutic effect of tamoxifen and protein kinase C inhibitors used in breast cancer therapy might involve TRPV6-mediated calcium entry. This study highlights a possible role of TRPV6 as therapeutic target in breast cancer therapy.

Estrogen receptor subtype beta2 is involved in neuromast development in zebrafish (Danio rerio) larvae

Estrogens are known to play a role in both reproductive and non-reproductive functions in mammals. Estrogens and their receptors are involved in the development of the central nervous system (brain development, neuronal survival and differentiation) as well as in the development of the peripheral nervous system (sensory-motor behaviors). In order to decipher possible functions of estrogens in early development of the zebrafish sensory system, we investigated the role of estrogen receptor beta(2) (ERbeta(2)) by using a morpholino (MO) approach blocking erbeta(2) RNA translation. We further investigated the development of lateral line organs by cell-specific labeling, which revealed a disrupted development of neuromasts in morphants. The supporting cells developed and migrated normally. Sensory hair cells, however, were absent in morphants' neuromasts. Microarray analysis and subsequent in situ hybridizations indicated an aberrant activation of the Notch signaling pathway in ERbeta(2) morphants. We conclude that signaling via ERbeta(2) is essential for hair cell development and may involve an interaction with the Notch signaling pathway during cell fate decision in the neuromast maturation process.

Distinct roles of estrogen receptors alpha and beta mediating acute vasodilation of epicardial coronary arteries.

This study investigated the contribution of estrogen receptors (ERs) alpha and beta for epicardial coronary artery function, vascular NO bioactivity, and superoxide (O(2)(-)) formation. Porcine coronary rings were suspended in organ chambers and precontracted with prostaglandin F(2alpha) to determine direct effects of the selective ER agonists 4,4',4''-(4-propyl-[(1)H]pyrazole-1,3,5-triyl)tris-phenol (PPT) or 2,3-bis(4-hydroxyphenyl)-propionitrile (DPN) or the nonselective ER agonist 17beta-estradiol. Indirect effects on contractility to U46619 and relaxation to bradykinin were assessed and effects on NO, nitrite, and O(2)(-) formation were measured in cultured cells. Within 5 minutes, selective ERalpha activation by PPT, but not 17beta-estradiol or the ERbeta agonist DPN, caused rapid, NO-dependent, and endothelium-dependent relaxation (49+/-5%; P<0.001 versus ethanol). PPT also caused sustained endothelium- and NO-independent vasodilation similar to 17beta-estradiol after 60 minutes (72+/-3%; P<0.001 versus ethanol). DPN induced endothelium-dependent NO-independent relaxation via endothelium-dependent hyperpolarization (40+/-4%; P<0.01 versus ethanol). 17beta-Estradiol and PPT, but not DPN, attenuated the responses to U46619 and bradykinin. All of the ER agonists increased NO and nitrite formation in vascular endothelial but not smooth muscle cells and attenuated vascular smooth muscle cell O(2)(-) formation (P<0.001). ERalpha activation had the most potent effects on both nitrite formation and inhibiting O(2)(-) (P<0.05). These data demonstrate novel and differential mechanisms by which ERalpha and ERbeta activation control coronary artery vasoreactivity in males and females and regulate vascular NO and O(2)(-) formation. The findings indicate that coronary vascular effects of sex hormones differ with regard to affinity to ERalpha and ERbeta, which will contribute to beneficial and adverse effects of hormone replacement therapy.

Estrogen receptor β expression and androgen receptor phosphorylation correlate with a poor clinical outcome in hormone-naive prostate cancer and are elevated in castration-resistant disease

Patients with advanced prostate cancer (PC) are usually treated with androgen withdrawal. While this therapy is initially effective, nearly all PCs become refractory to it. As hormone receptors play a crucial role in this process, we constructed a tissue microarray consisting of PC samples from 107 hormone-naïve (HN) and 101 castration-resistant (CR) PC patients and analyzed the androgen receptor (AR) gene copy number and the protein expression profiles of AR, Serin210-phosphorylated AR (pAR(210)), estrogen receptor (ER)β, ERα and the proliferation marker Ki67. The amplification of the AR gene was virtually restricted to CR PC and was significantly associated with increased AR protein expression (P<0.0001) and higher tumor cell proliferation (P=0.001). Strong AR expression was observed in a subgroup of HN PC patients with an adverse prognosis. In contrast, the absence of AR expression in CR PC was significantly associated with a poor overall survival. While pAR(210) was predominantly found in CR PC patients (P<0.0001), pAR(210) positivity was observed in a subgroup of HN PC patients with a poor survival (P<0.05). Epithelial ERα expression was restricted to CR PC cells (9%). ERβ protein expression was found in 38% of both HN and CR PCs, but was elevated in matched CR PC specimens. Similar to pAR(210), the presence of ERβ in HN patients was significantly associated with an adverse prognosis (P<0.005). Our results strongly suggest a major role for pAR(210) and ERβ in HN PC. The expression of these markers might be directly involved in CR tumor growth.

Mice deficient in interleukin-4 (IL-4) or IL-4 receptor alpha have higher resistance to sporozoite infection with Plasmodium berghei (ANKA) than do naive wild-type mice

BALB/c interleukin-4 (IL-4(-/-)) or IL-4 receptor-alpha (IL-4ralpha(-/-)) knockout (KO) mice were used to assess the roles of the IL-4 and IL-13 pathways during infections with the blood or liver stages of plasmodium in murine malaria. Intraperitoneal infection with the blood-stage erythrocytes of Plasmodium berghei (ANKA) resulted in 100% mortality within 24 days in BALB/c mice, as well as in the mutant mouse strains. However, when infected intravenously with the sporozoite liver stage, 60 to 80% of IL-4(-/-) and IL-4ralpha(-/-) mice survived, whereas all BALB/c mice succumbed with high parasitemia. Compared to infected BALB/c controls, the surviving KO mice showed increased NK cell numbers and expression of inducible nitric oxide synthase (iNOS) in the liver and were able to eliminate parasites early during infection. In vivo blockade of NO resulted in 100% mortality of sporozoite-infected KO mice. In vivo depletion of NK cells also resulted in 80 to 100% mortality, with a significant reduction in gamma interferon (IFN-gamma) production in the liver. These results suggest that IFN-gamma-producing NK cells are critical in host resistance against the sporozoite liver stage by inducing NO production, an effective killing effector molecule against Plasmodium. The absence of IL-4-mediated functions increases the protective innate immune mechanism identified above, which results in immunity against P. berghei infection in these mice, with no major role for IL-13.