Search

Sea fan, a type of gorgonian coral, originating from Maluku, Indonesia, which local people have used as medicinal ingredients for generations. Gorgonian has anti-inflammatory, anti-cancer, analgesic, gastroprotective, anti-viral, anti-bacterial, and anti-fouling activities with secondary metabolites steroid found in abundance. Steroid significantly inhibits the estrogen receptor that triggers breast cancer. However, the activity of these metabolites on sea fan has not been studied. Determination of specific receptor with Swiss Target Prediction, then the interaction ability of steroid of sea fan from binding pocket using LigandScout 4.3, while ligand-protein interaction with Autodock Tools 1.5.6. Based on the target prediction results, the steroid of sea fan significantly acts on the target class of estrogen receptor alpha (ER-α). Pharmacophores identification shows that steroid components can act as lead compounds to ER-α based on the pharmacophore fit scores are dinosterol; 4,24-dimethyl cholestanol; 4,24-dimethyl 22-dehydro cholestanol; 4-methyl 24-methylene cholestanol; and 4,24-dimethyl cholesta 7,22-dien-3ß-ol. The results of molecular docking showed only 4,24-dimethyl 22-dehydro cholestanol; 4,24-dimethyl cholesta 7,22-dien-3ß-ol; and 4,24-dimethyl cholestanol, which has the best binding affinity compared to tamoxifen as the reference ligand (drug). So, it can be concluded that steroids from the sea fan have the potential to inhibit ER-α. [ABSTRACT FROM AUTHOR]

The most common form of cancer among women is metastatic breast cancer. One of the world's three most common cancers, it is the second leading cause of death in the United States, following lung cancer. A plethora of drugs are available for breast cancer treatment. One of the promising new candidates for this type of tumor is Kisquali (Ribociclib), a selective cyclin-dependent kinase (CDK) 4 and 6 inhibitor. Ribociclib was recently developed by Novartis and approved by the USFDA under the trade name of "Kisquali" for the treatment of advanced receptor hormone positive (HR+), an inhibitor of human epidermal growth factor 2-negative cancer (HER2-). It functions by phosphorylation inhibition and can decrease the count of CDK4/6. In addition, Ribociclib also shows different interactions since the metabolism of the drug can be changed by enzyme inducers and inhibitors. Ribociclib was tested for multiple solid tumors and lymphomas in Phase I and II trials and further underwent Phase III studies in breast cancer. Results from Phase I and II trials on positive estrogen receptor (ER1) breast cancer indicate promising efficacy with controlled toxic effects, primarily neutropenia. All the successful approaches of this promising candidate are underlined in this study. [ABSTRACT FROM AUTHOR]

Soy milk contains high isoflavones that have biological activity similar to estrogen, capable of binding to a estrogen receptors, and is often referred to as phytoestrogens which can disrupt endocrine. ER is found in several mammalian tissues, including the reproductive tract. This study aims to analyze the effect of soy milk on ERa expression in MPOA and in spermatogonia cells, testosterone levels, and AR expression in testes. Twenty-four male Wistar rats (Rattus norvegicus) were divided into four groups: control group (given normal diet) and P1; P2; P3 (given the normal diet and soy milk powder at doses of 7.1; 14.2; 21.3 g/KgBW/day, respectively, for 6 weeks). IHC method was used to analyze the expression of ERa in MPOA and spermatogonia cells, and AR in testes. Testosterone levels were measured by ELISA. The results showed that the expression of ERa in MPOA and spermatogonia cells, AR expression in the testes, and testosterone levels were lower in treatment groups than in the control group. Soy milk exposure in male rats can affect the regulation of receptor expression and estrogen levels in the male reproductive system which may be related to endocrine disruptor processes and infertility. [ABSTRACT FROM AUTHOR]

The study aims to develop machine-learning models to predict cardiac adverse events in female breast cancer patients who receive adjuvant therapy. We selected breast cancer patients from a retrospective dataset of the Taipei Medical University Clinical Research Database and Taiwan Cancer Registry between January 2004 and December 2020. Patients were monitored at the date of prescribed chemo- and/or -target therapies until cardiac adverse events occurred during a year. Variables were used, including demographics, comorbidities, medications, and lab values. Logistics regression (LR) and artificial neural network (ANN) were used. The performance of the algorithms was measured by the area under the receiver operating characteristic curve (AUC). In total, 1321 patients (an equal 15039 visits) were included. The best performance of the artificial neural network (ANN) model was achieved with the AUC, precision, recall, and F1-score of 0.89, 0.14, 0.82, and 0.2, respectively. The most important features were a pre-existing cardiac disease, tumor size, estrogen receptor (ER), human epidermal growth factor receptor 2 (HER2), cancer stage, and age at index date. Further research is necessary to determine the feasibility of applying the algorithm in the clinical setting and explore whether this tool could improve care and outcomes. [ABSTRACT FROM AUTHOR]

The leaves of black adulsa [Graptophyllum pictum (L.) Griff.] contained flavonoid that could bind to estrogen receptor and induced fat catabolism in ovariectomy condition with no estrogen production from ovary. Fat accumulation in ovariectomy condition could induce hyperglycemia. This research was aimed to determine the effect of black adulsa leaves ethanol extract on glucose tolerance and pancreatic islets of langerhans in ovariectomized mice. This research used 30 female mice divided into six groups, namely, the normal control group (non-ovariectomy, C1, 0.2 ml distilled water), the ovariectomized control group (C2, 0.2ml distilled water), the hormonal control groups (C3, 0,2 ml esthero solution in 0,08 mg/kg) and the treatment groups with the black adulsa leaves ethanol extract T1, T2 and T3 (10 mg/kg, 20 mg/kg and 30 mg/kg) respectively. After the end of the research all mice were tested for glucose tolerance, sacrificed and the pancreas organ was cut off to make pancreas slide with paraffin method and Hematoxyllin-Eosin staining. The glucose tolerance was calculated by AUC value. The result of this research showed that the black adulsa leaves ethanol extract decreased glucose tolerance and increase the diameter of pancreatic islet of Langerhans, the optimal dose was 20 mg/kg for mouse. [ABSTRACT FROM AUTHOR]

By employing crude peroxidases extracted from sawi hijau (Brassica juncea) as biocatalyst, licarin A was synthesized from isoeugenol. The structure was elucidated and confirmed by mass spectrometer (MS) and nuclear magnetic resonance (NMR) analysis. This compound displayed moderate cytotoxicity effect on MCF-7 breast cancer cell with IC50 = 59.95±1.87 µg/mL, compared to doxorubicin with IC50 value of 0.88±0.34 µg/mL as the positive control. These results are indirectly in line with our previously published in silico tests which indicated that licarin A was not a potent ligand for estrogen receptor alpha (ERα), but either a non-ligand or a moderate ligand for ERα. [ABSTRACT FROM AUTHOR]

Pyrazole is a heterocyclic azo-derived compound with various biological activities, such as anticancer, antimicrobial, antioxidant, and anti-inflammation. This research aims to synthesize a fluorophenyl-containing pyrazole derivative, verify its toxicity value and predict its anti-breast cancer activity. The compound 5-(2-fluorophenyl)-3- (naphthalene-1-yl)-1-phenyl-1H-pyrazole was with success synthesized in two steps. Initially, the pyrazoline was synthesized by a one-pot cyclized reaction and assisted by microwave irradiation. Then, pyrazole was synthesized via oxidative aromatization reaction of pyrazoline with glacial acetic acid under conventional heating. The activity was evaluated by molecular docking simulation of the synthesized compound against Estrogen Receptor α (PDB ID: 3ERT) using AutoDock 4.2.6.ERα is a receptor protein bound to the native ligand 4-OHT used as a breast cancer receptor. The structure of synthesized pyrazole derivative was predicted by ultraviolet (UV), Fourier Transform Infrared (FTIR), Gas Chromatography Mass Spectroscopy (GC-MS), 1D and 2D nuclear magnetic resonance (NMR) spectroscopy data analysis. Furthermore, the toxicity was evaluated by the Brine Shrimp Lethality Test (BSLT) for pre-screening of anticancer drugs analysis, showing that the compound was toxic with LC50 values of 49.07 µg/mL. The result of the molecular docking study, a replacement fluorinated pyrazole compound showed potential inhibition against ERα with binding affinity and Ki worth of -10.77 kcal/mol and 12.69 nM, respectively. Thus, the fluorinated pyrazole compound is a promising candidate as an anti-breast cancer agent through antagonist activity on ERα. [ABSTRACT FROM AUTHOR]

Astrocytes are electrically non excitable cells but calcium signaling is widely considered a form of their excitability. Astroglial calcium signaling can be regulated by multiple pathway and the L-type Cav1.2 calcium channel is one of the most important mediator of calcium influx into astrocytes in central nervous system (CNS). A recent study demonstrated that 17β-Estradiol (E2) upregulated Cav1.2 protein mainly through estrogen receptor α (ERα) in rat-cultured cortical astrocytes. Given the larger and more complex architecture of human astrocytes than murine, here, we assessed the E2-mediated effect of Cav1.2 protein in human astrocytoma cell line U87-MG to examine whether there is species difference between rat and human by using Western blots. We found that in cultured U87 cells, E2 increased Cav1.2 protein though ERα like in primary cultures of rat cortical astrocytes. This provides further evidence about the effect of E2 on Cav1.2 protein in astrocytes. [ABSTRACT FROM AUTHOR]

Estrogen receptor alpha (ERα) is a common target for breast cancer treatment and is mainly involved in cell proliferation. Breadfruit (Artocarpus altilis) is a well-known traditional herb that has anticancer potential, specifically for inhibiting breast cancer proliferation. This study sought to identify the active compound from breadfruit as a candidate ERα inhibitor. This study used flavonoid compounds as anticancer candidates. Eleven flavonoids compounds were considered, including: cycloaltilisin 7, isocyclomorusin, cyclomorusin, cycloaltilisin, cyclomulberrin, isocyclomulberrin, quercetin, cyclocommunal, artocarpin, artonin E, and morusin. Research was conducted using the exploratory descriptive method. The first step was ligand and receptor preparation before the docking process using VegaZZ. The molecular docking process was calculated using AutoDock Vina in PyRx v.0.8. The docking site was predicted in the inhibitory site of ERα based on the control drug (tamoxifen). Screening for the best docking complex was considered according to highest binding affinity and accurate binding site. The selected compounds were predicted for pharmacokinetics to evaluate the possibility of absorption in the human intestinal tract. The potential of the active drug to pass the membrane was assessed based on the Lipinski rule of five. Finally, the biological process of the best compound was identified using PASS SERVER to explain the accuracy before conducting the experiment in the laboratory. The results suggest that isocyclomorusin had the lowest binding affinity (8.4 kcal/mol) and this compound could act as an anti-neoplastic (Pa > 0.7) towards breast cancer. Isocyclomorusin could be easily absorbed in the human intestine due to an HIA+ score above 0.9 and could pass the bilayer membrane in breast cancer cells because it meets the Lipinski rule of five standard. Based on the results of this study, it appears that isocyclomorusin is a potential candidate for anti- breast cancer treatment derived from Artocarpus altilis that could act as an ERα inhibitor. [ABSTRACT FROM AUTHOR]

A crosstalk between the estrogen receptor alpha (ERα) and tyrosine kinase receptors contribute to endocrine resistance. We investigated the effect of the four Smad-independent TGF-β signaling components and the distribution pattern of ERα expression on the response to adjuvant tamoxifen treatment in 122 estrogen positive breast cancer patients. We identified a low mRNA expression of TGF-βR1 in tamoxifen resistant group patients (TR) in contrast to tamoxifen sensitive group (TS). Similarly, negative TGF-βR1 expression was significantly higher in TR patients than in TS patients. The expression of TGF-βR1 was strongly correlated with the distribution pattern of ERα expression, level of CD44+/CD24-low cells and Akt (pS473) expression. The patients with a low mRNA expression of TGF-βR1 as well as with a negative TGF-βR1 expression had an unfavorable prognosis concerning progression-free survival. The expression of TGF-βR1 and the distribution pattern of ERα expression can be considered as additional molecular predictive markers for estrogen positive breast cancer patients treated with adjuvant tamoxifen. [ABSTRACT FROM AUTHOR]

Bisphenol A (BPA) is an industrial chemical used in the formation of polycarbonate plastics and epoxy resins, which are used in the manufacturing of food packaging and water bottles. BPA has been shown to mimic the hormone estrogen, allowing it to react with estrogen receptors and affect their function. Previous research has shown that exposure to BPA through food and beverage packaging can increase the risk of adverse health effects on the brain, prostate gland, mammary glands, behavior, and reproduction. Thus, BPA was banned from the manufacturing of everyday plastics, but was promptly replaced with BPA derivatives, like BPAF and BPS, which were thought to be more stable than BPA. However, these BPA replacements may have more potent consequences on human health. This research project aims to investigate the reproductive effects of BPA and BPA derivatives on Daphnia pulex. D. pulex are freshwater crustaceans that are used in research for their easy reproducibility and sensitivity to toxins. Previous studies have not examined the reproductive effects of BPA and BPA derivatives in D. pulex. Thus, we will examine the effects of BPA, BPAF, and BPS in varying concentrations on the reproduction rates and age of sexual maturity. Due to the estrogenic effects of BPA and BPA derivatives, we expect that reproduction rates will increase and D. pulex will reach sexual maturity earlier when exposed to BPA and BPA derivatives. The results of our findings could indicate possible impacts on D. pulex populations, freshwater ecosystems, and human health. [ABSTRACT FROM AUTHOR]

An abstract of the article "The effect of estrogen receptor agonists on pancreatic duct ligation induced experimental acute pancreatitis model" by Z. Guleken, D. Ozbeyli, M. Acikel-Elmas and company is presented.

Objective: Although hypertension can be a complication of diabetes mellitus, hypotension and reduced pressor response to vasoconstrictor agents have been observed, especially in type 1 diabetes. The mechanisms by which this reduction occurs remain unclear, but increased expression of iNOS seems to be involved at least in male rats. We previously observed reduced contractile response induced by noradrenaline (NE) in aortas of diabetic female (DF) rats, but the mechanisms were not investigated. It has been observed that estrogen receptor (ER)β activation induces expression of iNOS in vascular smooth muscle of diabetic male rats, but nothing is known in female. The objective of this study was to investigate whether the reduction of vasoconstrictor response in aortas of DF rats is due to increased expression of iNOS/ERβ and the effects of insulin. Methods and Results: Diabetes was induced in female Wistar rats (180-200g) by an injection of alloxan (40 mg/kg) and after 3 and 15 days, treatment with iNOS inhibitor L-NIL (3 mg/kg/day/30 days) and insulin (NPH, 6IU/day/15 days) began, respectively. At the end of the treatment period, we analyzed the iNOS mRNA expression, the ER-α and ER-β protein expression by immunohistochemistry, and concentration-response curves were performed in endothelium-denuded aortic rings to NE and potassium chloride (KCl). The results are expressed as means ± S.E.M., compared by ANOVA followed by Bartlett's test for homogeneity of variances and Tukey-Kramer multiple comparisons test. We observed that the expression of iNOS mRNA is increased in diabetic endothelium-denuded aortas (80%) in comparison to control aortas. Treatment with insulin did not correct it. The maximum contraction to NE (Control (n=6): 3.21 ±0.23 g; DF (n=7): 2.19±0.16 g; p < 0.05) and KCl (Control (n=8): 2.70±0.13 g; DF (n=9): 2.15±0.08 g; p < 0.05) was reduced in diabetic endothelium-denuded aortic rings. After treatment with L-NIL and insulin only the reduced maximum contraction to NE (L-NIL (n=6): 3.03±0.23 g; insulin (n=6): 3.12±0.16 g) was corrected. We found that ER-α immunostaining was similar among the groups. On the other hand, the ER-β immunostaining was increased in aorta of DF rats. Treatment with insulin, but not with L-NIL, corrected the increased ER-β immunostaining. Conclusion: Our data suggest that the increased iNOS and/or ER-p expression are involved in the reduced NE-induced contraction in DF rats, by interfering with the adrenergic receptor pathway, and not by reducing the ability of the smooth muscle to contract. The effects of the insulin treatment are selective on the adrenergic receptor pathway and may be dependent on ER-β, but not on iNOS, reduction. [ABSTRACT FROM AUTHOR]

Oestrogen is a known to act centrally as a modulator of autonomic function. Our previous study showed changes in oestrogen receptor (ER) subtype expression in the nucleus of the solitary tract (NTS), an area of the brainstem regulating autonomic reflexes, are associated with fluctuating plasma oestrogen levels during the oestrous cycle and after ovariectomy (OVX)¹. GABA transmission in the NTS is critical for baroreflex control of blood pressure (BP) and as the promoter sequences for several receptors, receptor associated proteins, enzymes and transporters involved in GABA transmission include potential oestrogen response element consensus sites we analysed mRNA expression levels for these markers in the NTS of normal cycling and OVX female rats. Female Wistar rats (approx. 150g, n=6) fed a phytoestrogen free diet were subjected to OVX or sham-OVX under anaesthesia (isofluorane, 5% in O2). Radiotelemetry probes (DSI) were implanted to record from the left carotid artery. BP, heart rate and activity levels were recorded for 3 or 6 weeks post surgery, at which point rats were killed under the same anaesthetic conditions. Micropunches of NTS tissue were taken for reverse transcription of mRNA and analysis by real-time PCR. Percentage body weight gain after 6 weeks in OVX rats (45.48 ± 1.1%; mean ± SE) was significantly greater than in sham-OVX rats (28.68 ± 1.7%, p=0.01), although food intake between the two groups was consistent (approx 110-115g/animal/week). After 3 weeks increases in systolic (+3.4%) and mean (+5.3%) BP were evident in OVX rats compared to starting values. These increases continued to 6 weeks, becoming significantly different (+10.3%, p=0.05; +12.55%, p=0.05). No significant changes in BP were observed in control rats over 3 or 6 weeks. Realtime PCR for the GABA-A subunit mRNAs revealed significantly decreased expression for 4 of the 14 tested (alpha1; alpha 5; gamma3, delta) in OVX rats at both 3 and 6 weeks. Additionally, at 3 weeks a reduction in beta1 was seen, with a reduction in beta3 at 6 weeks. In contrast, mRNA for the epsilon subunit appeared up-regulated. Expression levels for the GABA-B receptor subtypes BR1 and BR2 showed significant reductions (p<0.05) in OVX after 6 weeks, as was the case for the GABA transporter GAT1 and the GABA receptor-associated protein GABARAP. In contrast the GABA synthesising enzyme GAD67 and the GABA receptor-associated protein like 1 GABARAPL1 were increased (p<0.05) in OVX after 3 weeks. The data are consistent with the hypothesis that circulating oestrogen acts on ERs in the NTS to modulate inhibitory GABAergic influences on autonomic reflexes controlling BP through affecting both GABA synthesis/release mechanisms and GABA receptor composition. [ABSTRACT FROM AUTHOR]

Estrogen deficiency associated endothelial dysfunction contributes for the increased cardiovascular incidence in postmenopausal women. Because of the many complications presented by estrogen therapy, alternative therapies have emerged. The SERMs are a class of synthetic compounds that act as antagonists or agonists of the estrogen receptors. Tamoxifen (TAM) is the most widely used anti-estrogen for the management of breast cancer. Raloxifene (RAL) is used for the treatment and prevention of post-menopausal osteoporosis. This study evaluated the influence of RAL, TAM and 17-β estradiol (E) treatment on mesenteric bed (MB) vascular reactivity in rats with E deficiency. The investigation was conducted in accordance with the biomedical research guidelines for the care and use of laboratory animals, and it were approved by Ethics Committee (no012/2008). All the surgical experiments were carried out under anesthesia (Ketamine70mg/kg+xylazine10mg/kg,i.p). Female rats were studied (n=6/group): control (SHAM); ovariectomized (OVX), OVX treated with E (0.5µg/Kg/day), RAL (2mg/Kg/day) or TAM (1mg/Kg/day), 21 days after bilateral ovariectomy. On day 35, the MB was isolated, perfused and constricted with noradrenaline. Dose response curves of ACh were obtained in absence or presence of L-NAME (NOS inhibitor) or aminoguanidine (AG iNOS inhibitor). Inducible NOS (iNOS), endothelial NOS (eNOS) and NADP(H) oxidase protein expression by western blot were analyzed. The data are reported as means±SEM, compared by ANOVA. The vasodilatation obtained in the OVX was lower compared to the SHAM Emax81±3 vs 60±3 %relaxation P<0.05. In the presence of L-NAME EmaxSHAM 31±3; OVX 21±2; E 34±9; RAL 16±2; TAM 19±4 %relaxation, decreased in all groups. In the presence of AG EmaxSHAM 76±3 vs OVX 36±3 %relaxation P<0.05; the concentration-response curve for Ach was reduced further in the OVX group and the other groups did not change when compared with non-blocking EmaxE 79±4; RAL 80±8; TAM 63±3. The levels of iNOS and NADP(H) oxidase (NOX2) protein expression in MB were elevated in OVX iNOS: SHAM 0.84±0.05; OVX 0.99±0.04 P<0.05 and NOX2: SHAM 0.76±0.10; OVX 1.12±0.13 P<0.05, while levels of eNOS were reduced in OVX when compared to SHAM eNOS: SHAM 1.07±0.10; OVX 0.71±0.10 P<0.01. All treatments were able to restore the protein expression values to those similar to control group iNOS: E 0.81±0.05; RAL 0.65±0.07; TAM 0.69±0.06; eNOS E 1.13±0.08; RAL 0.91±0.02; TAM 0.99±0.08 and NOX2 E 0.80±0.07; RAL 0.58±0.04; TAM 0.68±0.02. The treatments were able to normalize the impaired vasorelaxation of estrogen-deficient rats, indicating that despite the estrogen and SERMs present structural differences in treatment efficacy was similar to reduce a possible inflammatory and improve vascular reactivity in rats with endothelial dysfunction. [ABSTRACT FROM AUTHOR]

The estrogen receptor beta (ERbeta) is emerging as an important regulator of pancreatic beta cell function (Soriano et al, 2009). Here we have evaluated the role of the ERbeta selective agonist, WAY200070, as an insulinotropic molecule and its antidiabetic actions in CB57 mice. We have demonstrated that it enhances glucose-stimulated insulin secretion (GSIS) both in mouse and human islets of Langerhans. In vivo experiments showed that a single-administration of WAY 200070 leads to an increase in plasma insulin levels with a concomitant improved response to a glucose load. Two-week treatment increased GSIS, pancreatic beta-cell mass and improved glucose and insulin sensitivity. In addition, streptozotocin-nicotinamide-induced diabetic mice treated with WAY200070 exhibited a significant improvement in plasma insulin levels and glucose tolerance as well as a regeneration of pancreatic beta-cell mass. Studies performed in db/db mice demonstrated that this compound restored first-phase insulin secretion, enhanced pancreatic beta-cell mass and favored the control of body weight. We conclude that ERbeta agonists should be considered as new targets for the treatment of diabetes (Alonso-Magdalena et al, 2013). [ABSTRACT FROM AUTHOR]

Estrogens importantly contribute to physiological homeostasis and exert their effects through genomic and non-genomic ("rapid") actions [1, 2]. Rapid signaling of estrogen, which has been first reported in the 1960s [3-5] involves membrane estrogen receptors (ERs), including membrane subpopulations of ERalpha and ERbeta. In the early 1990s, rapid increases in cyclic AMP in response to estrogen were reported in human coronary arteries as well as in mammary and uterine cells [6, 7]. Shortly thereafter, several laboratories independently reported the cloning of an orphan G protein-coupled receptor from vascular and cancer cells that was named GPR30 [8-11]. Research published between 2000 and 2005 provided evidence that GPR30 binds and signals via estrogen indicating that this intracellular receptor is involved in rapid, non-genomic estrogen signaling [12-14]. The receptor has since been designated as the G protein-coupled estrogen receptor (GPER) by the International Union of Pharmacology [15]. The availability of genetic tools such as different lines of GPER knock-out mice, as well as GPER-selective agonists and antagonists has advanced our understanding, but also added some confusion about the new functions of this receptor (reviewed in [16]). Research of the past decade has provided evidence that GPER is critically involved in the regulation of vascular tone and blood pressure, metablic control [17], inflammation, and reproductive biology, among others. It is important to note that GPER not only binds estrogens but also other substances, including SERMs, SERDs, and environmental ER activators (endocrine disruptors; xenoestrogens) and also interacts with other proteins [18]. The current knowledge and unresolved questions about GPER-dependent signaling and function in health an disease will be discussed, as well as controversies that have complicated our understanding of GPER function, including interactions with human ERa-36 and aldosterone as a potential ligand [18]. [ABSTRACT FROM AUTHOR]

Estrogen receptors exist in many cellular pools throughout most organs. This is true for the alpha and beta isoforms that are responsible for the actions of the sex steroid on normal organ development and function, and both opposing and promoting organ pathophysiology. Although many additional proteins have been speculated to act as estrogen receptors, scant evidence supports this role. In contrast, classical ERα and ERβ are found in multiple cellular pools, and only the complete knockout of these receptors produces a profound series of phenotypes that define the important functions of these sex steroid receptors. However, total deletion of the classical receptors does not inform us of the contributions of each cellular pool. We therefore have made transgenic mice, representing the selective loss of the nuclear receptor pool (membrane-only ERalpha (MORE) mice) or loss of the membrane pool (nuclearonly, NOER) mice. Using these mice, we have defined unique phenotypes, novel gene regulatory mechanisms, and metabolic signatures. For most complex organ development and biological functions, both membrane and nuclear ERα are generally required but in specific ways. [ABSTRACT FROM AUTHOR]