Does local vaginal estrogen after tension-free transobturator vaginal tape reduce overactive bladder symptoms in postmenopausal women? A prospective randomized, controlled study

Objective:We aimed to evaluate the efficacy of topical estrogen after transvaginal tension-free vaginal tape-obturator(TVT-O)in the treatment of de novo overactive bladder symptoms that appear after surgery.Methods:This is a prospective randomized controlled study performed in the Urology and Gynecology Departments,Kasr Al Ainy Hospital,Cairo University,Cairo,Egypt.Two hundred and ten postmenopausal females presenting during the period between January 2017 and November 2020 with stress urinary incontinence were included in the study.Patients were divided into two groups,105 patients in Group A(treatment group)and 105 patients in Group B(control group).Patients in Group A underwent transvaginal TVT-O followed by local vaginal estrogen treatment for 6 months,while patients in Group B underwent transvaginal TVT-O only.The study included any postmenopausal female with urodynamic stress urinary incontinence.All patients had to fulfill a 3-day bladder diary,overactive bladder symptoms score,urine analysis,urodynamic study,and post-voiding residual urine measurement by abdominal ultrasound preoperatively and at 3-month and 6-month follow-ups.Results:At 6-month follow-up,daytime frequency was reduced to 8%in Group A(increased to 21%in Group B)with a statistically significant difference between both groups(p=0.009).At 6-month follow-up,nocturia was 8%in Group A(11%in Group B)with no statistically significant difference between both groups(p=0.469).There was a statistically significant difference between both groups as regards to urinary urgency at 6-month follow-up(p=0.024).There was a statistically significant difference in postoperative wound healing events as regards to cure,hyperemia,gapping,and wound infection 1 week after intervention between both groups(p=0.008).No local or systemic side-effects were reported from local estrogen use.Conclusion:Local vaginal estrogen treatment given to postmenopausal patients after midurethral sling procedures can reduce the symptoms of daytime frequency and urinary urgency.Long-term follow-up is needed.

Estrogen restores disordered lipid metabolism in visceral fat of prediabetic mice

BACKGROUND Visceral obesity is increasingly prevalent among adolescents and young adults and is commonly recognized as a risk factor for type 2 diabetes.Estrogen[17β-estradiol(E2)]is known to offer protection against obesity via diverse me-chanisms,while its specific effects on visceral adipose tissue(VAT)remain to be fully elucidated.AIM To investigate the impact of E2 on the gene expression profile within VAT of a mouse model of prediabetes.METHODS Metabolic parameters were collected,encompassing body weight,weights of visceral and subcutaneous adipose tissues(VAT and SAT),random blood glucose levels,glucose tolerance,insulin tolerance,and overall body composition.The gene expression profiles of VAT were quantified utilizing the Whole Mouse Genome Oligo Microarray and subsequently analyzed through Agilent Feature Extraction software.Functional and pathway analyses were conducted employing Gene Ontology and Kyoto Encyclopedia of Genes and Genomes analyses,respectively.RESULTS Feeding a high-fat diet(HFD)moderately increased the weights of both VAT and SAT,but this increase was mitigated by the protective effect of endogenous E2.Conversely,ovariectomy(OVX)led to a significant increase in VAT weight and the VAT/SAT weight ratio,and this increase was also reversed with E2 treatment.Notably,OVX diminished the expression of genes involved in lipid metabolism compared to HFD feeding alone,signaling a widespread reduction in lipid metabolic activity,which was completely counteracted by E2 adminis-tration.This study provides a comprehensive insight into E2's local and direct protective effects against visceral adiposity in VAT at the gene level.CONCLUSION In conclusion,the present study demonstrated that the HFD-induced over-nutritional challenge disrupted the gene expression profile of visceral fat,leading to a universally decreased lipid metabolic status in E2 deficient mice.E2 treatment effectively reversed this condition,shedding light on the mechanistic role and therapeutic potential of E2 in combating visceral obesity.

Effect of estrogen pretreatment in GnRH antagonist protocol-Meta-analysis

Objective:To evaluate the effect of estrogen pre-treatment in patients with different ovarian response in antagonist protocol.Methods:Randomized controlled trials(RCTs)and retrospective studies about the effect of estrogen pre-treatment in antagonist prorocol were searched in PubMed,Web of Science,China National Knowledge Infrastructure,Wanfang Database.R software was used for meta-analysis.Results:Seven RCTs and two retrospective studies were included.In order to explore the source of heterogeneity,subgroup analysis was used,which was mainly conducted according to the ovarian response of the included population,which were divided into low responders,non-low responders and mixed responders.In the study about gonadotropin hormone(Gn)days,patients were divided into wash-out subgroup and non-wash-out subgroup according to drug use-pattern.Meta-results showed that the number of Gn days increased significantly in the non-wash-out subgroup(WMD=1.07,95%CI[0.83;1.31],I2=66%).The number of Gn days in the wash-out subgroup were not affected(WMD=-0.12,95%CI[-0.45;0.21],I2=0%).In the low-response subgroup,the number of oocytes retrieved(WMD=0.46,95%CI[-0.23;1.16],I2=81%),the fresh cycle clinical pregnancy rate(RR=0.77,95%CI[0.55;1.06],I2=73%)and the cycle cancellation rate(RR=0.80,95%CI[0.40;1.61],I2=83%)were not significantly changed with estrogen pre-treatment.In the non-low-response subgroup,the number of oocytes obtained(WMD=0.21,95%CI[-0.69;1.11],I2=2%),fresh cycle clinical pregnancy rate(RR=0.94,95%CI[0.77;1.14],I2=41%),live birth rate(RR=0.82,95%CI[0.62;1.08],I2=0%)and cycle cancellation rate(RR=0.89,95%CI[0.54;1.47],I2=2%)were not significantly changed with estrogen pre-treatment.Conclusions:Estrogen pre-treatment(with non-wash-out period)in antagonist protocol increases Gn days,dose not improve IVF outcomes in non-low responders and low responders.

The effect of estrogen-mediated ubiquitin on cardiovascular diseases:a bioinformatics analysis

Objective:Using data mining tools,study the potential pathways of estrogen’s cardiovascular effects.Methods:The GeneExpression Omnibus database was used to download the relevant high-throughput microarray dataset GSE72180,which was then analyzed for differential genes using the GEO2R online analysis tool,gene function and pathway enrichment analysis using DAVID 6.8,protein interaction network analysis using the STRING database,and core network extraction using the MCODE algorithm.Results:A total of 131 differential genes were identified and enriched for gene function and signaling pathway analysis,which indicated that these genes were related with focal adhesion and the HIF-1 signaling pathway.MCODE algorithm analysis extracted 1 core sub-network of these genes to be related to ubiquitin protein transferase activity,protein polyubiquitination,protein ubiquitination involved in ubiquitin-dependent proteolytic metabolic processes,ligase activity,and clustering on ubiquitin-mediated protein hydrolysis signaling pathway.Conclusion:By using data mining tools,it is possible to identify how estrogen may influence the cardiovascular system by controlling the ubiquitination process.This information may be used as a reference for etiology and preventive studies of cardiovascular illnesses.

Protective estrogen-like properties and mechanism of quercetin in rat cerebral cortex neurons

OBJECTIVE To investigate the effect of quercetin on primary cultured newborn rat cortex neuron cell which is estrogen depletion,and discuss the possible mechanism,to provide new ideas and strategies for developing a drug of neurodegenerative disease.METHODS Rat cortex neurons were isolated from one day old Sprague Dawley rats and treated with estrogen,quercetin and estrogen receptor antagonists(ICI182,780).Cell viability was determined by MTT assay,neurite outgrowth was measured by fluorescent microsope and estrogen receptors were determine by Western blot.RESULTS Quercetin functions like estrogen to increase cortex neuronal cell viability,the Que(50,100μmol·L^(-1))group compared with the control group could significantly improve the activity of the cortical neurons(P<0.05).It can also increase neurite out growth,the Que(50,100μmol·L^(-1))group significantly promoted the formation of synapse,most of the neurons were full,and the synapses of neurons became thick,growth,and connect to a dense neural network.And in the Western blot experiments,Que(50,100μmol·L^(-1))group could obviously increase the expression of estrogen receptor alpha protein,in addition,the neural protective effect of quercetin can be inhibited by ICI182,780.CONCLUSION Quercetin like estrogen can protected cortex neuronal and the effect of quercetin on cortex neuronal cells was mediated by estrogen receptor alpha.

New insights into estrogenic regulation of O^6-methylguanine DNA-methyltransferase (MGMT) in human breast cancer cells： Co-degradation of ER-α and MGMT proteins by fulvestrant or O^6-benzylguanine indicates fresh avenues for therapy

Endocrine therapy using estrogen receptor-u （ER-α） antagonists for attenuating horm2one-driven cell proliferation is a major treatment modality for breast cancers. To exploit any DNA repair deficiencies associated with endocrine therapy, we investigated the functional and physical interactions of ER-α with O^6-methylguanine DNA methyltransferase （MGMT）, a unique DNA repair protein that confers tumor resistance to various anticancer alkylating agents. The ER-α -positive breast cancer cell lines （MCF-7, T47D） and ER- negative cell lines （MDAMB- 468, MDAMB-231）, and established inhibitors of ER-α and MGMT, namely, ICI-182,780 （Faslodex） and O^6- benzylguanine, respectively, were used to study MGMT- ER interactions. The MGMT gene promoter was found to harbor one full and two half estrogen-responsive elements （EREs） and two antioxidant-responsive elements （AREs）. MGMT expression was upregulated by estrogen, downregulated by tamoxifen in Western blot and promoter-linked reporter assays. Similarly, both transient and stable transfections of Nrf-2 （nuclear factor-erythroid 2-related factor-2） increased the levels of MGMT protein and activity 3 to 4-fold reflecting novel regulatory nodes for this dragresistance determinant. Of the different ER-α antagonists tested, the pure anti-estrogen fulvestrant was most potent in inhibiting the MGMT activity in a dose, time and ER-α dependent manner, similar to O^6-benzylguanine. Interestingly, fulvestrant exposure led to a degradation of both ER-α and MGMT proteins and O^6-benzylguanine also induced a specific loss of ER-a and MGMT proteins in MCF-7 and T47D breast cancer cells with similar kinetics. Immunoprecipitation revealed a specific association of ER-a and MGMT proteins in breast cancer cells. Furthermore, silencing of MGMT gene expression triggered a decrease in the levels of both MGMT and ER-a proteins. The involvement of proteasome in the drug-induced degradation of both proteins was also demonstrated. Fulvestrant enhanced the cytotoxicity of MGMT-targeted alkylating agents, namely, temozolomide and BCNU by 3 to 4-fold in ER-α positive cells, but not in ER-negative cells. We conclude that MGMT and ER-α proteins exist as a complex and are co-targeted for ubiquitin-conjugation and subsequent proteasomal degradation. The findings offer a clear rationale for combining alkylating agents with endocrine therapy.

phytoestrogens/insoluble fibers and colonic estrogen receptor β: randomized, double-blind, placebo-controlled study

AIM:To assess the safety and effect of the supplementation of a patented blend of dietary phytoestrogens and insoluble fibers on estrogen receptor (ER)-β and biological parameters in sporadic colonic adenomas. METHODS:A randomized, double-blind placebo-controlled trial was performed. Patients scheduled to undergo surveillance colonoscopy for previous sporadic colonic adenomas were identified, and 60 eligible patients were randomized to placebo or active dietary intervention (ADI) twice a day, for 60 d before surveillance colonoscopy. ADI was a mixture of 175 mg milk thistle extract, 20 mg secoisolariciresinol and 750 mg oat fiber extract. ER-β and ER-α expression, apoptosis and proliferation (Ki-67 LI) were assessed in colon samples. RESULTS:No adverse event related to ADI was recorded. ADI administration showed a significant increases in ER-β protein (0.822 ± 0.08 vs 0.768 ± 0.10, P = 0.04) and a general trend to an increase in ER-β LI (39.222 ± 2.69vs 37.708 ± 5.31,P = 0.06), ER-β/ER-α LI ratio (6.564 ± 10.04 vs 2.437 ± 1.53, P = 0.06), terminal deoxynucleotidyl transferase-mediated dUTP nick end labeling (35.592 ± 14.97 vs 31.541 ± 11.54, P = 0.07) and Ki-67 (53.923 ± 20.91 vs 44.833 ± 10.38, P = 0.07) approximating statistical significance. A significant increase of ER-β protein (0.805 ± 0.13 vs 0.773 ± 0.13,P = 0.04), mRNA (2.278 ± 1.19vs 1.105 ± 1.07, P < 0.02) and LI (47.533 ± 15.47 vs 34.875 ± 16.67,P < 0.05) and a decrease of ER-α protein (0.423 ± 0.06vs 0.532 ± 0.11,P < 0.02) as well as a trend to increase of ER-β/ER-α protein in ADI vs placebo group were observed in patients without polyps (1.734 ± 0.20 vs 1.571 ± 0.42, P = 0.07). CONCLUSION:The role of ER-β on the control of apoptosis, and its amenability to dietary intervention, are supported in our study.

The Relationship of the Expression of Estrogen Receptor in Cartilage Cell and Osteoarthritis Induced by Bilateral Ovariectomy in Guinea Pig

To investigate the estrogen receptor（ER） expression in cartilage cell in the development of oste0arthritis induced by bilateral ovariectomy in guinea pig and to find their relationship. 30 two-month-old female guinea pigs were randomly divided into two groups （n=15 each） ： sham operation （control）group and ovariectomized group （OVX）; Scanning electorne microscope （SEM） and transmission electron microscope （TEM） were obtained to analysis the cartilage degeneration of the hind limb knee joint after 6 and 12 weeks of ovariectomy. Dextran-Coated-Charcoal （DCC） was taken to quantitively detect the expression of ER. The serum levels of estrogen and gestone were detected by immune contest assay. The results showed that ER do exist in the cartilages of the guinea pigs, with higher expression in the control group than in OVX group at the same time point （P〈0. 05）. It was increased also at 12 th week after operation than that of preoperation. The blood serum levels of estrogen and gestone showed a similar tendency to the expression of ER. Joint cartilage degeneration detected by SEM and TEM could be found at 6 th week, but severe degenerative lesions at 12 th week in the OVX group compared with the control group （P〈0.01）. The data suggested that bilateral ovariectomy in guinea pig lead to severe os.teoarthritis which mighgt be related to the lower serum level of estrogen and the downregulation of the expression of ER in the cartilage also.

Combined treatment with valproic acid and estrogen has neuroprotective effects in ovariectomized mice with Alzheimer’s disease

Postmenopausal women with Alzheimer’s disease exhibit dramatically reduced sensitivity to estrogen replacement therapy,which is though to be related to an estrogen receptor(ER)α/ERβratio imbalance arising from a significantly decreased level of ERs of the brain.The aim of our study was to investigate whether valproic acid(VPA)can enhance the beneficial effects of estrogen on cognitive function through restoration of ERαand ERβexpression in the brain.We removed the ovaries of female APP/PS1 mice to simulate the low estrogen levels present in postmenopausal women and then administered VPA(30 mg/kg,intraperitoneal injection,once daily),17β-estradiol(E2)(2.4μg,intraperitoneal injection,once daily),liquiritigenin(LG)(50μg/kg,intragastric infusion,once daily),VPA+E2,or VPA+LG for 4 successive weeks.Compared with treatment with a single drug,treatment with VPA+E2 or VPA+LG significantly increased the level of glycogen synthase kinase 3β,increased the expression of estrogen receptorα,reduced the expression of small ubiquitin-like modifiers,and increased the level of estrogen receptorβ.This resulted in enhanced sensitivity to estrogen therapy,reduced amyloidβaggregation,reduced abnormal phosphorylation of the tau protein,reduced neuronal loss,increased dendritic spine and postsynaptic density,and significantly alleviated memory loss and learning impairment in Alzheimer’s disease.This study was approved by the Chongqing Medical University Animal Protection and Ethics Committee,China on March 6,2013.

Xenoestrogens challenge 17β-estradiol protective effects in colon cancer

Several epidemiological,cellular,and molecular studies demonstrate the role of environmental chemicals with endocrine disrupting activities,typical of Westernized societies,in the pathogenesis of numerous diseases including cancer.Nonetheless this information,the design and execution of studies on endocrine disruptors are not yet cognizant that the specific actions of individual hormones often change with development and ageing,they may be different in males and females and may be mediated by different receptors isoforms expressed in different tissues or at different life stages.These statements are particularly true when assessing the hazard of endocrine disruptors against 17β-estradiol(E2)actions in that this hormone is crucial determinant of sexrelated differences in anatomical,physiological,and behavioral traits which characterize male and female physiology.Moreover,E2 is also involved in carcinogenesis.The oncogenic effects of E2 have been investigated extensively in breast and ovarian cancers where hormone-receptor modulators are now an integral part of targeted treatment.Little is known about the E2preventive signalling in colorectal cancer,although this disease is more common in men than women,the difference being more striking amongst pre-menopausal women and age-matched men.This review aims to dissect the role and action mechanisms of E2 in colorectal cancer evaluating the ability of estrogen disruptors(i.e.,xenoestrogens)in impair these E2 actions.Data discussed here lead to define the possible role of xenoestrogens in the impairment and/or activation of E2signals important for colorectal cancer prevention.

Effects of estrogen receptor modulators on cytoskeletal proteins in the central nervous system

Estrogen receptor modulators are compounds of interest because of their estrogenic agonistic/antagonistic effects and tissue specificity. These compounds have many clinical applications, particularly for breast cancer treatment and osteoporosis in postmenopausal women, as well as for the treatment of climacteric symptoms. Similar to estrogens, neuroprotective effects of estrogen receptor modulators have been described in different models. However, the mechanisms of action of these compounds in the central nervous system have not been fully described. We conducted a systematic search to investigate the effects of estrogen receptor modulators in the central nervous system, focusing on the modulation of cytoskeletal proteins. We found that raloxifene, tamoxifen, and tibolone modulate some cytoskeletal proteins such as tau, microtuble-associated protein 1（MAP1）, MAP2, neurofilament 38（NF38） by different mechanisms of action and at different levels： neuronal microfilaments, intermediate filaments, and microtubule-associated proteins. Finally, we emphasize the importance of the study of these compounds in the treatment of neurodegenerative diseases since they present the benefits of estrogens without their side effects.

Estrogen receptor beta treats Alzheimer's disease

In vitro studies have shown that estrogen receptor β can attenuate the cytotoxic effect of amyloid protein on PC12 cells through the Akt pathway without estrogen stimulation. In this study, we aimed to observe the effect of estrogen receptor β in Alzheimer＇s disease rat models established by intraventricular injection of amyloid β protein. Estrogen receptor β lentiviral particles delivered via intraventricular injection increased Akt content in the hippocampus, decreased interleukin-1β mRNA tumor necrosis factor a mRNA and amyloid β protein levels in the hippocampus, and improved the learning and memory capacities in AIzheimer＇s disease rats. Estrogen receptor β short hairpin RNA lentiviral particles delivered via intraventricular injection had none of the above impacts on AIzheimer＇s disease rats. These experimental findings indicate that estrogen receptor β, independent from estrogen, can reduce inflammatory reactions and amyloid β deposition in the hJppocampus of AIzheimer＇s disease rats, and improve learning and memory capacities. This effect may be mediated through activation of the Akt pathway.

Effect of Compound Recipe Gengniankang (更年康) on Senile Sexual Hormone and Expression of Estrogen Receptor in Bone of Climacteric Female Rats

Objective： To compare the therapeutic effect of Compound Recipe Gengniankang （更年康, GNK） with that of hormone replacement treatment （HRT） on climacteric female rats with osteoporosis, and to investigate the roles of estrogen and estrogen receptors in the mechanism of osteoporosis. Methods： Climacteric female rats with osteoporosis were chosen and divided into three groups （GNK group, HRT group and control group）. Apoptosis of ovarian granulose cells was measured by terminal-deoxynucleotidyl transferae mediated nick end labeling （TUNEL） assay. Serum level of estrdiol （E2）, follicle stimulating hormone （FSH）, luteinizing hormone （LH） were determined by the method of radioimmunoassay （RIA）. Reverse transcriptase polymerase chain reaction （RT-PCT） technology was used to evaluate the expression of estrogen receptor （ER） in bone. Bone mineral density （BMD） was measured by double energy X-ray absorption （DEXA）. Results： In the climacteric rats, BMD, serum E2, ER mRNA expression in bone decreased remarkably, and serum FSH, LH and apoptosis of ovarian granulose cells increased obviously. After treating with GNK, all the indexes were reversed except serum E2. The increase of E2 was not significant. Conclusion： GNK is effective on climacteric osteoporosis female rats. Its role is performed not by increasing serum E2 but by enhancing ER in the bone and inhibiting apoptosis of ovarian granulose cells. GNK can deter further exhaustion of ovarian function.

Estrogens and the regulation of glucose metabolism

The main estrogens:estradiol,estrone,and their acyl-esters have been studied essentially related to their classical estrogenic and pharmacologic functions.However,their main effect in the body is probably the sustained control of core energy metabolism.Estrogen nuclear and membrane receptors show an extraordinary flexibility in the modulation of metabolic responses,and largely explain gender and age differences in energy metabolism:part of these mechanisms is already sufficiently known to justify both.With regard to energy,the estrogen molecular species act essentially through four key functions:(1)Facilitation of insulin secretion and control of glucose availability;(2)Modulation of energy partition,favoring the use of lipid as the main energy substrate when more available than carbohydrates;(3)Functional protection through antioxidant mechanisms;and(4)Central effects(largely through neural modulation)on whole body energy management.Analyzing the different actions of estrone,estradiol and their acyl esters,a tentative classification based on structure/effects has been postulated.Either separately or as a group,estrogens provide a comprehensive explanation that not all their quite diverse actions are related solely to specific molecules.As a group,they constitute a powerful synergic action complex.In consequence,estrogens may be considered wardens of energy homeostasis.

Overexpression of estrogen receptor beta alleviates the toxic effects of beta-amyloid protein on PC12 cells via non-hormonal ligands

After binding to the estrogen receptor, estrogen can alleviate the toxic effects of beta-amyloid protein, and thereby exert a therapeutic effect on Alzheimer＇s disease patients. Estrogen can increase the incidence of breast carcinoma and endometrial cancer in post-menopausal women, so it is not suitable for clinical treatment of Alzheimer＇s disease. There is recent evidence that the estrogen receptor can exert its neuroprotective effects without estrogen dependence. Real-time quantitative PCR and flow cytometry results showed that, compared with non-transfected PC12 cells, adenovirus-mediated estrogen receptor β gene-transfected PC12 cells exhibited lower expression of tumor necrosis factor a and interleukin 1β under stimulation with beta-amyloid protein and stronger protection from apoptosis. The Akt-specific inhibitor Abi-2 decreased the anti-inflammatory and anti-apoptotic effects of estrogen receptor β gene-transfection. These findings suggest that overexpression of estrogen receptor β can alleviate the toxic effect of beta-amyloid protein on PC12 cells, without estrogen dependence. The Akt pathway is one of the potential means for the anti-inflammatory and anti-apoptotic effects of the estrogen receptor.

Expressions of estrogen receptor subtypes and c-met proto-oncogene in endometrial carcinoma and their correlation

Objective To investigate the expressions of estrogen receptor(ER)subtypes and c-met proto-oncogene in human endometrial carcinomas and to assess the clinical significance of ER and c-met in this carcinoma.Methods Reverse transcription PCR(RT-PCR)was used to detect the expressions of ERα,ERβ and c-met proto-oncogene mRNA in 30 samples of endometrial carcinoma and 11 samples of normal endometrium.Results The expression of ERα in endometrial carcinoma(0.70±0.40)was significantly reduced in comparison to that in normal endometrium(1.14±0.56,P<0.05).A similar finding was made for the expression of ERβ in carcinoma(0.24±0.18)versus normal tissues(0.48±0.20,P<0.05).In contrast,c-met mRNA expression was increased in endometrial carcinoma(1.45±0.72)compared to that in normal endometrium(0.42±0.31,P<0.01).A decrease tendency of the expression of ERα was also found from Stage Ⅰ(0.82±0.41)to a more severe Stag Ⅱ-Ⅲ of endometrial carcinoma(0.42±0.17,P<0.05).The analysis of ERα and ERβ mRNA revealed a decrease tendency from shallow to deep invasion of the uterine muscles(P<0.05).We found that the expressions of ERα and ERβ were negatively correlated with c-met proto-oncogene with a coefficient correlation of-0.63(P<0.01)and-0.32(P<0.05),respectively.Conclusion ERα and ERβ are both involved in mutagenic action of carcinogen.C-met proto-oncogene plays an important role in the carcinogenesis and development of endometrial carcinoma.C-met and ER expressions show a negative correlation in the development of endometrial carcinoma.

Molecular Mediators of Estrogen Reduction-induced Otolith Shedding

Objective Previous study suggested that estradiol(E2)plays an important role in otolith shedding by regulating the expression of otoconin 90(OC90).The purpose of this article is to provide further data on the effect and mechanism of E2 on the morphology of otolith.Methods The rats receiving bilateral ovariectomy(OVX)were used as animal models.Co-immunoprecipitation was used to observe the relationship between estrogen receptor(ER)and estrogen-related receptorα(ERRα).The morphology of otolith was observed under the scanning electron microscopy.Western blotting and qPCR were used for quantitative analysis of the roles of ER and ERRαin regulating OC90 expression.Results The looser otoliths were observed in rats receiving bilateral OVX,which could be reversed by supplementation with E2.The level of ERRαwas decreased in bilateral OVX rats.ER and ERRαinteracted with each other on the regulation of the expression of OC90.Conclusion Our results suggest ER and ERRαare both important downstream receptors involved in regulating OC90 expression in utricles of rats,and ERRαprobably functions by interacting with ER.This provides evidence for the mechanism of otolith shedding.And it may be significant for future studies of targeted prevention and therapies for benign paroxysmal positional vertigo.

Sex differences in estrogen receptor promoter expression in the area postrema

Estrogen receptor a is widely distributed in the rat brain, but the tissue- or target-specificity of the estrogen receptor a gene promoters remains unknown. In the present study, we used transgenic rats expressing enhanced green fluorescent protein under the control of the estrogen receptor a 0/B promoter to examine expression driven by this promoter in two significant nuclei that regulate cardiovascular activity, the area postrema and the nucleus tractus solitarius. Immunohistochemistry showed that enhanced green fluorescent protein-labeled cells were distributed in the area postrema and the nucleus tractus solitarius of both female and male transgenic rats, and a neural network of enhanced green fluorescent protein-positive fibers was seen between the area postrema and the nucleus tractus solitarius. The number of enhanced green fluorescent protein-labeled cells in the area postrema of female rats was significantly higher than in the males, but no significant difference was found in the number of enhanced green fluorescent protein-labeled cells in the nucleus tractus solitarius. The sex differences in the number of enhanced green fluorescent protein-labeled cells in the area postrema was not affected after ovariectomy or 1713-estradiol benzoate treatment in adult rats. Our results suggest that the effects of estrogen in the area postrema are related to the expression of estrogen receptor a under the control of the 0/B promoter, and changes in the sex hormone environment in the adult period do not affect estrogen receptor a expression in the area postrema or the nucleus tractus solitarius.

Isoflavone genistein protects high glucose-induced human aortic endothelial cell apoptosis through estrogen receptor-mediated pathway

Objective The aim of this study was to determine if isoflavone genistien has protective effects against high glucose-induced cell apoptosis in human aortic endlthelial cells, and investigate the possible mechanism for this protection. Methods Human aortic endothelial cells subjected to normal (5mmol/L) or high glucose (25mmol/L) were treated with genistein at 0, 50, 100nmol/L. Parallel experiments were performed with 100nM 17b-estradiol, and also in the presence and absence of the pure anti-estrogen ICI-182,780 (100nmol/L). The effects on cell apoptotic DNA fragmentation were determined using cell death ELISA, and the effects on cellular proliferation were determined using tritiated thymidine incorporation assay. Estrogen receptor expression was detected by Taqman quantitative PCR. Results Genistein at 100nmol/L significantly reduced high glucose-induced DNA fragmentation, and reversed cell DNA synthesis inhibition (P <0.001) after 24 hours' incubation. The effect of genistein was completely blocked by ICI-182,780 administration. Estrogen receptor beta, but not alpha was found to be expressed in these cells. Conclusion Isoflavone genistein shows protection against high glucose-induced cell damage through estrogen receptor beta, reducing apoptotic DNA damage and protecting from the inhibition of cell proliferation.

Combination of low-concentration of novel phytoestrogen(8,9)-furanyl-pterocarpan-3-ol from Pachyrhizus erosus attenuated tamoxifen-associated growth inhibition on breast cancer T47D cells

Objective:To investigate the estrogenic effect of(8,9)-furanyl-pterocarpan-3-ol(FPC)on growth of human breast cancer T47D cells and the interactions between the FPC and tamoxifen(TAM),on the growth of estrogen receptor-dependent breast cancer T47D cells.Methods:The proliferation effect of FPC were conducted on T47D cells in vitro by MTT test.T47D cells were treated with FPC alone(0.01-200μmol/L)or in combination with TAM 20 nmol/L.Furthermore,the expression of ERαor c-Myc were also determined by immunohistochemistry.Results:The results indicated that administration of an anti-estrogen TAM showed growth inhibitory effect on T47D cells,wheraes co-administered with low concentration(less than 1μmol/L)of FPC attenuated to promote cell proliferation.In contrast,the combination of TAM with higher doses(more than 20μmol/L)of FPC showed growth inhibitory.This result was supported by immunocytochemistry studies that the administration of 20 nmol/L TAM down-regulated ER-αand c-Myc,but the combination of 20 nmol/L TAM and 1μmol/L FPC robustly up-regulated expression of ER-α.Thus,the reduced growth inhibition of TAM 20 nmol/L by FPC 1μmol/L on T47D cells may act via the modulation of ER-α.Conclusions:The findings indicate and suggest that FPC had estrogenic activity at low concentrations and anti-estrogenic effect that are likely to be regulated by c-Myc and estrogen receptors.We also confirm that low concentration of FPC attenuated the growth-inhibitory effects of TAM on mammary tumor prevention.Therefore,the present study suggests that caution is warranted regarding the consumption of dietary FPC by breast cancer patients while on TMA therapy.