Effects Of Estrogen Research Articles

Unique cardiometabolic factors in women that contribute to modified cardiovascular disease risk.

Major risk factors of cardiovascular disease (CVD) include hypertension, obesity, diabetes mellitus and metabolic syndrome; all of which are considered inflammatory conditions. Women are disproportionately affected by inflammatory conditions, with sex differences emerging as early as adolescence. Hormonal fluctuations associated with reproductive events such as menarche, pregnancy and menopause, are hypothesized to promote a pro-inflammatory state in women. Moreover, women who have experienced inflammatory-type conditions such as polycystic ovarian syndrome (PCOS), gestational diabetes or pre-eclampsia, have a cardiometabolic phenotype that pre-disposes to increased risk of myocardial infarction, stroke and coronary heart disease. Women with no notable CVD risk factors are often relatively protected from CVD pre-menopause; but overtake men in risk of major cardiovascular events when the cardiovascular protective effects of oestrogen begin to wane. Sex differences and female-specific factors have long been considered challenging to study and this has led to an underrepresentation of females in clinical trials and lack of female-specific data from pre-clinical studies. However, there is now a clear prerogative to include females at all stages of research, despite inherent complexities and potential variability in data. This review explores recent advancements in our understanding of CVD in women. We summarise the underlying factors unique to women that can promote CVD risk factors, ultimately contributing to CVD burden and the emerging therapies aimed to combat this.

Metabolic status is a key factor influencing proteomic changes in ewe granulosa cells induced by chronic BPS exposure.

Bisphenol S (BPS) is the main substitute for bisphenol A (BPA), a well-known plasticiser and endocrine disruptor. BPS disrupts ovarian function in several species. Moreover, a few studies have reported that the effects of BPS might be modulated by the metabolic status, and none have characterised the granulosa cell (GC) proteome after chronic BPS exposure. This study aimed to decipher the mechanisms of action of chronic BPS exposure on the proteome of ewe GCs while considering the interaction between a deliberate contrasted metabolism and reproductive function. Forty ewes were split into two groups with contrasted diets: restricted (R, n = 20) and well-fed (WF, n = 20). The R and WF ewes were subdivided according to the dose of BPS administered through the diet (0-50µg/kg/day), forming four groups: R0, R50, WF0 and WF50. After 3-month BPS daily exposure, GCs were recovered during the pre-ovulatory stage and proteins were analysed by nano-liquid chromatography coupled with tandem mass spectrometry. Chronic exposure to BPS affected the GC proteome differently according to the ewe metabolic status. Fifty-nine out of 958 quantified proteins were differentially abundant between groups and are mainly involved in carbohydrate and lipid pathways. Unsupervised hierarchical clustering of differentially abundant proteins (DAPs) identified four clusters of 34, 6, 5 and 14 proteins according to the BPS exposure and diet interaction. Pairwise comparisons between groups also revealed a strong effect of BPS exposure and diet interaction. Functional analysis of DAPs highlighted that BPS upregulated β-glucuronidase (GUSB; p = 0.002), a protein especially able to deconjugate bisphenol glucuronides (BP-g). Moreover, among unexposed ewes, GUSB was detected only in well-fed ewes. Conjugation of glucuronides inhibits the oestrogenic activity of bisphenols. Upregulation of GUSB in ewes dosed with BPS would prolong the oestrogenic effects of BPS by deconjugating BPS-g into free BPS. In addition, literature has reported an up-regulation of GUSB in people suffering from obesity. Therefore, people suffering from obesity could be subjected to prolonged and aggravated exposure to BPS. These data highlighted the deleterious effects of BPS and its interaction with metabolic status.

17α-Ethynylestradiol alters testicular epigenetic profiles and histone-to-protamine exchange in mice

Spermatogenesis starts with the onset of puberty within the seminiferous epithelium of the testes. It is a complex process under intricate control of the endocrine system. Physiological regulations by steroid hormones in general and by estrogens in particular are due to their chemical nature prone to be disrupted by exogenous factors acting as endocrine disruptors (EDs). 17α-Ethynylestradiol (EE2) is an environmental pollutant with a confirmed ED activity and a well-known effect on spermatogenesis and chromatin remodeling in haploid germ cells. The aim of our study was to assess possible effects of two doses (2.5ng/ml; 2.5 μg/ml) of EE2 on both histone-to-protamine exchange and epigenetic profiles during spermatogenesis performing a multi/transgenerational study in mice. Our results demonstrated an impaired histone-to-protamine exchange with a significantly higher histone retention in sperm nuclei of exposed animals, when this process was accompanied by the changes of histone post-translational modifications (PTMs) abundancies with a prominent effect on H3K9Ac and partial changes in protamine 1 promoter methylation status. Furthermore, individual changes in molecular phenotypes were partially transmitted to subsequent generations, when no direct trans-generational effect was observed. Finally, the uncovered specific localization of the histone retention in sperm nuclei and their specific PTMs profile after EE2 exposure may indicate an estrogenic effect on sperm motility and early embryonic development via epigenetic mechanisms.

Sex Disparities in Cancer Immunotherapy: A Review

Cancer immunotherapy has revolutionized cancer treatment, particularly through immune checkpoint inhibitors (ICIs) targeting proteins like PD-1, PD-L1, and CTLA-4. While these therapies have shown significant survival benefits across various cancers, sex-based disparities in treatment response and outcomes have emerged. This review explores the mechanisms behind these differences, focusing on genetic, hormonal, and immune system variations between male and female patients. Women tend to exhibit stronger immune responses due to the presence of two X chromosomes and the immunostimulatory effects of estrogen, which enhances immune activity. Conversely, men’s single X chromosome and the immunosuppressive effects of testosterone contribute to a less vigorous immune response. These biological differences manifest in clinical outcomes, with men generally experiencing better overall survival rates from ICIs, while women are more prone to immune-related adverse events (irAEs), including autoimmune toxicities. However, in certain cases, women may demonstrate more robust long-term survival benefits from treatments such as CTLA-4 inhibitors, despite higher toxicity risks. Beyond ICIs, sex disparities also extend to adoptive cell therapies (ACT) and cancer vaccines, where female patients often display stronger immune responses but face increased risks of side effects, necessitating personalized approaches to therapy. The review also discusses emerging research on the tumor microenvironment (TME), gut microbiome, and sex-specific pharmacokinetics and pharmacodynamics as contributing factors to these disparities. Understanding these mechanisms is critical for improving cancer immunotherapy outcomes for both sexes. Future research should focus on investigating the role of sex hormones, the microbiome, and developing biomarkers to better predict responses to immunotherapy. Clinically, the findings highlight the need for tailored treatment strategies that account for sex-specific differences, aiming for more equitable and effective cancer care. Keywords: Cancer immunotherapy, Immune checkpoint inhibitors (ICIs), Sex-based disparities, PD-1 inhibitors, PD-L1 inhibitors, CTLA-4 inhibitors

Bisphenol A-induced polycystic ovary syndrome (PCOS) with hormonal and metabolic implications in rats.

There is a rising incidence of polycystic ovary syndrome (PCOS) cases worldwide in women of reproductive age due to environmental factors. We evaluated the effect of an environmental estrogen, bisphenol A for its reprotoxicity regarding the induction of PCOS in rats and also assessed its hormonal and metabolic implications. There was 66.6% and 50% disorder, in the estrus cycle at low (50µg/kg) and high (500µg/kg) doses of BPA. While animals treated with the positive control (dehydroepiandrosterone, DHEA at 6mg/100g) caused 100% disorder. Cystic and atretic follicles along with two corpus luteum were found in the low dose group. However, no corpus luteum was found in the high dose group. Furthermore, hyperplasia and hypertrophy were found in the myometrium, endometrium, and luminal epithelium of the uterus of the low dose and DHEA groups. Additionally, 17β estradiol, progesterone, DHEA, androstenedione, testosterone, dihydrotestosterone (DHT), dehydroepiandrosterone sulphate (DHEAS), antimullerian hormone (AMH), ratio of LH/FSH and testosterone/DHT were increased significantly (P < 0.01) in BPA groups. A significantly higher TSH (P < 0.01) indicates hypothyroidism. Furthermore, hyperglycemia, hyperinsulinemia, HOMA-IR, and HOMAβ indicate insulin resistance in the low-dose group. Thus, the low dose of BPA was found to be more potent as compared to the higher dose and defining the hyperandrogenic state. Our study revealed that BPA may not only be a causative factor in the induction of PCOS but also has metabolic implications bearing on its estrogenic nature.

Female sex hormones inversely regulate acute kidney disease susceptibility throughout life.

While epidemiological and experimental studies have demonstrated kidney-protective effects of estrogen and female sex in adulthood, some epidemiological data showed deterioration of kidney function during puberty when estrogen production increases. However, molecular mechanisms explaining these conflicting phenomena remain unknown. Here, we showed that the pubertal sex hormone surge in female mice increases susceptibility to kidney ischemia reperfusion injury partly via downregulation of insulin-like growth factor 1 receptor (IGF-1R) expression in proximal tubules. Adult mice ovariectomized pre-pubertally (at postnatal day 21) showed strong tolerance to kidney ischemia, which was partly reversed by the administration of 17β-estradiol, while adult mice ovariectomized post-pubertally (at 8 weeks of age) were vulnerable to kidney ischemia. Kidney tubular IGF-1R protein expression decreased during postnatal growth but was highly expressed in adult mice ovariectomized pre-pubertally and in infant mice, which might be partly explained by different expression of an E3 ligase (MDM2) of IGF-1R. Mice deficient of Igf-1r in proximal tubules (iIGF-1RKO mice) during postnatal kidney growth showed increased susceptibility to ischemic injury. RNA-seq and western blotting analysis using proximal tubular cells from pre-pubertally ovariectomized iIGF-1RKO and control mice revealed altered expression of cell cycle-associated molecules such as cyclin D1. These results suggest that Igf-1r deletion during postnatal growth renders proximal tubular cells susceptible to ischemia possibly via altered cell cycle regulation. Thus, our findings provide evidence that exposure to pubertal sex hormones leads to increased susceptibility to kidney ischemia, which is partly mediated by modulation of IGF-1R signaling.

Investigation into the Quantitative Structure-Biotoxicity Relationship of Antibiotics and their Estrogenic Receptor Disruption Effects.

In light of antibiotics being classified as environmental hormone-like compounds, their interference with the endocrine system has significantly impacted human health and ecological environments. This study employed Gaussian09 software's Density Functional Theory (DFT) to structurally optimize and perform frequency calculations on 23 representative antibiotic molecules, aiming to obtain microscopic quantum mechanical structural parameters.Physicochemical property parameters were acquired through the RDKit database in the ChemDes platform. Through multiple linear regression analysis, the primary factors affecting antibiotic biotoxicity (pLD50) were identified, leading to the establishment of a QSAR model. The predictive capability of the model was analyzed using leave-one-out cross-validation, and molecular docking was used to investigate the binding mode and mechanism of action between estrogen receptors (ER) and antibiotics. Research outcomes indicate that the established QSAR model C has regression coefficients R2and leave-one-out cross-validation coefficients Q2of 0.92474 and 0.74913, respectively, demonstrating good stability and predictive power. Analysis through molecular surface electrostatic potential, frontier molecular orbitals,molecular docking, and molecular dynamicsrevealed that the potential estrogenic disrupting effects are primarily due to hydrogen bonds and hydrophobic interactions between antibiotics and estrogen receptors. This provides a valuable exploration for identifying and screening PPCPs with potential estrogenic disrupting effects.

Genistein Enhances the Beneficial Effects of Exercise on Antioxidant and Anti-Inflammatory Balance and Cardiomyopathy in Ovariectomized Diabetic Rats.

This study aimed to investigate the effects of genistein, swimming exercise, and their co-treatment on heart oxidative stress, inflammation, and cardiomyopathy in ovariectomized diabetic rats. It is well-established that diabetes is a major risk factor for cardiovascular disease in both young and postmenopausal women. Genistein is a natural phytoestrogen that has estrogenic effects. Studies have shown that genistein has a positive impact on menopause, cardiovascular dis-ease, and diabetes in women. However, the impact of genistein treatment alone and in combination with exercise training on the management of cardiac disease in diabetic women after ovarian hor-mone deprivation has not been fully explored. The objective of this study was to evaluate the effect of genistein alone or in combination with exercise training on the cardiac expression of oxidative/inflammation biomarkers (MDA, OSI, TOS, TNF- α, and NF-κB) and miRNA-133, IGF-1, and Bcl-2 in the diabetic ovariectomized rats. A group of Wistar rats were randomly divided into seven groups, with eight rats in each group. The groups were named control, sham, ovariectomized group (OVX), OVX +diabetes (OD), OD+ genistein (1 mg/kg, eight weeks; daily SC), OD+exercise (eight weeks), and OD+ genistein+exercise (eight weeks). The rats were given a high-fat diet and low-dose streptozotocin injection to induce diabetes. After eight weeks, the rats were anesthetized, and their hearts were removed. The study assessed the effects of treatment by measuring the expression of miRNA-133 using Real-time Polymerase Chain Reaction (PCR) and the protein levels of Bcl-2, Bax, and IGF-1 using Western blotting. The study also evaluated the levels of inflammation and oxidative stress markers using ELISA. Pathological changes were also assessed using periodic acid Schiff and he-matoxylin & eosin. After ovariectomy, the levels of cardiac miRNA-133, IGF-1, and Bcl-2 expression were down-regulated, and the levels of MDA, OSI, TOS, TNF-α, and NF-κB were increased, with a reduced total antioxidant capacity. Diabetes had an additive effect on these factors. Genistein was found to have a positive impact on oxidative and inflammation levels, and it also increased the expression of miRNA-133, Bcl-2, and IGF-1 in rats with OD. Furthermore, the combination of genistein and exercise had a positive effect on miRNA-133, Bcl-2, and IGF-1 expression in the heart, leading to a decrease in Bax levels. The combined intervention showed a noticeable improve-ment in oxidative and inflammation conditions. Histological examination revealed some abnormal-ities in cardiac tissue, which were found to be improved with genistein and/or exercise treatments. Genistein or/and exercise as a natural replacement therapy could improve diabetic-induced cardiac complications in ovariectomized rats' hearts.

Sex differences in outcomes of percutaneous left atrial appendage closure

Abstract Background Atrial fibrillation (AF) is the most common arrhythmia in adults and is associated with an increased risk of embolic stroke. In a previous survey, 91% of nonrheumatic AF-related left atrial thrombi was originated in the left atrial appendage (LAA). Percutaneous left atrial appendage closure (LAAC) with the Watchman device has been shown to be noninferior to anticoagulation therapy in clinical trials for stroke prevention in nonrheumatic AF. It has been used in Japan since September 2019 only for patients who are at the high risk of bleeding events. The WATCHMAN family is the only left atrial appendage closure (LAAC) device in Japan. Since long time ago, sex differences have been attracting attention in the cardiology. Due to the cardiovascular protective effects of endogenous estrogens, premenopausal women are thought to be less likely to develop cardiovascular disease. Whereas, in area of AF, Female with AF have higher stroke risk and female with AF have severe after effect. However, there are few studies on sex differences in LAAC implantation outcomes. Purpose We aimed to identify the sex differences of outcomes of LAAC in Japanese patients. Methods A total of 118 consecutive patients who underwent LAAC at our hospital from January 2020 to August 2023 were prospectively analyzed. Various patient characteristics, comorbidities, and outcomes were identified and compared between male and female. Results Results are shown in Table. Female were older (79 vs. 73 years, p = 0.0009), thinner (Body mass index 22 vs. 24 kg/m2, p = 0.0326), and less likely to have had diabetes (19 vs. 40%, p = 0.0340). Pulmonary embolism was significantly more common in female after LAAC. If anticoagulants are discontinued after LAAC, women’s susceptibility to coagulation may become apparent. Conclusions LAAC was feasible and safe for Japanese patients of both genders. However, these results could have a relevant impact on the antithrombotic management of patients who are at the high risk of embolic considering sex difference. Especially, we should pay great attention when discontinuing anticoagulants after LAAC in female.

Estrogen enhances the proliferation, migration, and invasion of papillary thyroid carcinoma via the ERα/KRT19 signaling axis.

Estrogen is thought to be the reason for the higher prevalence of papillary thyroid carcinoma (PTC) in fertile women; however, more study is required to completely comprehend how estrogen affects PTC development at the cellular level. Therefore, we combined Oxford Nanopore Technologies (ONT) sequencing to explore molecular markers of PTC and to investigate the molecular mechanisms by which estrogen promotes PTC development. The expression levels of ESR1 (ERα) and KRT19 in normal thyroid tissues and cancer tissues as well as in different cancer stages, races, genders, age groups, histological subtypes and nodular metastasis status of the TCGA database were analyzed online by Ualcan; the relationship between ESR1, KRT19 and the survival of THCA patients was analyzed. A PTC xenograft tumor model was established. An ERα specific inhibitor (MPP) was administered and an EDU cell proliferation assay was used to verify the effect of estrogen on PTC proliferation. KRT19 was knocked down in KTC-1 cells, and the proliferation, migration, and invasion abilities of PTC cells were determined using CCK-8, immunofluorescence labeling, Western blot for EMT-related proteins, scratch assay, and Transwell assay. The role of ERα in relation to KRT19 was investigated by Western blot and immunofluorescence. The effects of ERα/KRT19 signaling axis on the proliferation, migration and invasion ability of PTC cells were evaluated using EDU cell proliferation assay and Transwell. Using ONT sequencing, 15 pairs of PTC tissue and paracancer tissue samples were collected. A PPI network was constructed to validate the differential expression of KRT19 in combination with biosignature analysis, and the protein interaction between KRT19 and ESR1 was verified using STRING. Ualcan showed that the expression of ESR1 and KRT19 was higher in THCA tissues than in normal thyroid tissues. E2 activation of ERα promoted the growth of PTC cells and tissues. si-KRT19 inhibited the proliferation, migration and invasion of PTC cells. KRT19 together with ERα formed the ERα/KRT19 signaling axis. E2 activation of the ERα/KRT19 signaling axis promoted the proliferation, migration, and invasion of PTC cells. ONT sequencing and STRING website verified that KRT19 is significantly differentially expressed in PTC and that ESR1 and KRT19 have protein interactions and are related to the estrogen signaling pathway. Using public databases, RNA sequencing, and bioinformatics, we discovered that E2 stimulates the ERα/KRT19 signaling axis to stimulate PTC proliferation, migration, and invasion.

Follicle-stimulating hormone induces depression-like phenotype by affecting synaptic function.

Depression is one of the most common affective disorders in people's life. Women are susceptibility to depression during puberty, peripartum and menopause transition, when they are suffering from sex hormone fluctuation. A lot of studies have demonstrated the neuroprotective effect of estrogen on depression in women, however, the effect of FSH on depression is unclear. In this study, we investigated the role of FSH on depression in mice. Our study demonstrated that FSH induced depression-like behaviors in mice in a dose-dependent manner. This induction was associated with elevated levels of pro-inflammatory cytokines, including IL-1β, IL-6, and TNF-α in both serum and hippocampal tissues. Additionally, FSH treatment resulted in impaired synaptic plasticity and a reduction in the expression of key synaptic proteins. It is noteworthy that the depression-like behaviors, inflammatory cytokines expression and synaptic plasticity impairment induced by FSH could be alleviated by knocking down the expression of FSH receptor (FSHR) in the hippocampus of the mice. Therefore, our findings reveal that FSH may play an important role in the pathogenesis of depression and targeting FSH may be a potential therapeutic strategy for depression during hormone fluctuation in women.

Inhibiting p38α and β MAPK affects testis development in the marsupial tammar wallaby.

The MAPK genes are critical for gonadal differentiation in eutherian mammals but their role in marsupial mammals is unknown. Characterisation and phylogenetic analyses of the tammar wallaby MAPK genes shows these genes are highly conserved with their orthologues in mammalian and non-mammalian species. We cultured sexually indifferent tammar gonads in the presence of p38α and β MAPK inhibitor, SB202190. SB202190 downregulated SOX9 and AMH levels in XY treated gonads when compared to controls, similar to the effects of oestrogen on the MAPK pathway in males. In contrast, XX gonads treated with the SB202190 inhibitor showed no change in mRNA expression between the control and treated gonads for any of the markers tested. This study confirms that components of the MAPK pathway drive testis differentiation via the key downstream genes SOX9 and AMH in marsupials as is observed in eutherian mammals.

A preliminary study on the effects of Xiang Shao granules on reproductive endocrinology in drugged ovariectomised rats

ObjectiveTo establish a rat model of pharmacological ovariectomy by GnRH-a injection and to preliminarily investigate the reproductive endocrine effects of Xiangshao granules on pharmacologically ovariectomized rats. Methods: A rat model of pharmacological ovariectomy was established by injecting female rats with Gonadotropin-releasing hormone agonist(GnRH-a).The rats were randomly divided into four groups: GnRH-a injected saline group (GnRH-a + NS); GnRH-a injected oestradiol group (GnRH-a + E2); GnRH-a injected Xiangshao granule group (GnRH-a + Xiangshao), and the control group of saline-injected rats (NS + NS). The number of rats per group was 6.According to observations of the rats' vaginal smears, modelling was determined as successful. Then corresponding drug gavage intervention was administered for 28 days, and rat body weight and anal temperature were measured every other day to adjust the drug intervention amount according to body weight changes. Plasma sex hormone levels (E2, FSH, LH), uterine weight, uterine index and endometrial histomorphological changes, ovarian weight, and ovarian index and ovarian histomorphological changes were measured in each group after the gavage.Results(1) Plasma sex hormone levels (E2, FSH, LH) of the GnRH-a + NS, GnRH-a + E2, and GnRH-a + Xiangshao granule groups were significantly lower than the NS + NS group (P < 0.001), while the E2 level of the GnRH-a + E2 group was higher than that of the GnRH-a + Xiangshao granule group (P < 0.05). The FSH level of the GnRH-a + E2 group was significantly lower than that of the GnRH-a + Xiangshao granule group (P < 0.05). The LH level of the GnRH-a + E2 group was significantly lower than those in the GnRH-a + NS and GnRH-a + Xiangshao granule groups (P < 0.001, P = 0.001). The LH and FSH levels of the GnRH-a + NS and GnRH-a + Xiangshao granule groups were not significantly different (P > 0.05). (2) Compared with the NS + NS group, the uterine weight and uterine index, and ovarian weight and ovarian index of GnRH-a injected rats in each model all significantly decreased (P < 0.001). Between the groups, the uterine weight and uterine index, and ovarian weight and ovarian index of GnRH-a + E2 and GnRH-a + Xiangshao granule groups were all significantly higher than those of the GnRH-a + NS group (P < 0.001, P < 0.05). The uterine weight and uterine index, and ovarian weight and ovarian index of the GnRH-a + E2 group increased compared with the GnRH-a + Xiangshao granule group (P < 0.05). (3) Compared with the NS + NS group, the number of primordial follicles of the GnRH-a + NS, GnRH-a + E2, and GnRH-a + Xiangshao granule groups increased significantly and the number of growing follicles and mature follicles significantly decreased. (4) Rats' uterine wall of the NS + NS and various GnRH-a groups was significantly thinner, with the endothelial layer atrophied, while the uterine wall of the GnRH-a + E2 and GnRH-a + Xiangshao granule groups was thicker obviously, with the number of vaginal folds and blood vessels also increasing. Specifically, the uterus and vagina improvements in the GnRH-a + E2 group were more obvious than in GnRH-a + NS and GnRH-a + Xiangshao granule groups.ConclusionGnRH-a injection can reduce the levels of sex hormones E2, FSH, and LH in rats, causing perimenopausal symptoms such as hot flashes, while Xiangshao and E2 granules could significantly improve such symptoms and exert a slight oestrogenic effect, to a lesser extent than E2 does.Trial registrationNot applicable.

Protection of HT22 neuronal cells against chemically-induced ferroptosis by catechol estrogens: protein disulfide isomerase as a mechanistic target

Ferroptosis is a form of regulated cell death, characterized by excessive iron-dependent lipid peroxidation. Biochemically, ferroptosis can be selectively induced by erastin through glutathione depletion or through inhibition of glutathione peroxidase 4 by RSL3, which leads to accumulation of cytotoxic lipid reactive oxygen species (ROS). Protein disulfide isomerase (PDI) was recently shown to mediate erastin/RSL3-induced ferroptosis and thus also become a new target for protection against chemically-induced ferroptosis. The present study aims to identify endogenous compounds that can protect against erastin/RSL3-induced ferroptotic cell death. We find that 2-hydroxyestrone, 2-hydroxyestradiol, 4-hydroxyestrone and 4-hydroxyestradiol, four major endogenous catechol estrogens, are effective inhibitors of PDI, and can strongly protect against chemically-induced ferroptotic cell death in cultured HT22 mouse hippocampal neuronal cells. The CETSA assay showed that these catechol estrogens can bind to PDI in live cells. PDI knockdown attenuates the protective effect of these catechol estrogens against chemically-induced ferroptosis. Mechanistically, inhibition of PDI’s catalytic activity by catechol estrogens abrogates erastin/RSL3-induced dimerization of nitric oxide synthase, thereby preventing the subsequent accumulation of cellular nitric oxide, ROS and lipid-ROS, and ultimately ferroptotic cell death. In addition, joint treatment of cells with catechol estrogens also abrogates erastin/RSL3-induced upregulation of nitric oxide synthase protein levels, which also contributes to the cytoprotective effect of the catechol estrogens. In conclusion, the present study demonstrates that the catechol estrogens are protectors of HT22 neuronal cells against chemically-induced ferroptosis, and inhibition of PDI’s catalytic activity by these estrogens contributes to a novel, estrogen receptor-independent mechanism of cytoprotection.

Proteomic Analysis Reveals Major Proteins and Pathways That Mediate the Effect of 17-β-Estradiol in Cell Division and Apoptosis in Breast Cancer MCF7 Cells.

Despite extensive research, the genes/proteins and pathways responsible for the physiological effects of estrogen remain elusive. In this study, we determined the effect of estrogen on global protein expression in breast cancer MCF7 cells using a proteomic method. The expression of 77 cytosolic, 74 nuclear, and 81 membrane/organelle proteins was significantly altered by 17-β-estradiol (E2). Protein enrichment analyses suggest that E2 may stimulate cell division primarily by promoting the G1 to S phase transition and advancing the G2/M checkpoint. The effect of E2 on cell survival was complex, as it could simultaneously enhance and inhibit apoptosis. Bioinformatics analysis suggests that E2 may enhance apoptosis by promoting the accumulation of the pore-forming protein Bax in the mitochondria and inhibit apoptosis by activating the PI3K/AKT/mTOR signaling pathway. We verified the activation of the PI3K signaling and the accumulation of Bax in the membrane/organelle fraction in E2-treated cells using immunoblotting. Treatment of MCF7 cells with E2 and the PI3K inhibitor Ly294002 significantly enhanced apoptosis compared to those treated with E2 alone, suggesting that combining estrogen with a PI3K inhibitor could be a promising strategy for treating ERα-positive breast cancer. Interestingly, many of the E2-upregulated proteins contained the HEAT, KH, and RRM domains.

Hormone Replacement Therapy and Alzheimer's Disease: Current State of Knowledge and Implications for Clinical Use.

Alzheimer's disease (AD) is a progressive neurodegenerative disorder responsible for over half of dementia cases, with two-thirds being women. Growing evidence from preclinical and clinical studies underscores the significance of sex-specific biological mechanisms in shaping AD risk. While older age is the greatest risk factor for AD, other distinct biological mechanisms increase the risk and progression of AD in women including sex hormones, brain structural differences, genetic background, immunomodulation and vascular disorders. Research indicates a correlation between declining estrogen levels during menopause and an increased risk of developing AD, highlighting a possible link with AD pathogenesis. The neuroprotective effects of estrogen vary with the age of treatment initiation, menopause stage, and type. This review assesses clinical and observational studies conducted in women, examining the influence of estrogen on cognitive function or addressing the ongoing question regarding the potential use of hormone replacement therapy (HRT) as a preventive or therapeutic option for AD. This review covers recent literature and discusses the working hypothesis, current use, controversies and challenges regarding HRT in preventing and treating age-related cognitive decline and AD. The available evidence indicates that estrogen plays a significant role in influencing dementia risk, with studies demonstrating both beneficial and detrimental effects of HRT. Recommendations regarding HRT usage should carefully consider the age when the hormonal supplementation is initiated, baseline characteristics such as genotype and cardiovascular health, and treatment duration until this approach can be more thoroughly investigated or progress in the development of alternative treatments can be made.

6816 The Estrogen Environment Characteristic of Endometriotic Lesion May Attenuate the Receptor γ-Mediated Antiproliferative Activity of Retinoids

Abstract Disclosure: M. Izawa: None. Y. Azuma: None. F. Taniguchi: None. Background: Endometriosis has been accepted as an estrogen-dependent disease, and the estrogen environment in endometriotic lesions has been proposed as a major background of the pathophysiology. Although the hormonal therapy targeting the reduction of estrogen has been employed to reduce endometriosis-associated symptoms, the limitation of therapy has been well recognized. How to overcome the limitation remains an urgent subject to be explored. [Objective:]We focused on retinoids, which have been known to induce an antiproliferative activity in tumors. Based on the retinoic acid receptor (RAR) expression profile in endometriotic lesions, we evaluated the antiproliferative activity of retinoids using endometriotic cells. Finally, we examined the effect of estrogen on antiproliferative activity. Methods: Endometriotic tissue and cells: Institutional Review Boards approved this project. The chocolate cyst lining in the ovaries of patients with endometriosis was the source of endometriotic tissue. Stromal cells collected from endometriotic tissues were used as endometriotic cells. RAR expression: RNAs were prepared from endometriotic tissues and cells, and single-stranded cDNAs were subjected to RT-PCR. Primers were designed using the UCSF genome browser. Protein expression was examined by Western blotting. Cell proliferation assay: Cells were treated with all-trans retinoic acid (ATRA), selective RAR modulators (sRARMs), BMS753, CD2314 and CD437, RARγ antagonist MM11253 and 17β-estradiol (E2). Viable cells were estimated using WST-8 assay. RNA-seq analysis: Cells were treated with retinoids and E2. RNA samples were used for polyA+ selected library and the strand-specific RNA-seq. Differentially expressed genes with p-values &amp;lt; 0.05 and log2 fold changes &amp;gt; 1 were extracted as responsive genes. Results: RAR expression: Transcripts of wild-type RARα, RARβ, and RARγ were demonstrated in arbitrary 10 regions of patient tissue, and in endometriotic cells. The expression of these RARs was almost at a comparable level. Effect of retinoids and/or estrogen on cell proliferation: Cell proliferation rate was significantly decreased in the presence of ATRA. Among sRARMs tested, only CD437 reduced the cell proliferation. The antiproliferative activity of ATRA was attenuated either in the presence of MM11253 or E2, respectively. ATRA- and/or E2-responsive gene expressions To explore gene expressions in response to retinoids and E2, RNA-seq analysis was performed. The results suggest the diversity of ATRA- and E2-responsive genes in endometriotic lesions.[Conclusion:]Endometriotic cell proliferation was significantly suppressed in response to retinoids through RARγ. The observation that the antiproliferative activity was attenuated in the presence of E2 suggests a suppressive environment against the activity of retinois in endometriotic legions. Presentation: 6/2/2024

8125 Long-term Effects of Gender Affirming Hormone Therapy (GAHT) on Lipid Profile

Abstract Disclosure: G. Le: None. S. Pinkson: None. J. Trejo: None. D. Tripathy: None. Long-term Effects of Gender Affirming Hormone Therapy (GAHT) on Lipid Profile There is differential effect of long-term Estrogen and Testosterone therapy on lipid profile. While oral estradiol therapy in post-menopausal women has been associated with increased serum triglyceride and HDL, testosterone therapy in hypogonadal men decreases total cholesterol, LDL and HDL cholesterol. However, the long-term effects of Estrogen and Testosterone on lipid profile in transgender patients are not clear. We conducted a retrospective study to analyze the long-term effects of GAHT in transgender men and women followed in Endocrinology Clinic at Veterans Affairs Hospital. 36 transgender men (age 38 ± 2 years, on IM Testosterone cypionate) and 54 transgender women (age 46 ± 2 years, 36 on E2 tablet, 12 on patch, 6 on IM) were followed for 46 ± 5 months and 61 ± 5 months, respectively. Total cholesterol, triglyceride, HDL, LDL cholesterol, systolic and diastolic blood pressures, and BMI were compared before and after initiation of therapy. As expected, following GAHT, total testosterone was higher (546 ± 48 vs. 35 ± 9 ng/dL, P&amp;lt;0.001) in transgender men; in transgender women, serum E2 was higher (110 ± 9 vs. 26 ± 2 pg/dL, P&amp;lt;0.001) and total testosterone was suppressed (444 ± 29 ng/dL vs. 66 ± 13 ng/dL). In transgender men, after a follow-up period of approximately 4 years, there were no significant changes in lipid profile (total cholesterol 178 ± 8 vs. 175 ± 8 mg/dL, triglyceride 121 ± 4 vs 134 ± 12 mg/dL, HDL 47 ± 2 vs. 44 ± 2 mg/dL, LDL 107 ± 7 vs. 106 ± 8 mg/dL, all p=NS). Similarly in transgender women, no difference in lipid profile (total cholesterol 170 ± 5 vs. 175 ± 4 mg/dL, triglyceride 118 ± 7 vs 140 ± 9 mg/dL, HDL 49 ± 2 vs. 53 ± 3 mg/dL, LDL 99 ± 4 vs. 97 ± 4 mg/dL, all p=NS) was observed after 5 years of GAHT. There were no differences in lipid profile regardless of E2 tablet, patch or IM therapy. In transgender men, there was an increase in diastolic blood pressure (72 ± 3 vs. 76 ± 2 mmHg, P&amp;lt;0.05) while in transgender women there was decrease in systolic blood pressure (124 ± 2 vs. 118 ± 2 mmHg, p&amp;lt;0.005), and slight increase in BMI (28 ± 0.9 vs. 30 ± 1 kg.m2, P&amp;lt;0.005). In conclusion, long-term testosterone therapy in transgender men and estrogen therapy in transgender women was not associated with worsening lipid profile. Estrogen therapy was associated with lower BP in transgender women and testosterone therapy led to higher BP in transgender men. Presentation: 6/2/2024

8125 Long-term Effects of Gender Affirming Hormone Therapy (GAHT) on Lipid Profile

Abstract Disclosure: G. Le: None. S. Pinkson: None. J. Trejo: None. D. Tripathy: None. There is differential effect of long-term Estrogen and Testosterone therapy on lipid profile. While oral estradiol therapy in post-menopausal women has been associated with increased serum triglyceride and HDL, testosterone therapy in hypogonadal men decreases total cholesterol, LDL and HDL cholesterol. However, the long-term effects of Estrogen and Testosterone on lipid profile in transgender patients are not clear. We conducted a retrospective study to analyze the long-term effects of GAHT in transgender men and women followed in Endocrinology Clinic at Veterans Affairs Hospital. 36 transgender men (age 38 ± 2 years, on IM Testosterone cypionate) and 54 transgender women (age 46 ± 2 years, 36 on E2 tablet, 12 on patch, 6 on IM) were followed for 46 ± 5 months and 61 ± 5 months, respectively. Total cholesterol, triglyceride, HDL, LDL cholesterol, systolic and diastolic blood pressures, and BMI were compared before and after initiation of therapy. As expected, following GAHT, total testosterone was higher (546 ± 48 vs. 35 ± 9 ng/dL, P&amp;lt;0.001) in transgender men; in transgender women, serum E2 was higher (110 ± 9 vs. 26 ± 2 pg/dL, P&amp;lt;0.001) and total testosterone was suppressed (444 ± 29 ng/dL vs. 66 ± 13 ng/dL). In transgender men, after a follow-up period of approximately 4 years, there were no significant changes in lipid profile (total cholesterol 178 ± 8 vs. 175 ± 8 mg/dL, triglyceride 121 ± 4 vs 134 ± 12 mg/dL, HDL 47 ± 2 vs. 44 ± 2 mg/dL, LDL 107 ± 7 vs. 106 ± 8 mg/dL, all p=NS). Similarly in transgender women, no difference in lipid profile (total cholesterol 170 ± 5 vs. 175 ± 4 mg/dL, triglyceride 118 ± 7 vs 140 ± 9 mg/dL, HDL 49 ± 2 vs. 53 ± 3 mg/dL, LDL 99 ± 4 vs. 97 ± 4 mg/dL, all p=NS) was observed after 5 years of GAHT. There were no differences in lipid profile regardless of E2 tablet, patch or IM therapy. In transgender men, there was an increase in diastolic blood pressure (72 ± 3 vs. 76 ± 2 mmHg, P&amp;lt;0.05) while in transgender women there was decrease in systolic blood pressure (124 ± 2 vs. 118 ± 2 mmHg, p&amp;lt;0.005), and slight increase in BMI (28 ± 0.9 vs. 30 ± 1 kg.m2, P&amp;lt;0.005). In conclusion, long-term testosterone therapy in transgender men and estrogen therapy in transgender women was not associated with worsening lipid profile. Estrogen therapy was associated with lower BP in transgender women and testosterone therapy led to higher BP in transgender men. Presentation: 6/2/2024

8530 Characterizing the Genomic Effects of Low-Dose Estrogen in Breast Cancer Cells

Abstract Disclosure: H. Kim: None. T.S. Nandu: None. W.L. Kraus: None. Estrogens are steroid hormones that play a key role in a wide range of physiological and pathological processes. The predominant nuclear receptor for estrogens, estrogen receptor-alpha (ERɑ), functions primarily as a nuclear transcription factor (TF) through ligand-dependent activation by 17β-estradiol (E2), the major naturally-occurring estrogen. The physiological levels of E2 are regulated by production, sequestration, and degradation, which can limit the amount of bioavailable E2. However, many studies examining the genomic effects of E2-regulated signaling in cell-based assays used supraphysiological levels of hormone. While this has allowed us to understand the extremes of E2 signaling, it limits our ability to examine cellular functions which operate at lower hormone concentrations. The genomic actions of ligand-bound ERɑ are mediated through transcriptional enhancer formation and function. Alterations in protein and DNA components dictate different enhancer molecular subtypes that specify distinct regulatory mechanisms and downstream cellular phenotypes. How the amount of available hormone affects these genomic processes is unknown. In order to understand the genomic effects of physiological low-dose levels of E2, we have treated MCF-7 ERɑ-positive human breast cancer cells with a range of E2 concentrations and examined the global regulation of gene expression using a multi-omics approach (RNA-seq, ERɑ ChIP-seq, H3K27ac ChIP-seq, PRO-seq, ATAC-seq). Interestingly, we identified gene sets that are preferentially expressed maximally at picomolar or nanomolar concentrations. We are using these genes sets to explore the mechanisms of estrogen-regulated gene expression at physiologically relevant of E2 concentrations. Analysis of nascent RNA transcription using PRO-seq indicates regulation at the transcriptional level. Preliminary ERɑ chromatin binding assays show that while many loci require high levels of E2 for maximum ERɑ binding, others show maximum ERɑ binding at lower doses of E2. Further analyses show distinct enhancer features, such as chromatin accessibility and H3K27ac enrichment, may play a role in determining the response to E2 dosage. We are now determining the molecular mechanisms of dosage sensitivity using a multipronged approach integrating genomics, molecular biology, and cell-based assays. With these studies, we hope to understand a long overlooked physiological aspect of E2 with a comprehensive and global analysis of signal-dependent genomic responses. Presentation: 6/3/2024