Chorio-retinal vessel density in women affected by functional hypothalamic amenorrhea: a monocentric observational cross-sectional study to evaluate the impact of hypoestrogenism on chorio-retinal vascularization.

PURPOSE: Functional hypothalamic amenorrhea (FHA) is characterized by an estrogen deficiency which in turn can cause vascular dysfunction. The aim of this study is to evaluate any changes in the chorio-retinal circulation in patients affected by FHA. 24 patients with FHA and 24 age-matched controls underwent a gynecological evaluation and an OCT angiography (OCTA) to study chorio-retinal vascularization. RESULTS: OCTA in FHA patients showed an increase in vessel density in the choriocapillaris (CC) layer (both in the fovea area, at 5% p value = 0.037 and in the whole area, at 5% p value = 0.028) and an increase in vascular density in the deep fovea (DVP) (at 10% p value = 0.096) in the whole district compared to controls. Simple linear regressions show a significant negative association between CC vessel density and insulin (p = 0.0002) and glucose values (p = 0.0335) for the fovea district and a negative association between DVP vessel density and endometrial thickness (at 10%, p value: 0.095) in the whole district. CONCLUSION: Our study shows that CC vessel density is increased in women affected by FHA. This could represent a compensation effort to supply the vascular dysfunction caused by estrogen deficiency. We also found an increasing trend in vascular density in DVP associated with the decrease of endometrial thickness, an indirect sign of estrogenization. Considering that these changes occur in absence of visual defects, they could be used as a biomarker to estimate hypoestrogenism-induced microcirculation changes before clinical appearance.

The effects of estrogens on spatial learning and memory in female rodents - A systematic review and meta-analysis.

Estrogens have inconsistent effects on learning and memory in both the clinical and preclinical literature. Preclinical literature has the advantage of investigating an array of potentially important factors contributing to the varied effects of estrogens on learning and memory, with stringently controlled studies. This study set out to identify specific factors in the animal literature that influence the effects of estrogens on cognition, for possible translation back to clinical practice. The literature was screened and studies meeting strict inclusion criteria were included in the analysis. Eligible studies included female ovariectomized rodents with an adequate vehicle for the estrogen treatment, with an outcome of spatial learning and memory in the Morris water maze. Training days of the Morris water maze were used to assess acquisition of spatial learning, and the probe trial was used to evaluate spatial memory recall. Continuous outcomes were pooled using a random effects inverse variance method and reported as standardized mean differences with 95 % confidence intervals. Subgroup analyses were developed a priori to assess important factors. The overall analysis favoured treatment for the later stages of training and for the probe trial. Factors including the type of estrogen, route, schedule of administration, age of animals, timing relative to ovariectomy, and duration of treatment were all found to be important. The subgroup analyses showed that chronic treatment with 17ß-estradiol, either cyclically or continuously, to young animals improved spatial recall. These results, observed in animals, can inform and guide further clinical research on hormone replacement therapy for cognitive benefits.

Effect of Menstrual Cycle and Hormonal Contraception on Musculoskeletal Health and Performance: Protocol for a Prospective Cohort Design and Cross-Sectional Comparison.

BACKGROUND: Women of reproductive age experience cyclical variation in the female sex steroid hormones 17ß-estradiol and progesterone during the menstrual cycle that is attenuated by some hormonal contraceptives. Estrogens perform a primary function in sexual development and reproduction but have nonreproductive effects on bone, muscle, and sinew tissues (ie, ligaments and tendons), which may influence injury risk and physical performance. OBJECTIVE: The purpose of the study is to understand the effect of the menstrual cycle and hormonal contraceptive use on bone and calcium metabolism, and musculoskeletal health and performance. METHODS: A total of 5 cohorts of physically active women (aged 18-40 years) will be recruited to participate: eumenorrheic, nonhormonal contraceptive users (n=20); combined oral contraceptive pill (COCP) users (n=20); hormonal implant users (n=20); hormonal intrauterine system users (n=20); and hormonal injection users (n=20). Participants must have been using the COCP and implant for at least 1 year and the intrauterine system and injection for at least 2 years. First-void urine samples and fasted blood samples will be collected for biochemical analysis of calcium and bone metabolism, hormones, and metabolic markers. Knee extensor and flexor strength will be measured using an isometric dynamometer, and lower limb tendon and stiffness, tone, and elasticity will be measured using a Myoton device. Functional movement will be assessed using a single-leg drop to assess the frontal plane projection angle and the qualitative assessment of single leg loading. Bone density and macro- and microstructure will be measured using ultrasound, dual-energy x-ray absorptiometry, and high-resolution peripheral quantitative computed tomography. Skeletal material properties will be estimated from reference point indentation, performed on the flat surface of the medial tibia diaphysis. Body composition will be assessed by dual-energy x-ray absorptiometry. The differences in outcome measures between the hormonal contraceptive groups will be analyzed in a one-way between-group analysis of covariance. Within the eumenorrheic group, the influence of the menstrual cycle on outcome measures will be assessed using a linear mixed effects model. Within the COCP group, differences across 2 time points will be analyzed using the paired-samples 2-tailed t test. RESULTS: The research was funded in January 2020, and data collection started in January 2022, with a projected data collection completion date of August 2024. The number of participants who have consented at the point of manuscript submission is 66. It is expected that all data analysis will be completed and results published by the end of 2024. CONCLUSIONS: Understanding the effects of the menstrual cycle and hormonal contraception on musculoskeletal health and performance will inform contraceptive choices for physically active women to manage injury risk. TRIAL REGISTRATION: ClinicalTrials.gov NCT05587920; https://classic.clinicaltrials.gov/ct2/show/NCT05587920. INTERNATIONAL REGISTERED REPORT IDENTIFIER (IRRID): DERR1-10.2196/50542.

Estrogen receptor-α signaling in tanycytes lies at the crossroads of fertility and metabolism.

BACKGROUND: Estrogen secretion by the ovaries regulates the hypothalamic-pituitary-gonadal axis during the reproductive cycle, influencing gonadotropin-releasing hormone (GnRH) and luteinizing hormone (LH) secretion, and also plays a role in regulating metabolism. Here, we establish that hypothalamic tanycytes-specialized glia lining the floor and walls of the third ventricle-integrate estrogenic feedback signals from the gonads and couple reproduction with metabolism by relaying this information to orexigenic neuropeptide Y (NPY) neurons. METHODS: Using mouse models, including mice floxed for Esr1 (encoding estrogen receptor alpha, ERα) and those with Cre-dependent expression of designer receptors exclusively activated by designer drugs (DREADDs), along with virogenic, pharmacological and indirect calorimetric approaches, we evaluated the role of tanycytes and tanycytic estrogen signaling in pulsatile LH secretion, cFos expression in NPY neurons, estrous cyclicity, body-weight changes and metabolic parameters in adult females. RESULTS: In ovariectomized mice, chemogenetic activation of tanycytes significantly reduced LH pulsatile release, mimicking the effects of direct NPY neuron activation. In intact mice, tanycytes were crucial for the estrogen-mediated control of GnRH/LH release, with tanycytic ERα activation suppressing fasting-induced NPY neuron activation. Selective knockout of Esr1 in tanycytes altered estrous cyclicity and fertility in female mice and affected estrogen's ability to inhibit refeeding in fasting mice. The absence of ERα signaling in tanycytes increased Npy transcripts and body weight in intact mice and prevented the estrogen-mediated decrease in food intake as well as increase in energy expenditure and fatty acid oxidation in ovariectomized mice. CONCLUSIONS: Our findings underscore the pivotal role of tanycytes in the neuroendocrine coupling of reproduction and metabolism, with potential implications for its age-related deregulation after menopause. SIGNIFICANCE STATEMENT: Our investigation reveals that tanycytes, specialized glial cells in the brain, are key interpreters of estrogen signals for orexigenic NPY neurons in the hypothalamus. Disrupting tanycytic estrogen receptors not only alters fertility in female mice but also impairs the ability of estrogens to suppress appetite. This work thus sheds light on the critical role played by tanycytes in bridging the hormonal regulation of cyclic reproductive function and appetite/feeding behavior. This understanding may have potential implications for age-related metabolic deregulation after menopause.

Treatment-induced anogenital melanosis is a very frequent finding in patients with vulvar lichen sclerosus.

Background: Pigmented lesions such as melanosis have rarely been reported in patients with vulvar lichen sclerosus (VLS) that is typically characterized by hypopigmented lesions. Objective: We aimed to analyze systematically anogenital melanosis in a large cohort of VLS patients. Methods: We analyzed the clinical data of 198 female patients with VLS. The anogenital lesions of all patients were professionally photographed in a standardized position and illumination. Severity classification of architectural findings followed an easy-to-use clinical score. A modified Melasma Area and Severity Index and an image analysis software were used to evaluate the area and intensity of pigmentation. Results: According to the clinical score, 79 (198/39.9%) patients showed grade 1 disease, 78 (198/39.4%) grade 2, 37 (198/18.7%) grade 3, and 4 (198/2%) grade 4 disease. About 111 (56.1%) of the 198 patients had anogenital melanosis with a median modified Melasma Area and Severity Index of 3.6 (0.4-14). Univariate analysis revealed that anogenital melanosis was positively correlated with the use of topical estrogens (P = .0018) and negatively correlated with the use of pulsed high-dose corticosteroids plus low-dose methotrexate (PHDC-LDM, P = .021). On multivariable analysis, the use of topical hormone therapy turned out to be a strong independent predictor for the presence of anogenital melanosis (odds ratio: 4.57, 95% confidence interval: 1.66-12.57, P = .0033), whereas PHDC-LDM use was an independent predictor for the absence of anogenital melanosis (odds ratio: 0.35, 95% confidence interval: 0.15-0.84, P = .018). Limitations: The study includes the retrospective monocentric design. Conclusion: Anogenital melanosis is a very frequent and so far, under-reported clinical finding in VLS patients. It is likely caused by the use of topical estrogens employed for VLS treatment. In contrast, patients with more severe disease and PHDC-LDM treatment appear to develop less likely anogenital melanosis.

Steroid sulfatase and sulfotransferases in the estrogen and androgen action of gynecological cancers: current status and perspectives.

Sulfatase (STS) and sulfotransferases (SULT) have important role in the biosynthesis and action of steroid hormones. STS catalyzes the hydrolysis of estrone-sulfate (E1-S) and dehydroepiandrosterone-sulfate (DHEA-S), while sulfotransferases catalyze the reverse reaction and require 3-phosphoadenosine-5-phosphosulfate as a sulfate donor. These enzymes control the concentration of active estrogens and androgens in peripheral tissues. Aberant expression of STS and SULT genes has been found in both, benign hormone-dependent diseases and hormone-dependent cancers. The aim of this review is to present the current knowledge on the role of STS and SULT in gynecological cancers, endometrial (EC) and ovarian cancer (OC). EC is the most common and OC the most lethal gynecological cancer. These cancers primarily affect postmenopausal women and therefore rely on the local production of steroid hormones from inactive precursors, either DHEA-S or E1-S. Following cellular uptake by organic anion transporting polypeptides (OATP) or organic anion transporters (OAT), STS and SULT regulate the formation of active estrogens and androgens, thus disturbed balance between STS and SULT can contribute to the onset and progression of cancer. The importance of these enzymes in peripheral estrogen biosynthesis has long been recognized, and this review provides new data on the important role of STS and SULT in the formation and action of androgens, their regulation and inhibition, and their potential as prognostic biomarkers.

Steroid metabolism and hormonal dynamics in normal and malignant ovaries.

The ovaries are key steroid hormone production sites in post-pubertal females. However, current research on steroidogenic enzymes, endogenous hormone concentrations and their effects on healthy ovarian function and malignant development is limited. Here, we discuss the importance of steroid enzymes in normal and malignant ovaries, alongside hormone concentrations, receptor expression and action. Key enzymes include STS, 3ß-HSD2, HSD17B1, ARK1C3, and aromatase, which influence ovarian steroidal action. Both androgen and oestrogen action, via their facilitating enzyme, drives ovarian follicle activation, development and maturation in healthy ovarian tissue. In ovarian cancer, some data suggest STS and oestrogen receptor α may be linked to aggressive forms, while various oestrogen-responsive factors may be involved in ovarian cancer metastasis. In contrast, androgen receptor expression and action vary across ovarian cancer subtypes. For future studies investigating steroidogenesis and steroidal activity in ovarian cancer, it is necessary to differentiate between disease subtypes for a comprehensive understanding.

Direct extraction of ten estrogens from milk samples with DVB/NVP-modified magnetic solid-phase extraction adsorbent followed by pre-column derivatization-UHPLC-MS/MS.

Estrogens and their analogues can cause harm to human health through the food chain. Ten estrogens in different milk samples were directly extracted by amphiphilic divinylbenzene/N-vinyl-2-pyrrolidone (DVB/NVP)-Fe3O4@SiO2-based magnetic solid-phase extraction (MSPE) followed by pre-column derivatization and ultra-high performance liquid chromatography tandem mass-spectrometry (UHPLC-MS/MS) detection. Under the optimal conditions, the limits of detection for ten analytes were in the range of 0.05-0.38 ng mL-1 in whole liquid milk matrix and 0.04-3.00 ng g-1 in milk powder matrix. The intra-/inter-day accuracy ranged in 83.4-113.8%, with RSDs in 2.5-15.0%. A total of 15 brands of liquid milk and milk powder samples were analyzed, and only estradiol was detected in three brands of boxed liquid milk within safe range. The proposed sample pretreatment eliminated the common protein precipitation process, improved the sample throughput, and has the potential for routine testing of estrogens and their analogues in market-sale milk samples.

Association between Disgust Sensitivity during Pregnancy and Endogenous Steroids: A Longitudinal Study.

The emotion of disgust protects individuals against pathogens, and it has been found to be elevated during pregnancy. Physiological mechanisms discussed in relation to these changes include immune markers and progesterone levels. This study aimed to assess the association between steroids and disgust sensitivity in pregnancy. Using a prospective longitudinal design, we analyzed blood serum steroid concentrations and measured disgust sensitivity via text-based questionnaires in a sample of 179 pregnant women during their first and third trimesters. We found positive correlations between disgust sensitivity and the levels of C19 steroids (including testosterone) and its precursors in the Δ5 pathway (androstenediol, DHEA, and their sulfates) and the Δ4 pathway (androstenedione). Additionally, positive correlations were observed with 5α/ß-reduced C19 steroid metabolites in both trimesters. In the first trimester, disgust sensitivity was positively associated with 17-hydroxypregnanolone and with some estrogens. In the third trimester, positive associations were observed with cortisol and immunoprotective Δ5 C19 7α/ß-hydroxy-steroids. Our findings show that disgust sensitivity is positively correlated with immunomodulatory steroids, and in the third trimester, with steroids which may be related to potential maternal-anxiety-related symptoms. This study highlights the complex relationship between hormonal changes and disgust sensitivity during pregnancy.

The Interaction of Vasopressin with Hormones of the Hypothalamo-Pituitary-Adrenal Axis: The Significance for Therapeutic Strategies in Cardiovascular and Metabolic Diseases.

A large body of evidence indicates that vasopressin (AVP) and steroid hormones are frequently secreted together and closely cooperate in the regulation of blood pressure, metabolism, water-electrolyte balance, and behavior, thereby securing survival and the comfort of life. Vasopressin cooperates with hormones of the hypothalamo-pituitary-adrenal axis (HPA) at several levels through regulation of the release of corticotropin-releasing hormone (CRH), adrenocorticotropic hormone (ACTH), and multiple steroid hormones, as well as through interactions with steroids in the target organs. These interactions are facilitated by positive and negative feedback between specific components of the HPA. Altogether, AVP and the HPA cooperate closely as a coordinated functional AVP-HPA system. It has been shown that cooperation between AVP and steroid hormones may be affected by cellular stress combined with hypoxia, and by metabolic, cardiovascular, and respiratory disorders; neurogenic stress; and inflammation. Growing evidence indicates that central and peripheral interactions between AVP and steroid hormones are reprogrammed in cardiovascular and metabolic diseases and that these rearrangements exert either beneficial or harmful effects. The present review highlights specific mechanisms of the interactions between AVP and steroids at cellular and systemic levels and analyses the consequences of the inappropriate cooperation of various components of the AVP-HPA system for the pathogenesis of cardiovascular and metabolic diseases.

Alcohol intake and endogenous sex hormones in women: Meta-analysis of cohort studies and Mendelian randomization.

BACKGROUND: The mechanisms underlying alcohol-induced breast carcinogenesis are not fully understood but may involve hormonal changes. METHODS: Cross-sectional associations were investigated between self-reported alcohol intake and serum or plasma concentrations of estradiol, estrone, progesterone (in premenopausal women only), testosterone, androstenedione, dehydroepiandrosterone sulfate, and sex hormone binding globulin (SHBG) in 45 431 premenopausal and 173 476 postmenopausal women. Multivariable linear regression was performed separately for UK Biobank, European Prospective Investigation into Cancer and Nutrition, and Endogenous Hormones and Breast Cancer Collaborative Group, and meta-analyzed the results. For testosterone and SHBG, we also conducted Mendelian randomization and colocalization using the ADH1B (alcohol dehydrogenase 1B) variant (rs1229984). RESULTS: Alcohol intake was positively, though weakly, associated with all hormones (except progesterone in premenopausal women), with increments in concentrations per 10 g/day increment in alcohol intake ranging from 1.7% for luteal estradiol to 6.6% for postmenopausal dehydroepiandrosterone sulfate. There was an inverse association of alcohol with SHBG in postmenopausal women but a small positive association in premenopausal women. Two-sample randomization identified positive associations of alcohol intake with total testosterone (difference per 10 g/day increment: 4.1%; 95% CI, 0.6-7.6) and free testosterone (7.8%; 4.1-11.5), and an inverse association with SHBG (-8.1%; -11.3% to -4.9%). Colocalization suggested a shared causal locus at ADH1B between alcohol intake and higher free testosterone and lower SHBG (posterior probability for H4, 0.81 and 0.97, respectively). CONCLUSIONS: Alcohol intake was associated with small increases in sex hormone concentrations, including bioavailable fractions, which may contribute to its effect on breast cancer risk.

The elucidation of species-specific receptor pharmacology: a case study using subtype selective para- and meta-carborane estrogen receptor agonists.

Estrogen receptors are essential pharmacological targets for treating hormonal disorders and estrogen-dependent malignancies. Selective activation of estrogen receptor (ER) ß is hypothesized to provide therapeutic benefit with reduced risk of unwanted estrogenic side-effects associated with ERα activity. However, activating ERß without activating α is challenging due to the high sequence and structural homology between the receptor subtypes. We assessed the impact of structural modifications to the parent compound OSU-ERß-12 on receptor subtype binding selectivity using cell-free binding assays. Functional selectivity was evaluated by transactivation in HEK-293 cells overexpressing human or murine estrogen receptors. In vivo selectivity was examined through the uterotrophic effects of the analogs after oral administration in estrogen-naïve female mice. Furthermore, we evaluated the in vivo pharmacokinetics of the analogs following single dose IV and oral administration. Regarding selectivity, a single compound exhibited greater functional selectivity than OSU-ERß-12 for human ERß. However, like others in the meta-carborane series, its poor in vivo pharmacokinetics limit its suitability for further development. Surprisingly, and at odds with their pharmacokinetic and in vitro human activity data, most analogs potently induced uterotrophic effects in estrogen-naïve female mice. Further investigation of activity in HEK293 cells expressing murine estrogen receptors revealed species-specific differences in the ER-subtype selectivity of these analogs. Our findings highlight species-specific receptor pharmacology and the challenges it poses to characterizing developmental therapeutics in preclinical species. Significance Statement This study investigates para- and meta-substituted carborane analogs targeting estrogen receptors, revealing the greater selectivity of carborane analogs for human ERß compared to the mouse homolog. These findings shed light on the intricacies of using preclinical species in drug development to predict human pharmacology. The report also provides insights for the refinement and optimization of carborane analogs as potential therapeutic agents for estrogen-related disease states.

Conversion of estriol to estrone: A bacterial strategy for the catabolism of estriol.

Natural estrogens, including estrone (E1), 17ß-estradiol (E2), and estriol (E3), are potentially carcinogenic pollutants commonly found in water and soil environments. Bacterial metabolic pathway of E2 has been studied; however, the catabolic products of E3 have not been discovered thus far. In this study, Novosphingobium sp. ES2-1 was used as the target strain to investigate its catabolic pathway of E3. The metabolites of E3 were identified by high performance liquid chromatography-high resolution mass spectrometry (HPLC-HRMS) combined with stable 13C3-labeling. Strain ES2-1 could almost completely degrade 20 mg∙L-1 of E3 within 72 h under the optimal conditions of 30°C and pH 7.0. When inoculated with strain ES2-1, E3 was initially converted to E1 and then to 4-hydroxyestrone (4-OH-E1), which was then cleaved to HIP (metabolite A6) via the 4, 5-seco pathway or cleaved to the B loop via the 9,10-seco pathway to produce metabolite with a long-chain ketone structure (metabolite B4). Although the ring-opening sequence of the above two metabolic pathways was different, the metabolism of E3 was achieved especially through continuous oxidation reactions. This study reveals that, E3 could be firstly converted to E1 and then to 4-OH-E1, and finally degraded into small molecule metabolites through two alternative pathways, thereby reducing E3 pollution in water and soil environments.

Estrogen receptor signaling and targets: Bones, breasts and brain (Review).

Estrogens are involved in a number of physiological functions, including in the development of the brain, growth, reproduction and metabolism. The biological actions of estrogens are achieved by binding to estrogen receptors (ERs) in numerous types of tissues. ERα and ERß belong to the nuclear receptor superfamily and the G­protein coupled ER1 (GPER1) is a membrane receptor. The primary biologically active estrogen, 17ß­estradiol demonstrates a high affinity for ERs. Mechanistically, estrogens bind to the ERs in the nucleus, and the complex then dimerize and bind to estrogen response elements (EREs) located in the promoter regions of the target genes. This is referred to as the genomic mechanism of ERs' function. Furthermore, ERs can also act through kinases and other molecular interactions leading to specific gene expression and functions, referred to as the non­genomic mechanism. While ERα and ERß exert their functions via both genomic and non­genomic pathways, GPER1 exerts its function primarily via the non­genomic pathways. Any aberrations in ER signaling can lead to one of a number of diseases such as disorders of growth and puberty, fertility and reproduction abnormalities, cancer, metabolic diseases or osteoporosis. In the present review, a focus is placed on three target tissues of estrogens, namely the bones, the breasts and the brain, as paradigms of the multiple facets of the ERs. The increasing prevalence of breast cancer, particularly hormone receptor­positive breast cancer, is a challenge for the development of novel antihormonal therapies other than tamoxifen and aromatase inhibitors, to minimize toxicity from the long treatment regimens in patients with breast cancer. A complete understanding of the mechanism of action of ERs in bones may highlight options for novel targeted treatments for osteoporosis. Likewise, the aging of the brain and related diseases, such as dementia and depression, are associated with a lack of estrogen, particularly in women following menopause. Furthermore, gender dysphoria, a discordance between experienced gender and biological sex, is commonly hypothesized to emerge due to discrepancies in cerebral and genital sexual differentiation. The exact role of ERs in gender dysphoria requires further research.

Selective estrogen receptor activation prior to global cerebral ischemia in female rats impacts microglial activation and anxiety-like behaviors without effects on CA1 neuronal injury.

Estrogen receptor (ER) activation by 17-ß estradiol (E2) can attenuate neuronal injury and behavioral impairments following global cerebral ischemia (GCI) in rodents. This study sought to further examine the discrete roles of ERs through characterization of the effects of selective ER activation on post-ischemic pro-inflammatory microglial activation, hippocampal neuronal injury, and anxiety-like behaviors. Forty-six ovariectomized (OVX) adult female Wistar rats received daily s.c injections (100 µg/kg/day) of propylpyrazole triol (PPT; ERα agonist), diarylpropionitrile (DPN; ERß agonist), G-1 (G-protein coupled ER agonist; GPER), E2 (activating all receptors), or vehicle solution (VEH) for 21 days. After final injection, rats underwent GCI via 4-vessel occlusion (n=8 per group) or sham surgery (n=6, vehicle injections). The Open Field Test (OFT), Elevated Plus Maze (EPM), and Hole Board Test (HBT) assessed anxiety-like behaviors. Microglial activation (Iba1, CD68, CD86) in the basolateral amygdala (BLA), CA1 of the hippocampus, and paraventricular nucleus of the hypothalamus (PVN) was determined 8 days post-ischemia. Compared to sham rats, Iba1 activation and CA1 neuronal injury were increased in all ischemic groups except DPN-treated rats, with PPT-treated ischemic rats also showing increased PVN Iba1-ir expression. Behaviorally, VEH ischemic rats showed slightly elevated anxiety in the EPM compared to sham counterparts, with no significant effects of agonists. While no changes were observed in the OFT, emotion regulation via grooming in the HBT was increased in G-1 rats compared to E2 rats. Our findings support selective ER activation to regulate post-ischemic microglial activation and coping strategies in the HBT, despite minimal impact on hippocampal injury.

Consumption of Phytoestrogens Affects Bone Health by Regulating Estrogen Metabolism.

Osteoporosis is a significant concern in bone health, and understanding its pathomechanism is crucial for developing effective prevention and treatment strategies. This article delves into the relationship between estrogen metabolism and bone mineralization, shedding light on how phytoestrogens can influence this intricate process. Estrogen, a hormone primarily associated with reproductive health, plays a pivotal role in maintaining bone density and structure. The article explores the positive effects of estrogen on bone mineralization, highlighting its importance in preventing conditions like osteoporosis. Phytoestrogens, naturally occurring compounds found in certain plant-based foods, are the focal point of the discussion. These compounds have the remarkable ability to mimic estrogen's actions in the body. The article investigates how phytoestrogens can modulate the activity of estrogen, thereby impacting bone health. Furthermore, the article explores the direct effects of phytoestrogens on bone mineralization and structure. By regulating estrogen metabolism, phytoestrogens can contribute to enhanced bone density and reduced risk of osteoporosis. Finally, the article emphasizes the role of plant-based diets as a source of phytoestrogens. By incorporating foods rich in phytoestrogens into one's diet, individuals may potentially bolster their bone health, adding a valuable dimension to the ongoing discourse on osteoporosis prevention. In conclusion, this article offers a comprehensive overview of 137 positions of literature on the intricate interplay between phytoestrogens, estrogen metabolism, and bone health, shedding light on their potential significance in preventing osteoporosis and promoting overall well-being.

Exploring the co-exposure effects of environmentally relevant microplastics and an estrogenic mixture on the metabolome of the Sydney rock oyster.

In aquatic environments the concurrent exposure of molluscs to microplastics (MPs) and estrogens is common, as these pollutants are frequently released by wastewater treatment plants into estuaries. Therefore, this study aimed to evaluate the independent and co-exposure impacts of polyethylene microplastics (PE-MPs) and estrogenic endocrine-disrupting chemicals (EEDCs) at environmentally relevant concentrations on polar metabolites and morphological parameters of the Sydney rock oyster. A seven-day acute exposure revealed no discernible differences in morphology; however, significant variations in polar metabolites were observed across oyster tissues. The altered metabolites were mostly amino acids, carbohydrates and intermediates of the Kreb's cycle. The perturbation of metabolites were tissue and sex-specific. All treatments generally showed an increase of metabolites relative to controls - a possible stimulatory and/or a potential hormetic response. The presence of MPs impeded the exposure of adsorbed and free EEDCs potentially due to the selective feeding behaviour of oysters to microplastics, favouring algae over similar-sized PE-MPs, and the formation of an eco/bio-corona involving faeces, pseudo-faeces, natural organic matter, and algae.

Environmentally relevant estrogens impaired spermatogenesis and sexual behaviors in male and female zebrafish.

Environmental estrogens (EEs) are found extensively in natural waters and negatively affect fish reproduction. Research on the reproductive toxicity of EEs mixtures in fish at environmentally relevant concentrations is scarce. In this study, adult male zebrafish were exposed for 60 days to EES (a mixture of EEs), EE2-low (5.55 ng/L, with an estrogenic potency equal to EES), and EE2-high (11.1 ng/L). After exposure, the expression levels of vtg1, vtg3, and esr1 in the livers in EES-treated fish remained unaltered, whereas they were significantly increased in EE2-treated fish. Both EE2-high and EES exposures notably reduced the gonad somatic index and sperm count. A disrupted spermatogenesis was also observed in the testes of EE2-high- and EES-exposed fish, along with an alteration in the expression of genes associated with spermatogonial proliferation (pcna, nanog), cell cycle transition (cyclinb1, cyclind1), and meiosis (aldh1a2, cyp26a1, sycp3). Both EE2 and EES significantly lowered plasma 11-ketotestosterone levels in males, likely by inhibiting the expression level of genes for its synthesis (scc, cyp17a1 and cyp11b2), and increased 17ß-estradiol (E2) levels, possibly through upregulating the expression of cyp19a1a. A significant increase in tnfrsf1a expression and the tnfrsf1a/tnfrsf1b ratio in EE2-high and EES-treated males also suggests increased apoptosis via the extrinsic pathway. Further investigation showed that both EE2-high and EES diminished the sexual behavior of male fish, accompanied with reduced E2 levels in the brain and the expression of genes in the kisspeptin/gonadotropin-releasing hormone system. Interestingly, the sexual behavior of unexposed females paired with treated males was also reduced, indicating a synergistic effect. This study suggests that EES have a more severe impact on reproduction than EE2-low, and EEs could interfere not only with spermatogenesis in fish, but also with the sexual behaviors of both exposed males and their female partners, thereby leading to a more significant disruption in fish reproduction.