Estrogen Treatment Research Articles

Bone Mineral Density in Transgender Adolescents Treated With Puberty Suppression and Subsequent Gender-Affirming Hormones

Bone mineral density (BMD) z scores in transgender adolescents decrease during puberty suppression with a gonadotropin-releasing hormone (GnRH) agonist. Previous research found that after short-term use of gender-affirming hormones (GAH), pretreatment z scores were not restored. Long-term follow-up studies are lacking. To assess BMD after long-term GAH treatment in transgender adults who used puberty suppression in adolescence. This single-center cohort study with follow-up duration of 15 years selected participants from a database containing all people visiting a gender identity clinic at an academic hospital in the Netherlands between 1972 and December 31, 2018. Recruitment occurred from March 1, 2020, to August 31, 2021. A total of 75 participants diagnosed with gender dysphoria who had used puberty suppression before age 18 years prior to receiving at least 9 years of long-term GAH were included. Puberty suppression with a GnRH agonist followed by GAH treatment. Lumbar spine, total hip, and femoral neck BMD and z scores before the start of puberty suppression, at start of GAH, and at short- and long-term follow-up. Among 75 participants, 25 were assigned male at birth, and 50 were assigned female at birth. At long-term follow-up, the median (IQR) age was 28.2 (27.0-30.8) years in participants assigned male at birth and 28.2 (26.6-30.6) years in participants assigned female at birth. The median (IQR) duration of GAH treatment was 11.6 (10.1-14.7) years among those assigned male at birth and 11.9 (10.2-13.8) years among those assigned female at birth. The z scores decreased during puberty suppression. In individuals assigned male at birth, the mean (SD) z score after long-term GAH use was -1.34 (1.16; change from start of GnRH agonist: -0.87; 95% CI, -1.15 to -0.59) at the lumbar spine, -0.66 (0.75; change from start of GnRH agonist: -0.12; 95% CI, -0.31 to 0.07) at the total hip, and -0.54 (0.84; change from start of GnRH agonist: 0.01; 95% CI, -0.20 to 0.22) at the femoral neck. In individuals assigned female at birth, after long-term GAH use, the mean (SD) z score was 0.20 (1.05; change from start of GnRH agonist: 0.09; 95% CI, -0.09 to 0.27) at the lumbar spine, 0.07 (0.91; change from start of GnRH agonist: 0.10; 95% CI, -0.06 to 0.26) at the total hip, and -0.19 (0.94; change from start of GnRH agonist: -0.20; 95% CI, -0.26 to 0.06) at the femoral neck. In this cohort study, after long-term use of GAH, z scores in individuals treated with puberty suppression caught up with pretreatment levels, except for the lumbar spine in participants assigned male at birth, which might have been due to low estradiol concentrations. These findings suggest that treatment with GnRH agonists followed by long-term GAH is safe with regard to bone health in transgender persons receiving testosterone, but bone health in transgender persons receiving estrogen requires extra attention and further study. Estrogen treatment should be optimized and lifestyle counseling provided to maximize bone development in individuals assigned male at birth.

Tilapia, a good model for studying reproductive endocrinology

The Nile tilapia (Oreochromis niloticus), with a system of XX/XY sex determination, is a worldwide farmed fish with a shorter sexual maturation time than that of most cultured fish. Tilapia show a spawning cycle of approximately 14 days and can be artificially propagated in the laboratory all year round to obtain genetically all female (XX) and all male (XY) fry. Its genome sequence has been opened, and a perfect gene editing platform has been established. With a moderate body size, it is convenient for taking enough blood to measure hormone level. In recent years, using tilapia as animal model, we have confirmed that estrogen is crucial for female development because 1) mutation of star2, cyp17a1 or cyp19a1a (encoding aromatase, the key enzyme for estrogen synthesis) results in sex reversal (SR) due to estrogen deficiency in XX tilapia, while mutation of star1, cyp11a1, cyp17a2, cyp19a1b or cyp11c1 affects fertility due to abnormal androgen, cortisol and DHP levels in XY tilapia; 2) when the estrogen receptors (esr2a/esr2b) are mutated, the sex is reversed from female to male, while when the androgen receptors are mutated, the sex cannot be reversed; 3) the differentiated ovary can be transdifferentiated into functional testis by inhibition of estrogen synthesis, and the differentiated testis can be transdifferentiated into ovary by simultaneous addition of exogenous estrogen and androgen synthase inhibitor; 4) loss of male pathway genes amhy, dmrt1, gsdf causes SR with upregulation of cyp19a1a in XY tilapia. Disruption of estrogen synthesis rescues the male to female SR of amhy and gsdf but not dmrt1 mutants; 5) mutation of female pathway genes foxl2 and sf-1 causes SR with downregulation of cyp19a1a in XX tilapia; 6) the germ cell SR of foxl3 mutants fails to be rescued by estrogen treatment, indicating that estrogen determines female germ cell fate through foxl3. This review also summarized the effects of deficiency of other steroid hormones, such as androgen, DHP and cortisol, on fish reproduction. Overall, these studies demonstrate that tilapia is an excellent animal model for studying reproductive endocrinology of fish.

The role of oestrogen therapy in reducing risk of Alzheimer's disease: systematic review.

Studies have shown a relationship between oestrogen and Alzheimer's disease. However, there is neither clear nor strong evidence on the use of oestrogen-only therapy in reducing the risk of Alzheimer's disease. To assess the effects of oestrogen-only therapy on reducing the risk of Alzheimer's disease. Inclusion criteria was determined with the PICO framework. Outcome was cognitive function measured by neuropsychological tests and strict protocols. Exclusion criteria included non-Alzheimer's dementia, progesterone-only therapy and pre-menopausal women. Searches were conducted in nine electronic healthcare databases, last searched in July 2022. Quality assessments conducted on randomised controlled trials (RCTs) were performed with the GRADE assessment, and cohort studies and case-control studies were assessed with the Newcastle-Ottawa Scale. Extracted data were used to analyse participants, interventions and outcomes. Twenty-four studies satisfied the search criteria (four RCTs, nine cohort studies, 11 case-control studies). Fifteen studies showed positive associations for oestrogen-only therapy reducing the risk of Alzheimer's disease, and the remaining nine found no evidence of association. Fifteen studies showed that oestrogen-only therapy effectively reduced the risk of Alzheimer's disease, whereas nine showed no correlation. Studies also investigated oestrogen-related variables such as length of oestrogen exposure, being an apolipoprotein E ε4 carrier and concomitant use of non-steroidal anti-inflammatory drugs, and their role in neuroprotection. This review was limited by the limited ranges of duration of oestrogen treatment and type of oestrogen-only therapy used. In conclusion, oestrogen-only therapy has potential for use in preventing Alzheimer's disease, although current evidence is inconclusive and requires further study.

Estrogenic regulation of claudin 5 and tight junction protein 1 gene expression in zebrafish: A role on blood-brain barrier?

The blood-brain barrier (BBB) is a physical interface between the blood and the brain parenchyma, playing key roles in brain homeostasis. In mammals, the BBB is established thanks to tight junctions between cerebral endothelial cells, involving claudin, occludin, and zonula occludens proteins. Estrogens have been documented to modulate BBB permeability. Interestingly, in the brain of zebrafish, the estrogen-synthesizing activity is strong due to the high expression of Aromatase B protein, encoded by the cyp19a1b gene, in radial glial cells (neural stem cells). Given the roles of estrogens in BBB function, we investigated their impact on the expression of genes involved in BBB tight junctions. We treated zebrafish embryos and adult males with 17β-estradiol and observed an increased cerebral expression of tight junction and claudin 5 genes in adult males only. In females, treatment with the nuclear estrogen receptor antagonist (ICI182,780 ) had no impact. Interestingly, telencephalic injuries performed in males decreased tight junction gene expression that was partially reversed with 17β-estradiol. This was further confirmed by extravasation experiments of Evans blue showing that estrogenic treatment limits BBB leakage. We also highlighted the intimate links between endothelial cells and neural stem cells, suggesting that cholesterol and peripheral steroids could be taken up by endothelial cells and used as precursors for estrogen synthesis by neural stem cells. Together, our results show that zebrafish provides an alternative model to further investigate the role of steroids on the expression of genes involved in BBB integrity, both in constitutive and regenerative physiological conditions. The link we described between capillaries endothelial cells and steroidogenic neural cells encourages the use of this model in understanding the mechanisms by which peripheral steroids get into neural tissue and modulate neurogenic activity.

OR31-01 The Dose-dependent Effect Of Estrogen On Bone Mineral Density In Trans Girls

Abstract Disclosure: L.S. Boogers: None. M.A. van der Loos: None. C.M. Wiepjes: None. A. van Trotsenburg: None. M. den Heijer: None. S.E. Hannema: None. Introduction: Treatment in transgender girls can consist of puberty suppression with Gonadotrophin-releasing hormone agonists (GnRHa) followed by estrogen treatment. A decrease in bone mineral density (BMD) Z-scores is a known effect of GnRHa. After initiation of estradiol BMD Z-scores remain relatively low, even after several years of treatment. It has been hypothesized that the estradiol dosage may be insufficient, explaining the persistently low Z-scores. Some trans girls are treated with a higher dosage of estradiol or ethinylestradiol in order to limit growth. This provides the opportunity to evaluate if a higher estradiol dosage results in a greater increase in BMD Z-scores. Methods: Trans girls diagnosed with gender dysphoria were included if they were treated with GnRHa for a minimum of one year prior to treatment with estradiol. Estradiol was increased to the regular dosage (2 mg), or high growth-reductive dosages of estradiol (6 mg) or ethinyl estradiol (100-200 μg (EE)) before the age of 18 years. BMD was assessed using DXA scans performed regularly during GnRHa and estrogen treatment. Z-scores of the lumbar spine were adjusted for height, and the development over time was compared between the different treatment groups. Results: A total of 100 trans girls were included with a mean duration of GnRHa treatment of 2.3±0.7 years. Mean BMD Z-score of the lumbar spine at start of PS was -0.26±0.84. During PS, Z-scores decreased in all three treatment groups to a mean Z-score of -0.99±0.86. After two years of estrogen treatment, Z-scores increased by 0.15 (95% CI 0.00 to 0.30) in the 2 mg estradiol group (n=65) versus 0.35 (95%CI 0.08 to 0.62) in individuals treated with 6 mg estradiol (n=21), and 0.74 (95%CI 0.27 to 1.21) in the EE group (n=14). Compared with 2 mg estradiol, the increase in trans girls treated with EE was significantly higher (0.59, 95% 0.10 to 1.08). There was no difference in individuals treated with 2 mg or 6 mg estradiol (0.20 , 95%CI -0.11 to 0.51). After three years of estrogen treatment, only in the individuals treated with EE, Z-scores were not significantly different from start of GnRHa (-0.01, 95%CI -0.38 to 0.36). Conclusion: When compared to the regular 2 mg dosage of estradiol, a higher estradiol dose, and especially treatment with EE resulted in a greater increase in BMD Z-scores in the lumbar spine in trans girls. This might indicate that 2 mg estradiol is insufficient as a maintenance dose during adolescence and that a higher adult dose is required to optimise BMD. Presentation: Sunday, June 18, 2023

Use of Fermented Red Clover Isoflavones in the Treatment of Overactive Bladder in Postmenopausal Women: A Randomized, Double-Blinded, Placebo-Controlled Trial.

Postmenopausal women are at risk of developing an overactive bladder (OAB). Conventional vaginal estrogen has shown promise for symptom relief. Isoflavones have proven effective as an alternative to estrogen treatment against menopause-related symptoms. However, its effect on OAB symptoms has not been studied. This study investigates if fermented red clover isoflavones reduce OAB symptoms in postmenopausal women. In this randomized, double-blinded, placebo-controlled trial, women were administered red clover extract (RCE) or a placebo twice daily for three months. Women filled out the International Consultation on Incontinence Questionnaire Overactive Bladder (ICIQ-OAB) and Urinary Incontinence Short Form (ICIQ-UI-SF), together with a fluid intake and voiding diary. A total of 33 women (16 in the RCE group and 17 in the placebo group) were included in the analysis. Baseline demographics and OAB characteristics were comparable across groups. Intake of RCE did not lead to significant relief in most urinary bladder symptom measures, although a significant reduction in the bother of urinary urgency (p = 0.033) and a tendency towards a decreased ICIQ-OAB score were observed (p = 0.056). In contrast, the placebo exhibited a significant decrease in the ICIQ-OAB score (p = 0.021) and in some diary outcomes. We found that an intake of isoflavones did not relieve OAB symptoms in postmenopausal women.

Efficacy of Fractional Laser on Steroid Receptors in GSM Patients.

To compare the efficacy of CO2 fractional laser with that of topical estriol for treating genitourinary syndrome of menopause and to investigate the relationship between epithelial thickness and vaginal atrophy. Twenty-five menopausal women were randomized to receive either laser or estrogen treatment. Vaginal biopsies before and after treatment were compared to assess the amount and distribution of estrogen and progesterone receptors. Estrogen receptor levels were statistically similar between groups before and after treatment. Although there was no change over time in the estrogen group, an increase in receptor levels was confirmed in the laser group. Changes in estrogen receptor levels showed no association with treatment. Progesterone receptor levels were statistically similar between groups throughout treatment. There was no change over time in both groups. These changes displayed no association with the type of treatment. There was no significant correlation between epithelium thickness and estrogen or progesterone receptor levels. Estrogen and progesterone receptor levels increased and were maintained, respectively, in the vaginal epithelium in both groups. There was no significant relationship between epithelium thickness and receptor density. Laser therapy had similar outcomes to the gold standard without involving the disadvantages of hormone therapy.

Impact of estrogen receptor expression level on response to neoadjuvant chemotherapy and prognosis in HER2-negative breast cancers

BackgroundBreast cancers with 1–10% cell staining for estrogen receptor (ER) present particular clinical features. The clinical data of estrogen receptor expression level and treatment effect are limited, particularly regarding chemotherapy benefit. We evaluated the pathologic response to neoadjuvant chemotherapy (NAC) in ER low positive tumors (ER staining 1-10%) and compared it with ER > 10% positive tumors (ER staining > 10%) and ER-negative tumors. We further explored the differences in recurrence and survival with respect to the ER expression level.MethodPatients with stages II and III HER2-negative primary breast cancer who received neoadjuvant chemotherapy followed by definitive surgery were categorized according to their ER percentages into three groups: ER-negative, ER low positive, and ER > 10% positive. Logistic regression models were used to assess the association between each variable and pathologic complete response (pCR). Kaplan‒Meier analysis was used to estimate survival outcomes. Cox models were used to adjust for patient and tumor characteristics.ResultsA total of 241 patients were analyzed. Of all patients included, 22 (9.1%) had ER low positive tumors, 159 (66.0%) had ER > 10% positive tumors, and 60 (24.9%) were ER-negative. Low ER positivity was significantly associated with a higher pCR rate than ER > 10% positivity (OR, 0.249; 95% CI, 0.067–0.923; P = 0.038). After a median follow-up time of 32 months, the disease-free survival (DFS) and overall survival (OS) of the patients with ER low positive tumors were significantly worse than those of the patients with ER > 10% positive tumors but similar to those with ER-negative tumors. After adjustment for covariates, ER low positive tumors were significantly associated with worse DFS than ER > 10% positive tumors.ConclusionOur results indicated that ER low positive breast cancer presents a better response to neoadjuvant chemotherapy and significantly worse prognosis for patients than those with ER > 10% positive tumors, but similar to the ER-negative group. These data support that this category of patients behaves clinically like patients with ER-negative breast cancer and should be treated differently from patients with ER > 10% positive tumors. Further prospective study is needed.

Oestrogen treatment restores dentate gyrus development in premature newborns by IGF1 regulation.

Prematurely-born infants cared for in the neonatal units suffer from memory and learning deficits. Prematurity diminishes neurogenesis and synaptogenesis in the hippocampal dentate gyrus (DG). This dysmaturation of neurons is attributed to elevated PSD95, NMDR2A, and IGF1 levels. Since oestrogen treatment plays key roles in the development and plasticity of DG, we hypothesized that 17β-estradiol (E2) treatment would ameliorate neurogenesis and synaptogenesis in the DG, reversing cognitive deficits in premature newborns. Additionally, E2-induced recovery would be mediated by IGF1 signalling. These hypotheses were tested in a rabbit model of prematurity and nonmaternal care, in which premature kits were gavage-fed and reared by laboratory personnel. We compared E2- and vehicle-treated preterm kits for morphological, molecular, and behavioural parameters. We also treated kits with oestrogen degrader, RAD1901, and assessed IGF1 signalling. We found that E2 treatment increased the number of Tbr2+ and DCX+ neuronal progenitors and increased the density of glutamatergic synapses in the DG. E2 treatment restored PSD95 and NMDAR2A levels and cognitive function in preterm kits. Transcriptomic analyses showed that E2 treatment contributed to recovery by influencing interactions between IGF1R and neurodegenerative, as well as glutamatergic genes. ERα expression was reduced on completion of E2 treatment at D7, followed by D30 elevation. E2-induced fluctuation in ERα levels was associated with a reciprocal elevation in IGF1/2 expression at D7 and reduction at D30. ERα degradation by RAD1901 treatment enhanced IGF1 levels, suggesting ERα inhibits IGF1 expression. E2 treatment alleviates the prematurity-induced maldevelopment of DG and cognitive dysfunctions by regulating ERα and IGF1 levels.

Estrogen receptor alpha regulates uterine epithelial lineage specification and homeostasis

Postnatal development of the uterus involves specification of undifferentiated epithelium into uterine-type epithelium. That specification is regulated by stromal-epithelial interactions as well as intrinsic cell-specific transcription factors and gene regulatory networks. This study utilized mouse genetic models of Esr1 deletion, endometrial epithelial organoids (EEO), and organoid-stromal co-cultures to decipher the role of Esr1 in uterine epithelial development. Organoids derived from wild-type (WT) mice developed a normal single layer of columnar epithelium. In contrast, EEO from Esr1 null mice developed a multilayered stratified squamous type of epithelium with basal cells. Co-culturing Esr1 null epithelium with WT uterine stromal fibroblasts inhibited basal cell development. Of note, estrogen treatment of EEO-stromal co-cultures and Esr1 conditional knockout mice increased basal epithelial cell markers. Collectively, these findings suggest that Esr1 regulates uterine epithelium lineage plasticity and homeostasis and loss of ESR1 promotes altered luminal-to-basal differentiation driven by ESR1-mediated paracrine factors from the stroma.

Abstract P3115: Disruption Of Assembly By Estrogen Limits Microtubule Proliferation In Failing Heart Cells

Right heart failure, resulting from high pressure in the pulmonary artery, is the leading cause of mortality in pulmonary arterial hypertension (PAH). Interestingly, females with PAH have superior right ventricular (RV) function, which can mostly explain improved survival in female patients. Microtubules are long filaments that regulate cellular contractility and transport within cardiac cells. The excess proliferation of microtubules is associated with pathological t-tubule remodeling in failing RV cardiomyocytes. Previous work suggests that the female hormone estrogen disrupts microtubule assembly. Here, we explored whether estrogen treatment could ameliorate the pathological proliferation of microtubules. By utilizing iPSC-derived cardiomyocytes with live-cell confocal imaging, we show that estrogen treatment leads to long pausing during microtubule growth, like the microtubule inhibitor colchicine. Additionally, estrogen treatment rescues microtubule overgrowth in endothelin-stressed primary cardiomyocytes (Fig. 1). We examined the molecular mechanism using purified tubulin, the building block of microtubules, and estrogen. In cell-free experiments, estrogen induced long pauses in microtubule growth. Our preliminary data suggest that estrogen, like colchicine, binds to free tubulin and co-polymerizes with it, disrupting microtubule assembly independent of estrogen receptors. We conclude that estrogen’s ability to limit microtubule proliferation could contribute to sex differences in RV function in PAH. Figure 1: Primary cardiomyocytes. Microtubule proliferation in endothelin-treated cells was rescued with estradiol.

Duration of oestrogen exposure does not affect reproductive outcome in artificial cycles: a retrospective analysis of more than 7000 hormonal replacement therapy cycles for an embryo transfer.

Optimal duration of oestrogen exposure before an embryo transfer in artificial cycles has not been defined yet, as its correlation with reproductive outcome remains controversial. The length of oestrogen treatment before starting luteal phase support varies significantly among patients. In this study, we conducted a retrospective analysis of a huge database of our own clinical results in artificial cycles in the past five years. The aim of this study was to assess the effect of the length of estrogen exposure on reproductive outcome and to evaluate if there is any optimal duration of estrogen exposure in order to maximize success rates. Differences in pregnancy rates according to oestrogen length, if present, were not clinically relevant. Our results suggest that the length of oestrogen exposure (in days) before exogenous progesterone administration do not affect clinical outcomes.

The duration of estrogen treatment before progesterone application does not affect neonatal and perinatal outcomes in frozen embryo transfer cycles.

To explore whether the duration of estrogen treatment before progesterone application affects neonatal and perinatal outcomes in artificial frozen embryo transfer (FET) cycles. This was a retrospective cohort study. Patients who underwent FET via artificial cycles and delivered a singleton live birth between January 2015 and August 2019 were included in the analysis. According to the duration of estrogen treatment before progesterone application, we divided the cycles into four groups: ①≤12 days, ②13-15 days, ③16-19 days, and ④≥20 days. The '≤12 days group' was considered the reference group. The main outcome measures were preterm birth (PTB), small-for-gestational age (SGA), low birth weight (LBW), macrosomia, large-for-gestational age (LGA), gestational diabetes mellitus (GDM), gestational hypertension, premature rupture and placenta previa. Overall, 2010 FET cycles with singleton live births were included for analysis. Cycles were allocated to four groups according to the duration of estrogen treatment before progesterone application: ①≤12 days (n=372), ②13-15 days (n=745), ③16-19 days (n=654), ④≥20 days (n=239). The neonatal outcomes, including PTB, SGA, LBW, macrosomia and LGA, were comparable among the groups (P=0.328, P=0.390, P=0.551, P=0.565, P=0.358). The rates of gestational hypertension, premature rupture and placenta previa (P=0.676, P=0.662, P=0.211) were similar among the groups. The rates of GDM among the four groups were 4.0% (15/372), 6.7% (50/745), 6.4% (42/654), and 11.3% (27/239), with statistical significance (P=0.006). After multiple logistic regression analysis, the duration of estrogen treatment did not affect the rate of GDM or other outcomes. The estrogen treatment duration before progesterone application does not affect neonatal and perinatal outcomes in single frozen blastocyst transfer cycles.

Transient receptor potential M2 channel in the hypothalamic preoptic area and its impact on thermoregulation during menopause

BackgroundDecreased estrogen levels can cause abnormal thermosensitivity of the preoptic area (POA) in the hypothalamus during menopause, which may cause hot flashes. Thermosensitive transient receptors (ThermoTRPs) affect the thermosensitivity of neurons. It is worth exploring whether ThermoTRPs change under low estrogen state and participate in the abnormal thermoregulation of POA. MethodsAdult female Sprague–Dawley rats were randomly divided into sham operation (SHAM), ovariectomy (OVX) and estrogen treatment after ovariectomy (OVX+E) groups. Under 10 ℃, 18 ℃, 25 ℃, 37 ℃ and 45 ℃ incubations, their skin temperature was monitored and the expression of TRPA1, TRPM8, TRPM2, and TRPV1 in POA were investigated. ResultsThe skin temperature of ovariectomized rats changed faster and more dramatically under different incubation temperatures. The results at mRNA level show that only the expression of TRPM2 decreased in POA of OVX group compared with the other two groups at 25 ℃, TRPA1 expression in POA of the three groups increased at 10 ℃, TRPM8 increased at 10 ℃ and 18 ℃, TRPV1 increased at 10 ℃ and 45 ℃, while the expression of TRPM2 decreased at 10 ℃ and 18 ℃ and increased at 37 ℃ and 45 ℃. In all these cases, the magnitudes of the changes were less in the OVX group relative to the other two groups. The further immunohistochemical and Western blot results of TRPM2 and the activated TRPM2 positive cells labeled by c-Fos were consistent with the results of mRNA level. ConclusionsThe expression and thermosensitivity of TRPM2 in POA changed greatly under different incubation temperatures, but the changes in ovariectomized rats were less. This may be the key factor triggering thermoregulation dysfunction under low estrogen and may cause hot flashes.

Expression and function of estrogen receptors and estrogen-related receptors in the brain and their association with Alzheimer's disease.

While estrogens are well known for their pivotal role in the female reproductive system, they also play a crucial function in regulating physiological processes associated with learning and memory in the brain. Moreover, they have neuroprotective effects in the pathogenesis of Alzheimer's disease (AD). Importantly, AD has a higher incidence in older and postmenopausal women than in men, and estrogen treatment might reduce the risk of AD in these women. In general, estrogens bind to and activate estrogen receptors (ERs)-mediated transcriptional machineries, and also stimulate signal transduction through membrane ERs (mERs). Estrogen-related receptors (ERRs), which share homologous sequences with ERs but lack estrogen-binding capabilities, are widely and highly expressed in the human brain and have also been implicated in AD pathogenesis. In this review, we primarily provide a summary of ER and ERR expression patterns in the human brain. In addition, we summarize recent studies on their role in learning and memory. We then review and discuss research that has elucidated the functions and importance of ERs and ERRs in AD pathogenesis, including their role in Aβ clearance and the reduction of phosphorylated tau levels. Elucidation of the mechanisms underlying ER- and ERR-mediated transcriptional machineries and their functions in healthy and diseased brains would provide new perspectives for the diagnosis and treatment of AD. Furthermore, exploring the potential role of estrogens and their receptors, ERs, in AD will facilitate a better understanding of the sex differences observed in AD, and lead to novel sex-specific therapeutic approaches.

The response of the brood pouch transcriptome to synthetic estrogen exposure in the Gulf pipefish (Syngnathus scovelli)

Endocrine disruptors have devastating impacts on the reproductive physiology of aquatic organisms. The Gulf pipefish, Syngnathus scovelli, is a sexually dimorphic species, which demonstrates predictable morphological, physiological, behavioral, and genetic responses to synthetic estrogen exposure. It has a broad geographic range, spanning freshwater and marine environments, making it a potential sentinel species across a wide range of habitats. In this study, we investigated the effects of ecologically relevant levels of 17α-ethinylestradiol (EE2) exposure on gene expression patterns in the male pipefish’s brood pouch. We also characterized the extent to which EE2-exposed males developed coloration patterns that are normally restricted to females. We identified differentially expressed genes in the brood pouches of pregnant and non-pregnant males when males were exposed to 5ng/L EE2 from the second to eighth day of pregnancy (which normally lasts about 2 weeks). Our result revealed several potential candidate genes that have a role in the brood pouch’s response to environmental estrogens. We also identified genes that were differentially expressed between mid-gestation pregnant males and non-pregnant males. We found an overall greater effect of EE2 exposure in the transcriptomes of non-pregnant males, which may explain why estrogen-exposed males exhibited difficulty receiving eggs in previous studies. The offspring developed similarly in the control and estrogen treatments, highlighting a potential link between the timing of EE2 exposure and its effects on male pregnancy. These results provide insight into how breeding pipefish populations may still exist even though they are found in freshwater and coastal locations where they are periodically exposed to potentially high concentrations of endocrine-disrupting compounds. We also present examples of female-typical coloration development on males due to EE2 exposure and identify candidate brood pouch genes that can be utilized as biomarkers, contributing to the development of the Gulf pipefish as a sentinel model for ecotoxicology.

Evaluation of a polymeric topical formulation of Endoxifen in an estrogen receptor positive breast cancer murine model

Breast cancer (BC) has surpassed lung cancer as the most diagnosed cancer and, in terms of mortality, is the fifth leading cause with 684,996 new deaths (6.7% of all cancer-related deaths) and the highest mortality amongst all cancers (15.5%) in women. Selective estrogen-receptor modulators (SERMs) have been used for the last thirty years for estrogen receptor-positive (ER+) BC prevention and treatment. Tamoxifen (TAM), the most widely used SERM, is orally administered and its long-term oral administration has been associated to toxicity and adverse side effects. Endoxifen (EDX) is one of the known active metabolites of TAM, with an affinity to ERα 100 times higher than TAM. Furthermore, EDX has shown antiproliferative activity against the ER+ BC cell line MCF-7. Alternative administration routes that avoid the metabolic processing of TAM seem an appealing alternative to its oral administration. With this aim, we have prepared a polymeric gel-like solution of Pluronic® F127 as vehicle for topical administration of EDX. In order to shed light on the potential clinical use of this formulation, we have compared it with the standard pharmaceutical form, i.e. orally administered TAM. The biodistribution, antitumor efficacy and toxic effects of topical EDX and oral TAM were evaluated in ER+ tumor xenograft athymic nu/nu mouse models. The results showed a statistically significant antitumor effect and reduced toxicity of topical EDX as compared to oral TAM or empty F127 gel. This novel administration route of SERMs could also have a strong impact in the prevention of BC at early development stages and could help to ameliorate the mortality and morbidity related to this disease.

P-620 First step for personalized luteal support in frozen-thaw embryo transfer: Understanding the factors associated with serum progesterone concentrations on embryo transfer day

Abstract Study question What factors determine serum progesterone (P) concentration on embryo transfer (ET) day after artificially prepared (AP) cycles receiving intramuscular progesterone (IM-P)? Summary answer Lower serum P concentrations on ET day in AP frozen-thaw cycles are associated with high body mass index(BMI) and low estradiol(E2) levels on ET day. What is known already Large sample sized studies reported low serum P levels on ET day in AP cycles related to low success rates. There are limited studies evaluating the pregnancy rates in patients with low serum P on ET day after the rescue doses. These studies included the patients who received vaginal P. There is no study evaluating rescue doses with low serum P concentration after IM-P. Common sense is that personalization of luteal phase support may increase the success rates. To adjust the P dosages, patient and cycle characteristics need to be analyzed for prediction of low serum P concentration. Study design, size, duration This retrospective cohort study conducted at Bahçeci Ankara IVF Center between November 2019 and February 2022. The study included 637 single or double frozen-thawed blastocyst transfers undergoing AP endometrium receiving 100 mg IM-P after incremental oestrogen treatment. Serum P concentrations were evaluated from the blood samples which were obtained between 117-119 hours after the first IM-P administration and 21±2 hours after last IM-P administration. Participants/materials, setting, methods A total of 637 patients, first frozen-thawed blastocyst ET cycles were analyzed. The mean age, BMI, duration of oestrogen treatment, ET day E2 and ET day P concentration of the study population were 31.9±5.1 years, 26.7 ±4.7 kg/m2, 13.9±1.3 days, 266.1±90.9 pg/ml and 30.2±9.3 ng/ml respectively. Correlation analysis for patient and cycle characteristics and serum P concentrations were evaluated. Multivariate linear regression analysis was performed to determine the independent factors. Main results and the role of chance The overall live birth rate in total study group was 50.7% (323/637). Female age, serum P concentrations on ET day, and number of embryos transferred were significantly associated with live birth. Bivariate correlation analysis revealed that ET day P concentrations were negatively correlated to BMI (r:-0.12, p: 0.002) and positively correlated to ET day E2 concentrations (r:0.14, p:0.001). However, no correlation to female age, causes of infertility, E2, P and LH concentrations on P administration day, duration of oestrogen treatment and presence or absence of GnRH agonist suppression. When a multivariate linear regression was performed to correct potential confounders, increasing BMI presented a negative correlation to ET day serum P concentrations (p = 0.003; 95% CI -0.384 to -0.079 ). On the contrary, significant positive correlations to ET day serum P concentrations were shown with ET day E2 levels (p = 0.01; 95% CI 0.003 to 0.018). Other patient and cycle characteristics were not found to be an independent factor for ET day P concentration. Limitations, reasons for caution The retrospective nature of the study is the main limitation. Only patients with IM-P were included therefore the results cannot be extrapolated to other P administration forms and needs to be validated. After determining the low serum P threshold in large sample size, the parameters should be re-evaluated. Wider implications of the findings Monitoring P levels and adjusting the doses of P administration (via personalization) may have a positive impact on outcome. Not only patient and cycle characteristics, also pharmacokinetic and pharmacogenetic studies are warranted to optimize luteal phase support. Personalization of the luteal phase can be achieved by this way. Trial registration number NA

P-333 Thin endometrium, randomised clinical trial using plasma rich in growth factors

Abstract Study question Does the use of platelet growth factors instilled into thin endometrium in oestrogen-replacement treatment cycles improve endometrial thickness? Summary answer The use of growth factors in thin endometrium improves endometrial growth What is known already Thin endometrium impairs implantation rates and IVF outcomes. To date there is no effective treatment to improve the proliferation. PRGF-Endoret is used in multiple clinical indications. The autologous collection of growth factors (PRGF), applied to the area to be treated, produces a controlled release of multiple molecules with regenerative capacity in the focus of the lesion. Study design, size, duration Prospective randomised clinical trial to determine the effects of PRGF-ENDORET therapy in patients with thin endometrium undergoing oestrogen treatment for embryo transfer. Twenty-two patients were included from March 2018 to May 2021. At the end of the trial, a complementary retrospective study was conducted analysing all the treatments of these patients without live birth(21) before and after participating in the study until December 2022. 15 embryotransfer in study group and 27 in control group. Participants/materials, setting, methods Patients of IVI Bilbao clinic with endometrium less than or equal to 5mm after 10 days of treatment. PRGF was prepared according to the PRGF-Endoret technique using the medical device developed by BTI Biotechnology Institute. The study group received three instillations of PRGF Endoret using a kitazato IUI cannula. The first instillation was performed with in situ activated coagulum and the 2nd and 3rd instillations with PRGF-rich supernatants that were previously stored at -20 °C. Main results and the role of chance The clinical trial showed a significant increase in endometrial thickness 1.3 ± 0.67 mm compared to the control group of 0.58 ± 0.51 mm. Prior to treatment the mean endometrial thickness was 4.29 ± 0.88 in the control group and 4.44 ± 0.40 in the study group. After randomisation the mean was 4.87 ± 0.76 in the control group and 5.74 ± 0.87 in the study group. 2 pregnancies only in the study group and 1 live birth. The retrospective study shows 0.7mm increase in mean endometrial thickness in the post-PRGF cycles in the study group patients. Of the 15 transfers that were performed a posteriori, there were implantation rate of 40% and a 20% live birth rate, 40% biochemical miscarriage and 20% clinical miscarriage, with a significant increase of 0.94mm compared to the endometrium of the instillation cycle. In the control group of patients who received a posteriori factors there was also a significant increase in thickness of 1.6mm compared to the study cycle with an implantation rate of 58.33% and a 33% live birth rate, 58.33 biochemical miscarriage and 25% clinical miscarriage. Comparing all the cycles of these patients before and after PRGF, no statistical significance was found, although there was an increase of 0.29mm. Limitations, reasons for caution The number of patients included was lower than initially planned, but once the statistical power was adjusted, its safety and efficacy was demonstrated. More studies should be done to demonstrate when to instil, how many times, when transfer, but it is clear that it is safe and effective. Wider implications of the findings The use of factors has been shown to increase endometrial thickness. It could be thought to open the door to favouring endometrial receptivity and therefore live birth. Trial registration number 2016-001716-38

P-792 The effect of subendometrial injection of autologous platelet rich plasma (PRP) guided by hysteroscopy in recurrent implantation failure patients - A pilot study

Abstract Study question Does the subendometrial injection of autologous platelet-rich plasma (PRP) guided by hysteroscopy achieve successful pregnancy outcome in recurrent implantation failure patients? Summary answer In this study we observed that subendometrial injection of autologous PRP is associated with higher implantation rates in recurrent implantation failure patients. What is known already The key success factors in IVF are to have a good endometrium lining and vascularity for successful implantation. These two factors directly affect the pregnancy outcomes of IVF. Although several approaches have been attempted to address these factors including estrogen treatment, aspirin, sildenafil, vitamin E, Granulocyte-Colony Stimulating Factor (G-CSF), there is no efficient method described. Additionally, some cases do not show a response to the medical treatment. In those cases, specifically, in previously failed IVF patients autologous Platelet Rich Plasma (PRP) injection into the sub-endometrial cavity with an ovum pick up needle has been preferred, as confirmed by literature. Study design, size, duration An open label, single center study. Total 130 women were selected for hysteroscopic instillation of PRP, all patients have previous unsuccessful IVF attempts in our clinic or were referred to our clinic. Study participants are of age 23 to 49 years. Study began in July 2020 and was completed in December 2022. Participants/materials, setting, methods 2 ml of autologous PRP was instilled in the junctional zone using a wallace needle through the hysteroscope's operating channel to inject the PRP beneath the superficial endometrium from day 6-14 of menstrual cycle. FET preparation was started from Day 2/3 of next menstrual cycle using 6 mg/daily estradiol hemihydrate (EV Active Tab CORONA Remedies). Main results and the role of chance Women who received hysteroscopic instillation of PRP in the sub-endometrial junction had higher pregnancy rates (82/130 [63.07%] (P-value = <0.05). In the subsequent cycle monitored to day 15, Endometrial thickness (ET) was 7 mm or thicker in 90 of 130 patients [69.23%] (P-value = <0.05) and 6-7 mm in 8 of 130 patients [6.15%]. Endometrial thickness did not improve in 32 of 130 patients [24.61%] and remained below 6 mm. Subendometrial blood flow increased significantly in 92 of 130 patients [70.76%] (P-value = <0.05). The mean increase in ET was 1.5 to 2 mm. The instillation of PRP caused no side effects and was well tolerated by all patients. In 47 patients (36.15%) we did not achieve clinical pregnancy while 1 had a biochemical pregnancy Based on paired ‘t’ test, it is concluded that there is statistically significant improvement in ET, vascularity and successful pregnancy outcome after PRP instillation. Limitations, reasons for caution Little is known about the best dosage and time for the instillation of PRP in endometrium. The importance of standard yet simple techniques and a highly repeatable protocol for clinical use is deciding factor which yet to finalize. It involves invasive procedure so may cause infections and anesthesia related complications. Wider implications of the findings Although PRP has still not gained universal acceptance in previously failed IVF patients for a variety of reasons, emerging evidences suggests that PRP could be an effective option compared to conventional approach especially, in patients with thin endometrium, advanced maternal age and primary ovarian insufficiency. Trial registration number Not applicable