E2 Deficiency Research Articles

New endocrine method of oral male contraception.

Essential for hormonal male contraception (HMC) is the inhibition of follicle-stimulating hormone (FSH), the hormone responsible for spermatogenesis. No drugs exist that can selectively suppress FSH without also inhibiting luteinizing hormone (LH), the hormone responsible for the biosynthesis of testosterone (T) and estradiol (E2) in men. The consequences are a loss of T and E2, with the accompanying symptoms and signs of T deficiency and E2 deficiency, respectively. The loss of T causes sexual function problems, including reduced libido and problems with erection and ejaculation. Moreover, T is not orally bioavailable, and there is a lack of suitable, orally bioavailable androgens to replace the loss of T. This has led to the use of nonoral T replacements, such as patches, gels, or parenteral administration of T or other androgens in current methods for HMC under development. In case these new HMC methods do not contain a testosterone preparation that is metabolized into E2, the suppression of LH will cause loss of E2 and symptoms of estrogen deficiency. We propose to investigate a new oral endocrine approach for HMC using a triple hormone drug called MANTE (Male oral contraception by a GnRH ANtagonist, Testosterone and an Estrogen). This method combines three novelties: (1) the use of an oral gonadotrophin-releasing hormone antagonist to suppress FSH and spermatogenesis, (2) a high dose of the natural adrenal androgen dehydroepiandrosterone to replace T, and (3) a low dose of an orally bioavailable estrogen, preferably estetrol (E4), to prevent signs and symptoms of estrogen deficiency.

The Loss of Estradiol by Androgen Deprivation in Prostate Cancer Patients Shows the Importance of Estrogens in Males.

The role of estradiol (E2; an estrogen) in men needs to be more appreciated. In this review, we address the clinical situations that allow the study of the clinical consequences of E2 deficiency in men and discuss the effects of restoration of levels of this reproductive steroid hormone. In men with advanced prostate cancer (PCa) undergoing androgen deprivation therapy (ADT), E2 is suppressed along with testosterone, leading to side effects affecting the quality of life. These include hot flashes, arthralgia, fatigue, mood changes, cognition problems, weight gain, bone loss, and increased risk of cardiovascular disease. Transdermal E2 alone for ADT has shown equivalent testosterone suppression compared to gonadotropin-releasing hormone (GnRH) agonists while also preventing estrogen-deficiency side effects, including hot flashes and bone loss. Co-treatment of ADT with fetal estrogen estetrol (E4) has shown significant improvements of estrogen-deficiency symptoms. These observations emphasize the need to raise awareness of the importance of estrogens in men among clinicians and the lay public.

Saturated fatty acids and omega-3 polyunsaturated fatty acids improve metabolic parameters in ovariectomized female mice.

In menopausal and postmenopausal women, obesity, cardiovascular disease, osteoporosis and gut dysbiosis are induced by loss of ovarian 17β-estradiol (E2). Dietary fatty acid profile high in omega-6 polyunsaturated fatty acids (PUFAs), specifically linoleic acid (LA), and low in coconut oil saturated fatty acids (SFAs) and omega-3 PUFAs may worsen symptoms of estrogen deficiency. To investigate this hypothesis, vehicle (Veh)- or estradiol benzoate (EB)-treated ovariectomized C57BL/6J and transgenic fat-1 mice were fed high-fat diet (HFD, 45% kcal fat) with a high LA:SFA ratio (22.5%:8%; 22.5% LA diet) or a HFD with a low LA:SFA ratio (1%:31%; 1% LA) diet for a period of 14-15 weeks. EB treatment rescued obesity, glucose intolerance, and bone loss in OVX mice. fat-1 mice fed 1% LA diet mitigated weight gain and adiposity in Veh-treated OVX mice. fat-1 mice fed 22.5% LA diet had increased EE and activity as wheel running in EB-treated OVX mice. Except for EB treatment, coconut oil SFAs and omega-3 FAs can protect against glucose intolerance. Apparent improvement of insulin sensitivity was achieved by EB treatment in both WT and fat-1 mice fed 1% LA diet, while fat-1 mice fed 22.5% LA diet was protected against insulin resistance without EB treatment. Increase of relative abundance of gut microbial taxa as SCFA producers were associated with omega-3 FAs production and improved energy homeostasis. These data suggest that a balanced dietary FA profile containing coconut oil SFAs, and a lower ratio of omega-6/omega-3 FAs is a safer strategy for alleviating metabolic disorders during E2 deficiency.

Common Regulators of Lipid Metabolism and Bone Marrow Adiposity in Postmenopausal Women.

A variety of metabolic disorders are associated with a decrease in estradiol (E2) during natural or surgical menopause. Postmenopausal women are prone to excessive fat accumulation in skeletal muscle and adipose tissue due to the loss of E2 via abnormalities in lipid metabolism and serum lipid levels. In skeletal muscle and adipose tissue, genes related to energy metabolism and fatty acid oxidation, such as those encoding peroxisome proliferator-activated receptor-γ coactivator 1α (PGC-1α) and estrogen-related receptor alpha (ERRα), are downregulated, leading to increased fat synthesis and lipid metabolite accumulation. The same genes regulate lipid metabolism abnormalities in the bone marrow. In this review, abnormalities in lipid metabolism caused by E2 deficiency were investigated, with a focus on genes able to simultaneously regulate not only skeletal muscle and adipose tissue but also bone metabolism (e.g., genes encoding PGC-1α and ERRα). In addition, the mechanisms through which mesenchymal stem cells lead to adipocyte differentiation in the bone marrow as well as metabolic processes related to bone marrow adiposity, bone loss, and osteoporosis were evaluated, focusing on the loss of E2 and lipid metabolic alterations. The work reviewed here suggests that genes underlying lipid metabolism and bone marrow adiposity are candidate therapeutic targets for bone loss and osteoporosis in postmenopausal women.

Male Idiopathic Hypogonadotropic Hypogonadism: Serum Insulin-like Growth Factor-1 and Oestradiol Levels.

Idiopathic hypogonadotropic hypogonadism (IHH) is a form of male infertility caused by a congenital defect in the secretion or action of gonadotropin-releasing hormone from the hypothalamus. Oestradiol emerged as the main sex steroid in the regulation of the hypothalamic-pituitary-testicular axis, reproductive function and growth hormone/insulin-like growth factor-1 (GH/IGF-1) axis in men. Moreover, GH/IGF-1 axis has been suggested to play a role in IHH. This study evaluated serum IGF-1 in IHH men and controls. Furthermore, we evaluated the association between serum total oestradiol (TE2) and IGF-1 levels in patients and controls. Parameters including age, body mass index and fertility history were analysed. This prospective study was conducted at the Royan institute. In 20 men with IHH and 20 controls, serum IGF-1 levels were estimated using chemiluminescence immunoassay and serum E2 levels were assessed by means of the electrochemiluminescence method. Kolmogorov-Smirnov test, parametric t-test or the Mann-Whitney and the Pearson correlation coefficient were performed. SPSS version 22 was used for the analysis of data. There was a significant decrease in serum IGF-1 levels in IHH patients compared with controls (145.1 ± 8.9 ng/ml vs. 229.6 ± 7.3 ng/ml P < 0.001, respectively). Furthermore, a significant decrease was observed in TE2 levels in IHH male patients (12.3 ± 2.5 pg/ml) compared with controls (31.9 ± 5.3 pg/ml P < 0.001). A positive correlation was observed between serum IGF-1 and TE2 levels in the total number of participants, suggesting that E2 deficiency in IHH cases can explain the lower levels of serum IGF-1. These findings suggest that the reduction in IGF-1 levels may be associated with the influence of E2 on the GH/IGF-1 axis, and may confirm the role of the GH/IGF-1 axis in IHH. Further investigations will be required to determine the exact mechanisms by which E2 and IGF-1 affect the reproductive neuroendocrine function.

MP49-12 A NOVEL BLADDER FIBROSIS PATHWAY THROUGH PDGFRα + CELLS ASSOCIATED WITH ESTROGEN DEFICIENCY AND REPLACEMENT

You have accessJournal of UrologyCME1 May 2022MP49-12 A NOVEL BLADDER FIBROSIS PATHWAY THROUGH PDGFRα+ CELLS ASSOCIATED WITH ESTROGEN DEFICIENCY AND REPLACEMENT Ken Lee, Masatoshi Eto, Kenton Sanders, and Sang don Koh Ken LeeKen Lee More articles by this author , Masatoshi EtoMasatoshi Eto More articles by this author , Kenton SandersKenton Sanders More articles by this author , and Sang don KohSang don Koh More articles by this author View All Author Informationhttps://doi.org/10.1097/JU.0000000000002624.12AboutPDF ToolsAdd to favoritesDownload CitationsTrack CitationsPermissionsReprints ShareFacebookLinked InTwitterEmail Abstract INTRODUCTION AND OBJECTIVE: E2 deficiency may induce fibrosis that leads to bladder dysfunction. We aimed at studying the effects of E2 on bladder function and assessing changes of bladder PDGFRα+ cells associated with inflammation and fibrosis. METHODS: C57BL/6 female mice were bilaterally ovariectomized (OVX) or sham surgery was performed at 7 weeks old and then E2 was applied subcutaneously in OVX mice for two weeks before experiment. Each protocol was done 1, 3 and 7 months after OVX. In vivo cystometrogram (CMG), mice were restrained with specific holder under awake condition. qPCR, western blotting (WB) and immunohistochemistry (IHC) was carried out to investigate the relationship between E2 deficiency/replacement and fibrosis marker. To further explore this, bladder was divided into urothelium/suburothelial layer (UT) and detrusor smooth muscle layer (SM) and then cultured with control media, E2 (10 ng/ml) or TNFα (100 ng/ml) for 7 days. Cultured tissues were frozen at -80°C to study fibrosis marker. RESULTS: Bladder compliance was decreased in 1, 3 and 7 month OVX groups (20.3±6.5, 10.2±1.5 and 14.2±2.7 μl/mmHg) compared to age-matched sham groups (35.1±6.1, 24.6±3.2 and 24.2±4.5 μl/mmHg), while E2 recovered bladder compliance. Bladder capacity was reduced in 3 and 7 month OVX groups compared to sham, but was not fully recovered by E2. Intercontraction interval (ICI) was reduced in 3 and 7 month OVX groups (10.3±1.8 and 10.7±1.5 min) compared to age-matched sham groups (17.0±1.1 and 17.0±3.0 min) but was not rescued by E2 treatment. Unexpectedly, E2 markedly increased the number of non-voiding contractions (NVCs). Estrogen receptor (ERα) was dominantly immunoreactive against detrusor, however bladder interstitial cells were immunopositive upon ERβ. Colocalizations of PDGFRα+ and ERβ positive interstitial cells were observed both in UT and SM. Expression of PDGFRα and collagen 1a1 was upregulated in 3 month OVX group compared to sham, while E2 replacement further increased the expression of PDGFRα and fibrosis markers compared to age-matched sham or OVX groups. In qPCR of cultured bladder tissue, TNFα dramatically upregulated the expression of Acta2, TIMP2, Tgfβ, Col1a1, Col1a2, cadherin and IL6 in UT but had marginal effects on SM. CONCLUSIONS: Urothelium/suburothelial layer may be common site for the initiation of fibrosis. Inflammation or E2 deficiency/replacement may cause fibrosis through the activation of PDGFRα+ cells. These novel findings might point to a novel approach toward the treatment of bladder fibrosis. Source of Funding: Supported by NIDDK, RO1 DK098388 © 2022 by American Urological Association Education and Research, Inc.FiguresReferencesRelatedDetails Volume 207Issue Supplement 5May 2022Page: e858 Advertisement Copyright & Permissions© 2022 by American Urological Association Education and Research, Inc.MetricsAuthor Information Ken Lee More articles by this author Masatoshi Eto More articles by this author Kenton Sanders More articles by this author Sang don Koh More articles by this author Expand All Advertisement PDF DownloadLoading ...

Influence of estradiol deficiency on the acute inflammatory response following a traumatic skeletal muscle injury

Abstract Estradiol (E2) influences the inflammatory response. Research has shown that skeletal muscle chemokine mRNA expression and neutrophil infiltration after a traumatic freeze injury are blunted in ovariectomized mice treated with placebo compared to E2-treated mice. How E2 deficiency alters the acute muscle inflammatory response is unclear with potential mechanisms including alterations in the number of circulating leukocytes, leukocyte chemotaxis, and/or muscle chemokine expression. To investigate these possibilities, female C57BL/6J mice underwent a sham or ovariectomy (OVX) surgery, 21–28 d later tibialis anterior (TA) muscles were freeze injured. TA muscles and blood were collected 24 h post injury. Total white blood cell (149%) and monocytes (427%) were elevated in OVX compared to Sham mice but there was no difference in the neutrophil counts (p≥0.64). To determine if E2 deficiency impacts leukocyte chemotaxis, isolated leukocytes from bone marrow of non-injured Sham or OVX mice were placed in a transwell migration assay. OVX leukocytes had greater chemotaxis towards CXCL1 (37%), CXCL2 (43%), and CXCL5 (27%) than Sham. To examine if E2 deficiency alters muscle CXCL1 and CXCL5 protein content contributing to chemotaxis, ELISA assays were performed. Surprisingly, muscle CXCL1 and CXCL5 contents were similar between OVX and Sham. Collectively, mice lacking E2 have relatively high blood leukocytes and chemotaxis suggesting a greater acute inflammatory response which appears not to be driven by changes in muscle chemokine expression. Additional studies need to consider possible negative regulators of the acute inflammatory response in OVX muscle. Supported by DAL and GW (R01AG031743 &amp; R01AG062899), and SLM (T32AR007612)

Estradiol deficiency reduces the satellite cell pool by impairing cell cycle progression.

The size of the satellite cell pool is reduced in estradiol (E2)-deficient female mice and humans. Here, we use a combination of in vivo and in vitro approaches to identify mechanisms, whereby E2 deficiency impairs satellite cell maintenance. By measuring satellite cell numbers in mice at several early time points postovariectomy (Ovx), we determine that satellite cell numbers decline by 33% between 10 and 14 days post-Ovx in tibialis anterior and gastrocnemius muscles. At 14 days post-Ovx, we demonstrate that satellite cells have a reduced propensity to transition from G0/G1 to S and G2/M phases, compared with cells from ovary-intact mice, associated with changes in two key satellite cell cycle regulators, ccna2 and p16INK4a. Further, freshly isolated satellite cells treated with E2 in vitro have 62% greater cell proliferation and require less time to complete the first division. Using clonal and differentiation assays, we measured 69% larger satellite cell colonies and enhanced satellite cell-derived myoblast differentiation with E2 treatment compared with vehicle-treated cells. Together, these results identify a novel mechanism for preservation of the satellite cell pool by E2 via promotion of satellite cell cycling.

Arsenic Induces Differential Neurotoxicity in Male, Female, and E2-Deficient Females: Comparative Effects on Hippocampal Neurons and Cognition in Adult Rats.

We earlier reported that arsenic induced hippocampal neuronal loss, causing cognitive dysfunctions in male rats. This neuronal damage mechanism involved an altered bone morphogenetic protein (BMP2)/Smad and brain-derived neurotrophic factor (BDNF)/TrkB signaling. Susceptibility to toxicants is often sex-dependent, and hence we studied the comparative effects of arsenic in adult male and female rats. We observed that a lower dose of arsenic reduced learning-memory ability, examined through passive avoidance and Y-maze tests, in male but not female rats. Again, male rats exhibited greater learning-memory loss at a higher dose of arsenic. Supporting this, arsenic-treated male rats demonstrated larger reduction in the hippocampal NeuN and %-surviving neurons, together with increased apoptosis and altered BMP2/Smad and BDNF/TrkB pathways compared to their female counterparts. Since the primary female hormone, estrogen (E2), regulates normal brain functions, we next probed whether endogenous E2 levels in females offered resistance against arsenic-induced neurotoxicity. We used ovariectomized (OVX) rat as the model for E2 deficiency. We primarily identified that OVX itself induced hippocampal neuronal damage and cognitive decline, involving an increased BMP2/Smad and reduced BDNF/TrkB. Further, these effects appeared greater in arsenic + OVX compared to arsenic + sham (ovary intact) or OVX rats alone. The OVX-induced adverse effects were significantly reduced by E2 treatment. Overall, our study suggests that adult males could be more susceptible than females to arsenic-induced neurotoxicity. It also indicates that endogenous E2 regulates hippocampal BMP and BDNF signaling and restrains arsenic-induced neuronal dysfunctions in females, which may be inhibited in E2-deficient conditions, such as menopause or ovarian failure.

Premenopausal and postmenopausal women during the COVID-19 pandemic.

The current global COVID-19 mortality rate is estimated to be around 3.4%; however, it is dependent on age, sex, and comorbidities.Epidemiological evidence shows gender disparities in COVID-19 severity and fatality, with non-menopausal females having milder severity and better outcomes than age-matched males. However, the difference vanishes when comparing postmenopausal women with age-matched men.It has been suggested that, to some extent, this is due to the protective role of female hormones, such as anti-Müllerian hormone and oestradiol (E2), in non-menopausal women.Oestrogens have been hypothesized to be crucial in modulating viral infection and the progression of the disease via an action on immune/inflammatory responses and angiotensin-converting enzyme type 2 expression. Hence, the most likely explanation is that, because the levels of oestrogen in females after menopause decrease, oestrogen no longer offers a beneficial effect as seen in younger females.The COVID-19 pandemic has highlighted the serious negative effects arising from the state of E2 deficiency. Therefore, hormone replacement therapy gains further support as the damaging effect of the decline in ovarian function affects many biological systems, and recently with the COVID-19 pandemic, oestrogen’s vital role within the immune system has become quite clear.However, additional clinical investigations regarding hormone replacement therapy are urgently needed to further verify the protective and therapeutic effects of E2 on menopausal women with COVID-19.

The importance of association between sexsteroids deficiency, reduction of bone mineral density and falling risk in men with implications in medical rehabilitation

Introduction. Endocrino-metabolic rehabilitation represent one of the most complex sector in clinical medicine, regarding functional rehabilitation. Sex hormones deficiency plays an important role in the etiology of osteoporosis in men. At the same time, with age, the trophic role of androgens on muscle decreases and determines an increased frequency of falls. The objective of our study is to determine the association between sexsteroids deficiency, reduction of bone mineral density (BMD) and falling risk in men. Methods. Our retrospective cross-sectional study included 146 men aged between 65–85 years with low BMD (study group) and 121 men with normal BMD (control group). The measurement of Total testosterone (Tt), free testosterone (Tf) and estradiol (E2) serum levels was performed using the immunoassay or the immunoenzymatic methods. Femoral neck and lumbar spine BMD was determined using Dual-energy X-ray absorptiometry (DEXA). The risk of falls was assessed by Tandem Standing, Up &amp; Go, Chair – Rising and walking speed tests. Results. We found a significantly association between Tf and E2 deficiency and low BMD (p=0.007). Also, in men with reduced BMD (study group) we observed significant lower levels of Tf (p&lt;0.001) and E2 (p=0.003) compared to control group. E2 deficiency was associated significantly with low BMD and increased fall risk (p=0.001). At the same time the results highlighted significant lower levels of Tf in patients with BMD reduction and increased risk of falls (p=0.002). Tt deficiency was not associated with BMD reduction (p=0.088) or increased risk of falling (p=0.277). Conclusions. This research revealed a significant association between male sexsteroids deficiency, low BMD and increase of falling risk, with implications in rehabilitation program. The risk of ostoporosis and for falling in man can be estimated by determining serum Tf and E2 levels. Keywords: sexsteroids deficiency; bone mineral density; falling risk,

Surgical Menopause and Estrogen Therapy Modulate the Gut Microbiota, Obesity Markers, and Spatial Memory in Rats.

Menopause in human females and subsequent ovarian hormone deficiency, particularly concerning 17β-estradiol (E2), increase the risk for metabolic dysfunctions associated with obesity, diabetes type 2, cardiovascular diseases, and dementia. Several studies indicate that these disorders are also strongly associated with compositional changes in the intestinal microbiota; however, how E2 deficiency and hormone therapy affect the gut microbial community is not well understood. Using a rat model, we aimed to evaluate how ovariectomy (OVX) and subsequent E2 administration drive changes in metabolic health and the gut microbial community, as well as potential associations with learning and memory. Findings indicated that OVX-induced ovarian hormone deficiency and E2 treatment had significant impacts on several health-affecting parameters, including (a) the abundance of some intestinal bacterial taxa (e.g., Bifidobacteriaceae and Porphyromonadaceae), (b) the abundance of microbial short-chain fatty acids (SCFAs) (e.g., isobutyrate), (c) weight/BMI, and (d) high-demand spatial working memory following surgical menopause. Furthermore, exploratory correlations among intestinal bacteria abundance, cognition, and BMI underscored the putative influence of surgical menopause and E2 administration on gut-brain interactions. Collectively, this study showed that surgical menopause is associated with physiological and behavioral changes, and that E2-linked compositional changes in the intestinal microbiota might contribute to some of its related negative health consequences. Overall, this study provides novel insights into interactions among endocrine and gastrointestinal systems in the post-menopausal life stage that collectively alter the risk for the development and progression of cardiovascular, metabolic, and dementia-related diseases.

Estrogen Attenuates Chronic Stress-Induced Cardiomyopathy by Adaptively Regulating Macrophage Polarizations via β2-Adrenergic Receptor Modulation.

Clinical demographics have demonstrated that postmenopausal women are predisposed to chronic stress-induced cardiomyopathy (CSC) and this has been associated with the decrease of estrogen. Meanwhile, recent studies have implicated unsolved myocardial proinflammatory responses, which are characterized by enormous CD86+ macrophage infiltrations as an underlying disease mechanism expediting the pathological remodeling of the heart during chronic stress. However, we had previously demonstrated that estrogen confers cardioprotection via the modulation of cardiomyocytes β2-adrenoceptors (β2AR)-Gs/Gi pathways during stress to lessen the incidence of stress-induced cardiovascular diseases in premenopausal women. Intriguingly, macrophages express β2AR profoundly as well; as such, we sought to elucidate the possibilities of estrogen modulating β2AR-Gs/Gi pathway to confer cardioprotection during stress via immunomodulation. To do this, ovariectomy (OVX) and sham operations (Sham) were performed on female Sprague-Dawley (SD) rats. Two weeks after OVX, the rats were injected with 40 μg/kg/day of estradiol (E2). Next, on day 36 after OVX, chronic stress was induced by a daily subcutaneous injection of 5 mg/kg/day of isoproterenol (ISO). The effect of E2 on relevant clinical cardiac function indexes (LVSP, LVEDP, + dp/dt and −dp/dt), myocardial architecture (cardiomyocyte diameter and fibrosis), β2AR alterations, and macrophage (CD86+ and CD206+) infiltrations were assessed. In vitro, peritoneal macrophages (PMΦ) were isolated from wild-type and β2AR-knockout female mice. The PMΦ were treated with ISO, E2, and β2AR blocker ICI 118,551 for 24 h, and flow cytometric evaluations were done to assess their phenotypic expression. E2 deficiency permitted the induction of CSC, which was characterized by cardiac dysfunctions, maladaptive myocardial hypertrophy, unresolved proinflammatory responses, and fibrosis. Nonetheless, E2 presence/supplementation during stress averted all the aforementioned adverse effects of chronic stress while preventing excessive depletion of β2AR. Also, we demonstrated that E2 facilitates timely resolution of myocardial proinflammation to permit reparative functions by enhancing the polarization of CD86+ to CD206+ macrophages. However, this adaptive immunomodulation is hampered when β2AR is inhibited. Taken together, the outcomes of this study show that E2 confers cardioprotection to prevent CSC via adaptive immunomodulation of macrophage phenotypes, and β2AR-mediated signaling is crucial for the polarizations of CD86+ to CD206+ macrophages.

SY4-5. Temporary hypertension as well as white coat hypertension in the first trimester as risk factors for preeclampsia

This study investigated the relationship among estrogen, placental blood flow and placental weight gain in rats treated with ketoconazole. Oral administration of ketoconazole (25 mg/kg/day) on Days 12–14 of pregnancy induced reduction of plasma estradiol-17β (E2) concentration, transient decrease in placental blood flow and increased intensity of a hypoxia-related marker in the placenta on Day 14 of pregnancy. On Day 20 of pregnancy, placental weights of ketoconazole-treated rats increased when compared to controls. Histologically, maternal sinusoidal area of the placenta decreased on Day 14 of pregnancy and the total area of maternal and fetal sinusoids increased on Day 20. All the changes disappeared by concomitant subcutaneous infusion of E2. These results indicate that ketoconazole-induced E2 deficiency causes transient decrease in placental blood flow associated with hypoxia and later placental weight gain in rats.

Estradiol deficiency and skeletal muscle apoptosis: Possible contribution of microRNAs.

Menopause leads to estradiol (E2) deficiency that is associated with decreases in muscle mass and strength. Here we studied the effect of E2 deficiency on microRNA (miR) signaling that targets apoptotic pathways. C57BL6 mice were divided into control (normal estrous cycle, n=8), OVX (E2 deficiency, n=7) and OVX+E2 groups (E2-pellet, n=4). Six weeks following the OVX surgery, mice were sacrificed and RNA isolated from gastrocnemius muscles. miR-profiles were studied with Next-Generation Sequencing (NGS) and candidate miRs verified using qPCR. The target proteins of the miRs were found using in silico analysis and measured at mRNA (qPCR) and protein levels (Western blot). Of the apoptosis-linked miRs present, eleven (miRs-92a-3p, 122-5p, 133a-3p, 214-3p, 337-3p, 381-3p, 483-3p, 483-5p, 491-5p, 501-5p and 652-3p) indicated differential expression between OVX and OVX+E2 mice in NGS analysis. In qPCR verification, muscle from OVX mice had lower expression of all eleven miRs compared with OVX+E2 (p<0.050). Accordingly, OVX had higher expression of cytochrome C and caspases 6 and 9 compared with OVX+E2 at the mRNA level (p<0.050). At the protein level, OVX also had lower anti-apoptotic BCL-W and greater pro-apoptotic cytochrome C and active caspase 9 compared with OVX+E2 (p<0.050). E2 deficiency downregulated several miRs related to apoptotic pathways thus releasing their targets from miR-mediated suppression, which may lead to increased apoptosis and contribute to reduced skeletal muscle mass.

Liraglutide improves lipid and carbohydrate metabolism of ovariectomized rats

Considering that post-menopausal women and ovariectomized rodents develop obesity associated with increased visceral fat, this study was developed to investigate if liraglutide, a glucagon-like peptide 1 (GLP1) analogue, could improve the metabolism of estrogen (E2) deficient females. Wistar rats were ovariectomized (OVX), and subdivided in four groups: sham saline, sham liraglutide, OVX saline, and OVX liraglutide. After sixty days, metabolic parameters of blood, heart, liver, brown (BAT) and white adipose tissue (WAT) visceral depots, and, heart oxidative homeostasis, were evaluated. Castration increased the animals' body weight, the relative weight of the WAT depots, hepatic triglycerides and cardiac glycogen content. Liraglutide treatment reversed these effects, decreased WAT depots weight and increased glucose oxidation and lipogenesis in BAT and WAT. In addition, liraglutide enhanced adrenalin (A) lipolytic effect. These results indicate that liraglutide may be a promising treatment to restore lipid homeostasis and prevent weight gain associated with E2 deficiency.

Dimethandrolone Undecanoate, a Novel, Nonaromatizable Androgen, Increases P1NP in Healthy Men Over 28 Days.

Dimethandrolone undecanoate (DMAU) is being developed as a male contraceptive. Daily oral administration of DMAU, a potent androgen that is not aromatized, markedly suppresses serum testosterone (T) and estradiol (E2) in healthy men. E2 deficiency can increase bone resorption in men. This work aimed to assess changes in bone turnover markers with DMAU administration in a 28-day study. A randomized, double-blind, placebo-controlled study was conducted. This study took place at 2 academic medical centers. Healthy men, age 18 to50 years (n = 81), participated. Men received 0, 100, 200, or 400 mg of oral DMAU for 28 days. Serum C-terminal telopeptide of type I collagen (CTX; bone resorption marker) and procollagen type I amino-terminal propeptide (P1NP; bone formation marker) were measured on days 1 and 28. Changes in bone turnover markers and serum hormones over the treatment period were measured. On day 28, median serum T and E2 were markedly suppressed in all treatment groups vs placebo (P < .001 for both). Percentage change (%) in serum P1NP significantly differed across treatment groups (P = .007): Serum P1NP significantly increased in the 200 mg (5%, interquartile range [IQR] -7% to 27%) and 400 mg (22%, IQR -1% to 40%) groups relative to placebo (-8%, IQR -20% to 0%). Change (%) in serum CTX did not differ between groups (P = .09). DMAU administration for 28 days to healthy men leads to marked suppression of serum T and E2, yet increases P1NP, a serum marker of bone formation. Longer-term studies of the potent androgen DMAU are warranted to determine its impact on bone health in men.

Estrogen Deficiency Accompanied by Oxidative Stress Sustains Heme Oxygenase 1 expression in Cardiomyocytes of Ovariectomized Rats

Background: Estrogen deficiency is one of the main causes of cardiovascular diseases (CVDs) after menopause, accompanied with the upregulation of oxidative stress. Two isoforms of heme oxygenase (HO), HO-1 and HO-2, have been implicated in the cytoprotective effects via the antioxidant and anti-inflammatory capacities. Aims: This study aimed to investigate the time-course of HO-1 and HO-2 expression in the cardiac tissue of ovariectomized rats and whether oxidative stress is involved in the regulation of HO alteration. Methods: Adult female rats were ovariectomized bilaterally to induce estrogen deficiency and randomly divided into (1) Sham, (2) ovariectomy (Ovx), (3) Ovx + E2 (17β estradiol, 50 μg/kg/day, intramuscular), and (4) Ovx + tempol (1 mM in drinking water, a superoxide dismutase [SOD] mimetic). Rats were sacrificed 12 weeks after Ovx; blood and myocardium samples were collected. Results: Showed that plasma E2 levels of Ovx and Ovx + tempol groups were significantly reduced as compared to Sham group after 4 weeks of Ovx. Superoxide anion in the cardiac tissue was significantly elevated 2 weeks after Ovx, and the increase was drastically reversed by the treatment with E2 and tempol. In addition, Ovx rats showed significantly higher levels of oxidized glutathione (GSSG) than those of Sham group, which were also significantly reduced by E2 and tempol administration. Western blot analysis indicated that HO-1 expression was significantly induced 1 week after Ovx and sustained at high levels until 12 weeks. E2 replacement did not immediately reverse HO-1 until treatment for 4 weeks as well as tempol administration for 5 weeks. Expression of the constitutive enzymes HO-2 did not show significant differences between Sham and Ovx groups, and E2 or tempol administration had no effect on cardiac HO-2 protein expression. Conclusion: E2 deficiency induced upregulation of superoxide anion in the myocardium, which might be the major contributor to the sustained HO-1 expression as adaptive responses to oxidative stress. This study provides new insight into the pathogenesis of CVDs after menopause.

Oestradiol affects skeletal muscle mass, strength and satellite cells following repeated injuries.

What is the central question of this study? Oestradiol (E2 ) plays an important role in regulating skeletal muscle strength in females. To what extent does E2 deficiency affect recovery of strength and satellite cell number when muscle is challenged by multiple injuries? What is the main finding and its importance? E2 deficiency impairs the adaptive potential of skeletal muscle following repeated injuries, as measured by muscle mass and strength. The impairment is likely multifactorial with our data indicating that one mechanism is reduction in satellite cell number. Our findings have implications for ageing, hormone replacement and regenerative medicine in regards to maintaining satellite cell number and ultimately the preservation of skeletal muscle's adaptive potential. Oestradiol's effects on skeletal muscle are multifactorial including the preservation of mass, contractility and regeneration. Here, we aimed to determine the extent to which oestradiol deficiency affects strength recovery when muscle is challenged by multiple BaCl2 -induced injuries and to assess how satellite cell number is influenced by the combination of oestradiol deficiency and repetitive skeletal muscle injuries. A longitudinal study was designed, using an in vivo anaesthetized mouse approach to precisely and repeatedly measure maximal isometric torque, coupled with endpoint fluorescence-activated cell sorting to quantify satellite cells. Isometric torque and strength gains were lower in ovariectomized mice at several time points after the injuries compared to those treated with 17β-oestradiol. Satellite cell number was 41-43% lower in placebo- than in oestradiol-treated ovariectomized mice, regardless of injury status or number of injuries. Together, these results indicate that the loss of oestradiol blunts adaptive strength gains and that the number of satellite cells likely contributes to the impairment.

Estradiol Replacement at the Critical Period Protects Hippocampal Neural Stem Cells to Improve Cognition in APP/PS1 Mice

It has been suggested that there is a critical window for estrogen replacement therapy (ERT) in postmenopausal women with Alzheimer’s disease (AD); however, supporting evidence is lacking. To address this issue, we investigated the effective period for estradiol (E2) treatment using a mouse model of AD. Four-month-old female APPswe/PSEN1dE9 (APP/PS1) mice were ovariectomized (OVX) and treated with E2 for 2 months starting at the age of 4 months (early period), 6 months (mid-period), or 8 months (late period). We then evaluated hippocampal neurogenesis, β-amyloid (Aβ) accumulation, telomerase activity, and hippocampal-dependent behavior. Compared to age-matched wild type mice, APP/PS1 mice with intact ovaries showed increased proliferation of hippocampal neural stem cells (NSCs) at 8 months of age and decreased proliferation of NSCs at 10 months of age; meanwhile, Aβ accumulation progressively increased with age, paralleling the reduced survival of immature neurons. OVX-induced depletion of E2 in APP/PS1 mice resulted in elevated Aβ levels accompanied by elevated p75 neurotrophin receptor (p75NTR) expression and increased NSC proliferation at 6 months of age, which subsequently declined; accelerated reduction of immature neurons starting from 6 months of age, and reduced telomerase activity and worsened memory performance at 10 months of age. Treatment with E2 in the early period post-OVX, rather than in the mid or late period, abrogated these effects, and p75NTR inhibition reduced the overproliferation of NSCs in 6-month-old OVX-APP/PS1 mice. Thus, E2 deficiency in young APP/PS1 mice exacerbates cognitive deficits and depletes the hippocampal NSC pool in later life; this can be alleviated by E2 treatment in the early period following OVX, which prevents Aβ/p75NTR-induced NSC overproliferation and preserves telomerase activity.