Androstenediol complements estrogenic bioactivity during the menopausal transition

Correlations of androstenediol with reproductive hormones and cortisol according to stages during the menopausal transition in Japanese women

Associations of androstenediol, which has both androgenic and estrogenic activities, with circulating reproductive hormones and stress hormone in women during the menopausal transition may be different depending on the menopausal stage. The aim of this study was to determine the changes in circulating androstenediol during the menopausal transition in Japanese women and the associations of androstenediol with estrogen, androgen and cortisol for each stage of the menopausal transition. We divided the 104 subjects into 6 stages by menstrual regularity and follicle-stimulating hormone level: mid reproductive stage, late reproductive stage, early menopausal transition, late menopausal transition, very early postmenopause and early postmenopause. Levels of dehydroepiandrosterone sulfate (DHEAS), estradiol, estrone, testosterone (T), free T, androstenedione and cortisol were measured. Serum androstenediol concentration was measured by using liquid chromatography mass spectrometry. There were no significant differences in androstenediol levels among the 6 stages. Levels of DHEA-S and testosterone showed significant and positive correlations with androstenediol in all stages. Estradiol levels showed negative correlations with androstenediol levels in the late menopausal transition and very early postmenopause (r=-0.452, p = 0.052 and r=-0.617, p = 0.006, respectively). Cortisol levels showed significant and positive correlations with androstenediol levels in the mid and late reproductive stages (r = 0.719, p = 0.003 and r = 0.808, p < 0.001, respectively).The associations of androstenediol with estradiol and cortisol were different depending on the stage of the menopausal transition. Androstenediol may play a compensatory role for estrogen deficiency from late menopausal transition to very early postmenopause.

Changes in excessive alcohol use among older women across the menopausal transition: a longitudinal analysis of the Study of Women's Health Across the Nation

Background

Recent data suggest that excessive alcohol use is increasing among women and older adults. Such trends are concerning, as women are more vulnerable to alcohol-related health consequences, and such health problems may be exacerbated with age. Furthermore, there are sex-specific factors that may influence alcohol consumption among women, including the hormonal changes associated with the menopausal transition and negative affect. The present study sought to investigate transitions in excessive drinking among women across the menopausal transition and included exploration of sex hormones (estradiol; testosterone) and depression.

Methods

The present study utilized publicly available data from the Study of Women Across the Nation (SWAN) and included 3302 women (42–52 years old at baseline), who completed 10 years of annual assessments. National Institute on Alcohol Abuse and Alcoholism (NIAAA) criteria were used as guidance when defining excessive drinking within the present dataset. At year 1, 170 women were identified as drinking excessively. Random-effect logistic regressions were used to examine transitions in excessive drinking.

Results

Women identified as excessive drinkers were more likely to transition to non-excessive drinking across all menopausal transition stages (ORs range = 3.71–5.11), while women were more likely to transition from non-excessive to excessive drinking during the early peri- and postmenopausal stages (OR = 1.52 and 1.98, respectively). Higher testosterone levels were associated with a decreased likelihood of transitioning to non-excessive drinking (OR = 0.59). Depression and estradiol levels were not related to transitions in drinking.

Conclusions

The present study demonstrates that the menopausal transition marks a period of instability in alcohol use among women. Further research is warranted to understand factors related to transitioning in and out of excessive drinking.

Smoking Across the Menopausal Transition in a 10-Year Longitudinal Sample: The Role of Sex Hormones and Depressive Symptoms

INTRODUCTION

Current cigarette smoking rates among older women remain problematic, especially given that this population experiences increased smoking-related health consequences. Despite these increased health concerns, little research to date has explored smoking patterns across the menopausal transition (pre-, early-peri-, late-peri-, and postmenopausal) or the effect of unique factors such as sex hormones and depression during this transition.

METHODS

This study used 10 yearly waves of data from the Study of Women's Health Across the Nation, a longitudinal dataset. Data included 1397 women endorsing ever smoking regularly at baseline. Random-effects logistic regression models were used to examine smoking transitions.

RESULTS

Although there were no associations between menopausal transition stage and smoking behavior, increased estradiol was associated with an increased likelihood of quitting regular smoking (eg, transitioning from regular smoking to non-regular or no smoking; odds ratio [OR] = 1.28), whereas increased testosterone was associated with an increased likelihood of relapsing to regular smoking (eg, transitioning from former or nonregular smoking to regular smoking OR = 2.56). Depression was associated with increased likelihood of continued smoking (OR = 0.97) and relapse (OR = 1.03).

CONCLUSIONS

The results emphasize the need to develop interventions to target initiated or continued smoking among women across the menopausal transition and specifically highlight the importance of developing treatments that target depressive symptoms in this population. In addition, although singular hormone measures were associated with smoking behavior, there is a need for future study of dynamic changes in hormones, as well as the impact of progesterone on smoking behaviors across the menopausal transition.

IMPLICATIONS

To date, no studies have examined smoking behaviors across the menopausal transition. In this study, although menopausal transition status was not significantly related to transitions in smoking behavior, important relationships between sex hormones and depression were observed. Increased estradiol was associated with an increased likelihood of quitting regular smoking, whereas increased testosterone was associated with an increased likelihood of relapsing to regular smoking behavior. Higher depression scores were related to continued smoking and relapse to regular smoking behavior. These results highlight the need to develop interventions to target smoking cessation among women across the menopausal transition.

Steroid receptors and vertebrate evolution

Considering that life on earth evolved about 3.7 billion years ago, vertebrates are young, appearing in the fossil record during the Cambrian explosion about 542 to 515 million years ago. Results from sequence analyses of genomes from bacteria, yeast, plants, invertebrates and vertebrates indicate that receptors for adrenal steroids (aldosterone, cortisol), and sex steroids (estrogen, progesterone, testosterone) also are young, with an estrogen receptor and a 3-ketosteroid receptor first appearing in basal chordates (cephalochordates: amphioxus), which are close ancestors of vertebrates. Duplication and divergence of the 3-ketosteroid receptor yielded an ancestral progesterone receptor and an ancestral corticoid receptor, the common ancestor of the glucocorticoid and mineralocorticoid receptors, in jawless vertebrates (cyclostomes: lampreys, hagfish). This was followed by evolution of an androgen receptor, distinct glucocorticoid and mineralocorticoid receptors and estrogen receptor-α and -β in cartilaginous fishes (Chondrichthyes: sharks). Further evolution of mineralocorticoid signaling occurred with the evolution of aldosterone synthase in lungfish, a forerunner of terrestrial vertebrates. Adrenal and sex steroid receptors are not found in echinoderms and hemichordates, which are ancestors in the lineage of cephalochordates and vertebrates. The evolution of steroid receptors at key nodes in the evolution of vertebrates, in which steroid receptors act as master switches to regulate differentiation, development, reproduction, immune responses, electrolyte homeostasis and stress responses, suggests an important role for steroid receptors in the evolutionary success of vertebrates, considering that the human genome contains about 22,000 genes, which is not much larger than genomes of invertebrates, such as Caenorhabditis elegans (~18,000 genes) and Drosophila (~14,000 genes).

The promiscuous estrogen receptor: Evolution of physiological estrogens and response to phytochemicals and endocrine disruptors

Many actions of estradiol (E2), the principal physiological estrogen in vertebrates, are mediated by estrogen receptor-α (ERα) and ERβ. An important physiological feature of vertebrate ERs is their promiscuous response to several physiological steroids, including estradiol (E2), Δ⁵-androstenediol, 5α-androstanediol, and 27-hydroxycholesterol. A novel structural characteristic of Δ⁵-androstenediol, 5α-androstanediol, and 27-hydroxycholesterol is the presence of a C19 methyl group, which precludes the presence of an aromatic A ring with a C3 phenolic group that is a defining property of E2. The structural diversity of these estrogens can explain the response of the ER to synthetic chemicals such as bisphenol A and DDT, which disrupt estrogen physiology in vertebrates, and the estrogenic activity of a variety of plant-derived chemicals such as genistein, coumestrol, and resveratrol. Diversity in the A ring of physiological estrogens also expands potential structures of industrial chemicals that can act as endocrine disruptors. Compared to E2, synthesis of 27-hydroxycholesterol and Δ⁵-androstenediol is simpler, leading us, based on parsimony, to propose that one or both of these steroids or a related metabolite was a physiological estrogen early in the evolution of the ER, with E2 assuming this role later as the canonical estrogen. In addition to the well-studied role of the ER in reproductive physiology, the ER also is an important transcription factor in non-reproductive tissues such as the cardiovascular system, kidney, bone, and brain. Some of these ER actions in non-reproductive tissues appeared early in vertebrate evolution, long before the emergence of mammals.

Vasomotor Symptoms Across the Menopause Transition: Differences Among Women

Vasomotor symptoms (VMS) are the primary menopausal symptoms, occurring in up 80% of women and peaking around the final menstrual period. The average duration is 10 years, longer in women with an earlier onset. Compared with non-Hispanic white women, black and Hispanic women are more likely and Asian women are less likely to report VMS. Risk factors include greater body composition (in the early stage of menopausal transition), smoking, anxiety, depression, sensitivity to symptoms, premenstrual syndrome, lower education, and medical treatments, such as hysterectomy, oophorectomy, and breast cancer-related therapies. VMS patterns over time and within higher-risk subgroups are heterogeneous across women.

Polymorphisms in Estrogen Synthesis Genes and Symptom Clusters During the Menopausal Transition and Early Postmenopause: Observations From the Seattle Midlife Women's Health Study

During the menopausal transition and early postmenopause, participants in the Seattle Midlife Women's Health Study (SMWHS) experienced one of the three symptom severity clusters identified through latent class analysis: severe hot flashes with moderate sleep, mood, cognitive, and pain symptoms (high-severity hot flash); low-severity hot flashes with moderate levels of all other symptom groups (moderate severity); and low levels of all symptom groups (low severity). In an effort to determine whether gene polymorphisms were associated with these symptom severity classes, we tested associations between gene polymorphisms in the estrogen synthesis pathways (cytochrome P450 19 [CYP 19] and 17 beta hydroxysteroid dehydrogenase [ 17HSDB1]) and the three symptom severity clusters. SMWHS participants ( N = 137) recorded symptoms monthly in diaries and provided buccal smears for genotyping. Multilevel latent class analysis with multinomial regression was used to determine associations between gene polymorphisms and symptom severity clusters. Only the 17HSDB1 polymorphisms ( rs615942 and rs592389) were associated significantly with the high-severity hot flash cluster versus the low-severity symptom cluster. None of the polymorphisms was associated with the moderate-severity cluster versus the low-severity symptom cluster. Findings of associations of the 17HSDB1 polymorphisms with the high-severity hot flash symptom cluster are consistent with those of an association between 17HSDB1 polymorphisms and hot flashes in the Study of Women and Health Across the Nation population and our previous findings of associations between these polymorphisms with greater estrone levels.

Characterizing the trajectories of vasomotor symptoms across the menopausal transition

OBJECTIVE

The aim of the study was to investigate the heterogeneity of temporal patterns of vasomotor symptoms (VMS) over the menopausal transition and identify factors associated with these patterns in a diverse sample of women.

METHODS

The Study of Women's Health Across the Nation is a multisite longitudinal study of women from five racial/ethnic groups transitioning through the menopause. The analytic sample included 1,455 women with nonsurgical menopause and a median follow-up of 15.4 years. Temporal patterns of VMS and associations with serum estradiol and follicle-stimulating hormone, race/ethnicity, body mass index, and demographic and psychosocial factors were examined using group-based trajectory modeling.

RESULTS

Four distinct trajectories of VMS were found: onset early (11 years before the final menstrual period) with decline after menopause (early onset, 18.4%), onset near the final menstrual period with later decline (late onset, 29.0%), onset early with persistently high frequency (high, 25.6%), and persistently low frequency (low, 27.0%). Relative to women with persistently low frequency of VMS, women with persistently high and early onset VMS had a more adverse psychosocial and health profile. Black women were overrepresented in the late onset and high VMS subgroups relative to white women. Obese women were underrepresented in the late onset subgroup. In multivariable models, the pattern of estradiol over the menopause was significantly associated with the VMS trajectory.

CONCLUSIONS

These data distinctly demonstrate heterogeneous patterns of menopausal symptoms that are associated with race/ethnicity, reproductive hormones, premenopause body mass index, and psychosocial characteristics. Early targeted intervention may have a meaningful impact on long-term VMS.

Changes in androstenedione, dehydroepiandrosterone, testosterone, estradiol, and estrone over the menopausal transition

Background

Previous reports have noted that dehydroepiandrosterone-sulfate (DHEAS) increases prior to the final menstrual period (FMP) and remains stable beyond the FMP. How DHEAS concentrations correspond with other sex hormones across the menopausal transition (MT) including androstenedione (A4), testosterone (T), estrone (E1), and estradiol (E2) is not known. Our objective was to examine how DHEAS, A4, T, E1, and E2 changed across the MT by White vs. African-American (AA) race/ethnicity.

Methods

We conducted a longitudinal observational analysis of a subgroup of women from the Study of Women’s Health Across the Nation observed over 4 visits prior to and 4 visits after the FMP (n = 110 women over 9 years for 990 observations). The main outcome measures were DHEAS, A4, T, E1, and E2.

Results

Compared to the decline in E2 concentrations, androgen concentrations declined minimally over the MT. T (β 9.180, p < 0.0001) and E1 (β 11.365, p < 0.0001) were higher in Whites than in AAs, while elevations in DHEAS (β 28.80, p = 0.061) and A4 (β 0.2556, p = 0.052) were borderline. Log-transformed E2 was similar between Whites and AAs (β 0.0764, p = 0.272). Body mass index (BMI) was not significantly associated with concentrations of androgens or E1 over time.

Conclusion

This report suggests that the declines in E2 during the 4 years before and after the FMP are accompanied by minimal changes in DHEAS, A4, T, and E1. There are modest differences between Whites and AAs and minimal differences by BMI.

Age-dependent Increases in Adrenal Cytochrome b5 and Serum 5-Androstenediol-3-sulfate

CONTEXT

Adrenal production of dehydroepiandrosterone sulfate (DHEA-S) increases throughout childhood owing to expansion of the zona reticularis (ZR). ZR features cells with a steroidogenic phenotype distinct from that of the adjacent zona fasciculata, with higher expression of cytochrome b₅ type A (CYB5A) and steroid sulfotransferase type 2A1 but decreased 3β-hydroxysteroid dehydrogenase type 2 (HSD3B2). In addition to DHEA-S, three adrenal Δ5-steroid sulfates could provide additional tools to define adrenal maturation.

OBJECTIVE

This study sought to simultaneously measure serum levels of four adrenal Δ5-steroid sulfates, pregnenolone sulfate (Preg-S), 17α-hydroxypregnenolone sulfate (17OHPreg-S), DHEA-S, and 5-androstenediol-3-sulfate (Adiol-S) as a function of age and relate their production to the age-dependent adrenal localization of CYB5A.

PARTICIPANTS AND METHODS

Δ5-steroid sulfates were quantified by liquid chromatography-tandem mass spectrometry in sera from 247 normal children (129 males,118 females) age 1.5-18 y and 42 adults (20 males, 22 females). Immunofluorescence localized HSD3B2 and CYB5A in normal adrenal glands from subjects age 2-35 y. Finally, HAC15 adrenocortical cells were transduced with lentiviral short hairpin RNA to suppress CYB5A expression.

RESULTS

Of the Δ5-steroid sulfates quantified, DHEA-S was most abundant. Adiol-S increased in parallel with DHEA-S. Steroid ratios (17OHPreg-S/DHEA-S) suggested increases in 17,20-lyase activity during childhood. Immunofluorescence analysis showed age-related increases in ZR CYB5A immunoreactivity. Furthermore, silencing CYB5A in HAC15 adrenocortical cells significantly reduced DHEA-S and Adiol-S production.

CONCLUSION

Adiol-S shows a similar age-related increase to that of DHEA-S. This likely results from the childhood expansion of CYB5A-expressing ZR, which enhances 17,20-lyase activity and the production of DHEA-S and Adiol-S.

Design, synthesis, and biological evaluation of new arylamide derivatives possessing sulfonate or sulfamate moieties as steroid sulfatase enzyme inhibitors

A series of new arylamide derivatives possessing terminal sulfonate or sulfamate moieties was designed and synthesized. The target compounds were tested for in vitro inhibitory effects against the steroid sulfatase (STS) enzyme in a cell-free assay system. The free sulfamate derivative 1j was the most active. It inhibited the enzymatic activity by 72.0% and 55.7% at 20 μM and 10 μM, respectively. Compound 1j was further tested for STS inhibition in JEG-3 placental carcinoma cells with high STS enzyme activity. It inhibited 93.9% of the enzyme activity in JEG-3 placental carcinoma cells at 20 μM with an efficacy near to that of the well-established drug STX64 as reference. At 10 μM, 1j inhibited 86.1% of the STS activity of JEG-3. Its IC₅₀ value against the STS enzyme in JEG-3 cells was 0.421 μM. Thus, 1j represents an attractive new non-steroidal lead for further optimization.

Conditions and possible mechanisms of VCD-induced ovarian failure

Perimenopause is an important period in women's lives, in which they experience a series of physiological changes. Current animal models of perimenopause fail to adequately replicate this particular stage in female life, while current in vitro models are too simplistic and cannot account for systemic effects. Neither the naturally-ageing animal model, nor the ovariectomised animal model, mimic the natural transitional process that is the menopause. In vivo and in vitro studies have confirmed that the occupational chemical, 4-vinylcyclohexene diepoxide (VCD), can cause selective destruction of the ovarian primordial and primary follicles of rats and mice by accelerating the apoptotic process, which successfully mimics the perimenopausal state in women. However, it is the in vivo VCD-induced rodent perimenopausal models that are currently the most widely used in research, rather than any of the available in vitro models. Studies on the mechanisms involved have found that VCD induces ovotoxicity via interference with the c-kit/kit ligand and apoptotic signalling pathways, among others. Overall, the VCD-induced perimenopausal animal models have provided some insight into female perimenopause, but they are far from ideal models of the human situation.

Identification of Immunoreactive Luteinizing Hormone Receptors in the Adrenal Cortex of the Female Rhesus Macaque

Female laboratory macaques were studied under a variety of treatment protocols to determine if immunoreactive luteinizing hormone/gonadal chorionic gonadotropin (LH/CG) receptors were present in the adrenal cortex. All adrenal tissues revealed an absence of immunoreactivity in the in the medulla while staining was present in all three outer zones of the cortex. Increased staining was observed in the zonae reticularis with least staining in the zonae glomerulosa. Moderate and variable staining was found in the zonae fasciculata. These results demonstrate that LH/CG receptors in the adrenal cortex may be more common in higher primates than previously recognized and help explain some aspects of the endocrine changes observed in mid-aged women during the menopausal transition when circulating LH concentrations are rising.

Trajectories and phenotypes with estrogen exposures across the lifespan: What does Goldilocks have to do with it?

This article is part of a Special Issue "Estradiol and cognition". Estrogens impact the organization and activation of the mammalian brain in both sexes, with sex-specific critical windows. Throughout the female lifespan estrogens activate brain substrates previously organized by estrogens, and estrogens can induce non-transient brain and behavior changes into adulthood. Therefore, from early life through the transition to reproductive senescence and beyond, estrogens are potent modulators of the brain and behavior. Organizational, reorganizational, and activational hormone events likely impact the trajectory of brain profiles during aging. A "brain profile," or quantitative brain measurement for research purposes, is typically a snapshot in time, but in life a brain profile is anything but static--it is in flux, variable, and dynamic. Akin to this, the only thing continuous and consistent about hormone exposures across a female's lifespan is that they are noncontinuous and inconsistent, building and rebuilding on past exposures to create a present brain and behavioral landscape. Thus, hormone variation is especially rich in females, and is likely the destiny for maximal responsiveness in the female brain. The magnitude and direction of estrogenic effects on the brain and its functions depend on a myriad of factors; a "Goldilocks" phenomenon exists for estrogens, whereby if the timing, dose, and regimen for an individual are just right, markedly efficacious effects present. Data indicate that exogenously-administered estrogens can bestow beneficial cognitive effects in some circumstances, especially when initiated in a window of opportunity such as the menopause transition. Could it be that the age-related reduction in efficacy of estrogens reflects the closure of a late-in-life critical window occurring around the menopause transition? Information from classic and contemporary works studying organizational/activational estrogen actions, in combination with acknowledging the tendency for maximal responsiveness to cyclicity, will elucidate ways to extend sensitivity and efficacy into post-menopause.

Estrogen Effects on Cognitive and Synaptic Health Over the Lifecourse

Estrogen facilitates higher cognitive functions by exerting effects on brain regions such as the prefrontal cortex and hippocampus. Estrogen induces spinogenesis and synaptogenesis in these two brain regions and also initiates a complex set of signal transduction pathways via estrogen receptors (ERs). Along with the classical genomic effects mediated by activation of ER α and ER β, there are membrane-bound ER α, ER β, and G protein-coupled estrogen receptor 1 (GPER1) that can mediate rapid nongenomic effects. All key ERs present throughout the body are also present in synapses of the hippocampus and prefrontal cortex. This review summarizes estrogen actions in the brain from the standpoint of their effects on synapse structure and function, noting also the synergistic role of progesterone. We first begin with a review of ER subtypes in the brain and how their abundance and distributions are altered with aging and estrogen loss (e.g., ovariectomy or menopause) in the rodent, monkey, and human brain. As there is much evidence that estrogen loss induced by menopause can exacerbate the effects of aging on cognitive functions, we then review the clinical trials of hormone replacement therapies and their effectiveness on cognitive symptoms experienced by women. Finally, we summarize studies carried out in nonhuman primate models of age- and menopause-related cognitive decline that are highly relevant for developing effective interventions for menopausal women. Together, we highlight a new understanding of how estrogen affects higher cognitive functions and synaptic health that go well beyond its effects on reproduction.

The role of androst-5-ene-3β,17β-diol (androstenediol) in cell proliferation in endometrium of women with polycystic ovary syndrome

Women with polycystic ovary syndrome (PCOS) show high prevalence of endometrial hyperplasia and adenocarcinoma. Endometrial proliferation is increased, evaluated by high levels of Ki67 (cell cycle marker) and low levels of p27 (negative regulator of cell cycle). Nevertheless, endometrial changes in cyclin D1 (positive regulator of cell cycle) in PCOS-women are not described. Androst-5-ene-3β,17β-diol (androstenediol), steroid with estrogenic activity present in endometria, could be related to increased endometrial cell proliferation. The objective of this study was to determine protein content of cyclin D1 and androstenediol levels in endometria from PCOS and control-women and to evaluate the possible mechanism favoring cell proliferation associated with hormonal characteristics of patients. Therefore, cyclin D1 protein content in PCOS-women and control-endometrial tissue were assessed by western blot and immunohistochemistry. The androstenediol levels were evaluated by ELISA. To further analyze the effect of steroids (androstenediol, 17β-estradiol, testosterone) in cell proliferation, levels of proteins cyclin D1, p27 and Ki67 were evaluated in an in vitro model of stromal endometrial cells T-HESC and St-T1b. An increase in cyclin D1 and androstenediol was observed in tissues from PCOS-women relative to control group (p<0.05). In the in vitro model, androstenediol exerted increase in cyclin D1 (p<0.05) and a decrease in p27 protein level (p<0.05), while Ki67 in St-T1b cells increased under this stimulus (p<0.05). Testosterone produces opposite effects in the levels of the above markers (p<0.05). Therefore, the hormonal imbalance associated with this syndrome could alter endometrial tissue homeostasis, promoting cell proliferation. Androstenediol is a molecule that could be involved by stimulating proliferation, whereas testosterone elicits a role of cell cycle repressor.

The menopause and aging, a comparative perspective

The neuroendocrinology of menopause is reviewed from a comparative perspective, with emphasis on laboratory rodent models. These changes are compared by the 2011 STRAW criteria (Stages of Reproductive Aging Workshop). Ovarian cell loss begins prenatally in all mammals studied, with exponential depletion of primary follicles and oocytes in association with loss of fecundity by midlife. Rodents and humans also share progressively increasing irregularity in ovulatory cycles and increasing fetal aneuploidy as oocyte depletion become imminent. Hypothalamic impairments of the estrogen-induced surge of pituitary gonadotrophins (luteinizing hormone, LH; follicle stimulating hormone, FSH) are prominent in middle-aged rodents, but sporadic in peri-menopausal women. In aging rodents, hypothalamic impairments of the LH surge have been experimentally associated with prolonged phases of sustained estradiol (E2) and very low progesterone (P4) ('unopposed estradiol'). Although peri-menopausal women also show hyper-estrogenic cycles, there is no indication for irreversible hypothalamic desensitization by E2. Ongoing cognitive assessments in clinical trials of estrogen therapy with and without P4 or other progestins may further inform about possible persisting effects of unopposed estrogens.This article is part of a Special Issue entitled 'Menopause'.

Ovarian adrenal interactions during the menopausal transition

Observations over the past decade using longitudinal data reveal a gender-specific shift in adrenal steroid production. This shift is represented by an increase in the circulating concentrations of delta 5 steroids in 85% of all women and is initiated only after the menopausal transition has begun. While the associated rise in the major adrenal androgen, dehydroepiandrosterone sulfate (DHEAS), is modest, the parallel rises in dehydroepiandrosteone (DHEA) and androstenediol (Adiol) are much more robust. These increases in circulating steroid concentrations are qualitatively similar on average between ethnicities but quantitatively different between individual women. Both circulating testosterone (T) and androstenedione (Adione) also rise concomitantly but modestly by comparison. This phenomenon presents a new and provocative aspect to the endocrine foundations of the menopausal transition and may provide important clues to understanding the fundamentals of mid-aged women's healthy aging, particularly an explanation for the wide diversity in phenotypes observed during the MT as well as their different responses to hormone replacement therapies. Experimental studies using the nonhuman primate animal model show an acute adrenal response to human chorionic gonadotropin (hCG) challenge as well as the presence of luteinizing hormone receptors (LHR) in their adrenal cortices. These experimental results support the concept that LHRs are recruited to the adrenal cortices of mid-aged women that subsequently function to respond to increasing circulating LH to shunt pregnenolone metabolites towards the delta 5 pathway. Future investigations are required to determine the relationship of these changes in adrenal function to symptoms and health outcomes of mid-aged women.

Continuously delivered ovarian steroids do not alter dendritic spine density or morphology in macaque dorsolateral prefrontal cortical neurons

Aged ovariectomized (OVX) female monkeys, a model for menopause in humans, show a decline in spine density in the dorsolateral prefrontal cortex (dlPFC) and diminished performance in cognitive tasks requiring this brain region. Previous studies in our laboratory have shown that long-term cyclic treatment with 17β-estradiol (E) produces an increase in spine density and in the proportion of thinner spines in layer III pyramidal neurons in the dlPFC of both young and aged OVX rhesus monkeys. Here we used 3D reconstruction of Lucifer yellow-loaded neurons to investigate whether clinically relevant schedules of hormone therapy would produce similar changes in prefrontal cortical neuronal morphology as long-term cyclic E treatment in young female monkeys. We found that continuously delivered E, with or without a cyclic progesterone treatment, did not alter spine density or morphology in the dlPFC of young adult OVX rhesus monkeys. We also found that the increased density of thinner spines evident in the dlPFC 24h after E administration in the context of long-term cyclic E therapy is no longer detectable 20days after E treatment. When compared with the results of our previously published investigations, our results suggest that cyclic fluctuations in serum E levels may cause corresponding fluctuations in the density of thin spines in the dlPFC. By contrast, continuous administration of E does not support sustained increases in thin spine density. Physiological fluctuations in E concentration may be necessary to maintain the morphological sensitivity of the dlPFC to E.

Dehydroepiandrosterone sulfate levels reflect endogenous luteinizing hormone production and response to human chorionic gonadotropin challenge in older female macaque (Macaca fascicularis)

OBJECTIVE

We propose that the adrenal gland of an older higher primate female animal model will respond to human chorionic gonadotropin (hCG) hormone challenge by secreting additional dehydroepiandrosterone sulfate (DHEAS). Such a response in surgically and chemically castrated animals will provide proof of concept and a validated animal model for future studies to explore the rise in DHEAS during the menopausal transition of women.

METHODS

Twenty-four 18- to 26-year-old female cynomolgus monkeys were screened for ovarian function and then either ovariectomized (n = 4) or treated with a gonadotropin-releasing hormone agonist (GnRHa; n = 20) to block ovarian steroid production. After a recovery period from surgical procedure or down-regulation, a single-dose challenge (1,000 IU/animal, IM) of hCG was then administered to determine if luteinizing hormone (LH)/chorionic gonadotropin could accelerate circulating DHEAS production. Serum DHEAS, bioactive LH, and urinary metabolites of ovarian sex steroids were monitored before, during, and after these treatments.

RESULTS

Circulating LH bioactivity and immunoreactive DHEAS concentrations were suppressed in all animals 14 days postadministration of GnRHa. Urinary metabolites of estradiol and progesterone remained low after the surgical procedure or a flare reaction to GnRHa. Circulating DHEAS levels were increased after hCG administration, and the increase in individual animals was proportional to the pretreatment DHEAS at baseline. Circulating DHEAS concentrations were positively correlated to endogenous LH bioactive concentrations prior to hCG challenge and were subsequently further elevated by the hCG challenge while no concomitant change in ovarian steroid hormone excretion was observed.

CONCLUSIONS

These data demonstrate a positive adrenal androgen response to LH/chorionic gonadotropin in older female higher primates and suggest a mechanism for the rise in adrenal androgen production during the menopausal transition in women. These results also illustrate that the nonhuman primate animal model can be effectively used to investigate this phenomenon.

Brief communication: Adrenal androgens and aging: Female chimpanzees (Pan troglodytes) compared with women

Ovarian cycling continues to similar ages in women and chimpanzees yet our nearest living cousins become decrepit during their fertile years and rarely outlive them. Given the importance of estrogen in maintaining physiological systems aside from fertility, similar ovarian aging in humans and chimpanzees combined with somatic aging differences indicates an important role for nonovarian estrogen. Consistent with this framework, researchers have nominated the adrenal androgen dehydroepiandrosterone (DHEA) and its sulfate (DHEAS), which can be peripherally converted to estrogen, as a biomarker of aging in humans and other primates. Faster decline in production of this steroid with age in chimpanzees could help explain somatic aging differences. Here, we report circulating levels of DHEAS in captive female chimpanzees and compare them with published levels in women. Instead of faster, the decline is slower in chimpanzees, but from a much lower peak. Levels reported for other great apes are lower still. These results point away from slowed decline but toward increased DHEAS production as one of the mechanisms underlying the evolution of human longevity.

Unbalanced estrogen metabolism in thyroid cancer

Well-differentiated thyroid cancer most frequently occurs in premenopausal women. Greater exposure to estrogens may be a risk factor for thyroid cancer. To investigate the role of estrogens in thyroid cancer, a spot urine sample was obtained from 40 women with thyroid cancer and 40 age-matched controls. Thirty-eight estrogen metabolites, conjugates and DNA adducts were analyzed by using ultraperformance liquid chromatography/tandem mass spectrometry and the ratio of adducts to metabolites and conjugates was calculated for each sample. The ratio of depurinating estrogen-DNA adducts to estrogen metabolites and conjugates significantly differed between cases and controls (p < 0.0001), demonstrating high specificity and sensitivity. These findings indicate that estrogen metabolism is unbalanced in thyroid cancer and suggest that formation of estrogen-DNA adducts might play a role in the initiation of thyroid cancer.

Modulation of higher-primate adrenal androgen secretion with estrogen-alone or estrogen-plus-progesterone intervention

OBJECTIVE

Circulating adrenal steroids rise during the menopausal transition in most middle-aged women and may contribute to differences in between-women symptoms and ultimate health outcomes. However, the mechanisms for this shift in adrenal steroid production in middle-aged women are not known. This study aims to determine whether hormone therapy (HT) for 1 year can modulate adrenal androgen production.

METHODS

Younger (9.8 [0.4] years, n = 20) and older (22.7 [0.4] years, n = 37) female laboratory macaques were ovariectomized, and each group was treated with different regimens of HT for up to 1 year. Changes in adrenal histology and circulating adrenal androgens were monitored after estrogen-alone (E) or estrogen plus progesterone (E + P) treatment, and these changes were compared with the same measures in similarly aged animals given vehicle.

RESULTS

Zona reticularis area, serum dehydroepiandrosterone (DHEA), and serum dehydroepiandrosterone sulfate (DHEAS) were higher in younger vehicle-treated animals compared with older vehicle-treated animals (P < 0.02). Both E and E + P treatments decreased circulating DHEAS in the younger group (P < 0.05). Although E treatment also decreased DHEAS in the older group, this was not statistically significant. In contrast, E + P treatment in the older group resulted in a rise in DHEAS over vehicle, which was significantly higher than the results of E treatment (P < 0.01). Circulating concentrations of DHEA exhibited similar trends, but these changes did not reach statistical significance.

CONCLUSIONS

These data demonstrate that intervention with ovarian steroids can modulate adrenal androgen production in female higher primates and that both animal age and type of HT regimen determine adrenal response.

What are the physiological estrogens?

Estradiol (E2) is the principal physiological estrogen in mammals. E2 and its active metabolites, estrone and estriol have a characteristic phenolic A ring, unlike progesterone, testosterone, cortisol and aldosterone, which have an A ring containing a C3-ketone, a Δ(4) bond and a C19 methyl group. Crystal structures of E2 in the estrogen receptor (ER) confirm the importance of the A ring in stabilizing E2 in the ER. However, other steroids, including Δ(5)-androstenediol, 5α-androstanediol and 27-hydroxycholesterol, which have a saturated A ring containing a 3β-hydroxyl and a C19 methyl group, also mediate physiological responses through binding to estrogen receptor-α (ERα) and ERβ. Moreover, selective estrogen response modulators (SERMs) with diverse structures also regulate transcription of ERα and ERβ. Our understanding of the physiological responses mediated by these "alternative" estrogens is in its infancy. Further studies of the role of these steroids and SERMs in regulating responses mediated by ERα and ERβ a variety of tissues, during different stages of development, are likely to uncover additional estrogenic activities.

Menopausal transition stage-specific changes in circulating adrenal androgens

OBJECTIVE

It is now recognized that mean circulating dehydroepiandrosterone sulfate (DHEAS) concentrations in most midlife women exhibit a positive inflection starting in early perimenopause, continuing through early postmenopause and returning to early perimenopausal levels by late postmenopause. This rise in mean DHEAS is accompanied by concomitant rises in testosterone (T), dehydroepiandrosteone (DHEA), and androstenedione (Adione) and an equal rise in androstenediol (Adiol). These observations suggest that there is a specific relationship between the circulating levels of steroids emanating from the adrenal glands, declining ovarian function, and the stages of the menopausal transition. This study was designed to test the hypothesis that the menopausal stage-specific change in circulating DHEAS is associated with concomitant changes in the circulating pattern of adrenal steroids and that some of these adrenal androgens could influence the circulating estrogen/androgen balance.

METHODS

Stored annual serum samples (N = 120) were first selected to represent four longitudinal DHEAS profiles of individual women to assess and compare changes in the adrenal contribution to circulating steroids.

RESULTS

Changes in mean circulating DHEAS levels in midlife women during the menopausal transition is associated with changes in mean circulating T, Adione, and Adiol. Mean Adione and T concentrations changed the least, whereas mean DHEAS and Adiol changed the most.

CONCLUSIONS

Changes in circulating steroid hormone emanating from the adrenal during the menopausal transition may be more important than the decline in ovarian function in terms of altering the estrogen/androgen balance.