Postmenopausal hormone replacement therapy--clinical implications

Estrogen receptors mediate the antidepressant effects of aerobic exercise: A possible new mechanism

Purpose

This study aimed to examine whether aerobic exercise exerts mood-modulating effects through an estrogen signaling mechanism.

Method

The experiment was divided into two parts. The first part is to compare the three modeling methods to obtain the most obvious method of depression-like phenotype for further study in the second part. The first part of ovariectomized rats (age, 13 weeks) was tested when rats were 14 or 22 weeks old or in the sixth week after 3 weeks of chronic restraint stress. The second part was to treat the animals with the most obvious depression-like phenotype in different ways, placebo treatment or estradiol (E2) replacement therapy was administered, aerobic training, or estrogen receptor antagonist treatment. The cognitive (Barnes maze and 3-chamber social tests), anxiety-like (open-field and elevated plus maze tests) and depression-like (sucrose preference and forced swim tests) behaviors of rats in both parts were analyzed to study the effects of estrogen depletion and aerobic exercise.

Results

Rats did not develop depressive symptoms immediately after ovariectomy, however, the symptoms became more pronounced with a gradual decrease in ovarian hormone levels. Compared with the placebo or control groups, the exercise and E2 groups showed improved performance in all behavioral test tasks, and the antidepressant effects of aerobic exercise were comparable to those of estrogen. Moreover, the estrogen receptor antagonist has markedly inhibited the antidepressant effects of aerobic exercise.

Conclusion

Estrogen receptors may mediate the antidepressant effects of aerobic exercise. In addition, an increasingly fragile ovarian hormonal environment may underlies chronic restraint stress-induced depression.

Increased phosphatase regenerating liver-1 trigger vascular remodeling in injured ovary via platelet-derived growth factor signaling pathway

Background

Vascular abnormalities in the ovary cause infertility accompanied by ovarian insufficiency due to a microenvironment of barren ovarian tissues. Placenta-derived mesenchymal stem cells (PD-MSCs, Naïve) treatment in ovarian dysfunction shows angiogenic effect, however, the therapeutic mechanism between ovarian function and vascular remodeling still unclear. Therefore, we examined whether by phosphatase regenerating liver-1 (PRL-1), which is correlated with angiogenesis in reproductive systems, overexpressed PD-MSCs could maximize the angiogenic effects in an ovarian tissues injured of rat model with partial ovariectomy and their therapeutic mechanism by enhanced vascular function via PDGF signaling.

Methods

PD-MSCs^PRL-1 (PRL-1) were generated by nonviral AMAXA gene delivery system and analyzed the vascular remodeling and follicular development in ovary. One week after Sprague–Dawley (SD) rats ovariectomy, Naïve and PRL-1 was transplanted. The animals were sacrificed at 1, 3 and 5 weeks after transplantation and vascular remodeling and follicular development were analyzed. Also, human umbilical vein endothelial cells (HUVECs) and ovarian explantation culture were performed to prove the specific effects and mechanism of PRL-1.

Results

Vascular structures in ovarian tissues (e.g., number of vessels, thickness and lumen area) showed changes in the Naïve and PRL-1-overexpressed PD-MSC (PRL-1) transplantation (Tx) groups compared to the nontransplantation (NTx) group. Especially, PRL-1 induce to increase the expression of platelet-derived growth factor (PDGF), which plays a role in vascular remodeling as well as follicular development, compared to the NTx. Also, the expression of genes related to pericyte and vascular permeability in arteries was significantly enhanced in the PRL-1 compared to the NTx (p < 0.05). PRL-1 enhanced the vascular formation and permeability of human umbilical vein endothelial cells (HUVECs) via activated the PDGF signaling pathway.

Conclusions

Our results show that PRL-1 restored ovarian function by enhanced vascular function via PDGF signaling pathway. These findings offer new insight into the effects of functionally enhanced stem cell therapy for reproductive systems and should provide new avenues to develop more efficient therapies in degenerative medicine.

Supplementary Information

The online version contains supplementary material available at 10.1186/s13287-022-02772-9.

Equol, a Dietary Daidzein Gut Metabolite Attenuates Microglial Activation and Potentiates Neuroprotection In Vitro

Estrogen deficiency has been well characterized in inflammatory disorders including neuroinflammation. Daidzein, a dietary alternative phytoestrogen found in soy (Glycine max) as primary isoflavones, possess anti-inflammatory activity, but the effect of its active metabolite Equol (7-hydroxy-3-(4′-hydroxyphenyl)-chroman) has not been well established. In this study, we investigated the anti-neuroinflammatory and neuroprotective effect of Equol in vitro. To evaluate the potential effects of Equol, three major types of central nervous system (CNS) cells, including microglia (BV-2), astrocytes (C6), and neurons (N2a), were used. Effects of Equol on the expression of inducible nitric oxide synthase (iNOS), cyclooxygenase (COX-2), Mitogen activated protein kinase (MAPK) signaling proteins, and apoptosis-related proteins were measured by western blot analysis. Equol inhibited the lipopolysaccharide (LPS)-induced TLR4 activation, MAPK activation, NF-kB-mediated transcription of inflammatory mediators, production of nitric oxide (NO), release of prostaglandin E2 (PGE-2), secretion of tumor necrosis factor-α (TNF-α) and interleukin 6 (IL-6), in Lipopolysaccharide (LPS)-activated murine microglia cells. Additionally, Equol protects neurons from neuroinflammatory injury mediated by LPS-activated microglia through downregulation of neuronal apoptosis, increased neurite outgrowth in N2a cell and neurotrophins like nerve growth factor (NGF) production through astrocytes further supporting its neuroprotective potential. These findings provide novel insight into the anti-neuroinflammatory effects of Equol on microglial cells, which may have clinical significance in cases of neurodegeneration.

Effect of progestins with different glucocorticoid activity on bone metabolism

OBJECTIVE

Progestins are commonly prescribed for hormone replacement therapy (HRT) and contraception. However, the effects of progestins on bone metabolism remain unclear and are often controversial.

DESIGN AND PATIENTS

This study was conducted to test the hypothesis that progestins with no significant glucocorticoid activity may be a better choice for HRT to achieve increased beneficial effects on bone metabolism than progestins with strong glucocorticoid activity. A total of 104 postmenopausal women aged 50-75 years with osteoporosis were allocated randomly to three groups: (1) conjugated oestrogen plus medroxyprogesterone acetate (HRT-MPA, with significant glucocorticoid activity); (2) conjugated oestrogen plus norethisterone (HRT-NET, with no significant glucocorticoid activity); and (3) control (no treatment).

MEASUREMENTS

Vertebral X-rays and bone mineral density (BMD) at distal 1/3 radius were assessed at baseline and every 6 months during the 2-year study period, along with markers of bone turnover. The occurrence of new nonvertebral fractures was identified by X-ray.

RESULTS

After the 2-year treatment, mean BMD changes relative to baseline in the HRT-MPA, HRT-NET and control groups were 1.6%, 2.3% and -1.9%, respectively. In addition, the rate of increase in HRT-NET was significantly greater than that in HRT-MPA (P = 0.019). The incidence of new fractures during the 2-year treatment in the control group was 26% (9/34). HRT-NET treatment significantly inhibited the occurrence of new fractures (RR 0.14, 95% CI 0.02-0.93, P = 0.04), while HRT-MPA treatment failed to show a statistically significant reduction (RR 0.41, 95% CI 0.14-1.24, P = 0.11). Both HRT-MPA and HRT-NET treatments significantly decreased serum osteocalcin levels by 29.4% and 23.5%, respectively, after 6 months of treatment, with the decrease in HRT-MPA being significantly greater than that in HRT-NET (P = 0.042).

CONCLUSIONS

These findings suggest that progestins with no significant glucocorticoid activity may be a better choice for HRT, resulting in increased beneficial effects on bone metabolism compared with progestins with strong glucocorticoid activity.

Effects of genistein on hot flushes in early postmenopausal women: a randomized, double-blind EPT- and placebo-controlled study

OBJECTIVE

We evaluated and compared the effects of the phytoestrogen genistein, estrogen-progestogen therapy (EPT), and placebo on hot flushes and endometrial thickness in postmenopausal women.

DESIGN

Ninety healthy, postmenopausal women, 47 to 57 years of age, were randomly assigned to receive for 1 year continuous EPT (n = 30; 1 mg 17beta-estradiol combined with 0.5 mg norethisterone acetate), the phytoestrogen genistein (n = 30; 54 mg/day), or placebo (n = 30). Endometrial safety was evaluated by intravaginal ultrasounds at baseline, 6 and 12 months.

RESULTS

By comparison with placebo, daily flushes reduced significantly by a mean of 22% (95% CI: -38 to -6.2; P < 0.01) after 3 months, by a mean of 29% (95% CI: -45 to -13; P < 0.001) after 6 months, and by a mean of 24% (95% CI: -43 to -5; P < 0.01) after 12 months of genistein treatment. Flush score decreased by a mean of 53% (95% CI: -79 to -26; P < 0.001) after 3 months, by a mean of 56% (95% CI: -83 to -28; P < 0.001) after 6 months, and by a mean of 54% (95% CI: -74 to -33; P < 0.001) after 12 months of EPT, as compared with placebo. No side effect was observed on the uterus of the participants.

CONCLUSIONS

The present study confirms that genistein might have positive effects on hot flushes without a negative impact on endometrial thickness and suggests a future role of this phytoestrogen as a strategically therapeutic alternative in the management of postmenopausal symptoms.

The effect of pregnancy and the oestrus cycle on purinergic and cholinergic responses of the rat urinary bladder

The urinary bladder undergoes plastic changes during physiological alterations such as pregnancy. This study has shown that bladders from pregnant rats weighed three times more than bladders from virgin rats. Each milligram of detrusor muscle from pregnant rats contracted more strongly to nerve stimulation (150% greater) and agonists (50% greater or more) compared to detrusor from virgin rats at any stage during the oestrus cycle. The purinergic component of nerve-mediated responses altered during the oestrus cycle, being greatest during oestrus (oestrogen and progesterone fall rapidly) and dioestrus (low oestrogen and progesterone), smaller during pregnancy and even smaller during pro-oestrus (high oestrogen and progesterone); in contrast the cholinergic component remained relatively unchanged. In conclusion, during pregnancy the detrusor muscle generates larger contractions compared to virgin detrusor muscle, probably due to hormonal influences on smooth muscle contraction mechanisms. As agonist responses were unchanged during the oestrus cycle, changes in the purinergic component of nerve stimulation was not due to altered P2 receptor expression but possibly to an increase in ATP release or a reduction in breakdown. The hormonal effect may have implications for the treatment of bladder disorders due to alterations in hormones, such as stress incontinence in post-menopausal women.

Efficacy of a new 7-day transdermal sequential estradiol/levonorgestrel patch in women

OBJECTIVE

To investigate the efficacy and tolerability of a new 7-day transdermal sequential estradiol/levonorgestrel patch (Fem7 Combi; Merck KGaA; Germany), versus placebo, as hormone replacement therapy in menopausal women.

METHODS

A multicentre, randomized, clinical study consisting of a 3-week screening phase, a 12-week double-blind, placebo-controlled treatment phase, and a 12-week open, follow-up phase. Women aged 40-65 years with an intact uterus and menopausal complaints were randomized to either 2 weeks of an estradiol mono patch (50 microg per 24 h) followed by 2 weeks of an estradiol/levonorgestrel combination patch (50 microg/10 microg per 24 h), or a placebo patch, for three 28-day cycles. Changes in the Kupperman Index and the frequency of hot flushes were assessed.

RESULTS

The sequential use of a 7-day estradiol patch and a 7-day estradiol/levonorgestrel patch was superior to placebo in reducing menopausal symptoms, and was well tolerated. At the end of the treatment phase, there was a statistically significant reduction in the Kupperman Index score versus placebo (P<0.0001), and a statistically significant difference between groups in the proportion of patients with a reduction in the number of hot flushes (at least 50% versus baseline). During the open follow-up phase, there was a marked reduction in the Kupperman Index score and the number of hot flushes for patients switched from placebo to active study medication. The active medication was effective throughout the 1-week application period.

CONCLUSIONS

The new 7-day transdermal sequential estradiol/levonorgestrel patch was well tolerated, providing rapid and effective relief of menopausal symptoms. The addition of low-dose levonorgestrel did not influence the beneficial effects of estradiol.

Delay in gallbladder emptying during the perimenopausal period

A pilot study has ascribed an important role in gallbladder motility and emptying to the perimenopausal period. To assess the effect of this period on gallbladder emptying and cholelithogenesis, 25 women in the perimenopausal period without gallbladder disease were submitted to cholangiography and two ultrasound exams. The time for gallbladder emptying and the presence of cholelithiasis were assessed. All patients presented a delay in gallbladder emptying with no relationship to the pre- or postmenopausal period. This finding was not related to lithogenesis. Gallbladder emptying time is longer during the perimenopausal period.

Hormone replacement therapy and 24-hour blood pressure profile of postmenopausal women

Menopause is associated with an increase in blood pressure (BP) and a decrease in physiologic nocturnal BP fall. These factors may play a role in the increased risk of cardiovascular events after menopause. Some studies indicate that transdermal estrogen replacement therapy may help restore the 24-h BP profile, but data on the effect of oral conjugated estrogens are lacking. We compared 24-h ambulatory BP profiles of 42 postmenopausal women not receiving hormone replacement therapy (HRT) and 20 women receiving HRT. HRT was associated with a significant increase in the proportion of dippers (50% in women not receiving HRT and 80% in women receiving HRT, P = .048). Increase in nocturnal dipping may account, in part, for the beneficial cardiovascular effects of HRT.

Progesterone- and dexamethasone-dependent osteoprogenitors in bone cell populations derived from rat vertebrae are different and distinct

Previous experiments have demonstrated that bone cell populations derived from explants of lumbar vertebral bone of adult female rats contain osteoprogenitors that require dexamethasone (Dex) or progesterone (Prog) to proliferate and differentiate into fully differentiated bone-forming osteoblasts. We now show that the Prog-dependent population cannot be detected in male rats after sexual maturation, but is present in prepubertal rats of both sexes and can be induced in adult male-derived populations by culturing the explants in medium containing 17beta-estradiol (10(-9)-10(-8) M). This suggested that the Prog- and Dex-dependent osteoprogenitors in adult female-derived populations were probably distinct populations and that the survival of the Prog-dependent osteoprogenitors and/or their ability to proliferate are dependent on the presence of estrogen. We then proceeded to prove this by using replica plating. When one of the paired colonies duplicated was cultured in medium containing Dex (10(-8) M) and the other in medium containing Prog (10(-5) M), 5.0% of duplicates formed bone in Prog only, 11.1% formed bone in Dex only, and 3.4% formed bone in both Prog and Dex. In all cases the size of the bone-forming colonies in Dex-treated cultures was larger than that in Prog-treated cultures, indicating that the effects of Dex on osteoprogenitor proliferation are greater than those of Prog. The results demonstrate the existence of three classes ofosteoprogenitors in adult female rat-derived bone cell populations: a class responding to Dex only, a class responding to Prog only, and a class responding to both Dex and Prog. The results also indicate that the effects of Prog are not mediated by Prog binding to the glucocorticoid receptor and imply that Prog plays an important role in maintaining bone mass through regulating the class of osteoprogenitors responsive to Prog.

Effects of estrogen and progesterone on urinary bladder in female rabbit: evaluation by quantitative morphometric analysis

OBJECTIVES

To investigate possible effects of estrogen and/or progesterone on the histologic characteristics of female rabbit urinary bladders, we carried out quantitative morphometric analysis of the rabbit bladders.

METHODS

Mature female rabbits were treated by ovariectomy with and without successive estrogen and/or progesterone administration. Area densities of the connective tissue (CT) and smooth muscle (SM) cells, the area of single SM cells, and the thickness of the bladder wall were determined by computer-assisted quantitative morphometric analysis.

RESULTS

Six weeks after each treatment, ovariectomy alone resulted in a decrease in CT density of the bladder. Successive estrogen treatment increased the bladder wet weight and SM cell density within the bladder wall. Progesterone treatment reduced CT degradation in ovariectomized rabbits. Sex steroids did not significantly influence the area of each SM cell. There was no significant difference in histologic characteristics between the rabbits treated by estrogen alone and those treated by combination (estrogen and progesterone) therapy.

CONCLUSIONS

Ovariectomy and successive hormonal replacement therapy resulted in morphologic changes within the rabbit urinary bladder. Cotreatment with progesterone did not significantly change the morphologic findings produced by estrogen treatment alone.

Estrogen replacement therapy after treatment for localized breast carcinoma. Patient responses and opinions

BACKGROUND

Women who reach menopause after receiving treatment for breast carcinoma have been advised to avoid estrogen replacement therapy (ERT), but the validity of this practice is being reappraised and the need for prospective studies is discussed. The likely response of potential participants to the tangible rather than theoretic option for ERT provides not only useful information for planning such studies but also important insights into the attitudes and expectations of breast cancer survivors.

METHODS

Women with a history of localized breast carcinoma, potentially eligible for participation in this prospective ERT study, were interviewed in person or by telephone and were asked to consider participation in a prospective, randomized study of ERT. In addition, information was obtained regarding their disease stage, estrogen receptor (ER) status, age at diagnosis, age at interview, and elapsed time since cancer treatment.

RESULTS

The authors contacted 555 women; 137 did not meet criteria for study participation. Among the 418 women eligible for the program, one-third indicated a lack of interest and cited travel, financial, or age considerations. One-third of the women were apprehensive about ERT risk and declined. Forty women (13%) were either already receiving ERT or were seeking a prescribing physician. Finally, 17% of the women enrolled in our study. There were no differences among the groups with respect to disease stage, ER status, age at diagnosis and interview, or time elapsed since cancer treatment.

CONCLUSIONS

Women with a history of breast carcinoma harbor considerable reluctance regarding ERT for the management of menopausal health concerns. However, a significant minority have already opted for ERT and up to 20% may become participants in clinical programs. Plans for large scale trials of ERT in this subset of women require careful attention to patient attitudes and concerns.

Benefit/risk of estrogen therapy in cardiovascular disease: current knowledge and future challenges

In the United States, cardiovascular disease represents the leading cause of death among women. A majority of the deaths are due to coronary disease. In addition, the incidence of heart attacks increases with age. Among those who are 65 years of age or older, the estimated heart attack rate is 374,000 per year for women, compared with 440,000 per year for men. In the past three decades, a number of observational studies have suggested that estrogen therapy can reduce the risk of coronary disease in postmenopausal women. This protective effect appears to be much greater in women who have existing coronary disease. These observational data point to the potential usefulness of estrogen therapy in preventing cardiovascular death among women. Although large, well-controlled, clinical trials are needed to confirm the benefit of estrogen therapy, several important findings strongly support the cardioprotective effect of estrogen therapy. For example, in monkeys estrogen prevents the accumulation of low-density lipoprotein (LDL) cholesterol (a known risk factor for heart disease) in coronary arteries, and estrogen has also been shown to increase high-density lipoprotein (HDL) cholesterol (a known cardioprotective factor). Estrogen also possesses a vasodilating property, which can improve cardiac performance in ischemic heart disease. In addition, recent studies have demonstrated that estrogens (especially equilin) exhibit a high antioxidant effect, which may also be related to cardioprotectivity. Although estrogen therapy has been observed to decrease the risk of coronary disease, long-term estrogen therapy has also been found to increase the risk of uterine carcinoma; the addition of progesterone to estrogen therapy may lessen this undesirable risk, however. On the other hand the addition of progesterone to estrogen therapy may decrease estrogen's beneficial effect on HDL cholesterol. What should be the present position on estrogen therapy in postmenopausal women? What is the best dosage regimen? Should it be used alone or in combination with a progesterone? These important issues are discussed, as are several current clinical trials addressing the issue of estrogen therapy in postmenopausal women.

Gynecologic effects of tamoxifen and the association with endometrial carcinoma

Tamoxifen has been used as an adjuvant therapy for breast cancer for nearly two decades. The benefits of adjuvant tamoxifen therapy in prolonging disease-free and overall survival have been shown in randomized clinical trials. Despite this, some developing evidence suggests that tamoxifen causes a 2- to 3-fold increase in endometrial cancer. This paper reviews the reports of endometrial carcinoma in tamoxifen-treated patients. Two hundred fifty cases of endometrial carcinoma are reported, but only one case is identified in a premenopausal woman. When documented, 77% (n=127) of the cases are good-grade (grade 1 or 2) and 80% (n=125) are stage-I disease. Since the distribution of good grade (79%) and stage I (74%) from the Surveillance, Epidemiology and End Results (SEER) data are comparable, concerns about more aggressive or late-stage disease appear to be unwarranted. The modest increase in the incidence of early-stage, good-grade endometrial carcinoma described during tamoxifen therapy suggests that it would be unreasonable to institute an aggressive detection strategy of endometrial biopsies. This approach would only lead to further detection bias and would not be cost-effective. Physicians should ensure that patients do not have pre-existing endometrial cancer prior to adjuvant tamoxifen therapy for breast cancer and, furthermore, they should educate patients about signs and symptoms of early endometrial carcinoma and when reported these should be followed up with a gynecologic examination.