Effect of selective estrogen receptor modulators on metabolic homeostasis

Sexual dimorphism of metabolic dysfunction-associated steatotic liver disease

Metabolic dysfunction-associated steatotic liver disease (MASLD) is the most common chronic liver condition. MASLD is a sexually dimorphic condition, with its development and progression influenced by sex chromosomes and hormones. Estrogens typically protect against, whereas androgens promote, MASLD. Therapeutic approaches for a sex-specific personalized medicine include estrogen replacement, androgen blockers, and novel drugs targeting hormonal pathways. However, the interactions between hormonal factors and inherited genetic variation impacts MASLD risk, necessitating more tailored therapies. Understanding sex disparities and the role of estrogens could improve MASLD interventions and management, whereas clinical trials addressing sex differences are crucial for advancing personalized treatment. This review explores the underappreciated impact of sexual dimorphism in MASLD and discusses the potential therapeutic application of sex-related hormones.

Short-term tamoxifen administration improves hepatic steatosis and glucose intolerance through JNK/MAPK in mice

Nonalcoholic fatty liver disease (NAFLD) which is a leading cause of chronic liver diseases lacks effective treatment. Tamoxifen has been proven to be the first-line chemotherapy for several solid tumors in clinics, however, its therapeutic role in NAFLD has never been elucidated before. In vitro experiments, tamoxifen protected hepatocytes against sodium palmitate-induced lipotoxicity. In male and female mice fed with normal diets, continuous tamoxifen administration inhibited lipid accumulation in liver, and improved glucose and insulin intolerance. Short-term tamoxifen administration largely improved hepatic steatosis and insulin resistance, however, the phenotypes manifesting inflammation and fibrosis remained unchanged in abovementioned models. In addition, mRNA expressions of genes related to lipogenesis, inflammation, and fibrosis were downregulated by tamoxifen treatment. Moreover, the therapeutic effect of tamoxifen on NAFLD was not gender or ER dependent, as male and female mice with metabolic disorders shared no difference in response to tamoxifen and ER antagonist (fulvestrant) did not abolish its therapeutic effect as well. Mechanistically, RNA sequence of hepatocytes isolated from fatty liver revealed that JNK/MAPK signaling pathway was inactivated by tamoxifen. Pharmacological JNK activator (anisomycin) partially deprived the therapeutic role of tamoxifen in treating hepatic steatosis, proving tamoxifen improved NAFLD in a JNK/MAPK signaling-dependent manner.

Estrogens in Adipose Tissue Physiology and Obesity-Related Dysfunction

Menopause-related decline in estrogen levels is accompanied by a change in adipose tissue distribution from a gynoid to an android and an increased prevalence of obesity in women. These unfavorable phenomena can be partially restored by hormone replacement therapy, suggesting a significant role for estrogen in the regulation of adipocytes' function. Indeed, preclinical studies proved the involvement of these hormones in adipose tissue development, metabolism, and inflammatory activity. However, the relationship between estrogen and obesity is bidirectional. On the one hand-their deficiency leads to excessive fat accumulation and impairs adipocyte function, on the other-adipose tissue of obese individuals is characterized by altered expression of estrogen receptors and key enzymes involved in their synthesis. This narrative review aims to summarize the role of estrogen in adipose tissue development, physiology, and in obesity-related dysfunction. Firstly, the estrogen classification, synthesis, and modes of action are presented. Next, their role in regulating adipogenesis and adipose tissue activity in health and the course of obesity is described. Finally, the potential therapeutic applications of estrogen and its derivates in obesity treatment are discussed.

Protective effects of combining SERMs with estrogen on metabolic parameters in postmenopausal diabetic cardiovascular dysfunction: The role of cytokines and angiotensin II

INTRODUCTION

The beneficial effects of the administration of selective estrogen receptor modulators (SERMs) and estrogen (E2), alone or in combination with each other, have been reported in postmenopausal diabetic cardiovascular dysfunction. In the present study, we determined the mechanism of action of SERMs and E2 on inflammatory balance, angiotensin II (Ang II) serum levels, and glycemic profile in a postmenopausal diabetic rat model.

METHODS

Ovariectomized rats with type 2 diabetes received daily SERMs (tamoxifen and raloxifene) and E2 for one month. After treatment, cardiovascular risk indices, glycemic profile, and serum Ang II, TNF-α and IL-10 levels were measured.

RESULTS

Type 2 diabetes caused an abnormal glycemic profile, which was exacerbated by ovariectomy. All treatments inhibited the effects of diabetes and ovariectomy on the glycemic profile, with combined treatments (SERMs + E2) showing stronger effects. Cardiovascular risk indices that became abnormal by diabetes and worsened by ovariectomy were improved in all treatment modalities. Also, combined treatment reduced serum Ang II, TNF-α, and the ratio of TNF-α to IL-10, indicating an improvement in inflammatory balance.

CONCLUSION

Our study showed the administration of SERMs and E2, alone or in combination, could be an effective alternative in the treatment of menopausal diabetes, and generally, the beneficial effects of combined treatments were more effective than the effects of E2 or SERMs alone. It appears that E2 or SERMs benefit the cardiovascular system by improving inflammatory balance and reducing Ang II levels.

Estradiol and Estrogen-like Alternative Therapies in Use: The Importance of the Selective and Non-Classical Actions

Estrogen is one of the most important female sex hormones, and is indispensable for reproduction. However, its role is much wider. Among others, due to its neuroprotective effects, estrogen protects the brain against dementia and complications of traumatic injury. Previously, it was used mainly as a therapeutic option for influencing the menstrual cycle and treating menopausal symptoms. Unfortunately, hormone replacement therapy might be associated with detrimental side effects, such as increased risk of stroke and breast cancer, raising concerns about its safety. Thus, tissue-selective and non-classical estrogen analogues have become the focus of interest. Here, we review the current knowledge about estrogen effects in a broader sense, and the possibility of using selective estrogen-receptor modulators (SERMs), selective estrogen-receptor downregulators (SERDs), phytoestrogens, and activators of non-genomic estrogen-like signaling (ANGELS) molecules as treatment.

How Protein Methylation Regulates Steroid Receptor Function

Steroid receptors (SRs) are members of the nuclear hormonal receptor family, many of which are transcription factors regulated by ligand binding. SRs regulate various human physiological functions essential for maintenance of vital biological pathways, including development, reproduction, and metabolic homeostasis. In addition, aberrant expression of SRs or dysregulation of their signaling has been observed in a wide variety of pathologies. SR activity is tightly and finely controlled by post-translational modifications (PTMs) targeting the receptors and/or their coregulators. Whereas major attention has been focused on phosphorylation, growing evidence shows that methylation is also an important regulator of SRs. Interestingly, the protein methyltransferases depositing methyl marks are involved in many functions, from development to adult life. They have also been associated with pathologies such as inflammation, as well as cardiovascular and neuronal disorders, and cancer. This article provides an overview of SR methylation/demethylation events, along with their functional effects and biological consequences. An in-depth understanding of the landscape of these methylation events could provide new information on SR regulation in physiology, as well as promising perspectives for the development of new therapeutic strategies, illustrated by the specific inhibitors of protein methyltransferases that are currently available.

Estrogens and the regulation of glucose metabolism

The main estrogens: estradiol, estrone, and their acyl-esters have been studied essentially related to their classical estrogenic and pharmacologic functions. However, their main effect in the body is probably the sustained control of core energy metabolism. Estrogen nuclear and membrane receptors show an extraordinary flexibility in the modulation of metabolic responses, and largely explain gender and age differences in energy metabolism: part of these mechanisms is already sufficiently known to justify both. With regard to energy, the estrogen molecular species act essentially through four key functions: (1) Facilitation of insulin secretion and control of glucose availability; (2) Modulation of energy partition, favoring the use of lipid as the main energy substrate when more available than carbohydrates; (3) Functional protection through antioxidant mechanisms; and (4) Central effects (largely through neural modulation) on whole body energy management. Analyzing the different actions of estrone, estradiol and their acyl esters, a tentative classification based on structure/effects has been postulated. Either separately or as a group, estrogens provide a comprehensive explanation that not all their quite diverse actions are related solely to specific molecules. As a group, they constitute a powerful synergic action complex. In consequence, estrogens may be considered wardens of energy homeostasis.

Sex Differences in Nonalcoholic Fatty Liver Disease: Estrogen Influence on the Liver-Adipose Tissue Crosstalk

Significance: Nonalcoholic fatty liver disease (NAFLD) is a hepatic and systemic disorder with a complex multifactorial pathogenesis. Owing to the rising incidence of obesity and diabetes mellitus, the prevalence of NAFLD and its impact on global health care are expected to increase in the future. Differences in NAFLD exist between males and females, and among females depending on their reproductive status. Clinical and preclinical data show that females in the fertile age are more protected against NAFLD, and studies in postmenopausal women and ovariectomized animal models support a protective role for estrogens. Recent Advances: An efficient crosstalk between the liver and adipose tissue is necessary to regulate lipid and glucose metabolism, protecting the liver from steatosis and insulin resistance contributing to NALFD. New advances in the knowledge of sexual dimorphism in liver and adipose tissue are providing interesting clues about the sex differences in NAFLD pathogenesis that could inspire new therapeutic strategies. Critical Issues: Sex hormones influence key master regulators of lipid metabolism and oxidative stress in liver and adipose tissue. All these sex-biased metabolic adjustments shape the crosstalk between liver and adipose tissue, contributing to the higher protection of females to NAFLD. Future Directions: The development of novel drugs based on the protective action of estrogens, but without its feminizing or undesired side effects, might provide new therapeutic strategies for the management of NAFLD. Antioxid. Redox Signal. 35, 753-774.

Comparison of metabolic changes after neoadjuvant endocrine and chemotherapy in ER-positive, HER2-negative breast cancer

Survival of breast cancer patients has improved, and treatment-related changes regarding metabolic profile deterioration after neoadjuvant systemic treatment (NST) become important issues in cancer survivors. We sought to compare metabolic profile changes and the neutrophil-to-lymphocyte ratio (NLR) between patients undergoing neoadjuvant chemotherapy (NCT) and neoadjuvant endocrine therapy (NET) 3 years after the treatment. In a prospective, randomized, phase III trial which compared 24 weeks of NCT with adriamycin and cyclophosphamide followed by docetaxel and NET with goserelin and tamoxifen (NEST), 123 patients in the Asan Medical Center were retrospectively reviewed to evaluate metabolic changes, such as body mass index (BMI), blood pressure (BP), total cholesterol (TC), fasting glucose, and the NLR. The mean age of patients was 42 years. The changes in BMI, serum glucose, and TC during NST and after 3 years were significantly different between NCT and NET. The proportion of overweight + obese group and the mean BMI were significantly increased during NCT (26.6% to 37.5%, 22.84 kg/m2 to 23.87 kg/m2, p < 0.05), and these attributes found to have normalized at the 3-year follow-up. In the NET group, BMI changes were not observed (p > 0.05, all). There were no differences in changes over time among in the Hypertension group during NCT and NET (p = 0.96). The mean value of serum TC and fasting glucose significantly increased (< 0.05, both) during NCT and decreased 3 years after NCT (p < 0.05); however, no significant changes were observed in the NET group. The NLR was increased from 1.83 to 3.18 after NCT (p < 0.05) and decreased from 1.98 to 1.43 (p < 0.05) after NET. Compared with minimal metabolic effect of NET, NCT worsens metabolic profiles, which were recovered over 3 years. The NLR was increased after NCT but decreased after NET.

Estetrol prevents Western diet-induced obesity and atheroma independently of hepatic estrogen receptor α

Estetrol (E4), a natural estrogen synthesized by the human fetal liver, is currently evaluated in phase III clinical studies as a new menopause hormone therapy. Indeed, E4 significantly improves vasomotor and genito-urinary menopausal symptoms and prevents bone demineralization. Compared with other estrogens, E4 was found to have limited effects on coagulation factors in the liver of women allowing to expect less thrombotic events. To fully delineate its clinical potential, the aim of this study was to assess the effect of E4 on metabolic disorders. Here, we studied the pathophysiological consequences of a Western diet (42% kcal fat, 0.2% cholesterol) in ovariectomized female mice under chronic E4 treatment. We showed that E4 reduces body weight gain and improves glucose tolerance in both C57Bl/6 and LDLR^-/- mice. To evaluate the role of hepatic estrogen receptor (ER) α in the preventive effect of E4 against obesity and associated disorders such as atherosclerosis and steatosis, mice harboring a hepatocyte-specific ERα deletion (LERKO) were crossed with LDLR^-/- mice. Our results demonstrated that, whereas liver ERα is dispensable for the E4 beneficial actions on obesity and atheroma, it is necessary to prevent steatosis in mice. Overall, these findings suggest that E4 could prevent metabolic, hepatic, and vascular disorders occurring at menopause, extending the potential medical interest of this natural estrogen as a new hormonal treatment.NEW & NOTEWORTHY Estetrol prevents obesity, steatosis, and atherosclerosis in mice fed a Western diet. Hepatic ERα is necessary for the prevention of steatosis, but not of obesity and atherosclerosis.

Selective Estrogen Receptor Modulators: A Potential Option For Non-Binary Gender-Affirming Hormonal Care?

Gender dysphoria describes the distress associated with having a gender identity that differs from one's birth-assigned sex. To relieve this distress, transgender, and gender diverse (henceforth, trans) individuals commonly undergo medical transition involving hormonal treatments. Current hormonal treatment guidelines cater almost exclusively for those who wish to transition from male to female or vice versa. In contrast, there is a dearth of hormonal options for those trans individuals who identify as non-binary and seek an androgynous appearance that is neither overtly male nor female. Though prolonged puberty suppression with gonadotrophin releasing hormone agonists (GnRHa) could in theory be gender-affirming by preventing the development of unwanted secondary sex characteristics, this treatment option would be limited to pre- or peri-pubertal adolescents and likely have harmful effects. Here, we discuss the theoretical use of Selective Estrogen Receptor Modulators (SERMs) for non-binary people assigned male at birth (AMAB) who are seeking an androgynous appearance through partial feminization without breast growth. Given their unique range of pharmacodynamic effects, SERMs may represent a potential gender-affirming treatment for this population, but there is a lack of knowledge regarding their use and potentially adverse effects in this context.

Under-carboxylated osteocalcin regulates glucose and lipid metabolism during pregnancy and lactation in rats

PURPOSE

Under-carboxylated osteocalcin (UcOC), a bone-released hormone is suggested to regulate energy metabolism. Pregnancy and lactation physiological conditions that require high levels of energy. The current study attempts to examine whether UcOC is involved in regulating energy metabolism during these conditions using adult Wistar rats.

METHODS AND RESULTS

Insulin tolerance tests indicated insulin resistance during late pregnancy (day 19 of pregnancy; P19) and insulin sensitivity during early lactation (day 6 of lactation; L6). Gene expression analyses suggested that muscle glucose metabolism was downregulated during P19 and enhanced during L6. Concomitantly, circulatory UcOC levels were lower during pregnancy but higher during early lactation; the rise in UcOC levels was tightly linked to the lactation process. Altering endogenous UcOC levels pharmacologically with warfarin and alendronate in P19 and L6 rats changed whole-body insulin response and muscle glucose transporter (Glut4) expression. Glut4 expression can be increased by either UcOC or estrogen receptors (ERs), both of which act independent of each other. A high fat diet decreased UcOC levels and insulin sensitivity in lactating rats, suggesting that diet can compromise UcOC-established energy homeostasis. Gene expression of lipid metabolism markers and triglyceride levels suggested that UcOC suppression during early pregnancy is an essential step in maternal lipid storage.

CONCLUSION

Taken together, we found that UcOC plays an important role in energy homeostasis via regulation of glucose and lipid metabolism during pregnancy and lactation.

Coronary Microvascular Dysfunction and Estrogen Receptor Signaling

Chest pain with non-obstructive coronary artery disease (NOCAD) occurs more frequently in women than in men and is mainly related to coronary microvascular disease (CMD). The majority of CMD patients are postmenopausal women, suggesting a role for lack of estrogens in the development and progression of CMD. Patients are often discharged without a clear treatment plan due to the limited understanding of etiology and diagnostic parameters of CMD and have significantly higher rates of future cardiovascular events. Thus, there is a need for a better understanding of the underlying biology, and CMD-specific diagnostic tests and therapies. In this article, we reviewed recent studies on CMD, estrogen action in coronary microvasculature, and diagnosis and treatment options for CMD in postmenopausal women.

A high AR:ERα or PDEF:ERα ratio predicts a sub-optimal response to tamoxifen therapy in ERα-positive breast cancer

PURPOSE

Approximately 30% oestrogen receptor alpha (ERα)-positive breast cancer (BC) patients exhibit intrinsic or recurrent resistance to adjuvant endocrine therapy with tamoxifen. The androgen receptor (AR) is expressed in about 90% of ERα-positive patients, with particularly high expression in tamoxifen-resistant tumours. Prostate-derived Ets factor (PDEF), which is a co-regulator of AR, plays a role in tamoxifen resistance in ERα-positive BC. The purpose of this research was to analyse the potential roles of AR, PDEF and ERα levels in the response to tamoxifen resistance in ERα-positive BC.

METHODS

The nuclear AR:ERα and PDEF:ERα ratios were examined immunohistochemically in a cohort of 225 ERα-positive pre-menopausal BC patients who had received adjuvant tamoxifen therapy.

RESULTS

For both AR:ERα and PDEF:ERα ratios, the optimal cutoff value was 2.0. Patients receiving adjuvant tamoxifen treatment who had a high AR:ERα (≥ 2.0) (HR = 3.90) or PDEF:ERα ratio (≥ 2.0) (HR = 2.77) had a beyond twofold increased risk of failure. Both the AR:ERα ratio (P = 0.001) and PDEF:ERα ratio (P = 0.002) were independently associated with the risk of tamoxifen treatment failure. Furthermore, both a high ratio of AR:ERα (≥ 2.0) and PDEF:ERα (≥ 2.0) were associated with shorter disease-free survival (DFS) and shorter disease-specific survival (DSS). In addition, both the AR:ERα ratio and PDEF:ERα ratio were independent predictors of DFS (both P < 0.0001) and DSS (P = 0.001 and P < 0.0001, respectively).

CONCLUSIONS

AR:ERα and PDEF:ERα ratios are independent predictors of the response to conventional ERα-directed tamoxifen endocrine therapy.

Wnt3a involved in the mechanical loading on improvement of bone remodeling and angiogenesis in a postmenopausal osteoporosis mouse model

Osteoporosis is a major health problem, making bones fragile and susceptible to fracture. Previous works showed that mechanical loading stimulated bone formation and accelerated fracture healing. Focusing on the role of Wnt3a (wingless/integrated 3a), this study was aimed to assess effects of mechanical loading to the spine, using ovariectomized (OVX) mice as a model of osteoporosis. Two-week daily application of this novel loading (4 N, 10 Hz, 5 min/d) altered bone remodeling with an increase in Wnt3a. Spinal loading promoted osteoblast differentiation, endothelial progenitor cell migration, and tube formation and inhibited osteoclast formation, migration, and adhesion. A transient silencing of Wnt3a altered the observed loading effects. Spinal loading significantly increased bone mineral density, bone mineral content, and bone area per tissue area. The loaded OVX group showed a significant increase in the number of osteoblasts and reduction in osteoclast surface/bone surface. Though expression of osteoblastic genes was increased, the levels of osteoclastic genes were decreased by loading. Spinal loading elevated a microvascular volume as well as VEGF expression. Collectively, this study supports the notion that Wnt3a-mediated signaling involves in the effect of spinal loading on stimulating bone formation, inhibiting bone resorption, and promoting angiogenesis in OVX mice. It also suggests that Wnt3a might be a potential therapeutic target for osteoporosis treatment.-Li, X., Liu, D., Li, J., Yang, S., Xu, J., Yokota, H., Zhang, P. Wnt3a involved in the mechanical loading on improvement of bone remodeling and angiogenesis in a postmenopausal osteoporosis mouse model.

Molecular mechanisms involved in the protective actions of Selective Estrogen Receptor Modulators in brain cells

Synthetic selective modulators of the estrogen receptors (SERMs) have shown to protect neurons and glial cells against toxic insults. Among the most relevant beneficial effects attributed to these compounds are the regulation of inflammation, attenuation of astrogliosis and microglial activation, prevention of excitotoxicity and as a consequence the reduction of neuronal cell death. Under pathological conditions, the mechanism of action of the SERMs involves the activation of estrogen receptors (ERs) and G protein-coupled receptor for estrogens (GRP30). These receptors trigger neuroprotective responses such as increasing the expression of antioxidants and the activation of kinase-mediated survival signaling pathways. Despite the advances in the knowledge of the pathways activated by the SERMs, their mechanism of action is still not entirely clear, and there are several controversies. In this review, we focused on the molecular pathways activated by SERMs in brain cells, mainly astrocytes, as a response to treatment with raloxifene and tamoxifen.

Mongolian Medicine echinops prevented postmenopausal osteoporosis and induced ER/AKT/ERK pathway in BMSCs

Hormone replacement medicine such as traditional Chinese medicine has proven to be effective in decreasing the risk of osteoporosis. Mongolian medicine echinops prevents osteoporosis, but its mechanism remains unclear. In this study, we explored the mechanism underlying echinops prevents and treats postmenopausal osteoporosis. Osteoporosis model was established by ovariectomy in rats. Rats were treated to Echinops (16.26, 32.5, or 65 mg/kg/day) by oral gavage for 3 months. Bone mineral density (BMD) was detected by micro-CT detection of left proximal medial metaphyseal tibia. Hematoxylin and eosin (H&E) and toluidine blue O staining were also performed. Serum levels of E2, ALP and testosterone were examined. Bone marrow-derived bone marrow stem cells (BMSCs) were isolated and treated with echinops-containing serum. Estrogen receptors (ER) including ERα and ERβ in bone specimens and BMSCs were detected by qRT-PCR. Cell viability and colon formation of BMSCs were detected. Expressions of ERα, ERβ, AKT, p-AKT, ERK, and p-ERK in BMSCs were detected by western blot. Results showed that echinops significantly increased trabecular interconnectivity, thickness of trabeculae, and connection of trabecula. Echinops significantly increased BMD and E2, but significantly reduced ALP and testosterone in dose-dependent manners. Echinops induced ERα and ERβ in both bone specimens and BMSCs. Echinops enhanced cell viability and ability of colony formation of BMSCs, and increased ERα, ERβ, p-AKT, and p-ERK. Thus, Mongolian echinops reduced bone loss and delayed the occurrence and development of osteoporosis, and increased ERα, ERβ, p-AKT, and P-ERK in BMSCs. These results provide experimental basis for clinical prevention and treatment of postmenopausal osteoporosis by echniops.

Translational Significance of Selective Estrogen Receptor Modulators in Psychiatric Disorders

Accumulating data from various clinical trial studies suggests that adjuvant therapy with ovarian hormones (estrogens) could be effective in reducing cognitive deficit and psychopathological symptoms in women with psychiatric disorders. However, estrogen therapy poses serious limitations and health issues including feminization in men and increased risks of thromboembolism, hot flashes, breast hyperplasia, and endometrium hyperplasia when used for longer duration in older women (aged ≥ 60 years) or in women who have genetic predispositions. On the other hand, selective estrogen receptor modulators (SERMs), which may (or may not) carry some risks of hot flashes, thromboembolism, breast hyperplasia, and endometrial hyperplasia, are generally devoid of feminization effect. In clinical trial studies, adjuvant therapy with tamoxifen, a triphenylethylene class of SERM, has been found to reduce the frequency of manic episodes in patients with bipolar disorder, whereas addition of raloxifene, a benzothiophene class of SERM, to regular doses of antipsychotic drugs has been found to reduce cognitive deficit and psychological symptoms in men and women with schizophrenia, including women with treatment refractory psychosis. These outcomes together with potent neurocognitive, neuroprotective, and cardiometabolic properties suggest that SERMs could be the potential targets for designing effective and safer therapies for psychiatric disorders.

Dangguijihwang-tang and Dangguijakyak-san Prevent Menopausal Symptoms and Dangguijihwang-tang Prevents Articular Cartilage Deterioration in Ovariectomized Obese Rats with Monoiodoacetate-Induced Osteoarthritis

We investigated whether dangguijakyak-san (DJY) and dangguijihwang-tang (DJH), oriental medicines traditionally used for inflammatory diseases, could prevent and/or delay the progression of postmenopausal symptoms and osteoarthritis in osteoarthritis-induced estrogen-deficient rats. Treated ovariectomized (OVX) rats consumed either 1% DJY or 1% DJH in the diets. Positive-control rats were given 30 μg/kg bw 17β-estradiol and control rats were given 1% fat as were the normal-control rats. All rats received high-fat diets for 8 weeks. At the 9th week, OVX rats received articular injections of monoiodoacetate (MIA) or saline (normal control) into the right knee. At 3 weeks after MIA injection, DJY reduced visceral-fat mass and improved glucose metabolism by reducing insulin resistance, whereas DJH increased BMD and decreased insulin resistance. DJH improved weight distribution in the right knee and maximum running velocity on a treadmill at days 14 and 21 as much as those of the positive control. TNF-α, IL-1β, and IL-6 levels in articular cartilage were much higher in the control than the positive control, whereas both DJY and DJH reduced the levels to those of the positive control. The histological analysis assessed articular cartilage damage near the tidemark and proteoglycan loss in the control versus the positive control; DJY and DJH prevented this damage and proteoglycan loss. In conclusion, DJY may provide an effective treatment for improving glucose tolerance, and DJH may be appropriate for preventing osteoarthritis.

MiR-203 inhibits estrogen-induced viability, migration and invasion of estrogen receptor α-positive breast cancer cells

Breast cancer is common in females, and accounts for a large proportion of cancer-related cases of mortality. MicroRNAs (miRs) have been found to be involved in the progression of breast cancer via mediation of tumor suppressor genes or oncogenes. Previously, miR-203 has been reported to play a suppressive role in breast cancer. In the present study, the effects of miR-203 on the malignant phenotypes of estrogen receptor α (ERα)-positive breast cancer cells were investigated. It was found that treatment with estradiol (E2) significantly enhanced the viability, migration and invasion of ERα-positive breast cancer MCF-7 cells, accompanied by the significant downregulation of miR-203 in a dose-dependent manner. Furthermore, MCF-7 cells were transfected with miR-203 mimics, resulting in a significant increase in miR-203 levels. Upregulation of miR-203 was found to significantly inhibit E2-induced upregulation of MCF-7 cell viability, migration and invasion. Upregulation of miR-203 also led to a significant decrease in the protein expression of ERα in MCF-7 cells. Using a luciferase reporter assay, ERα was identified as a direct target of miR-203 in MCF-7 cells. Finally, it was demonstrated that miR-203 was significantly downregulated in ERα-positive breast cancer tissues compared to their matched normal adjacent tissues. The expression levels of miR-203 were inversely correlated to the ERα levels in ERα-positive breast cancer tissues. Based on these results, it is proposed that miR-203 inhibits E2-induced viability, migration and invasion of ERα-positive breast cancer cells, and that this may be via direct targeting of ERα. Therefore, the present study highlights the importance of miR-203 and ERα in breast cancer progression.

Reduced dosing and liability in methadone maintenance treatment by targeting oestrogen signal for morphine addiction

Methadone maintenance treatment (MMT) is the major tapering therapy for morphine addictive patients. There have gender differences reported in response to MMT. This study discovered that the estrogen‐response element single nucleotide polymorphism (ERE‐SNP; rs16974799, C/T) of cytochrome 2B6 gene (cyp2b6; methadone catabolic enzyme) responded differently to MMT dosing. Oestradiol was associated with high MMT dosing, high enantiomer (R‐ or S‐) of 2‐ethylidene‐1,5‐dimethyl‐3,3‐dipheny‐pyrrolidine (EDDP; methadone metabolite) to methadone ratio and increased drug‐seeking behaviour, implicating oestradiol‐CYP‐EDDP/methadone axis decreasing MMT efficacy. In mouse model, oestrogen mitigates methadone antinociceptive response, facilitates methadone catabolism and up‐regulates methadone‐associated metabolizing enzymes. Oestrogen also ablates chronic methadone administration‐induced rewarding response. Mechanism dissection revealed the CC genotype of CYP2B6‐ERE‐SNP exerts higher ERE sequence alignment score, higher estrogenic response as compared to TT genotype. At last, preclinical study via targeting estrogen signal that tamoxifen (TMX; selective estrogen receptor modulator, SERM) could facilitate the tolerance phase rewarding response of methadone. Strikingly, TMX also reduces tapering/abstinence phases methadone liability in mice. In conclusion, this study demonstrates altering methadone metabolism through targeting estrogen signals might be able to free morphine addictive patients from the addiction of opioid replacement therapy. Therefore, the add‐on therapy clinical trial introducing SERM in MMT regimen is suggested.

Menopausal Hormone Therapy and Type 2 Diabetes Prevention: Evidence, Mechanisms, and Clinical Implications

Type 2 diabetes has reached epidemic proportions in the United States. Large, randomized controlled trials suggest that menopausal hormone therapy (MHT) delays the onset of type 2 diabetes in women. However, the mechanisms and clinical implications of this association are still a matter of controversy. This review provides an up-to-date analysis and integration of epidemiological, clinical, and basic studies, and proposes a mechanistic explanation for the effect of menopause and MHT on type 2 diabetes development and prevention. We discuss the beneficial effects of endogenous estradiol with respect to insulin secretion, insulin sensitivity, and glucose effectiveness; we also discuss energy expenditure and adipose distribution, both of which are affected by menopause and improved by MHT, which thereby decreases the incidence of type 2 diabetes. We reconcile differences among studies that investigated the effect of menopause and MHT formulations on type 2 diabetes. We argue that discrepancies arise from physiological differences in methods used to assess glucose homeostasis, ranging from clinical indices of insulin sensitivity to steady-state methods to assess insulin action. We also discuss the influence of the route of estrogen administration and the addition of progestogens. We conclude that, although MHT is neither approved nor appropriate for the prevention of type 2 diabetes due to its complex balance of risks and benefits, it should not be withheld from women with increased risk of type 2 diabetes who seek treatment for menopausal symptoms.

miR-148a Suppresses estrogen-induced viability and migration of breast cancer cells via inhibition of estrogen receptor α expression

MicroRNAs (miRs) play critical roles in the development and malignant progression of human cancers. miR-148a has previously been found to inhibit the migration and invasion of breast cancer cells. However, the underlying mechanism of miR-148a in regulating the viability and migration of estrogen receptor (ER) α-positive breast cancer cells is still unknown. In this study, ERα-positive breast cancer MCF7 cells were treated with estradiol (E2). Data from MTT and wound healing assays showed that E2 treatment promoted the viability and migration of MCF7 cells. A bioinformatics analysis and luciferase reporter assay identified ERα as a direct target of miR-148a. Ectopic expression of miR-148a significantly decreased the protein expression of ERα (P<0.01), while knockdown of miR-148a significantly increased the ERα protein level in MCF7 cells (P<0.01). Furthermore, miR-148a overexpression significantly inhibited the E2-induced viability and migration of MCF7 cells (P<0.01), similar to the effect of silencing ERα. However, overexpression of ERα rescued the suppressed viability and migration caused by miR-148a upregulation. Finally, it was found that E2 treatment led to a significant decrease in the miR-148a level in MCF7 cells (P<0.01). These results suggest that miR-148a can suppress the E2-induced viability and migration of MCF7 breast cancer cells via inhibition of ERα protein expression, expanding the understanding of miR function in ERα-positive breast cancer.

Tetragonia tetragonioides (Pall.) Kuntze protects estrogen-deficient rats against disturbances of energy and glucose metabolism and decreases proinflammatory cytokines

Tetragonia tetragonioides (Pall.) Kuntze (TTK) and JakYakGamCho-Tang (JGT) have been used for improving women's health and treating inflammatory diseases. We determined that the long-term consumption of these herbal extracts alleviates the progression of postmenopausal symptoms in high-fat-diet fed ovariectomized (OVX) rats, and further explored the mechanisms involved. Five groups of OVX rats were fed high fat diets that were supplemented with either 2% dextrin (control), 2% TTK (70% ethanol extract), 2% JGT (water extract), 1% JGT + 1% TTK (JGTT), or 30 µg/kg body weight/day of 17β-estradiol (positive control). After eight weeks of dietary intervention, the herbal treatments did not change the serum concentrations of 17β-estradiol or uterine weight in control rats, but they were higher in the positive-control group. TTK rats exhibited higher daily energy expenditure, particularly fat oxidation, without modifying the energy intake than the controls. TTK lowered the fat mass but lean body mass of the abdomen and leg were increased. JGT decreased periuterine fat mass and lean body mass more than the control but the decrease was not as much as TTK. TTK resulted in substantially lower serum concentrations of the proinflammatory cytokines, tumor necrosis factor-α (TNF-α) and monocyte chemoattractant protein-1, than the control and JGT had lesser effect than TTK. Insulin resistance, determined by homeostasis model assessment estimate for assessing insulin resistance (HOMA-IR) and insulin tolerance test, was reduced in the decreasing order of control, JGT, JGTT, and TTK and the HOMA-IR of TTK was similar to the positive control. TTK, but not JGT, enhanced glucose tolerance compared with the control, although the serum insulin levels in TTK were lower compared to the control. Interestingly, the β-cell masses were much greater in the TTK and JGTT groups than in the control, and they were comparable to the positive control. The increases in β-cell masses in TTK and JGTT groups were associated with enhanced β-cell proliferation and suppressed apoptosis, which was related to the decreased TNF-α and interleukin-1β expressions. In conclusion, JGTT did not improve menopausal symptoms better than TTK itself. TTK itself prevented the OVX-induced impairments in energy, lipid, and glucose metabolism, similar to the positive control, without changing serum 17β-estradiol levels and potentiating insulin signaling and decreasing proinflammatory cytokines. TTK may be a useful intervention to alleviate some menopausal symptoms similar to selective estrogen receptor modulators and should be investigated with further human study. Impact statement Menopause decreases the quality of life in middle-aged women and herbal remedies are sometimes used as alternatives for hormone replacement therapy, which may have detrimental side effects. Although several herbal extracts have been studied, no remedies improve all the menopausal symptoms. In this study, the 70% ethanol extract of Tetragonia tetragonioides (Pall.) Kuntze (TTK) reduced the symptoms of hot flushes and improved energy, glucose, and lipid metabolism in estrogen-deficient animals without increasing serum 17β-estradiol levels. This extract acts like a selective estrogen receptor modulator and it may be a useful intervention for alleviating menopausal symptoms. This is the first study to show that the 70% ethanol extract of TTK has the potential to treat menopause-associated symptoms and metabolic disturbances. It may be a useful intervention for alleviating the symptoms of menopause in women if its efficacy can be confirmed in human studies.

Type 2 Diabetes Mellitus and Cancer: The Role of Pharmacotherapy

Purpose Type 2 diabetes mellitus (T2DM) is becoming increasingly prevalent worldwide. Epidemiologic data suggest that T2DM is associated with an increased incidence and mortality from many cancers. The purpose of this review is to discuss the links between diabetes and cancer, the effects of various antidiabetic medications on cancer incidence and mortality, and the effects of anticancer therapies on diabetes. Design This study is a review of preclinical and clinical data regarding the effects of antidiabetic medications on cancer incidence and mortality and the effects of anticancer therapies on glucose homeostasis. Results T2DM is associated with an increased risk and greater mortality from many cancer types. Metformin use has been associated with a decrease in cancer incidence and mortality, and there are many ongoing randomized trials investigating the effects of metformin on cancer-related outcomes. However, data regarding the association of other antidiabetes medications with cancer incidence and mortality are conflicting. Glucocorticoids, hormone-based therapies, inhibitors that target the phosphatidylinositol 3-kinase-Akt-mammalian target of rapamycin pathway, and insulin-like growth factor 1 receptor-targeted therapy have been associated with high rates of hyperglycemia. These agents mediate their deleterious metabolic effects by reducing insulin secretion and increasing insulin resistance in peripheral tissues. Conclusion Studies must be performed to optimize cancer screening strategies in individuals with T2DM. A greater understanding of the mechanisms that link diabetes and cancer are needed to identify targets for therapy in individuals with diabetes who develop cancer. Data from clinical studies are needed to further elucidate the effects of antidiabetic medications on cancer incidence and progression. As several anticancer therapies alter glucose homeostasis, physicians need to be aware of these potential effects. Careful patient screening and monitoring during treatment with these agents is necessary.