The Estrogen Receptors: An Overview from Different Perspectives

Exploring the physiological role of the G protein-coupled estrogen receptor (GPER) and its associations with human diseases

Estrogen is a group of hormones that collaborate with the nervous system to impact the overall well-being of all genders. It influences many processes, including those occurring in the central nervous system, affecting learning and memory, and playing roles in neurodegenerative diseases and mental disorders. The hormone's action is mediated by specific receptors. Significant roles of classical estrogen receptors, ERα and ERβ, in various diseases were known since many years, but after identifying a structurally and locationally distinct receptor, the G protein-coupled estrogen receptor (GPER), its role in human physiology and pathophysiology was investigated. This review compiles GPER-related information, highlighting its impact on homeostasis and diseases, while putting special attention on functions and dysfunctions of this receptor in neurobiology and biobehavioral processes. Understanding the receptor modulation possibilities is essential for therapy, as disruptions in receptors can lead to diseases or disorders, irrespective of correct estrogen levels. We conclude that studies on the GPER receptor have the potential to develop therapies that regulate estrogen and positively impact human health.

Molecular and biochemical characterizations of a Fasciola gigantica retinoid X receptor-α isoform A (FgRXRα-A)

Fascioliasis is a parasitic infection in animals and humans caused by the parasitic flatworm genus Fasciola, which has two major species, F. hepatica and F. gigantica. A major concern regarding this disease is drug resistance, which is increasingly reported worldwide. Hence, the discovery of a novel drug as well as drug targets is crucially required. Therefore, this study aims to characterize the novel drug target in the adult F. gigantica. In the beginning, we hypothesized that the parasite might interact with some host molecules when it lives inside the liver parenchyma or bile ducts, specifically hormones and hormone-like molecules, through the specific receptors, primarily nuclear receptors (NRs), which are recognized as a major drug target in various diseases. The retinoid X receptor (RXR) is a member of subfamily 2 NRs that plays multitudinous roles in organisms by forming homodimers or heterodimers with other NRs. We obtained the full-length amino acid sequences of F. gigantica retinoid X receptor-alpha (FgRXRα-A) from the transcriptome of F. gigantica that existed in the NCBI database. The FgRXRα-A were computationally predicted for the basic properties, multiple aligned, phylogeny analyzed, and generated of 2D and 3D models. Moreover, FgRXRα-A was molecular cloned and expressed as a recombinant protein (rFgRXRα-A), then used for immunization for specific polyclonal antibodies. The native FgRXRα-A was detected in the parasite extracts and tissues, and the function was investigated by in vitro binding assay. The results demonstrated the conservation of FgRXRα-A to the other RXRs, especially RXRs from the trematodes. Interestingly, the native FgRXRα-A could be detected in the testes of the parasite, where the sex hormones are accumulated. Moreover, the binding assay revealed the interaction of 9-cis retinoic acid and FgRXRα-A, suggesting the function of FgRXRα-A. Our findings suggested that FgRXRα-A will be involved with the sexual reproduction of the parasite by forming heterodimers with other NRs, and it could be the potential target for further drug development of fascioliasis.

Tamoxifen protects photoreceptors in the sodium iodate model

Because the selective estrogen receptor modulator tamoxifen was shown to be retina-protective in the light damage and rd10 models of retinal degeneration, the purpose of this study was to test whether tamoxifen is retina-protective in a model where retinal pigment epithelium (RPE) toxicity appears to be the primary insult: the sodium iodate (NaIO3) model. C57Bl/6J mice were given oral tamoxifen (in the diet) or the same diet lacking tamoxifen, then given an intraperitoneal injection of NaIO3 at 25 mg/kg. The mice were imaged a week later using optical coherence tomography (OCT). ImageJ with a custom macro was utilized to measure retinal thicknesses in OCT images. Electroretinography (ERG) was used to measure retinal function one week post-injection. After euthanasia, quantitative real-time PCR (qRT-PCR) was performed. Tamoxifen administration partially protected photoreceptors. There was less photoreceptor layer thinning in OCT images of tamoxifen-treated mice. qRT-PCR revealed, in the tamoxifen-treated group, less upregulation of antioxidant and complement factor 3 mRNAs, and less reduction in the rhodopsin and short-wave cone opsin mRNAs. Furthermore, ERG results demonstrated preservation of photoreceptor function for the tamoxifen-treated group. Cone function was better protected than rods. These results indicate that tamoxifen provided structural and functional protection to photoreceptors against NaIO3. RPE cells were not protected. These neuroprotective effects suggest that estrogen-receptor modulation may be retina-protective. The fact that cones are particularly protected is intriguing given their importance for human visual function and their survival until the late stages of retinitis pigmentosa. Further investigation of this protective pathway could lead to new photoreceptor-protective therapeutics.

Metabolomic profiles of ovariectomized mice and their associations with body composition and frailty-related parameters in postmenopausal women

BACKGROUND

Menopause, a dramatical estrogen-deficient condition, is considered the most significant milestone in women's health.

PURPOSE

To investigate the metabolite changes attributed to estrogen deficiency using random forest (RF)-based machine learning (ML) modeling strategy in ovariectomized (OVX) mice as well as determine the clinical relevance of selected metabolites in older women.

METHODS AND RESULTS

Untargeted and targeted metabolomic analyses revealed that metabolites related to TCA cycle, sphingolipids, phospholipids, fatty acids, and amino acids, were significantly changed in the plasma and/or muscle of OVX mice. Subsequent ML classifiers based on RF algorithm selected alpha-ketoglutarate (AKG), arginine, carnosine, ceramide C24, phosphatidylcholine (PC) aa C36:6, and PC ae C42:3 in plasma as well as PC aa 34:1, PC aa C34:3, PC aa C36:5, PC aa C32:1, PC aa C36:2, and sphingosine in muscle as top featured metabolites that differentiate the OVX mice from the sham-operated group. When circulating levels of AKG, arginine, and carnosine, which showed the most significant changes in OVX mice blood, were measured in postmenopausal women, higher plasma AKG levels were associated with lower bone mass, weak grip strength, poor physical performance, and increased frailty risk.

CONCLUSIONS

Metabolomics- and ML-based methods identified the key metabolites of blood and muscle that were significantly changed after ovariectomy in mice, and the clinical implication of several metabolites was investigated by looking at their correlation with body composition and frailty-related parameters in postmenopausal women. These findings provide crucial context for understanding the diverse physiological alterations caused by estrogen deficiency in women.

A comprehensive meta-analysis to identify susceptibility genetic variants for precocious puberty

PURPOSE

Currently, several genetic variants in ERα gene (rs2234693 and rs9340799), ERβ gene (rs1256049 and rs4986938), KISS1 gene (rs4889, rs1132506 and rs5780218), LIN28B gene (rs314263, rs314276 and rs314280), and MKRN3 gene (rs2239669) have been repeatedly explored for their contribution to precocious puberty (PP) susceptibility. However, the results remain conflicting rather than conclusive. We here performed a meta-analysis to identify the real susceptibility genetic variants for PP.

METHODS

After screening by inclusion criteria, 20 related studies were finally included in this meta-analysis. The odds ratios and 95% confidence intervals were calculated to assess the strength of association. Sensitive analysis, publication bias, and trial sequential analysis (TSA) were performed to evaluate the stability and reliability of results.

RESULTS

Rs2234693, rs9340799, and rs1256049 were significantly associated with PP susceptibility (p < 0.0084). Stratified analysis according to ethnicity showed that rs2234693 and rs9340799 were significantly associated with PP susceptibility in Asian and Chinese populations. Stratified analysis according to PP subtype showed that rs2234693 and rs9340799 were significantly associated with idiopathic central PP susceptibility in Asian and Chinese populations (p < 0.0084). The results of publication bias, sensitivity analysis, and TSA provided solid evidence for the association between these three variants and PP susceptibility.

CONCLUSIONS

Rs2234693 and rs9340799 in ERα gene and rs1256049 in ERβ gene may serve as susceptive factors for PP development. The present finding should be confirmed in replication studies and reinforced in functional studies, which will ultimately improve the feasibility of the application of these three PP-susceptible loci in clinical practice.

Ginsenoside - a promising natural active ingredient with steroidal hormone activity

Ginsenosides are a class of natural products with hormone-like activity of triterpenoid saponins and have a variety of pharmacological activities such as anti-aging, immune regulation and cognitive improvement. With the great research interest in alternative medicine and natural products, they are gradually becoming research hotspots. Ginsenosides have a four-ring rigid steroid backbone similar to steroid hormones, and a series of experimental studies have shown that they can exhibit hormone-like activity by binding to nuclear receptors or affecting hormone levels, thereby affecting a wide range of inflammatory conditions, cancers, and menopause-related diseases. This review summarizes the mechanisms and potential health effects of ginsenosides exhibiting estrogen-like, glucocorticoid-like and androgen-like activities, providing an important reference for the exploration of safe phytohormone replacement therapy.

Functional hypothalamic amenorrhea: gut microbiota composition and the effects of exogenous estrogen administration

Functional hypothalamic amenorrhea (FHA) is characterized by estrogen deficiency that significantly impacts metabolic, bone, cardiovascular, mental, and reproductive health. Given the importance of environmental factors such as stress and body composition, and particularly considering the importance of estrogens in regulating the gut microbiota, some changes in the intestinal microenvironment are expected when all of these factors occur simultaneously. We aimed to assess whether the gut microbiota composition is altered in FHA and to determine the potential impact of hormonal replacement therapy (HRT) on the gut microbiota. This prospective observational study included 33 patients aged 18-34 yr with FHA and 10 age-matched healthy control women. Clinical, hormonal, and metabolic evaluations were performed at baseline for the FHA group only, whereas gut microbiota profile was assessed by 16S rRNA gene amplicon sequencing for both groups. All measurements were repeated in patients with FHA after receiving HRT for 6 mo. Gut microbiota alpha diversity at baseline was significantly different between patients with FHA and healthy controls (P < 0.01). At the phylum level, the relative abundance of Fusobacteria was higher in patients with FHA after HRT (P < 0.01), as was that of Ruminococcus and Eubacterium at the genus level (P < 0.05), which correlated with a decrease in circulating proinflammatory cytokines. FHA is a multidimensional disorder that is interconnected with dysbiosis through various mechanisms, particularly involving the gut-brain axis. HRT appears to induce a favorable shift in the gut microbiota in patients with FHA, which is also associated with a reduction in the systemic inflammatory status.NEW & NOTEWORTHY Our study marks the first comprehensive analysis of gut microbiota composition in FHA and the impact of HRT on it, along with biochemical, anthropometric, and psychometric aspects. Our results indicate distinct gut microbiota composition in patients with FHA compared with healthy individuals. Importantly, HRT prompts a transition toward a more beneficial gut microbiota profile and reduced inflammation. This study validates the concept of FHA as a multifaceted disorder interlinked with dysbiosis, particularly involving the gut-brain axis.

17β-Estradiol mediates TGFBR3/Smad2/3 signaling to attenuate the fibrosis of TGF-β1-induced bovine endometrial epithelial cells via GPER

Abnormal function and fibrosis of endometrium caused by cows' endometritis pose difficult implantation of embryos and uterine cavity adhesions. 17β-Estradiol (E2) serves as the most effective aromatized estrogen, and its synthetase and receptors have been detected in the endometrium. Studies have demonstrated the positive role of estrogen in combating pathological fibrosis in diverse diseases. However, it is still unknown whether E2 regulates endometrium fibrosis in bovine endometritis. Herein, we evaluated the expression patterns of transforming growth factor-β1 (TGF-β1), epithelial-mesenchymal transformation (EMT)-related proteins (α-SMA, vimentin N-cadherin and E-cadherin), cytochrome P450 19A1 (CYP19A1), and G protein-coupled estrogen receptor (GPER) in bovine healthy endometrium and Inflammatory endometrium. Our data showed that the inflamed endometrium presented low CYP19A1 and GPER expression, and significantly higher EMT process versus the normal tissue. Moreover, we established a TGF-β1-induced fibrosis model in BEND cells, and found that E2 inhibited the EMT process of BEND cells in a dose-dependent manner. The anti-fibrotic effect of E2 was blocked by the GPER inhibitor G15, but not the estrogen nuclear receptors (ERs) inhibitor ICI182780. Moreover, the GPER agonist G1 inhibited fibrosis and Smad2/3 phosphorylation but increased the expression of TGFBR3 in BEND cells. Transfection with TGFBR3 small interfering RNA blocked the effect of G1 on fibrosis of BEND cells and upregulated the expression of P-Smad2/3. Our in vivo data also showed that E2 and G1 affected uterus fibrosis in mice endometritis model caused by LPS, which was associated with the inhibition of TGFBR3/Smad2/3 signaling. In conclusion, our data implied that E2 alleviates the fibrosis of TGF-β1-induced BEND cells, which is associated with the GPER mediation of TGFBR3/Smad2/3 signaling.

Diffuse bilateral 18F-Fluoroestradiol pulmonary uptake in patients with metastatic estrogen receptor positive breast cancer: A case report

INTRODUCTION

Breast cancer is the most commonly diagnosed cancer in women and hormonal therapy is an established treatment for estrogen receptor (ER) positive breast cancers. 18F-Fluoroestradiol (FES) is an emerging radiotracer used to determine hormone status in patients with ER positive breast cancer as FES specifically binds to the alpha subtype of estrogen receptors. As with all radiotracers, FES demonstrates background uptake within various tissues and organs besides the targeted breast cancer and metastatic disease. To date, FES has mostly been shown to demonstrate uptake within the lungs from metastatic disease or in a more focal region after radiation therapy.

CASE AND OUTCOMES

We present two patients with stage IV ER positive breast cancer who underwent FES positron emission tomography and computed tomography (PET/CT) scans to evaluate for metastatic disease; both of which demonstrated diffuse bilateral mild-moderate pulmonary uptake. The first patient had a severe lung injury which was improving but still present at the time of her FES PET/CT. The second patient had a remote history of prior right breast radiation therapy for a prior breast cancer as well as emphysema and mild interstitial disease.

DISCUSSION

To date, FES uptake within the lungs has been shown to be secondary to fibrotic changes secondary to prior radiation therapy and the uptake is localized to a focal region within the lung corresponding to the localized region around the tumor needing radiation therapy. We present two FES PET/CT scans that demonstrate diffuse bilateral mild-moderate uptake. We believe the first patient's bilateral FES uptake was secondary to inflammatory changes from her acute lung injury. Our second patient has a remote history of right breast radiation therapy that would not account for her diffuse lung uptake but does have emphysema and mild interstitial disease which can account for the FES uptake seen in her FES PET/CT.

CONCLUSION

18F-Fluoroestradiol is an emerging radiotracer that binds to estrogen receptors and is being used to determine hormone receptor status in women with ER positive breast cancers, which is the most commonly diagnosed cancer in women. Therefore, it's important to understand where it might demonstrate uptake and why. We highlighted two unique cases of mild-moderate pulmonary uptake of FES to provide further information about FES. Overall, we conclude that diffuse bilateral mild-moderate FES uptake within the lungs is likely secondary to inflammation, interstitial disease, or a combination thereof.

Regulation of mRNA translation by estrogen receptor in breast cancer

Breast cancer is one of the leading causes of cancer-related fatalities and the most often diagnosed malignancy in women globally. Dysregulation of sex hormone signaling pathways mediated by the estrogen receptor (ER) in breast cancer is well characterized. Although ER is known to promote cell growth and survival by altering gene transcription, recent research suggests that its effects in cancers are also mediated through dysregulation of protein synthesis. This implies that ER can coordinately affect gene expression through both translational and transcriptional pathways, leading to the development of malignancy. In this review, we will cover the current understanding of how the ER controls mRNA translation in breast cancer and discuss any potential clinical implications of this phenomenon.

Association of probiotic ingestion with serum sex steroid hormones among pre- and postmenopausal women from the NHANES, 2013-2016

BACKGROUND

Sex hormone-related diseases, encompassing a wide range of conditions from reproductive disorders to certain cancers, pose significant health challenges worldwide. Recent scientific investigations have highlighted the intricate interplay between the gut microbiome and sex hormone regulation, indicating the potential for microbiota-targeted interventions in the management of such diseases. Although individual studies have elucidated the influence of the gut microbiome on sex hormones, a comprehensive cross-sectional examination of the population-wide prevalence of probiotic intake and its correlation with sex hormones is still lacking.

OBJECTIVES

This study aimed to evaluate the association of probiotic ingestion with sex hormones in pre- and post-menopausal women.

METHODS

We conducted an observational cohort study comprising a nationally representative sample of adults who participated in the National Health and Nutrition Examination Survey between 2013 and 2016. Probiotic ingestion was considered when a subject reported yogurt or probiotic supplement consumption during the 24-h dietary recall or during the Dietary Supplement Use 30-Day questionnaire. A survey-weighted generalized linear model was used to analyze the association between probiotic intake and female/male sex hormones. To reduce selection bias, we used propensity score matching (PSM).

RESULTS

This study included 2,699 women, with 537 of them consuming yogurt and/or dietary supplements containing probiotics, while the remaining 2,162 women did not consume any probiotics. The findings indicated that there were associations between probiotic intake and sex hormone levels in premenopausal and postmenopausal women. For premenopausal women, probiotic intake was positively associated with estradiol (E2) levels. On the contrary, in postmenopausal women, probiotic intake was inversely associated with total testosterone (TT) levels.

CONCLUSIONS

This study indicated that probiotic consumption was associated with higher E2 level in premenopausal women and lower TT level in postmenopausal women. Probiotic intake might be a sensible strategy for preventing sex hormone-related diseases.

Secoisolariciresinol diglucoside regulates estrogen receptor expression to ameliorate OVX-induced osteoporosis

OBJECTIVE

Secoisolariciresinol diglucoside (SDG) is a phytoestrogen that has been reported to improve postmenopausal osteoporosis (PMOP) caused by estrogen deficiency. In our work, we aimed to investigate the mechanism of SDG in regulating the expressions of ERs on PMOP model rats.

METHODS

Ovariectomization (OVX) was used to establish PMOP model in rats. The experiment was allocated to Sham, OVX, SDG and raloxifene (RLX) groups. After 12-week treatment, micro-CT was used to detect the transverse section of bone. Hematoxylin and Eosin staining and Safranine O-Fast Green staining were supplied to detect the femur pathological morphology of rats. Estradiol (E2), interleukin-6 (IL-6), bone formation and bone catabolism indexes in serum were detected using ELISA. Alkaline phosphatase (ALP) staining was used to detect the osteogenic ability of chondrocytes. Immunohistochemistry and Western blot were applied to detect the protein expressions of estrogen receptors (ERs) in the femur of rats.

RESULTS

Compared with the OVX group, micro-CT results showed SDG could lessen the injury of bone and improve femoral parameters, including bone mineral content (BMC) and bone mineral density (BMD). Pathological results showed SDG could reduce pathological injury of femur in OVX rats. Meanwhile, SDG decreased the level of IL-6 and regulated bone formation and bone catabolism indexes. Besides, SDG increased the level of E2 and conversed OVX-induced decreased the expression of ERα and ERβ.

CONCLUSION

The treatment elicited by SDG in OVX rats was due to the reduction of injury and inflammation and improvement of bone formation index, via regulating the expression of E2 and ERs.

The G Protein-Coupled Estrogen Receptor (GPER): A Critical Therapeutic Target for Cancer

Estrogens have been implicated in the pathogenesis of various cancers, with increasing concern regarding the overall rising incidence of disease and exposure to environmental estrogens. Estrogens, both endogenous and environmental, manifest their actions through intracellular and plasma membrane receptors, named ERα, ERβ, and GPER. Collectively, they act to promote a broad transcriptional response that is mediated through multiple regulatory enhancers, including estrogen response elements (EREs), serum response elements (SREs), and cyclic AMP response elements (CREs). Yet, the design and rational assignment of antiestrogen therapy for breast cancer has strictly relied upon an endogenous estrogen-ER binary rubric that does not account for environmental estrogens or GPER. New endocrine therapies have focused on the development of drugs that degrade ER via ER complex destabilization or direct enzymatic ubiquitination. However, these new approaches do not broadly treat all cancer-involved receptors, including GPER. The latter is concerning since GPER is directly associated with tumor size, distant metastases, cancer stem cell activity, and endocrine resistance, indicating the importance of targeting this receptor to achieve a more complete therapeutic response. This review focuses on the critical importance and value of GPER-targeted therapeutics as part of a more holistic approach to the treatment of estrogen-driven malignancies.

Tailoring Potential Natural Compounds for the Treatment of Luminal Breast Cancer

Breast cancer (BC) is the most diagnosed cancer worldwide, mainly affecting the epithelial cells from the mammary glands. When it expresses the estrogen receptor (ER), the tumor is called luminal BC, which is eligible for endocrine therapy with hormone signaling blockade. Hormone therapy is essential for the survival of patients, but therapeutic resistance has been shown to be worrying, significantly compromising the prognosis. In this context, the need to explore new compounds emerges, especially compounds of plant origin, since they are biologically active and particularly promising. Natural products are being continuously screened for treating cancer due to their chemical diversity, reduced toxicity, lower side effects, and low price. This review summarizes natural compounds for the treatment of luminal BC, emphasizing the activities of these compounds in ER-positive cells. Moreover, their potential as an alternative to endocrine resistance is explored, opening new opportunities for the design of optimized therapies.

Sex-Dependent Differences in Cholestasis: Why Estrogen Signaling May Be a Key Pathophysiological Driver

Primary biliary cholangitis (PBC) and primary sclerosing cholangitis (PSC) are cholestatic liver diseases that have significant clinical impact with debilitating symptoms and mortality. While PBC is predominantly seen in perimenopausal and postmenopausal women, men who are diagnosed with PBC have worse clinical outcomes and all-cause mortality. In contrast, 60% to 70% of patients with PSC are men; the data indicate that female sex may be an independent factor against PSC-related complications. These findings suggest a sex-dependent biological basis for these differences. Estrogen has been implicated in the pathogenesis of intrahepatic cholestasis of pregnancy and may induce cholestasis through a variety of interactions. However, it is unclear why some sexual dimorphic features may provide a protective effect despite known estrogen models that induce cholestasis. This article provides a brief introductory background and discusses the sexual dimorphism in clinical presentation in PSC and PBC. It also explores the role of estrogen signaling in pathogenesis and how it relates to intrahepatic cholestasis of pregnancy. Studies have already targeted certain molecules involved in estrogen signaling, and this review discusses these studies that identify estrogen-related receptor, estrogen receptor-α, estrogen receptor-β, farnesoid X receptor, and mast cells as possible targets, in addition to long noncoding RNA H19-induced cholestasis and sexual dimorphism. It also explores these interactions and their role in the pathogenesis of PBC and PSC.

Optimization of small molecule degraders and antagonists for targeting estrogen receptor based on breast cancer: current status and future

The estrogen receptor (ER) is a classical receptor protein that plays a crucial role in mediating multiple signaling pathways in various target organs. It has been shown that ER-targeting therapies inhibit breast cancer cell proliferation, enhance neuronal protection, and promote osteoclast formation. Several drugs have been designed to specifically target ER in ER-positive (ER+) breast cancer, including selective estrogen receptor modulators (SERM) such as Tamoxifen. However, the emergence of drug resistance in ER+ breast cancer and the potential side effects on the endometrium which has high ER expression has posed significant challenges in clinical practice. Recently, novel ER-targeted drugs, namely, selective estrogen receptor degrader (SERD) and selective estrogen receptor covalent antagonist (SERCA) have shown promise in addressing these concerns. This paper provides a comprehensive review of the structural functions of ER and highlights recent advancements in SERD and SERCA-related small molecule drugs, especially focusing on their structural optimization strategies and future optimization directions. Additionally, the therapeutic potential and challenges of novel SERDs and SERCAs in breast cancer and other ER-related diseases have been discussed.

Notch1 is involved in cell proliferation and neuronal differentiation in the HVC of zebra finch (Taeniopygia guttata)

Significant sex differences are found in songbirds' song control nuclei and their controlled song behaviors. To elucidate the underlying mechanisms, we explored the role of Notch1 during the development of the high vocal centre (HVC) and song learning in zebra finch. Our study first found that Notch1 positive cells were distributed in HVC with female-biased densities at posthatching day (PHD) 15, but male-biased at PHD 45 and adult. There were about 60 putative oestrogen-responsive elements within 2.5 kb upstream of Notch1, and Notch1 mRNA in the explants that contained the developing male HVC was significantly increased after estrogen addition into the cultured medium for 48 h. After injecting Notch1-interfering lentivirus into the male or female HVC at PHD 15, cell proliferation was significantly promoted in the ventricle zone overlying the HVC at PHD 23. In addition, neuronal differentiation towards Hu+ /BrdU+ at PHD 31, mature neurons (NeuN+/BrdU+) including those projecting to RA in HVC and the sizes of HVC and RA at adult increased significantly after Notch1-interfering lentiviruses were injected into the male HVC at PHD 15. However, the above measurements decreased, following the injection of the lentiviruses expressing Notch intracellular domain (NICD). Finally, the repeat numbers of syllables 'b' or 'c' of learned songs changed after the injection of Notch1-interfering or NICD-expressing lentiviruses into the HVC at PHD15. Our study suggests that Notch1 is related to the development of HVC and song learning in the zebra finch.

A review of multi-modal magnetic resonance imaging studies on perimenopausal brain: a hint towards neural heterogeneity

The population ageing process worldwide is leading to an increasing number of women in the perimenopausal phase. Many of the perimenopausal symptoms, such as headache, depression, insomnia, and cognitive decline, are neurological in nature. Therefore, the study of the perimenopausal brain is of great importance. In addition, relevant studies can also provide an imaging basis for multiple therapies to treat perimenopausal symptoms. Because of its non-invasive nature, magnetic resonance imaging (MRI) has now been widely applied to the study of perimenopausal brains, revealing alterations in the brain associated with symptoms during the menopause transition. In this review, we collected papers and works of literature on the perimenopausal brain using MRI techniques in the Web of Science database. We firstly described the general principles and analysis methods of different MRI modalities briefly and then reviewed the structural, functional, perfusion, and metabolic compounds changes in the brain of perimenopausal women respectively, and described the latest advances in probing the perimenopausal brain using MRI, resulting in summary diagrams and figures. Based on the summary of existing works of the literature, this review further provided a perspective on multi-modal MRI studies in the perimenopausal brain, suggesting that population-based, multi-center, and longitudinal studies will be beneficial to the comprehensive understanding of changes in the perimenopausal brain. In addition, we found a hint towards neural heterogeneity in the perimenopausal brain, which should be addressed by future MRI studies to provide more help for the precise diagnosis and personalized treatment of perimenopausal symptoms. KEY POINTS: • Perimenopause is not only a physiological transition but also a period of neurological transition. • Multi-modal MRI studies have revealed that perimenopause is accompanied by alterations in the brain, which is implicated in many perimenopausal symptoms. • The diversity in the multi-modal MRI findings may give a hint to neural heterogeneity in the perimenopausal brain.

Potential risk of tamoxifen: gut microbiota and inflammation in mice with breast cancer

Objective

Tamoxifen is an effective anti-tumor medicine, but evidence has been provided on tamoxifen-related inflammation as well as its impact on gut microbiota. In this study, we aimed to investigate tamoxifen-induced gut microbiota and inflammation alteration.

Methods

We established a BC xenograft mouse model using the MCF-7 cell line. 16S rRNA gene sequencing was used to investigate gut microbiota. qRT-PCR, western blotting, and cytometric bead array were used to investigate inflammation-related biomarkers. Various bioinformatic approaches were used to analyze the data.

Results

Significant differences in gut microbial composition, characteristic taxa, and microbiome phenotype prediction were observed between control, model, and tamoxifen-treated mice. Furthermore, protein expression of IL-6 and TLR5 was up-regulated in tamoxifen-treated mice, while the mRNA of Tlr5 and Il-6, as well as protein expression of IL-6 and TLR5 in the model group, were down-regulated in the colon. The concentration of IFN-γ, IL-6, and IL12P70 in serum was up-regulated in tamoxifen-treated mice. Moreover, correlation-based clustering analysis demonstrated that inflammation-negatively correlated taxa, including Lachnospiraceae-UCG-006 and Anaerotruncus, were enriched in the model group, while inflammation-positively correlated taxa, including Prevotellaceae_UCG_001 and Akkermansia, were enriched in the tamoxifen-treated group. Finally, colon histologic damage was observed in tamoxifen-treated mice.

Conclusion

Tamoxifen treatment significantly altered gut microbiota and increased inflammation in the breast cancer xenograft mice model. This may be related to tamoxifen-induced intestinal epithelial barrier damage and TLR5 up-regulation.

How Do Microorganisms Influence the Development of Endometriosis? Participation of Genital, Intestinal and Oral Microbiota in Metabolic Regulation and Immunopathogenesis of Endometriosis

Microorganisms inhabiting the human body play an extremely key role in its proper functioning, as well as in the development of the immune system, which, by maintaining the immune balance, allows you to enjoy health. Dysbiosis of the intestinal microbiota, or in the oral cavity or reproductive tract, understood as a change in the number and diversity of all microorganisms inhabiting them, may correlate with the development of many diseases, including endometriosis, as researchers have emphasized. Endometriosis is an inflammatory, estrogen-dependent gynecological condition defined by the growth of endometrial cells outside the uterine cavity. Deregulation of immune homeostasis resulting from microbiological disorders may generate chronic inflammation, thus creating an environment conducive to the increased adhesion and angiogenesis involved in the development of endometriosis. In addition, research in recent years has implicated bacterial contamination and immune activation, reduced gastrointestinal function by cytokines, altered estrogen metabolism and signaling, and abnormal progenitor and stem cell homeostasis, in the pathogenesis of endometriosis. The aim of this review was to present the influence of intestinal, oral and genital microbiota dysbiosis in the metabolic regulation and immunopathogenesis of endometriosis.

Estrogen alleviates acute and chronic itch in mice

Itching is associated with various skin diseases, including atopic dermatitis and allergic dermatitis, and leads to repeated scratching behavior and unpleasant sensation. Although clinical and laboratory research data have shown that estrogen is involved in regulating itch, the molecular and cellular basis of estrogen in itch sensation remains elusive. In the present study, it was found that estrogen-treated mice exhibited reduced scratching bouts when challenged with histamine, chloroquine, the proteinase-activated receptor-2 activating peptide SLIGRL-NH2 (SLIGRL), compound 48/80, and 5-hydroxytryptamine when compared with mice in the placebo group. Moreover, estrogen also suppressed scratching bouts in the mouse model of chronic itch induced by acetone-ether-water treatment. Notably, consistent with the behavioral tests, the present RNA-seq analysis showed that estrogen treatment caused significantly reduced expression levels of itch-related molecules such as Mas-related G-protein coupled receptor member A3, neuromedin B and natriuretic polypeptide b. In addition, estradiol attenuated histamine-induced and chloroquine-induced calcium influx in dorsal root ganglion neurons. Collectively, the data of the present study suggested that estrogen modulates the expression of itch-related molecules and suppresses both acute and chronic itch in mice.

Expression of Androgen and Estrogen Receptors in the Human Lacrimal Gland

Lacrimal gland dysfunction causes dry eye disease (DED) due to decreased tear production. Aqueous-deficient DED is more prevalent in women, suggesting that sexual dimorphism of the human lacrimal gland could be a potential cause. Sex steroid hormones are a key factor in the development of sexual dimorphism. This study aimed to quantify estrogen receptor (ER) and androgen receptor (AR) expression in the human lacrimal gland and compare it between sexes. RNA was isolated from 35 human lacrimal gland tissue samples collected from 19 cornea donors. AR, ERα, and ERβ mRNA was identified in all samples, and their expression was quantified using qPCR. Immunohistochemical staining was performed on selected samples to evaluate protein expression of the receptors. ERα mRNA expression was significantly higher than the expression of AR and ERβ. No difference in sex steroid hormone (SSH) receptor mRNA expression was observed between sexes, and no correlation was observed with age. If ERα protein expression is found to be concordant with mRNA expression, it should be investigated further as a potential target for hormone therapy of DED. Further research is needed to elucidate the role of sex steroid hormone receptors in sex-related differences of lacrimal gland structure and disease.

Non-Coding RNAs Modulating Estrogen Signaling and Response to Endocrine Therapy in Breast Cancer

The largest part of human DNA is transcribed into RNA that does not code for proteins. These non-coding RNAs (ncRNAs) are key regulators of protein-coding gene expression and have been shown to play important roles in health, disease and therapy response. Today, endocrine therapy of ERα-positive breast cancer (BC) is a successful treatment approach, but resistance to this therapy is a major clinical problem. Therefore, a deeper understanding of resistance mechanisms is important to overcome this resistance. An increasing amount of evidence demonstrate that ncRNAs affect the response to endocrine therapy. Thus, ncRNAs are considered versatile biomarkers to predict or monitor therapy response. In this review article, we intend to give a summary and update on the effects of microRNAs (miRNAs), long non-coding RNAs (lncRNAs) and circular RNAs (circRNAs) on estrogen signaling in BC cells, this pathway being the target of endocrine therapy, and their role in therapy resistance. For this purpose, we reviewed articles on these topics listed in the PubMed database. Finally, we provide an assessment regarding the clinical use of these ncRNA types, particularly their circulating forms, as predictive BC biomarkers and their potential role as therapy targets to overcome endocrine resistance.

Estro-progestin and progestogen intake: What’s the impact on hysteroscopic imaging?

Background: In current literature there is no report aimed to evaluate the effects of exogenous steroids on hysteroscopic imaging. Objectives: To evaluate the hysteroscopic features of endometrium in women undergoing female hormones administration. Material and Methods: We reviewed video-records of hysteroscopies carried-out in women taking estro-progestins (EP), progestogen (P) and Hormonal Replacement Therapy (HRT). All women underwent biopsies resulting in atrophic, functional, or dysfunctional pathological reports. Main Outcome Measures: Description of hysteroscopic pictures related to each schedule of therapy. Results: The study included 117 women. We evaluated 82, 24 and 11 women treated by EP, P and HRT, respectively. In EP users, imaging indistinguishable from physiological pictures was found when high oestrogen dosage and low-potency progestogen as 17-OH progesterone derivatives were administered. By enhancing progestogen potency with 19-norprogesterone and 19-nortestosterone derivatives we observed a promotion of progestogen differentiation such as polypoid-papillary pseudo-decidualisation, spiral artery differentiation, inhibition of gland-proliferation and endometrial atrophy. In P users we distinguished two patterns, depending on continuous or sequential schedules. Continuous therapy resulted in atrophic or proliferative-secretory features whereas sequential ones led to endometrial overgrowth reflecting stromal pseudo-decidualisation. Women undergoing HRT showed atrophic features in combined continuous and polypoid overgrowth in sequential schedules. In women taking Tibolone we found pictures ranging from atrophic to hyperplastic appearances. Conclusions: Exogenous steroids lead to significant endometrial moulding. Depending on schedule, hysteroscopic-view appears predictable and often showing overgrowths mimicking proliferative pathologies. In this case biopsy is recommended but in common practice physicians should gain awareness with hysteroscopic pictures induced from hormone administration. What is new? Systematic assessment of hysteroscopic pictures during estro-progestins intake.

The Co-Expression of Estrogen Receptors ERα, ERβ, and GPER in Endometrial Cancer

Estrogens have important roles in endometrial cancer (EC) and exert biological effects through the classical estrogen receptors (ERs) ERα and ERβ, and the G-protein-coupled ER, GPER. So far, the co-expression of these three types of ERs has not been studied in EC. We investigated ERα, ERβ, GPER mRNA and protein levels, and their intracellular protein distributions in EC tissue and in adjacent control endometrial tissue. Compared to control endometrial tissue, immunoreactivity for ERα in EC tissue was weaker for nuclei with minor, but unchanged, cytoplasmic staining; mRNA and protein levels showed decreased patterns for ERα in EC tissue. For ERβ, across both tissue types, the immunoreactivity was unchanged for nuclei and cytoplasm, although EC tissues again showed lower mRNA and protein levels compared to adjacent control endometrial tissue. The immunoreactivity of GPER as well as mRNA levels of GPER were unchanged across cancer and control endometrial tissues, while protein levels were lower in EC tissue. Statistically significant correlations of estrogen receptor α (ESR1) versus estrogen receptor β (ESR2) and GPER variant 3,4 versus ESR1 and ESR2 was seen at the mRNA level. At the protein level studied with Western blotting, there was significant correlation of ERα versus GPER, and ERβ versus GPER. While in clinical practice the expression of ERα is routinely tested in EC tissue, ERβ and GPER need to be further studied to examine their potential as prognostic markers, provided that specific and validated antibodies are available.

Synthesis, Regulatory Factors, and Signaling Pathways of Estrogen in the Ovary

New insights have been thrown for understanding the significant role of estrogen on various systems of humans. Increasing evidences have determined the significant roles of estrogen in female reproductive system. So, the normal synthesis and secretion of estrogen play important roles in maintaining the function of tissues and organs. The ovaries are the main synthetic organs of estrogen. In this review, we summarized the current knowledge of the estrogen synthesis in the ovaries. A series of factors and signaling pathways that regulate the synthesis of estrogen are expounded in detail. Understanding the regulating factors and potential mechanism related to estrogen synthesis will be beneficial for understanding estrogen disorder related diseases and may provide novel therapeutic targets.

Potential Regulation of miRNA-29 and miRNA-9 by Estrogens in Neurodegenerative Disorders: An Insightful Perspective

Finding a link between a hormone and microRNAs (miRNAs) is of great importance since it enables the adjustment of genetic composition or cellular functions without needing gene-level interventions. The dicer-mediated cleavage of precursor miRNAs is an interface link between miRNA and its regulators; any disruption in this process can affect neurogenesis. Besides, the hormonal regulation of miRNAs can occur at the molecular and cellular levels, both directly, through binding to the promoter elements of miRNAs, and indirectly, via regulation of the signaling effects of the post-transcriptional processing proteins. Estrogenic hormones have many roles in regulating miRNAs in the brain. This review discusses miRNAs, their detailed biogenesis, activities, and both the general and estrogen-dependent regulations. Additionally, we highlight the relationship between miR-29, miR-9, and estrogens in the nervous system. Such a relationship could be a possible etiological route for developing various neurodegenerative disorders.

Comprehensive analysis of cellular estrogen signaling in representative estrogen receptor ligands

The estrogen receptor (ER)-mediated signaling pathway in physiological and biochemical aspects is very important in the environment, including food. The physiological action of estrogen is mediated by ER alpha (ERα) and beta (ERβ), whose physiological action on estrogenic substances is complex because of the relatively low ligand-binding domain (LBD) similarity of the two ERs. In this study, the comprehensive activity of representative ER ligands was evaluated by using BRET-based ERα and ERβ dimerization and ER transactivation assays to differentiate the specific binding and function of ERα and ERβ from 12 representative natural and synthetic estrogenic substances. Results revealed that 11 chemicals mediated receptor ERα and ERβ dimerization, 7 out of 12 chemicals were confirmed to be estrogen agonists, and 5 chemicals were antagonistic. Overall, this study demonstrated consistency between BRET dimerization and transactivation responses, supporting potential supplementary application of mechanism-based BRET assays as high-throughput screening methods for evaluation of potential endocrine-disrupting activity of environmental agents. This study also provided information about receptor specificity of ligand-mediated estrogenic activity via dimerization assays and elucidated cellular estrogen signaling pathways.

Betulinic acid alleviates zearalenone-induced uterine injury in mice

Zearalenone (ZEA) is a mycotoxin with estrogen-like biological activity, which widely present in feed and raw materials, with strong reproductive system toxicity and a major threat to animal reproduction. Betulinic acid (BA) is a natural plant compound with antioxidant, anti-inflammatory and other pharmacological activities. However, the mechanism of ZEA-induced uterine injury and the protective effect of BA have not been reported. Our results show that ZEA could cause uterine histopathological damage and cellular ultrastructural damage, affecting the secretion of sex hormones, such as estradiol (E2) and progesterone (P4), and increase the mRNA and protein expression of estrogen receptor α (ERα). ZEA could inhibit the activities of catalase (CAT) and superoxide dismutase (SOD), increase the production of malondialdehyde (MDA) and reactive oxygen species (ROS), and cause uterine oxidative stress. Furthermore, ZEA affected the homeostasis of uterine cell proliferation and death by regulating the expression of proliferating cell nuclear antigen (PCNA) and activating the mitochondrial apoptotic pathway. ZEA-induced uterine injury might be related to the activation of p38/ERK MAPK signaling pathway. However, the regulatory effect of ZEA on the uterus was reversed after BA treatment. In conclusion, the uterus is an important target organ attacked by ZEA, and BA showed a good therapeutic effect.

Modulatory Effect of Gut Microbiota on the Gut-Brain, Gut-Bone Axes, and the Impact of Cannabinoids

The gut microbiome is a collection of microorganisms and parasites in the gastrointestinal tract. Many factors can affect this community's composition, such as age, sex, diet, medications, and environmental triggers. The relationship between the human host and the gut microbiota is crucial for the organism's survival and development, whereas the disruption of this relationship can lead to various inflammatory diseases. Cannabidiol (CBD) and tetrahydrocannabinol (THC) are used to treat muscle spasticity associated with multiple sclerosis. It is now clear that these compounds also benefit patients with neuroinflammation. CBD and THC are used in the treatment of inflammation. The gut is a significant source of nutrients, including vitamins B and K, which are gut microbiota products. While these vitamins play a crucial role in brain and bone development and function, the influence of gut microbiota on the gut-brain and gut-bone axes extends further and continues to receive increasing scientific scrutiny. The gut microbiota has been demonstrated to be vital for optimal brain functions and stress suppression. Additionally, several studies have revealed the role of gut microbiota in developing and maintaining skeletal integrity and bone mineral density. It can also influence the development and maintenance of bone matrix. The presence of the gut microbiota can influence the actions of specific T regulatory cells, which can lead to the development of bone formation and proliferation. In addition, its metabolites can prevent bone loss. The gut microbiota can help maintain the bone's equilibrium and prevent the development of metabolic diseases, such as osteoporosis. In this review, the dual functions gut microbiota plays in regulating the gut-bone axis and gut-brain axis and the impact of CBD on these roles are discussed.

Insights on the Dynamic Innovative Tumor Targeted-Nanoparticles-Based Drug Delivery Systems Activation Techniques

Anti-cancer conventional chemotherapeutic drugs novel formula progress, nowadays, uses nano technology for targeted drug delivery, specifically tailored to overcome therapeutic agents' delivery challenges. Polymer drug delivery systems (DDS) play a crucial role in minimizing off-target side effects arising when using standard cytotoxic drugs. Using nano-formula for targeted localized action, permits using larger effective cytotoxic doses on a single special spot, that can seriously cause harm if it was administered systemically. Therefore, various nanoparticles (NPs) specifically have attached groups for targeting capabilities, not seen in bulk materials, which then need activation. In this review, we will present a simple innovative, illustrative, in a cartoon-way, enumeration of NP anti-cancer drug targeting delivery system activation-types. Area(s) covered in this review are the mechanisms of various NP activation techniques.

Association of life-course reproductive duration with mortality: a population-based twin cohort study

BACKGROUND

Although age at menopause has been linked to mortality, the association between the entire reproductive lifespan and mortality remains unclear.

OBJECTIVE

This study aimed to examine to what extent life-course reproductive duration is associated with all-cause mortality and explore the role of a healthy lifestyle and familial background in such an association.

STUDY DESIGN

A total of 11,669 women (mean age, 63.54 years) from the Swedish Twin Registry were followed for up to 19 years. Information on reproductive duration (the interval between ages at menarche and menopause) and lifestyle factors (including smoking, alcohol consumption, and physical activity; divided into unfavorable/intermediate/favorable) was collected on the basis of a structured questionnaire. Survival status was obtained from the Sweden Cause of Death Register. The data were analyzed using generalized estimating equation models, Laplace regression, and conditional logistic regression.

RESULTS

In the generalized estimating equation model, compared with those with ≤34 reproductive years, the odds ratio (95% confidence interval) of all-cause mortality was 0.79 (0.68-0.90) for those with ≥40 reproductive years, which prolonged survival time by 0.84 (0.24-1.43) years. Women with ≥40 reproductive years plus a favorable lifestyle (odds ratio, 0.28; 95% confidence interval, 0.23-0.35) were at a lower risk of all-cause mortality than those with <40 reproductive years plus an unfavorable lifestyle. An additive interaction between ≥40 reproductive years and a favorable lifestyle on all-cause mortality was observed (attributable proportion, 0.584; 95% confidence interval, 0.016-1.151). The odds ratios in conditional logistic regression and generalized estimating equation models did not differ significantly (P=.67).

CONCLUSION

A longer reproductive lifespan is associated with reduced all-cause mortality and prolongs survival by 0.84 years. A favorable lifestyle may amplify the beneficial effect of longer reproductive lifespan on mortality. Familial background does not account for the observed association.

The Effect of Menopause on Antipsychotic Response

Background: It has been hypothesized that, whenever estrogen levels decline, psychosis symptoms in women increase. At menopause, this can happen in two main ways: (a) the loss of estrogen (mainly estradiol) can directly affect central neurotransmission, leading to increase in schizophrenia-related symptoms, and (b) the loss of estrogen can decrease the synthesis of enzymes that metabolize antipsychotic drugs, thus weakening their efficacy. Aims and Methods: The aim of this narrative review was to investigate the second possibility by searching PubMed and ClinicalTrials.gov for studies over the last two decades that investigated the metabolism of antipsychotics and their efficacy before and after menopause in women or that studied systemic and local estrogen level effects on the pharmacokinetics and pharmacodynamics of individual antipsychotic drugs. Results: The evidence suggests that symptom level in women with schizophrenia rises after menopause for many reasons beyond hormones but, importantly, there is an estrogen-dependent loss of efficacy related to antipsychotic treatment. Conclusion: Effective clinical intervention is challenging; nevertheless, several promising routes forward are suggested.

Demystifying the Functional Role of Nuclear Receptors in Esophageal Cancer

Esophageal cancer (EC), an aggressive and poorly understood disease, is one of the top causes of cancer-related fatalities. GLOBOCAN 2020 reports that there are 544,076 deaths and 604,100 new cases expected worldwide. Even though there are various advancements in treatment procedures, this cancer has been reported as one of the most difficult cancers to cure, and to increase patient survival; treatment targets still need to be established. Nuclear receptors (NRs) are a type of transcription factor, which has a key role in several biological processes such as reproduction, development, cellular differentiation, stress response, immunity, metabolism, lipids, and drugs, and are essential regulators of several diseases, including cancer. Numerous studies have demonstrated the importance of NRs in tumor immunology and proved the well-known roles of multiple NRs in modulating proliferation, differentiation, and apoptosis. There are surplus of studies conducted on NRs and their implications in EC, but only a few studies have demonstrated the diagnostic and prognostic potential of NRs. Therefore, there is still a paucity of the role of NRs and different ways to target them in EC cells to stop them from spreading malignancy. This review emphasizes the significance of NRs in EC by discussing their diverse agonists as well as antagonists and their response to tumor progression. Additionally, we emphasize NRs’ potential to serve as a novel therapeutic target and their capacity to treat and prevent EC.

Systematic pan-cancer analysis on the expression and role of regulator of chromatin condensation 1/small nucleolar RNA host gene 3/small nucleolar RNA host gene 12

Regulator of chromatin condensation 1 (RCC1) is the major guanine nucleotide exchange factor of RAN GTPase, which plays a key role in various biological processes such as cell cycle and DNA damage repair. Small nucleolar RNA host gene 3 (SNHG3) and small nucleolar RNA host gene12 are long-stranded non-coding RNAs (lncRNAs) and are located on chromatin very close to the sequence of Regulator of chromatin condensation 1. Many studies have shown that they are aberrantly expressed in tumor tissues and can affect the proliferation and viability of cancer cells. Although the effects of Regulator of chromatin condensation 1/small nucleolar RNA host gene 3/small nucleolar RNA host gene12 on cellular activity have been reported, respectively, their overall analysis on the pan-cancer level has not been performed. Here, we performed a comprehensive analysis of Regulator of chromatin condensation 1/small nucleolar RNA host gene 3/small nucleolar RNA host gene12 in 33 cancers through the Cancer Genome Atlas and Gene Expression Database. The results showed that Regulator of chromatin condensation 1/small nucleolar RNA host gene 3/small nucleolar RNA host gene12 were highly expressed in a variety of tumor tissues compared to normal tissues. The expression of Regulator of chromatin condensation 1/small nucleolar RNA host gene 3/small nucleolar RNA host gene12 in BRCA, LGG and LIHC was associated with TP53 mutations. In addition, Regulator of chromatin condensation 1/small nucleolar RNA host gene 3/small nucleolar RNA host gene12 expression was closely associated with the prognosis of patients with multiple tumors. Immunocorrelation analysis indicated that Regulator of chromatin condensation 1/small nucleolar RNA host gene 3/small nucleolar RNA host gene12 showed a correlation with multiple immune cell infiltration. The results of enrichment analysis suggested that Regulator of chromatin condensation 1/small nucleolar RNA host gene 3/small nucleolar RNA host gene12 was involved in the regulation of cell cycle, apoptosis and other pathways. We found that these effects were mainly mediated by Regulator of chromatin condensation 1, while the trend of small nucleolar RNA host gene 3/small nucleolar RNA host gene12 regulation was also consistent with regulator of chromatin condensation 1. The important role played by Regulator of chromatin condensation 1 in tumor diseases was further corroborated by the study of adjacent lncRNAs.These findings provide new and comprehensive insights into the role of Regulator of chromatin condensation 1/small nucleolar RNA host gene 3/small nucleolar RNA host gene12 in tumor development and show their potential as clinical monitoring and therapy.

Discovery of agonist-antagonist pairs for the modulation of Ca [2]+ and voltage-gated K+ channels of large conductance that contain beta1 subunits

Large conductance, calcium/voltage-gated potassium channels (BK) regulate critical body processes, including neuronal, secretory and smooth muscle (SM) function. While BK-forming alpha subunits are ubiquitous, accessory beta1 subunits are highly expressed in SM. This makes beta1 an attractive target for pharmaceutical development to treat SM disorders, such as hypertension or cerebrovascular spasm. Compounds activating BK via beta1 have been identified, yet they exhibit low potency and off-target effects while antagonists that limit agonist activity via beta 1 remain unexplored. Beta1-dependent BK ligand-based pharmacophore modeling and ZINC database searches identified 15 commercially available hits. Concentration-response curves on BK alpha + beta1 subunit-mediated currents were obtained in CHO cells. One potent (EC50 = 20 nM) and highly efficacious activator (maximal activation = ×10.3 of control) was identified along with a potent antagonist (KB = 3.02 nM), both of which were dependent on beta1. Our study provides the first proof-of-principle that an agonist/antagonist pair can be used to control beta1-containing BK activity.

Targeting chronic inflammation as a potential adjuvant therapy for osteoporosis

Systemic, chronic, low-grade inflammation (SCLGI) underlies the pathogenesis of various widespread diseases. It is often associated with bone loss, thus connecting chronic inflammation to the pathogenesis of osteoporosis. In postmenopausal women, osteoporosis is accompanied by SCLGI development, likely owing to estrogen deficiency. We propose that SCGLI persistence in osteoporosis results from failed inflammation resolution, which is mainly mediated by specialized, pro-resolving mediators (SPMs). In corroboration, SPMs demonstrate encouraging therapeutic effects in various preclinical models of inflammatory disorders, including bone pathology. Since numerous data implicate gut dysbiosis in osteoporosis-associated chronic inflammation, restoring balanced microbiota by supplementing probiotics and prebiotics could contribute to the efficient resolution of SCGLI. In the present review, we provide evidence for this hypothesis and argue that efficient SCGLI resolution may serve as a novel approach for treating osteoporosis, complementary to traditional anti-osteoporotic medications.

ESR2 expression in subcutaneous adipose tissue is related to body fat distribution in women, and knockdown impairs preadipocyte differentiation

OBJECTIVES

Estrogen signaling occurs mainly through estrogen receptor alpha (ESR1) and beta (ESR2). ESR2 expression is higher in subcutaneous adipose tissue (SAT) from postmenopausal compared to premenopausal women. The functional significance of altered ESR2 expression is not fully known. This study investigates the role of ESR2 in adipose tissue lipid and glucose metabolism.

METHODS

SAT were obtained by needle biopsies from 10 female subjects with T2D and 10 control subjects. Correlation analysis between ESR2 gene expression in SAT and markers of obesity and glucose metabolism. ESR2 knockdown was performed in preadipocytes isolated from SAT of females using CRISPR/Cas9 gene editing. In vitro differentiated knockdown adipocytes were characterized for differentiation rate, lipid storage, and glucose uptake.

RESULTS

ESR2 expression in SAT from females was negatively correlated with weight, waist-to-hip ratio, visceral adipose tissue volume, and markers of fatty acid oxidation, and positively correlated with markers related to lipid storage, and glucose transport. In SAT, ESR2 levels were found predominantly in mature adipocytes. In preadipocytes from females, ESR2 knockdown reduced preadipocyte differentiation compared to wild type cultures. This corresponded to reduced expression of markers of differentiation, lipogenesis, and lipolysis. Glucose uptake was reduced in adipocytes in knockdown cultures.

CONCLUSION

Our results indicate that ESR2 deficiency is associated with visceral adiposity and reduced subcutaneous adipocyte differentiation and lipid storage in women. High ESR2 expression, as seen after menopause, could be a contributing factor to SAT expansion. This provides insight into a possible target to promote a healthy obesity phenotype.

Calycosin suppresses colorectal cancer progression by targeting ERβ, upregulating PTEN, and inhibiting PI3K/Akt signal pathway

High intake of phytoestrogen has been reported to be associated with the prevention of colorectal cancer (CRC). Calycosin belongs to the phytoestrogen that has been shown to suppress CRC cells in our previous study. However, its anticancer activity and molecular mechanisms have not been elucidated. In this study, we analyzed the effect of calycosin on the viability and apoptosis of human CRC HCT116 and SW480 cells via MTT assay, flow cytometry assay, and caspase-3/7 activity assay. The protein expressions of estrogen receptor β (ERβ), PTEN, and PI3K/Akt signal pathways were determined by Western blot analysis. And then, the alterations of biological behavior in CRC cells transfected with ERβ siRNA were analyzed. Mouse xenograft models were further performed to detect the antitumor effect in vivo. The results show that calycosin reduces CRC cell viability, induces cell apoptosis, and suppresses xenograft tumor growth. The protein expressions of ERβ and PTEN are significantly upregulated following calycosin treatment, whereas p-AKT/AKT ratio and Bcl-2 level are downregulated. Suppressing ERβ with siRNA partially attenuates the reduction in viability and apoptosis induced by calycosin. Our results indicate that calycosin shows inhibitory effects on CRC cells, which might be obtained by targeting ERβ, upregulating PTEN, and inhibiting the PI3K/Akt signal pathway.

Is premature ovarian insufficiency associated with mortality? A three-decade follow-up cohort

OBJECTIVE

To evaluate the association between premature ovarian insufficiency (POI) and mortality.

MATERIALS AND METHODS

This was a secondary analysis of a long-term cohort of Chilean women who received preventive health care between 1990 and 1993. The exposure variable was POI and the outcome was death, and follow-up time was 30 years. Patient data were extracted from medical records. Data related to deaths were obtained from the records of the official government registry as of January 2021. Cox regression proportional hazard models were used to estimate crude and adjusted hazard ratios (HR) and 95 % confidence intervals (CI).

RESULTS

Data for a total of 1119 women were included in the analysis. Median age was 47 years (interquartile range: 44-52). The baseline prevalence of POI was 6.7 %. At the end of the follow-up, 34.7 % of women with POI had died, compared with 19.3 % of women without the condition (p < 0.001). A larger proportion of women with POI died from cardiovascular disease (12.0 % vs. 5.1 %; OR: 2.55, 95 % CI: 1.21-5.39) whereas there was no significant difference in cancer mortality (6.7 % vs. 7.7 %; OR: 0.86, 95 % CI: 0.34-2.19). In the adjusted Cox model, POI was among the main factors associated with mortality (hazard ratio [HR] 1.60, 95 % CI: 1.03-2.47), after diabetes (HR 2.51, 95 % CI: 1.40-4.51) and arterial hypertension (HR 1.75, 95 % CI: 1.29-2.37).

CONCLUSION

Although POI affects a small group of women, its association with mortality seems to be relevant; hence it is necessary to implement measures that reduce this risk.

ERα/β/DMP1 axis promotes trans-differentiation of chondrocytes to bone cells through GSK-3β/β-catenin pathway

Estrogen-induced premature closing of the growth plate in the long bones is a major cause of short stature after premature puberty. Recent studies have found that chondrocytes can directly trans-differentiate into osteoblasts in the process of endochondral bone formation, which indicates that cartilage formation and osteogenesis may be a continuous biological process. However, whether estrogen promotes the direct trans-differentiation of chondrocytes into osteoblasts remains largely unknown. Chondrocytes were treated with different concentrations of 17β-estradiol, and Alizarin Red staining and alkaline phosphatase activity assay were used to detected osteogenesis. Specific short hairpin RNA and tamoxifen were used to block the estrogen receptor (ER) pathway and osteogenic marker genes and downstream gene expression were detected using real-time quantitative polymerase chain reaction, western blot, and immunohistochemistry staining. The findings showed that 17β-estradiol promoted the chondrocyte osteogenesis in vitro, even at high concentrations. In addition, blocking of the ERα/β pathway inhibited the trans-differentiation of chondrocytes into osteogenic cells. Furthermore, we found that dentin matrix protein 1 (DMP1), which is a direct downstream molecular of ER, was involved in 17β-estradiol/ER pathway-regulated osteogenesis. As well, glycogen synthase kinase-3 beta (GSK-3β)/β-catenin signal pathway also participates in ERα/β/DMP1-regulated chondrocyte osteogenesis. The GSK-3β/β-catenin signal pathway was involved in ERα/β/DMP1-regulated chondrocyte osteogenesis. These findings suggest that ER/DMP1/GSK-3β/β-catenin plays a vital role in estrogen regulation of chondrocyte osteogenesis and provide a therapeutic target for short stature caused by epiphyseal fusion.

Exploring the impact of ovariectomy on hair growth: can ovariectomized mouse serve as a model for investigating female pattern hair loss in humans?

Female pattern hair loss (FPHL), a type of hair disease common in pre- and postmenopausal women, is characterized by thinning of hair to O-type, mainly at the crown. Although a mouse model of this disease has recently been established, its details are still unknown, and thus, warrants further analysis. In this study, 3 week-old and 7- to 8 week-old C57BL/6 female mice were divided into two groups: one group underwent ovariectomy (OVX), while the other underwent sham surgery. In the 3 week-old mice, the dorsal skin was collected at seven weeks of age, while in the 7- to 8 week-old mice, it was collected at 12 and 24 weeks of age. In the former group, both the pore size of the hair follicles (HFs) and diameter of the hair shaft of telogen HFs decreased upon OVX; while in the latter group, these factors increased significantly. Notably, the thickness of the dermis and subcutis increased significantly in the OVX group. It needs to be further elucidated whether OVX mouse could serve as an ideal mouse model for FPHL, but our results upon evaluation of skin thickness indicate that it could be used to establish a novel treatment for non-hair-related diseases, such as post-menopause-related skin condition.

Sex Hormones and Satellite Cell Regulation in Women

Recent years have seen growing scholarly interest in female physiology in general. Moreover, particular attention has been devoted to how concentrations of female sex hormones vary during the menstrual cycle and menopausal transition and how hormonal contraception and hormonal therapy influence skeletal muscle tissue. While much effort has been paid to macro outcomes, such as muscle function or mass, rather less attention has been paid to mechanistic work that may help explain the underlying mechanism through which sex hormones regulate skeletal muscle tissue. Evidence from animal studies shows a strong relationship between the female sex hormone estrogen and satellite cells (SCs), a population of muscle stem cells involved in skeletal muscle regulation. A few human studies investigating this relationship have been published only recently. Thus, the purpose of this study was to bring an updated review on female sex hormones and their role in SC regulation. First, we describe how SCs regulate skeletal muscle maintenance and repair and introduce sex hormone signaling within the muscle. Second, we present evidence from animal studies elucidating how estrogen deficiency and supplementation influence SCs. Third, we present results from investigations from human trials including women whose concentrations of female hormones differ due to menopause, hormone therapy, hormonal contraceptives, and the menstrual cycle. Finally, we discuss research and methodological recommendations for future studies aiming at elucidating the link between female sex hormones and SCs with respect to aging and training.

Sex differences in thrombosis as it affects acute ischemic stroke

Ischemic stroke is a devastating health problem, affecting approximately 800,000 patients in the US every year, making it the leading cause of combined death and disability in the country. Stroke has historically been thought of as predominantly impacting men, however it is becoming increasingly clear that stroke affects women to a greater degree than men. Indeed, women have worse outcomes compared to men following ischemic stroke. Recent clinical advances have shown great promise in acute stroke therapy, with the use of mechanical endovascular thrombectomy (with and without recombinant tissue plasminogen activator; rtPA) greatly improving outcomes. This observation makes it clear that removal of clots and reperfusion, either mechanically or pharmacologically, is critical for improving outcomes of patients following acute ischemic stroke. Despite these promising advances, long-term neurological sequelae persist in the post-stroke population. This review focuses on mechanisms of thrombosis (clot formation) as it pertains to stroke and important sex differences in thrombosis and responses to treatment. Finally, we describe recent data related to new therapeutic approaches to thrombolysis, with a particular focus on von Willebrand Factor (vWF).

The Evolution of Viviparity in Vertebrates

In the vertebrate tree of life, viviparity or live birth has independently evolved many times, resulting in a rich diversity of reproductive strategies. Viviparity is believed to be a mode of reproduction that evolved from the ancestral condition of oviparity or egg laying, where most of the fetal development occurs outside the body. Today, there is not a simple model of parity transition to explain this species-specific divergence in modes of reproduction. Most evidence points to a gradual series of evolutionary adaptations that account for this phenomenon of reproduction, elegantly displayed by various viviparous squamates that exhibit placentae formed by the appositions of maternal and embryonic tissues, which share significant homology with the tissues that form the placenta in therian mammals. In an era where the genomes of many vertebrate species are becoming available, studies are now exploring the molecular basis of this transition from oviparity to viviparity, and in some rare instances its possible reversibility, such as the Australian three-toed skink (Saiphos equalis). In contrast to the parity diversity in squamates, mammals are viviparous with the notable exception of the egg-laying monotremes. Advancing computational tools coupled with increasing genome availability across species that utilize different reproductive strategies promise to reveal the molecular underpinnings of the ancestral transition of oviparity to viviparity. As a result, the dramatic changes in reproductive physiology and anatomy that accompany these parity changes can be reinterpreted. This chapter will briefly explore the vertebrate modes of reproduction using a phylogenetic framework and where possible highlight the role of potential candidate genes that may help explain the polygenic origins of live birth.