Estrogen Biosynthesis and Signal Transduction in Ovarian Disease

Epigenetic Modulation of Estrogen Receptor Signaling in Ovarian Cancer

Ovarian cancer remains one of the leading causes of cancer-related deaths in women. There are several processes that are described to have a causal relationship in ovarian cancer development, progression, and metastasis formation, that occur both at the genetic and epigenetic level. One of the mechanisms involved in its pathogenesis and progression is estrogen signaling. Estrogen receptors (ER) α, ERβ, and G-protein coupled estrogen receptor 1 (GPER1), in concert with various coregulators and pioneer transcription factors, mediate the effects of estrogens primarily by the transcriptional regulation of estrogen responsive genes, thereby exerting pleiotropic effects including the regulation of cellular proliferation and apoptosis. The expression and activity of estrogen receptors and their coregulators have been demonstrated to be regulated by epigenetic mechanisms like histone modifications and DNA methylation. Here, we intend to summarize and to provide an update on the current understanding of epigenetic mechanisms regulating estrogen signaling and their role in ovarian cancer. For this purpose, we reviewed publications on this topic listed in the PubMed database. Finally, we assess to which extent drugs acting on the epigenetic level might be suitable for the treatment of ovarian cancer.

Steroid metabolism and hormonal dynamics in normal and malignant ovaries

The ovaries are key steroid hormone production sites in post-pubertal females. However, current research on steroidogenic enzymes, endogenous hormone concentrations and their effects on healthy ovarian function and malignant development is limited. Here, we discuss the importance of steroid enzymes in normal and malignant ovaries, alongside hormone concentrations, receptor expression and action. Key enzymes include STS, 3β-HSD2, HSD17B1, ARK1C3, and aromatase, which influence ovarian steroidal action. Both androgen and oestrogen action, via their facilitating enzyme, drives ovarian follicle activation, development and maturation in healthy ovarian tissue. In ovarian cancer, some data suggest STS and oestrogen receptor α may be linked to aggressive forms, while various oestrogen-responsive factors may be involved in ovarian cancer metastasis. In contrast, androgen receptor expression and action vary across ovarian cancer subtypes. For future studies investigating steroidogenesis and steroidal activity in ovarian cancer, it is necessary to differentiate between disease subtypes for a comprehensive understanding.

Research progress on the correlation between estrogen and estrogen receptor on postmenopausal sarcopenia

Estrogen is a necessary sex steroid and potent neuroprotective hormone. It plays a multifaceted role beyond the reproductive system, extending its influence to the brain, skeletal muscle, and other organs. Estrogen's role in cognition, mood, autonomic regulation, and neuroprotection involves interactions with neurotransmitters, neuromodulators in a distributed manner. Notably, the impact of estrogen on mitochondrial metabolism in skeletal muscle is particularly significant due to a unique modulated bioenergetic profiles, synaptic plasticity, and neuronal health. The deficiency of estrogen in menopause has been linked to changes in brain structure, connectivity, energy metabolism. Therewith, these are crucial factors in cognitive function and the risk of Alzheimer's diseases. Besides, it leads to endocrine and metabolic dysfunction, resulting in osteoporosis, metabolic syndrome, and a tendency toward decreased muscle mass and strength. Estrogen's influence on mitochondrial function is particularly relevant to aging, as it affects the production of ATP and the overall metabolic health of the brain. Estrogen decline in women skeletal muscle mass is usually related to sarcopenia, a prevalent disease observed in vulnerable elderly individuals. Therefore, estrogen is considered to play a crucial role in skeletal muscle homeostasis and motor ability, although the exact mechanism remains unclear. This paper reviews the literature on the impact of estrogen on postmenopausal skeletal muscle diseases and the underlying molecular mechanisms, especially in terms of mitochondrial metabolism. In summary, estrogen plays an important role in the health of skeletal muscle in postmenopausal women, and its impact on mitochondrial function and homeostasis offers potential targets for the development of new strategies to treat sarcopenia.

Estrogen: the forgotten player in metaflammation

Metaflammation is low-grade inflammation triggered by chronic metabolic imbalance and caused by dysregulated metabolites in metabolic inflammatory syndrome (MIS), which includes four diseases: obesity, type 2 diabetes mellitus (T2DM), atherosclerosis (AS), and nonalcoholic fatty liver diseases (NAFLD, recently proposed to be replaced by metabolic dysfunction-associated steatotic liver disease, MASLD). These diseases exhibit apparent sex dimorphism as regards MIS. Estrogen not only plays a crucial role in gender differences in adults but also possesses an anti-inflammatory effect on many metabolic diseases. In this study, we present a prediction of the differential proteins and signal transduction of estrogen in MIS through network pharmacology and review the validated studies on obesity, T2DM, AS, and NAFLD. Subsequently, we compared them to obtain valuable targets, identify current gaps, and provide perspectives for future research on the mechanisms of estrogen in metaflammation.

ERRα and ERRγ coordinate expression of genes associated with Alzheimer's disease, inhibiting DKK1 to suppress tau phosphorylation

Alzheimer's disease (AD) is a prevalent neurodegenerative disease characterized by cognitive decline and learning/memory impairment associated with neuronal cell loss. Estrogen-related receptor α (ERRα) and ERRγ, which are highly expressed in the brain, have emerged as potential AD regulators, with unelucidated underlying mechanisms. Here, we identified genome-wide binding sites for ERRα and ERRγ in human neuronal cells. They commonly target a subset of genes associated with neurodegenerative diseases, including AD. Notably, Dickkopf-1 (DKK1), a Wnt signaling pathway antagonist, was transcriptionally repressed by both ERRα and ERRγ in human neuronal cells and brain. ERRα and ERRγ repress RNA polymerase II (RNAP II) accessibility at the DKK1 promoter by modulating a specific active histone modification, histone H3 lysine acetylation (H3K9ac), with the potential contribution of their corepressor. This transcriptional repression maintains Wnt signaling activity, preventing tau phosphorylation and promoting a healthy neuronal state in the context of AD.

Impact of Dietary Isoflavones in Standard Chow on Reproductive Development in Juvenile and Adult Female Mice with Different Metabolic Phenotypes

Two factors influencing female reproduction have been repeatedly studied in different animal species and humans, namely, 1. secondary plant compounds, especially phytoestrogens (mainly isoflavones (IFs)), and 2. the physical constitution/metabolic phenotype (e.g., obesity). So far, these research results have only been considered separately. In this study, we investigated the influence on reproduction of both phytochemicals, mainly dietary IFs, and the metabolic phenotype represented by three mouse models considered as three distinct genetic groups (a control group, a mouse model with high metabolic activity, and a mouse line with obese body weight). The IF content in different investigated standard chows with similar macronutrient profiles varied significantly (p < 0.005), leading to high mean total plasma IF levels of up to 5.8 µmol/L in juvenile and 6.7 µmol/L in adult female mice. Reproductive performance was only slightly affected; only an IF dose-dependent effect on gestation length was observed in all genetic groups, as well as an effect on pregnancy rate in obese mice. Dietary IF exposure, however, caused earlier onset of vaginal opening by 4-10 days in juvenile mice (p < 0.05), dependent on the genetic group, resulting in a slight acceleration of sexual maturation in the already precocious obese model and to a strong earlier maturation in the otherwise late-maturing sporty model, bred for high treadmill performance. Therefore, our results may help to draw the missing line between the effect of dietary secondary plant constituents, such as IFs, and metabolic phenotype on sexual development.

CA-125:CA72-4 ratio - towards a promising cost-effective tool in ovarian cancer diagnosis and monitoring of post-menopausal women under hormone treatment

Ovarian cancer (OC) is the most lethal gynecological cancer in the developed world. Most cases are diagnosed at late stage III-IV with a very low 5-year overall survival rate. Several studies revealed an elevated risk of OC in users of hormone treatment (HT) compared with non-users. The extended duration of HT is a statistically significant risk factor. Carbohydrate antigen or cancer antigen 125 (CA-125) remains the best screening tool for OC; however, its value is limited due to low specificity, leading to unnecessary interventions, surgeries, and psychological harm. Additionally, the variability of ultrasound interpretation highlights the urgent need to develop a univariate index with higher sensitivity and specificity for early diagnosis of OC in women under HT. Herein we critically review the limitations of biomarkers for the detection of OC aiming to suggest an accurate and cost-effective diagnostic ratio that eliminates the impact of body mass index, age, HT, smoking, and benign ovarian diseases on measurements. Numerous studies combine biomarkers such as CA-125, human epididymis protein 4, and thymidine kinase 1 into diagnostic algorithms. Data suggest that the expression of estrogen receptors may have diagnostic and prognostic value, as the estrogen receptor α (ERα):estrogen receptor β (ERβ) ratio is significantly higher in OC than in normal tissue due to ERβ downregulation. A high positive correlation between expression of CA-125 and carbohydrate antigen or cancer antigen 72 - 4 (CA72-4) with ERα and ERβ, respectively, poses that a novel ratio CA-125:CA72-4 could be nodal for monitoring post-menopausal women under HT.

Efficacy and Safety of Intravaginal Estrogen in the Treatment of Atrophic Vaginitis: A Systematic Review and Meta-Analysis

OBJECTIVES

Postmenopausal females often experience genitourinary symptoms like vulvovaginal dryness due to estrogen decline. Hormone replacement therapy is effective in alleviating vaginal atrophy and genitourinary syndrome in this population. Evaluate local estrogen's safety and effectiveness for alleviating postmenopausal vaginal symptoms, including endometrial thickness, dyspareunia, vaginal pH, and dryness.

METHODS

We searched Google Scholar, Cochrane Library, ClinicalTrial.Gov, PubMed, and ScienceDirect databases until July 2023. All randomized controlled trials (RCTs) linking intravaginal estrogen supplementation to vaginal atrophy or vaginitis were included. The risk of bias was evaluated with RoB 2, and publication bias was assessed using Egger and Beggs analysis.

RESULTS

All evidence pertains to females. Eighteen studies (n = 4,723) compared estrogen with placebo. Patients using estrogen showed a significant increase in superficial cells (mean differences [MD]: 19.28; 95% confidence intervals [CI]: 13.40 to 25.16; I² = 90%; P < 0.00001) and a decrease in parabasal cells (MD: -24.85; 95% CI: -32.96 to -16.73; I² = 92%; P < 0.00001). Vaginal pH and dyspareunia significantly reduced in estrogen users (MD: -0.94; 95% CI: -1.05 to -0.84; I² = 96%) and (MD: -0.52; 95% CI: -0.63 to -0.41; I² = 99%), respectively. Estrogen did not significantly affect vaginal dryness (MD: -0.04; 95% CI: -0.18 to 0.11; I² = 88%). Adverse events like vulvovaginal pruritis, mycotic infection, and urinary tract infection were reported, but the association was insignificant (risk ratio: 0.95; 95% CI: 0.88 to 1.02; I² = 0%).

CONCLUSIONS

Our meta-analysis of 18 RCTs suggests promising potential for intravaginal estrogen therapy in alleviating vaginal atrophy and vaginitis in postmenopausal females.

Efficacy of acupuncture in animal models of various ovarian dysfunctions: a systematic review and meta-analysis

Objective

This study aims to assess the comprehensive and integrated modulatory effects of acupuncture and electroacupuncture on various ovarian dysfunctions.

Methods

We systematically searched for articles on animal experiments related to polycystic ovary syndrome (PCOS), premature ovarian failure (POF), premature ovarian insufficiency (POI), and perimenopausal syndrome (PMS) across multiple databases, including PubMed, Web of Science, Cochrane Library, Embase, and four Chinese language databases. The search covered the period from inception to November 2023. We conducted a comparative analysis between the acupuncture group and the model group (untreated) based on eligible literature. Our primary outcomes encompassed serum sex hormones (Luteinizing hormone, Follicle-stimulating hormone, Testosterone, Estradiol, Progesterone, and Anti-Müllerian hormone) and ovarian weight. Dichotomous data were synthesized to establish the relative risk (RR) of notable post-treatment improvement, while continuous data were pooled to determine the standardized mean difference (SMD) in post-treatment scores between the groups. Statistical analyses, including sensitivity analysis, Egger's test, and the trim-and-fill method, were executed using Stata 15.0 software.

Results

The meta-analysis encompassed 29 articles involving a total of 623 rats. In comparison to rat models of PCOS, the experimental group exhibited a reduction in serum levels of LH, T and LH/FSH ratio. However, no statistically significant differences were observed in AMH, FSH, E2 levels, and ovarian weight between the two groups. In the ovarian hypoplasia model rats, both acupuncture and electroacupuncture interventions were associated with an increase in E2 levels. However, the levels of LH and FSH did not exhibit a significant difference between the two groups.

Conclusions

Acupuncture or electroacupuncture facilitates the restoration of ovarian function primarily through the modulation of serum sex hormones, exerting regulatory effects across various types of ovarian dysfunction disorders.

Systematic review registration

https://www.crd.york.ac.uk/prospero/display_record.php?ID=CRD42022316279.

Correlation between the RNA Expression and the DNA Methylation of Estrogen Receptor Genes in Normal and Malignant Human Tissues

Estrogen plays a multifaceted function in humans via interacting with the estrogen receptors ERα, ERβ, and G protein-coupled estrogen receptor 1 (GPER1). Previous research has predominantly concentrated on elucidating the signaling route of estrogen. However, the comprehensive understanding of the expression profile and control of these estrogen receptors in various human tissues is not well known. In the present study, the RNA levels of estrogen receptors in various normal and malignant human tissues were retrieved from the human protein atlas, the cancer genome atlas (TCGA), and the genotype-tissue expression (GTEx) databases for analyzing the expression profile of estrogen receptors through gene expression profiling interactive analysis (GEPIA). The status of DNA methylation of estrogen receptor genes from TCGA were analyzed through the software Wanderer and cBioPortal. The MethSurv tool was utilized to estimate the relevance between specific cytosine-guanine (CG) methylation and tumor survival. The expression profile analysis revealed that ERα, ERβ, and GPER1 have unique expression patterns in diverse tissues and malignancies. The interesting results were the higher expression of ERβ RNA in the male testis than in females and the positive association between the RNA level of ERα and the androgen receptor in different human normal tissues. Especially, the significant changes in GPER1 expression in multiple malignancies showed a consistent decrease with no exception, which indicates the role of GPER1 in common tumor inhibition. The finding on the expression profile provides clues for exploring novel potential physiological and pathophysiological functions of estrogen. The DNA methylation analysis manifested that the expression of GPER1 and ERα showed a substantial correlation with the methylation of specific CG sites in the cis-regulating region of the gene. However, no such association was observed for ERβ. When comparing tumor tissues to normal tissues, the DNA methylation of certain CG sites of estrogen receptors showed a correlation with tumor survival but did not always correlate with the expression of that gene or with the expression of DNA methyltransferases. We proposed that the variation in DNA methylation at different CG sites in estrogen receptor genes had other functions beyond its regulatory role in its gene expression, and this might be associated with the progression and therapy efficiency of the tumor based on the modulation of the chromatin configuration.

Endometriosis-Associated Ovarian Cancer: From Molecular Pathologies to Clinical Relevance

Endometriosis is a chronic condition affecting reproductive-aged women, characterized by the growth of ectopic endometrial tissue. Despite being benign, endometriosis is associated with an increased risk of certain cancers, including endometriosis-associated ovarian cancer (EAOC). Ovarian cancer is rare, but more common in women with endometriosis, particularly endometrioid and clear-cell carcinomas. Factors such as hormonal imbalance, reproductive history, environmental exposures, and genetic predisposition contribute to the malignant transformation of endometriosis. Thus, understanding potential risk factors causing malignancy is crucial. Over the past few decades, various genetic mutations, microRNAs, as well as tumor microenvironmental factors have been identified, impacting pathways like PI3K/AKT/mTOR, DNA repair mechanisms, oxidative stress, and inflammation. Thus, this review aims to summarize molecular studies involved in EAOC pathogenesis as potential therapeutic targets. However, further research is needed to better understand the molecular and environmental factors driving EAOC development, to target the susceptibility of endometriotic lesions to malignant progression, and to identify effective therapeutic strategies.

Current Insights in Prolactin Signaling and Ovulatory Function

Prolactin (PRL) is a pleiotropic hormone released from lactotrophic cells of the anterior pituitary gland that also originates from extrapituitary sources and plays an important role in regulating lactation in mammals, as well as other actions. Acting in an endocrine and paracrine/autocrine manner, PRL regulates the hypothalamic-pituitary-ovarian axis, thus influencing the maturation of ovarian follicles and ovulation. This review provides a detailed discussion of the current knowledge on the role of PRL in the context of ovulation and ovulatory disorders, particularly with regard to hyperprolactinemia, which is one of the most common causes of infertility in women. Much attention has been given to the PRL structure and the PRL receptor (PRLR), as well as the diverse functions of PRLR signaling under normal and pathological conditions. The hormonal regulation of the menstrual cycle in connection with folliculogenesis and ovulation, as well as the current classifications of ovulation disorders, are also described. Finally, the state of knowledge regarding the importance of TIDA (tuberoinfundibular dopamine), KNDγ (kisspeptin/neurokinin B/dynorphin), and GnRH (gonadotropin-releasing hormone) neurons in PRL- and kisspeptin (KP)-dependent regulation of the hypothalamic-pituitary-gonadal (HPG) axis in women is reviewed. Based on this review, a rationale for influencing PRL signaling pathways in therapeutic activities accompanying ovulation disorders is presented.

Administration of adipose-derived mesenchymal stem cell conditioned medium improves ovarian function in polycystic ovary syndrome rats: involvement of epigenetic modifiers system

BACKGROUND

Polycystic ovary syndrome (PCOS) is a widespread heterogeneous disease that is in association with genetic, epigenetic, endocrine and environmental factors. Adipose-derived mesenchymal stem cell (ASC) and ASC-conditioned medium (ASC-CM) have shown promising abilities in tissue regeneration. In the present study, we aimed to investigate the effects of ASC and ASC-CM on epigenetic regulators, steroidal function and folliculogenesis in the letrozole-induced PCOS rats.

RESULTS

Based on the measurement of the oral glucose tolerance test and physical parameters including body weight, estrus cycle pattern as well as ovary dimensions, PCOS-induced rats in sham and control (CTRL) groups showed signs of reproductive dysfunctions such as lack of regular estrus cyclicity, metabolic disorders such as increased ovary dimension, body weight and blood glucose level alteration which were improved especially by ASC-CM administration.

Effects of Gender and Vitamin D on Vascular Reactivity of the Carotid Artery on a Testosterone-Induced PCOS Model

The negative cardiovascular effects of polycystic ovary syndrome (PCOS) and vitamin D deficiency (VDD) have been discussed previously; however, the sex differences between PCOS females and males are not yet known. Our aim was to investigate the effect of PCOS and VDD in the carotid artery of male and female Wistar rats. Females were treated with transdermal testosterone (Androgel) for 8 weeks, which caused PCOS. VDD and vitamin D supplementation were accomplished via diet. The carotid arteries' contraction and relaxation were examined using myography. Receptor density was investigated using immunohistochemistry. In PCOS females, angiotensin receptor density, angiotensin II-induced contraction, androgen receptor optical density, and testosterone-induced relaxation increased. The increased contractile response may increase cardiovascular vulnerability in women with PCOS. As an effect of VDD, estrogen receptor density increased in all our groups, which probably compensated for the reduced relaxation caused by VDD. Testosterone-induced relaxation was decreased as a result of VDD in males and non-PCOS females, whereas this reduction was absent in PCOS females. Male sex is associated with increased contraction ability compared with non-PCOS and PCOS females. VDD and Androgel treatment show significant gender differences in their effects on carotid artery reactivity. Both VDD and PCOS result in a dysfunctional vascular response, which can contribute to cardiovascular diseases.

PITX1 plays essential functions in cancer

PITX1, also known as the pituitary homeobox 1 gene, has emerged as a key regulator in animal growth and development, attracting significant research attention. Recent investigations have revealed the implication of dysregulated PITX1 expression in tumorigenesis, highlighting its involvement in cancer development. Notably, PITX1 interacts with p53 and exerts control over crucial cellular processes including cell cycle progression, apoptosis, and chemotherapy resistance. Its influence extends to various tumors, such as esophageal, colorectal, gastric, and liver cancer, contributing to tumor progression and metastasis. Despite its significance, a comprehensive review examining PITX1's role in oncology remains lacking. This review aims to address this gap by providing a comprehensive overview of PITX1 in different cancer types, with a particular focus on its clinicopathological significance.

Estrogens, Estrogen Receptors and Tumor Microenvironment in Ovarian Cancer

Ovarian cancer is one of the most common cancers in women and the most concerning issues in gynecological oncology in recent years. It is postulated that many factors may contribute to the development of ovarian cancer, including hormonal imbalance. Estrogens are a group of hormones that have an important role both in physiological and pathological processes. In ovarian cancer, they may regulate proliferation, invasiveness and epithelial to mesenchymal transition. Estrogen signaling also takes part in the regulation of the biology of the tumor microenvironment. This review summarizes the information connected with estrogen receptors, estrogens and their association with a tumor microenvironment. Moreover, this review also includes information about the changes in estrogen receptor expression upon exposition to various environmental chemicals.

The Role of G Protein-Coupled Estrogen Receptor (GPER) in Vascular Pathology and Physiology

OBJECTIVE

Estrogen is indispensable in health and disease and mainly functions through its receptors. The protection of the cardiovascular system by estrogen and its receptors has been recognized for decades. Numerous studies with a focus on estrogen and its receptor system have been conducted to elucidate the underlying mechanism. Although nuclear estrogen receptors, including estrogen receptor-α and estrogen receptor-β, have been shown to be classical receptors that mediate genomic effects, studies now show that GPER mainly mediates rapid signaling events as well as transcriptional regulation via binding to estrogen as a membrane receptor. With the discovery of selective synthetic ligands for GPER and the utilization of GPER knockout mice, significant progress has been made in understanding the function of GPER. In this review, the tissue and cellular localizations, endogenous and exogenous ligands, and signaling pathways of GPER are systematically summarized in diverse physiological and diseased conditions. This article further emphasizes the role of GPER in vascular pathology and physiology, focusing on the latest research progress and evidence of GPER as a promising therapeutic target in hypertension, pulmonary hypertension, and atherosclerosis. Thus, selective regulation of GPER by its agonists and antagonists have the potential to be used in clinical practice for treating such diseases.

Crosstalk between ferroptosis and steroid hormone signaling in gynecologic cancers

Ferroptosis is a novel types of regulated cell death and is widely studied in cancers and many other diseases in recent years. It is characterized by iron accumulation and intense lipid peroxidation that ultimately inducing oxidative damage. So far, signaling pathways related to ferroptosis are involved in all aspects of determining cell fate, including oxidative phosphorylation, metal-ion transport, energy metabolism and cholesterol synthesis progress, et al. Recently, accumulated studies have demonstrated that ferroptosis is associated with gynecological oncology related to steroid hormone signaling. This review trends to summarize the mechanisms and applications of ferroptosis in cancers related to estrogen and progesterone, which is expected to provide a theoretical basis for the prevention and treatment of gynecologic cancers.

Expression and function of estrogen receptors and estrogen-related receptors in the brain and their association with Alzheimer's disease

While estrogens are well known for their pivotal role in the female reproductive system, they also play a crucial function in regulating physiological processes associated with learning and memory in the brain. Moreover, they have neuroprotective effects in the pathogenesis of Alzheimer's disease (AD). Importantly, AD has a higher incidence in older and postmenopausal women than in men, and estrogen treatment might reduce the risk of AD in these women. In general, estrogens bind to and activate estrogen receptors (ERs)-mediated transcriptional machineries, and also stimulate signal transduction through membrane ERs (mERs). Estrogen-related receptors (ERRs), which share homologous sequences with ERs but lack estrogen-binding capabilities, are widely and highly expressed in the human brain and have also been implicated in AD pathogenesis. In this review, we primarily provide a summary of ER and ERR expression patterns in the human brain. In addition, we summarize recent studies on their role in learning and memory. We then review and discuss research that has elucidated the functions and importance of ERs and ERRs in AD pathogenesis, including their role in Aβ clearance and the reduction of phosphorylated tau levels. Elucidation of the mechanisms underlying ER- and ERR-mediated transcriptional machineries and their functions in healthy and diseased brains would provide new perspectives for the diagnosis and treatment of AD. Furthermore, exploring the potential role of estrogens and their receptors, ERs, in AD will facilitate a better understanding of the sex differences observed in AD, and lead to novel sex-specific therapeutic approaches.

Weighted Gene Co-Expression Network Analysis (WGCNA) Discovered Novel Long Non-Coding RNAs for Polycystic Ovary Syndrome

Polycystic ovary syndrome (PCOS) affects reproductive-age women. This condition causes infertility, insulin resistance, obesity, and heart difficulties. The molecular basis and mechanism of PCOS might potentially generate effective treatments. Long non-coding RNAs (lncRNAs) show control over multifactorial disorders' growth and incidence. Numerous studies have emphasized its significance and alterations in PCOS. We used bioinformatic methods to find novel dysregulated lncRNAs in PCOS. To achieve this objective, the gene expression profile of GSE48301, comprising PCOS patients and normal control tissue samples, was evaluated using the R limma package with the following cut-off criterion: p-value < 0.05. Firstly, weighted gene co-expression network analysis (WGCNA) was used to determine the co-expression genes of lncRNAs; subsequently, hub gene identification and pathway enrichment analysis were used. With the defined criteria, nine novel dysregulated lncRNAs were identified. In WGCNA, different colors represent different modules. In the current study, WGCNA resulted in turquoise, gray, blue, and black co-expression modules with dysregulated lncRNAs. The pathway enrichment analysis of these co-expressed modules revealed enrichment in PCOS-associated pathways, including gene expression, signal transduction, metabolism, and apoptosis. In addition, CCT7, EFTUD2, ESR1, JUN, NDUFAB1, CTTNB1, GRB2, and CTNNB1 were identified as hub genes, and some of them have been investigated in PCOS. This study uncovered nine novel PCOS-related lncRNAs. To confirm how these lncRNAs control translational modification in PCOS, functional studies are required.

Roles of Estrogen, Estrogen Receptors, and Estrogen-Related Receptors in Skeletal Muscle: Regulation of Mitochondrial Function

Estrogen is an essential sex steroid hormone that functions primarily in female reproductive system, as well as in a variety of tissues and organs with pleiotropic effects, such as in cardiovascular, nervous, immune, and musculoskeletal systems. Women with low estrogen, as exemplified by those in postmenopause, are therefore prone to suffer from various disorders, i.e., cardiovascular disease, dementia, metabolic syndrome, osteoporosis, sarcopenia, frailty, and so on. Estrogen regulates the expression of its target genes by binding to its cognate receptors, estrogen receptors (ERs) α and β. Notably, the estrogen-related receptors (ERRs) α, β, and γ are originally identified as orphan receptors that share substantial structural homology and common transcriptional targets with ERs. Accumulating evidence suggests that ERs and ERRs play crucial roles in skeletal muscles, such as muscle mass maintenance, muscle exercise physiology, and muscle regeneration. In this article, we review potential regulatory roles of ERs and ERRs in muscle physiology, particularly with regard to mitochondrial function and metabolism.