Reproductive functions of progesterone receptors

Krüppel-like factor 12 decreases progestin sensitivity in endometrial cancer by inhibiting the progesterone receptor signaling pathway

OBJECTIVE

This study aimed to clarify the mechanism by which Krüppel-like factor 12 (KLF12) affects progesterone sensitivity in endometrial cancer (EC) through the progesterone receptor PGR signaling pathway.

METHODS

The relationship of KLF12 with PGR in EC patients was examined by immunohistochemistry, and the expression of KLF12 and PGR in EC cell lines was detected by real-time PCR and western blotting. Cell proliferation assay, plate clone formation, cell apoptosis assay, and cell cycle analysis were conducted to determine the impact of KLF12 intervention on progesterone therapy. CUT&Tag analysis and the dual-luciferase reporter experiment were used to determine the underlying regulatory effect of KLF12 on the PGR DNA sequence. A subcutaneous xenograft nude mouse model was established to validate the in vivo effect of KLF12 on progesterone sensitivity via PGR expression modulation.

RESULTS

KLF12 demonstrated decreased progesterone sensitivity and a negative correlation with PGR expression in EC tissues. Progesterone sensitivity was increased by KLF12 deficiency through PGR overexpression, a result that could be significantly reversed by PGR downregulation. PGR was identified as a target gene of KLF12, which could directly bind to the PGR promotor region and inhibit its expression.

CONCLUSION

This study is the first to investigate the effect of KLF12 expression on EC cell resistance to progesterone. Our results offer important mechanistic insight into the direct regulation of the PGR promoter region, demonstrating that KLF12 expression strongly suppressed the PGR signaling pathway and, as a result, reduced progesterone sensitivity in EC patients.

Unraveling the Dynamics of Estrogen and Progesterone Signaling in the Endometrium: An Overview

The endometrium is crucial for the perpetuation of human species. It is a complex and dynamic tissue lining the inner wall of the uterus, regulated throughout a woman's life based on estrogen and progesterone fluctuations. During each menstrual cycle, this multicellular tissue undergoes cyclical changes, including regeneration, differentiation in order to allow egg implantation and embryo development, or shedding of the functional layer in the absence of pregnancy. The biology of the endometrium relies on paracrine interactions between epithelial and stromal cells involving complex signaling pathways that are modulated by the variations of estrogen and progesterone levels across the menstrual cycle. Understanding the complexity of estrogen and progesterone receptor signaling will help elucidate the mechanisms underlying normal reproductive physiology and provide fundamental knowledge contributing to a better understanding of the consequences of hormonal imbalances on gynecological conditions and tumorigenesis. In this narrative review, we delve into the physiology of the endometrium, encompassing the complex signaling pathways of estrogen and progesterone.

Human and fish differences in steroid receptors activation: A review

Steroid receptors (SRs) are transcription factors activated by steroid hormones (SHs) that belong to the nuclear receptors (NRs) superfamily. Several studies have shown that SRs are targets of endocrine disrupting chemicals (EDCs), widespread substances in the environment capable of interfering with the endogenous hormonal pathways and causing adverse health effects in living organisms and/or their progeny. Cell lines with SRs reporter gene are currently used for in vitro screening of large quantities of chemicals with suspected endocrine-disrupting activities. However, most of these cell lines express human SRs and therefore the toxicological data obtained are also extrapolated to non-mammalian species. In parallel, in vivo tests have recently been developed on fish species whose data are also extrapolated to mammalian species. As some species-specific differences in SRs activation by natural and synthetic chemicals have been recently reported, the aim of this review is to summarize those between human and fish SRs, as representatives of mammalian and non-mammalian toxicology, respectively. Overall, this literature study aims to improve inter-species extrapolation of toxicological data on EDCs and to understand which reporter gene cell lines expressing human SRs are relevant for the assessment of effects in fish and whether in vivo tests on fish can be properly used in the assessment of adverse effects on human health.

Effect of the gonadotropin surge on steroid receptor regulation in preovulatory follicles and newly formed corpora lutea in the cow

The objective of the study was to characterize the mRNA expression patterns of specific steroid hormone receptors namely, estrogen receptors (ESRRA-estrogen related receptor alpha and ESRRB-estrogen related receptor beta) and progesterone receptors (PGR) in superovulation-induced bovine follicles during the periovulation and subsequent corpus luteum (CL) formation. The bovine ovaries (n = 5 cow / group), containing preovulatory follicles or early CL, were collected relative to injection of the gonadotropin-releasing hormone (GnRH) at (I) 0 h, (II) 4 h, (III) 10 h, (IV) 20 h, (V) 25 h (preovulatory follicles) and (VI) 60 h (CL, 2-3 days after induced ovulation). In this experiment, we analyzed the steroid receptor mRNA expression and their localization in the follicle and CL tissue. The high mRNA expression of ESRRA, ESRRB, and PGR analyzed in the follicles before ovulation is significantly reduced in the group of follicles during ovulation (25 h after GnRH), rising again significantly after ovulation in newly formed CL, only for ESRRA and PGR (P < 0.05). Immunohistochemically, the nuclei of antral follicles' granulosa cells showed a positive staining for ESRRA, followed by higher activity in the large luteal cells just after ovulation (early CL). In contrast, the lower PGR immunopresence in preovulatory follicles increased in both small and large luteal cell nuclei after follicle ovulation. Our results of steroid receptor mRNA expression in this experimentally induced gonadotropin surge provide insight into the molecular mechanisms of the effects of steroid hormones on follicular-luteal tissue in the period close to the ovulation and subsequent CL formation in the cow.

The impact of reproductive hormones on T cell immunity; normal and assisted reproductive cycles

During pregnancy, a unique immune milieu is established systemically and locally at the maternal-fetal interface. While preparing for embryonic implantation, endometrial effectors significantly change their proportions and function, which are synchronized with hormonal changes. During assisted reproductive technology cycles, various cytokines, chemokines, and immune factors dynamically change with the altered receptor expressions on the immune effectors. Thus, the hormonal regulation of immune effectors is critical to maintaining the immune milieu. In this review, hormonal effects on T cell subsets are reviewed. Sex hormones affect T cell ontogeny and development, consequently affecting their functions. Like other T cell subsets, CD4+ T helper (Th) cells are modulated by estrogen, where low estrogen concentration promotes Th1-driven cell-mediated immunity in the uterus and in vitro by enhancing IFN-γ production, while a high estrogen level decreases it. The abundance and differentiation of T regulatory (Treg) cells are controlled by estrogen, inducing Treg expansion. Conversely, progesterone maintains immune homeostasis by balancing Th1/Th2 and Th17/Treg immunity, leading to maternal-fetal tolerance. Therefore, the understanding of the hormonal impact on various T cell subsets during the reproductive cycles is critical to improving reproductive outcomes in women with recurrent pregnancy losses, repeated implantation failures, and undergoing assisted reproductive cycles.

History of the Development of Knowledge about the Neuroendocrine Control of Ovulation-Recent Knowledge on the Molecular Background

The physiology of reproduction has been of interest to researchers for centuries. The purpose of this work is to review the development of our knowledge on the neuroendocrine background of the regulation of ovulation. We first describe the development of the pituitary gland, the structure of the median eminence (ME), the connection between the hypothalamus and the pituitary gland, the ovarian and pituitary hormones involved in ovulation, and the pituitary cell composition. We recall the pioneer physiological and morphological investigations that drove development forward. The description of the supraoptic-paraventricular magnocellular and tuberoinfundibular parvocellular systems and recognizing the role of the hypophysiotropic area were major milestones in understanding the anatomical and physiological basis of reproduction. The discovery of releasing and inhibiting hormones, the significance of pulse and surge generators, the pulsatile secretion of the gonadotropin-releasing hormone (GnRH), and the subsequent pulsatility of luteinizing (LH) and follicle-stimulating hormones (FSH) in the human reproductive physiology were truly transformative. The roles of three critical neuropeptides, kisspeptin (KP), neurokinin B (NKB), and dynorphin (Dy), were also identified. This review also touches on the endocrine background of human infertility and assisted fertilization.

Deciphering the role of PGRMC2 in the human endometrium during the menstrual cycle and in vitro decidualization using an in vitro approach

STUDY QUESTION

What is the human endometrial non-classical progesterone receptor (PGR) membrane component 2 (PGRMC2) expression pattern throughout the menstrual cycle and what role does it play during decidualization?

SUMMARY ANSWER

Endometrial PGRMC2 expression fluctuates during the human menstrual cycle and is abundantly expressed in human endometrial stromal cells (hEnSCs) during in vitro decidualization, process where PGRMC2 is involved in embryo implantation-related pathways.

WHAT IS KNOWN ALREADY

The endometrial response to progesterone is mediated by the classical and non-classical PGRs. We previously demonstrated that PGR membrane component 1 (PGRMC1) is critical for endometrial function, embryo implantation, and future placentation, however, the role(s) of PGRMC2, which is structurally similar to PGRMC1, have not been studied in the human endometrium.

STUDY DESIGN, SIZE, DURATION

This prospective study comprehensively evaluated the endometrial expression of PGRMC2 throughout the human menstrual cycle and during in vitro decidualization of hEnSCs (isolated from 77 endometrial biopsies that were collected from 66 oocyte donors), using immunohistochemistry, RT-qPCR, western blot, transcriptomic, and proteomic analyses. In addition, functional analysis was carried out to validate the implication of PGRMC2 in hEnSCs during embryo invasion using an in vitro outgrowth model.

PARTICIPANTS/MATERIALS, SETTING, METHODS

In vitro decidualization of hEnSCs was induced using co-treatment with cAMP and medroxyprogesterone 17-acetate progestin, and evaluated by measuring prolactin by ELISA and F-actin immunostaining. RT-qPCR was employed to compare expression with other PGRs. To reveal the function of PGRMC2 during the decidualization process, we specifically knocked down PGRMC2 with siRNAs and performed RNA-seq and quantitative proteomics techniques (SWATH-MS). The common differentially expressed genes (DEGs) and proteins (DEPs) were considered for downstream functional enrichment analysis. Finally, to verify its implication in the trophoblast invasion, an outgrowth model was carried out where hEnSCs with silenced PGRMC2 were co-cultured with human trophoblastic spheroids (JEG-3) following in vitro decidualization.

MAIN RESULTS AND THE ROLE OF CHANCE

In contrast to PGRMC1 and classical PGRs, endometrial PGRMC2 gene expression was significantly lower during the late- versus mid-secretory phase (P < 0.05). Accordingly, the elevated PGRMC2 protein abundance observed in the endometrial epithelial glands throughout the menstrual cycle dropped in the late secretory phase, when abundance decreased in all endometrial compartments. Nevertheless, PGRMC2 protein increased during the mid-secretory phase in stromal and glandular cells, and PGRMC2 mRNA (P < 0.0001) and protein (P < 0.001) levels were significantly enhanced in the membranes/organelles of decidualized hEnSCs, compared to non-decidualized hEnSCs. Notably, PGRMC1 and PGRMC2 mRNA were significantly more abundant than classical PGRs throughout menstrual cycle phases and in decidualized and non-decidualized hEnSCs (P < 0.05). RNA-seq and proteomics data revealed 4687 DEGs and 28 DEPs, respectively, in decidualized hEnSCs after PGRMC2 silencing. While functional enrichment analysis showed that the 2420 upregulated genes were mainly associated with endoplasmic reticulum function, vesicular transport, morphogenesis, angiogenesis, cell migration, and cell adhesion, the 2267 downregulated genes were associated with aerobic respiration and protein biosynthesis. The protein enrichment analysis showed that 4 upregulated and 24 downregulated proteins were related to aerobic respiration, cellular response, metabolism, localization of endoplasmic reticulum proteins, and ribonucleoside biosynthesis routes. Finally, PGRMC2 knockdown significantly compromised the ability of the decidualized hEnSCs to support trophoblast expansion in an outgrowth model (P < 0.05).

LARGE-SCALE DATA

Transcriptomic data are available via NCBI's Gene Expression Omnibus (GEO) under GEO Series accession number GSE251843 and proteomic data via ProteomeXchange with identifier PXD048494.

LIMITATIONS, REASONS FOR CAUTION

The functional analyses were limited by the discrete number of human endometrial biopsies. A larger sample size is required to further investigate the potential role(s) of PGRMC2 during embryo implantation and maintenance of pregnancy. Further, the results obtained in the present work should be taken with caution, as the use of a pure primary endometrial stromal population differentiated in vitro does not fully represent the heterogeneity of the endometrium in vivo, nor the paracrine communications occurring between the distinct endometrial cell types.

WIDER IMPLICATIONS OF THE FINDINGS

The repression of endometrial PGRMC2 during the late- versus mid-secretory phase, together with its overexpression during decidualization and multiple implications with embryo implantation not only highlighted the unknown roles of PGRMC2 in female reproduction but also the potential to exploit PGRMC2 signaling pathways to improve assisted reproduction treatments in the future.

STUDY FUNDING/COMPETING INTEREST(S)

This research was funded by Instituto de Salud Carlos III (ISCIII) granted to F.D. (PI20/00405 and PI23/00860), co-funded by the European Union. Y.M.-L. was supported by a predoctoral research grant from Generalitat Valenciana (ACIF/2019/262). R.G.-M. was supported by Generalitat Valenciana (CIAPOT/2022/15). P.d.C. was supported by a predoctoral grant for training in research into health (PFIS FI20/00086) from the Instituto de Salud Carlos III. I.D.-H. was supported by the Spanish Ministry of Science, Innovation and Universities (FPU18/01550). A.P. was supported by the Instituto de Salud Carlos III (PFIS FI18/00009). This research was also supported by IVI Foundation-RMA Global (1911-FIVI-103-FD). The authors declare no conflict of interest.

Candidate genes associated with reproductive traits in rabbits

In the era of scientific advances and genetic progress, opportunities in the livestock sector are constantly growing. The application of molecular-based methods and approaches in farm animal breeding would accelerate and improve the expected results. The current work aims to comprehensively review the most important causative mutations in candidate genes that affect prolificacy traits in rabbits. Rabbits are a source of excellent-tasting meat that is high in protein and low in fat. Their early maturity and intensive growth are highly valued all over the world. However, improving reproductive traits and prolificacy in rabbits could be very tricky with traditional selection. Therefore, traditional breeding programs need new methods based on contemporary discoveries in molecular biology and genetics because of the complexity of the selection process. The study and implementation of genetic markers related to production in rabbits will help to create populations with specific productive traits that will produce the desired results in an extremely short time. Many studies worldwide showed an association between different genes and productive traits in rabbits. The study of these polymorphisms and their effects could be useful for molecular-oriented breeding, particularly marker-assisted selection programs in rabbit breeding.

Regulation of PDGFRα+ cells and ICC in progesterone-mediated slow colon transit in pregnant mice

Background

Progesterone can inhibit intestinal smooth muscle contraction; however, the specific mechanism remains unclear. Besides smooth muscle cells, smooth muscle has two important mesenchymal cells, namely interstitial cells of Cajal (ICC) and PDGFRα+ cells, which induce the contraction and relaxation of smooth muscles. We aimed to explore the regulation of PDGFRα+ cells and ICC in progesterone-mediated colon slow transit in pregnant mice.

Methods

Colon transit experiments were performed in vivo and in vitro to observe slow colon transit. The expression of PDGFRα and c-KIT was detected by Western blot, RT-PCR, and immunofluorescence. An isometric tension experiment was performed to investigate smooth muscle contractions.

Results

The colon transit time in pregnant mice was longer than that in non-pregnant mice. Progesterone significantly blocks colonic smooth muscle contractions. However, when the relaxation and contraction of PDGFRα+ cells and ICC are blocked, progesterone cannot inhibit smooth muscle contraction. When the function of only PDGFRα+ cells are blocked, progesterone has a more obvious inhibitory effect on smooth muscle in the non-pregnant group than that in the pregnant group. However, when ICC alone was blocked, progesterone inhibited smooth muscle contractions more clearly in pregnant mice. The protein and mRNA expression of PDGFRα was higher and c-KIT was lower in pregnant mice. PDGFRα+ cells and ICC from smooth muscle all co-localize progesterone receptors.

Conclusions

Under the regulation of progesterone, the relaxation function of PDGFRα+ cells is enhanced and the contraction function of ICC is weakened, leading to the slow colon transit of pregnant mice.

Cycling matters: Sex hormone regulation of vascular potassium channels

Sex hormones and the reproductive cycle (estrus in rodents and menstrual in humans) have a known impact on arterial function. In spite of this, sex hormones and the estrus/menstrual cycle are often neglected experimental factors in vascular basic preclinical scientific research. Recent research by our own laboratory indicates that cyclical changes in serum concentrations of sex -hormones across the rat estrus cycle, primary estradiol, have significant consequences for the subcellular trafficking and function of KV. Vascular potassium channels, including KV, are essential components of vascular reactivity. Our study represents a small part of a growing field of literature aimed at determining the role of sex hormones in regulating arterial ion channel function. This review covers key findings describing the current understanding of sex hormone regulation of vascular potassium channels, with a focus on KV channels. Further, we highlight areas of research where the estrus cycle should be considered in future studies to determine the consequences of physiological oscillations in concentrations of sex hormones on vascular potassium channel function.

New insights on the potential effect of progesterone in Covid-19: Anti-inflammatory and immunosuppressive effects

BACKGROUND

Coronavirus disease 2019 (COVID-19) is a pandemic disease caused by severe acute respiratory syndrome CoV type 2 (SARS-CoV-2). COVID-19 is higher in men than women and sex hormones have immune-modulator effects during different viral infections, including SARS-CoV-2 infection. One of the essential sex hormones is progesterone (P4).

AIMS

This review aimed to reveal the association between P4 and Covid-19.

RESULTS AND DISCUSSION

The possible role of P4 in COVID-19 could be beneficial through the modulation of inflammatory signaling pathways, induction of the release of anti-inflammatory cytokines, and inhibition release of pro-inflammatory cytokines. P4 stimulates skew of naïve T cells from inflammatory Th1 toward anti-inflammatory Th2 with activation release of anti-inflammatory cytokines, and activation of regulatory T cells (Treg) with decreased interferon-gamma production that increased during SARS-CoV-2 infection. In addition, P4 is regarded as a potent antagonist of mineralocorticoid receptor (MR), it could reduce MRs that were activated by stimulated aldosterone from high AngII during SARS-CoV-2. P4 active metabolite allopregnanolone is regarded as a neurosteroid that acts as a positive modulator of γ-aminobutyric acid (GABAA ) so it may reduce neuropsychiatric manifestations and dysautonomia in COVID-19 patients.

CONCLUSION

Taken together, the anti-inflammatory and immunomodulatory properties of P4 may improve central and peripheral complications in COVID-19.

Parental factors that impact the ecology of human mammary development, milk secretion, and milk composition-a report from "Breastmilk Ecology: Genesis of Infant Nutrition (BEGIN)" Working Group 1

The goal of Working Group 1 in the Breastmilk Ecology: Genesis of Infant Nutrition (BEGIN) Project was to outline factors influencing biological processes governing human milk secretion and to evaluate our current knowledge of these processes. Many factors regulate mammary gland development in utero, during puberty, in pregnancy, through secretory activation, and at weaning. These factors include breast anatomy, breast vasculature, diet, and the lactating parent's hormonal milieu including estrogen, progesterone, placental lactogen, cortisol, prolactin, and growth hormone. We examine the effects of time of day and postpartum interval on milk secretion, along with the role and mechanisms of lactating parent-infant interactions on milk secretion and bonding, with particular attention to the actions of oxytocin on the mammary gland and the pleasure systems in the brain. We then consider the potential effects of clinical conditions including infection, pre-eclampsia, preterm birth, cardiovascular health, inflammatory states, mastitis, and particularly, gestational diabetes and obesity. Although we know a great deal about the transporter systems by which zinc and calcium pass from the blood stream into milk, the interactions and cellular localization of transporters that carry substrates such as glucose, amino acids, copper, and the many other trace metals present in human milk across plasma and intracellular membranes require more research. We pose the question of how cultured mammary alveolar cells and animal models can help answer lingering questions about the mechanisms and regulation of human milk secretion. We raise questions about the role of the lactating parent and the infant microbiome and the immune system during breast development, secretion of immune molecules into milk, and protection of the breast from pathogens. Finally, we consider the effect of medications, recreational and illicit drugs, pesticides, and endocrine-disrupting chemicals on milk secretion and composition, emphasizing that this area needs much more research attention.

Role of progesterone on dexamethasone-induced alterations in placental vascularization and progesterone receptors in rats†

BACKGROUND

Intrauterine growth restriction (IUGR) is manifested by lower maternal progesterone levels, smaller placental size, and decreased placental vascularity indicated by lower expression of vascular endothelial growth factor (VEGF). Studies showed that progesterone increases angiogenesis and induces VEGF expression in different tissues. Therefore, the aim of the present study is to evaluate the effect of progesterone on placental vascular bed and VEGF expression and the modulation of nuclear and membranous progesterone receptors (PR) in dexamethasone-induced rat IUGR model.

METHODS

Pregnant Sprague-Dawley rats were allocated into four groups and given intraperitoneal injections of either saline, dexamethasone, dexamethasone, and progesterone or progesterone. Injections started on gestation day (DG) 15 and lasted until the days of euthanization (19 and 21 DG). Enzyme-linked immunosorbent assay was used to evaluate plasma progesterone levels. Real-time PCR and western blotting were used to evaluate gene and protein expressions of VEGF, and PR in labyrinth and basal placental zones. Immunohistochemistry was used to locate VEGF and different PRs in placental cells. Immunofluorescence was used to monitor the expression of blood vessel marker (αSMA).

RESULTS

Dexamethasone decreased the vascular bed fraction and the expression of VEGF in both placental zones. Progesterone co-treatment with dexamethasone prevented this reduction. Nuclear and membrane PRs showed tissue-specific expression in different placental zones and responded differently to both dexamethasone and progesterone.

CONCLUSIONS

Progesterone treatment improves the outcomes in IUGR pregnancy. Progesterone alleviated DEX-induced IUGR probably by promoting placental VEGF and angiogenesis.

The Regulators of Human Endometrial Stromal Cell Decidualization

Several factors are important for implantation and subsequent placentation in the endometrium, including immunity, angiogenesis, extracellular matrix, glucose metabolism, reactive oxidative stress, and hormones. The involvement or abnormality of these factors can impair canonical decidualization. Unusual decidualization can lead to perinatal complications, such as disruption of trophoblast invasion. Drastic changes in the morphology and function of human endometrial stromal cells (hESCs) are important for decidualization of the human endometrium; hESCs are used to induce optimal morphological and functional decidualization in vitro because they contain estrogen and progesterone receptors. In this review, we will focus on the studies that have been conducted on hESC decidualization, including the results from our laboratory.

Stochastic model of ERK-mediated progesterone receptor translocation, clustering and transcriptional activity

Progesterone receptor (PR) transcriptional activity is a key factor in the differentiation of the uterine endometrium. By consequence, progestin has been identified as an important treatment modality for endometrial cancer. PR transcriptional activity is controlled by extracellular-signal-regulated kinase (ERK) mediated phosphorylation, downstream of growth factor receptors such as EGFR. However, phosphorylation of PR also targets it for ubiquitination and destruction in the proteasome. Quantitative studies of these opposing roles are much needed toward validation of potential new progestin-based therapeutics. In this work, we propose a spatial stochastic model to study the effects of the opposing roles for PR phosphorylation on the levels of active transcription factor. Our numerical simulations confirm earlier in vitro experiments in endometrial cancer cell lines, identifying clustering as a mechanism that amplifies the ability of progesterone receptors to influence gene transcription. We additionally show the usefulness of a statistical method we developed to quantify and control variations in stochastic simulations in general biochemical systems, assisting modelers in defining minimal but meaningful numbers of simulations while guaranteeing outputs remain within a pre-defined confidence level.

Nuclear hormone receptors in demyelinating diseases

Demyelination results from the pathological loss of myelin and is a hallmark of many neurodegenerative diseases. Despite the prevalence of demyelinating diseases, there are no disease modifying therapies that prevent the loss of myelin or promote remyelination. This review aims to summarize studies in the field that highlight the importance of nuclear hormone receptors in the promotion and maintenance of myelination and the relevance of nuclear hormone receptors as potential therapeutic targets for demyelinating diseases. These nuclear hormone receptors include the estrogen receptor, progesterone receptor, androgen receptor, vitamin D receptor, thyroid hormone receptor, peroxisome proliferator-activated receptor, liver X receptor, and retinoid X receptor. Pre-clinical studies in well-established animal models of demyelination have shown a prominent role of these nuclear hormone receptors in myelination through their promotion of oligodendrocyte maturation and development. The activation of the nuclear hormone receptors by their ligands also promotes the synthesis of myelin proteins and lipids in mouse models of demyelination. There are limited clinical studies that focus on how the activation of these nuclear hormone receptors could alleviate demyelination in patients with diseases such as multiple sclerosis (MS). However, the completed clinical trials have reported improved clinical outcome in MS patients treated with the ligands of some of these nuclear hormone receptors. Together, the positive results from both clinical and pre-clinical studies point to nuclear hormone receptors as promising therapeutic targets to counter demyelination.

Physiological Action of Progesterone in the Nonhuman Primate Oviduct

Therapies that target progesterone action hold potential as contraceptives and in managing gynecological disorders. Recent literature reviews describe the role of steroid hormones in regulating the mammalian oviduct and document that estrogen is required to stimulate epithelial differentiation into a fully functional ciliated and secretory state. However, these reviews do not specifically address progesterone action in nonhuman primates (NHPs). Primates differ from most other mammals in that estrogen levels are >50 pg/mL during the entire menstrual cycle, except for a brief decline immediately preceding menstruation. Progesterone secreted in the luteal phase suppresses oviductal ciliation and secretion; at the end of the menstrual cycle, the drop in progesterone triggers renewed estrogen-driven tubal cell proliferation ciliation secretory activity. Thus, progesterone, not estrogen, drives fallopian tube cycles. Specific receptors mediate these actions of progesterone, and synthetic progesterone receptor modulators (PRMs) disrupt the normal cyclic regulation of the tube, significantly altering steroid receptor expression, cilia abundance, cilia beat frequency, and the tubal secretory milieu. Addressing the role of progesterone in the NHP oviduct is a critical step in advancing PRMs as pharmaceutical therapies.

Divergent Evolution of Progesterone and Mineralocorticoid Receptors in Terrestrial Vertebrates and Fish Influences Endocrine Disruption

There is much concern about disruption of endocrine physiology regulated by steroid hormones in humans, other terrestrial vertebrates and fish by industrial chemicals, such as bisphenol A, and pesticides, such as DDT. These endocrine-disrupting chemicals influence steroid-mediated physiology in humans and other vertebrates by competing with steroids for receptor binding sites, disrupting diverse responses involved in reproduction, development and differentiation. Here I discuss that due to evolution of the progesterone receptor (PR) and mineralocorticoid receptor (MR) after ray-finned fish and terrestrial vertebrates diverged from a common ancestor, each receptor evolved to respond to different steroids in ray-finned fish and terrestrial vertebrates. In elephant shark, a cartilaginous fish that diverged before the separation between ray-finned fish and terrestrial vertebrates, both progesterone and 17,20β-dihydroxy-progesterone activate the PR. During the evolution of ray-finned fish and terrestrial vertebrates, the PR in terrestrial vertebrates continued responding to progesterone and evolved to weakly respond to 17,20β-dihydroxy-progesterone. In contrast, the physiological progestin for the PR in zebrafish and other ray-finned fish is 17,20β-dihydroxy-progesterone, and ray-finned fish PR responds weakly to progesterone. The MR in fish and terrestrial vertebrates also diverged to have different responses to progesterone. Progesterone is a potent agonist for elephant shark MR, zebrafish MR and other fish MRs, in contrast to progesterone's opposite activity as an antagonist for aldosterone, the physiological mineralocorticoid for human MR. These different physiological ligands for fish and terrestrial vertebrate PR and MR need to be considered in applying data for their disruption by chemicals in fish and terrestrial vertebrates to each other.

The Role of Progesterone Receptors in Breast Cancer

The progesterone receptor (PR) modulates estrogen receptors α (ERα) action in breast cancer; it is an upregulated target gene of ER, and its expression is dependent on estrogen. PR is also a valuable prognostic biomarker in breast cancer, especially in hormone-positive breast cancer. High expression of PR is more frequently observed in tumors with a better baseline prognosis (ie, luminal A) than tumors with a poor baseline prognosis (ie, luminal B). In the following review, we present the role of PR in breast cancer, including the genomic characteristics and pathways in breast cancer, PR and endocrine therapy.

Kruppel-like factor 5 (Klf5) in fetal-maternal tissue during periimplantation and effects of ovarian steroid hormone antagonist on its expression during uterine receptivity of albino mice

Background

Embryo implantation is a tightly regulated sequence of events regulated by ovarian steroids, estrogen and progesterone, and their downstream targets. Ovarian steroids regulate most of the genes involved in embryo implantation and pregnancy. However, some factors are not regulated by ovarian steroids, estrogen, progesterone, or both. Kruppel-like factor 5 (Klf5) is an example of an ovarian steroid–independent factor having a role in cellular proliferation, differentiation. The detailed expression profile of Klf5 during uterine receptivity and periimplantation has not been studied till now. In the present research work, an attempt was made to investigate the expression pattern of Klf5 in mice fetal-maternal tissue during periimplantation (day 4–day 8). The expressional and functional independence of Klf5 on the ovarian steroids was studied using estrogen and progesterone antagonist. The study was carried out in female Swiss albino mice of LACA strain during the periimplantation period. KLF5 was localized in the fetal-maternal tissues using the immunofluorescence technique in paraffin-embedded tissues. Ovarian steroid antagonists were administered subcutaneously from day 1 to day 3 of gestation, and the uterus was collected on the morning of day 4. Klf5 protein and mRNA levels were studied by western blot and quantitative real-time PCR (qPCR), respectively.

Results

KLF5 was localized in the embryo, uterine luminal epithelium, glandular epithelium, and proliferating stromal cells during periimplantation. In ovarian steroid antagonist–treated groups, KLF5 was localized in the luminal and glandular epithelium and stroma. Western blot and qPCR confirmed translation and transcription of KLF5 during the experimental period. The KLF5 protein level significantly increased on day 6, day 7, and day 8 when compared with day 4 (P < 0.05). The mRNA level of Klf5 increased significantly on day 7 and day 8 when compared with day 4 (P < 0.05). In ovarian steroid antagonist–treated groups, protein and mRNA corresponding to Klf5 were observed. From this finding, it can be assumed that Klf5 may be a steroid-independent factor expressed during uterine receptivity.

Conclusion

Spatiotemporal KLF5 expression in fetal-maternal tissue was observed during the experimental period. The results suggest that Klf5 is an ovarian steroid–independent factor that may play a pivotal role in implantation, decidualization, and embryogenesis.

Mechanisms of Scarless Repair at Time of Menstruation: Insights From Mouse Models

The human endometrium is a remarkable tissue which may experience up to 400 cycles of hormone-driven proliferation, differentiation and breakdown during a woman's reproductive lifetime. During menstruation, when the luminal portion of tissue breaks down, it resembles a bloody wound with piecemeal shedding, exposure of underlying stroma and a strong inflammatory reaction. In the absence of pathology within a few days the integrity of the tissue is restored without formation of a scar and the endometrium is able to respond appropriately to subsequent endocrine signals in preparation for establishment of pregnancy if fertilization occurs. Understanding mechanisms regulating scarless repair of the endometrium is important both for design of therapies which can treat conditions where this is aberrant (heavy menstrual bleeding, fibroids, endometriosis, Asherman's syndrome) as well as to provide new information that might allow us to reduce fibrosis and scar formation in other tissues. Menstruation only occurs naturally in species that exhibit spontaneous stromal cell decidualization during the fertile cycle such as primates (including women) and the Spiny mouse. To take advantage of genetic models and detailed time course analysis, mouse models of endometrial shedding/repair involving hormonal manipulation, artificial induction of decidualization and hormone withdrawal have been developed and refined. These models are useful in modeling dynamic changes across the time course of repair and have recapitulated key features of endometrial repair in women including local hypoxia and immune cell recruitment. In this review we will consider the evidence that scarless repair of endometrial tissue involves changes in stromal cell function including mesenchyme to epithelial transition, epithelial cell proliferation and multiple populations of immune cells. Processes contributing to endometrial fibrosis (Asherman's syndrome) as well as scarless repair of other tissues including skin and oral mucosa are compared to that of menstrual repair.

Aldosterone and dexamethasone activate African lungfish mineralocorticoid receptor: Increased activation after removal of the amino-terminal domain

Aldosterone, the main physiological mineralocorticoid in humans and other terrestrial vertebrates, first appears in lungfish, which are lobe-finned fish that are forerunners of terrestrial vertebrates. Aldosterone activation of the MR regulates internal homeostasis of water, sodium and potassium, which was critical in the conquest of land by vertebrates. We studied transcriptional activation of the slender African lungfish MR by aldosterone, other corticosteroids and progesterone and find that aldosterone, 11-deoxycorticosterone, 11-deoxycortisol and progesterone have half-maximal responses (EC50 s) below 1 nM and are potential physiological mineralocorticoids. In contrast, EC50 s for corticosterone and cortisol were 23 nM and 66 nM, respectively. Unexpectedly, truncated lungfish MR, consisting of the DNA-binding, hinge and steroid-binding domains, had a stronger response to corticosteroids and progesterone than full-length lungfish MR, indicating that the N-terminal domain represses steroid activation of lungfish MR, unlike human MR in which the N-terminal domain contains an activation function. BLAST searches of GenBank did not retrieve a GR ortholog, leading us to test dexamethasone and triamcinolone for activation of lungfish MR. At 10 nM, both synthetic glucocorticoids are about 4-fold stronger than 10 nM aldosterone in activating full-length lungfish MR, leading us to propose that lungfish MR also functions as a GR.

Female Reproductive Systems: Hormone Dependence and Receptor Expression

The female reproductive system which consists of the ovaries, uterus (myometrium, endometrium), Fallopian tubes, cervix and vagina is exquisitely sensitive to the actions of steroid hormones. The ovaries play a key role in the synthesis of bioactive steroids (oestrogens, androgens, progestins) that act both within the tissue (intracrine/paracrine) as well as on other reproductive organs following release into the blood stream (endocrine action). Sex steroid receptors encoded by the oestrogen (ESR1, ESR2), progesterone (PR) and androgen (AR) receptor genes, which are members of the superfamily of ligand activated transcription factors are widely expressed within these tissues. These receptors play critical role(s) in regulation of cell proliferation, ovulation, endometrial receptivity, myometrial cell function and inflammatory cell infiltration. Our understanding of their importance has been informed by studies on human tissues and cells, which have employed immunohistochemistry as well as a wide range of molecular and genetic methods to identify which processes are dependent steroid ligand activation. The development of mice with targeted deletions of each of these receptors has provided complementary data that has extended our appreciation of cell-cell interactions in the fine tuning of reproductive tissue function. This large body of work has formed the basis of new and improved therapeutics to treat conditions such as infertility.

Interactions between main protease of SARS-CoV-2 and testosterone or progesterone using computational approach

SARS-CoV-2 is drastically spread across the globe in a short period of time and affects the lives of billions. There is a need to find the promising drugs like candidates against the inhibition of novel corona virus or SARS-CoV-2. Herein, the interaction on sex hormones (testosterone and progesterone) with Mpro of SARS-CoV-2 was investigated with the help of molecular docking. The binding energy for the formation complex between the progesterone and testosterone with main protease of SARS-CoV-2 are -86.05 and -91.84 kcal/mol, respectively. From this, it can be understood that testosterone showed better binding affinity with Mpro of nCoV and thus, more inhibition of the main protease. Then, the binding was further studied using molecular dynamics simulations at different temperatures (300, 310 and 325) K. It has been observed that the formations of complex between the Mpro of nCoV with testosterone/ progesterone is better at 300 K than 310 and 325 K. Further, it is found that the more effective binding of testosterone with Mpro of nCoV is observed than the progesterone based on the RMSD, RMSF and H-bond trajectories. Results indicate the promising nature of testosterone towards the inhibition of Mpro of nCoV.

NR4A1 Affects Endometrial Receptivity by Participating in Mesenchymal-Epithelial Transition of Endometrial Stromal Cells

Decidualization is a substantive differentiation process experienced by endometrium to prepare for pregnancy. During this process, the endometrial stromal cells are transformed to endometrial epithelial cells. The receptivity of endometrium is necessary for the decidualization and successful implantation of endometrium, while the main hormones coordinating this process are estrogen and progesterone (P). In our study, the immunofluorescence, qPCR, and western blot experiments were conducted on different types of clinical endometrial tissue samples. The experimental results show that in the endometrium of normal subjects during the luteal phase, the protein level and serum P4 level of the orphan nuclear receptor NR4A1 messenger RNA were all significantly higher than those of patients with endometriosis or primary infertility, and the two levels presented positive correlation. Through decidualization induction of the human endometrial stromal cells (hESCs) cultured in vitro and additional P treatment, the results of chromatin immunoprecipitation and other experiments show that the P treatment could upregulate the expression of NR4A1 in hESCs, and this process was mediated under the direct effect of progesterone receptor (PR) and NR4A1. When the NR4A1 in hESCs was silenced, the promotion of hESC proliferation by P was inhibited. P and overexpressed NR4A1 increased the expression of epithelial cell marker in decidual hESCs, and qPCR showed that NR4A1's response to P was earlier than that of the epithelial cell marker. The results of spheroid adhesion assay show that the silent NR4A1 had reduced the adhesion of decidual hESCs induced in vitro to embryo. To sum it up, NR4A1 participated in the decidualization process by responding to the P regulation via and by promoting the hESCs' mesenchymal-epithelial transition, so as to further influence the receptivity of endometrium.

What Do We Know about Classical and Non-Classical Progesterone Receptors in the Human Female Reproductive Tract? A Review

The progesterone hormone regulates the human menstrual cycle, pregnancy, and parturition by its action via the different progesterone receptors and signaling pathways in the female reproductive tract. Progesterone actions can be exerted through classical and non-classical receptors, or even a combination of both. The former are nuclear receptors whose activation leads to transcriptional activity regulation and thus in turn leads to slower but long-lasting responses. The latter are composed of progesterone receptors membrane components (PGRMC) and membrane progestin receptors (mPRs). These receptors rapidly activate the appropriate intracellular signal transduction pathways, and they can subsequently initiate specific cell responses or even modulate genomic cell responses. This review covers our current knowledge on the mechanisms of action and the relevance of classical and non-classical progesterone receptors in female reproductive tissues ranging from the ovary and uterus to the cervix, and it exposes their crucial role in female infertility.

Immuno-localization of estrogen receptor (ER) and progesterone receptor (PR) in the buffalo ovary in relation to their plasma hormonal levels

In this study, we examined the tissue distribution of estrogen receptor alpha (ERα) and progesterone receptor (PR) in different compartments of the buffalo ovary during follicular and luteal phases of the estrous cycle. The receptors were localized by immunohistochemistry. Image analysis was done to quantify the immune reactivity. ERα was localized in various cell types of buffalo ovaries differentially during follicular and luteal phases of the estrous cycle. Immunoreactivity of ERα was detected in the primordial, primary, secondary and tertiary follicles, atretic follicles, in cells of the deep and superficial stroma, and the tunica albuginea. Specific immunostaining was observed with anti-ERα antibodies in the nuclei of follicular cells/granulosa cells and theca cells. No reaction was observed in the ovarian surface epithelium. In the growing follicle and secondary follicle, the immunoreaction for these receptors was strong. While in the tertiary follicles weak immunoreactions were recorded in the granulosa cells and theca cells. The progesterone receptors (PR) as revealed by immunohistochemistry were localized in the nuclei of different groups of ovarian cells. It was detected in the primordial, primary, secondary and tertiary follicles, atretic follicles, in cells of the deep and superficial stroma, and the tunica albuginea and surface epithelium. PR was localized in follicular cells of preantral and antral follicles, the stroma of the ovary, endothelial cells of blood vessels. PR positivity was found in one or two granulosa cells of primordial and primary follicles, with moderate immunoreaction, but no staining in oocytes. In the antral follicles, both granulosa cells, as well as theca cells, were immunostained for PR. In the obliterative atretic follicles, the invading stromal cells were highly positive for PR. Follicular cells of the primordial follicle and granulosa cells and theca cells of tertiary follicles had statistically higher percentage positive cells in the follicular phase as compared to the luteal phase. No staining was observed in the negative controls.

Deciphering the Role of PGRMC1 During Human Decidualization Using an In Vitro Approach

CONTEXT

Non-classical membrane progesterone receptor (mPRs) and progesterone receptor membrane component 1 (PGRMC1) expression have been detected in endometrium, but their role in decidualization had not yet been investigated. We previously demonstrated PGRMC1 downregulation in receptive endometrium and that its overexpression inhibits decidualization. Furthermore, during decidualization, PGRMC1 mainly interacts with proteins involved in biosynthesis, intracellular transport, and mitochondrial activity.

OBJECTIVE

To determine PGRMC1 and mPRs signaling role during decidualization.

METHODS

Isolated primary endometrial stromal cells (EnSC) were decidualized in vitro in the presence of classic stimuli (E2 + P4), PGRMC1 inhibitor (AG205), or membrane-impermeable P4 (P4-BSA). Endometrial biopsies were obtained from 19 fertile oocyte donors attending the IVI-Valencia in vitro fertilization (IVF) clinic. EnSC decidualization was evaluated by prolactin ELISA and F-actin immunostaining. Progesterone receptor localization was evaluated by immunofluorescence. EnSC transcriptomic profiles were analyzed by microarray technology.

RESULTS

PGRMC1 inhibition during EnSC decidualization (AG205dEnSC) does not interfere with EnSC cytoskeletal rearrangements and prolactin secretion. However, global transcriptional profiling revealed more differentially expressed genes in AG205dEnSC than in dEnSC, compared with nondecidualized EnSC (ndEnSC). In silico analysis showed that PGRMC1 inhibition upregulated more genes related to metabolism, molecular transport, and hormonal biosynthesis compared with control dEnSC. EnSC decidualized in the presence of P4-BSA showed a similar behavior as ndEnSC in terms of morphological features, absence of prolactin secretion, and transcriptomic pattern.

CONCLUSION

Our findings associate PGRMC1 to hormonal biosynthesis, metabolism, and vesicular transport-important cellular functions for dEnSC supporting pregnancy. Activation of membrane P4 receptor signaling alone was unable to induce downstream effects needed for proper decidualization.

N-terminal domain regulates steroid activation of elephant shark glucocorticoid and mineralocorticoid receptors

Orthologs of human glucocorticoid receptor (GR) and human mineralocorticoid receptor (MR) first appear in cartilaginous fishes. Subsequently, the MR and GR diverged to respond to different steroids: the MR to aldosterone and the GR to cortisol and corticosterone. We report that cortisol, corticosterone and aldosterone activate full-length elephant shark GR, and progesterone, which activates elephant shark MR, does not activate elephant shark GR. However, progesterone inhibits steroid binding to elephant shark GR, but not to human GR. Together, this indicates partial functional divergence of elephant shark GR from the MR. Deletion of the N-terminal domain (NTD) from elephant shark GR (truncated GR) reduced the response to corticosteroids, while truncated and full-length elephant shark MR had similar responses to corticosteroids. Swapping of NTDs of elephant shark GR and MR yielded an elephant shark MR chimera with full-length GR-like increased activation by corticosteroids and progesterone compared to full-length elephant shark MR. Elephant shark MR NTD fused to GR DBD + LBD had similar activation as full-length MR, indicating that the MR NTD lacked GR-like NTD activity. We propose that NTD activation of human GR evolved early in GR divergence from the MR.

Developmental expression of genes involved in progesterone synthesis, metabolism and action during the post-natal cerebellar myelination

Progesterone is involved in dendritogenesis, synaptogenesis and maturation of cerebellar Purkinge cells, major sites of steroid synthesis in the brain. To study a possible time-relationship between myelination, neurosteroidogenesis and steroid receptors during development of the postnatal mouse cerebellum, we determined at postnatal days 5 (P5),18 (P18) and 35 (P35) the expression of myelin basic protein (MBP), components of the steroidogenic pathway, levels of endogenous steroids and progesterone's classical and non-classical receptors. In parallel with myelin increased expression during development, P18 and P35 mice showed higher levels of cerebellar progesterone and its reduced derivatives, higher expression of steroidogenic acute regulatory protein (StAR) mRNA, cholesterol side chain cleavage enzyme (P450scc) and 5α-reductase mRNA vs. P5 mice. Other steroids such as corticosterone and its reduced derivatives and 3β-androstanodiol (ADIOL) showed a peak increase at P18 compared to P5. Progesterone membrane receptors and binding proteins (PGRMC1, mPRα, mPRβ, mPRγ, and Sigma1 receptors) mRNAs levels increased during development while that of classical progesterone receptors (PR) remained invariable. PRKO mice showed similar MBP levels than wild type. Thus, these data suggests that progesterone and its neuroactive metabolites may play a role in postnatal cerebellar myelination.

FSH Promotes Progesterone Synthesis by Enhancing Autophagy to Accelerate Lipid Droplet Degradation in Porcine Granulosa Cells

Little is known about the molecular relationships among follicle stimulating hormone (FSH), lipid droplet (LD) degradation, and autophagy. In this study, we aimed to investigate the pathway by which FSH regulates autophagy and the potential role of autophagy in progesterone production. Our results revealed that FSH stimulated progesterone production in mammalian follicular granulosa cells (GCs) through a non-canonical pathway. In porcine secondary follicles cultured in vitro, FSH treatment increased the level of the autophagic marker, LC3-II, as well as increased the number of autophagic vacuoles in GCs. The underlying molecular mechanism and biological functions were then investigated in porcine GCs. Our results demonstrated that FSH could upregulate Beclin1 levels in porcine GCs; however, this effect was blocked by LY294002 (a PI3K/AKT inhibitor) and SP600125 (SAPK/JNK inhibitor). Further research confirmed that the transcriptional factor, c-Jun, was phosphorylated by FSH, then translocated into the nucleus from the cytoplasm and bound to the BECLIN1 promoter region, and that LY294002, SP600125, or c-Jun knockdown prevented the increase in Beclin1 levels induced by FSH. Interestingly, inhibition of autophagy using chloroquine or SP600125 decreased progesterone production in porcine GCs treated with FSH, although the expression of StAR and P450scc was not disturbed. Moreover, FSH treatment reduced the average number and size of LDs in porcine GCs, but these effects were eliminated by knocking down the key autophagy genes, ATG5 and BECLIN1; in addition, the effect of FSH on promoting progesterone secretion by the cells was also reduced significantly. Based on the above results, we concluded that FSH promoted progesterone production by enhancing autophagy through upregulation of Beclin1 via the PI3K/JNK/c-Jun pathway to accelerate LD degradation in porcine GCs, independent of the classical steroidogenic pathway.

Identification of reproduction-related genes and pathways in the Culter alburnus H-P-G axis and characterization of their expression differences in malformed and normal gynogenetic ovaries

This study applied RNA-seq technology to discover reproduction-related genes and pathways in female topmouth culter brain (including pituitary) and ovarian tissues. In functional analysis, 2479 and 2605 unigenes in the brain and ovary tissue were assigned to the "reproductive process" subcategory in addition to the 2660 and 2845 unigenes assigned to the "reproduction" subcategory. Twenty-three complete cDNA sequences were identified through the different gene expression (DGE) approach from five reproduction-related pathways (MAPK signaling pathway, neuroactive ligand-receptor interaction pathway, gonadotropin-releasing hormone signaling pathway, oocyte meiosis pathway, and steroid biosynthesis pathway). The expression levels of 16 candidate genes using qPCR in this study were in accordance with the results of transcriptome analysis. In addition, the expression levels of the FSH, 3β-HSD, PGR, and NPYR genes in malformed gynogenetic ovaries were considerably low, which was consistent with the progress of oocytogenesis in the ovaries of topmouth culter. The high expression of these four genes in the ovaries of normal topmouth culter suggested they might involve in the preparation for the shift of oogenesis to ovulation. Hence, our work identified a set of annotated gene products that are candidate factors affecting reproduction in the topmouth culter H-P-G axis. These results could be essential for further research in functional genomics and genetic editing for topmouth culter reproduction.

Progesterone Receptor Signaling in the Breast Tumor Microenvironment

The tumor microenvironment (TME) is a complex infrastructure composed of stromal, epithelial, and immune cells embedded in a vasculature ECM. The microenvironment surrounding mammary epithelium plays a critical role during the development and differentiation of the mammary gland, enabling the coordination of the complex multihormones and growth factor signaling processes. Progesterone/progesterone receptor paracrine signaling interactions in the microenvironment play vital roles in stem/progenitor cell function during normal breast development. In breast cancer, the female sex hormones, estrogen and progesterone, and growth factor signals are altered in the TME. Progesterone signaling modulates not only breast tumors but also the breast TME, leading to the activation of a series of cross-communications that are implicated in the genesis of breast cancers. This chapter reviews the evidence that progesterone and PR signaling modulates not only breast epitheliums but also the breast TME. Furthermore, crosstalk between estrogen and progesterone signaling affecting different cell types within the TME is discussed. A better understanding of how PR and progesterone affect the TME of breast cancer may lead to novel drugs or a therapeutic approach for the treatment of breast cancer shortly.

Is sleep deficit associated with infertility and recurrent pregnancy losses? Results from a prospective cohort study

INTRODUCTION

Biological rhythms, the innate cycle of changes in the body's physiological functions, are circadian if they have a 24-hour period. It is known that sleep is a key feature of human circadian rhythm but the relation between sleep and female fertility is largely unknown. This paucity of research is surprising given that circadian rhythms are paramount to human physiology and sleep is related to major female reproductive events. This study was designed to investigate whether there is a difference between the sleep and activity parameters of women with poor reproductive outcome compared with healthy, fertile parous women (comparator group) using subjective (questionnaires) and objective (actigraphy and light exposure) measures.

MATERIAL AND METHODS

A prospective cohort study in a tertiary in vitro fertilization referral center in the UK; composed of three study groups: women diagnosed with recurrent implantation failure, women with recurrent miscarriage (RM) and a comparison group (fertile women without endometrial pathology). Comparison women were selected gynecology patients without endometrial disease (ie perineal complaints or altruistic egg donors). Primary outcome was differences in objective length of sleep in each of the participant groups using actigraphy. Secondary outcomes were subjective sleep quality and quantity, using participant questionnaires, light exposure, and the feasibility of machine learning in activity-pattern interpretation.

RESULTS

Women with recurrent implantation failure slept daily on average for 7 hours 35 minutes (± 57 min), 53 minutes less than the comparison group (P = .03), although quality of their objective sleep, and quantity of their subjective sleep, were not significantly different. Women with recurrent miscarriage slept less that the comparison women (36 minutes less/night) but more than women with recurrent implantation failure (17 minutes more/night). No difference in light exposure was found between recurrent miscarriage and the recurrent implantation failure and comparison groups.

CONCLUSIONS

This study demonstrates an objective observation of sleep time reduction in women with subfertility, although it is not yet clear if this association is casual. Given our increased understanding of the internal body clock and circadian rhythm on fertility, our observation warrants further investigation.

Association of growth hormone (GH), insulin-like growth factor 2 (IGF2) and progesterone receptor (PGR) genes with some productive traits in Gabali rabbits

<p>The objectives of the present study were 1) to evaluate the polymorphism of growth hormone(GH), insulin-like growth factor 2 (IGF2) and progesterone receptor (PGR) genes in Sinai Gabali rabbits, and 2) to assess their associations with growth, litter size and milk production traits in Sinai Gabali rabbits. The C&gt;T, A&gt;Del and A&gt;G single nucleotide polymorphisms of GH, IGF2 and PGR genes were genotyped by polymerase chain reaction-restriction fragment length polymorphism using BstUI, HpyF31 and BsaI restriction enzymes, respectively. The C/T genotype of GH gene recorded the heaviest body weights for body weight (BW) at 8 wk (1190.22±19.29 g) and 12 wk of age (1842.46±30.19 g) and recorded the largest litter size at birth (LSB: 7.37±0.12 kits) traits. The Del/Del genotype of IGF2 gene showed the superiority over the other genotypes for BW at 4 wk (507.17±8.87 g), 8 wk (1239.39±14.0 g), and 12 wk of age (1950.15±18.1 g), as well as for daily weight gain from 4 to 8 wk (26.05±0.37 g/d), and from 8 to 12 wk of age (25.48±0.56 g/d) traits. The G/G genotype of the PGR gene showed superiority for LSB (7.51±0.13 kits) and litter size at weaning (6.53±0.14 kits) traits over the other genotypes. Regarding milk yield traits; the C/C, A/A and A/A genotypes of GH, IGF2 and PGR genes yielded more milk compared to the other genotypes. The means of total milk yield in 28 d for these genotypes were 2936±29 g, 2921±43 g and 2930±35 g, respectively. Thus, GH, IGF2 and PGR genes might be useful for marker-assisted selection programmes for improvement of rabbit growth, litter size and milk yield traits.</p>

Classical and Non-Classical Progesterone Signaling in Breast Cancers

Much emphasis is placed on estrogen (E2) and estrogen receptor (ER) signaling as most research is focused on understanding E2 and ER’s ability to enhance proliferative signals in breast cancers. Progesterone (P4) is important for normal mammary gland development, function and menstrual control. However, P4 and its receptors (PRs) in breast cancer etiology continue to be understudied and its role in breast cancer remains controversial. The Women’s Health Initiative (WHI) clinical trial clearly demonstrated the importance of progestogens in breast cancer development. P4 has historically been associated with classical-signaling through nuclear receptors, however non-classical P4 signaling via membrane receptors has been described. Progestogens have the ability to bind to nuclear and membrane receptors and studies have demonstrated that both can promote breast cancer cell proliferation and breast tumor growth. In this review, we attempt to understand the classical and non-classical signaling role of P4 in breast cancers because both nuclear and membrane receptors could become viable therapeutic options for breast cancer patients.

The effects of progesterone treatment on nuchal translucency in women with threatened miscarriage

This study aims to investigate the effects of progesterone on the possible changes in nuchal translucency (NT) levels for patients diagnosed with threatened miscarriage. The study group was composed of 125 patients diagnosed with threatened miscarriage and taking 400 mg/day micronized orally progesterone at least for two weeks, the control group was composed of 160 healthy pregnant women not taking any progesterone. Crown rump length (CRL) NT thickness, Pregnancy-associated plasma protein-A (PAPP-A), free beta human chorionic gonadotropin (Beta-HCG) levels of patients were measured for assessment of aneuploidy risk. Both of the groups were divided into four subgroups to determine the relationship between thickness of NT and progesterone use for specific CRL measurements. CRL in the first, second, third and fourth group was 45-55 mm, 55-65 mm, 65-75 mm, 75-84 mm, respectively. The two groups were age and BMI matched. In all groups of CRL there were no significant difference in Mom levels of NT thickness, PAPP-A and free Beta-HCG between the study and control groups. There havent been any relation between NT thickness and progesterone use.IMPACT STATEMENTWhat is already known about this subject? Recently some studies have claimed that progesterone use might have caused atypical blood flow pattern on foetal circulation, which could possibly increase NT. If the NT thickness is affected by the use of progesterone, then the false positive rate of detecting Down Syndrome screening tests would increase.What the results of this study add? In this study we did not found any relation between NT thickness and progesterone use.What the implications are of these findings for clinical practice and/or further research? Using orally progesterone due to threatened miscarriage do not change NT thickness levels. Further studies have to be done with a large number of participants.

Protective effect of the NAC and Sal on zinc oxide nanoparticles-induced reproductive and development toxicity in pregnant mice

The growing use of zinc oxide nanoparticles (ZnO NPs) in various applications has raised many concerns about the potential risks to human health. In this research, the protective effects of cellular oxidative stress inhibitor N-Acetyl-cysteine (NAC) and endoplasmic reticulum (ER) stress inhibitor Salubrinal (Sal) on reproductive toxicity induced by ZnO NPs were investigated. The results showed that application of these two kinds of cell stress inhibitors after oral ingestion of ZnO NPs could prevent the weight loss of pregnant mice; reduce zinc content in the uterus, placenta and fetus; reduce abnormal development of the offspring; and decrease fetal abortion. Furthermore, RT-qPCR, Western blot and immunofluorescence assay results indicated that NAC restored the expression of Gclc, reduced the expression of ATF4, JNK and Caspase-12, and decreased the expression of eNOS and IGF-1, in the placenta. Sal decreased the expression of ATF4, JNK and Caspase-12, and increased the expression of eNOS and IGF-1caused by the oral ingestion of ZnO NPs. These results indicated that treatment with NAC and Sal after oral exposure could reduce reproductive and development toxicity caused by ZnO NPs which induced reproductive and development toxicity that was probably caused by the activation of oxide stress and ER stress.

GFP expression pattern in pituitary and gonads under the control of nuclear progesterone receptor promoter in transgenic zebrafish

BACKGROUND

The nuclear progesterone receptor (Pgr) is a ligand-dependent transcription factor primarily responsible for mediating progesterone actions relevant for reproduction across vertebrates. Information on the cellular localization of Pgr expression in the reproductive system is required for developing a comprehensive approach to elucidate the role of Pgr in reproduction.

RESULTS

We generated transgenic zebrafish Tg(pgr:eGFP) that express enhanced green fluorescent protein (eGFP) driven by promoter sequence of pgr gene. The tissue distribution pattern of egfp mRNA is consistent with the pgr mRNA expression in Tg(pgr:eGFP). In the pituitary, GFP signals are found in the proximal pars distalis. In order to better discern the cellular localization of GFP signals in gonads, Tg(pgr:eGFP) line was crossed with Tg(gsdf:nfsB-mCherry) line, specifically expressing nitroreductase-mCherry fusion protein in granulosa and Sertoli cells in ovary and testis, respectively. Imaging of testis tissue showed that GFP expression was confined to Leydig cells. In the ovary, GFP expression colocalized with the mCherry signal in granulosa cells. Intriguingly, we also identified some non-granulosa cells close to where blood vessels branched, expressing stronger GFP signals than granulosa cells.

CONCLUSIONS

Analyzing Tg(pgr:eGFP) expression in zebrafish provided leads toward new routes to study the role of Pgr in reproduction.

Spring and Fall recrudescence in Podarcis siculus ovaries: A role for progesterone

In the lacertid Podarcis siculus the reproductive cycle is typically biphasic, with alternate recrudescence (Spring and Fall) and resting (Summer and Winter) phases. This study aimed to shed some light on the role exerted by progesterone during the two recrudescence periods; to this purpose, exogenous progesterone was administered intraperitoneally and the effects on oogonial proliferation, oocyte recruitment, and follicle cells apoptosis were determined. The presence and distribution of progesterone receptors was also investigated by immunohistochemistry and western blotting. Results indicate that progesterone would play different roles and follow different route of action in the two recrudescence periods thus confirming the complexity of the mechanisms controlling oogenesis in this species of vertebrate.

Progesterone: An enigmatic ligand for the mineralocorticoid receptor

The progesterone receptor (PR) mediates progesterone regulation of female reproductive physiology, as well as gene transcription in non-reproductive tissues, such as brain, bone, lung and vasculature, in both women and men. An unusual property of progesterone is its high affinity for the mineralocorticoid receptor (MR), which regulates electrolyte transport in the kidney in humans and other terrestrial vertebrates. In humans, rats, alligators and frogs, progesterone antagonizes activation of the MR by aldosterone, the physiological mineralocorticoid in terrestrial vertebrates. In contrast, in elephant shark, ray-finned fishes and chickens, progesterone activates the MR. Interestingly, cartilaginous fishes and ray-finned fishes do not synthesize aldosterone, raising the question of which steroid(s) activate the MR in cartilaginous fishes and ray-finned fishes. The simpler synthesis of progesterone, compared to cortisol and other corticosteroids, makes progesterone a candidate physiological activator of the MR in elephant sharks and ray-finned fishes. Elephant shark and ray-finned fish MRs are expressed in diverse tissues, including heart, brain and lung, as well as, ovary and testis, two reproductive tissues that are targets for progesterone, which together suggests a multi-faceted physiological role for progesterone activation of the MR in elephant shark and ray-finned fish. The functional consequences of progesterone as an antagonist of some terrestrial vertebrate MRs and as an agonist of fish and chicken MRs are not fully understood. The physiological activities of progesterone through binding to vertebrate MRs merits further investigation.

Immunohistochemical localization of progesterone receptors alpha (PRA) in ovary of the pseudopregnant rabbit

Progesterone plays an important role in the reproductive function and follicular development in mammals. The aim of the present study was to examine the localization of progesterone receptor alpha (PRA) in ovary of pseudopregnant rabbit by immunohistochemical methods. Samples were collected from 14 h. to 18 days of pseudopregnancy. At the first stage of pseudopregnancy (14 h.), the rabbit ovary showed moderate immunostaining of PRA in the granulosa cells and theca interna cells of preovulatory follicle and in the stroma cells. At the middle stage of pseudopregnancy (3-7 days), the rabbit ovary showed strong immunostaining of PRA in ovarian surface epithelial cells, follicular cells of the primary follicle, granulosa cells and theca interna cells of the growing and antral follicles. Moderate immunoexpression of PRA were observed in the large lutein cells and endothelial cells of the corpus haemorrhagicum and corpus luteum and in the stroma cells. At the end of pseudopregnancy (18 days) strong PRA reactions were detected in the small lutein cells of the regressed corpus luteum. Moderate to strong PRA immuno-expression were observed in the proliferated theca interna cells of the atretic antral follicles. The atretic large lutein cells of the regressed corpus luteum showed negative immunostaining for PRA. This study showed that the PRA positive small lutein cells of the regressed corpus luteum and the PRA positive proliferated theca interna cells of the atretic antral follicles were transformed into PRA positive interstitial gland cells. In conclusion, the present study had described the distribution of PRA in the ovary of pseudopregnant rabbit, which is not discussed before in the available literature. It also gives more information about follicular dynamic, formation and origin of interstitial glands, mechanism of ovulation, formation and regression of the corpus luteum.

Steroid receptors and vertebrate evolution

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

Uterine Gαq/11 signaling, in a progesterone-dependent manner, critically regulates the acquisition of uterine receptivity in the female mouse

A nonreceptive uterus is a major cause of embryo implantation failure. This study examined the importance of the Gαq/11-coupled class of GPCRs as regulators of uterine receptivity. Mice were created lacking uterine Gαq and Gα11; as a result, signaling by all uterine Gαq/11-coupled receptors was disrupted. Reproductive profiling of the knockout females revealed that on d 4 of pregnancy, despite adequate serum progesterone (P4) levels and normal P4 receptor (PR) expression, there was no evidence of PR signaling. This resulted in the down-regulation of heart and neural crest derivatives expressed 2, Kruppel-like factor 15, and cyclin G1 and the subsequent persistent proliferation of the luminal epithelium. Aquaporin (Aqp) 11 was also potently down-regulated, whereas Aqp5/AQP5 expression persisted, resulting in the inhibition of luminal closure. Hypertrophy of the myometrial longitudinal muscle was also dramatically diminished, likely contributing to the observed implantation failure. Further analyses revealed that a major mechanism via which uterine Gαq/11 signaling induces PR signaling is through the transcriptional up-regulation of leucine-rich repeat-containing GPCR 4 (Lgr4). LGR4 was previously identified as a trigger of PR activation and signaling. Overall, this study establishes that Gαq/11 signaling, in a P4-dependent manner, critically regulates the acquisition of uterine receptivity in the female mouse, and disruption of such signaling results in P4 resistance.-de Oliveira, V., Schaefer, J., Calder, M., Lydon, J. P., DeMayo, F. J., Bhattacharya, M., Radovick, S., Babwah, A. V. Uterine Gαq/11 signaling, in a progesterone-dependent manner, critically regulates the acquisition of uterine receptivity in the female mouse.

Transcriptional activation of elephant shark mineralocorticoid receptor by corticosteroids, progesterone, and spironolactone

The mineralocorticoid receptor (MR) is a nuclear receptor and part of a large and diverse family of transcription factors that also includes receptors for glucocorticoids, progesterone, androgens, and estrogens. The corticosteroid aldosterone is the physiological activator of the MR in humans and other terrestrial vertebrates; however, its activator is not known in cartilaginous fish, the oldest group of extant jawed vertebrates. Here, we analyzed the ability of corticosteroids and progesterone to activate the full-length MR from the elephant shark (Callorhinchus milii). On the basis of their measured activities, aldosterone, cortisol, 11-deoxycorticosterone, corticosterone, 11-deoxcortisol, progesterone, and 19-norprogesterone are potential physiological mineralocorticoids. However, aldosterone, the physiological mineralocorticoid in humans and other terrestrial vertebrates, is not found in cartilaginous or ray-finned fish. Although progesterone activates MRs in ray-finned fish, progesterone does not activate MRs in humans, amphibians, or alligator, suggesting that during the transition to terrestrial vertebrates, progesterone lost the ability to activate the MR. Both elephant shark MR and human MR are expressed in the brain, heart, ovary, testis, and other nonepithelial tissues, suggesting that MR expression in diverse tissues evolved in the common ancestor of jawed vertebrates. Our data suggest that 19-norprogesterone– and progesterone-activated MR may have unappreciated functions in reproductive physiology.

Ovulation: Parallels With Inflammatory Processes

The midcycle surge of LH sets in motion interconnected networks of signaling cascades to bring about rupture of the follicle and release of the oocyte during ovulation. Many mediators of these LH-induced signaling cascades are associated with inflammation, leading to the postulate that ovulation is similar to an inflammatory response. First responders to the LH surge are granulosa and theca cells, which produce steroids, prostaglandins, chemokines, and cytokines, which are also mediators of inflammatory processes. These mediators, in turn, activate both nonimmune ovarian cells as well as resident immune cells within the ovary; additional immune cells are also attracted to the ovary. Collectively, these cells regulate proteolytic pathways to reorganize the follicular stroma, disrupt the granulosa cell basal lamina, and facilitate invasion of vascular endothelial cells. LH-induced mediators initiate cumulus expansion and cumulus oocyte complex detachment, whereas the follicular apex undergoes extensive extracellular matrix remodeling and a loss of the surface epithelium. The remainder of the follicle undergoes rapid angiogenesis and functional differentiation of granulosa and theca cells. Ultimately, these functional and structural changes culminate in follicular rupture and oocyte release. Throughout the ovulatory process, the importance of inflammatory responses is highlighted by the commonalities and similarities between many of these events associated with ovulation and inflammation. However, ovulation includes processes that are distinct from inflammation, such as regulation of steroid action, oocyte maturation, and the eventual release of the oocyte. This review focuses on the commonalities between inflammatory responses and the process of ovulation.