Alterations in the expression, structure and function of progesterone receptor membrane component-1 (PGRMC1) in premature ovarian failure

Pleiotropy of Progesterone Receptor Membrane Component 1 in Modulation of Cytochrome P450 Activity

Progesterone receptor membrane component 1 (PGRMC1) is one of few proteins that have been recently described as direct modulators of the activity of human cytochrome P450 enzymes (CYP)s. These enzymes form a superfamily of membrane-bound hemoproteins that metabolize a wide variety of physiological, dietary, environmental, and pharmacological compounds. Modulation of CYP activity impacts the detoxification of xenobiotics as well as endogenous pathways such as steroid and fatty acid metabolism, thus playing a central role in homeostasis. This review is focused on nine main topics that include the most relevant aspects of past and current PGRMC1 research, focusing on its role in CYP-mediated drug metabolism. Firstly, a general overview of the main aspects of xenobiotic metabolism is presented (I), followed by an overview of the role of the CYP enzymatic complex (IIa), a section on human disorders associated with defects in CYP enzyme complex activity (IIb), and a brief account of cytochrome b5 (cyt b5)'s effect on CYP activity (IIc). Subsequently, we present a background overview of the history of the molecular characterization of PGRMC1 (III), regarding its structure, expression, and intracellular location (IIIa), and its heme-binding capability and dimerization (IIIb). The next section reflects the different effects PGRMC1 may have on CYP activity (IV), presenting a description of studies on the direct effects on CYP activity (IVa), and a summary of pathways in which PGRMC1's involvement may indirectly affect CYP activity (IVb). The last section of the review is focused on the current challenges of research on the effect of PGRMC1 on CYP activity (V), presenting some future perspectives of research in the field (VI).

Review: The putative role of Progesterone Receptor membrane Component 1 in bovine oocyte development and competence

Acquisition of developmental competence is a complex process in which many cell types cooperate to support oocyte maturation, fertilisation, and preimplantation embryonic development. In recent years, compelling evidence has shown that Progesterone Receptor Membra Component 1 (PGRMC1) is expressed in many cell types of the mammalian reproductive system where it exerts diverse functions. In the ovary, PGRMC1 affects follicular growth by controlling cell viability and proliferation of granulosa cells. PGRMC1 has also a direct role in promoting a proper completion of bovine oocyte maturation, as altering its function leads to defective chromosome segregation and polar body extrusion. Strikingly, the mechanism by which PGRMC1 controls mitotic and meiotic cell division seems to be conserved, involving an association with the spindle apparatus and the chromosomal passenger complex through Aurora kinase B. Conclusive data on a possible role of PGRMC1 in the preimplantation embryo are lacking and further research is needed to test whether the mechanisms that are set in place in mitotic cells also govern blastomere cleavage and subsequent differentiation. Finally, PGRMC1 is also expressed in oviductal cells and, as such, it might also impact fertilisation and early embryonic development, although this issue is completely unexplored. However, the study of PGRMC1 function in the mammalian reproductive system remains a complex matter, due to its pleiotropic function.

Chromosomal abnormalities detected by karyotyping among patients with secondary amenorrhea: a retrospective study

BACKGROUND

Chromosomal abnormalities (CAs) have been described in patients with secondary amenorrhea (SA). However, studies on this association are scarce.

OBJECTIVES

To evaluate the frequency and types of CAs detected by karyotyping in patients with SA.

DESIGN AND SETTING

This retrospective study was performed in a reference clinical genetic service in South Brazil.

METHODS

Data were obtained from the medical records of patients with SA who were evaluated between 1975 and 2022. Fisher's bicaudate exact test and Student's t-test were used, and P < 0.05 was considered significant.

RESULTS

Among 43 patients with SA, 14 (32.6%) had CAs, namely del (Xq) (n = 3), 45,X (n = 2), 46,X,r(X)/45,X (n = 2), 46,XX/45,X (n = 1), 46,X,i(q10)/45,X (n = 1), 47,XXX (n = 1), 46,XX/47,XXX (n = 1), 46,XX/47,XX,+mar (n = 1), 45,XX,trob(13;14)(q10;q10)/46,XXX,trob(13;14)(q10;q10) (n = 1), and 46,XX,t(2;21)(q23;q11.2) (n = 1). Additional findings were observed mostly among patients with CA compared with those without CA (P = 0.0021). No difference in the mean age was observed between the patients with SA with or without CAs (P = 0.268025).

CONCLUSIONS

CAs are common among patients with SA, especially those with short stature and additional findings. They are predominantly structural, involve the X chromosome in a mosaic, and are compatible with the Turner syndrome. Patients with SA, even if isolated, may have CAs, particularly del (Xq) and triple X.

Ovarian dysfunction in women with Turner syndrome

Ovarian dysfunction is one of the most common features of women with Turner syndrome. In these women, oocyte apoptosis is markedly accelerated from the early stage of fetal life. Reduction in the number of germ cells disturbs primordial follicle development and thereby leads to the formation of streak gonads. There are three possible causes of accelerated germ cell loss in 45,X ovaries. First, chromosomal pairing failure due to X chromosomal aneuploidy is believed to induce meiotic arrest. Indeed, it has been suggested that the dosage of the X chromosome is more critical for the survival of the oocytes than for other cells in the ovary. Second, impaired coupling between oocytes and granulosa cells may also contribute to germ cell apoptosis. Previous studies have shown that 45,X ovaries may tend to lose tight junctions which are essential for intercellular interactions. Lastly, ovarian dysfunction in women with Turner syndrome is partly attributable to the reduced dosage of several genes on the X chromosome. Specifically, BMP15, PGRMC1, and some other genes on the X chromosome have been implicated in ovarian function. Further studies on the mechanisms of ovarian dysfunction are necessary to improve the reproductive outcomes of women with Turner syndrome.

Membrane-Initiated Estrogen, Androgen, and Progesterone Receptor Signaling in Health and Disease

Rapid effects of steroid hormones were discovered in the early 1950s, but the subject was dominated in the 1970s by discoveries of estradiol and progesterone stimulating protein synthesis. This led to the paradigm that steroid hormones regulate growth, differentiation, and metabolism via binding a receptor in the nucleus. It took 30 years to appreciate not only that some cellular functions arise solely from membrane-localized steroid receptor (SR) actions, but that rapid sex steroid signaling from membrane-localized SRs is a prerequisite for the phosphorylation, nuclear import, and potentiation of the transcriptional activity of nuclear SR counterparts. Here, we provide a review and update on the current state of knowledge of membrane-initiated estrogen (ER), androgen (AR) and progesterone (PR) receptor signaling, the mechanisms of membrane-associated SR potentiation of their nuclear SR homologues, and the importance of this membrane-nuclear SR collaboration in physiology and disease. We also highlight potential clinical implications of pathway-selective modulation of membrane-associated SR.

Pleiotropic Actions of PGRMC Proteins in Cancer

Progesterone receptor membrane component (PGRMC) proteins play important roles in tumor growth, progression, and chemoresistance, of which PGRMC1 is the best characterized. The ancestral member predates the evolution of metazoans, so it is perhaps not surprising that many of the purported actions of PGRMC proteins are rooted in fundamental metabolic processes such as proliferation, apoptosis, and DNA damage responses. Despite mediating some of the actions of progesterone (P4) and being fundamentally required for female fertility, PGRMC1 and PGRMC2 are broadly expressed in most tissues. As such, these proteins likely have both progesterone-dependent and progesterone-independent functions. It has been proposed that PGRMC1 acquired the ability to mediate P4 actions over evolutionary time through acquisition of its cytochrome b5-like heme/sterol-binding domain. Diverse reproductive and nonreproductive diseases associate with altered PGRMC1 expression, epigenetic regulation, or gene silencing mechanisms, some of which include polycystic ovarian disease, premature ovarian insufficiency, endometriosis, Alzheimer disease, and cancer. Although many studies have been completed using transformed cell lines in culture or in xenograft tumor approaches, recently developed transgenic model organisms are offering new insights in the physiological actions of PGRMC proteins, as well as pathophysiological and oncogenic consequences when PGRMC expression is altered. The purpose of this mini-review is to provide an overview of PGRMC proteins in cancer and to offer discussion of where this field must go to solidify PGRMC proteins as central contributors to the oncogenic process.

Progesterone Signaling and Mammalian Ovarian Follicle Growth Mediated by Progesterone Receptor Membrane Component Family Members

How progesterone influences ovarian follicle growth is a difficult question to answer because ovarian cells synthesize progesterone and express not only the classic nuclear progesterone receptor but also members of the progestin and adipoQ receptor family and the progesterone receptor membrane component (PGRMC) family. Which type of progestin receptor is expressed depends on the ovarian cell type as well as the stage of the estrous/menstrual cycle. Given the complex nature of the mammalian ovary, this review will focus on progesterone signaling that is transduced by PGRMC1 and PGRMC2 specifically as it relates to ovarian follicle growth. PGRMC1 was identified as a progesterone binding protein cloned from porcine liver in 1996 and detected in the mammalian ovary in 2005. Subsequent studies focused on PGRMC family members as regulators of granulosa cell proliferation and survival, two physiological processes required for follicle development. This review will present evidence that demonstrates a causal relationship between PGRMC family members and the promotion of ovarian follicle growth. The mechanisms through which PGRMC-dependent signaling regulates granulosa cell proliferation and viability will also be discussed in order to provide a more complete understanding of our current concept of how progesterone regulates ovarian follicle growth.

Estimates of global research productivity in primary ovarian insufficiency from 2000 to 2021: Bibliometric analysis

BACKGROUND

Primary ovarian insufficiency (POI) is a heterogeneous disease with diverse clinical phenotypes and etiologies, which is defined as ovarian dysfunction under the age of 40 years. The global prevalence of POI is approximately about 1.1%, and it severely affects female fertility. Nevertheless, bibliometric analysis in this field is extremely limited. We aimed to visualize the research hotspots and trends of POI using bibliometric analysis and tried to predict the future development of this field.

METHODS

The original articles regarding POI were culled from the Web of Science Core Collection. Countries, institutions, journals, authors, and keywords in this field were visually analyzed by employing CiteSpace software and Microsoft Excel 2021 software.

RESULTS

A total of 2,999 publications were included for further bibliometric analysis after screening the titles and abstracts stringently. The number of literature regarding POI significantly increased yearly. These publications come from 78 countries. The USA was dominant in the field of POI in terms of the number of publications (865), average citations per item (57.36), and h-index (112). The Institut National De La Sante Et De La Recherche Medicale Inserm is the most high-yield institution in this field with 351 publications. Fertility and Sterility ranked first with the highest number of publications (152), followed by Human Reproduction (138). According to the keyword cluster analysis from 2000 to 2021, the eight keyword clusters encountered frequently were apoptosis, osteoporosis, fertility preservation, mutation, fragile x syndrome, adrenal insufficiency, DNA repair, ovarian reserve. Keyword citation burst analysis revealed that whole-exome sequencing, ovarian tissue cryopreservation, and DNA repair had a citation burst until 2021.

CONCLUSIONS

Great progress has been made in POI research over the past 20 years, which is widely researched but unevenly developed in the world. In terms of influence, the United States may be in the lead. The research hotspots in POI are mainly pathogenesis and treatment, including genetic mutation, hormone therapy, fertility preservation, and stem cell transplantation.

Genetics of ovarian insufficiency and defects of folliculogenesis

Primary ovarian insufficiency (POI) is determined by exhaustion of follicles in the ovaries, which leads to infertility before the age of 40 years. It is characterized by a strong familial and heterogeneous genetic background. Therefore, we will mainly discuss the genetic basis of POI in this review. We identified 107 genes related to POI etiology in mammals described by several independent groups. Thirty-four of these genes (AARS2, AIRE, ANTXR1, ATM, BMPR1B, CLPP, CYP17A1, CYP19A1, DCAF17, EIF2B, ERAL1, FANCA, FANCC, FMR1, FOXL2, GALT, GNAS, HARS2, HSD17B4, LARS2, LMNA, MGME1, NBN, PMM2, POLG, PREPL, RCBTB1, RECQL2/3/4, STAR, TWNK, and XRCC4/9) have been linked to syndromic POI and are mainly implicated in metabolism function and meiosis/DNA repair. In addition, the majority of genes associated with nonsyndromic POI, widely expanded by high-throughput techniques over the last decade, have been implicated in ovarian development and meiosis/DNA repair pathways (ATG7, ATG9, ANKRD31, BMP8B, BMP15, BMPR1A, BMPR1B, BMPR2, BNC1, BRCA2, CPEB1, C14ORF39, DAZL, DIAPH2, DMC1, ERCC6, FANCL, FANCM, FIGLA, FSHR, GATA4, GDF9, GJA4, HELQ, HSF2BP, HFM1, INSL3, LHCGR, LHX8, MCM8, MCM9, MEIOB, MSH4, MSH5, NANOS3, NOBOX, NOTCH2, NR5A1, NUP107, PGRMC1, POLR3H, PRDM1, PRDM9, PSMC3IP, SOHLH1, SOHLH2, SPIDR, STAG3, SYCE1, TP63, UBR2, WDR62, and XRCC2), whereas a few are related to metabolic functions (EIF4ENIF1, KHDRBS1, MRPS22, POLR2C). Some genes, such as STRA8, FOXO3A, KIT, KITL, WNT4, and FANCE, have been shown to cause ovarian insufficiency in rodents, but mutations in these genes have yet to be elucidated in women affected by POI. Lastly, some genes have been rarely implicated in its etiology (AMH, AMHR2, ERRC2, ESR1, INHA, LMN4, POF1B, POU5F1, REC8, SMC1B). Considering the heterogeneous genetic and familial background of this disorder, we hope that an overview of literature data would reinforce that genetic screening of those patients is worthwhile and helpful for better genetic counseling and patient management.

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.

Genomic Consideration in Chemotherapy-Induced Ovarian Damage and Fertility Preservation

Chemotherapy-induced ovarian damage and fertility preservation in young patients with cancer are emerging disciplines. The mechanism of treatment-related gonadal damage provides important information for targeting prevention methods. The genomic aspects of ovarian damage after chemotherapy are not fully understood. Several studies have demonstrated that gene alterations related to follicular apoptosis or accelerated follicle activation are related to ovarian insufficiency and susceptibility to ovarian damage following chemotherapy. This may accelerate follicular apoptosis and follicle reservoir utilization and damage the ovarian stroma via multiple molecular reactions after chemotherapy. This review highlights the importance of genomic considerations in chemotherapy-induced ovarian damage and multidisciplinary oncofertility strategies for providing high-quality care to young female cancer patients.

Premature ovarian insufficiency - the need for a genomic map

Premature ovarian insufficiency (POI) is a life-long disorder of heterogeneous etiology, presenting as adolescent primary amenorrhea in its most severe form, with an overall incidence of 1%. Idiopathic POI accounts for up to 70% of women with POI; and genomic, genetic, epidemiological, familial and cohort studies demonstrate a genetic component to this condition. Currently, the only genetic tests routinely performed in non-syndromic POI are FMR1 premutation and cytogenetics, the latter specifically for X-chromosome abnormalities. However, a myriad of genetic aberrations has been identified and implicated, some of which act in a monogenic Mendelian fashion. The presence of multiple genetic aberrations and the complexity of POI genomics are hardly surprising since the embryological formation of the primordial oocyte pool, postnatal oogenesis and folliculogenesis are all highly complex pathways. With this review, the aim is to discuss the current genetic etiologies in the emerging field of POI genomics. Promising candidate genes include STAG3, SYCE1, FIGLA, NOBOX, FSHR, BMP15 and INHA. This area has the potential to progress rapidly in light of advances in genomic technologies. The development of a POI genomic map not only will assist in understanding the underlying molecular mechanisms affecting ovarian function but will also be essential in designing predictive and diagnostic gene panels as well as future novel therapeutic strategies.

A kaleidoscopic view of ovarian genes associated with premature ovarian insufficiency and senescence

Ovarian infertility and subfertility presenting with premature ovarian insufficiency (POI) and diminished ovarian reserve are major issues facing the developed world due to the trend of delaying childbirth. Ovarian senescence and POI represent a continuum of physiological/pathophysiological changes in ovarian follicle functions. Based on advances in whole exome sequencing, evaluation of gene copy variants, together with family-based and genome-wide association studies, we discussed genes responsible for POI and ovarian senescence. We used a gene-centric approach to sort out literature deposited in the Ovarian Kaleidoscope database (http://okdb.appliedbioinfo.net) by sub-categorizing candidate genes as ligand-receptor signaling, meiosis and DNA repair, transcriptional factors, RNA metabolism, enzymes, and others. We discussed individual gene mutations found in POI patients and verification of gene functions in gene-deleted model organisms. Decreased expression of some of the POI genes could be responsible for ovarian senescence, especially those essential for DNA repair, meiosis and mitochondrial functions. We propose to set up a candidate gene panel for targeted sequencing in POI patients together with studies on mitochondria-associated genes in middle-aged subfertile patients.

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.

Onco-fertility and personalized testing for potential for loss of ovarian reserve in patients undergoing chemotherapy: proposed next steps for development of genetic testing to predict changes in ovarian reserve

Women of reproductive age undergoing chemotherapy face the risk of irreversible ovarian insufficiency. Current methods of ovarian reserve testing do not accurately predict future reproductive potential for patients undergoing chemotherapy. Genetic markers that more accurately predict the reproductive potential of each patient undergoing chemotherapy would be critical tools that would be useful for evidence-based fertility preservation counselling. To assess the possible approaches to take to develop personalized genetic testing for these patients, we review current literature regarding mechanisms of ovarian damage due to chemotherapy and genetic variants associated with both the damage mechanisms and primary ovarian insufficiency. The medical literature point to a number of genetic variants associated with mechanisms of ovarian damage and primary ovarian insufficiency. Those variants that appear at a higher frequency, with known pathways, may be considered as potential genetic markers for predictive ovarian reserve testing. We propose developing personalized testing of the potential for loss of ovarian function for patients with cancer, prior to chemotherapy treatment. There are advantages of using genetic markers complementary to the current ovarian reserve markers of AMH, antral follicle count and day 3 FSH as predictors of preservation of fertility after chemotherapy. Genetic markers will help identify upstream pathways leading to high risk of ovarian failure not detected by present clinical markers. Their predictive value is mechanism-based and will encourage research towards understanding the multiple pathways contributing to ovarian failure after chemotherapy.

Next Generation Sequencing Should Be Proposed to Every Woman With "Idiopathic" Primary Ovarian Insufficiency

Context

Primary ovarian insufficiency (POI) affects 1% of women under 40 years of age. POI is idiopathic in more than 70% of cases. Though many candidate genes have been identified in recent years, the prevalence and pathogenicity of abnormalities are still difficult to establish.

Objective

Our primary objective was to evaluate the prevalence of gene variations in a large prospective multicentric POI cohort. Our secondary objective was to evaluate the correlation between phenotype and genotype.

Methods

Two hundred and sixty-nine well-phenotyped POI patients were screened for variants of 18 known POI genes (BMP15, DMC1, EIF2S2, FIGLA, FOXL2, FSHR, GDF9, GPR3, HFM1, LHX8, MSH5, NOBOX, NR5A1, PGRMC1, STAG3, XPNPEP2, BHLB, and FSHB) by next generation sequencing (NGS). Abnormalities were classified as "variant" or "variant of unknown signification" (VUS) according to available functional tests or algorithms (SIFT, Polyphen-2, MutationTaster).

Results

One hundred and two patients (38%) were identified as having at least 1 genetic abnormality. Sixty-seven patients (25%) presented at least 1 variant. Forty-eight patients presented at least 1 VUS (18%). Thirteen patients (5%) had combined abnormalities. NOBOX variants were the most common gene variants involved in POI (9%). Interestingly, we saw no significant differences in the previous family history of POI, ethnic origin, age at onset of POI, primary amenorrhea, or secondary menstrual disturbances between the different genotypes.

Conclusion

In our study, a high percentage of patients presented gene variants detected by NGS analysis (38%). Every POI patient should undergo NGS analysis to improve medical cares of the patients.

Evaluation of Expression and Phosphorylation of Progesterone Receptor in Endometrial Stromal Cells of Patients with Recurrent Implantation Failure Compared to Healthy Fertile Women

Recurrent implantation failure (RIF) is the repeated failure of good-quality embryos in implantation process following several assisted reproduction cycles. Disruption of the endometrial receptivity is one of the main causes of RIF. Progesterone plays a pivotal role in the endometrial receptivity through the regulation of gene expression pattern by binding to its receptors in the endometrial cells. The aim of this study was to evaluate the expression level of progesterone receptor (PR) and its phosphorylated form in the endometrial stromal cells (eSC) of RIF patients and compare it to the eSC of healthy fertile women as control group. After isolation of the eSC from biopsy samples of RIF patients and healthy fertile women and their characterization, expression levels of PR mRNA, PR protein, and phospho-Ser294 PR protein were evaluated by quantitative real-time PCR and immunofluorescence staining, respectively. The results demonstrated a significant reduction in PR mRNA expression (P < 0.01.) and phospho-Ser294 PR protein (P < 0.05) level in RIF patients compared to the control group. These data for the first time suggest that the expression of PR and its phosphorylated form are impaired in RIF patients. Therefore, designing therapeutic methods for improving PR expression status and its regulation in the endometrium of RIF patients may help in improving the final reproductive outcomes of these cases.

Progesterone receptor membrane component 1 regulates lipid homeostasis and drives oncogenic signaling resulting in breast cancer progression

Background

PGRMC1 (progesterone receptor membrane component 1) is a highly conserved heme binding protein, which is overexpressed especially in hormone receptor-positive breast cancer and plays an important role in breast carcinogenesis. Nevertheless, little is known about the mechanisms by which PGRMC1 drives tumor progression. The aim of our study was to investigate the involvement of PGRMC1 in cholesterol metabolism to detect new mechanisms by which PGRMC1 can increase lipid metabolism and alter cancer-related signaling pathways leading to breast cancer progression.

Methods

The effect of PGRMC1 overexpression and silencing on cellular proliferation was examined in vitro and in a xenograft mouse model.

Next, we investigated the interaction of PGRMC1 with enzymes involved in the cholesterol synthesis pathway such as CYP51, FDFT1, and SCD1. Further, the impact of PGRMC1 expression on lipid levels and expression of enzymes involved in lipid homeostasis was examined. Additionally, we assessed the role of PGRMC1 in key cancer-related signaling pathways including EGFR/HER2 and ERα signaling.

Results

Overexpression of PGRMC1 resulted in significantly enhanced proliferation. PGRMC1 interacted with key enzymes of the cholesterol synthesis pathway, alters the expression of proteins, and results in increased lipid levels. PGRMC1 also influenced lipid raft formation leading to altered expression of growth receptors in membranes of breast cancer cells. Analysis of activation of proteins revealed facilitated ERα and EGFR activation and downstream signaling dependent on PGRMC1 overexpression in hormone receptor-positive breast cancer cells. Depletion of cholesterol and fatty acids induced by statins reversed this growth benefit.

Conclusion

PGRMC1 may mediate proliferation and progression of breast cancer cells potentially by altering lipid metabolism and by activating key oncogenic signaling pathways, such as ERα expression and activation, as well as EGFR signaling. Our present study underlines the potential of PGRMC1 as a target for anti-cancer therapy.

Hypothalamic Astrocyte Development and Physiology for Neuroprogesterone Induction of the Luteinizing Hormone Surge

Neural circuits in female rats sequentially exposed to estradiol and progesterone underlie so-called estrogen positive feedback that induce the surge release of pituitary luteinizing hormone (LH) leading to ovulation and luteinization of the corpus hemorrhagicum. It is now well-established that gonadotropin releasing hormone (GnRH) neurons express neither the reproductively critical estrogen receptor-α (ERα) nor classical progesterone receptor (PGR). Estradiol from developing ovarian follicles acts on ERα-expressing kisspeptin neurons in the rostral periventricular region of the third ventricle (RP3V) to induce PGR expression, and kisspeptin release. Circulating estradiol levels that induce positive feedback also induce neuroprogesterone (neuroP) synthesis in hypothalamic astrocytes. This local neuroP acts on kisspeptin neurons that express PGR to augment kisspeptin expression and release needed to stimulate GnRH release, triggering the LH surge. In vitro and in vivo studies demonstrate that neuroP signaling in kisspeptin neurons occurs through membrane PGR activation of Src family kinase (Src). This signaling cascade has been also implicated in PGR signaling in the arcuate nucleus of the hypothalamus, suggesting that Src may be a common mode of membrane PGR signaling. Sexual maturation requires that signaling between neuroP synthesizing astrocytes, kisspeptin and GnRH neurons be established. Prior to puberty, estradiol does not facilitate the synthesis of neuroP in hypothalamic astrocytes. During pubertal development, levels of membrane ERα increase in astrocytes coincident with an increase of PKA phosphorylation needed for neuroP synthesis. Currently, it is not clear whether these developmental changes occur in existing astrocytes or are due to a new population of astrocytes born during puberty. However, strong evidence suggests that it is the former. Blocking new cell addition during puberty attenuates the LH surge. Together these results demonstrate the importance of pubertal maturation involving hypothalamic astrocytes, estradiol-induced neuroP synthesis and membrane-initiated progesterone signaling for the CNS control of ovulation and reproduction.

Expression of genes that regulate follicle development and maturation during ovarian stimulation in poor responders

RESEARCH QUESTION

Sex hormone-binding globulin (SHBG), androgen receptor (AR), LH beta polypeptide (LHB), progesterone receptor membrane component 1 (PGRMC1) and progesterone receptor membrane component 2 (PGRMC2) regulate follicle development and maturation. Their mRNA expression was assessed in peripheral blood mononuclear cells (PBMC) of normal and poor responders, during ovarian stimulation.

DESIGN

Fifty-two normal responders and 15 poor responders according to the Bologna criteria were enrolled for IVF and intracytoplasmic sperm injection and stimulated with 200 IU of follitrophin alpha and gonadotrophin-releasing hormone antagonist. HCG was administered for final oocyte maturation. On days 1, 6 and 10 of stimulation, blood samples were obtained, serum hormone levels were measured, RNA was extracted from PBMC and real-time polymerase chain reaction was carried out to identify the mRNA levels. Relative mRNA expression of each gene was calculated by the comparative 2^-DDCt method.

RESULTS

Differences between mRNA levels of each gene on the same time point between the two groups were not significant. PGRMC1 and PGRMC2 mRNA levels were downregulated, adjusted for ovarian response and age. Positive correlations between PGRMC1 and AR (standardized beta = 0.890, P < 0.001) from day 1 to 6 and PGRMC1 and LHB (standardized beta = 0.806, P < 0.001) from day 1 to 10 were found in poor responders. PGRMC1 and PGRMC2 were positively correlated on days 6 and 10 in normal responders.

CONCLUSIONS

PGRMC1 and PGRMC2 mRNA are significantly decreased during ovarian stimulation, with some potential differences between normal and poor responders.

Zebrafish as a model for studying ovarian development: Recent advances from targeted gene knockout studies

Ovarian development is a complex process controlled by precise coordination of multiple factors. The targeted gene knockout technique is a powerful tool to study the functions of these factors. The successful application of this technique in mice in the past three decades has significantly enhanced our understanding on the molecular mechanism of ovarian development. Recently, with the advent of genome editing techniques, targeted gene knockout research can be carried out in many species. Zebrafish has emerged as an excellent model system to study the control of ovarian development. Dozens of genes related to ovarian development have been knocked out in zebrafish in recent years. Much new information and perspectives on the molecular mechanism of ovarian development have been obtained from these mutant zebrafish. Some findings have challenged conventional views. Several genes have been identified for the first time in vertebrates to control ovarian development. Focusing on ovarian development, the purpose of this review is to briefly summarize recent findings using these gene knockout zebrafish models, and compare these findings with mammalian models. These established mutants and rapid development of gene knockout techniques have prompted zebrafish as an ideal animal model for studying ovarian development.

Genetics of Primary Ovarian Insufficiency in the Next-Generation Sequencing Era

Primary ovarian insufficiency (POI) is characterized by amenorrhea, increased follicle-stimulating hormone (FSH) levels, and hypoestrogenism, leading to infertility before the age of 40 years. Elucidating the cause of POI is a key point for diagnosing and treating affected women. Here, we review the genetic etiology of POI, highlighting new genes identified in the last few years using next-generation sequencing (NGS) approaches. We searched the MEDLINE/PubMed, Cochrane, and Web of Science databases for articles published in or translated to English. Several genes were found to be associated with POI genetic etiology in humans and animal models (SPIDR, BMPR2, MSH4, MSH5, GJA4, FANCM, POLR2C, MRPS22, KHDRBS1, BNC1, WDR62, ATG7/ATG9, BRCA2, NOTCH2, POLR3H, and TP63). The heterogeneity of POI etiology has been revealed to be remarkable in the NGS era, and discoveries have indicated that meiosis and DNA repair play key roles in POI development.

Complex interactomes and post-translational modifications of the regulatory proteins HABP4 and SERBP1 suggest pleiotropic cellular functions

The 57 kDa antigen recognized by the Ki-1 antibody, is also known as intracellular hyaluronic acid binding protein 4 and shares 40.7% identity and 67.4% similarity with serpin mRNA binding protein 1, which is also named CGI-55, or plasminogen activator inhibitor type-1-RNA binding protein-1, indicating that they might be paralog proteins, possibly with similar or redundant functions in human cells. Through the identification of their protein interactomes, both regulatory proteins have been functionally implicated in transcriptional regulation, mRNA metabolism, specifically RNA splicing, the regulation of mRNA stability, especially, in the context of the progesterone hormone response, and the DNA damage response. Both proteins also show a complex pattern of post-translational modifications, involving Ser/Thr phosphorylation, mainly through protein kinase C, arginine methylation and SUMOylation, suggesting that their functions and locations are highly regulated. Furthermore, they show a highly dynamic cellular localization pattern with localizations in both the cytoplasm and nucleus as well as punctuated localizations in both granular cytoplasmic protein bodies, upon stress, and nuclear splicing speckles. Several reports in the literature show altered expressions of both regulatory proteins in a series of cancers as well as mutations in their genes that may contribute to tumorigenesis. This review highlights important aspects of the structure, interactome, post-translational modifications, sub-cellular localization and function of both regulatory proteins and further discusses their possible functions and their potential as tumor markers in different cancer settings.

The Genetics of Non-Syndromic Primary Ovarian Insufficiency: A Systematic Review

Several causes for primary ovarian insufficiency (POI) have been described, including iatrogenic and environmental factor, viral infections, chronic disease as well as genetic alterations. The aim of this review was to collect all the ge- netic mutations associated with non-syndromic POI. All studies, including gene screening, genome-wide study and as- sessing genetic mutations associated with POI, were included and analyzed in this systematic review. Syndromic POI and chromosomal abnormalities were not evaluated. Single gene perturbations, including genes on the X chromosome (such as BMP15, PGRMC1 and FMR1) and genes on autosomal chromosomes (such as GDF9, FIGLA, NOBOX, ESR1, FSHR and NANOS3) have a positive correlation with non-syndromic POI. Future strategies include linkage analysis of families with multiple affected members, array comparative genomic hybridization (CGH) for analysis of copy number variations, next generation sequencing technology and genome-wide data analysis. This review showed variability of the genetic factors associated with POI. These findings may help future genetic screening studies on large cohort of women.

Progesterone receptor membrane component 1 and 2 regulate granulosa cell mitosis and survival through a NFΚB-dependent mechanism†

Progesterone receptor membrane component 1 (PGRMC1) interacts with PGRMC2, and disrupting this interaction in spontaneously immortalized granulosa cells (SIGCS) leads to an inappropriate entry into the cell cycle, mitotic arrest, and ultimately cell death. The present study revealed that PGRMC1 and PGRMC2 localize to the cytoplasm of murine granulosa cells of nonatretric follicles with their staining intensity being somewhat diminished in granulosa cells of atretic follicles. Compared to controls (Pgrmc1fl/fl), the rate at which granulosa cells entered the cell cycle increased in nonatretic and atretic follicles of mice in which Pgrmc1 was conditionally deleted (Pgrmc1d/d) from granulosa cells. This increased rate of entry into the cell cycle was associated with a ≥ 2-fold increase in follicular atresia and the nuclear localization of nuclear factor-kappa-B transcription factor P65; (NFΚB/p65, or RELA). GTPase activating protein binding protein 2 (G3BP2) binds NFΚB/p65 through an interaction with NFΚB inhibitor alpha (IκBα), thereby maintaining NFΚB/p65's cytoplasmic localization and restricting its transcriptional activity. Since PGRMC1 and PGRMC2 bind G3BP2, studies were designed to assess the functional relationship between PGRMC1, PGRMC2, and NFΚB/p65 in SIGCs. In these studies, disrupting the interaction between PGRMC1 and PGRMC2 increased the nuclear localization of NFΚB/p65, and depleting PGRMC1, PGRMC2, or G3BP2 increased NFΚB transcriptional activity and the progression into the cell cycle. Taken together, these studies suggest that PGRMC1 and 2 regulate granulosa cell cycle entry in follicles by precisely controlling the localization and thereby the transcriptional activity of NFΚB/p65.

Mutational analysis of theFAM175A gene in patients with premature ovarian insufficiency

RESEARCH QUESTION

The family with sequence similarity 175 member A gene (FAM175A; also known as ABRAXAS1, CCDC98 and ABRA1), a member of the DNA repair family, contributes to the BRCA1 (BRCA1 DNA repair associated)-dependent DNA damage response and is associated with age at natural menopause. However, it remains poorly understood whether sequence variants in FAM175A are causative for premature ovarian insufficiency (POI). The aim of this study was to investigate whether mutations in the gene FAM175A were present in patients with POI.

DESIGN

A total of 400 women with idiopathic POI and 498 control women with regular menstruation (306 age-matched women and 192 women over 40 years old) were recruited. After Sanger sequencing of FAM175A, functional experiments were carried out to explore the deleterious effects of the identified variation. DNA damage was subsequently induced by mitomycin C (MMC), and DNA repair capacity and G2-M checkpoint activation were evaluated by examining the phosphorylation level of H2AX (H2A histone family, member X) and the percentage of mitotic cells, respectively.

RESULTS

One rare single-nucleotide polymorphism, rs755187051 in gene FAM175A, c.C727G (p.L243V), was identified in two patients but absent in the 498 controls. The functional experiments demonstrated that overexpression of variant p.L243V in HeLa cells resulted in a similar sensitivity to MMC-induced damage compared with cells transfected with wild-type FAM175A. Moreover, after treatment with MMC, there were no differences in DNA repair capacity and G2-M checkpoint activation between the mutant and wild-type genes.

CONCLUSION

Our results suggest that the p.L243V variant of FAM175A may not be causative for POI. The contribution of FAM175A to POI needs further exploration.

Sex chromosomes-linked single-gene disorders involved in human infertility

Human infertility is a healthcare problem that has a worldwide impact. Genetic causes of human infertility include chromosomal aneuploidies and rearrangements and single-gene defects. The sex chromosomes (X and Y) are critical players in human fertility since they contain several genes essential for sex determination and reproductive traits for both men and women. This paper provides a review of the most common sex chromosomes-linked single-gene disorders involved in human infertility and their corresponding phenotypes. In addition to the Y-linked SRY gene, which mutations may cause XY gonadal dysgenesis and sex reversal, the deletions of genes present in AZF regions of the Y chromosome (DAZ, RBMY, DBY and USP9Y genes) are implicated in varying degrees of spermatogenic dysfunction. Furthermore, a list of X-linked genes (KAL1, NR0B1, AR, TEX11, FMR1, PGRMC1, BMP15 and POF1 and 2 regions genes (XPNPEP2, POF1B, DACH2, CHM and DIAPH2)) were reported to have critical roles in pubertal and reproductive deficiencies in humans, affecting only men, only women or both sexes. Mutations in these genes may be transmitted to the offspring by a dominant or a recessive inheritance.

Variations in the inhibin gene in Kashmiri women with primary ovarian insufficiency

Inhibin is a glycoprotein produced by granulosa cells and its main function is the negative feedback control of follicle stimulating hormone (FSH) which has an important role in folliculogenesis. Mutation in the INHα gene leading to decreased bioactive inhibin has been associated with primary ovarian insufficiency (POI). The aim of this study was to investigate the role of variations in the INHα gene in increasing the susceptibility to POI in Kashmiri women. INHα c.769G > A mutation was analysed in 100 POI cases and 100 controls using PCR-RFLP and agarose gel electrophoresis. The INHα c.769G > A mutation was found in 10% of POI cases with 8% having heterozygous mutation and 2% having a homozygous mutation. The frequency of mutation in healthy controls was zero. Statistically, a very significant association was found between INHα c.769G > A mutation and the occurrence of POI (p = 0.0015). Moreover, the mutation was also significantly associated with high levels of FSH in POI patients (p < 0.0001). Given the significant association of INHα c.769G > A mutation with the increased FSH levels and POI in Kashmiri population, we suggest this mutation can be used to identify POI variants for screening of women susceptible to POI before the disease onset and can further facilitate putative therapy for such patients.

PGRMC1/2 promotes luteal vascularization and maintains the primordial follicles of mice

To determine whether conditional depletion of progesterone receptor membrane component (PGRMC) 1 and PGRMC2 affected ovarian follicle development, follicle distribution was assessed in ovaries of young (≈3-month-old) and middle-aged (≈6-month-old) control (Pgrmc1/2fl/fl) and double conditional PGRMC1/2-knockout (Pgrmc1/2d/d) mice. This study revealed that the distribution of primary, preantral and antral follicles was not altered in Pgrmc1/2d/d mice, regardless of the age. Although the number of primordial follicles was similar at ≈3 months of age, their numbers were reduced by ≈80% in 6-month-old Pgrmc1/2d/d mice compared to age-matched Pgrmc1/2fl/fl mice. The Pgrmc1/2d/d mice were generated using Pgr-cre mice, so ablation of Pgrmc1 and Pgrmc2 in the ovary was restricted to peri-ovulatory follicles and subsequent corpora lutea (CL). In addition, the vascularization of CL was attenuated in Pgrmc1/2d/d mice, although mRNA levels of vascular endothelial growth factor A (Vegfa) were elevated. Moreover, depletion of Pgrmc1 and Pgrmc2 altered the gene expression profile in the non-luteal component of the ovary such that Vegfa expression, a stimulator of primordial follicle growth, was elevated; Kit Ligand expression, another stimulator of primordial follicle growth, was suppressed and anti-Mullerian hormone, an inhibitor of primordial follicle growth, was enhanced compared to Pgrmc1/2fl/fl mice. These data reveal that luteal cell depletion of Pgrmc1 and 2 alters the expression of growth factors within the non-luteal component of the ovary, which could account for the premature demise of the adult population of primordial follicles. In summary, the survival of adult primordial follicles is dependent in part on progesterone receptor membrane component 1 and 2.

AG 205, a progesterone receptor membrane component 1 antagonist, ablates progesterone's ability to block oxidative stress-induced apoptosis of human granulosa/luteal cells†

The present studies were designed to determine whether progesterone (P4)-progesterone receptor membrane component 1 (PGRMC1) signaling is able to attenuate the apoptotic effects of oxidative stress induced by hydrogen peroxide (H2O2). To achieve this goal, freshly isolated human granulosa/luteal cells were maintained in culture. After several passages, the cells were treated with H2O2, which induced apoptosis within 2.5 h, while simultaneous treatment with P4 attenuated the apoptotic action of H2O2. AG 205, a PGRMC1 antagonist, eliminated P4's ability to prevent H2O2-induced apoptosis. AG 205 neither affected PGRMC1's cytoplasmic localization nor its interaction with PGRMC2, but appeared to reduce its presence within the nucleus. AG 205 also (1) increased the monomeric and decreased the higher molecular weight forms of PGRMC1 (i.e., dimers/oligomers) and (2) altered the expression of several genes involved in apoptosis. The most dramatic change was an approximate 8-fold increase in Harakiri (Hrk) mRNA. However, AG 205 did not induce apoptosis in the absence of H2O2. Taken together, these observations suggest that the higher molecular weight forms of PGRMC1 likely account in part for PGRMC1's ability to suppress the expression of Hrk. Harakiri is a BH-3 only member of the B-cell lymphoma 2 (BCL2) family that promotes apoptosis by binding to and antagonizing the antiapoptotic action of BCL2- and BCL2-like proteins. It is likely then that PGRMC1's ability to suppress Hrk is part of the mechanism through which P4-PGRMC1 signaling preserves the viability of human granulosa/luteal cells.

Primary ovarian insufficiency associated with autosomal abnormalities: from chromosome to genome-wide and beyond

OBJECTIVE

The pathophysiology of primary ovarian insufficiency (POI) is not well elucidated. Many candidate genetic aberrations are on the X-chromosome; on the contrary, many genetic perturbations are also on the autosomes. The aim of this review is to summarize the knowledge of genetic aberrations on autosomes from chromosomal rearrangement, gene abnormality, genome-wide association studies and epigenetics.

METHODS

Searches of electronic databases were performed. Articles and abstracts relevant to POI and genetic studies associated with autosomes were summarized in this interpretive literature review.

RESULTS

Various genetic aberrations located on the autosomes were found. These abnormalities are from chromosomal rearrangement, which might disrupt the critical region on chromosome loci or disturbance of the meiosis process. Specific gene aberrations are also identified. The genes that have functions in ovarian development, folliculogenesis, and steroidogenesis on autosomes are proposed to be involved from gene association studies. Gene-to-gene interaction or epistasis also might play a role in POI occurrence. Recently, genetic techniques to study the whole genome have emerged. Although no specific conclusion has been made, the studies using genome-wide association to find the specific aberration throughout the genome in POI have been published. Epigenetic mechanisms might also take part in the pathogenesis of POI.

CONCLUSIONS

The considerably complex process of POI is still not well understood. Further research is needed for gene functional validation studies to confirm the contribution of genes in POI, or additional genome-wide association studies using novel clustered regularly interspaced short palindromic repeat/Cas9 technique might make these mechanisms more comprehensible.

[Usefulness of CGH-array and SNP-array for the etiological diagnosis of premature ovarian insufficiency]

Premature ovarian insufficiency (POI) defined by the cessation of ovarian function before the age of 40 years and the increase of gonadotropins (> 25 UI/l) occurs in approximately 1-5% of women. Different mechanisms are responsible for POI: chemotherapy, radiotherapy, environmental factors or genetic causes but most frequently no cause is identified. In order to determine the etiology of POI, cytogenetic analyses such as karyotype are performed. The karyotype allows to identify abnormalities of the number of chromosomes as well as abnormalities of the structure such as translocations, deletions or insertions of a size greater than 5-10 Mb… Turner syndrome is the most frequent genetic cause of POI and deletions of the long arm of the X chromosome are other causes of POI identified by the karyotype. However, the resolution of the karyotype is low and other cytogenetic techniques were developed such as all genome microarray analysis. This technique includes CGH-array and SNP-array and allows to identify gain or loss of chromosomal material as small as 10 kb but not the balanced structural rearrangements. Different studies using microarray analysis in cohorts of patients presenting with POI identify candidate genes responsible for POI. Furthermore, they allowed to identify a recurrent microdeletion, which includes the CPEB1 gene, located in 15q25.2 in about 1.5% of patients with POI.

Pgrmc1 Knockout Impairs Oocyte Maturation in Zebrafish

Recent investigations suggest progestin receptor membrane component 1 (PGRMC1) associates with and transports a wide range of molecules such as heme, cytochromes P450, steroids with 21 carbons, membrane progestin receptor alpha (mPRα/Paqr7), epidermal growth factor receptor (EGFR), and insulin receptor. It is difficult to discriminate the true functions of PGRMC1 from the functions of its associated molecules using biochemical and pharmacological approaches. To determine the physiological function(s) of PGRMC1, we generated global knockouts for pgrmc1 (pgrmc1 ^-/-) in zebrafish. We found a reduction in both spawning frequency and the number of embryos produced by female mutants. We also observed reduced sensitivity of fully-grown immature oocytes to a progestin hormone and a reduced number of oocytes undergone meiotic maturation both in vivo and in vitro in pgrmc1 ^-/-. This reduced sensitivity to progestin corresponds well with significant reduced expression of mPRα, the receptor mainly responsible for mediating oocyte maturation and meiosis resumption in fish. The results provide in vivo and in vitro evidence for the physiological functions of Pgrmc1 in oocyte maturation and fertility, as well as a plausible molecular mechanism via regulation of mPRα, which in turn directly regulates oocyte maturation and affects fertility in zebrafish.

Primary ovarian insufficiency in classic galactosemia: current understanding and future research opportunities

Classic galactosemia is an inborn error of the metabolism with devastating consequences. Newborn screening has been successful in markedly reducing the acute neonatal symptoms from this disorder. The dramatic response to dietary treatment is one of the major success stories of newborn screening. However, as children with galactosemia achieve adulthood, they face long-term complications. A majority of women with classic galactosemia develop primary ovarian insufficiency and resulting morbidity. The underlying pathophysiology of this complication is not clear. This review focuses on the reproductive issues seen in girls and women with classic galactosemia. Literature on the effects of classic galactosemia on the female reproductive system was reviewed by an extensive Pubmed search (publications from January 1975 to January 2017) using the keywords: galactosemia, ovarian function/dysfunction, primary ovarian insufficiency/failure, FSH, oxidative stress, fertility preservation. In addition, articles cited in the search articles and literature known to the authors was also included in the review. Our understanding of the role of galactose metabolism in the ovary is limited and the pathogenic mechanisms involved in causing primary ovarian insufficiency are unclear. The relative rarity of galactosemia makes it difficult to accumulate data to determine factors defining timing of ovarian dysfunction or treatment/fertility preservation options for this group of women. In this review, we present reproductive challenges faced by women with classic galactosemia, highlight the gaps in our understanding of mechanisms leading to primary ovarian insufficiency in this population, discuss new advances in fertility preservation options, and recommend collaboration between reproductive medicine and metabolic specialists to improve fertility in these women.

Dynamic expression of PGRMC1 and SERBP1 in human endometrium: an implication in the human decidualization process

OBJECTIVE

To characterize PGRMC1 and SERBP1 in human endometrium and to investigate the putative role of PGRMC1 in endometrial decidualization.

DESIGN

The PGRMC1 and SERBP1 expression in human endometrium was determined throughout the menstrual cycle. We analyzed the colocalization of PGRMC1 and SERBP1. Then, endometrial stromal cells (ESCs) were isolated to investigate the functional effect of PGRMC1 overexpression on decidualization.

SETTING

IVI clinic.

PATIENT(S)

Endometrial biopsies were collected from fertile volunteers (n = 61) attending the clinic as ovum donors.

INTERVENTION(S)

Endometrial samples of 61 healthy fertile women.

MAIN OUTCOME MEASURE(S)

In vivo localization of PGRMC1 and SERBP1 was assessed by immunohistochemistry. The PGRMC1/SERBP1 colocalization was investigated in vitro and in vivo. Decidualization effect of PGRMC1 overexpression was evaluated in primary ESC cultures.

RESULT(S)

The PGRMC1 was detected in the endometrial stroma throughout the menstrual cycle, but decreased in the late secretory phase. The SERBP1 immunostaining was present in stroma and increased in the entire the menstrual cycle. The PGRMC1 and SERBP1 colocalized in the cytoplasmic fractions of nondecidualized and decidualized ESC. The PGRMC1 overexpression significantly inhibited in vitro decidualization.

CONCLUSION(S)

Our results suggest that classic P receptors (PRs) are not the only kind playing a role in the normal physiology of the endometrium. The human decidualization process could be altered by the overexpression or mislocalization of PGRMC1 in ESC.

The concentration-dependent effect of progesterone on follicle growth in the mouse ovary

Follicle growth in the mammalian ovary is coordinately controlled by multiple factors to sustain periodic ovulation. In this study, we investigated the role of progesterone on follicle growth in the mouse ovary. As the concentration of progesterone changes during the estrus cycle, we cultured the sliced mouse ovary in a medium containing 10 ng/ml, 100 ng/ml, and 1 μg/ml progesterone. Progesterone promoted the growth of primordial to primary follicles at 100 ng/ml, while it suppressed the growth of secondary follicles at 1 μg/ml. Follicles at other developmental stages in the cultured ovary were unaffected with different concentrations of progesterone. The number of ovulated oocytes increased in the medium containing 100 ng/ml progesterone but decreased in the presence of 1 μg/ml progesterone. Follicles expressed two types of progesterone receptors, progesterone receptor (PGR) and PGR membrane component 1 (PGRMC1). While PGR shows transient expression on granulosa cells of Graafian follicles, PGRMC1 expresses in granulosa cells of developing follicles. These results suggest that progesterone controls the growth of developing follicles through PGRMC1. Our study shows that the effect of progesterone on ovulation and follicle growth in mouse ovary is dependent on the concentration of progesterone and the follicle stage.

Genetics of primary ovarian insufficiency

Primary ovarian insufficiency (POI) is characterized by a loss of ovarian function before the age of 40 and account for one major cause of female infertility. POI relevance is continuously growing because of the increasing number of women desiring conception beyond 30 years of age, when POI prevalence is >1%. POI is highly heterogeneous and can present with ovarian dysgenesis and primary amenorrhea, or with secondary amenorrhea, and it can be associated with other congenital or acquired abnormalities. In most cases POI remains classified as idiopathic. However, the age of menopause is an inheritable trait and POI has a strong genetic component. This is confirmed by the existence of several candidate genes, experimental and natural models. The variable expressivity of POI defect may indicate that, this disease may frequently be considered as a multifactorial or oligogenic defect. The most common genetic contributors to POI are the X chromosome-linked defects. Here, we review the principal X-linked and autosomal genes involved in syndromic and non-syndromic forms of POI with the expectation that this list will soon be upgraded, thus allowing the possibility to predict the risk of an early age at menopause in families with POI.

Premature Ovarian Insufficiency: New Perspectives on Genetic Cause and Phenotypic Spectrum

Premature ovarian insufficiency (POI) is one form of female infertility, defined by loss of ovarian activity before the age of 40 and characterized by amenorrhea (primary or secondary) with raised gonadotropins and low estradiol. POI affects up to one in 100 females, including one in 1000 before the age of 30. Substantial evidence suggests a genetic basis for POI; however, the majority of cases remain unexplained, indicating that genes likely to be associated with this condition are yet to be discovered. This review discusses the current knowledge of the genetic basis of POI. We highlight genes typically known to cause syndromic POI that can be responsible for isolated POI. The role of mouse models in understanding POI pathogenesis is discussed, and a thorough list of candidate POI genes is provided. Identifying a genetic basis for POI has multiple advantages, such as enabling the identification of presymptomatic family members who can be offered counseling and cryopreservation of eggs before depletion, enabling personalized treatment based on the cause of an individual's condition, and providing better understanding of disease mechanisms that ultimately aid the development of improved treatments.

Progesterone Receptor Membrane Component 1 Mediates Progesterone-Induced Suppression of Oocyte Meiotic Prophase I and Primordial Folliculogenesis

Well-timed progression of primordial folliculogenesis is essential for mammalian female fertility. Progesterone (P4) inhibits primordial follicle formation under physiological conditions; however, P4 receptor that mediates this effect and its underlying mechanisms are unclear. In this study, we used an in vitro organ culture system to show that progesterone receptor membrane component 1 (PGRMC1) mediated P4-induced inhibition of oocyte meiotic prophase I and primordial follicle formation. We found that membrane-impermeable BSA-conjugated P4 inhibited primordial follicle formation similar to that by P4. Interestingly, PGRMC1 and its partner serpine1 mRNA-binding protein 1 were highly expressed in oocytes in perinatal ovaries. Inhibition or RNA interference of PGRMC1 abolished the suppressive effect of P4 on follicle formation. Furthermore, P4-PGRMC1 interaction blocked oocyte meiotic progression and decreased intra-oocyte cyclic AMP (cAMP) levels in perinatal ovaries. cAMP analog dibutyryl cAMP reversed P4–PGRMC1 interaction-induced inhibition of meiotic progression and follicle formation. Thus, our results indicated that PGRMC1 mediated P4-induced suppression of oocyte meiotic progression and primordial folliculogenesis by decreasing intra-oocyte cAMP levels.

PGRMC1 participates in late events of bovine granulosa cells mitosis and oocyte meiosis

Progesterone Receptor Membrane Component 1 (PGRMC1) is expressed in both oocyte and ovarian somatic cells, where it is found in multiple cellular sub-compartments including the mitotic spindle apparatus. PGRMC1 localization in the maturing bovine oocytes mirrors its localization in mitotic cells, suggesting a possible common action in mitosis and meiosis. To test the hypothesis that altering PGRMC1 activity leads to similar defects in mitosis and meiosis, PGRMC1 function was perturbed in cultured bovine granulosa cells (bGC) and maturing oocytes and the effect on mitotic and meiotic progression assessed. RNA interference-mediated PGRMC1 silencing in bGC significantly reduced cell proliferation, with a concomitant increase in the percentage of cells arrested at G2/M phase, which is consistent with an arrested or prolonged M-phase. This observation was confirmed by time-lapse imaging that revealed defects in late karyokinesis. In agreement with a role during late mitotic events, a direct interaction between PGRMC1 and Aurora Kinase B (AURKB) was observed in the central spindle at of dividing cells. Similarly, treatment with the PGRMC1 inhibitor AG205 or PGRMC1 silencing in the oocyte impaired completion of meiosis I. Specifically the ability of the oocyte to extrude the first polar body was significantly impaired while meiotic figures aberration and chromatin scattering within the ooplasm increased. Finally, analysis of PGRMC1 and AURKB localization in AG205-treated oocytes confirmed an altered localization of both proteins when meiotic errors occur. The present findings demonstrate that PGRMC1 participates in late events of both mammalian mitosis and oocyte meiosis, consistent with PGRMC1's localization at the mid-zone and mid-body of the mitotic and meiotic spindle.

Two girls with a de novo Xq rearrangement of paternal origin: t(X;9)(q24;q12) or rea(X)dup q

OBJECTIVE

We report on two rare Xq rearrangements, namely a t(X;9)(q24;q12) found in a mildly-affected girl (Patient 1) and a rea(X)dup q concomitant with a rob(14;21)mat in a Down syndrome girl (Patient 2).

CASE REPORT

Both rearrangements were characterized by banding techniques [Giemsa (G), constitutive heterochromatin (C), and bromodeoxyuridine (BrdU) pulse], fluorescence in situ hybridization (FISH) assays, human androgen receptor (HUMAR) assays, and microarray analyses. Patient 1 had a t(X;9)(q24;q12)dn. Patient 2 had a de novo rea(X)(qter→q23 or q24::p11.2→qter) concomitant with an unbalanced rob(14;21)mat. X-Inactivation studies in metaphases and DNA revealed a fully skewed inactivation: the normal homolog was silenced in Patient 1 and the rea(X) in Patient 2. Both rearranged X chromosomes were of paternal descent. Microarray analyses revealed no imbalances in Patient 1 whereas loss of Xp (∼52 Mb) and duplication of Xq (∼44 Mb) and 21q were confirmed in Patient 2.

CONCLUSION

Our observations further document the cytogenetic heterogeneity and predominant paternal origin of certain de novo X-chromosome rearrangements.

The Effects of Chronic Lifelong Activation of the AHR Pathway by Industrial Chemical Pollutants on Female Human Reproduction

Environmental chemicals, such as heavy metals, affect female reproductive function. A biological sensor of the signals of many toxic chemical compounds seems to be the aryl hydrocarbon receptor (AHR). Previous studies demonstrated the environmental of heavy metals in Taranto city (Italy), an area that has been influenced by anthropogenic factors such as industrial activities and waste treatments since 1986. However, the impact of these elements on female fertility in this geographic area has never been analyzed. Thus, in the present study, we evaluated the AHR pathway, sex steroid receptor pattern and apoptotic process in granulosa cells (GCs) retrieved from 30 women, born and living in Taranto, and 30 women who are living in non-contaminated areas (control group), who were undergoing in vitro fertilization (IVF) protocol. In follicular fluids (FFs) of both groups the toxic and essential heavy metals, such as chromiun (Cr), Manganese (Mn), iron (Fe), cobalt (Co), nickel (Ni), copper (Cu), zinc (Zn), cadmium (Cd) and lead (Pb), were also analyzed. Higher levels of Cr, Fe, Zn and Pb were found in the FFs of the women from Taranto as compared to the control group, as were the levels of AHR and AHR-dependent cytochrome P450 1A1 and 1B1; while CYP19A1 expression was decreased. The anti-apoptotic process found in the GCs of women fromTaranto was associated with the highest levels of progesterone receptor membrane component 1 (PGRMC1), a novel progesterone receptor, the expression of which is subjected to AHR activated by its highest affinity ligands (e.g., dioxins) or indirectly by other environmental pollutants, such as heavy metals. In conclusion, decreased production of estradiol and decreased number of retrieved mature oocytes found in women from Taranto could be due to chronic exposure to heavy metals, in particular to Cr and Pb.

Progesterone, Inflammatory Cytokine (TNF-α), and Oxidative Stress (H2O2) Regulate Progesterone Receptor Membrane Component 1 Expression in Fetal Membrane Cells

Progesterone receptor membrane component 1 (PGRMC1) is an important novel mediator of progesterone (P4) function in fetal membrane cells. We demonstrated previously that PGRMC1 is differentially expressed in fetal membranes among pregnancy subjects and diminished in preterm premature rupture of membrane subjects. In the current study, we aim to elucidate whether PGRMC1 expression is regulated by P4, tumor necrosis factor α (TNF-α), and H2O2 in fetal membrane cells. Primary cultured membrane cells were serum starved for 24 hours followed by treatments of P4, 17 hydroxyprogesterone caproate, and medroxyprogesterone 17 acetate (MPA) at 10(-7) mol/L with ethanol as vehicle control; TNF-α at 10, 20, and 50 ng/mL with phosphate-buffered saline (PBS) as control; and H2O2 at 10 and 100 μmol/L with culture media as control for 24, 48, and 72 hours. The messenger RNA (mRNA) and protein expression of PGRMC1 was quantified using polymerase chain reaction and Western blotting, respectively. We found that PGRMC1 protein expression was regulated by MPA, TNF-α, and H2O2 in a dose-dependent manner. This regulation is also specific to the type of cell (amnion, chorion, or decidua). The upregulation of PGRMC1 by MPA might be mediated through glucocorticoid receptor (GR) demonstrated using amnion and chorion cells model with GR knockdown by specific small interfering RNA transfection. The mRNA expression of PGRMC1 was decreased by H2O2 (100 μmol/L) treatment in amnion cells, which might ultimately result in downregulation of PGRMC1 protein as our data demonstrated. None of other treatments changed PGRMC1 mRNA level in these cells. We conclude that these stimuli act as regulatory factors of PGRMC1 in a cell-specific manner.

PGRMC1 Elevation in Multiple Cancers and Essential Role in Stem Cell Survival

Cancer is one of the leading causes of death in America, and there is an urgent need for new therapeutic approaches. The progesterone receptor membrane component 1 (PGRMC1) is a cytoch-rome b₅ related protein that binds heme and is associated with signaling, apoptotic suppression and autophagy. PGRMC1 is essential for tumor formation, invasion and metastasis, and is upregulated in breast, colon, lung and thyroid tumors. In the present study, we have analyzed PGRMC1 levels in over 600 tumor sections, including a larger cohort of lung tumors than in previous studies, and report the first clinical analysis of PGRMC1 levels in human oral cavity and ovarian tumors compared to corresponding nonmalignant tissues. PGRMC1 was highly expressed in lung and ovarian cancers and correlated with patient survival. PGRMC1 has been previously associated with drug resistance, a characteristic of cancer stem cells. The stem cell theory proposes that a subset of cancerous stem cells contribute to drug resistance and tumor maintenance, and PGRMC1 was detected in lung-tumor derived stem cells. Drug treatment with a PGRMC1 inhibitor, AG-205, triggered stem cell death whereas treatment with erlotinib and the ERK inhibitor, PD98059, did not, suggesting a specific role for PGRMC1 in cancer stem cell viability. Together, our data demonstrate PGRMC1 as a potential tumor biomarker across a variety of tumors, as well as a therapeutic target for cancer stem cells.

Molecular insights into the aetiology of female reproductive ageing

As age at pubertal onset declines and age at first pregnancy increases, the mechanisms that regulate female reproductive lifespan become increasingly relevant to population health. The timing of menarche and menopause can have profound effects not only on fertility but also on the risk of diseases such as type 2 diabetes mellitus, cardiovascular disease and breast cancer. Genetic studies have identified dozens of highly penetrant rare mutations associated with reproductive disorders, and also ∼175 common genetic variants associated with the timing of puberty or menopause. These findings, alongside other functional studies, have highlighted a diverse range of mechanisms involved in reproductive ageing, implicating core biological processes such as cell cycle regulation and energy homeostasis. The aim of this article is to review the contribution of such genetic findings to our understanding of the molecular regulation of reproductive timing, as well as the biological basis of the epidemiological links between reproductive ageing and disease risk.

Novel WT1 Missense Mutations in Han Chinese Women with Premature Ovarian Failure

Premature ovarian failure (POF) is a heterogeneous disease. Though dozens of candidate genes have been identified for the genetic etiology of POF, it is largely unexplained in majority of patients. Recently, Wt1^+/R394W mice was found to present POF-like phenotype, which indicates that WT1 might be a plausible candidate gene for non-syndromic POF. The coding region of WT1 gene was screened in 384 patients with POF and 6 novel variations were identified, including two missense mutations (p. Pro126Ser in exon1 and p. Arg370His in exon7) and four intronic variants (c.647-27C > T, c.647-13G > C, c.647-13G > A in intron1 and c.950 + 14T > C in intron 4). In vitro experiments showed that both mutant p. Pro126Ser and p. Arg370His repressed the expression of Amh and Cdh1, and induced the expression of Fshr and Cyp19 in mRNA level (P < 0.05). The expression changes of AMH, FSHR, CYP19 and CDH1 were confirmed by western blot. These genes (AMH, FSHR, CYP19 and CDH1) are required for granular cells (GCs) proliferation, differentiation and oocyte-GCs interaction. The novel mutant p. P126S and p. R370H in the WT1 gene potentially impaired GCs differentiation and oocyte-GCs interaction, which might result in loss of follicles prematurely. Therefore, WT1 is a plausible causal gene for POF.

Genetics of primary ovarian insufficiency: new developments and opportunities

BACKGROUND

Primary ovarian insufficiency (POI) is characterized by marked heterogeneity, but with a significant genetic contribution. Identifying exact causative genes has been challenging, with many discoveries not replicated. It is timely to take stock of the field, outlining the progress made, framing the controversies and anticipating future directions in elucidating the genetics of POI.

METHODS

A search for original articles published up to May 2015 was performed using PubMed and Google Scholar, identifying studies on the genetic etiology of POI. Studies were included if chromosomal analysis, candidate gene screening and a genome-wide study were conducted. Articles identified were restricted to English language full-text papers.

RESULTS

Chromosomal abnormalities have long been recognized as a frequent cause of POI, with a currently estimated prevalence of 10-13%. Using the traditional karyotype methodology, monosomy X, mosaicism, X chromosome deletions and rearrangements, X-autosome translocations, and isochromosomes have been detected. Based on candidate gene studies, single gene perturbations unequivocally having a deleterious effect in at least one population include Bone morphogenetic protein 15 (BMP15), Progesterone receptor membrane component 1 (PGRMC1), and Fragile X mental retardation 1 (FMR1) premutation on the X chromosome; Growth differentiation factor 9 (GDF9), Folliculogenesis specific bHLH transcription factor (FIGLA), Newborn ovary homeobox gene (NOBOX), Nuclear receptor subfamily 5, group A, member 1 (NR5A1) and Nanos homolog 3 (NANOS3) seem likely as well, but mostly being found in no more than 1-2% of a single population studied. Whole genome approaches have utilized genome-wide association studies (GWAS) to reveal loci not predicted on the basis of a candidate gene, but it remains difficult to locate causative genes and susceptible loci were not always replicated. Cytogenomic methods (array CGH) have identified other regions of interest but studies have not shown consistent results, the resolution of arrays has varied and replication is uncommon. Whole-exome sequencing in non-syndromic POI kindreds has only recently begun, revealing mutations in the Stromal antigen 3 (STAG3), Synaptonemal complex central element 1 (SYCE1), minichromosome maintenance complex component 8 and 9 (MCM8, MCM9) and ATP-dependent DNA helicase homolog (HFM1) genes. Given the slow progress in candidate-gene analysis and relatively small sample sizes available for GWAS, family-based whole exome and whole genome sequencing appear to be the most promising approaches for detecting potential genes responsible for POI.

CONCLUSION

Taken together, the cytogenetic, cytogenomic (array CGH) and exome sequencing approaches have revealed a genetic causation in ∼20-25% of POI cases. Uncovering the remainder of the causative genes will be facilitated not only by whole genome approaches involving larger cohorts in multiple populations but also incorporating environmental exposures and exploring signaling pathways in intragenic and intergenic regions that point to perturbations in regulatory genes and networks.

CSB-PGBD3 Mutations Cause Premature Ovarian Failure

Premature ovarian failure (POF) is a rare, heterogeneous disorder characterized by cessation of menstruation occurring before the age of 40 years. Genetic etiology is responsible for perhaps 25% of cases, but most cases are sporadic and unexplained. In this study, through whole exome sequencing in a non-consanguineous family having four affected members with POF and Sanger sequencing in 432 sporadic cases, we identified three novel mutations in the fusion gene CSB-PGBD3. Subsequently functional studies suggest that mutated CSB-PGBD3 fusion protein was impaired in response to DNA damage, as indicated by delayed or absent recruitment to damaged sites. Our data provide the first evidence that mutations in the CSB-PGBD3 fusion protein can cause human disease, even in the presence of functional CSB, thus potentially explaining conservation of the fusion protein for 43 My since marmoset. The localization of the CSB-PGBD3 fusion protein to UVA-induced nuclear DNA repair foci further suggests that the CSB-PGBD3 fusion protein, like many other proteins that can cause POF, modulates or participates in DNA repair.