Abdominal B (AbdB) Hoxa genes: regulation in adult uterus by estrogen and progesterone and repression in müllerian duct by the synthetic estrogen diethylstilbestrol (DES)

Retinoic acid antagonizes estrogen signaling to maintain adult uterine cell fate

Classical tissue recombination experiments demonstrate that cell-fate determination along the anterior-posterior axis of the Müllerian duct occurs prior to postnatal day 7 in mice. However, little is known about how these cell types are maintained in adults. In this study, we provide genetic evidence that a balance between antagonistic retinoic acid (RA) and estrogen signaling activity is required to maintain simple columnar cell fate in adult uterine epithelium. Transdifferentiation of simple columnar uterine epithelium into stratified cervicovaginal-like epithelium was observed in three related mouse genetic models, in which RA signaling was perturbed in the postnatal uterus. Single-cell RNA sequencing analysis identified the transformed epithelial cell populations and revealed extensive immune cell infiltration resulting from loss of RA signaling. Surprisingly, disruption of RA signaling led to dysregulated expression of a substantial number of estrogen target genes, suggesting that these two pathways may functionally oppose each other in determining and maintaining uterine epithelial cell fate. Consistent with this model, neonatal exposure to the strong synthetic estrogen, diethylstilbestrol, downregulated expression of a group of RA target genes and led to epithelial stratification and immune cell infiltration in wild-type uterus. Treating RA receptor triple conditional knockout pups with fulvestrant, an estrogen antagonist, reestablished the balance between the two signaling pathways, and effectively prevented the transformation of mutant simple columnar epithelia to metaplastic stratified epithelia. These findings implicate an essential role for RA signaling in maintaining uterine cytodifferentiation by antagonizing estrogen signaling in the postnatal uterus.

HOXA9 transcription factor is a double-edged sword: from development to cancer progression

The HOXA9 transcription factor serves as a molecular orchestrator in cancer stemness, epithelial-mesenchymal transition (EMT), metastasis, and generation of the tumor microenvironment in hematological and solid malignancies. However, the multiple modes of regulation, multifaceted functions, and context-dependent interactions responsible for the dual role of HOXA9 as an oncogene or tumor suppressor in cancer remain obscure. Hence, unravelling its molecular complexities, binding partners, and interacting signaling molecules enables us to comprehend HOXA9-mediated transcriptional programs and molecular crosstalk. However, it is imperative to understand its central role in fundamental biological processes such as embryogenesis, foetus implantation, hematopoiesis, endothelial cell proliferation, and tissue homeostasis before designing targeted therapies. Indeed, it presents an enormous challenge for clinicians to selectively target its oncogenic functions or restore tumor-suppressive role without altering normal cellular functions. In addition to its implications in cancer, the present review also focuses on the clinical applications of HOXA9 in recurrence and drug resistance, which may provide a broader understanding beyond oncology, open new avenues for clinicians for accurate diagnoses, and develop personalized treatment strategies. Furthermore, we have also discussed the existing therapeutic options and accompanying challenges in HOXA9-targeted therapies in different cancer types.

Single-cell transcriptomic profiling of the neonatal oviduct and uterus reveals new insights into upper Müllerian duct regionalization

The upper Müllerian duct (MD) is patterned and specified into two morphologically and functionally distinct organs, the oviduct and uterus. It is known that this regionalization process is instructed by inductive signals from the adjacent mesenchyme. However, the interaction landscape between epithelium and mesenchyme during upper MD development remains largely unknown. Here, we performed single-cell transcriptomic profiling of mouse neonatal oviducts and uteri at the initiation of MD epithelial differentiation (postnatal day 3). We identified major cell types including epithelium, mesenchyme, pericytes, mesothelium, endothelium, and immune cells in both organs with established markers. Moreover, we uncovered region-specific epithelial and mesenchymal subpopulations and then deduced region-specific ligand-receptor pairs mediating mesenchymal-epithelial interactions along the craniocaudal axis. Unexpectedly, we discovered a mesenchymal subpopulation marked by neurofilaments with specific localizations at the mesometrial pole of both the neonatal oviduct and uterus. Lastly, we analyzed and revealed organ-specific signature genes of pericytes and mesothelial cells. Taken together, our study enriches our knowledge of upper MD development, and provides a manageable list of potential genes, pathways, and region-specific cell subtypes for future functional studies.

Hox genes and patterning the vertebrate body

The diversity of vertebrate body plans is dizzying, yet stunning for the many things they have in common. Vertebrates have inhabited virtually every part of the earth from its coldest to warmest climates. They locomote by swimming, flying, walking, slithering, or climbing, or combinations of these behaviors. And they exist in many different sizes, from the smallest of frogs, fish and lizards to giraffes, elephants, and blue whales. Despite these differences, vertebrates follow a remarkably similar blueprint for the establishment of their body plan. Within the relatively small amount of time required to complete gastrulation, the process through which the three germ layers, ectoderm, mesoderm, and endoderm are created, the embryo also generates its body axis and is simultaneously patterned. For the length of this axis, the genes that distinguish the neck from the rib cage or the trunk from the sacrum are the Hox genes. In vertebrates, there was evolutionary pressure to maintain this set of genes in the organism. Over the past decades, much has been learned regarding the regulatory mechanisms that ensure the appropriate expression of these genes along the main body axes. Genetic functions continue to be explored though much has been learned. Much less has been discerned on the identity of co-factors used by Hox proteins for the specificity of transcriptional regulation or what downstream targets and pathways are critical for patterning events, though there are notable exceptions. Current work in the field is demonstrating that Hox genes continue to function in many organs long after directing early patterning events. It is hopeful continued research will shed light on remaining questions regarding mechanisms used by this important and conserved set of transcriptional regulators.

Single-cell transcriptomic profiling of the neonatal oviduct and uterus reveals new insights into upper Müllerian duct regionalization

The upper Müllerian duct (MD) is patterned and specified into two morphologically and functionally distinct organs, the oviduct and uterus. It is known that this regionalization process is instructed by inductive signals from the adjacent mesenchyme. However, the interaction landscape between epithelium and mesenchyme during upper MD development remains largely unknown. Here, we performed single-cell transcriptomic profiling of mouse neonatal oviducts and uteri at the initiation of MD epithelial differentiation (postnatal day 3). We identified major cell types including epithelium, mesenchyme, pericytes, mesothelium, endothelium, and immune cells in both organs with established markers. Moreover, we uncovered region-specific epithelial and mesenchymal subpopulations and then deduced region-specific ligand-receptor pairs mediating mesenchymal-epithelial interactions along the craniocaudal axis. Unexpectedly, we discovered a mesenchymal subpopulation marked by neurofilaments with specific localizations at the mesometrial pole of both the neonatal oviduct and uterus. Lastly, we analyzed and revealed organ-specific signature genes of pericytes and mesothelial cells. Taken together, our study enriches our knowledge of upper Müllerian duct development, and provides a manageable list of potential genes, pathways, and region-specific cell subtypes for future functional studies.

Hox genes in development and beyond

Hox genes encode evolutionarily conserved transcription factors that are essential for the proper development of bilaterian organisms. Hox genes are unique because they are spatially and temporally regulated during development in a manner that is dictated by their tightly linked genomic organization. Although their genetic function during embryonic development has been interrogated, less is known about how these transcription factors regulate downstream genes to direct morphogenetic events. Moreover, the continued expression and function of Hox genes at postnatal and adult stages highlights crucial roles for these genes throughout the life of an organism. Here, we provide an overview of Hox genes, highlighting their evolutionary history, their unique genomic organization and how this impacts the regulation of their expression, what is known about their protein structure, and their deployment in development and beyond.

Morphogenesis of the female reproductive tract along antero-posterior and dorso-ventral axes is dependent on Amhr2+ mesenchyme in mice†

Morphogenesis of the female reproductive tract is regulated by the mesenchyme. However, the identity of the mesenchymal lineage that directs the morphogenesis of the female reproductive tract has not been determined. Using in vivo genetic cell ablation, we identified Amhr2+ mesenchyme as an essential mesenchymal population in patterning the female reproductive tract. After partial ablation of Amhr2+ mesenchymal cells, the oviduct failed to develop its characteristic coiling due to decreased epithelial proliferation and tubule elongation during development. The uterus displayed a reduction in size and showed decreased cellular proliferation in both epithelial and mesenchymal compartments. More importantly, in the uterus, partial ablation of Amhr2+ mesenchyme caused abnormal lumen shape and altered the direction of its long axis from the dorsal-ventral axis to the left-right axis (i.e., perpendicular to the dorsal-ventral axis). Despite these morphological defects, epithelia underwent normal differentiation into secretory and ciliated cells in the oviduct and glandular epithelial cells in the uterus. These results demonstrated that Amhr2+ mesenchyme can direct female reproductive tract morphogenesis by regulating epithelial proliferation and lumen shape without affecting the differentiation of epithelial cell types.

Update on Mayer-Rokitansky-Küster-Hauser syndrome

This review presents an update of Mayer-Rokitansky-Küster-Hauser (MRKH) syndrome on its etiologic, clinical, diagnostic, psychological, therapeutic, and reproductive aspects. The etiology of MRKH syndrome remains unclear due to its intrinsic heterogeneity. Nongenetic and genetic causes that may interact during the embryonic development have been proposed with no definitive etiopathogenesis identified. The proportion of concomitant extragenital malformations varies in different studies, and the discrepancies may be explained by ethnic differences. In addition to physical examination and pelvic ultrasound, the performance of pelvic magnetic resonance imaging is crucial in detecting the presence of rudimentary uterine endometrium. MRKH syndrome has long-lasting psychological effects on patients, resulting in low esteem, poor coping strategies, depression, and anxiety symptoms. Providing psychological counseling and peer support to diagnosed patients is recommended. Proper and timely psychological intervention could significantly improve a patient's outcome. Various nonsurgical and surgical methods have been suggested for treatment of MRKH syndrome. Due to the high success rate and minimal risk of complications, vaginal dilation has been proven to be the first-line therapy. Vaginoplasty is the second-line option for patients experiencing dilation failure. Uterine transplantation and gestational surrogacy are options for women with MRKH syndrome to achieve biological motherhood.

Leveraging global multi-ancestry meta-analysis in the study of idiopathic pulmonary fibrosis genetics

The research of rare and devastating orphan diseases, such as idiopathic pulmonary fibrosis (IPF) has been limited by the rarity of the disease itself. The prognosis is poor-the prevalence of IPF is only approximately four times the incidence, limiting the recruitment of patients to trials and studies of the underlying biology. Global biobanking efforts can dramatically alter the future of IPF research. We describe a large-scale meta-analysis of IPF, with 8,492 patients and 1,355,819 population controls from 13 biobanks around the globe. Finally, we combine this meta-analysis with the largest available meta-analysis of IPF, reaching 11,160 patients and 1,364,410 population controls. We identify seven novel genome-wide significant loci, only one of which would have been identified if the analysis had been limited to European ancestry individuals. We observe notable pleiotropy across IPF susceptibility and severe COVID-19 infection and note an unexplained sex-heterogeneity effect at the strongest IPF locus MUC5B.

Studying Müllerian duct anomalies - from cataloguing phenotypes to discovering causation

Müllerian duct anomalies (MDAs) are developmental disorders of the Müllerian duct, the embryonic anlage of most of the female reproductive tract. The prevalence of MDAs is 6.7% in the general female population and 16.7% in women who exhibit recurrent miscarriages. Individuals affected by these anomalies suffer from high rates of infertility, first-trimester pregnancy losses, premature labour, placental retention, foetal growth retardation and foetal malpresentations. The aetiology of MDAs is complex and heterogeneous, displaying a range of clinical pictures that generally lack a direct genotype-phenotype correlation. De novo and familial cases sharing the same genomic lesions have been reported. The familial cases follow an autosomal-dominant inheritance, with reduced penetrance and variable expressivity. Furthermore, few genetic factors and molecular pathways underpinning Müllerian development and dysregulations causing MDAs have been identified. The current knowledge in this field predominantly derives from loss-of-function experiments in mouse and chicken models, as well as from human genetic association studies using traditional approaches, such as microarrays and Sanger sequencing, limiting the discovery of causal factors to few genetic entities from the coding genome. In this Review, we summarise the current state of the field, discuss limitations in the number of studies and patient samples that have stalled progress, and review how the development of new technologies provides a unique opportunity to overcome these limitations. Furthermore, we discuss how these new technologies can improve functional validation of potential causative alterations in MDAs.

Summary: Here, we review the current knowledge about Müllerian duct anomalies in the context of new high-throughput technologies and model systems and their implications in the prevention of these disorders.

The Possibility of Analyzing Endometrial Receptivity Using Cells from Embryo Transfer Catheters

It is very important to investigate the expression of endometrial receptive markers in the endometrium during implantation. Therefore, we examined whether it would be possible to analyze endometrial receptivity using cells from embryo transfer catheters. A total of 81 cycles from 81 consenting patients were enrolled in this study. The tip of the embryo transfer (ET) catheter was cut and immersed in a dedicated reagent. Confirmation of cell distribution was carried out using a Papanicolaou stain and immunocytochemistry. Protein expression was carried out by immunocytochemistry. The expressions of estrogen receptor α, progesterone receptor, and homeobox A10 mRNA were analyzed using quantitative reverse transcription-polymerase chain reaction. We analyzed the relationship between the gene expression profiles associated with pregnancy from endometrial cells. Samples collected from the ET catheter showed clear staining for endometrial cells. Most of the cells were endometrial epithelial cells. Cervical cells were not observed. The protein expression was also confirmed. Three genes were analyzed that are associated with endometrial receptivity. Progesterone receptor expression was 1.4-fold (p<0.05) and homeobox A10 was 2.8-fold (p<0.01) higher in patients who became non-pregnant group, compared to the pregnant group. Estrogen receptor α expression tended to be higher in the non-pregnant group (p=0.18). Our results suggest that endometrial receptivity can be evaluated using cells obtained from the ET catheter. This method may be useful for elucidating the cause of implantation failure by comparing a receptive and non-receptive endometrium at the time of ET.

Estrogen suppresses HOXB2 expression via ERα in breast cancer cells

The expression of HOXB2, a homeobox transcription factor, is altered in a variety of solid tumors. Using an in vivo screen to identify regulators of breast tumor growth in murine mammary fat pads, Boimel and co-workers recently identified HOXB2 as a tumor suppressor. However, the mechanistic underpinnings of its role in breast cancer is not understood. Given the emerging interaction of estrogen-regulated gene expression and altered HOX gene expression network in the pathophysiology of breast cancer, this study addressed the relationship between estrogen signaling and HOXB2 expression. Using a mouse model and human breast cancer cell lines, we show that estrogen suppresses HOXB2 expression. Suppression of HOXB2 by PPT, a known ERα agonist, in MCF-7 and T47D cells indicated the involvement of ERα, which was confirmed by siRNA-mediated ERα knockdown experiments. In-silico analysis of the upstream promoter region revealed the presence of three putative EREs. Chromatin immunoprecipitation experiments showed that upon estrogen binding, ERα engaged with EREs in the 5' upstream region of HOXB2 in MCF-7 and T47D cells. Future investigations should address the implications of estrogen-mediated suppression on the proposed tumor suppressor function of HOXB2.

Mechanistic Drivers of Müllerian Duct Development and Differentiation Into the Oviduct

The conduits of life; the animal oviducts and human fallopian tubes are of paramount importance for reproduction in amniotes. They connect the ovary with the uterus and are essential for fertility. They provide the appropriate environment for gamete maintenance, fertilization and preimplantation embryonic development. However, serious pathologies, such as ectopic pregnancy, malignancy and severe infections, occur in the oviducts. They can have drastic effects on fertility, and some are life-threatening. Despite the crucial importance of the oviducts in life, relatively little is known about the molecular drivers underpinning the embryonic development of their precursor structures, the Müllerian ducts, and their successive differentiation and maturation. The Müllerian ducts are simple rudimentary tubes comprised of an epithelial lumen surrounded by a mesenchymal layer. They differentiate into most of the adult female reproductive tract (FRT). The earliest sign of Müllerian duct formation is the thickening of the anterior mesonephric coelomic epithelium to form a placode of two distinct progenitor cells. It is proposed that one subset of progenitor cells undergoes partial epithelial-mesenchymal transition (pEMT), differentiating into immature Müllerian luminal cells, and another subset undergoes complete EMT to become Müllerian mesenchymal cells. These cells invaginate and proliferate forming the Müllerian ducts. Subsequently, pEMT would be reversed to generate differentiated epithelial cells lining the fully formed Müllerian lumen. The anterior Müllerian epithelial cells further specialize into the oviduct epithelial subtypes. This review highlights the key established molecular and genetic determinants of the processes involved in Müllerian duct development and the differentiation of its upper segment into oviducts. Furthermore, an extensive genome-wide survey of mouse knockout lines displaying Müllerian or oviduct phenotypes was undertaken. In addition to widely established genetic determinants of Müllerian duct development, our search has identified surprising associations between loss-of-function of several genes and high-penetrance abnormalities in the Müllerian duct and/or oviducts. Remarkably, these associations have not been investigated in any detail. Finally, we discuss future directions for research on Müllerian duct development and oviducts.

Assessment of the in vitro developmental toxicity of diethylstilbestrol and estradiol in the zebrafish embryotoxicity test

The present study investigated the developmental toxicity of diethylstilbestrol (DES) in the zebrafish embryotoxicity test (ZET). This was done to investigate whether the ZET would better capture the developmental toxicity of DES than the embryonic stem cells test (EST) that was previously shown to underpredict the DES-induced developmental toxicity as compared to in vivo data, potentially because the EST does not capture late events in the developmental process. The ZET results showed DES-induced growth retardation, cumulative mortality and dysmorphisms (i.e. induction of pericardial edema) in zebrafish embryos while the endogenous ERα agonist 17β-estradiol (E2) showed only growth retardation and cumulative mortality with lower potency compared to DES. Furthermore, the DES-induced pericardial edema formation in zebrafish embryos could be counteracted by co-exposure with ERα antagonist fulvestrant, indicating that the ZET captures the role of ERα in the mode of action underlying the developmental toxicity of DES. Altogether, it is concluded that the ZET differentiates DES from E2 with respect to their developmental toxicity effects, while confirming the role of ERα in mediating the developmental toxicity of DES. Furthermore, comparison to in vivo data revealed that, like the EST, in a quantitative way also the ZET did not capture the relatively high in vivo potency of DES as a developmental toxicant.

Developmental estrogenization: Prostate gland reprogramming leads to increased disease risk with aging

While estrogens are involved in normal prostate morphogenesis and function, inappropriate early-life estrogenic exposures, either in type, dose or timing, can reprogram the prostate gland and lead to increased disease risk with aging. This process is referred to as estrogen imprinting or developmental estrogenization of the prostate gland. The present review discusses published and new evidence for prostatic developmental estrogenization that includes extensive research in rodent models combined with epidemiology findings that together have helped to uncover the architectural and molecular underpinnings that promote this phenotype. Complex interactions between steroid receptors, developmental morphoregulatory factors, epigenetic machinery and stem-progenitor cell targets coalesce to hard wire structural, cellular and epigenomic reorganization of the tissue which retains a life-long memory of early-life estrogens, ultimately predisposing the gland to prostatitis, hyperplasia and carcinogenesis with aging.

New frontiers of developmental endocrinology opened by researchers connecting irreversible effects of sex hormones on developing organs

In the early 1960's, at Professor Bern's laboratory, University of California, Berkeley) in the US, Takasugi discovered ovary-independent, persistent vaginal changes in mice exposed neonatally to estrogen, which resulted in vaginal cancer later in life. Reproductive abnormalities in rodents were reported as a result of perinatal exposure to various estrogenic chemicals. Ten years later, vaginal cancers were reported in young women exposed in utero to the synthetic estrogen diethylstilbestrol (DES) and this has been called the "DES syndrome". The developing organism is particularly sensitive to developmental exposure to estrogens inducing long-term changes in various organs including the reproductive organs. The molecular mechanism underlying the persistent vaginal changes induced by perinatal estrogen exposure was partly demonstrated. Persistent phosphorylation and sustained expression of EGF-like growth factors, lead to estrogen receptor α (ESR1) activation, and then persistent vaginal epithelial cell proliferation. Agents which are weakly estrogenic by postnatal criteria may have major developmental effects, especially during a critical perinatal period. The present review outlines various studies conducted by four generations of investigators all under the influence of Prof. Bern. The studies include reports of persistent changes induced by neonatal androgen exposure, analyses of estrogen responsive genes, factors determining epithelial differentiation in the Müllerian duct, ESR and growth factor signaling, and polyovular follicles in mammals. This review is then expanded to the studies on the effects of environmental estrogens on wildlife and endocrine disruption in Daphnids.

Neonatal exposure to a glyphosate-based herbicide alters the uterine differentiation of prepubertal ewe lambs

The exposure to endocrine-disrupting compounds (EDCs), such as glyphosate-based herbicides (GBHs), during early life might alter female fertility. The aim of the present study was to evaluate the effects of neonatal exposure to a GBH on sheep uterine development. To achieve this, Friesian ewe lambs were exposed to GBH (2 mg/kg of body weight/day; n = 12) or vehicle (controls; n = 10) through s.c. injections, from postnatal day (PND) 1 to PND14; on PND45, the uteri were obtained to evaluate histomorphological and molecular parameters. Morphological parameters were determined by picrosirius-hematoxylin staining. Protein expression of Ki67 (as a cell proliferation marker), p27, and molecules involved in uterine organogenetic differentiation was measured by immunohistochemistry. We also determined the mRNA expression of the IGF molecular pathway by RT-PCR. Although histomorphology was not modified, the uteri of GBH-exposed ewe lambs showed lower cell proliferation, together with higher p27 protein expression. In addition, the uteri of GBH-exposed ewe lambs showed increased gene expression of insulin-like growth factor binding protein 3 (IGFBP-3), decreased expression of ERα in the luminal (LE) and glandular (GE) epithelia and in the subepithelial stroma (SS), and lower PR expression in the LE but higher in the GE and SS. In addition, GBH treatment decreased the uterine expression of Wnt5a in the GE, of Wnt7a in the SS, of β-catenin in the LE and GE, of Hoxa10 in the SS, and of Foxa2 in the GE as compared with controls. In conclusion, neonatal exposure to GBH decreased cell proliferation and altered the expression of molecules that control proliferation and development in the uterus. All these changes might have adverse consequences on uterine differentiation and functionality, affecting the female reproductive health of sheep. GBH may be responsible for uterine subfertility, acting as an EDC.

Hox-Positive Adult Mesenchymal Stromal Cells: Beyond Positional Identity

Homeotic genes (Hox) are universal regulators of the body patterning process in embryogenesis of metazoans. The Hox gene expression pattern (Hox code) retains in adult tissues and serves as a cellular positional identity marker. Despite previously existing notions that the Hox code is inherent in all stroma mesenchymal cells as a whole, recent studies have shown that the Hox code may be an attribute of a distinct subpopulation of adult resident mesenchymal stromal cells (MSC). Recent evidence allows suggesting a "non-canonical" role for Hox gene expression which is associated with renewal and regeneration in postnatal organs after damage. In tissues with high regenerative capacity, it has been shown that a special cell population is critical for these processes, a distinctive feature of which is the persistent expression of tissue-specific Hox genes. We believe that in the postnatal period Hox-positive subpopulation of resident MSC may serve as a unique regenerative reserve. These cells coordinate creation and maintenance of the correct structure of the stroma through a tissue-specific combination of mechanisms. In this article, we summarize data on the role of resident MSC with a tissue-specific pattern of Hox gene expression as regulators of correct tissue reconstruction after injury.

Wnt pathway: A mechanism worth considering in endocrine disrupting chemical action

Endocrine disrupting chemicals (EDCs) are defined as exogenous substances that can alter the development and functioning of the endocrine system. The Wnt signaling pathway is an evolutionarily conserved pathway consisting of proteins that transmit cell-to-cell receptors through cell surface receptors, regulating important aspects of cell migration, polarity, neural formation, and organogenesis, which determines the fate of the cell during embryonic development. Although the effects of EDCs have been studied in terms of many molecular mechanisms; because of its critical role in embryogenesis, the Wnt pathway is of special interest in EDC exposure. This review provides information about the effects of EDC exposure on the Wnt/β-catenin pathway focusing on studies on bisphenol A, di-(2-ethylhexyl) phthalate, diethylstilbestrol, cadmium, and 2,3,7,8-tetrachlorodibenzo-p-dioxin.

Pregnant women, prescription, and fetal risk

Since the historical scandal of thalidomide in the 1960s, practitioners and future mothers are fearful of drugs during pregnancy. In-uterine exposure to drugs can induce major malformation of the fetus or even intrauterine fetal death. Prescribing drugs to a pregnant woman requires particular attention, and it is necessary to consider both the maternal needs and the proven and potential fetal risks. In this chapter, we review the mechanisms for medication transfer from mother to fetus, fetal risk according to pregnancy timeline, and the main dangerous drugs during pregnancy. We also focus on three prescription debates, which are relevant for neurodevelopmental disorder, because they each point to a paradigmatic situation-diethylstilbestrol, which shows transgenerational adversary effects; valproate, which impacts neurodevelopment as a whole; and antidepressants for which the adverse impact on neurodevelopment is still controversial given the impact of depression itself. Finally, we consider the implications for practice and toxicologic research to promote risk prevention.

The in vivo developmental toxicity of diethylstilbestrol (DES) in rat evaluated by an alternative testing strategy

In the present study, we evaluated an alternative testing strategy to quantitatively predict the in vivo developmental toxicity of the synthetic hormone diethylstilbestrol (DES). To this end, a physiologically based kinetic (PBK) model was defined that was subsequently used to translate concentration-response data for the in vitro developmental toxicity of DES, obtained in the ES-D3 cell differentiation assay, into predicted in vivo dose-response data for developmental toxicity. The previous studies showed that the PBK model-facilitated reverse dosimetry approach is a useful approach to quantitatively predict the developmental toxicity of several developmental toxins. The results obtained in the present study show that the PBK model adequately predicted DES blood concentrations in rats. Further studies revealed that DES tested positive in the ES-D3 differentiation assay and that DES-induced inhibition of the ES-D3 cell differentiation could be counteracted by the estrogen receptor alpha (ERα) antagonist fulvestrant, indicating that the in vitro ES-D3 cell differentiation assay was able to mimic the role of ERα reported in the mode of action underlying the developmental toxicity of DES in vivo. In spite of this, combining these in vitro data with the PBK model did not adequately predict the in vivo developmental toxicity of DES in a quantitative way. It is concluded that although the EST qualifies DES as a developmental toxin and detects the role of ERα in this process, the ES-D3 cell differentiation assay of the EST apparently does not adequately capture the processes underlying DES-induced developmental toxicity in vivo.

Single cell RNA-seq study of wild type and Hox9,10,11 mutant developing uterus

The uterus is a remarkable organ that must guard against infections while maintaining the ability to support growth of a fetus without rejection. The Hoxa10 and Hoxa11 genes have previously been shown to play essential roles in uterus development and function. In this report we show that the Hoxa9,10,11, Hoxc9,10,11, Hoxd9,10,11 genes play a redundant role in the formation of uterine glands. In addition, we use single cell RNA-seq to create a high resolution gene expression atlas of the developing wild type mouse uterus. Cell types and subtypes are defined, for example dividing endothelial cells into arterial, venous, capillary, and lymphatic, while epithelial cells separate into luminal and glandular subtypes. Further, a surprising heterogeneity of stromal and myocyte cell types are identified. Transcription factor codes and ligand/receptor interactions are characterized. We also used single cell RNA-seq to globally define the altered gene expression patterns in all developing uterus cell types for two Hox mutants, with 8 or 9 mutant Hox genes. The mutants show a striking disruption of Wnt signaling as well as the Cxcl12/Cxcr4 ligand/receptor axis.

Surgical management of congenital uterine anomalies (including indications and surgical techniques)

The prevalence of congenital uterine anomalies (CUA) is reported to be 4.3-6.7% in the general population, 3.4%-8% in the infertile population, and 12.6-18.2% of those with recurrent miscarriages. They are the result of abnormal formation, differentiation, and fusion of the Müllerian or paramesonephric ducts during fetal life. To date, various classification systems have been proposed for the categorization of CUA, but the recently introduced ESHRE/ESGE classification seems to be a new, clear, and systematic categorization, which could be the basis for clinicians to rely on when they refer to CUA and their clinical impact either generally or concerning pregnancy outcomes. CUA are apparently related to an impaired reproductive outcome, while their exact clinical impact as well as the effectiveness of their treatment remain considered controversial. Surgery is indicated in women presenting with symptoms related to specific uterine anomalies, especially in those with fertility problems. In this review, indications, surgical techniques for the repair of CUA according to their classification, and fertility and pregnancy outcomes before and after surgery will be thoroughly reviewed.

Physiological and pathological implications of retinoid action in the endometrium

Retinol (vitamin A) and its derivatives, collectively known as retinoids, are required for maintaining vision, immunity, barrier function, reproduction, embryogenesis and cell proliferation and differentiation. Despite the fact that most events in the endometrium are predominantly regulated by steroid hormones (estrogens and progesterone), accumulating evidence shows that retinoid signaling is also involved in the development and maintenance of the endometrium, stromal decidualization and blastocyst implantation. Moreover, aberrant retinoid metabolism seems to be a critical factor in the development of endometriosis, a common gynecological disease, which affects up to 10% of reproductive age women and is characterized by the ectopic localization of endometrial-like tissue in the pelvic cavity. This review summarizes recent advances in research on the mechanisms and molecular actions of retinoids in normal endometrial development and physiological function. The potential roles of abnormal retinoid signaling in endometriosis are also discussed. The objectives are to identify limitations in current knowledge regarding the molecular actions of retinoids in endometrial biology and to stimulate new investigations toward the development potential therapeutics to ameliorate or prevent endometriosis symptoms.

Homeobox genes for embryo implantation: From mouse to human

The proper development of uterus to a state of receptivity and the attainment of implantation competency for blastocyst are 2 indispensable aspects for implantation, which is considered to be a critical event for successful pregnancy. Like many developmental processes, a large number of transcription factors, such as homeobox genes, have been shown to orchestrate this complicated but highly organized physiological process during implantation. In this review, we focus on progress in studies of the role of homeobox genes, especially the Hox and Msx gene families, during implantation, together with subsequent development of post-implantation uterus and related reproductive defects in both mouse models and humans, that have led to better understanding of how implantation is precisely regulated and provide new insights into infertility.

Comparative Aspects of Pre- and Postnatal Development of the Male Reproductive System

This review describes pre- and postnatal development of the male reproductive system in humans and laboratory animals, and highlights species differences in the timing and control of hormonal and morphologic events. Major differences are that the fetal testis is dependent on gonadotropins in humans, but is independent of such in rats; humans have an extended postnatal quiescent period, whereas rats exhibit no quiescence; and events such as secretion by the prostate and seminal vesicles, testicular descent, and the appearance of spermatogonia are all prenatal events in humans, but are postnatal events in rats. Major differences in the timing of the developmental sequence between rats and humans include: gonocyte transformation period (rat: postnatal day 0-9; human: includes gestational week 22 to 9 months of age); masculinization programming window (rat: gestational day 15.5-17.5; human: gestational week 9-14); and mini-puberty (rat: 0-6 hr after birth; human: 3-6 months of age). Endocrine disruptors can cause unique lesions in the prenatal and early postnatal testis; therefore, it is important to consider the differences in the timing of the developmental sequence when designing preclinical studies as identification of windows of sensitivity for endocrine disruption or toxicants will aid in interpretation of results and provide clues to a mode of action. Birth Defects Research 110:190-227, 2018. © 2017 Wiley Periodicals, Inc.

Long-Term Neonatal Estrogen Exposure Causes Irreversible Inhibition of LH Pulses by Suppressing Arcuate Kisspeptin Expression via Estrogen Receptors α and β in Female Rodents

Exposure to estrogen during the developmental period causes reproductive dysfunction in mammals, because the developing brain is highly sensitive to estrogens. In the present study, we report that long-term exposure to supraphysiological doses of estrogen during the neonatal critical period causes irreversible suppression of Kiss1/kisspeptin expression in the arcuate nucleus (ARC) via estrogen receptor-alpha (ERα) and ERβ, resulting in reproductive dysfunction in female rats. Daily estradiol-benzoate (EB) administration from days 0 to 10 postpartum caused persistent vaginal diestrus in female rats. The female rats showed profound suppression of pulsatile luteinizing hormone (LH) release and ARC Kiss1/kisspeptin expression even after ovariectomy at adulthood. In contrast, female rats treated with a single EB injection at day 5 postpartum exhibited persistent vaginal estrus and showed comparable LH pulses and numbers of ARC Kiss1-expressing cells to vehicle-treated controls after ovariectomy at adulthood. Because the LH secretory response to exogenous kisspeptin was spared in female rats with neonatal long-term estrogen exposure, the LH pulse suppression was most probably due to ARC kisspeptin deficiency. Furthermore, neonatal estrogen might act through both ERα and ERβ, because EB exposure significantly reduced the number of ARC Kiss1-expressing cells in wild-type mice but not in ERα or ERβ knockout mice. Taken together, long-term exposure to supraphysiological doses of estrogen in the developing brain might cause defects in ARC kisspeptin neurons via ERα and ERβ, resulting in inhibition of pulsatile LH release and lack of estrous cyclicity.

Molecular mechanisms of development of the human fetal female reproductive tract

Human female reproductive tract development rests mostly upon hematoxilyn and eosin stained sections despite recent advances on molecular mechanisms in mouse studies. We report application of immunohistochemical methods to explore the ontogeny of epithelial and mesenchymal differentiation markers (keratins, homobox proteins, steroid receptors), transcription factors and signaling molecules (TP63 and RUNX1) during human female reproductive tract development. Keratins 6, 7, 8, 10, 14 and 19 (KRT6, KRT7, KRT8, KRT10, KRT14, KRT19) were expressed in a temporally and spatially dynamic fashion. The undifferentiated Müllerian duct and uterovaginal canal, lined by simple columnar epithelia, expressed KRT7, KRT8 and KRT19. Glandular derivatives of the Müllerian duct (uterine tube, uterine corpus and endocervix) maintained expression of these keratins, while tissues that undergo stratified squamous differentiation (exocervix and vagina) expressed KRT6, KRT14 and KRT10 during development in an age-dependent fashion. TP63 and RUNX1 were expressed prior to KRT14, as these two transcription factors are known to be upstream from KRT14 in developing Müllerian epithelium. In the vagina, KRT10, a marker of terminal differentiation, appeared after endogenous estrogens transformed the epithelium to a thick glycogenated squamous epithelium. Uroplakin, a protein unique to urothelium, was expressed only in the bladder, urethra and vaginal introitus, but not in the female reproductive tract itself. Mesenchymal differentiation was examined through immunostaining for HOXA11 (expressed in uterine mesenchyme) and ISL1 (expressed in vaginal mesenchyme). A detailed ontogeny of estrogen receptor alpha (ESR1), progesterone receptor (PGR) and the androgen receptor (AR) provides the mechanistic underpinning for the teratogenicity of estrogens, progestins and androgens on female reproductive tract development. Immunohistochemical analysis of differentiation markers and signaling molecules advance our understanding of normal development of the human female reproductive tract. These observations demonstrate remarkable similarities in mouse and human female reproductive tract development, but also highlight some key differences.

G-protein coupled receptor 64 is required for decidualization of endometrial stromal cells

Although GPR64 has an important role for male fertility, its physiological roles in the female reproductive system are still unknown. In the present study, immunohistochemical analysis reveals a spatiotemporal expression of GPR64 in the uterus during early pregnancy. Observation of remarkable induction of GPR64 expression in uterine decidual cells points to its potential physiological significance on decidualization. The decidualization of uterine stromal cells is a key event in implantation. Progesterone (P4) signaling is crucial for the decidualization of the endometrial stromal cells for successful pregnancy. Therefore, we examined ovarian steroid hormone regulation of GPR64 expression in the murine uterus. P4 induced GPR64 expression in the epithelial and stromal cells of the uterus in ovariectomized wild-type mice, but not in PRKO mice. ChIP analysis confirmed that PGR proteins were recruited on progesterone response element of Gpr64 gene in the uteri of wild-type mice treated with P4. Furthermore, the expression of GPR64 was increased in human endometrial stromal cells (hESCs) during in vitro decidualization. Interestingly, small interfering RNA (siRNA)-mediated knockdown of GPR64 in hESCs remarkably reduced decidualization. These results suggest that Gpr64 has a crucial role in the decidualization of endometrial stromal cells.

Progesterone transfer among cohabitating female big brown bats (Eptesicus fuscus)

Experiments using female mice and bats have demonstrated that tritium-labeled 17β-estradiol (³H-E₂) can be absorbed via cutaneous and intranasal routes and distributed to reproductive and neural tissues. Radioactivity has also been measured in tissues of untreated females after 48h cohabitation with ³H-E₂ injected males. The present study was designed to quantify steroid transfer among female bats. Radioactive quantification via liquid scintillation counting revealed absorption of tritium-labeled progesterone (³H-P₄) in adult females 1h after cutaneous and intranasal application (10μCi). Subsequently, pairs of mature females were each housed for 48h with a single mature female that had been administered ³H-P₄ (50μCi) via intraperitoneal injection. Radioactivity was observed in all collected tissues of all non-injected females at levels significantly greater than the control group. Following the same paradigm, radioactivity was not observed in the tissues of untreated female bats that were housed with stimulus females treated with ³H-E₂ (50μCi). Enzyme immunoassays revealed measurable levels of unconjugated progesterone and estradiol in the urine of female bats, suggesting urine as a vector for steroid transfer. Given that bats of this species live in predominantly female roosts in very close contact, progesterone transfer among individuals is likely to occur in natural roosts.

Exposure to benzo[a]pyrene impairs decidualization and decidual angiogenesis in mice during early pregnancy

Benzo[a]pyrene (BaP) is a ubiquitous environmental persistent organic pollutant and a well-known endocrine disruptor. BaP exposure could alter the steroid balance in females. Endometrium decidualization and decidual angiogenesis are critical events for embryo implantation and pregnancy maintenance during early pregnancy and are modulated by steroids. However, the effect of BaP on decidualization is not clear. This study aimed to explore the effects of BaP on decidualization and decidual angiogenesis in pregnant mice. The result showed that the uteri in the BaP-treated groups were smaller and exhibited an uneven size compared with those in the control group. Artificial decidualization was detected in the uteri of the controls, but weakened decidualization response was observed in the BaP-treated groups. BaP significantly reduced the levels of estradiol, progesterone, and their cognate receptors ER and PR, respectively. The expression of several decidualization-related factors, including FOXO1, HoxA10, and BMP2, were altered after BaP treatment. BaP reduced the expression of cluster designation 34 (CD34), which indicated that the decidual angiogenesis was inhibited by BaP treatment. In addition, BaP induced the downregulation of vascular endothelial growth factor A. These data suggest that oral BaP ingestion compromised decidualization and decidual angiogenesis. Our results provide experimental data for the maternal reproductive toxicity of BaP during early pregnancy, which is very important for a comprehensive risk assessment of BaP on human reproductive health.

Retinoic acid signaling determines the fate of uterine stroma in the mouse Müllerian duct

The Müllerian duct develops into the oviduct, uterus, and vagina, all of which are quite distinct in their morphology and function. The epithelial fate of these female reproductive organs in developing mice is determined by factors secreted from the stroma; however, how stromal differentiation occurs in the female reproductive organs derived from the Müllerian duct is still unclear. In the present study, roles of retinoic acid (RA) signaling in developing female reproductive tracts were investigated. Retinol dehydrogenase 10 (RDH10) and aldehyde dehydrogenase family 1 subfamily A2 (ALDH1A2) mRNAs and proteins and transactivation activity of endogenous RA were found in the stroma of proximal Müllerian ducts and gradually decreased from the proximal to caudal regions in fetal mice. In organ-cultured Müllerian ducts, retinaldehyde or RA treatment induced uterine epithelial differentiation, defined as a layer of columnar epithelial cells negative for oviductal and vaginal epithelial markers. In contrast, inhibition of RA receptor (RAR) signaling induced vaginal epithelial differentiation, characterized as vaginal epithelial marker genes-positive stratified epithelium. Grafting experiments of the organ-cultured Müllerian duct revealed irreversible epithelial fate determination. Although RAR did not directly bind to the homeobox A10 (Hoxa10) promoter region, RA-RAR signaling stimulated Hoxa10 expression. Thus, RA-RAR signaling in the Müllerian duct determines the fate of stroma to form the future uterus and vagina.

Hoxa-10 and Cyclin D3 Overexpression in the Decidual Reaction in a Superovulation Protocol in Young Adult C57BL/6J Mice

Following the performance of a superovulation protocol, multiple nodules were observed bilaterally in the uterine horns of 31 of 276 (11.2%) C57BL/6 J female mice aged 8.5 ± 0.6 (mean and standard error of mean) weeks. These lesions prevented embryo collection, and the uterine decidual reaction was suspected. Samples of pathological uteri (n = 20) and the normal genital tracts of donors treated with a similar superovulation protocol (control group, n = 10) were collected. Immunohistochemistry was performed to evaluate pancytokeratin, desmin, vimentin, progesterone receptor (PR), estrogen receptor α (ERα), Ki-67, cyclin D3 and c-Myc expression, as well as quantitative polymerase chain reaction to assess cyclin D3, Hoxa-10 and heparin-binding epidermal growth factor-like growth factor (HB-EGF) mRNA expression. The uterine decidual reaction presented a high degree of structural organization and specifically affected the antimesometrial region of the endometrium. The abnormal decidual cells were large polygonal cells that were frequently polyploid or binucleated and strongly positive for desmin. Immunohistochemistry showed higher Ki-67 proliferation index and higher expression of PR and cyclin D3 in decidual cells in the antimesometrial aspect of the endometrium, compared to nondecidualized endometrial stromal cells in the mesometrial aspect of affected uteri, and compared to endometrial stromal cells in healthy uteri. High expression of cyclin D3 and Hoxa-10 mRNA was also observed in uteri affected by the decidual reaction. These results suggest that PR overexpression in endometrial stromal cells, likely due to high progesterone levels, triggers cyclin D3 and Hoxa-10 overexpression, which may be involved in the pathological mechanisms of the mouse uterine decidual reaction.

The reduced PDCD5 protein is correlated with the degree of tumor differentiation in endometrioid endometrial carcinoma

Endometrial cancer is one of the most common malignancies in the female genital tract. Programmed cell death 5 (PDCD5) is a newly identified apoptosis related gene and plays an important role in the development of some human tumors. However, the expression and clinical significance of PDCD5 in endometrial cancer have not been fully elucidated. Here, we evaluated the expression of PDCD5 in endometrioid endometrial carcinoma and control endometrium by qRT-PCR, western blot and immunohistochemistry, and analyzed the associations of PDCD5 expression with clinicopathological parameters of patients. In addition, we detected the expression of PDCD5 in control endometrial glandular epithelial cells and endometrioid endometrial carcinoma-derived cell line KLE by immunocytochemistry. The results showed that PDCD5 protein mainly expressed in the cytoplasm of glandular epithelial cells and endometrial carcinoma cells, and there was a low level of PDCD5 expression in the nuclei of the above cells. Furthermore, PDCD5 protein level was significantly lower in endometrial carcinoma samples than that in control endometrium. The decreased PDCD5 expression was correlated with the tumor differentiation degree. It is clear that PDCD5 protein expression was lower in middle and low differentiated endometrial carcinoma compared with control endometrium and high differentiated endometrial carcinoma. However, there were no significant differences of PDCD5 expression between the proliferative phase and the secretory phase of control endometrium, as well as between high differentiated endometrial carcinoma and controls. The results were verified in control glandular epithelial cells and KLE cells by immunocytochemistry. Therefore, PDCD5 may play a key role in the pathogenesis of endometrial cancer and may be a novel target for diagnosis and treatment of endometrial cancer.

FGFR2IIIb-MAPK Activity Is Required for Epithelial Cell Fate Decision in the Lower Müllerian Duct

Cell fate of lower Müllerian duct epithelium (MDE), to become uterine or vaginal epithelium, is determined by the absence or presence of ΔNp63 expression, respectively. Previously, we showed that SMAD4 and runt-related transcription factor 1 (RUNX1) were independently required for MDE to express ΔNp63. Here, we report that vaginal mesenchyme directs vaginal epithelial cell fate in MDE through paracrine activation of fibroblast growth factor (FGF) receptor-MAPK pathway. In the developing reproductive tract, FGF7 and FGF10 were enriched in vaginal mesenchyme, whereas FGF receptor 2IIIb was expressed in epithelia of both the uterus and vagina. When Fgfr2 was inactivated, vaginal MDE underwent uterine cell fate, and this differentiation defect was corrected by activation of MEK-ERK pathway. In vitro, FGF10 in combination with bone morphogenetic protein 4 and activin A (ActA) was sufficient to induce ΔNp63 in MDE, and ActA was essential for induction of RUNX1 through SMAD-independent pathways. Accordingly, inhibition of type 1 receptors for activin in neonatal mice induced uterine differentiation in vaginal epithelium by down-regulating RUNX1, whereas conditional deletion of Smad2 and Smad3 had no effect on vaginal epithelial differentiation. In conclusion, vaginal epithelial cell fate in MDE is induced by FGF7/10-MAPK, bone morphogenetic protein 4-SMAD, and ActA-RUNX1 pathway activities, and the disruption in any one of these pathways results in conversion from vaginal to uterine epithelial cell fate.

Local and systemic factors and implantation: what is the evidence?

Significant progress has been made in the understanding of embryonic competence and endometrial receptivity since the inception of assisted reproductive technology. The endometrium is a highly dynamic tissue that plays a crucial role in the establishment and maintenance of normal pregnancy. In response to steroid sex hormones, the endometrium undergoes marked changes during the menstrual cycle that are critical for acceptance of the nascent embryo. There is also a wide body of literature on systemic factors that impact assisted reproductive technology outcomes. Patient prognosis is impacted by an array of factors that tip the scales in her favor or against success. Recognizing the local and systemic factors will allow clinicians to better understand and optimize the maternal environment at the time of implantation. This review will address the current literature on endometrial and systemic factors related to impaired implantation and highlight recent advances in this area of reproductive medicine.

Effects of Endocrine-disrupting Chemicals on Female Reproductive Health

Endocrine-disrupting chemicals (EDCs) are increasingly prevalent in the environment and the evidence demonstrates that they affect reproductive health, has been accumulating for the last few decades. In this review of recent literature, we present evidence of the effects of estrogen-mimicking EDCs on female reproductive health especially the ovaries and uteri. As representative EDCs, data from studies with a pharmaceutical estrogen, diethylstilbestrol (DES), an organochlorine pesticide methoxychlor (MXC), a phytoestrogen (genistein), and a chemical used in plastics, bisphenol a (BPA) have been presented. We also discuss the effects of a commonly found plasticizer in the environment, a phthalate (DEHP), even though it is not a typical estrogenic EDC. Collectively, these studies show that exposures during fetal and neonatal periods cause developmental reprogramming leading to adult reproductive disease. Puberty, estrous cyclicity, ovarian follicular development, and uterine functions are all affected by exposure to these EDCs. Evidence that epigenetic modifications are involved in the progression to adult disease is also presented.

The Role of Hox Genes in Female Reproductive Tract Development, Adult Function, and Fertility

HOX genes convey positional identity that leads to the proper partitioning and adult identity of the female reproductive track. Abnormalities in reproductive tract development can be caused by HOX gene mutations or altered HOX gene expression. Diethylstilbestrol (DES) and other endocrine disruptors cause Müllerian defects by changing HOX gene expression. HOX genes are also essential regulators of adult endometrial development. Regulated HOXA10 and HOXA11 expression is necessary for endometrial receptivity; decreased HOXA10 or HOXA11 expression leads to decreased implantation rates. Alternation of HOXA10 and HOXA11 expression has been identified as a mechanism of the decreased implantation associated with endometriosis, polycystic ovarian syndrome, leiomyoma, polyps, adenomyosis, and hydrosalpinx. Alteration of HOX gene expression causes both uterine developmental abnormalities and impaired adult endometrial development that prevent implantation and lead to female infertility.

The Histone Methyltransferase Gene Absent, Small, or Homeotic Discs-1 Like Is Required for Normal Hox Gene Expression and Fertility in Mice

Chromatin remodeling influences gene expression in developing and adult organisms. Active and repressive marks of histone methylation dictate the embryonic expression boundaries of developmentally regulated genes, including the Hox gene cluster. Drosophila ash1 (absent, small or homeotic discs 1) gene encodes a histone methyltransferase essential for regulation of Hox gene expression that interacts genetically with other members of the trithorax group (TrxG). While mammalian members of the mixed lineage leukemia (Mll) family of TrxG genes have roles in regulation of Hox gene expression, little is known about the expression and function of the mammalian ortholog of the Drosophila ash1 gene, Ash1-like (Ash1l). Here we report the expression of mouse Ash1l gene in specific structures within various organs and provide evidence that reduced Ash1l expression has tissue-specific effects on mammalian development and adult homeostasis. Mutants exhibit partially penetrant postnatal lethality and failure to thrive. Surviving mutants have growth insufficiency, skeletal transformations, and infertility associated with developmental defects in both male and female reproductive organs. Specifically, expression of Hoxa11 and Hoxd10 are altered in the epididymis of Ash1l mutant males and Hoxa10 is reduced in the uterus of Ash1l mutant females. In summary, we show that the histone methyltransferase Ash1l is important for the development and function of several tissues and for proper expression of homeotic genes in mammals.

Laparoscopic endometrioma resection increases peri-implantation endometrial HOXA-10 and HOXA-11 mRNA expression

OBJECTIVE

To determine whether laparoscopic endometrioma resection alters peri-implantation endometrial HOXA-10, HOXA-11, LIF, ITGB3 and ITGAV mRNA expression.

DESIGN

Case-control study.

SETTING

Medical school.

PATIENT(S)

Twenty infertile patients with uni- or bilateral endometrioma, five infertile patients having nonendometriotic benign ovarian cyst, and five fertile control subjects.

INTERVENTION(S)

Mid-luteal-phase endometrial sampling was performed at the time of surgery. Second endometrial biopsies were obtained 3 months after laparoscopic endometrioma resection during the mid-luteal phase of the cycle.

MAIN OUTCOME MEASURE(S)

Endometrial HOXA-10, HOXA-11, LIF, ITGAV, and ITGB3 mRNA expressions were evaluated with the use of reverse-transcription polymerase chain reaction.

RESULT(S)

Significantly decreased endometrial ITGAV mRNA expression was noted in biopsies obtained from endometrioma and nonendometriotic cyst groups before surgery. Trends toward decreased endometrial HOXA-10, HOXA-11, LIF, and ITGB3 mRNA expressions were noted in the endometrioma and nonendometriotic cyst groups before surgery compared with the fertile subjects. However, the differences failed to show statistical significance. Compared with preoperative values, significantly increased HOXA-10 (12.1-fold change) and HOXA-11 (17.2-fold change) mRNA expressions were noted in endometrial biopsies obtained from subjects who were undergoing endometrioma surgery. Fold change in endometrial ITGAV mRNA after endometrioma surgery was found to be 30.1 and indicated a positive regulation. However, this fold increase was statistically insignificant. Expressions of these endometrial receptivity markers did not change significantly after surgical removal of nonendometriotic benign ovarian cysts.

CONCLUSION(S)

Laparoscopic endometrioma resection increases peri-implantation endometrial HOXA-10 and HOXA-11 mRNA expression, suggesting an improvement in endometrial receptivity.

The history of Distilbène® (Diethylstilbestrol) told to grandchildren--the transgenerational effect

The Distilbène® story is a dramatic episode which belongs to the history of medicine. It provided several useful lessons such as the importance of evidence-based medicine and the hazard to develop treatments during pregnancy without careful animal verifications. However, this experience has also provided unexpected progress by suggesting new pathophysiological concepts: fetal programming of adult diseases and/or transgenerational transmission of environmental effects through epigenetic modifications.

Epithelial cell identity in hyperplastic precursors of breast cancer

Introduction

In the adult human breast, hyperplastic enlarged lobular unit (HELU) and atypical ductal hyperplasia (ADH) are two common abnormalities that frequently coexist with ductal carcinoma in situ (DCIS). For this reason, they have been proposed as the early steps in a biological continuum toward breast cancer.

Methods

We investigated in silico the expression of 369 genes experimentally recognized as involved in establishing and maintaining epithelial cell identity and mammary gland remodeling, in HELUs or ADHs with respect to the corresponding patient-matched normal tissue.

Results

Despite the common luminal origin, HELUs and ADHs proved to be characterized by distinct gene profiles that overlap for 5 genes only. While HELUs were associated with the overexpression of progesterone receptor (PGR), ADHs were characterized by the overexpression of estrogen receptor 1 (ESR1) coupled with the overexpression of some proliferation-associated genes.

Conclusions

This unexpected finding contradicts the notion that in differentiated luminal cells the expression of estrogen receptor (ER) is dissociated from cell proliferation and suggests that the establishing of an ER-dependent signaling is able to sustain cell proliferation in an autocrine manner as an early event in tumor initiation. Although clinical evidence indicates that only a fraction of HELUs and ADHs evolve to invasive cancer, present findings warn that exposure to synthetic progestins, frequently administered as hormone-replacement therapy, and estrogens, when abnormally produced by adipose cells and persistently present in the stroma surrounding the mammary gland, may cause these hyperplastic lesions.

Neonatal exposure to low doses of endosulfan induces implantation failure and disrupts uterine functional differentiation at the pre-implantation period in rats

We investigated whether neonatal exposure to low doses of endosulfan affects fertility and uterine functional differentiation at pre-implantation in rats. Newborn female rats received the vehicle, 0.2 µg/kg/d of diethylstilbestrol (DES), 6 µg/kg/d of endosulfan (Endo6) or 600 µg/kg/d of endosulfan (Endo600) on postnatal days (PND) 1, 3, 5, and 7. On PND90, the rats were mated to evaluate their reproductive performance on gestational day (GD) 19 and their ovarian steroid serum levels, endometrial proliferation and implantation-associated proteins on GD5. DES and endosulfan decreased the pregnancy rate and the number of implantation sites. On GD5, DES and endosulfan did not change the serum levels of 17β-estradiol (E2) and progesterone (P); the endometrial proliferation decreased, which was associated with silencing of Hoxa10 in the Endo600-treated rats. Both doses of endosulfan increased the progesterone receptor (PR) expression, whereas the higher dose led additionally to an increase in estrogen receptor alpha (ERα). In the Endo600-treated rats, the down-regulation of Hoxa10 was associated with a deregulation of the steroid receptor coregulators. Alterations in endometrial proliferation and the endocrine pathway of Hoxa10/steroid receptors/coregulators might be the mechanism of endosulfan-induced implantation failure.

Amniotic membrane-derived mesenchymal cells and their conditioned media: potential candidates for uterine regenerative therapy in the horse

Amniotic membrane-derived mesenchymal cells (AMCs) are considered suitable candidates for a variety of cell-based applications. In view of cell therapy application in uterine pathologies, we studied AMCs in comparison to cells isolated from the endometrium of mares at diestrus (EDCs) being the endometrium during diestrus and early pregnancy similar from a hormonal standpoint. In particular, we demonstrated that amnion tissue fragments (AM) shares the same transcriptional profile with endometrial tissue fragments (ED), expressing genes involved in early pregnancy (AbdB-like Hoxa genes), pre-implantantion conceptus development (Erα, PR, PGRMC1 and mPR) and their regulators (Wnt7a, Wnt4a). Soon after the isolation, only AMCs express Wnt4a and Wnt7a. Interestingly, the expression levels of prostaglandin-endoperoxide synthase 2 (PTGS2) were found greater in AM and AMCs than their endometrial counterparts thus confirming the role of AMCs as mediators of inflammation. The expression of nuclear progesterone receptor (PR), membrane-bound intracellular progesterone receptor component 1 (PGRMC1) and membrane-bound intracellular progesterone receptor (mPR), known to lead to improved endometrial receptivity, was maintained in AMCs over 5 passages in vitro when the media was supplemented with progesterone. To further explore the potential of AMCs in endometrial regeneration, their capacity to support resident cell proliferation was assessed by co-culturing them with EDCs in a transwell system or culturing in the presence of AMC-conditioned medium (AMC-CM). A significant increase in EDC proliferation rate exhibited the crucial role of soluble factors as mediators of stem cells action. The present investigation revealed that AMCs, as well as their derived conditioned media, have the potential to improve endometrial cell replenishment when low proliferation is associated to pregnancy failure. These findings make AMCs suitable candidates for the treatment of endometrosis in mares.

Uterine factors

Uterine anomalies are one of the most common parental causes of recurrent pregnancy loss, occurring in about 19% of patients. Congenital uterine anomalies are most likely caused by HOX gene mutations, although the mechanism is probably polygenic. There are no known environmental causes other than estrogenic endocrine disruptors such as diethylstilbestrol. Acquired uterine anomalies may result from uterine trauma (adhesions) or benign growths of the myometrium (fibroids) or endometrium (polyps). Although randomized controlled trials are lacking, surgical treatment is recommended for repair of uterine septa, and for removal of severe adhesions and submucosal fibroids, especially if no other causes are identified.