Exposure of human fallopian tube epithelium to elevated testosterone results in alteration of cilia gene expression and beating

Human fallopian tube organoids provide a favourable environment for sperm motility

STUDY QUESTION

Does a human fallopian tube (HFT) organoid model offer a favourable apical environment for human sperm survival and motility?

SUMMARY ANSWER

After differentiation, the apical compartment of a new HFT organoid model provides a favourable environment for sperm motility, which is better than commercial media.

WHAT IS KNOWN ALREADY

HFTs are the site of major events that are crucial for achieving an ongoing pregnancy, such as gamete survival and competence, fertilization steps, and preimplantation embryo development. In order to better understand the tubal physiology and tubal factors involved in these reproductive functions, and to improve still suboptimal in vitro conditions for gamete preparation and embryo culture during IVF, we sought to develop an HFT organoid model from isolated adult stem cells to allow spermatozoa co-culture in the apical compartment.

STUDY DESIGN, SIZE, DURATION

Over a 2-year period, fallopian tube tissues were collected for organoid culture purposes from 10 'donor' patients undergoing bilateral salpingectomy by laparoscopy for definitive sterilization. After tissue digestion, isolated cells from the isthmus and ampulla regions were separately seeded in 3D Matrigel and cultured with conventional growth factors for organoid culture and specific factors for differentiation of the female genital tract.

PARTICIPANTS/MATERIALS, SETTING, METHODS

HFT organoids were characterized by light microscopy, scanning and transmission electron microscopy, immunofluorescence, and transcriptome analysis. Following simultaneous organoid culture on specific inserts, spermatozoa from five donors were placed either in control media or in the apical compartment of colon or HFT organoids (isthmus and ampulla separately) for 96 h. Vitality and motility and kinematic parameters were assessed at 0, 48, and 96 h on 200 spermatozoa in each condition and in duplicate and compared using the Wilcoxon test.

MAIN RESULTS AND THE ROLE OF CHANCE

Specific fallopian tube differentiation of our model was confirmed by immunofluorescence, transcriptome analysis, and electron microscopy observations that exhibited ciliated and secretory cells. We succeeded in releasing spermatozoa in the apical compartment of HFT organoids and in recovering them for sperm analysis. Sperm vitality values were similar in HFT organoids and in commercial sperm media. We demonstrated a superiority of the HFT organoid apical compartment for sperm motility compared with other controls (colon organoids, organoid culture media, and conventional commercial sperm fertilization media). At 48 h of incubation, progressive sperm motility was higher in the apical compartment of HFT organoids (ampulla 31% ± 17, isthmus 29% ± 15) than in commercial fertilization media (15% ± 15) (P < 0.05) and compared with all other conditions. At 96 h, progressive sperm motility was almost nil (<1%) in all conditions except for spermatozoa in HFT organoids (P < 0.05): 12% ± 15 and 13% ± 17 in ampulla and isthmus organoids, respectively. Computer-assisted sperm analysis (CASA) analysis also showed that the organoids were able to maintain significantly higher levels of kinematic parameters (curvilinear velocity, average path velocity, straight linear velocity, and amplitude of lateral movement of the head) and therefore more efficient mobility compared with commercial IVF media.

LARGE SCALE DATA

N/A.

LIMITATIONS, REASONS FOR CAUTION

This was an in vitro study in which conditions of organoid culture could not exactly mimic the in vivo environment of the extracellular matrix and vascularization of fallopian tubes.

WIDER IMPLICATIONS OF THE FINDINGS

This work opens up perspectives for better understanding of HFT physiology. For the first time, it highlights the possibility of developing HFT organoids for reproductive purposes. In the future, it could help us to improve gamete fertilizing abilities and embryo culture conditions during human ARTs.

STUDY FUNDING/COMPETING INTEREST(S)

This study was funded by a grant from the Occitanie region, and by financial allocations from the DEFE and IRSD research teams. The authors have no conflicts of interest to report.

Motile Cilia in Female and Male Reproductive Tracts and Fertility

Motile cilia are evolutionarily conserved organelles. In humans, multiciliated cells (MCCs), assembling several hundred motile cilia on their apical surface, are components of the monolayer epithelia lining lower and upper airways, brain ventricles, and parts of the reproductive tracts, the fallopian tube and uterus in females, and efferent ductules in males. The coordinated beating of cilia generates a force that enables a shift of the tubular fluid, particles, or cells along the surface of the ciliated epithelia. Uncoordinated or altered cilia motion or cilia immotility may result in subfertility or even infertility. Here, we summarize the current knowledge regarding the localization and function of MCCs in the human reproductive tracts, discuss how cilia and cilia beating-generated fluid flow directly and indirectly contribute to the processes in these organs, and how lack or improper functioning of cilia influence human fertility.

From fallopian tube epithelium to high-grade serous ovarian cancer: A single-cell resolution review of sex steroid hormone signaling

High-grade serous ovarian cancer (HGSOC) represents the most lethal subtype of ovarian cancer, largely due to being commonly diagnosed at advanced stages. The early molecular mechanisms underlying ovarian carcinogenesis remain poorly defined, posing challenges to the development of prevention and early detection strategies. Here we dissect the molecular mechanisms of sex steroid hormone signaling throughout the decades-long evolution of HGSOC precursor lesions, which predominantly originate from secretory epithelial cells of fallopian tubes (FT). We also discuss the prognostic significance of sex steroid receptor isoforms and steroid metabolizing enzymes in HGSOCs. Finally, we provide a comprehensive gene expression atlases of sex steroid receptors, steroidogenic, and steroid-metabolizing enzymes across different cell populations in pre- and postmenopausal FTs, and HGSOCs, using published single-cell RNA sequencing datasets. These atlases reveal that secretory epithelial cells and stromal populations in FTs express sex steroid receptors and enzymes responsible for the formation and inactivation of genotoxic estrogen metabolites. In HGSOC, epithelial cells express various HSD17B isoforms and steroid conjugating enzymes, suggesting an enhanced ability to finely regulate the levels of bioactive sex steroids.

Organ-on-a-chip: future of female reproductive pathophysiological models

The female reproductive system comprises the internal and external genitalia, which communicate through intricate endocrine pathways. Besides secreting hormones that maintain the female secondary sexual characteristics, it also produces follicles and offspring. However, the in vitro systems have been very limited in recapitulating the specific anatomy and pathophysiology of women. Organ-on-a-chip technology, based on microfluidics, can better simulate the cellular microenvironment in vivo, opening a new field for the basic and clinical research of female reproductive system diseases. This technology can not only reconstruct the organ structure but also emulate the organ function as much as possible. The precisely controlled fluidic microenvironment provided by microfluidics vividly mimics the complex endocrine hormone crosstalk among various organs of the female reproductive system, making it a powerful preclinical tool and the future of pathophysiological models of the female reproductive system. Here, we review the research on the application of organ-on-a-chip platforms in the female reproductive systems, focusing on the latest progress in developing models that reproduce the physiological functions or disease features of female reproductive organs and tissues, and highlighting the challenges and future directions in this field.

The ignored structure in female fertility: cilia in the fallopian tubes

Cilia in the fallopian tubes (CFT) play an important role in female infertility, but have not been explored comprehensively. This review reveals the detection techniques for CFT function and morphology, and the related analysis of female infertility and other gynaecological disorders. CFT differentiate from progenitor cells, and develop into primary cilia and motile cilia. Primary cilia coordinate multiple signalling pathways, and motile cilia produce laminar flow through bidirectional intraflagellar transport, which drives the movement of oocytes and gametes. Several methods for quantitative detection and protein analysis have been used to explore the factors contributing to the decrease in ciliary beat frequency (CBF), and the cellular mechanism of ciliary cell death and shedding. In both primary and secondary ciliary disorders associated with reproductive diseases, abnormal alterations in ciliary quantity, ciliary structure, CBF and ciliary signalling pathways result in abnormal tubal laminar flow, and diminished oocyte retrieval and transport capabilities.

A Review: Biomechanical Aspects of the Fallopian Tube Relevant to its Function in Fertility

The fallopian tube (FT) plays a crucial role in the reproductive process by providing an ideal biomechanical and biochemical environment for fertilization and early embryo development. Despite its importance, the biomechanical functions of the FT that originate from its morphological aspects, and ultrastructural aspects, as well as the mechanical properties of FT, have not been studied nor used sufficiently, which limits the understanding of fertilization, mechanotrasduction, and mechanobiology during embryo development, as well as the replication of the FT in laboratory settings for infertility treatments. This paper reviews and revives valuable information on human FT reported in medical literature in the past five decades relevant to the biomechanical aspects of FT. In this review, we summarized the current state of knowledge concerning the morphological, ultrastructural aspects, and mechanical properties of the human FT. We also investigate the potential arising from a thorough consideration of the biomechanical functions and exploring often neglected mechanical aspects. Our investigation encompasses both macroscopic measurements (such as length, diameter, and thickness) and microscopic measurements (including the height of epithelial cells, the percentage of ciliated cells, cilia structure, and ciliary beat frequency). Our primary focus has been on healthy women of reproductive age. We have examined various measurement techniques, encompassing conventional metrology, 2D histological data as well as new spatial measurement techniques such as micro-CT.

Expression and localization of apelin and apelin receptor protein in the oviduct of letrozole-induced hyperandrogenized mice

Apelin and its receptor (APJ) are expressed in the reproductive organs of some mammalian females. The function of oviduct has also been suggested to be compromised in the hyperandrogenism condition. However, expression of apelin and APJ has not been shown in the oviduct of hyperandrogenized mice. Thus, the present study has investigated the localization and expression of apelin and APJ in the letrozole-induced hyperandrogenized mice oviduct. Histomorphometric analysis showed decreased lumen of oviduct in the hyperandrogenized mice. Our results showed elevated expression of APJ and decreased abundance of apelin in the hyperandrogenized mice oviduct. This finding suggests impaired apelin signaling in the oviduct of hyperandrogenized mice. The expression of androgen receptor was upregulated while estrogen receptors were downregulated in the hyperandrogenized mice. The expression of HSP70 was also downregulated along with increased expression of active caspase 3 and BAX and decreased expression of BCL2 in hyperandrogenized mice. Furthermore, the phosphorylation of phospho-Ser473-Akt and phospho-Thr308-Akt also showed differential levels in the oviduct of hyperandrogenized mice. Whether this differential phosphorylation of Akt was solely due to impaired apelin signaling in the oviduct, remains unclear. Moreover, increased androgen signaling and suppressed estrogen signaling coincides with elevated apoptosis. In conclusion, hyperandrogenized conditions could also impair the gamete transport and fertilization process due to apoptosis in the oviduct. However, further study would be required to unravel the exact role of apelin signaling in the oviduct in relation to apoptosis.

Hormonal regulation of cilia in the female reproductive tract

This review intends to bridge the gap between our knowledge of steroid hormone regulation of motile cilia and the potential involvement of the primary cilium focusing on the female reproductive tract functions. The review emphasizes hormonal regulation of the motile and primary cilia in the oviduct and uterus. Steroid hormones including estrogen, progesterone, and testosterone act through their cognate receptors to regulate the development and biological function of the reproductive tracts. These hormones modulate motile ciliary beating and, in some cases, primary cilia function. Dysfunction of motile or primary cilia due to genetic anomalies, hormone imbalances, or loss of steroid hormone receptors impairs mammalian fertility. However, further research on hormone modulation of ciliary function, especially in the primary cilium, and its signaling cascades will provide insights into the pathogenesis of mammalian infertility and the development of contraceptives or infertility treatments targeting primary and/or motile cilia.

A new tissue-agnostic microfluidic device to model physiology and disease: the lattice platform

To accurately phenocopy human biology in vitro, researchers have been reducing their dependence on standard, static two-dimensional (2D) cultures and instead are moving towards three-dimensional (3D) and/or multicellular culture techniques. While these culture innovations are becoming more commonplace, there is a growing body of research that illustrates the benefits and even necessity of recapitulating the dynamic flow of nutrients, gas, waste exchange and tissue interactions that occur in vivo. However, cost and engineering complexity are two main factors that hinder the adoption of these technologies and incorporation into standard laboratory workflows. We developed LATTICE, a plug-and-play microfluidic platform able to house up to eight large tissue or organ models that can be cultured individually or in an interconnected fashion. The functionality of the platform to model both healthy and diseased tissue states was demonstrated using 3D cultures of reproductive tissues including murine ovarian tissues and human fallopian tube explants (hFTE). When exogenously exposed to pathological doses of gonadotropins and androgens to mimic the endocrinology of polycystic ovarian syndrome (PCOS), subsequent ovarian follicle development, hormone production and ovulation copied key features of this endocrinopathy. Further, hFTE cilia beating decreased significantly only when experiencing continuous media exchanges. We were then able to endogenously recreate this phenotype on the platform by dynamically co-culturing the PCOS ovary and hFTE. LATTICE was designed to be customizable with flexibility in 3D culture formats and can serve as a powerful automated tool to enable the study of tissue and cellular dynamics in health and disease in all fields of research.

Increased Local Testosterone Levels Alter Human Fallopian Tube mRNA Profile and Signaling

Fallopian tube epithelium (FTE) plays a critical role in reproduction and can be the site where High Grade Serous Ovarian Carcinoma (HGSOC) originates. Tumorigenic oviductal cells, which are the murine equivalent of human fallopian tube secretory epithelial cells (FTSEC), enhance testosterone secretion by the ovary when co-cultured with the ovary, suggesting that testosterone is part of the signaling axis between the ovary and FTSEC. Furthermore, testosterone promotes proliferation of oviductal cells. Oral contraceptives, tubal ligation, and salpingectomy, which are all protective against developing ovarian cancer, also decrease circulating levels of androgen. In the current study, we investigated the effect of increased testosterone on FTE and found that testosterone upregulates wingless-type MMTV integration family, member 4 (WNT4) and induces migration and invasion of immortalized human fallopian tube cells. We profiled primary human fallopian tissues grown in the microfluidic system SOLO-microfluidic platform –(MFP) by RNA sequencing and found that p53 and its downstream target genes, such as paired box gene 2 (PAX2), cyclin-dependent kinase inhibitor 1A (CDK1A or p21), and cluster of differentiation 82 (CD82 or KAI1) were downregulated in response to testosterone treatment. A microfluidic platform, the PREDICT-Multi Organ System (PREDICT-MOS) was engineered to support insert technology that allowed for the study of cancer cell migration and invasion through Matrigel. Using this system, we found that testosterone enhanced FTE migration and invasion, which was reversed by the androgen receptor (AR) antagonist, bicalutamide. Testosterone also enhanced FTSEC adhesion to the ovarian stroma using murine ovaries. Overall, these results indicate that primary human fallopian tube tissue and immortalized FTSEC respond to testosterone to shift expression of genes that regulate invasion, while leveraging a new strategy to study migration in the presence of dynamic fluid flow.

Proteomic Profiling of Fallopian Tube-Derived Extracellular Vesicles Using a Microfluidic Tissue-on-Chip System

The human fallopian tube epithelium (hFTE) is the site of fertilization, early embryo development, and the origin of most high-grade serous ovarian cancers (HGSOCs). Little is known about the content and functions of hFTE-derived small extracellular vesicles (sEVs) due to the limitations of biomaterials and proper culture methods. We have established a microfluidic platform to culture hFTE for EV collection with adequate yield for mass spectrometry-based proteomic profiling, and reported 295 common hFTE sEV proteins for the first time. These proteins are associated with exocytosis, neutrophil degranulation, and wound healing, and some are crucial for fertilization processes. In addition, by correlating sEV protein profiles with hFTE tissue transcripts characterized using GeoMx® Cancer Transcriptome Atlas, spatial transcriptomics analysis revealed cell-type-specific transcripts of hFTE that encode sEVs proteins, among which, FLNA, TUBB, JUP, and FLNC were differentially expressed in secretory cells, the precursor cells for HGSOC. Our study provides insights into the establishment of the baseline proteomic profile of sEVs derived from hFTE tissue, and its correlation with hFTE lineage-specific transcripts, which can be used to evaluate whether the fallopian tube shifts its sEV cargo during ovarian cancer carcinogenesis and the role of sEV proteins in fallopian tube reproductive functions.

Se(XY) matters: the importance of incorporating sex in microphysiological models

The development of microphysiological models is currently at the forefront of preclinical research. Although these 3D tissue models are being developed to mimic physiological organ function and diseases, which are often sexually dimorphic, sex is usually neglected as a biological variable. For decades, national research agencies have required government-funded clinical trials to include both male and female participants as a means of eliminating male bias. However, this is not the case in preclinical trials, which have been shown to favor male rodents in animal studies and male cell types in in vitro studies. In this Opinion, we highlight the importance of considering sex as a biological variable and outline five approaches for incorporating sex-specific features into current microphysiological models.

The Prevalence of Fallopian Tube Occlusion in Women with Polycystic Ovary Syndrome Seems Similar to Non-Subfertile Women: A Retrospective Cohort Study

There are limited data on how non-infectious risk factors influence tubal patency in women with subfertility. With hormonal shifts influencing tubal secretions, it has been argued that subfertile women with polycystic ovary syndrome (PCOS) have lower tubal patency. In a retrospective study, 216 women, who underwent diagnostic evaluation for PCOS and infertility, were included. Fallopian tube patency was tested using HSG, HyCoSy, and laparoscopic chromopertubation in 171 (79.2%), 28 (13.0%), and 17 (7.9%), respectively. Bilateral patency was found in 193 women (89.4%), unilateral patency in 13 (6.0%) and bilateral occlusion in 10 (4.6%) patients. Women with PCOS phenotypes C (odds ratio, OR 0.179, 95% CI: 0.039–0.828) and D (OR 0.256, 95% CI: 0.069–0.947) demonstrated lower risks for Fallopian tube occlusion. In conclusion, our data suggest that about 5% of infertile women with PCOS also have bilateral tubal occlusion, which seems similar to the rate in non-subfertile women. With 11% of participants having unilateral or bilateral tubal occlusion, this should reassure women with PCOS that their hormonal challenges do not seem to increase their risk for tubal factor subfertility.

Bioinformatics searching of diagnostic markers and immune infiltration in polycystic ovary syndrome

Polycystic ovary syndrome (PCOS) is one of the most common endocrine diseases in reproductive-aged women, and it affects numerous women worldwide. This study aimed to identify potential diagnostic markers and explore the infiltration of immune cells in PCOS, contributing to the development of potential therapeutic drugs for this disease. We identified five key genes: CBLN1 (AUC = 0.924), DNAH5 (AUC = 0.867), HMOX1 (AUC = 0.971), SLC26A8 (AUC = 0,933), and LOC100507250 (AUC = 0.848) as diagnostic markers of PCOS. Compared with paired normal group, naïve B cells, gamma delta T cells, resting CD4 memory T cells, and activated CD4 memory T cells were significantly decreased in PCOS while M2 macrophages were significantly increased. Significant correlations were presented between the five key genes and the components of immune infiltrate. The results of CMap suggest that four drugs, ISOX, apicidin, scriptaid, and NSC-94258, have the potential to reverse PCOS. The present study helps provide novel insights for the prevention and treatment of PCOS, and immune cell infiltration plays a role that cannot be ignored in the occurrence and progression of the disease.

An Ovarian Steroid Metabolomic Pathway Analysis in Basal and Polycystic Ovary Syndrome (PCOS)-like Gonadotropin Conditions Reveals a Hyperandrogenic Phenotype Measured by Mass Spectrometry

Prior work has demonstrated that murine ovarian explants and isolated ovarian follicles can recapitulate human-like 28-day cycles in vitro with normal patterns of estradiol and progesterone secretion in response to gonadotropin stimulation. The objective of this study was to manipulate the gonadotropin stimulation protocol to mimic polycystic ovary syndrome (PCOS) and assess the resulting changes in ovarian steroidogenesis. A secondary aim of the study was to develop a high-throughput, sensitive, and specific liquid chromatography with tandem mass spectrometry (LC-MS/MS) assay to measure seven steroid hormones (estrone, estradiol, progesterone, testosterone, androstenedione, dehydroepiandrosterone, and dihydrotestosterone) in conditioned culture media. Ovaries were harvested from 12-day-old CD-1 mice and cultured for 28 days, with ovulation induction on culture day 14. Media were supplemented human chorionic gonadotropin (hCG, a luteinizing hormone analog) and follicle stimulating hormone (FSH) at ratios of 1:0 (standard media), 1:1 (physiologic ratio), and 3:1 (PCOS-like ratio). Ovaries cultured in PCOS-like media displayed hyperandrogenism and impaired ovulation, two key features of a PCOS-like phenotype. Taken together, this first-of-its-kind presentation of hormone levels from single tissues creates a map of the enzymatic steps most acutely affected by gonadotropin dysregulation and may provide opportunities for assessing other potential insults in PCOS pathogenesis.

Top-quality embryo transfer is associated with lower odds of ectopic pregnancy

INTRODUCTION

The incidence of ectopic pregnancy is up to four times higher after in vitro fertilization/intracytoplasmic sperm injection (IVF/ICSI) than in spontaneous pregnancies, and the risk of ectopic pregnancy is increased by tubal factor infertility and the transfer of multiple embryos. However, the effect of embryo quality on the probability of ectopic pregnancy has not been investigated until now and it is not clear whether ovarian stimulation parameters affect the incidence of ectopic pregnancy.

MATERIAL AND METHODS

An historical cohort study of 15 006 clinical pregnancies (diagnosed by ultrasound at 6-8 gestational weeks) after non-donor IVF/ICSI with fresh embryo transfer (n = 8952) or frozen-thawed embryo transfer (n = 6054). Treatments were performed during 2000-2017 in Finland. A total of 9207 (61.4%) single and 5799 (38.6%) double embryo transfers of no more than one top-quality embryo were evaluated. We analyzed the effects of multiple factors on ectopic pregnancy by logistic regression, including type of cycle (fresh vs frozen embryo transfer), female age, number and quality of embryos transferred, tubal factor infertility and factors of ovarian response to gonadotropin stimulation.

RESULTS

Ectopic pregnancy was observed in 2.3% of cycles. There was no significant difference in ectopic pregnancy rate after fresh embryo transfer and frozen embryo transfer (2.2% vs 2.4%, p = 0.3). The ectopic pregnancy rate was lower in cycles with top-quality embryo transfer (1.9%) than of those where only non-top quality embryos were transferred (2.7%, p < 0.0001). Tubal factor infertility was diagnosed more often in ectopic pregnancy than in intrauterine pregnancies (21.2% vs 11.0%, p < 0.0001). Logistic regression revealed lower odds for ectopic pregnancy after a top-quality embryo transfer than after transfer of a non-top quality embryo (odds ratio [OR] 0.72, 95% confidence interval [CI] 0.56-0.92, p = 0.007). Transfer of two vs one embryo (OR 1.35, 95% CI 1.05-1.70, p = 0.02) and tubal factor infertility (OR 2.21, 95% CI 1.68-2.91, p < 0.0001) significantly increased the risk of ectopic pregnancy.

CONCLUSIONS

Transfer of non-top quality embryos is associated with a higher rate of ectopic pregnancy. This is particularly important to keep in mind in treatments with only non-top embryos available even in the absence of tubal factor infertility. To minimize the risk of ectopic pregnancy, the number of embryos transferred should be as low as possible.

Female Reproductive Systems: Hormone Dependence and Receptor Expression

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

Isolation of Fallopian Tube Epithelium for Assessment of Cilia Beating Frequency (CBF)

The fallopian tube epithelium (FTE) plays a critical role in reproduction and the genesis of ovarian cancer. The FTE columnar cells present with hair-like structures named "cilia" that are required for normal FTE function. Impairment of ciliary motion can lead to infertility, and it is influenced by hormonal signaling and endocrine disrupting compounds. Studying how cilia beating changes in response to these compounds is critical for understanding FTE physiology and pathology. In this protocol, we describe methods for isolating human fallopian tube epithelium, oviduct (murine equivalent of fallopian tube) epithelium, and ovaries. In addition, we describe methods for imaging and measuring cilia beating frequency using high-resolution time-lapse imaging.

Advancements in Microfluidic Systems for the Study of Female Reproductive Biology

The female reproductive tract is a highly complex physiological system that consists of the ovaries, fallopian tubes, uterus, cervix, and vagina. An enhanced understanding of the molecular, cellular, and genetic mechanisms of the tract will allow for the development of more effective assisted reproductive technologies, therapeutics, and screening strategies for female specific disorders. Traditional 2-dimensional and 3-dimensional static culture systems may not always reflect the cellular and physical contexts or physicochemical microenvironment necessary to understand the dynamic exchange that is crucial for the functioning of the reproductive system. Microfluidic systems present a unique opportunity to study the female reproductive tract, as these systems recapitulate the multicellular architecture, contacts between different tissues, and microenvironmental cues that largely influence cell structure, function, behavior, and growth. This review discusses examples, challenges, and benefits of using microfluidic systems to model ovaries, fallopian tubes, endometrium, and placenta. Additionally, this review also briefly discusses the use of these systems in studying the effects of endocrine disrupting chemicals and diseases such as ovarian cancer, preeclampsia, and polycystic ovarian syndrome.

Fallopian Tube-Derived Tumor Cells Induce Testosterone Secretion from the Ovary, Increasing Epithelial Proliferation and Invasion

The fallopian tube epithelium is the site of origin for a majority of high grade serous ovarian carcinomas (HGSOC). The chemical communication between the fallopian tube and the ovary in the development of HGSOC from the fallopian tube is of interest since the fimbriated ends in proximity of the ovary harbor serous tubal intraepithelial carcinoma (STICs). Epidemiological data indicates that androgens play a role in ovarian carcinogenesis; however, the oncogenic impact of androgen exposure on the fallopian tube, or tubal neoplastic precursor lesions, has yet to be explored. In this report, imaging mass spectrometry identified that testosterone is produced by the ovary when exposed to tumorigenic fallopian tube derived PTEN deficient cells. Androgen exposure increased cellular viability, proliferation, and invasion of murine cell models of healthy fallopian tube epithelium and PAX2 deficient models of the preneoplastic secretory cell outgrowths (SCOUTs). Proliferation and invasion induced by androgen was reversed by co-treatment with androgen receptor (AR) antagonist, bicalutamide. Furthermore, ablation of phosphorylated ERK reversed proliferation, but not invasion. Investigation of two hyperandrogenic rodent models of polycystic ovarian syndrome revealed that peripheral administration of androgens does not induce fallopian proliferation in vivo. These data suggest that tumorigenic lesions in the fallopian tube may induce an androgenic microenvironment proximal to the ovary, which may in turn promote proliferation of the fallopian tube epithelium and preneoplastic lesions.