Distribution and hormonal regulation of membrane progesterone receptors beta and gamma in ciliated epithelial cells of mouse and human fallopian tubes

Altered luteal expression patterns of genomic and non-genomic progesterone receptors in bitches at different reproductive states

The binding of steroid hormones to their specific receptors is necessary to exert their effects on target cells. Progesterone (P4), a steroid hormone, carries out its effects through both genomic and non-genomic (the cell membrane-associated) receptors. This study aimed to ascertain luteal expression patterns of genomic and non-genomic progesterone receptors in bitches in physiological (early dioestrus and early pregnant) and pathological (pyometra) reproductive states. Luteal tissue was collected from the bitches at early dioestrus (ED, n = 5), early pregnant (EP, n = 5), and pyometra (PY, n = 5). The expression profiles of Steroidogenic Acute Regulator Protein (STAR), Progesterone Receptor (PGR), Membrane Progestin Receptors (PAQR5, PAQR7 and PAQR8), and Progesterone Membrane Components (PGMRC1 and PGMRC2) were examined at the mRNA levels using Real-Time Polymerase Chain Reaction (RT-PCR). Protein levels of PGR, PGMRC1 and PGMRC2 were detected by western blotting (WB). The STAR expression was found in all groups, with a statistical difference observed between EP and PY groups (P < 0.05). The protein level of PGR was determined to be highest in the EP group and lowest in the PY group. The expression of PAQR8 increased in the EP group (P < 0.05). The PAQR5 exhibited high expression in the EP group and low expression in the PY group (P < 0.05). PGRMC1 was more elevated in the EP group and lower in the PY group (P < 0.05). Protein levels of PGMRC1 and PGMRC2 were also observed at the highest expression in EP group. According to the altered expression profiles for examined receptors, we suggest that those progesterone receptors have roles in early pregnancy or pyometra in bitches.

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.

Endometrial receptivity in women of advanced age: an underrated factor in infertility

BACKGROUND

Modern lifestyle has led to an increase in the age at conception. Advanced age is one of the critical risk factors for female-related infertility. It is well known that maternal age positively correlates with the deterioration of oocyte quality and chromosomal abnormalities in oocytes and embryos. The effect of age on endometrial function may be an equally important factor influencing implantation rate, pregnancy rate, and overall female fertility. However, there are only a few published studies on this topic, suggesting that this area has been under-explored. Improving our knowledge of endometrial aging from the biological (cellular, molecular, histological) and clinical perspectives would broaden our understanding of the risks of age-related female infertility.

OBJECTIVE AND RATIONALE

The objective of this narrative review is to critically evaluate the existing literature on endometrial aging with a focus on synthesizing the evidence for the impact of endometrial aging on conception and pregnancy success. This would provide insights into existing gaps in the clinical application of research findings and promote the development of treatment options in this field.

SEARCH METHODS

The review was prepared using PubMed (Medline) until February 2023 with the keywords such as 'endometrial aging', 'receptivity', 'decidualization', 'hormone', 'senescence', 'cellular', 'molecular', 'methylation', 'biological age', 'epigenetic', 'oocyte recipient', 'oocyte donation', 'embryo transfer', and 'pregnancy rate'. Articles in a language other than English were excluded.

OUTCOMES

In the aging endometrium, alterations occur at the molecular, cellular, and histological levels suggesting that aging has a negative effect on endometrial biology and may impair endometrial receptivity. Additionally, advanced age influences cellular senescence, which plays an important role during the initial phase of implantation and is a major obstacle in the development of suitable senolytic agents for endometrial aging. Aging is also accountable for chronic conditions associated with inflammaging, which eventually can lead to increased pro-inflammation and tissue fibrosis. Furthermore, advanced age influences epigenetic regulation in the endometrium, thus altering the relation between its epigenetic and chronological age. The studies in oocyte donation cycles to determine the effect of age on endometrial receptivity with respect to the rates of implantation, clinical pregnancy, miscarriage, and live birth have revealed contradictory inferences indicating the need for future research on the mechanisms and corresponding causal effects of women's age on endometrial receptivity.

WIDER IMPLICATIONS

Increasing age can be accountable for female infertility and IVF failures. Based on the complied observations and synthesized conclusions in this review, advanced age has been shown to have a negative impact on endometrial functioning. This information can provide recommendations for future research focusing on molecular mechanisms of age-related cellular senescence, cellular composition, and transcriptomic changes in relation to endometrial aging. Additionally, further prospective research is needed to explore newly emerging therapeutic options, such as the senolytic agents that can target endometrial aging without affecting decidualization. Moreover, clinical trial protocols, focusing on oocyte donation cycles, would be beneficial in understanding the direct clinical implications of endometrial aging on pregnancy outcomes.

Brain nuclear receptors and cardiovascular function

Brain-heart interaction has raised up increasing attentions. Nuclear receptors (NRs) are abundantly expressed in the brain, and emerging evidence indicates that a number of these brain NRs regulate multiple aspects of cardiovascular diseases (CVDs), including hypertension, heart failure, atherosclerosis, etc. In this review, we will elaborate recent findings that have established the physiological relevance of brain NRs in the context of cardiovascular function. In addition, we will discuss the currently available evidence regarding the distinct neuronal populations that respond to brain NRs in the cardiovascular control. These findings suggest connections between cardiac control and brain dynamics through NR signaling, which may lead to novel tools for the treatment of pathological changes in the CVDs.

Physiological Action of Progesterone in the Nonhuman Primate Oviduct

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

The role of SK3 in progesterone-induced inhibition of human fallopian tubal contraction

BACKGROUND

Normal motor activity of the fallopian tube is critical for human reproduction, and abnormal tubal activity may lead to ectopic pregnancy (EP) or infertility. Progesterone has an inhibitory effect on tubal contraction; however, the underlying mechanisms remain unclear. Small-conductance calcium-activated K⁺ channel 3 (SK3) is abundantly expressed in platelet-derived growth factor receptor α positive (PDGFRα+) cells and was reported to be important for the relaxation of smooth muscle. The present study aims to explore the expression of SK3 in the human fallopian tube and its role in progesterone-induced inhibition of tubal contraction.

METHODS

We collected specimens of fallopian tubes from patients treated by salpingectomy for EP (EP group) and other benign gynecological diseases (Non-EP group). The expression of SK3 was detected by quantitative real-time polymerase chain reaction, western blot, immunocytochemistry, and immunohistochemistry analyses. Isometric tension experiments were performed to investigate the role of SK3 in progesterone-induced inhibition of tubal contraction.

RESULTS

The baseline amplitude and frequency of human fallopian tube contraction were both statistically lower in the EP group compared with the non-EP group. The expression levels of SK3 in different portions of fallopian tubes from the non-EP group were significantly higher than in those from the EP group. Progesterone had an inhibitory effect on tubal contraction, mainly on the amplitude, in both groups, and SK3 as well as other calcium-activated K⁺ channels may be involved. SK3-expressing PDGFRα (+) cells were detected in the human fallopian tube.

CONCLUSIONS

The expression of SK3 is lower in the EP group, and SK3 is involved in the progesterone-induced inhibition of human fallopian tube contraction.

CmP signaling network unveils novel biomarkers for triple negative breast cancer in African American women

Breast cancer is the most diagnosed cancer worldwide and remains the second leading cause of cancer death. While breast cancer mortality has steadily declined over the past decades through medical advances, an alarming disparity in breast cancer mortality has emerged between African American women (AAW) and Caucasian American women (CAW). New evidence suggests more aggressive behavior of triple-negative breast cancer (TNBC) in AAW may contribute to racial differences in tumor biology and mortality. Progesterone (PRG) can exert its cellular effects through either its classic, non-classic, or combined responses through binding to either classic nuclear PRG receptors (nPRs) or non-classic membrane PRG receptors (mPRs), warranting both pathways equally important in PRG-mediated signaling. In our previous report, we demonstrated that the CCM signaling complex (CSC) consisting of CCM1, CCM2, and CCM3 can couple both nPRs and mPRs signaling cascades to form a CSC-mPRs-PRG-nPRs (CmPn) signaling network in nPR positive(+) breast cancer cells. In this report, we furthered our research by establishing the CSC-mPRs-PRG (CmP) signaling network in nPR(-) breast cancer cells, demonstrating that a common core mechanism exists, regardless of nPR(+⁣/⁣-) status. This is the first report stating that inducible expression patterns exist between CCMs and major mPRs in TNBC cells. Furthermore, we firstly show mPRs in TNBC cells are localized in the nucleus and participate in nucleocytoplasmic shuttling in a coordinately synchronized fashion with CCMs under steroid actions, following the same cellular distribution as other well-defined steroid hormone receptors. Finally, for the first time, we deconvoluted the CmP signalosome by using systems biology and TNBC clinical data, which helped us understand key factors within the CmP network and identify 6 specific biomarkers with potential clinical applications associated with AAW-TNBC tumorigenesis. These novel biomarkers could have immediate clinical implications to dramatically improve health disparities among AAW-TNBCs.

Effect of Steroid Hormones, Prostaglandins (E2 and F2α), Oxytocin, and Tumor Necrosis Factor Alpha on Membrane Progesterone (P4) Receptors Gene Expression in Bovine Myometrial Cells

Myometrium tissue shows the expression of non-genomic membrane progesterone (P4) receptors, such as progesterone receptor membrane components (PGRMC) 1 and 2 and membrane progestin receptors (mPR) alpha (mPRα), beta (mPRβ), and gamma (mPRγ). Their variable expression in the bovine uterus during the estrous cycle and early pregnancy suggests that ovarian steroids and luteotropic and/or luteolytic factors may regulate the expression of these receptors in the myometrium. Therefore, this study aimed to examine the effect of P4, estradiol (E2), P4 with E2, prostaglandins (PG) E2 and F2α, oxytocin (OT), and tumor necrosis factor α (TNFα) on the gene expression of PGRMC1, PGRMC2, serpine-1 mRNA-binding protein (SERBP1), and mPRα, mPRβ, and mPRγ in bovine myometrial cells from days 6 to 10 and 11 to 16 of the estrous cycle. The PGE2 concentration and mRNA expression were determined by EIA and real-time PCR, respectively. The data indicated that P4 and E2 can affect the mRNA expression of all studied receptors and SERPB1. However, PGE2, OT, and TNFα could only modulate the expression of PGRMC1, PGRMC2, and SERPB1, respectively. Steroids/factors changed the expression of PGRMC and mPR genes depending on the dose, the stage of the estrous cycle, and the types of receptors. This suggests that the local hormonal milieu may influence the activity of these receptors and P4 action in myometrial cells during the estrous cycle.

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.

Estrogen and Progesterone Receptor Immunoexpression in Fallopian Tubes among Postmenopausal Women Based on Time since the Last Menstrual Period

Existing data on the expression of estrogen receptor (ERα) and progesterone receptor (PR) in fallopian tubes in postmenopausal women are mostly inconclusive. Therefore, we assessed ERα and PR immunoexpression in the oviducts of these women. One hundred postmenopausal women were divided into three groups based on time elapsed since the last menstrual period: (A) 1–5 years, (B) 6–10 years, and (C) ≥11 years. In all groups, both in the glandular epithelium and stroma of the ampulla and isthmus of the oviduct, immunolocalization of ERα and PR were noted. The glandular epithelium of the ampulla showed a higher percentage of PR-positive cells than the isthmus in each group. Regarding ERα, there were no significant differences. In the glandular epithelium in both the ampulla and isthmus, the percentage of ERα- and PR-positive cells was significantly higher than that in the stroma in each study group and higher in the A group than in the C group. In conclusion, in postmenopausal women, time elapsed since the last menstrual period in the fallopian tubes was positively correlated with the following: (1) the epithelium showed vacuolation of cytoplasm with greater frequency, (2) the proportion of ciliated cells decreased, and (3) the percentage of ERα- and PR-positive cells also decreased. The obtained results indicate a significant decrease in ERα and PR expression depending on the time that has elapsed since the last menstruation, which is undoubtedly related to the loss of the reproductive function of the patients.

Calm the raging hormone - A new therapeutic strategy involving progesterone-signaling for hemorrhagic CCMs

Cerebral cavernous malformations (CCMs), one of the most common vascular malformations, are characterized by abnormally dilated intracranial microvascular capillaries resulting in increased susceptibility to hemorrhagic stroke. As an autosomal dominant disorder with incomplete penetrance, the majority of CCMs gene mutation carriers are largely asymptomatic but when symptoms occur, the disease has typically reached the stage of focal hemorrhage with irreversible brain damage, while the molecular "trigger" initiating the occurrence of CCM pathology remain elusive. Currently, the invasive neurosurgery removal of CCM lesions is the only option for the treatment, despite the recurrence of the worse symptoms frequently occurring after surgery. Therefore, there is a grave need for identification of molecular targets for therapeutic treatment and biomarkers as risk predictors for hemorrhagic stroke prevention. Based on reported various perturbed angiogenic signaling cascades mediated by the CCM signaling complex (CSC), there have been many proposed candidate drugs, targeting potentially angiogenic-relevant signaling pathways dysregulated by loss of function of one of the CCM proteins, which might not be enough to correct the pathological phenotype, hemorrhagic CCMs. In this review, we describe a new paradigm for the mechanism of hemorrhagic CCM lesions, and propose a new concept for the assurance of the CSC-stability to prevent the devastating outcome of hemorrhagic CCMs.

Levonorgestrel vs. Copper Intrauterine Devices for Emergency Contraception

BACKGROUND

In the United States, more intrauterine device (IUD) users select levonorgestrel IUDs than copper IUDs for long-term contraception. Currently, clinicians offer only copper IUDs for emergency contraception because data are lacking on the efficacy of the levonorgestrel IUD for this purpose.

METHODS

This randomized noninferiority trial, in which participants were unaware of the group assignments, was conducted at six clinics in Utah and included women who sought emergency contraception after at least one episode of unprotected intercourse within 5 days before presentation and agreed to placement of an IUD. We randomly assigned participants in a 1:1 ratio to receive a levonorgestrel 52-mg IUD or a copper T380A IUD. The primary outcome was a positive urine pregnancy test 1 month after IUD insertion. When a 1-month urine pregnancy test was unavailable, we used survey and health record data to determine pregnancy status. The prespecified noninferiority margin was 2.5 percentage points.

RESULTS

Among the 355 participants randomly assigned to receive levonorgestrel IUDs and 356 assigned to receive copper IUDs, 317 and 321, respectively, received the interventions and provided 1-month outcome data. Of these, 290 in the levonorgestrel group and 300 in the copper IUD group had a 1-month urine pregnancy test. In the modified intention-to-treat and per-protocol analyses, pregnancy rates were 1 in 317 (0.3%; 95% confidence interval [CI], 0.01 to 1.7) in the levonorgestrel group and 0 in 321 (0%; 95% CI, 0 to 1.1) in the copper IUD group; the between-group absolute difference in both analyses was 0.3 percentage points (95% CI, -0.9 to 1.8), consistent with the noninferiority of the levonorgestrel IUD to the copper IUD. Adverse events resulting in participants seeking medical care in the first month after IUD placement occurred in 5.2% of participants in the levonorgestrel IUD group and 4.9% of those in the copper IUD group.

CONCLUSIONS

The levonorgestrel IUD was noninferior to the copper IUD for emergency contraception. (Supported by the Eunice Kennedy Shriver National Institute of Child Health and Human Development and others; ClinicalTrials.gov number, NCT02175030.).

Pilot validation of blood-based biomarkers during pregnancy and postpartum in women with prior or current depression

Major depressive disorder (MDD) is more common in women than in men, and evidence of gender-related subtypes of depression is emerging. Previously identified blood-based transcriptomic biomarkers distinguished male and female subjects with MDD from those without the disorder. In the present pilot study, we investigated the performance of these biomarkers in pregnant and postpartum women with prior major depressive episodes, some of whom had current symptomatology. The symptom scores of 13 pregnant and 15 postpartum women were identified by the Inventory of Depressive Symptoms (IDS-SR-30) at the time of blood sampling. Blood levels of the 20 transcriptomic biomarkers and that of estrogen receptor 2 (ESR2), membrane progesterone receptor alpha and beta (mPRα, mPRβ) were measured. In pregnant women, transcript levels of ADCY3, ASAH1, ATP11C, CDR2, ESR2, FAM46A, mPRβ, NAGA, RAPH1, TLR7, and ZNF291/SCAPER showed significant association with IDS-SR-30 scores, of which ADCY3, FAM46A, RAPH1, and TLR7 were identified in previous studies for their diagnostic potential for major depression. ASAH1 and ATP11C were previously also identified as potential markers of treatment efficacy. In postpartum women, transcript levels of CAT, CD59, and RAPH1 demonstrated a trend of association with IDS-SR-30 scores. Transcript levels of ADCY3, ATP11C, FAM46A, RAPH1, and ZNF291/SCAPER correlated with ESR2 and mPRβ expressions in pregnant women, whereas these associations only existed for mPRβ in postpartum women. These results suggest that a blood biomarker panel can identify depression symptomatology in pregnant women and that expression of these biomarker genes are affected by estrogen and/or progesterone binding differently during pregnancy and postpartum.

Repeated hyperstimulation affects the ultrastructure of mouse fallopian tube epithelium

Controlled ovarian hyperstimulation (COH) is routinary used in assisted reproductive technologies (ARTs) to increase the yields of mature oocytes. The possibility that patients with a history of failures or poor-responders may develop side-effects following these treatments is still debated. Epidemiological studies reported controversial results about pregnancy outcome and the risk of developing gynecological cancers. By using a mouse model, here we compared the ultrastructural features of fallopian tubes (FTs) obtained from mice undergoing or not (control, CTR) four (4R) and eight (8R) rounds of gonadotropin stimulation. Although the morphological characteristics of oviductal layers seemed unaffected by repeated treatments, dose-response ultrastructural alterations in the ampulla appeared in the 4R group and even more in the 8R group. The targets were oviductal ciliated (CCs) and non-ciliated (NCCs) cells, which showed damaged mitochondria and glycogen accumulations in the cytoplasm. The drastic reduction of CCs, evident after 4R, was supported by the absence of cilia. After 8R, glycogen granules were significantly reduced and massive degeneration of mitochondria, which appeared swollen and/or vacuolated, occurred in NCCs. Moreover, disintegrated mitochondria were found at the periphery of mitophagic vacuoles with evident signs of cristolysis. The morphometric analysis evidenced a significant increase in the density and frequency of damaged mitochondria after 4R and 8R. The absence of cilia, necessary to sustain oviductal transport of oocytes, spermatozoa and embryos, may originate from either mitochondrial dysfunction or glycogen consumption. These results suggest that repeated COH treatments could induce alterations impairing fertilization and embryo transport toward the uterus.

Systemic distribution of progesterone receptor subtypes in human tissues

Progesterone receptor (PR) is expressed in a wide variety of human tissues, including both reproductive and non-reproductive tissues. Upon binding to the PR, progesterone can display several non-reproductive functions, including neurosteroid activity in the central nervous system, inhibition of smooth muscle contractile activity in the gastrointestinal tract, and regulating the development and maturation of the lung. PR exists as two major isoforms, PRA and PRB. Differential expression of these PR isoforms reportedly contributes to different biological activities of the hormone. However, the distribution of the PR isoforms in human tissues has remained virtually unexplored. In this study, we immunolocalized PR expression in various human tissues using PR (1294) specific antibody, which is capable of detecting both PRA and PRB, and PRB (250H11) specific antibody. Tissues from the uterus, ovary, breast, placenta, prostate, testis, cerebrum, cerebellum, pituitary, spinal cord, esophagus, stomach, small intestine, colon, pancreas, liver, kidney, urinary bladder, lung, heart, aorta, thymus, adrenal gland, thyroid, spleen, skin, and bone were examined in four different age groups (fetal, pediatric, young, and old) in male and female subjects. PR and PRB were detected in the nuclei of cells in the female reproductive system, in both the nuclei and cytoplasm of pituitary gland and pancreatic acinar cells, and only in the cytoplasm of cells in the testis, stomach, small intestine, colon, liver, kidney, urinary bladder, lung, adrenal gland, and skin. Of particular interest, total PRB expression overlapped with that of total PR expression in most tissues but was negative in the female fetal reproductive system. The findings indicate that progesterone could affect diverse human organs differently than from reproductive organs. These findings provide new insights into the novel biological roles of progesterone in non-reproductive organs.

Expression of membrane progestin receptors (mPRs) in the bovine corpus luteum during the estrous cycle and first trimester of pregnancy

Progesterone (P4) affects luteal cell function through nuclear P4 receptors and via nongenomic mechanisms, presumably involving membrane P4 receptors. There are 2 types of these receptors: progesterone receptor membrane component (PGRMC) and membrane progestin receptor (mPR), including mPR alpha (mPRα), beta (mPRβ), and gamma (mPRγ), which belong to the progestin and adipoQ receptor family (PAQR 7, 8, and 5, respectively). The aim of this study was to evaluate mRNA expression, protein expression, and localization of mPRα, mPRβ, and mPRγ in the bovine corpus luteum (CL) on days 2-5, 6-10, 11-16, and 17-20 of the estrous cycle as well as on weeks 3-5, 6-8, and 9-12 of pregnancy (n = 5/each period). The highest mPRα mRNA expression was found on days 11-16 (P < 0.05) and 17-20 (P < 0.001) of the estrous cycle compared with other stages of the estrous cycle and pregnancy. The mPRβ mRNA level was highest (P < 0.01) on days 11-20 of the estrous cycle and in all stages of pregnancy. mPRγ mRNA expression was highest (P < 0.001) on days 17-20 of the estrous cycle and also during weeks 9-12 of pregnancy compared with the other stages of the estrous cycle and pregnancy. Only the mPRα protein was changed during the estrous cycle; there were no significant differences in protein expression of mPRβ and mPRγ during the estrous cycle and pregnancy. Immunostaining for the mPRα, mPRβ, and mPRγ proteins was detectable in the CL sections at all stages of the estrous cycle and pregnancy. Strong positive staining was observed in small luteal cells; this reaction was less evident in large luteal cells. All proteins were also localized in endothelial cells of blood vessels. The obtained data indicate variable expression of mPRα, mPRβ, and mPRγ in bovine CL during the estrous cycle and first trimester of pregnancy and suggest that P4 may be involved in the regulation of CL function via these membrane receptors during both the estrous cycle and pregnancy.

Sex Steroid-Mediated Control of Oviductal Function in Cattle

In cattle, the oviduct is a tubular organ that connects the ovary and the uterus. The oviduct lumen stages a dynamic set of cellular and molecular interactions to fulfill the noble role of generating a new individual. Specific anatomical niches along the oviduct lumen provide the appropriate microenvironment for final sperm capacitation, oocyte capture and fertilization, and early embryo development and transport. To accomplish such complex tasks, the oviduct undergoes spatially and temporally-regulated morphological, biochemical, and physiological changes that are associated with endocrine events of the estrous cycle. Specifically, elevated periovulatory concentrations of estradiol (E2) and progesterone (P4) influence gene expression and morphological changes that have been associated positively to fertility in beef cattle. In this review, we explore how E2 and P4 influence oviductal function in the beginning of the estrous cycle, and prepare the oviductal lumen for interactions with gametes and embryos.

VLDL receptor regulates membrane progesterone receptor trafficking and non-genomic signaling

Progesterone mediates its physiological functions through activation of both transcription-coupled nuclear receptors and 7-transmembrane progesterone receptors (mPRs) that transduce progesterone's rapid non-genomic actions by coupling to various signaling modules. However, the immediate mechanisms of action downstream of mPRs remain in question. Herein we use an untargeted quantitative proteomics approach to identify mPR interactors to better define progesterone non-genomic signaling. Surprisingly, we identify the VLDL Receptor (VLDLR) as an mPR partner required for its plasma membrane localization. Knocking down VLDLR abolishes non-genomic progesterone signaling, a phenotype that is rescued by overexpressing VLDLR. Mechanistically, we show that the VLDLR is required for mPR trafficking from the ER to the Golgi. Taken together, our data define a novel function for the VLDLR as a trafficking chaperone required for the mPR subcellular localization and as such non-genomic progesterone-dependent signaling.

Primary cilia on porcine testicular somatic cells and their role in hedgehog signaling and tubular morphogenesis in vitro

The primary cilium is a microtubule-based sensory organelle found on nearly all eukaryotic cells but little is understood about its function in the testis. We investigate the role of primary cilia on testis cells in vitro by inhibiting formation of the primary cilium with Ciliobrevin D, a cell-permeable, reversible chemical inhibitor of ATPase motor cytoplasmic dynein. We analyzed cultured cells for the presence of primary cilia and their involvement in hedgehog signaling. Primary cilia were present on 89.3 ± 2.3 % of untreated testicular somatic cells compared to 3.1 ± 2.5 % cells with primary cilia for Ciliobrevin D-treated cells. Protein levels of Gli-2 and Smoothened were lower on Western blots after suppression of cilia with Ciliobrevin D. The inhibitor did not affect centrosome localization or cell proliferation, indicating that changes were due to ablation of the primary cilium. Testicular somatic cells have the ability to form three-dimensional tubules in vitro. In vitro-formed tubules were significantly longer and wider in the control group than in the Ciliobrevin D-treated group (9.91 ± 0.35 vs. 5.540 ± 1.08 mm and 339.8 ± 55.78 vs. 127.2 ± 11.9 μm, respectively) indicating that primary cilia play a role in tubule formation. Our results establish that the inhibition of ATPase motor cytoplasmic dynein perturbs formation of primary cilia in testicular somatic cells, affects the hedgehog signaling pathway and impairs tubule formation in vitro. These findings provide evidence for a role of cilia in the testis in cell signaling and tubular morphogenesis in vitro.

Membrane progesterone receptors in reproduction and cancer

Progesterone is a sexual steroid hormone that has a critical role in reproductive processes in males and females of several species, including humans. Furthermore, progesterone has been associated with pathological diseases such as breast, gynecological and brain cancer, regulating cell proliferation, apoptosis, and metastasis. In the past, progesterone actions were thought to be only mediated by its intracellular receptor (PR). However, recent evidence has demonstrated that membrane progesterone receptors (mPRs) mediate most of the non-classical progesterone actions. The role of the different mPRs subtypes in progesterone effects in reproduction and cancer is an emerging and exciting research area. Here we review studies to date regarding mPRs role in reproduction and cancer and discuss their functions and clinical relevance, suggesting mPRs as putative pharmacological targets and disease markers in cancer and diseases associated with reproduction.

Identification and characterization of a progestin and adipoQ receptor (PAQR) structurally related to Paqr7 in the ovary of Cynoglossus semilaevis and its potential role in regulating oocyte maturation

Membrane progestin receptors (mPRs) play an important role in the regulation of oocyte meiotic maturation in fish. However, details of the molecular endocrine mechanism regulating oocyte maturation in multiple spawning fish with asynchronous ovarian development remain unclear. The cDNA encoding a novel progestin and adipoQ receptor with structural similarity to mPRα (Paqr7), herein called Paqr7b, was cloned and sequenced from the ovary of half-smooth tongue sole Cynoglossus semilaevis. Phylogenetic analysis showed that Paqr7b represents an evolutionary intermediate between mPRα and mPRβ and shares high homology with other similar Paqr proteins in other teleost species. However, the tongue sole Paqr7b protein showed much greater homology to teleost mPRαs (average 52%) than mPRβs (average 40%), suggesting it may have arisen from gene duplication of mPRα. paqr7b and paqr7 mRNA exhibited similar patterns of tissue expression. The mRNA and protein of Paqr7b were ubiquitously detected in all tissues analyzed, including the ovary. Moreover, in situ hybridization results revealed that paqr7b was expressed in stage V oocytes, as well as in scattered cells in the pituitary. The expression of paqr7b mRNA in brain and ovary significantly increased from ovarian development stage II to stage V (P<0.05), and was maximal at stage V, and then sharply decreased at stage VI. The transcript level of paqr7b mRNA in the pituitary also peaked at stage V (P<0.05). Treatment of tongue sole ovarian follicles with gonadotropin consistently increased the expression level of Paqr7b protein and mRNA in both a dose- and stage-dependent manner. Microinjection of tongue sole oocytes with a morpholino antisense oligonucleotide to Paqr7b blocked the progestin induction of oocyte maturation. Our findings demonstrate an important role of Paqr7b in the regulation of oocyte maturation in tongue sole and suggest the receptor may also influence other aspects of reproduction, such as pituitary function.

Cloning and olfactory expression of progestin receptors in the Chinese black sleeper Bostrichthys sinensis

Our previous studies suggested that 17α,20β-dihydroxy-4-pregnen-3-one (DHP), an oocyte maturation inducing progestin, also acts as a sex pheromone in Chinese black sleeper Bostrichthys sinensis, a fish species that inhabits intertidal zones and mates and spawns inside a muddy burrow. The electro-olfactogram response to DHP increased during the breeding season. In the present study, we cloned the cDNAs of the nine progestin receptors (pgr, paqr5, 6, 7(a, b), 8, 9, pgrmc1, 2) from B. sinensis, analyzed their tissue distribution, and determined the expression in the olfactory rosette during the reproductive cycle in female and male fish. The deduced amino acid sequences of the nine progestin receptors share high sequence identities with those of other fish species and relatively lower homology with their mammalian counterparts, and phylogenetic analyses classified the nine B. sinensis progestin receptors into their respective progestin receptor groups. Tissue distribution of B. sinensis progestin receptors showed differential expression patterns, but all these nine genes were expressed in the olfactory rosette. Interestingly, paqr5 mRNA was found in the intermediate and basal parts of the olfactory epithelium but not in the central core using in situ hybridization, and its expression level was the highest in the olfactory rosette among the tissues examined. These results suggested Paqr5 may have an important role for transmitting progestin signaling in the olfactory system. The expression levels of paqr7a and paqr7b, pgr and pgrmc2 mRNA peaked around the mid meiotic stage, and that of paqr8 peaked at late meiotic stage in the olfactory rosette in males, while the olfactory expression of paqr5 decreased gradually as spermatogenesis progressed. In contrast, the expression of the progestin receptors did not change significantly during the development of the ovary in the olfactory rosette in females, except that of pgr. Interestingly, the changes of paqr8 expression in the olfactory rosette in males mirrored the changes of plasma DHP levels in females during the reproductive cycle, suggesting the Paqr8 may also be important for deciphering progestin signaling released by female. To our knowledge, this is the first time to demonstrate the presence of all known progestin receptors in a teleost olfactory rosette, and to show different expressions between the males and females during the reproductive cycle. This study provides the first evidence on changes of all purported progestin receptors during a reproductive cycle in teleost olfactory rosette, and suggests that distinct olfactory sensitivities to DHP may be due to the changes and compositions of each progestin receptor in B. sinensis.

Sex-dependent expression of anti-Müllerian hormone (amh) and amh receptor 2 during sex organ differentiation and characterization of the Müllerian duct development in Xenopus tropicalis

Amphibian gonadal differentiation involves the action of sex steroids. Recent research indicates that the anti-Müllerian hormone (AMH) is involved in testicular development in some lower vertebrate species. For amphibians there is a lack of data on ontogenetic expression of the AMH receptor AMHR2/amhr2 and of progesterone receptors (PGRS/pgrs). Here we expand the knowledge on amphibian sex differentiation by characterizing ontogenetic mRNA levels of amh, amhr2, intracellular and membrane pgrs (ipgr and mpgr beta) and cytochrome P450 19a1 (cyp19a1) (ovarian marker) in the urogenital complex of the model species Xenopus (Silurana) tropicalis. Furthermore, we characterized the ontogenetic development of the Müllerian ducts (precursors of the female reproductive tract) histologically. The developmental period investigated spanned from beginning of gonadal differentiation, Nieuwkoop and Faber (NF) stage 51, to 4weeks post-metamorphosis. The Müllerian ducts were first observed at NF 64 in both sexes. Male-enhanced amh mRNA levels from NF 53/54 to 6days post-metamorphosis and female-enhanced cyp19a1 levels from NF 53 to 4weeks post-metamorphosis were noted. The sexually dimorphic mRNA level profile was more distinct for amh than for cyp19a1. The pgrs mRNA levels increased over the studied period and showed no sex differences. At later developmental stages, the amhr2 mRNA level was increased in putative females compared with males. Our findings suggest that AMH has a role in gonadal differentiation in X. tropicalis. We propose relative gonadal amh mRNA level as a testicular marker during early gonadal development in amphibians.

Expression and immunolocalization of membrane progesterone receptors in the bovine oviduct

The oviduct plays a crucial role in the transport and maturation of gametes and ensures suitable conditions for fertility and early embryo development. One regulator of oviduct function is progesterone (P4), which affects the cell by interacting with nuclear progesterone receptors (PGRs) and through nongenomic mechanisms, presumably involving membrane PGRs. The aim of this study was to evaluate the expression of messenger RNAS (mRNAs) and proteins for progesterone receptor membrane component (PGRMC) 1 and 2 and membrane progestin receptors (mPR) α, β, and γ and to use immunohistochemistry to demonstrate their cell-specific localization in the bovine oviduct. Oviducts ipsilateral and contralateral to the corpus luteum or to the dominant follicle were collected from cows on days 6 to 12 (midluteal stage) and 18 to 20 (follicular stage) of the estrous cycle and divided into 3 parts (infundibulum, ampulla, and isthmus). There were no differences (P > 0.05) in the PGRMC1, PGRMC2, mPRα, β, and γ mRNA expression between ipsi- and contralateral oviducts. However, the same parts of the oviduct collected during the different stages of the estrous cycle showed higher (P < 0.05) mRNA levels of PGRMC1, PGRMC2, and mPRα on days 18 to 20 than on days 6 to 12 of the estrous cycle. mPRα and mPRβ mRNA levels were higher (P < 0.05) in the infundibulum than in the isthmus, whereas PGRMC1 expression was higher (P < 0.05) in the infundibulum than in ampulla. Immunohistochemistry was used to detect PGRMC1, PGRMC2, PRα, β, and γ proteins in all parts of both oviducts from days 6 to 12 and 18 to 20 of the estrous cycle. There were no differences in the staining intensity and cellular localization of the studied proteins between the ipsi- and contralateral oviducts and between the studied stages of the estrous cycle. A strong positive reaction was observed in luminal cells, but this reaction was less evident in myocytes and stromal cells. All proteins were also localized to the endothelial cells of blood vessels. These results suggest that membrane progesterone receptors, may be involved in the regulation of oviduct motility, secretory function, and blood flow in this organ.

Levonorgestrel decreases cilia beat frequency of human fallopian tubes and rat oviducts without changing morphological structure

Levonorgestrel, a derivative of progesterone, effectively protects women against unwanted pregnancy as an emergency contraceptive. Previous studies have not been successful in determining the mechanism by which levonorgestrel acts. In the present study we analysed cilia beat action and cilia morphology following levonorgestrel exposure in vitro and in vivo using both light and electron microscopy. There was a significant decrease in the ciliary beat frequency (CBF) of human fallopian tubes between mucosal explants bathed in 5 μmol/L levonorgestrel and those bathed in medium alone (P < 0.05). There was a tendency for CBF to decrease more in the ampulla than in isthmus, but there were no differences between the proliferative and secretory phases. In rat oviducts, levonorgestrel produced a similar reduction in CBF (~ 10%) compared with the saline control group (P < 0.05). Histological and ultrastructural analysis demonstrated no changes in the percentage of ciliated cells or in the classic '9 + 2' structure of cilia following levonorgestrel treatment in either system. Thus, levonorgestrel reduces CBF without damaging cilia morphology. Decreases in CBF may indicate a pathological role for levonorgestrel in the transportation of the ovum and zygote in the fallopian tube.

Relaxin affects cell organization and early and late stages of spermatogenesis in a coculture of rat testicular cells

Relaxin and its receptor RXFP1 are co-expressed in Sertoli cells, and relaxin can stimulate proliferation of Sertoli cells. In this study, we investigated a role of relaxin in spermatogenesis, using a short-term culture of testicular cells of the rat that allowed differentiation of spermatogonia to spermatids. Sertoli, germ, and peritubular myoid cells were the predominant cell types in the culture. Sertoli and germ cells expressed RXFP1. Cultures were incubated without (control) or with 0.5% fetal bovine serum (FBS) or 100 ng/mL H2 relaxin (RLN) for 2 days. Cell organization, number, and differentiation were analyzed after 2 (D2), 5 (D5) or 8 (D8) days of culturing. Although the proportion of germ cells decayed from D2 to D5, the relative contribution of HC, 1C, 2C, and 4C germ cell populations remained constant in the control group during the whole culture. RLN did not affect the proportion of germ cell populations compared with control, but increased gene and/or protein expression of the undifferentiated and differentiated spermatogonia markers PLZF and c-KIT, and of the post-meiotic marker Odf2 in D5. RLN favored organization of cells in tubule-like structures, the arrangement of myoid cells around the tubules, arrangement of c-KIT-positive spermatogonia at the basal region of the tubules, and expression of the cell junction protein β-catenin close to the plasma membrane region. Knockdown of relaxin with small interfering RNA (siRNA) reduced expression of β-catenin at the cell junctions, and shifted its expression to the nucleus. We propose that relaxin may affect spermatogenesis by modulating spermatogonial self renewal and favoring cell contact.

Progesterone-mediated effects on gene expression and oocyte-cumulus complex transport in the mouse fallopian tube

BACKGROUND

The fallopian tube transports the gametes to the fertilization site and delivers the embryo to the uterus at the optimal time for implantation. Progesterone and the classical progesterone receptor are involved in regulating both tubal ciliary beating and muscular contractions, likely via both genomic and non-genomic actions.

METHODS

To provide more details of the underlying mechanisms, we investigated the effect of progesterone on gene expression in mice fallopian tubes in vitro at 20 min, 2 h and 8 h post progesterone treatment using microarray and/or quantitative PCR. In parallel, oocyte cumulus complex transport was investigated in ovulating mice that were injected with one of the progesterone receptor antagonists, Org 31710 or CDB2194.

RESULTS

Microarray analyses did not reveal any apparently regulated genes 20 min after progesterone treatment, consistent with the proposed non-genomic action of progesterone controlling ciliary beating. After 2 h, 11 genes were identified as up-regulated. Analyses using quantitative PCR at 2 h and 8 h showed a consistent up-regulation of endothelin1 and a down-regulation of its receptor Endothelin receptor A by progesterone. We also confirmed that treatment with progesterone receptor antagonists before ovulation accelerates the transport of the oocyte cumulus complex.

CONCLUSIONS

This is the first study showing that progesterone regulates the expression of endothelin1 and endothelin receptor A in the fallopian tube. Together with previous studies of the effects of endothelin on muscular contractions in the fallopian tube, the results from this study suggest that endothelin is a mediator of the progesterone-controlled effects on muscular contraction and eventually gamete transport in the fallopian tube.

Human chorionic gonadotropin increases serum progesterone, number of corpora lutea and angiogenic factors in pregnant sheep

Early gestation is a critical period when implantation and placental vascularization are established, processes influenced by progesterone (P4). Although human chorionic gonadotropin (hCG) is not endogenously synthesized by livestock, it binds the LH receptor, stimulating P4 synthesis. We hypothesized treating pregnant ewes with hCG would increase serum P4, number of corpora lutea (CLs) and concepti, augment steroidogenic enzymes, and increase membrane P4 receptors (PAQRs) and angiogenic factors in reproductive tissues. The objective was to determine molecular alterations induced by hCG in pregnant sheep that may promote pregnancy. Ewes received either 600 IU of hCG or saline i.m. on day 4 post mating. Blood samples were collected daily from day 0 until tissue collection for serum P4 analysis. Reproductive tissues were collected on either day 13 or 25 of gestation and analyzed for PAQRs, CXCR4, proangiogenic factors and steroidogenic enzymes. Ewes receiving hCG had more CL and greater serum P4, which remained elevated. On day 25, StAR protein production decreased in CL from hCG-treated ewes while HSD3B1 was unchanged; further, expression of CXCR4 significantly increased and KDR tended to increase. PAQR7 and CXCR4 protein was increased in caruncle tissue from hCG-treated ewes. Maternal hCG exposure influenced fetal extraembryonic tissues, as VEGFA, VEGFB, FLT1, and ANGPT1 expression increased. Our results indicate hCG increases serum P4 due to augmented CL number per ewe. hCG treatment resulted in greater PAQR7 and CXCR4 in maternal endometrium and promoted expression of proangiogenic factors in fetal extraembryonic membranes. Supplementing livestock with hCG may boost P4 levels and improve reproductive efficiency.

Estradiol increases cAMP in the oviductal secretory cells through a nongenomic mechanism

In the rat oviduct, estradiol (E2) accelerates egg transport by a nongenomic action that requires previous conversion of E2 to methoxyestrogens via catechol-O-methyltranferase (COMT) and activation of estrogen receptor (ER) with subsequent production of cAMP and inositol triphosphate (IP3). However, the role of the different oviductal cellular phenotypes on this E2 nongenomic pathway remains undetermined. The aim of this study was to investigate the effect of E2 on the levels of cAMP and IP3 in primary cultures of secretory and smooth muscle cells from rat oviducts and determine the mechanism by which E2 increases cAMP in the secretory cells. In the secretory cells, E2 increased cAMP but not IP3, while in the smooth muscle cells E2 decreased cAMP and increased IP3. Suppression of protein synthesis by actinomycin D did not prevent the E2-induced cAMP increase, but this was blocked by the ER antagonist ICI 182 780 and the inhibitors of COMT OR 486, G protein-α inhibitory (Gαi) protein pertussis toxin and adenylyl cyclase (AC) SQ 22536. Expression of the mRNA for the enzymes that metabolizes estrogens, Comt, Cyp1a1, and Cyp1b1 was found in the secretory cells, but this was not affected by E2. Finally, confocal immunofluorescence analysis showed that E2 induced colocalization between ESR1 (ERα) and Gαi in extranuclear regions of the secretory cells. We conclude that E2 differentially regulates cAMP and IP3 in the secretory and smooth muscle cells of the rat oviduct. In the secretory cells, E2 increases cAMP via a nongenomic action that requires activation of COMT and ER, coupling between ESR1 and Gαi, and stimulation of AC.

Ependymal cell differentiation, from monociliated to multiciliated cells

Primary and motile cilia differ in their structure, composition, and function. In the brain, primary cilia are immotile signalling organelles present on neural stem cells and neurons. Multiple motile cilia are found on the surface of ependymal cells in all brain ventricles, where they contribute to the flow of cerebrospinal fluid. During development, monociliated ependymal progenitor cells differentiate into multiciliated ependymal cells, thus providing a simple system for studying the transition between these two stages. In this chapter, we provide protocols for immunofluorescence staining of developing ependymal cells in vivo, on whole mounts of lateral ventricle walls, and in vitro, on cultured ependymal cells. We also provide a list of markers we currently use to stain both types of cilia, including proteins at the ciliary membrane and tubulin posttranslational modifications of the axoneme.

TGF-β isoforms induce EMT independent migration of ovarian cancer cells

Background

Transforming growth factor beta (TGF-β) plays major roles in tumorigenesis by regulating cell growth, epithelial-to-mesenchymal transition (EMT), migration/invasion and metastasis. The epithelial markers E-cadherin, claudin-3 and claudin-4, commonly decreased in human adenocarcinomas are actually up regulated during ovarian carcinogenesis. In human ovarian cancer TGF-β1 may either suppress or promote tumor progression, but whether other TGF-β isoforms (TGF-β2 and TGF-β3) exert similar effects is not known.

Methods

In this study we investigated the ability of the TGF-β isoforms (TGF-β1-3) to induce proliferation and migration by BrdU labeling, scratch wound and trans-filter migration assays in the human serous adenocarcinoma cell-line NIH-OVCAR3. Transepithelial resistance was measured and EMT observed by light-microscopy. Expression of adherens-, tight-junction and EMT-related transcription factors was analyzed by qRT-PCR and immunoblotting.

Results

All TGF-β isoforms dose-dependently inhibited NIH-OVCAR3 cell growth, stimulated tumor cell migration with similar efficiency. The mesenchymal marker N-cadherin and claudin-1 expression was induced and occludin down regulated. However, migrating cells retained an epithelial shape and E-cadherin expression. The E-cadherin repressor SNAIL mRNA levels remained low independently of TGF-β1-3 treatment while ZEB1 expression was enhanced.

Conclusions

TGF-β1, TGF-β2 and TGF-β3 promote migration of NIH-OVCAR3 ovarian cancer cells independently of cell proliferation and without conversion to a complete EMT phenotype. Epithelial ovarian cancer commonly metastasis to the surrounding tissue or inside the peritoneum rather than invading blood vessels to set distance metastasis. Our result raises the question whether ovarian cancer primarily spread via collective migration than via single cell invasion.

Progesterone receptor-dependent regulation of genes in the oviducts of female mice

Oviducts play a critical role in gamete and embryo transport, as well as supporting early embryo development. Progesterone receptor (PGR) is a transcription factor highly expressed in oviductal cells, while its activating ligand, progesterone, surges to peak levels as ovulation approaches. Progesterone is known to regulate oviduct cilia beating and muscular contractions in vitro, but how PGR may mediate this in vivo is poorly understood. We used PGR null mice to identify genes potentially regulated by PGR in the oviducts during the periovulatory period. Histologically, oviducts from PGR null mice showed no gross structural or morphological defects compared with normal littermates. However, microarray analysis of oviducts at 8 h posthuman chorionic gonadotropin revealed >1,000 PGR-dependent genes. Using reverse-transcription polymerase chain reaction (RT-PCR) we selected 10 genes for validation based on their potential roles in oocyte/embryo transport and support. Eight genes were confirmed to be downregulated ( Adamts1, Itga8, Edn3, Prlr, Ptgfr, Des, Myocd, and Actg2) and one upregulated ( Agtr2) in PGR null oviducts. Expression of these genes was also assessed in oviducts of naturally cycling mice during ovulation and day 1 and day 4 of pregnancy. Adamts1, Itga8, Edn3, Prlr, and Ptgfr were significantly upregulated in oviducts at ovulation/mating. However, most genes showed basal levels of expression at other times. The exceptions were Prlr and Ptgfr, which showed pulsatile increases on day 1 and/or day 4 of pregnancy. This is the first, comprehensive study to elucidate putative PGR-regulated genes in the oviduct and reveals key downstream targets potentially mediating oocyte and embryo transport.

Tubal transport of gametes and embryos: a review of physiology and pathophysiology

With the advent of assisted reproductive technology in the past three decades, the clinical importance of fallopian tubes has been relatively overlooked. However, successful spontaneous conception requires normal function of the tube to provide not only a conduit for the gametes to convene and embryo to reach the uterine cavity, but also a physiologically optimized environment for fertilization and early embryonic development. In this review, after a brief description of normal human tubal anatomy and histology, we will discuss tubal transport and its principal effectors, including ciliary motion, muscular contractility and tubal fluid. Furthermore, we will discuss the ciliary ultrastructure and regulation of ciliary beat frequency by ovarian steroids, follicular fluid, angiotensin system, autonomic nervous system and other factors such as adrenomedullin and prostaglandins. In the last section, we describe the adverse impact of various pathological conditions, such as endometriosis, infection and smoking on tubal function and ciliary motility.

Expression of nuclear and membrane progesterone receptors in the canine oviduct during the periovulatory period

Important reproductive events take place in the canine oviduct in the presence of increasing concentrations of progesterone (P4). To investigate the potential effects of P4 on the canine oviduct, the expression of nuclear (PR) and membrane (PGRMC1 and 2, mPRα, β and γ) P4 receptors was studied by quantitative RT-PCR and immunohistochemistry. Oviducts were collected from Beagle bitches after the onset of pro-oestrus and before the LH peak (Pre-LH), after the LH peak and before ovulation (Pre-ov) and on Days 1, 4 and 7 post-ovulation (n=6 bitches/stage). PR mRNA concentrations decreased from Pre-LH to Day 7 in the ampulla and isthmus, whereas both PGRMC1 and 2 mRNA levels increased over the same period. The main change in mPR expression was an increase in mPRβ and γ mRNAs at Day 7 in the isthmus. Furthermore, PR proteins were expressed in the nuclei of luminal epithelial, stromal and muscular cells, whereas the expression of PGRMCs and mPRs was primarily cytoplasmic and localised in the luminal epithelium. The immunostaining for PR decreased at Day 4 in the stroma and muscle, whereas it remained strong in the epithelium from Pre-LH to Day 7. PGRMC1 staining was strong at Days 4 and 7 whereas PGRMC2 was highly expressed from Pre-ov to Day 7. The most intense immunostaining signals for all three mPRs were observed at Day 7. Our results strongly support the hypothesis that P4 is an important regulator of oviductal functions in the bitch through complementary classical and non-classical P4 pathways.

Progesterone-facilitated lordosis of estradiol-primed mice is attenuated by knocking down expression of membrane progestin receptors in the midbrain

Evidence is emerging of the role of membrane progestin receptors (referred to as mPRs herein: members of Progestin and AdipoQ Receptor (Paqr) family) as a novel brain target in mammals, such as rats. In the present study, the role of mPRs in mice was assessed to further elucidate the conservation of this mechanism across species. The brain target investigated was the midbrain ventral tegmental area (VTA) given its described role for rapid actions of progestins for reproduction. Studies tested the hypothesis that if mPRs are required for progestin-facilitated lordosis through actions in the VTA, then knockdown of mPRs in the VTA will attenuate lordosis. Ovariectomized (OVX) mice were subcutaneously injected with estradiol (E2) and progesterone (P4), and infused with antisense oligodeoxynucleotides (AS-ODNs) to mPRα (Paqr7) and/or mPRβ (Paqr8) or vehicle to the lateral ventricle or VTA. Mice were assessed for reproductive behavior (lordosis and aggression/rejection quotients) in a standard mating task. Results supported our hypothesis. E2+P4-facilitated lordosis was significantly reduced, and aggression/rejection increased, with infusions of mPRα, mPRβ, or mPRαβ AS-ODNs to the lateral ventricle, compared to vehicle. E2+P4-facilitated lordosis was significantly decreased, and aggression/rejection increased, with mPRβ or mPRαβ AS-ODNs to the VTA of C57/BL6 mice. Both mPRɑ and mPRβ AS-ODNs reduced lordosis, and increased aggression/rejection, of wildtype (C57/BL6x129) mice, but not nuclear PR knockout mice. Thus, mPRs may be a novel target of progestins for reproductive behavior of mice.

Patient-derived xenograft models to improve targeted therapy in epithelial ovarian cancer treatment

Despite increasing evidence that precision therapy targeted to the molecular drivers of a cancer has the potential to improve clinical outcomes, high-grade epithelial ovarian cancer (OC) patients are currently treated without consideration of molecular phenotype, and predictive biomarkers that could better inform treatment remain unknown. Delivery of precision therapy requires improved integration of laboratory-based models and cutting-edge clinical research, with pre-clinical models predicting patient subsets that will benefit from a particular targeted therapeutic. Patient-derived xenografts (PDXs) are renewable tumor models engrafted in mice, generated from fresh human tumors without prior in vitro exposure. PDX models allow an invaluable assessment of tumor evolution and adaptive response to therapy. PDX models have been applied to pre-clinical drug testing and biomarker identification in a number of cancers including ovarian, pancreatic, breast, and prostate cancers. These models have been shown to be biologically stable and accurately reflect the patient tumor with regards to histopathology, gene expression, genetic mutations, and therapeutic response. However, pre-clinical analyses of molecularly annotated PDX models derived from high-grade serous ovarian cancer (HG-SOC) remain limited. In vivo response to conventional and/or targeted therapeutics has only been described for very small numbers of individual HG-SOC PDX in conjunction with sparse molecular annotation and patient outcome data. Recently, two consecutive panels of epithelial OC PDX correlate in vivo platinum response with molecular aberrations and source patient clinical outcomes. These studies underpin the value of PDX models to better direct chemotherapy and predict response to targeted therapy. Tumor heterogeneity, before and following treatment, as well as the importance of multiple molecular aberrations per individual tumor underscore some of the important issues addressed in PDX models.

Pregnane xenobiotic receptors and membrane progestin receptors: role in neurosteroid-mediated motivated behaviours

Progestogens have actions in the midbrain ventral tegmental area (VTA) to mediate motivated behaviours, such as those involved in reproductive processes, among female rodents. In the VTA, the formation and actions of one progestogen, 5α-pregnan-3α-ol-20-one (3α,5α-THP), are necessary and sufficient to facilitate sexual responding (measured by lordosis) of female rodents. Although 3α,5α-THP can be produced after metabolism of ovarian progesterone, 3α,5α-THP is also a neurosteroid produced de novo in brain regions, such as the VTA. There can be dynamic changes in 3α,5α-THP production associated with behavioural experience, such as mating. Questions of interest are the sources and targets of 3α,5α-THP. Regarding sources, the pregnane xenobiotic receptor (PXR) may be a novel factor involved in 3α,5α-THP metabolism in the VTA (as well as a direct target of 3α,5α-THP). We have identified PXR in the midbrain of female rats, and manipulating PXR in this region reduces 3α,5α-THP synthesis and alters lordosis, as well as affective and social behaviours. Regarding targets, recent studies have focused on the role of membrane progestin receptors (mPRs). We have analysed the expression of two of the common forms of these receptors (mPRα/paqr7 and mPRβ/paqr8) in female rats. The expression of mPRα was observed in peripheral tissues and brain areas, including the hypothalamus and midbrain. The expression of mPRβ was only observed in brain tissues and was abundant in the midbrain and hypothalamus. To our knowledge, studies of these receptors in mammalian models have been limited to expression and regulation, instead of function. One question that was addressed was the functional effects of progestogens via mPRα and mPRβ in the midbrain of hormone-primed rats for lordosis. Studies to date suggest that mPRβ may be an important target of progestogens in the VTA for lordosis. Taken together, the result of these studies demonstrate that PXR is involved in the production of 3α,5α-THP in the midbrain VTA. Moreover, mPRs may be a target for the actions of progestogens in the VTA for lordosis.

The putative roles of nuclear and membrane-bound progesterone receptors in the female reproductive tract

Progesterone produced by the corpus luteum (CL) is a key regulator of normal cyclical reproductive functions in the females of mammalian species. The physiological effects of progesterone are mediated by the canonical genomic pathway after binding of progesterone to its specific nuclear progesterone receptor (PGR), which acts as a ligand-activated transcription factor and has two main isoforms, PGRA and PGRB. These PGR isoforms play different roles in the cell; PGRB acts as an activator of progesterone-responsive genes, while PGRA can inhibit the activity of PGRB. The ratio of these isoforms changes during the estrous cycle and pregnancy, and it corresponds to the different levels of progesterone signaling occurring in the reproductive tract. Progesterone exerts its effects on cells also by a non-genomic mechanism by the interaction with the progesterone-binding membrane proteins including the progesterone membrane component (PGRMC) 1 and 2, and the membrane progestin receptors (mPRs). These receptors rapidly activate the appropriate intracellular signal transduction pathways, and subsequently they can initiate specific cell responses or modulate genomic cell responses. The diversity of progesterone receptors and their cellular actions enhances the role of progesterone as a factor regulating the function of the reproductive system and other organs. This paper deals with the possible involvement of nuclear and membrane-bound progesterone receptors in the function of target cells within the female reproductive tract.

Membrane progestin receptors in the midbrain ventral tegmental area are required for progesterone-facilitated lordosis of rats

Progesterone (P₄) and its metabolites, rapidly facilitate lordosis of rats partly through actions in the ventral tegmental area (VTA). The study of membrane progestin receptors (mPRs), of the Progestin and AdipoQ Receptor (PAQR) superfamily, has been limited to expression and regulation, instead of function. We hypothesized that if mPRs are required for progestin-facilitated lordosis in the VTA, then mPRs will be expressed in this region and knockdown will attenuate lordosis. First, expression of mPR was examined by reverse-transcriptase polymerase chain reaction (RT-PCR) in brain and peripheral tissues of proestrous Long-Evans rats. Expression of mPRα (paqr7) was observed in peripheral tissues and brain areas, including hypothalamus and midbrain. Expression of mPRβ (paqr8) was observed in brain tissues and was abundant in the midbrain and hypothalamus. Second, ovariectomized rats were estrogen (E₂; 0.09 mg/kg, SC), and P₄ (4 mg/kg, SC) or vehicle-primed, and infused with antisense oligodeoxynucleotides (AS-ODNs) targeted against mPRα and/or mPRβ intracerebroventricularly or to the VTA. Rats were assessed for motor (open field), anxiety (elevated plus maze), social (social interaction), and sexual (lordosis) behavior. P₄-facilitated lordosis was significantly reduced with administration of AS-ODNs for mPRα, mPRβ, or co-administration of mPRα and mPRβ to the lateral ventricle, compared to vehicle. P₄-facilitated lordosis was reduced, compared to vehicle, by administration of mPRβ AS-ODNs, or co-administration of mPRα and mPRβ AS-ODNs, but not mPRα AS-ODNs alone, to the VTA. No differences were observed for motor, anxiety, or social behaviors. Thus, mPRs in the VTA are targets of progestin-facilitated lordosis of rats.

Enhanced beta-catenin expression and inflammation are associated with human ectopic tubal pregnancy

STUDY QUESTION

Is there a molecular link between Wnt signaling in fallopian tube inflammation and ectopic tubal implantation?

SUMMARY ANSWER

Enhanced beta-catenin expression, reduced E-cadherin expression and glycogen accumulation in the tubal epithelia and hyperplasia in tubal arteries were found in ectopic tubal pregnancy, consistent with the effects induced by Wnt signaling and inflammation.

WHAT IS KNOWN ALREADY

Chronic inflammation caused by infection can alter gene expression in the fallopian tube cells possibly leading to the development of ectopic pregnancy. Knockout mouse models have shown a relationship between Wnt/beta-catenin signaling and predisposition to tubal ectopic pregnancy.

STUDY DESIGN, SIZE, DURATION

Women with ectopic tubal pregnancy (n = 18) were included in the case group, while women with chronic salpingitis (n = 13) and non-pregnant women undergoing sterilization procedures or salpingectomy for benign uterine disease (n = 10) were set as the controls. This study was performed between January 2012 and November 2012.

PARTICIPANTS/MATERIALS, SETTING, METHODS

The ampullary segments of fallopian tubes were collected from patients. Tissues of tubal pregnancy were separated into implantation sites and non-implantation sites. Beta-catenin and E-cadherin expression were determined using immunohistological and immunofluorescence staining. Glycogen production was measured with periodic acid Schiff by staining. The diameter and wall thickness of tubal arteries were evaluated by histological analysis method.

MAIN RESULTS AND THE ROLE OF CHANCE

Immunohistological staining revealed that beta-catenin protein expression was 100% positive in the ectopic pregnant and inflamed tubal tissues, and the staining intensity was significantly higher than in non-pregnant tubal tissues. In contrast, E-cadherin expression was reduced in ectopic pregnant fallopian tubes, possibly as a consequence of increased Wnt signaling. Moreover, glycogen accumulated in the tubal cells, and hyperplasia was observed in the tubal arteries with ectopic pregnancy, which is consistent with the effects induced by Wnt signaling and inflammation. All these changes could create the permissive environment that promotes embryos to ectopically implant into the fallopian tube.

LIMITATIONS, REASONS FOR CAUTION

This finding requires a further confirmation about what activates Wnt signaling in ectopic tubal pregnancies. Also, it is generally recognized that Chlamydia infection is associated with ectopic pregnancy, and disturbs tubal epithelia via the Wnt signaling. However, the infection type in the samples used was salpingitis.

WIDER IMPLICATIONS OF THE FINDINGS

A better understanding of the underlying mechanisms leading to ectopic pregnancies may contribute to our knowledge of the pathogenesis of tubal disorders and infertility and to the prevention of tubal ectopic pregnancy.

The classical progesterone receptor mediates the rapid reduction of fallopian tube ciliary beat frequency by progesterone

BACKGROUND

The transport of gametes as well as the zygote is facilitated by motile cilia lining the inside of the fallopian tube. Progesterone reduces the ciliary beat frequency within 30 minutes in both cows and mice. This rapid reduction suggest the involvement of a non-genomic signaling mechanism, although it is not known which receptors that are involved. Here we investigated the possible involvement of the classical progesterone receptor in this process.

METHOD

The ciliary beat frequency of mice fallopian tube was measured ex vivo using an inverted bright field microscope and a high speed camera. The effects of the agonists progesterone and promegestone and an antagonist, mifeprestone, were investigated in wildtype mice. The effect of progesterone was also investigated in mice lacking the classical progesterone receptor.

RESULTS

Progesterone, as well as the more specific PR agonist promegestone, significantly reduced the CBF at concentrations of 10-100 nanomolar within 10-30 minutes. In the absence of progesterone, the PR antagonist mifeprestone had no effect on the ciliary beat frequency at a concentration of 1 micromolar. When ciliated cells were pre-incubated with 1 micromolar mifeprestone, addition of progesterone did not reduce the ciliary beat frequency. Accordingly, in ciliated cells from mice not expressing the classical progesterone receptor, exposure to 100 nanomolar progesterone did not reduce the ciliary beat frequency.

CONCLUSIONS

This is the first study to provide comprehensive evidence that the classical progesterone receptor mediates the rapid reduction of the tubal ciliary beat frequency by progesterone.

Characterization, neurosteroid binding and brain distribution of human membrane progesterone receptors δ and {epsilon} (mPRδ and mPR{epsilon}) and mPRδ involvement in neurosteroid inhibition of apoptosis

Three members of the progestin and adipoQ receptor (PAQR) family, PAQR-7, PAQR-8, and PAQR-5 [membrane progesterone (P4) receptor (PR) (mPR)α, mPRβ, and mPRγ], function as plasma mPRs coupled to G proteins in mammalian cells, but the characteristics of two other members, PAQR6 and PAQR9 (mPRδ and mPRε), remain unclear, because they have only been investigated in yeast expression systems. Here, we show that recombinant human mPRδ and mPRε expressed in MDA-MB-231 breast cancer cells display specific, saturable, high-affinity [(3)H]-P4 binding on the plasma membranes of transfected cells with equilibrium dissociation constants (K(d)s) of 2.71 and 2.85 nm, respectively, and low affinity for R5020, characteristics typical of mPRs. P4 treatment increased cAMP production as well as [(35)S]-guanosine 5'-triphosphate (GTP)γS binding to transfected cell membranes, which was immunoprecipitated with a stimulatory G protein antibody, suggesting both mPRδ and mPRε activate a stimulatory G protein (Gs), unlike other mPRs, which activate an inhibitory G protein (Gi). All five mPR mRNAs were detected in different regions of the human brain, but mPRδ showed greatest expression in many regions, including the forebrain, hypothalamus, amygdala, corpus callosum, and spinal cord, whereas mPRε was abundant in the pituitary gland and hypothalamus. Allopregnanolone and other neurosteroids bound to mPRδ and other mPRs and acted as agonists, activating second messengers and decreased starvation-induced cell death and apoptosis in mPRδ-transfected cells and in hippocampal neuronal cells at low nanomolar concentrations. The results suggest that mPRδ and mPRε function as mPRs coupled to G proteins and are potential intermediaries of nonclassical antiapoptotic actions of neurosteroids in the central nervous system.

Ciliary and flagellar structure and function--their regulations by posttranslational modifications of axonemal tubulin

Eukaryotic cilia and flagella are evolutionarily conserved microtubule-based organelles protruding from the cell surface. They perform dynein-driven beating which contributes to cell locomotion or flow generation. They also play important roles in sensing as cellular antennae, which allows cells to respond to various external stimuli. The main components of cilia and flagella, α- and β-tubulins, are known to undergo various posttranslational modifications (PTMs), including phosphorylation, palmitoylation, tyrosination/detyrosination, Δ2 modification, acetylation, glutamylation, and glycylation. Recent identification of tubulin-modifying enzymes, especially tubulin tyrosine ligase-like proteins which perform tubulin glutamylation and glycylation, has demonstrated the importance of tubulin modifications for the assembly and functions of cilia and flagella. In this chapter, we review recent work on PTMs of ciliary and flagellar tubulins in conjunction with discussing the basic knowledge.

Sex hormone-dependent regulation of cilia beat frequency in airway epithelium

Previous studies have demonstrated a female disadvantage in airway diseases, such as asthma and bronchiectasis. The basis for this sex disparity is unknown. We hypothesized that the female sex hormone, progesterone (P4), inhibits functions of the normal airway mucociliary apparatus. P4 receptor (PR) expression was evaluated in human lung and cultured primary human airway epithelial cells isolated from male and female lung transplant donors. PR expression was restricted to the proximal region of the cilia of airway epithelia, and was similar in men and women. Expression of isoform PR-B was more abundant than PR-A in cells from both sexes. Airway epithelial cell exposure to P4 decreased cilia beat frequency (CBF) by 42.3% (±7.2). Inhibition of CBF was prevented by coadministration of P4 with the active form of estrogen, 17β-estradiol, or the PR antagonist, mifepristone. P4 inhibition was time and dose dependent, with a significant decrease by 8 hours and maximal effect at 24 hours, accompanied by translocation of PR from the cilia to the nucleus. Inhibition of cilia beat was also prevented by treatment of cells with actinomycin D, suggesting that CBF inhibition is a transcriptionally mediated event. Together, these findings indicate that sex hormones influence the function of a key component of the mucociliary apparatus. These mechanisms may contribute to the sex disparity present in airway diseases and provide therapeutic targets for the treatment of these debilitating airway diseases.

Reproductive tract function and dysfunction in women

An appropriately developed and functional reproductive tract is essential for the natural production of offspring. However, abnormal development or disease, either within or external to the reproductive tract, can cause considerable morbidity and mortality. This Review describes the normal function of each section of the female reproductive tract. Some of the major conditions and diseases that cause reproductive tract dysfunction in women of reproductive age are reviewed, with a focus on endocrine-related dysfunction. As the female reproductive tract is vital for the continuation of the human species, it is crucial to have an improved understanding of how the cells and tissues of this system interact under normal conditions and to define how hormonal and genetic abnormalities cause pathophysiologic derangement of reproduction.

Early life progestin exposure causes arrested oocyte development, oviductal agenesis and sterility in adult Xenopus tropicalis frogs

Levonorgestrel (LNG) is a commonly used pharmaceutical progestin found in the environment. Information on the long-term toxicity of progestins following early life exposure is scant. We investigated the effects of developmental LNG exposure on sex differentiation, reproductive organ development and fertility in the model frog Xenopus tropicalis. Tadpoles were exposed to 0, 0.06 or 0.5nM LNG via the water from hatching until metamorphosis. At metamorphosis effects on gonadal differentiation were evaluated using a subsample of frogs. Remaining animals were held unexposed for nine months, at which time reproductive organ structure, function and fertility were determined. LNG exposure severely impaired oviduct and ovary development and fertility. All adult females in the 0.5nM group (n=10) completely lacked oviducts. They also displayed a significantly larger fraction of immature oocytes, arrested in meiotic prophase, than control females. Upon mating with unexposed males, only one of 11 LNG-exposed females laid eggs, whereas all control females did. No effects on testicular development, sperm count or male fertility were observed. At metamorphosis, no effects on sex ratio or gonadal histology were evident. The effects on ovarian and oviductal development were detected at adult age but not at metamorphosis, emphasising the importance of investigating the long-term consequences of developmental exposure. This is the first developmental reproductive toxicity study of a progestin in an aquatic vertebrate. Considering that several progestins are present in contaminated surface waters, further investigation into the sensitivity of frogs to progestins is warranted to understand the risk such compounds may pose to wild frog populations.

Cellular expression and localization of estrogen receptor α and progesterone receptor mRNA in the bovine oviduct combining laser-assisted microdissection, quantitative PCR, and in situ hybridization

The importance of using techniques that allow the study of pure populations of cells has been increasingly recognized. The authors used laser-assisted microdissection (LAM) in combination with quantitative real-time PCR (qPCR) to assess the relative expression of mRNAs encoding estrogen receptor α (ERα) and progesterone receptor (PR) in the different compartments of the bovine oviduct (epithelium, stroma, smooth muscle coat) during the follicular and mid-luteal phases of the estrus cycle. The localization of receptor mRNA was further studied using non-radioactive in situ hybridization (NISH). A special focus was on whether formalin fixation and paraffin embedding influence the quality and quantity of mRNA obtained from microdissected material. Distinct cyclic changes of the mRNA in the bovine oviduct were observed with elevated levels of PR mRNA transcripts in the epithelium and smooth muscle coat during the follicular phase. The expression of PR mRNA did not vary significantly in the stroma of the bovine oviduct during follicular and mid-luteal phases. In conclusion, the authors found that LAM with qPCR can precisely locate and accurately quantify mRNA expression in specific cell populations from formalin-fixed and paraffin-embedded oviductal tissue.