Mechanisms of Adiponectin Action in Fertility: An Overview from Gametogenesis to Gestation in Humans and Animal Models in Normal and Pathological Conditions

Adiponectin is the most abundant plasma adipokine. It mainly derives from white adipose tissue and plays a key role in the control of energy metabolism thanks to its insulin-sensitising, anti-inflammatory, and antiatherogenic properties. In vitro and in vivo evidence shows that adiponectin could also be one of the hormones controlling the interaction between energy balance and fertility in several species, including humans. Indeed, its two receptors—AdipoR1 and AdipoR2—are expressed in hypothalamic–pituitary–gonadal axis and their activation regulates Kiss, GnRH and gonadotropin expression and/or secretion. In male gonads, adiponectin modulates several functions of both somatic and germ cells, such as steroidogenesis, proliferation, apoptosis, and oxidative stress. In females, it controls steroidogenesis of ovarian granulosa and theca cells, oocyte maturation, and embryo development. Adiponectin receptors were also found in placental and endometrial cells, suggesting that this adipokine might play a crucial role in embryo implantation, trophoblast invasion and foetal growth. The aim of this review is to characterise adiponectin expression and its mechanism of action in male and female reproductive tract. Further, since features of metabolic syndrome are associated with some reproductive diseases, such as polycystic ovary syndrome, gestational diabetes mellitus, preeclampsia, endometriosis, foetal growth restriction and ovarian and endometrial cancers, evidence regarding the emerging role of adiponectin in these disorders is also discussed.

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WNK1 regulates uterine homeostasis and its ability to support pregnancy

10.1101/2020.03.27.012039 ◽

2020 ◽

Author(s):

Ru-pin Alicia Chi ◽

Tianyuan Wang ◽

Chou-Long Huang ◽

San-pin Wu ◽

Steven Young ◽

...

Keyword(s):

Reproductive Tract ◽

Embryo Implantation ◽

Ion Homeostasis ◽

Female Reproductive Tract ◽

Female Reproduction ◽

Endometrial Stromal Cells ◽

Endometrial Cells ◽

Akt Phosphorylation

AbstractWNK1 is an atypical kinase protein ubiquitously expressed in humans and mice. A mutation in its encoding gene causes hypertension in humans which is associated with abnormal ion homeostasis. Our earlier findings demonstrated that WNK1 is critical for in vitro decidualization in human endometrial stromal cells – pointing towards an unrecognized role of WNK1 in female reproduction. Here, we employed a mouse model with conditional WNK1 ablation from the female reproductive tract to define its in vivo role in uterine biology. Loss of WNK1 altered uterine morphology, causing endometrial epithelial hyperplasia, adenomyosis and a delay in embryo implantation, ultimately resulting in compromised fertility. Combining transcriptomic, proteomic and interactomic analyses revealed a novel regulatory pathway whereby WNK1 represses AKT phosphorylation through the phosphatase PP2A in endometrial cells from both humans and mice. We show that WNK1 interacts with PPP2R1A, an isoform of the PP2A scaffold subunit. This interaction stabilizes the PP2A complex, which then dephosphorylates AKT. Therefore, loss of WNK1 reduced PP2A activity, causing AKT hypersignaling. Using FOXO1 as a readout of AKT activity, we demonstrate that there was escalated FOXO1 phosphorylation and nuclear exclusion, leading to a disruption in the regulation of genes that are crucial for embryo implantation.

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Vitamin D3 Controls TLR4- and TLR2-Mediated Inflammatory Responses of Endometrial Cells

Gynecologic and Obstetric Investigation ◽

10.1159/000513590 ◽

2021 ◽

pp. 1-10

Author(s):

Alireza Ghanavatinejad ◽

Nesa Rashidi ◽

Mahroo Mirahmadian ◽

Simin Rezania ◽

Mahdokht Mosalaei ◽

...

Keyword(s):

Reproductive Tract ◽

Inflammatory Responses ◽

Female Reproductive Tract ◽

In Vivo Studies ◽

Endometrial Stromal Cells ◽

Endometrial Cells ◽

Tnf Α ◽

Tract Infections

Objectives: Vitamin D has potent immunoregulatory features and modulates innate and adaptive immune responses. There is a significant association between intrauterine infection-associated inflammatory responses and pregnancy complications such as abortion and preterm labor. Here, we investigated how 1,25 (OH)2 D3 could modulate inflammatory responses of endometrial cells. Design: This is an in vitro experimental study. Endometrial stromal cells (ESCs) and whole endometrial cells (WECs) were collected from 15 apparently normal women, and the immunomodulatory effects of 1,25 (OH)2 D3 on lipopolysaccharide (LPS)- or lipoteichoic acid (LTA)-treated ESCs and WECs were investigated. Participants/Materials, Setting, and Methods: Women with no history of abortion, infertility, endometriosis, or sign of vaginal infection were enrolled in this study. Endometrial samples were collected by gynecologists using a Pipelle pipette in the proliferative phase of the menstrual cycle. WECs and ESCs were collected and treated with either LPS or LTA. The levels of IL-6, IL-8, and TNF-α in culture supernatants were quantified using the ELISA technique. TLR2, TLR4, and MyD88 expressions were assessed by RT-qPCR. TLR4 expression at the protein level was studied by the Western blot technique. Results: 1,25 Dihydroxycholecalciferol (1,25 (OH)2 D3) significantly reduced TNF-α production in LPS-activated ESCs and TNF-α and IL-6 production by LTA-stimulated WECs. In contrast, 1,25 (OH)2 D3 pretreatment increased the production of IL-8 by LPS- and LTA-stimulated endometrial cells. 1,25 (OH)2 D3 pretreatment markedly reduced LPS-induced TLR4 protein expression by ESCs. LPS treatment of ESCs significantly induced MyD88 gene expression. This effect was reversed when these cells were pretreated with 1,25 (OH)2 D3 before stimulation with LPS. Limitations: Because of the small size of samples, doing experiments all together on some samples was not feasible. Confirmation of the results obtained here needs well-designed in vivo studies. Conclusions: 1,25 (OH)2 D3 is an immunomodulatory molecule essential for maintaining endometrial immune homeostasis by controlling potentially harmful inflammatory responses associated with female reproductive tract infections.

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CatSperζ regulates the structural continuity of sperm Ca2+ signaling domains and is required for normal fertility

eLife ◽

10.7554/elife.23082 ◽

2017 ◽

Vol 6 ◽

Cited By ~ 54

Author(s):

Jean-Ju Chung ◽

Kiyoshi Miki ◽

Doory Kim ◽

Sang-Hee Shim ◽

Huanan F Shi ◽

...

Keyword(s):

Reproductive Tract ◽

Female Reproductive Tract ◽

Targeted Disruption ◽

Vitro Fertilization ◽

Male Subfertility ◽

Epididymal Spermatozoa ◽

Mammalian Female ◽

Signaling Domains

We report that the Gm7068 (CatSpere) and Tex40 (CatSperz) genes encode novel subunits of a 9-subunit CatSper ion channel complex. Targeted disruption of CatSperz reduces CatSper current and sperm rheotactic efficiency in mice, resulting in severe male subfertility. Normally distributed in linear quadrilateral nanodomains along the flagellum, the complex lacking CatSperζ is disrupted at ~0.8 μm intervals along the flagellum. This disruption renders the proximal flagellum inflexible and alters the 3D flagellar envelope, thus preventing sperm from reorienting against fluid flow in vitro and efficiently migrating in vivo. Ejaculated CatSperz-null sperm cells retrieved from the mated female uterus partially rescue in vitro fertilization (IVF) that failed with epididymal spermatozoa alone. Human CatSperε is quadrilaterally arranged along the flagella, similar to the CatSper complex in mouse sperm. We speculate that the newly identified CatSperζ subunit is a late evolutionary adaptation to maximize fertilization inside the mammalian female reproductive tract.

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301 THE EFFECT OF EQUINE FOLICULLAR FLUID ON IN VITRO INDUCTION OF THE ACROSOME REACTION IN FROZEN - THAWED STALLION SPERMATOZOA

Reproduction Fertility and Development ◽

10.1071/rdv22n1ab301 ◽

2010 ◽

Vol 22 (1) ◽

pp. 307

Author(s):

D. S. Silva ◽

P. Rodriguez ◽

N. S. Arruda ◽

R. Rodrigues ◽

J. L. Rodrigues

Keyword(s):

Contact Area ◽

Follicular Fluid ◽

Acrosome Reaction ◽

Reproductive Tract ◽

Female Reproductive Tract ◽

Heparin Group ◽

Fluorescent Stain ◽

In Vitro Induction

The capacitation process occurs in vivo upon exposure of the spermatozoa through the female reproductive tract, but can be induced in vitro in the presence of several compounds. This study was conducted to assess the effect of heparin or equine follicular fluid on hyperactivated motility and in vitro induction acrosome reaction swim-up method with frozen-thawed stallion semen. Two hundred microliters of frozen-thawed equine semen was placed in a tube (45°C) to increase contact area and incubated at 37°C for 1 h. After incubation 800 μL of the supernatant was collected by centrifugation (500 × g, 10 min) to collect spermatozoa. The resulting pellet was resuspended in capacitation medium Fert-TALP supplemented with 5.0 μg mL-1 heparin or 100% follicular fluid and incubated for different times (1, 2, 3, 4, and 5 h) at 37°C. After incubation the hyperactivated motility and acrosome-reacted spermatozoa were evaluated. Hoechst stain was used to differentiate live and dead spermatozoa, and chlortetracycline (CTC) fluorescent stain was used to assess the capacitation response of sperm; data were analyzed by ANOVA. The effect of equine follicular fluid resulted in improved percentage of spermatozoa with acrosome reaction at all times of incubation (60, 63, 57, 52, and 58%) but immediately after 3 h of incubation, the hyperactivated motility decreased in heparin group and follicular fluid (42 and 30%, respectively).

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ESR1 Mutations Associated With Estrogen Insensitivity Syndrome Change Conformation of Ligand-Receptor Complex and Altered Transcriptome Profile

Endocrinology ◽

10.1210/endocr/bqaa050 ◽

2020 ◽

Vol 161 (6) ◽

Cited By ~ 1

Author(s):

Yin Li ◽

Katherine J Hamilton ◽

Lalith Perera ◽

Tianyuan Wang ◽

Artiom Gruzdev ◽

...

Keyword(s):

Molecular Mechanisms ◽

Reproductive Tract ◽

Biological Effects ◽

Estrogen Receptor Α ◽

Female Reproductive Tract ◽

Receptor Complexes ◽

Esr1 Gene ◽

Esr1 Mutations

Abstract Estrogen insensitivity syndrome (EIS) arises from rare mutations in estrogen receptor-α (ERα, encoded by ESR1 gene) resulting in the inability of estrogen to exert its biological effects. Due to its rarity, mutations in ESR1 gene and the underlying molecular mechanisms of EIS have not been thoroughly studied. Here, we investigate known ESR1 mutants, Q375H and R394H, associated with EIS patients using in vitro and in vivo systems. Comparison of the transcriptome and deoxyribonucleic acid methylome from stable cell lines of both Q375H and R394H clinical mutants shows a differential profile compared with wild-type ERα, resulting in loss of estrogen responsiveness. Molecular dynamic simulation shows that both ESR1 mutations change the ERα conformation of the ligand-receptor complexes. Furthermore, we generated a mouse model Esr1-Q harboring the human mutation using CRISPR/Cas9 genome editing. Female and male Esr1-Q mice are infertile and have similar phenotypes to αERKO mice. Overall phenotypes of the Esr1-Q mice correspond to those observed in the patient with Q375H. Finally, we explore the effects of a synthetic progestogen and a gonadotropin-releasing hormone inhibitor in the Esr1-Q mice for potentially reversing the impaired female reproductive tract function. These findings provide an important basis for understanding the molecular mechanistic consequences associated with EIS.

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Capacitation mechanisms, and the role of capacitation as seen in eutherian mammals

Reproduction Fertility and Development ◽

10.1071/rd9960581 ◽

1996 ◽

Vol 8 (4) ◽

pp. 581 ◽

Cited By ~ 157

Author(s):

RA Harrison

Keyword(s):

Cell Death ◽

Reproductive Tract ◽

Physiological State ◽

Hormonal Control ◽

Female Reproductive Tract ◽

Functional Heterogeneity ◽

Vitro Fertilization ◽

Range Of Functions

Capacitation, the process whereby spermatozoa are rendered capable of interacting with and fertilizing the egg, was discovered more than 40 years ago. However, our understanding of it is still far from satisfactory. Several factors conspire to obfuscate studies of capacitation mechanisms: the inherent functional heterogeneity of sperm populations, the range of functions used as parameters of capacitation (whence the endpoint of the process has become conceptually uncertain), and the several profound differences between model in vitro fertilization (IVF) systems and the situation in vivo in the female reproductive tract. Recent investigations in the author's laboratory have shown that bicarbonate/CO2, an essential component for successful IVF, causes rapid changes in lipid architecture of the sperm plasma membrane and slower changes in surface coating. These changes are accompanied by membrane destabilization and cell death. Evidence suggests that bicarbonate's actions are mediated through cyclic nucleotide signalling. Of particular note is the heterogeneity in rate of response to bicarbonate shown by individual cells in the sperm populations. Taken together with other observations, the findings suggest that capacitation is a series of positive destabilizing events that eventually lead to cell death. The 'capacitated' state would then be a window of destabilization within which spermatozoa can undergo a zona-induced acrosome reaction and display hyperactivated motility. Further along the destabilization pathway, spontaneous acrosome reactions would occur before total membrane degeneration. In vivo, capacitation would be a conflict between destabilization and sperm survival. Concentrations of bicarbonate are maintained low in the cauda epididymidis, where sperm survive for long periods, and one may speculate that hormonal control of local bicarbonate/CO2 in oviducal 'storage' sites in the female tract could allow 'safe' sequestering of live spermatozoa until around the time of ovulation; the environment may then change to produce a 'capacitating' effect, whence, due to the inherent functional heterogeneity of the sequestered population, small numbers of capacitated spermatozoa are released sequentially. In this way, a succession of spermatozoa in the correct physiological state may be provided for the freshly ovulated egg.

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Uterine glucocorticoid receptors are critical for fertility in mice through control of embryo implantation and decidualization

Proceedings of the National Academy of Sciences ◽

10.1073/pnas.1508056112 ◽

2015 ◽

Vol 112 (49) ◽

pp. 15166-15171 ◽

Cited By ~ 38

Author(s):

Shannon D. Whirledge ◽

Robert H. Oakley ◽

Page H. Myers ◽

John P. Lydon ◽

Francesco DeMayo ◽

...

Keyword(s):

Glucocorticoid Receptors ◽

Reproductive Tract ◽

Immune Cell ◽

Steroid Receptors ◽

Embryo Implantation ◽

Female Reproductive Tract ◽

Mouse Uterus ◽

Glucocorticoid Signaling ◽

Endocrine Organs

In addition to the well-characterized role of the sex steroid receptors in fertility and reproduction, organs of the female reproductive tract are also regulated by the hypothalamic–pituitary–adrenal axis. These endocrine organs are sensitive to stress-mediated actions of glucocorticoids, and the mouse uterus contains high levels of the glucocorticoid receptor (GR). Although the presence of GR in the uterus is well established, uterine glucocorticoid signaling has been largely ignored in terms of its reproductive and/or immunomodulatory functions on fertility. To define the direct in vivo function of glucocorticoid signaling in adult uterine physiology, we generated a uterine-specific GR knockout (uterine GR KO) mouse using the PRcre mouse model. The uterine GR KO mice display a profound subfertile phenotype, including a significant delay to first litter and decreased pups per litter. Early defects in pregnancy are evident as reduced blastocyst implantation and subsequent defects in stromal cell decidualization, including decreased proliferation, aberrant apoptosis, and altered gene expression. The deficiency in uterine GR signaling resulted in an exaggerated inflammatory response to induced decidualization, including altered immune cell recruitment. These results demonstrate that GR is required to establish the necessary cellular context for maintaining normal uterine biology and fertility through the regulation of uterine-specific actions.

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In vivo exposure to 17β-estradiol triggers premature sperm capacitation in cauda epididymis

Reproduction ◽

10.1530/rep-12-0472 ◽

2013 ◽

Vol 145 (3) ◽

pp. 255-263 ◽

Cited By ~ 14

Author(s):

Lukas Ded ◽

Natasa Sebkova ◽

Martina Cerna ◽

Fatima Elzeinova ◽

Pavla Dostalova ◽

...

Keyword(s):

Reproductive Tract ◽

Negative Impact ◽

Reproductive Potential ◽

Female Reproductive Tract ◽

Sperm Capacitation ◽

Epididymal Sperm ◽

Knock Out ◽

17Β Estradiol

Estrogens play a crucial role in spermatogenesis and estrogen receptor α knock-out male mice are infertile. It has been demonstrated that estrogens significantly increase the speed of capacitation in vitro; however this may lead to the reduction of reproductive potential due to the decreased ability of these sperm to undergo the acrosome reaction. To date the in vivo effect of estrogens on the ability of sperm to capacitate has not been investigated. Therefore, in this study, we exposed mice (n=24) to 17β-estradiol (E2) at the concentration of 20 ng/ml either during puberty from the fourth to seventh week of age (n=8), or continuously from birth for a period of 12 weeks (n=8) at which age the animals from both groups were killed. The capacitation status of epididymal and testicular sperm was analysed by tyrosine phosphorylation (TyrP) antibody (immunofluorescence and western blot) and chlortetracycline (CTC) assay. According to our results, in vivo exposure to increased E2 concentrations caused premature sperm capacitation in the epididymis. The effect of E2, however, seems reversible because after the termination of the exposure premature epididymal sperm capacitation is decreased in animals treated during puberty. Furthermore the changes in epididymal sperm capacitation status detected by TyrP and CTC positively correlate with plasma levels of E2 and the expression of the estrogen-dependent trefoil factor 1 (Tff1) gene in testicular tissue. Therefore, our data implicate that in vivo exposure to E2 under specific conditions leads to the premature capacitation of mouse sperm in epididymis with a potential negative impact on the sperm reproductive fitness in the female reproductive tract.

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Organs-On-Chip Models of the Female Reproductive System

Bioengineering ◽

10.3390/bioengineering6040103 ◽

2019 ◽

Vol 6 (4) ◽

pp. 103 ◽

Cited By ~ 2

Author(s):

Vanessa Mancini ◽

Virginia Pensabene

Keyword(s):

Cell Biology ◽

Reproductive Tract ◽

Hormonal Treatment ◽

Female Reproductive Tract ◽

Specific Cell ◽

Toxicity Screening ◽

Paracrine Signalling ◽

On Chip

Microfluidic-based technology attracts great interest in cell biology and medicine, in virtue of the ability to better mimic the in vivo cell microenvironment compared to conventional macroscale cell culture platforms. Recent Organs-on-chip (OoC) models allow to reproduce in vitro tissue and organ-level functions of living organs and systems. These models have been applied for the study of specific functions of the female reproductive tract, which is composed of several organs interconnected through intricate endocrine pathways and communication mechanisms. To date, a disease and toxicology study of this system has been difficult to perform. Thus, there is a compelling need to develop innovative platforms for the generation of disease model and for performing drug toxicity/screening in vitro studies. This review is focused on the analysis of recently published OoC models that recreate pathological and physiological characteristics of the female reproductive organs and tissues. These models aim to be used to assess changes in metabolic activity of the specific cell types and the effect of exposure to hormonal treatment or chemical substances on some aspects of reproduction and fertility. We examined these models in terms of device specifications, operating procedures, accuracy for studying the biochemical and functional activity of living tissues and the paracrine signalling that occurs within the different tissues. These models represent a powerful tool for understanding important diseases and syndromes affecting women all around the world. Immediate adoption of these models will allow to clarify diseases, causes and adverse events occurring during pregnancy such as pre-eclampsia, infertility or preterm birth, endometriosis and infertility.

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Genome-Wide Mutagenesis Identifies Factors Involved in Enterococcus faecalis Vaginal Adherence and Persistence

Infection and Immunity ◽

10.1128/iai.00270-20 ◽

2020 ◽

Vol 88 (10) ◽

Cited By ~ 1

Author(s):

Norhan Alhajjar ◽

Anushila Chatterjee ◽

Brady L. Spencer ◽

Lindsey R. Burcham ◽

Julia L. E. Willett ◽

...

Keyword(s):

Enterococcus Faecalis ◽

Reproductive Tract ◽

Female Reproductive Tract ◽

Complex Nature ◽

Aerobic Vaginitis ◽

Content Type ◽

Vaginal Colonization ◽

Vaginal Tract

ABSTRACT Enterococcus faecalis is a Gram-positive commensal bacterium native to the gastrointestinal tract and an opportunistic pathogen of increasing clinical concern. E. faecalis also colonizes the female reproductive tract, and reports suggest vaginal colonization increases following antibiotic treatment or in patients with aerobic vaginitis. Currently, little is known about specific factors that promote E. faecalis vaginal colonization and subsequent infection. We modified an established mouse vaginal colonization model to explore E. faecalis vaginal carriage and demonstrate that both vancomycin-resistant and -sensitive strains colonize the murine vaginal tract. Following vaginal colonization, we observed E. faecalis in vaginal, cervical, and uterine tissue. A mutant lacking endocarditis- and biofilm-associated pili (Ebp) exhibited a decreased ability to associate with human vaginal and cervical cells in vitro but did not contribute to colonization in vivo. Thus, we screened a low-complexity transposon (Tn) mutant library to identify novel genes important for E. faecalis colonization and persistence in the vaginal tract. This screen revealed 383 mutants that were underrepresented during vaginal colonization at 1, 5, and 8 days postinoculation compared to growth in culture medium. We confirmed that mutants deficient in ethanolamine catabolism or in the type VII secretion system were attenuated in persisting during vaginal colonization. These results reveal the complex nature of vaginal colonization and suggest that multiple factors contribute to E. faecalis persistence in the reproductive tract.

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