Oocyte-somatic cell interactions in the human ovary-novel role of bone morphogenetic proteins and growth differentiation factors

The Exploration of Poor Ovarian Response-Related Risk Factors: A Potential Role of Growth Differentiation Factor 8 in Predicting Ovarian Response in IVF-ET Patient

Controlled ovarian hyperstimulation (COH) is the most common therapeutic protocol to obtain a considerable number of oocytes in IVF-ET cycles. To date, the risk factors affecting COH outcomes remain elusive. Growth differentiation factor 8 (GDF-8), a member of transforming growth factor β (TGF-β) superfamily, has been long discerned as a crucial growth factor in folliculogenesis, and the aberrant expression of GDF-8 is closely correlated with the reproductive diseases. However, less is known about the level of GDF-8 in IVF-ET patients with different ovarian response. In the present study, the potential risk factors correlated with ovarian response were explored using logistic regression analysis methods. Meanwhile, the expression changes of GDF-8 and its responsible cellular receptors in various ovarian response patients were determined. Our results showed that several factors were intensely related to poor ovarian response (POR), including aging, obesity, endometriosis, surgery history, and IVF treatment, while irregular menstrual cycles and PCOS contribute to hyperovarian response (HOR). Furthermore, POR patients exhibited a decrease in numbers of MII oocytes and available embryos, thereby manifesting a lower clinical pregnancy rate. The levels of GDF-8, ALK5, and ACVR2B in POR patients were higher compared with those in control groups, whereas the expression level of ACVR2A decreased in poor ovarian response patients. In addition, clinical correlation analysis results showed that the concentration of GDF-8 was negatively correlated with LH and estradiol concentration and antral follicle count. Collectively, our observations provide a novel insight of ovarian response-associated risk factors, highlighting the potential role of GDF-8 levels in ovarian response during COH process.

Transcriptional changes of mouse ovary during follicle initial or cyclic recruitment mediated by extra hormone treatment

AIMS

Folliculogenesis contains gonadotropin-independent and -dependent stage. Disruption in any of this process would induce failure in retrieving capable oocytes during clinical treatment. However, there is still limited understanding of the molecular components specifically regulating this process.

MATERIAL AND METHODS

Ovaries of P3, P20 and exogenous gonadotropin-treated P22 mice were sampled and underwent RNA-seq to investigate the transcriptome variance during mouse folliculogenesis.

KEY FINDINGS

In our dataset, 1883 and 626 DEGs were captured for each stage respectively, which were further clustered into eight expression patterns. Pathway enrichment analysis identified distinct biological processes enriched in two stages, with the most prominent being the pathways related to metabolism, gene expression, cell cycle, immune system and DNA methylation. Transcriptional regulator inference yielded eight master transcription factors (i.e. Runx1, Stat3, Sox3, Pou5f1, Gata4, Foxl2, Cebpb, and Esr1) driving folliculogenesis.

SIGNIFICANCE

Our study revealed the temporal transcriptional reprogramming and gene expression dynamics during folliculogenesis mediated by extra hormone treatment, which could provide novel insights to controlled ovarian stimulation in future infertility treatment.

Interrelationships between kisspeptin and FSH in control of porcine ovarian cell functions

The existing knowledge of the direct action of kisspeptin on the ovary needs to be expanded. In our study, the direct effects of kisspeptin on basic ovarian cell functions and their response to FSH were examined. We studied the effect of kisspeptin alone (0, 1, 10, and 100 ng/mL) and of kisspeptin (1, 10, and 100 ng/mL) in combination with FSH (10 ng/mL) on cultured porcine granulosa cells. Markers of viability, proliferation (accumulation of proliferating cell nuclear antigen [PCNA] and cyclin B1), and apoptosis (accumulation of bax and caspase 3), as well as the release of steroid hormones and IGF-I were analyzed using the trypan blue exclusion test, quantitative immunocytochemistry, and ELISA. Addition of kisspeptin at lower doses (1 and 10 ng/mL) increased cell viability, the accumulation of PCNA and cyclin B1, decreased the accumulation of bax and caspase 3, and promoted release of progesterone, estradiol, and IGF-I, but not testosterone. A high dose (100 ng/mL) of kisspeptin had the opposite, inhibitory effect. The addition of FSH increased cell viability, proliferation, decreased apoptosis, and promoted progesterone, testosterone, estradiol, and IGF-I release. Kisspeptin at lower doses supported the stimulatory action of FSH on viability, PCNA and cyclin B1 accumulation, and release of progesterone and estradiol, promoted its inhibitory action on bax and caspase 3 accumulation, but did not modify its action on testosterone and IGF-I release. On the contrary, kisspeptin at a high dose inhibited and even reversed the FSH effect. FSH mimicked and promoted both the stimulatory and inhibitory action of kisspeptin on all examined ovarian functions besides IGF-I release. These observations show that kisspeptin can directly regulate basal ovarian cell functions. Furthermore, they demonstrate the functional interrelationships between kisspeptin and FSH in direct regulation of ovarian functions.

Identification of mRNAs and lncRNAs Involved in the Regulation of Follicle Development in Goat

Follicular development and maturation has a significant impact on goat reproductive performance, and it is therefore important to understand the molecular basis of this process. The importance of long non-coding RNAs (lncRNAs) in mammalian reproduction has been established, but little is known about the roles of lncRNAs in different follicular stages, especially in goats. In this study, RNA sequencing (RNA-seq) of large follicles (>10 mm) and small follicles (<3 mm) of Chuanzhong black goats was performed to investigate the regulatory mechanisms of lncRNAs and mRNAs in follicular development and maturation. A total of 8 differentially expressed lncRNAs (DElncRNAs) and 1,799 DEmRNAs were identified, and the majority of these were upregulated in small follicles. MRO, TC2N, CDO1, and NTRK1 were potentially associated with follicular maturation. KEGG pathway analysis showed that the DEmRNAs involved in ovarian steroidogenesis (BMP6, CYP11A1, CYP19A1, 3BHSD, STAR, LHCGR, and CYP51A1) and cAMP signaling play roles in regulating follicular maturation and developmental inhibition respectively. Five target pairs of DElncRNA-DEmRNA, namely, ENSCHIT00000001255-OTX2, ENSCHIT00000006005-PEG3, ENSCHIT00000009455-PIWIL3, ENSCHIT00000007977-POMP, and ENSCHIT00000000834-ACTR3 in co-expression analysis provide a clue in follicular development and maturation of lncRNA-mRNA interaction. Our findings provide a valuable resource for lncRNA studies, and could potentially provide a deeper understanding of the genetic basis and molecular mechanisms of goat follicular development and maturation.

Tissue engineering of the larynx: A contemporary review

Objective

Tissue engineering has been a topic of extensive research in recent years and has been applied to the regeneration and restoration of many organs including the larynx. Currently, research investigating tissue engineering of the larynx is either ongoing or in the preclinical trial stage.

Methods

A literature search was performed on the Advanced search field of PubMed using the keywords: “(laryncheal tissue engineering) AND (cartilage regeneration OR scaffolds OR stem cells OR biomolecules).” After applying the selection criteria, 65 articles were included in the study.

Results

The present review focuses on the rapidly expanding field of tissue‐engineered larynx, which aims to provide stem cell–based scaffolds combined with biological active factors such as growth factors for larynx reconstruction and regeneration. The trend in recent studies is to use new techniques for scaffold construction, such as 3D printing, are developed. All of these strategies have been instrumental in guiding optimization of the tissue‐engineered larynx, leading to a level of clinical induction beyond the in vivo animal experimental phase.

Conclusions

This review summarizes the current progress and outlines the necessary basic components of regenerative laryngeal medicine in preclinical fields. Finally, it considers the design of scaffolds, support of growth factors, and cell therapies toward potential clinical application.

Aberrant elevation of GDF8 impairs granulosa cell glucose metabolism via upregulating SERPINE1 expression in patients with PCOS

Clinical investigations have demonstrated that polycystic ovary syndrome (PCOS) is often accompanied by insulin resistance (IR) in more than 70% of women with PCOS. However, the etiology of PCOS with IR remains to be characterized. Growth differentiation factor 8 (GDF8) is an intraovarian factor that plays a vital role in the regulation of follicle development and ovulation. Previous studies have reported that GDF8 is a pathogenic factor in glucose metabolism disorder in IR patients. To date, the role of GDF8 on glucose metabolism of granulosa cell in PCOS patients remains to be determined. In the current study, we demonstrated that the expression and accumulation of GDF8 in human granulosa-lutein (hGL) cells and follicular fluid from PCOS patients were higher compared with those of non-PCOS women. GDF8 treatment caused glucose metabolism defects in hGL cells. Transcriptome sequencing results showed that SERPINE1 mediated GDF8-induced impairment of hGL glucose metabolism defects. Using pharmacological and small interfering RNA (siRNA)-mediated knockdown approaches, we demonstrated that GDF8 upregulated the expression of SERPINE1 via the ALK5-mediated SMAD2/3-SMAD4 signaling pathway. Interestingly, the extracellular signal-regulated kinase 1/2 (ERK1/2) signaling pathway was also activated with GDF8 treatment but did not participate in the effect of GDF8 on SERPINE1 expression. Our results also showed that TP53 was required for the GDF8-stimulated increase in SERPINE1 expression. Importantly, our study demonstrated that SB-431542 treatment significantly improved DHEA-induced PCOS-like ovaries. These findings support a potential role for GDF8 in metabolic disorders in PCOS.

Identification of Potential Biomarkers of Polycystic Ovary Syndrome via Integrated Bioinformatics Analysis

Polycystic ovary syndrome (PCOS) is a life-long reproductive, endocrine, and metabolic disorder that affects up to 17% of women of reproductive age. However, the effect of granulosa cells (GCs) transcriptome changes on oocyte capacity and follicular development in patients with PCOS has not been elucidated. This study aims to analyze transcriptome changes in GCs of PCOS from different perspectives and explore potential biomarkers for the diagnosis and treatment of PCOS. The gene expression profiles of GSE34526 and GSE107746 were obtained from the GEO database. Differentially expressed genes (DEGs) and key signaling pathways were identified. Gene Set Enrichment Analysis (GSEA) revealed that Toll-like receptors, NOD-like receptors, and NOTCH signaling pathways were obviously enriched in GCs of PCOS. We further analyzed DEGs from three aspects: transcription factors (TFs), secreted proteins, and follicular development. Compared with normal GCs, the DEGs encoding TFs and secretory proteins in GCs of PCOS remarkably changed. Besides, HAS2 and CBLN1, which are highly expressed in preovulatory follicular GCs and may trigger ovulation, were significantly decreased in GCs of PCOS. This study found candidate genes and signaling pathways in PCOS, providing new insights and foundations for the etiology of PCOS. Besides, HSA2 and CBLN1 may be potential therapeutic biomarkers for ovulation disorders in PCOS.

BMP2 increases the production of BDNF through the upregulation of proBDNF and furin expression in human granulosa-lutein cells

Locally produced in human granulosa cells of the developing follicle, bone morphogenetic protein 2 (BMP2) plays a crucial role in the regulation of ovarian folliculogenesis and luteal formation. Brain-derived neurotrophic factor (BDNF) is an intraovarian neurotrophic factor that has been shown to promote oocyte maturation and subsequent fertilization competency. At present, little is known regarding the intracellular regulation, assembly and secretion of endogenous BDNF in human granulosa cells. The aim of this study was to explore the effect of BMP2 on the expression and production of BDNF in human granulosa cells and the molecular mechanisms underlying this effect. An immortalized human granulosa cell line (SVOG) and primary human granulosa-lutein (hGL) cells were utilized as in vitro study models. Our results showed that BMP2 significantly increased the mRNA and secreted levels of BDNF. Additionally, BMP2 upregulated the expression of furin at the transcriptional and translational levels. Knockdown of endogenous furin partially attenuated the BMP2-induced increase in BDNF production, indicating that furin is involved in the maturation process of BDNF. Using pharmacological (kinase receptor inhibitors) and siRNA-mediated inhibition approaches, we demonstrated that BMP2-induced upregulation of BDNF and furin expression is most likely mediated by the activin receptor-like kinase (ALK)2/ALK3-SMAD4 signaling pathway. Notably, analysis using clinical samples revealed that there was a positive correlation between follicular fluid concentrations of BMP2 and those of BDNF. These results indicate that BMP2 increases the production of mature BDNF by upregulating the precursor BDNF and promoting the proteolytic processing of mature BDNF. Finally, we also investigated the effects of BMP2 on ovarian steroidogenesis and the results showed that BMP2 treatment significantly increased the accumulated level of estradiol (by upregulating the expression of FSH receptor and cytochrome P450 aromatase), whereas it decreased the accumulated level of progesterone (by downregulating the expression of LH receptors and steroidogenic acute regulatory protein) in primary hGL cells. Our findings provide a novel paracrine mechanism underlying the regulation of an intraovarian growth factor in human granulosa cells.

GDF9 polymorphisms: influence on ovarian response in women undergoing controlled ovarian hyperstimulation

OBJECTIVE

The study looked into the possible influence of GDF9 polymorphisms on ovarian response in women with a normal ovarian reserve undergoing controlled ovarian hyperstimulation for in vitro fertilization (IVF).

METHODS

This cross-sectional study included 67 women with normal ovarian reserve aged 30-39 years submitted to controlled ovarian hyperstimulation for IVF. We sequenced four polymorphisms in the GDF9 gene (C398G, C447T, G546A, and G646A) and analyzed their influence on follicular and oocyte outcomes.

RESULTS

The mutant allele C398G decreased the total number of follicles >17mm (6.49 vs. 4.33, p=0.001), total number of follicles (10.11 vs. 7.33, p=0.032), number of MII oocytes retrieved, and serum progesterone levels on trigger day. The C447T polymorphism was associated with a greater number of follicles between 12 and 14 mm on the day of r-hCG, while the G546A polymorphism was associated with lower serum progesterone levels on trigger day.

CONCLUSIONS

GDF9 gene polymorphisms C398G and C447T adversely affected ovarian response in women undergoing controlled ovarian hyperstimulation. These findings show that in addition to playing a role in the early stages of folliculogenesis, GDF9 polymorphisms have an important impact on the final stage of oocyte development.

The p38 signaling pathway mediates the TGF-β1-induced increase in type I collagen deposition in human granulosa cells

Type I collagen, which is mainly composed of collagen type I alpha 1 chain (COL1A1), is the most abundant extracellular matrix (ECM) protein in the mammalian ovary; and the cyclical remodeling of the ECM plays an essential role in the regulation of corpus luteum formation. Our previous studies have demonstrated that TGF-β1 is a potent inhibitor of luteinization in human granulosa-lutein (hGL) cells. Whether TGF-β1 can regulate the expression of COL1A1 during the luteal phase remains to be elucidated. The aim of this study was to investigate the effect of TGF-β1 on the regulation of COL1A1 expression and the underlying molecular mechanisms using an immortalized hGL cell line (SVOG cells) and primary hGL cells (obtained from 20 consenting patients undergoing IVF treatment). The results showed that TGF-β1 significantly upregulated the expression of COL1A1. Using inhibition approaches, including pharmacological inhibition (a specific p38 inhibitor, SB203580, and a specific ERK1/2 inhibitor, U0126) and specific siRNA-mediated knockdown inhibition, we demonstrated that TGF-β1 promoted the expression and production of COL1A1 in hGL cells, most likely via the ALK5-mediated p38 signaling pathway. Our findings provide insights into the molecular mechanisms by which TGF-β1 promotes the deposition of type I collagen during the late follicular phase in humans.

The regulation of IGFBP3 by BMP2 has a role in human endometrial remodeling

In mammals, bone morphogenetic protein 2 (BMP2) is a critical regulator of endometrial decidualization and early implantation. Insulin-like growth factor-binding protein 3 (IGFBP3) is highly expressed in the endometrium and at the maternal-fetal interface in multiple species, including humans. BMP2-induced IGFBP3 signaling has been confirmed to have a role in trophoblast cell invasion; however, the involvement of this signaling pathway in endometrial remodeling remains poorly understood. To determine the roles of BMP2 in regulating IGFBP3 expression during the transformation of endometrial stromal cells, we employed immortalized human endometrial stromal cells (HESCs) and primary human decidual stromal cells (HDSCs) as study models. We showed that BMP2 significantly increased the expression of IGFBP3 in a dose- and time-dependent manner in both HESCs and primary HDSCs. Additionally, the BMP2-induced upregulation of IGFBP3 is mediated by the inhibitor of DNA-binding 1 (ID1), and knockdown of ALK3 completely abolished BMP2-induced upregulation of ID1. Moreover, BMP2 increased the expression of matrix metalloproteinases 2 (MMP2) and promoted cell migration in HESCs and primary HDSCs. Knockdown of either IGFBP3 or ID1 significantly suppressed the basal and the BMP2-induced increase in MMP2 expression as well as the cell migration in both cell models. These data demonstrated that BMP2 upregulated the expression of ID1, which in turn induced the expression of IGFBP3, and these BMP2-induced cell activities were most likely mediated by the ALK3 type I receptor. The increased expression of IGFBP3 promoted the MMP2 expression and cell migration in both HESCs and HDSCs. These findings deepen our understanding of a newly identified mechanism by which BMP2 and IGFBP3 regulate endometrial remodeling in humans, which provides insight into potential therapies for endometrium-related diseases and pregnancy-induced complications.

Markers of vitality in ovaries of transmen after long-term androgen treatment: a prospective cohort study

BACKGROUND

Gender-affirming hormone therapy has been hypothesized to reduce the patient's reproductive potential in transmen, although the exact long-term effects on future fertility are unknown.

METHODS

In this prospective cohort study we aimed to evaluate ovaries of 20 transmen by using hormone serum levels, histomorphological analysis and fluorescence activated cells sorting (FACS) analysis - in order to assess the amount of vital cells.

RESULTS

The median total number of follicles per field of view was 39 (IQR 12-122). Of all follicles (n = 1661), the vast majority was primordial (n = 1505, 90.6%), followed by primary (n = 76, 4.6%), abnormal (n = 63, 3.8%) and secondary follicles (n = 17, 1.0%). FACS analysis was available for 13 samples (65.0%) and the median frequency of vital cells was 87.5% (IQR, 77.7-95.4%). Both a higher age (p = 0.032) and a lower BMI (p = 0.003) were significantly associated with a higher frequency of vital cells.

CONCLUSION

The majority of ovarian cells after long-term androgen treatment were vital in FACS analysis and histomorphological evaluation revealed a normal cortical follicle distribution. These results are currently exploratory, but might be promising for issues on fertility preservation.

TRIAL REGISTRATION

The study was approved by the ethics committee of the Medical University of Vienna (EK 2240/2016) and was retrospectively registered in the Current Controlled Trials Register (registration number NCT03649087 , date of registration: 28.08.2018).

Aberrant spliceosome expression and altered alternative splicing events correlate with maturation deficiency in human oocytes

Different strategies of ovarian stimulation are widely used in IVF to retrieve mature metaphase II (MII) oocytes for fertilization. On average, approximately 70% of recovered oocytes are mature, while personalized administration of hCG and/or GnRH agonist trigger and in vitro maturation (IVM) management can further improve the maturation rate. However, even under such conditions, a complete absence of oocyte maturation is still observed sporadically. The probable causes for such maturation-deficient (MD) oocytes - which arrest abnormally at metaphase I (MI) stage - are still under investigation. In the present study, using single-cell transcriptomic RNA sequencing (RNA-seq) and differential expression analysis, we showed that gene expression profiles were aberrant, and alternative splicing (AS) patterns were changed in MD oocytes when compared with normally mature (MN) oocytes. Gene ontology (GO) enrichment demonstrated that the differently expressed genes (DEGs) were mostly correlated with pre-mRNA splicing, RNA transportation, RNA processing, and mRNA regulation. Subsequently, analysis of AS events revealed that genes with altered AS patterns were primarily associated with metabolism and cell cycle. With these findings, we have demonstrated aberrant gene expression in complete maturation-deficient oocytes, and we propose that alterations in post-transcriptional regulation constitute a potential underlying mechanism governing oocyte maturation.

Thyroid hormones in ovarian follicular fluid: Association with oocyte retrieval in women undergoing assisted fertilization procedures

Objective:

Our aim was to analyze the role of thyroid hormones in follicular fluid (FF) in relation to the number of oocytes retrieved in women recruited for an assisted fertilization procedure.

Methods:

Retrospective cohort study of 51 women 37.5±3.3 years, range 29-42, evaluated after a controlled ovarian stimulation protocol in a University Hospital. FF was sampled by transvaginal ultrasound-guided aspiration after ovarian hyperstimulation and we measured T3 (T3f), T4 (T4f), TSH (TSHf) and free T4 (T4ff). The oocyte maturation rate was calculated as: Number of metaphase II oocytes/Number of oocytes retrieved x 100. Statistical analysis was performed using the SPSS-19 software.

Results:

Hormone levels in FF were: TSHf 1.3µIU/ml (0.4 - 2.7), T3f: 1.52±0.46 nmol/L, T4f 88.8±30.9nmol/L and T4ff: 15.44±2.57pmol/L. The number of oocytes recovered was dependent onT4f following the equation: Log (oocyte) = 0.379+0.042*T4f (r:0.352, p=0.012). After a logistic regression model analysis, T3f showed a tendency to be associated with the OMR: OR (95 % CI)= 0.977 (0.954 to 1.001), p=0.057.

Conclusions:

The correlation found between thyroid hormones and the number of oocytes retrieved suggests an interaction between thyroid and gonadal axes in relation to follicular development.

Paeonia lactiflora improves ovarian function and oocyte quality in aged female mice

Although ovarian aging is a key cause of decreased ovarian function and oocyte quality, it remains a problem in infertility treatment. Therefore, this study is aimed to investigate whether Paeonia lactiflora (PL), a herb improves ovarian function and oocyte quality using aged female mice. C57BL/6 female mice aged 8 months were treated orally every day with PL of 26.5 mg/kg (n=7) and 53 mg/kg (n=7) of body weight for 4 weeks using an oral zoned needle. The control group (n=7) was treated with normal saline. Ovaries and serum were collected for the H&E stain and the evaluation of reactive oxygen species (ROS) levels, respectively. In the second experiment, female mice were orally administered with PL (26.5 mg/kg: n=12, 53 mg/kg: n=12, control: n=12) and then superovulated with PMSG and hCG, and mated with male mice. Zygotes were retrieved and cultured for 4 days. Ovaries were provided for examination of expressions of genes associated with angiogenesis (VEGF and visfatin), anti-aging (Sirt1 and Sirt2), and follicular development (c-Kit, BMP-15, and GDF-9). PL significantly increased numbers of surviving follicles (primordial, primary, secondary, and antral), numbers of zygotes retrieved, embryo development rate, and ovarian expression of VEGF, visfatin, c-Kit, BMP-15, and GDF-9 at both doses. However, ovarian expression of Sirt1 and Sirt2 was increased at 53.0 mg/kg of PL. ROS levels were not affected by PL. These results suggest that PL may possess beneficial effects regarding ovarian function and oocyte quality, possibly by activation of ovarian angiogenesis and follicular development.

BMP-15 activity on in vitro development of collared peccary (Pecari tajacu Linnaeus, 1758) preantral follicles

This study investigated the effects of BMP-15 on the in vitro development of preantral follicles of collared peccaries. Ovarian fragments were cultured for 1 or 6 days in Tissue Culture Medium 199 (TCM199⁺ ) supplemented with BMP-15 at rates of 0, 1, 25 or 50 ng/ml. The fragments were analysed histologically by evaluating follicular morphology, activation and growth as well as the potential for proliferation of granulosa cells. Our results show the addition of 25 ng/ml BMP-15 in the medium provided the greatest percentage of normal follicles (79.67% ± 0.69) when compared to other treatments (p < .05); however, this result is similar to 1 ng/ml BMP-15 (74.00% ± 1.90, p > .05). Moreover, 25 and 50 ng/ml of BMP-15 promoted follicular activation. BMP-15 supplements did not affect oocyte and follicular growth. All concentrations of BMP-15 increased the number of nucleolus organizer regions (NORs) after 1 day of culture when compared to fresh fragments or the control samples (p < .05). However, at the end of the experiment, the number of NORs in follicles cultured in all treatments was higher than that observed in the fresh control (sample taken prior to culturing) (p > .05). In summary, the addition of 25 ng/ml BMP-15 to the culture medium of collared peccary preantral follicles maintained a high number of morphologically healthy follicles and stimulated the activation of primordial follicles after 6 days in culture.

Follicular wave dynamics and Growth factors gene expression in Braford heifers

The objectives of the present study were (experiment 1) to characterized development and dynamics of the dominant follicles (DF) and the corpus luteum (CL) to determine patterns of two (W2) and three (W3) follicular waves in beef heifers, and (experiment 2) to determine gene expression of growth factors gene expression in follicular cells of W2 and W3 heifer. Twenty-eight Braford heifers were used. Dominant follicular and CL were monitored daily by ultrasonography to identify the development W2 and W3 in heifers. Pre-ovulatory DF were aspirated on day 19 in W2 and on day 22 in W3 heifers. In W2 and W3, follicular cells (FC) of gene expression of growth differentiation factor 9, bone morphogenetic protein 15 (BMP15), fibroblast growth factor basic, transforming growth factor beta receptor 1, bone morphogenetic protein receptor type IB and fibroblast growth factor receptor 2 were evaluated. The regression of the DF of the first follicular wave and the emergency of the DF of the second follicular wave began later in the heifers W2 than in W3 (p = .02 and p < .01). The regression of the CL began earlier in the W2 than in W3 group (p < .01). Gene expression of growth factors and receptors was similar between groups. However, higher relative levels of BMP15 was observed in W2 group (p = .07). Results propose that wave patterns were regulated by the development time of the DF in the first wave and the life of the CL. Furthermore, higher levels of BMP15 could produce shorter life of CL. The present work suggest that ultrasonography associated with molecular assays could be used as an easy and effective tool to characterize follicular wave patterns.

A Comprehensive Review of Concentrated Growth Factors and Their Novel Applications in Facial Reconstructive and Regenerative Medicine

BACKGROUND

Concentrated growth factors (CGFs) are the latest generation of platelet concentrates. The objective of developing CGF is to increase therapeutic efficacy. However, few studies have supported the superiority of CGF in composition and efficacy. The reconstruction and regeneration process is complicated and long term, whereas bioactivity of CGF is not durable. The purpose of this review is threefold. The first is to recommend more comparative studies between CGF and other platelet concentrates. The second is to constitute a continuous drug delivery system by combining CGF with other biomaterials. Finally, the novel use of CGF in facial regenerative and reconstructive medicine will be highlighted.

METHODS

A comprehensive review of literature regarding the use of CGF in facial regenerative and reconstructive medicine was performed. Based on the inclusion and exclusion criteria, a total of 135 articles were included.

RESULTS

The use of CGF involving facial rejuvenation, cartilage grafting, facial bone defects, facial peripheral nerve injury and wounding is reviewed. The reconstructive and regenerative principles lie in firm fibrin scaffolds and continuous in situ delivery of multiple growth factors.

CONCLUSIONS

CGF represents an advance in personalized medicine concept. However, the current scientific evidences about the use of CGF are limited. More basic and clinical studies should be conducted to understand the characteristics and clinical application of CGF.

LEVEL OF EVIDENCE V

This journal requires that authors assign a level of evidence to each article. For a full description of these Evidence-Based Medicine ratings, please refer to the Table of Contents or the online Instructions to Authors www.springer.com/00266.

Morphokinetic analysis of cleavage stage embryos and assessment of specific gene expression in cumulus cells independently predict human embryo development to expanded blastocyst: a preliminary study

To assess whether morphokinetic features at the cleavage stage together with specific gene expression in cumulus cells (CCs) may be used to predict whether human embryos are able to achieve the expanded blastocyst stage on day 5. Eighty-one embryos were cultured using the Geri plus® time-lapse system. Twenty-seven embryos progressing to the expanded blastocyst stage (BL group) were compared with thirty-five embryos showing developmental arrest (AR group) and nineteen reaching the stage of early or not fully expanded blastocyst (nBL group). The analyzed morphokinetic variables were pronuclear appearance (tPNa), pronuclear fading (tPNf), and completion of cleavage to two, three, four, and eight cells (t2, t3, t4, and t8). CCs were analyzed by RT-qPCR for bone morphogenetic protein 15 (BMP15), cytochrome c oxidase subunit II (COXII), ATP synthase subunit 6 (MT-ATP6), connexin 43 (Cx43), and heme oxygenase-1 (HO-1). Embryos of BL group showed a significantly faster kinetic. BMP15, COXII, and MT-ATP6 mRNA expression was significantly higher in CCs of BL group embryos, whereas Cx43 and HO-1 mRNA levels were higher in AR group. Kinetic parameters and gene expression were not significantly different between either the BL and nBL groups or the AR and nBL groups. ROC curves showed that the most predictive cut-offs were t2 < 26.25 for morphokinetics and COXII > 0.3 for gene expression. Multivariable logistic regression analysis showed that morphokinetic variables and gene expression were both valuable, independent predictors of embryo development to expanded blastocyst. Our results suggest the possibility of developing integrated prediction models for early embryo selection at the cleavage stage.

Neurotrophins and glial cell line-derived neurotrophic factor in the ovary: physiological and pathophysiological implications

BACKGROUND

Neurotrophins [nerve growth factor (NGF), brain-derived neurotrophic factor (BDNF), neurotrophin-3 (NT-3), and neurotrophin-4 (NT-4)] and glial cell line-derived neurotrophic factor (GDNF) are soluble polypeptide growth factors that are widely recognized for their roles in promoting cell growth, survival and differentiation in several classes of neurons. Outside the nervous system, neurotrophin (NT) and GDNF signaling events have substantial roles in various non-neural tissues, including the ovary.

OBJECTIVE AND RATIONALE

The molecular mechanisms that promote and regulate follicular development and oocyte maturation have been extensively investigated. However, most information has been obtained from animal models. Even though the fundamental process is highly similar across species, the paracrine regulation of ovarian function in humans remains poorly characterized. Therefore, this review aims to summarize the expression and functional roles of NTs and GDNF in human ovarian biology and disorders, and to describe and propose the development of novel strategies for diagnosing, treating and preventing related abnormalities.

SEARCH METHODS

Relevant literature in the English language from 1990 to 2018 describing the role of NTs and GDNF in mammalian ovarian biology and phenotypes was comprehensively selected using PubMed, MEDLINE and Google Scholar.

OUTCOMES

Studies have shown that the neurotrophins NGF, BDNF, NT-3 and NT-4 as well as GDNF and their functional receptors are expressed in the human ovary. Recently, gathered experimental data suggest putative roles for NT and GDNF signaling in the direct control of ovarian function, including follicle assembly, activation of the primordial follicles, follicular growth and development, oocyte maturation, steroidogenesis, ovulation and corpus luteum formation. Additionally, crosstalk occurs between these ovarian regulators and the endocrine signaling system. Dysregulation of the NT system may negatively affect ovarian function, leading to reproductive pathology (decreased ovarian reserve, polycystic ovary syndrome and endometriosis), female infertility and even epithelial ovarian cancers.

WIDER IMPLICATIONS

A comprehensive understanding of the expression, actions and underlying molecular mechanisms of the NT/GDNF system in the human ovary is essential for novel approaches to therapeutic and diagnostic interventions in ovarian diseases and to develop more safe, effective methods of inducing ovulation in ART in the treatment of female infertility.

Plasma pentraxin 3 is higher in early ovarian hyperstimulation syndrome than in uncomplicated in vitro fertilization cycle of high-risk women

Purpose

Pentraxin 3 (PTX3) is a locally secreted, quicker responsive pro-inflammatory protein than C-reactive protein (CRP). We evaluated the value of PTX3 in the prediction of ovarian hyperstimulation syndrome (OHSS), a severe complication of in vitro fertilization (IVF).

Methods

This two-year prospective follow-up study included 27 women with uncomplicated IVF-cycles (IVF group) and 31 patients diagnosed with moderate or severe early OHSS (OHSS group). PTX3 was analysed from follicular fluid (FF) and serial blood samples with enzyme-linked immunoassay and CRP with particle-enhanced immunoturbidimetric assay. The value of PTX3 and CRP in detecting OHSS was examined with receiver operating characteristic (ROC) curve analysis and expressed as the area under the curve (AUC).

Results

The circulating PTX3 level peaked at two days after oocyte pick-up (OPU2), and in the OHSS group the level was 1.9 times higher (P = 0.006) than in the IVF group. However, in ROC curve analysis PTX3 (AUC 0.79, best cut off 1.1 µg/L) was not superior to CRP (AUC 0.87; best cut off 9.5 mg/L) in predicting early OHSS. In the IVF group, the FF-PTX3 concentration was 15–20 times higher than in the plasma. PTX3 level at OPU2 correlated with the number of punctured follicles (r = 0.56, n = 22, P = 0.006). Triggering with human chorionic gonadotrophin or early pregnancy had no effect on PTX3 level.

Conclusion

The elevated PTX3 concentration in OHSS at OPU2, when freeze-all embryos strategy is still possible to consider, indicates that PTX3 level could provide additional benefit in the risk assessment for early OHSS.

TGF-β1 promotes vitamin D-induced prostaglandin E2 synthesis by upregulating vitamin D receptor expression in human granulosa-lutein cells

There is increasing evidence showing the importance of vitamin D (Vit D) and its nuclear receptor, the Vit D receptor (VDR), in female reproductive health. Transforming growth factor-β1 (TGF-β1) and its functional receptors are expressed in human oocytes and granulosa cells that participate in follicular development and ovulation. Recently, Sma- and Mad-related protein 3 (SMAD3; a downstream effector of TGF-β1) has been proposed to mediate crosstalk between the Vit D and TGF-β1 signaling pathways, but this relationship has not been fully explored and has yet to be tested in human granulosa-lutein (hGL) cells. In this study, we showed that TGF-β1 significantly promoted the expression of VDR, and this stimulatory effect occurred through the activin receptor-like kinase 5 type I receptor-mediated SMAD3 and ERK1/2 signaling pathways in hGL cells. Additionally, we showed that Vit D increased the expression of cyclooxygenase 2 (COX-2) and the synthesis of prostaglandin E2 (PGE2) in a time- and dose-dependent manner. Furthermore, we demonstrated a synergistic effect of TGF-β1 and Vit D on the expression of COX-2 and synthesis of PGE2, and this effect could be attenuated by silencing the expression of VDR. Our findings indicate that TGF-β1 upregulates the expression of VDR, which promotes Vit D-induced COX-2 expression and subsequent PGE2 production by activating the SMAD3 and ERK1/2 signaling pathways in hGL cells.

The association of miR-25T>C, miR-32C>A, miR-125C>T, and miR-222G>T polymorphisms with a risk of primary ovarian insufficiency in Korean women

OBJECTIVE

The purpose of this study was to investigate the association of microRNA polymorphisms (miR-25T>C, miR-32C>A, miR-125C>T, and miR-222G>T) with primary ovarian insufficiency (POI) in Korean women.

METHODS

We conducted a case-control study of Korean women: 142 participants with POI and 266 controls with at least 1 live birth and no history of pregnancy loss.

RESULTS

The haplotype-based multifactor dimensionality reduction analysis revealed that the T-C-T-G (miR-25/-32/-125/-222), T-A-C-G (miR-25/-32/-125/-222), C-T-G (miR-32/-125/-222), A-C-G (miR-32/-125/-222), T-G (miR-122/-222), C-T (miR-32/-125), and C-C (miR-25/-32) inferred haplotypes were significantly less frequent in POI (P < 0.05), which suggested potential protective effects. Participants with POI had significantly increased luteinizing hormone levels (P < 0.05), but hormonal levels, including luteinizing hormone, were not significantly different between POI women and control women with miR-32/-125/-222.

CONCLUSIONS

After considering multiple comparisons, we concluded that miR-25T>C, miR-32C>A, miR-125C>T, and miR-222G>T had no relation with POI.

MiR-423-5p may regulate ovarian response to ovulation induction via CSF1

BACKGROUND

We have previously shown that hsa-miR-423-5p expression in ovarian granulosa cells is decreased in high ovarian response populations. The objective of the present study was to find the target gene and mechanism for miR-423-5p involved in ovarian response regulation.

METHODS

(a) TargetScan was used to predict the target gene of hsa-miR-423-5p. (b) A model for hsa-miR-423-5p overexpression or inhibition was constructed by transfecting KGN cells with lentivirus. CSF1 mRNA and protein expression and luciferase activity were measured. (c) The cell cycles of control and lentivirus treated KGN cells were analyzed. Western blot was used to measure the expression of CDKN1A in KGN cells. (d) The concentration of E₂ in KGN cell culture medium were measured.

RESULTS

(a) TargetScan revealed that the 3' un-translated region of CSF1 matched 11 bases at the 5' end of miR-423-5p, making it a likely target gene. (b) Overexpression or inhibition of miR-423-5p were associated with respective decreases or increases in CSF1 expression (both mRNA and protein) (p < 0.05) and luciferase activity (p < 0.05). (c) When miR-423-5p expression increased, the number of G0/G1 phase cells and the expression of CDKN1A protein increased while estradiol concentrations in the cell culture solution decreased (p < 0.05). However, when miR-423-5p expression decreased, the number of S phase cells increased and E2 concentrations increased while the expression of CDKN1A protein decreased (p < 0.05).

CONCLUSIONS

Colony stimulating factor 1 is a target gene of miR-423-5p and that it may regulate ovarian response to ovulation induction by affecting granulosa cells proliferation and estrogen secretion.

ALK4-SMAD3/4 mediates the effects of activin A on the upregulation of PAI-1 in human granulosa lutein cells

In the mammalian ovary, the proteolysis of the extracellular matrix is dynamically regulated by plasminogen activator and plasminogen activator inhibitor (PAI), and it is a critical event that influences various physiological and pathological processes. Activin A is a member of the transforming growth factor-β superfamily and is expressed at a high level in human luteal cells that play an essential role in the regulation of the luteal function. At present, it is not known whether activin A can regulate the expression and production of PAI in human granulosa lutein (hGL) cells. The present study aimed to examine the effects of activin A on the expression and production of intraovarian PAI-1 and the underlying molecular mechanisms. Using primary and immortalized hGL cells as the cell model, we demonstrated that activin A upregulated the expression of PAI-1 and increased the production of PAI-1 in an autocrine/paracrine manner. Additionally, using a dual inhibition approach (molecular inhibitors and siRNA-mediated knockdown), we showed that this biological function is mediated by the ALK4-mediated SMAD3-SMAD4-dependent signaling pathway. Our findings suggest that activin A may be involved in the regulation of luteal function via the induction of PAI-1 expression and an increase in PAI-1 production.

Versican expression level in cumulus cells is associated with human oocyte developmental competence

To study the relationship between the expression of 10 selected genes in cumulus cells and the corresponding oocyte development competence, and the effect of patient age and body mass index on gene expression of cumulus cells, we collected 354 cumulus cell masses associated with individual oocyte from 48 women. The expression levels of the genes involved in glucose metabolism (PFKP, PKM2, LDHA and GFPT) and expansion (HAS2, VCAN, TNFAIP6, PTGS2, PTX3 and SDC4) in cumulus cells were detected by reverse transcription polymerase chain reaction. These were compared among oocyte maturity, fertilization, embryo morphology and implantation, and analyzed the effect of the subject's age and body mass index. Cumulus cell PFKP expression from mature oocytes was higher than those from immature oocytes (P = 0.014), and VCAN expression was higher from oocytes that developed into high-quality embryos (P = 0.024). TNFAIP6 expression in cumulus cells from fertilized oocytes was lower than that from unfertilized oocytes (P = 0.044). The levels of VCAN, TNFAIP6, PTX3 and SDC4 were changed significantly as a function of the subject's age and body mass index. In conclusion, the level of VCAN expression in cumulus cells is positively correlated with the early embryo morphology score, and with further development could perhaps be used to evaluate oocyte developmental competence to complement embryonic morphological assessment.

ABBREVIATIONS

CCs: cumulus cells; GDF9: growth differentiation factor 9; BMP15: bone morphogenetic protein 15; PTGS2: prostaglandin synthase 2; HAS2: hyaluronic acid synthase 2; VCAN: versican; GREM1: gremlin 1; PFKP: phosphofructokinase, platelet; PKM2: pyruvate kinase isozyme type M2; LDHA: lactic dehydrogenase; GFPT: glucosaminefructo-6-phosphate transaminase; TNFAIP6: tumor necrosis factor 6 protein; PTX3: penetrin 3; SDC4: syndecan-4; BMI: body mass index; MD: median values; IQR: interquartile range; FSH: follicle-stimulating hormone; LH: luteinizing hormone; HCG: human chorionic gonadotropin; ICSI: intracytoplasmic sperm injection; GnRH: gonadotropin-releasing hormone; hMG: human menopausal gonadotropin; GV: germinal vesicle; M I: metaphase I; M II: metaphase II; cDNA: complementary DNA; SD: standard deviation.

Target prediction and validation of microRNAs expressed from FSHR and aromatase genes in human ovarian granulosa cells

MicroRNAs (miRNAs) are known post-transcriptional regulators of various biological processes including ovarian follicle development. We have previously identified miRNAs from human pre-ovulatory ovarian granulosa cells that are expressed from the intronic regions of two key genes in normal follicular development: FSH receptor (FSHR) and CYP19A1, the latter encoding the aromatase enzyme. The present study aims to identify the target genes regulated by these miRNAs: hsa-miR-548ba and hsa-miR-7973, respectively. The miRNAs of interest were transfected into KGN cell line and the gene expression changes were analyzed by Affymetrix microarray. Potential miRNA-regulated genes were further filtered by bioinformatic target prediction algorithms and validated for direct miRNA:mRNA binding by luciferase reporter assay. LIFR, PTEN, NEO1 and SP110 were confirmed as targets for hsa-miR-548ba. Hsa-miR-7973 target genes ADAM19, PXDN and FMNL3 also passed all verification steps. Additionally, the expression pattern of the miRNAs was studied in human primary cumulus granulosa cell culture in relation to the expression of their host genes and FSH stimulation. Based on our findings we propose the involvement of hsa-miR-548ba in the regulation of follicle growth and activation via LIFR and PTEN. Hsa-miR-7973 may be implicated in the modulation of extracellular matrix and cell-cell interactions by regulating the expression of its identified targets.

TGF-β1 Increases GDNF Production by Upregulating the Expression of GDNF and Furin in Human Granulosa-Lutein Cells

Glial cell line-derived neurotrophic factor (GDNF) is expressed at a high level in the human ovary and GDNF signaling is involved in the direct control of follicular activation and oocyte maturation. Transforming growth factor-β1 (TGF-β1) plays an important role in the regulation of various ovarian functions. Furin is an intracellular serine endopeptidase of the subtilisin family that is closely associated with the activation of multiple protein precursors. Despite the important roles of GDNF and TGF-β1 in the regulation of follicular development, whether TGF-β is able to regulate the expression and production of GDNF in human granulosa cells remains to be determined. The aim of this study was to investigate the effect of TGF-β1 on the production of GDNF and its underlying mechanisms in human granulosa-lutein (hGL) cells. We used two types of hGL cells (primary hGL cells and an established immortalized hGL cell line, SVOG cells) as study models. Our results show that TGF-β1 significantly induced the expression of GDNF and furin, which, in turn, increased the production of mature GDNF. Using a dual inhibition approach combining RNA interference and kinase inhibitors against cell signaling components, we showed that the TβRII type II receptor and ALK5 type I receptor are the principal receptors that mediated TGF-β1-induced cellular activity in hGL cells. Additionally, Sma- and Mad-related protein (SMAD)3 and SMAD4 are the downstream signaling transducers that mediate the biological response induced by TGF-β1. Furthermore, furin is the main proprotein convertase that induces the production of GDNF. These findings provide additional regulatory mechanisms by which an intrafollicular factor influences the production of another growth factor through a paracrine or autocrine interaction in hGL cells.

Luteinizing Hormone Action in Human Oocyte Maturation and Quality: Signaling Pathways, Regulation, and Clinical Impact

The ovarian follicle luteinizing hormone (LH) signaling molecules that regulate oocyte meiotic maturation have recently been identified. The LH signal reduces preovulatory follicle cyclic nucleotide levels which releases oocytes from the first meiotic arrest. In the ovarian follicle, the LH signal reduces cyclic nucleotide levels via the CNP/NPR2 system, the EGF/EGF receptor network, and follicle/oocyte gap junctions. In the oocyte, reduced cyclic nucleotide levels activate the maturation promoting factor (MPF). The activated MPF induces chromosome segregation and completion of the first and second meiotic divisions. The purpose of this paper is to present an overview of the current understanding of human LH signaling regulation of oocyte meiotic maturation by identifying and integrating the human studies on this topic. We found 89 human studies in the literature that identified 24 LH follicle/oocyte signaling proteins. These studies show that human oocyte meiotic maturation is regulated by the same proteins that regulate animal oocyte meiotic maturation. We also found that these LH signaling pathway molecules regulate human oocyte quality and subsequent embryo quality. Remarkably, in vitro maturation (IVM) prematuration culture (PMC) protocols that manipulate the LH signaling pathway improve human oocyte quality of cultured human oocytes. This knowledge has improved clinical human IVM efficiency which may become a routine alternative ART for some infertile patients.

The in vitro Analysis of Quality of Ovarian Follicle Culture Systems Using Time-Lapse Microscopy and Quantitative Real-Time PCR

BACKGROUND

The aim of ovarian follicle in vitro culture is to obtain mature oocytes. To evaluate the efficiency of in vitro culture system, the status of the cultured oocyte can be analyzed.

METHODS

The preantral ovarian follicles retrieved from 14-day-old C57Bl/6J mice were cultured in 3D alginate hydrogel. The status of oocytes obtained from mature (3 months old, group A) and immature (3 weeks old, group B) mice was compared to the status of oocytes retrieved from ovarian follicles cultured in vitro (Group C) using qRT-PCR analysis and time-lapse microscopy. In the qRT-PCR analysis, 8 samples for group A (80 oocytes), 8 samples for group B (80 oocytes), and 6 samples for group C (60 oocytes) were included. Time-lapse analysis was performed in group A (oocytes n=31), group B (n=45), and group C (n=21). Statistical analysis was done by Kruskal-Wallis and chi-square tests and differences were considered statistically significant if p<0,05.

RESULTS

The diameter of group C oocytes is lower in comparison to group A oocytes (67 μm vs. 75 μm, correspondingly). Groups B and C oocytes exhibited delayed meiosis in comparison to group A oocytes. Expression levels of six oocyte maturation genes (Ccnb, CDK1, Ccnh, Wee2, Mos and Epab) were evaluated using qRT-PCR analysis. Expression levels of Ccnh and Epab are lowered in group C oocytes compared to the expression levels of these genes in groups A and B oocytes (p< 0.05).

CONCLUSION

Oocytes obtained after ovarian follicles in vitro culture have reduced development competence, future fundamental changes of in vitro culture systems can be expected.

TOX3 Promotes Ovarian Estrogen Synthesis: An RNA-Sequencing and Network Study

BACKGROUND

Women who undergo chronic exposure to excessive estrogen are at a high risk of developing breast cancer. TOX3 has been reported to be highly expressed in breast tumors and is closely related to estrogen receptors. However, the effect of TOX3 on estrogen synthesis remains poorly understood.

METHODS

Using lentiviruses as a vector, we stably overexpressed TOX3 in the ovarian granulosa cell line KGN, the cells where estradiol is primarily produced, to investigate its role in estrogen production as well as cell viability and apoptosis. RNA-Sequencing was applied to uncover the global gene expression upon TOX3 overexpression.

RESULTS

We observed an increased level of cell viability and a reduced cell apoptosis rate after TOX3 overexpression, and the level of estradiol in the cell culture supernatant also increased significantly. Gene set enrichment analysis of the transcriptome showed that the ovarian steroidogenesis pathway was significantly enriched. Similarly, pathway mapping using the Kyoto Encyclopedia of Genes and Genomes and Gene Ontology analyses also showed that TOX3 overexpression affects the ovarian steroidogenesis pathway. Further experiments showed that upregulated FSHR, CYP19A1, and BMP6 accounted for the enhanced estrogen synthesis.

CONCLUSION

Our study demonstrated that TOX3 quantitatively and qualitatively stimulates estrogen synthesis by enhancing estrogen signaling pathway-related gene expression in ovarian granulosa cells. These findings suggest that TOX3 may play a vital role in the pathogenesis of breast cancer.

MicroRNAs regulate granulosa cells apoptosis and follicular development - A review

Objective

MicroRNAs (miRNAs) are the most abundant small RNAs. Approximately 2,000 annotated miRNAs genes have been found to be differentially expressed in ovarian follicles during the follicular development (FD). Many miRNAs exert their regulatory effects on the apoptosis of follicular granulosa cells (FGCs) and FD. However, accurate roles and mechanism of miRNAs regulating apoptosis of FGCs remain undetermined.

Methods

In this review, we summarized the regulatory role of each miRNA or miRNA cluster on FGCs apoptosis and FD on the bases of 41 academic articles retrieved from PubMed and web of science and other databases.

Results

Total of 30 miRNAs and 4 miRNAs clusters in 41 articles were reviewed and summarized in the present article. Twenty nine documents indicated explicitly that 24 miRNAs and miRNAs clusters in 29 articles promoted or induced FGCs apoptosis through their distinctive target genes. The remaining 10 miRNAs and miRNAs of 12 articles inhibited FGCs apoptosis. MiRNAs exerted modulation actions by at least 77 signal pathways during FGCs apoptosis and FD.

Conclusion

We concluded that miRNAs or miRNAs clusters could modulate the apoptosis of GCs (including follicular GCs, mural GCs and cumulus cells) by targeting their specific genes. A great majority of miRNAs show a promoting role on apoptosis of FGCs in mammals. But the accurate mechanism of miRNAs and miRNA clusters has not been well understood. It is necessary to ascertain clearly the role and mechanism of each miRNA or miRNA cluster in the future. Understanding precise functions and mechanisms of miRNAs in FGCs apoptosis and FD will be beneficial in developing new diagnostic and treatment strategies for treating infertility and ovarian diseases in humans and animals.

Regulation of the transcription factor E2F8 gene expression in bovine ovarian cells

Overexpression of the transcription factor, E2F8, has been associated with ovarian cancer. Objectives of this study were to determine: 1) if E2F8 gene expression in granulosa cells (GC) and theca cells (TC) change with follicular development, and 2) if E2F8 mRNA abundance in TC and GC is hormonally regulated. Using real-time PCR, E2F8 mRNA abundance in GC and TC was greater (P < 0.05) in small than large follicles. FGF9 induced an increase (P < 0.05) in E2F8 mRNA abundance by 1.6- to 7-fold in large-follicle (8-20 mm) TC and GC as well as in small-follicle (1-5 mm) GC. Abundance of E2F8 mRNA in TC was increased (P < 0.05) with FGF2, FGF9 or VEGFA treatments alone in vitro, and concomitant treatment of VEGFA with FGF9 increased (P < 0.05) abundance of E2F8 mRNA above any of the singular treatments; BMP4, WNT3A and LH were without effect. IGF1 amplified the stimulatory effect of FGF9 on E2F8 mRNA abundance by 2.7-fold. Collectively, our studies show for the first time that follicular E2F8 is developmentally and hormonally regulated indicating that E2F8 may be involved in follicular development.

Bone morphogenetic protein 6 affects cell-cell communication by altering the expression of Connexin43 in human granulosa-lutein cells

Connexin 43 (Cx43)-coupled gap junctions in granulosa cells play an important role in follicular development, oocyte maturation, and corpus luteum maintenance. Bone morphogenetic protein 6 (BMP6) is highly expressed in human oocytes and granulosa cells and is involved in the regulation of female reproduction. Currently, whether oocyte- and granulosa cell-derived BMP6 affects the expression of Cx43 and its related gap junction intercellular communication (GJIC) activity in human granulosa cells remains unknown. In this study, we demonstrate that BMP6 treatment significantly suppressed the expression of Cx43 in both primary and immortalized (SVOG) human granulosa-lutein cells. Using both pharmacological inhibitors and small interfering RNA-mediated knockdown approaches, we demonstrate that ALK2 and ALK3 BMP type I receptors are involved in BMP6-induced suppressive effects on Cx43 expression and GJIC activity in SVOG cells. Furthermore, these cellular activities are most likely mediated by the SMAD1/SMAD5-SMAD4-dependent signaling pathway. Notably, the ChIP analyses demonstrated that phosphorylated SMADs could bind to human Cx43 promoter. Our findings provide new insight into the molecular mechanisms by which an intrafollicular growth factor regulates cell-cell communication in human granulosa cells.

Effect of vitamin D supplementation on assisted reproduction technology (ART) outcomes and underlying biological mechanisms: protocol of a randomized clinical controlled trial. The "supplementation of vitamin D and reproductive outcome" (SUNDRO) study

Background

Vitamin D plays an important role in human physiology and pathology. The receptor for vitamin D regulates 0.5–5% of the human genome. Accordingly, vitamin D insufficiency has been shown to increase the risk of several diseases. In recent years, based on growing evidence, on a role of vitamin D has been also postulated in reproductive health both in animals and humans, especially in female fertility female fertility. In vitro fertilization success was shown to be higher in women with appropriate reserves of vitamin D. However a causal relation has not been demonstrated and randomized controlled trials testing the effectiveness of vitamin D supplementation in IVF are warranted.

Methods

This is a multicenter randomized double blinded placebo controlled study aimed at determining the benefits of vitamin D [25(OH)D] supplementation in improving clinical pregnancy rate in women undergoing IVF. Eligible women with a serum level of 25-hydroxyvitamin D [25(OH)D] < 30 ng/ml will be randomized. Recruited women will be given the drug (either 600,000 IU of 25(OH) D or placebo in a single oral administration) at the time of randomization. Two centres will participate and the sample size (700 women) is foreseen to be equally distributed between the two. Patients will be treated according to standard IVF protocols.

Discussion

The primary aim of the study is the cumulative clinical pregnancy rate per oocyte retrieval. Clinical pregnancy is defined as the presence of at least one intrauterine gestational sac with viable foetus at first ultrasound assessment (3 weeks after a positive human chorionic gonadotropin [hCG] assessment). Secondary outcomes include: 1) clinical and embryological variables; 2) oocyte and endometrium quality at a molecular level. To investigate this latter aspect, samples of cumulus cells, follicular and endometrial fluids will be obtained from a subgroup of 50 age-matched good-prognosis cases and controls.

Trial registration

The protocol was included in EudraCT on 22nd September 2015 with the registration number assigned ‘2015-004233-27’; it was submitted through the database of the Italian “Osservatorio Nazionale della Sperimentazione Clinica (OsSC)” - (National Monitoring Centre of Clinical Trials) to the National Competent Authority on 8th March 2016 and approved on 23rd June 2016.

mRNA and miRNA Transcriptome Profiling of Granulosa and Theca Layers From Geese Ovarian Follicles Reveals the Crucial Pathways and Interaction Networks for Regulation of Follicle Selection

Follicle development is characterized by the recruitment, growth, selection, and dominance of follicles, and follicle selection determines the lifetime reproductive performance. However, in birds, the molecular mechanisms underlying follicle selection still remain elusive. This study analyzed genome-wide changes in the mRNA and miRNA expression profiles in both the granulosa and theca layers of geese ovarian follicles before selection (4–6- and 8–10-mm follicles) and after selection (F5). The sequencing results showed that a higher number of both differentially expressed (DE) mRNAs and DE miRNAs were identified between 8–10-mm and F5 follicles compared with those between the 4–6- and 8–10-mm follicles, especially in the granulosa layer. Moreover, a Short Time-series Expression Miner analysis identified a large number of DE mRNAs and DE miRNAs that are associated with follicle selection. The functional enrichment analysis showed that DE genes in the granulosa layer during follicle selection were mainly enriched in five pathways related to junctional adhesion and two pathways associated with lipid metabolism. Additionally, an interaction network was constructed to visualize interactions among protein-coding genes, which identified 53 junctional adhesion- and 15 lipid regulation-related protein-coding genes. Then, a co-expression network between mRNAs and miRNAs in relation to junctional adhesion was also visualized and mainly included acy-miR-2954, acy-miR-218, acy-miR-2970, acy-miR-100, acy-miR-1329, acy-miR-199, acy-miR-425, acy-miR-181, and acy-miR-147. Furthermore, miRNA–mRNA interaction pairs related to lipid regulation were constructed including acy-miR-107, acy-miR-138, acy-miR-130, acy-miR-128, and acy-miR-101 during follicular selection. In summary, these data highlight the key roles of junctional adhesion and lipid metabolism during follicular selection and contribute to a better understanding of the mechanisms underlying follicle selection in birds.

S100-A9 protein in exosomes derived from follicular fluid promotes inflammation via activation of NF-κB pathway in polycystic ovary syndrome

Exosomes have recently emerged as key mediators of different physiological and pathological processes. However, there has been few report about proteomic analysis of exosomes derived from human follicular fluid and their association with the occurrence of PCOS. Herein, we used TMT‐tagged quantitative proteomic approach to identify proteomic profiles in exosomes derived from follicular fluid of PCOS patients and healthy controls. We identified 662 proteins in exosomes derived from human ovarian follicular fluid. Eighty‐six differently expressed proteins (P < .05) were found between PCOS and healthy women. The alterations in the proteomic profile were related to the inflammation process, reactive oxygen species metabolic process, cell migration and proliferation. Importantly, we observed that follicular fluid exosomes contain S100 calcium‐binding protein A9 (S100‐A9) protein. Exosome‐enriched S100‐A9 significantly enhanced inflammation and disrupted steroidogenesis via activation of nuclear factor kappa B (NF‐κB) signalling pathway. These data demonstrate that exosomal proteins are differentially expressed in follicular fluid during disease process, and some proteins may play important roles in the regulation of granulosa cell function. These results highlight the importance of exosomes as extracellular communicators in ovarian follicular development.

Early Steps of Mammary Stem Cell Transformation by Exogenous Signals; Effects of Bisphenol Endocrine Disrupting Chemicals and Bone Morphogenetic Proteins

Estrogens are major regulators of the mammary gland development, notably during puberty, via estrogen receptor (ER) activation, leading to the proliferation and differentiation of mammary cells. In addition to estrogens, the bone morphogenetic proteins (BMPs) family is involved in breast stem cell/progenitor commitment. However, these two pathways that synergistically contribute to the biology of the normal mammary gland have also been described to initiate and/or promote breast cancer development. In addition to intrinsic events, lifestyle habits and exposure to environmental cues are key risk factors for cancer in general, and especially for breast cancer. In the latter case, bisphenol A (BPA), an estrogen-mimetic compound, is a critical pollutant both in terms of the quantities released in our environment and of its known and speculated effects on mammary gland biology. In this review, we summarize the current knowledge on the actions of BMPs and estrogens in both normal mammary gland development and breast cancer initiation, dissemination, and resistance to treatment, focusing on the dysregulations of these processes by BPA but also by other bisphenols, including BPS and BPF, initially considered as safer alternatives to BPA.

TGF-β1 promotes hyaluronan synthesis by upregulating hyaluronan synthase 2 expression in human granulosa-lutein cells

Hyaluronan serves as a structural component of ovarian follicles, and hyaluronan-mediated signaling cascades lead to follicular development, oocyte maturation, and ovulation. Transforming growth factor-β (TGF-β1) is highly expressed in human oocytes and granulosa cells and involved in the regulation of follicular development and ovulation. Previous studies have shown the imperative role for TGF-β signaling in the regulation of hyaluronan-mediated cumulus expansion and ovulation in human granulosa-lutein (hGL) cells. However, the detailed underlying molecular mechanisms by which TGF-β regulates the synthesis of hyaluronan in hGL cells are not fully elucidated. Using both primary and immortalized hGL cells as study models, we provide the first data showing that TGF-β1 significantly promoted the synthesis of hyaluronan by upregulating the expression of hyaluronan synthase 2 in these cells. Additionally, using dual inhibition approaches, we show that the TGF-β type II (TβRII) receptor and TGF-β type I (ALK5) receptor are functional receptors that mediate stimulatory effects in response to TGF-β1. Moreover, we found that the canonical SMAD2/SMAD3-SMAD4 signaling pathway is the principal intracellular signaling pathway that upregulates the expressionhyaluronan synthase and subsequent hyaluronan synthesis. Notably, we showed that SNAIL transcription factor is a critical molecule mediating the TGF-β signaling, which contributes to the increase in hyaluronan synthesis. These results of our in vitro studies suggest that intraovarian TGF-β1 plays a functional role in the local regulation of hyaluronan synthesis in hGL cells.

The role of FSH and TGF-β superfamily in follicle atresia

Most of the mammalian follicles undergo a degenerative process called “follicle atresia”. Apoptosis of granulosa cells is the main characteristic of follicle atresia. Follicle stimulating hormone (FSH) and the transforming growth factor β (TGF-β) superfamily have important regulatory functions in this process. FSH activates protein kinase A and cooperating with insulin receptor substrates, it promotes the PI3K/Akt pathway which weakens apoptosis. Both Smad or non-Smad signaling of the transforming growth factor β superfamily seem to be related to follicle atresia, and the effect of several important family members on follicle atresia is concluded in this article. FSH and TGF-β are likely to mutually influence each other and what we have already known about the possible underlying molecular mechanism is also discussed below.

Isolation of female germline stem cells from porcine ovarian tissue and differentiation into oocyte-like cells

Historically, it had been widely accepted that the female mammalian ovary contained a limited number of oocytes that would reduce over time, without the possibility of replenishment. However, recent studies have suggested that female germline stem cells (FGSCs) could replenish the oocyte-pool in adults. The aim of this study was to isolate FGSCs from porcine ovaries and differentiate them into oocyte-like cells (OLCs). The FGSCs were successfully isolated from porcine ovarian tissue and cultured in vitro, in DMEM/F-12 medium supplemented with growth factors (EGF, FGF, GDNF, etc.) and a supplement (N21). These cells possessed spherical morphology and expressed specific germline characteristics (Vasa, Stella, Oct4, c-kit). By evaluating different conditions for in vitro differentiation of FGSCs, co-culturing the isolated FGSCs with MEF cells, under three-dimensional (3D) cell cultures, were shown to be optimal. FGSCs could successfully be differentiated into OLCs and reached about 70 µm in diameter, with a large number of surrounding somatic cells. Importantly, OLCs contained large nuclei, about 25–30 µm, with filamentous chromatin, similar to oocyte morphology, and expressed oocyte-specific markers (Gdf9, Zp2, SCP3, etc.) at the same level as oocytes. In conclusion, we successfully isolated FGSCs from porcine ovarian tissue and differentiated them into oocyte-like cells. This will provide a valuable model for studying a new, alternative source of oocytes.

Quercetin protects human granulosa cells against oxidative stress via thioredoxin system

Granulosa Cells (GCs) are sensitive to excessive production of reactive oxygen species (ROS). Quercetin (QUR) is a free radical scavenger which can alleviate oxidative stress through nuclear factor (erythroid-derived 2)-like 2 (Nrf2)/antioxidant response element (ARE) pathway and thioredoxin (Trx) system. We aimed to explore the probable protective role of QUR on cultured human GCs treated with hydrogen peroxide (H₂O₂) as an inducer of oxidative stress. MTT assay was applied for evaluating the cell cytotoxicity of QUR and H₂O₂. The rate of apoptotic cells and intracellular ROS generation were determined by Annexin V-FITC/PI staining and 2'-7'-dichlorodihydrofluorescein diacetate fluorescent probes (DCFH-DA), respectively. Quantitative real-time polymerase chain reaction (qRT-PCR) analysis and western blot analysis were used to evaluate the gene and protein expression of Nrf2 and kelch-like ech-associated protein 1 (Keap1)1. The Nrf2 and Trx activities were measured by Enzyme-linked Immunosorbent Assay (ELISA). The results indicated that QUR pretreatment can decrease ROS production and apoptosis induced by H₂O₂. In addition, QUR increased Nrf2 gene and protein expression, as well as its nuclear translocation. Moreover, in QUR-treated group, a lower level of Keap1 protein was observed, which was not reported as significant. The results also indicated a significant correlation between the expression of Nrf2 and Keap1 in QUR-treated group. Further, QUR protected GCs from oxidative stress by increasing Trx gene expression and activity. This study suggests that QUR as a supplementary factor may protect GCs from oxidative stress in diseases related to this condition.

ALK4-SMAD2/3-SMAD4 signaling mediates the activin A-induced suppression of PTX3 in human granulosa-lutein cells

As one of the members of the transforming growth factor-β (TGF-β) superfamily, activin A plays an important role in regulating follicular development and oocyte maturation. Pentraxin 3 (PTX3) is the key component that promotes the process of cumulus expansion during mammalian ovulation. At present, the regulation of PTX3 expression in human granulosa cells remains largely unknown. This study aimed to examine the effects of activin A on the expression of PTX3 in human granulosa-lutein (hGL) cells and to investigate the underlying molecular mechanisms. Using an established immortalized hGL cell line (SVOG) and primary hGL cells as study models, we demonstrated that activin A significantly increased the phosphorylation of SMAD2 and SMAD3, which suppressed the expression of PTX3 at both the mRNA and protein levels. Additionally, these effects induced by activin A were completely reversed by pretreatment with the TGF-β type I receptor inhibitor SB431542 and knockdown of ALK4. Furthermore, knockdown of SMAD2, SMAD3, or SMAD4 completely reversed the activin A-induced suppressive effects on PTX3 expression. Notably, the ChIP analyses demonstrated that phosphorylated SMADs could bind to human PTX3 promoter. Collectively, our results showed that the ALK4-SMAD2/3-SMAD4 signaling pathway most likely mediates the suppressive effect of activin A on PTX3 expression in hGL cells.

Follicular localization of growth differentiation factor 8 and its receptors in normal and polycystic ovary syndrome ovaries

Polycystic ovary syndrome (PCOS) is the most common endocrine disorder in women of reproductive age and its etiology has not been characterized. Growth differentiation factor 8 (GDF8) is a member of the transforming growth factor-β superfamily that plays a critical role in the regulation of ovarian functions. However, the expression pattern of GDF8 in the human ovary is not yet clear. This study examined the cellular distribution of GDF8 and its putative cellular receptors (ACVR2A, ACVR2B, and ALK5) in a series of normal (n = 34) and PCOS ovaries (n = 14). The immunostaining of GDF8, ACVR2A, ACVR2B, and ALK5 was detected in the oocytes regardless of the developmental stage. All these proteins were localized in antral follicles in normal and PCOS ovaries, and the expression of these proteins increased with increasing follicle diameter. A significantly higher expression of GDF8 was detected in the granulosa cells than in the matched theca cells (TCs). These proteins were also localized in the luteal cells of the corpus luteum. Granulosa cells and TCs of large antral follicles in PCOS ovaries display a higher expression of these proteins. The higher expression levels of GDF8 and its functional receptors (ACVR2A, ACVR2B, and ALK5) in antral follicles of PCOS ovaries than those in normal ovaries suggest the possible involvement of dysregulated GDF8 in the pathogenesis of PCOS.

Identification of potential metabolic biomarkers of polycystic ovary syndrome in follicular fluid by SWATH mass spectrometry

BACKGROUND

Polycystic ovary syndrome (PCOS) is a complex disorder associated with multiple metabolic disturbance, including defective glucose metabolism and insulin resistance. The altered metabolites caused by the related metabolic disturbance may affect ovarian follicles, which can be reflected in follicular fluid composition. The aim of this study is to investigate follicular fluid metabolic profiles in women with PCOS using an advanced sequential window acquisition of all theoretical fragment-ion spectra (SWATH) mass spectrometry.

MATERIALS AND METHODS

Nineteen women with PCOS and twenty-one healthy controls undergoing IVF/ET were recruited, and their follicular fluid samples were collected for metabolomic study. Follicular fluid metabolic profiles, including steroid hormones, free fatty acids, bioactive lipids, and amino acids were analyzed using the principal component analysis (PCA) and partial least squares to latent structure-discriminant analysis (PLS-DA) model.

RESULTS

Levels of free fatty acids, 3-hydroxynonanoyl carnitine and eicosapentaenoic acid were significantly increased (P < 0.05), whereas those of bioactive lipids, lysophosphatidylcholines (LysoPC) (16:0), phytosphingosine, LysoPC (14:0) and LysoPC (18:0) were significantly decreased in women with PCOS (P < 0.05). Additionally, levels of steroid hormone deoxycorticosterone and two amino acids, phenylalanine and leucine were higher in the PCOS patients (P < 0.05).

CONCLUSION

Women with PCOS display unique metabolic profiles in their follicular fluid, and this data may provide us with important biochemical information and metabolic signatures that enable a better understanding of the pathogenesis of PCOS.

LncRNA Gm2044 promotes 17β-estradiol synthesis in mpGCs by acting as miR-138-5p sponge

Long noncoding RNAs (lncRNAs) have been demonstrated to play vital roles in mammalian reproduction. Our previous research revealed that lncRNA Gm2044 is highly expressed in mouse spermatocytes and regulates male germ cell function. The gene annotation database BioGPS shows that Gm2044 is not only highly expressed in testicular tissue but also in ovarian tissue, which suggests that Gm2044 may be involved in female reproductive development. In this study, we confirmed that lncRNA Gm2044 promotes 17β-estradiol synthesis in mouse pre-antral follicular granulosa cells (mpGCs). Furthermore, bioinformatics methods, western blot, and the luciferase assay proved that Gm2044 functions as a miR-138-5p sponge to inhibit the direct target of miR-138-5p, Nr5a1, which enhances 17β-estradiol synthesis through cyp19a1 activation. Taken together, our results provide an insight into the mechanistic roles of lncRNA Gm2044 for 17β-estradiol synthesis by acting as competing-endogenous RNAs to modulate the function of mpGCs. Studying the potential lncRNAs, which regulate estradiol release, will be beneficial for the diagnosis and treatment of steroid hormone-related disease.

The never-ending search of an ideal culture system for domestic cat oocytes and embryos

In the domestic cat, in vitro fertilization started 40 years ago, but an ideal culture system has yet to be achieved. The physiological microenvironments, which interact with oocytes and embryos promoting their competence, have been investigated. However, recreating in vitro follicle- and oviduct-like conditions is challenging and a matter of both chemistry and physics. This review presents an excursus of the experimental investigations focused on the improvement of feline oocytes and embryos culture through the modulation of chemical and physical factors. Medium supplementation with components of follicular and oviductal fluids, or the use of different co-cultures, supports or substrata have been considered. Innovative and sophisticated systems as "organ-on-a-chip" might lead to the creation of artificial follicles and oviducts and they may represent the ideal combination of chemical and physical factors. Will the search ever end?