The incidence of apoptotic bodies in membrana granulosa can predict prognosis of ova from patients participating in in vitro fertilization programs

AKT, p-AKT, ERK1/2 and p-ERK1/2 in Mural Granulosa Cells Are Not Correlated to Different Ovarian Stimulation Protocols in Patients Undergoing Assisted Reproductive Treatment

(1) Background: In this paper we aim to study the relationship between the expression levels of molecules involved in apoptotic/survival pathways, considered as molecular markers of oocyte competence (i.e., AKT, p-AKT, ERK1/2, and p-ERK1/2) in mural granulosa cells (MGCs) and the administration of r-FSH alone or combined with exogenous r-LH, in ovarian stimulation protocol. Moreover, we aim to evaluate oocyte competence by comparing normally cleaved embryos that were transferred in the uterus, with embryos that were arrested during in vitro culture. (2) Methods: The study included 34 normo-responder women undergoing ICSI procedures. All subjects were divided into two groups. Group A consisted of 18 women stimulated with r-FSH and used as a control group; Group B consisted of 14 women stimulated with r-FSH combined with r-LH. The MGCs were obtained from individual follicles. Immunoblot analyses were carried out to analyze the AKT, p-AKT, ERK1/2, and p-ERK1/2 levels in MGCs and to correlate them with the ovarian stimulation protocol. Furthermore, the oocyte competence was evaluated, for each follicle, according to the development of the embryo during in vitro culture and the pregnancy outcome. (3) Results: We found no significant difference in the levels of molecules in isolated MGCs between groups A and B. These results, in light of our previous research, suggest for the first time, to our knowledge, that cumulus cells and mural granulosa cells in the same follicle show different expression levels of molecules involved in the apoptotic mechanism. (4) Conclusions: Our results could clarify some controversial data in the literature where cumulative cell pools of cumulus and granulosa were analyzed, described as ovarian follicle cells, and used as markers of oocyte competence. In this paper, we found evidence that cumulus and granulosa cells need to be analyzed separately.

Impact of endometriosis on the ovarian follicles

A significant body of evidence has supported a negative impact of endometriosis on ovarian follicles; however, the origin and relevance of this ovarian impairment in endometriosis is still a matter of debate. The ovarian damage can be caused by endometriosis itself or by surgeries aiming to remove endometriotic lesions. In this review, we summarized the existing knowledge on the mechanisms by which endometriosis can impact the ovarian follicles, from molecular to clinical points of view. From a molecular standpoint, the presence of endometriosis or its consequences can induce oxidative stress, inflammation, aberrant mitochondrial energy metabolism and inappropriate steroid production in granulosa cells, phenomena that may impair the quality of oocytes to variable degrees. These alterations may have clinical relevance on the accelerated exhaustion of the ovarian reserve, on the ovarian response to gonadotrophin stimulation in IVF cycles and on the competence of the oocytes. Critical points to be considered in current clinical practices related to fertility issues in endometriosis are discussed.

Serum anti-Müllerian hormone concentrations are related to embryo development: lessons from time-lapse imaging

Our objective was to study whether serum anti-Müllerian hormone (AMH) concentrations were associated with embryo morphokinetic events. This retrospective cohort study was performed in a private university-affiliated in vitro fertilization centre between March 2019 and December 2020 and included 902 oocytes cultured in a time-lapse imaging incubator, obtained from 114 intracytoplasmic sperm injection cycles performed. The relationship between AMH concentrations and morphokinetic events was investigated by considering the clustering of data (multiple embryos/patient). Evaluated kinetic markers were time to pronuclei appearance (tPNa) and fading (tPNf), time to two (t2), three (t3), four (t4), five (t5), six (t6), seven (t7), and eight cells (t8), (tSB) and time to the start of blastulation (tSB) and to blastulation (tB). Significant inverse relationships were observed between serum AMH concentrations and tPNf, t3, t4, t5, t6, t7, t8, and tB. The AMH was positively correlated with the KIDScore and implantation rate. Increased serum AMH concentrations correlated with faster embryo development. The clinical implications of this effect on embryo development warrant further investigation.

The Role of Lifestyle and Dietary Factors in the Development of Premature Ovarian Insufficiency

Premature ovarian insufficiency (POI) is a condition that arises from dysfunction or early depletion of the ovarian follicle pool accompanied by an earlier-than-normal loss of fertility in young women. Oxidative stress has been suggested as an important factor in the decline of fertility in women and POI. In this review, we discuss the mechanisms of oxidative stress implicated in ovarian ageing and dysfunction in relation to POI, in particular mitochondrial dysfunction, apoptosis and inflammation. Genetic defects, autoimmunity and chemotherapy, are some of the reviewed hallmarks of POI that can lead to increased oxidative stress. Additionally, we highlight lifestyle factors, including diet, low energy availability and BMI, that can increase the risk of POI. The final section of this review discusses dietary factors associated with POI, including consumption of oily fish, mitochondria nutrient therapy, melatonin, dairy and vitamins that can be targeted as potential interventions, especially for at-risk women and in combination with personalised nutrition. Understanding the impact of lifestyle and its implications for POI and oxidative stress holds great promise in reducing the burden of this condition.

The Effect of Clomiphene Citrate and Letrozole in Apoptotic Pathways and Cell Cycle in Human Primary Cumulus Cells and the Protective Effect of Estradiol

Clomiphene citrate (CC) and letrozole are ovulatory stimulants that, despite high ovulation rates, achieve low pregnancy rates. This study aimed to investigate the in vitro effects of CC and letrozole, alone or in combination with estradiol, on apoptosis in human cumulus cells. We performed a controlled prospective study using primary cumulus cell cultures from patients undergoing in vitro fertilization (n=22). Alpha-inhibin immunocytochemistry was used to assess cell culture purity and morphology. Cell viability was evaluated by MTT assay, cell cycle status by flow cytometry, and Caspase-3, Bax and SOD-2, and S26 gene expression by qPCR. Cells were treated for 24 hours in 5 conditioned media: CC, CC + estradiol, letrozole, letrozole + estradiol and control. None of the treatments affected cell viability, but letrozole reduced the mean percentage of cells in the S phase compared to control (24.79 versus 21.70, p=0.0014). Clomiphene treatment increased mRNA expression of Bax (4 fold) and SOD-2 (2 fold), which was reversed by co-treatment with estradiol. SOD-2 expression increased in cells treated with letrozole compared to control (4 fold), which was also reversed by estradiol. These findings suggest that clomiphene citrate and letrozole do not significantly affect the viability of human cumulus cells. Still, the expression of genes involved in apoptosis was modulated by these drugs alone and in association with estradiol, suggesting that CC and letrozole may have direct effects on cumulus cells beyond their known mechanisms of action.

PCOS and Role of Cumulus Gene Expression in Assessing Oocytes Quality

The global infertility rate has been declining from year to year. PCOS is one of the treatable accountable causes contributing to anovulatory infertility. Nevertheless, the success rate of treatments and live-birth outcomes especially involving assisted reproductive techniques is still not very promising. There is a reduction in the development potential of oocytes and high-quality embryos in PCOS patients compared to non-PCOS patients. A critical step in IVF treatment is the assessment of oocyte and embryo competence before embryo transfer. Oocytes in metaphase II are very fragile. Repeated morphological assessment on these oocytes may directly impair the quality and affect the whole process. Identification of potential biomarkers especially in the cumulus cells oocytes complex will help to predict the outcome and may create space for improvement. This review has explored gene expression in cumulus cells with regards to oocytes quality in both normal and PCOS women. The gene expression was classified according to their physiological function such as the contribution on cumulus expansion, cumulus cells apoptosis, and glucose metabolism. Collectively, the review suggested that positive expression of HAS2, PTX3, GREM1, and VCAN may correlate with good quality oocytes and can be used as an indicator among PCOS women.

The protective effect of sulforaphane against oxidative stress in granulosa cells of patients with polycystic ovary syndrome (PCOS) through activation of AMPK/AKT/NRF2 signaling pathway

Increased production of reactive oxygen species (ROS) in granulosa cells (GCs) causes oxidative stress (OS) and plays a role in pathogenesis of polycystic ovary syndrome (PCOS). Sulforaphane (SFN) has received a great deal of attention as potent antioxidant because of its ability to induce expression of antioxidant enzymes through nuclear factor (erythroid-derived 2)-like 2 (NRF2) signaling pathway. Therefore, the present study was done to investigate the protective effect of SFN against OS in granulosa-lutein cells (GLCs) of patients with PCOS through activation of AMP-activated protein kinase (AMPK)/AKT/NRF2 signaling pathway. GLCs were isolated from patients with PCOS and healthy fertile women, as control group, during egg retrieval procedure. Level of intracellular ROS and apoptosis was determined in the isolated cells. For investigating the protective effect of SFN against ROS production and apoptosis in GLCs, the cells were cultured for 24 h in the presence or absence of SFN. Finally, expression of AMPK, AKT, and NRF2 proteins and genes was evaluated by western blotting and quantitative real-time polymerase chain reaction (qRT-PCR), respectively. The results indicated the increased ROS and apoptosis levels in GLCs isolated from patients with PCOS compared to the control group. Addition of SFN to culture medium of GLCs of patients with PCOS reduced intracellular ROS and apoptosis levels, and increased expression of AMPK, AKT, and NRF2 proteins and genes. Our findings demonstrated the protective effect of SFN against OS by lowering level of ROS and apoptosis possibly through activation of AMPK, AKT, and NRF2 proteins and genes expression.

Granulosa cells apoptosis and follicular fluid hormones: comparison of progestin-primed ovarian stimulation versus GnRH antagonist protocols

OBJECTIVE

To explore the effect of progestin-primed ovarian stimulation protocol (PPOS) on mural granulosa cells (GCs) apoptosis and hormonal profiles in follicular fluid (FF) and efficacy over GnRH antagonist (GnRH-A) protocols.

METHODS

We performed a prospective cohort study from June through August 2017 at a tertiary teaching hospital. 63 Patients meeting our criteria were recruited in this prospective study voluntarily and stratified to PPOS or GnRH-A group randomly. Mural GCs and FF were collected during oocyte retrieval. Apoptosis of GCs was assessed using the Annexin V-affinity assay by flow cytometry and hormonal profiles in FF were measured using electrochemiluminescence.

RESULTS

A total of 63 women were assessed for eligibility, with 25 cases in PPOS group and 38 in GnRH-A group. Difference of early stage apoptosis rate, late stage apoptosis rate, and total apoptosis rate did not reach statistical significance between groups. Meanwhile, concentrations of hormones in FF were comparable in two groups. No statistically significant differences were observed in number of oocytes retrieved, mature oocyte rate, fertilization rate, and top-quality embryos rate. No patients experienced premature LH surge in both groups during the study.

CONCLUSION

Compared to GnRH antagonist protocol, PPOS had comparable laboratory outcomes, GCs apoptosis rate and hormonal profiles in FF. PPOS is an effective and safe alternative option to provide controlled ovarian hyperstimulation (COH).

Interplay Between mTOR and Hippo Signaling in the Ovary: Clinical Choice Guidance Between Different Gonadotropin Preparations for Better IVF

One of the most widely used types of assisted reproduction technology is the in vitro fertilization (IVF), in which women undergo controlled ovarian stimulation through the administration of the appropriate hormones to produce as many mature follicles, as possible. The most common hormone combination is the co-administration of gonadotropin-releasing hormone (GnRH) analogues with recombinant or urinary-derived follicle-stimulating hormone (FSH). In the last few years, scientists have begun to explore the effect that different gonadotropin preparations have on granulosa cells' maturation and apoptosis, aiming to identify new predictive markers of oocyte quality and successful fertilization. Two major pathways that control the ovarian development, as well as the oocyte-granulosa cell communication and the follicular growth, are the PI3K/Akt/mTOR and the Hippo signaling. The purpose of this article is to briefly review the current knowledge about the effects that the different gonadotropins, used for ovulation induction, may exert in the biology of granulosa cells, focusing on the importance of these two pathways, which are crucial for follicular maturation. We believe that a better understanding of the influence that the various ovarian stimulation protocols have on these critical molecular cascades will be invaluable in choosing the best approach for a given patient, thereby avoiding cancelled cycles, reducing frustration and potential treatment-related complications, and increasing the pregnancy rate. Moreover, individualizing the treatment plan will help clinicians to better coordinate assisted reproductive technology (ART) programs, discuss the specific options with the couples undergoing IVF, and alleviate stress, thus making the IVF experience easier.

Cell-free mitochondrial DNA in human follicular fluid: a promising bio-marker of blastocyst developmental potential in women undergoing assisted reproductive technology

BACKGROUND

Cell-free mitochondrial DNA (cf-mtDNA) in body fluids has attracted much attention for the purpose of monitoring disease because of the clinical advantages. This study investigated whether the cf-mtDNA content in human follicular fluid samples was associated with oocyte and embryo developmental competence.

METHODS

We collected 225 individual follicular fluid samples from 92 patients undergoing conventional in vitro fertilization (n = 53) or intracytoplasmic sperm injection (n = 39). cf-mtDNA and cell-free nuclear DNA (cf-nDNA) were measured using real-time quantitative PCR for the ND1 and β-globin genes. Multivariate logistic regression and linear regression were used to analyze data.

RESULTS

The relative cf-mtDNA content (cf-ND1/cf-β-globin ratio) in follicular fluid was significantly lower in the group showing blastocyst development than in the non-blastocyst group (P = 0.030). Additionally, the relative cf-mtDNA content was significantly and positively correlated with the age of the female patient (P = 0.009), while the relative cf-mtDNA content for older women (≥38 years old) with anti-Müllerian hormone (AMH) ≤1.1 ng/ml was significantly higher than in those with AMH > 1.1 ng/ml (P <0.05). The cf-nDNA content was significantly positively correlated with the antral follicle count (P = 0.012), and significantly negatively correlated with both the number of days of stimulation and the total dose of gonadotropin administration (P = 0.039 and P = 0.015, respectively). Neither cf-mtDNA nor cf-nDNA levels in follicular fluid were associated with oocyte maturation, fertilization, or Day 3 embryo morphological scoring.

CONCLUSIONS

The relative cf-mtDNA content in human follicular fluid was negatively correlated with blastulation and positively correlated with the patient age, indicating that it is a promising bio-marker to evaluate oocyte developmental competence.

Assessing ICSI outcome by combining non-invasive indicators: Early time-lapse morphokinetics and apoptosis in associated cumulus cells among women with the polycystic ovarian syndrome

Cumulus cells features and embryo developmental events can be considered as noninvasive indicators for embryo selection and clinical outcomes. A combination of time-lapse morphokinetic parameters and cumulus cell apoptosis in women with polycystic ovarian syndrome (PCOS) was evaluated for predicting pregnancy outcome. We assessed a total of 547 embryos from 100 intracytoplasmic sperm injection (ICSI) cycles. Time-lapse records were interpreted in time to pronuclear fading (tPNf), time to 2 to 8 cells (t2-t8), direct cleavage, reverse cleavage, and also for the presence of multinucleation. Percentages of apoptosis were identified in 100 associated cumulus cell samples using the TDT-mediated dUTP-biotin nick end-labeling assay. The significant decrease of apoptotic cumulus cells was detected in patients with chemical and clinical pregnancies as well as live birth among patients PCOS and in the tubal infertility group (p > 0.05). Furthermore, significantly higher implantation rate and also significantly lower cases of early pregnancy loss were observed in the group of oocytes with less apoptotic cumulus cells. Multivariate logistic regression analysis showed that tPNf together with cumulus cell apoptosis were independent prognostic factors of chemical pregnancy, clinical pregnancy rate, and live birth. Time-lapse embryo parameters may not reflect the cumulus cell apoptosis rate. However, the rate of apoptotic cumulus cells is significantly associated with ICSI outcome using Day 3 embryo transfer.

The effect of ovarian reserve and receptor signalling on granulosa cell apoptosis during human follicle development

The poor oocyte quality in older women has previously been linked to the depletion of the ovarian reserve of primordial follicles and an increase in granulosal apoptosis. Granulosa cells were collected from 198 follicles and individually analysed by flow cytometry. In the young IVF patients, the level of apoptosis was inversely proportional to the expression of bone morphogenetic protein (BMPR1B) and follicle stimulating hormone (FSH) receptors. Conversely, in the older patients this relationship became dysregulated. In the older patients, at the time of preovulatory maturation, the reduced apoptosis reflects the poor mitogenic growth turnover rate of healthy follicles rather than the death rate in an atretic follicle. Restoring an optimum receptor density and down-regulation of receptors may improve oocyte quality and the pregnancy rate in older women.

Implications of immune dysfunction on endometriosis associated infertility

Endometriosis is a complex, inflammatory disease that affects 6-10% of reproductive-aged women. Almost half of the women with endometriosis experience infertility. Despite the excessive prevalence, the pathogenesis of endometriosis and its associated infertility is unknown and a cure is not available. While many theories have been suggested to link endometriosis and infertility, a consensus among investigators has not emerged. In this extensive review of the literature as well as research from our laboratory, we provide potential insights into the role of immune dysfunction in endometriosis associated infertility. We discuss the implication of the peritoneal inflammatory microenvironment on various factors that contribute to infertility such as hormonal imbalance, oxidative stress and how these could further lead to poor oocyte, sperm and embryo quality, impaired receptivity of the endometrium and implantation failure.

Apoptotic biomarkers in cumulus cells in relation to embryo quality in polycystic ovary syndrome

PURPOSE

To investigate associations between gene expression pattern of apoptotic biomarkers in cumulus cells of polycystic ovary syndrome (PCOS) patients and the quality of oocytes and embryos.

METHODS

40 intracytoplasmic sperm injection patients, of whom 20 were PCOS and 20 were healthy women, were included in this study. Serum hormone levels were measured using Radioimmunoassay for each patient. The expression of survivin, caspase-3, and caspase-7 in 200 cumulus complexes surrounding mature oocytes (100 in PCOS versus 100 in control groups) collected individually at pick up was examined by real-time polymerase chain reaction (real-time PCR).

RESULTS

The expression levels of survivin were significantly lower in PCOS patients than those of normal women while caspase-3 and caspase-7 expression levels were higher in PCOS patients (p < 0.05). There was a statistically significant correlation between the levels of these genes and embryo quality.

CONCLUSIONS

This study reveals that the measurement of survivin, caspase-3, caspase-7 levels in cumulus cells of PCOS patients could be used as genetic biomarkers for oocyte and embryo selection under an ART program. However, further prospective studies are required to elucidate this issue.

The predictive value of serum concentrations of anti-Müllerian hormone for oocyte quality, fertilization, and implantation

Objective

This study aimed to identify a possible correlation between serum levels of anti-Müllerian hormone (AMH) and oocyte quality, embryo developmental competence, and implantation potential.

Methods

4488 oocytes obtained from 408 patients undergoing ICSI cycles were evaluated. Oocyte dimorphisms, embryo quality on days two and three, blastocyst formation competence, fertilization rates, implantation rates, and pregnancy rates were correlated with serum levels of AMH using Pearson's correlation coefficient and regression analysis.

Results

A positive correlation was observed between serum levels of AMH and number of retrieved oocytes (CC: 0.600, p<0.001), fertilization rate (CC:0.595, p=0.048), and number of obtained embryos (CC:0.495, p<0.001). AMH did not affect the quality of cleavage stage embryos or the chance of blastocyst formation. However, AMH levels affected oocyte quality (OR:0.75, CI 0.44-0.96, p<0.001), and implantation (CC:0,116, p=0.031) and pregnancy (OR:1.22, CI:1.03-1.53, p<0.001) rates.

Conclusion

Serum levels of AMH are a useful predictor of ovarian response to COS, oocyte quality, and fertilization. However, AMH levels may also compromise clinical outcomes; lower AMH levels did not impair embryo development.

Effect of GOLPH3 on cumulus granulosa cell apoptosis and ICSI pregnancy outcomes

Previous studies have shown that GOLPH3 mediates cell growth, proliferation and differentiation and inhibits cell apoptosis; however, the role of GOLPH3 in cumulus granulosa cells and the value of GOLPH3 in predicting ICSI pregnancy outcomes remain unknown until now. Our findings showed higher positive expression rate, score of staining intensity, and immunohistochemical score of GOLPH3 in the cumulus granulosa cells of the pregnant women relative to non-pregnant women, and a higher apoptotic rate of cumulus granulosa cells was detected in non-pregnant women than in pregnant women. Pearson correlation analyses revealed that pregnancy correlated negatively with GOLPH3 expression and apoptosis of cumulus granulosa cells, and positively with the number of follicles punctured, number of grade III oocytes, number of eggs retrieved for ICSI, number of zygotes, number of cleavage-stage embryos, number of top-quality embryos, number of blastocysts, number of top-quality blastocysts, and number of frozen embryos. GOLPH3 may be involved in the apoptosis of cumulus granulosa cells, which may correlate with oocyte maturation and egg development. GOLPH3 expression in cumulus granulosa cells may facilitate the selection of top-quality eggs and embryos, the prediction of the clinical pregnancy outcomes of ICSI, and the increase of the pregnancy rate.

Relationship between apoptosis and survival molecules in human cumulus cells as markers of oocyte competence

To select from a single patient the best oocytes able to reach the blastocyst stage, we searched for valuable markers for oocytes competence. We evaluated the DNA fragmentation index (DFI) and the level of some survival molecules, such as AKT, pAKT and pERK1/2, in individual cumulus cell-oocyte complexes (COC). The study included normo-responder women. The average age of the patients was 34.3. DFI in cumulus cells was evaluated using the terminal deoxynucleotidyl transferase (TdT) dUTP nick-end labelling (TUNEL) assay in situ. AKT, pAKT and pERK1/2 were measured by immunological assay and densitometric analysis of fluorescent signals using NIS-Elements BR 3.10 image software. Statistical analysis was performed using STATA SE/14.1. The study focused on 53 patients involved after informed consent. Out of 255 MII oocytes, 197 were fertilized and the derived embryos had the following evolution: 117 completed the development to blastocyst and were transferred to uterus; 57 were vitrified at the blastocyst stage; and 23 were arrested during in vitro culture at different stages of cleavage. We found a significant statistical difference between the DFI of cumulus cells of the arrested embryos and the transferred blastocysts (P = 0.004), confirming that DFI could be considered as a valuable marker of oocyte competence. In addition, the pAKT/DFI ratio was higher in cumulus cells of oocytes able to produce blastocysts, indicating that DFI is significantly lower when pAKT is higher (P = 0.043). This study demonstrates for the first time that the relationship between apoptosis and survival molecules can be used as a marker to select the best oocytes.

Soluble Fas Concentrations in the Follicular Fluid and Oocyte-Cumulus Complex Culture Medium From Women Undergoing In Vitro Fertilization: Association With Oocyte Maturity, Fertilization, and Embryo Quality

OBJECTIVE

Because soluble Fas (sFas) inhibits Fas-mediated apoptosis by preventing death signal transduction, we determined sFas concentrations in the follicular fluid (FF) and oocyte-cumulus complex culture medium (CM) from women undergoing in vitro fertilization (IVF) in order to associate its concentrations with oocyte maturity, fertilization, and embryo quality.

METHODS

We studied 82 follicles from 11 healthy women (mean age, 35.4 +/- 3.8 years) using a long protocol for IVF treatment. Individual FF and matched CM samples were immediately centrifuged at 4C and sFas concentrations were determined by sandwich enzyme-linked immunosorbent assays.

RESULTS

sFas concentrations were significantly higher in FF than in CM (P <.0001) and when oocytes were mature rather than immature (P <.002). Of 70 mature and 12 immature oocytes, 56 (80%) and two (16.6%), respectively, were fertilized. sFas concentrations in CM were significantly lower when mature oocytes were fertilized versus nonfertilized (P <.005). sFas concentrations in FF and CM were significantly related in an inverse manner to embryo quality (P = .004 and P = .0002, respectively).

CONCLUSION

FF and CM from women undergoing IVF contain sFas. The latter has anti-apoptotic properties and levels are higher: in FF when oocytes are mature and in CM when oocytes are nonfertilized. Furthermore, FF and CM sFas concentrations are negatively correlated with embryo quality.

Altered FoxO3 expression and apoptosis in granulosa cells of women with polycystic ovary syndrome

PURPOSE

To determine the level of apoptosis, and alteration of FoxO3 (forkhead box O3 transcription factor) expression and phosphorylation in human granulosa cells amongst polycystic ovary syndrome (PCOS) patients and control group.

METHODS

We recruited infertile women with PCOS (n = 14) and compared them with infertile women due to tubal blockage or male factor infertility (n = 14, controls). GnRH agonist and gonadotropins were used for ovarian stimulation. Follicular fluids from large follicles (>16 mm) were pooled and granulosa cells (GCs) were isolated using cell strainer methodology. Apoptosis of purified GCs was measured by flow cytometry using Annexin V and propidium iodide. Quantitative real-time PCR and western blotting were performed to assess alteration of FoxO3 expression and phosphorylation in GCs.

RESULTS

There were higher percentages of early and late apoptosis in GCs of PCOS patients than in the control group. FoxO3 mRNA level and total FoxO3 protein were significantly higher in PCOS group than in the control group. The ratio of p-FoxO3/total FoxO3 decreased significantly in PCOS than in the control group. It was inferred that unphosphorylated (active form) FoxO3 was higher in GCs of PCOS patients. Apoptosis was significantly and positively correlated with the total FoxO3 and negatively correlated with the p-FoxO3 protein levels in PCOS patients.

CONCLUSIONS

Activation and overexpression of FoxO3 in granulosa cells of PCOS women correlated with higher apoptosis levels in these cells suggesting that FoxO3 may be a candidate for the higher apoptosis in granulosa cells from women with PCOS.

Expression profiles of select genes in cumulus–oocyte complexes from young and aged mares

There is compelling evidence that oocytes from mares >18 years of age have a high incidence of inherent defects that result in early embryonic loss. In women, an age-related decrease in oocyte quality is associated with an increased incidence of aneuploidy and it has recently been determined that the gene expression profile of human oocytes is altered with advancing age. We hypothesised that similar age-related aberrations in gene expression occur in equine oocytes. Therefore, the aim of the present study was to compare gene expression profiles of individual oocytes and cumulus cells from young and aged mares, specifically evaluating genes that have been identified as being differentially expressed with advancing maternal age and/or aneuploidy in human oocytes. Expression of 48 genes was compared between 14 cumulus–oocyte complexes (COCs) from mares aged 3–12 years and 10 COCs from mares ≥18 years of age. Three genes (mitochondrial translational initiation factor 3 (IF3), heat shock transcription factor 5 (HSF5) and Y box binding protein 2 (YBX2)) were differentially expressed in oocytes, with all being more abundant in oocytes from young mares. Three genes (ADP-ribosylation factor-like 6 interacting protein 6 (ARL6IP6), BCL2-associated X protein (BAX) and hypoxia upregulated 1 (HYOU1)) were differentially expressed in cumulus cells, with all being more abundant in aged mares. The results of the present study confirm there are age-related differences in gene expression in equine COCs, which may be associated with the lower quality and decreased developmental competence of oocytes from aged mares.

Effects of two human chorionic gonadotropin doses administered to the ovarian states during the in vitro fertilization and embryo transfer program

The aim of the present study was to examine the effects of the human chorionic gonadotropin (hCG) dose on the pulsatility indices (PI) of the intraovarian artery on the day of follicle aspiration and the oocyte quality, intrafollicular oxidative stress and luteinization. PI was also measured on the day of hCG administration. A total of 15 patients were undergoing the in vitro fertilization and embryo transfer (IVF-ET) program. To estimate whether there was any difference between the intraovarian artery blood flow and oocyte development of the same patients treated with 5,000 or 10,000 IU hCG, the intraovarian artery blood flow was measured by transvaginal color ultrasonography pulsed wave Doppler, and the follicular fluids and the granulosa cells were collected at follicle aspiration. There were statistically significant differences between the same patients undergoing the two different hCG-dose treatments in which the first protocol included 10,000 IU and the second protocol included 5,000 IU hCG treatment. These differences were apparent in the PI of intraovarian artery blood flow on the day of follicle aspiration (P=0.0023), in the incidence of apoptosis in cumulus (ApoC) and mural (ApoM) granulosa cells (ApoC, P=0.0077; ApoM, P=0.0128), in the total oocytes retrieved (P=0.0342) and in the follicle fluid progesterone concentration (P=0.0044). There were no significant differences between the two protocols in the PI of intraovarian artery blood flow on the day of hCG administration (P=0.4326), serum steroid on the day of follicle aspiration [serum P, P>0.9999; serum estradiol (E₂), P=0.8589], follicle fluid E₂ concentration (P=0.8939), mature oocyte rate (P=0.3743) and total mature oocytes retrieved (P=0.2026). In conclusion, the dose of hCG administration can significantly affect the intraovarian artery blood flow and the development of follicles and oocytes in an IVF-ET program.

Viability of cumulus cells is associated with basal AMH levels in assisted reproduction

OBJECTIVE(S)

An interesting non-invasive approach to select embryos for transfer is analyzing the health state of somatic granulosa cells surrounding the oocyte addressing their mutual dependence. This prospective study was set up to analyse whether the DNA integrity of cumulus cells correlates with preimplantation development and basal AMH levels.

STUDY DESIGN

Therefore, 56 patients who gave written consent were enrolled. Sequential denudation of the cumulus-oocyte-complexes was performed in order to separate corona radiata from outer cumulus cells. DNA integrity of both cell types was analysed using a modified chromatin dispersion test.

RESULTS

The percentage of viable corona radiata cells per patient showed a linear correlation to blastulation (P<0.05). These innermost cells showed significantly lower rates of strand breaks (P<0.01) as compared to outer cumulus cells. Age-corrected AMH was significantly associated with the DNA integrity of outer cumulus cells (P<0.05).

CONCLUSION(S)

For the first time it could be shown that in fact clinical embryologists deal with two different entities of cumulus cells, inner and outer ones. It seems that any protective mechanism of the female gamete follows an outward gradient, so that negative effects, e.g. apoptosis, may impair outer cumulus cells first. Age-corrected AMH reflects quality of these outer cumulus cells.

KEYWORDS

AMH; Corona radiata cells; DNA fragmentation; Outer cumulus cells; SCD test.

Anti-Müllerian hormone levels in the follicular fluid of the preovulatory follicle: a predictor for oocyte fertilization and quality of embryo

This prospective study investigated the relationship between anti-Müllerian hormone (AMH) level in the follicular fluid (FF) and the quality of the oocyte and embryo. A total of 65 FF samples from 54 women were included in this study. FF was collected from the largest preovulatory follicle sized≥20 mm of mean diameter from each ovary. Samples were divided into 3 groups according to the FF AMH levels: below the 33th percentile (low group, FF AMH<2.1 ng/mL, n=21), between the 33th and the 67th percentile (intermediate group, FF AMH=2.1-3.6 ng/mL, n=22), and above the 67th percentile (high group, FF AMH>3.6 ng/mL, n=22). The quality of the ensuing oocytes and embryos was evaluated by fertilization rate and embryo score. FF AMH levels correlated positively with the matched embryo score on day 3 after fertilization (r=0.331, P=0.015). The normal fertilization rate was significantly lower in the low group than in the intermediate group (61.9% vs. 95.5% vs. 77.3%, respectively, P=0.028). Our results suggest that the FF AMH level could be a predictor of the ensuing oocyte and embryo quality.

Downregulated expression of peroxiredoxin 4 in granulosa cells from polycystic ovary syndrome

Peroxiredoxin 4 (PRDX4), a member of Peroxiredoxin (PRDX) family, is a typical 2-Cys PRDX. PRDX4 monitors the oxidative burden within cellular compartment and reduces hydrogen peroxide and alkyl hydroperoxide related to oxidative stress and apoptosis. Antioxidant, like PRDX4, may promote follicle development and participate in the pathophysiology of PCOS. In our previous study, we found that PRDX4 was expressed in mice oocyte cumulus oophorus complex, and that PRDX4 could be associated with follicle development. In this study, we explored the expression of PRDX4 in human follicles and possible role of PRDX4 in PCOS pathophysiology. Our data showed that PRDX4 was mainly expressed in granulosa cells in human ovaries. When compared to control group, both PRDX4 mRNA level and protein level decreased in PCOS group. The lowered levels of PRDX4 may relate to oxidative stress in the pathophysiologic progress of PCOS. Furthermore, expression of PRDX4 in the granulosa cells of in vivo or in vitro matured follicles was higher than that in immatured follicles, which suggested that PRDX4 may have a close relationship with follicular development. Altogether, our findings may provide new clues of the pathophysiologic mechanism of PCOS and potential therapeutic strategy using antioxidant, like PRDX4.

Expression and functional activity of PACAP and its receptors on cumulus cells: effects on oocyte maturation

Pituitary adenylate cyclase-activating polypeptide (PACAP) and its receptor PAC1-R (PACAP type 1 receptor) are transiently expressed in granulosa cells (GCs) of mouse preovulatory follicles and affect several parameters associated with the ovulatory process. We investigated the expression of PACAP and its receptors in cumulus cells (CCs) after the LH surge and their role on cumulus expansion/apoptosis and oocyte maturation. PACAP and PAC1-R expression increased in CCs isolated at different times after treatment with human chorionic gonadotropin (hCG). Moreover, PACAP was able to reverse the inhibition of oocyte meiotic maturation caused by hypoxantine in cumulus cell-oocyte complexes (COCs) and efficiently promoted male pronuclear formation after fertilisation. PACAP was also able to induce cumulus expansion and prevent CC apoptosis. Our results demonstrated the induction of PACAP and its receptors in CCs by LH and EGF, suggesting that PACAP may play a significant role in the complex interactions of gonadotropin and growth factors during ovulation and fertilisation.

The role of mitochondria from mature oocyte to viable blastocyst

The oocyte requires a vast supply of energy after fertilization to support critical events such as spindle formation, chromatid separation, and cell division. Until blastocyst implantation, the developing zygote is dependent on the existing pool of mitochondria. That pool size within each cell decreases with each cell division. Mitochondria obtained from oocytes of women of advanced reproductive age harbor DNA deletions and nucleotide variations that impair function. The combination of lower number and increased frequency of mutations and deletions may result in inadequate mitochondrial activity necessary for continued embryo development and cause pregnancy failure. Previous reports suggested that mitochondrial activity within oocytes may be supplemented by donor cytoplasmic transfer at the time of intracytoplasmic sperm injection (ICSI). Those reports showed success; however, safety concerns arose due to the potential of two distinct populations of mitochondrial genomes in the offspring. Mitochondrial augmentation of oocytes is now reconsidered in light of our current understanding of mitochondrial function and the publication of a number of animal studies. With a better understanding of the role of this organelle in oocytes immediately after fertilization, blastocyst and offspring, mitochondrial augmentation may be reconsidered as a method to improve oocyte quality.

Cellular and molecular basis for endometriosis-associated infertility

Endometriosis is a gynecological disease characterized by the presence of endometrial glandular epithelial and stromal cells growing in the extra-uterine environment. The disease afflicts 10%–15% of menstruating women causing debilitating pain and infertility. Endometriosis appears to affect every part of a woman’s reproductive system including ovarian function, oocyte quality, embryo development and implantation, uterine function and the endocrine system choreographing the reproductive process and results in infertility or spontaneous pregnancy loss. Current treatments are laden with menopausal-like side effects and many cause cessation or chemical alteration of the reproductive cycle, neither of which is conducive to achieving a pregnancy. However, despite the prevalence, physical and psychological tolls and health care costs, a cure for endometriosis has not yet been found. We hypothesize that endometriosis causes infertility via multifaceted mechanisms that are intricately interwoven thereby contributing to our lack of understanding of this disease process. Identifying and understanding the cellular and molecular mechanisms responsible for endometriosis-associated infertility might help unravel the confounding multiplicities of infertility and provide insights into novel therapeutic approaches and potentially curative treatments for endometriosis.

Markers of stem cells in human ovarian granulosa cells: is there a clinical significance in ART?

Background

The purpose of the study was to determine the incidence of gene expression of Oct-4 and DAZL, which are typical markers for stem cells, in human granulosa cells during ovarian stimulation in women with normal FSH levels undergoing IVF or ICSI and to discover any clinical significance of such expression in ART.

Methods

Twenty one women underwent ovulation induction for IVF or ICSI and ET with standard GnRH analogue-recombinant FSH protocol. Infertility causes were male and tubal factor. Cumulus–mature oocyte complexes were denuded separately and granulosa cells were analyzed for each patient separately using quantitative reverse-transcription–polymerase chain reaction analysis for Oct-4 and DAZL gene expression with G6PD gene as internal standard.

Results

G6PD and Oct-4 mRNA was detected in the granulosa cells in 47.6% (10/21). The median of Oct-4 mRNA/G6PD mRNA was 1.75 with intra-quarteral range from 0.10 to 98.21. The OCT-4 mRNA expression was statistically significantly correlated with the number of oocytes retrieved; when the Oct-4 mRNA expression was higher, then more than six oocytes were retrieved (p=0.037, Wilcoxon rank-sum). No detection of DAZL mRNA was found in granulosa cells. There was no additional statistically significant correlation between the levels of Oct-4 expression and FSH basal levels or estradiol peak levels or dosage of FSH for ovulation induction. No association was found between the presence or absence of Oct-4 mRNA expression in granulosa cells and ovarian response to gonadotropin stimulation. Also, no influence on pregnancy was observed between the presence or absence of Oct-4 mRNA expression in granulosa cells or to its expression levels accordingly.

Conclusions

Expression of OCT-4 mRNA, which is a typical stem cell marker and absence of expression of DAZL mRNA, which is a typical germ cell marker, suggest that a subpopulation of luteinized granulosa cells in healthy ovarian follicles (47.6%) consists of stem cells, which are not originated from primordial germ cells. Absence of Oct-4 gene expression in more than half of the cases means probably the end of the productive journey of these cells, towards the oocyte.

Expression of antiapoptosis gene survivin in luteinized ovarian granulosa cells of women undergoing IVF or ICSI and embryo transfer: clinical correlations

BACKGROUND

The purpose of the study was to determine the incidence of survivin gene expression in human granulosa cells during ovarian stimulation in Greek women with normal FSH levels, undergoing IVF or ICSI and to discover any correlation between levels of gene expression and clinical parameters, efficacy of ovulation or outcomes of assisted reproduction.

METHODS

Twenty nine women underwent ovulation induction for IVF or ICSI and ET with standard GnRH analogue-recombinant FSH protocol. Infertility causes were male and tubal factor. Cumulus-mature oocyte complexes were denuded and the granulosa cells were analyzed for each patient separately using quantitative reverse transcription polymerase chain reaction analysis for survivin gene expression with internal standard the ABL gene.

RESULTS

The ABL and survivin mRNA were detected in granulosa cells in 93.1%. The expression levels of survivin were significantly lower in normal women (male infertility factor) compared to women with tubal infertility factor (p = 0.007). There was no additional statistically significant correlation between levels of survivin expression and estradiol levels or dosage of FSH for ovulation induction or number of dominant follicles aspirated or number of retrieved oocytes or embryo grade or clinical pregnancy rates respectively.

CONCLUSIONS

High levels of survivin mRNA expression in luteinized granulosa cells in cases with tubal infertility seem to protect ovaries from follicular apoptosis. A subpopulation of patients with low levels of survivin mRNA in granulosa cells might benefit with ICSI treatment to bypass possible natural barriers of sperm-oocyte interactions.

Dose-dependent effects of gonadotropin on oocyte developmental competence and apoptosis

The aim of the present study was to evaluate the effect of gonadotropins (Gn) on oocyte maturation, developmental competence and apoptosis in an animal model. Bovine cumulus-oocyte complexes (COCs) were matured for 24 h in media supplemented with varying concentrations of Bravelle (B), B + Menopur (B+M) or B + Repronex (B + R) (Ferring Pharmaceuticals, Parsiappany, NJ, USA). Then, nuclear maturation, embryo development, and apoptosis in cumulus cells and oocytes were evaluated. Low to moderate Gn concentrations (75-75 00 mIUmL(-1)) effectively improved nuclear maturation and in vitro development. Higher concentrations of Gn (75 000 mIUmL(-1)) did not have any added beneficial effects and nuclear maturation and blastocyst rates in the presence of these concentrations were comparable to control (P>0.05). Most COCs showed slight apoptosis when exposed to 75, 750 and 75 00 mIUmL(-1) Gn; however, when the concentration was increased to 75 000 mIUmL(-1), the proportion of moderately apoptotic COCs increased. In conclusion, extremely high concentrations of Gn have detrimental effects on oocyte nuclear maturation and embryo development and increase apoptosis in cumulus cells, suggesting the importance of judicious use of Gn in assisted reproductive technologies (ART).

Differential granulosa cell gene expression in young women with diminished ovarian reserve

OBJECTIVE

To investigate if a diagnosis of diminished ovarian reserve (DOR) is associated with a differential gene profile of ovarian granulosa cells (GCs) in infertile women undergoing in vitro fertilization (IVF).

DESIGN

Prospective Cohort Study.

SETTING

Academic IVF Program.

PATIENTS

Infertile women <38 years were prospectively enrolled into 2 groups: normal ovarian reserve (NOR, follicle-stimulating hormone [FSH] < 10 mIU/mL, n = 4) and DOR (FSH ≥ 10.0 mIU/mL, n = 4).

INTERVENTIONS

Cumulus (C) and mural (M) GCs were isolated at egg retrieval; messenger RNA was extracted and transcribed.

MAIN OUTCOME MEASURE(S)

Differential gene expression in cerebellar granule cells (CGCs) in the 2 groups was assessed by cDNA microarray. Microarray findings were validated by quantitative real-time polymerase chain reaction (qRTPCR) in CGCs and explored in multinucleated giant cells (MGCs).

RESULTS

Of the 1256 differentially regulated genes identified in CGCs of women with DOR, the insulin-like growth factor (IGF) family was a biologically relevant gene family of a priori interest. Downregulation of IGF1 and IGF2 ligands (-3.28- and -2.54-fold, respectively), and their receptors, (-3.53- and -1.32-fold downregulation of IGF1R and IGF2R, respectively) was identified in luteinized CGCs in women with DOR compared to those with NOR. Downregulation of both IGF1 and IGF 2 ligands (-4.35- and 3.89-fold, respectively) was furthermore observed in MGCs in women with DOR compared to those with NOR; no differences in the expression of respective receptors were however observed in MGCs in the 2 groups.

CONCLUSIONS

Components of the IGF gene family are downregulated in GCs of women with DOR. These findings maybe contributory to the reproductive compromise observed in women with DOR, and merit further exploration.

[Follicular atresia: Its features as predictive markers for the outcome of assisted reproduction]

The mammalian ovary is an extremely dynamic organ in which excessive or defective follicles are rapidly and effectively eliminated continuously throughout reproductive life. More than 99 % of follicles disappear, due to apoptosis of granulosa cells, and only one or few of the surviving follicles successfully complete the path to ovulation. The balance between signals for cell death and survival determines the destiny of the follicles. In this review, we provide a short overview of the role of programmed cell death essentially in adult folliculogenesis. We highlight molecules involved in regulation of granulosa cell apoptosis. We further discuss the potential use of scores for apoptosis in granulosa cells and characteristics of follicular fluid as prognostic markers for predicting the outcome of assisted reproduction.

Mitochondrial dysfunction and apoptosis in cumulus cells of type I diabetic mice

Impaired oocyte quality has been demonstrated in diabetic mice; however, the potential pathways by which maternal diabetes exerts its effects on the oocyte are poorly understood. Cumulus cells are in direct contact with the oocyte via gap junctions and provide essential nutrients to support oocyte development. In this study, we investigated the effects of maternal diabetes on the mitochondrial status in cumulus cells. We found an increased frequency of fragmented mitochondria, a decreased transmembrane potential and an aggregated distribution of mitochondria in cumulus cells from diabetic mice. Furthermore, while mitochondrial biogenesis in cumulus cells was induced by maternal diabetes, their metabolic function was disrupted as evidenced by lower ATP and citrate levels. Moreover, we present evidence suggesting that the mitochondrial impairments induced by maternal diabetes, at least in part, lead to cumulus cell apoptosis through the release of cytochrome c. Together the deleterious effects on cumulus cells may disrupt trophic and signaling interactions with the oocyte, contributing to oocyte incompetence and thus poor pregnancy outcomes in diabetic females.

The human oocyte and cumulus cells relationship: new insights from the cumulus cell transcriptome

It is widely recognized that bi-directional communication exists between the human oocyte and cumulus cells (CCs) which is essential for the production of competent oocytes. CCs originate from granulosa cells (GCs) which differentiate into mural GCs and CCs during follicular antrum formation. CCs are biologically distinct from other follicular cells and perform specialized roles, transmitting signals within the ovary and supporting oocyte growth and maturation during the later stages of follicular development. This review details the results of transcriptomic analysis of CCs and considers what this data can teach us about the biology of CCs and their interactions with the oocyte. We also explore the potential for the gene expression data to reveal novel biomarkers of oocyte quality and assist the optimization of assisted reproductive technologies.

Maternal diabetes and oocyte quality

Maternal diabetes has been demonstrated to adversely affect preimplantation embryo development and pregnancy outcomes. Emerging evidence has implicated that these effects are associated with compromised oocyte competence. Several developmental defects during oocyte maturation in diabetic mice have been reported over past decades. Most recently, we further identified the structural, spatial and metabolic dysfunction of mitochondria in oocytes from diabetic mice, suggesting the impaired oocyte quality. These defects in the oocyte may be maternally transmitted to the embryo and then manifested later as developmental abnormalities in preimplantation embryo, congenital malformations, and even metabolic disease in the offspring. In this paper, we briefly review the effects of maternal diabetes on oocyte quality, with a particular emphasis on the mitochondrial dysfunction. The possible connection between dysfunctional oocyte mitochondria and reproductive failure of diabetic females, and the mechanism(s) by which maternal diabetes exerts its effects on the oocyte are also discussed.

N-acetyl cysteine: could it be an effective adjuvant therapy in ICSI cycles? A preliminary study

This randomized controlled trial tested the hypothesis that addition of N-acetyl cysteine (NAC) can increase the probability of pregnancy in intracytoplasmic sperm injection (ICSI) cycles using the long agonist protocol. Women undergoing ICSI cycles due to male factor were randomly assigned to receive either long protocol (group A, 38 women) or long protocol plus NAC (group B, 38 women). Clinical pregnancy was the primary outcome. Granulosa cell apoptosis, fertilization rate, number of grade-one embryos and ongoing pregnancy were the secondary outcomes. Clinical pregnancy rate was insignificantly higher in NAC group (52.6%) than control (47.4%). Early and late apoptosis were also insignificantly lower in group B than in group A. Irrespective of the used protocol, there was significant negative correlation between both early and late apoptosis and fertilization rate (both P<0.001) and the number of good-quality embryos (P=0.007 and P<0.001, respectively). Pregnant patients had significantly lower early and late apoptosis than those who didn't achieve pregnancy (P<0.001). In conclusion, NAC supplementation did not significantly increase the probability of pregnancy in ICSI cycles using long agonist protocol. It appears that granulosa cell apoptosis may be an important prognosticator for ICSI cycle outcome.

Reproductive aging is associated with altered gene expression in human luteinized granulosa cells

Declining reproductive success with aging is attributable to qualitative and quantitative deterioration in oocytes, which are nurtured by granulosa cells (GCs). This prospective study assesses whether reproductive aging is accompanied by differential gene expression in luteinized GCs from in vitro fertilization (IVF) patients. Women with nonovarian infertility etiologies were categorized as younger (< or =30, n = 3) or older (> or =40, n = 3). During oocyte retrieval, mural GCs were isolated; messenger RNA (mRNA) was extracted and transcribed for complementary DNA (cDNA) microarray analysis. Differential gene expression was confirmed by real-time polymerase chain reaction (PCR). Analysis revealed 120 genes were differentially expressed. Three genes were upregulated and 117 were downregulated (including interleukin [IL]-1beta, IL-1R2, and IL-6R) in GCs of older versus younger patients. Our data provide evidence of downregulation in IL-1 and IL-6 gene families in luteinized GCs with advancing age. Given previously recognized roles for the IL gene family in folliculogenesis and ovulation, our findings may partly explain ovulatory and luteal dysfunctions associated with reproductive aging.