Effect of apoptosis and reactive oxygen species production in human granulosa cells on oocyte fertilization and blastocyst development

Gonadotropin inhibitory hormone (GnIH) induces glucose metabolism disorders and ovarian dysfunction in ovarian white follicles of hens

Energy metabolism is crucial for reproduction, and disturbances in glucose metabolism are closely associated with reproductive disorders. The gonadotropin inhibitory hormone (GnIH) plays a crucial role in reproduction and glucose homeostasis in both birds and mammals. However, its specific effects on glucose metabolism-associated ovarian dysfunction in hens remain uncharacterized. In this study, we investigated the effects of GnIH on ovarian function and glucose homeostasis in hens using combined in vivo and in vitro approaches. Our results showed that GnIH and its receptor, GPR147, are predominantly expressed in white follicles. Continuous GnIH injection significantly reduced the ovarian index and the number of prehierarchical follicles, concurrently suppressing Fshr and LHr expression in white follicles. Additionally, metabolomic analyses indicate changes in key glucose metabolism pathways, indicating a regulatory role of GnIH in glucose metabolism. To validate our metabolomics findings, the effects of GnIH on glucose homeostasis in ovarian white follicles and granulosa cells (GCs) were further investigated through in vivo and in vitro studies. The results demonstrated that GnIH enhanced glucose transport, glycolysis and glycogen synthesis, but concurrently induced insulin resistance, oxidative stress, and mitochondrial dysfunction, ultimately leading to reduced energy levels and apoptosis in ovarian tissues. In summary, our study reveals that GnIH contributes to ovarian dysfunction via glucose metabolism dysregulation in hens, suggesting its potential as a therapeutic target for metabolic disorder-associated ovarian impairment in chickens.

miR-107 suppresses porcine granulosa cell proliferation and estradiol synthesis while promoting apoptosis via targeting PTGS2

The proliferation, steroid metabolism, and apoptosis of porcine ovarian granulosa cells (GCs) are critical for follicular development. MicroRNAs (miRNAs) are small endogenous RNAs that regulate gene expression post-transcriptionally and modulate signaling networks involved in various cellular processes. In this study, we identify miR-107, a conserved miRNA, as a key regulator of porcine follicle development through its effects on GCs proliferation, steroid metabolism, and apoptosis. Our findings demonstrate that miR-107 suppresses GCs proliferation and estradiol synthesis while promoting apoptosis. Mechanistically, miR-107 exerts its regulatory effects by targeting Prostaglandin-Endoperoxide Synthase 2 (PTGS2), binding to the 3' untranslated region (3'-UTR) of its mRNA. Overexpression of PTGS2 positively regulates porcine GCs function, significantly enhancing cell proliferation and steroid synthesis, reducing apoptosis, and increasing the protein levels of HSD3B1 and CYP19A1, which are key members of the ovarian steroidogenesis signaling pathway. These findings highlight the role of miR-107 in regulating porcine follicular development and underscore its potential as a molecular marker for influencing follicle growth and reproductive efficiency.

Bisphenol a Disrupts Steroidogenesis and Induces Apoptosis in Human Granulosa Cells Cultured In Vitro

Bisphenol A (BPA) is a common synthetic chemical compound classified as an endocrine disruptor. It affects multiple physiological systems in the body, including the female reproductive system, particularly granulosa cells (GCs) in the ovaries, where steroidogenesis occurs. This study investigated the impact of various BPA concentrations (environmentally relevant concentrations of 0.001 µM and 0.1 µM and toxicological concentration of 100 µM) and exposure times (24 and 72 h) on cell viability and counts and in vitro production of estradiol and progesterone in human GCs collected from waste follicular fluid of IVF patients. Gene expression analysis of 182 genes associated with steroidogenesis and apoptosis was performed in GCs using PCR arrays, followed by protein expression analysis by Western blot. Our results demonstrate that after longer BPA exposure (72 h), a higher concentration of BPA (100 µM) negatively affects the cellular viability and counts and significantly alters steroid hormone biosynthesis in vitro, leading to reduced concentrations of estradiol and progesterone in the culture medium. We found that all BPA concentrations altered the expression of different steroidogenesis- and apoptosis-related genes in GCs. At 0.001 μM, BPA exposure decreased the expression of TRIM25, UGT2B15, CASP3, and RPS6KA3 genes and increased the expression of NR6A1 and PPID genes. At 0.1 μM, BPA increased the expression of AR, HSD3B1, BID, IKBKG, and PPID genes while reducing the expression of TRIM25 and CASP3 genes. At the highest concentration of 100 μM, BPA upregulated the expression of AR, GPER30, BID, IKBKG, and PPID genes and downregulated the expression of FOXO1 and UGT2B15 genes. These results highlight BPA's concentration-specific effects on steroidogenesis and apoptosis and show its potential to compromise GC function, with possible negative implications for female fertility and ovarian health, even at environmentally relevant concentrations.

Mitophagy Protects Against Cisplatin-Induced Injury in Granulosa Cells

Cisplatin, a widely used chemotherapeutic agent, is known to induce premature ovarian insufficiency (POI) and infertility in women of reproductive age. Among the contributing factors, cisplatin-induced apoptosis of ovarian granulosa cells is considered a primary driver of ovarian dysfunction; however, the underlying mechanisms remain incompletely understood. In this study, we investigated the cytotoxicity of cisplatin on the granulosa cell line KGN in vitro and explored the associated mechanisms. Our results demonstrate that cisplatin induces KGN cell apoptosis in a dose-dependent manner and impairs mitochondrial function, as evidenced by excessive ROS production, membrane potential collapse, and reduced ATP synthesis. Mitophagy, a key cellular self-protection mechanism that selectively removes damaged mitochondria, was activated following cisplatin treatment, mitigating its detrimental effects on KGN cells. Activation of mitophagy with urolithin A (UA) ameliorated cisplatin-induced mitochondrial dysfunction and apoptosis, whereas inhibition of mitophagy with cyclosporine A (CsA) exacerbated these effects. Furthermore, pretreatment with the clinical drug melatonin significantly enhanced mitophagy, effectively attenuating cisplatin-induced apoptosis in KGN cells. This study proposes a novel therapeutic strategy for patients undergoing tumor chemotherapy, aiming to preserve treatment efficacy while reducing the adverse effects of chemotherapeutic agents on ovarian function, thereby improving patients' quality of life.

Exploring melatonin's multifaceted role in female reproductive health: From follicular development to lactation and its therapeutic potential in obstetric syndromes

BACKGROUND

Melatonin is mainly secreted by the pineal gland during darkness and regulates biological rhythms through its receptors in the suprachiasmatic nucleus of the hypothalamus. In addition, it also plays a role in the reproductive system by affecting the function of the hypothalamic-pituitary-gonadal axis, and by acting as a free radical scavenger thus contributing to the maintenance of the optimal physiological state of the gonads. Besides, melatonin can freely cross the placenta to influence fetal development. However, there is still a lack of overall understanding of the role of melatonin in the reproductive cycle of female mammals.

AIM OF REVIEW

Here we focus the role of melatonin in female reproduction from follicular development to delivery as well as the relationship between melatonin and lactation. We further summarize the potential role of melatonin in the treatment of preeclampsia, polycystic ovary syndrome, endometriosis, and ovarian aging.

KEY SCIENTIFIC CONCEPTS OF REVIEW

Understanding the physiological role of melatonin in female reproductive processes will contribute to the advancement of human fertility and reproductive medicine research.

B cell translocation gene 2 expression levels in human granulosa cells is negatively associated with in vitro fertilization/intracytoplasmic sperm injection outcomes: a pilot study

PURPOSE

This study aimed to monitor the expression of B-cell translocation gene 2 (BTG2) in granulosa cells of patients undergoing IVF/ICSI with respect blastocyst quality outcomes.

METHODS

We recruited 181 women undergoing IVF/ICSI cycles for infertility. Granulosa cells were extracted from follicular fluid. BTG2 expression level of granulosa cells were stratified into tertiles (low, middle, and high), and the patients of each tertile were compared for outcome indicators by Kruskal-Wallis analysis. Spearman's correlation analyses were used to evaluate the correlation between BTG2 mRNA levels and outcome indicators. Generalized linear models and generalized additive models with smoothing splines were used to adjust for potential confounders.

RESULTS

Patients in the low BTG2 tertile had higher oocyte retrieval, fertilization, blastocyst formation, and high-quality blastocyst rates than those in the high BTG2 tertile. Patients in the high BTG2 tertile exhibited a downward trend in implantation and clinical pregnancy rates compared to those in the low or middle BTG2 tertiles, whereas the early pregnancy loss rate showed an upward trend, although the difference was not significant. After adjusting for confounding factors, the expression level of BTG2 was negatively correlated with oocyte retrieval, blastocyst formation, and high-quality blastocyst rates. Stratified analysis of AMH > 4 ng/ml showed elevated BTG2 expression was associated with reduced oocyte retrieval, fertilization, cleavage, blastocyst formation, and high-quality blastocyst rates. No differences in these outcomes were observed in patients with AMH ≤ 4 ng/ml.

CONCLUSION

In women with high AMH levels (> 4 ng/ml) elevated BTG2 expression in granulosa cells was associated with poor quality blastocyst outcomes.

Vitamins, Coenzyme Q10, and Antioxidant Strategies to Improve Oocyte Quality in Women with Gynecological Cancers: A Comprehensive Review

BACKGROUND

Gynecological cancers, including ovarian, cervical, and endometrial cancers, significantly affect both survival and reproductive health in women. Cancer treatments such as chemotherapy and radiotherapy can impair ovarian function, reducing oocyte quality and fertility potential.

OBJECTIVE

This review aims to evaluate how vitamins and antioxidants can enhance fertility and fertility preservation outcomes for women diagnosed with gynecological cancers, particularly in the context of assisted reproductive technologies (ART). Standard treatments for these cancers, including hysterectomy, bilateral salpingo-oophorectomy, radiation, and chemotherapy, often compromise ovarian function and oocyte quality. This review focuses on the potential role of these interventions in improving oocyte quality, thereby supporting successful fertility preservation and ART outcomes.

METHODS

A comprehensive narrative review of the current literature was conducted, examining the effects of vitamins A, C, D3, E, and Coenzyme Q10 on oocyte quality, particularly in the context of oxidative stress and inflammation induced by cancer and its treatments.

RESULTS

The evidence suggests that certain vitamins and antioxidants may mitigate oxidative damage and enhance oocyte quality. Vitamin A supports cumulus-oocyte complex integrity, while vitamins C and E act as potent antioxidants, reducing oxidative stress in ovarian tissues. Vitamin D3 enhances ovarian reserve markers and modulates inflammatory cytokines. Coenzyme Q10 improves mitochondrial function and reduces DNA damage, increasing oocyte viability and fertilization potential.

CONCLUSIONS

The incorporation of specific vitamins and antioxidants into fertility preservation strategies may enhance oocyte quality in women with gynecological cancers. Although the preliminary findings are promising, further research is needed to determine optimal dosages and establish standardized protocols for clinical use.

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.

Follicular fluid composition and reproductive outcomes of women with polycystic ovary syndrome undergoing in vitro fertilization: A systematic review

Polycystic ovary syndrome (PCOS) is recognized as one of the most prevalent endocrinopathy in women at reproductive age. As affected women tend to have poorer assisted reproductive technology (ART) outcomes, PCOS has been suggested to endanger oocyte quality and competence development. The aim of this systematic review was to summarize the available evidence on how the follicular fluid (FF) profile of women with PCOS undergoing in vitro fertilization (IVF) treatment differs from the FF of normo-ovulatory women. For that, an electronic search in PubMed and Web of Science databases was conducted (up to December 2021). The Preferred Reporting Items for Systematic Reviews and Meta-Analyses - PRISMA guidelines were followed, and the Newcastle-Ottawa Scale was used to assess the risk of bias in the included studies. Data retrieved from papers included (n=42), revealed that the FF composition of women with PCOS compared to those without PCOS predominantly diverged at the following molecular classes: oxidative stress, inflammatory biomarkers, growth factors and hormones. Among those biomarkers, some were proposed as being closely related to pathophysiological processes, strengthening the hypothesis that low-grade inflammation and oxidative stress play a critical role in the pathogenesis of PCOS. Notwithstanding, it should be noticed that the available data on PCOS FF fingerprints derives from a limited number of studies conducted in a relatively small number of subjects. Furthermore, phenotypic heterogeneity of PCOS hampers wider comparisons and weakens putative conclusions. Therefore, future studies should be focused at comparing well characterized patient subgroups according to phenotypes.

Three-dimensional architecture of granulosa cell derived from oocyte cumulus complex, revealed by FIB-SEM

The oocyte cumulus complex is mainly composed of an oocyte, the perivitelline space, zona pellucida and numerous granulosa cells. The cumulus granulosa cells (cGCs) provide a particularly important microenvironment for oocyte development, regulating its growth, maturation and meiosis. In this study, we studied the internal structures and cell-to-cell connections of mouse cGCs using focused ion beam scanning electron microscopy (FIB-SEM). We reconstructed three-dimensional models to display characteristic connections between the oocyte and cGCs, and to illustrate various main organelles in cGCs together with their interaction relationship. A special form of cilium identified in granulosa cell was never reported in previous literature.

Plasma exosomes and contained MiRNAs affect the reproductive phenotype in polycystic ovary syndrome

Anovulation is the main feature of infertile women with polycystic ovary syndrome (PCOS), and there is very limited understanding of the role of plasma exosomes and miRNAs in it. To identify the effect of PCOS patients' plasma exosomes and exosomal miRNAs, we isolated plasma exosomes of PCOS patients and normal women and injected into 8-week-old ICR female mice via tail vein. The changes in estrus cycle, serum hormone levels, and ovarian morphology were observed. KGN cells were cultured and transfected with mimics and inhibitors of differentially expressed exosomal miRNAs (miR-18a-3p, miR-20b-5p, miR-106a-5p, miR-126-3p, and miR-146a-5p) and then tested for steroid hormone synthesis, proliferation, and apoptosis. The results showed that female ICR mice injected with plasma exosomes from PCOS patients presented ovarian oligo-cyclicity. Hormone synthesis and proliferation of granulosa cells were affected by differentially expressed PCOS plasma-derived exosomal miRNAs, of which miR-126-3p having the most evident effect. MiR-126-3p affected the proliferation of granulosa cells by inhibiting PDGFRβ and its downstream PI3K-AKT pathway. Our results demonstrated plasma exosomes and contained miRNAs in PCOS patients affect the estrus cycle of mice, hormone secretion, and proliferation of granulosa cells. This study provides a novel understanding about the function of plasma exosomes and exosomal miRNAs in PCOS.

The environment and female reproduction: Potential mechanism of cadmium poisoning to the growth and development of ovarian follicle

Cadmium (Cd) is ubiquitous in our environment and can easily bioaccumulate into the organism after passage through the respiratory and digestive tracts. Long-term exposure to Cd can result in the significant bioaccumulation in organism because of its long biological high-life (10-30 years), which exerts irreversible damages on the health of animals and humans. Although there are increased evidence of impeding the normal function of female reproduction resulted from Cd exposure, the mechanism of the negative action of Cd on the growth and development of ovarian follicle remains enigmatic. Thus, the purpose of the presented study is to summarize available literature which describing Cd-related toxicity involved in the adverse effects on the growth and development of the ovarian follicle. In conclusion, it is suggested that Cd causes damage to the folliculogenesis of mammalians, which results in the decline in the number and quality of ovulated oocytes and the failure in the fertilization. The mechanism behinds that may be linked to the interference to the production of reproductive hormones and the augment of reactive oxygen species (ROS). Furthermore, the enhanced ROS, in turn, impairs various molecules including proteins, lipids and DNA, as well as the balance of the antioxidant defense system, mitochondrial homeostasis, endoplasmic reticulum, autophagy and epigenetic modification. This review is expected to elaborate the toxic mechanism of Cd exposure to the growth and development of ovarian follicles and provide essential remediation strategies to alleviate the damage of Cd to female reproductive health.

Oocyte metabolic function, lipid composition, and developmental potential are altered by diet in older mares

Dietary supplementation is the most feasible method to improve oocyte function and developmental potential in vivo. During three experiments, oocytes were collected from maturing, dominant follicles of older mares to determine whether short-term dietary supplements can alter oocyte metabolic function, lipid composition, and developmental potential. Over approximately 8 weeks, control mares were fed hay (CON) or hay and grain products (COB). Treated mares received supplements designed for equine wellness and gastrointestinal health, flaxseed oil, and a proprietary blend of fatty acid and antioxidant support (reproductive support supplement (RSS)) intended to increase antioxidant activity and lipid oxidation. RSS was modified for individual experiments with additional antioxidants or altered concentrations of n-3 to n-6 fatty acids. Oocytes from mares supplemented with RSS when compared to COB had higher basal oxygen consumption, indicative of higher aerobic metabolism, and proportionately more aerobic to anaerobic metabolism. In the second experiment, oocytes collected from the same mares prior to (CON) and after approximately 8 weeks of RSS supplementation had significantly reduced oocyte lipid abundance. In the final experiment, COB was compared to RSS supplementation, including RSS modified to proportionately reduce n-3 fatty acids and increase n-6 fatty acids. The ability of sperm-injected oocytes to develop into blastocysts was higher for RSS, regardless of fatty acid content, than for COB. We demonstrated that short-term diet supplementation can directly affect oocyte function in older mares, resulting in oocytes with increased metabolic activity, reduced lipid content, and increased developmental potential.

Exosomal miR-143-3p derived from follicular fluid promotes granulosa cell apoptosis by targeting BMPR1A in polycystic ovary syndrome

Polycystic ovary syndrome (PCOS) is an endocrine disorder that occurs in women of reproductive age. Anovulation caused by abnormal follicular development is still the main characteristic of PCOS patients with infertile. Granulosa cell (GC) is an important part of the follicular microenvironment, the dysfunction of which can affect follicular development. Increasing evidence indicates that exosomal miRNAs derived from the follicular fluid (FF) of patients play critical roles during PCOS. However, which follicular fluid-derived exosomal miRNAs play a pivotal role in controlling granulosa cell function and consequently follicular development remain largely unknown, as does the underlying mechanism. Herein, we showed that miR-143-3p is highly expressed in the follicular fluid exosomes of patients with PCOS and can be delivered into granulosa cells. Furthermore, functional experiments showed that translocated miR-143-3p promoted granulosa cell apoptosis, which is important in follicle development. Mechanistically, BMPR1A was identified as a direct target of miR-143-3p. Overexpression of BMPR1A reversed the effects of exosomal miR-143-3p on GC apoptosis and proliferation by activating the Smad1/5/8 signaling pathway. These results demonstrate that miR-143-3p-containing exosomes derived from PCOS follicular fluid promoted granulosa cell apoptosis by targeting BMPR1A and blocking the Smad1/5/8 signaling pathway. Our findings provide a novel mechanism underlying the roles of exosomal-miRNAs in the follicular fluid of PCOS patients and facilitate the development of therapeutic strategies for PCOS.

The Effects of Organophosphate Esters Used as Flame Retardants and Plasticizers on Granulosa, Leydig, and Spermatogonial Cells Analyzed Using High-Content Imaging

The replacement of regulated brominated flame retardants and plasticizers with organophosphate esters (OPEs) has led to their pervasive presence in the environment and in biological matrices. Further, there is evidence that exposure to some of these chemicals is associated with reproductive toxicity. Using a high-content imaging approach, we assessed the effects of exposure to 9 OPEs on cells related to reproductive function: KGN human granulosa cells, MA-10 mouse Leydig cells, and C18-4 mouse spermatogonial cells. The effects of OPEs were compared with those of 2,2',4,4'-tetrabromodiphenyl ether (BDE-47), a legacy brominated flame retardant. Alterations in several important cell features, including cell survival, mitochondrial dynamics, oxidative stress, lysosomes, and lipid droplets, were analyzed. Most of the OPEs tested displayed higher cytotoxicity than BDE-47 in all 3 cell lines. Effects on phenotypic parameters were specific for each cell type. Several OPEs increased total mitochondria, decreased lysosomes, increased the total area of lipid droplets, and induced oxidative stress in KGN cells; these endpoints were differentially affected in MA-10 and C18-4 cells. Alterations in cell phenotypes were highly correlated in the 2 steroidogenic cell lines for a few triaryl OPEs. Potency ranking using 2 complementary approaches, Toxicological Prioritization Index analyses and the lowest benchmark concentration/administered equivalent dose method, revealed that while most of the OPEs tested were more potent than BDE-47, others showed little to no effect. We propose that these approaches serve as lines of evidence in a screening strategy to identify the potential for reproductive and endocrine effects of emerging chemicals and assist in regulatory decision-making.

Redox Regulation and Oxidative Stress in Mammalian Oocytes and Embryos Developed In Vivo and In Vitro

Oocytes and preimplantation embryos require careful regulation of the redox environment for optimal development both in vivo and in vitro. Reactive oxygen species (ROS) are generated throughout development as a result of cellular metabolism and enzyme reactions. ROS production can result in (i) oxidative eustress, where ROS are helpful signalling molecules with beneficial physiological functions and where the redox state of the cell is maintained within homeostatic range by a closely coupled system of antioxidants and antioxidant enzymes, or (ii) oxidative distress, where excess ROS are deleterious and impair normal cellular function. in vitro culture of embryos exacerbates ROS production due to a range of issues including culture-medium composition and laboratory culture conditions. This increase in ROS can be detrimental not only to assisted reproductive success rates but can also result in epigenetic and genetic changes in the embryo, resulting in transgenerational effects. This review examines the effects of oxidative stress in the oocyte and preimplantation embryo in both the in vivo and in vitro environment, identifies mechanisms responsible for oxidative stress in the oocyte/embryo in culture and approaches to reduce these problems, and briefly examines the potential impacts on future generations.

Clinical and Molecular Effects of GnRH Agonist and Antagonist on The Cumulus Cells in The In Vitro Fertilization Cycle

Background:

Gonadotropin-releasing hormone (GnRH) analogues have been extensively utilized in the ovarian stimulation cycle for suppression of endogenous rapid enhancement of luteinizing hormone (LH surge). Exclusive properties and functional mechanisms of GnRH analogues in in vitro fertilization (IVF) cycles are clearly described. This study was performed to evaluate clinical and molecular impacts of the GnRH agonist and antagonist protocols in IVF cycles. For This purpose, gene expression of cumulus cells (CCs) as well as clinical and embryological parameters were evaluated and compared between two groups (GnRH agonistand antagonist) during the IVF cycle.

Materials and Methods:

Twenty-one infertile individuals were enrolled in this study. Subjects were selected from two groups of GnRH agonist(n=10) treated patients and GnRH antagonist (n=11) treated individuals. The defined clinical embryological parameters were compared between the two groups. Expression of BAX, BCL-2, SURVIVIN, ALCAM, and VCAN genes were assessed in the CCs of the participants using the real-time polymerase chain reaction (PCR) technique.

Results:

The mean number of cumulus oocyte complex (COC), percentage of metaphase II (MII) oocytes, grade A embryo and clinical parameters did not show noticeable differences between the two groups. BAX gene expression in the CCs of the group treated with GnRH agonist was remarkably higher than those received GnRH antagonist treatment (P<0.001). The mRNA expression of BCL-2 and ALCM genes were considerably greater in the CCs of patients who underwent antagonist protocol in comparison to the group that received agonist protocol (P<0.001).

Conclusion:

Despite no considerable difference in the oocyte quality, embryo development, and clinical outcomes between the group treated with GnRH agonist and the one treated with antagonist protocol, the GnRH antagonist protocol was slightly more favorable. However, further clinical studies using molecular assessments are required to elucidate this controversial subject.

Expression of mRNAs for pro-and anti-apoptotic factors in granulosa cells and follicular fluid of women undergoing in vitro fertilization. A pilot study

Background

This observational clinical study evaluated the expression levels and predictive values of some apoptosis-related genes in granulosa cells (GCs) and follicular fluid (FF) of women undergoing in vitro fertilization (IVF).

Methods

GCs and FF were obtained at oocyte retrieval from 31 consecutive patients with heterogeneous infertility diagnosis (age: 34.3 ± 5.8 years, body mass index: 24.02 ± 3.12 kg/m2, duration of infertility: 4.2 ± 2.1 years). mRNA expression of pro-apoptotic (BAX, CASP3, CASP8) and anti-apoptotic (BCL2, AMH, AMHR, FSHR, LHR, CYP19A1) factors was determined by quantitative RT-PCR using ROCHE LightCycler 480.

Results

No significant difference in GC or FF mRNA expression of pro- and anti-apoptotic factors could be demonstrated between IVF patients with (9 patients) or without (22 patients) clinical pregnancy. Each transcript investigated was detected in FF, but their levels were markedly reduced and independent of those in GCs. The number of retrieved oocytes was positively associated with GC AMHR (r = 0.393, p = 0.029), but the day of embryo transfer was negatively associated with GC LHR (r = − 0.414, p = 0.020) and GC FSHR transcripts (r = − 0.535, p = 0.002). When pregnancy positive group was analysed separately the impact of apoptosis- related gene expressions on some selected measures of IVF success could be observed. Strong positive relationship was found between gene expression levels of pro- and anti-apoptotic factors in GCs.

Conclusion

Our study provides only marginal evidences for the apoptosis dependence of IVF outcome and suggests that the apoptosis process induces adaptive increases of the anti-apoptotic gene expression to attenuate apoptosis and to protect cell survival.

NRF2-mediated signaling is a master regulator of transcription factors in bovine granulosa cells under oxidative stress condition

Transcription factors (TFs) are known to be involved in regulating the expression of several classes of genes during folliculogenesis. However, the regulatory role of TFs during oxidative stress (OS) is not fully understood. The current study was aimed to investigate the regulation of the TFs in bovine granulosa cells (bGCs) during exposure to OS induced by H₂O₂ in vitro. For this, bGCs derived from ovarian follicles were cultured in vitro till their confluency and then treated with H₂O₂ for 40 min. Twenty-four hours later, cells were subjected to various phenotypic and gene expression analyses for genes related to TFs, endoplasmic reticulum stress, apoptosis, cell proliferation, and differentiation markers. The bGCs exhibited higher reactive oxygen species accumulation, DNA fragmentation, and endoplasmic reticulum stress accompanied by reduction of mitochondrial activity after exposure to OS. In addition, higher lipid accumulation and lower cell proliferation were noticed in H₂O₂-challenged cells. The mRNA level of TFs including NRF2, E2F1, KLF6, KLF9, FOS, SREBF1, SREBF2, and NOTCH1 was increased in H₂O₂-treated cells compared with non-treated controls. However, the expression level of KLF4 and its downstream gene, CCNB1, were downregulated in the H₂O₂-challenged group. Moreover, targeted inhibition of NRF2 using small interference RNA resulted in reduced expression of KLF9, FOS, SREBF2, and NOTCH1 genes, while the expression of KLF4 was upregulated. Taken together, bovine granulosa cells exposed to OS exhibited differential expression of various transcription factors, which are mediated by the NRF2 signaling pathway.

Melatonin provides protection against cisplatin-induced ovarian damage and loss of fertility in mice

RESEARCH QUESTION

Can melatonin provide non-invasive ovarian protection against damage caused by cis-diamminedichloroplatinum (cisplatin) and preserve fertility in female cancer patients? And if so, what is the possible mechanism?

DESIGN

Athymic BALB/c nude tumour-bearing female mice were used to demonstrate whether melatonin affects the antineoplastic effect when co-administrated with cisplatin. Sexually mature and newborn C57BL/6 female mice were used to evaluate the potential effects of melatonin on the ovarian follicle pool, pregnancy rate and litter number in cisplatin-treated mice. The ovaries underwent immunohistochemical, TdT (terminal deoxynucleotidyl transferase)-mediated dUTP nick-end labelling (TUNEL) and gene array analysis to explore the underlying mechanism. In addition, granulosa cells were isolated to investigate the potential protective mechanism of melatonin.

RESULTS

Melatonin not only enhanced the anti-cancer effect of cisplatin in tumour-bearing nude mice, but also reduced ovarian toxicity and preserved long-term fertility in cisplatin-treated C57BL/6 female mice. When co-administrated, melatonin was able to reduce the DNA damage and toxic effects on lipid peroxidation in the ovaries caused by cisplatin. Specifically, melatonin was able to largely restore lipid peroxidation in granulosa cells and thus prevent ovarian follicles from being depleted.

CONCLUSIONS

Melatonin has the potential to be used as a chemotherapeutic adjuvant to simultaneously improve the outcome of anti-cancer treatment and preserve ovarian function during cisplatin chemotherapy. Notably, its properties of DNA protection and antioxidant effects on follicles may benefit female cancer survivors and prevent premature ovarian failure as well as fertility loss caused by chemotherapy.

Pro-caspase-3 is constitutively expressed in luteinized granulosa cells from women undergoing controlled ovarian stimulation for in vitro fertilization

Apoptosis regulation in luteinized granulosa cells (LGC) during assisted reproduction procedures is still controversial. Caspase-3 is a major apoptosis mediator encoded by CASP3 and formed through cleavage of its precursor pro-caspase-3. The aim of this study was to investigate the expression patterns of pro-caspase-3 (mRNA and protein) and cleaved caspase-3 in human LGC. Thirty-five women undergoing controlled ovarian stimulation for in vitro fertilization were prospectively enrolled in the study. LGC were isolated from follicular fluid during oocyte pickup and evaluated by immunocytochemistry for pro-caspase-3 and cleaved caspase-3, and by real-time PCR for CASP3 mRNA expression. We found a positive staining of pro-caspase-3 in 77 % of the LGC (95 % confidence interval [CI] 60%-84%), whereas cleaved caspase-3 was found in only 4% of the cells (95 % CI 3%-6%). The abundance of cells expressing pro-caspase-3 was independent from CASP3 mRNA levels (r = 0.24, p = 0.255) and did not correlate with the amount of cleaved caspase-3 (r = -0.24, p = 0.186). Multivariable logistic regression showed that pro-caspase-3 positivity was not influenced by clinical characteristics such as age, cause or length of infertility, antral follicle count or hormonal drugs used to induce ovulation. These findings suggest that pro-caspase-3 is constitutively expressed in LGC, allowing quick cleavage into active caspase-3 and apoptosis triggering whenever needed in the course of gonadotropin-induced follicular development.

Looking Inside the World of Granulosa Cells: The Noxious Effects of Cigarette Smoke

The detrimental implications of tobacco smoke on systemic health have been widely established during the past few decades. Nonetheless, increasing evidence has begun to shed more light on the serious impact that smoke exposure could also have on mammal reproductive health in terms of overall ovarian dysfunction and gestation. A variety of these complications seem to be causally related to specific chemical substances contained in cigarette smoke and their possible effects on ovarian tissues and cells, such as granulosa cells. Granulosa cells represent the functional unit of the ovary and are able to establish a bidirectional cross-talk relationship with the oocyte during folliculogenesis, which makes them vital for its correct growth and development. Based on these premises, the current review focuses on the presence of related smoke-induced damages in granulosa cells. Data have been grouped according to the studied tobacco constituents and the molecular pathways involved, in order to synthesize their impact on granulosa cells and fertility. Attention is further brought to the correlation between electronic cigarettes and female reproduction, although there have been no investigations so far regarding e-cigarette-related granulosa cell exposure. We summarize how tobacco constituents are able to cause alterations in the "life" of granulosa cells, ranging from luteal steroidogenesis and follicular loss to granulosa cell apoptosis and activation of the autophagic machinery. Further studies have been conducted to elucidate the relationship between lifestyle and fertility as to reduce the morbidity connected with infertility.

Esculentoside A rescues granulosa cell apoptosis and folliculogenesis in mice with premature ovarian failure

Follicular atresia is one of the main processes for the loss of granulosa cells and oocytes from the mammalian ovary and any impairment to premature ovarian failure. Large numbers of studies have demonstrated that granulosa cell apoptosis causes follicular atresia, yet the rescue of these cells remains elusive. We aimed to use Esculentoside A (3-O-b-D-glucopyranosyl-1, 4-b-D-xylopyranosyl) phytolaccagenin, a saponin extracted from Phytolacca esculenta roots, as a potential rescue agent for the apoptosis of granulosa cells. Our results revealed the rescue of normal body and ovary weights, normal ovarian histo-architecture of ovaries, and hormones levels with regular estrus cycle. Consistently, the expression of proliferating and anti-apoptotic markers, i.e. KI67 and BCL-2 in granulosa cells, was enhanced. Meanwhile, the expressions of pro-apoptotic markers, which were BAX and CASPASEs (CASPASE-9 and CASPASE-3), were prominently reduced in Esculentoside A-induced premature ovarian failure mice. Additionally, PPARγ, a potential therapeutic target, has also rescued its expression by treating the premature ovarian failure mice with Esculentoside A. Our results advocated that Esculentoside A could restore folliculogenesis in premature ovarian failure mice. Furthermore, it has the potential to be investigated as a therapeutic agent for premature ovarian failure.

MicroRNA-181a promotes follicular granulosa cell apoptosis via sphingosine-1-phosphate receptor 1 expression downregulation†

Oxidative stress induces granulosa cell (GC) apoptosis and subsequent follicular atresia. Since our previous studies indicate that microRNA-181a (miR-181a) expression is increased in GCs undergoing apoptosis, the present study was designed to define the relationship between exposure to oxidative stressors in GCs and changes in miR-181a expression and function. To achieve this, we employed an H2O2-induced in vitro model and a 3-nitropropionic acid-induced in vivo model of ovarian oxidative stress. We demonstrated that in vitro miR-181a overexpression promoted GC apoptosis in a dose-dependent manner; sphingosine-1-phosphate (S1P) significantly reversed both H2O2-induced and miR-181a-induced apoptosis in GCs. Moreover, we identified sphingosine-1-phosphate receptor 1 (S1PR1), a critical receptor of S1P, as a novel target of miR-181a in GCs. MicroRNA-181a induced GC apoptosis by repressing S1PR1 expression in vitro. Importantly, increased miR-181a expression and decreased S1PR1 expression were detected in the in vivo ovarian oxidative stress model by Western blot analysis and immunohistochemistry. Furthermore, we found similar expression patterns of miR-181a and S1PR1 in GCs from patients with premature ovarian insufficiency. In conclusion, our results suggest that miR-181a directly suppresses expression of S1PR1, which has critical roles in mediating oxidative stress-induced GC apoptosis both in vitro and in vivo.

Effects of Grape Seed Extract and Proanthocyanidin B2 on In Vitro Proliferation, Viability, Steroidogenesis, Oxidative Stress, and Cell Signaling in Human Granulosa Cells

Reactive oxygen species (ROS) which lead to oxidative stress affect ovarian function. Grape seed extract (GSE) could be proposed as an effective antioxidant, particularly due to its proanthocyanidin content. In this study, we investigated a dose effect (0, 0.01, 0.1, 1, 10, 50, and 100 μg/mL) of GSE and proanthocyanidin B2 (GSPB2) on the ROS content, cell proliferation, cell viability, and steroidogenesis in both primary luteinized granulosa cells (hGC) and the tumor granulosa cell line (KGN). The levels of ROS were measured using ROS-Glo assay. Cell proliferation and viability were evaluated by [3H]-thymidine incorporation and Cell Counting Kit-8 (CCK8) assay, respectively. Steroid secretion was evaluated by radioimmunoassay. We also analyzed the cell cycle component protein level and signaling pathways by immunoblot and the NOX4 mRNA expression by RTqPCR. From 0.1 to 1 μg/mL, GSE and GSBP2 reduced the ROS cell content and the NOX4 mRNA levels, whereas, GSE and GSBP2 increased the ROS cell content from 50 to 100 μM in both hGC and KGN. GSE and GSPB2 treatments at 50 and 100 μg/mL induced a delay in G₁ to S phase cell cycle progression as determined by fluorescence-activated cell sorting. Consequently, they reduced cell growth, cyclin D2 amount, and Akt phosphorylation, and they increased protein levels of p21 and p27 cyclin-dependent kinase inhibitors. These data were also associated with an increase in cell death that could be due to a reduction in Bcl-2-associated death promoter (BAD) phosphorylation and an increase in the cleaved-caspase-3 level. All these negative effects were not observed at lower concentrations of GSE and GSPB2 (0.01 to 10 μg/mL). Interestingly, we found that GSE and GSPB2 treatments (0.1 to 100 μg/mL) improved progesterone and estradiol secretion and this was associated with a higher level of the cholesterol carriers, StAR (steroidogenic acute regulatory protein), CREB (Cyclic adenosine monophosphate Response Element-binding protein), and MAPK ERK1/2 (Mitogen-Activated Protein Kinases Extracellular signal-Regulated Kinases 1/2) phosphorylation in both hGC and KGN cells. Taken together, GSE and GSPB2 (0.1–10 μg/mL) in vitro treatments decrease oxidative stress and increase steroidogenesis without affecting cell proliferation and viability in human granulosa cells.

Apoptosis of mural granulosa cells is increased in women with diminished ovarian reserve

Purpose

To evaluate the relationship between apoptosis of granulosa cells in women with normal ovarian reserve versus diminished ovarian reserve, and relate that to follicular fluid hormones, and to clinical outcomes.

Methods

A prospective cohort study was initiated between October 2015 and June 2016 involving a total of 164 women undergoing IVF/ICSI cycles at a single IVF center. Mural and cumulus granulosa cells, and follicularfluid were collected during oocyte retrieval. Annexin V-FITC/PI apoptosis staining and flow cytometryanalysis were performed to evaluate apoptosis rate of mural granulosa cells and cumulus cells. Follicularfluid hormones were measured by ECLIA. Laboratory and clinical outcomes were analyzed.

Results

In mural granulosa cells, early, late and total apoptosis rates were significantly increased in women with diminished ovarian reserve when compare to women with normal ovarian reserve, along with lower AMHand progesterone levels (but higher estradiol levels) in follicular fluid. Early apoptosis rate of cumulus cellswas significantly higher in the non-pregnant group. The apoptosis rate of mural cells was negativelycorrelated with parameters related to ovarian response, oocyte yield, MII egg number, 2pn cleavagenumber, D3 good embryos number, blastocyst formation rate and frozen embryos number. A positivecorrelation was found between mural granulosa cell apoptosis and age.

Conclusion

A significantly higher apoptosis rate of mural granulosa cells was correlated with worse ovarian response, with fewer egg and embryo numbers in IVF/ICSI, as well as with age. Early apoptosis rate of cumulus cellsmight also have influence on clinical pregnancy.

Electronic supplementary material

The online version of this article (10.1007/s10815-019-01446-5) contains supplementary material, which is available to authorized users.

Endometrial mesenchymal stem cells isolated from menstrual blood repaired epirubicin-induced damage to human ovarian granulosa cells by inhibiting the expression of Gadd45b in cell cycle pathway

Background

To explore the effect of mesenchymal stem cells isolated from menstrual blood (MB-MSCs) on epirubicin-induced damage to human ovarian granulosa cells (GCs) and its potential mechanisms.

Methods

The estradiol, progesterone, anti-Müllerian hormone, inhibin A, and inhibin B levels were determined using enzyme-linked immunosorbent assay. The proliferation of GCs was detected by Cell Counting Kit-8 assays. The cell cycle distribution was detected by propidiumiodide single staining. The apoptosis of GCs was determined using Annexin V and 7-AAD double staining. The differentially expressed genes of GCs were analyzed with Affymetrix Human Transcriptome Array 2.0 gene chip and verified with Western blot analysis.

Results

Epirubicin inhibited the secretion of estradiol, progesterone, anti-Müllerian hormone, inhibin A, and inhibin B and the proliferation of GCs; arrested these GCs in G2/M phase; and promoted the apoptosis of GCs. However, MB-MSCs repaired epirubicin-induced damage to GCs. Differentially expressed genes of GCs, Gadd45b, CyclinB1, and CDC2, were found by microarray and bioinformatics analysis. Western blot showed that epirubicin upregulated Gadd45b protein expression and downregulated CyclinB1 and CDC2 protein expression, while MB-MSCs downregulated Gadd45b protein expression and upregulated CyclinB1 and CDC2 protein expression.

Conclusions

MB-MSCs repaired epirubicin-induced damage to GCs, which might be related to the inhibition of Gadd45b protein expression.

Effect of 3-nitropropionic acid inducing oxidative stress and apoptosis of granulosa cells in geese

The mechanism of action by which oxidative stress induces granulosa cell apoptosis, which plays a vital role in initiating follicular atresia, is not well understood. In the present study, the effect of 3-nitropropionic acid (3-NPA) on oxidative stress and apoptosis in granulosa cells in geese was investigated. Our results showed that treatment with 3-NPA at 5.0 mmol/l for 24 h increased intracellular reactive oxygen species (ROS) production by 25.4% and decreased granulosa cell viability by 45.5% (P<0.05). Catalase and glutathione peroxidase gene expression levels in granulosa cells treated with 3-NPA were 1.32- and 0.49-fold compared with those of the control cells, respectively (P <0.05). A significant decrease in the expression level of B-cell lymphoma 2 (Bcl-2) protein and remarkable increases in the levels of Bax, p53 and cleaved-Caspase 3 proteins and the ratio of Bax/Bcl-2 expression in granulosa cells treated with 3-NPA were observed (P<0.05). Furthermore, a 38.43% increase in the percentage of early apoptotic cells was also observed in granulosa cells treated with 3-NPA (P<0.05). Moreover, the expression levels of NF-κB, Nrf2, Fhc, Hspa2 and Ho-1 in granulosa cells treated with 3-NPA were elevated 4.36-, 1.63-, 3.62-, 27.54- and 10.48-fold compared with those of the control cells (P<0.05), respectively. In conclusion, the present study demonstrates that treatment with 3-NPA induces ROS production and apoptosis and inhibits the viability of granulosa cells in geese. Furthermore, 3-NPA triggers increases in the expression of cleaved-Caspase 3 protein and the ratio of Bax/Bcl-2 expression, and induces the early apoptosis of granulosa cells.

Molecular regulation of miR-378 on the development of mouse follicle and the maturation of oocyte in vivo

MicroRNAs (miRNAs) are small, endogenous, non-coding RNAs which can bind to completely or partially complementary sequences in the 3'UTR of target mRNAs, therefore degrading the mRNA or repressing translation. We previously reported that miR-378 played a role in estradiol production via suppression of aromatase translation in porcine granulosa cells and could affect oocyte maturation in vitro by inhibiting cumulus cell expansion. However, the role of miR-378 on ovary development in vivo is unknown. The current study aimed to uncover the molecular mechanism of miR-378 in regulating mouse follicular development via micro-injection of CMV-miR-378 lentivirus into the bursa of mouse ovary. The results showed that CMV-miR-378 lentivirus transduction in the mouse ovaries resulted in reduced ovary size, extended oestrous cycle (6-7 d in miR-378 overexpression group and 4-5 dyas in GFP control group) due to continuous oestrum, decreased percentage of oocytes in vitro maturation rate (IVM 60.8% vs. 89.4% in GFP control), increased apoptosis rate (Bax/Bcl2 in mRNA and protein level), decreased expression of genes associated with gap junction, such as connexin 43 (Cx-43) and connexin (Cx-37) and decreased expression of genes associated with follicular development, such as BMP15 and GDF9. Moreover, the number of pups/litter was consistently lower in the miR-378 group in each batch of the paired breeding. Our data suggest that miR-378 alters gene expression in cumulus cells and indirectly influences oocyte maturation competency, possibly via inhibition of oocyte-cumulus interaction or induction of apoptosis.

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.

Anti-hypercholesterolemic impacts of barley and date palm fruits on the ovary of Wistar albino rats and their offspring

A high cholesterol diet is related to ovarian dysfunction and infertility which has been increased among young ages consuming processed food products. The present study was conducted to evaluate the role of a high cholesterol diet on the ovaries of young female rats via assessments of histopathology, immunohistochemistry, oxidative stress and apoptic markers. Also, mating of hypercholesterolemic female rats was carried out to measure the fertility and numbers of their offspring. At the same time, phytotherapy was carried out through supplementing the diet with barley and/ or date palm fruits (10%) during the experiment to assess the phyto-therapeutic impacts in attenuation of drastic hypercholesterolemic effects. Hypercholesterolemic diet-fed rats exhibited damage of the ovarian follicles and increased follicular atresia. Furthermore, expression of cleaved caspase-3 was upregulated, while PCNA was downregulated in granulosa, theca and stroma cells. Hypercholesterolemic female rats showed marked depletion of antioxidative enzymes, increased lipid peroxidation and apoptotic markers. Alterations to the female serum hormones were detected. Offspring maternally fed on hypercholesterolemic diet showed a significant decrease of body weight and altered sex ratio. However, concomitant supplementation of barley and or date fruits to hypercholesterolemic groups revealed marked improvement of ovarian structure and function. On the basis of these evidences, it is believed that the enhanced synergistic effects of barley and/or date palm fruits in the amelioration of ovarian structure and functions were elicited by the potential antioxidant activity of their phytomicronutrients, polyphenols, β-glucan and trace elements. These materials scavenge free radicals from inflamed cells that can be used to establish an effective and novel therapeutic strategy for activating ovarian cell regeneration.

The Role of Follicular Fluid Thiol/Disulphide Homeostasis in Polycystic Ovary Syndrome

BACKGROUND

Oxidative stress has been proposed as a potential trigger in the etiopathogenesis of polycystic ovary syndrome-related infertility. Thiol/disulphide homeostasis, a recently identified oxidative stress marker, is one of the antioxidant mechanism in humans with critical roles in folliculogenesis and ovulation.

AIMS

To investigate follicular fluid thiol/disulphide homeostasis in the etiopathogenesis of polycystic ovary syndrome and to determine its association with in vitro fertilization outcome. The study procedures were approved by the local ethics committee.

STUDY DESIGN

Cross-sectional study.

Methods

Follicular fluid from 22 women with polycystic ovary syndrome and 20 ovulatory controls undergoing in vitro fertilization treatment was sampled. Thiol/disulphide homeostasis was analyzed via a novel spectrophotometric method.

Results

Follicular native thiol levels, as well as the native thiol/total thiol ratio, were lower in the polycystic ovary syndrome group than in the non-polycystic ovary syndrome group (p=0.041 and p<0.0001, respectively). Disulphide levels, disulphide/native thiol, and disulphide/total thiol ratios were increased in the polycystic ovary syndrome group (p<0.0001). A positive correlation between the fertilization rate and native thiol (p=0.01, r=0.53) and total thiol (p=0.01, r=0.052) among polycystic ovary syndrome patients was found. A positive predictive effect of native thiol level on the fertilization rate in the polycystic ovary syndrome group was also found (p=0.03, β=0.45, 95% CI= 0.031-0.643).

Conclusion

Deterioration of thiol/disulphide homeostasis, especially elevated disulphide levels, could be one of the etiopathogenetic mechanisms in polycystic ovary syndrome. Increased native thiol levels are related to the fertilization rate among polycystic ovary syndrome patients and are positive predictors of the fertilization rate among polycystic ovary syndrome patients. Improvement of thiol/disulphide homeostasis could be important in the treatment of polycystic ovary syndrome to increase in vitro fertilization success.

Granulosa Cell Apoptosis in the Ovarian Follicle-A Changing View

Recent studies challenge the previous view that apoptosis within the granulosa cells of the maturing ovarian follicle is a reflection of aging and consequently a marker for poor quality of the contained oocyte. On the contrary, apoptosis within the granulosa cells is an integral part of normal development and has limited predictive capability regarding oocyte quality or the ensuing pregnancy rate in in vitro fertilization programs. This review article covers our revised understanding of the process of apoptosis within the ovarian follicle, its three phenotypes, the major signaling pathways underlying apoptosis as well as the associated mitochondrial pathways.

Systemic analysis of gene expression profiles in porcine granulosa cells during aging

Current studies have revealed that aging is a negative factor that suppresses granulosa cell functions and causes low fertility in women. However, the difference in gene expression between normal and aging granulosa cells remains undefined. Therefore, the aim of this study was to investigate the gene expression profiles of granulosa cells during aging. Granulosa cells from young healthy porcine ovaries were aged in vitro by prolonging the culture time (for 48h). First, the extracellular ultrastructure was observed by scanning electron microscopy followed by RNA-seq and KEGG pathway analysis. The results showed that the extracellular ultrastructure was significantly altered by aging; cell membranes were rough, and cavitations were found. Moreover, the formations of filopodia were greatly reduced. RNA-seq data revealed that 3411 genes were differentially expressed during aging, of which 2193 genes were up-regulated and 1218 genes were down-regulated. KEGG pathway analysis revealed that 25 pathways including pathway in cancer, PI3K-Akt signaling pathway, focal adhesion, proteoglycans in cancer, and cAMP signaling pathway were the most changed. Moreover, several high differentially expressed genes (CEBPB, CXCL12, ANGPT2, IGFBP3, and BBOX1) were identified in aging granulosa cells, The expressions of these genes and genes associated with extracellular matrix remodeling associated genes (TIMP3, MMP2, MMP3, and CTGF), energy metabolism associated genes (SLC2A1, PPARγ) and steroidogenesis associated genes (StAR, CYP11A1 and LHCGR) were confirmed by quantitative PCR. This study identifies the differently changed pathways and their related genes, contributes to the understanding of aging in granulosa cells, and provides an important foundation for further studies.

Advanced oxidation protein products from the follicular microenvironment and their role in infertile women with endometriosis

Endometriosis (EM) is associated with oxidative stress. Advanced oxidation protein products (AOPPs) are novel markers of oxidative stress, which serve an important role as an inflammatory mediator in various chronic diseases. In order to examine the role of AOPPs in infertile women with EM, the present study analyzed the levels of AOPPs, estradiol (E₂) and progesterone (P₄) in the follicular fluid (FF) of 89 women with or without EM undergoing in vitro fertilization (IVF). The AOPP concentration in the FF of the EM group was significantly higher when compared with that of the control group (51.5±22.4 vs. 41.8±18.3 µmol/l; P<0.05). However, the FF P₄ levels and blastocyst rate were significantly lower in the EM group compared with the control group (P₄:1,249.6±465.4 vs. 1,752.7±565.4 ng/ml, P<0.05; blastocyst rate: 0.511±0.322 vs. 0.662±0.278; P<0.05). The AOPP concentration and P₄ level in the FF presented a significant negative correlation in the EM and control groups, as well as in the total cohort of patients (EM group: r=-0.406, P=0.006; control group: r=-0.315, P=0.035; total: r=-0.421, P<0.001). In addition, there was a significant negative correlation between the FF AOPP concentrations and blastocyst rate in the EM group and in the total cohort (EM group: r=-0.376, P=0.012; total: r=-0.367, P<0.001). In conclusion, these results suggested that AOPPs may be a potentially effective marker for predicting the oocyte quality and outcomes of IVF in infertile women with EM.

ROS activates autophagy in follicular granulosa cells via mTOR pathway to regulate broodiness in goose

Broodiness causes reduced reproductive ability in poultry, but its regulatory mechanism remains poorly understood. ROS (reactive oxygen species) and autophagy are important for follicular development, and the interaction between the two may play a role in regulating broodiness. We examined goose follicles for ROS and oxidation scavenger activities during the egg-laying and broody stages. The follicular granulosa cells were exposed to media containing H₂O₂, and the interactions between ROS and autophagy in follicular granulosa cells in vitro were analyzed using a Western blot method. We found that the activities of superoxide dismutase (SOD) and lactate dehydrogenase (LDH) were enhanced and the amount of malondialdehyde (MDA) decreased in broody goose follicles. H₂O₂ inhibited the cell viability and induced autophagy. Furthermore, it was also found that H₂O₂ regulated autophagy by reducing mTOR and increasing p53; however, H₂O₂ had no impact on Beclin1 or ATG12. It was also shown that the enhanced autophagy lessened ROS-induced damages. We conclude that ROS and autophagy both played important roles in regulating follicular development to control broodiness in geese, and ROS activated autophagy in follicular granulosa cells via the mTOR pathway.

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.

Effects of chronic heat stress on granulosa cell apoptosis and follicular atresia in mouse ovary

BACKGROUND

Heat stress is known to alter follicular dynamics and granulosa cell function and may contribute to the diminished reproductive efficiency commonly observed in mammals during the summer. Although several investigators have studied heat-induced ovarian injury, few reports have focused on the effects of chronic heat stress on ovarian function and the molecular mechanisms through which it induces ovarian injury.

METHODS

In Exp. 1, 48 female mice were assigned to a control or heat-stressed treatment. After exposure to a constant temperature of 25 °C for 7, 14, 21 or 28 d (n = 6) or to 42 °C for 3 h per d for 7, 14, 21 or 28 d (n = 6), the mice were euthanized and their ovaries were analyzed for follicular atresia, granulosa cell apoptosis, changes in the abundance of HSP70 protein and serum concentrations of estradiol. In Exp. 2, the expression of HSP70 and aromatase was quantified in antral follicles cultured in vitro at 37 or 42 °C for 24 h. In Exp. 3, granulosa cells from ovaries maintained at 37 or 41 °C for 2 h were analyzed for their expression of HSP70, Bim, caspase-3 and cleaved caspase-3.

RESULTS

In Exp. 1, body weight and food intake of heat-stressed mice decreased (P < 0.05) compared with control mice while the concentration of estradiol in serum was lower (P < 0.05) in heat-stressed mice than in control mice. Compared with control mice, the percentage of atretic follicles and the number of antral follicles with severe apoptotic signals were increased (P < 0.05) after 21 d of heat-stressed treatment. HSP70 protein was more abundant (P < 0.05) in heat-stressed mice than control mice. In Exp. 2, heat stress increased HSP70 and decreased aromatase proteins (P < 0.05) in antral follicles. In Exp. 3, TUNEL-positive granulosa cells from heat-stressed ovaries were observed concomitant with a significant increase in HSP70, Bim and cleaved caspase-3 protein.

CONCLUSION

Heat-stress in mice decrease estradiol in serum and aromatase in antral follicles but increased number of atretic follicles and granulosa cell undergoing apoptosis which may explain the decreased fertility commonly observed in heat-stressed animals.

Heat stress impairs mice granulosa cell function by diminishing steroids production and inducing apoptosis

Ovarian injury can be induced by heat stress. Mice granulosa cells (GCs) are critical for normal ovarian function and they synthesize a variety of growth factors and steroids for the follicle. Furthermore, the growth, differentiation, and maturate of theca cells and oocyte are dependent upon the synthesis of GCs. Due to the critical biological functions of GCs, we hypothesized that the apoptosis and dysfunction of GCs could also be induced by heat stress. We analyzed GCs apoptosis and evaluated the expression of apoptosis-related genes (caspase-3, Bax, Bcl-2) after heat treatment. Radio immunity assay was used to measure the secretion of 17β-estradiol (E2) and progesterone (P4). RT-PCR was used to evaluate the expression of steroids-related genes (Star, CYP11A1, CYP19A1). Our data suggested that heat stress inhibited GCs proliferation, induced GCs apoptosis, decreased E2 and P4 secretion, reduced the steroids-related genes mRNA expression. Besides, our results indicated that heat treatment-induced apoptosis of GCs through the mitochondrial pathway, which involved caspase-3 and Bax. The reduction in steroids secretion and mRNA expression of Star, CYP11A1, and CYP19A1 might also play a role in heat-induced GCs apoptosis and ovarian injury.

3-Nitropropionic acid induces ovarian oxidative stress and impairs follicle in mouse

Oxidative stress induces many serious reproductive diseases in female mammals and thus poses a serious threat to reproductive health. However, the relationship between reactive oxygen species (ROS)-induced oxidative stress and follicular development, oocyte and embryo quality is not clear. The aim of this study was to investigate the effect of ovarian oxidative stress on the health of follicle and oocyte development. Female ICR mice were dosed with 3-nitropropionic acid (3-NPA) at three different concentrations (6.25, 12.5 and 25 mg/kg) and saline (control) via continuous intraperitoneal injection for 7 days. The treatment with 12.5 mg/kg reduced the weight of mouse ovaries, and significantly increased ROS levels and the activities of antioxidant enzymes--total superoxide dismutase (T-SOD), glutathione peroxidase (GPx) and catalase (CAT)--in granulosa cells and ovarian tissues, but not in other tissues (brain, liver, kidney and spleen). The same treatment significantly increased the percentage of atretic large follicles, and reduced the number of large follicles, the number of ovulated oocytes, and the capacity for early embryonic development compared with controls. It also significantly decreased the ratio of Bcl-2 to Bax, while causing an increase in the mRNA expression of (SOD2, CAT and GP X) and ROS levels in granulosa cells. Collectively, these data indicate that 3-NPA induces granulosa cell apoptosis, large follicle atresia, and an increase of ROS levels in the ovary. Therefore, we have established an in vivo model of ovarian oxidative stress for studying the mechanism of resulting damage induced by free radicals and for the screening of novel antioxidants.