Polycystic Ovary Syndrome Oocytes Research Articles

Mfn2 regulates mitochondria-associated ER membranes to affect PCOS oocyte development.

This study aimed to investigate the role of mitochondrial-related protein Mfn2 in polycystic ovary syndrome (PCOS) and its impact on oocyte development. The pathological features of PCOS model mice were confirmed by hematoxylin-eosin staining and immunohistochemistry. The expression of Mfn2 and mitochondrial-related proteins in PCOS oocytes and granulosa cells was detected by qRT-PCR and Western blot. Mitochondrial quantity was measured by Mito-Tracker staining, and the structure of mitochondria-associated ER membranes (MAMs) was observed by transmission electron microscopy. The results showed that Mfn2 was significantly downregulated in PCOS oocytes and granulosa cells, and its expression was inhibited in oocytes at different developmental stages. Moreover, the structure of MAMs was also disrupted. Downregulation of Mfn2 expression led to a reduction in mitochondrial quantity in oocytes and granulosa cells, as well as disruption of MAM structure, while overexpression of Mfn2 had the opposite effect. In conclusion, this study indicates that Mfn2 affects the development of PCOS oocytes by regulating MAMs and may be involved in maintaining the stability of MAM structure and function, thereby affecting mitochondrial quantity and function. These findings provide new insights into the pathogenesis and treatment of PCOS.

O-105 Chromatin accessibility of oocytes contributes to PCOS transgenerational inheritance

Abstract Study question What is the underlying mechanism contributing to the transgenerational defects of oocytes and embryos of polycystic ovary syndrome (PCOS)? Summary answer The transgenerational inheritance of abnormal chromatin accessibility in the PCOS oocytes is responsible for the defect of oocytes and embryos in transgeneration. What is known already Studies have provided evidence of compromised oocyte quality and related adverse impacts. Observed PCOS animal-model oocyte defects include meiotic abnormalities, mitochondrial dysfunction, and increased oxidative stress. Elevated androgen levels are associated with reduced fertilization rates and lower cleavage rates during in vitro fertilization (IVF) treatment. PCOS could be transgenerationally transmitted, and unique altered gene expression has been observed in metaphase II (MII) oocytes from all offspring in PCOS mice. Study design, size, duration We profiled the transcriptome and chromatin accessibility of oocytes and preimplantation embryos in F0-F2 offspring of PCOS mice, to explored whether the inheritance of chromatin accessibility defects in PCOS oocytes was responsible for the abnormalities of oocytes and embryos in PCOS offspring. Besides, oocytes from 13 healthy women and 8 women with PCOS, 24 blood samples from 24 women with/without PCOS were analyzed to validate the molecular mechanisms of PCOS inheritance. Duration: 2019.5∼2022.12. Participants/materials, setting, methods PCOS mice models were established by means of DHEA-exposure. Smart-seq2 and DNase-seq were utilized to investigate the transcriptome and chromatin accessibility of oocytes and preimplantation embryos in F0-F2 offspring of PCOS mice. Bioinformatic analysis was applied to explore the differential gene expression and chromatin accessibility of oocytes and embryos in PCOS mice and offspring comparing to controls. Common gene signatures in the tissues of PCOS women and PCOS daughters are analyzed compared to control samples. Main results and the role of chance In PCOS mice, we observed transcriptional alteration in oocytes and 2-cell embryos compared to normal mice. There are 4229 and 1197 differentially expressed genes (DEGs) in PCOS oocytes and 2-cell embryos. The DEGs includes both maternal factors and zygotic genome activation (ZGA) genes. Interestingly, in PCOS 2-cell embryos, we observed hundreds of pre-activated genes which are silence in normal 2-cell embryo but expressed in PCOS 2-cell embryos. Notably, many DEGs in the oocytes of PCOS mice were also differentially expressed in the oocytes of F2 PCOS mice compared to control mice, supporting the transgenerational inheritance of transcriptional alteration in PCOS oocytes. Mechanismly, the changes of chromatin accessibility were associated with the DEGs in PCOS oocytes and embryos. In particular, chromatin accessibility of the pre-activated gene promoters is elevated in PCOS oocytes compared to that in normal oocytes. Furthermore, many of the abnormal chromatin accessibility signals detected in F0 PCOS oocytes were also observed in F2 PCOS oocytes. Finally, our data showed that some DEGs in the oocytes of PCOS mice were also differentially expressed in human PCOS oocytes compared to the control oocytes. Common genes identified in PCOS offspring may be used as potential predictors of PCOS phenotype. Limitations, reasons for caution Which factors contribute to the abnormalities of chromatin accessibility in PCOS oocytes are still unknown. Wider implications of the findings The candidate genes may be used as potential predictors of PCOS phenotype and provide the clues for PCOS offspring . Trial registration number not applicable

Effects of n-3 PUFA supplementation on oocyte in vitro maturation in mice with polycystic ovary syndrome

n-3 PUFAs are classic antioxidant that can be used to treat follicular dysplasia and hyperinsulinemia caused by excessive oxidative stress in PCOS women. To investigate the effect of n-3 PUFA supplementation on the oocyte quality of polycystic ovary syndrome (PCOS) mice during in vitro maturation, a PCOS mouse model was established by dehydroepiandrosterone (DHEA). The GV oocytes of the control and PCOS groups were collected and cultured in vitro with or without n-3 PUFAs. After 14 h, the oocytes were collected. Our data demonstrated that the oocyte maturation rate of PCOS mice significantly increased after the addition of 50 µM n-3 PUFAs. The results of immunofluorescence showed that the abnormal rates of spindles and chromosomes in the PCOS + n-3 PUFA group were lower than those in the PCOS group. The mRNA expression of an antioxidant-related gene (Sirt1) and DNA damage repair genes (Brca1/Msh2) was found to be significantly rescued after n-3 treatment. Additionally, the results of living cell staining showed that the addition of n-3 PUFAs could reduce the levels of reactive oxygen species and mitochondrial superoxide in PCOS oocytes. In conclusion, the addition of 50 µM n-3 PUFAs during the in vitro maturation of PCOS mouse oocytes can improve the maturation rate by reducing the level of oxidative stress and the rate of spindle/chromosome abnormalities, providing valuable support during the IVM process.

The boosting effects of melatonin on the expression of related genes to oocyte maturation and antioxidant pathways: a polycystic ovary syndrome- mouse model

BackgroundMelatonin, as a free radical scavenger exhibiting genomic actions, regulates the antioxidant genes expression and apoptosis mechanisms. In polycystic ovary syndrome (PCOS) patients, an imbalance between free radicals and antioxidants in follicular fluid leads to oxidative stress, aberrant folliculogenesis, and intrinsic defects in PCOS oocytes. In this experimental mouse model study, oocytes of PCOS and the control groups were cultured in different melatonin concentrations (10− 5, 10− 6, and 10− 7 M) to investigate the expression of oocyte maturation-related genes (Gdf9/Bmp15), antioxidant-related genes (Gpx1/Sod1), apoptotic biomarkers (Bcl2/Bax) and total intracellular ROS levels.ResultsGdf9 and Bmp15, Gpx1 and Sod1 were up-regulated in PCOS and control oocytes cultured in all melatonin concentrations compared to those cultured in IVM basal medium (P < 0.05). A significant decrease in the total ROS level was observed in all groups cultured in the supplemented cultures. Melatonin increased Bcl2 and decreased Bax gene expression in PCOS and control oocytes compared to non-treated oocytes.ConclusionsMelatonin increased antioxidant gene expression and regulated the apoptosis pathway, effectively reducing the adverse effects of culture conditions on PCOS oocytes. Furthermore, it influenced the expression of oocyte maturation-related genes in PCOS, providing valuable support during the IVM process.

Metformin improves epigenetic modification involved in oocyte growth and embryo development in polycystic ovary syndrome mice model.

The possible relationship between dehydroepiandrosterone (DHEA)-induced polycystic ovary syndrome (PCOS) and epigenetic changes (ECs) leading to the impaired oocyte quality, has not been investigated yet. So, this study aimed to provide an insight into the relationship of the impaired oocyte quality with ECs in a mice DHEA-induced PCOS model and to further reveal the effect of metformin treatment. For this purpose, 80 female BALB/C mice were randomly divided into four equal groups, named as the control, sham, (DHEA) and DHEA + Metformin groups. The alterations in acetylation of H4K5 and H4K16, and in methylation of DNA (5MeC) and H3K9 were evaluated using immunocytochemical. Moreover, the expression of Hdac1, Hdac2, Dnmt1, and Dnmt3a genes involved in ECs were analyzed using reverse-transcription polymerase chain reaction. As well, the levels of mitochondrial membrane potential (MMP), oxidative stress (OS), embryo development, ovarian morphology, sexual hormone, ovulatory function, and AMPKα phosphorylation activity were compared in all the studied groups. Metformin attenuated the damages induced by DHEA as indicated by the normalized the estrous cycle, the improved ovarian morphology, the decreased sexual hormone and OS levels, and the increased MMP and AMPKα phosphorylation levels. In the metformin group, the Dnmt1, Dnmt3a, and Hdac2 genes have significantly upregulated compared to the DHEA group. However, metformin was found to have no effect on the expression level of Hdac1. In this regard, significant decrease and increase were observed in both the acetylated H4K16 and methylated H3K9 within MII oocytes in the DHEA + Metformin group compared with the DHEA group. Our results show that metformin could enhance the developmental competence of PCOS oocytes via reducing OS and ECs.

Molecular Features of Polycystic Ovary Syndrome Revealed by Transcriptome Analysis of Oocytes and Cumulus Cells.

Polycystic ovary syndrome (PCOS) is typically characterized by a polycystic ovarian morphology, hyperandrogenism, ovulatory dysfunction, and infertility. Furthermore, PCOS patients undergoing ovarian stimulation have more oocytes; however, the poor quality of oocytes leads to lower fertilization and implantation rates, decreased pregnancy rates, and increased miscarriage rates. The complex molecular mechanisms underlying PCOS and the poor quality of oocytes remain to be elucidated. We obtained matched oocytes and cumulus cells (CCs) from PCOS patients, compared them with age-matched controls, and performed RNA sequencing analysis to explore the transcriptional characteristics of their oocytes and CCs. Moreover, we validated our newly confirmed candidate genes for PCOS by immunofluorescence. Unsupervised clustering analysis showed that the overall global gene expression patterns and transposable element (TE) expression profiles of PCOS patients tightly clustered together, clearly distinct from those of controls. Abnormalities in functionally important pathways are found in PCOS oocytes. Notably, genes involved in microtubule processes, TUBB8 and TUBA1C, are overexpressed in PCOS oocytes. The metabolic and oxidative phosphorylation pathways are also dysregulated in both oocytes and CCs from PCOS patients. Moreover, in oocytes, differentially expressed TEs are not uniformly dispersed in human chromosomes. Endogenous retrovirus 1 (ERV1) elements located on chromosomes 2, 3, 4, and 5 are rather highly upregulated. Interestingly, these correlate with the most highly expressed protein-coding genes, including tubulin-associated genes TUBA1C, TUBB8P8, and TUBB8, linking the ERV1 elements to the occurrence of PCOS. Our comprehensive analysis of gene expression in oocytes and CCs, including TE expression, revealed the specific molecular features of PCOS. The aberrantly elevated expression of TUBB8 and TUBA1C and ERV1 provides additional markers for PCOS and may contribute to the compromised oocyte developmental competence in PCOS patients. Our findings may also have implications for treatment strategies to improve oocyte maturation and the pregnancy outcomes for women with PCOS.

Transcriptome Profiling of Oocytes at the Germinal Vesicle Stage from Women from Mongolia with Polycystic Ovary Syndrome.

BackgroundPolycystic ovary syndrome (PCOS) is one of the most common endocrine disorders. Evidence indicates that genetic and environmental factors contribute to the pathogenesis of PCOS. The molecular basis of PCOS is not well understood.MethodsWhole-genome RNA sequencing was performed on single oocyte at the germinal vesicle (GV) stage from females with normal ovulation and females with PCOS. All subjects were women from Mongolia undergoing intracytoplasmic sperm injection in vitro fertilization (ICSI-IVF) who met the Rotterdam criteria for PCOS. Women with normal ovulation who were undergoing ICSI-IVF owing to male factor infertility were recruited as control subjects.ResultsA total of 1313 differentially expressed genes were found by bio-informatics software in the GV oocytes of PCOS patients and compared with the control group. There were 367 upregulated and 946 downregulated genes (fold change > 2, false discovery rate < 0.01). When compared with the healthy controls, it was shown that the DEGs like VEGF, IGF, FADS1 et al were investigated as potential causes of PCOS oocytes. The DEGs were related to kinase activity, cell proliferation, gene regulation, and the signaling pathways of phosphatidylinositol 3-kinase, Hippo, and ECM-receptor pathway in patients with PCOS. In addition, the interconnected gene co-expression network was constructed by gene bionetwork analysis, indicating that ITGB5, ITGB3, and CAV2 were the core genes in regulating the module expression of DEGs in PCOS.ConclusionRNA sequencing analysis demonstrated DEGs were linked to inflammation, cardiovascular disease, and lipid metabolism in the GV oocytes of women with PCOS. We hypothesize that ITGB5, ITGB3, and CAV2 may be involved in metabolic disorders associated with the different phenotypes of PCOS.

In Vitro Oocyte Maturation Rate of Mice with Polycystic Ovarian Syndrome in the Presence of α-Linolenic Acid Antioxidant

Background: One of the most common endocrine and metabolic disorders is Polycystic ovary syndrome (PCOS), which has been reported in about 10% of women during the reproductive age. Objectives: This study was designed to investigate the efficiency of α-Linolenic acid (ALA) on in vitro maturation (IVM) and the quality of mouse oocytes with PCOS. Methods: Female NMRI mice (30 - 35 day-old) were developed by the injection of 4 mg estradiol valerate dissolved in 0.2 mg sesame oil for 60 consecutive days. In the following, the PCOS ovaries were dissected and oocytes were cultured in the maturation medium supplemented with different dosages of α-linolenic acid (0, 50, 100 µM). The presence of the first polar body was considered the sign of the nuclear maturation of the oocyte. The expression of mitochondrial transcription factor A (TFAM) gene in mature oocytes was investigated by Quantitative Real-time PCR. Results: The in vitro maturation and TFAM gene expression rates of PCOS oocytes in the medium treated with 50 µM of ALA (84 ± 7.9 and 0.46 ± 0.09, respectively) were significantly higher than the control group (P &lt; 0.05). Conclusions: The ALA could improve the IVM rate and quality of PCOS oocytes by higher expression of TFAM gene.

Single-Cell Transcriptomic Analysis Reveals Mitochondrial Dynamics in Oocytes of Patients With Polycystic Ovary Syndrome.

Polycystic ovary syndrome (PCOS), characterized by polycystic ovarian morphology, ovarian follicular maturation arrest, and hormonal disorders, affects numerous women in the reproductive age worldwide. A recent study has found that mitochondria are likely to play an essential role in oocyte quality. However, it is still unclear whether oocyte development failure is associated with mitochondria in patients with PCOS. We analyzed the single-cell RNA sequencing data from the previous study, including data from 14 oocytes from 7 healthy fertile women and 20 oocytes from 9 patients with PCOS at the germinal vesicle (GV) stage, metaphase I (MI) stage, and metaphase II (MII) stage. We revealed the transcriptomic dynamics by weighted gene co-expression network analysis (WGCNA) and investigated the differences between stages using PCA and Deseq2 analyses to identify the differential expression genes (DEGs). Gene ontology (GO) was performed using clusterProfiler R package and Metascape. Our results indicated that specific gene modules were related to different stages of oocyte development using WGCNA. Functional enrichment analysis and gene co-expression network analysis found significant enrichment of the mitochondrial regulation genes at the GV stage. PCA (principal component analysis) and differential gene expression analysis suggested that GV was significantly different from the MI and MII stages between the two groups. Further analysis demonstrated that the upregulated differentially expressed genes at the GV stage of patients with PCOS mainly related to mitochondrial function, such as COX6B1, COX8A, COX4l1, and NDUFB9. Meanwhile, these genes tended to be activated at the MII stage in healthy cells, suggesting that some mitochondrial functions may be prematurely activated at the GV stage of PCOS oocytes, whereas this process occurs at the MII stage in healthy oocytes. Collectively, our study showed that aberrant mitochondrial function at the GV stage may contribute to a decline in oocyte quality of PCOS patients.

Thymoquinone reduces intracytoplasmic oxidative stress and improves epigenetic modification in polycystic ovary syndrome mice oocytes, during in-vitro maturation.

Although in-vitro maturation (IVM) of oocytes has been presented as an alternative treatment to traditional stimulated in-vitro fertilization, the culture condition can be improved by natural antioxidants. Thus, we investigated the protective effect of Thymoquinone (TQ) during IVM in the polycystic ovary syndrome (PCOS) mice model. The induction of PCOS was made by dehydroepiandrosterone via subcutaneous injection, in prepubertal female B6D2F1-mice. After 21 days later, germinal vesicle (GV)-stage-oocytes were extracted and incubated in IVM media containing 0, 1.0, 10.0, and 100.0 μM of TQ. To assess fertilization and blastulation rates, after 22-24 hr, the treated oocytes were fertilized in-vitro with epididymal spermatozoa. Some other oocytes were evaluated for maturation, epigenetic, and oxidative stress markers. Similarly, the mRNA expression of epigenetic enzymes genes (Dnmt1 and Hdac1), three maternally derived genes (Mapk, CyclinB, and Cdk1) and apoptosis-related genes (Bax and Bcl2) were assessed. Our results showed that the maturation, fertilization, and blastulation rates were significantly higher in the 10.0 μM TQ-treated group compared with the untreated group and likewise with in-vivo matured oocytes. The Bax expression was reduced in 10.0 μM TQ matured oocytes, but Bcl2, Dnmt1, Hdac1, Cdk1, and Mapk were upregulated in this group compared to other groups. Furthermore, dimethylation of histone-3 at lysine-9 (H3K9m2) and DNA methylation were significantly increased whereas H4K12 acetylation (H4K12ac) was decreased in the 10.0 μM TQ-treated group in comparison with control and in-vivo matured oocytes. Therefore, our results are suggesting that 10.0 μM TQ may enhance the developmental competence of PCOS oocytes via the modulation of oxidative stress and epigenetic alterations.

Improvement of oocyte in vitro maturation from mice with polycystic ovary syndrome by human mesenchymal stromal cell-conditioned media.

The outcome of in vitro maturation (IVM) in the patients with polycystic ovary syndrome (PCOS) is poor. Abnormal intraovarian paracrine interplay alters microenvironment for oocyte development through folliculogenesis and decreases developmental competence of oocytes inpatients with PCOS. Mesenchymal stromal cells (MSCs) secrete a variety of cytokines and growth factors that could promote oocyte maturationin vitro. Thus, in the current study we aimed to evaluate the effect of human bone marrow MSC-conditioned media (hBM-MSC-CM), as a supplement, to enrich IVM medium for PCOS germinal vesicles (GVs). For this purpose, oocytes at GV and metaphase II (MII) stages were harvested from PCOS mice. The GVs were randomly divided into four groups and incubated for 24 hours in an IVM medium (TCM199, as the control group) or TCM199 supplemented by 25%, 50%, and 75% of hBM-MSC-CM (PCOS-CM25, PCOS-CM50, and PCOS-CM75 groups, respectively) so as to evaluate which dose(s) could enhance maturation rate of the GVs and their subsequent in vitro fertilization (IVF) outcome. Furthermore, MII oocytes and their subsequent IVF outcome were considered as the in vivo matured (PCOS-IVO) group. The data showed that supplementation of IVM medium with 50% hBM-MSC-CM significantly increased cytoplasmic and nuclear maturation of the GVs (P < 0.001), and also fertilization and two-cell rate (P < 0.001) and blastocyst formation (P < 0.01) of in vitro matured oocytes from mice with PCOS. Overall, higher oocyte maturation and fertilization outcome in PCOS-CM50 group proposed that enrichment of IVM medium with hBM-MSC-CM could be considered as a promising approach to improve IVM of PCOS oocytes.

Single-cell expression analysis of BMP15 and GDF9 in mature oocytes and BMPR2 in cumulus cells of women with polycystic ovary syndrome undergoing controlled ovarian hyperstimulation.

To detect expression of bone morphogenetic protein 15 (BMP15) and growth differentiation factor 9 (GDF9) in oocytes, and their receptor type 2 receptor for BMPs (BMPR2) in cumulus cells in women with polycystic ovary syndrome (PCOS) undergoing in vitro fertilization (IVF), and determine if BMPR2, BMP15, and GDF9 expression correlate with hyperandrogenism in FF of PCOS patients. Prospective case-control study. Eighteen MII-oocytes and their respective cumulus cells were obtained from 18 patients with PCOS, and 48 MII-oocytes and cumulus cells (CCs) from 35 controls, both subjected to controlled ovarian hyperstimulation (COH), and follicular fluid (FF) was collected from small (10-14 mm) and large (>18 mm) follicles. RNeasy Micro Kit (Qiagen) was used for RNA extraction and gene expression was quantified in each oocyte individually and in microdissected cumulus cells from cumulus-oocyte complexes retrieved from preovulatory follicles using qRT-PCR. Chemiluminescence and RIA assays were used for hormone assays. BMP15 and GDF9 expression per oocyte was higher among women with PCOS than the control group. A positive correlation was found between BMPR2 transcripts and hyperandrogenism in FF of PCOS patients. Progesterone values in FF were lower in the PCOS group. We inferred that BMP15 and GDF9 transcript levels increase in mature PCOS oocytes after COH, and might inhibit the progesterone secretion by follicular cells in PCOS follicles, preventing premature luteinization in cumulus cells. BMPR2 expression in PCOS cumulus cells might be regulated by androgens.

Metabolism and karyotype analysis of oocytes from patients with polycystic ovary syndrome

Polycystic ovary syndrome (PCOS) is associated with metabolic disturbances which include impaired insulin signalling and glucose metabolism in ovarian follicles. The oocyte is metabolically dependent upon its follicle environment during development, but it is unclear whether PCOS or polycystic ovarian (PCO) morphology alone affect oocyte metabolism and energy-demanding processes such as meiosis. Immature human oocytes were donated by PCOS (n = 14), PCO (n = 14) and control (n = 46) patients attending the assisted conception programme at Leeds Teaching Hospitals NHS Trust. Oocytes were cultured individually and carbohydrate metabolism was assessed during overnight in vitro maturation (IVM). Meiotic status was assessed and oocyte intracellular nicotinamide adenine dinucleotide phosphate (NAD(P)H) content and mitochondria activity were measured prior to karyotype analysis by multifluor in situ hybridization. Patient aetiology had no significant effect on oocyte maturation potential or incidence of numerical chromosome abnormalities (44%), although PCOS and PCO oocytes were more likely to suffer predivision. Group G chromosomes were most likely to be involved in non-disjunction and predivision. PCOS was associated with increased glucose consumption (2.06 +/- 0.43 and 0.54 +/- 0.12 pmol/h for PCOS and control oocytes, respectively) and increased pyruvate consumption (18.4 +/- 1.2 and 13.9 +/- 0.9 pmol/h for PCOS and control oocytes, respectively) during IVM. Prior prescription of metformin significantly attenuated pyruvate consumption by maturing oocytes (8.5 +/- 1.8 pmol/h) from PCOS patients. Oocytes from PCO patients had intermediate metabolism profiles. Higher pyruvate turnover was associated with abnormal oocyte karyotypes (13.4 +/- 1.9 and 19.9 +/- 2.1 pmol/h for normal versus abnormal oocytes, respectively). Similarly, oocyte NAD(P)H content was 1.35-fold higher in abnormal oocytes. The chromosomal constitution of in vitro matured oocytes from PCOS is similar to that of controls, but aspects of oocyte metabolism are perturbed by PCOS. Elevated pyruvate consumption was associated with abnormal oocyte karyotype.

In vitro maturation in women with PCOS

OBJECTIVE: In vitro maturation (IVM) was established in our InviMed centers in Poland as a new method for treating infertility. The procedure was applied in our center in patients showing Polycystic Ovary Syndrome (PCOS). DESIGN: The aim of the study was to compare the outcome of maturation, fertilization, embryo scoring and pregnancy rates in patients with PCOS, undergoing IVM procedure with patients with mechanical cause of infertility (control). MATERIALS AND METHODS: Twenty nine patients determined as PCOS underwent 32 IVM cycles. The control group (n=28) underwent conventional ICSI procedure. IVM patients were mildly stimulated using 150 I.U. Gonal-F for 3-4 days. IVM take place according to the procedure of MediCult IVM System (MediCult, Denmark). ICSI was performed 30 hours (Day 0) after IVM medium (MediCult, Denmark). Injected oocytes were then cultured in MediCult ISM1 medium. Number of retrieved oocytes, rates of fertilization and cleavage, quality of embryos and pregnancy rates were compared with PCOS and control group, by Yate's corrected χ2 test. Patients of control group were stimulated in the short protocol using 75 IU of Fostimon with GnRH antagonist Cetrotide. Ovulation was induced by Ovitrelle. Following ICSI, oocytes cultured identically as PCOS oocytes. RESULTS: The mean number of aspirated cumulus enclosed oocytes (CEOs) per patient was 8,8 and was significantly lower in comparison to the control (17,0). A significant difference in the rate of CEOs which reached the MII stage was observed after 30h in the PCO group in comparison to the control (138/257 (53,7%) vs 409/509 (79,4%), respectively, p<0,01). It was not observed differences in fertilization rate (122/156 (78,2%) vs 337/377 (89,4%) however a significant difference was found in cleavage rates (101/119 (84,9%) vs 177/184 (96,2%), p<0.05). A higher value of the mean fragmentation grade of 4-5cell stage embryos was observed on day 2 in the PCO group in comparison to the control group (1,6 vs 1,3 respectively; p<0.01). Twenty six embryo transfers (ET) were performed in the PCO group, resulted in 9 pregnancies (34,6%); 23 ETs were performed in the control group resulted in 13 pregnancies (46,4%; mean of 2.3 vs 2.0 embryos per patient, respectively). CONCLUSIONS: IVM was found to be an efficient method in patients with PCO syndrome. Since our results are based on a small number of patients, further investigation is taking.

Implications of Polycystic Ovary Syndrome on Oocyte Development

Human follicle development requires the recruitment of primordial follicles into a cohort of growing follicles from which one follicle is selected to ovulate a mature oocyte. During this developmental process, complex endocrine and intraovarian paracrine signals create a changing intrafollicular hormonal milieu. With this microenvironment, appropriate cumulus cell-oocyte signaling governs oocyte developmental competence, defined as the ability of the oocyte to complete meiosis and undergo fertilization, embryogenesis, and term development. Many of these mechanisms are perturbed in polycystic ovary syndrome (PCOS), a heterogeneous syndrome characterized by ovarian hyperandrogenism, hyperinsulinemia from insulin resistance, and reduced fecundity. In addition to these endocrinopathies, PCOS also is characterized by paracrine dysregulation of follicle development by intraovarian proteins of the transforming growth factor-beta family. Consequently, PCOS patients undergoing ovarian stimulation for in vitro fertilization are at increased risks of impaired oocyte developmental competence, implantation failure, and pregnancy loss. Recent data demonstrate links between endocrine/paracrine factors and oocyte gene expression in PCOS and suggest that new clinical strategies to optimize developmental competence of PCOS oocytes should target correction of the entire follicle growth and oocyte development process.

Molecular Abnormalities in Oocytes from Women with Polycystic Ovary Syndrome Revealed by Microarray Analysis

Polycystic ovary syndrome (PCOS), the most common cause of anovulatory infertility, is characterized by increased ovarian androgen production and arrested follicle development and is frequently associated with insulin resistance. These PCOS phenotypes are associated with exaggerated ovarian responsiveness to FSH and increased pregnancy loss. The objective of this study was to examine whether the perturbations in follicle growth and the intrafollicular environment affect gene expression and ultimately development of the PCOS oocyte. Oocyte cDNA was subjected to microarray and PCR analysis. This study was conducted at a university laboratory. The study comprised 10 normal ovulatory women and nine women with PCOS. The intervention was GnRH analog/recombinant human FSH therapy for in vitro fertilization. The main outcome measure was mRNA abundance of oocyte-expressed genes. Cluster analysis revealed differences in global gene expression profiles between normal and PCOS oocytes. Of the 8123 transcripts expressed in the oocytes, 374 genes showed significant differences in mRNA abundance in PCOS oocytes. Annotation of the data demonstrated that a subset of these genes was associated with chromosome alignment and segregation during mitosis and/or meiosis. Furthermore, 68 of the differentially expressed genes contained putative androgen receptor and/or peroxisome proliferating receptor gamma binding sites. These analyses demonstrated that normal and PCOS oocytes that are morphologically indistinguishable and of high quality exhibit different gene expression profiles. Promoter analysis suggests that androgens and other activators of nuclear receptors may play a role in differential gene expression in the PCOS oocyte. Likewise, annotation of the differentially expressed genes suggests that defects in meiosis or early embryonic development may contribute to reduced developmental competency of PCOS oocytes.

Aberrant expression of growth differentiation factor-9 in oocytes of women with polycystic ovary syndrome.

Polycystic ovary syndrome (PCOS) is a major cause of female infertility. Despite substantial effort, the etiology and pathogenesis of PCOS and polycystic ovaries (PCO) in women remain unknown. Recent studies in laboratory animals have documented a link between dysfunction of two oocyte growth factors, growth differentiation factor-9 (GDF-9) and bone morphogenetic factor-15 (BMP-15), and aberrant folliculogenesis. Because aberrant follicle development is a hallmark of PCOS, we wondered whether the expression patterns of these growth factors might be disrupted in PCOS and PCO oocytes. To address this issue, we compared the pattern and level of expression of GDF-9 and BMP-15 mRNA in ovaries from normal cycling (n = 12), PCOS (n = 5), and PCO (n = 7) patients. In situ hybridization studies showed that the expression of GDF-9 and BMP-15 is restricted to the oocytes in all ovaries examined. Interestingly, a decreased level of GDF-9 signal was observed in developing PCOS and PCO oocytes, compared with normal. This difference was evident throughout folliculogenesis, beginning at recruitment initiation and continuing through the small Graafian follicle stage. By contrast, there were no qualitative or quantitative changes in the expression of BMP-15 mRNA in PCOS oocytes during folliculogenesis. There were also no significant differences between normal and PCOS and PCOs in the levels of the mRNA encoding the housekeeping gene, cyclophilin. Together, these results indicate that the expression of GDF-9 mRNA is delayed and reduced in PCOS and PCO oocytes during their growth and differentiation phase. Because oocyte-derived GDF-9 is crucial for normal folliculogenesis and female fertility, we suggest that a dysregulation of oocyte GDF-9 expression may contribute to aberrant folliculogenesis in PCOS and PCO women.

Ovulation and the Polycystic Ovary Syndrome

In the 1930s, Stein and Leventhal added amenorrhoea to anovulatory dysfunctional uterine bleeding among the known clinical manifestations of the polycystic ovary syndrome (PCOS). Whatever the menstrual pattern, infrequent or absent ovulation with symmetrical enlargement of the ovaries is now a familiar abnormality in women of reproductive age. Diagnosis of PCOS has developed from just the clinically obvious to an appreciation, through ultrasound imaging of the ovaries and endocrine testing, of its subtler forms. Today's clinicians will identify PCOS on the ultrasound image of many small follicles apparent in the periphery of both ovaries, on raised serum unbound testosterone assays, on exaggeration of serum LH levels with the start of pulsatile GnRH therapy, and on follicular overresponsiveness to injections of FSH. Once among the most treatable causes of infertility, ovulation-induction for PCOS remained unsophisticated while microsurgery and assisted conception dissolved frontiers for other causes of infertility. Whereas we now have the benefit of high technology embryo cryostorage to cope with embarrassingly high yields of PCOS oocytes, we still need to explain why, the bigger the ovaries, the more likely (we have long known it to be) that PCOS can be cured simply by reducing ovarian mass. Some cases of PCOS are hereditary and most seem constitutionally determined. PCOS is so common that the questions must be asked, Are we appreciating an extreme of normal? Could the milder forms of PCOS have--or could PCOS have had--evolutionary usefulness?