Intrafollicular Concentrations of the Oocyte-secreted Factors GDF9 and BMP15 Vary Inversely in Polycystic Ovaries.

CONTEXT: The oocyte-secreted factors growth differentiation factor 9 (GDF9) and bone morphogenetic protein 15 (BMP15) play essential roles in follicle development and oocyte maturation, and aberrant regulation might contribute to the pathogenesis of polycystic ovary syndrome. OBJECTIVE: Are there measurable differences in concentrations of GDF9, BMP15, and the GDF9/BMP15 heterodimer in small antral follicle fluids from women with and without polycystic ovaries (PCO)? DESIGN AND SETTING: Follicle fluids (n = 356) were collected from 4- to 11-mm follicles in unstimulated ovaries of 87 women undergoing ovarian tissue cryopreservation for fertility preservation. PATIENTS: Twenty-seven women with PCO were identified and 60 women without PCO-like characteristics (non-PCO women) were matched according to age and follicle size. MAIN OUTCOME MEASURES: Intrafollicular concentrations of GDF9, BMP15, GDF9/BMP15 heterodimer, anti-Mullerian hormone (AMH), inhibin-A and -B, total inhibin, activin-B and -AB, and follistatin were measured using enzyme-linked immunosorbent assays. RESULTS: The detectability of GDF9, BMP15, and the GDF9/BMP15 heterodimer were 100%, 94.4%, and 91.5%, respectively, and concentrations were significantly negatively correlated with increasing follicle size (P < 0.0001). GDF9 was significantly higher in women with PCO (PCO: 4230 ±â€…189 pg/mL [mean ±â€…SEM], n = 188; non-PCO: 3498 ±â€…199 pg/mL, n = 168; P < 0.03), whereas BMP15 was lower in women with PCO (PCO: 431 ±â€…40 pg/mL, n = 125; non-PCO: 573 ±â€…55 pg/mL, n = 109; P = 0.10), leading to a significantly higher GDF9:BMP15 ratio in women with PCO (P < 0.01). Significant positive associations between BMP15 and AMH, activins, and inhibins in non-PCO women switched to negative associations in women with PCO. CONCLUSIONS: Intrafollicular concentrations of GDF9 and BMP15 varied inversely in women with PCO reflecting an aberrant endocrine environment. An increased GDF9:BMP15 ratio may be a new biomarker for PCO.

Androgen Reduces Mitochondrial Respiration in Mouse Brown Adipocytes: A Model for Disordered Energy Balance in Polycystic Ovary Syndrome.

Polycystic ovary syndrome (PCOS) is a common endocrinopathy that is associated with an adverse metabolic profile including reduced postprandial thermogenesis. Although abnormalities in adipose tissue function have been widely reported in women with PCOS, less is known about direct effects of androgen on white and, particularly, brown adipocytes. The purpose of this study was to investigate the effect of the nonaromatizable androgen dihydrotestosterone (DHT) on (1) lipid accumulation and expression of adipogenic markers in immortalized mouse brown adipose cell lines (IMBATs), (2) mitochondrial respiration in IMBATs, (3) mitochondrial DNA content and gene expression, (4) expression of brown adipose tissue (BAT) markers and thermogenic activation. In addition, we profiled the relative levels of 38 adipokines secreted from BAT explants and looked at androgen effects on adipokine gene expression in both IMBATs and immortalized mouse white adipose (IMWATs) cell lines. Androgen treatment inhibited IMBAT differentiation in a dose-dependent manner, reduced markers of adipogenesis, and attenuated the ß-adrenoceptor-stimulated increase in uncoupling protein-1 (UCP1) expression. In explants of mouse interscapular BAT, androgen reduced expression of UCP1, peroxisome proliferator-activated receptor-γ coactivator-1 (PCG-1) and Cidea. Significantly, as well as affecting genes involved in thermogenesis in BAT, androgen treatment reduced mitochondrial respiration in IMBATs, as measured by the Seahorse XF method. The results of this study suggest a role for excess androgen in inhibiting brown adipogenesis, attenuating the activation of thermogenesis and reducing mitochondrial respiration in BAT. Together, these data provide a plausible molecular mechanism that may contribute to reduced postprandial thermogenesis and the tendency to obesity in women with PCOS.

Gene Expression in Granulosa Cells From Small Antral Follicles From Women With or Without Polycystic Ovaries.

CONTEXT: Polycystic ovary syndrome (PCOS) is the most common cause of anovulation. A key feature of PCOS is arrest of follicles at the small- to medium-sized antral stage. OBJECTIVE AND DESIGN: To provide further insight into the mechanism of follicle arrest in PCOS, we profiled (i) gonadotropin receptors; (ii) characteristics of aberrant steroidogenesis; and (iii) expression of anti-Müllerian hormone (AMH) and its receptor in granulosa cells (GCs) from unstimulated, human small antral follicles (hSAFs) and from granulosa lutein cells (GLCs). SETTING: GCs from hSAFs were collected at the time of cryopreservation of ovarian tissue for fertility preservation and GLCs collected during oocyte aspiration before in vitro fertilization/intracytoplasmic sperm injection. PARTICIPANTS: We collected hSAF GCs from 31 women (98 follicles): 10 with polycystic ovaries (PCO) and 21 without. GLCs were collected from 6 women with PCOS and 6 controls undergoing IVF. MAIN OUTCOME MEASURES: Expression of the following genes: LHCGR, FSHR, AR, INSR, HSD3B2, CYP11A1, CYP19, STAR, AMH, AMHR2, FST, INHBA, INHBB in GCs and GLCs were compared between women with PCO and controls. RESULTS: GCs in hSAFs from women with PCO showed higher expression of LHCGR in a subset (20%) of follicles. Expression of FSHR (P < 0.05), AR (P < 0.05), and CYP11A1 (P < 0.05) was lower, and expression of CYP19A1 (P < 0.05), STAR (P < 0.05), HSD3B2 (P = NS), and INHBA (P < 0.05) was higher in PCO GCs. Gene expression in GL cells differed between women with and without PCOS but also differed from that in GCs. CONCLUSIONS: Follicle arrest in PCO is characterized in GCs by differential regulation of key genes involved in follicle growth and function.

Quantitative Differences in TGF-ß Family Members Measured in Small Antral Follicle Fluids From Women With or Without PCO.

CONTEXT: Members of the TGF-ß family have been implicated in aberrant follicle development in women with polycystic ovaries (PCO). OBJECTIVE: Are there quantitative differences in the concentrations of TGF-ß family members in fluid from human small antral follicles (hSAFs) in women with or without PCO? DESIGN AND SETTING: Follicle fluids (FFs) were collected from 4- to 11-mm hSAFs obtained from women undergoing ovarian tissue cryopreservation for fertility preservation. PATIENTS: FFs from 16 women with PCO (FF = 93) and 33 women without PCO (FF = 92). MAIN OUTCOME MEASURES: Intrafollicular concentrations of growth differentiation factor-9 (GDF9); anti-Müllerian hormone (AMH); inhibin-A and inhibin-B; total inhibin; activin-A, activin-B, and activin-AB; follistatin; follistatin-like-3; estradiol; and testosterone. RESULTS: Activin-B concentrations were reported in hSAFs, and concentrations were 10 times higher than activin-A and activin-AB concentrations. Activin-B showed significant associations with other growth factors. Concentrations of inhibin-A and inhibin-B were significantly lower in FFs from women with PCO, especially in hSAFs <8 mm in diameter. AMH concentrations did not differ between the groups in hSAFs <8 mm; however, AMH remained high in hSAFs >8 mm in women with PCO but decreased in women without PCO. Estradiol was significantly lower in FFs from women with PCO and showed significant associations with AMH. Concentrations of GDF9 showed significantly higher concentrations in PCO FFs of follicles >6 mm. CONCLUSIONS: Altered concentrations of TGF-ß family members in hSAFs from women with PCO highlight altered growth factor signaling as a potential mechanism for follicle growth arrest.

SMAD3 directly regulates cell cycle genes to maintain arrest in granulosa cells of mouse primordial follicles.

Primordial follicles, consisting of granulosa cell (GC)-enveloped oocytes are maintained in a state of developmental arrest until activated to grow. The mechanism that operates to maintain this arrested state in GCs is currently unknown. Here, we show the TGFß-activated transcription factor SMAD3 is expressed in primordial GC nuclei alongside the cell cycle proteins, cyclin D2 (CCND2) and P27. Using neonatal C57/Bl6 mouse ovaries densely populated with primordial follicles, CCND2 protein co-localised and was detected in complex with P27 by immunofluorescence and co-immunoprecipitation, respectively. In the same tissue, SMAD3 co-precipitated with DNA sequences upstream of Ccnd2 and Myc transcription start sites implicating both as direct SMAD3 targets. In older ovaries follicle growth was associated with nuclear exclusion of SMAD3 and reduced P27 and CCND2 in GCs, alongside elevated Myc expression. Brief (2 H) exposure of neonatal ovaries to TGFß1 (10 ng/ml) in vitro led to immediate dissociation of SMAD3 from the Ccnd2 and Myc promoters. This coincided with elevated Myc and phospho-S6, an indicator of mTOR signalling, followed by a small increase in mean primordial GC number after 48 H. These findings highlight a concentration-dependent role for TGFß signalling in the maintenance and activation of primordial follicles, through SMAD-dependent and independent signalling pathways, respectively.

Nuclear exclusion of SMAD2/3 in granulosa cells is associated with primordial follicle activation in the mouse ovary.

Maintenance and activation of the limited supply of primordial follicles in the ovary are important determinants of reproductive lifespan. Currently, the molecular programme that maintains the primordial phenotype and the early events associated with follicle activation are not well defined. Here, we have systematically analysed these events using microscopy and detailed image analysis. Using the immature mouse ovary as a model, we demonstrate that the onset of granulosa cell (GC) proliferation results in increased packing density on the oocyte surface and consequent GC cuboidalization. These events precede oocyte growth and nuclear translocation of FOXO3a, a transcription factor important in follicle activation. Immunolabelling of the TGFß signalling mediators and transcription factors SMAD2/3 revealed a striking expression pattern specific to GCs of small follicles. SMAD2/3 were expressed in the nuclei of primordial GCs but were mostly excluded in early growing follicles. In activated follicles, GC nuclei lacking SMAD2/3 generally expressed Ki67. These findings suggest that the first phenotypic changes during follicle activation are observed in GCs, and that TGFß signalling is fundamental for regulating GC arrest and the onset of proliferation.

Androgen Action in the Ovary.

Androgen production by the ovary is an essential requirement for normal cyclical secretion of estradiol but its physiological role extends to important actions on both preantral and antral follicle development, including promotion of granulosa cell proliferation. It is likely only in mature antral follicles that androgens encourage apoptosis and consequent follicle atresia, and this may be an important mechanism to ensure mono-follicular ovulation in primates, including humans. Recent studies have provided new insight into the mechanism of androgen signaling in the ovary which involves both genomic and non-genomic effects that are complementary in effecting a cellular response. In polycystic ovary syndrome, a condition characterized by intra-ovarian androgen excess, aberrant development of both preantral and antral follicles is a salient feature. We present evidence that local action of androgens plays a part in such abnormalities. Finally, we review the role of androgens in follicle atresia and conclude that the effects are part of the normal physiology of follicle maturation.

Low-dose gonadotropin induction of ovulation in anovulatory women: still needed in the age of IVF.

Low-dose, step-up gonadotropin is the treatment of choice for women with polycystic ovary syndrome (PCOS) who have not conceived after anti-oestrogen treatment and as an effective alternative to pulsatile GnRH in women with hypogonadotropic hypogonadism (HH). There has been, however, no large-scale, comparative study between the two groups using low-dose gonadotropins. Here, we performed a retrospective, comparative analysis, in a single clinic database, of efficacy and safety of induction of ovulation using low-dose gonadotropins in 364 women with PCOS and 80 women with HH. The rate of ovulation was high in both PCOS (83%) and HH (84%) but mono-follicular, ovulatory cycles were more prevalent in PCOS than in HH (77% vs 53%, P < 0.0001) and the proportion of cycles that were abandoned was higher in HH than in PCOS (25% vs 15%, P < 0.0001). The median threshold dose of gonadotropin required to induce ovulation was 75 IU/day in PCOS and 113 IU/day in HH (P < 0.001) and the range of doses was greater in HH women. Forty-nine percent of women with PCOS and 65% of those with HH conceived (more than 90% within 6 cycles of treatment) and had at least one pregnancy. Multiple pregnancies (all twins) occurred in only 4% of women with PCOS and 5% of those with HH. These findings emphasise the efficacy and safety of low-dose gonadotropin treatment for both clomiphene-resistant women with PCOS and those with HH. These results highlight the importance of choosing the more physiological approach of gonadotropin induction of ovulation in both groups as the most appropriate treatment, in preference to IVF.

Genetic Correlation Profile of Schizophrenia Mirrors Epidemiological Results and Suggests Link Between Polygenic and Rare Variant (22q11.2) Cases of Schizophrenia.

New methods in genetics research, such as linkage disequilibrium score regression (LDSR), quantify overlap in the common genetic variants that influence diverse phenotypes. It is becoming clear that genetic effects often cut across traditional diagnostic boundaries. Here, we introduce genetic correlation analysis (using LDSR) to a nongeneticist audience and report transdisciplinary discoveries about schizophrenia. This analytical study design used publically available genome wide association study (GWAS) data from approximately 1.5 million individuals. Genetic correlations between schizophrenia and 172 medical, psychiatric, personality, and metabolomic phenotypes were calculated using LDSR, as implemented in LDHub in order to identify known and new genetic correlations. Consistent with previous research, the strongest genetic correlation was with bipolar disorder. Positive genetic correlations were also found between schizophrenia and all other psychiatric phenotypes tested, the personality traits of neuroticism and openness to experience, and cigarette smoking. Novel results were found with medical phenotypes: schizophrenia was negatively genetically correlated with serum citrate, positively correlated with inflammatory bowel disease, and negatively correlated with BMI, hip, and waist circumference. The serum citrate finding provides a potential link between rare cases of schizophrenia (strongly influenced by 22q11.2 deletions) and more typical cases of schizophrenia (with polygenic influences). Overall, these genetic correlation findings match epidemiological findings, suggesting that common variant genetic effects are part of the scaffolding underlying phenotypic comorbidity. The "genetic correlation profile" is a succinct report of shared genetic effects, is easily updated with new information (eg, from future GWAS), and should become part of basic disease knowledge about schizophrenia.

Onset and Heterogeneity of Responsiveness to FSH in Mouse Preantral Follicles in Culture.

The obligatory role of follicle-stimulating hormone (FSH) in normal development and function of ovarian antral follicles is well recognized, but its function in preantral growth is less clear. The specific objective of this study was to investigate the response, in culture, to FSH of mouse preantral follicles of increasing size, focusing particularly on growth rate and gene expression. Preantral follicles were mechanically isolated from ovaries of C57BL/6 mice, 12 to 16 days postpartum, and single follicles cultured for up to 96 hours in medium alone (n = 511) or with recombinant human FSH 10 ng/mL (n = 546). Data were grouped according to initial follicle diameter in 6 strata ranging from <100 to >140 µm. Follicles of all sizes grew in the absence of FSH (P < 0.01, paired t test). All follicles grew at a faster rate (P < 0.0001) in the presence of 10 ng/mL FSH but larger follicles showed the greatest change in response to FSH. Even the smallest follicles expressed FSH receptor messenger RNA (mRNA). FSH-induced growth was inhibited by KT5720, an inhibitor of protein kinase A (PKA), implicating the PKA pathway in FSH-induced follicle growth. In response to FSH in vitro, FSH receptor mRNA (measured by quantitative polymerase chain reaction) was reduced (P < 0.01), as was Amh (P < 0.01), whereas expression of StAR (P < 0.0001) and the steroidogenic enzymes Cyp11a1 (P < 0.01) and Cyp19 (P < 0.0001) was increased. These results show heterogeneous responses to FSH according to initial follicle size, smaller follicles being less FSH dependent than larger preantral follicles. These findings strongly suggest that FSH has a physiological role in preantral follicle growth and function.

Adiponectin and its receptors in the ovary: further evidence for a link between obesity and hyperandrogenism in polycystic ovary syndrome.

Polycystic ovary syndrome (PCOS), characterized by ovarian androgen excess, is the commonest endocrine disorder in women. Obesity increases androgen synthesis, a phenomenon attributed to the accompanying hyperinsulinemia. Our hypothesis was that adipokines, fat cell-derived hormones, play a direct role in modulating ovarian androgen secretion. Therefore, the aims of this study were to explore the effects of adipokines (in particular, adiponectin) on ovarian steroidogenesis and compare the expression of adiponectin receptors in ovaries from women with and without PCO. Sections of archived human ovaries (nine from women with normal ovaries and 16 with PCOS, classified histologically, with reference to menstrual history and ultrasound) were analysed by quantitative morphometry and the proportion of positive-labelling cells compared. In addition, studies of androgen production in relation to adipokine function in primary bovine theca cell culture were also performed. A significantly lower proportion of theca cells expressed adiponectin receptors 1 and 2 (AdipoR1, AdipoR2) in polycystic ovaries than in normal ovaries. In cultured theca cells, adiponectin suppressed androstenedione production and gene expression of LH receptor and key enzymes in the androgen synthesis pathway. Moreover, knockdown of genes for AdipoR1 and AdipoR2 was associated with increased androstenedione secretion by bovine theca cells. These results provide evidence for a direct link between fat cell metabolism and ovarian steroidogenesis, suggesting that disruption of adiponectin and/or its receptors plays a key role in pathogenesis of hyperandrogenism in PCOS.

Role of Insulin-like growth factors in initiation of follicle growth in normal and polycystic human ovaries.

CONTEXT: Polycystic ovary syndrome (PCOS), the commonest cause of anovulatory infertility, is characterized by disordered follicle development including increased activation and accelerated growth of preantral follicles. Data from experimental animals and preliminary results from studies of human ovarian tissue suggest that IGFs affect preantral follicle development. OBJECTIVE: Our objectives were to investigate the expression of the type-1 IGF receptor (IGFR-1) in the human ovary and to determine whether IGFs are involved in stimulating the transition of follicles from primordial to primary stage in normal and polycystic ovaries. DESIGN: We used archived ovarian tissue for protein expression studies and small cortical biopsies for follicle isolation and for tissue culture. SETTING: This was a laboratory-based study, using clinical tissue samples. PATIENTS: A total of 54 women, 33 with normal ovaries and 21 with polycystic ovaries, were classified by reference to menstrual cycle history and ultrasonography. MAIN OUTCOME MEASURES: We evaluated expression of IGFR-1 mRNA in isolated preantral follicles and of IGFR-1 protein in archived ovarian tissue samples from normal and polycystic ovaries and effects of exogenous IGF-1 on preantral follicle development and survival in cultured fragments of normal and polycystic ovaries. RESULTS: IGFR-1 mRNA and protein was expressed in preantral follicles at all stages of development and enhanced expression was noted in PCOS follicles during early preantral development. IGF-1 stimulated initiation of follicle growth in normal tissue but had little effect on preantral follicle growth in polycystic ovaries in which, characteristically, there was a higher proportion of follicles that had entered the growing phase even before culture. CONCLUSIONS: IGFs are plausible candidates in regulation of initiation of human follicle growth, and accelerated preantral follicle growth in PCOS may be due to increased activity of endogenous IGFs.

Characterization and significance of adhesion and junction-related proteins in mouse ovarian follicles.

In the ovary, initiation of follicle growth is marked by cuboidalization of flattened granulosa cells (GCs). The regulation and cell biology of this shape change remains poorly understood. We propose that characterization of intercellular junctions and associated proteins is key to identifying as yet unknown regulators of this important transition. As GCs are conventionally described as epithelial cells, this study used mouse ovaries and isolated follicles to investigate epithelial junctional complexes (tight junctions [TJ], adherens junctions [AJ], and desmosomes) and associated molecules, as well as classic epithelial markers, by quantitative PCR and immunofluorescence. These junctions were further characterized using ultrastructural, calcium depletion and biotin tracer studies. Junctions observed by transmission electron microscopy between GCs and between GCs and oocyte were identified as AJs by expression of N-cadherin and nectin 2 and by the lack of TJ and desmosome-associated proteins. Follicles were also permeable to biotin, confirming a lack of functional TJs. Surprisingly, GCs lacked all epithelial markers analyzed, including E-cadherin, cytokeratin 8, and zonula occludens (ZO)-1alpha+. Furthermore, vimentin was expressed by GCs, suggesting a more mesenchymal phenotype. Under calcium-free conditions, small follicles maintained oocyte-GC contact, confirming the importance of calcium-independent nectin at this stage. However, in primary and multilayered follicles, lack of calcium resulted in loss of contact between GCs and oocyte, showing that nectin alone cannot maintain attachment between these two cell types. Lack of classic markers suggests that GCs are not epithelial. Identification of AJs during GC cuboidalization highlights the importance of AJs in regulating initiation of follicle growth.

Follicle dynamics and anovulation in polycystic ovary syndrome.

BACKGROUND: Polycystic ovary syndrome (PCOS) is the commonest cause of anovulatory infertility and menstrual cycle abnormalities, but the factors responsible for failure to select a dominant follicle remain unclear. METHOD: Source is authors' own studies and search of the relevant literature. RESULTS: Arrest of antral follicle growth is associated with an abnormal endocrine environment involving hypersecretion of luteinizing hormone and insulin (and perhaps hyperandrogenism). The net effect is secondary suppression of FSH, which leads to inhibition of maturation of otherwise healthy follicles in the cohort. There is, however, emerging evidence for an intrinsic abnormality of folliculogenesis in PCOS that affects the very earliest, gonadotrophin independent, stages of follicle development. There is an increased density of small pre-antral follicles and an increased proportion of early growing follicles. These abnormalities in anovulatory PCOS are further defined by abnormal granulosa cell proliferation and disparate growth of oocyte and surrounding granulosa cells. This suggests that the normal 'dialogue' between oocyte and granulosa cells in these early growing follicles is altered. There is evidence that abnormal, local (follicle-to-follicle) signalling of anti-Müllerian hormone may play a part in disordered folliculogenesis, but it is plausible that other local regulators that have been implicated in normal and abnormal pre-antral follicle development-such as insulin-like growth factors and sex steroids-have a role in aberrant folliculogenesis in PCOS. CONCLUSIONS: Significant abnormalities in the very earliest stages of folliculogenesis may be the root cause of anovulation in PCOS.

Abnormal preantral folliculogenesis in polycystic ovaries is associated with increased granulosa cell division.

CONTEXT: Polycystic ovary syndrome (PCOS) is the most common endocrine disorder in women, but its etiology remains obscure. Recent data suggest that an intrinsic abnormality of early follicle development in the ovary is key to the pathogenesis of PCOS. We have recently found that in PCOS the proportion of primordial follicles is decreased with a reciprocal increase in the proportion of primary follicles. OBJECTIVE: Our aim was to examine whether the accelerated transition of follicles from primordial to primary stages in polycystic ovaries (PCO) is due to increased granulosa cell (GC) division. DESIGN: This study is a comparison of expression of minichromosome maintenance protein 2 (MCM2) (present in the nuclei of cells that are licensed to divide) in archive tissue from normal and PCO. SETTING: This is a laboratory-based study. PATIENTS: There were 16 women with regular cycles (six with normal and 10 with PCO) and five anovulatory women with PCO, classified histologically, with reference to menstrual history and ultrasound. MAIN OUTCOME MEASURES: The presence of MCM2 expression in the GCs of 1,371 follicles was determined. RESULTS: GC proliferation was increased in anovulatory PCO compared with both normal and ovulatory PCO, with an increased proportion of preantral follicles with MCM2-positive GCs (P

Prolonged survival in culture of preantral follicles from polycystic ovaries.

CONTEXT: In polycystic ovary syndrome (PCOS), an increased proportion of follicles leave the primordial (resting) pool and initiate growth. However, there is little evidence for a reduced reproductive life span (early menopause) in women with PCOS, suggesting that the dynamics of follicle growth, and of follicle loss by atresia, is altered in PCOS. OBJECTIVE: The aim of this study was to investigate the possibility that loss of preantral follicles by atresia is reduced in PCOS, leading to prolonged follicle survival. DESIGN: We compared follicle growth in normal and polycystic ovaries using cultures of small ovarian biopsies. SETTING: Tissue samples were obtained at routine laparoscopy from 12 patients with anovulatory PCOS and 16 controls and processed in an ovarian physiology laboratory. MAIN OUTCOME MEASURES: We performed morphometric analysis of follicle population in tissue fixed at time of biopsy (d 0) or after 5, 10, or 15 d in culture. Analyses included assessment of follicle and oocyte diameter, number and proportion of primordial and growing follicles, and number and proportion of atretic follicles. RESULTS: In tissue fixed on d 0, the proportion of healthy growing follicles was, as expected, greater in ovaries from PCOS patients than in normal ovaries (64 vs. 28%; P = 0.0005), but there were no differences between PCOS and normal tissue during culture. The rate of atresia throughout the period of culture in follicles was, however, significantly lower in PCOS tissue (P < 0.0001). After culture, 80% of follicles in normal ovarian tissue were atretic compared with 53% in PCOS biopsies. CONCLUSION: Follicles from polycystic ovaries demonstrate a decreased rate of atresia in culture, suggesting a mechanism for maintaining a larger follicle pool throughout reproductive life.

Disordered follicle development in ovaries of prenatally androgenized ewes.

Exposure to excess androgens in utero induces irreversible changes in gonadotrophin secretion and results in disrupted reproductive endocrine and ovarian function in adulthood, in a manner reminiscent of the common clinical endocrinopathy of polycystic ovary syndrome (PCOS). We have recently identified an abnormality in early follicle development in PCOS which we suggested might be an androgenic effect. We propose that altered ovarian function in androgenized ewes is due to prenatal androgens not only causing an abnormality of gonadotrophin secretion, but also exerting a direct effect on the early stages of folliculogenesis. Therefore, in this study, we explored the possible differences between small preantral follicles in the ovarian cortex of androgenized female lambs with those of normal lambs. At 8 months of age, small ovarian cortical biopsies (approximately 5 mm3) were obtained at laparotomy from nine female lambs that had been exposed to androgens in utero from embryonic days 30 to 90 of a 147-day pregnancy, and 11 control female lambs. Further, ovarian tissue was obtained at 20 months of age from ten androgenized and nine control animals. Tissue was either fixed immediately for histology or cultured for up to 15 days prior to fixing. The number of follicles in haematoxylin and eosin-stained sections was counted and recorded along with the stage of development. Before culture, the total follicle density (follicles/mm3 tissue) was not statistically significantly different between the two types of ovary at either 8 or 20 months of age. Furthermore, there were no statistically significant differences in the density of follicles at each stage of development. However, there was a lower percentage of primordial follicles, but a higher percentage of primary follicles, in biopsies taken at 8 months from androgenized lambs when compared with controls. At 20 months, the proportions of follicles at the primordial and primary stages were not significantly different between the two groups, but this was mainly attributable to an increase in the proportion of growing follicles in biopsies from control animals. Culture of ovarian cortex from 8-month-old lambs resulted in a progressive increase in the proportion of growing follicles when compared with tissue fixed on the day of surgery. However, there was no difference between androgenized and control tissue in the percentage of growing follicles. The increase in the proportion of growing follicles in the cortex of androgenized animals is reminiscent of similar observations in human polycystic ovaries and suggests that excess exposure to androgen in early life plays a part in the accelerated progression of follicle development from the primordial to the primary stage in polycystic ovaries.

Development of polycystic ovary syndrome: involvement of genetic and environmental factors.

We have recently proposed that polycystic ovary syndrome (PCOS) has its origin in fetal life. This hypothesis is based on data from animal models (rhesus monkey or sheep that have been exposed prenatally to high doses of androgen) and is supported by clinical studies. It is suggested that, in human females, exposure to excess androgen, at any stage from fetal development of the ovary to the onset of puberty, leads to many of the characteristic features of PCOS, including abnormalities of luteinizing hormone secretion and insulin resistance. It is likely that, in humans with PCOS, the development of the PCOS phenotype results primarily from a genetic predisposition for the fetal ovary to hypersecrete androgen. At present, it is unclear whether the maternal environment directly influences the development of PCOS in the offspring. Maternal androgen excess is unlikely to affect the fetus, because the placenta presents an effective barrier, but metabolic disturbances during pregnancy could affect development of the syndrome in the fetus. In postnatal life, the natural history of PCOS can be further modified by factors affecting insulin secretion and/or action, most importantly, nutrition. We now have evidence for a disorder of early follicular development in the polycystic ovary that is consistent with an increased population of primordial follicles in the fetal ovary. It remains to be determined whether this phenomenon is the cause or the effect of increased exposure to androgen within the ovary. PCOS is the commonest endocrine disorder in women. It is not only a very prevalent cause of anovulatory infertility, menstrual disturbances and hirsutism, but it is also a major risk factor for the development of type 2 diabetes mellitus in later life. The aetiology of the syndrome remains uncertain but there is increasing evidence for a genetic basis. PCOS very often becomes clinically manifest during adolescence with maturation of the hypothalamic-pituitary-ovarian axis but the genesis of the syndrome may be during very early development - perhaps even in utero. In this review, this hypothesis is explored in the light of clinical, biochemical and genetic research.

Anti-müllerian hormone protein expression is reduced during the initial stages of follicle development in human polycystic ovaries.

CONTEXT: Polycystic ovary syndrome, the most common cause of anovulatory infertility, is characterized by disordered folliculogenesis, notably increased progression from the primordial to the primary stages. This ovarian phenotype is similar to that observed in mice lacking anti-müllerian hormone (AMH). OBJECTIVE: The objective of this study is to investigate whether AMH is involved in accelerating the transition of follicles from primordial to primary stages in polycystic ovaries. DESIGN: This study compares AMH expression in archive tissue from normal and polycystic ovaries. SETTING: This is a laboratory-based study. PATIENTS: Ovarian tissue from seven normoovulatory women and 16 women with polycystic ovaries (five of whom were anovulatory) was used in this study. Ovaries were classified by histology and with reference to menstrual cycle history and ultrasound. MAIN OUTCOME MEASURE: Presence and intensity of AMH expression in 1403 follicles was the main outcome measure. RESULTS: AMH was observed from the primordial stage onward. AMH immunostaining was observed in significantly fewer primordial (P = 0.007) and transitional follicles (P = 0.001) in ovaries from anovulatory women with polycystic ovaries compared with women with regular cycles and either normal or polycystic ovaries. AMH-negative follicles had fewer pregranulosa cells in the largest cross-section of the follicle at both the primordial (median, four and six for AMH-negative and -positive follicles, respectively; P < 0.0001) and transitional stages (median six and nine; P < 0.0007) in normal tissue, and fewer at the transitional stage (median, seven and 11; P < 0.0001) in tissue from anovulatory women with polycystic ovaries. This suggests that AMH expression is associated with granulosa cell mitosis. CONCLUSIONS: These findings indicate a relative deficiency of AMH in primordial and transitional follicles in ovaries from anovulatory women with polycystic ovaries. This may contribute to disordered early follicle development in polycystic ovary syndrome.

Gonadotrophin regimens and oocyte quality in women with polycystic ovaries.

The systemic endocrine environment during the later stages of follicle development has a crucial role in co-ordinating follicular and oocyte maturation before ovulation. Polycystic ovary syndrome (PCOS) is associated with abnormal circulating hormones, abnormal peri-follicular vascularity and significant abnormalities of granulosa cell function. After induction of ovulation, fertilization rates in vivo in women with PCOS are normal, but there is an increased risk of early pregnancy loss, particularly in obese patients. After in-vitro maturation of oocytes or following ovulation induction for IVF, oocyte and embryo quality in vitro are not obviously impaired in PCOS. In some reports however, specific endocrine abnormalities, such as hyperinsulinaemia/insulin resistance, have been noted to be associated with reduced fertilization rates and abnormal early embryonic development.