Granulosa cell survival and proliferation are altered in polycystic ovary syndrome

Developmental Programming: Does Prenatal Steroid Excess Disrupt the Ovarian VEGF System in Sheep?

Prenatal testosterone (T), but not dihydrotestosterone (DHT), excess disrupts ovarian cyclicity and increases follicular recruitment and persistence. We hypothesized that the disruption in the vascular endothelial growth factor (VEGF) system contributes to the enhancement of follicular recruitment and persistence in prenatal T-treated sheep. The impact of T/DHT treatments from Days 30 to 90 of gestation on VEGFA, VEGFB, and their receptor (VEGFR-1 [FLT1], VEGFR-2 [KDR], and VEGFR-3 [FLT4]) protein expression was examined by immunohistochemistry on Fetal Days 90 and 140, 22 wk, 10 mo (postpubertal), and 21 mo (adult) of age. Arterial morphometry was performed in Fetal Day 140 and postpubertal ovaries. VEGFA and VEGFB expression were found in granulosa cells at all stages of follicular development with increased expression in antral follicles. VEGFA was present in theca interna, while VEGFB was present in theca interna/externa and stromal cells. All three receptors were expressed in the granulosa, theca, and stromal cells during all stages of follicular development. VEGFR-3 increased with follicular differentiation with the highest level seen in the granulosa cells of antral follicles. None of the members of the VEGF family or their receptor expression were altered by age or prenatal T/DHT treatments. At Fetal Day 140, area, wall thickness, and wall area of arteries from the ovarian hilum were larger in prenatal T- and DHT-treated females, suggestive of early androgenic programming of arterial differentiation. This may facilitate increased delivery of endocrine factors and thus indirectly contribute to the development of the multifollicular phenotype.

Molecular aspects of bovine cystic ovarian disease pathogenesis

Cystic ovarian disease (COD) is one of the main causes of reproductive failure in cattle and causes severe economic loss to the dairy farm industry because it increases both days open in the post partum period and replacement rates due to infertility. This disease is the consequence of the failure of a mature follicle to ovulate at the time of ovulation in the estrous cycle. This review examines the evidence for the role of altered steroid and gonadotropin signaling systems and the proliferation/apoptosis balance in the ovary with cystic structures. This evidence suggests that changes in the expression of ovarian molecular components associated with these cellular mechanisms could play a fundamental role in the pathogenesis of COD. The evidence also shows that gonadotropin receptor expression in bovine cystic follicles is altered, which suggests that changes in the signaling system of gonadotropins could play a fundamental role in the pathogenesis of conditions characterized by altered ovulation, such as COD. Ovaries from animals with COD exhibit a disrupted steroid receptor pattern with modifications in the expression of coregulatory proteins. These changes in the pathways of endocrine action would trigger the changes in proliferation and apoptosis underlying the aberrant persistence of follicular cysts.

Free Spanish abstract: A Spanish translation of this abstract is freely available at http://www.reproduction-online.org/content/149/6/R251/suppl/DC1.

Estrogen and progesterone receptor subtype expression in granulosa cells from women with polycystic ovary syndrome

We evaluated gene expression of estrogen and progesterone nuclear receptors in granulosa cells (GCs) of polycystic ovary syndrome (PCOS) women compared to women with normal cycling ovaries (control group) to achieve a better understanding of ovarian steroid status in patients with PCOS. In this prospective study, 40 patients with PCOS and 40 women with normal ovulatory function who underwent in vitro fertilization (IVF) for treatment of tubal and/or male infertility were recruited. Follicular fluid was collected from patients and GCs were isolated from follicular fluid and then were purified with Micro Beads conjugated to monoclonal anti-human CD45 antibodies. RNA was extracted and reverse transcription was performed. Gene expression of estrogen and progesterone receptors was determined by quantitative real time PCR (qRT-PCR). Estrogen receptor β (ERβ) expression was significantly higher than ERα expression in both groups (p < 0.002). ERα and ERβ mRNA expression in PCOS was significantly lower than control group (p < 0.002). The expression levels of PRA and PRB in PCOS was significantly lower than control group (p < 0.002). In conclusion, a significant reduction of these genes in GCs from follicles of women with PCOS could be considered as a sign for maturation defect or follicular arrest in GCs.

MicroRNA-93 promotes ovarian granulosa cells proliferation through targeting CDKN1A in polycystic ovarian syndrome

CONTEXT

MicroRNAs (miRNAs) are small, noncoding RNAs that negatively regulate gene expression post-transcriptionally. Whether differently expressed miRNAs contribute to promoting granulosa cell proliferation in polycystic ovarian syndrome disease (PCOS) remains unknown.

OBJECTIVE

We explored whether certain miRNAs are involved in the ovarian dysfunction of PCOS and the mechanism of increased granulosa cells proliferation. Patients and Cells: miRNA expression was analyzed in excised ovarian cortexes from 16 women with PCOS and 8 non-PCOS. An immortalized human granulosa (KGN) cell was used for the mechanism study.

MAIN OUTCOME MEASURES

Expressions of miRNAs in ovarian cortexes were measured using qRT-PCR and KGN granulosa cells were cultured for proliferation assays after overexpression or inhibition of miR-93 or after insulin treatment. Bioinformatics were used to identify the potential miRNA targets. Protein expression analysis, luciferase assays, and rescue assays were used to confirm the substrate of miR-93.

RESULTS

MiR-93 expression was higher in PCOS ovarian cortex and its identified target, CDKN1A, was downregulated. MiR-93 overexpression promoted cell proliferation and G1 to S transition. Knocking down CDKN1A promoted cell growth and cell cycle progression in granulosa cells, and CDKN1A re-introduction reversed the promotional role of miR-93. High concentrations of insulin induced upregulation of miR-93, stimulated KGN cells proliferation and reduced CDKN1A expression.

CONCLUSIONS

miR-93 was increased in PCOS granulosa cells and targeted CDKN1A to promote proliferation and cell cycle progression. Insulin could upregulate the expression of miR-93 and stimulate cell proliferation. This might provide a new insight into the dysfunction of granulosa cells in PCOS.

Granulosa cell-derived induced pluripotent stem cells exhibit pro-trophoblastic differentiation potential

Introduction

Human induced pluripotent stem cells (hiPSCs) have been derived from various somatic cell types. Granulosa cells, a group of cells which surround oocytes and are obtained from the (normally discarded) retrieved egg follicles of women undergoing infertility treatment, are a possible cell source for induced pluripotent stem cell (iPSC) generation. Here, we explored the possibility of using human granulosa cells as a donor cell type for iPSC reprogramming, and compared granulosa cell-derived iPSCs (iGRAs) with those derived from other cell sources, to determine the potential ability of iGRA differentiation.

Methods

Granulosa cells were collected from egg follicles retrieved from women undergoing infertility treatment. After short-term culture, the granulosa cells derived from different patients were mixed in culture, and infected with retroviruses encoding reprogramming factors. The resulting iPSC clones were selected and subjected to microsatellite DNA analysis to determine their parental origin. IGRAs were subjected to RT-PCR, immunofluorescence staining, and in vitro and in vivo differentiation assays to further establish their pluripotent characteristics.

Results

Microsatellite DNA analysis was used to demonstrate that hiPSCs with different parental origins can be simultaneously reprogrammed by retroviral transfection of a mixed human granulosa cell population obtained from multiple individuals. The iGRAs resemble human embryonic stem cells (hESCs) in many respects, including morphological traits, growth requirements, gene and marker expression profiles, and in vitro and in vivo developmental propensities. We also demonstrate that the iGRAs express low levels of NLRP2, and differentiating iGRAs possess a biased differentiation potential toward the trophoblastic lineage. Although NLRP2 knockdown in hESCs promotes trophoblastic differentiation of differentiating hESCs, it does not result in exit from pluripotency. These results imply that NLRP2 may play a role in regulating the trophoblastic differentiation of human pluripotent stem cells.

Conclusions

These findings provide a means of generating iPSCs from multiple granulosa cell populations with different parental origins. The ability to generate iPSCs from granulosa cells not only enables modeling of infertility-associated disease, but also provides a means of identifying potential clinical interventions through iPSC-based drug screening.

Electronic supplementary material

The online version of this article (doi:10.1186/s13287-015-0005-5) contains supplementary material, which is available to authorized users.

Defective CFTR-regulated granulosa cell proliferation in polycystic ovarian syndrome

Polycystic ovarian syndrome (PCOS) is one of the most frequent causes of female infertility, featured by abnormal hormone profile, chronic oligo/anovulation, and presence of multiple cystic follicles in the ovary. However, the mechanism underlying the abnormal folliculogenesis remains obscure. We have previously demonstrated that CFTR, a cAMP-dependent Cl(-) and HCO3 (-) conducting anion channel, is expressed in the granulosa cells and its expression is downregulated in PCOS rat models and human patients. In this study, we aimed to investigate the possible involvement of downregulation of CFTR in the impaired follicle development in PCOS using two rat PCOS models and primary culture of granulosa cells. Our results indicated that the downregulation of CFTR in the cystic follicles was accompanied by reduced expression of proliferating cell nuclear antigen (PCNA), in rat PCOS models. In addition, knockdown or inhibition of CFTR in granulosa cell culture resulted in reduced cell viability and downregulation of PCNA. We further demonstrated that CFTR regulated both basal and FSH-stimulated granulosa cell proliferation through the HCO3 (-)/sAC/PKA pathway leading to ERK phosphorylation and its downstream target cyclin D2 (Ccnd2) upregulation. Reduced ERK phosphorylation and CCND2 were found in ovaries of rat PCOS model compared with the control. This study suggests that CFTR is required for normal follicle development and that its downregulation in PCOS may inhibit granulosa cell proliferation, resulting in abnormal follicle development in PCOS.

Is AMH a regulator of follicular atresia?

We discuss the hypothesis that AMH is an intraovarian regulator that inhibits follicular atresia within the human ovary. Several indirect lines of evidence derived from clinical and basic science studies in a variety of different patient populations and model systems collectively support this hypothesis. Evidence presented herein include 1) timing of onset of menopause in women with polycystic ovary syndrome, 2) site of cellular origin and timing of AMH production, 3) AMH's influence on other critical growth factors and enzymes involved in folliculogenesis, and 4) AMH's inhibition of granulosa apoptosis. If this hypothesis is true, it may provide insight for treatment strategies for prevention and treatment of premature ovarian insufficiency, slowing natural ovarian aging, and/or delaying eventual ovarian failure. Such findings may lead to the development of 1) AMH agonists for retarding the onset of menopause and/or as a chemoprotectant prior to cancer therapy and 2) AMH antagonists for the treatment of PCOS.

The effect of calcium and vitamin D supplementation on menstrual cycle, body mass index and hyperandrogenism state of women with poly cystic ovarian syndrome

BACKGROUND

Poly cystic ovary syndrome (PCOS) is considered one of the most common endocrine disorders of women in reproductive age. The aim of this study was evaluating the efficacy of calcium and Vitamin D supplementation on the regularity of menstrual cycles, body mass index (BMI) and hyper androgenism state of women with PCOS.

MATERIALS AND METHODS

In this clinical trial, 80 women with PCOS were evaluated. They randomly located in four groups receiving metformin (group 1), metformin plus calcium and Vitamin D (group 2), calcium and Vitamin D (group 3) and placebo (group 4) for 4 months. BMI, regularity of menstrual cycles, hyperandrogenism (hirsutism and acne) and serum calcium and Vitamin D levels were compared in four studying groups at baseline and 4 months after the trial.

RESULTS

All studied subjects were similar at baseline (P > 0.05). After trial, the frequency of hirsutism and acne were not different among groups. Frequency regular menstrual cycle and dominant follicle were significantly higher in group 1 and 2 than others (P < 0.05). After trial, there was no significant difference with respect to BMI among groups.

CONCLUSION

Vitamin D and calcium supplementation in addition to metformin therapy in women with PCOS could result in a better outcome in a variety of PCOS symptoms including menstrual regularity, and ovulation.

The effect of metformin treatment in vivo on acute and long-term energy metabolism and progesterone production in vitro by granulosa cells from women with polycystic ovary syndrome

STUDY QUESTION

What are the consequences of polycystic ovary syndrome (PCOS) pathology and metformin-pretreatment in vivo in women with PCOS on the metabolism and steroid production of follicular phenotype- and long-term cultured-granulosa cells (GC)?

SUMMARY ANSWER

PCOS pathology significantly compromised glucose metabolism and the progesterone synthetic capacity of follicular- and long-term cultured-GCs and the metabolic impact of PCOS on GC function was alleviated by metformin-pretreatment in vivo.

WHAT IS KNOWN ALREADY

Granulosa cells from women with PCOS have been shown to have an impaired insulin-stimulated glucose uptake and lactate production in vitro. However, these results were obtained by placing GCs in unphysiological conditions in culture medium containing high glucose and insulin concentrations. Moreover, existing data on insulin-responsive steroid production in vitro by PCOS GCs vary.

STUDY DESIGN, SIZE AND DURATION

Case-control experimental research comparing glucose uptake, pyruvate and lactate production and progesterone production in vitro by GCs from three aetiological groups, all undergoing IVF; healthy control women (Control, n = 12), women with PCOS treated with metformin in vivo (Metformin, n = 8) and women with PCOS not exposed to metformin (PCOS, n = 8). The study was conducted over a period of 3 years between 2007 and 2010.

PARTICIPANTS/MATERIALS, SETTING, METHODS

Rotterdam criteria were used for the diagnosis of PCOS; all subjects were matched for age, BMI and baseline FSH. Individual patient cultures were undertaken with cells incubated in a validated, physiological, serum-free culture medium containing doses of 0–6 mM glucose and 0–100 ng/ml insulin for 6 h and 144 h to quantify the impact of treatments on acute and long-term metabolism, respectively, and progesterone production. The metabolite content of spent media was measured using spectrophotometric plate reader assay. The progesterone content of spent media was measured by enzyme-linked immunosorbent assay. Viable GC number was quantified after 144 h of culture by the vital dye Neutral Red uptake assay.

MAIN RESULTS AND THE ROLE OF CHANCE

Granulosa cells from women with PCOS pathology revealed reduced pyruvate production and preferential lactate production in addition to their reduced glucose uptake during cultures (P < 0.05). Metformin pretreatment alleviated this metabolic lesion (P < 0.05) and enhanced cell proliferation in vitro (P < 0.05), but cells retained a significantly reduced capacity for progesterone synthesis compared with controls (P < 0.05).

LIMITATIONS, REASONS FOR CAUTION

Although significant treatment effects were detected in this small cohort, further studies are required to underpin the molecular mechanisms of the effect of metformin on GCs.

WIDER IMPLICATIONS OF THE FINDINGS

The individual patient culture strategy combined with multifactorial experimental design strengthens the biological interpretation of the data. Collectively, these results support the notion that there is an inherent impairment in progesterone biosynthetic capacity of the GCs from women with PCOS. The positive, acute metabolic effect and the negative long-term steroidogenic effect on GCs following metformin exposure in vivo may have important implications for follicular development and luteinized GC function when the drug is used in clinical practice.

STUDY FUNDING/COMPETING INTEREST(S)

No competing interests. This work was supported by the UK Medical Research Council Grant Reference number G0800250.

Developmental programming: Impact of prenatal testosterone treatment and postnatal obesity on ovarian follicular dynamics

Prenatal testosterone (T) excess leads to reproductive dysfunctions in sheep with obesity exaggerating such defects. Developmental studies found ovarian reserve is similar in control and prenatal T sheep at fetal day 140, with prenatal T females showing increased follicular recruitment and persistence at 10 months of age (postpubertal). This study tested if prenatal T sheep show accelerated depletion prepubertally and if depletion of ovarian reserve would explain loss of cyclicity in prenatal T females and its amplification by postnatal obesity. Stereological examinations were performed at 5 (prepubertal, control and prenatal T) and 21 months (control, prenatal T and prenatal T obese, following estrus synchronization) of age. Obesity was induced by overfeeding from weaning. At 5 months, prenatal T females had 46% less primordial follicles than controls (P < 0.01), supportive of increased follicular depletion. Depletion rate was slower and a higher percentage of growing follicles was present in 21 month than 5 month old prenatal T females (P < 0.01). Postnatal obesity did not exaggerate the impact of prenatal T on follicular recruitment indicating that compounding effects of obesity on loss of cyclicity females is not due to depletion of ovarian reserve. Assessment of follicular dynamics across several time points during the reproductive life span (this and earlier study combined) provides evidence supportive of a shift in follicular dynamics in prenatal T females from one of accelerated follicular depletion initiated prior to puberty to stockpiling of growing follicles after puberty, a time point critical in the development of the polycystic ovary syndrome phenotype.

Evidence for decreased expression of ADAMTS-1 associated with impaired oocyte quality in PCOS patients

CONTEXT

Polycystic ovary syndrome (PCOS) is the most common cause of dysfunctional ovulation-affecting female fertility. A disintegrin and metalloproteinase with thrombospondin-like motifs (ADAMTS-1) is required for normal ovulation and subsequent fertilization, and the expression of ADAMTS-1 may be altered in PCOS granulosa cell (GC)-reflecting abnormalities in ovulatory signaling.

OBJECTIVE

The purpose of this paper is to analyze the differential expression of ADAMTS-1 in PCOS patients associated with impaired oocyte quality.

DESIGN AND SETTING

A prospective comparative experimental study was performed at a clinical reproductive medicine center.

PATIENTS

Women with PCOS (n = 40) and normovulatory controls (n = 40) undergoing controlled ovarian hyperstimulation and in vitro fertilization were recruited in our study.

MAIN OUTCOME MEASURES

Differential expression of ADAMTS-1 in GCs was analyzed with immunocytochemistry in PCOS patients and normal controls, and ADAMTS-1 mRNA expression was quantified by RT-PCR. Furthermore, the correlation between ADAMTS-1 mRNA and oocyte quality was analyzed.

RESULTS

The expression of ADAMTS-1 was decreased in PCOS patients compared with normally ovulating women and was closely related to lower oocyte recovery, oocyte maturity, and fertilization rate.

CONCLUSION

Our study provides evidence that the dysregulated expression of ADAMTS-1 in PCOS may influence oocyte quality-via GCs-oocyte paracrine and endocrine mechanism.

Increased expression of kindlin 2 in luteinized granulosa cells correlates with androgen receptor level in patients with polycystic ovary syndrome having hyperandrogenemia

Hyperandrogenemia is the leading defect in patients with polycystic ovary syndrome (PCOS) and considered to be involved in the ovulation dysfunction of PCOS. During the process of ovulation, granulosa cells (GCs) undergo epithelial-mesenchymal transition (EMT), and integrin-interacting protein kindlin 2 is a well-known regulator in EMT. Therefore, our objective here was to compare the expression levels of kindlin 2 in luteinized GCs between patients with PCOS and control women and the relationship between kindlin 2 and PCOS pathogenesis. In this study, kindlin 2 expression was significantly increased in luteinized GCs from patients with PCOS, and kindlin 2 could be induced by testosterone both in vitro and in vivo. Meanwhile, kindlin 2 was positively correlated with androgen receptor (AR) in PCOS GCs. Taken together, kindlin 2 may play a role in luteinized GCs, especially in the case of excess androgen. Further studies are required to assess the specific role of kindlin 2 in follicular development and PCOS pathogenesis.

Genetic factors modulate the impact of pubertal androgen excess on insulin sensitivity and fertility

Polycystic ovary syndrome (PCOS) is the most common endocrine disorder of reproductive age women. The syndrome is caused by a combination of environmental influences and genetic predisposition. Despite extensive efforts, the heritable factors contributing to PCOS development are not fully understood. The objective of this study was to test the hypothesis that genetic background contributes to the development of a PCOS-like reproductive and metabolic phenotype in mice exposed to excess DHEA during the pubertal transition. We tested whether the PCOS phenotype would be more pronounced on the diabetes-prone C57BL/6 background than the previously used strain, BALB/cByJ. In addition, we examined strain-dependent upregulation of the expression of ovarian and extra-ovarian candidate genes implicated in human PCOS, genes containing known strain variants, and genes involved with steroidogenesis or insulin sensitivity. These studies show that there are significant strain-related differences in metabolic response to excess androgen exposure during puberty. Additionally, our results suggest the C57BL/6J strain provides a more robust and uniform experimental platform for PCOS research than the BALB/cByJ strain.

Oxidative status in granulosa cells of infertile women undergoing IVF

Studies on elevated reactive oxygen species (ROS) levels in granulosa cells (GC) and its subsequent effect on fertilization are limited. Oxidative stress (OS) mediated alterations in GC of infertile women undergoing in vitro fertilization (IVF) and embryo transfer (ET) was investigated. GC were obtained from 28 women with endometriosis (Group A), 26 women with polycystic ovary syndrome (PCOS) (Group B), and 32 women with tubal factor infertility (Group C). GC characteristics including cell count, viability, morphology and number of oocytes retrieved, and oocyte quality were assessed. OS parameters such as ROS, mitochondrial membrane potential (MMP), and DNA fragmentation were also studied and IVF outcome parameters assessed. An ∼20 fold increase in GC ROS generation was observed in Group B as compared to Group C. Though not as high as Group B, Group A also showed significantly high ROS levels compared with Group C. More than 100-fold decrease in MMP in Group B compared with Group C was observed. A similar trend was observed in Group A, where MMP decreased 7 fold. Significant apoptosis was evident in Groups A and B supported by depolarization of MMP and significant increase in DNA damage. IVF outcome parameters including fertilization rate, good quality embryo formation rate, and pregnancy outcome were adversely affected in Group B. It is hypothesized that ∼20 fold increase in ROS generation in GC of PCOS women plays an adverse role in affecting the IVF success rate. It was of note that the IVF outcome parameters of women with endometriosis were not affected.

Metformin: the hidden chronicles of a magic drug

Metformin, a biguanide is well known treatment for type 2 diabetes mellitus that has diverse mechanism of actions. Various studies have elucidated the role of this drug in different pathologies. The well-known United Kingdom Prospective Diabetic Study (UKPDS) has observed its survival benefits in a large cohort of individuals. Data has been conclusive that metformin also has beneficial role in lipid disorders as it improves the markers of metabolic syndrome. Studies have also shown the beneficial roles in antipsychotic induced weight gain as well as HIV lipodystrophy syndrome. Evidence is accumulating that metformin also improves the fertility in females with Polycystic Ovarian Syndrome (PCOS). It also delays aging and is effective in aging related disorders and is equally effective in inflammation related disorders at least in different rodent studies. Metformin's major effect has been shown in various cancers ranging from solid to hematological malignancies. Researchers are working to reveal more benefits of this magic drug but it remains an unexplored territory for the medical community.

Effects of resveratrol on growth and function of rat ovarian granulosa cells

OBJECTIVE

To evaluate the effects of resveratrol on growth and function of granulosa cells. Previously, we demonstrated that resveratrol exerts profound proapoptotic effects on theca-interstitial cells.

DESIGN

In vitro study.

SETTING

Research laboratory.

ANIMAL(S)

Immature Sprague-Dawley female rats.

INTERVENTION(S)

Granulosa cells were cultured in the absence or presence of resveratrol.

MAIN OUTCOME MEASURE(S)

DNA synthesis was determined by thymidine incorporation assay, apoptosis by activity of caspases 3/7, cell morphology by immunocytochemistry, steroidogenesis by mass spectrometry, antimüllerian hormone (AMH), and vascular endothelial growth factor (VEGF) expression by polymerase chain reaction and Western blot.

RESULT(S)

Resveratrol induced a biphasic effect on DNA synthesis, whereby a lower concentration stimulated thymidine incorporation and higher concentrations inhibited it. Additionally, resveratrol slightly increased the cell number and modestly decreased the activity of caspases 3/7 with no effect on cell morphology or progesterone production. However, resveratrol decreased aromatization and VEGF expression, whereas AMH expression remained unaltered.

CONCLUSION(S)

Resveratrol, by exerting cytostatic but not cytotoxic effects, together with antiangiogenic actions mediated by decreased VEGF in granulosa cells, may alter the ratio of theca-to-granulosa cells and decrease vascular permeability, and therefore may be of potential therapeutic use in conditions associated with highly vascularized theca-interstitial hyperplasia and abnormal angiogenesis, such as those seen in women with polycystic ovary syndrome.

The effects of calcitriol on improvement of insulin resistance, ovulation and comparison with metformin therapy in PCOS patients: a randomized placebo- controlled clinical trial

BACKGROUND

Polycystic ovary syndrome (PCOS) is the most common endocrine disorder in females of reproductive age. Insulin resistance is a frequent metabolic disturbance in PCOS. Vitamin D deficiency is a common problem. Accumulating evidence suggests that vitamin D has a role on insulin sensitivity so may contribute to reduction of hyperandrogenemia.

OBJECTIVE

The aim was to determine the effects of vitamin D treatment in metabolic components and ovulation evidence in PCOS.

MATERIALS AND METHODS

Fifty one untreated PCOS patients were randomly divided into three groups and treated with calcitriol, metformin, or placebo. Before and 3 months after treatment, ovulation evidence was assessed by ovarian trans abdominal sonography. Plasma fasting glucose, insulin, homeostasis model assessment insulin resistance (HOMA-IR), 25-hydroxyvitamin D, parathyroid hormone and androgen levels were measured before and after treatment. A 75gr glucose test was performed before and after treatment and two set of results was compared.

RESULTS

Three patients did not continue this study. Only 11 patient (22.9%) had sufficient vitamin D levels (>30 ng/ml). Metformin caused a significant decrease in weight (p=0.027), insulin level (p=0.043), and insulin resistance (p=0.048). Systolic blood pressure and PTH significantly improved after calcitriol (p=0.029, p=0.009 respectively). An improvement in ovulation was detected after calcitriol and seven patients, without evidence of ovulation before treatment, illustrated ovulation after 3 months. Difference with calcitriol in ovulation was significant versus other two methods (p=0.02).

CONCLUSION

Calcitriol treatment in PCOS may be prior to metformin in ovulation induction.

XIAP: a potential determinant of ovarian follicular fate

X-linked inhibitor of apoptosis protein (XIAP), a member of the inhibitor of apoptosis protein family, is involved in regulating a number of functions including receptor-mediated intracellular signalling and early development. Its role as an endogenous caspase inhibitor, however, is the most highly characterised. Consequently, this protein has been implicated as an anti-apoptotic factor in the ovary.In vitroandin vivostudies have begun dissecting the stimuli and signalling networks that lead to XIAP upregulation in granulosa cells. The objective of this review is to briefly summarise the current knowledge concerning XIAP and its interactions with different caspases. Furthermore, XIAP's emerging role in the mammalian ovary will be explored and comparison is made with its functions in the mammary gland. Finally, the idea that XIAP may act as a molecular signalling switch in granulosa cells following detachment from underlying layers to promote follicular atresia will be introduced.

Developmental programming: impact of prenatal testosterone excess on ovarian cell proliferation and apoptotic factors in sheep

Prenatal testosterone (T) excess leads to reproductive dysfunctions in sheep, which include increased ovarian follicular recruitment and persistence. To test the hypothesis that follicular disruptions in T sheep stem from changes in the developmental ontogeny of ovarian proliferation and apoptotic factors, pregnant Suffolk sheep were injected twice weekly with T propionate or dihydrotestosterone propionate (DHT; a nonaromatizable androgen) from Days 30 to 90 of gestation. Changes in developmental expression of proliferating cell nuclear antigen (PCNA), BCL2, BAX, activated CASP3, and FAS/FASLG were determined at Fetal Days 90 and 140, 22 wk, 10 mo, and 21 mo of age by immunocytochemisty. Prenatal T treatment induced changes in expression of proliferative and apoptotic markers in a follicle-, age-, and steroid-specific manner. Changes in BAX were evident only during fetal life and PCNA, BCL2, and CASP3 only postnatally. Prenatal T and not DHT increased PCNA and decreased BCL2 in granulosa/theca cells of antral follicles at 10 and 21 mo but decreased CASP3 in granulosa/theca cells of antral follicles at 22 wk (prepubertal) and 10 and 21 mo. Both treatments decreased BAX immunostaining in granulosa cells of Fetal Day 90 primordial/primary follicles. Neither treatment affected FAS expression at any developmental time point in any follicular compartment. Effects on BAX appear to be programmed by androgenic actions and PCNA, BCL2, and CASP3 by estrogenic actions of T. Overall, the findings demonstrate that fetal exposure to excess T disrupts the ovarian proliferation/apoptosis balance, thus providing a basis for the follicular disruptions evidenced in these females.

Overexpression of ribosomal RNA in cumulus cells of patients with polycystic ovary syndrome

OBJECTIVE

To evaluate the level of ribosomal RNA (rRNA) in cumulus cells (CCs) from women with polycystic ovary syndrome (PCOS) undergoing ICSI.

MATERIALS AND METHODS

The study population included three healthy oocyte donors (control) and three patients with PCOS. RNA expression in CCs was assessed using quantitative real-time PCR assay to measure the pre-rRNA transcripts (5'ETS region), 18 S, 5.8 S and 28 S rRNA.

RESULTS

The level of 18 S rRNA is 3.9 times higher (p = 0.036) and the level of 5.8 S rRNA is 2.9 times higher (p = 0.049) in CCs of PCOS patients than in CCs of healthy women. The fold change in expression of 28 S rRNA in CCs of PCOS patients also exceeds that in the control group, but did not reach a statistical significance (p = 0.342).

CONCLUSION

Our observations support the idea that CCs of PCOS patients contain comparatively more ribosomes that CCs of healthy oocyte donors that may indicate a higher proliferation rate or up-regulated translation of protein factors in ССs of PCOS patients.

Serum 25-Hydroxyvitamin D Levels, phosphoprotein enriched in diabetes gene product (PED/PEA-15) and leptin-to-adiponectin ratio in women with PCOS

Background

Polycystic ovary syndrome (PCOS) is frequently associated with hypovitaminosis D. Vitamin D is endowed with pleiotropic effects, including insulin resistance (IR) and apoptotic pathway. Disruption of the complex mechanism that regulated ovarian apoptosis has been reported in PCOS. Phosphoprotein enriched in diabetes gene product (PED/PEA-15), an anti-apoptotic protein involved in type 2 diabetes mellitus (T2DM), is overexpressed in PCOS women, independently of obesity. Leptin-to-adiponectin ratio (L/A) is a biomarker of IR and low-grade inflammation in PCOS. The aim of the study was to investigate the levels of 25-hydroxy vitamin D (25(OH)D), and L/A, in association with PED/PEA-15 protein abundance, in both lean and overweight/obese (o/o) women with PCOS.

Patients and Methods

PED/PEA-15 protein abundance and circulating levels of 25(OH)D, L/A, sex hormone-binding globulin, and testosterone were evaluated in 90 untreated PCOS patients (25 ± 4 yrs; range 18-34) and 40 healthy controls age and BMI comparable, from the same geographical area. FAI (free androgen index) and the homeostasis model assessment of insulin resistance (HoMA-IR) index were calculated.

Results

In o/o PCOS, 25(OH)D levels were significantly lower, and L/A values were significantly higher than in lean PCOS (p < 0.001), while there were no differences in PED/PEA-15 protein abundance. An inverse correlation was observed between 25(OH)D and BMI, PED/PEA-15 protein abundance, insulin, HoMA-IR, FAI (p < 0.001), and L/A (p < 0.05). At the multivariate analysis, in o/o PCOS L/A, insulin and 25(OH)D were the major determinant of PED/PEA-15 protein abundance (β = 0.45, β = 0.41, and β = -0.25, respectively).

Conclusions

Lower 25(OH)D and higher L/A were associated to PED/PEA-15 protein abundance in PCOS, suggesting their involvement in the ovarian imbalance between pro-and anti-apoptotic mechanisms, with high L/A and insulin and low 25(OH)D levels as the main determinants of PED/PEA-15 protein variability. Further studies, involving also different apoptotic pathways or inflammatory cytokines and granulosa cells are mandatory to better define the possible bidirectional relationships between 25(OH)D, PED/PEA-15 protein abundance, leptin and adiponectin in PCOS pathogenesis.

Sustained fertility from 22 to 41 years of age in women with polycystic ovarian syndrome

BACKGROUND

Subfertility due to chronic anovulation is common in women with polycystic ovary syndrome (PCOS) and is often treated with IVF. Women with PCOS have an increased ovarian follicle and oocyte count, increased ovarian reserve and/or a slower rate of follicle atresia. If so, one would expect women with PCOS to display a delayed reduction in fertility with advancing age as compared with eumenorrheic women.

METHODS

To test this hypothesis, we compared oocyte count and live birth rates among two groups undergoing IVF, 500 women with PCOS and 500 eumenorrheic women with infertility due to tubal factor only.

RESULTS

Across the age range of 22-41 years, oocyte count and live birth rates remained stable in women with PCOS. In the eumenorrheic comparison group, these parameters decreased significantly with age.

CONCLUSIONS

Women with PCOS display sustained fertility with advancing age as compared with infertile eumenorrheic women.

Human chorionic gonadotropin up-regulates expression of myeloid cell leukemia-1 protein in human granulosa-lutein cells: implication of corpus luteum rescue and ovarian hyperstimulation syndrome

CONTEXT

The corpus luteum is a dynamic endocrine structure with periodic development and regression during menstrual cycles. Its lifespan can be prolonged by human chorionic gonadotropin (hCG). However, the signal mechanisms of this phenomenon remain unclear.

OBJECTIVE

Our objective was to investigate the molecular mechanisms of hCG in the maintenance of the viability of granulosa-lutein cells.

DESIGN

Granulosa-lutein cells were obtained from women undergoing in vitro fertilization. We examined the effects of hCG on the survival of cultured granulosa-lutein cells. The signal pathway inducing antiapoptotic protein was investigated.

RESULTS

hCG enhanced viability of granulosa-lutein cells through antiapoptosis but not proliferation, because the apoptotic marker of annexin V was decreased, but the proliferative markers of Ki67 and proliferating cell nuclear antigen were not increased. Myeloid cell leukemia-1 (Mcl-1) protein, but not B-cell lymphoma protein-2 or B-cell lymphoma protein-xL, was significantly induced by hCG and LH. The granulosa-lutein cells secreted vascular endothelial growth factor that induced endothelial permeability. Mcl-1 small interfering RNA increased DNA fragmentation and diminished the antiapoptotic effect of hCG. hCG induced Mcl-1 expression through the LH/hCG receptor, adenylate cyclase, protein kinase A, and cAMP response element-binding protein signal pathway. Flavopiridol inhibited Mcl-1 production, released cytochrome c, and induced apoptosis of granulosa-lutein cells.

CONCLUSIONS

We first demonstrate that hCG prevents apoptosis of granulosa-lutein cells through the induction of Mcl-1 protein via the LH/hCG receptor and a cAMP response element-binding protein-dependent pathway. We may have found the molecular mechanism for luteal rescue during early pregnancy. Mcl-1 prevents apoptosis and increases cell viability but not proliferation as mechanisms for luteal rescue. Mcl-1 is a key molecule of hCG signaling.

Downregulation of both gene expression and activity of Hsp27 improved maturation of mouse oocyte in vitro

BACKGROUND

Heat shock protein 27 (Hsp27), a member of the small heat shock protein family, is an apoptosis regulator. Our previous proteomic study showed that Hsp27 mainly expressed in human oocyte, and that Hsp27 expression was downregulated in the ovaries derived from women with the polycystic ovary syndrome (PCOS), a well known endocrinal disorder with abnormal apoptotic activity and folliculogenesis. However, the exact effects of Hsp27 downregulation on oocyte development have not yet been clarified.

METHODS

The expression of Hsp27 gene was downregulated in the mouse oocytes cultured in vitro using siRNA adenovirus infection, while the activity of Hsp27 was decreased by microinjection of polyclonal Hsp27 antibody into the cytoplasm of germinal vesicle (GV) oocytes. Oocyte maturation rate was evaluated by morphological observation. Early stage of apoptosis was determined using Annexin-V staining analysis and some critical apoptotic factors and cytokines were also monitored at both mRNA level by real time RT-PCR and protein expression level by immunofluorescence and western blot.

RESULTS

Hsp27 expressed at high level in maturing oocytes. Infection with AdshHsp27, and microinjection of Hsp27 antibody into GV oocytes, resulted in the improved oocyte development and maturation. Germinal vesicle breakdown (GVBD) rates were significantly increased in two AdshHsp27-treated groups (88.7%, 86.0%) and Hsp27 antibody-injected group (77.0%) when compared with control (76.2% in AdGFP, 64.4% in IgG-injected), respectively. In addition, the rates of metaphase II (MII) development in two AdshHsp27-treated groups (73.8%, 76.4%) and Hsp27 antibody-injected group (67.3%) were higher than that in the controls (59.6% in AdGFP, 55.1% in IgG-injected). We also found that the rates of early stage of apoptosis in Hsp27 downregulated groups (46.5% and 45.6%) were higher than that in control group (34.1%) after 8 h of IVM. Similarly, downregulation of Hsp27 caused a significantly enhanced the expression of apoptotic factors (caspase 8, caspase 3) and cytokines (bmp 15 and gdf 9).

CONCLUSIONS

Downregulation of Hsp27 improved the maturation of mouse oocytes, while increased early stage of apoptosis in oocytes by inducing the activation of extrinsic, caspase 8-mediated pathway.

PPAR-gamma coactivator-1alpha regulates progesterone production in ovarian granulosa cells with SF-1 and LRH-1

Previously, we demonstrated that bone marrow-derived mesenchymal stem cells (MSCs) differentiate into steroidogenic cells such as Leydig and adrenocortical cells by the introduction of steroidogenic factor-1 (SF-1) and treatment with cAMP. In this study, we employed the same approach to differentiate umbilical cord blood (UCB)-derived MSCs. Despite UCB-MSCs differentiating into steroidogenic cells, they exhibited characteristics of granulosa-luteal-like cells. We found that peroxisome proliferator-activated receptor-gamma coactivator-1alpha (PGC-1alpha) was expressed and further induced by cAMP stimulation in UCB-MSCs. Consistent with these results, tissue-specific expression of Pgc-1alpha was observed in rat ovarian granulosa cells. PGC-1alpha binds to the NR5A family [SF-1 and liver receptor homolog-1 (LRH-1)] of proteins and markedly enhances their transcriptional activities. Reporter assays revealed that PGC-1alpha activated the promoter activities of SF-1 and LRH-1 target genes. Infection of KGN cells (a human cell line derived from granulosa cells) with adenoviruses expressing PGC-1alpha resulted in the induction of steroidogenesis-related genes and stimulation of progesterone production. PGC-1alpha also induced SF-1 and LRH-1, with the latter induced to a greater extent. Knockdown of Pgc-1alpha in cultured rat granulosa cells resulted in attenuation of gene expression as well as progesterone production. Transactivation of the NR5A family by PGC-1alpha was repressed by Dax-1. PGC-1alpha binds to the activation function 2 domain of NR5A proteins via its consensus LXXLL motif. These results indicate that PGC-1alpha is involved in progesterone production in ovarian granulosa cells by potentiating transcriptional activities of the NR5A family proteins.

Metformin decreases IGF1-induced cell proliferation and protein synthesis through AMP-activated protein kinase in cultured bovine granulosa cells

Although its mechanism of action is still unclear, metformin is an anti-diabetic drug effective to restore cyclicity and spontaneous ovulation in women with polycystic ovary syndrome. It may also reduce the risk of cancer. We have recently shown that metformin treatment decreases steroidogenesis through AMP-activated kinase (AMPK) in granulosa cells of various species. Here, we investigated the effects and the molecular mechanisms of metformin in IGF1-induced proliferation and protein synthesis in cultured bovine granulosa cells. Treatment with metformin (10 mM) for 24 h reduced cell proliferation and the levels of cyclin D2 and E, and increased the associations cyclin D2/p21 and cyclin D2/p27 without affecting cell viability in response to IGF1 (10(-8) M). It also decreased IGF1-induced protein synthesis and phosphorylation of P70S6 kinase and ribosomal S6 protein. Interestingly, metformin treatment for 1 h decreased MAPK3/1 (ERK1/2) and P90RSK phosphorylation without affecting AKT phosphorylation in response to IGF1. Adenovirus-mediated expression of dominant-negative AMPK totally abolished the effects of metformin on cell proliferation and phosphorylation of P70S6K in response to IGF1. It also eliminated the inhibitory effects of metformin on MAPK3/1 and P90RSK phosphorylation. Taken together, our results strongly suggest that metformin reduces cell growth, protein synthesis, MAPK3/1, and P90RSK phosphorylation in response to IGF1 through an AMPK-dependent mechanism in cultured bovine granulosa cells.

The hypoxia-inducible factor 1/NOR-1 axis regulates the survival response of endothelial cells to hypoxia

Hypoxia induces apoptosis but also triggers adaptive mechanisms to ensure cell survival. Here we show that the prosurvival effects of hypoxia-inducible factor 1 (HIF-1) in endothelial cells are mediated by neuron-derived orphan receptor 1 (NOR-1). The overexpression of NOR-1 decreased the rate of endothelial cells undergoing apoptosis in cultures exposed to hypoxia, while the inhibition of NOR-1 increased cell apoptosis. Hypoxia upregulated NOR-1 mRNA levels in a time- and dose-dependent manner. Blocking antibodies against VEGF or SU5614 (a VEGF receptor 2 inhibitor) did not prevent hypoxia-induced NOR-1 expression, suggesting that NOR-1 is not induced by the autocrine secretion of VEGF in response to hypoxia. The reduction of HIF-1 alpha protein levels by small interfering RNAs, or by inhibitors of the phosphatidylinositol-3 kinase (PI3K)/Akt pathway or mTOR, significantly counteracted hypoxia-induced NOR-1 upregulation. Intracellular Ca(2+) was involved in hypoxia-induced PI3K/Akt activation and in the downstream NOR-1 upregulation. A hypoxia response element mediated the transcriptional activation of NOR-1 induced by hypoxia as we show by transient transfection and chromatin immunoprecipitation assays. Finally, the attenuation of NOR-1 expression reduced both basal and hypoxia-induced cIAP2 (cellular inhibitor of apoptosis protein 2) mRNA levels, while NOR-1 overexpression upregulated cIAP2. Therefore, NOR-1 is a downstream effector of HIF-1 signaling involved in the survival response of endothelial cells to hypoxia.

An imbalance between apoptosis and proliferation contributes to follicular persistence in polycystic ovaries in rats

BACKGROUND

Cystic ovarian disease is an important cause of infertility that affects bovine, ovine, caprine and porcine species and even human beings. Alterations in the ovarian micro-environment of females with follicular cysts could alter the normal processes of proliferation and programmed cell death in ovarian cells. Thus, our objective was to evaluate apoptosis and proliferation in ovarian cystic follicles in rats in order to investigate the cause of cystic follicle formation and persistence.

METHODS

We compared the number of in situ apoptotic cells by TUNEL assay, expression of active caspase-3 and members of Bcl-2 family by immunohistochemistry; and cell proliferation by the expression of the proliferation markers: PCNA and Ki-67.

RESULTS

The proliferation index was low in granulosa of tertiary and cystic follicles of light exposed rats when compared with tertiary follicles of control animals, while in theca interna only cystic follicles presented low proliferation index when compared with tertiary follicles (p < 0.05). The granulosa of cysts exhibited a similar cell DNA fragmentation to early atretic follicles. In the granulosa and theca interna, active caspase-3 shown similar immunostaining levels in tertiary and cystic follicles (p < 0.05). The granulosa cells presented high expression of Bcl-2, Bcl-xL and Bcl-w in the tertiary and cystic follicles with diminishing intensity in the atretic follicles, except with Bcl-w where the intensity was maintained in the atretic follicles (p < 0.05). The expression of Bax was weak in the healthy and cystic follicles. In the theca interna, Bcl-2 expression was the same as the pattern found in the granulosa; no differences were found between tertiary and cystic follicles from both groups for Bcl-xL and Bcl-w. The expression of Bax in this layer was higher in the tertiary follicles of the treated animals (p < 0.05) while the values for cystic follicles were similar to those in the tertiary follicles of controls. The theca externa showed low expression of the pro and anti-apoptotic proteins.

CONCLUSION

These results show that the combination of weak proliferation indices and low apoptosis observed in follicular cysts, could explain the cause of the slow growth of cystic follicles and the maintenance of a static condition without degeneration, which leads to their persistence. These alterations may be due to structural and functional modifications that take place in these cells and could be related to hormonal changes in animals with this condition.

First evidence of genetic association between AKT2 and polycystic ovary syndrome

OBJECTIVE

Insulin resistance has been reported in up to 70% of women with polycystic ovary syndrome (PCOS). Physiologic and genetic data currently implicate post-insulin receptor signaling defects in substrates such as glycogen synthase kinase 3beta (GSK3beta). The AKT2 gene was chosen as a candidate for PCOS because its product affects glucose metabolism and mitogenic signaling, interacts with GSK3beta, and mediates cell survival in the ovary.

RESEARCH DESIGN AND METHODS

Subjects were recruited from the reproductive endocrinology clinic at the University of Alabama at Birmingham, and control subjects were recruited from the surrounding community; 287 white women with PCOS and 187 white control subjects were genotyped for four single nucleotide polymorphisms (SNPs) in AKT2. Genotyping took place at Cedars-Sinai Medical Center in Los Angeles. SNPs and haplotypes were tested for association with PCOS risk and phenotypic markers of PCOS.

RESULTS

Minor allele carriers of SNPs rs3730051 and rs8100018 had increased odds of PCOS (odds ratio [OR] 2.2, P = 0.004, and 2.4, P = 0.001, respectively). The haplotype T-G-C-T was significantly associated with PCOS (OR 2.0, P = 0.01). Carriers of the risk haplotypes for both AKT2 and GSK3B had a further increased odds of PCOS (OR 3.1, P = 0.005).

CONCLUSIONS

These data suggest that polymorphisms in two components of the insulin signaling pathway, AKT2 and GSK3B, are associated with PCOS. The presence of multiple lesions in a single pathway may confer increased risk.

Selective impairment in glycogen synthase kinase-3 and mitogen-activated protein kinase phosphorylation: comparisons with the hyperandrogenic and the hyperinsulinemic rats

OBJECTIVE

To characterize and compare the effect of DHEA and insulin plus hCG on ovarian morphology, estrous cycle, hormonal levels, insulin sensitivity, and the regulation of insulin signaling in rats.

DESIGN

Animal model study.

SETTING

University laboratory.

ANIMAL(S)

Female Sprague-Dawley rats.

INTERVENTION(S)

Female rats received DHEA or insulin plus hCG by continuous administration.

MAIN OUTCOME MEASURE(S)

Ovarian morphology, estrous cycle, hormonal levels, insulin sensitivity, protein levels, and phosphorylation state of glycogen synthase kinase-3beta and extracellular regulated kinase 1/2 in the ovary.

RESULT(S)

Rats treated with DHEA displayed anovulation, insulin resistance, and polycystic ovaries characterized by cysts and a diminished granulosa layer. In contrast, insulin plus hCG results in acyclicity with increasing androgen biosynthesis and ovarian morphology different from that in DHEA-treated rats. Moreover, we found that insulin-stimulated serine-phosphorylation of glycogen synthase kinase-3beta was higher in insulin plus hCG-treated rats but lower in DHEA-treated rats. Furthermore, basal and insulin-stimulated tyrosine-phosphorylation of extracellular regulated kinase 1/2 was higher in DHEA-treated rats than in controls.

CONCLUSION(S)

Notwithstanding that both the hyperandrogenism and the hyperinsulinemia synergistic with hCG-treated rats displayed the typical traits of human polycystic ovary syndrome, there is a divergence in the insulin-signaling pathway in the ovarian tissue, which may have a role in the pathogenesis of polycystic ovary syndrome.