Dysregulation of cytochrome P450 17alpha-hydroxylase messenger ribonucleic acid stability in theca cells isolated from women with polycystic ovary syndrome

Biochemical classification diagnosis of polycystic ovary syndrome based on serum steroid hormones

Polycystic ovary syndrome (PCOS) is a metabolic disorder with clinical heterogeneity. PCOS women with non-hyperandrogenemia (NA) might be misdiagnosed due to a lack of diagnostic markers. This study aims to systematically analyze the differences in steroid hormones between PCOS women with hyperandrogenemia (HA) and NA, and to screen classification diagnosis models for PCOS. The serum samples from 54 HA-PCOS, 79 NA-PCOS and 60 control women (Non-PCOS) aged between 18 and 35 were measured by an integrated steroid hormone-targeted quantification assay using LC-MS/MS. The levels of serum androgens, corticosteroids, progestins and estrogens in the steroid hormone biosynthesis pathway were analyzed in PCOS and Non-PCOS women. Eight machine learning methods including Linear Discriminant Analysis (LDA), K-nearest Neighbors (KNN), Boosted Logistic Regression (LogitBoost), Naive Bayes (NB), C5.0 algorithm (C5), Random Forest (RF), Support Vector Machines (SVM), and Neural Network (NNET) were performed, evaluated and selected for classification diagnosis of PCOS. A 10-fold cross-validation on the training set was performed. The whole metabolic flux from cholesterol to downstream steroid hormones increased significantly in PCOS, especially in HA-POCS women. The RF model was chosen for the classification diagnosis of HA-PCOS, NA-PCOS, and Non-PCOS women due to the maximum average accuracy (0.938, p<0.001), AUC (0.989, p<0.001), and kappa (0.906, p<0.001), and the minimum logLoss (0.200, p<0.001). Five steroid hormones including testosterone, androstenedione, total 2-methoxyestradiol, total 4-methoxyestradiol, and free estrone were selected as the decision trees for the simplified RF model. A total of 37 women were included in the validation set. The diagnostic sensitivity for HA-PCOS, NA-PCOS, and Non-PCOS was 100 %, 93.3 % and 91.7 %, respectively. HA-PCOS, NA-PCOS, and Non-PCOS women showed obvious different steroid hormone profiles. The simplified RF model based on two androgens and three estrogens could be effectively applied to the classification diagnosis of PCOS, further reducing the missed diagnosis rate of NA-PCOS.

Therapeutic effects and molecular mechanisms of quercetin in gynecological disorders

Quercetin is a representative flavonoid that is widely present in fruits, herbs, and vegetables. It is also an important active core component in traditional Chinese medicines. As an important flavonoid, quercetin has various properties and exerts antioxidant, anti-inflammatory, and cardioprotective effects. The public interest in quercetin is increasing, and quercetin has been used to prevent or treat numerous of diseases, such as polycystic ovary syndrome (PCOS), cancer, autoimmune diseases and chronic cardiovascular diseases, in clinical experiments and animal studies due to its powerful antioxidant properties and minimal side effects. Quercetin exerts marked pharmacological effects on gynecological disorders; however, there have been no reviews about the potential health benefits of quercetin in the context of gynecological disorders, including PCOS, premature ovary failure (POF), endometriosis (EM), ovarian cancer (OC), cervical cancer (CC) and endometrial carcinoma (EC). Thus, this review aimed to summarize the biological effects of quercetin on gynecological disorders and its mechanisms.

Understanding hirsutism in PCOS

INTRODUCTION

Hirsutism is a prevalent condition among women and represents a primary clinical feature of polycystic ovary syndrome (PCOS).

AREAS COVERED

Our study aims to address the principal challenges associated with this hyperandrogenic manifestation in PCOS women. Our narrative review based on the available indexed literature explored the complexities of establishing mFG cutoff values for various ethnic groups, investigated hirsutism during peri- and postmenopausal stages, and examined the role of oxyandrogens.

EXPERT OPINION

Hirsutism may have a negative impact on the quality of life and on the mental health, being associated with anxiety and depression. Future perspectives for its diagnosis include the use of artificial intelligence and the consideration of the distress caused by excessive hair growth.

Effects of Berberine on glucolipid metabolism among dehydroepiandrosterone-induced rats of polycystic ovary syndrome with insulin-resistance

Polycystic ovary syndrome (PCOS) is a set of endocrine disorder syndrome characterized by ovulation disorder. Increased insulin resistance (IR) and compensatory hyperinsulinemia play a vital role in the pathogenesis of PCOS. Therefore, insulin sensitizing agents have been studied in the treatment of PCOS. Berberine (BBR) has been proved to alleviate IR in patients with PCOS, but the mechanism remained unclear. This study was aimed to verify the regulatory mechanism of BBR on PCOS-IR rats. Firstly, we established a female rat PCOS-IR model induced by dehydroepiandrosterone (DHEA) and found that estrus cycle was disrupted in the PCOS-IR group, serum fasting insulin (FINS) level and the homeostasis model assessment of insulin resistance (HOMA-IR) index were significantly higher than normal control group. BBR treatment could recover estrous cycle, reduce abnormal serum hormone levels like luteotropic hormone (LH) and testosterone (T). Most importantly, BBR could concentration-dependently reduce serum FINS level in PCOS-IR rat model. Meanwhile, BBR may improve the abnormal lipid metabolism levels in PCOS-IR group by decreasing low density lipoprotein (LDL), total cholesterol (TC) and triglyceride (TG). Histological results showed that BBR can also protect normal histological structures of ovaries in PCOS-IR rats. Our results indicated that BBR plays a protective role in PCOS-IR, increasing insulin sensitivity, improving hyperandrogens and recovering abnormal blood lipids. Therefore, Our research provides novel insights for therapeutic treatment of BBR in patients with glucolipid metabolic disturbances.

Therapeutic Potential of Mesenchymal Stem Cells in PCOS

Polycystic ovary syndrome (PCOS) is a major reproductive endocrine disorder affecting different facets of a woman's life, comprising reproduction, metabolism, and mental health. Recently, several research groups have brought attention to the therapeutic capacity of mesenchymal stem cells (MSCs) for the treatment of female reproductive disorders. It is highlighted that the treatment with bone marrow mesenchymal stem cells (BMMSCs) considerably diminishes the levels of some inflammatory markers as well as essential genes for ovarian production of androgens, which are considerably higher in theca cells of PCOS women than in those of healthy cases. In addition, studies show that BMMSCs improve in vitro maturation (IVM) of germinal vesicles (GVs) and the number of antral follicles while lessening the number of primary and preantral follicles in mice with PCOS compared to healthy controls. Regarding adipose- derived mesenchymal stem cells (AdMSCs), these cells restore the ovarian structure, enhance the number of oocytes and corpora luteum, and diminish the number of aberrant cystic follicles in PCOS rats. Some research also indicates that umbilical cord mesenchymal stem cells (UC-MSCs) alleviate the inflammation of granulosa cells in women with PCOS. Therefore, due to the limited research on MSC therapy in PCOS, in this review, we summarize the current knowledge on the therapeutic potential of three types of MSCs: BMMSCs, AdMSCs, UC-MSCs and their secretome in the treatment of PCOS.

Single-Cell RNA-Seq Identifies Pathways and Genes Contributing to the Hyperandrogenemia Associated with Polycystic Ovary Syndrome

Polycystic ovary syndrome (PCOS) is a common endocrine disorder characterized by hyperandrogenemia of ovarian thecal cell origin, resulting in anovulation/oligo-ovulation and infertility. Our previous studies established that ovarian theca cells isolated and propagated from ovaries of normal ovulatory women and women with PCOS have distinctive molecular and cellular signatures that underlie the increased androgen biosynthesis in PCOS. To evaluate differences between gene expression in single-cells from passaged cultures of theca cells from ovaries of normal ovulatory women and women with PCOS, we performed single-cell RNA sequencing (scRNA-seq). Results from these studies revealed differentially expressed pathways and genes involved in the acquisition of cholesterol, the precursor of steroid hormones, and steroidogenesis. Bulk RNA-seq and microarray studies confirmed the theca cell differential gene expression profiles. The expression profiles appear to be directed largely by increased levels or activity of the transcription factors SREBF1, which regulates genes involved in cholesterol acquisition (LDLR, LIPA, NPC1, CYP11A1, FDX1, and FDXR), and GATA6, which regulates expression of genes encoding steroidogenic enzymes (CYP17A1) in concert with other differentially expressed transcription factors (SP1, NR5A2). This study provides insights into the molecular mechanisms underlying the hyperandrogenemia associated with PCOS and highlights potential targets for molecular diagnosis and therapeutic intervention.

Associations of LH and FSH with reproductive hormones depending on each stage of the menopausal transition

INTRODUCTION

Associations of luteinizing hormone (LH) with androgens during the menopausal transition and associations between follicle-stimulating hormone (FSH) levels and various diseases related to reproductive hormones in postmenopause have received much attention. LH and FSH are also known to be associated with activities of enzymes related to reproductive hormones. We examined the associations of LH and FSH with androgens and estrogens in each stage of the menopausal transition according to a classification from menopausal transition to postmenopause.

METHODS

This study was a cross-sectional design. We basically used the Stage of Reproductive Aging Workshop (STRAW) + 10. We divided the 173 subjects into 6 groups according to menstrual regularity and follicle-stimulating hormone level: mid reproductive stage (Group A), late reproductive stage (Group B), early menopausal transition (Group C), late menopausal transition (Group D), very early postmenopause (Group E) and early postmenopause (Group F). Levels of LH, FSH, dehydroepiandrosterone sulfate (DHEAS), estradiol, estrone, testosterone (T), free T, androstenedione and androstenediol were measured.

RESULTS

In Group A, LH showed significant positive correlations with androstenedione and estrone. In Group D, LH was positively associated with T and free T and was negatively associated with estradiol. In Groups B, C, D and F, LH showed significant positive correlations with FSH, and there was a tendency for an association between LH and FSH in Group E. FSH was associated with estradiol but not with estrone in Groups C and D.

CONCLUSION

The associations of LH and FSH with reproductive hormones are different depending on the stage of the menopausal transition.

TRIAL REGISTRATION

Trial registration number 2356-1; Date of registration: 18/02/2018, retrospectively registered.

Loci on chromosome 12q13.2 encompassing ERBB3, PA2G4 and RAB5B are associated with polycystic ovary syndrome

Polycystic ovary syndrome (PCOS) is characterized by hyperandrogenemia of ovarian theca cell origin. We report significant association of androgen production with 15 single nucleotide variants (SNVs) identified by exome sequencing of theca cells from women with PCOS and normal ovulatory women. Ten SNVs are located within a 150 kbp region on 12q13.2 which encompasses loci identified in PCOS genome-wide association studies (GWAS) and contains PCOS candidate genes ERBB3 and RAB5B. The region also contains PA2G4 which encodes a transcriptional corepressor of androgen receptor and androgen receptor-regulated genes. PA2G4 has not previously been recognized as related to PCOS in published GWAS studies. Two of the SNVs are predicted to have functional consequences (ERBB3 missense SNV, PA2G4 promoter SNV). PA2G4 interacts with the ERBB3 cytoplasmic domain containing the missense variant, suggesting a potential signaling pathway disruption that could lead to the PCOS ovarian phenotype. Single cell RNA sequencing of theca cells showed significantly less expression of PA2G4 after forskolin treatment in PCOS cells compared to normal cells (padj = 3.82E-30) and in cells heterozygous for the PA2G4 promoter SNV compared to those without the SNV (padj = 2.16E-11). This is consistent with a functional effect of the PA2G4 promoter SNV. No individual SNV was significantly associated with PCOS in an independent family cohort, but a haplotype with minor alleles of three SNVs was found preferentially in women with PCOS. These findings suggest a functional role for 12q13.2 variants in PCOS and implicate variants in ERBB3 and PA2G4 in the pathophysiology of PCOS.

Low temperature plasma protects against inflammatory agents-mediated dysfunction of theca cells via enhancing MANF expression

BACKGROUND

Low temperature plasma (LTP) exerts a protective effect in inflammation via enhancing MANF expression. Hyperactivation and dysfunction of theca cells induced by inflammatory agents is accompanied by polycystic ovary syndrome (PCOS), which is a common reproductive and endocrine disorder. However, the effect of LTP on theca cells is still unknown.

METHODS AND RESULTS

Theca cells were stimulated with IL-1β or TNF-α for 12 h, then treated with LTP for 100 s. After 8 h, medium supernatant and theca cells were collected. Production of androgen from theca cells were detected by ELISA. The PCNA and Annexin V levels in theca cells were detected by using immunofluorescent staining. The levels of PCNA, BCL-2 and BAX were evaluated by western blot and qPCR. MTT assay was used to detect the viability of theca cells. The proportions of apoptosis of theca cells were detected by Flow cytometry. The mRNA levels of androgenic genes were detected by qPCR. The MANF levels in medium supernatant and cell lysate were detected by using ELISA, western and qPCR. BIP and CHOP expressions were detected by using western blot and qPCR. We found that LTP irradiation decreased inflammatory agents-induced upregulation of androgen and androgenic genes in theca cells. And LTP irradiation relieves IL-1β or TNF-α-induced pathological proliferation and apoptosis in theca cells. In terms of mechanism, LTP irradiation increased MANF level in theca cells to inhibit BIP and CHOP expression.

CONCLUSION

These evidences suggest the protective effect of LTP on theca cells in inflammatory microenvironment, and LTP has the potential clinical application of PCOS.

Apigenin exerts protective effect and restores ovarian function in dehydroepiandrosterone induced polycystic ovary syndrome rats: a biochemical and histological analysis

BACKGROUND

Polycystic ovarian syndrome (PCOS) is one of the major causes encouraging the elevation of androgens, obesity along with menstrual complications. Here we study the effect of Apigenin in rat model of polycystic ovarian syndrome.

METHODS

Female Sprague Dawley (SD) rats were treated with Dehydroepiandrosterone (DHEA) (6 mg/100g) opting the post-pubertal approach for developing rat model of polycystic ovarian syndrome, Metformin was used as standard. The treatments were given for 21 days along with coloproctological analysis. After the treatment regimen, the biochemical analysis was carried in plasma samples, whereas the ovaries were submitted for histopathological analysis.

RESULTS

The treatment of DHEA resulted in disturbed lipid profile and anti-oxidant status along with increased weight, ovarian diameter and cysts in rats confirming the development of PCOS. However, treatment of Apigenin showed ameliorative effect by improving the lipid profile and anti-oxidant status, the treatment also normalised the body weight, reduced ovarian diameter, cysts and restored the healthy follicles compared to control rats. The treatment of Apigenin also suppressed the levels of oestradiol and testosterone compared to control group, also, levels of progesterone were increased in Apigenin treated group of rats. The treatment of Apigenin suppressed the levels of inflammatory cytokines TNF-α and IL-6. It was observed that the effect of Apigenin were to some extent parallel to standard drug Metformin.

CONCLUSION

The findings confirmed that Apigenin ameliorates the disturbed hormonal levels, lipid profile and antioxidant status in PCOS rats.

Differentiating Polycystic Ovary Syndrome from Adrenal Disorders

Although polycystic ovary syndrome (PCOS) is primarily considered a hyperandrogenic disorder in women characterized by hirsutism, menstrual irregularity, and polycystic ovarian morphology, an endocrinological investigation should be performed to rule out other hyperandrogenic disorders (e.g., virilizing tumors, non-classical congenital adrenal hyperplasia (NCAH), hyperprolactinemia, and Cushing’s syndrome) to make a certain diagnosis. PCOS and androgen excess disorders share clinical features such as findings due to hyperandrogenism, findings of metabolic syndrome, and menstrual abnormalities. The diagnosis of a woman with these symptoms is generally determined based on the patient’s history and rigorous clinical examination. Therefore, distinguishing PCOS from adrenal-originated androgen excess is an indispensable step in diagnosis. In addition to an appropriate medical history and physical examination, the measurement of relevant basal hormone levels and dynamic tests are required. A dexamethasone suppression test is used routinely to make a differential diagnosis between Cushing’s syndrome and PCOS. The most important parameter for differentiating PCOS from NCAH is the measurement of basal and ACTH-stimulated 17-OH progesterone (17-OHP) when required in the early follicular period. It should be kept in mind that rapidly progressive hyperandrogenic manifestations such as hirsutism may be due to an androgen-secreting adrenocortical carcinoma. This review discusses the pathophysiology of androgen excess of both adrenal and ovarian origins; outlines the conditions which lead to androgen excess; and aims to facilitate the differential diagnosis of PCOS from certain adrenal disorders.

Follicular Fluid: A Powerful Tool for the Understanding and Diagnosis of Polycystic Ovary Syndrome

Polycystic ovary syndrome (PCOS) represents one of the leading causes of anovulatory infertility and affects 5% to 20% of women worldwide. Until today, both the subsequent etiology and pathophysiology of PCOS remain unclear, and patients with PCOS that undergo assisted reproductive techniques (ART) might present a poor to exaggerated response, low oocyte quality, ovarian hyperstimulation syndrome, as well as changes in the follicular fluid metabolites pattern. These abnormalities originate a decrease of Metaphase II (MII) oocytes and decreased rates for fertilization, cleavage, implantation, blastocyst conversion, poor egg to follicle ratio, and increased miscarriages. Focus on obtaining high-quality embryos has been taken into more consideration over the years. Nowadays, the use of metabolomic analysis in the quantification of proteins and peptides in biological matrices might predict, with more accuracy, the success in assisted reproductive technology. In this article, we review the use of human follicular fluid as the matrix in metabolomic analysis for diagnostic and ART predictor of success for PCOS patients.

De Novo and Depot-Specific Androgen Production in Human Adipose Tissue: A Source of Hyperandrogenism in Women with Obesity

INTRODUCTION

Obesity in women is often associated with hyperandrogenism, but the role of adipose tissue (AT) in androgen synthesis remains unclear. Therefore, we studied whether AT could be a source of androgens promoting hyperandrogenism.

METHODS

Subcutaneous and visceral (visc) AT was collected from lean and obese women. Androgen levels were evaluated in serum, AT, and cell-culture supernatant. Gene and protein expression of steroidogenic enzymes were determined.

RESULTS

Obese subjects had elevated serum androgen levels, which reduced after weight loss. Androgens were measurable in AT and in cell-culture supernatants of adipocytes. Steroids were higher in AT from obese women, with the highest difference for testosterone in visc AT (+7.9-fold, p = 0.032). Steroidogenic enzymes were expressed in human AT with depot-specific differences. Obese women showed a significantly higher expression of genes of the backdoor pathway and of CYP19 in visc AT.

CONCLUSION

The whole steroidogenic machinery of the classical and backdoor pathways of steroidogenesis, and the capacity for androgen biosynthesis, were found in both AT depots and cultured adipocytes. Therefore, we hypothesize that AT is a de novo site of androgen production and the backdoor pathway of steroidogenesis might be a new pathomechanism for hyperandrogenism in women with obesity.

The role of polymorphism in various potential genes on polycystic ovary syndrome susceptibility and pathogenesis

Polycystic ovary syndrome (PCOS) is the most common endocrinopathies affecting the early reproductive age in women, whose pathophysiology perplexes many researchers till today. This syndrome is classically categorized by hyperandrogenism and/or hyperandrogenemia, menstrual and ovulatory dysfunction, bulky multi follicular ovaries on Ultrasonography (USG), and metabolic abnormalities such as hyperinsulinemia, dyslipidemia, obesity. The etiopathogenesis of PCOS is not fully elucidated, but it seems that the hypothalamus-pituitary-ovarian axis, ovarian, and/or adrenal androgen secretion may contribute to developing the syndrome. Infertility and poor reproductive health in women's lives are highly associated with elevated levels of androgens. Studies with ovarian theca cells taken from PCOS women have demonstrated increased androgen production due to augmented ovarian steroidogenesis attributed to mainly altered expression of critical enzymes (Cytochrome P450 enzymes: CYP17, CYP21, CYP19, CYP11A) in the steroid hormone biosynthesis pathway. Despite the heterogeneity of PCOS, candidate gene studies are the widely used technique to delineate the genetic variants and analyze for the correlation of androgen biosynthesis pathway and those affecting the secretion or action of insulin with PCOS etiology. Linkage and association studies have predicted the relationship between genetic variants and PCOS risk among families or populations. Several genes have been proposed as playing a role in the etiopathogenesis of PCOS, and the presence of mutations and/or polymorphisms has been discovered, which suggests that PCOS has a vital heritable component. The following review summarizes the influence of polymorphisms in crucial genes of the steroidogenesis pathway leading to intraovarian hyperandrogenism which can result in PCOS.

The interference effects of bisphenol A on the synthesis of steroid hormones in human ovarian granulosa cells

Numerous studies have shown that endocrine-disrupting chemicals are one of the important pathogenic factors in women with polycystic ovary syndrome. Our previous study has revealed that bisphenol A (BPA) can cause steroid hormone imbalance, polycystic ovary, and estrus cycle disorder. In this study, we aimed to explore the effect of BPA, a typical environmental estrogen, on the synthesis of steroid hormones in human ovarian granulosa KGN cells. Exposure of KGN cells to BPA (0.5, 5, 50, and 500 μg/L) resulted in the decrease of progesterone (P), estradiol (E2), and the ratio of estradiol to testosterone (E2/T). BPA affected the expression of genes related to steroid hormone synthesis in KGN cells, including the decreased expression of the steroidogenic acute regulatory protein, ferredoxin, and ferredoxin reductase genes during progesterone synthesis; upregulating the expression of cytochrome p450 oxidoreductase gene associated with E2 and T synthesis; and the downregulated cytochrome P450 family 1 subfamily A member 1 and cytochrome P450 family 1 subfamily B member 1 in E2 degradation. BPA also reduced the expression of stimulatory G proteins (GS) in follicle-stimulating hormone receptor (FSHR)/GS/adenylate cyclase (AC) signaling pathway. In summary, our research has demonstrated that environment-relevant level of BPA exposure leads to steroid hormone synthesis disorder in human ovarian granulosa cells, which might cause the reduction of gene expression in hormone synthesis and the suppression of the FSHR/GS/AC signaling pathway.

Steroid metabolome profiling of follicular fluid in normo- and hyperandrogenic women with polycystic ovary syndrome

Polycystic ovary syndrome (PCOS) is a heterogeneous disease defined by the presence of at least two of the following features: hyperandrogenism, oligoanovulation (OA), and polycystic ovarian morphology (PCOM). Hyperandrogenism is considered the cornerstone of PCOS. However, the most prevalent phenotype in Chinese women with PCOS is OA + PCOM [normo-androgenic PCOS (NA-PCOS)]. It has been reported that PCOS women have higher androgen levels in follicular fluid (FF), but whether NA-PCOS women have the same intrafollicular steroid profiles as hyperandrogenic PCOS (HA-PCOS) women has not been explored. In this study, we analyzed 17 steroids in stimulated size-matched ovarian follicles (16-18 mm) from 166 controls and 141 PCOS women [87 NA-PCOS and 54 HA-PCOS women, defined by a single serum testosterone (T) immunoassay measurement] using liquid chromatography tandem mass spectrometry, and investigated their relationship with baseline characteristics. No significant differences in intrafollicular steroid levels and product/precursor ratios between NA-PCOS and HA-PCOS women were observed, though HA-PCOS women had significantly higher serum luteinizing hormone and T levels than NA-PCOS women. NA-PCOS and HA-PCOS women had significantly higher levels of androstenedione (AD), T and free androgen index, higher enzyme activity of P450c17 (AD/17OH-progesterone), 3βHSD2 (17OH-progesterone /17OH-pregnenolone) and P450c11 (corticosterone /11-deoxycorticosterone), lower levels of pregnenolone, 17OH-pregnenolone and 11-deoxycorticosterone, and decreased enzyme activity of P450aro (estrone/AD and estradiol/T) and 5α-reductase (dihydrotestosterone/T) in FF than controls. NA-PCOS women had significantly higher intrafollicular cortisol levels and lower 11βHSD2 (cortisone/cortisol) activity than controls. Baseline serum T levels were slightly correlated with intrafollicular estrogens (E1: r = 0.192, p = 0.019; E2: r = 0.248, p = 0.002; E3: r = 0.248, p = 0.002) and androgens (DHEAS: r = 0.276, p = 0.001; AD: r = 0.185, p = 0.032; T: r = 0.173, p = 0.044) in controls and PCOS women respectively. Serum anti-Müllerian hormone (AMH) levels and antral follicle count (AFC) were correlated with intrafollicular cortisol (AMH: r = 0.380, p = 0.000; AFC: r = 0.177, p = 0.036) and corticosterone (AMH: r = 0.212, p = 0.048; AFC: r = 0.219, p = 0.009) levels in PCOS women. In conclusion, NA-PCOS and HA-PCOS women had statistically similar steroid metabolome profiles in FF, both of which showed a generally decreased steroidogenesis and hyperandrogenism compared to controls.

Effects of IL-18 on the proliferation and steroidogenesis of bovine theca cells: Possible roles in the pathogenesis of polycystic ovary syndrome

Interleukin 18 (IL-18) is a pleiotropic pro-inflammatory cytokine and is associated with arrested follicle development and anovulation which are the typical pathological changes of PCOS. Theca cells (TCs) have a key role in follicular growth and atresia. But whether IL-18 can directly affect ovarian TCs function is unknown. Therefore, the objective of this study was to determine the effect of IL-18 on proliferation and steroidogenesis of bovine TCs and to explore the biological effect of IL-18 on folliculogenesis. This work revealed that at 300-1000 pg/mL, IL-18 led to a time- and dose-dependently increase in cell proliferation (P < .05). IL-18 increased 17-hydroxyprogesterone (17OHP4) and androstenedione (A2) secretion with up-regulation of key steroidogenesis-related genes CYP11A1 and CYP17A1 (P < .05). Furthermore, our data demonstrated that the IL-18R protein is predominantly expressed in small-follicle (3-6 mm) TCs than large follicles (8-22 mm) by immunohistochemistry. We also found that the stimulation effects of IL-18 on TCs can be reversed with the addition of IL-18BP as early as at 4 hours of culture and reached the peak at 16 hours. We conclude that IL-18 appears to target TCs in bovine, and suggest an important role for this cytokine in ovarian function. Present findings further validate potential effects of IL-18 in the conditions associated with follicular dysplasia and excessive growth of ovarian TCs (such as PCOS). But additional research is needed to further understand the mechanism of action of IL-18 in theca cells as well as its precise role in folliculogenesis.

Hyperandrogenism in polycystic ovarian syndrome and role of CYP gene variants: a review

Background

Polycystic ovary syndrome (PCOS) is a multifactorial endocrine disorder characterized by anovulation, hyperandrogenism, and polycystic ovarian morphology. The pathophysiology of PCOS is not clear; however, disturbance in hypothalamic-pituitary-ovarian axis and abnormal steroidogenesis along with genetic and environmental factors act as main contributors to this disorder.

Main text

Hyperandrogenism, the hallmark feature of PCOS, is clinically manifested as hirsutism, acne, and alopecia. Excessive androgen production by ovaries as well as from adrenals contributes to hyperandrogenism. Abnormalities in the neuroendocrine system like increased pulse frequency of gonadotropin-releasing hormone, stimulating the pituitary for excessive production of luteinizing hormone than that of follicle-stimulating hormone is seen in PCOS women. Excess LH stimulates ovarian androgen production, whereas a relative deficit in FSH impairs follicular development. The imbalance in LH: FSH causes proliferation of ovarian theca cells leading to increased steroidogenesis, and ultimately leading to hyperandrogenism in PCOS women. Various genetic factors have been shown to be associated with abnormal steroidogenesis. CYP genes involved in steroidogenesis play an important role in androgen production and are considered as key players in hyperandrogenism in PCOS.

Conclusion

Polymorphisms in CYP genes can aggravate the hyperandrogenic phenotype in women with PCOS by either upregulating or downregulating their expression, thus increasing androgens further. However, this hypothesis needs to be validated by further studies.

Adipose Tissue is a Potential Source of Hyperandrogenism in Obese Female Rats

OBJECTIVE

Obesity in females is often associated with metabolic complications and hyperandrogenism, but the sources of androgens are not completely understood. Therefore, this study investigated whether adipose tissue could be a source of androgens promoting hyperandrogenism development in obese female rats.

METHODS

Gene expression of steroidogenic enzymes and testosterone levels were determined in periovarian and inguinal adipose tissue and in the supernatant of cultured preadipocytes and adipocytes. The conversion of pregnenolone to androgens was analyzed by thin-layer chromatography.

RESULTS

Substantial amounts of testosterone in adipose tissue (25-153 ng/g tissue) and in the supernatant of adipocytes (0.33-0.69 ng/ten thousand cells]) were found. StAR and steroidogenic enzymes encoded by genes including Cyp11A1, Cyp17A1, Cyp19, Hsd3b2, Hsd17b3, and Srd5a2 were expressed in adipose tissue and cultured cells. Thin layer chromatography data revealed that preadipocytes and adipocytes were able to convert pregnenolone to testosterone. Higher levels for all steroidogenic enzymes were found in both depots of obese animals compared with lean animals, with significantly higher levels in inguinal tissue.

CONCLUSIONS

The whole steroidogenic machinery and capacity for testosterone biosynthesis were found in fat depots of female rats. These findings support the hypothesis that adipose tissue may contribute substantially to the hyperandrogenism in female obesity.

Tetragonia tetragonioides (Pall.) Kuntze Regulates Androgen Production in a Letrozole-Induced Polycystic Ovary Syndrome Model

Tetragonia tetragonioides (Pall.) Kuntze (TTK) is a medicinal plant traditionally used to treat various diseases such as diabetic, inflammatory, and female-related disorders. Polycystic ovary syndrome (PCOS) is a common endocrinological disorder in women of reproductive age, and hyperandrogenism is a prominent feature of PCOS resulting in anovulation and infertility. In this study, we investigated the effects of a TTK extract on androgen generation and regulation of steroidogenic enzymes in vitro and in vivo. Human adrenocortical NCI-H295R cells were used to assess the effects of TTK extract on production of dehydroepiandrosterone and testosterone, as well as the protein expression of steroidogenic enzymes. Further, a letrozole-induced PCOS rat model was used in vivo to assess whether dietary administration of TTK extract restores normal hormones and reduces PCOS symptoms. TTK extract significantly inhibited forskolin (FOR)-induced androgen production in NCI-H295R cells and serum luteinizing hormone, testosterone, and follicular cysts, but not estradiol, were reduced in letrozole-induced PCOS rats orally administered the TTK extract. In addition, TTK extract inhibits androgen biosynthesis through the ERK-CREB signaling pathway, which regulates CYP17A1 or HSD3B2 expression. TTK extract could be utilized for the prevention and treatment of hyperandrogenism and other types of PCOS.

Therapeutic potentials of Quercetin in management of polycystic ovarian syndrome using Letrozole induced rat model: a histological and a biochemical study

BACKGROUND

PCOS is a leading endocrinopathy of young women instigating androgens elevation, insulin resistance, obesity, cardiometabolic and menstrual complications. The study investigated the effects of quercetin in a letrozole induced rat model of polycystic ovarian syndrome, which displayed both clinical and metabolic features as in PCOS women.

METHODS

Female Sprague Dawley (SD) rats were divided into four groups; control group received aqueous solution of carboxymethyl (CMC 0.5%); PCOS group administered with letrozole (1 mg/kg) dissolved in solution (CMC 0.5%); Metformin group given with metformin (20 mg/kg) + letrozole (1 mg/kg); and Quercetin group provided with quercetin (30 mg/kg) + letrozole (1 mg/kg). All doses were given orally via gavage, for 21 consecutive days and colpocytological analysis was carried till end. After 21rst day, blood was taken out, centrifuged and plasma was kept for biochemical analysis (ELISA, anti-oxidant enzymes, lipid profile) and the reproductive organs were dissected out for histopathological evaluation.

RESULTS

Quercetin as a chief member of flavonoid, showed beneficial effects by decreasing body weight, ovarian diameter, cysts and restoring healthy follicles, follicle's extra-glandular layers, and corpora lutea in contrast to the positive control. Additionally, lipid profile and anti-oxidant status were also maintained to baseline which was very high in diseased rats (p < 0.001).Quercetin depicted a mark regulation in steroidogenesis by decreasing the levels of testosterone (0.78 ng/ml ± 0.14 in quercetin vs. PCOS positive control 1.69 ng/ml ± 0.17, p < 0.001) and estradiol (8.85 pg/ml ± 0.19 in quercetin vs. PCOS positive 1.61 pg/ml ± 0.29) and increasing progesterone levels (34.47 ng/ml ± 1.65 in quercetin vs. 11.08 ng/ml ± 1.17 in PCOS positive). The effects of quercetin were moderately parallel to the standard drug available in market i.e. metformin.

CONCLUSION

The present study has confirmed that quercetin has the potentials to alleviate the hormonal and metabolic disturbances occurring in PCOS.

Antiandrogen Treatment Ameliorates Reproductive and Metabolic Phenotypes in the Letrozole-Induced Mouse Model of PCOS

Polycystic ovary syndrome (PCOS), the most common endocrinopathy in women of reproductive age, is characterized by hyperandrogenism, anovulation, and polycystic ovaries. Although its etiology is unknown, excess androgens are thought to be a critical factor driving the pathology of PCOS. We previously demonstrated that continuous exposure to the aromatase inhibitor letrozole (LET) in mice produces many hallmarks of PCOS, including elevated testosterone (T) and luteinizing hormone, anovulation, and obesity. In the current study, we sought to determine whether androgen receptor (AR) actions are responsible for any of the phenotypes observed in LET mice. C57BL/6 female mice were subcutaneously implanted with LET or placebo control and subsequently treated with the nonsteroidal AR antagonist flutamide or vehicle control. Flutamide treatment in LET females reversed elevated T levels and restored ovarian expression of Cyp17a1 (critical for androgen synthesis) to normal levels. Pituitary expression of Lhb was decreased in LET females that received flutamide treatment, with no changes in expression of Fshb or Gnrhr. Flutamide treatment also restored estrous cycling and reduced the number of ovarian cyst-like follicles in LET females. Furthermore, body weight and adipocyte size were decreased in flutamide-treated LET females. Altogether, our findings provide strong evidence that AR signaling is responsible for many key reproductive and metabolic PCOS phenotypes and further establish the LET mouse model as an important tool for the study of androgen excess.

Treatment strategies for women with polycystic ovary syndrome

Polycystic ovary syndrome (PCOS) is a common endocrine disorder in women, and it is the main cause of infertility in women of reproductive age due to anovulation. PCOS also increases the risk of diseases such as cardiovascular disease and type 2 diabetes in women with this disorder. The mechanism of pathogenesis is not clear, as it may be related to heredity, the environment and internal embryonic factors; thus, the treatment strategies remain unclear. This review summarizes current treatments for PCOS worldwide. Lifestyle modification (LSM) is considered the first-line treatment, regardless of fertility status, without the addition of metformin. Oral contraceptive (OC) pills should be used as a first-line treatment for long-term management for patients with no reproductive requirements. For patients with fertility requirements, ovulation therapy is an effective treatment. For refractory ovulation disorders, patients can choose from among the latest treatments, including ovarian hippocampal signal path block theory, the theory of leptin, inositol treatment, bilateral ovarian drilling to stimulate ovulation and assisted reproductive technology. Because current treatments cannot cure PCOS, lifelong administration is still the mainstream method of management; however, the optimal treatment plan needs further research and exploration.

Ovarian Follicular Theca Cell Recruitment, Differentiation, and Impact on Fertility: 2017 Update

The major goal of this review is to summarize recent exciting findings that have been published within the past 10 years that, to our knowledge, have not been presented in detail in previous reviews and that may impact altered follicular development in polycystic ovarian syndrome (PCOS) and premature ovarian failure in women. Specifically, we will cover the following: (1) mouse models that have led to discovery of the derivation of two precursor populations of theca cells in the embryonic gonad; (2) the key roles of the oocyte-derived factor growth differentiation factor 9 on the hedgehog (HH) signaling pathway and theca cell functions; and (3) the impact of the HH pathway on both the specification of theca endocrine cells and theca fibroblast and smooth muscle cells in developing follicles. We will also discuss the following: (1) other signaling pathways that impact the differentiation of theca cells, not only luteinizing hormone but also insulinlike 3, bone morphogenic proteins, the circadian clock genes, androgens, and estrogens; and (2) theca-associated vascular, immune, and fibroblast cells, as well as the cytokines and matrix factors that play key roles in follicle growth. Lastly, we will integrate what is known about theca cells from mouse models, human-derived theca cell lines from patients who have PCOS and patients who do not have PCOS, and microarray analyses of human and bovine theca to understand what pathways and factors contribute to follicle growth as well as to the abnormal function of theca.

Pathologic significance of SET/I2PP2A-mediated PP2A and non-PP2A pathways in polycystic ovary syndrome (PCOS)

SET (SE translocation, SET), a constitutive inhibitor of protein phosphatase 2A (PP2A), is a multifunctional oncoprotein involved in DNA replication, histone modification, nucleosome assembly, gene transcription and cell proliferation. It is widely expressed in human tissues including the gonadal system and brain. Intensive studies have shown that overexpressed SET plays an important role in the development of Alzheimer's disease (AD), and may also contribute to the malignant transformation of breast and ovarian cancers. Recent studies indicated that through interaction with PP2A, SET may upregulate androgen biosynthesis and contribute to hyperandrogenism in polycystic ovary syndrome (PCOS) patients. This review article summarizes data concerning the SET expression in ovaries from PCOS and normal women, and analyzes the role/regulatory mechanism of SET for androgen biosynthesis in PCOS, as well as the significance of this action in the development of PCOS. The potential value of SET-triggered pathway as a therapeutic target and the application of anti-SET reagents for treating hyperandrogenism in PCOS patients are also discussed.

Relationship between Advanced Glycation End Products and Steroidogenesis in PCOS

BACKGROUND

Women with PCOS have elevated levels of the harmful Advanced Glycation End Products (AGEs), which are highly reactive molecules formed after glycation of lipids and proteins. Additionally, AGEs accumulate in the ovaries of women with PCOS potentially contributing to the well-documented abnormal steroidogenesis and folliculogenesis.

MAIN BODY

A systematic review of articles and abstracts available in PubMed was conducted and presented in a systemic manner. This article reports changes in steroidogenic enzyme activity in granulosa and theca cells in PCOS and PCOS-models. It also described the changes in AGEs and their receptors in the ovaries of women with PCOS and presents the underlying mechanism(s) whereby AGEs could be responsible for the PCOS-related changes in granulosa and theca cell function thus adversely impacting steroidogenesis and follicular development. AGEs are associated with hyperandrogenism in PCOS possibly by altering the activity of various enzymes such as cholesterol side-chain cleavage enzyme cytochrome P450, steroidogenic acute regulatory protein, 17α-hydroxylase, and 3β-hydroxysteroid dehydrogenase. AGEs also affect luteinizing hormone receptor and anti-Mullerian hormone receptor expression as well as their signaling pathways in granulosa cells.

CONCLUSIONS

A better understanding of how AGEs alter granulosa and theca cell function is likely to contribute meaningfully to a conceptual framework whereby new interventions to prevent and/or treat ovarian dysfunction in PCOS can ultimately be developed.

A Dietary Medium-Chain Fatty Acid, Decanoic Acid, Inhibits Recruitment of Nur77 to the HSD3B2 Promoter In Vitro and Reverses Endocrine and Metabolic Abnormalities in a Rat Model of Polycystic Ovary Syndrome

Hyperandrogenism is the central feature of polycystic ovary syndrome (PCOS). Due to the intricate relationship between hyperandrogenism and insulin resistance in PCOS, 50%-70% of these patients also present with hyperinsulinemia. Metformin, an insulin sensitizer, has been used to reduce insulin resistance and improve fertility in women with PCOS. In previous work, we have noted that a dietary medium-chain fatty acid, decanoic acid (DA), improves glucose tolerance and lipid profile in a mouse model of diabetes. Here, we report for the first time that DA, like metformin, inhibits androgen biosynthesis in NCI-H295R steroidogenic cells by regulating the enzyme 3β-hydroxysteroid dehydrogenase/Δ5-Δ4-isomerase type 2 (HSD3B2). The inhibitory effect on HSD3B2 and androgen production required cAMP stimulation, suggesting a mechanistic action via the cAMP-stimulated pathway. Specifically, both DA and metformin reduced cAMP-enhanced recruitment of the orphan nuclear receptor Nur77 to the HSD3B2 promoter, coupled with decreased transcription and protein expression of HSD3B2. In a letrozole-induced PCOS rat model, treatment with DA or metformin reduced serum-free testosterone, lowered fasting insulin, and restored estrous cyclicity. In addition, DA treatment lowered serum total testosterone and decreased HSD3B2 protein expression in the adrenals and ovaries. We conclude that DA inhibits androgen biosynthesis via mechanisms resulting in the suppression of HSD3B2 expression, an effect consistently observed both in vitro and in vivo. The efficacy of DA in reversing the endocrine and metabolic abnormalities of the letrozole-induced PCOS rat model are promising, raising the possibility that diets including DA could be beneficial for the management of both hyperandrogenism and insulin resistance in PCOS.

Phosphatidylinositide 3-kinase inhibition: A new potential target for the treatment of polycystic ovarian syndrome

CONTEXT

Quercetin, a flavonoid, has been tried in traditional medicine for treating many disorders and reported to have inhibitory action on PI3 kinase.

OBJECTIVE

This study investigates the effect of quercetin on testosterone propionate induced polycystic ovary syndrome (PCOS) model, which shows both metabolic and endocrine features of PCOS.

MATERIALS AND METHODS

Female pre-pubertal Sprague-Dawley rats were randomly divided into four groups: normal control, PCOS control, quercetin, and metformin treated. PCOS was induced by testosterone propionate (10 mg/kg, s.c.) and treatments were carried out orally at the dose of 150 mg/kg from the 6th week. At the 6th and 10th week, blood was collected to investigate metabolic indices, and reproductive biochemical parameters including morphology of ovary, uterus, and estrous cyclicity were assessed. The ovaries were processed to determine CYP17A1 gene expression.

RESULTS

The treatment with quercetin did not modify body weight gain but uterine (296.7 ± 5.11 versus 263.0 ± 8.60 mg) and ovary weights (49.5 ± 1.93 versus 37.8 ± 3.43 mg) were found to be decreased significantly (p <0.05) as compared with the PCOS control group. The PCOS control group showed hyperinsulinemia, hyperandrogenemia, and dyslipidemia. Treatment with quercetin showed statistically significant (p <0.01) improvement in insulin (12.46 ± 0.3 versus 10.0 ± 0.28 μU/ml), testosterone (0.65 ± 0.02 versus 0.29 ± 0.02 μU/ml), luteinising hormone (20.6 ± 0.28 versus 15.1 ± 0.36 U/ml), and lipid profile. Histological examination of ovary and uterus confirmed the disease occurrence and remission state in the diseased and treated groups, respectively. Quercetin also demonstrated PI3 kinase inhibition in a docking study and decreased CYP17A1 gene expression.

DISCUSSION AND CONCLUSION

Thus, we can conclude that quercetin may have beneficial effect in PCOS by virtue of inhibition of PI3K which attributes to a decrease in the expression of CYP17A1 gene, having a key role in steroidogenesis.

Functional genomics of PCOS: from GWAS to molecular mechanisms

Polycystic ovary syndrome (PCOS) is a common endocrinopathy characterized by increased ovarian androgen biosynthesis, anovulation, and infertility. PCOS has a strong heritable component based on familial clustering and twin studies. Genome-wide association studies (GWAS) identified several PCOS candidate loci including LHCGR, FSHR, ZNF217, YAP1, INSR, RAB5B, and C9orf3. We review the functional roles of strong PCOS candidate loci focusing on FSHR, LHCGR, INSR, and DENND1A. We propose that these candidates comprise a hierarchical signaling network by which DENND1A, LHCGR, INSR, RAB5B, adapter proteins, and associated downstream signaling cascades converge to regulate theca cell androgen biosynthesis. Future elucidation of the functional gene networks predicted by the PCOS GWAS will result in new diagnostic and therapeutic approaches for women with PCOS.

Metformin induces a prompt decrease in LH-stimulated testosterone response in women with PCOS independent of its insulin-sensitizing effects

BACKGROUND

The use of insulin-sensitizing drugs has been shown to improve both the reproductive and the metabolic aspects of PCOS. However, the mechanisms by which metformin exerts its effects in PCOS are still not completely understood. There is growing evidence of a direct effect of metformin on ovarian steroidogenesis, independent of its effects on insulin sensitivity.

METHODS

We evaluated the short-term effects of metformin compared to placebo on basal and LH- stimulated androgen secretion as well as on hormonal and metabolic parameters in 19 women with PCOS during a four-day randomized, double-blinded placebo-controlled clinical trial. In a three month follow-up evaluation, we investigated the longer-term therapeutic effects of metformin on ovulation, metabolic and endocrine parameters.

RESULTS

Compared to placebo, 2 days of metformin was associated with a borderline significant reduction in the free androgen index (FAI) (p = 0.05) and with a reduction in the serum concentration of LH-stimulated testosterone (T) (p = 0.03). Following three months of use, a decline in serum T was observed, independent of changes in weight, metabolic parameters, or insulin sensitivity.

CONCLUSIONS

In women with PCOS, Metformin induces a prompt decrease in LH-stimulated T secretion after only several days of use. This action precedes the medication's effects on insulin sensitivity or weight loss.

Developmental programming: prenatal steroid excess disrupts key members of intraovarian steroidogenic pathway in sheep

Prenatal testosterone (T) excess disrupts ovarian cyclicity and increases circulating estradiol levels as well as follicular recruitment and persistence culminating in multifollicular ovary similar to women with polycystic ovary syndrome. We tested whether prenatal T excess, by androgenic or estrogenic action, disrupts the steroid biosynthetic machinery in sheep in a cell-, follicle stage-, age-, and treatment-specific manner consistent with the ovarian disruptions and increased estradiol release. Impact of T/dihydrotestosterone (DHT) treatments from days 30-90 of gestation on steroidogenic acute regulatory protein, 3β-hydroxysteroid dehydrogenase, cytochrome P-450 17α-hydroxylase/C17, 20-lyase (CYP17A1), and cytochrome P-450 aromatase (CYP19A1) were examined on fetal day 90, 140 and 10 months (postpubertal), and 21 months (adult, no DHT group) of age by immunohistochemistry. All 4 markers changed in a cell-, follicle stage-, and age-specific manner. Both treatments increased steroidogenic acute regulatory protein expression in preantral follicles of postpubertal and adult females. Effects of prenatal T and DHT on 3β-hydroxysteroid dehydrogenase differed in a follicle- and age-specific manner. CYP17A1 was reduced in the theca interna of antral follicles by T, but not DHT, in 10- and 21-month-old females. CYP19A1 was reduced by both T and DHT at all ages barring an increase on fetal day 140. Reduced granulosa CYP19A1 and thecal CYP17A1 in adults likely disrupt the intrafollicular androgen/estrogen balance contributing to follicular persistence. The reduced thecal CYP17A1 expression suggests that the hyperandrogenic ovarian phenotype may originate from increased enzyme activity or alternatively via a different isoform of CYP17. The reduced CYP19A1 in antral follicles of adults indicates that the increased circulating estradiol release likely arises from the increased number of persisting follicles.

Resveratrol potentiates effects of simvastatin on inhibition of rat ovarian theca-interstitial cells steroidogenesis

BACKGROUND

Polycystic ovary syndrome (PCOS) is characterized by ovarian enlargement, hyperplastic theca compartment and increased androgen production due to, at least in part, excessive expression of several key genes involved in steroidogenesis. Previously, our group has demonstrated that simvastatin, competitive inhibitor of 3-hydroxy-3-methyl-glutaryl-CoA reductase (HMG-CoA reductase), a rate-limiting step of the mevalonate pathway, reduces rat-theca interstitial cell steroidogenesis by inhibiting Cyp17a1 gene expression, the key enzyme of the androgen biosynthesis pathway. Recently, we demonstrated that resveratrol, a bioflavonoid abundant in red grapes, decreases rat theca-interstitial cell steroidogenesis and this suppressive effect is mediated through mechanisms independent of the mevalonate pathway. The present study evaluated the effect of combining simvastatin and resveratrol treatments on rat theca-interstitial cell steroidogenesis.

METHODS

Rat theca-interstitial cells isolated from 30 day-old female rats were cultured for up to 48 h with or without simvastatin (1 μM) and/or resveratrol (3-10 μM). Steroidogenic enzymes gene expression was evaluated by quantitative real time PCR and steroid levels were measured by liquid chromatography-mass spectrometry. Comparisons between groups were performed using ANOVA and Tukey test.

RESULTS

Resveratrol potentiated inhibitory effects of simvastatin on androstenedione and androsterone production in theca-interstitial cells. This suppressive effect correlated with profound inhibition in Cyp17a1 mRNA expression in the presence of a combination of resveratrol and simvastatin.

CONCLUSIONS

The present findings indicate that resveratrol potentiates the simvastatin-induced inhibitory effect on theca-interstitial cell androgen production, raising the possibility of development of novel treatments of PCOS.

Decreased myo-inositol to chiro-inositol (M/C) ratios and increased M/C epimerase activity in PCOS theca cells demonstrate increased insulin sensitivity compared to controls

Previous studies from our and other labs have shown that insulin resistance is associated with an inositol imbalance of excess myo-inositol and deficient chiro-inositol together with a deficiency of myo-inositol to chiro-inositol epimerase in vivo and in vitro. In this report, we utilized well characterized theca cells from normal cycling women, with normal insulin sensitivity, and theca cells from women with polycystic ovary syndrome (PCOS), with increased insulin sensitivity to examine the myo-inositol to chiro-inisitol (M/C) ratio and the myo-inositol to chiro-inositol epimerase activity. PCOS theca cells with increased insulin sensitivity were specifically used to investigate whether the inositol imbalance and myo-inositol to chiro-inositol epimerase are regulated in a similar or the opposite direction than that observed in insulin resistant cells. The results of these studies are the first to demonstrate that in insulin sensitive PCOS theca cells the inositol imbalance goes in the opposite direction to that observed in insulin resistant cells, and there is a decreased M/C ratio and an increased myo-inositol to chiro-inositol epimerase activity. Further biochemical and genetic studies will probe the mechanisms involved.

SET/PP2A system regulates androgen production in ovarian follicles in vitro

SET has multiple cell functions including nucleosome assembly, histone binding, transcription control, and cell apoptosis. In ovaries SET is predominantly expressed in theca cells and oocytes. In our study, SET overexpression in theca cells stimulated testosterone production whereas SET knockdown decreased testosterone production. Moreover, SET negatively regulated PP2A activity. Treatment with PP2A inhibitor okadaic acid (OA) led to increased testosterone synthesis, while treatment with PP2A activators resulted in the decreased testosterone synthesis. Furthermore, PP2A knockdown confirmed the key role of PP2A in the testosterone synthesis, and OA was able to block the AdH1-SiRNA/SET-mediated inhibition of testosterone production. The central role of PP2A in SET-mediated regulation of testosterone production was confirmed by the finding that SET promoted the lyase activity of P450c17 and that PP2A inhibited its lyase activity. Taken together, these results reveal a specific, SET-initiated, PP2A-mediated, pathway that leads to the increased lyase activity of P450c17 and testosterone biosynthesis.

SET protein up-regulated testosterone production in the cultured preantral follicles

BACKGROUND

We found previously that the expression of SET gene was up-regulated in polycystic ovaries. Evidences suggested that SET protein was essential for regulating both the promoter activity of CYP17A1 and the biological activity of P450c17. In this study, we explored whether SET regulated androgen production in preantral follicles.

METHODS

The mouse preantral follicles were cultured in vitro. Testosterone secretion and expression of steroidogenic enzymes were observed in the preantral follicles treated in vitro by SET overexpression and knockdown.

RESULTS

Testosterone levels in the media of the AdCMV-SET infected follicles significantly increased, and the CYP17A1 and HSD3B2 expression also significantly increased (P < 0.05). Testosterone levels in AdSiRNA-SET infected group decreased, and so did CYP17A1 and HSD3B2 expression (P < 0.05).

CONCLUSIONS

SET played a positive role in regulating ovarian androgen biosynthesis by enhancing the transcription of steroidogenic enzymes CYP17A1 and HSD3B2, which maybe contribute to the hyperandrogenism in PCOS.

Apolipoprotein A-IV as a novel gene associated with polycystic ovary syndrome

Polycystic ovary syndrome (PCOS) is a common endocrine-metabolic disorder, affecting 6-10% of women of reproductive age. The etiology remains poorly understood. To investigate the differentially expressed proteins from PCOS patients versus healthy women, the protein expression in follicular fluid was analyzed using two-dimensional electrophoresis (2-DE). Since follicular fluid contains a number of secretory proteins required for oocyte fertilization and follicle maturation, it is possible that follicular fluid can be used as a provisional source for identifying pivotal proteins associated with PCOS. In this study, six overexpressed proteins [kininogen 1, cytokeratin 9, antithrombin, fibrinogen γ-chain, apolipoprotein A-IV (apoA-IV) precursor and α-1-B-glycoprotein (A1BG)] in follicular fluids from PCOS patients were identified with matrix-assisted laser desorption/ionization-time-of-flight mass spectrometry (MALDI-TOF-MS) and nano LC-MS/MS. Western blot analysis confirmed that the protein expression levels of apoA-IV precursor and A1BG were increased in follicular fluid from PCOS patients compared with those from normal controls. The analysis of protein expression for other proteins revealed individual variation. These results facilitate the understanding of the molecular mechanisms of PCOS and provide candidate biomarkers for the development of diagnostic and therapeutic tools.

Expression of SET Protein in the Ovaries of Patients with Polycystic Ovary Syndrome

Background. We previously found that expression of SET gene was up-regulated in polycystic ovaries by using microarray. It suggested that SET may be an attractive candidate regulator involved in the pathophysiology of polycystic ovary syndrome (PCOS). In this study, expression and cellular localization of SET protein were investigated in human polycystic and normal ovaries. Method. Ovarian tissues, six normal ovaries and six polycystic ovaries, were collected during transsexual operation and surgical treatment with the signed consent form. The cellular localization of SET protein was observed by immunohistochemistry. The expression levels of SET protein were analyzed by Western Blot. Result. SET protein was expressed predominantly in the theca cells and oocytes of human ovarian follicles in both PCOS ovarian tissues and normal ovarian tissues. The level of SET protein expression in polycystic ovaries was triple higher than that in normal ovaries (P < 0.05). Conclusion. SET was overexpressed in polycystic ovaries more than that in normal ovaries. Combined with its localization in theca cells, SET may participate in regulating ovarian androgen biosynthesis and the pathophysiology of hyperandrogenism in PCOS.

Cholesterol side-chain cleavage gene expression in theca cells: augmented transcriptional regulation and mRNA stability in polycystic ovary syndrome

Hyperandrogenism is characteristic of women with polycystic ovary syndrome (PCOS). Ovarian theca cells isolated from PCOS follicles and maintained in long-term culture produce elevated levels of progestins and androgens compared to normal theca cells. Augmented steroid production in PCOS theca cells is associated with changes in the expression of genes for several steroidogenic enzymes, including CYP11A1, which encodes cytochrome P450 cholesterol side-chain cleavage. Here, we further examined CYP11A1 gene expression, at both the transcriptional and post-transcriptional level in normal and PCOS theca cells propagated in long-term culture utilizing quantitative RT-PCR, functional promoter analyses, and mRNA degradation studies. The minimal element(s) that conferred increased basal and cAMP-dependent CYP11A1 promoter function were determined. CYP11A1 mRNA half-life in normal and PCOS theca cells was compared. Results of these cumulative studies showed that basal and forskolin stimulated steady state CYP11A1 mRNA abundance and CYP11A1 promoter activity were increased in PCOS theca cells. Deletion analysis of the CYP11A1 promoter demonstrated that augmented promoter function in PCOS theca cells results from increased basal regulation conferred by a minimal sequence between -160 and -90 bp of the transcriptional start site. The transcription factor, nuclear factor 1C2, was observed to regulate basal activity of this minimal CYP11A1 element. Examination of mRNA stability in normal and PCOS theca cells demonstrated that CYP11A1 mRNA half-life increased >2-fold, from approximately 9.22+/-1.62 h in normal cells, to 22.38+/-0.92 h in PCOS cells. Forskolin treatment did not prolong CYP11A1 mRNA stability in either normal or PCOS theca cells. The 5'-UTR of CYP11A1 mRNA confers increased basal mRNA stability in PCOS cells. In conclusion, these studies show that elevated steady state CYP11A1 mRNA abundance in PCOS cells results from increased transactivation of the CYP11A1 promoter and increased CYP11A1 mRNA stability.

Resveratrol reduces steroidogenesis in rat ovarian theca-interstitial cells: the role of inhibition of Akt/PKB signaling pathway

Polycystic ovary syndrome is characterized by theca-interstitial hyperplasia and increased expression of steroidogenic genes, leading to excessive androgen production. Resveratrol, a natural polyphenol, promotes apoptosis and reduces rat theca-interstitial cell growth, in part by inhibiting the mevalonate pathway and decreasing the availability of substrates of isoprenylation [farnesyl-pyrophosphate (FPP) and geranylgeranyl-pyrophosphate (GGPP)]. This study evaluated the effect of resveratrol on rat theca-interstitial cell steroidogenesis. Because resveratrol may activate sirtuins, this study also investigated whether steroidogenesis was affected by sirtuin inhibitors (nicotinamide, sirtinol). Theca-interstitial cells were cultured with or without resveratrol (1-10 μm), GGPP (30 μm), FPP (30 μm), nicotinamide (1 mm), and/or sirtinol (10 μm). Resveratrol did not affect progesterone levels but reduced androgen production in a concentration-dependent fashion (androstenedione by up to 78% and androsterone by up to 76%). This inhibitory effect correlated with a decrease in mRNA expression of genes regulating androgen production, especially Cyp17a1 (by up to 73%). GGPP and FPP had no effect on androgen levels and Cyp17a1 mRNA levels and did not alter the effects induced by resveratrol. Similarly, sirtuin inhibitors did not reverse resveratrol-induced inhibition of steroidogenesis. However, resveratrol decreased activity of serine-threonine kinase/protein kinase B pathway, a cell-signaling pathway involved in ovarian steroidogenesis. The present findings indicate that resveratrol reduces androgen production primarily by inhibiting Cyp17a1 mRNA expression, and this inhibition may be mediated, in part, by blocking the activity of the serine-threonine kinase/protein kinase B pathway. These findings may be of clinical relevance to conditions associated with excessive production of androgens by theca cells, such as polycystic ovary syndrome.

Saturated fatty acid exposure induces androgen overproduction in bovine adrenal cells

BACKGROUND

Polycystic ovary syndrome (PCOS) is mainly defined by hyperandrogenemia, from ovarian and adrenal origin, and is characterized by insulin resistance (IR). Studies found that raising in vivo non-esterified fatty acid (NEFA) levels, which induces lipotoxicity, increases androgen levels and IR. The aim of this study was therefore to determine the effects of in vitro over-exposure to NEFA on androgen synthesis in a bovine adrenocortical cell model.

METHODS

Bovine fasciculata/reticularis cells were cultured for 2days in the absence or presence of ACTH (10nmol/L) or Forskolin (fsk, 10μmol/L), alone or in combination with the saturated fatty acid (FA) palmitate (100μmol/L). Steroid production was measured in medium and corrected for initial cell seeding count. CYP17 protein expression and ERK1/2 phosphorylation were assessed by Western blotting.

RESULTS

Under unstimulated conditions, dehydroepiandrosterone (DHEA) levels were barely detected and no difference was observed after palmitate exposure, which was also the case for CYP17 expression and ERK1/2 phosphorylation. Under stimulation, palmitate exposure increased DHEA production by 38% and 69%, for ACTH and fsk, respectively, as compared to untreated conditions (Ps⩽0.05). In palmitate-treated vs untreated cells, fsk-stimulated ERK1/2 phosphorylation was reduced by 46% (P=0.0047), but stimulated CYP17 expression was not significantly affected.

CONCLUSION

In a model of androgen-producing cells, under stimulated conditions, overexposure to saturated FAs significantly increases androgen production and reduces MEK/ERK activation. Therefore, this study is the first to demonstrate that lipotoxicity can directly trigger androgen overproduction in vitro, in addition to its well-described impact on IR, which strongly supports a central role of lipotoxicity in PCOS pathophysiology.

Simvastatin reduces steroidogenesis by inhibiting Cyp17a1 gene expression in rat ovarian theca-interstitial cells

Polycystic ovary syndrome (PCOS) is characterized by ovarian enlargement, theca-interstitial hyperplasia, and increased androgen production by theca cells. Previously, our group has demonstrated that statins (competitive inhibitors of 3-hydroxy-3-methyl-glutaryl-coenzyme A reductase, a rate-limiting step of the mevalonate pathway) reduce proliferation of theca-interstitial cells in vitro and decrease serum androgen levels in women with PCOS. The present study evaluated the effect of simvastatin on rat ovarian theca-interstitial cell steroidogenesis. Because actions of statins may be due to reduced cholesterol availability and/or isoprenylation of proteins, the present study also investigated whether steroidogenesis was affected by cell- and mitochondrion-permeable 22-hydroxycholesterol, isoprenylation substrates (farnesyl-pyrophosphate [FPP] and geranylgeranyl-pyrophosphate [GGPP]), as well as selective inhibitors of farnesyltransferase (FTI) and geranylgeranyltransferase (GGTI). Theca-interstitial cells were cultured for 12, 24, and 48 h with or without simvastatin, GGPP, FPP, FTI, GGTI, and/or 22-hydroxycholesterol. Simvastatin decreased androgen levels in a time- and concentration-dependent fashion. This inhibitory effect correlated with a decrease in mRNA levels of Cyp17a1, the gene encoding the key enzyme regulating androgen biosynthesis. After 48 h, GGPP alone and FPP alone had no effect on Cyp17a1 mRNA expression; however, the inhibitory action of simvastatin was partly abrogated by both GGPP and FPP. The present findings indicate that statin-induced reduction of androgen levels is likely due, at least in part, to the inhibition of isoprenylation, resulting in decreased expression of CYP17A1.

Understanding polycystic ovarian syndrome pathogenesis: an updated of its genetic aspects

Polycystic ovary syndrome (PCOS) is the most frequent cause of female infertility. It is also characterized by metabolic defects that raise the risk for cardiovascular disease. Despite the progress in the definition of the clinical aspects of the syndrome, only very few definite data are available about the ethiopathogenetic mechanisms that subtend PCOS. It is likely that the PCOS phenotype derives from the interaction between environmental and genetic factors. While environmental factors have easily been investigated, the individuation of the genetic factors seem to be more complex. Indeed, PCOS appears to be inherited as a complex, polygenic trait. Several family studies have been conducted with the aim to clarify the genetic aspects of PCOS, but their findings are often conflicting and not conclusive.Moreover, it is difficult to establish with certainty which genes are involved and their effective role in the development of the syndrome because in PCOS, genetic analysis is hampered by low fecundity, lack of a male phenotype, absence of an animal model, and dissimilarity of the diagnostic criteria used to select the patients. Since multiple biochemical pathways are implicated in PCOS pathogenesis, genes of steroid hormone metabolism, gonadotropin release and action, insulin secretion and action, adipose tissue metabolism and others have been investigated. Nevertheless, none of them seems to play a key role in the ethiopathogenesis of PCOS. This article reviews the large body of literature generated to support the presence of genetic abnormalities in PCOS women by taking in consideration the most important studies regarding PCOS candidate genes.

The Genetic Basis of the Polycystic Ovary Syndrome: A Literature Review Including Discussion of PPAR-gamma

Polycystic ovary syndrome (PCOS) is the most common endocrine disorder of the women of reproductive age. Familial clustering of PCOS has been consistently reported suggesting that genetic factors play a role in the development of the syndrome although PCOS cases do not exhibit a clear pattern of Mendelian inheritance. It is now well established that PCOS represents a complex trait similar to type-2 diabetes and obesity, and that both inherited and environmental factors contribute to the PCOS pathogenesis. A large number of functional candidate genes have been tested for association or linkage with PCOS phenotypes with more negative than positive findings. Lack of universally accepted diagnostic criteria, difficulties in the assignment of male phenotype, obscurity in the mode of inheritance, and particularly small sample size of the study populations appear to be major limitations for the genetic studies of PCOS. In the near future, utilizing the genome-wide scan approach and the HapMap project will provide a stronger potential for the genetic analysis of the syndrome.