Angiopoietins/TIE2 system and VEGF are involved in ovarian function in a DHEA rat model of polycystic ovary syndrome

Hyperinsulinemia impairs decidualization via AKT-NR4A1 signaling: new insight into polycystic ovary syndrome (PCOS)-related infertility

BACKGROUND

Investigating the underlying molecular mechanisms responsible for endometrial dysfunction in women with PCOS is essential, particularly focusing on the role of hyperinsulinemia.

METHODS

We explored the role of insulin in the decidualization process using a synthetic decidualization assay. To dissect the effects of PI3K/AKT-NR4A signaling, we employed small interfering RNAs (siRNAs) targeting the NR4A genes and inhibitors of the PI3K/AKT pathway. We also investigated the disruption of AKT-NR4A1 signaling in the endometrium of PCOS female rats induced with dehydroepiandrosterone (DHEA). Quantitative real-time PCR (qRT-PCR) and Western blot (WB) analyses were utilized to evaluate gene expression regulation.

RESULTS

Insulin was found to suppress the expression of decidualization markers in human endometrial stromal cells (hESC) in a dose-dependent manner, concurrently triggering an inappropriate activation of the PI3K/AKT pathway. Members of the NR4A family, as downstream effectors in the PI3K/AKT pathway, were implicated in the insulin-induced disruptions during the decidualization process. Moreover, the endometrium of PCOS models showed significantly elevated levels of phosphorylated (Ser473) AKT, with a corresponding reduction in Nr4a1 protein.

CONCLUSIONS

Our research demonstrates that insulin negatively regulates decidualization in hESC via the PI3K/AKT-NR4A pathway. In vivo analysis revealed a significant dysregulation of the AKT-NR4A1 pathway in the endometrium of PCOS rats. These findings offer novel insights into the pathogenesis of infertility and endometrial disorders associated with hyperinsulinemia in PCOS.

The role of macrophages in polycystic ovarian syndrome and its typical pathological features: A narrative review

Polycystic ovarian syndrome (PCOS) is the most common endocrine and metabolic disorder in women of childbearing age, with ovulatory dysfunction, hyperandrogenism, and polycystic ovarian morphology (PCOM) as the clinical features. Androgen excess, insulin resistance, obesity, adipose tissue dysfunction, ovulatory dysfunction, and gut microbiota dysbiosis are the main pathological features and pathogenesis of PCOS and are related to systemic chronic low-grade inflammation and chronic ovarian tissue inflammation in PCOS. With the advances in immune-endocrine interaction studies, research on the role of immune cells in the occurrence and development of PCOS is gradually increasing. As the core of innate immunity, macrophages play an indispensable role in systemic inflammatory response. Meanwhile, they are involved in maintaining the stability and function of the ovary as the most abundant immune cells in ovarian tissue. Studies in humans and mice have found that the polarization of macrophages into M1 type plays multiple roles in the pathogenesis of PCOS. This review describes the distribution characteristics of macrophage subpopulations in patients and animal models with PCOS, discusses the role of macrophage-related metabolic inflammation in PCOS, and summarizes the relationship between macrophages and PCOS-related pathological features and its possible mechanisms, to further understand the pathogenesis of PCOS and reveal the role of macrophages in it. In addition, research on immune-endocrine interactions can also provide direction for finding new therapeutic targets for PCOS.

The effects of low-level laser therapy on polycystic ovarian syndrome in rats: three different dosages

The main objective of this in vivo study was to investigate the effect of different low-level laser therapy (LLLT) doses on polycystic ovary syndrome (PCOS). In the present experimental study, a single dosage of estradiol valerate (EV) was administered to induce PCOS in female rats. After administration of the EV for induction of PCOS, rats were divided into 5 groups (n = 8/group): C group (animals that were not exposed to any form of procedure), PC group (no treatment following EV induction), L1 group (1 J/cm2 LLLT treatment following EV induction), L2 group (2 J/cm2 LLLT treatment following EV induction), L3 group (6 J/cm2 LLLT treatment following EV induction). The results indicated that no significant difference was found in the serum levels of luteinizing hormone (LH), follicle-stimulating hormone (FSH), and progesterone (P4) between the C and L2 groups (p < 0.05). Although the serum levels of testosterone (T) were significantly higher in the C group compared with other groups (p < 0.05), the L2 group was determined to be the closest to the C group. Additionally, the LH, FSH, and T receptor level of the L2 group was closest to the C group. In conclusion, a 2 J/cm2 dosage of LLLT (L2 group) can be considered the most potentially effective treatment of PCOS in the rat. However, more studies are needed to determine the optimal dose of LLLT for the treatment of PCOS.

A meta-analysis of effects of vitamin E supplementation alone and in combination with omega-3 or magnesium on polycystic ovary syndrome

Vitamin E supplementation might have favorable effects on risk factors of polycystic ovary syndrome (PCOS). This systematic review and meta-analysis aimed to summarize the effects of vitamin E supplementation or vitamin E in combination with omega-3 or magnesium on PCOS. PubMed, Scopus, ISI Web of Science, Cochrane, Embase electronic databases, and Google scholar were searched for all available articles up to September 2022. Randomized controlled trials (RCTs) that examined the effect of vitamin E supplementation or vitamin E in combination with omega-3 or magnesium on lipid and glycemic profiles, anthropometric measurements, biomarkers of inflammation and oxidative stress, hormonal profile, and hirsutism score in patients with PCOS were included. Ten RCTs (with 504 participants) fulfilled the eligible criteria. Vitamin E supplementation or vitamin E in combination with omega-3 or magnesium in comparison to placebo could significantly reduce serum levels of TG (weighted mean difference: - 18.27 mg/dL, 95% CI - 34.68 to - 1.87), VLDL (- 5.88 mg/dL, 95% CI - 8.08 to - 3.68), LDL-c (- 12.84 mg/dL, 95% CI - 22.15 to - 3.52), TC (- 16.30 mg/dL, 95% CI - 29.74 to - 2.86), TC/HDL-c ratio (- 0.52, 95% CI - 0.87 to - 0.18), hs-CRP (- 0.60 ng/mL, 95% CI - 0.77 to - 0.44), hirsutism score (- 0.33, 95% CI - 0.65 to - 0.02) and significantly increase nitric oxide levels (2.79 µmol/L, 95% CI 0.79-4.79). No significant effect was found on HDL-c, glycemic indices, hormonal profile, anthropometric measurements, and other biomarkers of inflammation or oxidative stress. This meta-analysis highlights the potential anti-hyperlipidemic, anti-oxidant, and anti-inflammatory properties of vitamin E supplementation alone or in combination with omega-3 or magnesium on PCOS patients.

The Complex Roles of Adipokines in Polycystic Ovary Syndrome and Endometriosis

Polycystic ovary syndrome (PCOS) and endometriosis are frequent diseases of the female reproductive tract causing high morbidity as they can significantly affect fertility and quality of life. Adipokines are pleiotropic signaling molecules secreted by white or brown adipose tissues with a central role in energy metabolism. More recently, their involvement in PCOS and endometriosis has been demonstrated. In this review article, we provide an update on the role of adipokines in both diseases and summarize previous findings. We also address the results of multi-omics approaches in adipokine research to examine the role of single nucleotide polymorphisms (SNPs) in genes coding for adipokines and their receptors, the secretome of adipocytes and to identify epigenetic alterations of adipokine genes that might be conferred from mother to child. Finally, we address novel data on the role of brown adipose tissue (BAT), which seems to have notable effects on PCOS. For this review, original research articles on adipokine actions in PCOS and endometriosis are considered, which are listed in the PubMed database.

The Effect of Hydroalcoholic Calendula Officinalis Extract on Androgen-Induced Polycystic Ovary Syndrome Model in Female Rat

Background. Polycystic ovary syndrome (PCOS) is the most common hormonal disorder in women of reproductive age, and the major cause of infertility. Today, using medicinal plants instead of chemical drugs could be an alternative treatment option for PCOS. The purpose of this study was to determine the effect of Calendula officinalis hydroalcoholic extract on PCOS in rats. Method. 60 female adult rats were randomly divided into six groups, including control, sham, PCOS group, and treated PCOS groups receiving hydroalcoholic extract of Calendula officinalis with different dosages of 200, 500, and 1000 mg/kg. PCOS was induced by subcutaneous injection of DHEA 6 mg/100 g bw for 35 days. For two weeks, the extract was taken orally. The serum glucose, insulin, sex hormone levels, and oxidative status were measured at the end of the experiment. The ovaries were dissected for histomorphometric and pathological analysis. Results. When compared to the control and sham groups, the PCOS group showed a significant increase in glucose, insulin, testosterone, and malondialdehyde (MDA) concentrations, cystic and atretic follicles, and thickness of the theca and tunica albuginea layers, and a significant decrease in LH concentration, total antioxidant capacity, corpus luteum, antral follicles, and oocyte diameter. The mean concentration of FSH, on the other hand, did not change significantly. A trend of improvement was found in the treated groups with high doses of Calendula officinalis extract. Conclusion. In rats with PCOS and nonovulation, Calendula officinalis hydroalcoholic extract improved oxidative stress, restored folliculogenesis, and increased ovulation.

Superior mesenteric ganglion neural modulation of ovarian angiogenesis, apoptosis and proliferation by the neuroactive steroid allopregnanolone

Allopregnanolone (ALLO), a potent neuroactive steroid, is synthesized and active in the peripheral nervous system. Previous studies have shown that ALLO participates in the central regulation of reproduction with effects on ovarian physiology, although there is little evidence for its ability to modulate peripheral tissues. The present study aimed to determine whether ALLO, administered to an ex vivo system that comprises the superior mesenteric ganglion (SMG), the ovarian nervous plexus (ONP) and the ovary (O), or to the denervated ovary (DO), was able to modify ovarian apoptosis, proliferation and angiogenesis. For this purpose, the SMG-ONP-O system and DO were incubated during 120 min at 37°C, in the presence of two ALLO doses (0.06 µm and 6 µm). The intrinsic and extrinsic pathways of apoptosis were analyzed. Incubation of the SMG-ONP-O system with ALLO 0.06 µm led to an increase in the BAX/BCL-2 ratio and a reduction of FAS-L mRNA levels. ALLO 6 µm induced a decrease of FAS-L levels. Incubation of DO with ALLO 0.06 µm reduced FAS-L, whereas ALLO 6 µm significantly increased it. Cyclin D1 mRNA was measured to evaluate proliferation. Treatment with ALLO 6 µm increased proliferation in both SMG-ONP-O and DO. ALLO 0.06 µm produced an increase of Cyclin D1 in DO only. Administration of either ALLO dose led to a higher ovarian expression of vascular endothelial growth factor in the SMG-ONP-O system, but a lower one in the DO system. ALLO 6 µm induced ovarian sensitization to GABA by increasing GABA_A receptor expression. In conclusion, ALLO participates in the peripheral neural modulation of ovarian physiology. It can also interact directly with the ovarian tissue, modulating key mechanisms involved in normal and pathological processes in a dose-dependent manner.

Progress of Adipokines in the Female Reproductive System: A Focus on Polycystic Ovary Syndrome

Adipose tissue, one type of loose connective tissue in the human body, maintains the primary task of energy storage. Adipose tissue is not only an energy reservoir but also plays a vital role as the largest endocrine organ of the whole body via releasing a variety of adipokines, which participate in many pathophysiological processes, such as energy metabolism regulation, glucose and lipid metabolism, and inflammation. Polycystic ovary syndrome (PCOS) is a disorder that mainly involves the female reproductive system, affecting women of childbearing age particularly. Insulin resistance (IR) and hyperandrogenemia (HA) have been implicated as a critical link involving the etiology and outcome of PCOS. A great deal of studies has bridged the gap between adipokines (such as Adiponectin, Chemerin, Metrnl, Apelin, Resistin, Visfatin, Leptin, Vaspin, Lipocalin 2, and Omentin) and reproductive fitness. In this review, we will focus on the adipokines' functions on PCOS and come up with some points of view on the basis of current research.

Reduced Endothelin-2 and Hypoxic Signaling Pathways in Granulosa-Lutein Cells of PCOS Women

Granulosa-lutein cells (GLCs) from PCOS women display reduced HIF-1α and EDN2 levels, suggesting their role in PCOS etiology. Here, we investigated the mechanisms involved in aberrant EDN2 expression in PCOS, and its association with HIF-1α. Various HIF-1α-dependent factors were studied in GLCs from PCOS and compared to normally ovulating women. MicroRNA-210 (miR-210), its target genes (SDHD and GPD1L), and HIF-1α-responsive genes (EDN2 and VEGFA) differed in GLCs from PCOS, compared with those of healthy women. Levels of miR-210—designated hypoxiamiR—and EDN2 were reduced in the PCOS GLCs; concomitantly, GPD1L and SDHD levels were elevated. Cultured GLCs retained low EDN2 expression and had low HIF-1α levels, providing evidence for a disrupted hypoxic response in the PCOS GLCs. However, VEGFA expression was elevated in these cells. Next, miR-210 levels were manipulated. miR-210-mimic stimulated EDN2 twice as much as the miR-NC-transfected cells, whereas miR-210-inhibitor diminished EDN2, emphasizing the importance of hypoxiamiR for EDN2 induction. Intriguingly, VEGFA transcripts were reduced by both miR-210-mimic and -inhibitor, demonstrating that EDN2 and VEGFA are distinctly regulated. Disrupted hypoxic response in the GLCs of periovulatory follicles in PCOS women may play a role in ovulation failure, and in the reduced fertility prevalent in this syndrome.

Reduced Angiopoietin-2 as a Predictive Biomarker for Clomiphene Citrate Resistance in Polycystic Ovary Syndrome

Background:

Even though angiopoeitin-2 and interleukin (IL)-23 are known to be altered in polycystic ovary syndrome (PCOS), their association with clomiphene citrate (CC) resistance has not been studied.

Aim:

The objective of the study was to investigate whether angiopoietin-2 levels are associated with inflammation and CC resistance in PCOS.

Settings and Design:

This study was conducted in a tertiary care hospital.

Materials and Methods:

Eighty-one women diagnosed with PCOS and on treatment with CC were enrolled in the study. Angiopoeitin-2 and IL -23 were analyzed in all the subjects.

Results:

Angiopoietin-2 was significantly reduced (P = 0.018), and body mass index (BMI) (P = 0.049) and duration of infertility (0.006) were significantly increased in PCOS women with CC resistance compared to those who are sensitive to CC. In CC resistant PCOS, IL-23 predicts reduction in angiopoietin-2 levels (P = 0.010). Among angiopoietin-2, IL-23, BMI, and duration of infertility, we found that angiopoeitn-2 (P = 0.020) and duration of infertility (0.036) can predict resistance to CC therapy among PCOS subjects.

Conclusion:

We conclude that reduced angiopoietin-2 levels predict CC resistance in women with PCOS.

Role of Vascular Endothelial Growth Factor (VEGF) in Human Embryo Implantation: Clinical Implications

Vascular endothelial growth factor (VEGF) is a well-known angiogenic factor that plays a critical role in various physiological and pathological processes. VEGF also contributes to the process of embryo implantation by enhancing embryo development, improving endometrial receptivity, and facilitating the interactions between the developing embryo and the endometrium. There is a correlation between the alteration of VEGF expression and reproductive failure, including recurrent implantation failure (RIF) and recurrent miscarriage (RM). In order to clarify the role of VEGF in embryo implantation, we reviewed recent literature concerning the expression and function of VEGF in the reproductive system around the time of embryo implantation and we provide a summary of the findings reported so far. We also explored the effects and the possible underlying mechanisms of action of VEGF in embryo implantation.

Effect of Vitamin E on Serum Levels of Vascular Endothelial Growth Factor and Angiopoietin-1 in Women with Polycystic Ovary Syndrome: A Pilot Randomized, Placebo-Controlled Trial

Background

Angiogenesis disturbances are common in women with polycystic ovary syndrome (PCOS). Vitamin E has antiangiogenic properties. Data on the effects of vitamin E on angiogenesis in PCOS is limited, so the current study was conducted to evaluate its effects on angiogenic indices in PCOS patients.

Materials and Methods

This randomized, double-blind, placebo-controlled trial was performed on 43 women aged 20-40 years, diagnosed with PCOS (Rotterdam criteria). It was performed at the referral clinic affiliated to Tabriz University of Medical Sciences, Tabriz, Iran, from April 2017 to September 2017. Patients were randomly assigned into two groups to receive either 400 IU/day vitamin E -as alpha tocopheryl acetate- (n=22) or placebo (n=21), for 8 weeks. Anthropometric, and angiogenic parameters including body weight, fat mass and fat free mass, vascular endothelial growth factor (VEGF), basic fibroblast growth factor (bFGF), angiopoietin-1 (Ang- 1), and angiopoietin-2 (Ang-2) were measured by standard methods at the beginning and at the end of study. Statistical Package for Social Science version 25 was used for statistical analysis and P<0.05 were considered significant.

Results

After adjusting for potential confounders, we observed that vitamin E supplementation significantly reduced body weight, fat mass, Ang-1, Ang-1/Ang-2 ratio and VEGF (P<0.01). We did not observe any considerable effect for vitamin E on Ang-2 level or bFGF.

Conclusion

Vitamin E supplementation for 8 weeks in the PCOS women had beneficial effects on body weight, Ang- 1, Ang-1/Ang-2 ratio, and VEGF level (Registration number: IRCT201610193140N18).

Berberine exerts a protective effect on rats with polycystic ovary syndrome by inhibiting the inflammatory response and cell apoptosis

BACKGROUND

Polycystic ovary syndrome (PCOS) is a common endocrine disease of the female reproductive system that seriously affects women's health. Berberine (BBR) has many pharmacological properties and is used as an insulin sensitizer. This study aimed to investigate the effect of BBR on PCOS and explore its related mechanisms.

METHODS

Forty-two rats were randomly divided into the following six groups (n = 7 per group): control, control + BBR, PCOS-normal diet (ND), PCOS-ND + BBR, PCOS-high-fat diet (HFD), and PCOS-HFD + BBR. The PCOS rat models were established by injecting rats with dehydroepiandrosterone. Further, the rats were gavaged with BBR (150 mg/kg/d) for 6 weeks. Then, the body weight, HOMA-IR, and testosterone levels of all rats were determined. Cell apoptosis of ovary granulosa cells was determined by a TUNEL assay kit. Real-time quantification PCR (RT-qPCR) and western blotting were utilized to evaluate the expression of TLR4, LYN, PI3K, Akt, NF-kB, TNF-α, IL-1, IL-6, and caspase-3.

RESULTS

BBR reduced the levels of insulin resistance and testosterone in PCOS rats. Additionally, the cell apoptosis rate increased significantly in PCOS rats (P < 0.05) and decreased after BBR treatment (P < 0.05). The results of RT-qPCR and western blotting showed that the expression levels of TLR4, LYN, PI3K, Akt, NF-kB, TNF-α, IL-1, IL-6, and caspase-3 significantly increased in PCOS rats, while BBR suppressed their expression levels.

CONCLUSIONS

BBR may relieve PCOS pathology and IR values by inhibiting cell apoptosis and by regulating the expression levels of TLR4, LYN, PI3K, Akt, NF-kB, TNF-α, IL-1, IL-6, and caspase-3.

High expression of Tie-2 predicts poor prognosis in primary high grade serous ovarian cancer

Background

Antiangiogenic therapy, although part of standard treatment in ovarian cancer, has variable efficacy. Furthermore, little is known about the prognostic biomarkers and factors influencing angiogenesis in cancer tissue. We evaluated the expression of angiopoietin-2 and two endothelial tyrosine kinase receptors, Tie-1 and Tie-2, and assessed their value in the prediction of survival in patients with malignant epithelial ovarian cancer. We also compared the expression of these factors between primary high grade serous tumors and their distant metastasis.

Materials and methods

We evaluated 86 women with primary epithelial ovarian cancer. Matched distal omental metastasis were investigated in 18.6% cases (N = 16). The expression levels of angiogenic factors were evaluated by immunohistochemistry in 306 specimens and by qRT-PCR in 111 samples.

Results

A high epithelial expression level of Tie-2 is a significant prognostic factor in primary high grade serous ovarian cancer. It predicted significantly shorter overall survival both in univariate (p<0.001) and multivariate survival analyses (p = 0.022). Low angiopoietin-2 expression levels in primary ovarian tumors were significantly associated with shorter overall survival (p = 0.015) in the univariate survival analysis. A low expression of angiopoietin-2 was also significantly related to high grade tumors, size of residual tumor after primary surgery and the recurrence of cancer (p = 0.008; p = 0.012; p = 0.018) in the whole study population. The expression of angiopoietin-2 and Tie-2 was stronger in distal omental metastasis than in primary high grade serous tumors in matched-pair analysis (p = 0.001; p = 0.002).

Conclusions

The angiogenic factor, angiopoietin-2, and its receptor Tie-2 seem to be significant prognostic factors in primary epithelial ovarian cancer. Their expression levels are also increased in metastatic lesions in comparison with primary tumors.

Cardiovascular Risk Factors and Differential Transcriptomic Profile of the Subcutaneous and Visceral Adipose Tissue and Their Resident Stem Cells

Background: The increase in the incidence of obesity and obesity-related cardiovascular risk factors (CVRFs) over the last decades has brought attention on adipose tissue (AT) pathobiology. The expansion of AT is associated with the development of new vasculature needed to perfuse the tissue; however, not all fat depots have the same ability to induce angiogenesis that requires recruitment of their own endothelial cells. In this study we have investigated the effect of different CVRFs, on the angiogenic capacity of the subcutaneous (SAT) and visceral (VAT) adipose tissue and on the function of their mesenchymal cell reservoir. Methods: A transcriptomic approach was used to compare the different angiogenic and inflammatory profiles of the subcutaneous and visceral fat depots from individuals with obesity, as well as their resident stem cells (ASCs). Influence of other risk factors on fat composition was also measured. Finally, the microvesicles (MVs) released by ASCs were isolated and their regenerative potential analyzed by molecular and cellular methodologies. Results: Obesity decreases the angiogenic capacity of AT. There are differences between SAT and VAT; from the 21 angiogenic-related genes analyzed, only three were decreased in SAT compared with those decreased in VAT. ASCs isolated from both fat depots showed significant differences; there was a significant up-regulation of the VEGF-pathway on visceral derived ASCs. ASCs release MVs that stimulate endothelial cell migration and angiogenic capacity. Conclusions: In patients with obesity, SAT expresses a greater number of angiogenic molecules than VAT, independent of the presence of other CVRFs.

Apelin/Apelin receptor: A new therapeutic target in Polycystic Ovary Syndrome

Polycystic ovary syndrome (PCOS) is an endocrinopathy, and it accounts for 75% of non-ovulatory infertile in women of childbearing age. It is clear that obesity, insulin resistance, dyslipidaemia coexist in PCOS. Apelin, as an endogenous ligand of the previously orphan receptor, is an adipokine that secreted by adipose tissue. Apelin and apelin receptors are expressed in many tissues and organ to regulate their physiological functions. Studies have shown that Apelin/apelin-receptor also expressed in ovary such as follicles, granulosa cells. Furthermore, Apelin/apelin-receptor play roles in vascular establishment and hormone metabolism in ovary. These indicate that the Apelin/apelin-receptor play an important role in the development of follicle. Apelin/apelin-receptor are increased in ovary of PCOS, which are associated with abnormal ovarian hormones and function. These are important causes of menstrual cycle disorders and anovulation. Moreover, apelin now appears clearly as a new player in energy metabolism. Apelin can regulate glucose and lipid metabolism but also modulate insulin secretion. And plasma apelin concentrations are elevated in obesity and type 2 diabetes patients. Interestedly, obesity and type 2 diabetes are also companied with polycystic ovary syndrome patients. We speculate apelin/apelin-receptor may play a vital role in pathogenesis of polycystic ovary syndrome, but the underlying mechanisms remain under exploration. Here, we review apelin/apelin-receptor, as a new therapeutic target, have effects on ovarian function and energy metabolism in polycystic ovary syndrome.

MiR-185-5p Protects Against Angiogenesis in Polycystic Ovary Syndrome by Targeting VEGFA

Polycystic Ovary Syndrome (PCOS) is a heterogeneous endocrine disease with high incidences in women of reproductive age. Although miR-185-5p (miR-185) was decreased in PCOS patients, the exact function of miR-185 on PCOS development still requires further investigation. In this study, rat injected with dehydroepiandrosterone (DHEA) was established as a PCOS model. A lentivirus carrying miR-185 was employed to examine its effect on PCOS symptoms. Then we performed the luciferase reporter assay to validate the interactions between miR-185 and vascular endothelial growth factor A (VEGFA). Finally, human ovarian microvascular endothelial cells (HOMECs) were induced by VEGF to explore the role of miR-185 in the angiogenic process. The results showed that miR-185 overexpression improved insulin level alteration and ovarian histological lesion in PCOS rats. We also found that miR-185 reduced the excessive angiogenesis as indicated by alterations of VEGFA, ANGPT1/2, PDGFB/D, α-SMA and CD31 in the ovary of PCOS rats. Luciferase reporter assay identified that VEGFA directly interacted with miR-185, and its expression level was negatively regulated by miR-185. The in vitro results further demonstrated that miR-185-induced suppression of cell proliferation, migration and tube formation was attenuated by VEGF in HOMECs. In summary, this is the first study to show that miR-185 can target VEGFA to inhibit angiogenesis, thus improving the development of PCOS. These findings develop a molecular candidate for PCOS prevention and therapy.

Downregulation of Lnc-OC1 attenuates the pathogenesis of polycystic ovary syndrome

Long non-coding RNAs (lncRNAs) play a vital role in the progression of many human diseases. The aim of this study is to explore the relationship between lncRNA-ovarian cancer associated 1 (Lnc-OC1) and PCOS. In this study, we found that Lnc-OC1 was significantly higher in PCOS granulosa cells (GCs) compared to non-PCOS GCs. Lnc-OC1 knockdown inhibited cell viability and promoted cell apoptosis, expression of aromatase mRNA and production of estradiol in KGN cells. In PCOS mice, Lnc-OC1 promoted the serum insulin release, production of angiogenesis-related factors and IκBα phosphorylation, which could be partially restored by Lnc-OC1 shRNA. These results suggest that Lnc-OC1 plays an important part in the pathogenesis of PCOS.

Quercetin modulates granulosa cell mRNA androgen receptor gene expression in dehydroepiandrosterone-induced polycystic ovary in Wistar rats via metabolic and hormonal pathways

Background It is estimated that about 5-10% of women suffer from polycystic ovarian syndrome (PCOS) which is a major cause of female reproductive dysfunction. This study examined the role of quercetin on dehydroepiandrosterone (DHEA)-induced PCO in Wistar rats. Methods Twenty-eight pre-pubertal female Wistar rats that are 21 days old weighing 16-21 g were sorted into four groups (n = 7). Group I served as control and was given distilled water only, Group II were injected with 6 mg/100 g BW of DHEA in 0.2 mL of corn oil subcutaneously, Group III received 100 mg/kg BW of quercetin orally and Group IV received 6 mg/100 g BW of DHEA in 0.2 mL of corn oil subcutaneously and 100 mg/kg BW of quercetin orally. Rats were sacrificed after 15 days by cervical dislocation method. Blood samples and ovaries were collected for hormonal, biochemical, and histopathological analysis and expressions of mRNA androgen receptor gene were determined using RT-qPCR. All data were analysed using one-way ANOVA. Results A significant decrease (p < 0.05) in the antioxidant and metabolic enzyme activity in the DHEA treated group was observed when compared with control. DHEA co-administration with quercetin showed a significant decrease in malondialdehyde and cytokines when compared with DHEA treated group. Also a significant increase in progesterone, metabolic and antioxidant enzyme activity was observed. The histopathology demonstrates a reduction in cystic and atretic cells, improved expression of BCl2, E-Cadherin and a decrease in Bax. Conclusions Quercetin alleviated DHEA-induced PCO. These effects could be attributed to its antioxidant property.

Metformin has a direct effect on ovarian cells that is dependent on organic cation transporters

Metformin (MET) is the most widely prescribed hypoglycemic drug in type 2 diabetes and Polycystic Ovary Syndrome. Besides its effects on glucose metabolism, MET exerts beneficial effects on these patients' fertility. However, the exact mechanisms of action of MET on female fertility are still unclear. In this work, we analyzed a possible direct effect of MET on ovarian cells. We found expression of the organic cation transporters OCT1, OCT2 and OCT3, responsible for MET uptake into the cells, in rat granulosa cells and human cumulus cells. Furthermore, MET increased pAMPK and decreased VEGF levels both in vivo and in rat granulosa cells in culture. These last effects were reversed when OCTs were inhibited. Our results suggest that MET acts directly on ovarian cells regulating cell metabolism and VEGF expression. Our findings are relevant to optimize PCOS fertility treatment and to explore ovarian MET actions in other female pathologies.

Vitamin C suppresses ovarian pathophysiology in experimental polycystic ovarian syndrome

BACKGROUND

Polycystic ovary syndrome (PCOS), also known as the Stein-Leventhal syndrome is one of the most common causes of anovulation, infertility and hyperandrogenism in women, affecting between 5-10 % of women of reproductive age (12-35 years) worldwide. Despite substantial effort to define the cause of PCOS, its pathophysiology remains poorly understood. Consequently, determining the mechanisms of PCOS and the possible treatment is the major goal of medical research in endocrine and reproductive physiology.

AIM

To investigate the mechanism of ovarian metabolic changes in dehydroepiandrosterone (DHEA)-induced polycystic ovary in Wistar rats treated with vitamin C.

METHODS

Twenty-eight immature female Wistar rats weighing (16-21 g) were randomly divided into four groups (n = 7/group): group I served as control and was given water, group II were injected with DHEA (6 mg/100 g in 0.2 ml corn oil subcutaneously to induce PCOS condition), group III received 150 mg/kg BW of Vitamin C orally, group IV were co-administered with 6 mg/kg BW DHEA in 0.2 ml of corn oil subcutaneously and 150 mg/kg BW of Vitamin C orally. All treatments lasted for 15 days. Twenty-four hours after the last administration, the rats were sacrificed by cervical dislocation. Blood samples and ovaries were collected for reproductive hormonal analysis, biochemical and histopathological analysis. The expressions of mRNA androgen receptor gene in the ovary were determined by real-time reverse transcriptase polymerase chain reaction. All data were analysed using one-way ANOVA.

RESULTS

There was a significant decrease (p < 0.05) in the antioxidant and metabolic enzyme activity in the DHEA treated group compared with the control group. DHEA co-administration with Vitamin C showed a significant decrease in Malondialdehyde, cytokines and Estrogen and a significant increase (p < 0.05) in antioxidant and metabolic enzymes compared with DHEA treated group only. The histopathological evaluation demonstrates a reduction in cystic and atretic ovaries, increased expression of Bcl₂ and E-Cadherin with a reduction in Bax expression in the group co-administered with DHEA and Vitamin C. The DHEA group showed overexpression of mRNA Androgen Receptor gene in the ovaries compared to the control group.

CONCLUSION

This study shows that Vitamin C plays a protective role against DHEA-Induced Polycystic Ovary in Wistar rats via its antioxidant and anti-apoptotic mechanisms.

The Role of the Brain in the Pathogenesis and Physiology of Polycystic Ovary Syndrome (PCOS)

Polycystic ovary syndrome (PCOS) is a common reproductive endocrine disorder, affecting at least 10% of women of reproductive age. PCOS is typically characterized by the presence of at least two of the three cardinal features of hyperandrogenemia (high circulating androgen levels), oligo- or anovulation, and cystic ovaries. Hyperandrogenemia increases the severity of the condition and is driven by increased luteinizing hormone (LH) pulse secretion from the pituitary. Indeed, PCOS women display both elevated mean LH levels, as well as an elevated frequency of LH pulsatile secretion. The abnormally high LH pulse frequency, reflective of a hyperactive gonadotropin-releasing hormone (GnRH) neural circuit, suggests a neuroendocrine basis to either the etiology or phenotype of PCOS. Several studies in preclinical animal models of PCOS have demonstrated alterations in GnRH neurons and their upstream afferent neuronal circuits. Some rodent PCOS models have demonstrated an increase in GnRH neuron activity that correlates with an increase in stimulatory GABAergic innervation and postsynaptic currents onto GnRH neurons. Additional studies have identified robust increases in hypothalamic levels of kisspeptin, another potent stimulator of GnRH neurons. This review outlines the different brain and neuroendocrine changes in the reproductive axis observed in PCOS animal models, discusses how they might contribute to either the etiology or adult phenotype of PCOS, and considers parallel findings in PCOS women.

Fetal programming by androgen excess in rats affects ovarian fuel sensors and steroidogenesis

Fetal programming by androgen excess is hypothesized as one of the main factors contributing to the development of polycystic ovary syndrome (PCOS). PCOS is more than a reproductive disorder, as women with PCOS also show metabolic and other endocrine alterations. Since both ovarian and reproductive functions depend on energy balance, the alterations in metabolism may be related to reproductive alterations. The present study aimed to evaluate the effect of androgen excess during prenatal life on ovarian fuel sensors and its consequences on steroidogenesis. To this end, pregnant rats were hyperandrogenized with testosterone and the following parameters were evaluated in their female offspring: follicular development, PPARG levels, adipokines (including leptin, adiponectin, and chemerin as ovarian fuel sensors), serum gonadotropins (LH and FSH), the mRNA of their ovarian receptors, and the expression of steroidogenic mediators. At 60 days of age, the prenatally hyperandrogenized (PH) female offspring displayed both an irregular ovulatory phenotype and an anovulatory phenotype with altered follicular development and the presence of cysts. Both PH groups showed altered levels of both proteins and mRNA of PPARG and a different expression pattern of the adipokines studied. Although serum gonadotropins were not impaired, there were alterations in the mRNA levels of their ovarian receptors. The steroidogenic mediators Star, Cyp11a1, Cyp17a1, and Cyp19a1 were altered differently in each of the PH groups. We concluded that androgen excess during prenatal life leads to developmental programming effects that affect ovarian fuel sensors and steroidogenesis in a phenotype-specific way.

Animal models of polycystic ovary syndrome: A review of hormone-induced rodent models focused on hypothalamus-pituitary-ovary axis and neuropeptides

BACKGROUND

Polycystic ovary syndrome (PCOS) is a common endocrine disorder among women of reproductive age and a major cause of infertility; however, the pathophysiology of this syndrome is not fully understood. This can be addressed using appropriate animal models of PCOS. In this review, we describe rodent models of hormone-induced PCOS that focus on the perturbation of the hypothalamic-pituitary-ovary (HPO) axis and abnormalities in neuropeptide levels.

METHODS

Comparison of rodent models of hormone-induced PCOS.

MAIN FINDINGS

The main method used to generate rodent models of PCOS was subcutaneous injection or implantation of androgens, estrogens, antiprogestin, or aromatase inhibitor. Androgens were administered to animals pre- or postnatally. Alterations in the levels of kisspeptin and related molecules have been reported in these models.

CONCLUSION

The most appropriate model for the research objective and hypothesis should be established. Dysregulation of the HPO axis followed by elevated serum luteinizing hormone levels, hyperandrogenism, and metabolic disturbance contribute to the complex etiology of PCOS. These phenotypes of the human disease are recapitulated in hormone-induced PCOS models. Thus, evidence from animal models can help to clarify the pathophysiology of PCOS.

Evaluation of the Rho A/Rho-kinase pathway in the uterus of the rat model of polycystic ovary syndrome

The aim of this study was to investigate the expression of RhoA/Rho-kinase in the uterus and the effect of Rho-kinase inhibitors on uterine contractions of dehydroepiandrosterone (DHEA) induced polycystic ovary syndrome (PCOS) rats. Forty-four female Sprague-Dawley (21 days old) rats divided into three groups: The control group (n = 14, any procedure was not performed), vehicle group (n = 14, 0.2 ml of sesame oil, subcutaneous injection, 20 days) and PCOS group (n = 16, DHEA 6 mg/100 g in 0.2 ml of sesame oil, subcutaneous injection, 20 days). The myometrium thickness and uterine wet weight were assessed. The mRNA and protein expressions of Rho A, the effect of Rho-kinase inhibitors (fasudil and Y-27632) on KCl, carbachol, and PGF2α induced contractions were evaluated in the uterus. In the PCOS group, the myometrium thickness and uterine wet weight significantly increased compared to the control group and vehicle group. The mRNA expression level and the immunoreactive score of Rho A, ROCK 1, ROCK 2 were similar in all groups. In the PCOS group, KCl, carbachol, and PGF2α induced uterine contractions significantly increased compared to the control group and vehicle group. Fasudil and Y-27632 significantly inhibited KCl, carbachol, and PGF2α induced uterine contractions in all groups. In conclusion, the expression of Rho A, ROCK 1, ROCK 2 not changed although myometrium thickness, uterine wet weight and the contractile responses of uterus increased in the PCOS group. The results suggest that the Rho-kinase inhibitors effectively suppressed increased contractions in the PCOS group they might be potential therapeutic agents.

Endogenous Ovarian Angiogenesis in Polycystic Ovary Syndrome-Like Rats Induced by Low-Frequency Electro-Acupuncture: The CLARITY Three-Dimensional Approach

We sought to determine the role of ovarian vascularity and neo-angiogenesis in the development of mature follicles in polycystic ovary syndrome (PCOS) and to identify any changes induced by low-frequency electro-acupuncture (EA). Twenty-eight 21-day-old female Wistar rats were randomly divided into four groups—Control, Obesity, PCOS-like, and PCOS-like-EA (n = 7/group). Rats in the Obesity group were fed a high-fat diet throughout the experiment. Rats in the PCOS-like and PCOS-like-EA groups were implanted with a sustained-release tube containing 5α-dihydrotestosterone (DHT) beneath the skin of the neck. Rats in the PCOS-like-EA group received low-frequency EA treatment starting at 70 days for 30 min five times a week for four weeks. At the end of the experiment, all rats were euthanized and perfused with hydrogel. The ovaries were collected for clarification and imaging, and ovarian vascularity and neo-angiogenesis were analyzed. Compared with Control and Obesity rats, the ovaries in DHT-induced PCOS-like rats were smaller in size and had fewer mature follicles and corpora lutea. EA increased angiogenesis in the antral follicles of PCOS-like rats, which in turn promoted follicle maturation, ovulation, and CL formation. Therefore, endogenous ovarian angiogenesis plays a very important role in follicular maturation and might be one of the peripheral and direct mechanisms of EA on PCOS.

Dehydroepiandrosterone Ameliorates Abnormal Mitochondrial Dynamics and Mitophagy of Cumulus Cells in Poor Ovarian Responders

Mitochondrial dysfunction is related to reproductive decline in humans, with consequences for in vitro fertilization (IVF). We assessed whether dehydroepiandrosterone (DHEA) could regulate mitochondrial homeostasis and mitophagy of cumulus cells (CCs) in poor ovarian responders (PORs). A total of 66 women who underwent IVF treatment at the Reproductive Medicine Center of Kaohsiung Veterans General Hospital were included in this study. Twenty-eight normal ovarian responders (NOR) and 38 PORs were enrolled. PORs were assigned to receive DHEA supplementation (n = 19) or not (n = 19) before IVF cycles. DHEA prevents mitochondrial dysfunction by decreasing the activation of DNM1L and MFF, and increasing MFN1 expression. Downregulation of PINK1 and PRKN occurred after DHEA treatment, along with increased lysosome formation. DHEA not only promoted mitochondrial mass but also improved mitochondrial homeostasis and dynamics in the CCs of POR. We also observed effects of alterations in mRNAs known to regulate mitochondrial dynamics and mitophagy in the CCs of POR. DHEA may prevent mitochondrial dysfunction through regulating mitochondrial homeostasis and mitophagy.

Ovarian angiogenesis in polycystic ovary syndrome

Polycystic ovary syndrome (PCOS) is the most prevalent endocrine pathology among women in reproductive age. Its main symptoms are oligo or amenorrhea, hyperandrogenism and the presence of ovarian cysts. It is also associated with infertility, obesity and insulin resistance. Mainly due to its heterogeneity, PCOS treatments are directed to manage its symptoms and to prevent associated diseases. The correct formation and regression of blood vessels during each ovarian cycle is indispensable for proper follicular development, ovulation and corpus luteum formation. The importance of these processes opened a new and promising field: ovarian angiogenesis. Vascular alterations characterize numerous pathologies, either with increased, decreased or abnormal angiogenesis. In the last years, several anomalies of ovarian angiogenesis have been described in women with PCOS. Therefore, it has been suggested that these alterations may be associated with the decreased - or lack of - ovulation rates and for the formation of cysts in the PCOS ovaries. Restoration of a proper vessel formation in the ovaries may lead to improved follicular development and ovulation in these patients. In the present review, we attempt to summarize the alterations in ovarian angiogenesis that have been described in women with PCOS. We also discuss the therapeutic approaches aimed to correct these alterations and their beneficial effects on the treatment of infertility in PCOS.

Assessment of growth and metabolism characteristics in offspring of dehydroepiandrosterone-induced polycystic ovary syndrome adults

Polycystic ovary syndrome (PCOS) is a common reproductive disorder that has many characteristic features including hyperandrogenemia, insulin resistance and obesity, which may have significant implications for pregnancy outcomes and long-term health of women. Daughters born to PCOS mothers constitute a high-risk group for metabolic and reproductive derangements, but no report has described potential growth and metabolic risk factors for such female offspring. Hence, we used a mouse model of dehydroepiandrosterone (DHEA)-induced PCOS to study the mechanisms underlying the pathology of PCOS by investigating the growth, developmental characteristics, metabolic indexes and expression profiles of key genes of offspring born to the models. We found that the average litter size was significantly smaller in the DHEA group, and female offspring had sustained higher body weight, increased body fat and triglyceride content in serum and liver; they also exhibited decreased energy expenditure, oxygen consumption and impaired glucose tolerance. Genes related to glucolipid metabolism such as Pparγ, Acot1/2, Fgf21, Pdk4 and Inhbb were upregulated in the liver of the offspring in DHEA group compared with those in controls, whereas Cyp17a1 expression was significantly decreased. However, the expression of these genes was not detected in male offspring. Our results show that female offspring in DHEA group exhibit perturbed growth and glucolipid metabolism that were not observed in male offspring.

Tankyrase inhibition regulates corpus luteum development and luteal function in gonadotropin-treated rats

Tankyrases are physiological regulators of Axin, a protein involved in several cellular processes, including Wnt signaling. Here, we investigated the effect of a specific Tankyrase inhibitor (XAV939) in follicular-luteal dynamics, and its possible relationship with ovarian vascular development. Studies were designed to analyze the effect of intrabursa administration of XAV939 in gonadotropin-treated prepubertal rats. In particular, we examined follicle and corpus luteum development, steroidogenesis, angiogenic markers, and apoptotic parameters. We found that in vivo inhibition of Wnt signaling impaired corpus luteum development, with a decrease in the number of corpora lutea balanced by a high number of cysts; decreased circulating progesterone levels, likely due to a decrease in Steroidogenic acute regulatory protein content in the corpus luteum; and increased pro-apoptotic parameters. In addition, Extracellular signal-regulated kinase phosphorylation, Vascular endothelium growth factor 120 content, and endothelial cell area were diminished in corpora lutea of inhibitor-treated ovaries. Thus, Wnt/β-catenin signaling appears to participate in the regulation of corpus luteum development and luteal cell function.

Abnormality of Klotho Signaling Is Involved in Polycystic Ovary Syndrome

This study investigated the involvement of the klotho-associated signaling in the apoptosis of granulosa cells (GCs) from the ovaries of patients with polycystic ovary syndrome (PCOS) and PCOS animals. Primary GCs were obtained from 26 healthy women and 43 women with PCOS. The PCOS animal model was established by the injection of dehydroepiandrosterone (DHEA). Klotho protein and associated microRNA expression in human primary GCs and rats' ovarian tissues were measured by Western blot and real-time polymerase chain reaction, respectively. Results showed that significantly lower miR-126-5p and miR-29a-5p microRNA expressions, higher klotho protein expression, lower insulin growth factor 1 (IGF-1R) and Wnt family member 1 (Wnt1) protein expressions, and lower Akt phosphorylation at Ser⁴⁷³ and Thr³⁰⁸ residues were observed in the GCs from patients with PCOS and the ovarian tissues of PCOS rats compared to that in GCs from healthy women and ovarian tissues of normal control rats, respectively. Knockdown of klotho gene expression normalized IGF-1R and Wnt1 protein expressions and Akt phosphorylation in GCs from patients with PCOS and the ovarian tissues from PCOS rats; it also blocked the effects of insulin on apoptosis and proliferation in GCs from patients with PCOS and inhibited caspase-3 activity in ovarian tissues of PCOS rats. Knockdown of klotho gene expression increased the pregnancy rate in DHEA-treated female rats and increased the body weight of their newborns through normalizing the ovarian function and decreasing the formation of cystic follicles. In conclusion, the miR-126-5p, miR-29a-5p/klotho/insulin-IGF-1, Wnt, and Akt signal pathway may be involved in the apoptosis of GCs and subsequent development of PCOS.

Endocannabinoid receptor blockade increases vascular endothelial growth factor and inflammatory markers in obese women with polycystic ovary syndrome

CONTEXT

Animal studies suggest that cannabinoid receptor-1 (CB-1) blockade reduces inflammation and neovascularization by decreasing vascular endothelial growth factor (VEGF) levels associated with a reduction in inflammatory markers, thereby potentially reducing cardiovascular risk.

OBJECTIVE

To determine the impact of CB1 antagonism by rimonabant on VEGF and inflammatory markers in obese PCOS women.

DESIGN

Randomized, open-labelled parallel study.

SETTING

Endocrinology outpatient clinic in a referral centre.

SUBJECTS

Twenty patients with PCOS (PCOS) and biochemical hyperandrogenaemia with a body mass index of ≥30 kg/m² were recruited. Patients were randomized to 1·5 g daily of metformin or 20 mg daily of rimonabant.

MAIN OUTCOME MEASURES

Post hoc review to detect VEGF and pro-inflammatory cytokines TNF-α, IL-1β, IL-1ra, IL-2, IL6, IL-8, IL-10 and MCP-1 before and after 12 weeks of treatment.

RESULTS

After 12 weeks of rimonabant treatment, there was a significant increase in VEGF (99·2 ± 17·6 vs 116·2 ± 15·8 pg/ml, P < 0·01) and IL-8 (7·4 ± 11·0 vs 18·1 ± 13·2 pg/ml, P < 0·05) but not after metformin (VEGF P = 0·7; IL-8 P = 0·9). There was no significant difference in the pro-inflammatory cytokines TNF-α, IL-1β, IL-1ra, IL-2, IL6, IL-8, IL-10 and MCP-1 following either treatment.

CONCLUSION

This study suggests that rimonabant CB-I blockade paradoxically raised VEGF and the cytokine IL-8 in obese women with PCOS that may have offset the potential benefit associated with weight loss.

Decreased levels of sRAGE in follicular fluid from patients with PCOS

This study aimed to explore the association between soluble receptor for advanced glycation end products (sRAGE) levels in follicular fluid and the number of oocytes retrieved and to evaluate the effect of sRAGE on vascular endothelial growth factor (VEGF) in granulosa cells in patients with polycystic ovarian syndrome (PCOS). Two sets of experiments were performed in this study. In part one, sRAGE and VEGF protein levels in follicular fluid samples from 39 patients with PCOS and 35 non-PCOS patients were measured by ELISA. In part two, ovarian granulosa cells were isolated from an additional 10 patients with PCOS and cultured. VEGF and SP1 mRNA and protein levels, as well as pAKT levels, were detected by real-time PCR and Western blotting after cultured cells were treated with different concentrations of sRAGE. Compared with the non-PCOS patients, patients with PCOS had lower sRAGE levels in follicular fluid. Multi-adjusted regression analysis showed that high sRAGE levels in follicular fluid predicted a lower Gn dose, more oocytes retrieved, and a better IVF outcome in the non-PCOS group. Logistic regression analysis showed that higher sRAGE levels predicted favorably IVF outcomes in the non-PCOS group. Multi-adjusted regression analysis also showed that high sRAGE levels in follicular fluid predicted a lower Gn dose in the PCOS group. Treating granulosa cells isolated from patients with PCOS with recombinant sRAGE decreased VEGF and SP1 mRNA and protein expression and pAKT levels in a dose-dependent manner.

Altered Circulating Inflammatory Cytokines Are Associated with Anovulatory Polycystic Ovary Syndrome (PCOS) Women Resistant to Clomiphene Citrate Treatment

Background

Polycystic ovary syndrome (PCOS) is a common gynecological disease characterized by chronic oligoanovulation, clinical/biochemical hyperandrogenism, polycystic ovaries, and insulin resistance. Accumulating evidence has shown that PCOS-related ovarian dysfunction is the main cause of anovulatory infertility. Clomiphene citrate (CC) is the first-line therapy for PCOS patients; however, approximately 15–40% PCOS patients are resistant to CC treatment. It has been demonstrated that PCOS is a chronic pro-inflammatory state, as some pro-inflammatory cytokines were elevated in the peripheral circulation of PCOS patients, but whether altered inflammatory cytokines expression in PCOS patients is associated with blunted response to CC remains unknown.

Material/Methods

We recruited 44 CC-resistant PCOS patients, along with 55 age and body mass index (BMI)-matched CC-sensitive PCOS patients. Ovulation was induced by administrating 50–100 mg/day CC on days 5 to 9 of each menstrual cycle. The cytokine profiles were detected by cytokine antibody microarrays and further validated by ELISAs.

Results

CC-resistant patients had higher levels of high-sensitivity C-reactive protein (hsCRP) than the CC-sensitive individuals. A growth factor, angiopoietin-2, was significantly reduced [1.64 (0.93–1.95) vs. 1.08 (0.85–1.34), p<0.05], while a chemokine CXCL-16 was significantly increased (9.10±2.35 vs. 10.41±2.82, p<0.05) in CC-resistant patients compared to the CC-sensitive subjects. CXCL-16 was positively correlated with hsCRP (r=0.33, p<0.01). Logistic regression analysis showed that angiopoietin-2 and CXCL-16 are associated with CC resistance.

Conclusions

Circulating cytokines are disturbed in CC-resistant PCOS patients. Altered angiopoietin-2 and CXCL-16 levels might compromise the responsiveness of the ovary to CC through up-regulating angiogenesis and inflammation.

Local administration of platelet-derived growth factor B (PDGFB) improves follicular development and ovarian angiogenesis in a rat model of Polycystic Ovary Syndrome

Alterations in ovarian angiogenesis are common features in Polycystic Ovary Syndrome (PCOS) patients; the most studied of these alterations is the increase in vascular endothelial growth factor (VEGF) production by ovarian cells. Platelet-derived growth factor B (PDGFB) and D (PDGFD) are decreased in follicular fluid of PCOS patients and in the ovaries of a rat model of PCOS. In the present study, we aimed to analyze the effects of local administration of PDGFB on ovarian angiogenesis, follicular development and ovulation in a DHEA-induced PCOS rat model. Ovarian PDGFB administration to PCOS rats partially restored follicular development, decreased the percentage of cysts, increased the percentage of corpora lutea, and decreased the production of anti-Müllerian hormone. In addition, PDGFB administration improved ovarian angiogenesis by reversing the increase in periendothelial cell area and restoring VEGF levels. Our results shed light into the mechanisms that lead to altered ovarian function in PCOS and provide new data for potential therapeutic strategies.

Aberrant expression of angiopoietin-like proteins 1 and 2 in cumulus cells is potentially associated with impaired oocyte developmental competence in polycystic ovary syndrome

Polycystic ovary syndrome (PCOS) is a heterogeneous endocrine disorder associated with obesity, insulin resistance, hyperandrogenism, alterations in ovarian angiogenesis and impaired oocyte competence. Emerging evidence demonstrates that angiopoietin-like protein 1 (ANGPTL1) and angiopoietin-like protein 2 (ANGPTL2) have an important influence on angiogenesis, androgen biosynthesis, insulin resistance and adipocytes function. In this study, we set out to determine the potential relationship between ANGPTL1, ANGPTL2 and oocyte competence in PCOS through analyzing the expression levels and dynamic pattern of the two genes in cumulus cells (CCs) during different phases of nuclear maturation of PCOS patients and control groups undergoing controlled ovarian hyperstimulation (COH) for in vitro fertilization and embryo transfer. We found that the relative abundance of ANGPTL1 and ANGPTL2 transcripts in CCs from patients with PCOS showed dynamic changes during oocyte maturation. Specifically, their expressions were increased significantly at the Metaphase II stage. In summary, the present novel evidence indicates that the expression patterns of ANGPTL1 and ANGPTL2 mRNAs are disordered during oocyte maturation in PCOS, which were potentially related to aberrant oocyte quality and developmental potency, at least in part, via pathological angiogenesis and metabolism.

VEGF and VEGFR2 in dentigerous cysts associated with impacted third molars

The aims of this study were to determine the presence and distribution of vascular endothelial growth factor (VEGF) and vascular endothelial growth factor receptor-2 (VEGFR2) in dentigerous cysts compared with normal dental follicles as a control tissue and to evaluate endothelial cells and proliferating cells as indicators of angiogenic activity in these tissues.Twenty specimens histologically diagnosed as dentigerous cysts and 20 dental follicle specimens were included. Immunohistochemistry (IHC) using anti-VEGF and anti-VEGFR2 antibodies stained for the growth factor and its receptor, while anti-CD34 and anti-CD146 antibodies were used to identify endothelial cells. Anti-proliferating cell nuclear antigen (PCNA) antibody detected proliferating cells within the specimens. Slides were examined microscopically and results evaluated using kappa statistics, negative binomial regression and ordinal logistic regression.The mean age for patients with dentigerous cysts was 23 years and they were more common in males. Proteins for VEGF, VEGFR2, PCNA, CD34, and CD146 were expressed in all dentigerous cysts and dental follicles. VEGF and VEGFR2 were expressed on several cell types within the tissues, however there was a significantly greater percentage of positive staining in dentigerous cysts compared with dental follicles (odds ratio = 31.24, p < 0.001). CD34(+), CD146(+), and PCNA(+) cells were observed in both dentigerous cysts and dental follicles but for all markers there were significantly more positive cells in dentigerous cysts (p < 0.001); this was especially evident in cases associated with inflammation. PCNA was seen in most endothelial cells lining small thin walled blood vessels suggesting endothelial proliferation. There was a high level of intra- and inter-examiner agreement (kappa 0.77 and 0.75, respectively).VEGF and VEGFR2 and angiogenic activity are present in dental follicles and dentigerous cysts and may contribute to local bone resorption for tooth eruption or the development and progression of dentigerous cysts.

The effect of androgens on ovarian follicle maturation: Dihydrotestosterone suppress FSH-stimulated granulosa cell proliferation by upregulating PPARγ-dependent PTEN expression

Intraovarian hyperandrogenism is one of the determining factors of follicular arrest in women with polycystic ovary syndrome (PCOS). Using androgenized rat models, we investigated the effects of androgens on metabolism, as well as on factors involved in follicular arrest and the reduced number of estrus cycles. The dihydrotestosterone (DHT)-treated rats had fewer estrus cycles, higher numbers of large arrested follicles and an increased in body weight gain compared with the dehydroepiandrostenedione (DHEA)- and placebo-treated rats. In cultured rat granulosa cells, DHT suppressed follicle stimulating hormone (FSH)-induced granulosa cell proliferation and increased the accumulation of cells in the G2/M phase. DHT decreased phosphorylated Akt (p-Akt) and cyclin D1 levels through increasing PTEN. DHT-promoted PTEN expression was regulated by peroxisome proliferator-activated receptor gamma (PPARγ) in granulosa cells. Meanwhile, in the large follicles of the DHT-treated rats, the expressions of PPARγ and PTEN were higher, but the expression of p-Akt and proliferating cell nuclear antigen (PCNA) were lower. Conclusively, DHT and DHEA produced differential effects on metabolism in prepubertal female rats like clinical manifestations of women with PCOS. DHT treatment may affect ovarian follicular maturation by altering granulosa cell proliferation through the regulation of enhancing PPARγ dependent PTEN/p-Akt expression in the granulosa cells.

Fab fragment glycosylated IgG may play a central role in placental immune evasion

STUDY QUESTION

How does the placenta protect the fetus from immune rejection by the mother?

SUMMARY ANSWER

The placenta can produce IgG that is glycosylated at one of its Fab arms (asymmetric IgG; aIgG) which can interact with other antibodies and certain leukocytes to affect local immune reactions at the junction between the two genetically distinct entities.

WHAT IS KNOWN ALREADY

The placenta can protect the semi-allogenic fetus from immune rejection by the immune potent mother. aIgG in serum is increased during pregnancy and returns to the normal range after giving birth. aIgG can react to antigens to form immune complexes which do not cause a subsequent immune effector reaction, including fixing complements, inducing cytotoxicity and phagocytosis, and therefore has been called 'blocking antibody'.

STUDY DESIGN, SIZE, DURATION

Eighty-eight human placentas, four trophoblast cell lines (TEV-1, JAR, JEG and BeWo), primary culture of human placental trophoblasts and a gene knock-out mouse model were investigated in this study.

PARTICIPANTS/MATERIALS, SETTING, METHODS

The general approach included the techniques of cell culture, immunohistochemistry, in situ hybridization, immuno-electron microscopy, western blot, quantitative PCR, protein isolation, glycosylation analysis, enzyme digestion, gene sequencing, mass spectrophotometry, laser-guided microdissection, enzyme-linked immunosorbent assay, pulse chase assay, double and multiple staining to analyze protein and DNA and RNA analysis at the cellular and molecular levels.

MAIN RESULTS AND THE ROLE OF CHANCE

Three major discoveries were made: (i) placental trophoblasts and endothelial cells are capable of producing IgG, a significant portion of which is aberrantly glycosylated at one of its Fab arms to form aIgG; (ii) the asymmetrically glycosylated IgG produced by trophoblasts and endothelial cells can react to immunoglobulin molecules of human, rat, mouse, goat and rabbit at the Fc portion; (iii) asymmetrically glycosylated IgG can react to certain leukocytes in the membrane and cytoplasm, while symmetric IgG from the placenta does not have this property.

LIMITATIONS, REASONS FOR CAUTION

Most of the experiments were performed in vitro. The proposed mechanism calls for verification in normal and abnormal pregnancy.

WIDER IMPLICATIONS OF THE FINDINGS

This study identified a number of new phenomena suggesting that aIgG produced by the placenta would be able to react to detrimental antibodies and leukocytes and interfere with their immune reactions against the placenta and the fetus. This opens a new dimension for further studies on pregnancy physiology and immunology. Should the mechanism proposed here be confirmed, it will have a direct impact on our understanding of the physiology and pathology of human reproduction and offer new possibilities for the treatment of many diseases including spontaneous abortion, infertility and pre-eclampsia. It also sheds light on the mechanism of immune evasion in general including that of cancer.

The local effects of ovarian diathermy in an ovine model of polycystic ovary syndrome

In order to develop a medical alternative to surgical ovarian diathermy (OD) in polycystic ovary syndrome (PCOS) more mechanistic information is required about OD. We therefore studied the cellular, molecular and vascular effects of diathermy on the ovary using an established ovine model of PCOS. Pregnant sheep were treated twice weekly with testosterone propionate (100 mg) from day 30–100 gestation. Their female offspring (n = 12) were studied during their second breeding season when the PCOS-like phenotype, with anovulation, is fully manifest. In one group (n = 4) one ovary underwent diathermy and it was collected and compared to the contralateral ovary after 24 hours. In another group a treatment PCOS cohort underwent diathermy (n = 4) and the ovaries were collected and compared to the control PCOS cohort (n = 4) after 5 weeks. Ovarian vascular indices were measured using contrast-enhanced ultrasound and colour Doppler before, immediately after, 24 hours and five weeks after diathermy. Antral follicles were assessed by immunohistochemistry and ovarian stromal gene expression by quantitative RT-PCR 24 hours and 5 weeks after diathermy. Diathermy increased follicular atresia (P<0.05) and reduced antral follicle numbers after 5 weeks (P<0.05). There was an increase in stromal CCL2 expression 24 hours after diathermy (P<0.01) but no alteration in inflammatory indices at 5 weeks. Immediately after diathermy there was increased microbubble transit time in the ovarian microvasculature (P = 0.05) but this was not seen at 24 hours. However 24 hours after diathermy there was a reduction in the stromal Doppler blood flow signal (P<0.05) and an increased ovarian resistance index (P<0.05) both of which persisted at 5 weeks (P<0.01; P<0.05). In the ovine model of PCOS, OD causes a sustained reduction in ovarian stromal blood flow with an increased ovarian artery resistance index associated with atresia of antral follicles.

Platelet-derived growth factor BB and DD and angiopoietin1 are altered in follicular fluid from polycystic ovary syndrome patients

Polycystic ovary syndrome (PCOS) is the most common endocrinological pathology among women of reproductive age, and is characterized by abnormalities in ovarian angiogenesis, among other features. Consistent with this association, follicular fluid (FF) concentration and ovarian expression of vascular endothelial growth factor (VEGF) are increased in PCOS patients. In this study, we examined the protein levels of platelet-derived growth factor (PDGF) BB and DD (PDGFBB and PDGFDD), angiopoietin 1 and 2 (ANGPT1 and ANGPT2), and their soluble receptor sTIE2 in FF from PCOS and control patients undergoing assisted reproductive techniques. We also analyzed the effect of FF from PCOS and control patients on tight and adherens junction protein expression in an endothelial cell line. PDGFBB and PDGFDD were significantly lower whereas ANGPT1 concentration was significantly higher in FF from PCOS patients than from control patients. No changes were found in the concentration of ANGPT2 or sTIE2. Expression of claudin-5 was significantly increased in endothelial cells incubated for 24 hr in the presence of FF from PCOS versus from control patients, while vascular-endothelial cadherin, β-catenin, and zonula occludens 1 expression were unchanged. The changes observed in the levels of PDGF isoforms and ANGPT1 may prevent VEGF-induced vascular permeability in the PCOS ovary by regulating endothelial-cell-junction protein levels. Restoring the levels of angiogenic factors may provide new insights into PCOS treatment and the prevention of ovarian hyperstimulation syndrome in affected women.

The thrombospondin-1 receptor CD36 is an important mediator of ovarian angiogenesis and folliculogenesis

BACKGROUND

Ovarian angiogenesis is a complex process that is regulated by a balance between pro- and anti-angiogenic factors. Physiological processes within the ovary, such as folliculogenesis, ovulation, and luteal formation are dependent upon adequate vascularization and anything that disrupts normal angiogenic processes may result in ovarian dysfunction, and possibly infertility. The objective of this study was to evaluate the role of the thrombospondin-1 (TSP-1) receptor CD36 in mediating ovarian angiogenesis and regulating ovarian function.

METHODS

The role of CD36 was evaluated in granulosa cells in vitro and ovarian morphology and protein expression were determined in wild type and CD36 null mice.

RESULTS

In vitro, CD36 inhibition increased granulosa cell proliferation and decreased apoptosis. Granulosa cells in which CD36 was knocked down also exhibited an increase in expression of survival and angiogenic proteins. Ovaries from CD36 null mice were hypervascularized, with increased expression of pro-angiogenic vascular endothelial growth factor (VEGF) and its receptor VEGFR-2. Ovaries from CD36 null mice contained an increase in the numbers of pre-ovulatory follicles and decreased numbers of corpora lutea. CD36 null mice also had fewer number of offspring compared to wild type controls.

CONCLUSIONS

The results from this study demonstrate that CD36 is integral to the regulation of ovarian angiogenesis by TSP-1 and the expression of these family members may be useful in the control of ovarian vascular disorders.

Ontogeny of the ovary in polycystic ovary syndrome

Activation of primordial follicles into the growing pool, selection of the dominant follicle, and its eventual ovulation require complex endocrine and metabolic interactions as well as intraovarian paracrine signals to coordinate granulosa cell proliferation, theca cell differentiation, and oocyte maturation. Early preantral follicle development relies mostly upon mesenchymal-epithelial cell interactions, intraovarian paracrine signals, and oocyte-secreted factors, whereas development of the antral follicle depends on circulating gonadotropins as well as locally derived regulators. In women with polycystic ovary syndrome (PCOS), ovarian hyperandrogenism, hyperinsulinemia from insulin resistance, and altered intrafollicular paracrine signaling perturb the activation, survival, growth, and selection of follicles, causing accumulation of small antral follicles within the periphery of the ovary, giving it a polycystic morphology. Altered adipocyte-ovarian interactions further compound these adverse events on follicle development and also can harm the oocyte, particularly in the presence of increased adiposity. Finally, endocrine antecedents of PCOS occur in female infants born to mothers with PCOS, which suggests that interactions between genes and the maternal-fetal hormonal environment may program ovarian function after birth.

Tumor necrosis factor-alpha promoter polymorphisms are associated with idiopathic primary ovarian insufficiency in Korean women

OBJECTIVE

To investigate the possible association between primary ovarian insufficiency (POI) and TNF-α gene polymorphisms in Korean women.

DESIGN

Case-control study.

SETTING

An urban university-based hospital in South Korea.

PATIENT(S)

A cohort of 135 Korean POI patients and 236 controls.

INTERVENTION(S)

None.

MAIN OUTCOME MEASURE(S)

We analyzed TNF-α gene variants of all participants using the polymerase chain reaction-restriction fragment length polymorphism assay.

RESULT(S)

The TNF-α -1031TC+CC, -238GA+AA, -1031TC+CC/-308GG, -1031TT/-308GA+AA, -1031TC+CC/-238GA+AA, and -308GG/-238GA+AA genotypes were significantly more frequent in POI patients than in controls. Among the haplotypes for the three TNF-α loci, the -1031C/-308G/-238A haplotype was more frequent in POI patients than in controls and conferred POI susceptibility. In analyses of two loci, the -1031T/-308A, -1031C/-308G, -1031C/-238A, and -308G/-238A haplotypes were more frequent in POI patients.

CONCLUSION(S)

The TNF-α -1031C and -238A alleles had strong association with POI. The TNF-α -308A allele showed limited significance for POI risk with the presence of the -1031T allele. Our data suggest that the minor alleles of TNF-α promoter polymorphisms may increase POI risk in Korean women.