Effect of hyperandrogenism on ovarian function

Hyperandrogenism and Polycystic ovary syndrome: Effects in pregnancy and offspring development

Polycystic ovary syndrome (PCOS) is one of the major endocrine disorders affecting women of reproductive age. Its etiology remains unclear. It is suggested that environmental factors, and particularly the intrauterine environment, play key roles in PCOS development. Besides the role of androgens in PCOS pathogenesis, exposure to endocrine disruptors, as is Bisphenol A, could also contribute to its development. Although PCOS is considered one of the leading causes of ovarian infertility, many PCOS patients can get pregnant. Some of them by natural conception and others by assisted reproductive technique treatments. As hyperandrogenism (one of PCOS main features) affects ovarian and uterine functions, PCOS women, despite reaching pregnancy, could present high-risk pregnancies, including implantation failure, an increased risk of gestational diabetes, preeclampsia, and preterm birth. Moreover, hyperandrogenism may also be maintained in these women during pregnancy. Therefore, as an altered uterine milieu, including hormonal imbalance, could affect the developing organisms, monitoring these patients throughout pregnancy and their offspring development is highly relevant. The present review focuses on the impact of androgenism and PCOS on fertility issues and pregnancy-related outcomes and offspring development. The evidence suggests that the increased risk of pregnancy complications and adverse offspring outcomes of PCOS women would be due to the factors involved in the syndrome pathogenesis and the related co-morbidities. A better understanding of the involved mechanisms is still needed and could contribute to a better management of these women and their offspring. This article is categorized under: Reproductive System Diseases > Molecular and Cellular Physiology Reproductive System Diseases > Environmental Factors.

Expression and regulation of estrogen receptor 2 and its coregulators in mouse granulosa cells

The cooperative effects of estrogen and oocyte-derived paracrine factors (ODPFs) play critical roles in the normal development of ovarian follicles; however, the mechanism underlying this cooperation has not been well studied. The present study aimed to determine whether ODPFs affect estrogen signaling by regulating the expression of estrogen receptor (ESR) and its coregulators in mouse granulosa cells. Some transcripts encoding ESR coregulators were differentially expressed between cumulus and mural granulosa cells (MGCs). The transcript levels of ESR coregulators, including nuclear receptor corepressor 1 and activator 2, in cumulus cells were significantly suppressed by ODPFs; however, they increased when cumulus cell-oocyte complexes were treated with the transforming growth factor beta receptor I inhibitor, SB431542. Moreover, MGCs exhibited significantly higher ESR2 protein and transcript levels than those in cumulus cells. ODPFs promoted Esr2 expression in cumulus cells but had no effect on that in MGCs. Overall, regulation of the expression of ESR2 and its coregulators in cumulus cells by oocytes seems to be one of the mechanisms underlying estrogen-oocyte cooperation in well-developed antral follicles in mice.

Influence of Vitamin D on the Vasoactive Effect of Estradiol in a Rat Model of Polycystic Ovary Syndrome

We examined the vasoactive effect of estradiol in a rat model of early PCOS and the influence of vitamin D deficiency (VDD). We created a model of chronic hyperandrogenism and VDD in adolescent female Wistar rats (N = 46) with four experimental groups: vitamin D supplemented (T-D+), VDD (T-D-), hyperandrogenic and vitamin D supplemented (T+D+), and hyperandrogenic and VDD (T+D-). T+ groups received an 8-week-long transdermal Androgel treatment, D-animals were on vitamin D-reduced diet and D+ rats were supplemented orally with vitamin D3. Estrogen-induced vasorelaxation of thoracic aorta segments were measured with a wire myograph system with or without the inhibition of endothelial nitric oxide synthase (eNOS) or cyclooxygenase-2 (COX-2). The distribution of estrogen receptor (ER), eNOS and COX-2 in the aortic wall was assessed by immunohistochemistry. VDD aortas showed significantly lower estradiol-induced relaxation independently of androgenic status that was further decreased by COX-2 inhibition. COX-2 inhibition failed to alter vessel function in D+ rats. Inhibition of eNOS abolished the estradiol-induced relaxation in all groups. Changes in vascular function in VDD were accompanied by significantly decreased ER and eNOS staining. Short-term chronic hyperandrogenism failed to, but VDD induced vascular dysfunction, compromised estrogen-dependent vasodilatation and changes in ER and eNOS immunostaining.

Upregulation of Cyp19a1 and PPAR-γ in ovarian steroidogenic pathway by Ficus religiosa: A potential cure for polycystic ovary syndrome

ETHNOPHARMACOLOGICAL RELEVANCE

Quite a few plants are in use to treat female infertility and associated problems. Availing the cues from traditional knowledge, phytochemical studies and ethnopharmacological evidences, the aphrodisiac plant Ficus religiosa (F. religiosa) is widely in use to cure infertility in women. For instance, the juice of leaf and aerial root of F. religiosa is reported to normalize the dysregulated menstrual cycle in women. Besides, it is believed that regular circumambulation of F. religiosa during the early hours of the morning helps women in alleviating infertility which could be attributed to the potential phytovolatiles released from F. religiosa. However, the evidences for therapeutic potential of F. religiosa in treating female infertility are arbitrary and mostly anecdotal.

AIM OF THE STUDY

The present study was aimed at examining if extracts of fresh and/or dry leaf of F. religiosa would cure polycystic ovary syndrome (PCOS) in the rat model.

METHODS

Rats were divided into seven groups; control (Group I), PCOS-induced (P.O, Letrozole -1 mg/kg BW for 21 days) and untreated (Group II), PCOS-induced and treated with the leaf extracts of F. religiosa (Groups III-VI), and, PCOS-induced and treated with pioglitazone (Group VII). The estrous intervals, body and organ weights (ovary and uterus), and serum hormones (testosterone, luteinizing hormone [LH], estrogen, and progesterone) were measured, and the expression of Cyp19a1 (aromatase), and Peroxisome Proliferator-Activated Receptor-γ (PPAR-γ) were assessed in the experimental rats. The levels of 3β-hydroxysteroid dehydrogenase (3β-HSD), 17β-hydroxysteroid dehydrogenase (17β-HSD), and antioxidants (MDA, GSH, GPx, SOD, and CAT) were also quantified. Besides, the putative volatile compounds in the esterified leaf extracts were identified using Gas Chromatography-Mass Spectrometry (GC-MS).

RESULTS

Letrozole treatment induced irregular estrous and altered weight of organs and hormonal milieu, which were reverted to normal in leaf extracts-treated PCOS-induced rats. Remarkably, fresh leaf treatment up-regulated Cyp19a1and PPAR-γ and increased the levels of 3β-HSD and 17β-HSD. We found 3-acetoxy-3-hydroxy-propionic acid in fresh and dry leaf extracts, which we attribute to efficacy of the extracts in alleviating PCOS.

CONCLUSION

Put together, our findings suggest the leaves of F. religiosa as potential in alleviating PCOS, mainly due to the presence of putative volatile molecules. Further screening of the leaves of F. religiosa is recommended to identify other key molecules and to develop a systematic therapeutic intervention for PCOS.

L-Carnitine improves endocrine function and folliculogenesis by reducing inflammation, oxidative stress and apoptosis in mice following induction of polycystic ovary syndrome

Polycystic ovary syndrome (PCOS) is related to low levels of serum l-carnitine, which has antioxidant, anti-inflammatory and antiapoptotic properties. The aim of this study was to investigate the effect of l-carnitine on folliculogenesis in mice following induction of PCOS. PCOS was induced by daily injections of testosterone enanthate (1mg per 100g, s.c., for 35 days). NMRI mice (21 days old) were divided into four groups (n=6 per group): Control, Control+l-carnitine, PCOS and PCOS+l-carnitine. Mice were treated with 500mgkg-1, i.p., l-carnitine every second day for 28 days. Ovaries were studied stereologically and serum concentrations of FSH, LH, testosterone, interleukin (IL)-6 and tumour necrosis factor (TNF)-α were determined using ELISA kits. Serum concentrations of malondialdehyde (MDA) and the ferric ion reducing antioxidant power (FRAP) were also analysed. Apoptosis of follicles was evaluated by terminal deoxyribonucleotidyl transferase-mediated dUTP-digoxigenin nick end-labelling (TUNEL). CD31 was assessed immunohistochemically. Data were analysed using one-way analysis of variance (ANOVA) and Tukey's test, differences considered significant at P<0.05.The total volume of the ovary, cortex volume, oocyte volume, zona pellucida thickness and the number of antral follicles increased significantly, whereas the number of primary and preantral follicles decreased significantly, in the PCOS+l-carnitine versus PCOS group. In the PCOS+l-carnitine group, serum concentrations of FSH and FRAP increased significantly, whereas there were significant decreases in serum concentrations of testosterone, LH, MDA, IL-6 and TNF-α, as well as in the percentage of TUNEL-positive apoptotic cells, compared with the PCOS group. l-Carnitine improves folliculogenesis and is therefore suggested as a therapeutic supplement in the treatment of PCOS.

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.

Improvement of the folliculogenesis by transplantation of bone marrow mesenchymal stromal cells in mice with induced polycystic ovary syndrome

BACKGROUND

Many studies have reported that inflammation and oxidative stress are involved in the pathogenesis of polycystic ovary syndrome (PCOS). Bone marrow mesenchymal stromal cells (BM-MSCs) have anti-oxidant and anti-inflammation properties. In this study, we investigate the beneficial effect of stem cell therapy on folliculogenesis in mice with induced PCOS METHODS: Mouse model of PCOS was performed through daily injection of testosterone enanthate (1 mg/100 g/body weight subcutaneous (s.c).) for a period of 5 weeks. Naval Medical Research Institute (NMRI) mice (21 days old) were divided into three groups: control, PCOS and PCOS + BM-MSCs. BM-MSCs were labeled with Hoechst 33342 (0.5 µg/mL) and then injected into the mice (10⁶/animal, via the tail vein) at 1 and 14 days after PCOS confirmation. Mice were humanely killed at 2 weeks after last transplantation. Ovarian stereological studies were done. Follicle-stimulating hormone (FSH), Luteinizing hormone (LH), testosterone, interleukin (IL)-6 and tumor necrosis factor (TNF)-α serum levels were measured. The levels of malondialdehyde (MDA) and total antioxidant capacity (TAC) in serum were analyzed. Apoptotic index for ovarian follicles was assessed using Terminal deoxynucleotidyl transferase-mediated dUTP nick-end labelling (TUNEL). CD31 expression in ovarian vessels was assessed with the immunohistochemistry.

RESULTS

There was a significant increase in the total volume of ovary, cortex, number of antral follicles, volume of oocyte and zona pellucida thickness, and there was a significant decrease in the primary and preantral follicles number in the PCOS + BM-MSCs group compared with the PCOS group. There was a significant increase in the serum level of FSH and TAC and a significant decrease in the serum level of testosterone, LH, MDA and percentage of TUNEL-positive apoptotic cells in the PCOS + BM-MSCs group in comparison with the PCOS group.

DISCUSSION

BM-MSC transplantation improves folliculogenesis in mice with induced PCOS. BM-MSC therapy can be an operative treatment for PCOS via anti-inflammatory, anti-oxidant and anti-apoptotic properties.

Alterations of polyunsaturated fatty acid metabolism in ovarian tissues of polycystic ovary syndrome rats

The metabolism of polyunsaturated fatty acids (PUFAs) remains poorly characterized in ovarian tissues of patients with polycystic ovary syndrome (PCOS). This study aimed to explore alterations in the levels of PUFAs and their metabolites in serum and ovarian tissues in a PCOS rat model treated with a high‐fat diet and andronate. Levels of PUFAs and their metabolites were measured using gas/liquid chromatography‐mass spectrometry after the establishment of a PCOS rat model. Only 3 kinds of PUFAs [linoleic acid, arachidonic acid (AA) and docosahexaenoic acid] were detected in both the circulation and ovarian tissues of the rats, and their concentrations were lower in ovarian tissues than in serum. Moreover, significant differences in the ovarian levels of AA were observed between control, high‐fat diet‐fed and PCOS rats. The levels of prostaglandins, AA metabolites via the cyclooxygenase (COX) pathway, in ovarian tissues of the PCOS group were significantly increased compared to those in the controls. Further studies on the mechanism underlying this phenomenon showed a correlation between decreased expression of phosphorylated cytosolic phospholipase A2 (p‐cPLA2) and increased mRNA and protein expression of COX2, potentially leading to a deeper understanding of altered AA and prostaglandin levels in ovarian tissues of PCOS rats.

Early ovarian follicular development in prepubertal Wistar rats acutely exposed to androgens

Androgens may directly modulate early ovarian follicular development in preantral stages and androgen excess before puberty may disrupt this physiological process. Therefore, the aim of this study was to investigate the dynamics of follicular morphology and circulating androgen and estradiol levels in prepubertal Wistar rats acutely exposed to androgens. Prepubertal female Wistar rats were distributed into three groups: control, equine chorionic gonadotropin (eCG) intervention and eCG plus dehydroepiandrosterone (DHEA) intervention (eCG+DHEA). Serum DHEA, testosterone and estradiol levels were determined, and ovarian morphology and morphometry were assessed. The eCG+DHEA group presented increased serum estradiol and testosterone levels as compared with the control group (P<0.01), and higher serum DHEA concentration v. the eCG-only and control groups (P<0.01). In addition, the eCG+DHEA group had a higher number of, and larger-sized, primary and secondary follicles as compared with the control group (P<0.05). The eCG group presented intermediate values for number and size of primary and secondary follicles, without significant differences as compared with the other two groups. The number of antral follicles was higher in the eCG+DHEA and eCG groups v. controls (P<0.05). The number of primordial, atretic and cystic follicles were similar in all groups. In conclusion, the present experimental model using an acute eCG+DHEA intervention was useful to investigate events involved in initial follicular development under hyperandrogenic conditions, and could provide a reliable tool to study defective follicular development with possible deleterious reproductive consequences later in life.