Insulin resistance is documented in clamp studies in 75% of women with polycystic ovary syndrome (PCOS). Although it is not included in the diagnostic criteria of PCOS, there is a crucial role of ...this metabolic impairment, which along with hormonal abnormalities, increase each other in a vicious circle of PCOS pathogenesis. Insulin resistance in this group of patients results from defects at the molecular level, including impaired insulin receptor-related signaling pathways enhanced by obesity and its features: Excess visceral fat, chronic inflammation, and reactive oxygen species. While lifestyle intervention has a first-line role in the prevention and management of excess weight in PCOS, the role of anti-obesity pharmacological agents in achieving and maintaining weight loss is being increasingly recognized. Glucagon-like peptide-1 receptor agonists (GLP1-RAs) not only act by reducing body weight but also can affect the mechanisms involved in insulin resistance, like an increasing expression of glucose transporters in insulin-dependent tissues, decreasing inflammation, reducing oxidative stress, and modulating lipid metabolism. They also tend to improve fertility either by increasing LH surge in hypothalamus-pituitary inhibition due to estrogen excess connected with obesity or decreasing too high LH levels accompanying hyperinsulinemia. GLP1-RAs seem promising for effective treatment of obese PCOS patients, acting on one of the primary causes of PCOS at the molecular level.
Polycystic ovarian syndrome (PCOS), the most common endocrinopathy affecting women worldwide, is characterized by elevated luteinizing hormone (LH) pulse frequency due to the impaired suppression of ...gonadotrophin-releasing hormone (GnRH) release by steroid hormone negative feedback. Although neurons that co-express kisspeptin, neurokinin B, and dynorphin (KNDy cells) were recently defined as the GnRH/LH pulse generator, little is understood about their role in the pathogenesis of PCOS. We used a prenatal androgen-treated (PNA) mouse model of PCOS to determine whether changes in KNDy neurons or their afferent network underlie altered negative feedback. First, we identified elevated androgen receptor gene expression in KNDy cells of PNA mice, whereas progesterone receptor and dynorphin gene expression was significantly reduced, suggesting elevated androgens in PCOS disrupt progesterone negative feedback via direct actions upon KNDy cells. Second, we discovered GABAergic and glutamatergic synaptic input to KNDy neurons was reduced in PNA mice. Retrograde monosynaptic tract-tracing revealed a dramatic reduction in input originates from sexually dimorphic afferents in the preoptic area, anteroventral periventricular nucleus, anterior hypothalamic area and lateral hypothalamus. These results reveal 2 sites of neuronal alterations potentially responsible for defects in negative feedback in PCOS: changes in gene expression within KNDy neurons, and changes in synaptic inputs from steroid hormone-responsive hypothalamic regions. How each of these changes contribute to the neuroendocrine phenotype seen in in PCOS, and the role of specific sets of upstream KNDy afferents in the process, remains to be determined.
Abstract
The mechanisms that link hyperandrogenism and insulin (INS) resistance (HAIR) to the increased miscarriage rate in women with polycystic ovary syndrome (PCOS) remain elusive. Previous ...studies demonstrate that increased uterine and placental ferroptosis is associated with oxidative stress-induced fetal loss in a pre-clinical PCOS-like rat model. Here, we investigated the efficacy and molecular mechanism of action of the antioxidant N-acetylcysteine (NAC) in reversing gravid uterine and placental ferroptosis in pregnant rats exposed to 5α-dihydrotestosterone (DHT) and INS. Molecular and histological analyses showed that NAC attenuated DHT and INS-induced uterine ferroptosis, including dose-dependent increases in anti-ferroptosis gene content. Changes in other molecular factors after NAC treatment were also observed in the placenta exposed to DHT and INS, such as increased glutathione peroxidase 4 protein level. Furthermore, increased apoptosis-inducing factor mitochondria-associated 2 mRNA expression was seen in the placenta but not in the uterus. Additionally, NAC was not sufficient to rescue DHT + INS-induced mitochondria-morphological abnormalities in the uterus, whereas the same treatment partially reversed such abnormalities in the placenta. Finally, we demonstrated that NAC selectively normalized uterine leukemia inhibitory factor, osteopontin/secreted phosphoprotein 1, progesterone receptor, homeobox A11 mRNA expression and placental estrogen-related receptor beta and trophoblast-specific protein alpha mRNA expression. Collectively, our data provide insight into how NAC exerts beneficial effects on differentially attenuating gravid uterine and placental ferroptosis in a PCOS-like rat model with fetal loss. These results indicate that exogenous administration of NAC represents a potential therapeutic strategy in the treatment of HAIR-induced uterine and placental dysfunction.
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•Chronic low-grade inflammation is involved in PCOS.•IL-1β and IL-18 levels were changed in PCOS.•AIM2 and NALP3 inflammasome components were increased in PCOS.•IL-18 as well as IL-1β ...expression, is due to activation of inflammasome.
Inflammasome complex mediated interleukin 1β (IL-1β) and interleukin 18 (IL-18) production may be involved in immunopathogenesis of polycystic ovary syndrome (PCOS). Therefore, this study was conducted to investigate involved inflammasome pathways in PCOS. Therefore, inflammasome genes expression and serum level of IL-1β were evaluated in 30 patients with confirmed PCOS and 30 women without PCOS. A remarkable increase in expression of the nucleotide binding and oligomerization domain (NOD)-like receptor (NLR) family pyrin domain-containing 3 (NALP3), absent in melanoma 2 (AIM2), IL-18 and associated speck-like protein containing a caspase recruitment domain (CARD); (ASC) genes in PCOS were observed (p < 0.05). In contrast, expression level of NALP1, NALP12, NLR family apoptosis inhibitory proteins (NAIP), NLR family caspase recruitment domain (CARD) domain containing 4 (NLRC4) and IL-1β genes was not significant. Although the IL-1β protein level in serum of COS patients with BMI ≥ 25 was significantly higher than PCOS patient with BMI < 25, but there was no significant difference in non-PCOS individuals with BMI < 25 or ≥25. Furthermore, significant correlation between expression of AIM2 (r = 0.83, p = 0.032) and NALP3 (r = 0.59, p = 0.0001) was observed with IL-18, while a positive correlation (r = 0.84, p = 0.0001) was revealed between NAIP and IL-1β. Based on the obtained results on inflammasome components along with increased expression of IL-1β especially in overweight patients, it can be concluded that IL-18 expression as well as IL-1β is probably due to activation of AIM2, NALP3 or NAIP inflammasome, which may play a critical role in immunopathology of PCOS.
Abstract
Polycystic ovary syndrome (PCOS) is associated with hyperandrogenism and growth arrest of antral follicles. Previously, we found that endoplasmic reticulum (ER) stress is activated in ...granulosa cells of antral follicles in PCOS, evidenced by activation of unfolded protein response (UPR) genes. Based on this observation, we hypothesized that ER stress is activated by androgens in granulosa cells of antral follicles, and that activated ER stress promotes apoptosis via induction of the UPR transcription factor C/EBP homologous protein (CHOP) and subsequent activation of death receptor (DR) 5. In this study, we found that testosterone induced expression of various UPR genes, including CHOP, as well as DR5, in cultured human granulosa-lutein cells (GLCs). Pretreatment with the ER stress inhibitor tauroursodeoxycholic acid (TUDCA) inhibited testosterone-induced apoptosis and expression of DR5 and CHOP. Knockdown of CHOP inhibited testosterone-induced DR5 expression and apoptosis, and knockdown of DR5 inhibited testosterone-induced apoptosis. Pretreatment with flutamide, as well as knockdown of androgen receptor, decreased testosterone-induced DR5 and CHOP expression, as well as apoptosis. Expression of DR5 and CHOP was upregulated in GLCs obtained from patients with PCOS, as well as in granulosa cells of antral follicles in ovarian sections obtained from patients with PCOS and dehydroepiandrosterone-induced PCOS mice. Treatment of PCOS mice with TUDCA decreased apoptosis and DR5 expression in granulosa cells of antral follicles, with a concomitant reduction in CHOP expression. Taken together, our findings indicate that ER stress activated by hyperandrogenism in PCOS promotes apoptosis of granulosa cells of antral follicles via induction of DR5.
Polycystic ovary syndrome (PCOS) affects 5–10% of women of reproductive age, causing a range of reproductive, metabolic and endocrine defects including anovulation, infertility, hyperandrogenism, ...obesity, hyperinsulinism, and an increased risk of type 2 diabetes and cardiovascular disease. Hyperandrogenism is the most consistent feature of PCOS, but its etiology remains unknown, and ethical and logistic constraints limit definitive experimentation in humans to determine mechanisms involved. In this study, we provide the first comprehensive characterization of reproductive, endocrine, and metabolic PCOS traits in 4 distinct murine models of hyperandrogenism, comprising prenatal dihydrotestosterone (DHT, potent nonaromatizable androgen) treatment during days 16–18 of gestation, or long-term treatment (90 days from 21 days of age) with DHT, dehydroepiandrosterone (DHEA), or letrozole (aromatase inhibitor). Prenatal DHT-treated mature mice exhibited irregular estrous cycles, oligo-ovulation, reduced preantral follicle health, hepatic steatosis, and adipocyte hypertrophy, but lacked overall changes in body-fat composition. Long-term DHT treatment induced polycystic ovaries displaying unhealthy antral follicles (degenerate oocyte and/or > 10% pyknotic granulosa cells), as well as anovulation and acyclicity in mature (16-week-old) females. Long-term DHT also increased body and fat pad weights and induced adipocyte hypertrophy and hypercholesterolemia. Long-term letrozole-treated mice exhibited absent or irregular cycles, oligo-ovulation, polycystic ovaries containing hemorrhagic cysts atypical of PCOS, and displayed no metabolic features of PCOS. Long-term dehydroepiandrosterone treatment produced no PCOS features in mature mice. Our findings reveal that long-term DHT treatment replicated a breadth of ovarian, endocrine, and metabolic features of human PCOS and provides the best mouse model for experimental studies of PCOS pathogenesis.
Eucommia ulmoides Oliv. leaves are the dry leaves of Eucommia ulmoides Oliv. Modern studies have shown that Eucommia ulmoides Oliv. leaves and its extracts have many pharmacological effects, such as ...regulating hypothalamus pituitary ovary (HPO) axis function, estrogen like effects, correcting insulin resistance (IR), regulating lipids, and reducing weight, which are consistent with the clinical manifestations in polycystic ovary syndrome (PCOS) patients. PCOS patients often have HPO axis disorder, low estrogen, high androgen, high IR complication rate, and obesity. Previous preclinical studies have shown that total flavonoids from Eucommia ulmoides Oliv. leaves (TFEL) can improve the imbalance in sex hormone secretion in perimenopausal animal models by regulating the function of the HPO axis. Thus, it is important to understand if flavonoids are the active parts of Eucommia ulmoides Oliv. leaves that interfere with polycystic ovary syndrome with insulin resistance (PCOS-IR), and determine the regulatory role they play in sex hormones and IR?
Investigate the phosphatidylinositol 3-kinase/protein kinase B (PI3K/AKT) signaling pathway in the ovary and kisspeptin/insulin like growth factor/leptin receptor1/androgen receptor (Kiss1/IGF-1/LEPR/AR) in the HPO axis to determine the mechanism of TFEL intervention in a rat model of PCOS-IR model rats.
A rat model of PCOS-IR was established using a high-fat diet (49 d) combined with letrozole (1 mg/kg·d, for 28 d). Then, metformin (300 mg/kg·d) and TFEL (220 mg/kg·d, 110 mg/kg·d, and 55 mg/kg·d) were administered continuously for 21 days. At the end of the experiment, samples were taken and the related indexes were measured.
TFEL reduced the body weight, Lee's index, ovarian index, ovarian area and ovarian volume, increased serum E2, SHBG levels and ISI, decreased serum levels of T, LEP, INS, and FBG (whole blood), and reduced the HOMA-IR in rats with PCOS-IR. TFEL downregulate Kiss1, IGF-1, and AR in the arcuate nucleus of hypothalamus, and upregulate Kiss1, downregulate IGF-1 and AR in the pituitary gland, and upregulate Kiss1, downregulate IGF-1, LEPR, and AR in the ovary of rats with PCOS-IR. TFEL could downregulate p-IRS-1Ser307, upregulate IRS-1, p-IRS-1Tyr895, PI3Kp85α, p-PI3Kp85α, AKT, p-AKT, and GLUT4 in the ovary, and ameliorated histopathological changes in the ovary and pancreas of rats with PCOS-IR.
TFEL can inhibit ovarian hyperplasia, regulate disorders of glucose and lipid metabolism and improve the secretion of sex hormones, by regulating the expression of PI3K/AKT signaling pathway-related proteins in the ovary and Kiss1/IGF-1/LEPR/AR in the HPO axis.
Schematic diagram of TFEL action in PCOS-IR model rats. TFEL plays a protective role in PCOS-IR model rats by activating the PI3K/AKT signaling pathway and then regulating the expression of Kiss1, IGF-1, LEPR, and AR in the HPO axis. Display omitted
To compare the prevalence of polycystic ovary syndrome (PCOS) phenotypes and obesity among patients detected in referral versus unselected populations.
Systematic review and meta-analysis.
Not ...applicable.
Thirteen thousand seven hundred ninety-six reproductive-age patients with PCOS, as defined by the extended Rotterdam 2003 criteria.
Review of PUBMED, EMBASE, and Cochrane Library, 2003-2016. Only observational studies were included. Data were extracted using a web-based, piloted form and combined for meta-analysis.
PCOS phenotypes were classified as follows: phenotype A, clinical and/or biochemical hyperandrogenism (HA) + oligo-/anovulation (OA) + polycystic ovarian morphology (PCOM); phenotype B, HA+OA; phenotype C, HA+PCOM; and phenotype D, OA+PCOM.
Forty-one eligible studies, reporting on 43 populations, were identified. Pooled estimates of detected PCOS phenotype prevalence were consequently documented in referral versus unselected populations, as 1 phenotype A, 50% (95% confidence interval CI, 46%-54%) versus 19% (95% CI, 13%-27%); 2 phenotype B, 13% (95% CI, 11%-17%) versus 25% (95% CI, 15%-37%); 3 phenotype C, 14% (95% CI, 12%-16%) versus 34% (95% CI, 25-46%); and 4 phenotype D, 17% (95% CI, 13%-22%) versus 19% (95% CI, 14%-25%). Differences between referral and unselected populations were statistically significant for phenotypes A, B, and C. Referral PCOS subjects had a greater mean body mass index (BMI) than local controls, a difference that was not apparent in unselected PCOS.
The prevalence of more complete phenotypes in PCOS and mean BMI were higher in subjects identified in referral versus unselected populations, suggesting the presence of significant referral bias.
To derive and internally validate a clinical prediction model for live birth (LB) in women with polycystic ovary syndrome (PCOS) undergoing in vitro fertilization (IVF).
Retrospective cohort study.
...Four academic reproductive endocrinology clinics.
A total of 207 women with PCOS confirmed using Rotterdam criteria undergoing their first fresh IVF cycle.
Not applicable.
The primary outcome was cumulative LB per IVF cycle start. This included any LB that resulted from either fresh embryo transfer or any subsequent frozen embryo transfer from embryos obtained at the index oocyte retrieval. A prediction model was derived using multivariable logistic regression. Covariates considered for inclusion in the prediction model included demographic characteristics, medical history, and prior fertility treatment. Predicted probabilities for LB were calculated using the prediction model which included the 90% shrinkage factor for each adjusted odds ratio.
The final model, on the basis of maximization of the area under the receiver operating characteristic curve, included age < 35 years, White race, presence of polycystic ovaries on ultrasound (polycystic ovary morphology), normal body mass index (<25 kg/m
), being metabolically healthy (no metabolic risk factors), and being a nonresponder to ovulation induction agents including letrozole and clomiphene citrate. The area under the receiver operating characteristic curve score for the model was 0.68 (95% confidence interval CI: 0.60, 0.77). Predicted probabilities of LB ranged from 8.1% (95% CI: 2.8, 21.5) for a woman who had no favorable predictors to 74.2% (95% CI: 59.5, 84.9) for a woman who had all favorable predictors.
Our study demonstrated that, in addition to anovulation, the underlying pathophysiology and associated comorbidities alter the likelihood of a successful pregnancy in women with PCOS undergoing IVF. Further validation of this model is needed before it can serve as a tool to personalize prediction estimates for the probability of LB in women with PCOS.
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