Hyperandrogenism and insulin resistance-induced fetal loss: evidence for placental mitochondrial abnormalities and elevated reactive oxygen species production in pregnant rats that mimic the clinical features of polycystic ovary syndrome

Cytochrome c oxidase IV isoform 1 (COX4-1) regulates the proliferation, migration and invasion of trophoblast cells via modulating mitochondrial function

INTRODUCTION

Spontaneous miscarriage is a common complication of early pregnancy. Previous studies have shown that mitochondrial function plays an important role in establishment of a successful pregnancy. Cytochrome c oxidase subunit 4 isoform 1 (COX4I1), a component of electron transport chain complex Ⅳ, is required for coupling the rate of ATP production to energetic requirements. However, there is very limited research on its role in trophoblast biology and how its dysfunction may contribute to spontaneous miscarriage.

METHODS

Placental villi (7-10 weeks gestational age) collected from either induced termination of pregnancy or after spontaneous miscarriage were examined for expression of COX4I1. COX4I1 was knocked down by siRNA transfection of primary isolates of EVT cells. Real-time cell analysis (RTCA) and 5-Ethynyl-2'-deoxyuridine (EdU) were used to detect changes in proliferation ability after COX4I1 knockdown of EVT cells. Migration and invasion indices were determined by RTCA. Mitochondrial morphology was observed via MitoTracker staining. Oxidative phosphorylation, ATP production, and glycolysis in COX4I1-deficient cells and controls were assessed by a cellular energy metabolism analyzer (Seahorse).

RESULTS

In placental villous tissue, COX4I1 expression was significantly decreased in the spontaneous miscarriage group. Knockdown of COX4I1 inhibited EVT cell proliferation, increased the migration and invasion ability and mitochondrial fusion of EVT cells. Mitochondrial respiration and glycolysis were impaired in COX4I1-deficient EVT cells. Knockdown of MMP1 could rescue the increased migration and invasion induced by COX4I1 silencing.

DISCUSSION

Low expression of COX4I1 leads to mitochondrial dysfunction in EVT, resulting in altered trophoblast function, and ultimately to pregnancy loss.

[Analysis of Risk Factors for Recurrent Pregnancy Loss in Patients Undergoing in vitro Fertilization-Embryo Transfer]

Objective

Recurrent pregnancy loss (RPL) presents a formidable challenge for individuals undergoing in vitro fertilization-embryo transfer (IVF-ET), forming both a clinical dilemma and a focal point for scientific inquiry. This study endeavors to investigate the intricate interplay between clinical features, such as age, body mass index (BMI), and waist-to-hip ratio (WHR), and routine laboratory parameters, including sex hormones, blood composition, liver and thyroid functions, thyroid antibodies, and coagulation indicators, in RPL patients undergoing IVF-ET. By meticulously analyzing these variables, we aim to uncover the latent risk factors predisposing individuals to RPL. Identifying potential factors such as advanced maternal age, obesity, and insulin resistance will provide clinicians with vital insights and empirical evidence to strengthen preventive strategies aimed at reducing miscarriage recurrence.

Methods

This retrospective case-controlled study included RPL patients who underwent IVF-ET treatment at Sun Yat-sen Memorial Hospital, Sun Yat-sen University, between January 2012 and March 2021 as the case cohort, compared with women receiving assisted reproductive treatment due to male infertility as the control cohort. The fasting peripheral blood was collected 5 days before the first menstrual cycle at least 12 weeks after the last abortion. The clinical characteristics and relevant laboratory indexes of the two groups were compared. Employing both univariate and multivariate logistic regression analyses, we sought to unearth potential high-risk factors underlying RPL. Additionally, a linear trend analysis was conducted to assess the linear relationship between total testosterone (TT) levels and the number of miscarriages.

Results

In contrast to the control cohort, the RPL cohort exhibited significant increases in age, BMI, and WHR (P<0.05). Notably, TT levels were markedly lower in the RPL cohort (P=0.022), while no significant differences were observed between the two groups concerning basal follicle-stimulating hormone, luteinizing hormone, estradiol, progesterone, prolactin levels, and anti-Müllerian hormone levels (P>0.05). Moreover, fasting insulin (FINS) levels and HOMA-IR index were notably elevated in the RPL cohort relative to the control cohort (P<0.001), although no significant differences were observed in fasting blood glucose levels (P>0.05). Furthermore, the neutrophil (NEU) count and NEU-to-lymphocyte ratio were notably higher in the RPL cohort (P<0.01). Univariate logistic regression analysis identified several factors, including age≥35 years old, BMI≥25 kg/m2, WHR>0.8, FINS>10 mU/L, HOMA-IR>2.14, NEU count>6.3×109 L－1, and an elevated NEU/lymphocyte ratio (NLR), as significantly increasing the risk of RPL (P<0.05). Although TT levels were within the normal range for both cohorts, higher TT levels were associated with a diminished RPL risk (odds ratio [OR]=0.67, 95% confidence interval [CI]: 0.510-0.890, P=0.005). After adjustments for confounding factors, age≥35 years old (OR=1.91, 95% CI: 1.06-3.43), WHR>0.8 (OR=2.30, 95% CI: 1.26-4.19), and FINS>10 mU/L (OR=4.50, 95% CI: 1.30-15.56) emerged as potent risk factors for RPL (P<0.05). Conversely, higher TT levels were associated with a reduced RPL risk (OR=0.59, 95% CI: 0.38-0.93, P=0.023). Furthermore, the linear trend analysis unveiled a discernible linear association between TT levels and the number of miscarriages (P trend=0.003), indicating a declining trend in TT levels with escalating miscarriage occurrences.

Conclusion

In patients undergoing IVF-ET, advanced maternal age, lower TT levels, increased WHR, and elevated FINS levels emerged as potent risk factors for RPL. These findings provide clinicians with valuable insights and facilitate the identification of patients who are at high risks and the formulation of preventive strategies to reduce the recurrence of miscarriages.

d-galactose causes embryonic development arrest and placental development disorders in mice by increasing ROS and inhibiting SIRT1/FOXO3a axis

INTRODUCTION

Does an elevation in d-Galactose (D-Gal) levels within the body contribute to abnormal embryonic development and placental dysfunction during pregnancy?

METHODS

Mouse embryos were cultivated to the blastocyst stage under varying concentrations of D-Gal. The blastocyst formation rate was measured, and the levels of reactive oxygen species (ROS), sirtuin 1 (SIRT1), and forkhead box O3a (FOXO3a) in blastocysts were assessed. Mice were intraperitoneally injected with either saline or D-Gal with or without SRT1720. On the 14th day of pregnancy, the fetal absorption rate and placental weight were recorded. Placental levels of superoxide dismutase (SOD) and malondialdehyde (MDA) were determined. The expression of senescence-related factors, such as senescence-associated β-galactosidase (SA-β-gal) in the placenta was examined, and the expression of placental SIRT1, FOXO3a and p21 was evaluated by immunohistochemistry and Western blotting.

RESULTS

D-Gal adversely affects early embryonic development in vitro, resulting in a decreased blastocyst formation rate. Furthermore, D-Gal downregulates SIRT1 and FOXO3a while increasing ROS levels in blastocysts. Concurrently, D-Gal induces placental dysfunction, characterized by an elevated fetal absorption rate, reduced placental weight, diminished SOD activity, and increased MDA content. The senescence-related factor SA-β-gal was detected in the placenta, along with altered expression of placental SIRT1, FOXO3a, and p21. The SIRT1 agonist SRT1720 mitigated this damage by increasing SIRT1 and FOXO3a expression.

DISCUSSION

The inhibition of early embryonic development and placental dysfunction induced by D-Gal may be attributed to the dysregulation of SIRT1. Activating SIRT1 emerges as a potentially effective strategy for alleviating the adverse effects of D-Gal exposure.

New insights into the treatment of polycystic ovary syndrome: HKDC1 promotes the growth of ovarian granulocyte cells by regulating mitochondrial function and glycolysis

Polycystic ovary syndrome (PCOS) is an endocrine disease, and its pathogenesis and treatment are still unclear. Hexokinase domain component 1 (HKDC1) participates in regulating mitochondrial function and glycolysis. However, its role in PCOS development remains unrevealed. Here, female C57BL/6 mice were intraperitoneally injected with dehydroepiandrosterone (DHEA; 60 mg/kg body weight) to establish an in vivo model of PCOS. In vitro, KGN cells, a human ovarian granular cell line, were used to explore the potential mechanisms. DHEA-treated mice exhibited a disrupted estrus cycle, abnormal hormone levels, and insulin resistance. Dysfunction in mitochondria and glycolysis is the main reason for PCOS-related growth inhibition of ovarian granular cells. Here, we found that the structure of mitochondria was impaired, less ATP was generated and more mitochondrial Reactive Oxygen Species were produced in HKDC1-silenced KGN cells. Moreover, HKDC1 knockdown inhibited glucose consumption and decreased the production of glucose-6-phosphate and lactic acid. Conclusively, HKDC1 protects ovarian granulocyte cells from DHEA-related damage at least partly by preserving mitochondrial function and maintaining glycolysis.

The effect of β-cell dysfunction on reproductive outcomes of PCOS undergoing IVF or ICSI embryo transfer cycles: a retrospective cohort study

Objective

To investigate the effects of β-cell dysfunction on IVF outcomes in women with PCOS.

Methods

This retrospective cohort study includes 1,212 women with PCOS undergoing their first IVF cycle between September 2010 and December 2019. Beta-cell dysfunction was measured by homeostasis model assessment of β-cell function (HOMA-β) index.

Results

In quartiles of HOMA-β, the incidence of miscarriage dramatically increased from 10.2% (Q1) to 31.1% (Q4) (P for trend <0.001). Likewise, the incidence of miscarriage in quartiles of HOMA-β also showed a similar trend (P for trend <0.001). After adjusting for confounding factors, logistic regression analyses showed that high HOMA-IR values were independently associated with a high risk of miscarriage, with the odds ratios (OR) and 95% confidence intervals for quartiles 2-4 versus quartile 1 were 1.30 (0.69-2.46), 1.82 (0.97-3.43), and 3.57 (1.86-6.85), respectively (P for trend <0.001). When analyzed jointly, women in the highest HOMA-IR and highest HOMA-β group exhibited the highest risk for miscarriage compared with all other groups. Furthermore, higher HOMA-IR values were associated with higher risks of miscarriage among PCOS women regardless of HOMA-β values.

Conclusions

β-cell dysfunction is independently associated with increased miscarriage rate and decreased live birth rate in women with PCOS. It also plays a synergistic role with IR in terms of the reproductive outcomes, while the influence of IR overweighs that of β-cell dysfunction.

Research hotspots of polycystic ovary syndrome and hyperandrogenism from 2008 to 2022: bibliometric analysis

BACKGROUND

Polycystic Ovary Syndrome (PCOS) is the most frequent endocrine disorder in female adults, and hyperandrogenism (HA) is the typical endocrine feature of PCOS. This study aims to investigate the trends and hotspots in the study of PCOS and HA.

METHODS

Literature on Web of Science Core Collection (WoSCC) from 2008 to 2022 was retrieved, and bibliometric analysis was conducted using VOSviewer and CiteSpace software.

RESULTS

A total of 2,404 papers were published in 575 journals by 10,121 authors from 2,434 institutions in 86 countries. The number of publications in this field is generally on the rise yearly. The US, China and Italy contributed almost half of the publications. Monash University had the highest number of publications, while the University of Adelaide had the highest average citations and the Karolinska Institute had the strongest cooperation with other institutions. Lergo RS contributed the most to the field of PCOS and HA. The research on PCOS and HA mainly focused on complications, adipose tissue, inflammation, granulosa cells, gene and receptor expression.

CONCLUSION

Different countries, institutions, and authors should facilitate cooperation and exchanges. This study will be helpful for better understanding the frontiers and hotspots in the areas of PCOS and HA.

Placental mRNA Expression of Neurokinin B Is Increased in PCOS Pregnancies with Female Offspring

Current research suggests that polycystic ovary syndrome (PCOS) might originate in utero and implicates the placenta in its pathogenesis. Kisspeptin (KISS1) and neurokinin B (NKB) are produced by the placenta in high amounts, and they have been implicated in several pregnancy complications associated with placental dysfunction. However, their placental expression has not been studied in PCOS. We isolated mRNA after delivery from the placentae of 31 PCOS and 37 control women with term, uncomplicated, singleton pregnancies. The expression of KISS1, NKB, and neurokinin receptors 1, 2, and 3 was analyzed with real-time polymerase chain reaction, using β-actin as the reference gene. Maternal serum and umbilical cord levels of total testosterone, sex hormone-binding globulin (SHBG), free androgen index (FAI), androstenedione, dehydroepiandrosterone sulfate (DHEAS), Anti-Mullerian hormone (AMH), and estradiol were also assessed. NKB placental mRNA expression was higher in PCOS women versus controls in pregnancies with female offspring. NKB expression depended on fetal gender, being higher in pregnancies with male fetuses, regardless of PCOS. NKB was positively correlated with umbilical cord FAI and AMH, and KISS1 was positively correlated with cord testosterone and FAI; there was also a strong positive correlation between NKB and KISS1 expression. Women with PCOS had higher serum AMH and FAI and lower SHBG than controls. Our findings indicate that NKB might be involved in the PCOS-related placental dysfunction and warrant further investigation. Studies assessing the placental expression of NKB should take fetal gender into consideration.

Defective Uterine Spiral Artery Remodeling and Placental Senescence in a Pregnant Rat Model of Polycystic Ovary Syndrome

Pregnancy-related problems have been linked to impairments in maternal uterine spiral artery (SpA) remodeling. The mechanisms underlying this association are still unclear. It is also unclear whether hyperandrogenism and insulin resistance, the two common manifestations of polycystic ovary syndrome, affect uterine SpA remodeling. We verified previous work in which exposure to 5-dihydrotestosterone (DHT) and insulin (INS) in rats during pregnancy resulted in hyperandrogenism, insulin intolerance, and higher fetal mortality. Exposure to DHT and INS dysregulated the expression of angiogenesis-related genes in the uterus and placenta and also decreased expression of endothelial nitric oxide synthase and matrix metallopeptidases 2 and 9, increased fibrotic collagen deposits in the uterus, and reduced expression of marker genes for SpA-associated trophoblast giant cells. These changes were related to a greater proportion of unremodeled uterine SpAs and a smaller proportion of highly remodeled arteries in DHT + INS-exposed rats. Placentas from DHT + INS-exposed rats exhibited decreased basal and labyrinth zone regions, reduced maternal blood spaces, diminished labyrinth vascularity, and an imbalance in the abundance of vascular and smooth muscle proteins. Furthermore, placentas from DHT + INS-exposed rats showed expression of placental insufficiency markers and a significant increase in cell senescence-associated protein levels. Altogether, this work demonstrates that increased pregnancy complications in polycystic ovary syndrome may be mediated by problems with uterine SpA remodeling, placental functionality, and placental senescence.

Intergenerational Hyperglycemia Impairs Mitochondrial Function and Follicular Development and Causes Oxidative Stress in Rat Ovaries Independent of the Consumption of a High-Fat Diet

We analyzed the influence of maternal hyperglycemia and the post-weaning consumption of a high-fat diet on the mitochondrial function and ovarian development of the adult pups of diabetic rats. Female rats received citrate buffer (Control-C) or Streptozotocin (for diabetes induction-D) on postnatal day 5. These adult rats were mated to obtain female pups (O) from control dams (OC) or from diabetic dams (OD), and they received a standard diet (SD) or high-fat diet (HFD) from weaning to adulthood and were distributed into OC/SD, OC/HFD, OD/SD, and OD/HFD. In adulthood, the OGTT and AUC were performed. These rats were anesthetized and euthanized for sample collection. A high percentage of diabetic rats were found to be in the OD/HFD group (OD/HFD 40% vs. OC/SD 0% p < 0.05). Progesterone concentrations were lower in the experimental groups (OC/HFD 0.40 ± 0.04; OD/SD 0.30 ± 0.03; OD/HFD 0.24 ± 0.04 vs. OC/SD 0.45 ± 0.03 p < 0.0001). There was a lower expression of MFF (OD/SD 0.34 ± 0.33; OD/HFD 0.29 ± 0.2 vs. OC/SD 1.0 ± 0.41 p = 0.0015) and MFN2 in the OD/SD and OD/HFD groups (OD/SD 0.41 ± 0.21; OD/HFD 0.77 ± 0.18 vs. OC/SD 1.0 ± 0.45 p = 0.0037). The number of follicles was lower in the OD/SD and OD/HFD groups. A lower staining intensity for SOD and Catalase and higher staining intensity for MDA were found in ovarian cells in the OC/HFD, OD/SD, and OD/HFD groups. Fetal programming was responsible for mitochondrial dysfunction, ovarian reserve loss, and oxidative stress; the association of maternal diabetes with an HFD was responsible for the higher occurrence of diabetes in female adult pups.

Serum metabolomics probes the molecular mechanism of action of acupuncture on metabolic pathways related to glucose metabolism in patients with polycystic ovary syndrome-related obesity

Polycystic ovary syndrome (PCOS) is a common endocrine syndrome, and obesity is the most common clinical manifestation. Acupuncture is effective in treating PCOS, but the differences in the biological mechanisms of acupuncture therapy and Western medicine treatment have not been determined. Thus, the purpose of this study was to find glucose metabolism-related pathways in acupuncture treatment and differentiate them from Western medical treatment. Sixty patients with PCOS-related obesity were randomly distributed into three groups: patients receiving (1) acupuncture treatment alone, (2) conventional Western medicine treatment, and (3) acupuncture combined with Western medicine treatment. A targeted metabolomics approach was used to identify small molecules and metabolites related to glucose metabolism in the serum of each group, and ultra-high-performance liquid chromatography-tandem mass spectrometry was used to analyze different metabolic fractions. The results showed acupuncture treatment modulates the activity of citric and succinic acids in the tricarboxylic acid cycle, regulates glycolytic and gluconeogenesis pathways, and improves the levels of sex hormones and energy metabolism. The intervention effects on the metabolic pathways were different between patients receiving combination therapy and patients receiving acupuncture therapy alone, suggesting that the dominant modulatory effect of Western drugs may largely conceal the efficacy of acupuncture intervention.

Sex-Specific Effects of Prenatal Hypoxia and a Placental Antioxidant Treatment on Cardiac Mitochondrial Function in the Young Adult Offspring

Prenatal hypoxia is associated with placental oxidative stress, leading to impaired fetal growth and an increased risk of cardiovascular disease in the adult offspring; however, the mechanisms are unknown. Alterations in mitochondrial function may result in impaired cardiac function in offspring. In this study, we hypothesized that cardiac mitochondrial function is impaired in adult offspring exposed to intrauterine hypoxia, which can be prevented by placental treatment with a nanoparticle-encapsulated mitochondrial antioxidant (nMitoQ). Cardiac mitochondrial respiration was assessed in 4-month-old rat offspring exposed to prenatal hypoxia (11% O2) from gestational day (GD)15-21 receiving either saline or nMitoQ on GD 15. Prenatal hypoxia did not alter cardiac mitochondrial oxidative phosphorylation capacity in the male offspring. In females, the NADH + succinate pathway capacity decreased by prenatal hypoxia and tended to be increased by nMitoQ. Prenatal hypoxia also decreased the succinate pathway capacity in females. nMitoQ treatment increased respiratory coupling efficiency in prenatal hypoxia-exposed female offspring. In conclusion, prenatal hypoxia impaired cardiac mitochondrial function in adult female offspring only, which was improved with prenatal nMitoQ treatment. Therefore, treatment strategies targeting placental oxidative stress in prenatal hypoxia may reduce the risk of cardiovascular disease in adult offspring by improving cardiac mitochondrial function in a sex-specific manner.

Ovarian Endocrine Status and ART 0utcomes in Women within PCOS Based on Different Testosterone Levels

Background

It is estimated that in women at reproductive age, the risk of polycystic ovary syndrome (PCOS) is about 5-21%. In PCOS cases with ovulation dysfunction, assisted reproductive techniques (ART) are useful for infertility treatment.

Objective

This study aimed to evaluate the ART outcome in infertile PCOS women based on different testosterone levels. Finally, the relationships between testosterone in different levels and reproductive parameters including endocrine status, the response of ovaries, and pregnancy outcomes were assessed.

Methods

In this retrospective study, 352 infertile PCOS women were examined. The women were categorised into five groups according to their testosterone levels: A = T < 0.4, B = 0.4 < T > 0.6, C = 0.6 < T > 0.8, D = 0.8 < T > 1.0 and E = T > 1.0 ng/dL. All study cases were in similar hyper-stimulation protocol and finally, hormonal profile and ART outcomes were compared between testosterone levels. P value ≤ 0.05 was statistically significant.

Results

In testosterone levels >1.0, the levels of anti-mullerian hormone (AMH) and luteinising hormone (LH) were higher than in other testosterone level groups. AMH (P = 0.05) and LH (P = 0.001) levels showed significant differences. No correlation was present between testosterone levels and ART outcomes, including stimulation duration, endometrial thickness, oocyte numbers, numbers of matured oocytes, number of obtained embryos, fertilisation rate, implantation rate clinical pregnancy and abortion rate.

Conclusions

Serum testosterone levels did not show any correlation with pregnancy outcomes in ART cycles of PCOS. However, basal testosterone levels are a good predictor for ovarian reserve and ovarian response. Consequently, we suggest that some prospective studies must be designed to approve the role of testosterone in the prediction of the outcome of pregnancy in ART cycles.

Association between female circulating heavy metal concentration and abortion: a systematic review and meta-analysis

Objective

This study aimed to evaluate the association between blood heavy metal (zinc (Zn), copper (Cu), lead (Pb), and cadmium (Cd)) concentrations and spontaneous abortion (SA) and recurrent pregnancy loss (RPL) and explore the possible endocrine dysfunction associated with it.

Methods

A literature search was performed in the PubMed, Embase, Cochrane Library, and Web of Science databases up to April 2023. The overall effects were expressed as the standard mean difference (SMD). Subgroup analysis was performed according to the type of abortion (SA or RPL). Stata 16.0 was utilized for data analysis.

Results

Based on the integrated findings, abortion women showed significantly lower Zn (SMD = -1.05, 95% CI: -1.74 to -0.36, p = 0.003) and Cu concentrations (SMD = -1.42, 95% CI: -1.97 to -0.87, p <0.001) and higher Pb (SMD = 1.47, 95% CI: 0.89-2.05, p <0.001) and Cd concentrations (SMD = 1.15, 95% CI: 0.45-1.85, p = 0.001) than normal pregnant women. Subgroup analysis showed that Zn and Cu deficiency and Cd and Pb exposure were significantly (p <0.05) associated with RPL, whereas Cu deficiency and Cd and Pb exposure were significantly (p <0.05) associated with SA.

Conclusion

Zn and Cu deficiencies and Pb and Cd exposure were associated with abortion. Endocrine dysfunction, such as insulin resistance, vitamin D insufficiency, and abnormal thyroid and sex hormone concentrations, is thought to be involved in heavy metal-related abortion.

Mitochondrial Dysfunction in PCOS: Insights into Reproductive Organ Pathophysiology

Polycystic ovary syndrome (PCOS) is a complex, but relatively common endocrine disorder associated with chronic anovulation, hyperandrogenism, and micro-polycystic ovaries. In addition to reduced fertility, people with PCOS have a higher risk of obesity, insulin resistance, and metabolic disease, all comorbidities that are associated with mitochondrial dysfunction. This review summarizes human and animal data that report mitochondrial dysfunction and metabolic dysregulation in PCOS to better understand how mitochondria impact reproductive organ pathophysiology. This in-depth review considers all the elements regulating mitochondrial quantity and quality, from mitochondrial biogenesis under the transcriptional regulation of both the nuclear and mitochondrial genome to the ultrastructural and functional complexes that regulate cellular metabolism and reactive oxygen species production, as well as the dynamics that regulate subcellular interactions that are key to mitochondrial quality control. When any of these mitochondrial functions are disrupted, the energetic equilibrium within the cell changes, cell processes can fail, and cell death can occur. If this process is ongoing, it affects tissue and organ function, causing disease. The objective of this review is to consolidate and classify a broad number of PCOS studies to understand how various mitochondrial processes impact reproductive organs, including the ovary (oocytes and granulosa cells), uterus, placenta, and circulation, causing reproductive pathophysiology. A secondary objective is to uncover the potential role of mitochondria in the transgenerational transmission of PCOS and metabolic disorders.

Polycystic ovarian syndrome and miscarriage in IVF: systematic revision of the literature and meta-analysis

PURPOSE

To evaluate the risk of miscarriage in IVF cycles in women with PCOS.

METHODS

Systematic review and meta-analysis. Systematic search of MEDLINE, EMBASE and Google Scholar. The language search was restricted to English, Spanish and French, from 2000 to 2019, with crosschecking of references from relevant articles. Inclusion criteria were: (1) IVF cycles (2) a group of patients with PCOS was considered separately, (3) the miscarriage rate was reported, (4) there was a control group, (5) definition of PCOS according the Rotterdam criteria. Exclusion criteria were been excluded from the meta-analysis: (1) publication prior to the year 2000, (2) animal studies, (3) reviews, (4) abstracts or conference papers, (5) letters, (6) case reports, (7) studies comparing different IVF techniques, (8) studies comparing groups with and without metformin or other treatments, (9) studies on induced abortions. Risk of bias was assessed by the Newcastle-Ottawa score (NOS). All the included studies had a low risk of bias (NOS scores ranging 7-8). The review protocol was registered in PROSPERO (CRD42020186713). Seventeen studies were included in the meta-analysis. There was a total of 10,472 pregnancies (2650 in PCOS and 7822 in controls) of which 1885 were miscarriages (682 in PCOS and 1203 in controls). We considered the miscarriage rate (MR), preclinical MR, early MR, and late MR.

RESULTS

In IVF pregnancies the risk of miscarriage was significantly increased when considering miscarriages in total (RR = 1.59; CI = 1.45-1.75), preclinical miscarriages (RR = 1.59; CI = 1.35-1.88), and early miscarriages (RR = 1.44; CI = 1.16-1.79). The increased miscarriage rate persisted in Chinese and Western populations when considered separately. The risk of miscarriage was increased in the subgroup of fresh transfers (RR = 1.21; CI = 1.06-1.39) as well as in the subgroup including either fresh or frozen transfers (RR = 1.95; CI = 1.72-2.22).

CONCLUSION

PCOS is linked to an increased MR in IVF pregnancies both of miscarriages in total, and to an increase in preclinical and early miscarriages.

PROSPERO NUMBER

CRD42020186713.

The impact of early pregnancy metabolic disorders on pregnancy outcome and the specific mechanism

Miscarriage is the most common complication of pregnancy. The most common causes of early miscarriage are chromosomal abnormalities of the embryo, maternal endocrine abnormalities, organ malformations, and abnormal immune factors. Late miscarriages are mostly caused by factors such as cervical insufficiency. However, the causes of 50% of miscarriages remain unknown. Recently, increasing attention has been given to the role of metabolic abnormalities in miscarriage. In this review, we mainly discuss the roles of four major metabolic pathways (glucose, lipid, and amino acid metabolism, and oxidation‒reduction balance) in miscarriage and the metabolism-related genes that lead to metabolic disorders in miscarriage. Depending on aetiology, the current treatments for miscarriage include hormonal and immunological drugs, as well as surgery, while there are few therapies for metabolism. Therefore, we also summarize the drugs for metabolism-related targets. The study of altered metabolism underlying miscarriage not only helps us to understand the mechanisms involved in miscarriage but also provides an important basis for clinical research on new therapies.

Regulatory mechanisms of HMGB1 and its receptors in polycystic ovary syndrome-driven gravid uterine inflammation

High-mobility group box 1 (HMGB1) is critical for inflammatory homeostasis and successful pregnancy, and there is a strong association among elevated levels of HMGB1, polycystic ovary syndrome (PCOS), chronic inflammation and pregnancy loss. However, the mechanisms responsible for PCOS-driven regulation of uterine HMGB1 and its candidate receptors [toll-like receptor (TLR) 2 and 4] and inflammatory responses during pregnancy remain unclear. In this study, we found a gestational stage-dependent decrease in uterine HMGB1 and TLR4 protein abundance in rats during normal pregnancy. We demonstrated that increased expression of HMGB1, TLR2 and TLR4 proteins was associated with activation of inflammation-related signalling pathways in the gravid uterus exposed to 5α-dihydrotestosterone and insulin, mimicking the clinical features (hyperandrogenism and insulin resistance) of PCOS and this elevation was completely inhibited by treatment with the androgen receptor (AR) antagonist flutamide. Interestingly, acute exposure to lipopolysaccharide suppressed HMGB1, TLR4 and inflammation-related protein abundance but did not affect androgen levels or AR expression in the gravid uterus with viable fetuses. Furthermore, immunohistochemical analysis revealed that, in addition to being localized predominately in the nuclear compartment, HMGB1 immunoreactivity was also detected in the cytoplasm in the PCOS-like rat uterus, PCOS endometrium and pregnant rat uterus with haemorrhagic and resorbed fetuses, possibly via activation of nuclear factor κB signalling. These results suggest that both AR-dependent and AR-independent mechanisms contribute to the modulation of HMGB1/TLR2/TLR4-mediated uterine inflammation. We propose that the elevation of HMGB1 and its receptors and disruption of the pro-/anti-inflammatory balance in the gravid uterus may participate in the pathophysiology of PCOS-associated pregnancy loss.

Genetic parameters estimation and genome molecular marker identification for gestation length in pigs

Gestation length (GL) plays an important role in piglet maturation of major organs and development of body, while the genetic molecular markers of GL have not been extensively identified. In this study, according to the 5,662 effective records of 3,072 sows, the heritability and repeatability of GL were estimated through the dmuai of DMU Version 6.5.1 with a repeatability model, namely, h 2 = 0.1594 and r e 2 = 0.2437. Among these sows, 906 individuals were genotyped with the GeneSeek Genomic Profiler (GGP) Porcine 50K Chip and imputed to the genome-wide level (9,212,179 SNPs) by the online software PHARP v1 for subsequent quality control and GWAS analyses. Further, the Fst was also performed to measure whether the actual frequency of genotypes in different GL phenotypes deviated from the theoretical proportion of genetic balance. We observed the highest degree of differentiation (average Fst value = 0.0376) in the group of 114 and 118 days, and identified a total of 1,002 SNPs strongly associated with GL. Through screening the genes located within a 500 kb distance on either side of the significant SNPs, we proposed 4,588 candidate genes. By the functional annotation, these candidates were found to be mainly involved in multicellular organism metabolism, early endosome, embryo implantation and development, and body and organ signaling pathway. Because of the simultaneous confirmation by GWAS and Fst analyses, there were 20 genes replied to be the most promising candidates including HUNK, ARHGDIB, ERP27, RERG, NEDD9, TMEM170B, SCAF4, SOD1, TIAM1, ENSSSCG00000048838, ENSSSCG00000047227, EDN1, HIVEP1, ENSSSCG00000043944, LRATD1, ENSSSCG00000048577, ENSSSCG00000042932, ENSSSCG00000041405, ENSSSCG00000045589, and ADTRP. This study provided effective molecular information for the genetic improvement of GL in pigs.

Does the risk of embryo abnormality increase in PCOS women? A secondary analysis of a multi-center randomized controlled trial

CONTEXT

Some studies reported the early miscarriage rate was higher in PCOS women. However, whether the risk of embryo abnormalities increases in PCOS women is lack of evidence.

OBJECTIVE

To evaluate the association between polycystic ovarian syndrome (PCOS) and embryo ploidy.

DESIGN

A secondary analysis of multi-center randomized controlled trial which was conducted from July 2017 to June 2018. The original intent was to identify whether preimplantation genetic test for aneuploidy (PGT-A) improves the live birth rate as compared with in-vitro fertilization (IVF).

SETTING

14 reproductive centers.

PATIENTS

190 patients diagnosed with PCOS and 1:1 age-matched non-PCOS patients were chosen from PGT-A group. A total of 380 patients with 1118 embryos were included in our study.

INTERVENTIONS

Women diagnosed with PCOS.

MAIN OUTCOME MEASURES

Embryonic aneuploidy and embryonic mosaic.

RESULTS

After adjusted for potential confounders, the rate of embryonic aneuploidy and embryonic mosaic in PCOS group were comparable with control group [embryonic aneuploid rate PCOS group: 14.0% vs control group: 18.3%, adjusted OR (95%CI): 0.78(0.54,1.12), P = 0.19; embryonic mosaic rate 10.9% vs 10.1%, adjusted OR (95%CI): 0.91(0.59,1.40), P = 0.66]. We further stratified PCOS women into four groups according to phenotype. The rate of aneuploid and mosaic embryos was comparable between each of PCOS phenotype and control group. There was still no significant difference of embryonic aneuploid and embryo mosaic rates within four phenotypes.

CONCLUSIONS

The risk of aneuploid and mosaic embryos was not increased in PCOS women. Thus, we suggests that the miscarriage rate arising from abnormal embryonic chromosomes could be similar between PCOS and non-PCOS women.

Quercetin and polycystic ovary syndrome

Polycystic ovary syndrome (PCOS) is a reproductive endocrine disease, and results to opsomenorrhea or amenorrhea, hairy, acne, acanthosis, infertility, abortion. In the long term, PCOS may also increase the risk of endometrial cancer, diabetes, hypertension, dyslipidemia and other diseases. Till now there is no specific drug for PCOS due to the unclearness of the cause and pathogenesis, as current treatments for PCOS only target certain symptoms. Quercetin (QUR) is a flavonoid drug widely found in Chinese herbal medicines, fruits, leaves, vegetables, seeds and plants roots. Studies on other diseases have found that QUR has anti-oxidant, anti-inflammatory, anti-insulin resistance, anti-cancer and other effects. Some studies have shown that serum testosterone (T), luteinizing hormone (LH), the LH/follicule-stimulating hormone (FSH) ratio, fasting glucose, fasting insulin, HOMA-IR and lipid levels are reduced in PCOS patients with QUR treatment. However, the mechanisms of QUR in PCOS patients have not been completely elucidated. In this review, we retrospect the basic characteristics of QUR, and in vitro studies, animal experiments and clinical trials of QUR and plant extracts containing QUR in the treatment of PCOS. We also summarized the effects and mechanism of QUR in ovarian cells in vitro and PCOS model rats, the changes in relevant parameters after QUR administration in PCOS patients, and its potentially therapeutic applications.

Construction of Oxidative Stress-Related Genes Risk Model Predicts the Prognosis of Uterine Corpus Endometrial Cancer Patients

Oxidative stress contributes significantly to cancer development. Recent studies have demonstrated that oxidative stress could alter the epigenome and, in particular, DNA methylation. This study aimed to explore the potential link between oxidative stress and uterine corpus endometrial carcinoma (UCEC). An analysis of RNA-seq data and relevant clinical information was conducted with data from The Cancer Genome Atlas (TCGA), and oxidative stress genes were obtained from Gene Set Enrichment Analysis (GSEA). Differentially expressed genes (DEGs) in normal and tumor groups of UCEC were analyzed using GO and KEGG enrichment analysis. As a result of survival analysis, Lasso regression analysis of DEGs, a risk score model of oxidative stress-related genes (OSRGs) was constructed. Moreover, this study demonstrated that OSRGs are associated with immune cell infiltration in UCEC, suggesting oxidative stress may play a role in UCEC development by activating immune cells. We discovered 136 oxidative stress-related DEGs in UCEC, from which we screened 25 prognostic genes significantly related to the overall survival of UCEC patients. BCL2A1, CASP6, GPX2, HIC1, IL19, MSX1, RNF183, SFN, TRPM2 and HIST1H3C are associated with a good prognosis while CDKN2A, CHAC1, E2F1, GSDME, HMGA1, ITGA7, MCM4, MYBL2, PPIF, S100A1, S100A9, STK26 and TRIB3 are involved in a poor prognosis in UCEC. A 7-OSRGs-based risk score (H3C1, CDKN2A, STK26, TRPM2, E2F1, CHAC1, MSX1) was generated by Lasso regression. Further, an association was found between H3C1, CDKN2A, STK26, TRPM2, E2F1, CHAC1 and MSX1 expression levels and the immune infiltrating cells, including CD8 T cells, NK cells, and mast cells in UCEC. NFYA and RFX5 were speculated as common transcription factors of CDKN2A, TRPM2, E2F1, CHAC1, and MSX1 in UCEC.

Increased risk of abortion after frozen-thawed embryo transfer in women with polycystic ovary syndrome phenotypes A and D

Polycystic ovary syndrome (PCOS) is associated with adverse pregnancy outcomes, including an increased risk of abortion, premature delivery, and even neonatal outcomes. After removing the effect of COH on patients, studying the pregnancy outcomes of patients with different PCOS phenotypes after FET may better reflect the impact of different PCOS phenotypes on ART outcomes. Data of 8903 patients who underwent FET between January 2017 and October 2019 were retrospectively collected and evaluated. All patients were divided into a control group and four phenotype groups based on Rotterdam criteria. The main outcomes were pregnancy outcomes after FET. We found significantly higher abortion (P = 0.010) and lower ongoing pregnancy (P = 0.023) rates for women with PCOS phenotypes A and D compared to those in the control group. After adjusting for potential confounders, PCOS phenotypes A and D were associated with an elevated risk of abortion (adjusted OR, 1.476, P = 0.016; adjusted OR, 1.348, P = 0.008, respectively). The results of this study suggest that when performing FET, clinicians should individually manage women with PCOS phenotypes A and D to reduce the rate of abortion and increase the rate of LB, and achieve better pregnancy outcomes.

Abnormal Endometrial Receptivity and Oxidative Stress in Polycystic Ovary Syndrome

Polycystic ovary syndrome (PCOS) is a common endocrine and metabolic disorder in women of childbearing age. Individual heterogeneity is evident, and the prevalence rate ranges between 6 and 15% globally. The prevalence rate of PCOS in Chinese women of childbearing age is 5.6%. The main manifestations are infertility, sparse menstruation, irregular vaginal bleeding, long-term endometrial hyperplasia, and endometrial cancer. PCOS is often associated with hyperandrogenemia, insulin resistance, hyperinsulinemia, obesity, metabolic syndrome, and intestinal flora disorder. Although there have been many studies in the past, the underlying pathophysiological mechanism of the disease is still unclear. Studies have shown that PCOS diseases and related complications are closely related to local oxidative stress imbalance in the endometrium, leading to poor endometrial receptivity and effects on pregnancy. Previous reviews have mainly focused on the abnormal mechanism of ovarian oxidative stress in women with PCOS, while reviews on endometrial receptivity and oxidative stress are relatively insufficient. This study reviews the abnormal cellular and molecular mechanisms of oxidative stress due to comorbidities in women with PCOS, leading to a downregulation of endometrial receptivity.

Materno-fetal iron transfer and the emerging role of ferroptosis pathways

A successful pregnancy and the birth of a healthy baby depend to a great extent on the controlled supply of essential nutrients via the placenta. Iron is essential for mitochondrial energy supply and oxygen distribution via the blood. However, its high reactivity requires tightly regulated transport processes. Disturbances of maternal-fetal iron transfer during pregnancy can aggravate or lead to severe pathological consequences for the mother and the fetus with lifelong effects. Furthermore, high intracellular iron levels due to disturbed gestational iron homeostasis have recently been associated with the non-apoptotic cell death pathway called ferroptosis. Therefore, the investigation of transplacental iron transport mechanisms, their physiological regulation and potential risks are of high clinical importance. The present review summarizes the current knowledge on principles and regulatory mechanisms underlying materno-fetal iron transport and gives insight into common pregnancy conditions in which iron homeostasis is disturbed. Moreover, the significance of the newly emerging ferroptosis pathway and its impact on the regulation of placental iron homeostasis, oxidative stress and gestational diseases will be discussed.

Insulin Resistance is a Risk Factor for Early Miscarriage and Macrosomia in Patients With Polycystic Ovary Syndrome From the First Embryo Transfer Cycle: A Retrospective Cohort Study

Objective

The objective of the study was to explore the effect of insulin resistance on pregnancy outcomes in patients with polycystic ovary syndrome (PCOS) from the first embryo transfer cycle.

Design

This was a single-center, retrospective, observational cohort study.

Patients

Included in the study were women with PCOS for the first embryo transfer.

Main Outcome Measures

Early miscarriage rate and macrosomia rate were the main outcome measures.

Results

With increased HOMA-IR, the early miscarriage rate (7.14, 13.21, and 16.22%, respectively; P = 0.039), macrosomia rate (5.78, 11.79, and 17.58%, respectively; P = 0.026) and the incidence of gestational diabetes (GDM) (10.00, 14.50, and 25.67% respectively; P = 0.002) significantly increased, while the live birth rate markedly decreased (63.03, 55.27, and 47.88%, respectively; P = 0.004). No significant difference was found in clinical pregnancy rate, late miscarriage rate, low birthweight rate and baby gender ratio (all P >0.05). After adjusting for confounding factors, HOMA-IR was an independent risk factor of early miscarriage rate and macrosomia rate.

Conclusion

Insulin resistance is an independent risk factor for early miscarriage and macrosomia in PCOS patients during the first embryo transfer cycle. It is essential to give more attention before and after pregnancy for PCOS women with high HOMA-IR.

Diet-induced maternal obesity impacts feto-placental growth and induces sex-specific alterations in placental morphology, mitochondrial bioenergetics, dynamics, lipid metabolism and oxidative stress in mice

AIM

The current study investigated the impact of maternal obesity on placental phenotype in relation to fetal growth and sex.

METHODS

Female C57BL6/J mice were fed either a diet high in fat and sugar or a standard chow diet, for 6 weeks prior to, and during, pregnancy. At day 19 of gestation, placental morphology and mitochondrial respiration and dynamics were assessed using high-resolution respirometry, stereology, and molecular analyses.

RESULTS

Diet-induced maternal obesity increased the rate of small for gestational age fetuses in both sexes, and increased blood glucose concentrations in offspring. Placental weight, surface area, and maternal blood spaces were decreased in both sexes, with reductions in placental trophoblast volume, oxygen diffusing capacity, and an increased barrier to transfer in males only. Despite these morphological changes, placental mitochondrial respiration was unaffected by maternal obesity, although the influence of fetal sex on placental respiratory capacity varied between dietary groups. Moreover, in males, but not females, maternal obesity increased mitochondrial complexes (II and ATP synthase) and fission protein DRP1 abundance. It also reduced phosphorylated AMPK and capacity for lipid synthesis, while increasing indices of oxidative stress, specifically in males. In females only, placental mitochondrial biogenesis and capacity for lipid synthesis, were both enhanced. The abundance of uncoupling protein-2 was decreased by maternal obesity in both fetal sexes.

CONCLUSION

Maternal obesity exerts sex-dependent changes in placental phenotype in association with alterations in fetal growth and substrate supply. These findings may inform the design of personalized lifestyle interventions or therapies for obese pregnant women.

Androgen Excess Induced Mitochondrial Abnormality in Ovarian Granulosa Cells in a Rat Model of Polycystic Ovary Syndrome

BACKGROUND

Androgen excess could profoundly lead to follicular dysplasia or atresia, and finally result in polycystic ovary syndrome (PCOS); however, the exact mechanism remains to be fully elucidated.

METHODS

PCOS model rats were induced by dehydroepiandrosterone, and their fertility was assessed. The ovarian granulosa cells (GCs) from matured follicles of PCOS model rats were collected and identified by immunofluorescence. The mitochondrial ultrastructure was observed by transmission electron microscope and the mitochondrial function was determined by detecting the adenosine triphosphate (ATP) content and mtDNA copy number. Besides, the expressions of respiratory chain complexes and ATP synthases in relation to mitochondrial function were analyzed.

RESULTS

The PCOS model rats were successfully induced, and their reproductive outcomes were obviously adverse. The GCs layer of the ovarian was apparently cut down and the mitochondrial ultrastructure of ovarian GCs was distinctly destroyed. The ATP content and mtDNA copy number of ovarian GCs in PCOS model rats were greatly reduced, and the expressions of NDUFB8 and ATP5j were significantly down-regulated without obvious deletion of mtDNA 4834-bp.

CONCLUSIONS

Androgen excess could damage mitochondrial ultrastructure and function of GCs in rat ovary by down-regulating expression of NDUFB8 and ATP5j in PCOS.

Obesity and Maternal-Placental-Fetal Immunology and Health

Obesity rates in women of childbearing age is now at 29%, according to recent CDC reports. It is known that obesity is associated with oxidative stress and inflammation, including disruptions in cellular function and cytokine levels. In pregnant women who are obese, associated placental dysfunction can lead to small for gestational age (SGA) infants. More frequently, however, maternal obesity is associated with large for gestational age (LGA) newborns, who also have higher incidence of metabolic disease and asthma due to elevated levels of inflammation. In addition, anthropogenic environmental exposures to "endocrine disrupting" and "forever" chemicals affect obesity, as well as maternal physiology, the placenta, and fetal development. Placental function is intimately associated with the control of inflammation during pregnancy. There is a large amount of literature examining the relationship of placental immunology, both cellular and humoral, with pregnancy and neonatal outcomes. Cells such as placental macrophages and NK cells have been implicated in spontaneous miscarriage, preeclampsia, preterm birth, perinatal neuroinflammation, and other post-natal conditions. Differing levels of placental cytokines and molecular inflammatory mediators also have known associations with preeclampsia and developmental outcomes. In this review, we will specifically examine the literature regarding maternal, placental, and fetal immunology and how it is altered by maternal obesity and environmental chemicals. We will additionally describe the relationship between placental immune function and clinical outcomes, including neonatal conditions, autoimmune disease, allergies, immunodeficiency, metabolic and endocrine conditions, neurodevelopment, and psychiatric disorders.

The role of nuclear factor erythroid 2-related factor 2 (NRF2) in normal and pathological pregnancy: A systematic review

OBJECTIVE

A homeostatic balance between reactive oxygen species production and the antioxidant redox system is an important component of normal pregnancy. Nuclear Factor Erythroid 2-Related Factor 2 (Nrf2) preserves cellular homeostasis by enhancing the cell's innate antioxidant status to reduce oxidative stress and inflammatory damage to the cell during pregnancy. Active Nrf2, in the nucleus of the cell, transactivates various antioxidant genes. The objective of this systematic review was to synthesize evidence on the role of Nrf2 in various adverse pregnancy outcomes (APOs).

METHODS

We conducted a systematic review of the role of Nrf2 in pregnancy. Articles written in English, Portuguese, and Spanish were obtained from three different databases from inception until January 2021. The titles, abstracts and full text were reviewed independently by six reviewers. The quality of the included studies was assessed using a quality assessment tool developed to assess basic science and clinical studies. Nrf2 expression (gene and protein), functional contributions, and association with APOs were assessed.

RESULTS

A total of 747 citations were identified; 80 were retained for full review. Most studies on Nrf2 have been carried out using placental tissues and placenta-derived cells. Limited studies have been conducted using fetal membranes, uterus, and cervix. Nuclear translocation of Nrf2 results in transactivation of antioxidant enzymes, including glutathione peroxidase, hemeoxygenase-1, and superoxide dismutase in gestational cells during pregnancy. This antioxidant response maintains cellular homeostasis during pregnancy. This promotes trophoblast cell survival and prevents cell death and abnormal angiogenesis in the placenta. Excessive and insufficient Nrf2 response may promote oxidative and reductive stress, respectively. This Nrf2 dysregulation has been associated with APOs including gestational diabetes mellitus, intrauterine growth restriction, reproductive toxicity, preeclampsia, and preterm birth.

CONCLUSION

Several studies have localized and reported an association between Nrf2's differential expression in reproductive tissues and the pathogenesis of APOs. However, a comprehensive functional understanding of Nrf2 in reproductive tissues is still lacking. Nrf2's activation and functions are complex, and therefore, current in vitro and in vivo studies are limited in their experimental approaches. We have identified key areas for future Nrf2 research that is needed to fill knowledge gaps.

Polycystic ovary syndrome and risk of stillbirth: a nationwide register-based study

OBJECTIVE

To investigate whether polycystic ovary syndrome (PCOS) is associated with increased risk of stillbirth and whether any such association is linked to PCOS with a severe hyperandrogenic profile.

DESIGN

Nationwide register-based cohort study.

SETTING

Sweden.

POPULATION

The cohort consisted of women giving birth to singleton infants in 1997-2015. All women with a diagnosis of PCOS in the period 1997-2017 and a randomly selected reference group of women without PCOS diagnosis were included. PCOS with a severe hyperandrogenic profile was defined as a PCOS diagnosis with at least two dispensations of prescribed anti-androgens during 2005-2017.

METHODS

The risk of stillbirth in women with PCOS was estimated through multiple logistic regression, using women without PCOS as a reference. Risks were expressed as adjusted odds ratios (aORs) with 95% confidence intervals (95% CIs), adjusted for maternal age, parity, body mass index, type-1 diabetes, educational level and country of birth.

MAIN OUTCOME MEASURES

Stillbirth, at ≥22 weeks of gestation in 2008-2015 and at ≥28 weeks of gestation in 1997-2007.

RESULTS

Compared with women without PCOS (n = 241 750), women with PCOS (n = 41 851) had a 50% increased risk of stillbirth (aOR 1.50, 95% CI 1.28-1.77). The incidence of stillbirth in women with PCOS was particularly increased at term. Women with PCOS and a severe hyperandrogenic profile (n = 13 713) did not have a stronger association with stillbirth than women with PCOS who did not have such a profile.

CONCLUSIONS

PCOS is associated with stillbirth and should be considered as a possible risk factor in antenatal care. Further research is warranted to investigate possible causal mechanisms.

TWEETABLE ABSTRACT

Women with PCOS have increased risk of stillbirth, and the incidence is particularly increased at term.

Suppression of uterine and placental ferroptosis by N-acetylcysteine in a rat model of polycystic ovary syndrome

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.

Hyperandrogenemia alters mitochondrial structure and function in the oocytes of obese mouse with polycystic ovary syndrome

Capsule

Hyperandrogenemia in an obese PCOS mouse model results in altered glucose/insulin metabolism and mitochondrial structure and function in the oocytes, in part explaining adverse outcomes and inheritance patterns seen in PCOS.

Objective

To study the oocyte quality by means of mitochondrial structure and function in a well-established classic PCOS mouse model.

Design

Animal study using an obese PCOS mouse model compared with control.

Setting

Animal research facility in a tertiary care university hospital setting.

Animals

C57/B6J mice.

Intervention

Three week old mice had subdermal implants of DHT controlled release pellet or placebo for 90 days.

Main Outcome Measures

The mouse model was validated by performing glucose tolerance test, HbA1c levels, body weight and estrous cycle analyses. Oocytes were subsequently isolated and were used to investigate mitochondrial membrane potential, oxidative stress, lipid peroxidation, ATP production, mtDNA copy number, transcript abundance, histology and electron microscopy.

Results

Results showed glucose intolerance and hyperinsulinemia along with dysregulated estrus cycle. Analysis of the oocytes demonstrated impaired inner mitochondrial membrane function, increased ATP production and mtDNA copy number, altered RNA transcript abundance and aberrant ovarian histology. Electron microscopy of the oocytes showed severely impaired mitochondrial ultrastructure.

Conclusion

The obese PCOS mouse model shows a decreased oocyte quality related to impaired mitochondrial function.

Is fertility reduced in ovulatory women with polycystic ovary syndrome? An opinion paper

Polycystic ovary syndrome (PCOS) is the most common cause of anovulatory infertility; however, whether women with PCOS and spontaneous or drug-induced ovulatory cycles have the same reproductive potential as non-PCOS controls is a matter of debate. In the present opinion paper, the author takes the opportunity to summarize the collective evidence supporting the hypothesis of reduced fertility potential in women with PCOS, regardless of ovulatory status, and speculate that reduced reproductive potential may be caused by altered oocytes, embryo and endometrial competence, and infertility-related co-morbidities as well as an increased risk of pregnancy complications.

Alterations of endometrial epithelial-mesenchymal transition and MAPK signalling components in women with PCOS are partially modulated by metformin in vitro

Growing evidence suggests that epithelial-mesenchymal transition (EMT) and its regulator mitogen-activated protein kinase (MAPK) contribute to endometria-related reproductive disorders. However, the regulation of EMT and MAPK signalling components in the endometrium from polycystic ovary syndrome (PCOS) patients has not been systematically investigated and remains elusive. In humans, how metformin induces molecular alterations in the endometrial tissues under PCOS conditions is not completely clear. Here, we recruited 7 non-PCOS patients during the proliferative phase (nPCOS), 7 non-PCOS patients with endometrial hyperplasia (nPCOSEH), 14 PCOS patients during the proliferative phase (PCOS) and 3 PCOS patients with endometrial hyperplasia (PCOSEH). Our studies demonstrated that compared with nPCOS, PCOS patients showed decreased Claudin 1 and increased Vimentin and Slug proteins. Similar to increased Slug protein, nPCOSEH and PCOSEH patients showed increased N-cadherin protein. Western blot and immunostaining revealed increased epithelial phosphorylated Cytokeratin 8 (p-CK 8) expression and an increased p-CK 8:CK 8 ratio in PCOS, nPCOSEH and PCOSEH patients compared to nPCOS patients. Although nPCOSEH and PCOSEH patients showed increased p-ERK1/2 and/or p38 protein levels, the significant increase in p-ERK1/2 expression and p-ERK1/2:ERK1/2 ratio was only found in PCOS patients compared to nPCOS patients. A significant induction of the membrane ERβ immunostaining was observed in the epithelial cells of PCOS and PCOSEH patients compared to nPCOS and nPCOSEH patients. While in vitro treatment with metformin alone increased Snail and decreased Claudin 1, N-cadherin and α-SMA proteins, concomitant treatment with metformin and E2 increased the expression of CK 8 and Snail proteins and decreased the expression of Claudin 1, ZO-1, Slug and α-SMA proteins. Our findings suggest that the EMT contributes to the switch from a healthy state to a PCOS state in the endometrium, which might subsequently drive endometrial injury and dysfunction. We also provide evidence that metformin differentially modulates EMT protein expression in PCOS patients depending on oestrogenic stimulation.

Increased uterine androgen receptor protein abundance results in implantation and mitochondrial defects in pregnant rats with hyperandrogenism and insulin resistance

Abstract

In this study, we show that during normal rat pregnancy, there is a gestational stage-dependent decrease in androgen receptor (AR) abundance in the gravid uterus and that this is correlated with the differential expression of endometrial receptivity and decidualization genes during early and mid-gestation. In contrast, exposure to 5α-dihydrotestosterone (DHT) and insulin (INS) or DHT alone significantly increased AR protein levels in the uterus in association with the aberrant expression of endometrial receptivity and decidualization genes, as well as disrupted implantation. Next, we assessed the functional relevance of the androgen-AR axis in the uterus for reproductive outcomes by treating normal pregnant rats and pregnant rats exposed to DHT and INS with the anti-androgen flutamide. We found that AR blockage using flutamide largely attenuated the DHT and INS-induced maternal endocrine, metabolic, and fertility impairments in pregnant rats in association with suppressed induction of uterine AR protein abundance and androgen-regulated response protein and normalized expression of several endometrial receptivity and decidualization genes. Further, blockade of AR normalized the expression of the mitochondrial biogenesis marker Nrf1 and the mitochondrial functional proteins Complexes I and II, VDAC, and PHB1. However, flutamide treatment did not rescue the compromised mitochondrial structure resulting from co-exposure to DHT and INS. These results demonstrate that functional AR protein is an important factor for gravid uterine function. Impairments in the uterine androgen-AR axis are accompanied by decreased endometrial receptivity, decidualization, and mitochondrial dysfunction, which might contribute to abnormal implantation in pregnant PCOS patients with compromised pregnancy outcomes and subfertility.

Key messages

The proper regulation of uterine androgen receptor (AR) contributes to a normal pregnancy process, whereas the aberrant regulation of uterine AR might be linked to polycystic ovary syndrome (PCOS)-induced pregnancy-related complications.

In the current study, we found that during normal rat pregnancy there is a stage-dependent decrease in AR abundance in the gravid uterus and that this is correlated with the differential expression of the endometrial receptivity and decidualization genes Spp1, Prl, Igfbp1, and Hbegf.

Pregnant rats exposed to 5α-dihydrotestosterone (DHT) and insulin (INS) or to DHT alone show elevated uterine AR protein abundance and implantation failure related to the aberrant expression of genes involved in endometrial receptivity and decidualization in early to mid-gestation.

Treatment with the anti-androgen flutamide, starting from pre-implantation, effectively prevents DHT + INS-induced defects in endometrial receptivity and decidualization gene expression, restores uterine mitochondrial homeostasis, and increases the pregnancy rate and the numbers of viable fetuses.

This study adds to our understanding of the mechanisms underlying poor pregnancy outcomes in PCOS patients and the possible therapeutic use of anti-androgens, including flutamide, after spontaneous conception.

Supplementary Information

The online version contains supplementary material available at 10.1007/s00109-021-02104-z.

Recent updates on animal models for understanding the etiopathogenesis of polycystic ovarian syndrome

Polycystic ovarian syndrome (PCOS) is the primary cause of female infertility affecting several women worldwide. Changes in hormonal functions such as hyperandrogenism are considered a significant factor in developing PCOS in women. In addition, many molecular pathways are involved in the pathogenesis of PCOS in women. To have better insights about PCOS, it is data from clinical studies carried on women suffering from PCOS should be collected. However, this approach has several implications, including ethical considerations, cost involved and availability of subject. Moreover, during the early drug development process, it is always advisable to use non-human models mimicking human physiology as they are less expensive, readily available, have a shorter gestation period and less risk involved. Many animal models have been reported that resemble the PCOS pathways in human subjects. However, the models developed on rats and mice are more preferred over other rodent/non-rodent models due to their closer resemblance with human PCOS development mechanism. The most extensively reported PCOS models for rats and mice include those induced by using testosterone, letrozole and estradiol valerate. As the pathophysiology of PCOS is complex, none of the explored models completely surrogates the PCOS related conditions occurring in women. Hence, there is a need to develop an animal model that can resemble the pathophysiology of PCOS in women. The review focuses on various animal models explored to understand the pathophysiology of PCOS. The article also highlights some environmental and food-related models that have been used to induce PCOS.

Complementary and Alternative Medicine for Threatened Miscarriage: Advantages and Risks

Threatened miscarriage is one of the most common complications causing pregnancy loss, and it affects approximately 20% of confirmed pregnancies. More and more women are seeking treatment with complementary and alternative medicine (CAM) for this common complication, and it has been reported that women have had successful pregnancies after threatened miscarriage when being treated with CAM, which mainly includes Chinese herbal medicines, acupuncture, and nutritional supplements as well as psychological interventions and other approaches. However, many experts are concerned about the safety and adverse events of certain CAM approaches in women with threatened miscarriage. Therefore, this review focuses on the status of CAM for threatened miscarriage and presents the potential therapeutic efficacy and safety of CAM based on some clinical and experimental studies. We thus hope to provide some instructive suggestions for the application of CAM for treating threatened miscarriage in the future.

Placental mitochondrial function in response to gestational exposures

Poor environmental conditions, including malnutrition, hypoxia and obesity in the mother increase the risk of pregnancy complications, such as pre-eclampsia and gestational diabetes mellitus, which impacts the lifelong health of the mother and her offspring. The placenta plays an important role in determining pregnancy outcome by acting as an exchange interface and endocrine hub to support fetal growth. Mitochondria are energy powerhouses of cells that fuel placental physiology throughout pregnancy, including placental development, substrate exchange and hormone secretion. They are responsive to environmental cues and changes in mitochondrial function may serve to mediate or mitigate the impacts of poor gestational environments on placental physiology and hence, the risks of pregnancy complications. Thus, a more integrated understanding about the role of placental mitochondria in orchestrating changes in relation to environmental conditions and pregnancy outcome is paramount. This review summarises the functions of mitochondria in the placenta and findings from humans and experimental animals that demonstrate how mitochondrial structure and function are altered in different gestational environments (namely complicated pregnancies and adverse environmental conditions). Together the available data suggest that mitochondria in the placenta play a major role in determining placental physiology, fetal growth and pregnancy outcome.

Long non-coding RNA lnc-CCNL1-3:1 promotes granulosa cell apoptosis and suppresses glucose uptake in women with polycystic ovary syndrome

Polycystic ovary syndrome (PCOS) is a common endocrine and metabolic disease in premenopausal women. Long non-coding RNAs (lncRNAs) constitute important factors in numerous biological processes. However, their roles in PCOS pathogenesis require further clarification. Our study aims to elucidate the roles of lncRNA lnc-CCNL1-3:1 (CCNL) in PCOS. CCNL expression in human luteinized granulosa cells (hLGCs) derived from women with and without PCOS was detected. The full length of CCNL was obtained by 5' and 3' rapid amplification of cDNA ends. CCNL roles in granulosa cell apoptosis, mitochondrial function, and glucose uptake were evaluated. The binding relationship between CCNL and forkhead box O1 (FOXO1) was determined by RPISeq, RNA immunoprecipitation, subcellular fractionation, and immunofluorescence. In KGN cells and hLGCs, CCNL overexpression upregulated FOXO1 expression, promoted cell apoptosis, reduced glucose transport capability, and impaired mitochondrial function, and these effects were partially abolished by silencing FOXO1. The interaction of CCNL with FOXO1 might prevents FOXO1 exclusion from the nucleus and subsequent degradation in the cytosol. We determined that CCNL serve as a facilitator in the processes of PCOS. CCNL might participate in PCOS pathologies such as follicular atresia and insulin resistance.

Endometrial function in women with polycystic ovary syndrome: a comprehensive review

BACKGROUND

Polycystic ovary syndrome (PCOS) is the most common cause of anovulatory infertility. An endometrial component has been suggested to contribute to subfertility and poor reproductive outcomes in affected women.

OBJECTIVE AND RATIONALE

The aim of this review was to determine whether there is sufficient evidence to support that endometrial function is altered in women with PCOS, whether clinical features of PCOS affect the endometrium, and whether there are evidence-based interventions to improve endometrial dysfunction in PCOS women.

SEARCH METHODS

An extensive literature search was performed from 1970 up to July 2020 using PubMed and Web of Science without language restriction. The search included all titles and abstracts assessing a relationship between PCOS and endometrial function, the role played by clinical and biochemical/hormonal factors related to PCOS and endometrial function, and the potential interventions aimed to improve endometrial function in women with PCOS. All published papers were included if considered relevant. Studies having a specific topic/hypothesis regarding endometrial cancer/hyperplasia in women with PCOS were excluded from the analysis.

OUTCOMES

Experimental and clinical data suggest that the endometrium differs in women with PCOS when compared to healthy controls. Clinical characteristics related to the syndrome, alone and/or in combination, may contribute to dysregulation of endometrial expression of sex hormone receptors and co-receptors, increase endometrial insulin-resistance with impaired glucose transport and utilization, and result in chronic low-grade inflammation, immune dysfunction, altered uterine vascularity, abnormal endometrial gene expression and cellular abnormalities in women with PCOS. Among several interventions to improve endometrial function in women with PCOS, to date, only lifestyle modification, metformin and bariatric surgery have the highest scientific evidence for clinical benefit.

WIDER IMPLICATIONS

Endometrial dysfunction and abnormal trophoblast invasion and placentation in PCOS women can predispose to miscarriage and pregnancy complications. Thus, patients and their health care providers should advise about these risks. Although currently no intervention can be universally recommended to reverse endometrial dysfunction in PCOS women, lifestyle modifications and metformin may improve underlying endometrial dysfunction and pregnancy outcomes in obese and/or insulin resistant patients. Bariatric surgery has shown its efficacy in severely obese PCOS patients, but a careful evaluation of the benefit/risk ratio is warranted. Large scale randomized controlled clinical trials should address these possibilities.

Novel mechanisms underlying anti-polycystic ovary like syndrome effects of electroacupuncture in rats: suppressing SREBP1 to mitigate insulin resistance, mitochondrial dysfunction and oxidative stress

Background

Acupuncture, a therapy of traditional Chinese medicine, is confirmed to exert the therapeutic action on polycystic ovary syndrome (PCOS). However, the detailed therapeutic mechanisms of acupuncture in PCOS remain ambiguous. In this study, we further investigated whether electroacupuncture (EA) alleviated PCOS-like symptoms in rats via regulating a metabolic regulator, sterol regulatory element binding protein-1 (SREBP1).

Methods

The PCOS-like rat model was built by hypodermic injection with dehydroepiandrosterone (DHEA). The rats were subjected to EA intervention (ST29 and SP6 acupuncture points) for 5 weeks. Primary granulosa cells were isolated from control and PCOS-like rats for evaluating insulin resistance, mitochondrial dysfunction and oxidative stress in vitro.

Results

The expression of SREBP1 was increased in PCOS-like rats, which was suppressed by EA treatment. In addition, lentivirus-mediated overexpression of SREBP1 restrained EA treatment-induced improvement in pathological changes, serum hormone levels and insulin resistance in rats. In addition, overexpression of SREBP1 repressed insulin-stimulated phosphorylation of insulin receptor β (IR) and AKT in primary granulosa cells. Moreover, upregulation of SREBP1 further exacerbated mitochondrial dysfunction and oxidative stress in granulosa cells isolated from PCOS-like rats. Mechanically, EA treatment suppressed SREBP1 expression through inducing the activation of AMP-activated protein kinase (AMPK) signaling pathway in PCOS-like rats.

Conclusion

EA intervention alleviated PCOS-like symptoms in rats via improving IR, mitochondrial dysfunction and oxidative stress through regulating SREBP1, a lipid metabolism regulator. Our findings illuminate the novel protective mechanisms of EA in the treatment of PCOS.

Effect of in vitro sodium fluoride treatment on CAT, SOD and Nrf mRNA expression and immunolocalisation in chicken (Gallus domesticus) embryonic gonads

In this study, we examined the effect of sodium fluoride (NaF) on oxidative stress in chicken embryonic gonads. Following exposure to varying concentrations of NaF for 6 h, mRNA expression and immunolocalisation of catalase (CAT), sodium dismutase (SOD1 and SOD2) and nuclear respiratory factors (Nrf1 and Nrf) were analysed in the gonads. In the ovary, a dose-dependent increase in mRNA expression of CAT, Nrf1 and Nrf2 following NaF exposure was found, while the intensity of immunolocalised CAT, SOD2 and Nrf1 was higher in NaF-treated groups. In the testis, no effect of NaF on CAT, SOD1 and Nrf1 mRNA levels was observed; however, NaF (3.5-14.2 mM) elevated Nrf2 mRNA expression. NaF, at a dose of 7.1 mM, increased the immunoreactivity of Nrf1 and SOD2. Further experiments evaluated the ovary and testes when incubated with NaF (7.1 mM), vitamin C (Vitamin C, 4 mM) or NaF + Vitamin C. mRNA expression of all four examined genes in the whole ovary and immunoreactivity of Nrf1 and CAT in the ovarian medulla increased in each experimental group. Similar effects were observed in the testis, where mRNA expression, as well as CAT and Nrf2 immunoreactivity, increased in Vitamin C and NaF + Vitamin C-treated groups. In summary, NaF exposure generated oxidative stress which is manifested by increased expression of free radical scavenging enzymes in chicken embryonic gonads. High doses of Vitamin C did not reverse this effect.

Prevention of preterm birth: Proactive and reactive clinical practice-are we on the right track?

Preterm birth remains the major cause of death and disability among children under the age of five. In developing countries antenatal preterm birth prevention clinics are set up to provide cervical length surveillance and/or treatment modalities such as cerclage or progesterone for those women with identified risk factors such as previous cervical treatment or preterm birth. However, 85% of women have no risk factors for PTB and currently there is no biomarker to screen women early in pregnancy. Women will present unexpectedly in threatened preterm labour and we have no choice but to adopt a re-active approach to their care by using predication and preparation strategies such as fetal fibronectin, tocolytic therapy and steroids. Despite these strategies approximately 15-20% of these women will give birth preterm before 34 weeks. There is a urgent need to re-design primary, secondary and tertiary prevention strategies for spontaneous preterm labour (sPTL) in singleton pregnancies aimed at identifying and addressing key gaps in clinical practice and research.

Testosterone Decreases Placental Mitochondrial Content and Cellular Bioenergetics

Placental mitochondrial dysfunction plays a central role in the pathogenesis of preeclampsia. Since preeclampsia is a hyperandrogenic state, we hypothesized that elevated maternal testosterone levels induce damage to placental mitochondria and decrease bioenergetic profiles. To test this hypothesis, pregnant Sprague–Dawley rats were injected with vehicle or testosterone propionate (0.5 mg/kg/day) from gestation day (GD) 15 to 19. On GD20, the placentas were isolated to assess mitochondrial structure, copy number, ATP/ADP ratio, and biogenesis (Pgc-1α and Nrf1). In addition, in vitro cultures of human trophoblasts (HTR-8/SVneo) were treated with dihydrotestosterone (0.3, 1.0, and 3.0 nM), and bioenergetic profiles using seahorse analyzer were assessed. Testosterone exposure in pregnant rats led to a 2-fold increase in plasma testosterone levels with an associated decrease in placental and fetal weights compared with controls. Elevated maternal testosterone levels induced structural damage to the placental mitochondria and decreased mitochondrial copy number. The ATP/ADP ratio was reduced with a parallel decrease in the mRNA and protein expression of Pgc-1α and Nrf1 in the placenta of testosterone-treated rats compared with controls. In cultured trophoblasts, dihydrotestosterone decreased the mitochondrial copy number and reduced PGC-1α, NRF1 mRNA, and protein levels without altering the expression of mitochondrial fission/fusion genes. Dihydrotestosterone exposure induced significant mitochondrial energy deficits with a dose-dependent decrease in basal respiration, ATP-linked respiration, maximal respiration, and spare respiratory capacity. In summary, our study suggests that the placental mitochondrial dysfunction induced by elevated maternal testosterone might be a potential mechanism linking preeclampsia to feto-placental growth restriction.

Excessive reactive oxygen species induce apoptosis via the APPL1-Nrf2/HO-1 antioxidant signalling pathway in trophoblasts with missed abortion

AIMS

Previous evidence has demonstrated that oxidative stress is related to the pathogenesis of missed abortion (MA), but the specific mechanism remains obscure. The adaptor protein APPL1 is one of the differential proteins in chorionic trophoblasts. Thus, this study aimed to assess the potential influence of APPL1 on oxidative stress responses as well the possible molecular mechanisms involving in MA.

MAIN METHODS

In the present study, the chorionic trophoblasts and the HTR-8/SVneo cell line were researched in vitro. Small interfering RNA (siRNA) was used to suppress the expression of APPL1. The fluorescent probes DHE and DCFH-DA were used to assess the intracellular reactive oxidative species (ROS). The activity of superoxide dismutase (SOD) was determined. Apoptosis was detected by TUNEL and flow cytometry. Cell viability was determined using Cell Counting Kit-8. Protein expression was detected by immunohistochemistry, western blotting, and reverse transcription-quantitative PCR.

KEY FINDINGS

The application of oxidant in normal chorionic trophoblasts induced cell death and overproduction of ROS, which was consistent with MA. In addition, knockdown of APPL1 in HTR-8/SVneo cells resulted in increased ROS and apoptosis, which could be rescued by pretreatment with antioxidants. Mechanistically, we report that overproduction of ROS in trophoblasts and disturbed SOD, APPL1 and Nrf2/HO-1 antioxidant responses constitute important contributors to apoptosis.

SIGNIFICANCE

Our results suggest that APPL1 has antioxidant properties that suppress oxidative stress and apoptosis via the Nrf2/HO-1 pathway. Moreover, antioxidant N-acetylcysteine (NAC) effectively restored the impaired antioxidative defense system elicited by excess ROS, as a potential therapeutic reagent for MA.

Mitochondrial Dysfunction in Polycystic Ovary Syndrome

Polycystic ovary syndrome (PCOS) is one of the most common female reproductive metabolisms. It is an endocrine disease that affects reproductive women and often exhibits with hyperandrogenemia, insulin resistance (IR), low inflammation, and an increased risk of type 2 diabetes mellitus, metabolic syndrome, and cardiovascular events such as hypertension and dyslipidemia in patients. However, the molecular mechanism of PCOS is still unclear. Recently, an increasing number of studies have shown that the oxidative stress induced by mitochondrial dysfunction has negative effects on IR, lipid metabolism, and follicular development, suggesting that mitochondrial dysfunction plays an essential role in the development of PCOS. Abnormal mitochondrial DNA copy number in patients with PCOS, and mitochondrial gene mutations, has been the focus of research in recent years, and functional mitochondrial diseases have been gradually accepted as a related factor in PCOS. This review is intended to summarize and discuss previous and recent studies and findings on the connections between mitochondrial dysfunction and PCOS.

Prenatally androgenized female rats develop uterine hyperplasia when adult

Prenatal hyperandrogenization (PH) is hypothesized as one of the main factors contributing to the development of polycystic ovary syndrome (PCOS). In this study, we aimed to investigate the impact of prenatal exposure to androgen excess on the uterus when animals reach their adulthood. We found that PH altered the morphology of the uteri that show a hyperplastic morphology with increased total uterine thickness as well as luminal epithelium thickness, with both enhanced and altered distribution of glands as compared with controls. Morphological alterations were associated with an unbalanced homeostasis as assessed by the expression of regulators of cell cycle progression and cell death dynamics. PH also causes disturbances in the cell cycle of the uterine tissue and dysregulates cell death and survival pathways leading to the development of uterine hyperplasia. These findings suggest that PH may have a deleterious effect on the uterus.

Perturbed ovarian and uterine glucocorticoid receptor signaling accompanies the balanced regulation of mitochondrial function and NFκB-mediated inflammation under conditions of hyperandrogenism and insulin resistance

AIM

This study aimed to determine whether glucocorticoid receptor (GR) signaling, mitochondrial function, and local inflammation in the ovary and uterus are intrinsically different in rats with hyperandrogenism and insulin resistance compared to controls.

MAIN METHODS

Female Sprague Dawley rats were exposed to daily injections of human chorionic gonadotropin and/or insulin.

KEY FINDINGS

In both the ovary and the uterus, decreased expression of the two GR isoforms was concurrent with increased expression of Fkbp51 but not Fkbp52 mRNA in hCG + insulin-treated rats. However, these rats exhibited contrasting regulation of Hsd11b1 and Hsd11b2 mRNAs in the two tissues. Further, the expression of several oxidative phosphorylation-related proteins decreased in the ovary and uterus following hCG and insulin stimulation, in contrast to increased expression of many genes involved in mitochondrial function and homeostasis. Additionally, hCG + insulin-treated rats showed increased expression of ovarian and uterine NFκB signaling proteins and Tnfaip3 mRNA. The mRNA expression of Il1b, Il6, and Mmp2 was decreased in both tissues, while the mRNA expression of Tnfa, Ccl2, Ccl5, and Mmp3 was increased in the uterus. Ovaries and uteri from animals co-treated with hCG and insulin showed increased collagen deposition compared to controls.

SIGNIFICANCE

Our observations suggest that hyperandrogenism and insulin resistance disrupt ovarian and uterine GR activation and trigger compensatory or adaptive effects for mitochondrial homeostasis, allowing tissue-level maintenance of mitochondrial function in order to limit ovarian and uterine dysfunction. Our study also suggests that hyperandrogenism and insulin resistance activate NFκB signaling resulting in aberrant regulation of inflammation-related gene expression.