Haptoglobin levels, but not Hp1-Hp2 polymorphism, are associated with polycystic ovary syndrome

Proteomics in the study of female fertility: an update

INTRODUCTION

Female fertility has been a field of interest for the scientific community throughout the years. The contribution of proteomics in the study of female fertility as well as female infertility and in vitro fertilization (IVF) has been significant. Proteomics is a recently developed field, extensively applied to the identification and quantification of proteins, which could be used as potential biomarkers in a diagnostic, prognostic, or predictive manner in a variety of medical conditions.

AREAS COVERED

The present review focuses on proteomic studies of the oocyte and endometrial environment as well as on conditions related to infertility, such as polycystic ovarian syndrome, endometriosis, obesity, and unexplained infertility. Moreover, this review presents studies that have been done in an effort to search for fertility biomarkers in individuals following the IVF procedure.

EXPERT OPINION

The comprehension of the molecular pathways behind female fertility and infertility could contribute to the diagnosis, prognosis, and prediction of infertility. Moreover, the identification of proteomic biomarkers for IVF cycles could predict the possible outcome of an IVF cycle, prevent an unsuccessful IVF, and monitor the IVF cycle in a personalized manner, leading to increased success rates. [Figure: see text].

Genome-wide association study for single nucleotide polymorphism associated with mural and cumulus granulosa cells of PCOS (polycystic ovary syndrome) and non-PCOS patients

Background

The genetic make-up of local granulosa cells and their function in the pathophysiology of polycystic ovary syndrome (PCOS) is crucial to a full comprehension of the disorder. The major purpose of this study was to compare the Single Nucleotide Polymorphism (SNP) of cumulus granulosa cells (CGCs) and mural granulosa cells (MGCs) between healthy individuals and women with PCOS using genome-wide association analysis (GWA). A case–control study was conducted in a total of 24 women diagnosed with PCOS and 24 healthy non-PCOS women of reproductive age aggregated into 4 samples of 6 patients each. GWA studies entail several processes, such as cell separation, cellular DNA extraction, library preparation followed by interpretation using bioinformatics databases. SNP locations were identified by reference gene also involves the use of Matrix-assisted laser desorption/ionisation-time of flight (MALDI-TOF) mass spectrometry (MS) (MALDI-TOF-MS) for the first sorting. Hybridization with the gene chip was followed by reading the SNP genotypes according to the publications in the literature. TASSEL (Trait Analysis by aSSociation, Evolution and Linkage) program and methods were used for GWA studies.

Results

An aggregate of 21,039 SNP calls were obtained from our samples. Genes of autoimmune illnesses, obesity, inflammatory illnesses, nervous system diseases such as retinitis pigmentosa, autism, neural tube defects, and Alzheimer's disease; and various malignancies such as lung cancer, colorectal cancer, breast cancer were also identified in these cells. Gene ranking score reveals that granulosa cells carry key genes of neurological system and reproductive systems especially in brain and testis, respectively.

Conclusions

Mural and Cumulus Granulosa cells were shown to have the PCOS directly and indirectly related genes MMP9, PRKAA2, COMT and HP. We found that the expression of ARID4B, MUC5AC, NID2, CREBBP, GNB1, KIF2C, COL18A1, and HNRNPC by these cells may contribute to PCOS.

Graphical abstract

Updates in diagnosing polycystic ovary syndrome-related infertility

INTRODUCTION

Polycystic ovary syndrome (PCOS) is a condition that affects approximately 13% of reproductive age women and is characterized by androgen excess, menstrual irregularity and altered ovarian morphology. PCOS presents a complex etiology and pathophysiology, which still requires a detailed investigation of biochemical signatures to identify the molecules and mechanisms that govern it.

AREAS COVERED

This narrative review summarizes the main molecular alterations found in the ovarian follicular fluid, endometrium and placenta of women with PCOS, and the genotypes potentially associated with the outcome of infertility treatments in PCOS.

EXPERT OPINION

PCOS is associated with multiple alterations in growth factors, sex steroid hormones, reactive oxygen species, proinflammatory cytokines and adipokines, which contribute to follicle arrest/ anovulation or suboptimal corpus luteum function, and ultimately to menstrual irregularity and hyperandrogenic symptoms. A panel of PCOS biomarkers should include, besides ovarian products, markers of adipose tissue function, insulin resistance, vascular health, and low-grade chronic inflammation. The effects of ovarian stimulation drugs on infertile women with PCOS are likely to be modified by genetic factors, but the available evidence is heterogeneous; therefore, future studies should evaluate standard treatments and pre-specified outcomes of interest to provide more conclusive answers.

Hirsutism, Normal Androgens and Diagnosis of PCOS

Hirsutism is defined as the presence of terminal hair with male pattern distribution in women. While in the general population, hirsutism affects around 4-11% of women, it is the main manifestation of hyperandrogenism in women with polycystic ovary syndrome (PCOS), with a prevalence estimated at 65-75%. Hirsutism in PCOS is associated with both androgen excess and individual response of the pilosebaceous unit to androgens. The modified Ferriman-Gallwey (mFG) scoring system has been widely used in clinical practice to visually score excessive terminal hair, thus standardizing hirsutism evaluation and facilitating data comparison. Although a universal mFG score cutoff would be useful for comparisons, ethnic variations, as well as skin type and other factors, should be considered when evaluating hirsutism in distinct populations. In turn, androgen levels, measured by conventional techniques, have been shown to correlate poorly with the severity of hirsutism. Indeed, while most women with PCOS and hirsutism also have higher than reference values for serum androgen levels, some of them may not present with biochemical hyperandrogenism, representing a challenge to the diagnosis of PCOS. In this article, we critically review this not uncommon condition in women with PCOS presenting with hirsutism but normal androgen levels.

Polycystic ovary syndrome: clinical and laboratory variables related to new phenotypes using machine-learning models

PURPOSE

Polycystic Ovary Syndrome (PCOS) is the most frequent endocrinopathy in women of reproductive age. Machine learning (ML) is the area of artificial intelligence with a focus on predictive computing algorithms. We aimed to define the most relevant clinical and laboratory variables related to PCOS diagnosis, and to stratify patients into different phenotypic groups (clusters) using ML algorithms.

METHODS

Variables from a database comparing 72 patients with PCOS and 73 healthy women were included. The BorutaShap method, followed by the Random Forest algorithm, was applied to prediction and clustering of PCOS.

RESULTS

Among the 58 variables investigated, the algorithm selected in decreasing order of importance: lipid accumulation product (LAP); abdominal circumference; thrombin activatable fibrinolysis inhibitor (TAFI) levels; body mass index (BMI); C-reactive protein (CRP), high-density lipoprotein cholesterol (HDL-c), follicle-stimulating hormone (FSH) and insulin levels; HOMA-IR value; age; prolactin, 17-OH progesterone and triglycerides levels; and family history of diabetes mellitus in first-degree relative as the variables associated to PCOS diagnosis. The combined use of these variables by the algorithm showed an accuracy of 86% and area under the ROC curve of 97%. Next, PCOS patients were gathered into two clusters in the first, the patients had higher BMI, abdominal circumference, LAP and HOMA-IR index, as well as CRP and insulin levels compared to the other cluster.

CONCLUSION

The developed algorithm could be applied to select more important clinical and biochemical variables related to PCOS and to classify into phenotypically different clusters. These results could guide more personalized and effective approaches to the treatment of PCOS.

Metabolic profile of women with PCOS in Brazil: a systematic review and meta-analysis

BACKGROUND

Polycystic ovary syndrome (PCOS) is a common endocrine disease affecting women of reproductive age and associated with reproductive and metabolic dysfunction. Few studies are available regarding metabolic traits in Brazilian women with PCOS. The aim of this systematic review and meta-analysis was to summarize the available evidence regarding metabolic traits and comorbidities in Brazilian women with polycystic ovary syndrome (PCOS).

METHODS

We systematically searched PubMed, Cochrane Central Register of Controlled Trials, and Embase for cross-sectional, case-control, or cohort studies focusing on populations of different regions from Brazil, published until July 31, 2019. Studies were selected if they reported PCOS diagnostic criteria. Studies without a control group were included if they presented relevant metabolic data.

RESULTS

Of 4856 studies initially identified, 27 were included in the systematic review and 12 were included in the meta-analysis, for a total of 995 women with PCOS defined by Rotterdam criteria and 2275 controls from different regions of Brazil. Obesity, metabolic syndrome and IGT were prevalent, and standard mean differences for BMI (SMD 0.67, 95% CI, 0.29, 1.05), waist circumference (SMD 0.22, 95% CI 0.02, 0.41), systolic (SMD 0.66, 95% CI 0.30, 1.01) and diastolic blood pressure (SMD 0.55, 95% CI 0.24, 0.87), glucose (SMD 0.21, 95% CI 0.04, 0.38) and HOMA (SMD 0.78, 95% CI 0.52, 1.04) were significantly higher in Brazilian women with PCOS compared to controls. Lipid profile was more adverse in PCOS vs. non-PCOS women. Between-study heterogeneities were low/moderate for glucose and HOMA and moderate/high for the other variables.

CONCLUSIONS

The data of this systematic review and meta-analysis indicate that Brazilian women with PCOS have a worse metabolic profile than women without PCOS with no important regional differences. The prevalence of metabolic changes is intermediate in Brazil vs. other countries.

Metabolic Features of Women With Polycystic Ovary Syndrome in Latin America: A Systematic Review

BACKGROUND

Polycystic ovary syndrome (PCOS) is an endocrine disorder that commonly affects women of childbearing age and has been associated with metabolic and reproductive abnormalities. Only a few studies have investigated metabolic traits in women with PCOS in Latin America. Therefore, we conducted a systematic review to provide an overview of the available evidence on the metabolic profile of Latin American women with PCOS.

METHODS

We searched PubMed, Cochrane Central Register of Controlled Trials, and Embase databases for cross-sectional, case-control, or cohort studies focusing on populations of countries in South and Central America and Mexico, published until October 31, 2019. We selected studies that reported the diagnostic criteria for PCOS. In the absence of a control group, we included studies if they reported relevant metabolic data.

RESULTS

The initial search yielded 4878 records, of which 41 studies were included in the systematic review. Sample sizes ranged from 10 to 288 in PCOS groups and from 10 to 1500 in control groups. The prevalence of phenotypes A and B (classic PCOS) ranged from 65.8% to 87.5% as reported in studies from Argentina, Brazil, and Chile. Metabolic syndrome ranged from 33.3% to 44.0% for phenotype A, from 15.0% to 58.0% for phenotype B, from 11.9% to 36.0% for phenotype C, and from 14.2% to 66.0% for phenotype D. Women with PCOS had higher body mass index, waist circumference, blood pressure, glucose, and homeostasis model assessment index as well as a more adverse lipid profile than those without PCOS.

CONCLUSIONS

Evidence from the present systematic review suggests that anthropometric and metabolic profiles are worse in women with PCOS who live in different Latin American countries than in women without PCOS living in the same region. Additional studies assessing metabolic comorbidities, such as diabetes, and distinct PCOS phenotypes in different Latin American countries are warranted and may produce invaluable information for primary and secondary prevention of PCOS in the region. This systematic review was registered with PROSPERO under number CRD42016038537.

SYSTEMATIC REVIEW REGISTRATION

PROSPERO, identifier CRD42016038537.

Haptoglobin: From hemoglobin scavenging to human health

Haptoglobin (Hp) belongs to the family of acute-phase plasma proteins and represents the most important plasma detoxifier of hemoglobin (Hb). The basic Hp molecule is a tetrameric protein built by two α/β dimers. Each Hp α/β dimer is encoded by a single gene and is synthesized as a single polypeptide. Following post-translational protease-dependent cleavage of the Hp polypeptide, the α and β chains are linked by disulfide bridge(s) to generate the mature Hp protein. As human Hp gene is characterized by two common Hp1 and Hp2 alleles, three major genotypes can result (i.e., Hp1-1, Hp2-1, and Hp2-2). Hp regulates Hb clearance from circulation by the macrophage-specific receptor CD163, thus preventing Hb-mediated severe consequences for health. Indeed, the antioxidant and Hb binding properties of Hp as well as its ability to stimulate cells of the monocyte/macrophage lineage and to modulate the helper T-cell type 1 and type 2 balance significantly associate with a variety of pathogenic disorders (e.g., infectious diseases, diabetes, cardiovascular diseases, and cancer). Alternative functions of the variants Hp1 and Hp2 have been reported, particularly in the susceptibility and protection against infectious (e.g., pulmonary tuberculosis, HIV, and malaria) and non-infectious (e.g., diabetes, cardiovascular diseases and obesity) diseases. Both high and low levels of Hp are indicative of clinical conditions: Hp plasma levels increase during infections, inflammation, and various malignant diseases, and decrease during malnutrition, hemolysis, hepatic disease, allergic reactions, and seizure disorders. Of note, the Hp:Hb complexes display heme-based reactivity; in fact, they bind several ferrous and ferric ligands, including O₂, CO, and NO, and display (pseudo-)enzymatic properties (e.g., NO and peroxynitrite detoxification). Here, genetic, biochemical, biomedical, and biotechnological aspects of Hp are reviewed.

Role of gut microbiota in the development of insulin resistance and the mechanism underlying polycystic ovary syndrome: a review

Polycystic ovary syndrome (PCOS) is a complex endocrine and metabolic disorder. Typically, it is characterized by hirsutism, hyperandrogenism, ovulatory dysfunction, menstrual disorders and infertility. To date, its pathogenesis remains unclear. However, insulin resistance (IR) is considered as the primary pathological basis for its reproductive dysfunction. On the other hand, a condition in which insulin is over-secreted is called hyperinsulinemia. IR/Hyperinsulinemia is associated with chronic inflammation, hormonal changes, follicular dysplasia, endometrial receptivity changes, and abortion or infertility. Additionally, it increases incidence of complications during pregnancy and has been associated with anxiety, depression, and other psychological disorders. Gut microbiota, the "second genome" acquired by the human body, can promote metabolism, immune response through interaction with the external environment. Gut microbiota dysbiosis can cause IR, which is closely linked to the occurrence of PCOS. This article reviewed recent findings on the roles of gut microbiota in the development of insulin resistance and the mechanism underlying polycystic ovary syndrome.

Haptoglobin phenotype influences the effectiveness of diet-induced weight loss in middle-age abdominally obese women with metabolic abnormalities

BACKGROUND & AIMS

Haptoglobin (Hp) is associated with risks of obesity and cardiometabolic dysfunction; however, the role of the Hp phenotype in diet-induced weight loss remains to be elucidated. This study investigated whether the Hp phenotype contributes to inter-individual variations in body weight reduction as well as changes in the metabolic profile.

METHODS

Secondary data analysis from a randomized controlled trial. In total, 151 abdominally obese Taiwanese women with ≥2 metabolic components were randomized to each of four dietary programs [calorie restriction (CR), calorie restriction plus fish oil supplementation (CRF), calorie restricted meal replacement (CRMR), and calorie restricted meal replacement with fish oil supplementation (CRMRF)] for 12 weeks. Abdominal obesity was defined as a waist circumference (WC) ≥ 80 cm in women. Hp phenotyping was performed by plasma gel electrophoresis.

RESULTS

The prevalence of the Hp 1-1, 2-1, and 2-2 phenotypes were 12.58%, 41.06% and 46.35%, respectively. The mean age was 50.59 ± 12.22 years, and mean reduction in the percent body weight was 4.7% ± 3.8%. The Hp 1-1 phenotype exhibited significant decreases in the WC, body fat mass, plasma insulin levels, free hemoglobin and homeostatic model assessment of insulin resistance (HOMA-IR) compared to the Hp 2-1 or Hp 2-2 phenotypes after adjusting for the baseline age, WC, metabolic syndrome (MetS), and dietary programs (all adjusted p < 0.05). A greater improvement in the prevalence of central obesity and, to a lesser extent, MetS was also found in women with the Hp 1-1 phenotype.

CONCLUSIONS

Obese women with the Hp 1-1 phenotype might obtain greater benefits in terms of reducing abdominal fat and improving insulin sensitivity in response to hypocaloric diet-induced weight reduction. The findings from this study support potential gene-diet interactions affecting weight loss. This trial was registered at ClinicalTrials.gov as NCT01768169.

CLINICAL TRIAL REGISTRY

This trial was registered at ClinicalTrials.gov as NCT01768169.

Proteomics of reproduction: Prospects and perspectives

In recent years, proteomics has been used widely in reproductive research in order to understand the molecular mechanisms related to gametes at the cellular level and the role of proteins involved in fertilization. Network and pathway analysis using bioinformatic tools have paved way to obtain a wider picture on the possible pathways associated with the key differentially expressed proteins (DEPs) and its implication in various infertility scenarios. A brief overview of advanced techniques and bioinformatic tools used for reproductive proteomics is presented. Key findings of proteomic-based studies on male and female reproduction are also presented. Furthermore, the chapter sheds light on the cellular pathways and potential biomarkers associated with male and female infertility. Proteomics coupled with bioinformatic analysis provides an ideal platform for non-invasive management of infertility in couples.

Polycystic Ovary Syndrome as a systemic disease with multiple molecular pathways: a narrative review

Polycystic Ovary Syndrome (PCOS) is characterized by hyperandrogenism, amenorrhea, and polycystic ovaries. This endocrinopathy is associated with many metabolic disorders such as dyslipidemia and insulin resistance, with increased risk of type 2 diabetes mellitus, metabolic syndrome, and cardiovascular complications. Inflammation is likely to play an important role in the promoting these metabolic imbalances, while prothrombotic and pro-oxidative mechanisms further contribute to the cardiovascular risk of these patients. The etiology of PCOS is still not fully understood, but there is evidence of genetic and environmental components. This review aims to discuss some molecular pathways associated with PCOS that could contribute to the better understanding about this syndrome. Recent evidence suggests that intrauterine exposure of female mice to an excess of anti-Müllerian hormone may induce PCOS features in their post-natal life. High cytokine levels and cytokine gene polymorphisms also appear to be associated with the pathophysiology of PCOS. Furthermore, high levels of microparticles may contribute to the altered hemostasis and enhanced inflammation in PCOS. All these mechanisms may be relevant to clarify some aspects of PCOS pathogenesis and inspire new strategies to prevent the syndrome as well as treat its symptoms and mitigate the risk of long-term complications.