The evaluation of endometrial sulfate glycosaminoglycans in women with polycystic ovary syndrome

Genome-wide association study (GWAS) identified PCOS susceptibility variants and replicates reported risk variants

BACKGROUND

Genetic predisposition and environmental factors are considered risk factors for polycystic ovary syndrome (PCOS). Genome-wide association studies (GWAS) have been reported from various subpopulations to evaluate SNPs associated with PCOS risk. No PCOS-associated GWAS study has been reported from India so far.

PURPOSE

The current study was conducted to identify the PCOS-susceptible loci among the North Indian population and to validate the significant loci reported by previous GWAS studies.

METHODS

A total of 272 participants with 134 PCOS patients and 138 age-matched healthy controls were recruited. Genomic DNA was isolated and genotyped by using Infinium Global Screening Array v3.0 microchip considering HWE 10e-5 statistically significant.

RESULTS

A total of fifteen markers have been identified as candidate PCOS risk factors. Only two SNPs, namely rs17186366 and rs11171739 have been identified through replication analysis while comparing the previously reported PCOS GWAS data. In-silico analysis was performed to study the functional impact of identified significant genes for gene ontology, pathways related to gene set, and cluster analysis to determine protein-protein interaction among genes or gene products.

CONCLUSION

The study suggests that multiple variants play an important role in PCOS pathogenesis and emphasizes the importance of further genetic studies among Indian subpopulations. The study also validates two previously reported SNPs in the Indian population. What this study adds to clinical work Study summarizes the importance of candidate gene markers validated by replication and in-silico functional study, significantly involved in PCOS pathogenesis in the studied population. These markers can be used in the future as diagnostic markers for clinical phenotype identification.

Sex-specific genetic architecture of late-life memory performance

BACKGROUND

Women demonstrate a memory advantage when cognitively healthy yet lose this advantage to men in Alzheimer's disease. However, the genetic underpinnings of this sex difference in memory performance remain unclear.

METHODS

We conducted the largest sex-aware genetic study on late-life memory to date (Nmales  = 11,942; Nfemales  = 15,641). Leveraging harmonized memory composite scores from four cohorts of cognitive aging and AD, we performed sex-stratified and sex-interaction genome-wide association studies in 24,216 non-Hispanic White and 3367 non-Hispanic Black participants.

RESULTS

We identified three sex-specific loci (rs67099044-CBLN2, rs719070-SCHIP1/IQCJ-SCHIP), including an X-chromosome locus (rs5935633-EGL6/TCEANC/OFD1), that associated with memory. Additionally, we identified heparan sulfate signaling as a sex-specific pathway and found sex-specific genetic correlations between memory and cardiovascular, immune, and education traits.

DISCUSSION

This study showed memory is highly and comparably heritable across sexes, as well as highlighted novel sex-specific genes, pathways, and genetic correlations that related to late-life memory.

HIGHLIGHTS

Demonstrated the heritable component of late-life memory is similar across sexes. Identified two genetic loci with a sex-interaction with baseline memory. Identified an X-chromosome locus associated with memory decline in females. Highlighted sex-specific candidate genes and pathways associated with memory. Revealed sex-specific shared genetic architecture between memory and complex traits.

Hormonal and Metabolic Factors Influence the Action of Progesterone on the Endometrium of Women with Polycystic Ovary Syndrome

Hormonal and metabolic factors may influence endometrial quality and interfere with the action of progesterone. Therefore, the aim of our study was to address this issue. Participants were recruited from an outpatient reproductive endocrinology clinic at an academic tertiary medical care centre. All subjects underwent endometrial biopsy (EB) in the follicular phase of the cycle prior to treatment. Thereafter, they were treated with micronized progesterone (400 mg/day × 10 days intravaginally) from days 14-28 of the next cycle. A second EB was performed between days 21-24 of the cycle (the second phase). The metabolic and hormonal serum levels were evaluated during the implantation window. EB samples were analysed using light microscopy for histomorphometric analysis. The endometrium of women with Polycystic Ovarian Syndrome (PCOS) in the second phase demonstrated a uniform surface epithelium with less leukocyte infiltration and an absence of apoptotic figures compared to the control group. (p < 0.021). The thickness of the surface epithelium in the second phase of the PCOS group correlated positively with free and bioavailable testosterone values. The number of stromal cells increases with increasing insulin levels. Our results suggest that histomorphometric abnormalities of the endometrium persist and are linked to androgen and insulin levels despite progesterone supplementation in PCOS.

Altered Molecular Pathways and Biomarkers of Endometrial Receptivity in Infertile Women with Polycystic Ovary Syndrome

Anovulation is the most prominent cause of infertility in polycystic ovary syndrome (PCOS) patients. Although ovulation can be corrected pharmacologically, the number of pregnancies remains low. Even if excellent embryos are transferred by IVF, it does not change the high miscarriage rate of PCOS patients. These facts collectively indicate that there is a disorder of endometrial development and receptivity to the embryo in PCOS patients, including the decrease of receptive ability, inhibition of embryo adhesion, undersupply of energy, poor blood perfusion, and pro-inflammatory status in the endometrium. However, it has never received the same attention as ovulatory dysfunction. Here we list some alternations of endometrial receptivity in women with PCOS, discuss the underlying intricate mechanisms, and try to find out the possible therapeutic targets, which may bring new perspectives to those who are able to provide high-quality embryos.

Surgical and nutritional interventions for endometrial receptivity: A case report and review of literature

BACKGROUND

Polycystic ovary syndrome (PCOS) is an endocrine disease that combines metabolic, reproductive, and psychological dysfunctions. Ovulation disorders and impaired endometrial receptivity in PCOS can cause infertility. Insulin resistance (IR) is a pathological state of inadequate response to insulin that affects reproduction in PCOS, as damage caused by IR at the endometrial level becomes an obstacle for embryo implantation. Reversing IR resulted in spontaneous pregnancies in PCOS patients, indicating that metabolic corrections improve endometrial dysfunctions. Mesenchymal stem-cell treatment has also corrected endometrial quality and lead to pregnancies in patients with Asherman’s syndrome. We propose a combination of nutritional intervention with the surgical placement of stem cells to improve endometrial quality to achieve pregnancy in a PCOS patient undergoing in vitro fertilization (IVF) treatment.

CASE SUMMARY

After two failed IVF cycles, a metabolic intervention, consisting of a ketogenic diet with daily consumption of 50 g of carbohydrates (CH), was indicated until pregnancy. Metabolic Syndrome was assessed using the Harmonizing Definition (3 of 5 pathologies: Central obesity, hypertension, hyperglycemia, hypertriglyceridemia, and dyslipidemia), and the Homeostatic Model Assessment of IR (HOMA-IR) was used to measure the level of IR. Once IR improved, endometrial quality improved. However, two day 5-thawed embryos (euploid, donated oocyte–partner's sperm) failed to implant, suggesting endometrial quality improvement was insufficient. Therefore, transmyometrial implantation of mesenchymal stem cells from the stromal vascular fraction of adipose tissue was performed to enrich the endometrial stem cell niche. Minimal endometrial mean thickness for embryo transfer (6.9 mm) was achieved three months after stem cell treatment and continuous dietary control of IR. Two euploid-day 5-thawed embryos (donated oocyte–partner's sperm) were transferred, and embryo implantation was confirmed on day 14 by β-hCG serum levels. Currently, a 37 wk baby girl is born.

CONCLUSION

In PCOS, endometrial quality can be improved by combining nutrient-based metabolic correction with endometrial stem cell niche enrichment.

Effects of clinical and metabolic variables and hormones on the expression of immune protein biomarkers in the endometrium of women with polycystic ovary syndrome and normal-cycling controls

BACKGROUND

Women with polycystic ovary syndrome (PCOS) are at an elevated risk of endometrial cancer, which may be associated with the continuous proliferative state caused by the interaction between hormones and metabolic factors.

OBJECTIVE

To investigate the impact of hormones and metabolic factors in the proliferation and death of endometrium during the proliferative phase.

METHODS

Cross-sectional study with 11 women with PCOS and eight normal-cycling non-PCOS controls at the Federal University of the State of Rio de Janeiro from February 2011 to June 2019. Clinical, biochemical, and hormonal data were collected to analyze their influence on the expression of biomarkers related to the endometrial tissue breakdown. Hysteroscopy and endometrial biopsies were conducted, and the endometrial samples underwent immunohistochemistry for markers of apoptosis B-cell lymphoma 2 (BCL2), cleaved caspase-3 (CASP3), fas cell surface death receptor (FAS), FAS ligand (FASLG), BCL2 associated X (BAX), marker of proliferation Ki-67 (MKI67), and cell death using terminal deoxynucleotidyl transferase dUTP nick and labeling (TUNEL).

RESULTS

CASP3 and TUNEL expressions were lower in both stroma and endometrium gland of PCOS women than in controls. MKI67 and homeostasis indexes (BCL2/BAX; FASLG/FAS) in the endometrium of the PCOS group were significantly higher. Body mass index (BMI) values were positively correlated with the expression of MKI67 and MKI67/TUNEL ratio in the endometrial stroma compartment. Fasting insulin levels were positively correlated with the expression of BCL2, and DHEA-S levels were negatively correlated with the expression of CASP3 of women with PCOS.

CONCLUSION

BMI, insulin, and DHEA-S influence the endometrial homeostasis breakdown in PCOS in the endometrium stroma.

The Disorders of Endometrial Receptivity in PCOS and Its Mechanisms

Polycystic ovary syndrome (PCOS) is a mysterious and complicated endocrine disease with the combination of metabolic, reproductive, psychological dysfunctions. Impaired endometrial receptivity and ovulation disorders/anovulation are both important causes of PCOS-related infertility. However, change in endometrium has never received the same attention as ovulatory dysfunction. Besides, putting emphasis on endometrial function may be more realistic for PCOS-related infertility, given the wide use of assisted reproductive technology. The present review focuses on the disorders of endometrial receptivity of patients with PCOS, summarizes the changes of the indicators of endometrial receptivity including leukemia inhibitory factor, homeobox genes A, pinopodes, αvβ3-integrin, and intercellular junctions and also analyzes the possible mechanisms of decreased endometrial receptivity and its relationship with the main endocrine and metabolic disorders of PCOS such as hyperandrogenism, inflammation, insulin resistance, and obesity. Despite several biomarkers have been found to be associated with decreased endometrial receptivity in PCOS, the clinical relevance of these findings still awaits future clarification.

The Complicated Effects of Extracellular Vesicles and Their Cargos on Embryo Implantation

As a rate-limiting step in pregnancy, embryo implantation is highly dependent on intercellular communication. Extracellular vesicles (EVs) are newly identified to be important in the course of intercellular communication. EVs have been isolated from a wide variety of biofluids and tissues, including plasma, liver, uterine, semen, embryo, etc. The present and future use of EVs not only as biomarkers, but also as targeting drug delivery system, is promisingly pave the way for advanced comprehension of implantation failure in reproductive diseases. However, as the precise mechanisms of EVs in embryo implantation has not been elucidated yet. Herein, we summarize the current knowledge on the diverse effects of EVs from various sources and their cargos such as microRNA, long non-coding RNA, protein, etc. on embryo implantation, and the potential mechanisms of EVs in reproductive diseases such as recurrent implantation failure, polycystic ovary syndrome and endometriosis. It is essential to note that many of the biologically plausible functions of EVs in embryo implantation discussed in present literatures still need further research in vivo.

Polycystic Ovary Syndrome and the Forgotten Uterus

Polycystic ovary syndrome (PCOS) is a common disorder that affects various facets of fertility. Although the ovarian and metabolic aspects of the disease is well studied, its role in uterine dysfunction is not well understood. Our objective was to review the features of endometrial and uterine aberrations in women with PCOS. A systematic literature search was performed in PubMed, Medline, and the Cochrane Library databases for papers published in English up to March 2020. The following key words were used for the search: polycystic ovary syndrome, poly cystic ovarian disease, polycystic ovaries, PCOS, PCOD, PCO, PCOM, oligoovulation, anovulation, oligomenorrhea, amenorrhea, hyperandrogenism and this was combined with terms; endometrium, infertility, uterus, progesterone resistance, endometrial hyperplasia, pregnancy outcomes, preterm delivery. In this review, we highlight various uterine pathologies that are associated with PCOS and explore its impact on fertility. We also discuss key uterine molecular pathways that are altered in PCOS that may be related to infertility, endometrial hyperplasia and cancer.

ITLNI identified by comprehensive bioinformatic analysis as a hub candidate biological target in human epithelial ovarian cancer

Background

Epithelial ovarian cancer (EOC) is a female malignant tumor. Bioinformatics has been widely utilized to analyze genes related to cancer progression. Targeted therapy for specific biological factors has become more valuable.

Materials and methods

Gene expression profiles of GSE18520 and GSE27651 were downloaded from Gene Expression Omnibus. We used the “limma” package to screen differentially expressed genes (DEGs) between EOC and normal ovarian tissue samples and then used Clusterprofiler to do functional and pathway enrichment analyses. We utilized Search Tool for the Retrieval of Interacting Genes Database to assess protein–protein interaction (PPI) information and the plug-in Molecular Complex Detection to screen hub modules of PPI network in Cytoscape, and then performed functional analysis on the genes in the hub module. Next, we utilized the Weighted Gene Expression Network Analysis package to establish a co-expression network. Validation of the key genes in databases and Gene Expression Profiling Interactive Analysis (GEPIA) were completed. Finally, we used quantitative real-time PCR to validate hub gene expression in clinical tissue samples.

Results

We analyzed the DEGs (96 samples of EOC tissue and 16 samples of normal ovarian tissue) for functional analysis, which showed that upregulated DEGs were strikingly enriched in phosphate ion binding and the downregulated DEGs were significantly enriched in glycosaminoglycan binding. In the PPI network, CDK1 was screened as the most relevant protein. In the co-expression network, one EOC-related module was identified. For survival analysis, database and clinical sample validation of genes in the turquoise module, we found that ITLN1 was positively correlated with EOC prognosis and had lower level in EOC than in normal tissues, which was consistent with the results predicted in GEPIA.

Conclusion

In this study, we exhibited the key genes and pathways involved in EOC and speculated that ITLN1 was a tumor suppressor which could be used as a potential biomarker for treating EOC, Gene Expression Omnibus, prognosis.

Small leucine-rich proteoglycans (SLRPs) in the endometrium of polycystic ovary syndrome women: a pilot study

Background

Small leucine-rich proteoglycans (SLRPs) play an important role in tissue homeostasis and cell proliferation since these proteoglycans sequester multiple growth factors. However, the content of SLRPs in the endometrium of polycystic ovary syndrome (PCOS) women is unknown. Our purpose was to test the hypothesis that excessive endometrial proliferation in PCOS may be partly related to abnormalities in SLRPs.

Methods

In a cross section study a total of 20 endometrial samples were collected from 10 patients with PCOS and 10 ovulatory women during their proliferative (pre-ovulatory) phase. The study subjects were matched for age, body mass index and race. The age range was 20 to 35 years. All volunteers were evaluated in reproductive endocrinology clinic, Gynecology Division, Clinics Hospital, University of São Paulo Medical School Profile and concentration of small leucine-rich proteoglycans (decorin, lumican, fibromodulin and biglycan) were determined by immunohistochemical testing and Western blotting.

Results

Decorin and lumican demonstrated higher immunoreactivity and relative expression in the endometrium of women with PCOS compared to that of women with regular menstrual cycles.

Conclusion

Our data suggests that the endometrium of PCOS women demonstrate a greater content of SLRP than controls; decorin and lumican, in particular, were found in higher concentrations in the endometrium of PCOS women during the proliferative phase. These differences may, in part, explain the excess of endometrial proliferation frequently observed in PCOS. Further studies are warranted.

Concentration of glycosaminoglycan in ovariectomized mice uterus after treatment with ovarian steroids

The aim of this study was to evaluate the amount of non- and sulfated glycosaminoglycans in the ovariectomized mice uterus, after treatment with ovarian steroids. For this purpose, 50 adult female mice were divided into five groups with 10 animals/each: control group: CG (ovary intact), and ovariectomized groups: OG (vehicle), EG (estradiol), PG (progesterone) and EPG (estradiol combined to progesterone). The treatments started 30 days after ovariectomy. All the animals were treated for 50 consecutive days. These hormones were administered in a sterile oily solution via gavage. Twenty-four hours after the last treatment, all animals were euthanized, removing the uterine horn for biochemical analyses. To quantify, the hyaluronic acid (HA) used ELISA-like fluorometric assay, and the sulfated glycosaminoglycans (GAGs) used agarose gel electrophoresis. The amount of HA was significantly higher in the group treated with progesterone (PG) compared to the others groups (p < 0.05), and in the group treated with estradiol (EG), the amount of chondroitin/dermatan sulfate was significantly higher compared to the others groups (p < 0.05), and in the group treated with progesterone (PG), the amount of heparan sulfate was significantly lower compared to the others groups, except to control group (p < 0.05). Our results showed that the estroprogestative therapy after long time (50 days) profoundly affected the amount of glycosaminoglycans in uterine. These changes may be indicative of uterine pathology such as the development of tumor.

Expression and function of transient receptor potential channels in the female bovine reproductive tract

The epithelium lining the oviduct is critical for early reproductive events, many of which are mediated via intracellular calcium ions. Despite this, little is known about the regulation of calcium homeostasis in the oviductal epithelium. Epithelial transient receptor potential channels (TRPCs) modulate calcium flux in other tissues, and their expression and functional regulation have therefore been examined using the bovine oviduct as a model for the human. The effects of FSH, LH, 17β-estradiol, and progesterone on TRPCs expression and intracellular calcium flux were determined. Transient receptor potential channels 1, 2, 3, 4, and 6 were expressed in the bovine reproductive tract, and their gene expression varied throughout the estrous cycle. In more detailed studies undertaken on TRPC1 and 6, we show that protein expression varied through the estrus cycle; specifically, 17β-estradiol, FSH, and LH individually and in combination upregulated TRPC1 and 6 expression in cultured bovine oviduct epithelial cells although progesterone antagonized these effects. Functional studies showed changes in calcium mobilization in bovine oviduct epithelial cells were dependent on TRPCs. In conclusion, TRPC1, 2, 3, 4, and 6 are present in the epithelium lining the bovine oviduct, and TRPC1 and 6 vary through the estrous cycle suggesting an important role in early reproductive function.