Laparoscopic Ovarian Drilling Improves Endometrial Homeobox Gene Expression in PCOS

Hyperandrogenism and Its Possible Effects on Endometrial Receptivity: A Review

Endometrial receptivity is a state of the endometrium defined by its readiness for embryo implantation. When the receptivity of the endometrium is impaired due to hyperandrogenism or androgen excess, this condition can lead to pregnancy loss or infertility. Hyperandrogenism encompasses a wide range of clinical manifestations, including polycystic ovary syndrome (PCOS), idiopathic hirsutism, hirsutism and hyperandrogaenemia, non-classical congenital adrenal hyperplasia, hyperandrogenism, insulin resistance, acanthosis nigricans (HAIR-AN), ovarian or adrenal androgen-secreting neoplasms, Cushing's syndrome, and hyperprolactinaemia. Recurrent miscarriages have been shown to be closely related to elevated testosterone levels, which alter the endometrial milieu so that it is less favourable for embryo implantation. There are mechanisms for endometrial receptivity that are affected by excess androgen. The HOXA gene, aVβ3 integrin, CDK signalling pathway, MECA-79, and MAGEA-11 were the genes and proteins affect endometrial receptivity in the presence of a hyperandrogenic state. In this review, we would like to explore the other manifestations of androgen excess focusing on causes other than PCOS and learn possible mechanisms of endometrial receptivity behind androgen excess leading to pregnancy loss or infertility.

The Effect of Metformin and Carbohydrate-Controlled Diet on DNA Methylation and Gene Expression in the Endometrium of Women with Polycystic Ovary Syndrome

Polycystic ovary syndrome (PCOS) is an endocrine disease associated with infertility and metabolic disorders in reproductive-aged women. In this study, we evaluated the expression of eight genes related to endometrial function and their DNA methylation levels in the endometrium of PCOS patients and women without the disease (control group). In addition, eight of the PCOS patients underwent intervention with metformin (1500 mg/day) and a carbohydrate-controlled diet (type and quantity) for three months. Clinical and metabolic parameters were determined, and RT-qPCR and MeDIP-qPCR were used to evaluate gene expression and DNA methylation levels, respectively. Decreased expression levels of HOXA10, GAB1, and SLC2A4 genes and increased DNA methylation levels of the HOXA10 promoter were found in the endometrium of PCOS patients compared to controls. After metformin and nutritional intervention, some metabolic and clinical variables improved in PCOS patients. This intervention was associated with increased expression of HOXA10, ESR1, GAB1, and SLC2A4 genes and reduced DNA methylation levels of the HOXA10 promoter in the endometrium of PCOS women. Our preliminary findings suggest that metformin and a carbohydrate-controlled diet improve endometrial function in PCOS patients, partly by modulating DNA methylation of the HOXA10 gene promoter and the expression of genes implicated in endometrial receptivity and insulin signaling.

Surgical removal of FIGO type 0 and 1 fibroids ameliorates the expression of endometrial proinflammatory transcription factors and receptivity modulators

OBJECTIVE

To reveal whether hysteroscopic removal of the International Federation of Gynecology and Obstetrics (FIGO) types 0 and 1 fibroids makes any changes in the expression of homeobox genes (HOXA10, HOXA11), leukemia inhibitory factor, and nuclear factor-kappa B (NF-kB).

DESIGN

A case-control study.

SETTING

University-based in vitro fertilisation center.

PATIENT(S)

This study consisted of a total of 29 participants, 21 with FIGO types 0 and 1 fibroids and 8 with normal uterine cavity without fibroids.

INTERVENTION(S)

Patients in FIGO types 0 and 1 fibroids group underwent hysteroscopic myomectomy. The patients in the control group underwent laparoscopic tubal ligation. Endometrial cells were collected by flushing method from all participants before and 3 months after myomectomy. Real-time polymerase chain reaction was used to detect HOXA10, HOXA11, and LIF mRNA expressions in endometrial flushing samples. The relative expressions of homeobox and LIF mRNA were calculated with comparative ΔCt method. Endometrial NF-kB concentration was measured quantitatively by enzyme-linked immunosorbent assay.

MAIN OUTCOME MEASURE(S)

To compare endometrial HOXA10, HOXA11, and LIF mRNA expressions as well as endometrial NF-kB concentration before and after myomectomy.

RESULT(S)

Premyomectomy NF-kB levels of type 0 (4.22 ± 1.02 ng/mL) and type 1 fibroid (6.44 ± 2.30 ng/mL) were significantly higher than the values of control group (0.54 ± 0.10 ng/mL). Surgical removal of type 0 and 1 fibroids resulted in a significant decrease in endometrial NF-kB levels (1.33 ± 0.02 ng/mL vs 1.65 ± 0.27 ng/mL, respectively). In type 0 fibroid group, after myomectomy, there was a 11.1-fold increase in HOXA10 mRNA, 4.23-fold in HOXA11 mRNA, and 7.63-fold in LIF mRNA. In the type 1 fibroid group, after myomectomy, there was a 16.3-fold increase in HOXA10 mRNA, 8.34-fold in HOXA11 mRNA, and 9.38-fold in LIF mRNA. A nonsignificant change was detected in homeobox and LIF mRNA after tubal sterilization. A negative and significant correlation was found between endometrial NF-kB and HOXA10 (r=-0.67), HOXA11 (r=-0.71) and LIF (r=-0.54).

CONCLUSION(S)

High proinflammatory NF-kB concentration and low homeobox and LIF mRNA expressions were detected in the presence of type 0 or 1 fibroids that returned to normal values after hysteroscopic myomectomy.

Endometrial Injury Upregulates Expression of Receptivity Genes in Women with Implantation Failure

BACKGROUND

Homeobox genes A10 (HOXA10) and A11 (HOXA11), members of the abdominal B gene family, are responsible for embryonic survival and implantation. This study was planned to investigate whether endometrial injury alters the expression of both transcripts in women with implantation failure.

METHODS

A total of 54 women with implantation failure were divided into two equal groups as experimental (scratching) and sham (no scratching). Participants in the scratching group were exposed to endometrial injury in the mid-luteal phase, and those in the sham group were exposed to endometrial flushing. The scratching group, but not the sham group, underwent prior endometrial sampling. A second endometrial sampling was performed on the scratching group in the mid-luteal phase of the following cycle. The mRNA and protein levels of the HOXA10 and 11 transcripts were determined in endometrial samples collected before and after injury/flushing. Participants in each group underwent IVF/ET in the cycle after the second endometrial sampling.

RESULTS

Endometrial injury caused a 60.1-fold (p < 0.01) increase in HOXA10 mRNA and a 9.0-fold increase in HOXA11 mRNA (p < 0.02). Injury resulted in a significant increase in both HOXA10 (p < 0.001) and HOXA11 protein expression (p < 0.003). There was no significant change in HOXA10 and 11 mRNA expressions after flushing. Clinical pregnancy, live birth, and miscarriage rates of the both groups were similar.

CONCLUSIONS

Endometrial injury increases homeobox transcript expression at both mRNA and protein levels.

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.

Ovarian drilling down-regulates endometrial nuclear factor-κB p65 expression in women with PCOS: A prospective case-control study

Objective:

To investigate the impact of laparoscopic ovarian drilling (LOD) on the expression of endometrial NFκB p65 (Rel A) in women with clomiphene-resistant polycystic ovary syndrome (PCOS).

Materials and Methods:

The study group comprised 25 normal-weight women with PCOS undergoing LOD and 14 control women without PCOS. Endometrial NF-κB p65 levels evaluated before and after LOD following immunohistochemical staining. The semiquantitative method was used to evaluate the intensity of NF-κB p65 levels. NF-κB p65 was found to higher in the endometrium of patients with PCOS compared to controls. LOD leads to significant down-regulation in endometrial NF-κB p65 expression. NF-κB p65 expression of PCOS and fertile control were similar after LOD. After LOD, H-score values decreased approximately 3-fold. The H-score of the control subjects was lower than the preoperative and postoperative H-score values of the control women with ovarian cyst.

Results:

Expression of endometrial NF-κB p65 did not change following ovarian cystectomy. The laterality of the ovarian cyst did not cause any change in preoperative H-score values.

Conclusion:

By downregulating the endometrial NF-κB p65 expression LOD improved physiological inflammation in women with PCOS.

Research progress of endometrial receptivity in patients with polycystic ovary syndrome: a systematic review

Polycystic ovary syndrome (PCOS) is a neuroendocrine heterogeneous disease that frequently occurs in women of reproductive age, causing serious damage to the fertility, quality of life, and physical and mental health of patients. The current studies have proved that satisfactory endometrial receptivity is one of the conditions that must be met during the process of spermatovum position, adhesion and invasion, as well as the subsequent blastocyst division and embryo development. Women with PCOS may suffer a series of pathological processes such as changes in the expression levels of hormones and related receptors, imbalances in the proportion of miscellaneous cytokines, insulin resistance, low-grade chronic inflammation and endometrial morphological changes, which will damage endometrial receptivity from various aspects and obstruct fertilized egg nidation and embryonic development, thus causing adverse reproductive health events including infertility and abortion. This article reviews the research progress about characteristics and related influencing factors of endometrial receptivity in PCOS patients.

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.

Inflammation and reproductive function in women with polycystic ovary syndrome†

Polycystic ovary syndrome (PCOS) is one of the most frequent endocrinopathies, affecting 5-10% of women of reproductive age, and is characterized by the presence of ovarian cysts, oligo, or anovulation, and clinical or biochemical hyperandrogenism. Metabolic abnormalities such as hyperinsulinemia, insulin resistance, cardiovascular complications, dyslipidemia, and obesity are frequently present in PCOS women. Several key pathogenic pathways overlap between these metabolic abnormalities, notably chronic inflammation. The observation that this mechanism was shared led to the hypothesis that a chronic inflammatory state could contribute to the pathogenesis of PCOS. Moreover, while physiological inflammation is an essential feature of reproductive events such as ovulation, menstruation, implantation, and labor at term, the establishment of chronic inflammation may be a pivotal feature of the observed reproductive dysfunctions in PCOS women. Taken together, the present work aims to review the available evidence about inflammatory mediators and related mechanisms in women with PCOS, with an emphasis on reproductive function.

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.