Sex Steroid Receptors in Polycystic Ovary Syndrome and Endometriosis: Insights from Laboratory Studies to Clinical Trials

Implantation and Decidualization in PCOS: Unraveling the Complexities of Pregnancy

Polycystic Ovary Syndrome (PCOS) is a prevalent endocrine disorder in women of reproductive age, affecting 5-15% globally with a large proportion undiagnosed. This review explores the multifaceted nature of PCOS and its impact on pregnancy, including challenges in fertility due to hormonal imbalances and insulin resistance. Despite restoring ovulation pharmacologically, women with PCOS face lower pregnancy rates and higher risks of implantation failure and miscarriage. Our review focuses on the complexities of hormonal and metabolic imbalances that impair endometrial receptivity and decidualization in PCOS. Disrupted estrogen signaling, reduced integrity of endometrial epithelial tight junctions, and insulin resistance impair the window of endometrial receptivity. Furthermore, progesterone resistance adversely affects decidualization. Our review also examines the roles of various immune cells and inflammatory processes in the endometrium, contributing to the condition's reproductive challenges. Lastly, we discuss the use of rodent models in understanding PCOS, particularly those induced by hormonal interventions, offering insights into the syndrome's impact on pregnancy and potential treatments. This comprehensive review underscores the need for advanced understanding and treatment strategies to address the reproductive complications associated with PCOS, emphasizing its intricate interplay of hormonal, metabolic, and immune factors.

Androgen excess: a hallmark of polycystic ovary syndrome

Polycystic ovarian syndrome (PCOS) is a metabolic, reproductive, and psychological disorder affecting 6-20% of reproductive women worldwide. However, there is still no cure for PCOS, and current treatments primarily alleviate its symptoms due to a poor understanding of its etiology. Compelling evidence suggests that hyperandrogenism is not just a primary feature of PCOS. Instead, it may be a causative factor for this condition. Thus, figuring out the mechanisms of androgen synthesis, conversion, and metabolism is relatively important. Traditionally, studies of androgen excess have largely focused on classical androgen, but in recent years, adrenal-derived 11-oxygenated androgen has also garnered interest. Herein, this Review aims to investigate the origins of androgen excess, androgen synthesis, how androgen receptor (AR) signaling mediates adverse PCOS traits, and the role of 11-oxygenated androgen in the pathophysiology of PCOS. In addition, it provides therapeutic strategies targeting hyperandrogenism in PCOS.

The effect of calorie-restriction along with thylakoid membranes of spinach on the gut-brain Axis Pathway and oxidative stress biomarkers in obese women with polycystic ovary syndrome: a Randomized, Double-blind, placebo-controlled clinical trial

BACKGROUND

Women with polycystic ovary syndrome (PCOS) have higher intestinal mucosal permeability, leading to the lipopolysaccharide (LPS) leakage and endotoxemia. This, in turn, leads to oxidative stress (OS) and neuro-inflammation caused by the gut-brain axis, affecting the neurotrophic factors levels such as brain-derived neurotrophic factor (BDNF) and S100 calcium-binding protein B (S100 B) levels. In this study, it was hypothesized that the thylakoid membranes of spinach supplementation along with a hypocaloric diet may have improved the LPS levels, neurotrophic factors, and OS in PCOS patients.

METHODS

In this double-blind, randomized, placebo-controlled, and clinical trial, 48 women with obesity and diagnosed with PCOS based on Rotterdam criteria were randomly assigned to thylakoid (N = 21) and placebo groups (N = 23). A personalized hypocaloric diet with 500 calories less than the total energy expenditure was prescribed to all patients. The participants were daily supplemented with either a 5 g/day thylakoid-rich spinach extract or a placebo (5 g cornstarch) for 12 weeks along with a prescribed low-calorie diet. Anthropometric measurements and biochemical parameters were assessed at baseline and after the 12-week intervention.

RESULTS

A statistically significant decrease in the LPS levels (P < 0.001) and an increase in the BDNF levels (P < 0.001) were recorded for the participants receiving the oral thylakoid supplements and a low-calorie diet. Furthermore, significant decreases were observed in fasting blood glucose, insulin, homeostatic model of assessment for insulin resistance, free testosterone index, and follicle-stimulating hormone / luteinizing hormone ratio in both groups (P < 0.05). No significant differences were detected between the two groups regarding the changes in malondialdehyde, catalase, total antioxidant capacity, and S100B levels (P > 0.05).

CONCLUSIONS

In sum, the thylakoid membranes of spinach supplemented with a hypocaloric diet reduced the LPS levels, increased the BDNF levels, and improved the glycemic profile and sex-hormone levels; however, they had no effects on the OS markers levels after 12 weeks of intervention.

An interplay of Progesterone, Leukemia Inhibitor Factor and Interleukin-6 in the window of implantation; Impact on fertility

BACKGROUND

The process of implantation is crucial for the initiation of conception and hence fertility. In addition to a number of factors, it is regulated by a cross talk of gonadotrophins [Luteinizing Hormone (LH), Follicle Stimulatory Hormone (FSH)], ovarian steroids [Estrogen (Et), Progesterone (Pt)] and cytokines [Leukemia inhibitory factor (LIF) and Interleukin 6 (IL6)]. These biomarkers are chief players of implantation.

OBJECTIVE

We aimed to explore the role of gonadotrophins (LH, FSH, LH/FSH ratio), ovarian steroids (Et, Pt) and cytokines (LIF, IL6) in the implantation process. This aim was achieved by comparing these hormones and cytokines in the fertile and infertile groups [Polycystic ovaries (PCOs), endometriosis, unexplained infertility (Uex-IF)] and finding their association in all study groups.

METHODS

A case control study conducted from October 2020-March 2023. A total of 135 infertile women (with PCOs, Uex-IF, and endometriosis) and 177 fertile women (matched for age and BMI) were selected. Levels of 'Et', 'Pt', 'LIF' and, 'IL6' were estimated using Enzyme Linked Immunosorbent Assay (ELISA). LH and FSH values were obtained from hospital desk records. The Independent Student'st-test was used to compare fertile and infertile groups. One-way ANOVA test was used to compare more than two groups, and Pearson's chi-square (χ2) test was employed to compare percentages of variables. Pearson correlation analysis was performed to assess the associations and correlations. A p value < 0.05 was considered statistically significant.

RESULTS

Significantly higher levels of LIF and IL6 were observed in fertile women compared to infertile women. Pt levels were significantly greater in the fertile group than in the infertile group. The FSH/LH ratio was significantly higher in the fertile group. Among infertile women, PCOs (71%) and Uex-IF (91%) exhibited lower Pt levels than the fertile controls (p < 0.01), but these levels remained within the reference range (RR). Among the fertile group (81%), levels of LIF within the RR were significantly higher compared to those with Uex-IF (49%) and females with endometriosis (37%). Moreover, the highest number of participants (57%) with Uex-IF exhibited IL6 levels significantly below the RR in comparison to the fertile group and infertile groups (PCOS and endometriosis). However, lower levels of IL6 were observed in women with Uex-IF. In the control group, LIF exhibited a significant positive correlation with IL6 (r = 0.370), Pt (r = 0.496), Et (r = 0.403), and LH (r = 0.428). Among women with PCOs, LIF showed a significant positive correlation with IL6 (r = 0.443), Pt (r = 0.607), and LH (r = 0.472). In cases of Uex-IF, LIF demonstrated a significant positive correlation with IL6 (r = 0.727). Females with endometriosis displayed a significant positive correlation between LIF and IL6 (r = 0.535) as well as Pt (r = 0.605). In fertile women, a positive correlation was observed between LH and IL6 (r = 0.197, p = 0.009), LIF (r = 0.428, p = 0.000), Pt (r = 0.238, p = 0.001), and Et (r = 0.356, p = 0.000). Furthermore, a positive correlation was found between LH and LIF (r = 0.472, p = 0.000) in women with PCOs.

CONCLUSION

Elevated levels of Pt were found to increase the production of LIF in fertile females. However, infertile females with PCOs and Uex-IF exhibited deficient levels of Pt, supporting its role as a biomarker for successful implantation in infertile women. These females showed decreased levels of gonadotropins as well as reduced LH/FSH ratio and diminished secretion of receptivity marker LIF, in addition to reduced Pt secretion. This suggests that reduced gonadotropin levels contribute to a lower LH/FSH ratio, resulting in decreased Pt secretion and ultimately leading to low levels of LIF, thereby causing impaired implantation in women with PCOs and Uex-IF. The exploration of low levels of LIF in patients with endometriosis requires further investigation. The significantly low levels of IL6 in the Uex-IF group elucidate the role of this cytokine in association with decreased Pt and LIF synthesis within this group.

Molecular Research on Polycystic Ovary Syndrome (PCOS)

Polycystic ovary syndrome (PCOS) is an endocrine systemic disorder with a prevalence of between 5% and 20% that commonly affects childbearing-aged women [...].

Clinical significance of serum Th1/Th2 cytokines in patients with endometriosis

Endometriosis (EMS) is a challenging gynecological disorder prevalent in reproductive-aged women, and Th1/Th2 cytokines are implicated in EMS progression. This study probed the serum levels and clinical values of Th1/Th2 cytokines in EMS patients. Firstly, the clinic characteristics of EMS and control patients were recorded. The levels of interferon (IFN)-γ, interleukin (IL)-2, IL-4, and IL-10 in the serum of EMS and control patients were identified, respectively. The correlations between Th1 and Th2 cytokines and the diagnostic values of these cytokines in EMS were analyzed. We observed that EMS patients had obvious differences from the controls in dysmenorrhea, dyspareunia, pelvic pain, nulliparous, and CA125 levels. Serum IFN-γ and IL-2 were lower while IL-4 and IL-10 were higher in EMS patients. Serum IFN-γ, IL-4 were negatively correlated with serum IL-2, and IL-10 in EMS patients. Th1/Th2 cytokines may help the diagnosis of EMS. Serum IFN-γ and IL-2 were independent protective factors for EMS while dysmenorrhea, dyspareunia, nulliparous, and serum IL-4 and IL-10 were independent risk factors for EMS. Collectively, serum Th1/Th2 cytokine levels helped the diagnosis of EMS, with IFN-γ and IL-2 serving as independent protective factors whilst IL-4 and IL-10 serving as independent risk factors.

Kelulut Honey Regulates Sex Steroid Receptors in a Polycystic Ovary Syndrome Rat Model

Reproductive and metabolic anomalies in polycystic ovary syndrome (PCOS) have been associated with the dysregulation of sex steroid receptors. Kelulut honey (KH) has been shown to be beneficial in PCOS-induced rats by regulating folliculogenesis and the oestrus cycle. However, no study has been conducted to evaluate KH's effect on sex steroid receptors in PCOS. Therefore, the current study examined the effects of KH, metformin, or clomiphene alone and in combination on the mRNA expression and protein distribution of androgen receptor (AR), oestrogen receptor α (ERα), oestrogen receptor β (ERβ), and progesterone receptor (PR) in PCOS-induced rats. The study used female Sprague-Dawley rats, which were treated orally with 1 mg/kg/day of letrozole for 21 days to develop PCOS. PCOS-induced rats were then divided and treated orally for 35 days with KH, metformin, clomiphene, KH + metformin, KH+ clomiphene and distilled water. In this study, we observed aberrant AR, ERα, ERβ and PR expression in PCOS-induced rats compared with the normal control rats. The effects of KH treatment were comparable with clomiphene and metformin in normalizing the expression of AR, ERα, and ERβ mRNA. However, KH, clomiphene and metformin did not affect PR mRNA expression and protein distribution. Hence, this study confirms the aberrant expression of sex steroid receptors in PCOS and demonstrates that KH treatment could normalise the sex steroid receptors profile. The findings provide a basis for future clinical trials to utilize KH as a regulator of sex steroid receptors in patients with PCOS.

Kelulut Honey Ameliorates Oestrus Cycle, Hormonal Profiles, and Oxidative Stress in Letrozole-Induced Polycystic Ovary Syndrome Rats

Kelulut honey (KH) has been proven to have excellent antioxidative and anti-inflammatory properties with unique physicochemical characteristics. Therefore, we investigated the isolated and combined effects of KH, metformin, or clomiphene in alleviating oxidative stress and reproductive and metabolic abnormalities in polycystic ovary syndrome (PCOS). Female Sprague-Dawley (SD) rats were given 1 mg/kg/day of letrozole for 21 days to induce PCOS. PCOS rats were then divided into six treatment groups: untreated, metformin (500 mg/kg/day), clomiphene (2 mg/kg/day), KH (1 g/kg/day), combined KH (1 g/kg/day) and metformin (500 mg/kg/day), and combined KH (1 g/kg/day) and clomiphene (2 mg/kg/day). All treatments were administered orally for 35 days. The physicochemical characteristics of KH were assessed through hydroxymethylfurfural, free acidity, diastase number, moisture content, sugar profile, metals, and mineral compounds. Additionally, we determined the semivolatile organic compounds present in KH through gas chromatography-mass spectrometry (GC/MS) analysis. KH and its combination with metformin or clomiphene were shown to improve the oestrus cycle, hormonal profile, and oxidative stress in PCOS rats. However, KH did not reduce the fasting blood glucose, insulin, and body weight gain in PCOS rats. These findings may provide a basis for future studies to discover the potential use of KH as a complementary treatment for women with PCOS.