Polycystic Ovary Syndrome and Oxidative Stress-From Bench to Bedside

Protective effect of afamin protein against oxidative stress related injury in human ovarian granulosa cells

BACKGROUND

Ovarian granulosa cells (GCs) play crucial roles in follicular growth and development. Their normal function is influenced by various factors, including oxidative stress, which is a significant factor. Afamin protein is a vitamin E-specific binding protein that acts as a vitamin E carrier in follicular fluid. Although the mechanism of the protective effect of afamin on human ovarian GCs is still unclear, there is evidence it has an antioxidant effect in neuronal cells.

METHODS

In this study, we investigated the protective effects of afamin proteins on testosterone propionate (TP)-induced ovarian GCs using a human ovarian tumor granulosa cell line (KGN).

RESULTS

The results showed that afamin reduced TP-induced oxidative stress in KGN cells by decreasing the levels of oxidative damage markers, enhancing the activity of antioxidant enzymes, and exerting a protective effect on GCs. Supplementation with afamin repaired mitochondrial dysfunction by improving mitochondrial membrane potential damage and ATP levels. It counteracted TP-induced apoptosis by decreasing the activity of Caspase-3 and upregulating the expression of the anti-apoptotic gene (BCL-2) while downregulating the expression of the pro-apoptotic gene BCL-2-associated X protein (BAX). In addition, afamin regulated the expression of genes related to ovarian steroid hormone synthesis, ameliorating the endocrine dysfunction observed in TP-induced KGN cells.

CONCLUSION

Therefore, Afamin proteins may serve as important complementary factors that protect GCs from other types of damage, such as oxidative stress, and may help improve ovarian follicle quality and female reproductive function.

Metabolic and hormonal profiling in polycystic ovarian syndrome: insights into INSR gene variations

BACKGROUND

Polycystic Ovary Syndrome (PCOS) is a hormonal disorder characterized by irregular periods, excess androgen levels, and polycystic ovaries, affecting many women of reproductive age.

METHODS AND RESULTS

This study employed statistical and molecular analyses to compare hormone and metabolic markers between PCOS patients and controls. Sanger sequencing identified two INSR gene variants linked to high insulin and pre-diabetic conditions. Statistically, no significant age differences were detected (p = 0.492) between the overall PCOS patient pool and controls. However, a substantial variation in Vitamin D levels was observed within PCOS patients compared to controls (p = 0.0006), suggesting an association with PCOS. Correlations between Vitamin D and insulin, as well as HbA1c levels (R2 = 0.141 and 0.143, respectively), suggest Vitamin D's potential impact on glycemic control. Significant differences were found in HbA1c (p < 0.0001), insulin (p < 0.0001), and LDL (p = 0.0004) levels between PCOS patients and controls, highlighting marked disparities in these metabolic markers. LH levels also showed a significant contrast (p < 0.0001), while progesterone levels displayed a notable difference (p = 0.007) between the two groups. Correlation analyses within PCOS patients demonstrated associations among LDL, HbA1c, and insulin, with no such correlations observed in control cases. Additionally, Sanger sequencing identified two INSR gene variants, c.3614C > T (p.Pro1205Leu) and c.3355C > T (p.Arg1119Trp), associated with high insulin, LH, and pre-diabetic conditions. These amino acid changes may trigger metabolic imbalances and hormonal irregularities, potentially contributing to the development of PCOS.

CONCLUSIONS

The findings highlight the multifaceted nature of PCOS, revealing significant metabolic, hormonal, and genetic differences compared to controls. These insights may inform tailored interventions and management strategies for the complex associations characteristic of PCOS.

Altered mitochondrial homeostasis on bisphenol-A exposure and its association in developing polycystic ovary syndrome: A comprehensive review

Polycystic ovary syndrome (PCOS) is a heterogeneous endocrinopathy that is known to be one of the most common reproductive pathologies observed in premenopausal women around the globe and is particularly complex as it affects various endocrine and reproductive metabolic pathways. Endocrine-disrupting chemicals (EDCs) are considered to be environmental toxicants as they have hazardous health effects on the functioning of the human endocrine system. Among various classes of EDCs, bisphenol A (BPA) has been under meticulous investigation due to its ability to alter the endocrine processes. As there is emerging evidence suggesting that BPA-induced mitochondrial homeostasis dysfunction in various pathophysiological conditions, this review aims to provide a detailed review of how various pathways associated with ovarian mitochondrial homeostasis are impaired on BPA exposure and its mirroring effects on the PCOS phenotype. BPA exposure might cause significant damage to the mitochondrial morphology and functions through the generation of reactive oxygen species (ROS) and simultaneously downregulates the total antioxidant capacity, thereby leading to oxidative stress. BPA disrupts the mitochondrial dynamics in human cells by altering the expressions of mitochondrial fission and fusion genes, increases the senescence marker proteins, along with significant alterations in the mTOR/AMPK pathway, upregulates the expression of autophagy mediating factors, and downregulates the autophagic suppressor. Furthermore, an increase in apoptosis of the ovarian granulosa cells indicates impaired folliculogenesis. As all these key features are associated with the pathogenesis of PCOS, this review can provide a better insight into the possible associations between BPA-induced dysregulation of mitochondrial homeostasis and PCOS.

Apelin receptor modulation mitigates letrozole-induced polycystic ovarian pathogenesis in mice

AIMS

Polycystic ovarian syndrome (PCOS) is one of the most common (about 5-20%) reproductive disorders in women of reproductive age; it is characterized by polycystic ovaries, hyperandrogenism, and oligo/ anovulation. The levels and expression of ovarian adipokines are deregulated in the PCOS. Apelin is an adipokine that acts through its receptor (APJ) and is known to express in the various tissues including the ovary. It has also been suggested that apelin and APJ could be targeted as therapeutic adjuncts for the management of PCOS. However, no study has been conducted on the management of PCOS by targeting the apelin system. Thus, we aimed to evaluate its impact on combating PCOS-associated ovarian pathogenesis.

METHODS

The current work employed a letrozole-induced-hyperandrogenism PCOS-like mice model to investigate the effects of apelin13 and APJ, antagonist ML221. The PCOS model was induced by oral administration of letrozole (1 mg/kg) for 21 days. A total of four experimental groups were made, control, PCOS control, PCOS + aplein13, and PCOS + ML221. The treatment of apelin13 and ML221 was given from day 22 for two weeks.

KEY FINDINGS

The letrozole-induced PCOS-like features such as hyperandrogenism, cystic follicle, decreased corpus luteum, elevated levels of LH/FSH ratio, and up-regulation of ovarian AR expression were ameliorated by apelin13 and ML221 treatment. However, the PCOS-augmented oxidative stress and apoptosis were suppressed by apelin 13 treatments only. ML221 treatment still showed elevated oxidative stress and stimulated apoptosis as reflected by decreased antioxidant enzymes and increased active caspase3 and Bax expression. The expression of ERs was elevated in all groups except control. Furthermore, the PCOS model showed elevated expression of APJ and apelin13 treatment down-regulated its own receptor. Overall, observing the ovarian histology, corpus luteum formation, and decreased androgen levels by both apelin13 and ML221 showed ameliorative effects on the cystic ovary.

SIGNIFICANCE

Despite the similar morphological observation of ovarian histology, apelin13 and ML221 exhibited opposite effects on oxidative stress and apoptosis. Therefore, apelin13 (which down-regulates APJ) and ML221 (an APJ antagonist) may have suppressed APJ signalling, which would account for our findings on the mitigation of polycystic ovarian syndrome. In conclusion, both apelin13 and ML221 mediated mitigation have different mechanisms, which need further investigation.

Exploring Therapeutic Potential of Catalase: Strategies in Disease Prevention and Management

The antioxidant defense mechanisms play a critical role in mitigating the deleterious effects of reactive oxygen species (ROS). Catalase stands out as a paramount enzymatic antioxidant. It efficiently catalyzes the decomposition of hydrogen peroxide (H2O2) into water and oxygen, a potentially harmful byproduct of cellular metabolism. This reaction detoxifies H2O2 and prevents oxidative damage. Catalase has been extensively studied as a therapeutic antioxidant. Its applications range from direct supplementation in conditions characterized by oxidative stress to gene therapy approaches to enhance endogenous catalase activity. The enzyme's stability, bioavailability, and the specificity of its delivery to target tissues are significant hurdles. Furthermore, studies employing conventional catalase formulations often face issues related to enzyme purity, activity, and longevity in the biological milieu. Addressing these challenges necessitates rigorous scientific inquiry and well-designed clinical trials. Such trials must be underpinned by sound experimental designs, incorporating advanced catalase formulations or novel delivery systems that can overcome existing limitations. Enhancing catalase's stability, specificity, and longevity in vivo could unlock its full therapeutic potential. It is necessary to understand the role of catalase in disease-specific contexts, paving the way for precision antioxidant therapy that could significantly impact the treatment of diseases associated with oxidative stress.

Association Between Triglyceride Glucose Index and Infertility in Reproductive-Aged Women: A Cross-Sectional Study

Purpose

In recent years, female infertility has become a research hotspot in the field of health management, and its cause may be related to insulin resistance (IR). We used a novel and practical IR indicator, the TyG index to explore its association with infertility.

Patients and Methods

We calculated the TyG index using data from adult women who participated in the National Health and Nutrition Examination Survey (NHANES) from 2013 to 2018. Then, we used multivariate logistic regression, smooth curve fitting, and subgroup analysis to examine the association between the TyG index and infertility in women.

Results

Logistic regression models showed a positive correlation between the TyG index and infertility, which remained significant even after adjusting for all confounders (OR=1.51,95% CI:1.14-2.00, p=0.005). This association was consistent in all subgroups (age, education level, marital status, BMI, smoking, alcohol consumption, hypertension, diabetes, pelvic inflammatory disease/PID treatment, and menstrual regularity in the past 12 months) (p>0.05 for all interactions). However, the diagnostic power of the TyG index for infertility was limited (AUC=0.56, 95% CI: 0.52-0.61).

Conclusion

The TyG index is positively correlated with infertility, but its diagnostic value is limited. Further research is needed on the TyG index as an early predictor of infertility.

Cellular senescence of granulosa cells in the pathogenesis of polycystic ovary syndrome

Polycystic ovary syndrome (PCOS) is one of the most common endocrine disorders in women of reproductive age, but its pathology has not been fully characterized and the optimal treatment strategy remains unclear. Cellular senescence is a permanent state of cell-cycle arrest that can be induced by multiple stresses. Senescent cells contribute to the pathogenesis of various diseases, owing to an alteration in secretory profile, termed 'senescence-associated secretory phenotype' (SASP), including with respect to pro-inflammatory cytokines. Senolytics, a class of drugs that selectively eliminate senescent cells, are now being used clinically, and a combination of dasatinib and quercetin (DQ) has been extensively used as a senolytic. We aimed to investigate whether cellular senescence is involved in the pathology of PCOS and whether DQ treatment has beneficial effects in patients with PCOS. We obtained ovaries from patients with or without PCOS, and established a mouse model of PCOS by injecting dehydroepiandrosterone. The expression of the senescence markers p16INK4a, p21, p53, γH2AX, and senescence-associated β-galactosidase and the SASP-related factor interleukin-6 was significantly higher in the ovaries of patients with PCOS and PCOS mice than in controls. To evaluate the effects of hyperandrogenism and DQ on cellular senescence in vitro, we stimulated cultured human granulosa cells (GCs) with testosterone and treated them with DQ. The expression of markers of senescence and a SASP-related factor was increased by testosterone, and DQ reduced this increase. DQ reduced the expression of markers of senescence and a SASP-related factor in the ovaries of PCOS mice and improved their morphology. These results indicate that cellular senescence occurs in PCOS. Hyperandrogenism causes cellular senescence in GCs in PCOS, and senolytic treatment reduces the accumulation of senescent GCs and improves ovarian morphology under hyperandrogenism. Thus, DQ might represent a novel therapy for PCOS.

Exploring the Therapeutic Potential of Sodium Hydrosulfide in Alleviating Oxidative Stress and Ovarian Dysfunction in a Rat Model of Polycystic Ovary Syndrome

Background

Oxidative stress is known to play a key role in the occurrence of polycystic ovary syndrome (PCOS) as the most common cause of anovulatory infertility. The purpose of the current study was to investigate whether diminished activity of ovarian enzymes responsible for hydrogen sulfide (H2S) production, cystathionine β-synthase (CBS), and cystathionine γ-lyase (CSE) contributes to oxidative stress in PCOS. The study also explored whether administration of sodium hydrosulfide (NaSH), an H2S donor, could ameliorate PCOS symptoms by reducing oxidative stress.

Methods

The total eighteen rats were randomly assigned into three groups (n=6): control, PCOS, and PCOS+NaSH. PCOS was induced by intramuscular injection of estradiol valerate to induce PCOS in the PCOS and PCOS+NaSH groups. The PCOS+NaSH group received 30 μmol/L of NaSH in drinking water for 27 days after PCOS induction. Ovarian tissue samples were analyzed for oxidative stress indices including malondialdehyde (MDA) levels and superoxide dismutase (SOD) activity. Additional analyses measured H2S levels, CBS, and CSE activity.

Results

PCOS induction led to a significant decrease in SOD activity, H2S levels, and CBS and CSE activity, accompanied by a significant increase in MDA levels (p<0.0001). Furthermore, PCOS caused severe histological alterations in the ovaries. However, administration of NaSH effectively restored all measured parameters to pre-PCOS induction levels (p<0.0001).

Conclusion

This study showed that the decrease in the activity of H2S-producing enzymes and H2S levels may contribute to oxidative stress in PCOS. Therefore, administration of NaSH as a H2S donor can be considered as a potential therapeutic strategy for PCOS patients.

The potential of therapeutic strategies targeting mitochondrial biogenesis for the treatment of insulin resistance and type 2 diabetes mellitus

Type 2 diabetes mellitus (T2DM) is a persistent metabolic disorder marked by deficiencies in insulin secretion and/or function, affecting various tissues and organs and leading to numerous complications. Mitochondrial biogenesis, the process by which cells generate new mitochondria utilizing existing ones plays a crucial role in energy homeostasis, glucose metabolism, and lipid handling. Recent evidence suggests that promoting mitochondrial biogenesis can alleviate insulin resistance in the liver, adipose tissue, and skeletal muscle while improving pancreatic β-cell function. Moreover, enhanced mitochondrial biogenesis has been shown to ameliorate T2DM symptoms and may contribute to therapeutic effects for the treatment of diabetic nephropathy, cardiomyopathy, retinopathy, and neuropathy. This review summarizes the intricate connection between mitochondrial biogenesis and T2DM, highlighting the potential of novel therapeutic strategies targeting mitochondrial biogenesis for T2DM treatment and its associated complications. It also discusses several natural products that exhibit beneficial effects on T2DM by promoting mitochondrial biogenesis.

NRF2 attenuation aggravates detrimental consequences of metabolic stress on cultured porcine parthenote embryos

The nuclear factor erythroid 2-related factor 2 (NRF2) is a crucial transcription factor that plays a central role in regulating oxidative stress pathways by binding antioxidant response elements, but its involvement in early embryo development remains largely unexplored. In this study, we demonstrated that NRF2 mRNA is expressed in porcine embryos from day 2 to day 7 of development, showing a decrease in abundance from day 2 to day 3, followed by an increase on day 5 and day 7. Comparable levels of NRF2 mRNA were observed between early-cleaving and more developmental competent embryos and late-cleaving and less developmental competent embryos on day 4 and day 5 of culture. Attenuation of NRF2 mRNA significantly decreased development of parthenote embryos to the blastocyst stage. When NRF2-attenuated embryos were cultured in presence of 3.5 mM or 7 mM glucose, development to the blastocyst stage was dramatically decreased in comparison to the control group (15.9% vs. 27.8% for 3.5 mM glucose, and 5.4% vs. 25.3% for 7 mM glucose). Supplementation of melatonin moderately improved the development of NRF2-attenuated embryos cultured in presence of 0.6 mM glucose. These findings highlight the importance of NRF2 in early embryo development, particularly in embryos cultured under metabolically stressful conditions.

Comment on Meneghini et al. The Impact of Nutritional Therapy in the Management of Overweight/Obese PCOS Patient Candidates for IVF. Nutrients 2023, 15, 4444

We read with great interest the recent article by Meneghini et al. on the assessment of the effects of different alimentary regimens, included Mediterranean diet (MD), on polycystic ovary syndrome (PCOS) patients prior to in vitro fertilization cycles [...].

A review of nitric oxide and oxidative stress in typical ovulatory women and in the pathogenesis of ovulatory dysfunction in PCOS

Polycystic ovary syndrome (PCOS) is a heterogeneous functional endocrine disorder associated with a low-grade, chronic inflammatory state. Patients with PCOS present an increased risk of metabolic comorbidities and often menstrual dysregulation and infertility due to anovulation and/or poor oocyte quality. Multiple mechanisms including oxidative stress and low-grade inflammation are believed to be responsible for oocyte deterioration; however, the influence of nitric oxide (NO) insufficiency in oocyte quality and ovulatory dysfunction in PCOS is still a matter for debate. Higher production of superoxide (O2•-) mediated DNA damage and impaired antioxidant defense have been implicated as contributory factors for the development of PCOS, with reported alteration in superoxide dismutase (SOD) function, an imbalanced zinc/copper ratio, and increased catalase activity. These events may result in decreased hydrogen peroxide (H2O2) accumulation with increased lipid peroxidation events. A decrease in NO, potentially due to increased activity of NO synthase (NOS) inhibitors such as asymmetric dimethylarginine (ADMA), and imbalance in the distribution of reactive oxygen species (ROS), such as decreased H2O2 and increased O2•-, may offset the physiological processes surrounding follicular development, oocyte maturation, and ovulation contributing to the reproductive dysfunction in patients with PCOS. Thus, this proposal aims to evaluate the specific roles of NO, oxidative stress, ROS, and enzymatic and nonenzymatic elements in the pathogenesis of PCOS ovarian dysfunction, including oligo- anovulation and oocyte quality, with the intent to inspire better application of therapeutic options. The authors believe more consideration into the specific roles of oxidative stress, ROS, and enzymatic and nonenzymatic elements may allow for a more thorough understanding of PCOS. Future efforts elaborating on the role of NO in the preoptic nucleus to determine its influence on GnRH firing and follicle-stimulating hormone/Luteinizing hormone (FSH/LH) production with ovulation would be of benefit in PCOS. Consequently, treatment with an ADMA inhibitor or NO donor may prove beneficial to PCOS patients experiencing reproductive dysfunction and infertility.