Role of inflammation and oxidative stress in the etiology of primary ovarian insufficiency

Metabolome-wide Mendelian randomization for age at menarche and age at natural menopause

BACKGROUND

The role of metabolism in the variation of age at menarche (AAM) and age at natural menopause (ANM) in the female population is not entirely known. We aimed to investigate the causal role of circulating metabolites in AAM and ANM using Mendelian randomization (MR).

METHODS

We combined MR with genetic colocalization to investigate potential causal associations between 658 metabolites and AAM and between 684 metabolites and ANM. We extracted genetic instruments for our exposures from four genome-wide association studies (GWAS) on circulating metabolites and queried the effects of these variants on the outcomes in two large GWAS from the ReproGen consortium. Additionally, we assessed the mediating role of the body mass index (BMI) in these associations, identified metabolic pathways implicated in AAM and ANM, and sought validation for selected metabolites in the Avon Longitudinal Study of Parents and Children (ALSPAC).

RESULTS

Our analysis identified 10 candidate metabolites for AAM, but none of them colocalized with AAM. For ANM, 76 metabolites were prioritized (FDR-adjusted MR P-value ≤ 0.05), with 17 colocalizing, primarily in the glycerophosphocholines class, including the omega-3 fatty acid and phosphatidylcholine (PC) categories. Pathway analyses and validation in ALSPAC mothers also highlighted the role of omega and polyunsaturated fatty acids levels in delaying age at menopause.

CONCLUSIONS

Our study suggests that metabolites from the glycerophosphocholine and fatty acid families play a causal role in the timing of both menarche and menopause. This underscores the significance of specific metabolic pathways in the biology of female reproductive longevity.

Advanced oxidation protein products attenuate the autophagy-lysosome pathway in ovarian granulosa cells by modulating the ROS-dependent mTOR-TFEB pathway

Oxidative stress dysfunction has recently been found to be involved in the pathogenesis of premature ovarian insufficiency (POI). Previously, we found that advanced oxidation protein products (AOPPs) in plasma were elevated in women with POI and had an adverse effect on granulosa cell proliferation. However, the mechanism underlying the effects of AOPPs on autophagy-lysosome pathway regulation in granulosa cells remains unclear. In this study, the effect of AOPPs on autophagy and lysosomal biogenesis and the underlying mechanisms were explored by a series of in vitro experiments in KGN and COV434 cell lines. AOPP-treated rat models were employed to determine the negative effect of AOPPs on the autophagy-lysosome systems in vivo. We found that increased AOPP levels activated the mammalian target of rapamycin (mTOR) pathway, and inhibited the autophagic response and lysosomal biogenesis in KGN and COV434 cells. Furthermore, scavenging of reactive oxygen species (ROS) with N-acetylcysteine and blockade of the mTOR pathway with rapamycin or via starvation alleviated the AOPP-induced inhibitory effects on autophagy and lysosomal biogenesis, suggesting that these effects of AOPPs are ROS-mTOR dependent. The protein expression and nuclear translocation of transcription factor EB (TFEB), the key regulator of lysosomal and autophagic function, were also impaired by the AOPP-activated ROS-mTOR pathway. In addition, TFEB overexpression attenuated the AOPP-induced impairment of autophagic flux and lysosomal biogenesis in KGN and COV434 cells. Chronic AOPP stimulation in vivo also impaired autophagy and lysosomal biogenesis in granulosa cells of rat ovaries. The results highlight that AOPPs lead to impairment of autophagic flux and lysosomal biogenesis via ROS-mTOR-TFEB signaling in granulosa cells and participate in the pathogenesis of POI.

Germline cell de novo mutations and potential effects of inflammation on germline cell genome stability

Uncontrolled pathogenic genome mutations in germline cells might impair adult fertility, lead to birth defects or even affect the adaptability of a species. Understanding the sources of DNA damage, as well as the features of damage response in germline cells are the overarching tasks to reduce the mutations in germline cells. With the accumulation of human genome data and genetic reports, genome variants formed in germline cells are being extensively explored. However, the sources of DNA damage, the damage repair mechanisms, and the effects of DNA damage or mutations on the development of germline cells are still unclear. Besides exogenous triggers of DNA damage such as irradiation and genotoxic chemicals, endogenous exposure to inflammation may also contribute to the genome instability of germline cells. In this review, we summarized the features of de novo mutations and the specific DNA damage responses in germline cells and explored the possible roles of inflammation on the genome stability of germline cells.

Protective role of stem cells in POI: Current status and mechanism of action, a review article

Premature ovarian insufficiency (POI) has far-reaching consequences on women's life quality. Due to the lack of full recognition of the etiology and complexity of this disease, there is no appropriate treatment for infected patients. Recently, stem cell therapy has attracted the attention of regenerative medicine scholars and offered promising outcomes for POI patients. Several kinds of stem cells, such as embryonic stem cells (ESCs), mesenchymal stem cells (MSCs), and induced pluripotent stem cells (iPSCs) have been used for the treatment of ovarian diseases. However, their potential protective mechanisms are still unknown. Undoubtedly, a better understanding of the therapeutic molecular and cellular mechanisms of stem cells will address uncover strategies to increase their clinical application for multiple disorders such as POI. This paper describes a detailed account of the potential properties of different types of stem cells and provides a comprehensive review of their protective mechanisms, particularly MSC, in POI disorder. In addition, ongoing challenges and several strategies to improve the efficacy of MSC in clinical use are addressed. Therefore, this review will provide proof-of-concept for further clinical application of stem cells in POI.

The effect of hydrogen-rich water on letrozole-induced polycystic ovary syndrome in rats

RESEARCH QUESTION

What is the effect of hydrogen-rich water on rats with polycystic ovary syndrome (PCOS)?

DESIGN

Female rats were divided into four groups, each consisting of eight animals. The control group received a carboxymethyl cellulose (CMC) solution, the molecular hydrogen (H2) group was given hydrogen-rich water and a CMC solution, the PCOS group was administered letrozole dissolved in a CMC solution and the PCOS + H2 group was given hydrogen-rich water and letrozole dissolved in a CMC solution. Blood and tissue samples were then collected, and biochemical and histopathological analyses were conducted on the samples.

RESULTS

The histopathological analysis showed a reduction in the number of cysts in the PCOS + H2 group compared with the PCOS group (P < 0.0001). Additionally, the malondialdehyde, cortisol and testosterone data revealed a significant decrease in the PCOS + H2 group compared with the PCOS group (P = 0.0458, P = 0.0003, P = 0.0041, respectively). The glutathione also showed a statistically significant increase in the PCOS + H2 group compared with the PCOS group (P = 0.0012).

CONCLUSION

The study findings demonstrate that hydrogen-rich water reduces the number of cysts and oxidative damage in rats with PCOS.

Impaired immune response against SARS-CoV-2 infection is the major factor indirectly altering reproductive function in COVID-19 patients: a narrative review

Coronavirus disease 2019 (COVID-19) is an infectious disease affecting multiple systems and organs, including the reproductive system. SARS-CoV-2, the virus that causes COVID-19, can damage reproductive organs through direct (angiotensin converting enzyme-2, ACE-2) and indirect mechanisms. The immune system plays an essential role in the homeostasis and function of the male and female reproductive systems. Therefore, an altered immune response related to infectious and inflammatory diseases can affect reproductive function and fertility in both males and females. This narrative review discussed the dysregulation of innate and adaptive systems induced by SARS-CoV-2 infection. We reviewed the evidence showing that this altered immune response in COVID-19 patients is the major indirect mechanism leading to adverse reproduction outcomes in these patients. We summarized studies reporting the long-term effect of SARS-CoV-2 infection on women's reproductive function and proposed the chronic inflammation and chronic autoimmunity characterizing long COVID as potential underlying mechanisms. Further studies are needed to clarify the role of autoimmunity and chronic inflammation (long COVID) in altered female reproduction function in COVID-19.

Elevated cell-free mitochondria DNA level of patients with premature ovarian insufficiency

BACKGROUND

Premature ovarian insufficiency (POI) patients present with a chronic inflammatory state. Cell-free mitochondria DNA (cf-mtDNA) has been explored as a reliable biomarker for estimating the inflammation-related disorders, however, the cf-mtDNA levels in POI patients have never been measured. Therefore, in the presenting study, we aimed to evaluate the levels of cf-mtDNA in plasma and follicular fluid (FF) of POI patients and to determine a potential role of cf-mtDNA in predicting the disease progress and pregnancy outcomes.

METHODS

We collected plasma and FF samples from POI patients, biochemical POI (bPOI) patients and control women. Quantitative real-time PCR was used to measure the ratio of mitochondrial genome to nuclear genome of cf-DNAs extracted from the plasma and FF samples.

RESULTS

The plasma cf-mtDNA levels, including COX3, CYB, ND1 and mtDNA79, were significantly higher in overt POI patients than those in bPOI patients or control women. The plasma cf-mtDNA levels were weakly correlated with ovarian reserve, and could not be improved by regular hormone replacement therapy. The levels of cf-mtDNA in FF, rather than those in plasma, exhibited the potential to predict the pregnancy outcomes, although they were comparable among overt POI, bPOI and control groups.

CONCLUSIONS

The increased plasma cf-mtDNA levels in overt POI patients indicated its role in the progress of POI and the FF cf-mtDNA content may hold the value in predicting pregnancy outcomes of POI patients.

Whole exome sequencing reveals novel variants associated with diminished ovarian reserve in young women

Background: Diminished ovarian reserve is one of the most important causes of female infertility. In the etiology study of DOR, besides age, it is known that chromosomal abnormality, radiotherapy, chemotherapy and ovarian surgery can result in DOR. For young women without obvious risk factors, gene mutation should be considered as a possible cause. However, the specific molecular mechanism of DOR has not been fully elucidated.

Methods: In order to explore the pathogenic variants related to DOR, twenty young women under 35 years old affected by DOR without definite factors damaging ovarian reserve were recruited as the research subjects, and five women with normal ovarian reserve were recruited as the control group. Whole exome sequencing was applied as the genomics research tool.

Results: As a result, we obtained a set of mutated genes that may be related to DOR, where the missense variant on GPR84 was selected for further study. It is found that GPR84Y370H variant promotes the expression of proinflammatory cytokines (TNF-α, IL12B, IL-1β) and chemokines (CCL2, CCL5), as well as the activation of NF-κB signaling pathway.

Conclusion: In conclusion, GPR84Y370H variant was identified though analysis for WES results of 20 DOR patients. The deleterious variant of GPR84 could be the potential molecular mechanism of non-age-related pathological DOR through its role in promoting inflammation. The findings of this study can be used as a preliminary research basis for the development of early molecular diagnosis and treatment target selection of DOR.

Regenerative potential of different extracellular vesicle subpopulations derived from clonal mesenchymal stem cells in a mouse model of chemotherapy-induced premature ovarian failure

AIMS

Some studies have shown that mesenchymal stem cells (MSCs) and their derived extracellular vesicles (MSC-EVs) can restore ovarian function in premature ovarian failure (POF), however, concerns about their efficacy are attributed to the heterogeneity of the cell populations and EVs. Here, we assessed the therapeutic potential of a homogeneous population of clonal MSCs (cMSCs) and their EVs subpopulations in a mouse model of POF.

MAIN METHODS

Granulosa cells were treated with cyclophosphamide (Cy) in the absence or presence of cMSCs, or cMSCs-derived EV subpopulations (EV20K and EV110K, isolated by high-speed centrifugation and differential ultracentrifugation, respectively). In addition, POF mice were treated with cMSCs, EV20K and/or EV110K.

KEY FINDINGS

cMSC and both EV types protected granulosa cells from Cy-induced damage. Calcein-EVs were detected in the ovaries. Moreover, cMSC and both EV subpopulations significantly increased body weight, ovary weight, and the number of follicles, restored FSH, E2, and AMH levels, increased the granulosa cell numbers and restored the fertility of POF mice. cMSC, EV20K, and EV110K alleviated inflammatory-related genes expression (Tnf-α and IL8), and improved angiogenesis via upregulation expression of Vegf and Igf1 at the mRNA level and VEGF and αSMA at the protein level. They also inhibited apoptosis through the PI3K/AKT signaling pathway.

SIGNIFICANCE

The administration of cMSCs and two cMSC-EVs subpopulations improved ovarian function and restored fertility in a POF model. EV20K is more cost-effective and feasible in terms of isolation, particularly in good manufacturing practice (GMP) facilities for treatment of POF patients in comparison with conventional EVs (EV110K).

Oxidant-antioxidant balance in girls with precocious puberty: a case-control study

This case-control study aims to evaluate the oxidant-antioxidant balance in girls having central precocious puberty (CPP) and premature thelarche (PT). Thirty-four girls having CPP, 24 girls having PT, and 49 healthy growing girls between 7 and 9 years of age admitted to child health supervision were enrolled. Total antioxidant and oxidant capacity, myeloperoxidase, catalase, superoxide dismutase, total thiol, native thiol, and disulfide levels were analyzed in serum samples. Low total oxidant status (<12.0) was found to be highest in the CPP group, lowest in the control group, and the PT group was in between them. After controlling bone age and z score for body mass index, generalized linear models revealed lower oxidative stress index values in the CPP and the PT groups than the control group. Other studied parameters did not differ among groups. Precocious puberty in girls is associated with some changes in the oxidant-antioxidant status.

Association of Coenzyme Q10 with Premature Ovarian Insufficiency

The aim of the study was to analyze the relationship between levels of coenzyme Q10 (CoQ10) and the risk of premature ovarian insufficiency (POI). In this cross-sectional case–control study, 32 women with POI and 58 women with normal menstrual cycles were recruited. The serum levels of follicle-stimulating hormone (FSH), luteinizing hormone (LH), anti-Müllerian hormone (AMH), CoQ10 and total cholesterol were measured. The association of CoQ10 with POI was assessed using binary logistic regression analysis. The CoQ10/total cholesterol ratio was significantly lower in the women with POI than in the women with normal menstrual cycles (120.94 ± 25.35 nmol/mmol vs 138.97 ± 39.19 nmol/mmol, P = 0.021). The serum CoQ10/total cholesterol ratio was inversely associated with POI (the unadjusted odds ratio (OR) = 0.984, 95% CI: 0.970–0.998, P = 0.027). The same trend was found after adjusting for confounding factors (such as age, body mass index, annual household income and education) (OR = 0.976, 95% CI: 0.956–0.996, P = 0.020). The serum CoQ10/total cholesterol ratio was inversely associated with POI, indicating that antioxidant deficiency may be a risk associated with the development of POI. CoQ10 may be a protective factor for ovarian tissue.

Bone marrow mesenchymal stem cells in premature ovarian failure: Mechanisms and prospects

Premature ovarian failure (POF) is a common female reproductive disorder and characterized by menopause, increased gonadotropin levels and estrogen deficiency before the age of 40 years old. The etiologies and pathogenesis of POF are not fully clear. At present, hormone replacement therapy (HRT) is the main treatment options for POF. It helps to ameliorate perimenopausal symptoms and related health risks, but can't restore ovarian function and fertility fundamentally. With the development of regenerative medicine, bone marrow mesenchymal stem cells (BMSCs) have shown great potential for the recovery of ovarian function and fertility based on the advantages of abundant sources, high capacity for self-renewal and differentiation, low immunogenicity and less ethical considerations. This systematic review aims to summarize the possible therapeutic mechanisms of BMSCs for POF. A detailed search strategy of preclinical studies and clinical trials on BMSCs and POF was performed on PubMed, MEDLINE, Web of Science and Embase database. A total of 21 studies were included in this review. Although the standardization of BMSCs need more explorations, there is no doubt that BMSCs transplantation may represent a prospective therapy for POF. It is hope to provide a theoretical basis for further research and treatment for POF.

Single-nucleus RNA Sequencing reveals the mechanism of cigarette smoke exposure on diminished ovarian reserve in mice

The systematic toxicological mechanism of cigarette smoke (CS) on ovarian reserve has not been extensively investigated. Female 8-week-old C57BL/6 mice at peak fertility were exposed to CS or indoor air only for 30 days (100 mice per group) and the effects of CS on ovarian reserve were assessed using Single-Nucleus RNA Sequencing (snRNA-seq). In addition, further biochemical experiments, including immunohistochemical staining, ELISA, immunofluorescence staining, transmission electron microscopy, cell counting kit-8 assay, flow cytometry analysis, senescence-associated β-galactosidase staining, and western blotting, were accomplished to confirm the snRNA-seq results. We identified nine main cell types in adult ovaries and the cell-type-specific differentially expressed genes (DEGs) induced by CS exposure. Western blot results verified that down-regulation of antioxidant genes (Gpx1 and Wnt10b) and the steroid biosynthesis gene (Fdx1) occurred in both ovarian tissue and human granulosa cell-like tumor cell line (KGN cells) after CS exposure. Five percent cigarette smoke extract (CSE) effectively stimulated the production of reactive oxygen species (ROS), DNA damage, cellular senescence and markedly inhibited KGN cell proliferation by inducing G1-phase cell cycle arrest. Moreover, down-regulation of Gja1, Lama1 and the Ferroptosis indicator (Gpx4) in granulosa cells plays a significant role in ultrastructural changes in the ovary induced by CS exposure. These observations suggest that CS exposure impaired ovarian follicle reserve might be caused by REDOX imbalance in granulosa cells. The current study systematically determined the damage caused by CS in mouse ovaries and provides a theoretical basis for early clinical prediction, diagnosis and intervention of CS exposure-associated primary ovarian insufficiency (POI), and is of great significance in improving female reproductive health.

Metabolic differences in women with premature ovarian insufficiency: a systematic review and meta-analysis

Objective

This review aimed to investigate the metabolic profile of women with premature ovarian insufficiency (POI) compared relative to women with normal ovarian functioning.

Methods

A systematic search of PubMed, EMBASE, and the Web of Science for observational studies published up until the 6^th of July 2021 that compared the metabolic profile of POI women with a healthy control group were assessed. Mean differences (MD) and 95% confidence interval (CI) were pooled using the fixed or random effect models.

Results

A total of 21 studies involving 1573 women with POI and 1762 control women were included. POI patients presented significantly higher waist circumference, total cholesterol, low-density lipoprotein, high-density lipoprotein, triglycerides, and fasting glucose. Additionally, POI patients had marginally higher insulin level. However, the differences in systolic, and diastolic blood pressure were non-significant relative to the control group.

Conclusions

POI is associated with alterations in certain metabolic parameters compared to control women. This finding highlights the importance of early screening and the lifelong management of metabolic health for women with POI.

Supplementary Information

The online version contains supplementary material available at 10.1186/s13048-022-01041-w.

Complementary and Alternative Medicine for Premature Ovarian Insufficiency: A Review of Utilization and Mechanisms

Premature ovarian insufficiency (POI) is defined as a decline in ovarian function before the age of 40 and is one of the leading causes of infertility in women. The etiology is complex, and the pathogenesis is not clear. The main treatment is hormone replacement therapy, but a growing body of data confirms that such treatment can increase the risk of endometrial disease and cardiovascular disease. Complementary and alternative medicine (CAM) has been widely used in patients with POI due to its limited adverse reactions and high efficiency. According to literature reports, CAM therapy for POI mainly includes traditional Chinese medicine, acupuncture, psychotherapy, dietary supplements, and exercise therapy. This article reviews the application of CAM in the treatment of POI and attempts to determine the therapeutic effects and the mechanisms behind these effects based on existing clinical and experimental studies in order to provide theoretical support for the treatment of POI.

Lipid Profile in Patients With Primary Ovarian Insufficiency: A Systematic Review and Meta-Analysis

BACKGROUNDS

A large number of studies have investigated the effect of early menopause on cardiovascular disease (CVD) outcomes and the relationship between the levels of lipid profile and primary ovarian insufficiency (POI). However, the results are inconsistent. The aim of this meta-analysis was to assess whether the levels of total cholesterol (TC), triglyceride (TG), high density lipoprotein (HDL) and low density lipoprotein (LDL) changed in women with POI relative to healthy controls.

METHODS

To identify eligible studies, references published prior to December 2021 were searched in the PubMed, Embase, Cochrane Library and Web of Science databases. DerSimonian-Laird random-effects model was used to estimate the overall standard mean difference (SMD) between POI and healthy control subjects. Subgroup analysis and sensitivity analysis were preformed, and publication bias was assessed.

RESULTS

A total of 12 studies featuring 846 women with primary ovarian insufficiency and 959 healthy women were selected for analysis. The meta-analysis showed that the levels of TC (SMD: 0.60; 95% CI: 0.32 to 0.89; P<0.0001), TG (SMD: 0.36; 95% CI: 0.12 to 0.60; P=0.003), LDL (SMD: 0.46; 95% CI: 0.16 to 0.76; P=0.003) were significantly increased in women with POI. There was no significant change in the level of HDL (SMD: 0.25; 95% CI: -0.12 to 0.61; P=0.19). Subgroup analysis showed that the heterogeneity in this meta-analysis of the correlation between lipid profile and POI might come from by region, sample size, number of cases, mean body mass index (BMI) value of cases and mean age of cases.

CONCLUSIONS

Scientific evidence suggests that the lipid profile levels were altered in patients with primary ovarian insufficiency compared to healthy controls. Therefore, we recommend that early medical intervention (e.g., hormone replacement therapy) to minimize the risk of CVD morbidity and mortality associated with dyslipidemia in patients with POI.

SYSTEMATIC REVIEW REGISTRATION

PROSPERO, identifier CRD42021297088.

Xenoestrogens impact brain estrogen receptor signaling during the female lifespan: A precursor to neurological disease?

Xenoestrogens, foreign synthetic chemicals mimicking estrogens, are lurking in our surroundings. Climate change may alter their toxicity and bioavailability. Since xenoestrogens have extremely high lipid solubility and are structurally similar to natural endogenous estrogens, they can bind to estrogen receptors (ERs) -alpha (ER-α) and -beta (ER-β). Scientific evidence accumulated over the past decades have suggested that natural 17β-estradiol (E2; a potent estrogen), via activation of its receptors, plays a pivotal role in regulation of brain development, differentiation, metabolism, synaptic plasticity, neuroprotection, cognition, anxiety, body temperature, feeding and sexual behavior. In the brain, ER-β is predominantly expressed in the various regions, including cerebral cortex and hippocampus, that have been shown to play a key role in cognition. Therefore, disturbances in function of ER-β mediated E2 signaling by xenoestrogens can lead to deleterious effects that potentiate a variety of neurological diseases starting from prenatal to post-menopause in women. The goal of this review is to identify the possible neurological effects of xenoestrogens that can alter estrogen receptor-mediated signaling in the brain during different stages of the female lifespan.

Establishment and Mechanism Study of a Primary Ovarian Insufficiency Mouse Model Using Lipopolysaccharide

This study is aimed at establishing a lipopolysaccharide- (LPS-) induced primary ovarian insufficiency (POI) mouse model and investigating the underlying mechanism. C57BL/6N female mice were intraperitoneally injected with low-dose LPS (0.5 mg/kg) once daily for 14 days, high-dose LPS (2.5 mg/kg) twice weekly for 2 weeks, or cyclophosphamide (CTX; 150 mg/kg) once weekly for 2 weeks. Ovarian function was assessed by measuring the length of estrous cycle, the number of primordial follicles, and the levels of serum hormones. Expression and production of interleukin 1β (IL-1β) were determined to evaluate ovarian inflammation. Histopathological examination was performed to examine ovarian fibrosis. TUNEL assay was carried out to evaluate granulosa cell apoptosis. Western blotting was performed to measure the levels of inflammation-, fibrosis-, and apoptosis-related proteins in the mouse ovaries. Like CTX, both low- and high-dose LPS significantly impaired ovarian functions in mice, as evidenced by extended lengths of estrous cycles, reduced counts of primordial follicles, and alterations in the levels of serum hormones. Also, LPS promoted granulosa cell apoptosis and ovarian fibrosis in mice. However, LPS but not CTX promoted IL-1β expression and production in mice. Moreover, LPS but not CTX enhanced TLR, p-p65, p65, and MyD88 expression in mouse ovaries, suggesting that LPS differs from CTX in triggering ovarian inflammation. In general, continuous low-dose LPS stimulation was less potent than high-dose LPS to affect the ovarian functions. In conclusion, LPS may induce ovarian inflammation, fibrosis, and granulosa cell apoptosis and can be used to establish a POI model in mice.

Moving beyond inclusion: Methodological considerations for the menstrual cycle and menopause in research evaluating effects of dietary nitrate on vascular function

Recent reports have acknowledged the underrepresentation of women in the field of dietary nitrate (NO₃^-) research. Undoubtedly, greater participation from women is warranted to clarify potential sex differences in the responses to dietary NO₃^- interventions. However, careful consideration for the effects of sex hormones - principally 17β-estradiol - on endogenous nitric oxide (NO) synthesis and dietary NO₃^- reductase capacity is necessary for improved interpretation and reproducibility of such investigations. From available literature, we present a narrative review describing how hormonal variations across the menstrual cycle, as well as with menopause, may impact NO biosynthesis catalyzed by NO synthase enzymes and NO₃^- reduction via the enterosalivary pathway. In doing so, we address methodological considerations related to the menstrual cycle and hormonal contraceptive use relevant for the inclusion of premenopausal women along with factors to consider when testing postmenopausal women. Adherence to such methodological practices may explicate the utility of dietary NO₃^- supplementation as a means to improve vascular function among women across the lifespan.

Melatonin protects against excessive autophagy-induced mitochondrial and ovarian reserve function deficiency though ERK signaling pathway in Chinese hamster ovary (CHO) cells

Excessive autophagy-induced follicular atresia of ovarian granulosa cells might be one of the pathogenesis of Premature Ovarian Insufficiency (POI), and melatonin (MT) exerted many beneficial effects on mitochondria. However, there was little report regarding the beneficial effects of MT on excessive autophagy-induced mitochondrial and ovarian reserve function deficiency, and the mechanisms have not been clearly identified. Autophagy played a protective role in cells survival, however, high level of autophagy could lead to cell death. In this report, firstly, Chinese hamster ovary cell damage model stably expressing EGFP-LC3 was established. Next, we systematically investigated the protective effects of MT on mitochondrial and ovarian reserve function and molecular mechanisms using this cell damage model. Our results revealed that 10^-9 M MT not only protected against the decline of anti-mullerian hormone (AMH) expression induced by excessive autophagy, but also rescued excessive autophagy-induced impairment of mitochondrial expression and mitochondrial membrane potential. Furthermore, MT protected against excessive autophagy-induced decrease of nucleus-encoded proteins including SDHA and mitofilin, and mitochondrial dynamic-related proteins including OPA1, MFN2, and DRP1. MT also decreased mitochondrial oxidative stress, increased antioxidant enzyme superoxide dismutase 2 (SOD2) expression and ameliorated the G2/M cell cycle arrest induced by excessive autophagy. Finally, MT inhibited excessive autophagy-induced activation of extracellular signal regulated kinase (ERK) signaling pathway. In conclusion, our study showed that MT rescued impairment of mitochondrial and ovarian reserve function, and production of mitochondrial ROS and cell cycle arrest induced by excessive autophagy through down-regulated ERK pathway, implying the potential therapeutic drug target for POI.

Network Pharmacology Approach for Predicting Targets of Zishen Yutai Pills on Premature Ovarian Insufficiency

METHODS

A comprehensive strategy based on several Chinese herb databases and chemical compound databases was established to screen active compounds of ZSYTP and predict target genes. For network pharmacological analysis, network construction and gene enrichment analysis were conducted and further verified by molecular docking.

RESULTS

A total of 476 target genes of ZSYTP were obtained from 205 active compounds. 13 herbs of ZSYTP overlapped on 8 active compounds based on the compound-target-disease network (C-T network). 20 biological processes and 9 pathways were strongly connected to the targets of ZSYTP in treating POI, including negative regulation of gene expression, mRNA metabolic process, hypoxia-inducible factor 1 (HIF-1) signaling pathway, and gluconeogenesis. Finally, molecular docking was visualized.

CONCLUSION

Intriguingly, the signal pathways and biological processes uncovered in this study implicate inflamm-aging and glucose metabolism as potential pathological mechanisms of POI. The therapeutic effect of ZSYTP could be mediated by regulating glucose metabolism and HIF-1 signal pathway. Collectively, this study sheds light on the therapeutic potential of ZSYTP on POI.

Advanced Oxidation Protein Products Induce G1/G0-Phase Arrest in Ovarian Granulosa Cells via the ROS-JNK/p38 MAPK-p21 Pathway in Premature Ovarian Insufficiency

The mechanism underlying the role of oxidative stress and advanced oxidation protein products (AOPPs) in the aetiology of premature ovarian insufficiency (POI) is poorly understood. Here, we investigated the plasma AOPP level in POI patients and the effects of AOPPs on granulosa cells both in vitro and in vivo. KGN cells were treated with different AOPP doses, and cell cycle distribution, intracellular reactive oxygen species (ROS), and protein expression levels were measured. Sprague–Dawley (SD) rats were treated daily with PBS, rat serum albumin, AOPP, or AOPP+ N-acetylcysteine (NAC) for 12 weeks to explore the effect of AOPPs on ovarian function. Plasma AOPP concentrations were significantly higher in both POI and biochemical POI patients than in controls and negatively correlated with anti-Müllerian hormone and the antral follicle count. KGN cells treated with AOPP exhibited G1/G0-phase arrest. AOPP induced G1/G0-phase arrest in KGN cells by activating the ROS-c-Jun N-terminal kinase (JNK)/p38 mitogen-activated protein kinase (MAPK)-p21 pathway. Pretreatment with NAC, SP600125, SB203580, and si-p21 blocked AOPP-induced G1/G0-phase arrest. In SD rats, AOPP treatment increased the proportion of atretic follicles, and NAC attenuated the adverse effects of AOPPs in the ovary. In conclusion, we provide mechanistic evidence that AOPPs may induce cell cycle arrest in granulosa cells via the ROS-JNK/p38 MAPK-p21 pathway and thus may be a novel biomarker of POI.

The effect of Bu Shen Huo Xue Tang on autoimmune premature ovarian insufficiency via Modulation of the Nrf2/Keap1 signaling pathway in mice

ETHNOPHARMACOLOGICAL RELEVANCE

Bu Shen Huo Xue Tang (BSHXT) is a traditional Chinese medicine formula that is clinically used in the treatment of premature ovarian insufficiency (POI). However, its therapeutic mechanism remains unclear.

AIM OF THE STUDY

This study aimed to investigate the underlying molecular mechanism of pharmacological activity of BSHXT, via the Nrf2/Keap1 signaling pathway, in the treatment of autoimmune POI.

MATERIALS AND METHODS

The chemical composition of BSHXT was analyzed using ultra-performance liquid chromatography quadrupole time-of-flight tandem mass spectrometry. The autoimmune POI mouse model was induced by immunizing mice twice, with zona pellucida (ZP) glycoprotein 3 antigen. The autoimmune POI mice were continuously administered BSHXT for 28 days. Body weight and organ indices were recorded. The pathological morphology of the ovaries was observed. The estrous cycle of each mouse was recorded. Immunofluorescence assay was used to detect the levels of ZP antibodies in the mouse ovaries. The levels of ZP antibodies, follicle-stimulating hormone (FSH), anti-Müllerian hormone (AMH), estradiol (E₂), luteinizing hormone (LH), superoxide dismutase (SOD), and malondialdehyde (MDA) were measured. The expression of genes and proteins involved in the Nrf2/Keap1 signaling pathway were measured by Q-PCR and IHC, respectively.

RESULTS

Twenty-one compounds were identified in the BSHXT water extract. BSHXT was found to increase the body weight and ovarian index, improve ovarian function, and reduce disorders in the estrus cycle. It also reduced the expression of ZP antibodies in the ovaries and serum of POI mice. BSHXT significantly increased E₂ and AMH levels and decreased FSH and LH levels. It also increased the levels of SOD, and reduced MDA levels. The levels of Nrf2 and Keap1 were also increased, and the expression of Nrf2, HO-1 and NQO1 genes was upregulated.

CONCLUSIONS

BSHXT has a therapeutic effect on autoimmune POI in mice, which may be a result of the enhanced antioxidant capacity and activation of the Nrf2/Keap1 signaling pathway. BSHXT is a good drug candidate for use as a protective agent for POI and may be used in clinical practice.

Maternal and Neonatal Complications in Patients With Diminished Ovarian Reserve in In-Vitro Fertilization/Intracytoplasmic Sperm Injection Cycles

BACKGROUND

Diminished ovarian reserve (DOR) is one of the most intractable clinical issues in human reproduction and is reported to be associated with raised risk of recurrent pregnancy loss and aneuploid blastocysts. In this study, we aimed to explore whether DOR was also associated with maternal and neonatal complications in in-vitro fertilization/intracytoplasmic sperm injection cycles.

METHODS

A retrospective cohort study including women below 40 years of age who achieved singleton live birth after fresh embryo transfer in in-vitro fertilization/intracytoplasmic sperm injection cycles in a single center from January 2012 to June 2019 was conducted. Participants with DOR, defined as basal follicle-stimulating hormone (FSH) ≥ 10IU/L and antimullerian hormone (AMH) < 1.2ng/ml, were enrolled as the study group. The controls were 1:2 matched by age and body mass index with FSH < 10IU/L and AMH ≥ 1.2ng/ml. Maternal and neonatal complications were compared between the DOR group and the controls.

RESULTS

A total of 579 women, 193 in the DOR group and 386 matched as controls, were included in this study. Compared to controls, the incidence of hypertensive disorders of pregnancy was significantly increased in the DOR group (5.7% vs. 2.1%, P = 0.021). DOR patients also presented slightly higher incidences of preterm birth (10.9% vs. 7.5%, P = 0.174) and low birthweight (6.2% vs. 5.4%, P = 0.704) yet without statistical significances. The incidences of gestational diabetes mellitus and placenta previa were comparable between the two groups.

CONCLUSION

Compared to women with normal ovarian reserve, women with diminished ovarian reserve might have elevated incidence of hypertensive disorders of pregnancy. Patients with diminished ovarian reserve might need more strict antenatal care.

The peri-menopause in a woman's life: a systemic inflammatory phase that enables later neurodegenerative disease

The peri-menopause or menopausal transition—the time period that surrounds the final years of a woman’s reproductive life—is associated with profound reproductive and hormonal changes in a woman’s body and exponentially increases a woman’s risk of cerebral ischemia and Alzheimer’s disease. Although our understanding of the exact timeline or definition of peri-menopause is limited, it is clear that there are two stages to the peri-menopause. These are the early menopausal transition, where menstrual cycles are mostly regular, with relatively few interruptions, and the late transition, where amenorrhea becomes more prolonged and lasts for at least 60 days, up to the final menstrual period. Emerging evidence is showing that peri-menopause is pro-inflammatory and disrupts estrogen-regulated neurological systems. Estrogen is a master regulator that functions through a network of estrogen receptors subtypes alpha (ER-α) and beta (ER-β). Estrogen receptor-beta has been shown to regulate a key component of the innate immune response known as the inflammasome, and it also is involved in regulation of neuronal mitochondrial function. This review will present an overview of the menopausal transition as an inflammatory event, with associated systemic and central nervous system inflammation, plus regulation of the innate immune response by ER-β-mediated mechanisms.

Towards an understanding of women's brain aging: the immunology of pregnancy and menopause

Women are at significantly greater risk of developing Alzheimer's disease and show higher prevalence of autoimmune conditions relative to men. Women's brain health is historically understudied, and little is therefore known about the mechanisms underlying epidemiological sex differences in neurodegenerative diseases, and how female-specific factors may influence women's brain health across the lifespan. In this review, we summarize recent studies on the immunology of pregnancy and menopause, emphasizing that these major immunoendocrine transition phases may play a critical part in women's brain aging trajectories.

Exosomal miRNA-17-5p derived from human umbilical cord mesenchymal stem cells improves ovarian function in premature ovarian insufficiency by regulating SIRT7

Premature ovarian insufficiency (POI) is clinically irreversible in women aged over 40 years. Although numerous studies have demonstrated satisfactory outcomes of mesenchymal stem cell therapy, the underlying therapeutic mechanism remains unclear. Exosomes were collected from the culture medium of human umbilical cord mesenchymal stem cells (hUMSCs) and assessed by electron microscopy and Western blot (WB) analysis. Then, exosomes were added to the culture medium of cyclophosphamide (CTX)-damaged human granulosa cells (hGCs), and the mixture was injected into the ovaries of CTX-induced POI model mice before detection of antiapoptotic and apoptotic gene expression. Next, the microRNA expression profiles of hUMSC-derived exosomes (hUMSC-Exos) were detected by small RNA sequencing. The ameliorative effect of exosomal microRNA-17-5P (miR-17-5P) was demonstrated by miR-17-5P knockdown before assessment of ovarian phenotype and function, reactive oxygen species (ROS) levels and SIRT7 expression. Finally, SIRT7 was inhibited or overexpressed by RNA interference or retrovirus transduction, and the protein expression of PARP1, γH2AX, and XRCC6 was analyzed. The ameliorative effect of hUMSC-Exos on POI was validated. Our results illustrated that hUMSC-Exos restored ovarian phenotype and function in a POI mouse model, promoted proliferation of CTX-damaged hGCs and ovarian cells, and alleviated ROS accumulation by delivering exosomal miR-17-5P and inhibiting SIRT7 expression. Moreover, our findings elucidated that miR-17-5P repressed PARP1, γH2AX, and XRCC6 by inhibiting SIRT7. Our findings suggest a critical role for exosomal miR-17-5P and its downstream target mRNA SIRT7 in hUMSC transplantation therapy. This study indicates the promise of exosome-based therapy for POI treatment.

Protective effects of mangafodipir against chemotherapy-induced ovarian damage in mice

BACKGROUND

Given the seriousness of chemotherapy-induced ovarian injury in female cancer patients, the preservation of fertility, including through the use of cryopreservation technology and pharmaceuticals, requires investigation. Previous studies have shown that damage to the ovaries is related to oxidative stress caused by anticancer drugs. Therefore, superoxide dismutase (SOD) may represent a key factor in the pharmacological protection of the ovaries. The aim of our study was to identify the effects of mangafodipir, a manganese chelate and SOD-mimetic, on suppression of apoptosis in granulosa cells and primordial follicle activation induced by anticancer drugs.

METHODS

Cell viability assays using methyltrichlorosilane solutions and immunoblotting for cleaved caspase-3 were performed in in vitro experiments with the simultaneous addition of mangafodipir to human non-luteinized granulosa cell line (HGrC) cultures treated with hydrogen peroxide (H₂O₂), cisplatin, or paclitaxel. Count and morphological analyses of follicles at each developing stage in the ovaries and immunohistochemistry for cleaved caspase-3, Ki67 and 4-hydroxynonenal, a marker for oxidative stress, were also performed using mangafodipir-injected 6-week-old female ICR mice treated with cisplatin or paclitaxel. Further, mangafodipir was injected into 6-week-old female BALB/c mice inoculated with ES-2 to analyze whether mangafodipir inhibits the anti-tumor effects of cisplatin or paclitaxel treatment.

RESULTS

Mangafodipir attenuated apoptosis induced by H₂O₂ and anticancer drugs in vitro. Mangafodipir also decreased the expression of 4-hydroxynonenal and reduced cisplatin- and paclitaxel-induced apoptosis in granulosa cells in vivo. In addition, mangafodipir inhibited the loss of primordial follicles. Tumor xenograft studies in mice showed that mangafodipir did not affect anticancer drug antitumor effects.

CONCLUSIONS

Oxidative stress might be one of the mechanisms of cisplatin- and paclitaxel-induced the loss of primordial follicles. Mangafodipir can reduce cisplatin- and paclitaxel-induced apoptosis in granulosa cells and primordial follicle activation partially via its SOD activity. At the same time, mangafodipir might have other potential mechanisms to inhibit the activation of primordial follicles. Further, mangafodipir attenuated the ovarian damage caused by cisplatin and paclitaxel without affecting their antitumor activities. Mangafodipir, therefore, though its efficacy might be limited, may be a new option for the preservation of fertility during anticancer treatment.

Inflammation: Bridging Age, Menopause and APOEε4 Genotype to Alzheimer's Disease

Neuro-inflammatory processes that contribute to development of Alzheimer’s are evident early in the latent prodromal phase and worsen during the course of the disease. Despite substantial mechanistic and clinical evidence of inflammation, therapeutic approaches targeting inflammation have failed to alter the course of the disease. Disparate results from epidemiological and clinical trials targeting inflammation, highlight the complexity of the inflammatory process. Herein we review the dynamics of the inflammatory process across aging, midlife endocrine transitions, and the APOEε4 genotype and their contribution to progression of Alzheimer’s disease (AD). We discuss the chronic inflammatory processes that are activated during midlife chronological and endocrine aging, which ultimately limit the clearance capacity of microglia and lead to immune senescence. Aging, menopause, and APOEε4 combine the three hits of a compromised bioenergetic system of menopause with the chronic low grade innate inflammation of aging with the APOEε4 dyslipidemia and adaptive immune response. The inflammatory immune response is the unifying factor that bridges across each of the risk factors for AD. Immune system regulators that are specific to stage of disease and inflammatory phenotype would provide a therapeutic strategy to disconnect the bridge that drives disease. Outcomes of this analysis provide plausible mechanisms underlying failed clinical trials of anti-inflammatory agents in Alzheimer’s patients. Further, they highlight the need for stratifying AD clinical trial cohorts based on inflammatory phenotype. Combination therapies that include targeted use of anti-inflammatory agent’s specific to the immune phenotype are considered.