Effects of Environment and Lifestyle Factors on Premature Ovarian Failure

Possible association between subclinical hypothyroidism and age at menopause in Colombian women

OBJECTIVE

To evaluate the association between subclinical hypothyroidism with early menopause, premature menopause, and last menstrual bleeding before the natural age of menopause.

METHODS

This was a cross-sectional study conducted in 643 postmenopausal women aged 40-69 years. Groups were formed according to last menstrual episode: ≥45 [Natural age at menopause], 40-44 and [Early menopause], <40 [Premature menopause], and <45 [last menstrual episode before the natural age of menopause]. The Zulewski scale was applied to identify manifestations related to hypothyroidism and subclinical hypothyroidism, diagnosed with a serum TSH > 4.5 µIU/mL plus T4-free between 0.7 and 1.9 ng/dL.

RESULTS

It was found that 24.4% had the last menstrual episode before the natural age of menopause, 18.6% had early menopause, and 5.7% had premature menopause. Subclinical hypothyroidism was diagnosed in 4.5% of patients. Among women with subclinical hypothyroidism, there was a higher frequency of early menopause, premature menopause, and last menstrual episode before the natural age of menopause, than in women without subclinical hypothyroidism (p < 0.05). Paresthesia (50%) and dry skin (40.7%) were the most reported hypothyroidism-related manifestations. Early menopause, premature menopause, and last menstrual episode before the natural age of menopause were associated with subclinical hypothyroidism, OR: 3.37 [95% CI: 1.40-8.10], OR: 4.31 [95% CI: 1.24-14.97], and OR: 3.57 [95% CI: 1.57-8.10], respectively.

CONCLUSIONS

The last menstrual episode before the natural age of menopause, early menopause, and premature menopause were significantly associated with a higher chance of subclinical hypothyroidism.

Linking reproductive tract microbiota to premature ovarian insufficiency: Pathophysiological mechanisms and therapies

Over the past decade, research on the human microbiota has become a hot topic. Among them, the female reproductive tract (FRT) also has a specific microbiota that maintains the body's health and dynamic balance, especially in the reproductive aspect. When the FRT ecosystem is dysregulated, changes in immune and metabolic signals can lead to pathological and physiological changes such as chronic inflammation, epithelial barrier disruption, changes in cell proliferation and apoptosis, and dysregulation of angiogenesis and metabolism, thereby causing disruption of the female endocrine system. Premature ovarian insufficiency (POI), a clinical syndrome of ovarian dysfunction, is primarily influenced by immune, genetic, and environmental factors. New evidence suggests that dysbiosis of the FRT microbiota and/or the presence of specific bacteria may contribute to the occurrence and progression of POI. This influence occurs through both direct and indirect mechanisms, including the regulation of estrogen metabolism. The use of probiotics or microbiota transplantation to regulate the microbiome has also been proven to be beneficial in improving ovarian function and the quality of life in women with premature aging. This article provides an overview of the interrelationships and roles between the FRT microbiome and POI in recent years, to fully understand the risk factors affecting female reproductive health, and to offer insights for the future diagnosis, treatment, and application of the FRT microbiome in POI patients.

Stem cell-based therapeutic potential in female ovarian aging and infertility

Premature ovarian insufficiency (POI) is defined as onset of menopause characterized by amenorrhea, hypergonadotropism, and hypoestrogenism, before the age of 40 years. The POI is increasing, which seriously affects the quality of patients' life. Due to its diversity of pathogenic factors, complex pathogenesis and limited treatment methods, the search for finding effective treatment of POI has become a hotspot. Stem cells are characterized by the ability of self-renewal and differentiation and play an important role in the regeneration of injured tissues, which is therapy is expected to be used in the treatment of POI. The aim of this review is to summarize the pathogenic mechanisms and the research progress of POI treatment with stem cells from different sources.

Identification of energy metabolism anomalies and serum biomarkers in the progression of premature ovarian failure via extracellular vesicles' proteomic and metabolomic profiles

BACKGROUND

Premature ovarian failure (POF) is a clinical condition characterized by the cessation of ovarian function, leading to infertility. The underlying molecular mechanisms remain unclear, and no predictable biomarkers have been identified. This study aimed to investigate the protein and metabolite contents of serum extracellular vesicles to investigate underlying molecular mechanisms and explore potential biomarkers.

METHODS

This study was conducted on a cohort consisting of 14 POF patients and 16 healthy controls. The extracellular vesicles extracted from the serum of each group were subjected to label-free proteomic and unbiased metabolomic analysis. Differentially expressed proteins and metabolites were annotated. Pathway network clustering was conducted with further correlation analysis. The biomarkers were confirmed by ROC analysis and random forest machine learning.

RESULTS

The proteomic and metabolomic profiles of POF patients and healthy controls were compared. Two subgroups of POF patients, Pre-POF and Pro-POF, were identified based on the proteomic profile, while all patients displayed a distinguishable metabolomic profile. Proteomic analysis suggested that inflammation serves as an early factor contributing to the infertility of POF patients. For the metabolomic analysis, despite the dysfunction of metabolism, oxidative stress and hormone imbalance were other key factors appearing in POF patients. Signaling pathway clustering of proteomic and metabolomic profiles revealed the progression of dysfunctional energy metabolism during the development of POF. Moreover, correlation analysis identified that differentially expressed proteins and metabolites were highly associated, with six of them being selected as potential biomarkers. ROC curve analysis, together with random forest machine learning, suggested that AFM combined with 2-oxoarginine was the best diagnostic biomarker for POF.

CONCLUSIONS

Omics analysis revealed that inflammation, oxidative stress, and hormone imbalance are factors that damage ovarian tissue, but the progressive dysfunction of energy metabolism might be the critical pathogenic pathway contributing to the development of POF. AFM combined with 2-oxoarginine serves as a precise biomarker for clinical POF diagnosis.

The crucial role of HFM1 in regulating FUS ubiquitination and localization for oocyte meiosis prophase I progression in mice

BACKGROUND

Helicase for meiosis 1 (HFM1), a putative DNA helicase expressed in germ-line cells, has been reported to be closely associated with premature ovarian insufficiency (POI). However, the underlying molecular mechanism has not been clearly elucidated. The aim of this study was to investigate the function of HFM1 in the first meiotic prophase of mouse oocytes.

RESULTS

The results suggested that the deficiency of HFM1 resulting in increased apoptosis and depletion of oocytes in mice, while the oocytes were arrested in the pachytene stage of the first meiotic prophase. In addition, impaired DNA double-strand break repair and disrupted synapsis were observed in the absence of HFM1. Further investigation revealed that knockout of HFM1 promoted ubiquitination and degradation of FUS protein mediated by FBXW11. Additionally, the depletion of HFM1 altered the intranuclear localization of FUS and regulated meiotic- and oocyte development-related genes in oocytes by modulating the expression of BRCA1.

CONCLUSIONS

These findings elaborated that the critical role of HFM1 in orchestrating the regulation of DNA double-strand break repair and synapsis to ensure meiosis procession and primordial follicle formation. This study provided insights into the pathogenesis of POI and highlighted the importance of HFM1 in maintaining proper meiotic function in mouse oocytes.

The influence of environmental factors on premature ovarian insufficiency and ovarian aging

Premature ovarian insufficiency and ovarian aging are complex conditions that affect women's reproductive health and overall well-being. They are both characterized by hypergonadotropic hypogonadism and infertility, and together affect about 1 in 100 women by the age of 40. This review explores the influence of environmental factors on the development and progression of premature ovarian insufficiency and ovarian aging. When referring to environmental factors, we include a wide range of external agents and conditions, including chemicals, socioeconomic factors and lifestyle choices. Through a review of the literature, we attempt to highlight the link between environmental factors and ovarian health. We examine the impact of endocrine-disrupting chemicals, such as bisphenol A and phthalates, on ovarian function and investigate the mechanisms by which these chemicals can disrupt hormone signaling pathways, leading to alterations in ovarian reserve, oocyte quality, and folliculogenesis. Moreover, we explore lifestyle factors like obesity, stress, smoking and alcohol in relation to their effects on ovarian aging. Epigenetic changes may play a crucial role in the prevalence of premature ovarian insufficiency. Understanding the impact of environmental factors on premature ovarian insufficiency and ovarian aging is very important in public and clinical health contexts. By identifying risk factors, healthcare providers can develop targeted and strategic prevention and intervention plans. Furthermore, this knowledge can promote reproductive health and minimize exposure to harmful environmental agents.

A Literature Review and a Proposed Classification of the Relationships between Ovulatory Infertility and Lifestyle Factors Based on the Three Groups of Ovulation Disorders Classified by WHO

Ovulatory infertility is a serious clinical problem whose direct causes are still largely unknown. In addition to pathologies that make it impossible for a couple to establish a pregnancy, there are a number of other factors that have a bearing on fertility, including lifestyle factors, and particularly diet. Although numerous studies have been performed linking such factors to ovulatory infertility, most of them lack the necessary clinical significance, instead focusing on observational data and suggesting or establishing associative relationships. This article consists of a literature review focusing on connections between lifestyle factors such as diet, physical exercise, oxidative stress, sleep, and supplementation, and ovulatory infertility. Special emphasis was given to issues such as obesity and insulin resistance and their mutual relationship with other factors linked to ovulatory infertility. In addition, based on the conclusions of the literature review, the authors have proposed a classification of relationships between ovulation disorders and lifestyle factors in ovulatory infertility within the framework of the WHO classification of ovulation disorders. Furthermore, areas that merit further research have been indicated as well as those that do not. WHO Group II disorders gained prominence in the results of the study as the number of links with lifestyle factors and ovulatory infertility found in the course of the review greatly exceeded those for Groups I and III. The data presented in the article show that the issues of proper diet and physical exercise are those that could benefit from robust clinical studies focused specifically on ovulation infertility, while studies concerning the relationship between oxidative stress, sleep, and supplementation and ovulatory infertility do not seem to be promising directions as far as clinical significance is concerned.

MicroRNA-22-3p in human umbilical cord mesenchymal stem cell-secreted exosomes inhibits granulosa cell apoptosis by targeting KLF6 and ATF4-ATF3-CHOP pathway in POF mice

BACKGROUND

Human umbilical cord mesenchymal stem cells (hUCMSCs)-derived exosomes carrying microRNAs (miRNAs) have promising therapeutic potential in various disorders, including premature ovarian failure (POF). Previous evidence has revealed the low plasma level of miR-22-3p in POF patients. Nevertheless, exosomal miR-22-3p specific functions underlying POF progression are unclarified.

METHODS

A cisplatin induced POF mouse model and in vitro murine ovarian granulosa cell (mOGC) model were established. Exosomes derived from miR-22-3p-overexpressed hUCMSCs (Exos-miR-22-3p) were isolated. CCK-8 assay and flow cytometry were utilized for measuring mOGC cell viability and apoptosis. RT-qPCR and western blotting were utilized for determining RNA and protein levels. The binding ability between exosomal miR-22-3p and Kruppel-like factor 6 (KLF6) was verified using luciferase reporter assay. Hematoxylin-eosin staining, ELISA, and TUNEL staining were performed for examining the alteration of ovarian function in POF mice.

RESULTS

Exos-miR-22-3p enhanced mOGC viability and attenuated mOGC apoptosis under cisplatin treatment. miR-22-3p targeted KLF6 in mOGCs. Overexpressing KLF6 reversed the above effects of Exos-miR-22-3p. Exos-miR-22-3p ameliorated cisplatin-triggered ovarian injury in POF mice. Exos-miR-22-3p repressed ATF4-ATF3-CHOP pathway in POF mice and cisplatin-treated mOGCs.

CONCLUSION

Exosomal miR-22-3p from hUCMSCs alleviates OGC apoptosis and improves ovarian function in POF mouse models by targeting KLF6 and ATF4-ATF3-CHOP pathway.

Epigenetic regulation in premature ovarian failure: A literature review

Premature ovarian failure (POF), or premature ovarian insufficiency (POI), is a multifactorial and heterogeneous disease characterized by amenorrhea, decreased estrogen levels and increased female gonadotropin levels. The incidence of POF is increasing annually, and POF has become one of the main causes of infertility in women of childbearing age. The etiology and pathogenesis of POF are complex and have not yet been clearly elucidated. In addition to genetic factors, an increasing number of studies have revealed that epigenetic changes play an important role in the occurrence and development of POF. However, we found that very few papers have summarized epigenetic variations in POF, and a systematic analysis of this topic is therefore necessary. In this article, by reviewing and analyzing the most relevant literature in this research field, we expound on the relationship between DNA methylation, histone modification and non-coding RNA expression and the development of POF. We also analyzed how environmental factors affect POF through epigenetic modulation. Additionally, we discuss potential epigenetic biomarkers and epigenetic treatment targets for POF. We anticipate that our paper may provide new therapeutic clues for improving ovarian function and maintaining fertility in POF patients.

Approach to the Patient With New-Onset Secondary Amenorrhea: Is This Primary Ovarian Insufficiency?

Menstrual cyclicity is a marker of health for reproductively mature women. Absent menses, or amenorrhea, is often the initial sign of pregnancy-an indication that the system is functioning appropriately and capable of generating the intended evolutionary outcome. Perturbations of menstrual regularity in the absence of pregnancy provide a marker for physiological or pathological disruption of this well-orchestrated process. New-onset amenorrhea with duration of 3 to 6 months should be promptly evaluated. Secondary amenorrhea can reflect structural or functional disturbances occurring from higher centers in the hypothalamus to the pituitary, the ovary, and finally, the uterus. Amenorrhea can also be a manifestation of systemic disorders resulting in compensatory inhibition of reproduction. Identifying the point of the breakdown is essential to restoring reproductive homeostasis to maintain future fertility and reestablish reproductive hormonal integrity. Among the most challenging disorders contributing to secondary amenorrhea is primary ovarian insufficiency (POI). This diagnosis stems from a number of possible etiologies, including autoimmune, genetic, metabolic, toxic, iatrogenic, and idiopathic, each with associated conditions and attendant medical concerns. The dual assaults of unanticipated compromised fertility concurrently with depletion of the normal reproductive hormonal milieu yield multiple management challenges. Fertility restoration is an area of active research, while optimal management of estrogen deficiency symptoms and the anticipated preventive benefits of hormone replacement for bone, cardiovascular, and neurocognitive health remain understudied. The state of the evidence for an optimal, individualized, clinical management approach to women with POI is discussed along with priorities for additional research in this population.

Estimates of global research productivity in primary ovarian insufficiency from 2000 to 2021: Bibliometric analysis

BACKGROUND

Primary ovarian insufficiency (POI) is a heterogeneous disease with diverse clinical phenotypes and etiologies, which is defined as ovarian dysfunction under the age of 40 years. The global prevalence of POI is approximately about 1.1%, and it severely affects female fertility. Nevertheless, bibliometric analysis in this field is extremely limited. We aimed to visualize the research hotspots and trends of POI using bibliometric analysis and tried to predict the future development of this field.

METHODS

The original articles regarding POI were culled from the Web of Science Core Collection. Countries, institutions, journals, authors, and keywords in this field were visually analyzed by employing CiteSpace software and Microsoft Excel 2021 software.

RESULTS

A total of 2,999 publications were included for further bibliometric analysis after screening the titles and abstracts stringently. The number of literature regarding POI significantly increased yearly. These publications come from 78 countries. The USA was dominant in the field of POI in terms of the number of publications (865), average citations per item (57.36), and h-index (112). The Institut National De La Sante Et De La Recherche Medicale Inserm is the most high-yield institution in this field with 351 publications. Fertility and Sterility ranked first with the highest number of publications (152), followed by Human Reproduction (138). According to the keyword cluster analysis from 2000 to 2021, the eight keyword clusters encountered frequently were apoptosis, osteoporosis, fertility preservation, mutation, fragile x syndrome, adrenal insufficiency, DNA repair, ovarian reserve. Keyword citation burst analysis revealed that whole-exome sequencing, ovarian tissue cryopreservation, and DNA repair had a citation burst until 2021.

CONCLUSIONS

Great progress has been made in POI research over the past 20 years, which is widely researched but unevenly developed in the world. In terms of influence, the United States may be in the lead. The research hotspots in POI are mainly pathogenesis and treatment, including genetic mutation, hormone therapy, fertility preservation, and stem cell transplantation.