Novel approaches to fertility restoration in women with premature ovarian insufficiency

Society for endocrinology guideline for understanding, diagnosing and treating female hypogonadism

Female hypogonadism (FH) is a relatively common endocrine disorder in women of premenopausal age, but there are significant uncertainties and wide variation in its management. Most current guidelines are monospecialty and only address premature ovarian insufficiency (POI); some allude to management in very brief and general terms, and most rely upon the extrapolation of evidence from the studies relating to physiological estrogen deficiency in postmenopausal women. The Society for Endocrinology commissioned new guidance to provide all care providers with a multidisciplinary perspective on managing patients with all forms of FH. It has been compiled using expertise from Endocrinology, Primary Care, Gynaecology and Reproductive Health practices, with contributions from expert patients and a patient support group, to help clinicians best manage FH resulting from both POI and hypothalamo-pituitary disorders, whether organic or functional.

Primary ovarian insufficiency: update on clinical and genetic findings

Primary ovarian insufficiency (POI) is a disorder of insufficient ovarian follicle function before the age of 40 years with an estimated prevalence of 3.7% worldwide. Its relevance is emerging due to the increasing number of women desiring conception late or beyond the third decade of their lives. POI clinical presentation is extremely heterogeneous with a possible exordium as primary amenorrhea due to ovarian dysgenesis or with a secondary amenorrhea due to different congenital or acquired abnormalities. POI significantly impacts non only on the fertility prospect of the affected women but also on their general, psychological, sexual quality of life, and, furthermore, on their long-term bone, cardiovascular, and cognitive health. In several cases the underlying cause of POI remains unknown and, thus, these forms are still classified as idiopathic. However, we now know the age of menopause is an inheritable trait and POI has a strong genetic background. This is confirmed by the existence of several candidate genes, experimental and natural models. The most common genetic contributors to POI are the X chromosome-linked defects. Moreover, the variable expressivity of POI defect suggests it can be considered as a multifactorial or oligogenic defect. Here, we present an updated review on clinical findings and on the principal X-linked and autosomal genes involved in syndromic and non-syndromic forms of POI. We also provide current information on the management of the premature hypoestrogenic state as well as on fertility preservation in subjects at risk of POI.

Plasma-derived from human umbilical cord blood restores ovarian function and improves serum reproductive hormones levels in mice with premature ovarian insufficiency (POI) through cytokines and growth factors

Premature ovarian insufficiency (POI) patients experience a decline in ovarian function and a reduction in serum reproductive hormones, leading to a significant impact on the outcomes of assisted reproductive technology. Despite the absence of an effective clinical treatment to restore fertility in POI patients, recent research has indicated that cord blood plasma (CBP) derived from human umbilical cord blood (hUCB) may offer therapeutic benefits for various degenerative diseases. The primary aim of this study is to explore approaches for enhancing ovarian function and serum reproductive hormones through the administration of CBP in a murine model. Initially, hUCB was utilized to obtain CBP (CBP), which was subsequently analyzed for cytokine and growth factor profiles in comparison to adult blood plasma (ABP) by use of flow cytometry. Subsequently, POI mouse models were established through the induction of 4-vinylcyclohexene diepoxide, followed by the injection of CBP into the tail. At 7, 14, and 21 days posttreatment, mouse ovaries and blood were collected, and their estrus cycle, body weight, and ovarian weights were evaluated using precise electronic balance. Finally, ovarian morphology and follicle number were assessed through HE staining, while serum levels of anti-Müllerian hormone (AMH), estradiol (E2) and follicle-stimulating hormone (FSH) were determined by ELISA. Our study revealed that individuals with CBP exhibited significantly lower concentrations of proinflammatory cytokines, including IL-β (p < 0.01) and IL-2 (p < 0.05), while displaying elevated levels of anti-inflammatory cytokines and chemokines, such as IL-2, IL-4, IL-6, IL-8, IL-12P70, IL-17A, IP-10, interferon-γ, and tumor necrosis factor-α (p < 0.01). Furthermore, CBP demonstrated remarkably higher levels of growth factors, including transforming growth factor-β1, vascular endothelial growth factor, and insulin-like growth factor-1 (p < 0.01) than ABP. Notably, our investigation also revealed that CBP restored the content of serum reproductive hormones, such as AMH, E2, and FSH (p < 0.05), and increased the number of primordial and primary follicles (p < 0.01) and decreased the number of luteal and atretic follicles (p < 0.01) in vivo. Our findings suggested that CBP-secreted cytokines and growth factors could be restored POI ovarian function, enhanced serum reproductive hormones and rescued follicular development in vivo. These findings further support the potential of CBP as a promising strategy in clinical applications for POI related infertility.

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.

Use of mesenchymal stem cells to enhance or restore fertility potential: a systematic review of available experimental strategies

STUDY QUESTION

To what extent does regenerative medicine with stem cell therapy help to address infertility issues for future clinical application?

SUMMARY ANSWER

Regenerative medicine using different stem cell sources is yielding promising results in terms of protecting the ovarian reserve from damage and senescence, and improving fertility potential in various preclinical settings.

WHAT IS KNOWN ALREADY

Regenerative medicine using stem cell therapy is emerging as a potential strategy to address a number of issues in the field of human reproduction. Indeed, different types of adult and fetal mesenchymal stem cells (MSCs) have been tested with promising results, owing to their ability to differentiate into different tissue lineages, move toward specific injured sites (homing), and generate a secretome with wound-healing, proangiogenic, and antioxidant capacities.

STUDY DESIGN SIZE DURATION

Guided by the checklist for preferred reporting items for systematic reviews and meta-analyses, we retrieved relevant studies from PubMed, Medline, and Embase databases until June 2023 using the following keywords: 'mesenchymal stem cells' AND 'ovarian follicles' OR 'ovarian tissue culture' OR 'ovarian follicle culture' OR 'cumulus oocyte complex'. Only peer-reviewed published articles written in English were included.

PARTICIPANTS/MATERIALS SETTING METHODS

The primary outcome for the experimental strategies was evaluation of the ovarian reserve, with a focus on follicle survival, number, and growth. Secondary outcomes involved analyses of other parameters associated with the follicle pool, such as hormones and growth factors, ovarian tissue viability markers including oxidative stress levels, oocyte growth and maturation rates, and of course pregnancy outcomes.

MAIN RESULTS AND THE ROLE OF CHANCE

Preclinical studies exploring MSCs from different animal origins and tissue sources in specific conditions were selected (n = 112), including: in vitro culture of granulosa cells, ovarian tissue and isolated ovarian follicles; ovarian tissue transplantation; and systemic or intraovarian injection after gonadotoxic or age-related follicle pool decline. Protecting the ovarian reserve from aging and gonadotoxic damage has been widely tested in vitro and in vivo using murine models and is now yielding initial data in the first ever case series of patients with premature ovarian insufficiency. Use of MSCs as feeder cells in ovarian tissue culture was found to improve follicle outcomes and oocyte competence, bringing us one step closer to future clinical application. MSCs also have proved effective at boosting revascularization in the transplantation site when grafting ovarian tissue in experimental animal models.

LIMITATIONS REASONS FOR CAUTION

While preclinical results look promising in terms of protecting the ovarian reserve in different experimental models (especially those in vitro using various mammal experimental models and in vivo using murine models), there is still a lot of work to do before this approach can be considered safe and successfully implemented in a clinical setting.

WIDER IMPLICATIONS OF THE FINDINGS

All gathered data on the one hand show that regenerative medicine techniques are quickly gaining ground among innovative techniques being developed for future clinical application in the field of reproductive medicine. After proving MSC effectiveness in preclinical settings, there is still a lot of work to do before MSCs can be safely and effectively used in different clinical applications.

STUDY FUNDING/COMPETING INTERESTS

This study was supported by grants from the Fonds National de la Recherche Scientifique de Belgique (FNRS-PDR T.0077.14, FNRS-CDR J.0063.20, and grant 5/4/150/5 awarded to Marie-Madeleine Dolmans), Fonds Spéciaux de Recherche, and the Fondation St Luc. None of the authors have any competing interest to disclose.

REGISTRATION NUMBER

N/A.

Hormones and Aging: An Endocrine Society Scientific Statement

Multiple changes occur across various endocrine systems as an individual ages. The understanding of the factors that cause age-related changes and how they should be managed clinically is evolving. This statement reviews the current state of research in the growth hormone, adrenal, ovarian, testicular, and thyroid axes, as well as in osteoporosis, vitamin D deficiency, type 2 diabetes, and water metabolism, with a specific focus on older individuals. Each section describes the natural history and observational data in older individuals, available therapies, clinical trial data on efficacy and safety in older individuals, key points, and scientific gaps. The goal of this statement is to inform future research that refines prevention and treatment strategies in age-associated endocrine conditions, with the goal of improving the health of older individuals.

The Trends and Hotspots in Premature Ovarian Insufficiency Therapy from 2000 to 2022

This study aims to map the knowledge structure and themes trends of primary ovarian insufficiency (POI) therapy to help researchers rapidly master the hotspots and prospects of POI therapy from the increasing number of publications. The literature search and bibliometric analyses were performed by using Web of Science Core Collection and VOSviewer. Annual publications from 2000 to 2022 continued to increase with some fluctuations. The most productive country, organization, and journal were the USA, Shanghai Jiao Tong University, and Human Reproduction, respectively. Harvard University was the organization with the highest citation. Fertility and Sterility and Nelson, L.M. were the most influential journal and author, respectively. Seven clusters separated by keywords association showed the extensive scope of POI therapy. The hotspots of POI therapy were hormone replacement therapy and fertility preservation, and the innovative treatment strategies including in vitro activation and mesenchymal stem cells had development potential. In addition, our result showed that the high-cited articles were published in journals with high impact factors. The paper provides a comprehensive overview of the development and hotspots of POI therapy, allowing researchers to recognize the current status and future directions of POI therapy.

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.

Mitochondria: Their relevance during oocyte ageing

The oocyte is recognised as the largest cell in mammalian species and other multicellular organisms. Mitochondria represent a high proportion of the cytoplasm in oocytes and mitochondrial architecture is different in oocytes than in somatic cells, characterised by a rounder appearance and fragmented network. Although the number of mitochondria per oocyte is higher than in any other mammalian cell, their number and activity decrease with advancing age. Mitochondria integrate numerous processes essential for cellular function, such as metabolic processes related to energy production, biosynthesis, and waste removal, as well as Ca²⁺ signalling and reactive oxygen species (ROS) homeostasis. Further, mitochondria are responsible for the cellular adaptation to different types of stressors such as oxidative stress or DNA damage. When these stressors outstrip the adaptive capacity of mitochondria to restore homeostasis, it leads to mitochondrial dysfunction. Decades of studies indicate that mitochondrial function is multifaceted, which is reflected in the oocyte, where mitochondria support numerous processes during oocyte maturation, fertilization, and early embryonic development. Dysregulation of mitochondrial processes has been consistently reported in ageing and age-related diseases. In this review, we describe the functions of mitochondria as bioenergetic powerhouses and signal transducers in oocytes, how dysfunction of mitochondrial processes contributes to reproductive ageing, and whether mitochondria could be targeted to promote oocyte rejuvenation.