Hippo signaling disruption and ovarian follicle activation in infertile patients

Ovarian Puncture Triggers an Inflammatory Response that did not Affect Late Folliculogenesis, Ovulation Rate, and Fertility

Ovarian puncture has been widely used in assisted reproduction, but there are still gaps about its effects on ovarian morphophysiology, as well as the relationship between inflammation caused by this procedure and the follicular growth and fertility. The aim of this study was to investigate the effects of ovarian puncture on folliculogenesis and fertility. Mice (n = 24) were divided into two groups: (1) SHAM-both ovaries were exposed and repositioned and (2) Punctured-ovaries were exposed, punctured, and repositioned. After 96 h of surgery, ovaries were collected for morphofunctional analysis. New females were used for the superovulation (n = 10) and fertility assays (n = 10). Increased volumetric density of inflammatory cells-p = 0.0005, p = 0.0013; hemorrhagic foci-p < 0.0001; and inflammatory exudate-p < 0.0001 could be noticed on the punctured group, compared to SHAM. The percentage of primordial follicles was lower on the punctured ovaries (p = 0.00294). Ovarian puncture has also induced an increase in the proliferation of granulosa cells of primary (p = 0.0321) and antral follicles (p = 0.0395), and an increased apoptotic index of antral follicles (p = 0.0100). There was no influence on expression of some genes related to inflammation, collagen deposition and folliculogenesis progression. The reproductive aspects (oocyte retrieval and number of fetuses per female) were not altered (p > 0.05). Taken together, our findings strongly suggest that ovarian puncture results in a local inflammation that affects follicular growth and atresia. However, it does not affect female fertility, which strengthens the safety of this procedure.

Neuromedin S regulates goat ovarian granulosa cell proliferation and steroidogenesis via endoplasmic reticulum Ca2+-YAP1-ATF4-c-Jun pathway

Neuromedin S (NMS) plays key roles in reproductive regulation, while its function and mechanism in follicular development remain unclear. The current study aims to investigate the specific role and mechanisms of NMS and its receptors in regulating the proliferation and steroidogenesis of ovarian granulosa cells (GCs). Phenotypically, a certain concentration of NMS addition promoted the proliferation and estrogen production of goat GCs, accompanied by an increase in the G1/S cell population and upregulation of the expression levels of cyclin D1, cyclin dependent kinase 6, steroidogenic acute regulatory protein, cytochrome P450, family 11, subfamily A, polypeptide 1, 3beta-hydroxysteroid dehydrogenase, and cytochrome P450, family 11, subfamily A, polypeptide 1, while the effects of NMS treatment were effectively hindered by knockdown of neuromedin U receptor type 2 (NMUR2). Mechanistically, activation of NMUR2 with NMS maintained endoplasmic reticulum (ER) calcium (Ca2+) homeostasis by triggering the PLCG1-IP3R pathway, which helped preserve ER morphology, sustained an appropriate level of endoplasmic reticulum unfolded protein response (UPRer), and suppressed the nuclear translocation of activating transcription factor 4. Moreover, NMS maintained intracellular Ca2+ homeostasis to activate the calmodulin 1-large tumor suppressor kinase 1 pathway, ultimately orchestrating the regulation of goat GC proliferation and estrogen production through the Yes1 associated transcriptional regulator-ATF4-c-Jun pathway. Crucially, the effects of NMS were mitigated by concurrent knockdown of the NMUR2 gene. Collectively, these data suggest that activation of NMUR2 by NMS enhances cell proliferation and estrogen production in goat GCs through modulating the ER and intracellular Ca2+ homeostasis, leading to activation of the YAP1-ATF4-c-Jun pathway. These findings offer valuable insights into the regulatory mechanisms involved in follicular growth and development, providing a novel perspective for future research.

Endometrial stem cell-derived exosomes repair cisplatin-induced premature ovarian failure via Hippo signaling pathway

Stem cells have been documented as a new therapeutic method for ovarian injuries such as premature ovarian failure (POF). However, effects of exosomes (Exos) derived from human endometrial stem cells (EnSCs) on diminished ovarian failure remain to be carefully elucidated. Our study aims to investigate the mechanisms of EnSC-Exos in the recovery of the cisplatin-induced granulosa cell injury model in vitro or POF mouses model in vivo and whether the Hippo signaling pathway is involved in the regulation. In this study, we established successful construction of the cisplatin-induced granulosa cell injury model and evaluated Hippo signaling pathway activation in cisplatin-damaged granulosa cells (GCs). Furthermore, laser scanning confocal microscope and immunofluorescence demonstrated that EnSC-Exos can be transferred to cisplatin-damaged GCs to decrease apoptosis. In addition, the enhanced expression of YAP at the protein level as well as YAP/TEAD target genes, such as CTGF, ANKRD1, and the increase of YAP into the nucleus in immunofluorescence staining after the addition of EnSC-Exos to cisplatin-damaged GCs confirmed the suppression of Hippo signaling pathway. While in vivo, EnSC-Exos successfully remedied POF in a mouse model. Collectively, our findings suggest that chemotherapy-induced POF was associated with the activating of Hippo signaling pathway. Human EnSC-Exos significantly elevated the proliferation of ovarian GCs and the ovarian function by regulating Hippo signaling pathway. These findings provide new insights for further understanding of EnSC-Exos in the recovery of ovary function.

Effects of chemical in vitro activation versus fragmentation on human ovarian tissue and follicle growth in culture

STUDY QUESTION

What is the effect of the chemical in vitro activation (cIVA) protocol compared with fragmentation only (Frag, also known as mechanical IVA) on gene expression, follicle activation and growth in human ovarian tissue in vitro?

SUMMARY ANSWER

Although histological assessment shows that cIVA significantly increases follicle survival and growth compared to Frag, both protocols stimulate extensive and nearly identical transcriptomic changes in cultured tissue compared to freshly collected ovarian tissue, including marked changes in energy metabolism and inflammatory responses.

WHAT IS KNOWN ALREADY

Treatments based on cIVA of the phosphatase and tensin homolog (PTEN)-phosphatidylinositol 3-kinase (PI3K) pathway in ovarian tissue followed by auto-transplantation have been administered to patients with refractory premature ovarian insufficiency (POI) and resulted in live births. However, comparable effects with mere tissue fragmentation have been shown, questioning the added value of chemical stimulation that could potentially activate oncogenic responses.

STUDY DESIGN SIZE DURATION

Fifty-nine ovarian cortical biopsies were obtained from consenting women undergoing elective caesarean section (C-section). The samples were fragmented for culture studies. Half of the fragments were exposed to bpV (HOpic)+740Y-P (Frag+cIVA group) during the first 24 h of culture, while the other half were cultured with medium only (Frag group). Subsequently, both groups were cultured with medium only for an additional 6 days. Tissue and media samples were collected for histological, transcriptomic, steroid hormone, and cytokine/chemokine analyses at various time points.

PARTICIPANTS/MATERIALS SETTING METHODS

Effects on follicles were evaluated by counting and scoring serial sections stained with hematoxylin and eosin before and after the 7-day culture. Follicle function was assessed by quantification of steroids by ultra-performance liquid chromatography tandem-mass spectrometry at different time points. Cytokines and chemokines were measured by multiplex assay. Transcriptomic effects were measured by RNA-sequencing (RNA-seq) of the tissue after the initial 24-h culture. Selected differentially expressed genes (DEGs) were validated by quantitative PCR and immunofluorescence in cultured ovarian tissue as well as in KGN cell (human ovarian granulosa-like tumor cell line) culture experiments.

MAIN RESULTS AND THE ROLE OF CHANCE

Compared to the Frag group, the Frag+cIVA group exhibited a significantly higher follicle survival rate, increased numbers of secondary follicles, and larger follicle sizes. Additionally, the tissue in the Frag+cIVA group produced less dehydroepiandrosterone compared to Frag. Cytokine measurement showed a strong inflammatory response at the start of the culture in both groups. The RNA-seq data revealed modest differences between the Frag+cIVA and Frag groups, with only 164 DEGs identified using a relaxed cut-off of false discovery rate (FDR) <0.1. Apart from the expected PI3K-protein kinase B (Akt) pathway, cIVA also regulated pathways related to hypoxia, cytokines, and inflammation. In comparison to freshly collected ovarian tissue, gene expression in general was markedly affected in both the Frag+cIVA and Frag groups, with a total of 3119 and 2900 DEGs identified (FDR < 0.001), respectively. The top enriched gene sets in both groups included several pathways known to modulate follicle growth such as mammalian target of rapamycin (mTOR)C1 signaling. Significant changes compared to fresh tissue were also observed in the expression of genes encoding for steroidogenesis enzymes and classical granulosa cell markers in both groups. Intriguingly, we discovered a profound upregulation of genes related to glycolysis and its upstream regulator in both Frag and Frag+cIVA groups, and these changes were further boosted by the cIVA treatment. Cell culture experiments confirmed glycolysis-related genes as direct targets of the cIVA drugs. In conclusion, cIVA enhances follicle growth, as expected, but the mechanisms may be more complex than PI3K-Akt-mTOR alone, and the impact on function and quality of the follicles after the culture period remains an open question.

LARGE SCALE DATA

Data were deposited in the GEO data base, accession number GSE234765. The code for sequencing analysis can be found in https://github.com/tialiv/IVA_project.

LIMITATIONS REASONS FOR CAUTION

Similar to the published IVA protocols, the first steps in our study were performed in an in vitro culture model where the ovarian tissue was isolated from the regulation of hypothalamic-pituitary-ovarian axis. Further in vivo experiments will be needed, for example in xeno-transplantation models, to explore the long-term impacts of the discovered effects. The tissue collected from patients undergoing C-section may not be comparable to tissue of patients with POI.

WIDER IMPLICATIONS OF THE FINDINGS

The general impact of fragmentation and short (24 h) in vitro culture on gene expression in ovarian tissue far exceeded the effects of cIVA. Yet, follicle growth was stimulated by cIVA, which may suggest effects on specific cell populations that may be diluted in bulk RNA-seq. Nevertheless, we confirmed the impact of cIVA on glycolysis using a cell culture model, suggesting impacts on cellular signaling beyond the PI3K pathway. The profound changes in inflammation and glycolysis following fragmentation and culture could contribute to follicle activation and loss in ovarian tissue culture, as well as in clinical applications, such as fertility preservation by ovarian tissue auto-transplantation.

STUDY FUNDING/COMPETING INTERESTS

This study was funded by research grants from European Union's Horizon 2020 Research and Innovation Programme (Project ERIN No. 952516, FREIA No. 825100), Swedish Research Council VR (2020-02132), StratRegen funding from Karolinska Institutet, KI-China Scholarship Council (CSC) Programme and the Natural Science Foundation of Hunan (2022JJ40782). International Iberian Nanotechnology Laboratory Research was funded by the European Union's H2020 Project Sinfonia (857253) and SbDToolBox (NORTE-01-0145-FEDER-000047), supported by Norte Portugal Regional Operational Programme (NORTE 2020), under the PORTUGAL 2020 Partnership Agreement, through the European Regional Development Fund. No competing interests are declared.

Basal characteristics of patients who responded to Ovarian Fragmentation for Follicular Activation (OFFA) or In Vitro Activation (IVA): a systematic review and meta-analysis

A systematic review and meta-analysis were performed to identify if there is a subset of patients with POI who are more likely to show follicular growth after ovarian fragmentation for follicular activation (OFFA) or in vitro activation (IVA). Five studies met inclusion criteria for meta-analysis with a total of 164 patients. Forty-three patients showed follicle development (26.21%). Of those, the pregnancy rate was 35.58% (11/43) and the live birth rate was 20.93% (9/43). Our meta-analysis showed that age was not associated with follicle growth. However, lower baseline FSH, lower duration of amenorrhea/diagnosis, and presence of follicles remaining in biopsy were statistically significant for follicle development. Patients with basal characteristics mentioned before may have more chances to show follicle growth after OFFA or IVA. Taking into account that approximately 20% of patients with follicle growth had live birth, these results are very promising. Given the overall certainty of evidence, future studies are needed to confirm said results.

Oocyte in-vitro maturation primed with letrozole-HCG versus FSH-HCG in women with oocyte maturation abnormalities: a retrospective study

RESEARCH QUESTION

Are there differences between in-vitro maturation (IVM) primed with letrozole-human chorionic gonadotrophin (HCG) and IVM primed with FSH-HCG in women with oocyte maturation abnormalities (OMAs), defined as at least two failed IVF cycles where immature oocytes were retrieved?

DESIGN

This retrospective study was conducted at a private fertility clinic from January 2009 to April 2023. The final analysis included 75 women in Group 1 (IVM primed with FSH-HCG) and 52 women in Group 2 (IVM primed with letrozole-HCG).

RESULTS

A significantly higher median number of oocytes was obtained in Group 1 compared with Group 2 {9 [interquartile range (IQR) 1-5] versus 5 (IQR 1-18); P < 0.001}. However, no differences in oocyte maturation stage at collection were found between the groups (P > 0.05). At the end of IVM, Group 1 had 73/666 mature oocytes and Group 2 had 106/322 mature oocytes, and the median metaphase II oocyte rate per patient was higher in Group 2 [33.3% (IQR 66.7-100.0%) versus 0.0% (IQR 0.0-22.2%); P < 0.001]. Moreover, Group 2 demonstrated a higher median fertilization rate [66.7% (IQR 50.0-100.0%) versus 50.0% (IQR 0.0-66.7%); P = 0.027]. Group 2 had a higher proportion of Grade 2 embryos (58.5% versus 6.3%), and Group 1 had a higher proportion of Grade 3 embryos (93.8% vs 24.4%; P < 0.001). Notably, all pregnancies obtained in the study were in Group 2 (5 versus 0; P = 0.042).

CONCLUSIONS

IVM primed with letrozole-HCG in women with prior failed IVF cycles due to OMAs may result in mature oocytes, clinical pregnancies and live births. The effectiveness of letrozole priming for the subtypes of OMAs needs further investigation, with studies including greater numbers of cases.

Enhanced solute transport and steady mechanical stimulation in a novel dynamic perifusion bioreactor increase the efficiency of the in vitro culture of ovarian cortical tissue strips

Introduction: We report the development and preliminary evaluation of a novel dynamic bioreactor to culture ovarian cortical tissue strips that leverages tissue response to enhanced oxygen transport and adequate mechanical stimulation. In vitro multistep ovarian tissue static culture followed by mature oocyte generation, fertilization, and embryo transfer promises to use the reserve of dormant follicles. Unfortunately, static in vitro culture of ovarian tissue does not promote development of primordial to secondary follicles or sustain follicle viability and thereby limits the number of obtainable mature oocytes. Enhancing oxygen transport to and exerting mechanical stimulation on ovarian tissue in a dynamic bioreactor may more closely mimic the physiological microenvironment and thus promote follicle activation, development, and viability. Materials and Methods: The most transport-effective dynamic bioreactor design was modified using 3D models of medium and oxygen transport to maximize strip perifusion and apply tissue fluid dynamic shear stresses and direct compressive strains to elicit tissue response. Prototypes of the final bioreactor design were manufactured with materials of varying cytocompatibility and assessed by testing the effect of leachables on sperm motility. Effectiveness of the bioreactor culture was characterized against static controls by culturing fresh bovine ovarian tissue strips for 7 days at 4.8 × 10-5 m/s medium filtration flux in air at -15% maximal total compressive strain and by assessing follicle development, health, and viability. Results and Conclusions: Culture in dynamic bioreactors promoted effective oxygen transport to tissues and stimulated tissues with strains and fluid dynamic shear stresses that, although non-uniform, significantly influenced tissue metabolism. Tissue strip culture in bioreactors made of cytocompatible polypropylene preserved follicle viability and promoted follicle development better than static culture, less so in bioreactors made of cytotoxic ABS-like resin.

Network pharmacology and experimental validation on yangjing zhongyu decoction against diminished ovarian reserve

ETHNOPHARMACOLOGICAL RELEVANCE

Diminished ovarian reserve (DOR) was considered a refractory reproductive endocrine condition that negatively affected female reproductivity. Yangjing Zhongyu Decoction (YJZYD) had effects on treating infertility. However, there were few studies on the mechanisms of YJZYD preserving ovarian reserve.

AIM OF THE STUDY

To explore the possible mechanisms of YJZYD against DOR by UPLC-ESI-MS/MS, network pharmacology, and experimental validation.

METHODS

The chemicals of YJZYD were measured by UPLC-ESI-MS/MS. The correlating targets of YJZYD and DOR were identified by the ETCM database, GeneCards database, and PubMed database. The common targets were employed with the DAVID database and visualized with the PPI network. GO and KEGG enrichment analyses were carried out to explore biological progression and pathways. In vivo experiments, energy production was assessed by ATP, and apoptosis rate was analyzed by TUNEL. The serum FSH, AMH, and E2 levels were evaluated by ELISA. Western blotting and immunohistochemistry were used to measure the expression of SIRT1, PGC1α, NRF1, COX IV, FSHR, CYP19A1, PI3K, p-Akt, Akt, Bcl-2, and Bax.

RESULTS

132 components in YJZYD were identified by UPLC-ESI-MS/MS. 149 overlapped targets were extracted from YJZYD and DOR, and the top 20 common targets included AKT1 and CYP19A1. ATP binding was involved in GO analysis. In the KEGG enrichment analysis, the metabolic pathway was the top, and the PI3K-Akt signaling pathway was included. In vivo experiments, YJZYD improved ovarian index and histomorphology. After YJZYD treatment, serum FSH, E2, and AMH were well-modulated, and the content of ATP was up-regulated. Besides, the expression of Bax was suppressed in ovarian tissue, while the expressions of SIRT1, PGC1α, NRF1, COX IV, FSHR, CYP19A1, PI3K, Bcl-2, and p-Akt/Akt were enhanced.

CONCLUSION

YJZYD could attenuate reproductive endocrine disturbance and ovarian lesions in vivo by mediating steroidogenesis, energy metabolism, and cell apoptosis. This study uncovered the mechanisms of YJZYD against DOR, providing a theoretical basis for further study.

TT-10 may attenuate ibuprofen-induced ovarian injury in mice by activating COX2-PGE2 and inhibiting Hippo pathway

Ibuprofen (IBU) is a non-steroidal anti-inflammatory drug that has been found in recent years to cause ovarian damage. The aim of this study is to explore the molecular mechanisms of IBU damage to the ovary and drugs to combat it. We established in vivo (IBU doses of 50, 100 and 200 mg/kg-day) and in vitro (IBU concentrations of 50, 100 and 200 μM in culture medium) models of ovarian damage in mice simulating clinical doses and found that IBU not only caused ovarian damage in mice in a dose-response relationship, but also decreased estradiol (E2) and prostaglandin E2 (PGE2) levels in serum/media with increasing IBU doses. In damaged ovaries, the cyclooxygenase 2 (COX2)-PGE2 pathway is inhibited, the Hippo pathway is activated, circPVT1 is decreased, and miR-149 is elevated. TT-10 is an activator of YES-associated protein (YAP)-transcriptional enhancer factor domain activity. Then, 100 μM IBU-induced ovarian damage model was selected for YAP activation (Hippo pathway inhibition) experiment, and TT-10 was found to interfere with IBU-induced ovarian damage and increase E2 level in the medium, and 10 μM of TT-10 had the best protective effect. TT-10 also inhibited the Hippo pathway, activated the COX2-PGE2 pathway, elevated circPVT1 expression, and decreased miR-149 expression in the ovary. It has been hypothesized that clinical doses of IBU damage mouse ovaries by inhibiting COX2-PGE2 and activating the Hippo pathway, whereas TT-10 protects the ovaries through the inverse regulation of these two pathways.

Potential Therapeutic Options for Premature Ovarian Insufficiency: Experimental and Clinical Evidence

Premature ovarian insufficiency (POI) is a condition in which a woman experiences premature decline in ovarian function before the age of 40 years, manifested by menstrual disorders, decreased fertility, and possibly postmenopausal symptoms such as insomnia, hot flashes, and osteoporosis, and is one of the predominant clinical syndromes leading to female infertility. Genetic, immunologic, iatrogenic and other factors, alone or in combination, have been reported to trigger POI, yet the etiology remains unknown in most cases. The main methods currently used clinically to ameliorate menopausal symptoms due to hypoestrogenemia in POI patients are hormone replacement therapy, while the primary methods available to address infertility in POI patients are oocyte donation and cryopreservation techniques, both of which have limitations to some degree. In recent years, researchers have continued to explore more efficient and safe therapies, and have achieved impressive results in preclinical trials. In this article, we will mainly review the three most popular therapies and their related signaling pathways published in the past ten years, with the aim of providing ideas for clinical applications.

Overactivation or Apoptosis: Which Mechanisms Affect Chemotherapy-Induced Ovarian Reserve Depletion?

Dormant primordial follicles (PMF), which constitute the ovarian reserve, are recruited continuously into the cohort of growing follicles in the ovary throughout female reproductive life. Gonadotoxic chemotherapy was shown to diminish the ovarian reserve pool, to destroy growing follicle population, and to cause premature ovarian insufficiency (POI). Three primary mechanisms have been proposed to account for this chemotherapy-induced PMF depletion: either indirectly via over-recruitment of PMF, by stromal damage, or through direct toxicity effects on PMF. Preventative pharmacological agents intervening in these ovotoxic mechanisms may be ideal candidates for fertility preservation (FP). This manuscript reviews the mechanisms that disrupt follicle dormancy causing depletion of the ovarian reserve. It describes the most widely studied experimental inhibitors that have been deployed in attempts to counteract these affects and prevent follicle depletion.

Making a good egg: human oocyte health, aging, and in vitro development

Mammalian eggs (oocytes) are formed during fetal life and establish associations with somatic cells to form primordial follicles that create a store of germ cells (the primordial pool). The size of this pool is influenced by key events during the formation of germ cells and by factors that influence the subsequent activation of follicle growth. These regulatory pathways must ensure that the reserve of oocytes within primordial follicles in humans lasts for up to 50 years, yet only approximately 0.1% will ever be ovulated with the rest undergoing degeneration. This review outlines the mechanisms and regulatory pathways that govern the processes of oocyte and follicle formation and later growth, within the ovarian stroma, through to ovulation with particular reference to human oocytes/follicles. In addition, the effects of aging on female reproductive capacity through changes in oocyte number and quality are emphasized, with both the cellular mechanisms and clinical implications discussed. Finally, the details of current developments in culture systems that support all stages of follicle growth to generate mature oocytes in vitro and emerging prospects for making new oocytes from stem cells are outlined.

Facilitation of Ovarian Response by Mechanical Force-Latest Insight on Fertility Improvement in Women with Poor Ovarian Response or Primary Ovarian Insufficiency

The decline in fertility in aging women, especially those with poor ovarian response (POR) or primary ovarian insufficiency (POI), is a major concern for modern IVF centers. Fertility treatments have traditionally relied on gonadotropin- and steroid-hormone-based IVF practices, but these methods have limitations, especially for women with aging ovaries. Researchers have been motivated to explore alternative approaches. Ovarian aging is a complicated process, and the deterioration of oocytes, follicular cells, the extracellular matrix (ECM), and the stromal compartment can all contribute to declining fertility. Adjunct interventions that involve the use of hormones, steroids, and cofactors and gamete engineering are two major research areas aimed to improve fertility in aging women. Additionally, mechanical procedures including the In Vitro Activation (IVA) procedure, which combines pharmacological activators and fragmentation of ovarian strips, and the Whole Ovary Laparoscopic Incision (WOLI) procedure that solely relies on mechanical manipulation in vivo have shown promising results in improving follicle growth and fertility in women with POR and POI. Advances in the use of mechanical procedures have brought exciting opportunities to improve fertility outcomes in aging women with POR or POI. While the lack of a comprehensive understanding of the molecular mechanisms that lead to fertility decline in aging women remains a major challenge for further improvement of mechanical-manipulation-based approaches, recent progress has provided a better view of how these procedures promote folliculogenesis in the fibrotic and avascular aging ovaries. In this review, we first provide a brief overview of the potential mechanisms that contribute to ovarian aging in POI and POR patients, followed by a discussion of measures that aim to improve ovarian folliculogenesis in aging women. At last, we discuss the likely mechanisms that contribute to the outcomes of IVA and WOLI procedures and potential future directions.

The role of Hippo pathway in ovarian development

The follicle is the functional unit of the ovary, whereby ovarian development is largely dependent on the development of the follicles themselves. The activation, growth, and progression of follicles are modulated by a diverse range of factors, including reproductive endocrine system and multiple signaling pathways. The Hippo pathway exhibits a high degree of evolutionary conservation between both Drosophila and mammalian systems, and is recognized for its pivotal role in regulating cellular proliferation, control of organ size, and embryonic development. During the process of follicle development, the components of the Hippo pathway show temporal and spatial variations. Recent clinical studies have shown that ovarian fragmentation can activate follicles. The mechanism is that the mechanical signal of cutting triggers actin polymerization. This process leads to the disruption of the Hippo pathway and subsequently induces the upregulation of downstream CCN and apoptosis inhibitors, thereby promoting follicle development. Thus, the Hippo pathway plays a crucial role in both the activation and development of follicles. In this article, we focused on the development and atresia of follicles and the function of Hippo pathway in these processes. Additionally, the physiological effects of Hippo pathway in follicle activation are also explored.

Iron overload triggering ECM-mediated Hippo/YAP pathway in follicle development: a hypothetical model endowed with therapeutic implications

Disruption of iron homeostasis plays a negative role in follicle development. The dynamic changes in follicle growth are dependent on Hippo/YAP signaling and mechanical forces. However, little is known about the liaison between iron overload and the Hippo/YAP signalling pathway in term of folliculogenesis. Here, based on the available evidence, we established a hypothesized model linking excessive iron, extracellular matrix (ECM), transforming growth factor-β (TGF-β) and Hippo/Yes-associated protein (YAP) signal regarding follicle development. Hypothetically, the TGF-β signal and iron overload may play a synergistic role in ECM production via YAP. We speculate that the dynamic homeostasis of follicular iron interacts with YAP, increasing the risk of ovarian reserve loss and may enhance the sensitivity of follicles to accumulated iron. Hence, therapeutic interventions targeting iron metabolism disorders, and Hippo/YAP signal may alter the consequences of the impaired developmental process based on our hypothesis, which provides potential targets and inspiration for further drug discovery and development applied to clinical treatment.

Intraovarian Platelet-Rich Plasma Injections: Safety and Thoughts on Efficacy Based on a Single Centre Experience With 469 Women

BACKGROUND

Ovarian rejuvenation is an innovative procedure intended to restore ovarian fertility and development during the climacteric and has been used to enhance fertility in women with premature ovarian insufficiency (POI). This retrospective study was conducted to determine the effects of an intraovarian platelet-rich plasma (PRP) injection on ovarian stimulation outcomes in women referred to an in vitro fertilisation centre. Methods-Population: This was a retrospective observational study, and the inclusion criteria included women of reproductive age with at least one ovary with a history of infertility, hormonal abnormalities, an absence of a menstrual cycle, and premature ovarian failure. During the patient's first consultation, a detailed reproductive history was recorded, a pelvic scan for ovarian size was conducted, and hormonal analysis for follicle-stimulating hormone (FSH), anti-Müllerian hormone (AMH), estradiol (E2), and luteinizing hormone (LH) was conducted.

RESULTS

In the study, 469 women with a history of infertility, hormonal abnormalities, an absence of a menstrual cycle, and premature ovarian failure had hormonal levels recorded up to four months after treatment, and these were included in the study. The volume of peripheral blood required to prepare 6-8 mL of PRP for administration was 40-60 mL. The initial concentration of platelets in the peripheral blood sample was about 25000/µL, whereas the prepared PRP had a concentration of 900.000/µL. A volume of approximately 2-4 mL per ovary, depending on the ovarian volume, was used for the intraovarian injection. PRP intervention had significant effects on FSH concentration at the α = 0.05 level. Statistically significant increases in normal values of FSH and E2were observed for months three and four after the PRP intervention for all age groups.

CONCLUSIONS

The results of our observational study revealed that a PRP intraovarian injection is associated with improved ovarian tissue and function. Future randomised clinical trials are needed to shed light on the use of PRP in ovarian rejuvenation before offering it routinely in clinical practice.

Genome-wide association study analysis to resolve the key regulatory mechanism of biomineralization in Pinctada fucata martensii

Biomineralization-controlled exo-/endoskeleton growth contributes to body growth and body size diversity. Molluscan shells undergo ectopic biomineralization to form the exoskeleton and biocalcified "pearl" involved in invading defence. Notably, exo-/endoskeletons have a common ancestral origin, but their regulation and body growth are largely unknown. This study employed the pearl oyster, Pinctada fucata marntensii, a widely used experimental model for biomineralization in invertebrates, to perform whole-genome resequencing of 878 individuals from wild and breeding populations. This study characterized the genetic architecture of biomineralization-controlled growth and ectopic biomineralization. The insulin-like growth factor (IGF) endocrine signal interacted with ancient single-copy transcription factors to form the regulatory network. Moreover, the "cross-phylum" regulation of key long noncoding RNA (lncRNA) in bivalves and mammals indicated the conserved genetic and epigenetic regulation in exo-/endoskeleton growth. Thyroid hormone signal and apoptosis regulation in pearl oysters affected ectopic biomineralization in pearl oyster. These findings provide insights into the mechanism underlying the evolution and regulation of biomineralization in exo-/endoskeleton animals and ectopic biomineralization.

Application value of Early-Follicular Phase Long-Acting Gonadotropin-Releasing Hormone Agonist Long Protocol in patients with resistant ovary syndrome

BACKGROUND

Resistant ovarian syndrome(ROS) is a rare disease. It is difficult to diagnose and treat. Most of the literature reports on assisted pregnancy treatment for ROS patients are individual case reports. In this paper, the ovulation stimulation protocol and assisted pregnancy process of ROS infertile patients in our reproductive center were summarized and analyzed to provide information and support for the clinical treatment of ROS patients.

METHODS

From January 2017 to March 2022, assisted reproductive technology treatments and clinical characteristics parameters of six patients with ROS were retrospectively reviewed. Based on controlled ovarian stimulation protocols, these stimulation cycles were separated into four groups: Early-Follicular Phase Long-Acting Gonadotropin-Releasing Hormone Agonist Long Protocol (EFLL) group (n = 6), Progestin Primed Ovarian Stimulation(PPOS) protocol group (n = 5), mild-stimulation protocol group (n = 2), and Natural cycle protocol group (n = 3).

RESULTS

A total of 16 cycles of ovulation stimulation were carried out in 6 patients with ROS. A total of 19 oocytes were retrieved, as well as 13 MII oocytes, 11 two pronuclear(2PN) fertilized embryos, and 8 excellent embryos. The oocytes acquisition rate was 50% and the fertilization rate of 2PN was 57.9%, and the excellent embryo rate was 72.7%. The EFLL protocol obtained 17 oocytes, 12 MII oocytes, 11 2PN fertilized embryos, and 8 excellent embryos; the mild-stimulation protocol obtained 1 oocyte; the Natural cycle protocol obtained 1 oocyte, and oocytes were not matured after in vitro maturation (IVM); the PPOS protocol obtained no oocytes. Compared with three other protocols, The fertilization rate of 2PN (64.7%) and excellent embryo rate (72.7%) in the EFLL protocol were higher than those of other protocols(0%). Two fresh cycle embryo transfers resulted in live births, while two frozen-thawed embryo transfer cycles resulted in one live birth and one clinical pregnancy using the EFLL protocol.

CONCLUSION

Although the current study is based on a small sample of participants, the findings suggest that the EFLL protocol can be employed for ovarian stimulation and may result in a live birth in ROS patients.

Accentuated Hippo pathway and elevated miR-132 and miR-195a lead to changes of uteri and ovaries in offspring mice following prenatal exposure to vinclozolin

Vinclozolin (VCZ) has been identified as a broad-spectrum fungicide and an environmental endocrine disruptor. Also, the Hippo signaling pathway controls organ size by regulating cell proliferation and apoptosis, and moreover, overexpression of microRNA-132 (miR-132) and microRNA-195 (miR-195) inhibits cell proliferation and promotes apoptosis. So, in this study, the experimental mice were orally given 400 mg/kg/day VCZ (suspended in corn oil) at gestational day 12-18, while those of the control group were fed with corn oil of equal volume. Then unilateral ovaries and mid-uteri were isolated from 10 randomly-selected mice at the postnatal 1st week (7 days), 3rd week (20-21 days), and 7th week (48-49 days) respectively to observe gene levels, while 6 of the contralateral ovaries and uteri were subsequently examined for proteins respectively. Besides, 16 from both groups were determined with serum estradiol (E2) at week 7, of which 6 were randomized for histological observation. Here we found the levels of E2 reduced in VCZ-group at week 7, with fewer follicles and injured endometrium. Meanwhile, in VCZ mice of all ages, increased miR-132 and miR-195a, decreased G protein-coupled estrogen receptor (GPER), elevated phosphorylated large tumor suppressor (pLATS) and phosphorylated yes-associated protein (pYAP), and decreased yes-associated protein (YAP) were observed in their ovaries and uteri. These findings suggested ovarian and uterine dysplasia in the offspring induced by gestational VCZ-exposure were mainly attributed to higher miR-132 and miR-195a and accentuated Hippo-pathway.

Ovarian rescue in women with premature ovarian insufficiency: facts and fiction

The ovary has a comparatively short functional lifespan compared with other organs, and genetic and pathological injuries can further shorten its functional life. Thus, preserving ovarian function should be considered in the context of women with threats to ovarian reserve, such as ageing, premature ovarian insufficiency (POI) and diminished ovarian reserve (DOR). Indeed, one-third of women with POI retain resting follicles that can be reactivated to produce competent oocytes, as proved by the in-vitro activation of dormant follicles. This paper discusses mechanisms and clinical data relating to new therapeutic strategies using ovarian fragmentation, stem cells or platelet-rich plasma to regain ovarian function in women of older age (>38 years) or with POI or DOR. Follicle reactivation techniques show promising experimental outcomes and have been successful in some cases, when POI is established or DOR diagnosed; however, there is scarce clinical evidence to warrant their widespread clinical use. Beyond these contexts, also discussed is how new insights into the biological mechanisms governing follicular dynamics and oocyte competence may play a role in reversing ovarian damage, as no technique modifies oocyte quality. Additional studies should focus on increasing follicle number and quality. Finally, there is a small but important subgroup of women lacking residual follicles and requiring oocyte generation from stem cells.

Biomechanical forces and signals operating in the ovary during folliculogenesis and their dysregulation: implications for fertility

BACKGROUND

Folliculogenesis occurs in the highly dynamic environment of the ovary. Follicle cyclic recruitment, neo-angiogenesis, spatial displacement, follicle atresia and ovulation stand out as major events resulting from the interplay between mechanical forces and molecular signals. Morphological and functional changes to the growing follicle and to the surrounding tissue are required to produce oocytes capable of supporting preimplantation development to the blastocyst stage.

OBJECTIVE AND RATIONALE

This review will summarize the ovarian morphological and functional context that contributes to follicle recruitment, growth and ovulation, as well as to the acquisition of oocyte developmental competence. We will describe the changes occurring during folliculogenesis to the ovarian extracellular matrix (ECM) and to the vasculature, their influence on the mechanical properties of the ovarian tissue, and, in turn, their influence on the regulation of signal transduction. Also, we will outline how their dysregulation might be associated with pathologies such as polycystic ovary syndrome (PCOS), endometriosis or premature ovarian insufficiency (POI). Finally, for each of these three pathologies, we will highlight therapeutic strategies attempting to correct the altered biomechanical context in order to restore fertility.

SEARCH METHODS

For each area discussed, a systematic bibliographical search was performed, without temporal limits, using PubMed Central, Web of Science and Scopus search engines employing the keywords extracellular matrix, mechanobiology, biomechanics, vasculature, angiogenesis or signalling pathway in combination with: ovary, oogenesis, oocyte, folliculogenesis, ovarian follicle, theca, granulosa, cumulus, follicular fluid, corpus luteum, meiosis, oocyte developmental competence, preimplantation, polycystic ovary syndrome, premature ovarian insufficiency or endometriosis.

OUTCOMES

Through search engines queries, we yielded a total of 37 368 papers that were further selected based on our focus on mammals and, specifically, on rodents, bovine, equine, ovine, primates and human, and also were trimmed around each specific topic of the review. After the elimination of duplicates, this selection process resulted in 628 papers, of which 287 were cited in the manuscript. Among these, 89.2% were published in the past 22 years, while the remaining 8.0%, 2.4% or 0.3% were published during the 1990s, 1980s or before, respectively. During folliculogenesis, changes occur to the ovarian ECM composition and organization that, together with vasculature modelling around the growing follicle, are aimed to sustain its recruitment and growth, and the maturation of the enclosed oocyte. These events define the scenario in which mechanical forces are key to the regulation of cascades of molecular signals. Alterations to this context determine impaired folliculogenesis and decreased oocyte developmental potential, as observed in pathological conditions which are causes of infertility, such as PCOS, endometriosis or POI.

WIDER IMPLICATIONS

The knowledge of these mechanisms and the rules that govern them lay a sound basis to explain how follicles recruitment and growth are modulated, and stimulate insights to develop, in clinical practice, strategies to improve follicular recruitment and oocyte competence, particularly for pathologies like PCOS, endometriosis and POI.

Mechanisms of primordial follicle activation and new pregnancy opportunity for premature ovarian failure patients

Primordial follicles are the starting point of follicular development and the basic functional unit of female reproduction. Primordial follicles are formed around birth, and most of the primordial follicles then enter a dormant state. Since primordial follicles are limited in number and can't be renewed, dormant primordial follicles cannot be reversed once they enter the growing state. Thus, the orderly occurrence of primordial follicles selective activation directly affects the rate of follicle consumption and thus determines the length of female reproductive lifespan. Studies have found that appropriately inhibiting the activation rate of primordial follicles can effectively slow down the rate of follicle consumption, maintain fertility and delay ovarian aging. Based on the known mechanisms of primordial follicle activation, primordial follicle in vitro activation (IVA) technique has been clinically developed. IVA can help patients with premature ovarian failure, middle-aged infertile women, or infertile women due to gynecological surgery treatment to solve infertility problems. The study of the mechanism of selective activation of primordial follicles can contribute to the development of more efficient and safe IVA techniques. In this paper, recent mechanisms of primordial follicle activation and its clinical application are reviewed.

Hippo Signaling in the Ovary: Emerging Roles in Development, Fertility, and Disease

Emerging studies indicate that the Hippo pathway, a highly conserved pathway that regulates organ size control, plays an important role in governing ovarian physiology, fertility, and pathology. Specific to the ovary, the spatiotemporal expression of the major components of the Hippo signaling cascade are observed throughout the reproductive lifespan. Observations from multiple species begin to elucidate the functional diversity and molecular mechanisms of Hippo signaling in the ovary in addition to the identification of interactions with other signaling pathways and responses to various external stimuli. Hippo pathway components play important roles in follicle growth and activation, as well as steroidogenesis, by regulating several key biological processes through mechanisms of cell proliferation, migration, differentiation, and cell fate determination. Given the importance of these processes, dysregulation of the Hippo pathway contributes to loss of follicular homeostasis and reproductive disorders such as polycystic ovary syndrome (PCOS), premature ovarian insufficiency, and ovarian cancers. This review highlights what is currently known about the Hippo pathway core components in ovarian physiology, including ovarian development, follicle development, and oocyte maturation, while identifying areas for future research to better understand Hippo signaling as a multifunctional pathway in reproductive health and biology.

Perfluorooctanoic acid (PFOA) promotes follicular growth and alters expression of genes that regulate the cell cycle and the Hippo pathway in cultured neonatal mouse ovaries

Perfluorooctanoic acid (PFOA) is a synthetic chemical resistant to biodegradation and is environmentally persistent. PFOA is found in many consumer products and is a major source of water contamination. While PFOA has been identified as a contaminant of concern for reproductive health, little is known about the effects of PFOA on ovarian follicular development and growth. Recent evidence indicates that the Hippo pathway is an important regulator of ovarian physiology. Here, we investigated the effects of PFOA on ovarian folliculogenesis during the neonatal period of development and potential impacts on the Hippo signaling pathway. Post-natal day 4 (PND4) neonatal ovaries from CD-1 mice were cultured with control medium (DMSO <0.01% final concentration) or PFOA (50 μM or 100 μM). After 96 h, ovaries were collected for histological analysis of folliculogenesis, gene and protein expression, and immunostaining. Results revealed that PFOA (50 μM) increased the number of secondary follicles, which was accompanied by increases in mRNA transcripts and protein of marker of proliferation marker Ki67 with no impacts on apoptosis markers Bax, Bcl2, or cleaved caspase-3. PFOA treatment (50 μM and 100 μM) stimulated an upregulation of transcripts for cell cycle regulators Ccna2, Ccnb2, Ccne1, Ccnd1, Ccnd2, and Ccnd3. PFOA also increased abundance of transcripts of Hippo pathway components Mst1/2, Lats1, Mob1b, Yap1, and Taz, as well as downstream Hippo pathway targets Areg, Amotl2, and Cyr61, although it decreased transcripts for anti-apoptotic Birc5. Inhibition of the Hippo pathway effector YAP1 with Verteporfin resulted in the attenuation of PFOA-induced follicular growth and proliferation. Together, these findings suggest that occupationally relevant levels of PFOA (50 μM) can stimulate follicular activation in neonatal ovaries potentially through activation of the Hippo pathway.

A synopsis of global frontiers in fertility preservation

Since 2007, the Oncofertility Consortium Annual Conference has brought together a diverse network of individuals from a wide range of backgrounds and professional levels to disseminate emerging basic and clinical research findings in fertility preservation. This network also developed enduring educational materials to accelerate the pace and quality of field-wide scientific communication. Between 2007 and 2019, the Oncofertility Consortium Annual Conference was held as an in-person event in Chicago, IL. The conference attracted approximately 250 attendees each year representing 20 countries around the world. In 2020, however, the COVID-19 pandemic disrupted this paradigm and precluded an in-person meeting. Nevertheless, there remained an undeniable demand for the oncofertility community to convene. To maintain the momentum of the field, the Oncofertility Consortium hosted a day-long virtual meeting on March 5, 2021, with the theme of "Oncofertility Around the Globe" to highlight the diversity of clinical care and translational research that is ongoing around the world in this discipline. This virtual meeting was hosted using the vFairs ® conference platform and allowed over 700 people to participate, many of whom were first-time conference attendees. The agenda featured concurrent sessions from presenters in six continents which provided attendees a complete overview of the field and furthered our mission to create a global community of oncofertility practice. This paper provides a synopsis of talks delivered at this event and highlights the new advances and frontiers in the fields of oncofertility and fertility preservation around the globe from clinical practice and patient-centered efforts to translational research.

Biomechanical characteristics of the ovarian cortex in POI patients and functional outcomes after drug-free IVA

PURPOSE

There is increasing evidence that the ovarian extracellular matrix (ECM) plays a critical role in follicle development. The rigidity of the cortical ECM limits expansion of the follicle and consequently oocyte maturation, maintaining the follicle in its quiescent state. Quiescent primordial, primary, and secondary follicles still exist in primary ovarian insufficiency (POI) patients, and techniques as in vitro activation (IVA) and drug-free IVA have recently been developed aiming to activate these follicles based on the Hippo signaling disruption that is essential in mechanotransduction. In this context, we analyze the effect of drug-free IVA in POI patients, comparing the relationship between possible resumption ovarian function and biomechanical properties of ovarian tissue.

METHODS

Nineteen POI patients according to ESHRE criteria who underwent drug-free IVA by laparoscopy between January 2018 and December 2019 and were followed up for a year after the intervention. A sample of ovarian cortex taken during the intervention was analyzed by atomic force microscopy (AFM) in order to quantitatively measure tissue stiffness (Young's elastic modulus, E) at the micrometer scale. Functional outcomes after drug-free were analyzed.

RESULTS

Resumption of ovarian function was observed in 10 patients (52.6%) and two of them became pregnant with live births. There were no differences in clinical characteristics (age and duration of amenorrhea) and basal hormone parameters (FSH and AMH) depending on whether or not there was activation after surgery. However, ovarian cortex stiffness was significantly greater in patients with ovarian activity after drug-free IVA: median E = 5519 Pa (2260-11,296) vs 1501 (999-3474); p-value < 0.001.

CONCLUSIONS

Biomechanical properties of ovarian cortex in POI patients have a great variability, and higher ovarian tissue stiffness entails a more favorable status when drug-free IVA is applied in their treatment. This status is probably related to an ovary with more residual follicles, which would explain a greater possibility of ovarian follicular reactivations after treatment.

Preliminary report of intraovarian injections of autologous platelet-rich plasma (PRP) in extremely poor prognosis patients with only oocyte donation as alternative: a prospective cohort study

STUDY QUESTION

Does intraovarian injection of platelet-rich plasma (PRP) change ovarian function in patients with extremely low functional ovarian reserve (LFOR) who, otherwise, would likely only have a chance of pregnancy through third-party oocyte donation?

SUMMARY ANSWER

No clinically significant effects of PRP treatment on ovarian function were observed over 1 year of follow-up.

WHAT IS KNOWN ALREADY

Several investigators have reported improved responses to ovulation induction after treatment with PRP. However, previous published reports have involved, at most, only small case series. Whether PRP actually improves ovarian performance is, therefore, still unknown. PRP is nevertheless widely offered as an ‘established’ fertility treatment, often under the term ‘ovarian rejuvenation’.

STUDY DESIGN, SIZE, DURATION

We are reporting a prospective cohort study of 80 consecutive patients at ages 28–54 with LFOR, defined by anti-Müllerian hormone &lt;1.1 ng/ml, FSH &gt;12 mIU/ml or at least one prior IVF cycle with ≤3 oocytes within 1 year. The women were followed for 1 year after an intraovarian PRP procedure.

PARTICIPANTS/MATERIALS, SETTING, METHODS

PRP (1.5 ml) was injected into the cortex of ovaries with an average of 12 injections per ovary. Study participants were followed every 3 days for 2 weeks after PRP treatment with estradiol and FSH measurements and vaginal ultrasound to observe follicle growth and thereafter followed weekly. Beginning 1 month after their PRP treatment, participants underwent one or more cycles of ovarian stimulation for IVF. Outcome measures were endocrine response, and numbers of oocytes and embryos produced in response to a maximal gonadotropin stimulation before and after PRP treatment.

MAIN RESULTS AND THE ROLE OF CHANCE

In this study, women failed to demonstrate statistically significant outcome benefits from intraovarian PRP. However, two 40-year-old very poor-prognosis patients, with prior failed IVF cycles that never reached embryo transfer at other centers, achieved pregnancy, resulting in an ongoing pregnancy rate of 4.7% among patients who, following PRP, produced at least one oocyte (n = 42).

LIMITATIONS, REASONS FOR CAUTION

As an observational study of patients who performed poorly in past ovarian stimulation cycles, the improvement may be accounted for by regression to the mean. Similar considerations may also explain the occurrence of the two pregnancies.

WIDER IMPLICATIONS OF THE FINDINGS

This study demonstrates that, even in extremely poor prognosis patients due to LFOR, sporadic pregnancies are possible. The study, however, does not allow for the conclusion that those pregnancies were the consequence of PRP treatments. A case series, indeed, does not allow for such conclusions, even if results are more suggestive than here. This registered study, therefore, must be viewed as a preliminary report, with further data expected from this study but also from two other prospectively randomized ongoing registered studies with more controlled patient selection.

STUDY FUNDING/COMPETING INTEREST(S)

This work was supported by intramural funds from The Center for Human Reproduction and the not-for-profit research Foundation for Reproductive Medicine, both in New York, NY, USA. N.G. and D.H.B. are listed as co-inventors on several US patents. Some of these patents relate to pre-supplementation of hypo-androgenic infertile women with androgens, such as dehydroepiandrosterone and testosterone and, therefore, at least peripherally relate to the subject of this manuscript. They, as well as D.F.A., have also received research support, travel funds and speaker honoraria from several pharmaceutical and medical device companies, though none related to the here presented subject and manuscript. N.G. is a shareholder in Fertility Nutraceuticals and he and D.H.B. receive royalty payments from Fertility Nutraceuticals LLC. E.M. has no conflicts of interest to declare.

TRIAL REGISTRATION NUMBER

NCT04275700

Protective Effects of Antioxidants on Cyclophosphamide-Induced Ovarian Toxicity

The most common limitation of anticancer chemotherapy is the injury to normal cells. Cyclophosphamide, which is one of the most widely used alkylating agents, can cause premature ovarian insufficiency and infertility since the ovarian follicles are extremely sensitive to their effects. Although little information is available about the pathogenic mechanism of cyclophosphamide-induced ovarian damage, its toxicity is attributed to oxidative stress, inflammation, and apoptosis. The use of compounds with antioxidant and cytoprotective properties to protect ovarian function from deleterious effects during chemotherapy would be a significant advantage. Thus, this article reviews the mechanism by which cyclophosphamide exerts its toxic effects on the different cellular components of the ovary, and describes 24 cytoprotective compounds used to ameliorate cyclophosphamide-induced ovarian injury and their possible mechanisms of action. Understanding these mechanisms is essential for the development of efficient and targeted pharmacological complementary therapies that could protect and prolong female fertility.

Oocyte maturation abnormalities - A systematic review of the evidence and mechanisms in a rare but difficult to manage fertility pheneomina

A small proportion of infertile women experience repeated oocyte maturation abnormalities (OMAS). OMAS include degenerated and dysmorphic oocytes, empty follicle syndrome, oocyte maturation arrest (OMA), resistant ovary syndrome and maturation defects due to primary ovarian insufficiency. Genetic factors play an important role in OMAS but still need specifications. This review documents the spectrum of OMAS and to evaluate the multiple subtypes classified as OMAS. In this review, readers will be able to understand the oocyte maturation mechanism, gene expression and their regulation that lead to different subtypes of OMAs, and it will discuss the animal and human studies related to OMAS and lastly the treatment options for OMAs. Literature searches using PubMed, MEDLINE, Embase, National Institute for Health and Care Excellence were performed to identify articles written in English focusing on Oocyte Maturation Abnormalities by looking for the following relevant keywords. A search was made with the specified keywords and included books and documents, clinical trials, animal studies, human studies, meta-analysis, randomized controlled trials, reviews, systematic reviews and options written in english. The search detected 3,953 sources published from 1961 to 2021. After title and abstract screening for study type, duplicates and relevancy, 2,914 studies were excluded. The remaining 1,039 records were assessed for eligibility by full-text reading and 886 records were then excluded. Two hundred and twenty seven full-text articles and 0 book chapters from the database were selected for inclusion. Overall, 227 articles, one unpublished and one abstract paper were included in this final review. In this review study, OMAS were classified and extensively evaluatedand possible treatment options under the light of current information, present literature and ongoing studies. Either genetic studies or in vitro maturation studies that will be handled in the future will lead more informations to be reached and may make it possible to obtain pregnancies.

Perfluorooctanoic acid promotes proliferation of the human granulosa cell line HGrC1 and alters expression of cell cycle genes and Hippo pathway effector YAP1

Perfluorooctanoic acid (PFOA) is a common environmental contaminant that belongs to a group of manmade fluorinated chemicals called per- and polyfluoroalkyl substances (PFAS). Due to the pervasive nature of PFOA, the environmental health risks of PFOA contamination and exposure on reproductive health have increasing concern. In the present study, we exposed HGrC1 cells, an immortalized human granulosa cell line, to environmentally relevant (1-10 μM) concentrations of PFOA. Results indicated that HGrC1 cells treated with PFOA had increased proliferation and migration relative to vehicle treated controls. No differences in cell apoptosis were observed with 1-10 μM PFOA. Gene expression analysis revealed increases in mRNA transcripts for cell cycle regulators CCND1, CCNA2, and CCNB1. Upregulation of YAP1 protein and downstream target CTGF protein was also observed, suggesting that the Hippo pathway is involved in the proliferation and migratory effects of PFOA on HGrC1 cells. Further, the YAP1 inhibitor Verteporfin prevented the stimulatory effects of PFOA on HGrC1 cells. Together, these findings support a role for the Hippo pathway effector YAP1 in response to PFOA exposure in human granulosa cells.

The role of cellular senescence in female reproductive aging and the potential for senotherapeutic interventions

BACKGROUND

Advanced maternal age is associated with decreased oocyte quantity and quality as well as uterine and placental dysfunctions. These changes lead to infertility, pregnancy complications and birth defects in the offspring. As the mean age of giving birth is increasing worldwide, prevention of age-associated infertility and pregnancy complications, along with the more frequent use of ART, become extremely important. Currently, significant research is being conducted to unravel the mechanisms underlying female reproductive aging. Among the potential mechanisms involved, recent evidence has suggested a contributing role for cellular senescence, a cellular state of irreversible growth arrest characterized by a hypersecretory and pro-inflammatory phenotype. Elucidating the role of senescence in female reproductive aging holds the potential for developing novel and less invasive therapeutic measures to prevent or even reverse female reproductive aging and increase offspring wellbeing.

OBJECTIVE AND RATIONALE

The review will summarize the positive and negative implications of cellular senescence in the pathophysiology of the female reproductive organs during aging and critically explore the use of novel senotherapeutics aiming to reverse and/or eliminate their detrimental effects. The focus will be on major senescence mechanisms of the ovaries, the uterus, and the placenta, as well as the potential and risks of using senotherapies that have been discovered in recent years.

SEARCH METHODS

Data for this review were identified by searches of MEDLINE, PubMed and Google Scholar. References from relevant articles using the search terms 'Cellular Senescence', 'Aging', 'Gestational age', 'Maternal Age', 'Anti-aging', 'Uterus', 'Pregnancy', 'Fertility', 'Infertility', 'Reproduction', 'Implant', 'Senolytic', 'Senostatic', 'Senotherapy' and 'Senotherapeutic' where selected. A total of 182 articles published in English between 2005 and 2020 were included, 27 of which focus on potential senotherapies for reproductive aging. Exclusion criteria were inclusion of the terms 'male' and 'plants'.

OUTCOMES

Aging is a major determinant of reproductive wellbeing. Cellular senescence is a basic aging mechanism, which can be exploited for therapeutic interventions. Within the last decade, several new strategies for the development and repurposing of drugs targeting senescent cells have emerged, such as modulators of the anti-inflammatory response, oxidative stress, DNA damage, and mitochondria and protein dysfunctions. Several studies of female reproductive aging and senotherapies have been discussed that show promising results for future interventions.

WIDER IMPLICATIONS

In most countries of the Organization for Economic Co-operation and Development, the average age at which women give birth is above 30 years. Currently, in countries such as the Netherlands, Australia, Spain, Finland, Germany and the UK, birth rates among 30- to 34-year-olds are now higher than in any other age groups. This review will provide new knowledge and scientific advancement on the senescence mechanisms during female reproductive aging, and benefit fundamental and clinical scientists and professionals in the areas of reproduction, cancer, immunobiology and fibrosis.

Overexpression of Lin28a induces a primary ovarian insufficiency phenotype via facilitation of primordial follicle activation in mice

Lin28a is an RNA binding protein and increasing evidence has indicated its role in regulating female fertility. Lin28a has been reported to be involved in ovarian follicle activation. However, its role and mechanisms in regulating primordial follicle activation have not yet been explored. To test whether overexpression of Lin28a activates ovarian primordial follicles, studies were conducted in wild type (WT) and Lin28a Tg mice. Female Lin28a Tg mice at 4-month old exhibited significantly smaller litter size and fewer ovulated oocytes when compared with the WT mice. By 6-month of age, these parameters in Lin28a Tg mice were less than 20% of the WT mice. At postnatal day (PD) 14, the number of primordial follicles was significantly decreased but the number of primary follicles was significantly increased in the transgenic mice. The number of primordial follicles, secondary and antral follicles in these mice were drastically reduced at PD21. In the ovary of Lin28a Tg mice, there were activation of Wnt/β-catenin signaling and its downstream mTOR pathway. Interestingly, overexpression of Lin28a, which can also act as transcriptional activator, activated Wnt signaling through enhancing the transcription of Wnt co-receptor LRP5. In conclusion, overexpression of Lin28a induced a primary ovarian insufficiency phenotype in long term via facilitating Wnt/β-catenin signaling leading to activation of primordial follicles.

Female Oncofertility: Current Understandings, Therapeutic Approaches, Controversies, and Future Perspectives

Recent advances in early detection and oncological therapies have ameliorated the survival rate of young cancer patients. Yet, ovarian impairment induced by chemotherapy and radiotherapy is still a challenging issue. This review, based on clinical and lab-based studies, summarizes the evidence of gonadotoxicity of chemoradiotherapy, the recent approaches, ongoing controversies, and future perspectives of fertility preservation (FP) in female patients who have experienced chemo- or radio-therapy. Existing data indicate that chemotherapeutic agents induce DNA alterations and massive follicle activation via the phosphoinositide 3-kinase (PI3K)/Akt signaling pathway. Meanwhile, the radiation causes ionizing damage, leading to germ cell loss. In addition to the well-established methods, numerous therapeutic approaches have been suggested, including minimizing the follicle loss in cryopreserved ovarian grafts after transplantation, in vitro activation or in vitro growing of follicles, artificial ovarian development, or fertoprotective adjuvant to prevent ovarian damage from chemotherapy. Some reports have revealed positive outcomes from these therapies, whereas others have demonstrated conflictions. Future perspectives are improving the live birth rate of FP, especially in patients with adverse ovarian reserve, eliminating the risk of malignancy reintroducing, and increasing society’s awareness of FP importance.

Impact of the antioxidant quercetin on morphological integrity and follicular development in the in vitro culture of Bos indicus female ovarian fragments

We evaluated the effect of quercetin on the in vitro culture of bovine ovarian fragments in relation to morphology, development, and oxidative stress. Ovaries (n = 12) from Nelore heifers (n = 6) were used. Each pair of ovaries was divided into nine fragments, and one fragment from each animal was fixed in Bouin solution for 24 h (histology control) or frozen (- 80°C; control for oxidative stress). Other ovarian fragments (n = 8) were distributed into concentrations of 0, 10, 25, and 50 μg/mL of quercetin added to the culture medium for 5 or 10 d. Data were analyzed by chi-square test or ANOVA followed by Tukey's test (P < 0.05). Treatment with 25 μg/mL quercetin resulted in the highest proportion of total intact follicles for 5 (67.3%) and 10 d (57.1%); the concentration of 25 μg/mL also presented the best proportion of developing follicles for 5 d (68.7%) and 10 d (62.8%). Treatment with 25 μg/mL quercetin resulted in significant ferric reduction for 10 d of culture, but not for 5 d. No difference (P > 0.1) was observed in the production of reactive oxygen species or in the oxidative degradation of lipids between treatments and non-cultivated controls. Treatment with 25 μg/mL quercetin preserved the morphological integrity of the developing follicles for 5 and 10 d of culture, in addition to promoting the best antioxidant potential after 10 d of culture in bovine ovarian fragments.

Mechanobiology of the female reproductive system

BACKGROUND

Mechanobiology in the field of human female reproduction has been extremely challenging technically and ethically.

METHODS

The present review provides the current knowledge on mechanobiology of the female reproductive system. This review focuses on the early phases of reproduction from oocyte development to early embryonic development, with an emphasis on current progress.

MAIN FINDINGS RESULTS

Optimal, well-controlled mechanical cues are required for female reproductive system physiology. Many important questions remain unanswered; whether and how mechanical imbalances among the embryo, decidua, and uterine muscle contractions affect early human embryonic development, whether the biomechanical properties of oocytes/embryos are potential biomarkers for selecting high-quality oocytes/embryos, whether mechanical properties differ between the two major compartments of the ovary (cortex and medulla) in normally ovulating human ovaries, whether durotaxis is involved in several processes in addition to embryonic development. Progress in mechanobiology is dependent on development of technologies that enable precise physical measurements.

CONCLUSION

More studies are needed to understand the roles of forces and changes in the mechanical properties of female reproductive system physiology. Recent and future technological advancements in mechanobiology research will help us understand the role of mechanical forces in female reproductive system disorders/diseases.

A blueprint of the topology and mechanics of the human ovary for next-generation bioengineering and diagnosis

Although the first dissection of the human ovary dates back to the 17^th century, the biophysical characteristics of the ovarian cell microenvironment are still poorly understood. However, this information is vital to deciphering cellular processes such as proliferation, morphology and differentiation, as well as pathologies like tumor progression, as demonstrated in other biological tissues. Here, we provide the first readout of human ovarian fiber morphology, interstitial and perifollicular fiber orientation, pore geometry, topography and surface roughness, and elastic and viscoelastic properties. By determining differences between healthy prepubertal, reproductive-age, and menopausal ovarian tissue, we unravel and elucidate a unique biophysical phenotype of reproductive-age tissue, bridging biophysics and female fertility. While these data enable to design of more biomimetic scaffolds for the tissue-engineered ovary, our analysis pipeline is applicable for the characterization of other organs in physiological or pathological states to reveal their biophysical markers or design their bioinspired analogs.

Although the first dissection of the human ovary dates back to the 17th century, its characterization is still limited. Here, the authors have unraveled a unique biophysical and topological phenotype of reproductive-age tissue, bridging biophysics and female fertility and providing a blueprint for the artificial ovary.

Molecular profiling of follicular fluid microRNAs in young women affected by Hodgkin lymphoma

RESEARCH QUESTION

Treatments for Hodgkin lymphoma have improved but one of their common effects is gonadal toxicity, which contributes to fertility damage of patients and induces temporary or irreversible loss of fertility. Could micro-RNA (miRNA) expression profiles in follicular fluid be influenced by Hodgkin lymphoma? Could their alteration affect molecular pathways involved in follicle growth and oocyte maturation?

DESIGN

miRNA expression profile was investigated in follicular fluid samples from young women affected by Hodgkin lymphoma compared with healthy controls by NanoString technology. Bioinformatic analysis was used to verify miRNA involvement in follicle development and miRNA deregulation with Hodgkin lymphoma in a larger cohort of follicular fluid samples was confirmed by real-time quantitative polymerase chain reaction.

RESULTS

Thirteen miRNAs are deregulated in Hodgkin lymphoma samples compared with controls and are involved in molecular pathways related to cancer, gametogenesis and embryogenesis. Among them, let-7b-5p, miR-423-5p, miR-503-5p, miR-574-5p and miR-1303 are implicated in biological processes related to follicle development and oocyte maturation. Let-7b-5p holds the central position in the regulatory network of miRNA-mRNA interactions, has the highest number of mRNA target genes shared with the other differentially expressed miRNAs and is significantly downregulated in Hodgkin lymphoma follicular fluid samples.

CONCLUSIONS

These data led us to question the potential influence of miRNA deregulation on oocyte quality. Further studies are needed to verify the reproductive potential of young patients with Hodgkin lymphoma before starting chemotherapy protocols and an adequate protocol of fertility preservation needs to be guaranteed.

Qilin Pill Exerts Therapeutic Effect on Resection-Induced Premature Ovarian Insufficiency Rats by Inhibiting the MAPK and PI3K-AKT Signaling Pathways

Background

The Qilin pill (QLP) is a traditional Chinese compound prescription comprising 15 herbs that has demonstrated significant therapeutic effects on premature ovarian insufficiency (POI) in recent years. However, a pharmacological evaluation of QLP on ovarian function remains to be conducted, and the key mechanism of QLP treatment on POI is unclear.

Methods

Premature ovarian insufficiency rats were established by bilateral partial ovariectomy. The model rats were administrated with low (QLP-L), medium (QLP-M) and high (QLP-H) doses of QLP for 4 weeks to evaluate the ovarian function in terms of estrous cycle, hormone level, and follicle count. The mechanism of QLP in the treatment of POI was systematically explored by network pharmacology, and expression levels of the MAPK and PI3K-AKT signaling pathways were verified by Western blotting and molecular docking.

Results

The rat model of resection-induced POI was successfully established, and QLP could significantly recover the estrous cycle, decrease serum FSH levels, and decelerate follicle depletion after 4 weeks of administration. The optimal dose of QLP in the experiment was preliminarily determined to be 0.9 g/kg. Based on the network pharmacology methods, we constructed the compound-target network and protein protein interaction (PPI) network of QLP for the treatment of POI. The experimental verification of the enrichment analysis showed that QLP inhibited the MAPK and PI3K-AKT signaling pathways, and the key compounds and key targets involved were verified by molecular docking.

Conclusion

QLP exerted significant therapeutic effects on resection-induced POI rats, and this was achieved by the inhibition of the MAPK and PI3K-AKT signaling pathways. This study is the first to systematically investigate the effects and mechanism of QLP on POI rats, which will provide valuable guidance in clinic.

Pathophysiology and management of classic galactosemic primary ovarian insufficiency

Classic galactosemia is an inborn error of carbohydrate metabolism associated with early-onset primary ovarian insufficiency (POI) in young women. Our understanding of the consequences of galactosemia upon fertility and fecundity of affected women is expanding, but there are important remaining gaps in our knowledge and tools for its management, and a need for continued dialog so that the special features of the condition can be better managed. Here, we review galactosemic POI and its reproductive endocrinological clinical sequelae and summarize current best clinical practices for its management. Special consideration is given to the very early-onset nature of the condition in the pediatric/adolescent patient. Afterward, we summarize our current understanding of the reproductive pathophysiology of galactosemia, including the potential action of toxic galactose metabolites upon the ovary. Our work establishing that ovarian cellular stress reminiscent of endoplasmic reticulum (ER) stress is present in a mouse model of galactosemia, as well as work by other groups, are summarized.

LAY SUMMARY

Patients with the condition of classic galactosemia need to maintain a strict lifelong diet that excludes the sugar galactose. This is due to having mutations in enzymes that process galactose, resulting in the buildup of toxic metabolic by-products of the sugar. Young women with classic galactosemia often lose the function of their ovaries very early in life (termed 'primary ovarian insufficiency'), despite adherence to a galactose-restricted diet. This means that in addition to the consequences of the disease, these women also face infertility and the potential need for hormone replacement therapy. This article summarizes current strategies for managing the care of galactosemic girls and women and also what is known of how the condition leads to early primary ovarian insufficiency.

Current Understandings of Core Pathways for the Activation of Mammalian Primordial Follicles

The mammalian ovary has two main functions-producing mature oocytes for fertilization and secreting hormones for maintaining the ovarian endocrine functions. Both functions are vital for female reproduction. Primordial follicles are composed of flattened pre-granulosa cells and a primary oocyte, and activation of primordial follicles is the first step in follicular development and is the key factor in determining the reproductive capacity of females. The recent identification of the phosphatidylinositol 3 kinase (PI3K)/phosphatase and tensin homolog deleted on chromosome 10 (PTEN) signaling pathway as the key controller for follicular activation has made the study of primordial follicle activation a hot research topic in the field of reproduction. This review systematically summarizes the roles of the PI3K/PTEN signaling pathway in primordial follicle activation and discusses how the pathway interacts with various other molecular networks to control follicular activation. Studies on the activation of primordial follicles have led to the development of methods for the in vitro activation of primordial follicles as a treatment for infertility in women with premature ovarian insufficiency or poor ovarian response, and these are also discussed along with some practical applications of our current knowledge of follicular activation.

Effects of a gel culture system made of polysaccharides (xanthan gum and locust bean gum) on in vitro bovine oocyte development and gene expression of the granulosa cells

Xanthan gum (XG) and locust bean gum (LBG) are nontoxic polysaccharides that produce culture substrates. The present study examined the effect of XG-LBG gel on in vitro bovine oocyte growth and gene expression in granulosa cells. Oocytes and granulosa cell complexes (OGCs) were cultured in vitro on plastic culture plate (Plate) or XG-LBG gel for 16 days. OGCs formed a dome-like cavity surrounding the oocytes on plate but formed a spherical follicle structure on XG-LBG gel. The total granulosa cell numbers of the OGCs and their survival rate was greater for OGCs cultured on XG-LBG gel than for those cultured on plate. Oocytes grown on XG-LBG gels had higher lipid and mitochondrial content, as well as a larger diameter, than their plate counterparts. When oocytes grown in vitro were subjected to in vitro maturation and fertilization, the normal fertilization rate was significantly higher for oocytes developed on XG-LBG gel than that of oocytes cultured on the plate counterpart. RNAseq of the granulosa cells revealed that genes associated with focal adhesion, phosphatidylinositol 3'-kinase-Akt and Hippo signaling, and regulation of actin cytoskeleton were upregulated in granulosa cells of OGCs cultured on XG-LBG gel compared with those cultured on plate.

A Prepubertal Mice Model to Study the Growth Pattern of Early Ovarian Follicles

Early folliculogenesis begins with the activation of the follicle and ends with the formation of the follicular antrum, which takes up most of the time of folliculogenesis. In this long process, follicles complete a series of developmental events, including but not limited to granulosa cell (GC) proliferation, theca folliculi formation, and antrum formation. However, the logical or temporal sequence of these events is not entirely clear. This study demonstrated in a mouse model that completion of early folliculogenesis required a minimum of two weeks. The oocyte reached its largest size in the Type 4-5 stage, which was therefore considered as the optimum period for studying oogenesis. Postnatal days (PD) 10-12 were regarded as the crucial stage of theca folliculi formation, as Lhcgr sharply increased during this stage. PD13-15 was the rapid growth period of early follicles, which was characterized by rapid cell proliferation, the sudden emergence of the antrum, and increased Fshr expression. The ovarian morphology remained stable during PD15-21, but antrum follicles accumulated gradually. Atresia occurred at all stages, with the lowest rate in Type 3 follicles and no differences among early Type 4-6 follicles. The earliest vaginal opening was observed at PD24, almost immediately after the first growing follicular wave. Therefore, the period of PD22-23 could be considered as a suitable period for studying puberty initiation. This study objectively revealed the pattern of early folliculogenesis and provided time windows for the study of biological events in this process.

Melatonin delays ovarian aging in mice by slowing down the exhaustion of ovarian reserve

Studies have shown that melatonin (MLT) can delay ovarian aging, but the mechanism has not been fully elucidated. Here we show that granulosa cells isolated from mice follicles can synthesize MLT; the addition of MLT in ovary culture system inhibited follicle activation and growth; In vivo experiments indicated that injections of MLT to mice during the follicle activation phase can reduce the number of activated follicles by inhibiting the PI3K-AKT-FOXO3 pathway; during the early follicle growth phase, MLT administration suppressed follicle growth and atresia, and multiple pathways involved in folliculogenesis, including PI3K-AKT, were suppressed; MLT deficiency in mice increased follicle activation and atresia, and eventually accelerated age-related fertility decline; finally, we demonstrated that prolonged high-dose MLT intake had no obvious adverse effect. This study presents more insight into the roles of MLT in reproductive regulation that endogenous MLT delays ovarian aging by inhibiting follicle activation, growth and atresia.

In Vitro Activation Early Follicles: From the Basic Science to the Clinical Perspectives

Development of early follicles, especially the activation of primordial follicles, is strictly modulated by a network of signaling pathways. Recent advance in ovarian physiology has been allowed the development of several therapies to improve reproductive outcomes by manipulating early folliculogenesis. Among these, in vitro activation (IVA) has been recently developed to extend the possibility of achieving genetically related offspring for patients with premature ovarian insufficiency and ovarian dysfunction. This method was established based on basic science studies of the intraovarian signaling pathways: the phosphoinositide 3-kinase (PI3K)/Akt and the Hippo signaling pathways. These two pathways were found to play crucial roles in folliculogenesis from the primordial follicle to the early antral follicle. Following the results of rodent experiments, IVA was implemented in clinical practice. There have been multiple recorded live births and ongoing pregnancies. Further investigations are essential to confirm the efficacy and safety of IVA before used widely in clinics. This review aimed to summarize the published literature on IVA and provide future perspectives for its improvement.

Resumed ovarian function and pregnancy in early menopausal women by whole dimension subcortical ovarian administration of platelet-rich plasma and gonadotropins

OBJECTIVE

This study was designed to investigate if whole dimension subcortical ovarian administration of platelet-rich plasma with gonadotropin, in proximity to most ovarian follicles, is effective in restoring ovarian functions in women during early menopause.

METHODS

Platelet-rich plasma, prepared from 40 mL of autologous peripheral blood using the buffy coat method, was injected into extended subcortical area of bilateral ovaries along with recombinant follicle-stimulating hormone (rFSH) (Gonal-F 300IU) under laparoscopic guidance. The posttreatment ovarian folliculogenesis and serum levels of FSH, luteinizing hormone (LH), and estradiol were followed up for 6 months at weekly to monthly intervals. IVF was carried out in women resuming ovulatory functions.

RESULTS

Twelve early menopausal women with mean age of 44.42 ± 2.84 were enrolled. After treatment, 11 women resumed their menstrual period in 37.1 ± 23.5 days. Their average serum FSH was 70.47 ± 20.92 and 26.22 ± 17.55 IU/L, luteinizing hormone was 34.81 ± 11.86 and 14.3 ± 12.8 IU/L, before and after treatment, respectively. The mid-cycle E2 was 251.1 ± 143.8 pg/mL. Ten oocyte retrievals were carried out among six participants, four of them received controlled ovarian stimulation and another two using natural ovulation cycles. Thirteen mature eggs were retrieved which were then ICSI fertilized to obtain 10 normally fertilized 2PN oocytes. Two participants had cleavage stage embryos transferred of which one achieved clinical pregnancy.

CONCLUSIONS

Whole dimension subcortical ovarian administration of platelet-rich plasma with gonadotropin was shown to restore ovarian functions, at least temporarily, and could increase the probability of pregnancy using autologous oocytes in women with early menopause.

Ovarian Fragmentation and AKT Stimulation for Expansion of Fertile Lifespan

Since the first baby was born after in vitro fertilization, the female infertility treatment has been well-developed, yielding successful outcomes. However, successful pregnancies for patients with premature ovarian insufficiency and diminished ovarian reserve are still difficult and diverse therapies have been suggested to improve the chances to have their genetically linked offspring. Recent studies demonstrated that the activation Akt pathway by using a phosphatase and tensin homolog enzyme inhibitor and a phosphatidylinositol-3 kinase stimulator can activate dormant primordial follicles in both mice and human ovaries. Subsequent researches suggested that the disruption of Hippo signaling pathway by ovarian fragmentation increased the expression of downstream growth factors and secondary follicle growth. Based on the combination of ovarian fragmentation and Akt stimulation, the in vitro activation (IVA) approach has resulted in successful follicle growth and live births in premature ovarian insufficiency patients. The approach with disruption of Hippo signaling only was also shown to be effective for treating poor ovarian responders with diminishing ovarian reserve, including advanced age women and cancer patients undergoing sterilizing treatments. This review aims to summarize the effectiveness of ovarian fragmentation and Akt stimulation on follicle growth and the potential of IVA in extending female fertile lifespan.