Crosstalk between PTEN/PI3K/Akt Signalling and DNA Damage in the Oocyte: Implications for Primordial Follicle Activation, Oocyte Quality and Ageing

Susceptibility of Brca1(L63X/+) rat to ovarian reserve dissipation by chemotherapeutic agents to breast cancer

BRCA1 is one of the causative genes for hereditary breast and ovarian cancer syndrome with a high risk of early-onset breast cancer. Whereas olaparib (OLA), an inhibitor of poly-ADP-ribose polymerase, has been applied as adjuvant therapy to those cancer patients, its effect on ovarian reproductive function remains unelucidated. Recently, a rat model (MUT; Brca1(L63X/+) mutation) mimicking a human BRCA1 pathogenic variant has been established. Using this model, we evaluated the effects of OLA on ovarian reproductive function in comparison with the wild-type (WT) rats. MUT showed a significantly reduced number of primordial follicles and subfertility in accordance with aging. Oxidative stress was significantly elevated in the young MUT granulosa cells (GCs) accompanied by increased mTOR but decreased PTEN signals. OLA administration in MUT further decreased primordial follicles, with gene set enrichment analysis, indicating upregulated DNA repair pathways. Furthermore, a combination of OLA and cyclophosphamide (CPA) induced empty primordial follicles, recognized as CPA-induced severe ovarian toxicity. Whereas OLA + CPA caused greater reduction in primordial follicles both in MUT and WT in comparison with CPA alone, MUT ovaries were more susceptible to oxidative stress, potentially depleting primordial follicles via activation of GCs and inducing oocyte death due to accumulated DNA damage by OLA treatment. Our findings in this preclinical model underscore the importance of evaluating ovarian reserve prior to chemotherapy by performing reproductive consultation with female patients with BRCA1 pathogenic variants.

Butylphthalide identified via Samul-tang-induced transcriptomic signatures improves oocyte quality in aged mice

Samul-tang (SM) is a traditional prescription widely used in clinical practice for the management of gynecological diseases, especially for menstrual regulation and infertility treatment. We previously reported its efficacy in increasing mature oocyte production and improving ovarian reserves, potentially regulated by rat sarcoma virus (Ras) signaling in the ovaries of aged mice. Although the main ingredients of SM are known, the bioactive compounds responsible for protecting ovarian function during aging remain unidentified. This study aimed to identify the active compounds that significantly contribute to the therapeutic potential of SM against age-related decline in ovarian function. The combination of butylphthalide and oleanolic acid improved mature oocyte production similar to that in SM-administered aged mice. Subsequently, we identified butylphthalide as an active compound that mimicked SM's effect on enhancing ovarian reserve. This study introduces a novel strategy for identifying active compounds in multi-component herbal medicines by evaluating compound combinations in an in vivo model, offering promising therapeutic avenues for age-related female infertility through targeted gene expression modulation.

Upregulation of PD-L1 contributes to improving the apoptosis of granulosa cells via the PI3K/AKT pathway in PCOS

PURPOSE

Polycystic ovary syndrome (PCOS) is a leading cause of anovulatory infertility and closely correlated with apoptosis in ovarian granulosa cells (GCs). Programmed cell death protein-1/programmed cell death ligand-1 (PD-1/PD-L1) pathway plays an important role throughout gestation and the pathogenesis of adverse pregnancy outcomes, but its mechanism in PCOS remains unclear.

METHODS

The RNA sequencing data for PCOS patients were downloaded from the Gene Expression Omnibus (GEO) databases. Bioinformatics analysis was conducted to identify differentially expressed PD-1/PD-L1 pathway genes (DEPPGs) and related signaling pathways. PCOS mouse model was established by injecting dehydroepiandrosterone (DHEA), apoptosis of ovarian GCs in PCOS mouse were detected by TUNEL staining. The main genes and proteins in the PI3K/AKT signaling pathway and apoptosis were detected by qRT-PCR and Western blot analyses after PD-L1 intervention in GCs. Finally, the hub gene of differentially expressed PI3K/AKT pathway genes (DEPAGs) in GCs was evaluated in PCOS patients.

RESULTS

The DEPPGs in GCs and oocyte were identified, showing enrichment in Th1 and Th2 cell differentiation, apoptosis, and PI3K/AKT signaling pathway. More apoptosis was observed in ovarian GCs of PCOS mice. In vitro experiments showed that PI3K/AKT pathway was activated and the apoptosis of GCs was suppressed after PD-L1 intervention. The hub gene COL1A1 was upregulated in the GCs of PCOS patients.

CONCLUSIONS

PD-L1 may reduce the apoptosis of GCs through PI3K/AKT signaling pathway activation, providing a novel strategy for inhibiting the apoptosis of GCs in PCOS.

Network pharmacology and molecular docking reveal the mechanism of action of Bergapten against non‑small cell lung cancer

Non-small cell lung cancer (NSCLC) is a leading cause of cancer mortality worldwide, necessitating new treatment approaches with minimal side effects. In the present study, the potential of Bergapten (5-methoxypsoralen), a natural furanocoumarin compound, as a therapeutic agent against NSCLC was investigated by using network pharmacology, molecular docking and in vitro validation. Bergapten targets were identified using the Traditional Chinese Medicine Systems Pharmacology Database and Analysis Platform and SwissTarget databases, whilst lung cancer-related targets were sourced from GeneCards and DisGeNET. Protein-protein interaction analysis and molecular docking were performed to identify key targets. The inhibitory effects of Bergapten on lung cancer cells were assessed using Cell Counting Kit-8 assays, wound healing assays, cell migration experiments, flow cytometry and western blotting. SC79 was used to verify the regulation of Bergapten on the PI3K/AKT pathway. Network pharmacology identified 51 targets, one signaling pathway and four Gene Ontology projects associated with the action of Bergapten against NSCLC. Key targets identified included glycogen synthase kinase-3β, Janus kinase 2, phosphatidylinositol-4,5-bisphosphate 3-kinase, catalytic subunit α and protein tyrosine kinase 2. In vitro experiments demonstrated that Bergapten significantly inhibited cell viability, promoted apoptosis, induced cellular senescence and inhibited the PI3K/AKT signaling pathway in NSCLC cells. In conclusion, Bergapten exerts its anti-NSCLC effects through the PI3K/AKT pathway, promoting cell senescence and inhibiting inflammation. These findings suggest that Bergapten has potential as a therapeutic agent for NSCLC.

Menopause mysteries: the exosome-inflammation connection

Extracellular vesicles, or exosomes, are produced by every type of cell and contain metabolites, proteins, lipids, and nucleic acids. Their role in health and disease is to influence different aspects of cell biology and to act as intermediaries between cells. Follicular fluid exosomes or extracellular vesicles (FF-EVs) secreted by ovarian granulosa cells are critical mediators of ovary growth and maturation. The movement and proteins of these exosomes are crucial in the regulation of cellular communication and the aging of cells, a process termed inflammaging. Menopause, a natural progression in the aging of females, is often accompanied by numerous negative symptoms and health issues. It can also act as a precursor to more severe health problems, including neurological, cardiovascular, and metabolic diseases, as well as gynecological cancers. Researchers have discovered pathways that reveal the diverse effects of exosome-driven cellular communication and oocyte development in the follicular fluid. It also explores the complex functions of FF exosomal proteins in the pathologies associated with menopause.

Equol Alleviates the In Vitro Aging-Induced Disruption of Porcine Oocytes

Oocyte quality is crucial for determining the subsequent embryo developmental capacity and reproductive outcomes. However, aging is detrimental to oocyte quality. Previous studies have demonstrated that soy isoflavones have positive effects on the reproductive performance of female pigs. Equol, the primary metabolite of soy isoflavones, is renowned for its antioxidant properties and its ability to scavenge reactive oxygen species (ROS). However, the potential role of equol in reversing aging-mediated oocyte decline has not yet been elucidated. In this study, we treated the porcine oocytes with different concentrations of equol (2.5, 5 and 10 μM) during prolonged in vitro culture. Our findings showed that aging led to decreased embryonic developmental capacity, indicating the decline of oocyte quality. We further found that aging disrupted spindle assembly and chromosome arrangement, impaired actin polymerisation and reduced mitochondrial activity and function. Moreover, aging increased ROS levels; thereafter, DNA damage and apoptosis was induced in the porcine oocytes. Interestingly, treatment with 2.5 μM equol during the aging process significantly mitigated the above-mentioned defective parameters in porcine oocytes and finally improved embryo development rates. Collectively, these results imply that equol has potential benefits in attenuating the aging-mediated defects on porcine oocytes.

Prenatal Silicon Dioxide Nanoparticles Exposure Reduces Female Offspring Fertility Without Affecting Males

Silicon dioxide nanoparticles (SiO2 NPs) are widely utilized in biomedicine due to their controllable size and biocompatibility. While previous studies have demonstrated that prenatal exposure to SiO2 NPs can traverse the placental barrier and induce neurotoxicity in offspring. However, their reproductive toxicity remains unclear. Here, it is found that prenatal SiO2 NPs exposure led to subfertility in female offspring, evidenced by decreased ovulation potential, ovarian reserve, and litter size. In contrast, male offspring maintained normal sperm production and fertility. Mechanistic analyses revealed that prenatal SiO2 NPs exposure disrupted meiotic recombination and increased oocyte apoptosis, resulting in reduced postnatal primordial follicle formation in females. Conversely, meiotic recombination occurring postnatally in male offspring remained unaffected. Notably, treatment with carboxylate (COOH)-functionalized SiO2 nanoparticles (SiO2-COOH NPs) has a minimal impact on fertility in female offspring. Further research, including clinical studies, is needed to confirm these findings in humans. These findings demonstrated gender-specific reproductive toxicity induced by prenatal SiO2 NPs exposure and highlighted the importance of considering nanoparticle safety in prenatal contexts.

Berberine promotes primordial follicle activation and increases ovulated oocyte quantity in aged mice

BACKGROUND

Primordial follicle activation is vital for the reproduction of women with advanced age and premature ovarian insufficiency (POI). But there is a lack of effective and safe therapeutic options to activate their primordial follicles in vivo. Berberine (BBR) possesses multiple pharmacological properties, but its impact on primordial follicle activation remains unclear.

METHODS

The role of BBR on primordial activation was investigated by neonatal mouse ovary culture and intraperitoneal injection, and by human ovarian fragment culture. Furthermore, the effect of BBR on the quantity of ovulated oocytes was investigated by the intragastric administration of aged mice.

RESULTS

BBR in vitro culture and in vivo intraperitoneal injection significantly increased growing follicle number and phosphorylated protein kinase B (p-Akt) levels in neonatal mouse ovaries. BBR also significantly increased the relative fluorescence intensities of p-Akt in the oocytes of primordial follicles. BBR-increased the number of growing follicles and the levels of p-Akt were blocked by LY294002, an inhibitor of phosphatidylinositol 3-kinase (PI3K). Furthermore, BBR intragastric administration significantly increased the quantity of ovulated oocytes in aged mice. Moreover, BBR significantly increased growing follicle proportion and p-Akt levels in cultured human ovarian fragments.

CONCLUSION

BBR promotes mouse and human primordial follicle activation through the PI3K/Akt pathway in oocytes, and improves the quantity of ovulated oocytes in aged mice. Our results suggest a potential use of oral medicine BBR to improve fertility in POI patients and aged women.

Efficient, High-Quality Engineering of Therapeutic Extracellular Vesicles on an Integrated Nanoplatform

Engineered extracellular vesicles (EVs) have been recognized as important therapeutics for gene and cell therapy. To achieve clinically desired therapy, technologies for EV engineering have high demands on the efficacy in producing EVs and their qualities, which, however, remain challenging to conventional routes due to their limited control on therapeutic payload delivery, EV secretion, and extracellular microenvironments. Here, we report a nanoplatform (denoted as PURE) that enables efficient electro-transfection while stimulating cells to produce high-quality EVs carrying functional RNAs. PURE further employs an ammonium removal zone to maintain the physiological conditions of the extracellular microenvironment and an EV uptake zone that efficiently (87.1%) captures EVs in situ with porous hydrogels. The platform achieved about a 12-fold higher yield of engineered EVs and a 146-fold abundance of desired therapeutics compared to those naturally secreted from cells. The PURE-engineered miR-130a-EVs were validated for effectively upregulating the mTOR signaling pathway in both in vitro and in vivo. Their therapeutic capability was then verified by enhancing the in vitro activation of primordial follicles. In vivo applications further highlighted the therapeutic effects of miR-130a-EVs in restoring ovary function in aged mice. The PURE platform represents a strategy for the clinical translation of EV-mediated therapy.

Elevated RBP4 in Subclinical Ketosis Cows Inhibits Follicular Granulosa Cell Proliferation and Steroid Hormone Synthesis

The mechanism by which subclinical ketosis (SCK) causes postpartum reproductive disorders in dairy cows remains unclear. In this study, cows within the day 14 to 21 postpartum period were categorized into the SCK group or the control group. Subsequently, they were monitored until 45 d to 60 d postpartum and divided into the SCK anestrus group (SCK-AE, n = 12) and the control estrus group (C-E, n = 12). In comparison to the C-E group, the RBP4 and p-AKT of the SCK-AE group exhibited increased levels in serum, liver, and ovaries. In the in vitro experimental cultivation of granulosa cells (GCs), after adding RBP4, cell proliferation, steroid hormone secretion and synthesis, and GLUT4 secretion were inhibited, and cell apoptosis was exacerbated. After silencing STRA6 (RBP4 receptor), cell proliferation and steroid hormone secretion and synthesis, as well as the inhibition of GLUT4, were alleviated, and the situation of cell apoptosis also improved. The SC79 activator could promote the phosphorylation of AKT, thus alleviating the increased cell proliferation, steroid hormone secretion and synthesis, GLUT4 inhibition, and apoptosis rate in cow GCs induced by RBP4 stimulation. Our research indicates that elevated RBP4 levels in SCK cows inhibit the proliferation, apoptosis, and steroid hormone synthesis of GCs through the STRA6 receptor and the PI3K/AKT pathway.

Novel Advances in Cell-Free Therapy for Premature Ovarian Failure (POF): A Comprehensive Review

Premature ovarian failure (POF), is a condition characterized by the early decline of ovulation function. POF is a complex disorder that can be caused by various factors, and the idiopathic form represents a significant proportion of POF patients. Hormone replacement therapy (HRT) is currently considered the first-line treatment for POF. This review aims to provide a comprehensive overview of recent advancements in platelet-rich plasma (PRP), in vitro activation (IVA), stem cell therapy, exosome therapy, microRNAs, and mitochondrial targeting therapies as a promising cell-free therapeutic approach in reproductive medicine. PLT-Exos, a new generation of cells, has been used to treat POF for more than a decade and has been shown to attenuate oocyte morphology and promote the differentiation of theca cells through the upregulation of PI3K/Akt and Bcl2, as well as the downregulation of the Smad and Bax signaling pathways. This review summarizes the current state of the art in the field of PLT-Exos and discusses the advantages and limitations of their potential clinical applications.

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.

Unveiling hidden connections in omics data via pyPARAGON: an integrative hybrid approach for disease network construction

Network inference or reconstruction algorithms play an integral role in successfully analyzing and identifying causal relationships between omics hits for detecting dysregulated and altered signaling components in various contexts, encompassing disease states and drug perturbations. However, accurate representation of signaling networks and identification of context-specific interactions within sparse omics datasets in complex interactomes pose significant challenges in integrative approaches. To address these challenges, we present pyPARAGON (PAgeRAnk-flux on Graphlet-guided network for multi-Omic data integratioN), a novel tool that combines network propagation with graphlets. pyPARAGON enhances accuracy and minimizes the inclusion of nonspecific interactions in signaling networks by utilizing network rather than relying on pairwise connections among proteins. Through comprehensive evaluations on benchmark signaling pathways, we demonstrate that pyPARAGON outperforms state-of-the-art approaches in node propagation and edge inference. Furthermore, pyPARAGON exhibits promising performance in discovering cancer driver networks. Notably, we demonstrate its utility in network-based stratification of patient tumors by integrating phosphoproteomic data from 105 breast cancer tumors with the interactome and demonstrating tumor-specific signaling pathways. Overall, pyPARAGON is a novel tool for analyzing and integrating multi-omic data in the context of signaling networks. pyPARAGON is available at https://github.com/netlab-ku/pyPARAGON.

Autoimmune thyroid disease and ovarian hypofunction: a review of literature

Thyroid hormones(THs) are essential for the proper functioning of the ovaries, and multiple studies have shown that thyroid abnormalities, especially during adolescence and reproductive age, can lead to lifelong ovarian dysfunction. Autoimmune thyroid disease (AITD), one of the most common organ specific autoimmune diseases, is mainly mediated by cellular autoimmune reactions, and has strong inflammatory infiltration and immune active cells, including chemokines and cytokines, which are important components of ovarian aging. This suggests that autoimmune and inflammatory molecular processes may play a role in the emergence of ovarian dysfunction. The purpose of this review is to summarize recent in vivo and in vitro evidence of a complex relationship between AITD and ovarian dysfunction. AITD is closely related to the decline of ovarian function from the perspective of antibody, cytokine, oxidative stress, and genetic factors. Finally, some of the currently known treatments for AITD and hypo ovarian disease are summarized.

Patients with gynecological malignancies are similar to other IVF patients without cancer for clinical and molecular reproductive parameters and DNA damage response pattern

This study intended to investigate if gynecological cancers compromise ovarian function and reduce the success of assisted reproduction techniques (ART). No clinical and molecular data together is available on this issue for gynecological or other organ cancers. Steroidogenic pathways and DNA damage response characteristics of the granulosa cells retrieved from the 39 gynecological cancer patients were analyzed together with their clinical ART characteristics in comparison to 31 control ART patients. Patients with gynecological malignancies were similar to the control IVF patients for the number of mature oocytes retrieved, fertilization rates and embryo development competency. Molecular analyses of the granulosa cells retrieved from these cancer patients did not detect any perturbations in gonadotropin receptor expression and response, sex steroid production, cholesterol utilization/storage and, DNA damage response pattern in comparison to control IVF patients without cancer. This study provides the first reassuring clinical and molecular combined data set that the presence of gynecological malignancy does not appear to have any detrimental effect on clinical IVF cycle characteristics and ovarian functioning at molecular level.

Research progress on the prevention and treatment of chemotherapy-induced ovarian damage

Chemotherapy is a main treatment option for malignant tumors, but it may cause various adverse effects, including dysfunction of female endocrine system and fertility. Chemotherapy-induced ovarian damage has been concerned with ovarian preservation but also the prevention and treatment of ovarian dysfunction. In this article, the mechanisms of ovarian injury caused by chemotherapy, including apoptosis of the follicle and supporting cells, follicle "burn out", ovarian stromal and microvascular damage; and influencing factors, including age at diagnosis, initial low pre-treatment anti-Müllerian hormone levels, toxicity, dose and regimen of chemotherapy drugs are reviewed based on the latest research results and clinical practice. The article also discusses measures and frontier therapies for the prevention and treatment of ovarian injury, including the application of gonadotropin releasing hormone agonists or antagonists, tyrosine kinase inhibitors, antioxidants, sphingosine-1-phosphate, ceramide-1-phosphate, mammalian target of rapamycin inhibitors, granulocyte-colony stimulating factor, stem cell therapy and artificial ovaries.

Postoperative Reproductive Outcomes in Patients with Endometriosis-Associated Infertility: A Single-Center Retrospective Study

OBJECTIVES

Endometriosis is a chronic inflammatory disease known to contribute to infertility. Laparoscopic excision of endometriotic lesions represents a standard treatment modality for symptomatic women. Our study aims to assess the potential benefits of laparoscopic excision of endometriosis in patients experiencing infertility associated with the condition, as well as to define the clinical factors that may impact the cumulative pregnancy rate.

DESIGN

In this retrospective analysis, a total of 102 patients with endometriosis-related infertility were enrolled.

MATERIALS, SETTING, METHODS

All participants underwent reproductive surgery and were then categorized into two groups: those who conceived were assigned to group A, while those who did not were assigned to group B. The correlation between clinical factors and pregnancy rate was assessed using the log-rank test, and both univariate and multivariate analyses were conducted utilizing the Cox regression model.

RESULTS

The median age of the patients was 33.5 years, with a median follow-up duration of 70 months. Throughout the study period, 71 patients (69.6%) conceived (group A), while the remaining 31 patients (30.4%) did not conceive (group B), irrespective of the use of Assisted-Reproduction Technologies. The Cox regression model revealed that factors such as the duration of infertility, presence of deep infiltrating endometriosis, bowel endometriosis, rASRM stages, pelvic adhesions, and recurrent disease negatively impacted postoperative conception rates. Conversely, complete excision and coagulation of endometriotic lesions, as well as ablation of ovarian endometriomas, emerged as independent positive predictive factors for postoperative clinical pregnancy.

LIMITATIONS

Limitations of this study is retrospective design of the study, as well as a small number of patients.

CONCLUSIONS

Complete excision of endometriosis during reproductive surgery may yield a positive effect and optimize the likelihood of pregnancy in patients with endometriosis-related infertility.

Pregnancy outcomes in women with primary ovarian insufficiency in assisted reproductive technology therapy: a retrospective study

Purpose

This study aims to retrospectively estimate cumulative reproductive outcomes in women with primary ovarian insufficiency (POI) in assisted reproductive technology (ART) therapy.

Methods

A total of 139 patients diagnosed with POI were reviewed in this study. Firstly, they were divided into two groups according to oocyte origin: using their own oocytes (OG group) or accepting oocyte donations (OD I group). Secondly, the patients were split depending on the pregnancy outcome. In the OG group, nine patients decided to use others' oocytes after a failure of attempting to use their own, and this population was the oocyte donation II group (OD II group).

Results

There were 88 patients who used their own oocytes, while 51 patients accepted oocyte donations. In the OG group, there are only 10 (7.2%) patients who got pregnant, and patients in the OD group had worse hormone levels (FSH 71.37 ± 4.18 vs. 43.98 ± 2.53, AMH 0.06 ± 0.04 vs. 1.15 ± 0.15, and AFC 0.10 ± 0.06 vs. 1.15 ± 0.15) and more years of infertility (5.04 ± 0.48 vs. 3.82 ± 0.30), which explained why they choose oocyte donation. In all the three groups, baseline characteristics were comparable between pregnant women and non-pregnant women. Of the 10 pregnant patients in the OG group, four of them used luteal-phase short-acting long protocol and had pregnancies successfully in their first cycles.

Conclusion

Ovarian stimulation in POI women requires more cost and time. For those with a stronger desire to have genetic offspring, luteal-phase short-acting long protocol may help them obtain pregnancy rapidly.

Differential expression of follicular fluid exosomal microRNA in women with diminished ovarian reserve

PURPOSE

Decreased ovarian reserve function is mainly characterized by female endocrine disorders and fertility decline. Follicular fluid (FF) exosomal microRNAs (miRNAs) have been shown to regulate the function of granulosa cells (GCs). The present study explored differentially expressed miRNAs (DEmiRNAs) in patients with diminished ovarian reserve (DOR).

METHODS

FF was collected from 12 DOR patients and 12 healthy controls. DEmiRNAs between the two groups were identified and analyzed using high-throughput sequencing technology and validated by real-time quantitative PCR (RT-qPCR).

RESULTS

A total of 592 DEmiRNAs were identified using high-throughput miRNA sequencing, of which 213 were significantly upregulated and 379 were significantly downregulated. The sequencing results were further validated by RT-qPCR. These DEmiRNA target genes were mainly involved in the cancer pathway, phosphoinositide 3-kinase (PI3K)/protein kinase B (AKT) signaling pathway, regulation of actin cytoskeleton signaling pathway, and biological processes related to protein binding, nucleoplasm, cytoplasm, and cell membrane.

CONCLUSION

FF exosomal miRNAs are significantly differentially expressed in DOR patients versus non-DOR patients, underscoring their crucial role in regulating the pathogenesis of DOR.

Effects of calorie, protein, and branched chain amino acid restriction on ovarian aging in mice

Calorie restriction (CR) is an intervention that promotes longevity and preserves the ovarian reserve. Some studies have observed that the positive impacts of CR can be linked to restriction of protein (PR) and branched-chain amino acids (BCAAs) independent of calorie intake. The aim of this study was to compare the effects of protein and BCAA restriction to 30% CR on the ovarian reserve of female mice. For this, 3 month-old C57BL/6 female mice (n = 35) were randomized into four groups for four months dietary interventions including: control group (CTL; n = 8), 30% CR (CR; n = 9), protein restriction (PR; n = 9) and BCAA restriction (BCAAR; n = 9). Body mass gain, body composition, food intake, serum levels of BCAAs, ovarian reserve and estrous cyclicity were evaluated. We observed that CR, protein and BCAA restriction prevented weight gain and changed body composition compared to the CTL group. The BCAA restriction did not affect the ovarian reserve, while both PR and CR prevented activation of primordial follicles. This prevention occurred in PR group despite the lack of reduction of calorie intake compared to CTL group, and CR did not reduce protein intake in levels similar to the PR group. BCAA restriction resulted in increased calorie intake compared to CTL and PR mice, but only PR reduced serum BCAA levels compared to the CTL group. Our data indicates that PR has similar effects to CR on the ovarian reserve, whereas BCAA restriction alone did not affect it.

Brca2(p.T1942fs/+) dissipates ovarian reserve in rats through oxidative stress in follicular granulosa cells

Pathogenic variants of BRCA1/2 constitute hereditary breast and ovarian cancer (HBOC) syndrome, and BRCA1/2 mutant is a risk for various cancers. Whereas the clinical guideline for HBOC patients has been organized for the therapy and prevention of cancer, there is no recommendation on the female reproductive discipline. Indeed, the role of BRCA1/2 pathogenic variants in ovarian reserve has not been established due to the deficiency of appropriate animal models. Here, we used a rat model of Brca2(p.T1942fs/+) mutant of Sprague-Dawley strain with CRISPR-Cas9 editing to evaluate ovarian reserve in females. Fertility and ovarian follicles were evaluated and anti-Müllerian hormone (AMH) was measured at 8-32 weeks of age with a comparison between the wild-type and the mutant rats (MUT). MUT revealed a significantly smaller number of deliveries with fewer total pups. Furthermore, MUT showed a significant decrease in primordial follicles at 20 weeks and a low AMH level at 28 weeks. RNA-sequencing of the ovary at 10 weeks detected acceleration of the DNA damage repair pathway, which was accompanied by oxidative stress-induced DNA double-strand breaks, a decrease in PTEN, and an increase in mTOR in follicular granulosa cells. In conclusion, Brca2(p.T1942fs/+) dissipates primordial follicles via early activation of granulosa cells through oxidative stress, leading to earlier termination of fertility.

The Dominant Mechanism of Cyclophosphamide-Induced Damage to Ovarian Reserve: Premature Activation or Apoptosis of Primordial Follicles?

Cyclophosphamide (CPM), a part of most cancer treatment regimens, has demonstrated high gonadal toxicity in females. Initially, CPM is believed to damage the ovarian reserve by premature activation of primordial follicles, for the fact that facing CPM damage, primordial oocytes show the activation of PTEN/PI3K/AKT pathways, accompanied by accelerated activation of follicle developmental waves. Meanwhile, primordial follicles are dormant and not considered the target of CPM. However, many researchers have found DNA DSBs and apoptosis within primordial oocytes under CPM-induced ovarian damage instead of premature accelerated activation. A stricter surveillance system of DNA damage is also thought to be in primordial oocytes. So far, the apoptotic death mechanism is considered well-proved, but the premature activation theory is controversial and unacceptable. The connection between the upregulation of PTEN/PI3K/AKT pathways and DNA DSBs and apoptosis within primordial oocytes is also unclear. This review aims to highlight the flaw and/or support of the disputed premature activation theory and the apoptosis mechanism to identify the underlying mechanism of CPM's injury on ovarian reserve, which is crucial to facilitate the discovery and development of effective ovarian protectants. Ultimately, this review finds no good evidence for follicle activation and strong consistent evidence for apoptosis.

Acupuncture Combined with Bushen-Jianpi Decoction Ameliorates the Ovarian Function of Diminished Ovarian Reserve Rats by Regulating Phosphoinositide 3-Kinase/AKT Signaling

OBJECTIVE

This study aimed to explore the therapeutic efficiency as well as mechanism of acupuncture combined with Bushen-Jianpi decoction (BJD) to treat rats with diminished ovarian reserve (DOR).

METHODS

A DOR rat model was constructed using zona pellucida 3 peptide, and acupuncture, BJD, and their combination were administered as therapeutic interventions. We measured changes in the ovarian indexes, the number of follicles at all levels, the serum levels of sex hormones and immune factors, the expression levels of phosphoinositide 3-kinase (PI3K), AKT, p-AKT, and caspase-3, and the changes in the proportions of splenic T cell subtypes, including T-helper 17 (Th17), Tc17, regulatory T (Treg), CD4+, and CD8+ cells.

RESULTS

Acupuncture combined with BJD induced a decrease in the levels of follicle-stimulating and luteinizing hormones, and the effect was greater than that elicited by BJD or acupuncture alone (P < 0.05). Additionally, this combination treatment effectively abrogated the increase in the levels of interleukin-2 (IL-2), IL-17, anti-zona pellucida antibody, and cleaved caspase-3 (P < 0.05), while promoting the regulation of IL-6 and p-AKT (P < 0.01). Furthermore, treatment with acupuncture combined with BJD restored the proportions of CD4+ cells and the CD4+ / CD8+ T cell ratio (P < 0.01), decreased the proportion of CD8+ T and Th17 cells (P < 0.01), and increased the proportions of Tc17 and Treg cells (P < 0.01).

CONCLUSION

Combining acupuncture with BJD can enhance ovarian function in DOR rats. The regulation of sex hormone levels and immune function in rats may be attributed to the adjustment of the mRNA and proteins levels of PI3K, AKT, and caspase-3 in the PI3K/AKT signaling pathway, which leads to an improvement in the immune function of DOR rats.

Comparative miRNA expression profile analysis of porcine ovarian follicles: new insights into the initiation mechanism of follicular atresia

Follicular atresia occurs in every stage of ovarian development, which is relevant to female fertility. In the past decade, increasing studies have confirmed that miRNAs, a class of short non-coding RNAs, play an important role in follicular atresia by post-transcription regulation of their target genes. However, the function of miRNAs on follicular atresia initiation is unknown. In the present study, high-throughput small RNA sequencing was performed to analyze differential miRNA expression profiles between healthy (HF) follicles and early atretic (EAF) follicles. A total of 237 conserved miRNA were detected, and the miR-143 is the highest expressed in follicles. Meanwhile, we also found wide sequence variations (isomiRs) in porcine ovarian miRNA, including in 5'un-translation region, core seed sequences and 3'untranslation region. Furthermore, we identified 22 differentially expressed miRNAs in EAF groups compared to HF group, of which 3 miRNAs were upregulated, as well as 19 miRNAs were downregulated, and then the RT-PCR was performed to validate these profiles. The target genes of these differentially expressed miRNAs were predicted by using miRwalk, miRDB, and Targetscan database, respectively. Moreover, the gene ontology and KEGG pathway enrichment established that the regulating functions and signaling pathways of these miRNAs contribute to follicular atresia initiation and cell fate. In conclusion, this study provides new insights into the changes of miRNAs in early atretic follicles to demonstrate their molecular regulation in ovarian follicular atretic initiation.

The stromal microenvironment and ovarian aging: mechanisms and therapeutic opportunities

For decades, most studies of ovarian aging have focused on its functional units, known as follicles, which include oocytes and granulosa cells. However, in the ovarian stroma, there are a variety of somatic components that bridge the gap between general aging and ovarian senescence. Physiologically, general cell types, microvascular structures, extracellular matrix, and intercellular molecules affect folliculogenesis and corpus luteum physiology alongside the ovarian cycle. As a result of damage caused by age-related metabolite accumulation and external insults, the microenvironment of stromal cells is progressively remodeled, thus inevitably perturbing ovarian physiology. With the established platforms for follicle cryopreservation and in vitro maturation and the development of organoid research, it is desirable to develop strategies to improve the microenvironment of the follicle by targeting the perifollicular environment. In this review, we summarize the role of stromal components in ovarian aging, describing their age-related alterations and associated effects. Moreover, we list some potential techniques that may mitigate ovarian aging based on their effect on the stromal microenvironment.

miR-302d Targeting of CDKN1A Regulates DNA Damage and Steroid Hormone Secretion in Bovine Cumulus Cells

(1) Background: DNA damage in cumulus cells hinders oocyte maturation and affects steroid hormone secretion. It is crucial to identify the key factors that regulate cellular DNA damage and steroid hormone secretion. (2) Methods: Treatment of bovine cumulus cells with bleomycin to induce DNA damage. The effects of DNA damage on cell biology were determined by detecting changes in DNA damage degree, cell cycle, viability, apoptosis, and steroid hormones. It was verified that mir-302d targeted regulation of CDKN1A expression, and then affected DNA damage and steroid hormone secretion in cumulus cells. (3) Results: Bleomycin induced increased DNA damage, decreased G1-phase cells, increased S-phase cells, inhibited proliferation, promoted apoptosis, affected E2 and P4 secretion, increased CDKN1A expression, and decreased miR-302d expression. Knockdown of CDKN1A reduced DNA damage, increased G1-phase cells, decreased G2-phase cells, promoted proliferation, inhibited apoptosis, increased E2 and P4 secretion, and increased the expression of BRCA1, MRE11, ATM, CDK1, CDK2, CCNE2, STAR, CYP11A1, and HSD3B1. The expression of RAD51, CCND1, p53, and FAS was decreased. Overexpression of CDKN1A resulted in the opposite results. miR-302d targets CDKN1A expression to regulate DNA damage and then affects the cell cycle, proliferation, apoptosis, steroid hormone secretion, and the expression of related genes. (4) Conclusions: miR-302d and CDKN1A were candidate molecular markers for the diagnosis of DNA damage in bovine cumulus cells.

Circular RNA as new serum metabolic biomarkers in patients with premature ovarian insufficiency

OBJECTIVE

Quantitative real-time PCR (qPCR) is used to detect the differential expression of circular RNAs in patients of premature ovarian insufficiency (POI), to explore the new biomarkers of POI that can be detected from blood as soon as possible.

METHODS

The study collected plasma samples from 30 patients in POI group and 30 normal people group who meet the inclusion criteria, who visited the gynecology clinic of The First Affiliated Hospital of Guangzhou University of Chinese Medicine from July 2019 to December 2020. Then, circRNAs in plasma were extracted for qPCR validation.

RESULTS

1. qPCR technology was performed on hsa_circRNA_008901 and hsa_circRNA_403959, and it was found that the levels of both were considerably downregulated in POI group. Clinical evaluation showed that both hsa_circRNA_008901 and hsa_circRNA_403959 have good diagnostic value for POI. 2. According to miRNA Regulatory Element (MRE) analysis, the predicted target miRNAs of hsa_circRNA_008901 are: hsa-miR-548c-3p, hsa-miR-924, hsa-miR-4677-5p, hsa-miR-6786-3p and hsa-miR-7974; the predicted target miRNAs of hsa_circRNA_403959 are: hsa-miR-1207-5p, hsa-miR-4691-5p, hsa-miR-4763-3p, hsa-miR-6807-5p and hsa-miR-7160-5p.

CONCLUSION

Compared with the normal group, the expression levels of hsa_circRNA_008901 and hsa_circRNA_403959 in the POI group were downregulated, suggesting that these two circRNAs may be potential biomarkers of POI. Bioinformatics analysis indicated that hsa_circRNA_008901 and hsa_circRNA_403959 may regulate their binding miRNA through the action form of "molecular sponge", and then regulate the signaling pathway regulated by miRNA, and ultimately affect the disease progression of POI.

Impact of human ovarian tissue manipulation on follicles: evidence of a potential first wave of follicle activation during fertility preservation procedures

PURPOSE

The aim of this study was to investigate the impact of processing human ovarian tissue on follicle activation dynamics.

METHODS

Fresh ovarian tissue was retrieved from 9 women undergoing laparoscopic surgery for benign conditions. Biopsies from each patient were divided into 3 fragments, the first of which was immediately fixed in the operating room (T0) and the second and third just after processing at 25 (T25) and (T90) 90 min. To evaluate follicle activation, markers of the PI3K and Hippo signaling pathways were immunolabeled at each time point, targeting phospho-Akt (p-Akt) by immunohistochemistry and yes-associated protein (YAP) cellular localization in the granulosa cell layer by immunofluorescence.

RESULTS

Four hundred forty primordial follicles were evaluated for p-Akt and 420 for YAP. Significantly stronger p-Akt expression was observed at T25 (23.01 ± 13.45%; p=0.04) and T90 (38.99 ± 25.21%; p<0.001) than at T0 (2.72 ± 3.35%). A significant nucleus-to-cytoplasm shift in YAP was detected at T25 (1.21 ± 0.25; p=0.015 compared to T0 (0.95 ± 0.09), while T90 (1.10 ± 0.16) values were similar to T25.

CONCLUSION

Our data prove that ovarian tissue manipulation significantly impacts follicle dynamics by stimulating the PI3K and Hippo signaling pathways involved in primordial follicle activation. Further experimental evidence must nevertheless be gathered to understand and gain control of follicle activation mechanisms in non-physiological conditions (like ovarian tissue manipulation), in order to optimize fertility preservation and restoration strategies.

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.

Human ovarian cryopreservation: vitrification versus slow freezing from histology to gene expression

Cryopreservation of ovarian tissue is one of the strategies offered to girls and women needing gonadotoxic treatment to preserve their fertility. The reference method to cryopreserve is slow freezing; vitrification is an alternative method. The aim was to evaluate which of the two is the best method for human ovarian tissue cryopreservation. Each ovary was divided into three groups: (i) fresh; (ii) slow freezing; and (iii) vitrification. An evaluation of the follicular density, quality and the expression six genes (CYP11A, STAR, GDF9, ZP3, CDK2, CDKN1A) were performed. We observed no significant difference in follicular density within these three groups. Slow freezing altered the primordial follicles compared to the fresh tissue (31.8% vs 55.9%, p = 0.046). The expression of genes involved in steroidogenesis varied after cryopreservation compared to the fresh group; CYP11A was under-expressed in slow freezing group (p = 0.01), STAR was under-expressed in the vitrification group (p = 0.01). Regarding the expression of genes involved in cell cycle regulation, CDKN1A was significantly under-expressed in both freezing groups (slow freezing: p = 0.0008; vitrification: p = 0.03). Vitrification had no effect on the histological quality of the follicles at any stage of development compared to fresh tissue. There was no significant difference in gene expression between the two techniques.

Association between single-nucleotide polymorphism in PIK3CD gene and litter size in Small Tail Han sheep

The p110δ isoform of the PI3K catalytic subunit (encoded by the PIK3CD gene) is a key component of the PI3K pathway for follicle growth in mammalian ovarian granulosa cells. Nevertheless, little is known about the association of its polymorphisms with ovine litter size. In this study, the distribution of different genotypes of two SNPs in the PIK3CD gene was calculated in more than forty sheep breeds, and the associations between SNPs and litter size in Small Tail Han (STH) sheep were also analyzed. Besides, the mRNA expression of the PIK3CD gene was also detected in some reproduction-related tissues. The results showed that the "A" allele frequency was higher in rs412889931 (g.41926327G > A) in a typical polytocous sheep breed (p < 0.01). The association's analysis showed rs412889931 was correlated with ovine fecundity as assessed by three parity litter sizes (p < 0.05). Finally, we found the expression of PIK3CD in the ovary had significant differences in different fecundity sheep breeds, indicating that SNP may regulate the litter size by influencing the PIK3CD gene expression. The present results demonstrated that rs412889931 could be used in the marker-assisted selection of the litter size in sheep breeding.

The oocyte: the key player in the success of assisted reproduction technologies

The ovulation of a mature oocyte at metaphase II of meiosis, with optimal potential to undergo fertilisation by a sperm cell, complete meiosis and sustain the switch to mitotic division, and support early embryo development, involves a protracted and disrupted/delayed series of processes. Many of these are targeted for exploitation in vivo , or recapitulation in vitro , by the livestock industry. Reproductive technologies, including AI, multiple ovulation embryo transfer, ovum pick-up, in vitro embryo production, and oestrus and ovulation synchronisation, offer practitioners and producers the opportunity to produce offspring from genetically valuable dams in much greater numbers than they would normally have in their lifetime, while in vitro oocyte and follicle culture are important platforms for researchers to interrogate the physiological mechanisms driving fertility. The majority of these technologies target the ovarian follicle and the oocyte within; thus, the quality and capability of the recovered oocyte determine the success of the reproductive intervention. Molecular and microscopical technologies have grown exponentially, providing powerful platforms to interrogate the molecular mechanisms which are integral to or affected by ART. The development of the bovine oocyte from its differentiation in the ovary to ovulation is described in the light of its relevance to key aspects of individual interventions, while highlighting the historical timeline.

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.

Diminished Ovarian Reserve in Endometriosis: Insights from In Vitro, In Vivo, and Human Studies-A Systematic Review

Endometriosis, a prevalent disorder in women of reproductive age, is often associated with undesired infertility. Ovarian reserve, an essential measure of ovarian function that is crucial for maintaining fecundity, is frequently diminished in women with endometriosis. Though the causative relationship between endometriosis and reduced ovarian reserve is not fully understood due to the lack of standardized and precise measurements of ovarian reserve, there is ongoing discussion regarding the impact of interventions for endometriosis on ovarian reserve. Therefore, in this review, we investigate articles that have related keywords and which were also published in recent years. Thereafter, we provide a comprehensive summary of evidence from in vitro, in vivo, and human studies, thereby shedding light on the decreased ovarian reserve in endometriosis. This research consolidates evidence from in vitro, in vivo, and human studies on the diminished ovarian reserve associated with endometriosis, as well as enhances our understanding of whether and how endometriosis, as well as its interventions, contribute to reductions in ovarian reserve. Furthermore, we explore potential strategies to modify existing therapy options that could help prevent diminished ovarian reserve in patients with endometriosis.

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.

Transcriptomic profiling of human granulosa cells between women with advanced maternal age with different ovarian reserve

BACKGROUND

Age-related diminished ovarian reserve (DOR) is not absolute. Some advanced maternal age (AMA) still have normal ovarian reserve (NOR) and often show better pregnancy outcomes. Exploring the transcriptomic profile of granulosa cells (GCs) in AMA could lead to new ideas for mitigating age-related diminished ovarian reserve.

AIM

This study aimed to analyze the transcriptomic profile of GCs in AMA with different ovarian reserve.

RESULTS

In total, 6273 statistically significant differential expression genes (DEGs) (|log2fc|> 1, q < 0.05) were screened from the two groups, among which 3436 genes were upregulated, and 2837 genes were downregulated in the DOR group. Through Gene Ontology (GO) and Kyoto Encyclopedia of Genes and Genomes (KEGG) pathway enrichment analysis, the potential functions of dysregulated genes in AMA with DOR or NOR were predicted. The GO enrichment analysis revealed that the DEGs were mainly enriched in obsolete oxidation-reduction process, mitochondrion, metal ion binding, ATP binding, etc. The KEGG pathway enrichment analysis revealed that the above-mentioned DEGs were mainly enriched in ferroptosis, regulation of actin cytoskeleton, oxidative phosphorylation, etc. Meanwhile, verification of the mRNA expression levels of DEGs revealed the possible involvement of "ferroptosis" in age-related diminished ovarian reserve.

CONCLUSIONS

From a new clinical perspective, we presented the first data showing the transcriptomic profile in GCs between AMA with different ovarian reserve. At the same time, we identified the role of ferroptosis in the GCs of AMA, providing a new biological basis for studying ovarian aging and improving pregnancy outcomes of AMA.

Human umbilical cord mesenchymal stem cell‑derived exosomes improve ovarian function in natural aging by inhibiting apoptosis

Prolonging the reproductive lifespan is beneficial for preserving the physical and psychological health of women. The transplantation of mesenchymal stem cell (MSC)‑derived exosomes (MSC‑Exos) has been reported to be a promising regenerative therapeutic strategy for restoring the function of aging ovaries. The present study thus evaluated the therapeutic efficacy of exosomes derived from human umbilical cord‑MSCs (hUCMSC‑Exos) in a mouse model of natural ovarian aging (NOA), and further investigated the role of exosomal microRNAs (miRNAs/miRs) in the mechanisms of this creative therapy. Specifically, following the administration of hUCMSC‑Exos in mice with NOA, ovarian function was found to improve, as indicated by the restoration of follicle numbers and hormone levels. These exosomes were found to exhibit the ability to inhibit PTEN expression and suppress apoptosis both in vivo and in vitro. Subsequently, miRNA sequencing of the exosomes was performed, following which bioinformatics analysis was used to identify the highly expressed miRNAs that are capable of targeting PTEN expression. Through high‑throughput sequencing and molecular analyses, miR‑21‑5p was found to be the highest in ranking in terms of expression, suggesting that hUCMSC‑Exos can preserve ovarian function by suppressing PTEN expression to inhibit apoptosis by delivering miR‑21‑5p. On the whole, the results of the present study suggest that the application of exosomes can be used to restore ovarian function in mice with NOA. These positive findings also suggest that the transplantation of exosomes derived from MSCs holds promise as an agent against ovarian aging.

Regulation of follicular activation signaling pathways by in vitro inhibition of YAP/TAZ activity in mouse ovaries

The Hippo pathway plays a crucial role in the regulation of follicular activation, which constitutes the first step of the folliculogenesis process. Disruption of this pathway occurs in several non-physiological contexts, after fragmentation for ovarian tissue cryopreservation procedures or chemotherapy exposure, leading to massive follicular growth and depletion. This study aimed to investigate the effect of controlling the Hippo pathway using verteporfin (VERT) during in vitro ovarian culture and to evaluate its potential preventive effects on chemotherapy-induced follicle activation using a mouse model. After exposure of cut ovaries to different concentrations of VERT for 3 h, a dose-dependent effect of VERT was observed that reached significant inhibition of YAP activity at 3 µmol/L. To assess the potential effect of controlling chemotherapy-induced Hippo pathway disruption, whole mouse ovaries were exposed to VERT alone or as a co-treatment with 4-hydroperoxycylophosphamide (4HC). VERT co-treatment prevented chemotherapy-induced YAP activation but had a limited impact on downstream effector gene, Ccn2. Surprisingly, VERT co-treatment also prevented mTOR and survival signaling pathway alterations following chemotherapy exposure. These results suggest an interaction between the two main signaling pathways regulating follicle activation and a protective effect of VERT on 4HC-induced DNA damage.

Network analysis and experimental approach to investigate the potential therapeutic mechanism of zishen yutai pills on premature ovarian insufficiency

Background

As society continues to develop, women are more at risk of gonadotoxic substance exposure. Consequently, the incidence of premature ovarian insufficiency (POI) has increased significantly in the past decades. Hormone replacement therapy (HRT) is recommended as the standard treatment to relieve hypoestrogenic symptoms; however, its potential side effects and contraindications have drawn widespread controversy and concern. As such, the Chinese medicine Zishen Yutai Pill (ZSYTP) commonly used for treating miscarriage and menoxenia, is a highly promising alternative drug candidate against POI, however its therapeutic mechanism has not been completely elucidated.

Objective

To systematically analyze the potential therapeutic targets of ZSYTP on POI, we combined network pharmacology analysis and molecular docking to predict critical target genes, with experimental validation on POI murine models.

Methods

The active compounds of ZSYTP were collected from three online databases, and the candidate targets were predicted based on the chemical structure. The POI-related targets were obtained from four databases. A PPI network was constructed to find the key target genes between ZSYTP and POI, while GO and KEGG enrichment analyses were employed to study the mechanism of ZSYTP against POI. The binding capability of the key co-targets with active components was examined by molecular docking. We used a cyclophosphamide (CTX)-inducible POI mouse model to verify our predictions by histopathological observation, immunohistochemical staining (caspase-3, TUNEL assay), hormone determination (FSH, AMH) and ribonucleic acid sequencing (RNA Seq). Progynova was also used to study the difference between ZSYTP and HRT.

Result

We identified 21 target genes as the hub between ZSYTP and POI. The GO and KEGG analyses revealed that the molecular mechanism of ZSYTP against POI were mainly based on the regulation of gene and protein expression. A variety of signaling pathways may be involved in the treatment of ZSYTP against POI, especially PI3K-AKT, HIF-1 and the AGE-RAGE cascades. Docking simulation showed that G1, C1, SR5, and F1 had relatively lower binding energy. In vivo, ZSYTP significantly reversed CTX-induced ovarian damage in follicle number, hormone level and apoptosis, with an overall improved therapeutic effect compared to Progynova. Results from RNA-Seq revealed that the PI3K-AKT, Hippo, AGE-RAGE, and Rap1 signaling pathways and regulation of inflammation, immune response, and lipid metabolism may mediate the protective effects of ZSYTP against POI, which is different than Progynova's mechanism of action.

Conclusions

Collectively, this study indicates that ZSYTP could be a highly promising alternative as a non-HRT-based therapy for POI. Its mechanism involves multiple signaling pathways, alleviating ovarian apoptosis and recovering AMH and FSH level. However, the discrepancy between different research techniques highlight the necessity of further experimental verification from other aspects such as translation and posttranslational modification.

The Aging Ovary and the Tales Learned Since Fetal Development

BACKGROUND

While the term "aging" implies a process typically associated with later life, the consequences of ovarian aging are evident by the time a woman reaches her forties, and sometimes earlier. This is due to a gradual decline in the quantity and quality of oocytes which occurs over a woman's reproductive lifespan. Indeed, the reproductive potential of the ovary is established even before birth, as the proper formation and assembly of the ovarian germ cell population during fetal life determines the lifetime endowment of oocytes and follicles. In the ovary, sophisticated molecular processes have been identified that regulate the timing of ovarian aging and these are critical to ensuring follicular maintenance.

SUMMARY

The mechanisms thought to contribute to overall aging have been summarized under the term the "hallmarks of aging" and include such processes as DNA damage, mitochondrial dysfunction, telomere attrition, genomic instability, and stem cell exhaustion, among others. Similarly, in the ovary, molecular processes have been identified that regulate the timing of ovarian aging and these are critical to ensuring follicular maintenance. In this review, we outline critical processes involved in ovarian aging, highlight major achievements for treatment of ovarian aging, and discuss ongoing questions and areas of debate.

KEY MESSAGES

Ovarian aging is recognized as what may be a complex process in which age, genetics, environment, and many other factors contribute to the size and depletion of the follicle pool. The putative hallmarks of reproductive aging outlined herein include a diversity of plausible processes contributing to the depletion of the ovarian reserve. More research is needed to clarify if and to what extent these putative regulators do in fact govern follicle and oocyte behavior, and how these signals might be integrated in order to control the overall pattern of ovarian aging.

The Role of Lifestyle and Dietary Factors in the Development of Premature Ovarian Insufficiency

Premature ovarian insufficiency (POI) is a condition that arises from dysfunction or early depletion of the ovarian follicle pool accompanied by an earlier-than-normal loss of fertility in young women. Oxidative stress has been suggested as an important factor in the decline of fertility in women and POI. In this review, we discuss the mechanisms of oxidative stress implicated in ovarian ageing and dysfunction in relation to POI, in particular mitochondrial dysfunction, apoptosis and inflammation. Genetic defects, autoimmunity and chemotherapy, are some of the reviewed hallmarks of POI that can lead to increased oxidative stress. Additionally, we highlight lifestyle factors, including diet, low energy availability and BMI, that can increase the risk of POI. The final section of this review discusses dietary factors associated with POI, including consumption of oily fish, mitochondria nutrient therapy, melatonin, dairy and vitamins that can be targeted as potential interventions, especially for at-risk women and in combination with personalised nutrition. Understanding the impact of lifestyle and its implications for POI and oxidative stress holds great promise in reducing the burden of this condition.

MicroRNA-144-3p protects against chemotherapy-induced apoptosis of ovarian granulosa cells and activation of primordial follicles by targeting MAP3K9

Premature ovarian failure (POF) is defined by amenorrhea, ovarian atrophy, hypoestrogenism, elevated gonadotropin level, and infertility under the age of 40. POF is frequently induced by chemotherapeutic agents. However, the underlying mechanisms regarding chemotherapy-mediated damage to ovarian function are unclear. In this study, enhanced apoptosis of granulosa cells (GCs) and aberrant activation of primordial follicles were observed in a POF mouse model induced by cisplatin. We subsequently observed significant downregulation of miR-144-3p and upregulation of mitogen-activated protein kinase kinase kinase 9 (MAP3K9) in primary ovarian GCs from POF mice, as revealed by microarrays. Furthermore, MAP3K9 expression was higher in human ovarian granulosa cells (COV434) treated with cisplatin and was identified as a novel target of miR-144-3p. Functional analysis revealed that miR-144-3p attenuated cisplatin induced apoptosis of GCs via silencing MAP3K9 expression, which suppressed the activity of the downstream p38 mitogen activated protein kinase (MAPK) pathway. Meanwhile, miR-144-3p prevented premature primordial follicle depletion in cisplatin-induced POF mice through targeting Map3k9, which led to a decline in the phosphorylation and activation of the phosphatidylinositol-4,5-bisphosphate 3-kinase (PI3K)/protein kinase b (AKT) pathway. Taken together, this study revealed the protective effects of miR-144-3p on ovarian function and shed light on the epigenetic regulatory mechanism in the development of POF, which might provide new biomarkers for the ovarian reserve.

Investigation of the Mechanisms and Experimental Verification of Yulin Formula in the Treatment of Diminished Ovarian Reserve via Network Pharmacology

Purpose

The aim of this study is to examine, using network pharmacology analysis and experimental validation, the pharmacological processes by which Yulin Formula (YLF) reduces cyclophosphamide-induced diminished ovarian reserve (DOR).

Methods

First, information about the active components, associated targets, and related genes of YLF and DOR was gathered from open-access databases. The primary targets and pathways of YLF to reduce DOR were predicted using studies of functional enrichment from the Kyoto Encyclopedia of Genes and Genomes (KEGG), Gene Ontology (GO), and Protein-Protein Interaction (PPI) networks. Second, we built a cyclophosphamide-induced diminished ovarian reserve (DOR) rat model to verify the primary target proteins implicated in the predicted signaling pathway to explore the mechanism of improve ovarian function of YLF.

Results

98 targets met the targets of the 82 active ingredients in YLF and DOR after searching the intersection of the active ingredient targets and DOR targets. Fourteen targets, including AKT and Caspase-3 among others, were hub targets, according to the PPI network study. The PI3K/AKT pathway was revealed to be enriched by numerous targets by the GO and KEGG enrichment studies, and it was used as a target for in vivo validation. Animal studies showed that YLF administration not only reduced the number of atretic follicles, the proportion of TUNEL-positive ovarian cells, the rate of apoptosis of granulosa cells (GCs) and the proportion of abnormal mitochondria in DOR rats, but also reversed the high expression of Caspase-3, Caspase-9, BAX, cytochrome C, PI3K and P-AKT, improving the ovarian reserve in cyclophosphamide (CTX)-induced DOR rats.

Conclusion

Our research results predicted the active ingredients and potential targets of YLF-interfering DOR by an integrated network pharmacology approach, and experimentally validated some key target proteins participated in the predicted signaling pathway. A more comprehensive understanding of the pharmacological mechanism of YLF for DOR treatment was obtained.

Exploring biomarkers of premature ovarian insufficiency based on oxford nanopore transcriptional profile and machine learning

Premature ovarian insufficiency (POI) is a reproductive endocrine disorder characterized by infertility and perimenopausal syndrome, with a highly heterogeneous genetic etiology and its mechanism is not fully understood. Therefore, we utilized Oxford Nanopore Technology (ONT) for the first time to characterize the full-length transcript profile, and revealed biomarkers, pathway and molecular mechanisms for POI by bioinformatics analysis and machine learning. Ultimately, we identified 272 differentially expressed genes, 858 core genes, and 25 hub genes by analysis of differential expression, gene set enrichment, and protein-protein interactions. Seven candidate genes were identified based on the intersection features of the random forest and Boruta algorithm. qRT-PCR results indicated that COX5A, UQCRFS1, LCK, RPS2 and EIF5A exhibited consistent expression trends with sequencing data and have potential as biomarkers. Additionally, GSEA analysis revealed that the pathophysiology of POI is closely associated with inhibition of the PI3K-AKT pathway, oxidative phosphorylation and DNA damage repair, as well as activation of inflammatory and apoptotic pathways. Furthermore, we emphasize that downregulation of respiratory chain enzyme complex subunits and inhibition of oxidative phosphorylation pathways play crucial roles in the pathophysiology of POI. In conclusion, our utilization of long-read sequencing has refined the annotation information within the POI transcriptional profile. This valuable data provides novel insights for further exploration into molecular regulatory networks and potential biomarkers associated with POI.

Importance of oxygen tension in human ovarian tissue in vitro culture

STUDY QUESTION

Is there any difference between 20% and 5% oxygen (O2) tension in vitro culture (IVC) on the viability and quality of human follicles contained in cultured ovarian cortex?

SUMMARY ANSWER

An O2 tension of 5% yields higher follicle viability and quality than does 20% O2 tension after 6 days of IVC.

WHAT IS KNOWN ALREADY

The primordial follicle (PMF) pool resides within the ovarian cortex, where the in vivo O2 tension ranges between 2% and 8%. Some studies suggest that lowering O2 tension to physiological levels may improve in vitro follicle quality rates.

STUDY DESIGN, SIZE, DURATION

This prospective experimental study included frozen-thawed ovarian cortex from six adult patients (mean age: 28.5 years; age range: 26-31 years) who were undergoing laparoscopic surgery for non-ovarian diseases. Ovarian cortical fragments were cultured for 6 days at (i) 20% O2 with 5% CO2 and (ii) 5% O2 with 5% CO2. Non-cultured fragments served as controls.

PARTICIPANTS/MATERIALS, SETTING, METHODS

Cortical fragments were used for the following analyses: hematoxylin and eosin staining for follicle count and classification; Ki67 staining to evaluate PMF proliferation; cleaved caspase-3 immunostaining to identify follicle apoptosis; 8-hydroxy-2-deoxyguanosine and gamma-H2AX (γH2AX) immunolabeling to detect oxidative stress damage and DNA double-strand breaks (DSBs) in oocytes and granulosa cells (GCs); and β-galactosidase staining to assess follicle senescence. Droplet digital PCR was also performed to further explore the gene expression of superoxide dismutase 2 (SOD2) and glutathione peroxidase 4 (GPX4) from the antioxidant defense system and cyclin-dependent kinase inhibitors (p21 and p16) as tissue senescence-related genes.

MAIN RESULTS AND THE ROLE OF CHANCE

Apoptosis (P = 0.002) and follicle senescence (P < 0.001) rates were significantly lower in the 5% O2 group than in the 20% O2 group. Moreover, GCs in follicles in the 20% O2 group exhibited significantly (P < 0.001) higher oxidative stress damage rates than those in the 5% O2 group. DNA DSB damage rates in GCs of follicles were also significantly higher (P = 0.001) in the 20% O2 group than in the 5% O2 group. SOD2 expression was significantly greater in the 5% O2 group compared to the 20% O2 group (P = 0.04) and the non-cultured group (P = 0.002). Expression of p21 was significantly increased in both the 20% O2 (P = 0.03) and 5% O2 (P = 0.008) groups compared to the non-cultured group. Moreover, the 20% O2 group showed significantly greater p16 expression (P = 0.04) than the non-cultured group, while no significant variation was observed between the 5% O2 and no culture groups.

LARGE SCALE DATA

N/A.

LIMITATIONS, REASONS FOR CAUTION

This study focuses on improving follicle outcomes during the first step of ovarian tissue IVC, where follicles remain in situ within the tissue. The impact of O2 tension in further steps, such as secondary follicle isolation and maturation, was not investigated here.

WIDER IMPLICATIONS OF THE FINDINGS

Our findings suggest that 5% O2 tension culture is a promising step toward potentially solving the problem of poor follicle viability after IVC.

STUDY FUNDING/COMPETING INTEREST(S)

This study was supported by grants from the Fonds National de la Recherche Scientifique de Belgique (FNRS-PDR T.0064.22, CDR J.0063.20 and grant 5/4/150/5 awarded to M.M.D.). The authors have nothing to disclose.

Inhibition of phosphodiesterase PDE8B reduces activation of primordial follicles in mouse ovaries

In the ovaries, cyclic adenosine 3',5'-monophosphate (cAMP) is a second messenger supporting the generation of steroids. Phosphodiesterases (PDEs) are regulators of intracellular cAMP, and therefore, potential regulators of ovarian function. Interestingly, the family of PDE genes are differentially expressed in human oocytes and granulosa cells from primordial and primary follicles, suggesting diverse roles. In this study, we addressed the functions of PDE3B and PDE8B in primordial follicle regulation using inhibitors of PDE3B and PDE8B in murine ovary primary in vitro cultures. Inhibition of PDE8B in ovarian cultures prevented primordial follicle activation, while inhibition of PDE3B had no effect on follicle distribution in the ovary, under the tested conditions. As cAMP levels may increase steroid levels, we assessed the protein levels of the steroidogenic acute regulatory protein (StAR) and aromatase enzymes, and found that inhibition of PDE3B reduced StAR protein levels, whereas inhibition of PDE8 did not alter StAR expression in our murine ovary culture system conditions. Our results showed that ketotifen-induced inhibition of PDE8B can decrease primordial follicle activation, whereas we observed no effect of follicle distribution, when PDE3B was inhibited. Expression of the StaR enzyme was not altered when PDE8B was inhibited, which might reflect not sufficient inhibition by ketotifen to induce StAR alterations, or redundant mechanisms.

From in vivo to in vitro: exploring the key molecular and cellular aspects of human female gametogenesis

Human oogenesis is a highly complex and not yet fully understood process due to ethical and technological barriers that limit studies in the field. In this context, replicating female gametogenesis in vitro would not only provide a solution for some infertility problems, but also be an excellent study model to better understand the biological mechanisms that determine the formation of the female germline. In this review, we explore the main cellular and molecular aspects involved in human oogenesis and folliculogenesis in vivo, from the specification of primordial germ cells (PGCs) to the formation of the mature oocyte. We also sought to describe the important bidirectional relationship between the germ cell and the follicular somatic cells. Finally, we address the main advances and different methodologies used in the search for obtaining cells of the female germline in vitro.

The Late Effects of Cancer Treatment on Female Fertility and the Current Status of Fertility Preservation-A Narrative Review

Fertility counseling should be offered to all individuals of young reproductive age early in the patient's trajectory following a cancer diagnosis. Systemic cancer treatment and radiotherapy often have an inherent gonadotoxic effect with the potential to induce permanent infertility and premature ovarian failure. For the best chances to preserve a patient's fertility potential and to improve future quality of life, fertility preservation methods should be applied before cancer treatment initiation, thus multidisciplinary team-work and timely referral to reproductive medicine centers specialized in fertility preservation is recommended. We aim to review the current clinical possibilities for fertility preservation and summarize how infertility, as a late effect of gonadotoxic treatment, affects the growing population of young female cancer survivors.

Mechanisms of ovarian aging in women: a review

Ovarian aging is a natural and physiological aging process characterized by loss of quantity and quality of oocyte or follicular pool. As it is generally accepted that women are born with a finite follicle pool that will go through constant decline without renewing, which, together with decreased oocyte quality, makes a severe situation for women who is of advanced age but desperate for a healthy baby. The aim of our review was to investigate mechanisms leading to ovarian aging by discussing both extra- and intra- ovarian factors and to identify genetic characteristics of ovarian aging. The mechanisms were identified as both extra-ovarian alternation of hypothalamic-pituitary-ovarian axis and intra-ovarian alternation of ovary itself, including telomere, mitochondria, oxidative stress, DNA damage, protein homeostasis, aneuploidy, apoptosis and autophagy. Moreover, here we reviewed related Genome-wide association studies (GWAS studies) from 2009 to 2021 and next generation sequencing (NGS) studies of primary ovarian insufficiency (POI) in order to describe genetic characteristics of ovarian aging. It is reasonable to wish more reliable anti-aging interventions for ovarian aging as the exploration of mechanisms and genetics being progressing.

Exogenous Hydrogen Sulfide Activates PI3K/Akt/eNOS Pathway to Improve Replicative Senescence in Human Umbilical Vein Endothelial Cells

Background

Endothelial cell senescence is one of the key mechanistic factors in the pathogenesis of atherosclerosis. In terms of molecules, the phosphatidylinositol 3-kinase/protein kinase B/endothelial nitric oxide synthase (PI3K/Akt/eNOS) signaling plays an important role in the prevention and control of endothelial cell senescence, while hydrogen sulfide (H2S) improves the induced precocious senescence of endothelial cells through the PI3K/Akt/eNOS pathway. Comparatively, replicative senescence in endothelial cells is more in line with the actual physiological changes of human aging. This study aims to investigate the mechanism by which H2S improves endothelial cell replicative senescence and the involvement of the PI3K/Akt/eNOS pathway.

Methods

we established a model of replicative senescence in human umbilical vein endothelial cells (HUVECs) and explored the effect of 200 μmol/L sodium hydrosulfide (NaHS; a donor of H2S) on senescence, which was determined by cell morphology, the expression level of plasminogen activator inhibitor 1 (PAI-1), and the positive rate of senescence-associated β-galactosidase (SA-β-Gal) staining. Cell viability was detected by MTT assay to evaluate the effect of NaHS and the PI3K inhibitor, LY294002. Meanwhile, the protein expression of PI3K, Akt, p-Akt, and eNOS in endothelial cells of each group was detected by Western blot.

Results

the replicative senescence model was established in HUVECs at the passage of 16 cumulative cell population doubling values (CPDL). Treatment with NaHS not only significantly reduced the expression of PAI-1 and the positive rate of SA-β-Gal in HUVEC's replicative senescence model but also notably increased the expression of PI3K, p-Akt, p-eNOS, and the content of nitric oxide(NO). However, the effects of NaHS on the expression of the pathway and the content of NO in HUVECs were abolished when LY294002 specifically inhibited PI3K.

Conclusion

NaHS improves the replicative senescence of HUVECs with the contribution of the PI3K/Akt/eNOS pathway.