Cyclophosphamide triggers follicle activation and "burnout"; AS101 prevents follicle loss and preserves fertility

Anti-Müllerian hormone signaling in the ovary involves stromal fibroblasts: a study in humans and mice provides novel insights into the role of ovarian stroma

STUDY QUESTION

What is the involvement of ovarian stroma in the anti-Müllerian hormone (AMH) signaling pathway and which stromal cells are involved?

SUMMARY ANSWER

Mouse and human ovaries show high expression of AMH receptor II (AMHR2) in the stromal fibroblasts surrounding the follicles and activation of the post-AMHR2 pathway by recombinant AMH was evidenced by increased phosphorylation of SMAD1,5 and 9, increased expression AMHR2 and upregulation of αSMA, suggesting fibroblast activation to initiate myofibroblast differentiation.

WHAT IS KNOWN ALREADY

AMH secreted by small growing follicles, regulates ovarian activity. It suppresses initial primordial follicle (PMF) recruitment and FSH-dependent growth. AMH signal transduction is mediated by AMHR2, activating intracellular SMAD proteins and other signaling cascades to induce target-gene expression. Although AMHR2 expression has been reported within the follicle unit, there is evidence suggesting it may be identified in the stroma as well.

STUDY DESIGN, SIZE, DURATION

Fresh murine ovaries were extracted from BALB/c mice (6 weeks old; n = 12 and 21 days old; n = 56). Frozen-thawed ovarian fragments were obtained from 10 women, aged 18-35, who had undergone ovarian tissue cryopreservation and donated frozen ovarian tissue for research.

PARTICIPANTS/MATERIALS, SETTING, METHODS

Murine (6 weeks old) and human donor ovaries were immunostained for AMHR2 and Collagen 1α/αSMA/VCAM1, with additional vimentin staining in mice. Murine (21 days old) and human donor ovaries were used for fibroblast isolation and subsequent 7-day cultures. Prior to assessing AMH effects on isolated fibroblast culture, purity validation tests were implemented to ensure the absence of epithelial, immune, endothel, granulosa, and theca ovarian cell populations. The fibroblast culture's homogeneity was validated by RT-qPCR and western-blot assays, confirming negativity for E-cadherin, CD31, aromatase, CYP17A1, and positivity for αSMA and vimentin. Fibroblasts were then subjected to rAMH treatment in vitro (200 ng/ml) for 0-72 h, with an additional time point of 96 h for human samples, followed by RT-qPCR, western blot, and immunocytochemistry (ICC) for AMHR2 expression. AMHR2 post-receptor signaling was examined by pSMAD1,5,9 levels via western blot. Activated fibroblast marker, αSMA, was assessed via western blot and ICC.

MAIN RESULTS AND THE ROLE OF CHANCE

Immunostaining of mouse and human ovarian tissue showed that stromal cells around follicles at all developmental stages exhibit high AMHR2 expression, while granulosa cells of growing follicles show considerably lower levels. The majority of these AMHR2-positive stromal cells were identified as fibroblasts (Collagen1α in mice and human; vimentin in mice). RT-qPCR, western blot, and immunostaining were performed on cultured mouse and human fibroblasts, confirming that they consisted of a pure fibroblast population (αSMA/vimentin positive and negative for other cell-type markers). A total of 99.81% (average 28.94 ± 1.34 cells/field in mice) and 100% (average 19.20 ± 1.39 cells/field in human samples) of these fibroblasts expressed AMHR2 (ICC). rAMH treated cultured fibroblasts showed increased pSMAD1,5 and 9 levels, demonstrating the effects of AMH on its downstream signaling pathway. pSMAD1,5 and 9 expression increased, as detected by western blot: 1.92-fold in mice (48 h, P = 0.026) and 2.37-fold in human samples (48 h, P = 0.0002). In addition, rAMH treatment increased AMHR2 protein expression, as observed in ICC (human): a 2.57-fold upregulation of AMHR2 Mean Fluorescence Intensity (MFI) (96 h, P = 0.00036), and western blot, showing a 4.2-fold time-dependent increase (48 h, P = 0.026) in mice and 2.4-fold change (48 h, P = 0.0003) in human donors. Exposure to rAMH affected AMHR2 transcription upregulation, with a 6.48-fold change (72 h, P = 0.0137) in mice and a 7.87-fold change (72 h, P < 0.0001) in humans. rAMH treatment induced fibroblast activation (αSMA positive), demonstrating the dynamic effects of AMH on fibroblast behavior. αSMA expression elevation was detected in ICC with a 2.28-fold MFI increase in humans (96 h, P = 0.000067), and in western blot with a 5.12-fold increase in mice (48 h, P = 0.0345) and a 2.69-fold increase in humans (48 h, P ≤ 0.0001). Activated AMHR2-positive stained fibroblast fractions were solely located around growing follicles, in both human and mice. In addition, a small population of AMHR2-positive stained theca cells (VCAM1 positive) was observed.

LARGE SCALE DATA

N/A.

LIMITATIONS, REASONS FOR CAUTION

Ex vivo, fibroblast gene expression might be changed by adhesion to the tissue-culture plate. Nevertheless, cultured fibroblasts (with and without rAMH) are subjected to the same conditions. Observations or significant differences can therefore be considered reliable. In addition, the presented effect of rAMH on fibroblasts is not directly linked to the known inhibitory effect of AMH on follicle activation.

WIDER IMPLICATIONS OF THE FINDINGS

Clarifying the populations of AMH-responsive cells in the ovary provides a foundation for further investigation of the complex AMH signaling across the ovary. The composition of AMH-releasing and -responsive cells can shed light on the communication network between follicles and their environment, which may elucidate the mechanisms behind the AMH inhibitory effect on PMF activation.

STUDY FUNDING/COMPETING INTEREST(S)

This work was financially supported by grants from the Kahn Foundation. There are no competing interests in this study.

TRIAL REGISTRATION NUMBER

N/A.

Ovarian microenvironment: challenges and opportunities in protecting against chemotherapy-associated ovarian damage

BACKGROUND

Chemotherapy-associated ovarian damage (CAOD) is one of the most feared short- and long-term side effects of anticancer treatment in premenopausal women. Accumulating detailed data show that different chemotherapy regimens can lead to disturbance of ovarian hormone levels, reduced or lost fertility, and an increased risk of early menopause. Previous studies have often focused on the direct effects of chemotherapeutic drugs on ovarian follicles, such as direct DNA damage-mediated apoptotic death and primordial follicle burnout. Emerging evidence has revealed an imbalance in the ovarian microenvironment during chemotherapy. The ovarian microenvironment provides nutritional support and transportation of signals that stimulate the growth and development of follicles, ovulation, and corpus luteum formation. The close interaction between the ovarian microenvironment and follicles can determine ovarian function. Therefore, designing novel and precise strategies to manipulate the ovarian microenvironment may be a new strategy to protect ovarian function during chemotherapy.

OBJECTIVE AND RATIONALE

This review details the changes that occur in the ovarian microenvironment during chemotherapy and emphasizes the importance of developing new therapeutics that protect ovarian function by targeting the ovarian microenvironment during chemotherapy.

SEARCH METHODS

A comprehensive review of the literature was performed by searching PubMed up to April 2024. Search terms included 'ovarian microenvironment' (ovarian extracellular matrix, ovarian stromal cells, ovarian interstitial, ovarian blood vessels, ovarian lymphatic vessels, ovarian macrophages, ovarian lymphocytes, ovarian immune cytokines, ovarian oxidative stress, ovarian reactive oxygen species, ovarian senescence cells, ovarian senescence-associated secretory phenotypes, ovarian oogonial stem cells, ovarian stem cells), terms related to ovarian function (reproductive health, fertility, infertility, fecundity, ovarian reserve, ovarian function, menopause, decreased ovarian reserve, premature ovarian insufficiency/failure), and terms related to chemotherapy (cyclophosphamide, lfosfamide, chlormethine, chlorambucil, busulfan, melphalan, procarbazine, cisplatin, doxorubicin, carboplatin, taxane, paclitaxel, docetaxel, 5-fluorouraci, vincristine, methotrexate, dactinomycin, bleomycin, mercaptopurine).

OUTCOMES

The ovarian microenvironment shows great changes during chemotherapy, inducing extracellular matrix deposition and stromal fibrosis, angiogenesis disorders, immune microenvironment disturbance, oxidative stress imbalances, ovarian stem cell exhaustion, and cell senescence, thereby lowering the quantity and quality of ovarian follicles. Several methods targeting the ovarian microenvironment have been adopted to prevent and treat CAOD, such as stem cell therapy and the use of free radical scavengers, senolytherapies, immunomodulators, and proangiogenic factors.

WIDER IMPLICATIONS

Ovarian function is determined by its 'seeds' (follicles) and 'soil' (ovarian microenvironment). The ovarian microenvironment has been reported to play a vital role in CAOD and targeting the ovarian microenvironment may present potential therapeutic approaches for CAOD. However, the relation between the ovarian microenvironment, its regulatory networks, and CAOD needs to be further studied. A better understanding of these issues could be helpful in explaining the pathogenesis of CAOD and creating innovative strategies for counteracting the effects exerted on ovarian function. Our aim is that this narrative review of CAOD will stimulate more research in this important field.

REGISTRATION NUMBER

Not applicable.

Chemotherapy drug combinations induced maternal ovarian damage and long-term effect on fetal reproductive system in mice

With the postponement of female reproductive age and the higher incidence of cancer in young people, fertility preservation has become increasingly important in childbearing age. Chemotherapy during pregnancy is crucial for maternal cancer treatments and fetal outcomes. It is a need to further study ovarian damage caused by chemotherapy drug combinations and long-term effects on offspring development, and a detailed understanding of side effects of chemotherapy drugs. In this study, chemotherapy drug combinations significantly impacted on ovarian function, especially epirubicin/cyclophosphamide (EC) combination led to an unbalance in the development of the left and right ovary. Exposure to EC and cisplatin/paclitaxel (TP) increased the number of progenitor follicles while decreased the count of antral follicles and corpora luteum. As to the estrus cycle, EC exposure resulted in a longer estrus period and diestrus period, while TP exposure only extended the diestrus period. EC and TP affected steroid biosynthesis by reducing the expression of SF1 and P450arom.γ-H2AX was detected in both EC and TP exposure groups. As to the impact on the offspring from 4T1 tumor-bearing pregnant mice injected with EC, no significant difference was observed in the physical and neurological development compared to the control, but the ovarian weights, estrus cycles of the offspring were significantly different. Chemotherapy drug combinations exhibit ovarian toxicity, not only causing direct damage on the follicle cells but also disrupting steroid biosynthesis. The reproductive system of offspring from maternal tumor-bearing mice exposed to chemotherapy drugs was observed disorder, but the concrete mechanism still needs further exploration.

tsRNA-3043a intensifies apoptosis and senescence of ovarian granulosa cells to drive premature ovarian failure by targeting FLT1

Premature ovarian failure (POF) represents the pathological aging of the ovary. The tRNA-derived small fragments (tsRNAs) play significant roles in diseases; however, whether tsRNAs are involved in POF remains unknown. The cell and mice models of POF were established, and the tsRNAs profile in the ovarian tissues of POF mice was revealed through sequencing. The functions of tsRNA-3043a and its target gene FLT1 in POF cells and mice were detected. POF mice were characterized by a decreased number of normal follicles, ovarian weight, SOD level, and serum contents of E2, LH, and FSH. A total of 81 tsRNAs were aberrantly expressed in the ovarian tissue of POF mice. The expression of tsRNA-3043a was up-regulated in POF mice. tsRNA-3043a mimics inhibited the proliferation and promoted apoptosis, lipid accumulation, and cellular senescence of ovarian granulosa KGN cells, as well as altered the transcriptome. tsRNA-3043a inhibitor had the opposite effect. tsRNA-3043a targets and binds to FLT1. Overexpression of FLT1 protected KGN cells from pathological aging. tsRNA-3043a promotes the progression of POF by inhibiting FLT1 in vitro and in vivo. tsRNA-3043a targets FLT1 and promotes apoptosis and senescence of ovarian granulosa cells, leading to the progression of POF. This study provides a new target for pharmacological intervention in POF.

Growth factor-loaded ovarian extracellular matrix hydrogels promote in vivo ovarian niche regeneration and enhance fertility in premature ovarian insufficiency preclinical models

Premature ovarian insufficiency (POI) means menopause before 40 years of age affecting about 1 % of women. Approaches based on cell therapy and the paracrine effects of stem cells or bioproducts such as platelet-rich plasma have been proposed, but concerns remain about undesired systemic effects, as well as the need to optimize delivery methods through bioengineering methods. This study explores the efficacy of decellularized bovine ovarian cortex extracellular matrix (OvaECM) hydrogels alone and as a growth factor (GF) carrier (OvaECM+GF) in a chemotherapy-induced POI murine model. In vitro assays showed a gradual release of GF from the OvaECM sustained for two weeks. Chemotherapy drastically reduced follicle numbers, but OvaECM+GF treatment restored pre-antral follicle development. Moreover, this treatment notably regenerated the ovarian microenvironment by increasing cell proliferation and microvessel density while reducing chemotherapy-induced apoptosis and fibrosis. Whole-ovary RNA sequencing and gene set enrichment analysis revealed an upregulation of regeneration-related genes and a downregulation of apoptotic pathways. The OvaECM+GF treatment also yielded significantly better outcomes following ovarian stimulation and in vitro fertilization. After two consecutive crossbreeding cycles, OvaECM+GF-treated mice showed normal reproductive function. This research showcases the biocompatibility and efficacy of OvaECM to reverse POI in mice, setting a foundation to explore innovative bioengineering-based POI therapies. STATEMENT OF SIGNIFICANCE: Premature ovarian insufficiency (POI) affects about 1 % of women worldwide, causing early menopause before 40 years old. Current treatments alleviate symptoms but do not restore ovarian function. This study explores an innovative approach using ovarian cortex extracellular matrix hydrogels to deliver growth factors into the murine ovarian niche and reverse POI. In vitro release kinetic assays demonstrated a gradual and sustained release of growth factors. In a POI-induced mouse model, intraovarian injections of the hydrogel encapsulating growth factors restored pre-antral follicle development, increased cell proliferation, reduced apoptosis and fibrosis, and improved ovarian response and in vitro fertilization outcomes. Long-term benefits included larger litter sizes. This innovative technique shows promise in regenerating the ovarian environment and improving reproductive outcomes.

Histological assessment for investigation of dose-dependent ovarian toxicity of cyclophosphamide in the rat

Background

Cyclophosphamide (CPA) have significant effects on ovarian follicles which lead to ovarian toxicity and impair the normal female reproductive function. This study aimed to evaluate the dose-dependent effects of CPA on rat follicle numbers.

Methods

The experimental groups consisted of rats administered a single intraperitoneal injection of CPA at doses of either 50, 75,150, or 200 mg/kg followed by daily doses of 8 mg/kg for 14 days and control group given no treatment. After the treatment period, the histological evaluation was done.

Results

Primordial and primary follicles were affected by all doses of CPA, but differential follicle counts revealed that graaf and preantral follicles were most sensitive to CPA, followed by primary and primordial follicles. The greatest reduction in all type of studied follicles caused by CPA doses of 50 mg/kg.

Conclusion

Differential follicle counts revealed that CPA-induced ovarian toxicity is exhibited in structural feature of the ovary, particularly in destruction of graaf and preantral follicles in a dose-dependent manner so that the highest decrease in all type of studied follicles caused by 50 mg/kg of CPA and is suggested as the best concentration for ovotoxicity induction. These findings give insight into ovarian response to structural disruption of folliculogenesis.

Intraovarian PRP injection improves oocyte quality and early embryo development in mouse models of chemotherapy-induced diminished ovarian reserve

Intraovarian injection of platelet-rich plasma (PRP) has been recently proposed, with encouraging results to provide an alternative option to patients diagnosed with POR or POI. However, the broad spectrum of PRP effects on the reproductive function and the mechanisms of action in follicular activation, response to stimulation, and embryo quality have not yet been studied. In this study, we first induced poor ovarian reserve (POR) and premature ovarian insufficiency (POI) ovarian phenotypes in CD1 mice undergoing PRP or sham intraovarian injection. PRP administration reduced those alterations induced by chemotherapy in ovarian stroma and follicle morphology in both the POR and POI conditions. After ovarian stimulation, we found that PRP did not modify the MII-oocyte yield. Nevertheless, the amount of obtained 2-cell embryos and fertilization rate were increased, being especially relevant for the POI model. Further in vitro embryo culture led to improved blastocyst formation rates and higher numbers of good quality blastocysts in PRP vs. sham females in both the POR and POI conditions. These positive results of PRP injection were also validated in the C57Bl/6 stain. Altogether, our findings suggest a possible effect on oocyte and embryo quality. This effect is likely due to the increase of local paracrine signaling through the released growth factors in PRP-treated ovaries.

The Protective Effect of Adipose-Derived Stromal Vascular Fraction on Ovarian Function in Rats with Cyclophosphamide-Induced Ovarian Damage

OBJECTIVE

The aim of this study was to investigate if adipose-derived stromal vascular fraction (SVF) treatment has any protective effect on ovarian function in rats with cyclophosphamide (CP) induced ovarian damage.

DESIGN

This was an experimental animal study.

PARTICIPANTS/MATERIALS, SETTING, METHODS

25 mature cycling Wistar-Albino rats were randomized into four groups (n = 5 per group). Rats in groups 1 and 2 received single dose of intraperitoneal (i.p.) 1 mL/kg sodium chloride 0.9% (NaCl). Groups 3 and 4 received single dose of 75 mg/kg i.p. CP. On seventh day, SVF was prepared from adipose tissues of 5 additional rats and groups 1 and 3 received 0.9% NaCl i.p. injections while groups 2 and 4 received 0.2 mL i.p. injections of SVF. On day 21 all rats were euthanized, and serum anti-mullerian hormone (AMH) levels, primordial, primary, secondary, antral, and atretic follicle counts, AMH positive staining follicle counts along with AMH staining intensity of the follicles were evaluated.

RESULTS

Among two CP induced ovarian damaged groups, SVF treated group showed significantly higher secondary and antral follicle and lower atretic follicle counts, significantly higher mean serum AMH levels, AMH positive antral follicle count and higher intensity of AMH positive follicle scores for primary, secondary, and antral follicles when compared to untreated group. Moreover, group 1 showed no significant difference for all parameters except antral follicle count and AMH positive staining intensity scores for antral follicles when compared to group 4.

LIMITATIONS

This study was conducted on experimental rat model.

CONCLUSION

Our study demonstrated a significant protective effect of SVF against CP-induced ovarian damage which reveals the apparent need for further investigation of its precise mechanisms of action as it may provide a new treatment approach for women with premature ovarian failure.

The Protective Effect of GnRH Agonist Triptorelin on the Histomorphometric Parameters of the Utero-ovarian Tissue in the Doxorubicin- and Cyclophosphamide-treated Mice

One of the common side effects of chemotherapy drugs is ovarian failure and uterine dysfunction, which can occur after the administration of doxorubicin and/or cyclophosphamide. In clinics, gonadotropin-releasing hormone agonists (GnRHa) are used to modulate the toxic effect of chemotherapy and intercept infertility with some controversy and limited histological knowledge. This study aimed to evaluate the serological and histological features of protective effects of triptorelin, (GnRHa), on utero-ovarian tissue in the mice treated with cyclophosphamide and/or doxorubicin. Forty-eight female BALB/c mice were randomly divided into 8 groups as follows: Group I: normal saline; Group II: triptorelin; Group III: cyclophosphamide; Group IV: doxorubicin; Group V: cyclophosphamide + doxorubicin; and Groups VI, VII, and VIII: after injection of cyclophosphamide, doxorubicin, or cyclophosphamide + doxorubicin, administration of triptorelin (1 mg/kg; intraperitoneally) for 15 consecutive days, respectively. On the 21st day, the ovaries and uterine horns were dissected and weighed. Then, tissue processing and staining were performed for further histological and stereological studies. Triptorelin treatment in the damaged groups significantly increased the number of primordial and pre-antral follicles and granulosa cells. It decreased the number of atretic follicles compared to cyclophosphamide and/or doxorubicin-treated groups (P < 0.05). Triptorelin also significantly improved the volume of the ovary, cortex, medulla, oocytes in the primordial and antral follicles, uterus, endometrium, myometrium, uterine glands, and endometrial blood vessels in the damaged groups (P < 0.05). Triptorelin treatment prevents the destructive effects of cyclophosphamide and/or doxorubicin on utero-ovarian tissue.

Sleep Deprivation Triggers the Excessive Activation of Ovarian Primordial Follicles via β2 Adrenergic Receptor Signaling

Sleep deprivation (SD) is observed to adversely affect the reproductive health of women. However, its precise physiological mechanisms remain largely elusive. In this study, using a mouse model of SD, it is demonstrated that SD induces the depletion of ovarian primordial follicles, a phenomenon not attributed to immune-mediated attacks or sympathetic nervous system activation. Rather, the excessive secretion of stress hormones, namely norepinephrine (NE) and epinephrine (E), by overactive adrenal glands, has emerged as a key mediator. The communication pathway mediated by the KIT ligand (KITL)-KIT between granulosa cells and oocytes plays a pivotal role in primordial follicle activation. SD heightened the levels of NE/E that stimulates the activation of the KITL-KIT/PI3K and mTOR signaling cascade in an β2 adrenergic receptor (ADRB2)-dependent manner, thereby promoting primordial follicle activation and consequent primordial follicle loss in vivo. In vitro experiments further corroborate these observations, revealing that ADRB2 upregulates KITL expression in granulosa cells via the activation of the downstream cAMP/PKA pathway. Together, these results reveal the significant involvement of ADRB2 signaling in the depletion of ovarian primordial follicles under sleep-deprived conditions. Additionally, ADRB2 antagonists are proposed for the treatment or prevention of excessive activation of primordial follicles induced by SD.

An overview of different methods to establish a murine premature ovarian failure model

Premature ovarian failure (POF)is defined as the loss of normal ovarian function before the age of 40 and is characterized by increased gonadotropin levels and decreased estradiol levels and ovarian reserve, often leading to infertility. The incomplete understanding of the pathogenesis of POF is a major impediment to the development of effective treatments for this disease, so the use of animal models is a promising option for investigating and identifying the molecular mechanisms involved in POF patients and developing therapeutic agents. As mice and rats are the most commonly used models in animal research, this review article considers studies that used murine POF models. In this review based on the most recent studies, first, we introduce 10 different methods for inducing murine POF models, then we demonstrate the advantages and disadvantages of each one, and finally, we suggest the most practical method for inducing a POF model in these animals. This may help researchers find the method of creating a POF model that is most appropriate for their type of study and suits the purpose of their research.

Protective Effect of Bio-Scaffold Against Vitrification Damage in Mouse Ovarian Tissue

Ovarian tissue cryopreservation is regarded as useful method for fertility preservation. This study aimed to preserve most of the follicular reserve from the destructive effects of cryoprotectant solutions and liquid nitrogen. For this purpose, 48 female NMRI mice (8 weeks old) were randomly divided into six groups: Fresh (not vitrified), Vitrification (not encapsulated), Alginate 1 (encapsulated in 1% alginate hydrogel before placing in vitrification solutions), Alginate 2 (encapsulated in 1% alginate hydrogel before placing in liquid nitrogen), Aloe vera 1 (encapsulated in Aloe vera pieces before placing in vitrification solutions), Aloe vera 2 (encapsulated in Aloe vera pieces before placing in liquid nitrogen). After vitrification and warming, the histological evaluation showed that the average number of intact primordial follicles decreased significantly in all groups compared to the Fresh group. (P < 0.05). Results of evaluating the expression of apoptosis-related genes showed that the ratio of Bax/Bcl2 and P53 significantly decreased in the Alginate 2 group compared with the vitrification group. The level of Kit gene (KIT proto-oncogeni receptor tyrosine kinase gene) expression was either the same or lower in the experimental groups than in the vitrification group, but there was no statistically significant difference. Levels of tissue nitric oxide (NO) and malondialdehyde (MDA) in Alginate groups 1 and 2 showed a significant decrease compared with the vitrification group (P < 0.05). To conclude, Encapsulation of ovaries in 1% alginate hydrogel before immersion in liquid nitrogen may reduce the damage caused by cryopreservation.

Mature oocyte found during ovarian tissue cryopreservation in an early adolescent female

A 15-year-old female with Hodgkin's lymphoma underwent ovarian tissue cryopreservation for preserving fertility in Reproductive Department of Sir Run Run Shaw Hospital, Zhejiang University School of Medical after receiving one course of chemotherapy. During the ovarian tissue cryopreservation, one MⅡmature oocyte and three germinal vesicle oocytes were found. The three immature oocytes underwent in vitro maturation but failed. Ultimately, one mature oocyte and 12 ovarian cortex slices were cryopreserved using vitrification. This case indicates that for patients with established gonadal axis feedback, ovarian tissue cryopreservation may not be the only method for fertility preservation. It is advisable to consider ovarian stimulation and oocyte retrieval for oocyte cryopreservation. Alternatively, for individuals in the ovulation phase of their menstrual cycle, attempting oocyte retrieval before ovarian tissue cryopreservation to obtain mature oocytes from the natural cycle, followed by oocyte cryopreservation, may enhance the likelihood of successful fertility preservation.

Fertility protection during chemotherapy treatment by boosting the NAD(P)+ metabolome

Chemotherapy induced ovarian failure and infertility is an important concern in female cancer patients of reproductive age or younger, and non-invasive, pharmacological approaches to maintain ovarian function are urgently needed. Given the role of reduced nicotinamide adenine dinucleotide phosphate (NADPH) as an essential cofactor for drug detoxification, we sought to test whether boosting the NAD(P)+ metabolome could protect ovarian function. We show that pharmacological or transgenic strategies to replenish the NAD+ metabolome ameliorates chemotherapy induced female infertility in mice, as measured by oocyte yield, follicle health, and functional breeding trials. Importantly, treatment of a triple-negative breast cancer mouse model with the NAD+ precursor nicotinamide mononucleotide (NMN) reduced tumour growth and did not impair the efficacy of chemotherapy drugs in vivo or in diverse cancer cell lines. Overall, these findings raise the possibility that NAD+ precursors could be a non-invasive strategy for maintaining ovarian function in cancer patients, with potential benefits in cancer therapy.

FGF2 promotes the proliferation of injured granulosa cells in premature ovarian failure via Hippo-YAP signaling pathway

Young women undergoing anticancer treatment are at risk of premature ovarian failure (POF). Endometrial-derived stem cells (EnSCs) have demonstrated significant therapeutic potential for treating ovarian insufficiency, although the underlying mechanisms remain to be fully understood. This study aims to further investigate the therapeutic effects of EnSCs, particularly through the paracrine action of fibroblast growth factor 2 (FGF2), on POF. The findings show that exogenous FGF2 enhances the survival of ovarian granulosa cells damaged by cisplatin. FGF2 stimulates the proliferation of these damaged cells by suppressing the Hippo signaling pathway and activating YAP expression. In vivo experiments also revealed that FGF2 treatment significantly improves ovarian reserve and endocrine function in mice with POF. These results suggest that FGF2 can boost the proliferative capacity of damaged ovarian granulosa cells through the Hippo-YAP signaling pathway, providing a theoretical foundation for using EnSCs and FGF2 in clinical treatments for POF.

Drug-free in vitro activation combined with ADSCs-derived exosomes restores ovarian function of rats with premature ovarian insufficiency

BACKGROUND

Drug-free in vitro activation (IVA) is a new protocol to activate residual dormant follicles for fertility restoration in patients with premature ovarian insufficiency (POI). However, several deficiencies have reduced its clinical efficacy rate. Our previous studies have confirmed that the combination of adipose-derived stem cells (ADSCs) and drug-free IVA can improve the effectiveness of drug-free IVA and restore ovarian function of rats with POI. Increasing evidence has demonstrated that mesenchymal stem cell-derived exosomes have similar therapeutic effects as their source cells. Here, we performed a preclinical study to evaluate the therapeutic effects of ADSCs-derived exosomes (ADSCs-Exos) combined with drug-free IVA in the POI rats and the mechanism in restoring ovarian function.

RESULTS

In vivo, the effects of ADSCs-Exos were comparable to those of ADSCs, and the ADSCs-Exos combined with drug-free IVA was better than ADSCs-Exos alone therapy in promoting follicular development. Moreover, transplantation of ADSCs/ADSCs-Exos lead to up-regulation of BCL-2 expression and down-regulation of the expression of Bax and Cleaved Caspase-3, thus reducing the apoptosis of chemotherapy-induced follicle cells, and further promoting the development of the follicles and rescuing ovarian function in POI-damaged ovary. In vitro, ovarian fragmentation could activate follicular growth and development, and in combination with ADSCs-Exos could prevent the loss of follicles, promote follicular proliferation and inhibit apoptosis.

CONCLUSIONS

ADSCs-Exos combined drug-free IVA had remarkable therapeutic effects in restoring ovarian function of POI rats, and markedly promoted follicular development and inhibited apoptosis of ovarian cells in vitro. Our study confirmed that the combination therapy might be a promising and effective treatment for POI.

The role of cellular senescence in ovarian aging

This review explores the relationship between ovarian aging and senescent cell accumulation, as well as the efficacy of senolytics to improve reproductive longevity. Reproductive longevity is determined by the age-associated decline in ovarian reserve, resulting in reduced fertility and eventually menopause. Cellular senescence is a state of permanent cell cycle arrest and resistance to apoptosis. Senescent cells accumulate in several tissues with advancing age, thereby promoting chronic inflammation and age-related diseases. Ovaries also appear to accumulate senescent cells with age, which might contribute to aging of the reproductive system and whole organism through SASP production. Importantly, senolytic drugs can eliminate senescent cells and may present a potential intervention to mitigate ovarian aging. Herein, we review the current literature related to the efficacy of senolytic drugs for extending the reproductive window in mice.

What reproductive follow-up for adolescent and young women after cancer? A review

Fertility capacity has been shown to be one of the main concerns of young cancer survivors. Gonadotoxic treatments may lead to both premature ovarian failure and/or infertility. This review aimed to define which, and when, reproductive indicators should be followed-up to help doctors to counsel patients regarding their fertility and ovarian function, and to determine if a second stage of fertility preservation after the end of cancer treatment is clinically relevant. Longitudinal assessment of anti-Müllerian hormone (AMH) concentrations during cancer treatment indicates the degree of follicular depletion, and allows discrimination between low and high gonadotoxic treatments. Sustained low AMH concentrations after treatment, especially in the case of alkylating protocols, may reduce the duration of the conception window significantly, and expose the patient to the risk of premature ovarian failure. It remains unknown whether this may impact further fertility capacity because of the lack of systematic follow-up of adolescent and young adult (AYA) women after chemo-radiotherapy. It appears that dedicated reproductive follow-up of AYA women under cancer treatment is needed to refine fertility preservation strategies, and to determine if low AMH concentrations after treatment impact the chance of pregnancy in this specific survivor population.

Ovarian function in patients with systemic lupus erythematosus: Pathogenesis, drug application and prospective therapies

Systemic lupus erythematosus (SLE) is a chronic autoimmune disease in which multiple organs are damaged that prevails in fertile women. Currently, glucocorticoids and immunosuppressants are widely used to treat SLE patients. However, ovarian dysfunction occurs following the use of these drugs in women with SLE. Here, we summarize recent progress in terms of understanding ovarian injury, the effects of drug application and strategies to improve ovarian function in women with SLE. This review could be helpful to precisely cure SLE in women desiring to have offspring.

Therapeutic effects of saffron (Crocus sativus L) on female reproductive system disorders: A systematic review

The effect of Crocus sativus on several disorders has been discussed or even confirmed, but the efficacy of this herb on the female reproductive system has not been well presented. In this regard, this systematic review comprehensively discussed the efficacy of C. sativus and its main phytochemical compounds on the female reproductive system and its disorders for the first time. In this systematic review, scientific databases, including PubMed, Web of Sciences, Google Scholar, Scopus, and Scientific Information Database, were explored profoundly. In vivo, in vitro, and human studies published until the end of July 2023, which had investigated the pharmacological properties of C. sativus, crocin, crocetin, safranal, or picrocrocin on the female reproductive system, were selected. A total of 50 studies conducted on the effect of C. sativus on the female reproductive system were acquired. These studies confirmed the efficacy of C. sativus or its main phytochemical ingredients in several aspects of the female reproductive system, including regulation of sex hormones, folliculogenesis, ovulation, and protection of the ovary and uterus against several oxidative stress. Several retrieved studies indicated that this herb also can alleviate the symptoms of patients suffering from dysmenorrhea, premenstrual syndrome, menopause, polycystic ovary disease (PCOD), and sexual dysfunction. Furthermore, it is a promising candidate for future studies or even trials regarding ovarian and cervical cancers. This review concluded that C. sativus can improve the symptoms of several female reproductive system disorders, which is particularly due to the presence of phytochemical ingredients, such as crocin, crocetin, and safranal.

Cyclophosphamide induces ovarian granulosa cell ferroptosis via a mechanism associated with HO-1 and ROS-mediated mitochondrial dysfunction

Abnormal granulosa cell (GC) death contributes to cyclophosphamide (CTX) induced primary ovarian insufficiency (POI). To investigate the contribution of GCs to POI, gene profiles of GCs exposed to CTX were assessed using RNA-Seq and bioinformatics analysis. The results showed the differentially expressed genes (DEGs) were enriched in the ferroptosis-related pathway, which is correlated with upregulated heme oxygenase 1 (HO-1) and downregulated glutathione peroxidase-4 (GPX4). Using CTX-induced cell culture (COV434 and KGN cells), the levels of iron, reactive oxygen species (ROS), lipid peroxide, mitochondrial superoxide, mitochondrial morphology and mitochondrial membrane potential (MMP) were detected by DCFDA, MitoSOX, C11-BODIPY, MitoTracker, Nonylacridine Orange (NAO), JC-1 and transmission electron microscopy respectively. The results showed iron overload and disrupted ROS, including cytoROS, mtROS and lipROS homeostasis, were associated with upregulation of HO-1 and could induce ferroptosis via mitochondrial dysfunction in CTX-induced GCs. Moreover, HO-1 inhibition could suppress ferroptosis induced GPX4 depletion. This implies a role for ROS in CTX-induced ferroptosis and highlights the effect of HO-1 modulators in improving CTX-induced ovarian damage, which may provide a theoretical basis for preventing or restoring GC and ovarian function in patients with POI.

Rapamycin prevents cyclophosphamide-induced ovarian follicular loss and potentially inhibits tumour proliferation in a breast cancer xenograft mouse model

STUDY QUESTION

To what extent and via what mechanism does the concomitant administration of rapamycin (a follicle activation pathway inhibitor and antitumour agent) and cyclophosphamide (a highly toxic ovarian anticancer agent) prevent cyclophosphamide-induced ovarian reserve loss and inhibit tumour proliferation in a breast cancer xenograft mouse model?

SUMMARY ANSWER

Daily concomitant administration of rapamycin and a cyclic regimen of cyclophosphamide, which has sufficient antitumour effects as a single agent, suppressed cyclophosphamide-induced primordial follicle loss by inhibiting primordial follicle activation in a breast cancer xenograft mouse model, suggesting the potential of an additive inhibitory effect against tumour proliferation.

WHAT IS KNOWN ALREADY

Cyclophosphamide stimulates primordial follicles by activating the mammalian target of the rapamycin (mTOR) pathway, resulting in the accumulation of primary follicles, most of which undergo apoptosis. Rapamycin, an mTOR inhibitor, regulates primordial follicle activation and exhibits potential inhibitory effects against breast cancer cell proliferation.

STUDY DESIGN, SIZE, DURATION

To assess ovarian follicular apoptosis, 3 weeks after administering breast cancer cells, 8-week-old mice were randomized into three treatment groups: control, cyclophosphamide, and cyclophosphamide + rapamycin (Cy + Rap) (n = 5 or 6 mice/group). Mice were treated with rapamycin or vehicle control for 1 week, followed by a single dose of cyclophosphamide or vehicle control. Subsequently, the ovaries were resected 24 h after cyclophosphamide administration (short-term treatment groups). To evaluate follicle abundance and the mTOR pathway in ovaries, as well as the antitumour effects and impact on the mTOR pathway in tumours, 8-week-old xenograft breast cancer transplanted mice were randomized into three treatment groups: vehicle control, Cy, and Cy + Rap (n = 6 or 7 mice/group). Rapamycin (5 mg/kg) or the vehicle was administered daily for 29 days. Cyclophosphamide (120 mg/kg) or the vehicle was administered thrice weekly (long-term treatment groups). The tumour diameter was measured weekly. Seven days after the last cyclophosphamide treatment, the ovaries were harvested, fixed, and sectioned (for follicle counting) or frozen (for further analysis). Similarly, the tumours were resected and fixed or frozen.

PARTICIPANTS/MATERIALS, SETTING, METHODS

Terminal deoxynucleotidyl transferase dUTP nick end labelling (TUNEL) was performed to examine ovarian follicular apoptosis in the short-term treatment groups. All subsequent experiments were conducted in the long-term treatment groups. Tumour growth was evaluated using the tumour volume index. The tumour volume index indicates the relative volume, compared to the volume 3 weeks after tumour cell injection (at treatment initiation) set to 100%. Tumour cell proliferation was evaluated by Ki-67 immunostaining. Activation of the mTOR pathway in tumours was assessed using the protein extracts from tumours and analysed by western blotting. Haematoxylin and eosin staining of ovaries was used to perform differential follicle counts for primordial, primary, secondary, antral, and atretic follicles. Activation of the mTOR pathway in ovaries was assessed using protein extracts from whole ovaries and analysed by western blotting. Localization of mTOR pathway activation within ovaries was assessed by performing anti-phospho-S6 kinase (downstream of mTOR pathway) immunohistochemistry.

MAIN RESULTS AND THE ROLE OF CHANCE

Ovaries of the short-term treatment groups were resected 24 h after cyclophosphamide administration and subjected to TUNEL staining of apoptotic cells. No TUNEL-positive primordial follicles were detected in the control, Cy, and Cy + Rap groups. Conversely, many granulosa cells of growing follicles were TUNEL positive in the Cy group but negative in the control and Cy + Rap groups. All subsequent experimental results were obtained from the long-term treatment groups. The tumour volume index stabilized at a mean of 160-200% in the Cy group and 130% in the Cy + Rap group throughout the treatment period. In contrast, tumours in the vehicle control group grew continuously with a mean tumour volume index of 600%, significantly greater than that of the two treatment groups. Based on the western blot analysis of tumours, the mTOR pathway was activated in the vehicle control group and downregulated in the Cy + Rap group when compared with the control and Cy groups. Ki-67 immunostaining of tumours showed significant inhibition of cell proliferation in the Cy + Rap group when compared with that in the control and Cy groups. The ovarian follicle count revealed that the Cy group had significantly fewer primordial follicles (P < 0.001) than the control group, whereas the Cy + Rap group had significantly higher number of primordial follicles (P < 0.001, 2.5 times) than the Cy group. The ratio of primary to primordial follicles was twice as high in the Cy group than in the control group; however, no significant difference was observed between the control group and the Cy + Rap group. Western blot analysis of ovaries revealed that the mTOR pathway was activated by cyclophosphamide and inhibited by rapamycin. The phospho-S6 kinase (pS6K)-positive primordial follicle rate was 2.7 times higher in the Cy group than in the control group. However, this effect was suppressed to a level similar to the control group in the Cy + Rap group.

LARGE SCALE DATA

None.

LIMITATIONS, REASONS FOR CAUTION

The combinatorial treatment of breast cancer tumours with rapamycin and cyclophosphamide elicited inhibitory effects on cell proliferative potential compared to cyclophosphamide monotherapy. However, no statistically significant additive effect was observed on tumour volume. Thus, the beneficial antitumour effect afforded by rapamycin administration on breast cancer could not be definitively proven. Although rapamycin has ovarian-protective effects, it does not fully counteract the ovarian toxicity of cyclophosphamide. Nevertheless, rapamycin is advantageous as an ovarian protective agent as it can be used in combination with other ovarian protective agents, such as hormonal therapy. Hence, in combination with other agents, mTOR inhibitors may be sufficiently ovario-protective against high-dose and cyclic cyclophosphamide regimens.

WIDER IMPLICATIONS OF THE FINDINGS

Compared with a cyclic cyclophosphamide regimen that replicates human clinical practice under breast cancer-bearing conditions, the combination with rapamycin mitigates the ovarian follicle loss of cyclophosphamide without interfering with the anticipated antitumour effects. Hence, rapamycin may represent a new non-invasive treatment option for cyclophosphamide-induced ovarian dysfunction in breast cancer patients.

STUDY FUNDING/COMPETING INTEREST(S)

This work was not financially supported. The authors declare that they have no conflict of interest.

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.

Effects of maternal taxane chemotherapy exposure on daughters' ovarian reserve and fertility potential

OBJECTIVE

To investigate the long-term effects of in utero taxane exposure on exposed daughters' ovarian reserve and reproductive potential.

DESIGN

Pregnant dams were treated with a single, human-relevant animal-equivalent dose of saline, docetaxel, or paclitaxel at embryonic day 16.5. In utero-exposed daughters were aged to multiple postnatal time points for ovarian and endocrine analysis or were bred to assess fertility and fecundity. Granddaughters of treated dams were assessed also for ovarian follicle composition and atresia.

SETTING

Laboratory study.

ANIMALS

C57BL/6 mice.

INTERVENTION(S)

In utero exposure to saline, docetaxel, or paclitaxel.

MAIN OUTCOME MEASURE(S)

Ovarian follicle composition, rates of follicle atresia, and rates of multioocyte follicles were analyzed in all exposure groups. Serum hormone levels and oocyte retrieval outcomes following ovarian hyperstimulation were also assessed. Finally, animals from all exposure groups were bred with the number of litters, pups per litter, live births, interlitter time interval, and age at the last litter analyzed.

RESULT(S)

We found that docetaxel and paclitaxel exposure in utero results in ovarian toxicity later in life, significantly affecting folliculogenesis as well as increasing the rate of follicular abnormalities, including follicle atresia and multioocyte follicles. Furthermore, viability staining indicates that the ovaries of daughters exposed to taxanes in utero demonstrate a significantly higher number of terminal deoxynucleotidyl transferase dUTP nick end labeling-positive follicles. Hormone measurements also revealed that serum follicle-stimulating hormone concentration was significantly altered in taxane-exposed daughters, with the ratio of luteinizing hormone to follicle-stimulating hormone significantly elevated, specifically after paclitaxel exposure, coincident with the inability of these animals to properly respond to ovarian stimulation. Breeding studies over the course of a year also suggest that these taxane-exposed mice are fertile, although the duration of their fertility is shortened and they produce significantly fewer litters. Finally, ovarian effects are apparent in granddaughters of mice treated with docetaxel, suggesting persistent and multigenerational effects of taxane exposure.

CONCLUSION(S)

Our studies demonstrate that in utero exposure to taxane-based therapy during late gestation has a significant effect on the long-term reproductive health of exposed daughters (as well as their daughters) and will be instrumental in helping clinicians better understand which chemotherapies for maternal malignancy are least detrimental to a developing fetus.

Hypoxia Leads to Diminished Ovarian Reserve in an Age-Dependent Manner

OBJECTIVES

Perinatal hypoxia causes premature activation and initiation of growth in dormant follicles, leading to diminished ovarian reserve. An indirect mechanism such as the release of stress-related hormones may influence ovarian follicle recruitment under hypoxic conditions. We wanted to determine whether hypoxic ovarian damage results from increased follicle growth and "burnout" or from increased apoptosis and whether this damage is age-dependent.

DESIGN

Animal study was conducted.

PARTICIPANTS/MATERIALS, SETTING, METHODS

Using adult 6-week-old (n = 8) and one-day-old newborn (n = 20) ICR (CD-1) female mice, ovarian follicular counts were conducted on H&E-stained sections.

METHODS

Immunohistochemistry was performed on sections stained with Ki-67, anti-Caspase 3, and anti-FOXO3A.

RESULTS

Exposure to hypoxia resulted in significantly reduced proportion of primordial follicles versus normoxia in both adult dams and newborn pups (3.17 ± 2.75 vs. 17.89 ± 4.4%; p = 0.004; 40.59 ± 14.88 vs. 81.92 ± 31.56%, p = 0.001, respectively), concomitant with increased growing-primary and secondary follicles, and more pronounced in adult dams versus newborn pups (6-fold vs. 2-fold, respectively). Ki67 staining revealed higher scores of cell proliferation in follicular granulosa cells after exposure to hypoxia than normoxia. However, Caspase 3 and Foxo3A staining did not show any differences in these markers of apoptosis in oocytes, granulosa cells, theca cells, or stromal cells when exposed to hypoxia versus normoxia.

LIMITATIONS

The current study has several limitations; first, the sample size for each group is relatively small, which could limit the generalizability of the findings. Second, the study used an ex vivo culture system, which may not fully capture the complex interactions that occur in the whole animal. Third, the exposure to hypoxia only lasted for 3 h, which may not be long enough to observe all the potential effects. In addition, the study only analyzed specific markers of apoptosis in a few cell types, and other cell types or apoptotic pathways might be involved. Lastly, the study provides evidence for accelerated follicular activation and decreased ovarian reserve, but the underlying mechanisms are not fully explored.

CONCLUSIONS

Direct tissue hypoxia led to premature activation and initiation of growth in dormant follicles leading to diminished ovarian reserve. Hypoxic damage is age-dependent, with adult ovaries more susceptible than newborn ovaries. These findings support the possibility of follicular "burn out" as a potential mechanism responsible for hypoxia-induced loss of ovarian reserve.

Anti-Mullerian hormone attenuates both cyclophosphamide-induced damage and PI3K signalling activation, while rapamycin attenuates only PI3K signalling activation, in human ovarian cortex in vitro

STUDY QUESTION

What are the effects of cyclophosphamide exposure on the human ovary and can anti-Mullerian hormone (AMH) and rapamycin protect against these?

SUMMARY ANSWER

Exposure to cyclophosphamide compromises the health of primordial and transitional follicles in the human ovarian cortex and upregulates PI3K signalling, indicating both direct damage and increased follicular activation; AMH attenuates both of these chemotherapy-induced effects, while rapamycin attenuates only PI3K signalling upregulation.

WHAT IS KNOWN ALREADY

Studies primarily in rodents demonstrate that cyclophosphamide causes direct damage to primordial follicles or that the primordial follicle pool is depleted primarily through excessive initiation of follicle growth. This increased follicular activation is mediated via upregulated PI3K signalling and/or reduced local levels of AMH production due to lost growing follicles. Furthermore, while rodent data show promise regarding the potential benefits of inhibitors/protectants alongside chemotherapy treatment to preserve female fertility, there is no information about the potential for this in humans.

STUDY DESIGN, SIZE, DURATION

Fresh ovarian cortical biopsies were obtained from 17 healthy women aged 21-41 years (mean ± SD: 31.8 ± 4.9 years) at elective caesarean section. Biopsies were cut into small fragments and cultured for 24 h with either vehicle alone (DMSO), the active cyclophosphamide metabolite 4-hydroperoxycyclophosphamide (4-HC) alone, 4-HC + rapamycin or 4-HC+AMH. Two doses of 4-HC were investigated, 0.2 and 2 μM in separate experiments, using biopsies from seven women (aged 27-41) and six women (aged 21-34), respectively. Biopsies from four women (aged 28-38) were used to investigate the effect of rapamycin or AMH only.

PARTICIPANTS/MATERIALS, SETTING, METHODS

Histological analysis of ovarian tissue was undertaken for follicle staging and health assessment. Western blotting and immunostaining were used to assess activation of PI3K signalling by measuring phosphorylation of AKT and phosphorylated FOXO3A staining intensity, respectively.

MAIN RESULTS AND THE ROLE OF CHANCE

Exposure to either dose of 4-HC caused an increase in the proportion of unhealthy primordial (P < 0.0001, both doses) and transitional follicles (P < 0.01 for low dose and P < 0.01 for high dose) compared to vehicle. AMH significantly reduced follicle damage by approximately half in both of the investigated doses of 4-HC (P < 0.0001), while rapamycin had no protective effect on the health of the follicles. Culture with AMH or rapamycin alone had no effect on follicle health. Activation of PI3K signalling following 4-HC exposure was demonstrated by both Western blotting data showing that 4-HC increased in AKT phosphorylation and immunostaining showing increased phosphorylated FOXO3A staining of non-growing oocytes. Treatment with rapamycin reduced the activation of PI3K signalling in experiments with low doses of 4-HC while culture with AMH reduced PI3K activation (both AKT phosphorylation and phosphorylated FOXO3A staining intensity) across both doses investigated.

LIMITATIONS, REASONS FOR CAUTION

These in vitro studies may not replicate in vivo exposures. Furthermore, longer experiment durations are needed to determine whether the effects observed translate into irreparable deficits of ovarian follicles.

WIDER IMPLICATIONS OF THE FINDINGS

These data provide a solid foundation on which to explore the efficacy of AMH in protecting non-growing ovarian follicles from gonadotoxic chemotherapies. Future work will require consideration of the sustained effects of chemotherapy treatment and potential protectants to ensure these agents do not impair the developmental competence of oocytes or lead to the survival of oocytes with accumulated DNA damage, which could have adverse consequences for potential offspring.

STUDY FUNDING/COMPETING INTEREST(S)

This work was supported by grants from TENOVUS Scotland, the Academy of Medical Sciences (to R.R.), the Medical Research Council (G1100357 to R.A.A., MR/N022556/1 to the MRC Centre for Reproductive Health), and Merck Serono UK (to R.A.A.). R.R., H.L.S., N.S., and E.E.T. declare no conflicts of interest. R.A.A. reports grants and personal fees from Roche Diagnostics and Ferring Pharmaceuticals, and personal fees from IBSA and Merck outside the submitted work.

TRIAL REGISTRATION NUMBER

N/A.

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.

Characterization of the molecular mechanisms that govern anti-Müllerian hormone synthesis and activity

The roles of anti-Müllerian hormone (AMH) continue to expand, from its discovery as a critical factor in sex determination, through its identification as a regulator of ovarian folliculogenesis, its use in fertility clinics as a measure of ovarian reserve, and its emerging role in hypothalamic-pituitary function. In light of these actions, AMH is considered an attractive therapeutic target to address diverse reproductive needs, including fertility preservation. Here, we set out to characterize the molecular mechanisms that govern AMH synthesis and activity. First, we enhanced the processing of the AMH precursor to >90% by introducing more efficient proprotein convertase cleavage sites (RKKR or ISSRKKRSVSS [SCUT]). Importantly, enhanced processing corresponded with a dramatic increase in secreted AMH activity. Next, based on species differences across the AMH type II receptor-binding interface, we generated a series of human AMH variants and assessed bioactivity. AMHSCUT potency (EC50 4 ng/mL) was increased 5- or 10-fold by incorporating Gln484 Met/Leu535 Thr (EC50 0.8 ng/mL) or Gln484 Met/Gly533 Ser (EC50 0.4 ng/mL) mutations, respectively. Furthermore, the Gln484 Met/Leu535 Thr double mutant displayed enhanced efficacy, relative to AMHSCUT . Finally, we identified residues within the wrist pre-helix of AMH (Trp494 , Gln496 , Ser497 , and Asp498 ) that likely mediate type I receptor binding. Mutagenesis of these residues generated gain- (Trp494 Phe or Gln496 Leu) or loss- (Ser497 Ala) of function AMH variants. Surprisingly, combining activating type I and type II receptor mutations only led to modest additive increases in AMH potency/efficacy. Our study is the first to characterize AMH residues involved in type I receptor binding and suggests a step-wise receptor-complex assembly mechanism, in which enhancement in the affinity of the ligand for either receptor can increase AMH activity beyond the natural level.

Optimal timing to retrieve oocytes for fertility preservation in patients with acute myeloid leukemia: two cases of controlled ovarian stimulation using DuoStim with a literature review

Fertility preservation (FP) for hematological malignancies is difficult because immediate chemotherapy is needed after diagnosis. We report two cases of acute myeloid leukemia (AML) treated with controlled ovarian stimulation (COS) and oocyte cryopreservation using DuoStim after first-line chemotherapy. In Cases 1 and 2, COS and oocyte retrieval (OR) were performed using DuoStim 116 and 51 days after first-line chemotherapy, respectively, and 14 and 6 unfertilized oocytes, respectively, were cryopreserved. Another round of COS and OR was performed using the random-start method 82 days after first-line chemotherapy, and 22 unfertilized oocytes were cryopreserved. DuoStim is useful to maximize OR for patients with a short interval for FP. Many oocytes can be retrieved depending on the timing of recruitment from primary to secondary follicles, although ovarian reserve capacity declines immediately after first-line chemotherapy. Aggressive FP should be performed before allogeneic hematopoietic stem cell transplantation becomes necessary.

A Journey to Reach the Ovary Using Next-Generation Technologies

Although effective in terms of the chances of future live birth, the current methods for fertility preservation, such as oocyte, embryo, or ovarian tissue cryopreservation, cannot be offered to all cancer patients in all clinical contexts. Expanding options for fertility preservation is crucial to addressing the need to encompass all situations. One emerging strategy is pharmacoprotection, a non-invasive approach that has the potential to fill existing gaps in fertility preservation. In addition to the identification of the most effective therapeutic agents, the potential for off-target effects remains one of the main limitations of this strategy for clinical application, particularly when healthy ovarian tissue is targeted. This review focuses on the advances in pharmacoprotective approaches and the challenge of targeting the ovaries to deliver these agents. The unique properties of gold nanoparticles (AuNPs) make them an attractive candidate for this purpose. We discuss how AuNPs meet many of the requirements for an ideal drug delivery system, as well as the existing limitations that have hindered the progression of AuNP research into more clinical trials. Additionally, the review highlights microRNA (miRNA) therapy as a next-generation approach to address the issues of fertility preservation and discusses the obstacles that currently impede its clinical availability.

TNF-α and IFN-γ prestimulation enhances the therapeutic efficacy of human amniotic epithelial stem cells in chemotherapy-induced ovarian dysfunction

BACKGROUND

Exposure to a harsh ovarian microenvironment induced by chemotherapeutic agents seriously affects the remodeling of ovarian function and follicular development, leading to premature ovarian failure or insufficiency (POF/POI). For decades, the effectiveness of stem cell therapies in POI animal models has been intensively studied; however, strategies to enhance the therapeutic effect of stem cells remain challenging.

METHODS

In this study, we first observed the pathological changes of the ovaries at different time points during chemotherapy, including the number of follicles, granulosa cell proliferation, oxidative stress damage, ovarian fibrosis, and inflammatory reaction. Moreover, we investigated whether activated hAECs stimulated by the proinflammatory cytokines tumor necrosis factor-α (TNF-α) and interferon-γ (IFN-γ) were more effective than native hAECs in repairing ovarian injury induced by chemotherapy.

RESULTS

The inhibitory effect of chemotherapy drugs on ovarian granulosa cells (GCs) in growing follicles mainly occurred on day 3 after chemotherapy in a mouse model. Then, continued ovarian injury, including oxidative damage and cell death cascades, resulted in the depletion of follicular reserves and inflammation-related ovarian fibrosis. Cytokine array demonstrated that activated hAECs secreted high levels of paracrine cytokines related to extracellular matrix (ECM) remodeling, angiogenesis, and immunomodulation. An in vivo study showed that the engraftment rate of activated hAECs in damaged ovaries was higher than that of native hAECs. Furthermore, activated hAECs in damaged ovaries had significantly upregulated expression of the antioxidant proteins thioredoxin1/2. In addition, activated hAECs had increased numbers of mature follicles and ameliorated the ovarian microenvironment by promoting angiogenesis and reducing ovarian fibrosis.

CONCLUSIONS

These results indicated that secondary ovarian damage induced by chemotherapy, including oxidative stress damage, chronic inflammatory response, and ovarian tissue fibrosis should be attended. Prestimulation with the proinflammatory factors TNF-α and IFN-γ could enhance the therapeutic efficacy of hAECs against chemotherapy-induced ovarian dysfunction, which may become a new feasible strategy to improve the therapeutic potential of hAECs in regenerative medicine.

Anti-Müllerian hormone beyond an ovarian reserve marker: the relationship with the physiology and pathology in the life-long follicle development

Anti-Müllerian hormone (AMH), an indirect indicator of the number of remaining follicles, is clinically used as a test for ovarian reserve. Typically, a decline suggests a decrease in the number of remaining follicles in relation to ovarian toxicity caused by interventions, which may implicate fertility. In contrast, serum AMH levels are elevated in patients with polycystic ovary syndrome. AMH is produced primarily in the granulosa cells of the preantral and small antral follicles. Thus it varies in association with folliculogenesis and the establishment and shrinking of the follicle cohort. Ovarian activity during the female half-life, from the embryonic period to menopause, is based on folliculogenesis and maintenance of the follicle cohort, which is influenced by developmental processes, life events, and interventions. AMH trends over a woman's lifetime are associated with in vivo follicular cohort transitions that cannot be observed directly.

CHEK2 signaling is the key regulator of oocyte survival after chemotherapy

Cancer treatments can damage the ovarian follicle reserve, leading to primary ovarian insufficiency and infertility among survivors. Checkpoint kinase 2 (CHEK2) deficiency prevents elimination of oocytes in primordial follicles in female mice exposed to radiation and preserves their ovarian function and fertility. Here, we demonstrate that CHEK2 also coordinates the elimination of oocytes after exposure to standard-of-care chemotherapy drugs. CHEK2 activates two downstream targets-TAp63 and p53-which direct oocyte elimination. CHEK2 knockout or pharmacological inhibition preserved ovarian follicle reserve after radiation and chemotherapy. However, the lack of specificity for CHEK2 among available inhibitors limits their potential for clinical development. These findings demonstrate that CHEK2 is a master regulator of the ovarian cellular response to damage caused by radiation and chemotherapy and warrant the development of selective inhibitors specific to CHEK2 as a potential avenue for ovario-protective treatments.

Deciphering reproductive aging in women using a NOD/SCID mouse model for distinct physiological ovarian phenotypes

Female fertility is negatively correlated with age, with noticeable declines in oocyte quantity and quality until menopause. To understand this physiological process and evaluate human approaches for treating age-related infertility, preclinical studies in appropriate animal models are needed. Thus, we aimed to characterize an immunodeficient physiological aging mouse model displaying ovarian characteristics of different stages during women's reproductive life. NOD/SCID mice of different ages (8-, 28-, and 36-40-week-old) were employed to mimic ovarian phenotypes of young, Advanced Maternal Age (AMA), and old women (~18-20-, ~36-38-, and >45-years-old, respectively). Mice were stimulated, mated, and sacrificed to recover oocytes and embryos. Then, ovarian reserve, follicular growth, ovarian stroma, mitochondrial dysfunction, and proteomic profiles were assessed. Age-matched C57BL/6 mice were employed to cross-validate the reproductive outcomes. The quantity and quality of oocytes were decreased in AMA and Old mice. These age-related effects associated spindle and chromosome abnormalities, along with decreased developmental competence to blastocyst stage. Old mice had less follicles, impaired follicle activation and growth, an ovarian stroma inconducive to growth, and increased mitochondrial dysfunctions. Proteomic analysis corroborated these histological findings. Based on that, NOD/SCID mice can be used to model different ovarian aging phenotypes and potentially test human anti-aging treatments.

Effects of resveratrol on HIF-1α/VEGF pathway and apoptosis in vitrified duck ovary transplantation

Preservation of ovarian tissues is an effective way to ensure genetic diversity of susceptible natural bird populations that are in danger of extinction. We examined whether the addition of the plant phenol resveratrol to vitrification solutions ameliorates the damaging effects of tissue hypoxia and reperfusion injury when the tissues are transplanted. Duck ovary tissues were frozen in the presence of varying concentrations of resveratrol in cryopreservation solutions and then transplanted under the renal capsules of 2-day-old Shelducks. Samples of the transplanted tissues were examined on days 3- and 9- post transplantation for activation of hypoxia-, antioxidant- and apoptosis-related gene expression and apoptosis. Resveratrol significantly increased expression of VEGF, HIF-1α, Nrf2, CAT and Bcl-2 mRNA and decreased BAX and Caspase-3 mRNA and reduced numbers of TUNEL-positive cells after vitrification and heterotopic ovarian transplantation. Resveratrol improved the antioxidant capacity, reduced apoptosis and activated the HIF-1α/VEGF pathway to promote angiogenesis 3- and 9-days following transplantation. These results indicated that the addition of resveratrol to vitrification solutions intended for long-term cryopreservation of ovary tissues improves survival in storage and the grafts following transplantation. This study provides a theoretical basis for the successful transplantation of avian ovarian tissue after vitrification.

Chemotherapy-induced ovarian damage and protective strategies

More than 9.2 million women worldwide suffer from cancer, and about 5% of them are at reproductive age. Chemotherapy-induced impairment of fertility affects the quality of life of these women. Several chemotherapeutic agents have been proven to cause apoptosis and autophagy by inducing DNA damage and cellular stress. Injuries to the ovarian stroma and micro-vessel network are also considered as pivotal factors resulting in ovarian dysfunction induced by chemotherapeutic agents. Primordial follicle pool over-activation may also be the mechanism inducing damage to the ovarian reserve. Although many studies have explored the mechanisms involved in chemotherapy-induced reproductive toxicity, the exact molecular mechanisms have not been elucidated. It is essential to understand the mechanisms involved in ovarian damage, in order to develop potential protective treatments to preserve fertility. In this article, we reviewed the current knowledge on the mechanism of chemotherapy-induced ovarian damage and possible protective strategies that prevent the ovary from such damages.

The transcriptome reveals the molecular regulatory network of primordial follicle depletion in obese mice

OBJECTIVE

To explore the dynamic transcriptional regulatory network of primordial follicle fate in obese mice to elucidate the potential mechanism of primordial follicle depletion.

DESIGN

Experimental study and transcriptomic analysis.

ANIMALS

Healthy (n=15) and obese (n=15) female mice.

INTERVENTIONS

Six-week-old CD-1 mice were divided into healthy and high-fat diet groups and fed continuously for 12 weeks. The diet of healthy mice contained 10% fat. The diet of high-fat mice contained 60% fat.

MAIN OUTCOME MEASURES

Primordial to primary follicle transition rate, gene expression changes, enriched Kyoto Encyclopedia of Genes and Genomes pathways, and ferroptosis.

RESULTS

Primordial follicle depletion was increased in the ovaries of obese mice. We found that deposited fat around primordial and primary follicles of obese mice was higher than that for healthy mice. The proliferation of granulosa cells around primary follicles was increased in obese mice. In addition, we uncovered specific gene signatures associated with the primordial to primary follicle transition (PPT) in obese mice using laser capture microdissection RNA sequencing analysis. Gene set enrichment analysis indicated that ferroptosis, cell oxidation, vascular endothelial growth factor, and mammalian target of rapamycin signaling were increased significantly in the primordial follicles of obese mice. Notably, the ferritin, acyl CoA synthetase long-chain family member 4, and solid carrier family 7 member 11 associated proteins of the ferroptosis signaling pathway were significantly increased in the PPT phase of obese mice.

CONCLUSION

Our work suggests that ferroptosis is a key pathway activated within immature ovarian follicles in the context of obesity and that the process may be involved in the physiological regulation of the PPT as well.

FOXO3 and PTEN expression in the ovary of girls with extra-gonadal cancer with or without chemotherapy treatment prior to cryopreservation

BACKGROUND

FOXO3/pFOXO3 and PTEN expression is known to regulate the dormancy/activation of ovarian primordial follicles. How chemotherapy could influence the expression of FOXO3 and PTEN in pre- and post-menarcheal girls with extra-gonadal cancer remains unexplored.

METHODS

Ovarian samples were collected from 27 girls suffering from extra-gonadal cancer. Of these, 8 patients had received chemotherapy before the time of sample collection. Ovarian tissue collected at the time of surgery was fixed in 10% formaldehyde for FOXO3/pFOXO3 and PTEN immunohistochemistry or immunofluorescence, or stored at -80 °C for Western blot, or preserved in RNA later for RT-PCR.

RESULTS

PTEN was detected in a limited number of primordial follicle-enclosed oocytes in approximately fifty percent of the patients, regardless of whether they had received anti-cancer treatment or not. However, there was a significant decrease in PTEN detection in patients who underwent chemotherapy treatment prior to the retrieval of the sample. Both primordial follicle-enclosed oocytes that expressed FOXO3 and those that did not were identified in patients who were treated with chemotherapy and those who were not. FOXO3-positive primordial follicles exhibited either nuclear FOXO3 localization or cytoplasmic pFOXO3 localization. Furthermore, transitional primordial follicles that expressed nuclear FOXO3 and cytoplasmic pFOXO3 were also observed. Primary follicle-enclosed oocytes displayed cytoplasmic pFOXO3 localization, whereas in more advanced stages of folliculogenesis, the expression moved to the somatic stratum. No significant statistical differences were identified in the detection of FOXO3 and pFOXO3 in patients who had or had not received chemotherapy prior to sample collection.

CONCLUSION

Primordial follicles expressing and not expressing FOXO3 were equally present in both the ovaries of patients who underwent chemotherapy and those who did not. The expression of FOXO3 remained unaltered in response to chemotherapy treatment. Notably, the detection of PTEN was significantly reduced in the treated patients, thereby warranting in-depth investigation, given the limited sample size examined in the present study.

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.

Inhibition of checkpoint kinase prevents human oocyte apoptosis induced by chemotherapy and allows enhanced tumour chemotherapeutic efficacy

STUDY QUESTION

Could inhibition of the checkpoint kinase (CHEK) pathway protect human oocytes and even enhance the anti-tumour effects, during chemotherapy?

SUMMARY ANSWER

CHEK inhibitors prevented apoptosis of human oocytes induced by chemotherapy and even enhanced the anti-tumour effects.

WHAT IS KNOWN ALREADY

CHEK inhibitors showed ovarian protective effects in mice during chemotherapy, while their role in human oocytes is unclear.

STUDY DESIGN, SIZE, DURATION

This experimental study evaluated the ovarian reserve of young patients (120 patients) with cancer, exposed or not exposed to taxane and platinum (TP)-combined chemotherapy. Single RNA-sequencing analysis of human primordial oocytes from 10 patients was performed to explore the mechanism of oocyte apoptosis induced by TP chemotherapy. The damaging effects of paclitaxel (PTX) and cisplatin on human oocytes were also evaluated by culturing human ovaries in vitro. A new mouse model that combines human ovarian xenotransplantation and patient-derived tumour xenografts was developed to explore adjuvant therapies for ovarian protection. The mice were randomly allocated to four groups (10 mice for each group): control, cisplatin, cisplatin + CK1 (CHEK1 inhibitor, SCH 900776), and cisplatin + CK2 (CHEK2 inhibitor, BML277).

PARTICIPANTS/MATERIALS, SETTING, METHODS

In the prospective cohort study, human ovarian follicles were counted and serum AMH levels were evaluated. RNA-sequencing analysis was conducted, and staining for follicular damage (phosphorylated H2AX histone; γH2AX), terminal deoxynucleotidyl transferase-mediated dUTP-biotin nick end labelling (TUNEL) assays and assessments of apoptotic biomarkers (western blot and immunofluorescence) were conducted in human ovaries. After the treatments, histological analysis was performed on human ovarian samples to investigate follicular populations, and oocyte damage was measured by γH2AX staining, BAX staining, and TUNEL assays. At the same time, the tumours were evaluated for volume, weight, and apoptosis levels.

MAIN RESULTS AND THE ROLE OF CHANCE

Patients who received TP chemotherapy showed decreased ovarian reserves. Single RNA-sequencing analysis of human primordial oocytes indicated that TP chemotherapy induced apoptosis of human primordial oocytes by causing CHEK-mediated TAp63α phosphorylation. In vitro culture of human ovaries showed greater damaging effects on oocytes after cisplatin treatment compared with that after PTX treatment. Using the new animal model, CHEK1/2 inhibitors prevented the apoptosis of human oocytes induced by cisplatin and even enhanced its anti-tumour effects. This protective effect appeared to be mediated by inhibiting DNA damage via the CHEK-TAp63α pathway and by generation of anti-apoptotic signals in the oocytes.

LARGE SCALE DATA

N/A.

LIMITATIONS, REASONS FOR CAUTION

This was a preclinical study performed with human ovarian samples, and clinical research is required for validation.

WIDER IMPLICATIONS OF THE FINDINGS

These findings highlight the therapeutic potential of CHEK1/2 inhibitors as a complementary strategy for preserving fertility in female cancer patients.

STUDY FUNDING/COMPETING INTEREST(S)

This work was financially supported by the National Natural Science Foundation of China (nos. 82001514 and 81902669) and the Fundamental Research Funds for the Central Universities (2021yjsCXCY087). The authors declare no conflict of interest.

Does the addition of metformin to carboplatin treatment decreases ovarian reserve damage associated with carboplatin usage?

BACKGROUND

We aimed to determine whether adding metformin to carboplatin treatment would reduce the damage to ovarian reserve associated with carboplatin use.

METHODS

We included 35 adult female non-pregnant albino Wistar rats approximately three months old, weighing 220-310 g. The rats were divided into five groups of seven rats according to the treatment they received. Carboplatin and salin was given to Group 2, and carboplatin plus metformin was given to Group 3. Group 4 was administered only metformin. Group 5 was administered only salin. Carboplatin was given to Groups 2 and 3 as a single dose on the 15th day, while metformin was given to Groups 3 and 4 during the 28-day experiment. After oophorectomy, histopathologic analyses of primordial, primary, secondary, and tertiary Graff follicles according to the epithelial cells surrounding the oocyte and total follicular number were conducted per section. Serum Anti-Mullerian Hormone (AMH), tissue catalase, and malonyl dialdehyde levels were measured and compared within each group.

RESULTS

The baseline and 15th-day serum AMH values of the menstrual cycle were compared among the groups, and no statistically significant differences were observed (p > 0.05). Group 3, which was given both carboplatin and metformin, had statistically significantly higher 28th-day AMH levels than Group 2, which was given only carboplatin and saline (p < 0.001). The number of primordial follicles in Group 3 was found to be statistically significantly higher than in Group 2 (p < 0.001). Tissue catalase enzyme levels in Group 3 were statistically significantly higher than in Group 2 (p < 0.001). Tissue malondialdehyde levels in Group 2 were statistically significantly higher than tissue malondialdehyde levels in Groups 3 and 4 (p < 0.001).

CONCLUSIONS

Metformin may attenuate carboplatin-induced ovarian damage, possibly through its antioxidative effects.

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.

Fertility preservation after gonadotoxic treatments for cancer and autoimmune diseases

BACKGROUND

The indications for fertility preservation (FP) have expanded. A few patients who underwent gonadotoxic treatment did not have the opportunity to receive FP, leading to concerns that these patients may develop premature ovarian insufficiency. However, the usefulness of FP in women with reduced ovarian reserve has also been questioned. Progestin-primed ovarian stimulation can improve the controlled ovarian stimulation (COS) protocol, but there is limited data on the efficacy of FP with progestin-primed ovarian stimulation.

METHODS

We conducted a prospective study of 43 women with cancer or autoimmune diseases before and after gonadotoxic treatment at the reproductive unit of Keio University Hospital, counselled between 1 January 2018 and 31 December 2021. After counselling, informed consent was obtained for FP from 43 patients, with those who underwent gonadotoxic treatment of the primary disease being prioritised. Gonadotropin-releasing hormone analogue or progestin was used to suppress luteinising hormone in COS before or after gonadotoxic treatment. The number of cryopreserved mature oocytes was the primary outcome.

RESULTS

Forty-three patients and 67 assisted reproductive technology cycles were included in the analysis. The median age at entry was 32 [inter quartile range (IQR), 29-37] years. All patients in the post-gonadotoxic treatment group had their oocytes frozen. Gonadotoxic treatment resulted in fewer oocytes [median 3 (IQR 1-4); pre-gonadotoxic treatment group: five patients, 13 cycles] vs. median 9 (IQR 5-14; pre-gonadotoxic treatment group: 38 patients, 54 cycles; P < 0.001). Although anti-Müllerian hormone levels were lower in the post-gonadotoxic treatment group (n = 5, 13 cycles, median 0.29 (IQR 0.15-1.04) pg/mL) than in the pre-gonadotoxic treatment group (n = 38, 54 cycles, median 1.89 (IQR 1.15-4.08) pg/mL) (P = 0.004), oocyte maturation rates were higher in the post-gonadotoxic treatment group [median 100 (IQR 77.5-100) %] than in the pre-gonadotoxic group [median 90.3 (IQR 75.0-100) %; P = 0.039]. Five patients in the pre-gonadotoxic treatment group had their cryopreserved embryos thawed, of which three had live births.

CONCLUSIONS

Oocytes obtained for FP from women with cancer or autoimmune disease for FP are of satisfactory quality, regardless of whether they are obtained post-gonadotoxic treatment or COS protocols.

G-CSF-mobilized peripheral blood mononuclear cells combined with platelet-rich plasma restored the ovarian function of aged rats

BACKGROUND

Regenerative medicine with peripheral blood mononuclear cell (PBMC) transplantation sheds light on the issue of premature ovarian insufficiency (POI). However, the efficiency of PBMC treatment in natural ovarian aging (NOA) remains unclear.

METHODS

Thirteen-month-old female Sprague-Dawley (SD) rats were used to verify the NOA model. Seventy-two NOA rats were randomly divided into three groups: the NOA control group, PBMC group, and PBMC+platelet-rich plasma (PRP) group. PBMCs and PRP were transplanted by intraovarian injection. The effects on ovarian function and fertility were measured after transplantation.

RESULTS

Transplantation of PBMCs could restore the normal estrous cycle, consistent with the recovery of serum sex hormone levels, increased follicle numbers at all stages, and restoration of fertility by facilitating pregnancy and live birth. Moreover, when combined with PRP injection, these effects were more significant. The male-specific SRY gene was detected in the ovary at all four time points, suggesting that PBMCs continuously survived and functioned in NOA rats. In addition, after PBMC treatment, the expression of angiogenesis-related and glycolysis-related markers in the ovaries was upregulated, which indicated that these effects were associated with angiogenesis and glycolysis.

CONCLUSIONS

PBMC transplantation restores the ovarian functions and fertility of NOA rats, and PRP could enhance the efficiency. Increased ovarian vascularization, follicle production, and glycolysis are likely the major mechanisms.

Human UC-MSC-derived exosomes facilitate ovarian renovation in rats with chemotherapy-induced premature ovarian insufficiency

Premature ovarian insufficiency (POI) induced by chemotherapy is an intractable disorder with a considerable incidence that commonly results in insufficient fertility and concomitant complications in female patients. Due to limitations in the current progress in POI diagnosis and treatment, there is an urgent need to develop novel remedies to improve ovarian function and protect fertility. The ameliorative effect of human umbilical cord mesenchymal stem cells (hUCMSCs) and exosomes derived from them in POI treatment could be a new hope for patients. Herein, we identified exosomes from hUCMSCs (hUCMSC-Exos). Then, systematic infusion of hUCMSC-Exos was accomplished via tail intravenous injection to investigate the feasibility of the treatment of rats with chemotherapy-induced POI by intraperitoneal injection of cyclophosphamide (CTX) and busulfan (BUS). Ovarian functions in the indicated group were evaluated, including oestrous cycle, serum sex hormone levels, follicle counts, ovarian pathological changes, proliferation and apoptosis of granulosa cells (GCs), and reproductive ability testing. Furthermore, the potential influence of hUCMSC-Exos on ovarian tissues was illuminated by conducting RNA-seq and multifaceted bioinformatics analyses. POI rats with hUCMSC-Exos transplantation exhibited a decrease in follicle-stimulating hormone (FSH) and apoptosis of GCs but an increase in oestradiol (E2), anti-Müllerian hormone (AMH), and the number of ovarian follicles and foetuses in the uterus. And the immunomodulation- and cellular vitality-associated gene sets in rats had also undergone moderate changes. Our data indicated the feasibility of hUCMSC-Exos in improving ovarian function and protecting fertility in chemotherapy-induced POI rats. HUCMSC-Exos can improve the local microenvironment of ovarian tissue in POI rats by participating in immune regulation, cellular viability, inflammation regulation, fibrosis and metabolism, and other related signal pathways.

Dingkun Pill modulate ovarian function in chemotherapy-induced premature ovarian insufficiency mice by regulating PTEN/PI3K/AKT/FOXO3a signaling pathway

ETHNOPHARMACOLOGICAL RELEVANCE

Dingkun Pill (DKP) is a traditional Chinese medicine that has been shown to have beneficial effects on reproductive function. However, the specific mechanism underlying its effect on POI is not well understood.

AIM OF THE STUDY

To investigate the effect of different doses of Dingkun Pill on ovarian function in cyclophosphamide (CTX)-induced premature ovarian insufficiency (POI) mice and to explore its molecular mechanism through PTEN/PI3K/AKT/FOXO3a signaling pathway. This study will provide valuable insights into the potential clinical application of Dingkun Pill for the treatment of POI.

MATERIALS AND METHODS

Fifty female ICR mice were randomly divided into normal control (NC) group, model control (MC) group, and Dingkun Pill low, medium, high dose (DKP-L, M, H) groups. Mice were injected with CTX to construct the POI model. Mice in the DKP-L, M, and H groups were given 0.9 g/kg, 1.8 g/kg, and 3.6 g/kg of Dingkun Pill suspension for 21 days, respectively. Mice in the NC and MC groups were given the same amount of normal saline by gavage. Changes in body weight, estrous cycle and gonadal index were observed in each group of mice. Serum levels of FSH, LH, E2 and AMH were detected by ELISA. Hematoxylin-eosin (HE) staining observed the changes of ovarian pathological morphology and follicle counts at all levels. qRT-PCR was used to measure the levels of the PTEN and FOXO3a genes in ovarian tissue. The expression of PTEN/PI3K/AKT/FOXO3a signaling pathway related proteins were detected by Western-blot and immunohistochemistry(IHC).

RESULTS

In POI mice, Dingkun Pill increased body weight, promoted the recovery of estrous cycle, increased ovarian index, and improved pathological morphology of the ovaries. The FSH level decreased in the medium dose group (P < 0.05), the LH level reduced significantly in the medium and high dose groups (P < 0.01), and the E2 level in the high dose group increased (P < 0.05). There was no significant difference in AMH levels across all dose groups. The number of growing follicles improved at all levels in the low and medium dose groups, but declined significantly in the high dose group. However, the number of corpus luteum increased significantly in the high dose group (P < 0.001), and the atretic follicles in the three dose groups decreased. Results from qRT-PCR, Western-blot and IHC showed that the moderate dose of Dingkun Pill suppressed the levels of the p-PI3K and p-AKT proteins by upregulating the expression of PTEN in the ovarian tissues of POI mice, thereby inhibiting the expression of the key protein p-FOXO3a. However, the inhibitory effect of the higher dose may be less than that of the lower and intermediate dose groups.

CONCLUSIONS

The Dingkun Pill modulated hormonal levels, promoted follicle growth and induced ovulation in mice with CTX-induced POI, with better results in the low and moderate dose groups. Its mechanism may be related to the regulation of the PTEN/PI3K/AKT/FOXO3a signaling pathway.

Adolescent exposure to low-dose Δ9-tetrahydrocannabinol depletes the ovarian reserve in female mice

Cannabis use by adolescents is widespread, but its effects on the ovaries remain largely unknown. Δ9-tetrahydrocannabinol (THC) exerts its pharmacological effects by activating, and in some conditions hijacking, cannabinoid receptors (CBRs). We hypothesized that adolescent exposure to THC affects ovarian function in adulthood. Peripubertal female C57BL/6N mice were given THC (5 mg/kg) or its vehicle, once daily by intraperitoneal injection. Some mice received THC from postnatal day (PND) 30-33 and their ovaries were harvested PND34; other mice received THC from PND30-43, and their ovaries were harvested PND70. Adolescent treatment with THC depleted ovarian primordial follicle numbers by 50% at PND70, 4 weeks after the last dose. The treatment produced primordial follicle activation, which persisted until PND70. THC administration also caused DNA damage in primary follicles and increased PUMA protein expression in oocytes of primordial and primary follicles. Both CB1R and CB2R were expressed in oocytes and theca cells of ovarian follicles. Enzymes involved in the formation (N-acylphosphatidylethanolamine phospholipase D) or deactivation (fatty acid amide hydrolase) of the endocannabinoid anandamide were expressed in granulosa cells of ovarian follicles and interstitial cells. Levels of mRNA for CBR1 were significantly increased in ovaries after adolescent THC exposure, and upregulation persisted for at least 4 weeks. Our results support that adolescent exposure to THC may cause aberrant activation of the ovarian endocannabinoid system in female mice, resulting in substantial loss of ovarian reserve in adulthood. Relevance of these findings to women who frequently used cannabis during adolescence warrants investigation.

The effect and mechanism of Zigui-Yichong-Fang on improving ovarian reserve in premature ovarian insufficiency by activating SIRT1/Foxo3a pathway

ETHNOPHARMACOLOGICAL RELEVANCE

Zigui-Yichong-Fang (ZGYCF) is a traditional Chinese medicine prescription for the treatment of infertility. It is clinically used to regulate the hormone level of patients, improve ovarian reserve function and increase pregnancy rate. However, the exact mechanism of action is not yet clear.

AIMS OF THE STUDY

This study aims to explore the potential impact of ZGYCF on POI and its mechanism.

MATERIALS AND METHODS

Ultra-high performance liquid chromatography-tandem mass spectrometry (UHPLC-MS/MS) was used to identify the main compounds of ZGYCF. After confirming the therapeutic effect of ZGYCF on cyclophosphamide-induced POI mice, RNA sequencing (RNA-seq) analysis was carried out to explore the mechanism. Then, the effects of ZGYCF on SIRT1 deacetylated Foxo3a and apoptosis were verified from multiple perspectives by serum hormone level, mRNA validation, histomorphology and protein expression, acetylation modification and other experiments.

RESULTS

ZGYCF can improve the morphological changes of ovarian tissue in POI model mice, reduce the damage of primordial follicles and other follicles at all stages, and protect ovarian reserve. The results of transcriptome sequencing showed that the genes expression of PI3K signal and apoptosis signal pathway were increased in POI model mice; ZGYCF can up-regulate the expression of SIRT1 gene and the expression of estradiol, apoptosis inhibition and other signal pathway genes. In addition, ZGYCF can reduce follicular damage and ovarian cell apoptosis in POI model mice through activating the deacetylation of Foxo3a by SIRT1, and improve ovarian reserve function.

CONCLUSIONS

ZGYCF may improve ovarian reserve function of CTX-induced POI mice by activating SIRT1-mediated deacetylation of Foxo3a, and play a role in the treatment of POI.

BDNF promotes mouse follicular development and reverses ovarian aging by promoting cell proliferation

BACKGROUND

Brain-derived neurotrophic factor (BDNF) plays an important role in ovarian function including follicle development and oocyte maturation, and embryonic development. However, whether BDNF treatment can reimpose ovarian aging and impaired fertility remains elusive. In this study, we investigated the reproductive outcomes of BDNF treatment and potential mechanisms in aged mice.

METHOD

"Aged" mice (35-37 weeks old, n = 68) were treated with recombinant human BDNF protein (rhBDNF, 1 µg/200 µL) through daily intraperitoneal (IP) injection for 10 days with/without ovulation induction. Reproductive age mice (8-10 weeks old, n = 28) were treated with ANA 12 (a selective BDNF receptor, TrkB antagonist) through daily IP injection for 5 days with/without ovulation induction. Ovarian function was assessed by ovarian weight, number of follicles, and sex hormone productions. Following induction of ovulation, the number of total oocytes or abnormal oocytes, and blastocyst formation were assessed. Reproductive functions of the mice were evaluated, including pregnancy rate, mating duration for conception, implantation sites, litter size, and weight of offspring. Finally, the molecular mechanism of the effects of BDNF on ovarian cell functions in mice were examined by Western blot and immunofluorescence.

RESULTS

rhBDNF treatment increased the ovarian weight, number of follicles, number and quality of oocytes including increased blastocysts formation, blood estrogen levels, and pregnancy rate in 35-37-week-old mice. Conversely, BDNF receptor antagonist, ANA 12, treatment decreased the ovarian volume and number of antral follicles and increased the proportion of abnormal oocytes in 8-10-week-old mice. We further demonstrated that BDNF treatment promoted ovarian cell proliferation as well as activation of TrkB and cyclinD1-creb signalling.

CONCLUSION

We demonstrated that ten consecutive days of daily IP injection of rhBDNF rescued ovarian function in aged mice. Our results further indicate that TrkB and cyclin D1-creb signaling may underlie the BDNF function in ovaries. Targeting BDNF-TrkB signaling is a potential novel therapeutic strategy to reverse ovarian aging.