Müllerian inhibiting substance/anti-Müllerian hormone as a fertility preservation agent

AMH protects the ovary from doxorubicin by regulating cell fate and the response to DNA damage

Anti-Müllerian hormone (AMH) protects the ovarian reserve from chemotherapy, and this effect is most pronounced with Doxorubicin (DOX). However, the mechanisms of DOX toxicity and AMH rescue in the ovary remain unclear. Herein, we characterize these mechanisms in various ovarian cell types using scRNAseq. In the mesenchyme, DOX activates the intrinsic apoptotic signaling pathway through p53 class mediators, particularly affecting theca progenitors, while co-treament with AMH halts theca differentiation and reduces apoptotic gene expression. In preantral granulosa cells, DOX upregulates the cell cycle inhibitor Cdkn1a and dysregulates Wnt signaling, which are ameliorated by AMH co-treatment. Finally, in follicles, AMH induces Id3 , a protein involved in DNA repair, which is necessary to prevent the accumulation of DNA lesions marked by γ-H2AX in granulosa cells. Altogether this study characterizes cell, and follicle stage-specific mechanisms of AMH protection of the ovary, offering promising new avenues for fertility preservation in cancer patients undergoing chemotherapy.

Highlights

Doxorubicin treatment induces DNA damage that activates the p53 pathway in stromal and follicular cells of the ovary.AMH inhibits the proliferation and differentiation of theca and granulosa cells and promotes follicle survival following Doxorubicin insult.AMH treatment mitigates Doxorubicin-induced DNA damage in the ovary by preventing the accumulation of γ-H2AX-positive unresolved foci, through increased expression of ID3, a protein involved in DNA repair.

Ovarian Reserve Disorders, Can We Prevent Them? A Review

The ovarian reserve is finite and begins declining from its peak at mid-gestation until only residual follicles remain as women approach menopause. Reduced ovarian reserve, or its extreme form, premature ovarian insufficiency, stems from multiple factors, including developmental, genetic, environmental exposures, autoimmune disease, or medical/surgical treatment. In many cases, the cause remains unknown and resulting infertility is not ultimately addressed by assisted reproductive technologies. Deciphering the mechanisms that underlie disorders of ovarian reserve could improve the outcomes for patients struggling with infertility, but these disorders are diverse and can be categorized in multiple ways. In this review, we will explore the topic from a perspective that emphasizes the prevention or mitigation of ovarian damage. The most desirable mode of fertoprotection is primary prevention (intervening before ablative influence occurs), as identifying toxic influences and deciphering the mechanisms by which they exert their effect can reduce or eliminate exposure and damage. Secondary prevention in the form of screening is not recommended broadly. Nevertheless, in some instances where a known genetic background exists in discrete families, screening is advised. As part of prenatal care, screening panels include some genetic diseases that can lead to infertility or subfertility. In these patients, early diagnosis could enable fertility preservation or changes in family-building plans. Finally, Tertiary Prevention (managing disease post-diagnosis) is critical. Reduced ovarian reserve has a major influence on physiology beyond fertility, including delayed/absent puberty or premature menopause. In these instances, proper diagnosis and medical therapy can reduce adverse effects. Here, we elaborate on these modes of prevention as well as proposed mechanisms that underlie ovarian reserve disorders.

A screen of repurposed drugs identifies AMHR2/MISR2 agonists as potential contraceptives

We identified the anti-Mullerian hormone (also known as Müllerian inhibiting substance or MIS) as an inhibitory hormone that induces long-term contraception in mammals. The type II receptor to this hormone, AMHR2 (also known as MISR2), represents a promising druggable target for the modulation of female reproduction with a mechanism of action distinct from steroidal contraceptives. We designed an in vitro platform to screen and validate small molecules that can activate MISR2 signaling and suppress ovarian folliculogenesis. Using a bone morphogenesis protein (BMP)–response element luciferase reporter cell–based assay, we screened 5,440 compounds from a repurposed drug library. Positive hits in this screen were tested for specificity and potency in luciferase dose–response assays, and biological activity was tested in ex vivo Mullerian duct regression bioassays. Selected candidates were further evaluated in ex vivo follicle/ovary culture assays and in vivo in mice and rats. Here, we report that SP600125, CYC-116, gandotinib, and ruxolitinib can specifically inhibit primordial follicle activation and repress folliculogenesis by stimulating the MISR2 pathway.

Protective effects of a SIRT1 inhibitor on primordial follicle activation and growth induced by cyclophosphamide: insights from a bovine in vitro folliculogenesis system

Purpose

Although oncological advances have improved survival rates of female cancer patients, they often suffer a reduced fertility due to treatment side effects. In the present study, we evaluated the potential fertoprotective effects of the specific inhibitor of SIRT1, EX-527, on the gonadotoxic action exerted by cyclophosphamide (CPM) on loss of primordial follicles (PFs).

Methods

The effects of the CPM metabolite phosphoramide mustard (PM) on follicle activation, growth and viability and the protective action of EX-527 against PM effects were evaluated on bovine ovarian cortical strips in vitro cultured for 1 or 6 days. To understand whether PFs exposed to PM plus EX-527 were able to activate and grow to the secondary stage after suspension of the treatment, strips cultured for 3 days in PM plus EX-527 for 3 days were transferred to plain medium until day 6. Follicle growth and health were evaluated through histology and viability assay at a confocal microscope. In order to investigate the molecular pathways underlying the ovarian response to PM in the presence of EX-527, we analysed the protein level of SIRT1, HuR, PARP1 and SOD2 after 1 day of in vitro culture.

Results

We found that (1) PM, the main CPM active metabolite, promotes PF activation; (2) the ovarian stress response induced by PM includes a SIRT1-dependent pathway; and (3) EX-527 reduces PF activation and growth induced by PM.

Conclusion

SIRT1 can represent a candidate molecule to be targeted to protect ovarian follicles from alkylating agents and EX-527 could represent a potential fertoprotective agent for cancer patients.

Clinical Utility of Anti-Mullerian Hormone in Pediatrics

CONTEXT

Anti-Mullerian hormone (AMH) was originally described in the context of sexual differentiation in the male fetus but has gained prominence now as a marker of ovarian reserve and fertility in females. In this mini-review, we offer an updated synopsis on AMH and its clinical utility in pediatric patients.

DESIGN AND RESULTS

A systematic search was undertaken for studies related to the physiology of AMH, normative data, and clinical role in pediatrics. In males, AMH, secreted by Sertoli cells, is found at high levels prenatally and throughout childhood and declines with progression through puberty to overlap with levels in females. Thus, serum AMH has clinical utility as a marker of testicular tissue in males with differences in sexual development and cryptorchidism and in the evaluation of persistent Mullerian duct syndrome. In females, serum AMH has been used as a predictive marker of ovarian reserve and fertility, but prepubertal and adolescent AMH assessments need to be interpreted cautiously. AMH is also a marker of tumor burden, progression, and recurrence in germ cell tumors of the ovary.

CONCLUSIONS

AMH has widespread clinical diagnostic utility in pediatrics but interpretation is often challenging and should be undertaken in the context of not only age and sex but also developmental and pubertal stage of the child. Nonstandardized assays necessitate the need for assay-specific normative data. The recognition of the role of AMH beyond gonadal development and maturation may usher in novel diagnostic and therapeutic applications that would further expand its utility in pediatric care.

Current and Future Perspectives for Improving Ovarian Tissue Cryopreservation and Transplantation Outcomes for Cancer Patients

Although advances in cancer treatment and early diagnosis have significantly improved cancer survival rates, cancer therapies can cause serious side effects, including ovarian failure and infertility, in women of reproductive age. Infertility following cancer treatment can have significant adverse effects on the quality of life. However, established methods for fertility preservation, including embryo or oocyte cryopreservation, are not always suitable for female cancer patients because of complicated individual conditions and treatment methods. Ovarian tissue cryopreservation and transplantation is a promising option for fertility preservation in pre-pubertal girls and adult patients with cancer who require immediate treatment, or who are not eligible to undergo ovarian stimulation. This review introduces various methods and strategies to improve ovarian tissue cryopreservation and transplantation outcomes, to help patients and clinicians choose the best option when considering the potential complexity of a patient's situation. Effective multidisciplinary oncofertility strategies, involving the inclusion of a highly skilled and experienced oncofertility team that considers cryopreservation methods, thawing processes and devices, surgical procedures for transplantation, and advances in technologies, are necessary to provide high-quality care to a cancer patient.

Continuous treatment with cisplatin induces the oocyte death of primordial follicles without activation

Chemotherapy directly or indirectly affects organs in a short-term or continuous manner. Endocrine organs are especially sensitive to cancer treatment, leading to concerns among patients regarding their quality of life afterward. Side effects to the ovary include damage to the ovarian reserve, resulting in follicle loss, endocrine hormone deficiency, and infertility. It has been previously demonstrated that continuous treatment with 2 mg/kg cisplatin for 15 days can activate primordial follicles, suggesting that the response in the oocytes of primordial follicles was dependent on cisplatin concentration and administration frequency. However, our results demonstrate that continuous treatment with 2 mg/kg cisplatin for 15 days leads to the same consequence as with the continuous treatment of 5 mg/kg cisplatin: the death of oocytes in primordial follicles without indication of activation. Moreover, animals co-injected with melatonin and cisplatin did not display any significant differences from those treated with cisplatin only contrary to the known results. 6-hydroxymelatonin, a metabolite of melatonin, could not prevent follicle destruction, implying that melatonin does not confer the protection of ovarian follicles, either directly or indirectly. Altogether, our data support that fertoprotectants against cisplatin must target molecules that control cell death pathways in the oocytes of primordial follicles.

Consequences of chemotherapeutic agents on primordial follicles and future clinical applications

The ovarian reserve is necessary for female fertility and endocrine health. Commonly used cancer therapies diminish the ovarian reserve, thus, resulting in primary ovarian insufficiency, which clinically presents as infertility and endocrine dysfunction. Prepubertal children who have undergone cancer therapies often experience delayed puberty or cannot initiate puberty and require endocrine support to maintain a normal life. Thus, developing an effective intervention to prevent loss of the ovarian reserve is an unmet need for these cancer patients. The selection of adjuvant therapies to protect the ovarian reserve against cancer therapies underlies the mechanism of loss of primordial follicles (PFs). Several theories have been proposed to explain the loss of PFs. The "burn out" theory postulates that chemotherapeutic agents activate dormant PFs through an activation pathway. Another theory posits that chemotherapeutic agents destroy PFs through an "apoptotic pathway" due to high sensitivity to DNA damage. However, the mechanisms causing loss of the ovarian reserve remains largely speculative. Here, we review current literature in this area and consider the mechanisms of how gonadotoxic therapies deplete PFs in the ovarian reserve.