The removal and cryostorage of ovarian cortical biopsies is now offered as a fertility preservation option for young women. The only available option to restore fertility using this tissue is by ...transplantation, which may not be possible for all patients. The full potential of this tissue to restore fertility could be achieved by the development of in vitro systems that support oocyte development from the most immature stages to maturation. The techniques of in vitro growth (IVG) combined with in vitro maturation (IVM) are being developed with human tissue, but comparing different systems has been difficult because of the scarcity of tissue so nonhuman primates are being used as model systems. There are many challenges to developing a complete culture system that would support human oocyte development, and this review outlines the approaches being taken by several groups using tissue from women and nonhuman primate models to support each of the stages of oocyte development.
In vitro follicle development (IVFD) is an adequate model to obtain basic knowledge of folliculogenesis and provides a tool for ovarian toxicity screening. IVFD yielding competent oocytes may also ...offer an option for fertility and species preservation. To promote follicle growth and oocyte maturation in vitro, various culture systems are utilized for IVFD in rodents, domestic animals, wild animals, nonhuman primates, and humans. Follicle culture conditions have been improved by optimizing gonadotropin levels, regulatory factors, nutrient supplements, oxygen concentration, and culture matrices. This review summarizes quality assessment of oocytes generated from in vitro-developed antral follicles from the preantral stage, including oocyte epigenetic and genetic profile, cytoplasmic and nuclear maturation, preimplantation embryonic development following in vitro fertilization, as well as pregnancy and live offspring after embryo transfer. The limitations of oocyte quality evaluation following IVFD and the gaps in our knowledge of IVFD to support proper oocyte development are also discussed. The information may advance our understanding of the requirements for IVFD, with a goal of producing competent oocytes with genetic integrity to sustain embryonic development resulting in healthy offspring. Summary Sentence Although advances in current IVFD systems have greatly enhanced oocyte growth and maturation, further optimization is required to improve oocyte competence with genetic integrity for proper embryonic development.
Cisplatin, a platinum-containing alkylating agent, is used in the treatment of various tumors owing to its potent antitumor activity. However, it causes permanent and adverse effects, particularly ...hearing loss and depletion of ovarian reserve. Until recently, there were no clinically available protective agents to mitigate the adverse side effects of cisplatin-induced cytotoxicity. In 2022, sodium thiosulfate (STS) was approved by the Food and Drug Administration for mitigating hearing loss in children and adolescents undergoing cisplatin treatment. Consequently, our investigation aimed to determine if STS could protect ovarian reserve against cisplatin-induced gonadotoxicity. In an ex vivo culture, the cisplatin-only group exhibited a loss of primordial follicles, while post-STS administration after cisplatin exposure effectively protected primordial follicles. However, when post-STS was administrated either 6 or 4 h after cisplatin exposure, it did not confer protection against cisplatin-induced gonadotoxicity in postnatal day 7 or adolescent mouse models. Immunofluorescence assays using γH2AX and cPARP revealed that oocytes within primordial follicles exhibited DNA damage after cisplatin exposure, irrespective of post-STS administration. This underscores the rapid and heightened sensitivity of oocytes to gonadotoxicity. In addition, oocytes demonstrated an increased expression of pCHK2 rather than pERK, suggesting that the pathway leading to oocyte death differs from the pathway observed in the inner ear cell death following cisplatin exposure. These results imply that while the administration of STS after cisplatin is highly beneficial in preventing hearing loss, it does not confer a protective effect on the ovaries in mouse models.
The phosphoinositide 3-kinase/AKT (protein kinase B) signaling pathway negatively regulates follicle activation via the forkhead box O (FOXO) transcription factor in rodents. FOXO3 knockout mice ...exhibit global activation of primordial follicles leading to early depletion of ovarian follicles and subsequent infertility. Whether a similar mechanism for follicle activation exists in the primate ovary is unclear. In the current study, protein localization of FOXO1, 3, and 4 as well as their upstream regulator, AKT/p-AKT, was examined in rhesus macaque ovaries of three developmental stages: fetal, prepubertal, and adult. FOXO1 protein is expressed in granulosa cells of fetal, prepubertal, and adult ovaries. FOXO3 is distributed sparsely in the mitotically active germ cells, but its expression decreases following follicle formation in the macaque fetal ovary. In addition, FOXO3 is seldom with interanimal variation in the prepubertal ovary and is absent in the adult ovary. FOXO4 is nondetectable in fetal ovaries, although it is expressed in some theca cells of antral follicles and some stromal cells in prepubertal and adult ovaries. Our results suggest that the regulation and/or function of FOXO3 in the primate primordial follicle may differ than that of the rodent. Nevertheless, AKT/p-AKT is expressed in macaque primordial oocytes, suggesting that similar upstream events but different downstream effects may regulate primordial follicle activation in nonhuman primates compared to rodents. Elucidation of the mechanism responsible for follicle activation in primates will be crucial for understanding primary ovarian insufficiency, improving female fertility, and applying techniques for in vitro maturation of follicles for fertility preservation in cancer survivors. Summary Sentence FOXO3 protein localizes in the oocyte of fetal and prepubertal but not adult ovaries while FOXO1 and 4 are expressed in granulosa and theca cells, receptively in the rhesus macaque.
Abstract The Multispecies Ovary Tissue Histology Electronic Repository (MOTHER) is a publicly accessible repository of ovary histology images. MOTHER includes hundreds of images from nonhuman ...primates, as well as ovary histology images from an expanding range of other species. Along with an image, MOTHER provides metadata about the image, and for selected species, follicle identification annotations. Ongoing work includes assisting scientists with contributing their histology images, creation of manual and automated (via machine learning) processing pipelines to identify and count ovarian follicles in different stages of development, and the incorporation of that data into the MOTHER database (MOTHER-DB). MOTHER will be a critical data repository storing and disseminating high-value histology images that are essential for research into ovarian function, fertility, and intra-species variability.
Men have two practical choices for contraception; the condom which has a high typical use failure rate or vasectomy. New male hormonal and non-hormonal contraceptives are under development that ...target either the production of sperm (spermatogenesis) or the delivery of sperm. One particular target is the sperm protein EPPIN, which is present on the surface of human spermatozoa. EP055 is a small organic compound that targets EPPIN on the surface of sperm and inhibits motility. EP055 was tested in cynomolgus (Macaca fascicularis) males to determine its plasma half-life after intravenous (i.v.) infusion of a single dose and for binding to its target tissues. Our initial study demonstrated a plasma half-life for EP055 of 10.6 minutes. In a second study examination of macaque testis, epididymis, and plasma after i.v. infusion of a single dose of compound EP055 (63.25 mg/kg) demonstrated that EP055 was detected in testis and epididymis two hours and six hours post-infusion. We initiated a trial in rhesus (Macaca mulatta) males to assess the availability of EP055 in semen and its effect on sperm motility as a measure of the drug's efficacy. Four macaques were infused with a low dose (75-80 mg/kg) followed by a recovery period and a subsequent high dose (125-130 mg/kg) of EP055. After high dose administration, sperm motility fell to approximately 20% of pretreatment levels within 6 hours post-infusion; no normal motility was observed at 30 hours post-infusion. Recovery of sperm motility was obvious by 78 hours post-infusion; with full recovery in all animals by 18 days post-infusion. EP055 has the potential to be a male contraceptive that would provide a reversible, short-lived pharmacological alternative.
In vitro ovarian follicle cultures may provide fertility-preserving options to women facing premature infertility due to cancer
therapies. An encapsulated three-dimensional (3-D) culture system ...utilizing biomaterials to maintain cell-cell communication
and support follicle development to produce a mature oocyte has been developed for the mouse. We tested whether this encapsulated
3-D system would also support development of nonhuman primate preantral follicles, for which in vitro growth has not been
reported. Three questions were investigated: Does the cycle stage at which the follicles are isolated affect follicle development?
Does the rigidity of the hydrogel influence follicle survival and growth? Do follicles require luteinizing hormone (LH), in
addition to follicle-stimulating hormone (FSH), for steroidogenesis? Secondary follicles were isolated from adult rhesus monkeys,
encapsulated within alginate hydrogels, and cultured individually for â¤30 days. Follicles isolated from the follicular phase
of the menstrual cycle had a higher survival rate ( P < 0.05) than those isolated from the luteal phase; however, this difference may also be attributed to differing sizes of
follicles isolated during the different stages. Follicles survived and grew in two hydrogel conditions (0.5% and 0.25% alginate).
Follicle diameters increased to a greater extent ( P < 0.05) in the presence of FSH alone than in FSH plus LH. Regardless of gonadotropin treatment, follicles produced estradiol,
androstenedione, and progesterone by 14â30 days in vitro. Thus, an alginate hydrogel maintains the 3-D structure of individual
secondary macaque follicles, permits follicle growth, and supports steroidogenesis for â¤30 days in vitro. This study documents
the first use of the alginate system to maintain primate tissue architecture, and findings suggest that encapsulated 3-D culture
will be successful in supporting the in vitro development of human follicles.
The goal of the Multispecies Ovary Tissue Histology Electronic Repository (MOTHER) project is to establish a collection of nonhuman ovary histology images for multiple species as a resource for ...researchers and educators. An important component of sharing scientific data is the inclusion of the contextual metadata that describes the data. MOTHER extends the Ecological Metadata Language (EML) for documenting research data, leveraging its data provenance and usage license with the inclusion of metadata for ovary histology images. The design of the MOTHER metadata includes information on the donor animal, including reproductive cycle status, the slide and its preparation. MOTHER also extends the ezEML tool, called ezEML+MOTHER, for the specification of the metadata. The design of the MOTHER database (MOTHERDB) captures the metadata about the histology images, providing a searchable resource for discovering relevant images. MOTHER also defines a curation process for the ingestion of a collection of images and its metadata, verifying the validity of the metadata before its inclusion in the MOTHER collection. A Web search provides the ability to identify relevant images based on various characteristics in the metadata itself, such as genus and species, using filters.
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