A dozen years of ovarian tissue cryopreservation at a pediatric hospital: tracking program and patient metrics while adapting to increasing needs.

Objective: To review the program and patient metrics for ovarian tissue cryopreservation (OTC) within a comprehensive pediatric fertility preservation program in its first 12 years of development. Design: Retrospective review. Setting: A tertiary children's hospital in a large urban center between March 2011 and February 2023. Patients: Pediatric patients who underwent OTC. Interventions: Unilateral oophorectomy for OTC. Main Outcome Measures: Patient demographics and clinical course information were collected for analysis. Results: A total of 184 patients underwent OTC in the first 12 years. One hundred fifteen patients were prepubertal at the time of OTC, and 69 were postpubertal. In total, 128 patients (69.6%) received part of their planned therapy before OTC. Starting in 2018, 104 participants (92.0%) donated tissue to research, 99 participants (87.6%) donated blood, and 102 (90.2%) donated media to research. There was a decrease in the median age of patients who underwent OTC from 16.4-6.6 years and an overall increase in the proportion of patients per year that were prepubertal. Forty-eight (26.0%) patients who underwent OTC were outside referrals and traveled from as far as Seattle, Washington. Conclusion: During the first 12 years of this program, oncofertility research increased, annual tissue cryopreservation cases increased, and the median age of those who underwent OTC decreased. The program was adapted to build a stand-alone gonadal tissue processing suite and specialized in prepubertal ovarian tissue processing. The program will continue to adapt to patient needs in the upcoming decades because restoration technologies advance through research supported by this and collaborating programs.

Thawing fertility: A View of Ovarian Tissue Cryopreservation Processes and Review of Ovarian Transplant Research.

Individuals with a disease or treatment that will increase their risk of premature gonadal insufficiency may opt to undergo fertility preservation. Those who are post-pubertal can often cryopreserve gametes, sperm or eggs, to expand their biological family using assisted reproductive technologies. Ovarian tissue cryopreservation (OTC) and testicular tissue cryopreservation may be an option for individuals who are unable to utilize standard fertility preservation techniques. The development of OTC was critical for many patients, including prepubertal children with ovaries that do not yet produce eggs, adolescents who make few good quality eggs and adult women with ovaries who cannot undergo ovarian stimulation. The only option to restore fertility and hormone production following OTC is through ovarian tissue transplantation (OTT). OTC and OTT have been successful for some patients. While OTC is no longer considered experimental by the American Society of Reproductive Medicine, the process is far from standardized. Significant research needs to be done, especially at the point of OTT, to improve the success and longevity of the ovarian tissue function. This article lists the main steps from surgical procurement of the ovarian tissue to transplantation and restoration of function. Our pediatric hospital program has had to decide which options in procurement, processing, cryopreservation and warming will be used in our clinical lab. The options and limitations within the research and analyses are briefly discussed. Literature focusing on techniques to improve OTT effectiveness and longevity was reviewed. OTT studies that performed xenograft experiments after pretreatment of the tissue graft by a ligand or drug, treatment of host, or encapsulation of the ovarian tissue were identified. The intended effects of the treatments include increasing vascularization, reducing apoptosis and directing activation or suppression of primordial follicles. Robust research in this area must continue with rigorous analyses to make strides for improving fertility preservation and restoration options for patients.

Ovarian Tissue Cryopreservation for Fertility Preservation in Patients with Hemoglobin Disorders: A Comprehensive Review.

Hemoglobin diseases like sickle cell disease (SCD) and ß-thalassemia (BT) present fertility challenges for affected patients. SCD and BT result from abnormal hemoglobin production or structure and pose numerous health concerns. Despite medical advancements improving the quality of life or even providing cures, SCD and BT pose unique fertility concerns for women. Young women with these disorders already contend with reduced ovarian reserve and a narrower fertile window, a situation that is compounded by the gonadotoxic effects of treatments like medications, transfusions, stem cell transplants, and gene therapy. While crucial for disease control, these interventions may lead to reproductive health issues, increasing infertility and early menopause risks. Ovarian tissue cryopreservation (OTC) offers potential for future motherhood to women with hemoglobin disorders facing infertility related to curative treatments. OTC involves surgically removing, preparing, and freezing ovarian tissue containing primordial follicles capable of producing mature oocytes, offering advantages over oocyte cryopreservation alone. However, the application of OTC for patients with hemoglobin disorders presents unique challenges, including special health risks, financial barriers, and access to care. This comprehensive literature review delves into the current state of ovarian tissue cryopreservation for fertility preservation in patients with hemoglobin disorders. Empowering patients with informed reproductive choices in the context of their hemoglobin disorders stands as the ultimate goal.

Vitamin C Synergistically Enhances Protective Effects of Vitamin E Against Preantral Follicle Degeneration of Ovine Vitrified/Warmed Ovarian Tissue.

This study aimed to evaluate whether the addition of vitamins E and C as two conventional antioxidants improves the cryotolerance of preantral follicles enclosed in ovine ovarian tissue slices. For this purpose, ovarian slices were obtained from abattoired juvenile lambs and randomly distributed to the following groups: fresh, toxicity, vitrified (control), and three treatment groups in two experiments. Vitamin E, vitamin C, or vitamin E + C was added to the vitrification media alone in the first experiment and added to all vitrification, warming, and culture media in the second experiment. Finally, the treated tissues were cultured in vitro for 12 hours. The histological analysis showed that single or combined use of vitamins E and C increases intact preantral follicles in comparison to the control in two experiments (p < 0.05), and simultaneous use of vitamins E and C had a synergistic effect on increasing the percentage of normal preantral follicles in experiment 2 (p < 0.05). Due to the better results in Experiment 2, stromal cell density, antioxidant activity, and molecular evaluation were followed only in this experiment. The vitamin E + C group had higher stromal cell density compared with control group (p < 0.05). Vitamin E strengthened antioxidant capacity compared with the control and vitamin C groups (p < 0.05). This effect was exacerbated when used in combination with vitamin C (p < 0.05). The expression of all evaluated genes (BMP4, BMP15, GDF9, and KITLG) was significantly increased in ovarian tissue treated with vitamin E + C compared with the control group (p < 0.05). This increase was also observed in BMP4, GDF9, and KITLG genes compared with the vitamin C group (p < 0.05). In conclusion, this study revealed the positive effects of vitamins E and C on preantral follicle viability and to some extent a synergistic action of vitamin C on the protective effects of vitamin E against preantral follicle degeneration and increasing antioxidant capacity and development of preantral follicles after ovine ovarian tissue vitrification.

Clinical dilemmas in ovarian tissue cryopreservation.

Ovarian tissue cryopreservation (OTC) is increasingly offered globally as a fertility preservation strategy for both postpubertal women and prepubertal girls, with subsequent reimplantation of cryopreserved ovarian cortex resulting in a rapidly growing number of live births. There remains very limited evidence of efficacy from tissue stored when the patient was prepubertal or from conditions affecting the ovary directly, e.g., Turner syndrome. Although OTC is becoming a more established practice, several clinical dilemmas remain from a practical and ethical standpoint. This review discusses the challenges regarding optimal patient selection for the procedure, the use of OTC in patients with a poor prognosis, the potential of reimplantation of tissue contaminated with malignant cells, and the role of OTC in those with an intrinsic ovarian disorder.

De novo design of a nanoregulator for the dynamic restoration of ovarian tissue in cryopreservation and transplantation.

The cryopreservation and transplantation of ovarian tissue underscore its paramount importance in safeguarding reproductive capacity and ameliorating reproductive disorders. However, challenges persist in ovarian tissue cryopreservation and transplantation (OTC-T), including the risk of tissue damage and dysfunction. Consequently, there has been a compelling exploration into the realm of nanoregulators to refine and enhance these procedures. This review embarks on a meticulous examination of the intricate anatomical structure of the ovary and its microenvironment, thereby establishing a robust groundwork for the development of nanomodulators. It systematically categorizes nanoregulators and delves deeply into their functions and mechanisms, meticulously tailored for optimizing ovarian tissue cryopreservation and transplantation. Furthermore, the review imparts valuable insights into the practical applications and obstacles encountered in clinical settings associated with OTC-T. Moreover, the review advocates for the utilization of microbially derived nanomodulators as a potent therapeutic intervention in ovarian tissue cryopreservation. The progression of these approaches holds the promise of seamlessly integrating nanoregulators into OTC-T practices, thereby heralding a new era of expansive applications and auspicious prospects in this pivotal domain.

A systematic review on safety and surgical and anesthetic risks of elective abdominal laparoscopic surgery in infants to guide laparoscopic ovarian tissue harvest for fertility preservation for infants facing gonadotoxic treatment.

Background: Infertility is an important late effect of childhood cancer treatment. Ovarian tissue cryopreservation (OTC) is established as a safe procedure to preserve gonadal tissue in (pre)pubertal girls with cancer at high risk for infertility. However, it is unclear whether elective laparoscopic OTC can also be performed safely in infants <1 year with cancer. This systematic review aims to evaluate the reported risks in infants undergoing elective laparoscopy regarding mortality, and/or critical events (including resuscitation, circulatory, respiratory, neurotoxic, other) during and shortly after surgery. Methods: This systematic review followed the Preferred reporting Items for Systematic Review and Meta-Analyses (PRISMA) reporting guideline. A systematic literature search in the databases Pubmed and EMbase was performed and updated on February 15th, 2023. Search terms included 'infants', 'intubation', 'laparoscopy', 'mortality', 'critical events', 'comorbidities' and their synonyms. Papers published in English since 2000 and describing at least 50 patients under the age of 1 year undergoing laparoscopic surgery were included. Articles were excluded when the majority of patients had congenital abnormalities. Quality of the studies was assessed using the QUIPS risk of bias tool. Results: The Pubmed and Embase databases yielded a total of 12,401 unique articles, which after screening on title and abstract resulted in 471 articles to be selected for full text screening. Ten articles met the inclusion criteria for this systematic review, which included 1778 infants <1 years undergoing elective laparoscopic surgery. Mortality occurred once (death not surgery-related), resuscitation in none and critical events in 53/1778 of the procedures. Conclusion: The results from this review illustrate that morbidity and mortality in infants without extensive comorbidities during and just after elective laparoscopic procedures seem limited, indicating that the advantages of performing elective laparoscopic OTC for infants with cancer at high risk of gonadal damage may outweigh the anesthetic and surgical risks of laparoscopic surgery in this age group.

Thymol increases primordial follicle activation, protects stromal cells, collagen fibers and down-regulates expression of mRNA for superoxide dismutase 1, catalase and periredoxin 6 in cultured bovine ovarian tissues.

This study aims to investigate the influence of thymol on primordial follicle growth and survival, as well as on collagen fibers and stromal cells density in bovine ovarian tissues cultured in vitro. The activity of superoxide dismutase (SOD), catalase (CAT) and glutathione peroxidase (GPX), the thiol levels and the expression of mRNAs for SOD1, CAT, periredoxin 6 (PRDX6) and GPX1 were also investigated. Ovarian cortical tissues were cultured in α-MEM+ alone or with thymol (400, 800, 1600 or 3200 µg/mL) for six days. Before and after culture, the tissues were processed for histological analysis to evaluate follicular activation, growth, morphology, ovarian stromal cell density and collagen fibers. The levels of mRNA for SOD1, CAT, GPX1 and PRDX6 were evaluated by real-time PCR. The results show that tissues cultured with thymol (400 and 800 µg/mL) had increased percentages of normal follicles, when compared to tissues cultured in other treatments. At concentrations of 400 and 800 µg/mL, thymol maintained the rate of normal follicles similar to the uncultured control. In addition, 400 µg/mL thymol increased follicle activation, collagen fibers and stromal cell density of when compared to tissues cultured in control medium. The presence of 800 µg/mL thymol in culture medium increased CAT activity, while 400 or 800 µg/mL thymol reduced mRNA levels for SOD1, CAT and PRDX6, but did not alter GPX1 expression. In conclusion, 400 µg/mL thymol increases primordial follicle activation, preserves stromal cells, collagen fibers, and down-regulates expression of mRNA for SOD1, CAT and PRDX6 in cultured bovine ovarian tissues.

Current practices in oncofertility counseling: updated evidence on fertility preservation and post-treatment pregnancies in young women affected by early breast cancer.

INTRODUCTION: Anticancer treatments have significantly contributed to increasing cure rates of breast cancer in the last years; however, they can also lead to short- and long-term side effects, including gonadotoxicity, and compromised fertility in young women. Oncofertility is a crucial issue for young patients who have not yet completed their family planning at the time of cancer diagnosis. AREAS COVERED: This review aims to cover all the latest available evidence in the field of oncofertility, including the gonadotoxicity of currently adopted anticancer therapies in the curative breast cancer setting, the available strategies for fertility preservation and the feasibility of achieving a pregnancy following anticancer treatment completion. EXPERT OPINION: Over the past years, a significant progress has been made in oncofertility care for young women with breast cancer. In the context of the currently available evidence, every young woman with newly diagnosed breast cancer should receive a proper and complete oncofertility counseling before starting any anticancer treatment to increase her chances of future pregnancies.

Maximizing Success: An Overview of Optimizing the Ovarian Tissue Transplantation Site.

Ovarian tissue cryopreservation and transplantation (OTCT) has emerged in recent years as a potential method for reversing abnormal endocrine and reproductive functions, particularly in patients receiving gonadotoxic cancer treatments having longer survival rates. From its first rodent experiments to human trials, OTCT has evolved tremendously, opening new windows for further utilization. Since then, significant progress has been achieved in terms of techniques used for surgical removal of the tissue, optimal fragment size, freezing and thawing procedures, and appropriate surgical sites for the subsequent reimplementation of the graft. In addition, various approaches have been proposed to decrease the risk of ischemic injury, which is the leading cause of significant follicle loss during neo-angiogenesis. This review aims to discuss the pros and cons of ovarian and retroperitoneal transplantation sites, highlighting the justifications for the viability and efficacy of different transplantation sites as well as the potential advantages and drawbacks of retroperitoneal or preperitoneal area.

[Fertility preservation through natural and artificial ovaries: a review].

Ovarian tissue cryopreservation (OTC) is currently the exclusive choice for preserving fertility in both young girls before reaching puberty and young women who require immediate chemotherapy. Ovarian tissue transplantation has proven to be effective in restoring hormonal cycles and fertility. However, in certain cancer cases, there is a potential risk of inadvertently reintroducing malignant cells when transplanting cryopreserved ovarian tissue. Therefore, the use of an artificial ovary as an innovative and complementary approach allows for the development of isolated follicles, facilitates oocyte maturation and ovulation, and can partially restore endocrine function. This paper presents a comprehensive overview of techniques used to preserve fertility in natural ovarian tissues, including slow freezing, vitrification and hydrogel encapsulation methods. Additionally, it reviews fertility preservation techniques for artificial ovarian tissues, such as strategies involving hydrogel-encapsulated follicle, scaffolding for constructing ovarian microtissues, and 3D printing engineering. Lastly, this article explores current challenges and difficulties encountered in preserving ovarian tissue fertility, while also anticipating future trends in development, making it a valuable reference for the implementation of ovarian tissue fertility preservation.

First report on successful delivery after retransplantation of vitrified, rapid warmed ovarian tissue in Europe.

RESEARCH QUESTION: Cryopreservation of ovarian tissue is one feasible option to preserve female fertility prior to cancer treatment. The slow freezing protocol represents the current standard approach, while vitrification has been suggested as a promising alternative. This paper reports the follow-up and first successful delivery after retransplantation of vitrified, rapid warmed ovarian tissue in Europe. DESIGN: After the patient received a diagnosis of breast cancer, ovarian tissue was removed laparoscopically and sent via overnight transportation to University Hospital Bonn for vitrification on site. The patient was treated with chemotherapy, leading to ovarian failure. After 2 years, retransplantation of the vitrified, rapid warmed tissue was conducted on site. RESULTS: Two months after grafting, the patient reported regular menstrual cycles. After 1 further month a clinical pregnancy occurred, which ended in a spontaneous abortion at the 8th week of pregnancy. Six months after grafting, another naturally conceived pregnancy was determined, resulting in the birth of a healthy boy 14 months after retransplantation of the ovarian tissue. CONCLUSIONS: Complementing the successful deliveries reported by the groups of Suzuki (Japan) and Silber (USA) regarding vitrified tissue, the current results confirm the high potential of this cryopreservation method in a clinical routine setting as an alternative approach to the widespread slow freezing method.

Fertility preservation in women with endometriosis: Oocyte cryopreservation and other techniques.

In recent years, advancements in cryopreservation techniques for oocytes, embryos, and ovarian tissue have enabled offering fertility preservation (FP) options to women with endometriosis. It is recommended to always conduct specialized counselling on FP, especially before considering surgical interventions for endometriosis. The decision regarding the methods of FP, the timing, and to which women affected by endometriosis these techniques should be offered are still subjects of discussion. However, several studies suggest that it can be proposed before surgical interventions for endometriosis, particularly if the patient is undergoing mono or bilateral endometrioma surgery. The most recommended technique is ovarian stimulation, followed by oocyte cryopreservation. Nevertheless, the literature contains various studies describing FP through embryo cryopreservation or the retrieval and cryopreservation of ovarian tissue.

Enhancement of Vascularization and Ovarian Follicle Survival Using Stem Cells in Cryopreserved Ovarian Tissue Transplantation-A Systematic Review.

The increase in cancer survival rates has put a focus on ensuring fertility preservation procedures for cancer patients. Ovarian tissue cryopreservation presents the only option for prepubertal girls and patients who require immediate start of treatment and, therefore, cannot undergo controlled ovarian stimulation. We aimed to provide an assessment of stem cells' impact on cryopreserved ovarian tissue grafts in regard to the expression of growth factors, angiogenesis promotion, tissue oxygenation, ovarian follicle survival and restoration of endocrine function. For this systematic review, we searched the Scopus and PubMed databases and included reports of trials using murine and/or human cryopreserved ovarian tissue for transplantation or in vitro culture in combination with mesenchymal stem cell administration to the grafting site. Of the 1201 articles identified, 10 met the criteria. The application of stem cells to the grafting site has been proven to support vascular promotion and thereby shorten the period of tissue hypoxia, which is reflected in the increased number of remaining viable follicles and faster recovery of ovarian endocrine function. Further research is needed before implementing the use of stem cells in OT cryopreservation and transplantation procedures in clinical practice. Complex ethical dilemmas make this process more difficult.

Persistent organic pollutants dysregulate energy homeostasis in human ovaries in vitro.

Exposure to persistent organic pollutants (POPs), such as dichlorodiphenyltrichloroethane (DDT) and polychlorinated biphenyls (PCBs), has historically been linked to population collapses in wildlife. Despite international regulations, these legacy chemicals are still currently detected in women of reproductive age, and their levels correlate with reduced ovarian reserve, longer time-to-pregnancy, and higher risk of infertility. However, the specific modes of action underlying these associations remain unclear. Here, we examined the effects of five commonly occurring POPs - hexachlorobenzene (HCB), p,p'-dichlorodiphenyldichloroethylene (DDE), 2,3,3',4,4',5-hexachlorobiphenyl (PCB156), 2,2',3,4,4',5,5'-heptachlorobiphenyl (PCB180), perfluorooctane sulfonate (PFOS) - and their mixture on human ovaries in vitro. We exposed human ovarian cancer cell lines COV434, KGN, and PA1 as well as primary ovarian cells for 24 h, and ovarian tissue containing unilaminar follicles for 6 days. RNA-sequencing of samples exposed to concentrations covering epidemiologically relevant levels revealed significant gene expression changes related to central energy metabolism in the exposed cells, indicating glycolysis, oxidative phosphorylation, fatty acid metabolism, and reactive oxygen species as potential shared targets of POP exposures in ovarian cells. Alpha-enolase (ENO1), lactate dehydrogenase A (LDHA), cytochrome C oxidase subunit 4I1 (COX4I1), ATP synthase F1 subunit alpha (ATP5A), and glutathione peroxidase 4 (GPX4) were validated as targets through qPCR in additional cell culture experiments in KGN. In ovarian tissue cultures, we observed significant effects of exposure on follicle growth and atresia as well as protein expression. All POP exposures, except PCB180, decreased unilaminar follicle proportion and increased follicle atresia. Immunostaining confirmed altered expression of LDHA, ATP5A, and GPX4 in the exposed tissues. Moreover, POP exposures modified ATP production in KGN and tissue culture. In conclusion, our results demonstrate the disruption of cellular energy metabolism as a novel mode of action underlying POP-mediated interference of follicle growth in human ovaries.

Ferroptosis: First evidence in premature duck ovary induced by polyvinyl chloride microplastics.

Ferroptosis is frequently observed in fibrosis and diseases related to iron metabolism disorders in various mammalian organs. However, research regarding the damage mechanism of ferroptosis in the female reproductive system of avian species remains unclear. In this study, Muscovy female ducks were divided into three groups which were given purified water, 1 mg/L polyvinyl chloride microplastics (PVC-MPs) and 10 mg/L PVC-MPs for two months respectively, to investigate the ferroptosis induced by PVC-MPs caused ovarian tissue fibrosis that lead to premature ovarian failure. The results showed that the high accumulation of PVC-MPs in ovarian tissue affected the morphology and functional activity of ovarian granulosa cells (GCs) and subsequently caused the follicular development disorders and down-regulated the immunosignaling of ovarian steroidogenesis proteins 3ß-hydroxysteroid dehydrogenase (3ß-HSD), 17ß-hydroxysteroid dehydrogenase (17ß-HSD), CYP11A1 cytochrome (P450-11A1) and CYP17A1 cytochrome (P450-17A1) suggested impaired ovarian function. In addition, PVC-MPs significantly up-regulated positive expression of collagen fibers, significantly increased lipid peroxidation and malondialdehyde (MDA) level, along with encouraged overload of iron contents in the ovarian tissue were the characteristics of ferroptosis. Further, immunohistochemistry results confirmed that immunosignaling of ferroptosis related proteins Acyl-CoA synthetase (ACSL4), Cyclooxygenase 2 (COX2) and ferritin heavy chain 1 (FTH1) were significantly increased, but solute carrier family 7 member 11 (SLC7A11) and glutathione peroxidase (GPX4) were decreased by PVC-MPs in the ovarian tissue. In conclusion, our study demonstrates that PVC-MPs induced ferroptosis in the ovarian GCs, leading to follicle development disorders and ovarian tissue fibrosis, and ultimately contributing to various female reproductive disorders through regulating the proteins expression of ferroptosis.

Restoring Ovarian Fertility and Hormone Function: Recent Advancements, Ongoing Efforts and Future Applications.

The last 20 years have seen substantial improvements in fertility and hormone preservation and restoration technologies for a growing number of cancer survivors. However, further advancements are required to fill the gaps for those who cannot use current technologies or to improve the efficacy and longevity of current fertility and hormone restoration technologies. Ovarian tissue cryopreservation (OTC) followed by ovarian tissue transplantation (OTT) offers those unable to undergo ovarian stimulation for egg retrieval and cryopreservation an option that restores both fertility and hormone function. However, those with metastatic disease in their ovaries are unable to transplant this tissue. Therefore, new technologies to produce good-quality eggs and restore long-term cyclic ovarian function are being investigated and developed to expand options for a variety of patients. This mini-review describes current and near future technologies including in vitro maturation, in vitro follicle growth and maturation, bioprosthetic ovaries, and stem cell applications in fertility restoration research by their proximity to clinical application.

Omaveloxolone Prevents Polystyrene Microplastic-Induced Ovarian Granulosa Cell Apoptosis via the Keap1/Nrf2/HO-1 Pathway in Rats.

Microplastics (MPs) are persistent environmental pollutants that enter the circulatory system and subsequently reduce sperm quantity and quality. However, the influence of polystyrene MPs (PS-MPs) on the ovary and relevant mechanisms remain elusive. Herein, we aimed to examine the impact of PS-MPs on oxidative disorders in ovarian tissues and elucidate the underlying mechanisms. Healthy female rats were treated with different concentrations of 0.5 µm PS-MPs (diluted in deionized H2O) for 90 days. Upon examination of hematoxylin-eosin-stained ovarian tissue sections, the number of growing follicles was reduced in PS-MP-treated rats when compared with that in control rats. Enzyme-linked immunosorbent assays revealed that PS-MP exposure markedly reduced anti-Müllerian hormone (AMH) levels. Treatment with PS-MPs downregulated superoxide dismutase, glutathione, and catalase activities in ovarian tissues while upregulating malondialdehyde levels. Furthermore, exposure to PS-MP blocked the Keap1/Nrf2/HO-1 signal transduction pathway. PS-MPs also triggered apoptosis in the ovarian tissue, as evidenced by increased TUNEL staining and expression levels of cleaved caspase-9, Bax, and Bcl-2. To reactivate the Keap1/Nrf2/HO-1 pathway, rats were co-administered PS-MPs and omaveloxolone (Oma), an Nrf2 activator, for 1 week. We found that Oma could counteract the PS-MP-mediated effects on oxidative disorder, apoptosis, AMH production, and follicle number in rat ovarian tissues. To develop an in vitro model, granulosa cells (GCs) were treated with 10 µM H2O2 for 12 h to induce oxidative stress. H2O2-stimulated GCs exhibited attenuated cell growth and upregulated apoptosis and oxidative stress. Oma administration could ameliorate the H2O2-induced effects in terms of regulating cell viability, apoptosis, and oxidative stress in GCs. In summary, PS-MPs could induce apoptosis and oxidative stress via the Keap1/Nrf2/HO-1 signaling pathway in both rats and GCs.

Assessing the effect of adipose-tissue-derived stem cell conditioned medium on follicles and stromal cells in bovine ovarian tissue culture.

RESEARCH QUESTION: Does adipose-tissue-derived stem cell conditioned medium (ASC-CM) supplementation enhance follicle and stromal cell outcomes in vitro? DESIGN: Bovine ovaries (n = 8) were sectioned and cultured in vitro for 8 days in two different groups: (i) standard culture (OT Ctrl D8); and (ii) culture with ASC-CM supplementation (OT + CM D8). Half of the culture medium was replaced every other day, and stored to measure the production of oestradiol. Follicle classification was established using haematoxylin and eosin staining. Follicle and stromal cell DNA fragmentation was assessed by TUNEL assays, while growth differentiation factor-9 (GDF-9) staining served as a marker of follicle quality. Additionally, three factors, namely vascular endothelial growth factor (VEGF), interleukin 6 (IL-6) and transforming growth factor beta 1 (TGF-ß1), were evaluated in ASC-CM in order to appraise the potential underlying mechanisms of action of ASC. RESULTS: The OT + CM D8 group showed a significantly higher proportion of secondary follicles (P = 0.02) compared with the OT Ctrl D8 group. The OT + CM D8 group also demonstrated significantly lower percentages of TUNEL-positive follicles (P = 0.014) and stromal cells (P = 0.001) compared with the OT Ctrl D8 group. Furthermore, follicles in the OT + CM D8 group exhibited a significant increase (P = 0.002) in expression of GDF-9 compared with those in the OT Ctrl D8 group, and oestradiol production was significantly higher (P = 0.04) in the OT + CM D8 group. All studied factors were found to be present in ASC-CM. VEGF and IL-6 were the most widely expressed factors, while TGF-ß1 showed the lowest expression. CONCLUSIONS: Addition of ASC-CM to culture medium enhances follicle survival, development and oestradiol production, and promotes the viability of stromal cells. VEGF, IL-6 and TGF-ß1 could be paracrine mediators underlying the beneficial effects.

Conceptos de criobiología y fisiología ovárica en la preservación de la fertilidad / Concepts of cryobiology and ovarian physiology in fertility preservation

La criobiología se enfoca en entender cómo reaccionan los materiales biológicos a temperaturas muy bajas. Este campo ha experimentado avances significativos, particularmente en el ámbito de la reproducción asistida, donde se han desarrollado programas para preservar la fertilidad. Estos desarrollos revisten importancia crítica para quienes exploran alternativas en materia de fertilidad y preservación de gametos. Por otro lado, la preservación de la fertilidad tiene como objetivo proteger la capacidad reproductiva de una persona por diferentes condiciones de salud, tratamientos médicos o razones sociales que la puedan comprometer. Las técnicas aceptadas para la preservación de fertilidad en humanos son la criopreservación de gametos y de embriones. Existe evidencia prometedora creciente sobre distintas técnicas experimentales dentro de este campo, como la crioconservación del tejido gonadal, o estrategias de maduración in vitro, así como nuevas metodologías en los protocolos criogénicos que supondrán una optimización de los resultados y un punto de inflexión dentro del campo de la reproducción asistida. Este trabajo tiene como objetivo explorar el estado del arte de las estrategias actuales ofrecidas a las mujeres en el contexto de preservación de la fertilidad, revisar los avances en criobiología y su papel en la evolución de este ámbito.(AU)

Cryobiology focuses on understanding how biological materials react to very low temperatures. This field has experienced significant advances, particularly in the field of assisted reproduction, where programs have been developed to preserve fertility. These developments are of critical importance for those exploring alternatives in fertility and gamete preservation. Fertility preservation aims to protect a person's reproductive capacity under various health conditions, medical treatments, and social reasons that may compromise it. Accepted techniques for human fertility preservation include the cryopreservation of gametes and embryos. There is growing promising evidence on different experimental techniques within this field, such as cryopreservation of gonadal tissue or in vitro maturation strategies, as well as new methodologies in cryogenic protocols that will optimize results and mark a turning point in the field of assisted reproduction. This work aims to explore the current state-of-the-art strategies offered to women in the context of fertility preservation, review advances in cryobiology, and its role in the evolution of this area.(AU)