Restoration of ovarian activity and pregnancy after transplantation of cryopreserved ovarian tissue: a review of 60 cases of reimplantation

Fertility outcomes several years after urgent fertility preservation for patients with breast cancer

OBJECTIVE

To study the fertility outcomes of women who tried to conceive after breast cancer (BC) treatment and fertility preservation.

DESIGN

Retrospective observational, bicentric cohort study.

SETTING

University hospital.

PATIENTS

Patients with BC.

INTERVENTION

All patients who had undergone fertility preservation before BC treatment between January 2013 and July 2019 were included (n = 844). The endpoint date was March 1, 2022. Patients with missing data on pregnancy attempts after a cancer diagnosis (n = 195) were excluded from the pregnancy analysis.

MAIN OUTCOME MEASURES

Cumulative incidences of pregnancy and live birth (LB) were calculated. For women who became pregnant, the time to conception was calculated between the first fertility preservation consultation and the estimated day of conception. For those who did not conceive, we considered the time between the first fertility preservation consultation and the endpoint date, or the date of patient death. A Cox regression model was used to study the predictive factors for pregnancy and LB.

RESULTS

Among the 649 patients with available data on pregnancy attempts after BC diagnosis, 255 (39.3% [35.5-43.2]) tried to conceive (median follow-up of 6.5 years). Overall, 135 (52.9% [46.6-59.2]) of these patients achieved a pregnancy, mainly through unassisted conception (79.3% [72.8-84.8]), and 99 reported an LB (representing 38.8% of patients who attempted conception). In our cohort, 48 months after the first fertility preservation consultation, the cumulative incidence of pregnancy was 33.1% ([27.6-37.9]). After adjustment for age, parity, type of chemotherapy administration, and endocrine therapy, only multiparity at diagnosis and absence of chemotherapy were positive predictive factors of pregnancy after cancer. Of the 793 patients who had vitrified oocytes and embryos, 68 used them (27% [21.3-32.5] of the patients who tried to conceive), resulting in 8 LBs (11.8% [5.2-21.9]). Women who used their cryopreserved oocytes and embryos were older at the first consultation of fertility preservation (hazard ratio 1.71 [1.42-2.21]), and chose more often to vitrify embryos (hazard ratio 1.76 [1.28-2.23]).

CONCLUSION

Although pregnancy rates after fertility preservation for patients with BC are low, most conceptions are achieved without medical assistance. Our findings provide useful information to advise women on the different techniques of fertility preservation, their efficacy, and safety, as well as the relatively high chances of unassisted conception.

Ovarian tissue autotransplantation improves longevity in mice

In this study, we show the improvement in life longevity in an experimental mouse model after step-by-step autologous ovarian transplantation and compare its effects with exogenic transdermal estradiol usage. This has proven to be more efficient than "traditional" hormonal replacement therapy. Despite the high speed and effectiveness of estradiol replacement deficiency in blood by its oral or transdermal use, no significant increase in the life longevity of animals and possibly in women was noted. The function of the transplanted fragment is usually limited to 6-12 months. This is enough for oncofertility purposes, sometimes, but not for longevity improvement. We performed periodical tissue return (autologous transplantation), containing both the cortex and medulla in the experimental mouse model, which resulted in a statistically reliable improvement in longevity. Our experience indicates the important role of medullary ovarian factors in slowing the aging process in the body and increasing the life expectancy in the experiment. As shown, the transdermal estrogen supportive therapy for ovarian deficiency improves estrogen levels but causes much slower decreases in the follicle stimulating hormone (FSH) and luteinizing hormone (LH). Moreover, we attained the best longevity with step-by-step periodic ovarian autotransplantation, thus making "prosthetics" of ovarian function longer than it is preplanned physiologically [direct correlation between the levels of FSH and lifespan (r = 0.98)]. The experimental model we suggested could be projected to other mammals or humans as cortical transplantation provides the same results for reproduction restoration in mice and humans and even for hormone level normalization, but there is still a lack of information about anti-aging factors in the ovarian medulla and cortex. Hence, we consider that the most important factor for the anti-aging ovarian transplantation technology is to preserve and transfer both the medulla and cortex as parts of the whole ovary.

Prospective solutions to ovarian reserve damage during the ovarian tissue cryopreservation and transplantation procedure

Birth rates continue to decline as more women experience fertility issues. Assisted reproductive technologies are available for patients seeking fertility treatment, including cryopreservation techniques. Cryopreservation can be performed on gametes, embryos, or gonadal tissue and can be used for patients who desire to delay in vitro fertilization treatment. This review focuses on ovarian tissue cryopreservation, the freezing of ovarian cortex containing immature follicles. Ovarian tissue cryopreservation is the only available treatment for the restoration of ovarian function in patients who undergo gonadotoxic treatments, and its wide adoption has led to its recent designation as "no longer experimental" by the American Society for Reproductive Medicine. and subsequent transplantation can restore native endocrine function and can support the possibility of pregnancy and live birth for the patient. Importantly, there are multiple steps in the procedure that put the ovarian reserve at risk of damage. The graft is highly susceptible to ischemic reperfusion injury and mass primordial follicle growth activation, resulting in a "burnout", phenomenon. In this review, we summarize current efforts to combat the loss of primordial follicles in grafts through improvements in freeze and thaw protocols, transplantation techniques, and pharmacologic adjuvant treatments. We conducted a review of the literature, with emphasis on emergent research in the last 5 years. Regarding freeze and thaw protocols, we discuss the widely accepted slow freezing approach and newer vitrification protocols. Discussion of improved transplantation techniques includes consideration of the transplantation location of the ovarian tissue and the importance of graft sites in promoting neovascularization. Finally, we discuss pharmacologic treatments being studied to improve tissue performance postgraft. Of note, there is significant research into the efficacy of adjuvants used to reduce ischemic injury, improve neovascularization, and inhibit hyperactivation of primordial follicle growth activations. Although the "experimental" label has been removed from ovarian tissue cryopreservation and subsequent transplantation, there is a significant need for further research to better understand sources of ovarian reserve damage to improve outcomes. Future research directions are provided as we consider how to reach the most hopeful results for women globally.

Assessment of apoptosis and oxidative stress in cryopreserved ovary after grafting in fibrin-alginate scaffold with endothelial cells and melatonin in wistar rats

OBJECTIVE

Infertility is a significant public health concern affecting 10-15 % of couples. Young women undergoing gonadotoxic treatment are at higher risk of ovarian dysfunction and infertility. To mitigate this risk, ovarian tissue freezing and transplantation have been developed as a novel strategy. However, challenges such as follicular loss and dysfunction during the freezing process, and ovarian damage during transplantation, persist. This study aimed to investigate the potential of using appropriate antifreeze, antioxidant, wound healing, and biological hydrogels to reduce these injuries. Specifically, the effect of fibrin scaffold with endothelial cells and melatonin on apoptotic gene expression and antioxidants in cryopreserved ovaries after transplantation was examined.

METHODS

A total of 36 adult female wistar rats) 6-8-week-old and weighing from 200 to 220 g) were divided equally into six groups (n = 6): 1) control group (C), 2) transplanted ovarian tissue after vitrification and thawing process (Group 1), 3) transplanted vitrified/thawed ovarian tissue while encapsulated in Fib/Alg hydrogel (Group 2), 4) transplanted vitrified/thawed ovarian tissue while encapsulated in Fib/Alg hydrogel in addition with melatonin (Group 3), 5) transplanted vitrified/thawed ovarian tissue while encapsulated in Fib/Alg hydrogel in addition with endothelial cells (Group 4) and 6) transplanted vitrified/thawed ovarian tissue while encapsulated in Fib/Alg hydrogel in addition with melatonin endothelial cells (Group 5). The ovaries were auto-transplanted in the rats' lumbar region. After 14 days, the ovaries were removed. Antioxidant levels (SOD, GPx, MDA, and TAC) were evaluated using ELISA, and apoptotic gene expressions (Bax/Bcl2 and caspase 3) were analyzed by real-time RT-PCR to determine apoptosis.

RESULTS

In the transplanted frozen ovary group, Bax/Bcl2 and caspase 3 gene expression increased significantly (P < 0.05), while antioxidant levels (SOD, GPx, MDA, and TAC) decreased. The encapsulated frozen ovary group showed decreased gene expression and increased antioxidant levels. The ovary group encapsulated with fibrin scaffold, endothelial cells, and melatonin had the most significant decrease in gene expression and increase in antioxidant levels (P < 0.05).

CONCLUSION

Coordinated action of Fibrin-based scaffold with endothelial cells and melatonin could decrease apoptosis gene expression and increase antioxidant levels in cryopreserved ovaries after transplantation, providing valuable insights into preserving fertility in young women undergoing gonadotoxic treatment.

A Cross-Sectional Survey of Healthcare Professionals' Knowledge, Attitude and Current Behaviours towards Female Fertility Preservation Services within the UK

(1) Background: This study aims to establish the knowledge, attitudes and current behaviours towards female fertility preservation (FP) services amongst healthcare professionals (HCPs) in the UK. (2) Methods: An online survey was advertised publicly on the social media platform Instagram between 25 February 2021 and 11 March 2021. (3) Results: In total, 415 participants fulfilled the inclusion criteria and completed the survey. The majority of HCPs discussed FP techniques either never 39.5% (n = 164), once a year 20.7% (n = 86) or once a month 17.8% (n = 74). The majority rated their knowledge of each type of FP method as 'very poor' or 'poor' and strongly disagreed 14.2% (n = 59) or disagreed 42.2% (n = 175) with the statement they 'felt confident to counsel a patient on FP'. The majority either agreed 37.8% (n = 157) or strongly agreed 22.2% (n = 92) that it was their responsibility to discuss FP and 38.1% (n = 158) agreed or strongly agreed 19.5% (n = 81) they considered the desire for future fertility when planning treatment. The majority 87.2% (n = 362) had not experienced formal training on FP. (4) Conclusions: Discrepancies in knowledge remain regarding techniques of FP, referral pathways, awareness of facilities offering services and existing educational resources. Many HCPs recognise the importance of FP and their responsibility to initiate discussions. The knowledge that FP may not delay the treatment of cancer has also improved; however, training in FP is scarce.

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

Hemoglobin diseases like sickle cell disease (SCD) and β-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.

Survival and hormone production of isolated mouse follicles in three-dimensional artificial scaffolds after stimulation with bpV(HOpic)

PURPOSE

To preserve fertility before gonadotoxic therapy, ovarian tissue can be removed, cryopreserved, and transplanted back again after treatment. An alternative is the artificial ovary, in which the ovarian follicles are extracted from the tissue, which reduces the risk of reimplantation of potentially remaining malignant cells. The PTEN inhibitor bpV(HOpic) has been shown to activate human, bovine and alpacas ovarian follicles, and it is therefore considered a promising substance for developing the artificial ovary. The purpose of this study was to examine the impact of different scaffolds and the vanadate derivative bpV(HOpic) on mice follicle survival and hormone secretion over 10 days.

METHODS

A comparative analysis was performed, studying the survival rates (SR) of isolated mice follicle in four different groups that differed either in the scaffold (polycaprolactone scaffold versus polyethylene terephthalate membrane) or in the medium-bpV(HOpic) versus control medium. The observation period of the follicles was 10 days. On days 2, 6, and 10, the viability and morphology of the follicles were checked using fluorescence or confocal microscopy. Furthermore, hormone levels of estrogen (pmol/L) and progesterone (nmol/L) were determined.

RESULTS

When comparing the SR of follicles among the four groups, it was observed that on day 6, the study groups utilizing the polycaprolactone scaffold with bpV(HOpic) in the medium (SR: 0.48 ± 0.18; p = 0.004) or functionalized in the scaffold (SR: 0.50 ± 0.20; p = 0.003) exhibited significantly higher survival rates compared to the group using only the polyethylene terephthalate membrane (SR: 0). On day 10, a significantly higher survival rate was only noted when comparing the polycaprolactone scaffold with bpV(HOpic) in the medium to the polyethylene terephthalate membrane group (SR: 0.38 ± 0.20 versus 0; p = 0.007). Higher levels of progesterone were only significantly associated with better survival rates in the group with the polycaprolactone scaffold functionalized with bpV(HOpic) (p = 0.017).

CONCLUSION

This study demonstrates that three-dimensional polycaprolactone scaffolds improve the survival rates of isolated mice follicles in comparison with a conventional polyethylene terephthalate membrane. The survival rates slightly improve with added bpV(HOpic). Furthermore, higher rates of progesterone were also partly associated with improved survival.

In Vitro Maturation, In Vitro Oogenesis, and Ovarian Longevity

This paper will review a remarkable new approach to in vitro maturation "IVM" of oocytes from ovarian tissue, based on our results with in vitro oogenesis from somatic cells. As an aside benefit we also have derived a better understanding of ovarian longevity from ovary transplant. We have found that primordial follicle recruitment is triggered by tissue pressure gradients. Increased pressure holds the follicle in meiotic arrest and prevents recruitment. Therefore recruitment occurs first in the least dense inner tissue of the cortico-medullary junction. Many oocytes can be obtained from human ovarian tissue and mature to metaphase 2 in vitro with no need for ovarian stimulation. Ovarian stimulation may only be necessary for removing the oocyte from the ovary, but this can also be accomplished by simple dissection at the time of ovary tissue cryopreservation. By using surgical dissection of the removed ovary, rather than a needle stick, we can obtain many oocytes from very small follicles not visible with ultrasound. A clearer understanding of ovarian function has come from in vitro oogenesis experiments, and that explains why IVM has now become so simple and robust. Tissue pressure (and just a few "core genes" in the mouse) direct primordial follicle recruitment and development to mature oocyte, and therefore also control ovarian longevity. There are three distinct phases to oocyte development both in vitro and in vivo: in vitro differentiation "IVD" which is not gonadotropin sensitive (the longest phase), in vitro gonadotropin sensitivity "IVG" which is the phase of gonadotropin stimulation to prepare for meiotic competence, and IVM to metaphase II. On any given day 35% of GVs in ovarian tissue have already undergone "IVD" and "IVG" in vivo, and therefore are ready for IVM.

Fertility preservation in adult male patients with cancer: a systematic review and meta-analysis

STUDY QUESTION

Does sperm cryopreservation serve as a feasible and effective method for preserving fertility in adult male patients with cancer?

SUMMARY ANSWER

Sperm cryopreservation is an effective fertility preservation method and may benefit patients with cancer.

WHAT IS KNOWN ALREADY

Sperm cryopreservation is the only way to efficiently preserve male fertility. It is an important procedure in ART. Recently, due to remarkable advances in cancer treatment, an increasing number of studies have reported the outcomes of sperm cryopreservation in patients with cancer.

STUDY DESIGN SIZE DURATION

We conducted an extensive literature search for relevant studies published through to 31 December 2021, in the following databases: CENTRAL, CNKI, Cochrane Systematic Reviews, EMBASE, MEDLINE, PUBMED, and Web of Science. The search terms used were '(cryopreservation OR freeze OR freezing OR banking OR cryostorage OR storage) AND (sperm OR semen OR spermatozoon) AND (cancer OR tumor OR malignancy OR neoplasm)'.

PARTICIPANTS/MATERIALS SETTING METHODS

We included all studies that reported offering or attempting to cryopreserve sperm before or during cancer treatment in male patients considered at risk of treatment-related fertility impairment. We evaluated the eligibility of all data in each study. The major exclusion criteria were as follows: non-cancer patients; pediatric and adolescent cancer patients; not reporting the use of cryopreserved sperm; use of fresh semen for ART; not reporting the number of patients with cancer offered sperm cryopreservation or attempting to do so before or during treatment; using an experimental fertility preservation technique such as preservation of testicular tissue or spermatogonial stem cells; duplicate data; abstracts, case report, comments, reviews, or editorials; insufficient data reported. The quality of the included studies was assessed using the Newcastle-Ottawa scale and the Methodological Index for Non-Randomized Studies.

MAIN RESULTS AND THE ROLE OF CHANCE

This meta-analysis included 69 non-randomized studies, with 32 234 patients referred for sperm analysis and 23 178 patients cryopreserving at least one sperm sample. The pooled failed-to-cryopreserve rate was 10% (95% CI, 8-12%), and the sperm disposal and sperm use rates were 23% (95% CI, 16-30%) and 9% (95% CI, 8-10%), respectively. The pregnancy, miscarriage, and delivery rates were 28% (95% CI, 22-33%), 13% (95% CI, 10-17%), and 20% (95% CI, 15-25%), respectively. Subgroup analysis showed higher pregnancy and delivery rates, as well as a lower failed-to-cryopreserve rate, in recent studies compared to those released a decade ago. The studies from Asia reported higher sperm disposal and pregnancy rates than in other continents. Our analysis showed clinical pregnancy rates per cycle of 34% (27-41%), 24% (14-35%), and 9% (5-15%) and delivery rates per cycle of 23% (17-30%), 18% (11-26%), and 5% (1-9%) for ICSI, IVF, and IUI, respectively.

LIMITATIONS REASONS FOR CAUTION

As with all meta-analyses, some limitations should be considered. The first limitation of our study is that the data span 36 years. During this time, the World Health Organization has revised its sperm analysis standards, and other important changes have been made. There is also a limitation in that the outcome does not analyze the correlation between the type of cancer and sperm quality. Many of the earlier studies were limited by small sample sizes and a lack of control groups. Furthermore, almost all studies did not consider the severity of the disease, which could potentially have a substantial impact on the results. Consequently, further research should evaluate the effect of the type of cancer and, in particular, the severity of the condition on sperm quality in order to draw more precise conclusions. Similarly, it is inappropriate that most studies failed to differentiate between patients with different types of tumors and instead drew generalized conclusions that are presumed to apply to all patients with cancer. In the present analysis, we did not have in-depth information on patients' disease, and although extensive efforts were made to conduct a thorough systematic review and meta-analysis of the outcomes for patients with various types of tumors, the results must be acknowledged as being subject to bias. However, the use of average results obtained in each study, without the patient-level data, might also represent a source of bias.

WIDER IMPLICATIONS OF THE FINDINGS

Sperm cryopreservation is an effective fertility preservation method and may benefit patients with cancer. The observed utilization rate of frozen sperm at 9% may underestimate the actual usage, as the short follow-up period is inadequate for obtaining comprehensive data on the use of frozen sperm in young cancer survivors. ART plays an important role in fertility preservation and the achievement of pregnancy, with this meta-analysis showing that ICSI delivers better clinical outcomes than IVF or IUI in patients with cancer undergoing fertility preservation.

STUDY FUNDING/COMPETING INTERESTS

This work was supported by the National Natural Science Foundation of China (grant no. 82001634, 81960550), and the China Postdoctoral Science Foundation (2019M661521). There are no competing interests to declare.

REGISTRATION NUMBER

CRID 42022314460.

Chinese Expert Consensus on ovarian function and fertility preservation of cervical cancer in pregnancy (2023)

Cervical cancer in pregnancy (CCIP) refers to cervical cancer diagnosed during pregnancy, the most common gynecological malignant tumor. Because of the special physiological changes of CCIP, although preserving ovarian function and fertility is very important, the methods are very limited. There is no guideline or consensus on the preservation methods of ovarian function and fertility in this special period. Therefore, the Committee of Fertility Protection and Preservation of China Association for the Promotion of Health Science and Technology, combined with the Chinese Society of Gynecological Endocrinology affiliated to the International Society of Gynecological Endocrinology, Society Endocrinology Branch of Beijing Institute of Obstetrics & Gynecology, combined with Society on Fertility Preservation affiliated with the Chinese Preventive Medicine Association, organized relevant experts from different disciplines to formulate this consensus, in order to guide ovarian function and fertility preservation of CCIP patients.

Preservation of fertility in female and male prepubertal patients diagnosed with cancer

Over the past two decades, the importance of fertility preservation has grown not only in the realm of medical and clinical patient care, but also in the field of basic and applied research in human reproduction. With advancements in cancer treatments resulting in higher rates of patient survival, it is crucial to consider the quality of life post-cure. Therefore, fertility preservation must be taken into account prior to antitumor treatments, as it can significantly impact a patient's future fertility. For postpubertal patients, gamete cryopreservation is the most commonly employed preservation strategy. However, for prepubertal patients, the situation is more intricate. Presently, ovarian tissue cryopreservation is the standard practice for prepubertal girls, but further scientific evidence is required in several aspects. Testicular tissue cryopreservation, on the other hand, is still experimental for prepubertal boys. The primary aim of this review is to address the strategies available for possible fertility preservation in prepubertal girls and boys, such as ovarian cryopreservation/transplantation, in vitro follicle culture and meiotic maturation, artificial ovary, transplantation of cryopreserved spermatogonia, and cryopreservation/grafting of immature testicular tissue and testicular organoids.

TurnerFertility trial: fertility preservation in young girls with Turner syndrome by freezing ovarian cortex tissue-a prospective intervention study

OBJECTIVE

To evaluate which girls with Turner syndrome (TS) could benefit from fertility preservation by ovarian tissue cryopreservation on the basis of karyotype, puberty status, and hormonal data.

DESIGN

Prospective intervention study; participants were included between 2018 and 2020.

SETTING

Tertiary hospital in the Netherlands.

PATIENTS

In total, 106 girls with TS aged between 2 and 18 years were included. Girls with minor X chromosome deletions, Y chromosomal content, active infections, or contraindications for surgery were excluded.

INTERVENTION

A laparoscopic unilateral ovariectomy was performed to obtain ovarian cortical tissue for cryopreservation. One tissue fragment per participant was used to determine the number of follicles per ovary by serial sectioning and staining. Chromosome analysis was performed on lymphocytes and buccal cells. A blood sample was taken before the ovariectomy for hormonal analysis.

MAIN OUTCOME MEASURES

The presence of follicles in ovarian cortex tissue from girls with TS in relation to karyotype, puberty status, and hormonal data.

RESULTS

A unilateral ovariectomy was performed on 93 girls with TS. Complications after surgery occurred in 5 girls, including luxation of psychological symptoms in 2 girls. In 13 (14%) girls, a 46,XX cell line was found in buccal cells that was absent in lymphocytes. Follicles were observed in 30 (32%) of the 93 girls and were found mainly in girls with a 46,XX cell line in lymphocytes or buccal cells (Phi coefficient = 0.55). Spontaneous onset of puberty (Phi coefficient = 0.59), antimüllerian hormone (AMH; point-biserial correlation [r] = 0.82), inhibin B (r = 0.67), and follicle-stimulating hormone (r = -0.46) levels were also correlated strongly with the presence of follicles. Furthermore, AMH levels had a significant correlation with the number of follicles per ovary (r = 0.66).

CONCLUSION

Favorable predictive markers for the presence of follicles included either a 46,XX cell line, spontaneous onset of puberty, or a combination of measurable AMH and normal follicle-stimulating hormone levels. Karyotyping of two peripheral cell lines in girls with TS is recommended to reveal hidden mosaicisms. Ovarian tissue cryopreservation should be offered with caution in a research setting to those with a sufficient ovarian reserve, considering the significant loss of follicles after ovarian tissue cryopreservation and autotransplantation. Physicians should pay attention to the mental health of the girls during the whole process.

CLINICAL TRIAL REGISTRATION NUMBER

Trial registration number: NCT03381300- Preservation of Ovarian Cortex Tissue in Girls With Turner Syndrome - Full Text View - ClinicalTrials.gov. Registered on: December 21, 2017. First patient recruited on January 1, 2018.

Innovative Strategies for Fertility Preservation in Female Cancer Survivors: New Hope from Artificial Ovary Construction and Stem Cell-Derived Neo-Folliculogenesis

Recent advances in anticancer treatment have significantly improved the survival rate of young females; unfortunately, in about one third of cancer survivors the risk of ovarian insufficiency and infertility is still quite relevant. As the possibility of becoming a mother after recovery from a juvenile cancer is an important part of the quality of life, several procedures to preserve fertility have been developed: ovarian surgical transposition, induction of ovarian quiescence by gonadotropin-releasing hormone agonists (GnRH-a) treatment, and oocyte and/or ovarian cortical tissue cryopreservation. Ovarian tissue cryostorage and allografting is a valuable technique that applies even to prepubertal girls; however, some patients cannot benefit from it due to the high risk of reintroducing cancer cells during allograft in cases of ovary-metastasizing neoplasias, such as leukemias or NH lymphomas. Innovative techniques are now under investigation, as in the construction of an artificial ovary made of isolated follicles inserted into an artificial matrix scaffold, and the use of stem cells, including ovarian stem cells (OSCs), to obtain neo-folliculogenesis and the development of fertilizable oocytes from the exhausted ovarian tissue. This review synthesizes and discusses these innovative techniques, which potentially represent interesting strategies in oncofertility programs and a new hope for young female cancer survivors.

Melatonin and endothelial cell-loaded alginate-fibrin hydrogel promoted angiogenesis in rat cryopreserved/thawed ovaries transplanted to the heterotopic sites

BACKGROUND

Ischemic niche can promote follicular atresia following the transplantation of cryopreserved/thawed ovaries to the heterotopic sites. Thus, the promotion of blood supply is an effective strategy to inhibit/reduce the ischemic damage to ovarian follicles. Here, the angiogenic potential of alginate (Alg) + fibrin (Fib) hydrogel enriched with melatonin (Mel) and CD144⁺ endothelial cells (ECs) was assessed on encapsulated cryopreserved/thawed ovaries following transplantation to heterotopic sites in rats.

METHODS

Alg + Fib hydrogel was fabricated by combining 2% (w/v) sodium Alg, 1% (w/v) Fib, and 5 IU thrombin at a ratio of 4: 2: 1, respectively. The mixture was solidified using 1% CaCl₂. Using FTIR, SEM, swelling rate, and biodegradation assay, the physicochemical properties of Alg + Fib hydrogel were evaluated. The EC viability was examined using an MTT assay. Thirty-six adult female rats (aged between 6 and 8 weeks) with a normal estrus cycle were ovariectomized and enrolled in this study. Cryopreserved/thawed ovaries were encapsulated in Alg + Fib hydrogel containing 100 µM Mel + CD144⁺ ECs (2 × 10⁴ cells/ml) and transplanted into the subcutaneous region. Ovaries were removed after 14 days and the expression of Ang-1, and Ang-2 was monitored using real-time PCR assay. The number of vWF⁺ and α-SMA⁺ vessels was assessed using IHC staining. Using Masson's trichrome staining, fibrotic changes were evaluated.

RESULTS

FTIR data indicated successful interaction of Alg with Fib in the presence of ionic cross-linker (1% CaCl₂). Data confirmed higher biodegradation and swelling rates in Alg + Fib hydrogel compared to the Alg group (p < 0.05). Increased viability was achieved in encapsulated CD144⁺ ECs compared to the control group (p < 0.05). IF analysis showed the biodistribution of Dil⁺ ECs within hydrogel two weeks after transplantation. The ratio of Ang-2/Ang-1 was statistically up-regulated in the rats that received Alg + Fib + Mel hydrogel compared to the control-matched groups (p < 0.05). Based on the data, the addition of Mel and CD144⁺ ECs to Alg + Fib hydrogel reduced fibrotic changes. Along with these changes, the number of vWF⁺ and α-SMA⁺ vessels was increased in the presence of Mel and CD144⁺ ECs.

CONCLUSIONS

Co-administration of Alg + Fib with Mel and CD144⁺ ECs induced angiogenesis toward encapsulated cryopreserved/thawed ovarian transplants, resulting in reduced fibrotic changes.

Impacts of vitrification on the transcriptome of human ovarian tissue in patients with gynecological cancer

Objective: This study investigated the effects of a vitrification/warming procedure on the mRNA transcriptome of human ovarian tissues.

Design: Human ovarian tissues were collected and processed through vitrification (T-group) and then subjected to RNA sequencing (RNA-seq) analysis, HE, TdT-mediated dUTP nick-end labeling (TUNEL), and real-time quantitative PCR, and the results were compared to those of the fresh group (CK).

Results: A total of 12 patients, aged 15–36 years old, with a mean anti-Müllerian hormone level of 4.57 ± 3.31 ng/mL were enrolled in this study. According to the HE and TUNEL results, vitrification effectively preserved human ovarian tissue. A total of 452 significantly dysregulated genes (|log2FoldChange| &gt; 1 and p &lt; 0.05) were identified between the CK and T groups. Among these, 329 were upregulated and 123 were downregulated. A total of 372 genes were highly enriched for 43 pathways (p &lt; 0.05), which were mainly related to systemic lupus erythematous, cytokine–cytokine receptor interaction, the TNF signaling pathway, and the MAPK signaling pathway. IL10, AQP7, CCL2, FSTL3, and IRF7 were significantly upregulated (p &lt; 0.01), while IL1RN, FCGBP, VEGFA, ACTA2, and ASPN were significantly downregulated in the T-group (p &lt; 0.05) compared to the CK group, which agreed with the results of the RNA-seq analysis.

Conclusion: These results showed (for the first time to the authors’ knowledge) that vitrification can induce changes in mRNA expression in human ovarian tissues. Further molecular studies on human ovarian tissues are required to determine whether altered gene expression could result in any downstream consequences.

Estradiol-independent restoration of T-cell function in post-reproductive females

Aging leads to a general decline in protective immunity. The most common age-associated effects are in seen T-cell mediated immune function. Adult mice whose immune systems show only moderate changes in T-cell subsets tend to live longer than age-matched siblings that display extensive T-cell subset aging. Importantly, at the time of reproductive decline, the increase in disease risks in women significantly outpace those of men. In female mice, there is a significant decline in central and peripheral naïve T-cell subsets at the time of reproductive failure. Available evidence indicates that this naïve T-cell decline is sensitive to ovarian function and can be reversed in post-reproductive females by transplantation of young ovaries. The restoration of naïve T-cell subsets due to ovarian transplantation was impressive compared with post-reproductive control mice, but represented only a partial recovery of what was lost from 6 months of age. Apparently, the influence of ovarian function on immune function may be an indirect effect, likely moderated by other physiological functions. Estradiol is significantly reduced in post-reproductive females, but was not increased in post-reproductive females that received new ovaries, suggesting an estradiol-independent, but ovarian-dependent influence on immune function. Further evidence for an estradiol-independent influence includes the restoration of immune function through the transplantation of young ovaries depleted of follicles and through the injection of isolated ovarian somatic cells into the senescent ovaries of old mice. While the restoration of naïve T-cell populations represents only a small part of the immune system, the ability to reverse this important functional parameter independent of estradiol may hold promise for the improvement of post-reproductive female immune health. Further studies of the non-reproductive influence of the ovary will be needed to elucidate the mechanisms of the relationship between the ovary and health.

Fertility preservation: improved neovascularization and follicle viability in cryopreserved bovine ovarian cortex transplants by remaining medulla tissue

OBJECTIVE

To investigate the advantages of cryopreserved medulla-containing ovarian cortex grafts with those of commonly used sole cortex grafts for fertility preservation by analyzing tissue quality, neovascularization processes, and the number of vital follicles.

DESIGN

Experimental setting of cryopreserved bovine ovarian cortex tissue grafts with or without medulla tissue.

SETTING

Laboratory animal research at Ulm University, Ulm, Germany.

ANIMALS

Bovine ovaries and fertilized chicken eggs.

INTERVENTION(S)

Experimental setting of bovine ovarian tissue samples grafted on the chicken chorioallantoic membrane (CAM) after cryopreservation and thawing to examine histologic tissue integrity, apoptosis and proliferation immunohistochemically, blood vessel counts and determine the presence of neutral red-stained vital follicles.

MAIN OUTCOME MEASURE(S)

We used hematoxylin and eosin staining to visualize tissue structures, immunohistochemistry with anti-caspase 3 to detect apoptosis, anti-Ki67 to examine proliferation, blood vessel count on the chicken CAM to investigate neovascularization processes, and neutral red staining to evaluate vital follicles.

RESULT(S)

We demonstrated that in all analyzed tissue samples, after cryopreservation, thawing, and grafting on the chicken CAM, there was excellent tissue integrity and quality, as shown by extremely rare apoptosis processes analyzed using immunohistochemical caspase 3 staining (sole cortex, 0.54%; thin medulla-containing cortex, 0.43%; thick medulla-containing cortex, 0.13%; and sole medulla, 2.82%). Moreover, we detected increased neovascularization in the vicinity of medulla and medulla-containing grafts (small blood vessels: cortex 8.7, thin medulla-containing cortex 9.9, thick medulla-containing cortex 9.7, and medulla 9.8; very small blood vessels: cortex 7.0, thin medulla-containing cortex 13.0, thick medulla-containing cortex 12.0, and medulla 15.0), with higher Ki67-detected proliferation (cortex, 17.58%; thin medulla-containing cortex, 20.28%; thick medulla-containing cortex, 20.56%; and medulla, 29.9%). Additionally, we identified an increased number of vital follicles in medulla-containing cortex grafts compared with the number of vital follicles in sole cortex tissue (cortex, 256.1; thin medulla-containing cortex, 338.2; thick medulla-containing cortex, 346.6; and medulla, 8.1).

CONCLUSION(S)

In this experimental setting, bovine medulla-containing cortex tissue had excellent tissue structure and quality after cryopreservation and thawing and increased neovascularization and an augmented vital follicle count after grafting than the commonly used sole cortex tissue. Therefore, we suggest reconsidering the current cryopreservation and grafting processes in humans for fertility preservation by favoring retain medulla tissue at the ovarian cortex.

Why Turner patients with 45, X monosomy should not be excluded from fertility preservation services

In this case report, we highlight the practical dilemma, i.e. to perform ovarian tissue cryopreservation surgery in a 45, X Turner Syndrome patient or not, by reporting on the presence of follicles in a 13-year-old female diagnosed with 45, X monosomy and an unmeasurable anti-müllerian hormone serum level. We compare our results with previous research, highlight the challenges we faced in this case and provide recommendations for daily practice. Hereby, we demonstrate that excluding certain subgroups of Turner Syndrome patients (e.g. monosomy patients, and/or girls with an anti-müllerian hormone level below 2.0 ng/l) may be premature, especially based on the current state of published research data. This practical example of a challenging dilemma in the counselling of Turner Syndrome patients for fertility preservation is of interest for clinicians involved in fertility counselling and Turner Syndrome care.

Management of a Girl With Delayed Puberty and Elevated Gonadotropins

A girl presenting with delayed puberty and elevated gonadotropins may have a range of conditions such as Turner syndrome (TS), primary ovarian insufficiency (POI), and 46,XY disorders of sexual development (DSD). An organized and measured approach to investigation can help reach a timely diagnosis. Management of young people often requires specialist multidisciplinary input to address the endocrine and nonendocrine features of these complex conditions, as well as the psychological challenges posed by their diagnosis. Next-generation sequencing within the research setting has revealed several genetic causes of POI and 46,XY DSD, which may further facilitate an individualized approach to care of these young people in the future. Pubertal induction is required in many and the timing of this may need to be balanced with other issues specific to the condition (eg, allowing time for information-sharing in 46,XY DSD, optimizing growth in TS). Shared decision-making and sign-posting to relevant support groups from the outset can help empower young people and their families to manage these conditions. We describe 3 clinical vignettes of girls presenting with delayed puberty and hypergonadotropic amenorrhea and discuss their clinical management in the context of current literature and guidelines.

Failed ovarian cortex transplant but successful ovulation induction in a cancer survivor with premature ovarian failure: A paradox

Better diagnostic and treatment modalities for malignancies occurring in childhood and young age have increased the overall survival of the affected young girls and boys, but this has come at a cost of developing premature ovarian failure in girls and azoospermia in boys because of the gonadotoxicity of chemotherapy and radiotherapy. Thus, young girls and women of reproductive age who are at risk of ovarian failure due to cancer treatment must be mandatorily offered fertility preservation in any form such as cryopreservation of mature metaphase II oocytes after ovarian stimulation with gonadotropins and oocyte recovery and cryopreservation of embryos if the young female has a partner. However, these modalities may require the postponement of chemotherapy. Thus, in such instances, cryopreservation of ovarian tissue remains the only option. Herein, we report a case of a nulligravid young female patient who had stage IV Hodgkin's lymphoma and had to be taken up for immediate fertility preservation owing to the advanced stage of the disease. Therefore, cryopreservation of ovarian tissue was performed. The uniqueness of the case is that after remission of the disease was achieved with chemotherapy, transplantation of the ovarian tissue was carried out which was not successful, but the desire for motherhood prompted to carry out an ovulation induction in the remnant native ovary with a severely compromised ovarian reserve, and she conceived.

Ovarian Tissue Cryopreservation in Children and Adolescents

Cancer during childhood and adolescence remains a major public health issue, affecting a significant portion of this age group. Although newer anti-cancer treatments have improved survival rates, this comes at a cost in terms of gonadotoxic effects. As a result, the preservation of fertility is important. Ovarian tissue cryopreservation, one of the newest methods, has some advantages, especially for prepubertal patients: no need for ovarian stimulation, thus, no further risk for estrogen-sensitive cancer types, and preservation of more and better-quality primordial follicles of the ovarian cortex. The most frequent indications include treatment with alkylating agents, ovarian-focused radiotherapy, leukemias, lymphomas, brain and neurological tumors, as well as Turner syndrome and benign hemoglobinopathies. An expected survival exceeding 5 years, the absence of systematic disease and an overall risk of premature ovarian insufficiency over 50% are among the criteria that need to be fulfilled in order for a patient to undertake this method. Orthotopic transplantation is more frequently used, since it can allow both live birth and the recovery of endocrine function. Reimplantation of malignant cells is always a major risk and should always be taken into consideration. Histological analysis, as well as immunohistochemical and molecular methods, are needed in order to improve the search for malignant cells before transplantation. Ovarian tissue cryopreservation appears to be a method with specific benefits, indications and risks which can be an important tool in terms of preserving fertility in younger women.

Medical Grade Honey as a Promising Treatment to Improve Ovarian Tissue Transplantation

Ovarian tissue cryopreservation is a female fertility preservation technique that presents major challenges for the maintenance of follicular viability after transplantation. The aim of this study was to evaluate and compare the application of L-Mesitran Soft®, a product containing 40% medical grade honey (MGH), with other strategies to improve ovarian grafts' viability. For this purpose, bovine ovarian tissue was vitrified, warmed and randomly assigned to culture groups: (1) control, (2) MGH 0.2% in vitro, (3) MGH in vivo (direct application in the xenotransplantation), (4) vascular endothelial growth factor (VEGF 50 ng/mL) and (5) vitamin D (100 Nm), during a 48 h period. A sixth group (6) of fragments was thawed on transplantation day and was not cultured. The tissue was xenotransplanted into immunodeficient (Rowett nude homozygous) ovariectomized rats. Grafts were analyzed 48 h after culture, and 7 and 28 days after transplantation. The tissue was subjected to histological and immunohistochemical analysis. Treatments using MGH showed the highest angiogenic and cell proliferation stimulation, with cellular apoptosis, within a healthy cellular turnover pathway. In conclusion, MGH should be considered as a potentially effective and less expensive strategy to improve ovarian tissue transplantation.

Fertility preservation for patients with cancer

Background: The survival rate of cancer patients is increasing owing to the early diagnosis and treatment methods. Radiotherapy and chemotherapy may cause serious complications, such as ovarian failure and infertility. In particular, preservation of fertility in women of reproductive age with cancer could improve their quality of life as well as reduce social and psychological pain.Current Concepts: Embryo or oocyte cryopreservation is a method of fertility preservation; however, it cannot be utilized by all women with cancer because of the complications of the condition and treatment method. Ovarian tissue cryopreservation and transplantation enables fertility preservation in those needing immediate cancer treatment, such as chemotherapy or radiotherapy, or those unqualified for ovarian stimulation. A recent review reported that frozen-thawed ovarian transplantation led to approximately 130 live births with a conception rate of approximately 30%. Endocrine function recovery occurred in 92.9% of the patients between 3.5 and 6.5 months after transplantation.Discussion and Conclusion: In this study, we introduced various methods and strategies for improving the outcomes of ovarian tissue cryopreservation and transplantation. These results could serve as a reference for patients and clinicians to choose the best options for fertility preservation based on the patient’s current situation and condition.

Ovarian Stem Cells (OSCs) from the Cryopreserved Ovarian Cortex: A Potential for Neo-Oogenesis in Women with Cancer-Treatment Related Infertility: A Case Report and a Review of Literature

Cancer treatment related infertility (CTRI) affects more than one third of young women undergoing anti-cancer protocols, inducing a premature exhaustion of the ovarian reserve. In addition to ovarian suppression by GnRHa, oocyte and cortex cryopreservation has gained interest in patients with estrogen-sensitive tumors for whom the hormonal burst to prompt the multiple follicular growth could provide a further pro-life tumor pulsing. On the other hand, cortex reimplantation implies a few drawbacks due to the unknown consistency of the follicles to be reimplanted or the risk of reintroducing malignant cells. The capability of ovarian stem cells (OCSs) from fresh ovarian cortex fragments to differentiate in vitro to mature oocytes provides a tool to overcome these drawbacks. In fact, since ovarian cortex sampling and cryopreservation is practicable before gonadotoxic treatments, the recruitment of OSCs from defrosted fragments could provide a novel opportunity to verify their suitability to be expanded in vitro as oocyte like cells (OLCs). Here, we describe in very preliminary experiments the consistency of an OSC population from a single cryopreserved ovarian cortex after thawing as well as both their viability and their suitability to be further explored in their property to differentiate in OLCs, thus reinforcing interest in stemness studies in the treatment of female CTRI.

Shortening the duration between ovarian removal and cryopreservation helps preserve fertility and maintain ovarian reserve after transplantation in mice

OBJECTIVE

To evaluate the effect of storage of ovaries before cryopreservation on long-term fertility and ovarian reserve after transplantation in mice.

DESIGN

Experimental study.

SETTING

University hospital.

ANIMAL(S)

C57BL/6J and C57BL/6J-Tg (CAG-GFP) female mice.

INTERVENTION(S)

Storage and cryopreservation of mouse ovaries. Long-term fertility analysis of mice transplanted with thawed ovaries.

MAIN OUTCOME MEASURE(S)

Estrous cycles, number of live births, ovarian weight, and follicular counts of ovarian grafts.

RESULT(S)

At the first mating 3 months after ovarian transplantation, the mean number of live births was 2.6 ± 0.6 in the control group (no storage); in the storage groups, the mean number of live births was 2.9 ± 0.7 after 4 hours, 1.3 ± 0.5 after 8 hours, 0.2 ± 0.2 after 12 hours, and 0.8 ± 0.5 after 24 hours of storage; the difference from the control group was significant in the 12-hour storage group. At the second mating 6 months after ovarian transplantation, the mean number of live births was 1.8 ± 0.6 in the control group and 2.4 ± 0.6 and 0.3 ± 0.2 in the 4- and 8-hour storage groups, respectively; no live births occurred in the 12- and 24-hour storage groups. Seven months after ovarian transplantation, the numbers of primordial, primary, early secondary, and late secondary follicles were significantly lower in the 8-, 12-, and 24-hour storage groups than in the control group.

CONCLUSION(S)

In mice, shortening the storage time of ovaries before cryopreservation preserved fertility and ovarian reserve after transplantation, indicating that human ovaries might be cryopreserved immediately after harvesting or transported as quickly as possible to a cryopreservation facility to allow young patients with cancer to preserve long-term fertility and ovarian reserve.

The role of Hippo pathway signaling and A-kinase anchoring protein 13 in primordial follicle activation and inhibition

OBJECTIVE

To determine whether the mechanotransduction and pharmacomanipulation of A-kinase anchoring protein 13 (AKAP13) altered Hippo signaling pathway transcription and growth factors in granulosa cells. Primary ovarian insufficiency is the depletion or dysfunction of primordial ovarian follicles. In vitro activation of ovarian tissue in patients with primary ovarian insufficiency alters the Hippo and phosphatase and tensin homolog/phosphatidylinositol 3-kinase/protein kinase B/forkhead box O3 pathways. A-kinase anchoring protein 13 is found in granulosa cells and may regulate the Hippo pathway via F-actin polymerization resulting in altered nuclear yes-associated protein (YAP)/transcriptional coactivator with PDZ-binding motif coactivators and Tea domain family (TEAD) transcription factors.

DESIGN

Laboratory studies.

SETTING

Translational science laboratory.

PATIENT(S)

None.

INTERVENTION(S)

COV434 cells, derived from a primary human granulosa tumor cell line, were studied under different cell density and well stiffness conditions. Cells were transfected with a TEAD-luciferase (TEAD-luc) reporter as well as expression constructs for AKAP13 or AKAP13 mutants and then treated with AKAP13 activators, inhibitors, and follicle-stimulating hormone.

MAIN OUTCOME MEASURE(S)

TEAD gene activation or inhibition was measured by TEAD-luciferase assays. The messenger ribonucleic acid levels of Hippo pathway signaling molecules, including connective tissue growth factor (CTGF), baculoviral inhibitors of apoptosis repeat-containing 5, Ankyrin repeat domain-containing protein 1, YAP1, and TEAD1, were measured by quantitative real-time polymerase chain reaction. Protein expressions for AKAP13, CTGF, YAP1, and TEAD1 were measured using Western blot.

RESULT(S)

Increased TEAD-luciferase activity and expression of markers for cellular growth were associated with decreased cell density, increased well stiffness, and AKAP13 activator (A02) treatment. Additionally, decreased TEAD-luc activity and expression of markers for cellular growth were associated with AKAP13 inhibitor (A13) treatment, including a reduced expression of the BIRC5 and ANKRD1 (YAP-responsive genes) transcript levels and CTGF protein levels. There were no changes in TEAD-luc with follicle-stimulating hormone treatment, supporting Hippo pathway involvement in the gonadotropin-independent portion of folliculogenesis.

CONCLUSION(S)

These findings suggest that AKAP13 mediates Hippo-regulated changes in granulosa cell growth via mechanotransduction and pharmacomanipulation. The AKAP13 regulation of the Hippo pathway may represent a potential target for regulation of follicle activation.

Fertility Preservation in Female Patients with Cancer

Advances in cancer treatment with resultant dramatic improvements in long-term survival have led to increasing awareness of the wide range of medical and social issues faced by survivors of malignancy. The potential deleterious effects on fertility are a significant worry of women and trans gender men, and the rising trend in delaying childbearing and the higher proportion of patients who have not completed their family at the time of diagnosis increases the demand for an optimised fertility-preservation service. Fertility preservation for this group following a diagnosis of cancer is a rapidly expanding area of reproductive medicine, although provision for such treatment often varies by region. In the past, there were few treatment options, but with dramatic improvements in oocyte cryopreservation and, more recently, ovarian tissue cryopreservation, this area of fertility care has broadened substantially. This review will be exploring areas that apply to all cisgender women, but not necessarily all trans men and non-binary individuals. There are specific considerations in fertility preservation for trans people, which are beyond the scope of this paper. All individuals with female reproductive organs should be offered the opportunity to discuss fertility preservation prior to starting potential gonadotoxic treatment. Failure to do this may negatively influence their anticancer treatment choices and adherence to treatment regimens. There are currently few networks streamlined around offering this service and as demand for these treatment options increases, it is recognised that these complex patients require specialist management within recognised care pathways. Here we are looking to describe some of the unique challenges associated with providing a state-of-the-art service, particularly in a financially unpredictable climate in the midst of the COVID-19 pandemic.

A comparison of fertility preservation outcomes in patients who froze oocytes, embryos, or ovarian tissue for medically indicated circumstances: a systematic review and meta-analysis

OBJECTIVE

To compare obstetric outcomes in patients cryopreserving reproductive cells or tissues before gonadotoxic therapy.

DESIGN

A literature search was conducted following PRISMA guidelines on Embase, Medline, and Web of Science. Studies reporting obstetric outcomes in cancer patients who completed cryopreservation of oocyte, embryo, or ovarian tissue were included.

SETTING

Not applicable.

PATIENT(S)

Cancer patients attempting pregnancy using cryopreserved cells or tissues frozen before cancer therapy.

INTERVENTION(S)

Oocyte, embryo, or ovarian tissue cryopreservation for fertility preservation in cancer.

MAIN OUTCOME MEASURE(S)

The total numbers of clinical pregnancies, live births, and miscarriages in women attempting pregnancy using cryopreserved reproductive cells or tissues were calculated. A meta-analysis determined the effect size of each intervention.

RESULT(S)

The search returned 4,038 unique entries. Thirty-eight eligible studies were analyzed. The clinical pregnancy rates were 34.9%, 49.0%, and 43.8% for oocyte, embryo, and ovarian tissue cryopreservation, respectively. No significant differences were found among groups. The live birth rates were 25.8%, 35.3%, and 32.3% for oocyte, embryo, and ovarian tissue cryopreservation, respectively, with no significant differences among groups. The miscarriage rates were 9.2%, 16.9%, and 7.5% for oocyte, embryo, and ovarian tissue cryopreservation, respectively. Significantly fewer miscarriages occurred with ovarian tissue cryopreservation than with embryo cryopreservation.

CONCLUSION(S)

This enquiry is required to counsel cancer patients wishing to preserve fertility. Although the limitations of this study include heterogeneity, lack of quality studies, and low utilization rates, it serves as a starting point for comparison of reproductive and obstetric outcomes in patients returning for family-planning after gonadotoxic therapy.

In-vitro maturation and transplantation of cryopreserved ovary tissue: understanding ovarian longevity

RESEARCH QUESTION

Is it possible to use experience gained from 24 years of frozen ovarian transplantation, and from recent experience with in-vitro gametogenesis to accomplish simple and robust in-vitro maturation (IVM) of oocytes from human ovarian tissue?

DESIGN

A total of 119 female patients between age 2 and 35 years old underwent ovary cryopreservation (as well as in-vitro maturation of oocytes and IVM in the last 13 individuals) over a 24-year period. Up to 22 years later, 17 returned to have their ovary tissue thawed and transplanted back.

RESULTS

Every woman had a return of ovarian function 5 months after transplant, similar to previous observations. As observed before, anti-Müllerian hormone (AMH) concentration rose as FSH fell 4 months later. The grafts continued to work up to 8 years. Of the 17, 13 (76%) became pregnant with intercourse at least once, resulting in 19 healthy live births, including six live births from three women who had had leukaemia. Of the harvested germinal vesicle oocytes, 35% developed with simple culture media into mature metaphase II oocytes.

CONCLUSIONS

The authors concluded the following. First, ovary tissue cryopreservation is a robust method for preserving fertility even for women with leukaemia, without a need to delay cancer treatment. Second, many mature oocytes can often be obtained from ovary tissue with simple media and no need for ovarian stimulation. Third, ovarian stimulation only be necessary for removing the oocyte from the ovary, which can also be accomplished by simple dissection at the time of ovary freezing. Finally, pressure and just eight 'core genes' control primordial follicle recruitment and development.

A case of two ovarian tissue transplantations that led to a biochemical pregnancy in Japan

Ovarian tissue cryopreservation (OTC) and ovarian tissue transplantation (OTT) are fertility preservation options for prepubertal girls or those in whom cancer treatment cannot be delayed. They are important to increasing number of cancer survivors, but there are very few reports on this topic in Japan. This is the first report of a biochemical pregnancy after OTT in Japan. An 18-year-old woman, diagnosed with Ewing sarcoma of the seventh thoracic vertebra, underwent tumor resection. OTC was performed before postoperative chemotherapy. After 7 years, she decided to undergo OTT following the diagnosis of chemotherapy-induced premature ovarian insufficiency. On postoperative day 104, ovarian stimulation was started, yielding one embryo after 3 days. Embryo transfer was performed during a hormone replacement cycle. At 6 weeks and 1 day, the human chorionic gonadotropin level was 81.5 mIU/mL; however, no gestational sac was observed on ultrasonography, indicating a biochemical pregnancy. Our data will be useful for the further development of fertility preservation options in Japan in the future.

Gene expression profile in experimental frozen-thawed ovarian grafts treated with scaffold-base delivery of adipose tissue-derived stem cells

PURPOSE

Gelfoam scaffold is a feasible and safe non-invasive technique for Adipose tissue-derived Stem Cell (ASC)-delivery in the treatment of frozen-thawed ovarian autografts. This study seeks to analyze the genes expression profile of rat frozen-thawed ovarian autografts treated with scaffold-based delivery of adipose tissue-derived stem cells.

METHODS

Eighteen adult Wistar rats were distributed into three groups: Control (frozen-thawed only); Group 1 (G1) and Group 2 (G2) (frozen-thawed ovaries treated with culture medium or ASC, respectively). Both treatments were performed immediately after autologous retroperitoneal transplant with scaffold-based delivery. The ovarian grafts were retrieved 30 days after transplantation. Quantitative gene expression (qPCR) for apoptosis, angiogenesis, and inflammatory cytokines (84 genes in each pathway) were evaluated by RT-PCR. Graft morphology (HE), apoptosis (cleaved-caspase-3), neoangiogenesis (VEGF), and cellular proliferation (Ki-67) were assessed.

RESULTS

In grafts treated with ASC, the apoptosis pathway showed the highest number of genes over-regulated - 49 genes - compared to inflammation cytokines and angiogenesis pathway - 36 and 23 genes respectively, compared to grafts treated with culture medium. Serpinb5 family was highlighted in the angiogenesis pathway and Cxcl6 in the inflammation cytokines pathway. In the apoptosis pathway, the most over-regulated gene was Capsase14. ASC treatment promoted the reduction of cleaved caspase-3 in the theca internal layer and increased cell proliferation by Ki-67 in the granulosa layer without altering VEGF. A mild inflammatory infiltrate was observed in both groups.

CONCLUSION

ASC therapy in rat frozen-thawed ovarian autografts promoted an abundance of genes involved with apoptosis and inflammatory cytokines without compromising the ovary graft morphology and viability for short time. Further studies are necessary to evaluate the repercussion of apoptosis and inflammation on the graft in the long term.

Ovarian tissue bank for fertility preservation and anti-menopause hormone replacement

Traditional fertility preservation methods such as embryo or oocyte cryopreservation cannot meet the needs of a cancer patient or for personal reasons. The cryopreservation of ovarian tissue can be an alternative and has become a hot spot to preserve fertility or hormone replacement. The freezing of ovarian tissue can be carried out at any time without ovarian hyperstimulation to retrieve follicles. It is an ideal strategy to preserve reproductive function in children, adolescent cancer patients, and patients who are in urgent need of cancer treatment. With the increasing demands of women with premature ovarian failure or in menopause, ovarian tissue transplantation is also an alternative for hormone replacement that can provide physiological doses of hormone levels, which can avoid a series of risks such as thrombosis, breast cancer, or other hormone-dependent tumors, caused by oral hormone replacement. Hence, ovarian tissue banking can be regarded as a mainstream strategy for fertility preservation and anti-menopause hormone replacement in further clinical investigation.

Review of ovarian tissue cryopreservation techniques for fertility preservation

Ovarian failure and ovarian malfunction are among major fertility problems in women of reproductive age (18-35 years). It is known that various diseases, such as ovarian cancer and premature ovarian failure, besides certain treatments, such as radiotherapy and chemotherapy of other organs, can affect the normal process of folliculogenesis and cause infertility. In recent years, various procedures have been proposed for the treatment of infertility. One of the newest methods is the use of cryopreservation ovarian fragments after cancer treatment. According to some studies, this method yields very satisfactory results. Although ovarian tissue cryopreservation (OTC) is an accepted technique of fertility preservation, the relative efficacy of cryopreservation protocols remains controversial. Considering the controversies about these methods and their results, in this study, we aimed to compare different techniques of ovarian cryopreservation and investigate their advantages and disadvantages. Reviewing the published articles may be possible to identify appropriate strategies and improve infertility treatment in these patients.

Female Oncofertility: Current Understandings, Therapeutic Approaches, Controversies, and Future Perspectives

Recent advances in early detection and oncological therapies have ameliorated the survival rate of young cancer patients. Yet, ovarian impairment induced by chemotherapy and radiotherapy is still a challenging issue. This review, based on clinical and lab-based studies, summarizes the evidence of gonadotoxicity of chemoradiotherapy, the recent approaches, ongoing controversies, and future perspectives of fertility preservation (FP) in female patients who have experienced chemo- or radio-therapy. Existing data indicate that chemotherapeutic agents induce DNA alterations and massive follicle activation via the phosphoinositide 3-kinase (PI3K)/Akt signaling pathway. Meanwhile, the radiation causes ionizing damage, leading to germ cell loss. In addition to the well-established methods, numerous therapeutic approaches have been suggested, including minimizing the follicle loss in cryopreserved ovarian grafts after transplantation, in vitro activation or in vitro growing of follicles, artificial ovarian development, or fertoprotective adjuvant to prevent ovarian damage from chemotherapy. Some reports have revealed positive outcomes from these therapies, whereas others have demonstrated conflictions. Future perspectives are improving the live birth rate of FP, especially in patients with adverse ovarian reserve, eliminating the risk of malignancy reintroducing, and increasing society’s awareness of FP importance.

Ovarian tissue cryopreservation in young females with cancer and its impact on ovarian follicle density

BACKGROUND

Cancer therapy in young females results in irreversible damage to their ovaries potentially leading to premature ovarian failure (POF) and infertility. Ovarian follicle density (FD) serves as a key predictor of reproductive potential for a woman. FD is significantly reduced after cryopreservation in adult women with cancer. FD in young females with cancer has not been investigated. The specific aim of this study was to assess the efficacy of ovarian tissue cyropreservation (OTC) in young females with cancer by evaluating its impact on FD.

METHODS

An IRB approved prospective human and animal trial enrolled girls (ages 6-18 years) with cancer at high risk for POF from July 1, 2012 through June 30, 2018. All participants underwent pre-operative ultrasounds evaluating their ovaries.  Following a normal ultrasound, each patient underwent a left ovarian tissue harvest prior to cancer therapy. The ovarian tissue was sectioned for use in pathologic analysis, fertility preservation and xenotransplantation before and after cryopreservation. Comparative statistical analyses of the means of FD before and after cryopreservation were implemented using mixed regression modeling that accounted for the correlation among samples from the same patient and differences in age.

RESULTS

Six girls were enrolled (mean, 12 years; median, 13 years, range, 6-17 years). Pathologic analysis was carried out in all viable grafts and ovarian follicle densities were determined. Mean ovarian follicle density (+/- SEM) before cryopreservation was 50.5 +/- 4.26 follicles/mm² and after cryopreservation was 44.1 +/- 4.25 follicles/mm², p < 0.001. Following cryopreservation, on average the ovarian tissue retained 89.0.% of the FD of paired fresh samples (95% CI 82.8%, 95.2%).

CONCLUSIONS

FD in young females with cancer is significantly reduced following OTC. However, the degree of reduction may be less than that reported in adult women. This is the first study in adolescent girls to provide histologic evidence of preservation of ovarian follicle density and potential efficacy of the ovarian tissue cryopreservation strategy.  By providing this evidence base, the potential benefit to young females with cancer and their family may be prognostically and clinically significant.

Hormonal Characteristics of Women Receiving Ovarian Tissue Transplantation with or without Endogenous Ovarian Activity

Ovarian tissue cryopreservation (OTC) and transplantation of frozen/thawed ovarian tissue (OTT) are used for fertility preservation in girls and women. Here, we evaluated the hormonal characteristics of women with or without postmenopausal levels of FSH at the time of OTT to study differences and conditions that best support the initiation of ovarian function. A total of 74 women undergoing OTT (n = 51 with menopausal levels of FSH; n = 23 with premenopausal levels) were followed by measurements of FSH, LH, AMH, and oestradiol. Concentrations of FSH and LH returned to premenopausal levels after 20 weeks on average, with a concomitant increase in oestradiol. Despite resumption of ovarian activity, AMH concentrations were in most instances below the detection limit in the menopausal group, suggesting a low ovarian reserve. Despite a higher age in the premenopausal group, they more often experienced an AMH increase than the menopausal group, suggesting that conditions in the premenopausal ovary better sustain follicle survival, perhaps due to the higher concentrations of oestradiol. Collectively, this study highlights the need for improving follicle survival after OTT. Age and the amount of tissue transplanted are important factors that influence the ability to regain ovarian activity and levels of FSH may need to be downregulated and oestradiol increased prior to OTT.

Proliferating cell nuclear antigen presentation, as a marker of folliculogenesis, in the transplanted ovarian tissue

AIM

One of the most important ways to understand the ovarian biology is studding the initiation of primordial follicle development and subsequent folliculogenesis control. In this study, proliferating cell nuclear antigen (PCNA) presentation was used as a marker of follicular development in the thawed ovarian tissue (OT) following transplantation onto chick embryo chorioallantoic membrane (CAM) using two methods of freezing of slow freezing and vitrification.

METHODS

Samples of OT from 10 patients were subjected to slow freezing and vitrification. After warming, CAM transplantation was done and PCNA proliferation index (PI; percent of PCNA-positive granulosa cells) was calculated for each follicle stage. Image J software was used to determine the mean staining intensity.

RESULTS

PCNA was positive for granulosa cells and oocytes nuclei, but negative for ooplasm. There were no remarkable PCNA staining in the granulosa cells of primordial follicles, but increased significantly as follicle progression (p < 0.05). Proliferation rate was also insignificantly higher in the vitrified than slow freezing group, before and after transplantation (p < 0.05). Lower PCNA presentation index was observed after CAM transplantation (p < 0.05). The earliest stage of follicular recruitment took place in the transitional follicles, before squamous cells transform to cuboidal cells.

CONCLUSION

PCNA showed that follicles had proliferation power after cryopreservation. Higher presentation after vitrification may indicate accelerated folliculogenesis in the thawed OT.

Genomic Consideration in Chemotherapy-Induced Ovarian Damage and Fertility Preservation

Chemotherapy-induced ovarian damage and fertility preservation in young patients with cancer are emerging disciplines. The mechanism of treatment-related gonadal damage provides important information for targeting prevention methods. The genomic aspects of ovarian damage after chemotherapy are not fully understood. Several studies have demonstrated that gene alterations related to follicular apoptosis or accelerated follicle activation are related to ovarian insufficiency and susceptibility to ovarian damage following chemotherapy. This may accelerate follicular apoptosis and follicle reservoir utilization and damage the ovarian stroma via multiple molecular reactions after chemotherapy. This review highlights the importance of genomic considerations in chemotherapy-induced ovarian damage and multidisciplinary oncofertility strategies for providing high-quality care to young female cancer patients.

Applying plastic surgery principles to ovarian tissue transplantation

Ovarian tissue cryopreservation (OTC) and transplantation is an innovative procedure increasingly utilized to help preserve fertility after gonadotoxic treatments especially in cancer patients. Approximately 30% of autotransplanted patients are able to achieve live birth, typically with the help of in-vitro fertilization. Numerous techniques and grafting sites have been described to continue to increase this figure. In the field of plastic surgery, tissue grafting has been successful performed for thousands of years and knowledge in this area has been significantly refined. A qualitative review of the literature using PubMed, Cochrane, SCOPUS and Medline databases was performed to look for articles relating to ovarian tissue transplantation (OTT) and comparisons made to plastic surgery tissue grafting. Many parallels were found between the principles of grafting in plastic surgery and the principles of OTT, including pre-operative patient optimization, suitable donor site selection, tissue harvest and preparation, graft site choice, immobilization of the graft and post-operative care. Consideration of the benefits and risks of using orthotopic versus heterotopic recipient sites is also highly important with regards to graft take, morbidity and ease of access of oocyte collection. We believe that ongoing discussion between disciplines can have the potential to improve knowledge, surgical techniques and patient outcomes.

Ovarian Decellularized Bioscaffolds Provide an Optimal Microenvironment for Cell Growth and Differentiation In Vitro

Ovarian failure is the most common cause of infertility. Although numerous strategies have been proposed, a definitive solution for recovering ovarian functions and restoring fertility is currently unavailable. One innovative alternative may be represented by the development of an “artificial ovary” that could be transplanted in patients for re-establishing reproductive activities. Here, we describe a novel approach for successful repopulation of decellularized ovarian bioscaffolds in vitro. Porcine whole ovaries were subjected to a decellularization protocol that removed the cell compartment, while maintaining the macrostructure and microstructure of the original tissue. The obtained bioscaffolds were then repopulated with porcine ovarian cells or with epigenetically erased porcine and human dermal fibroblasts. The results obtained demonstrated that the decellularized extracellular matrix (ECM)-based scaffold may constitute a suitable niche for ex vivo culture of ovarian cells. Furthermore, it was able to properly drive epigenetically erased cell differentiation, fate, and viability. Overall, the method described represents a powerful tool for the in vitro creation of a bioengineered ovary that may constitute a promising solution for hormone and fertility restoration. In addition, it allows for the creation of a suitable 3D platform with useful applications both in toxicological and transplantation studies.

Cryoprotectant agents for ovarian tissue vitrification: Systematic review

Studies on the cryopreservation of ovarian tissue usually compare slow freezing versus vitrification and aim to optimize protocols, evaluate combinations or concentrations of cryoprotectant agents (CPAs), exposure time, and the addition of synthetic polymers. This systematic review aimed to identify the different CPAs used for the vitrification of human or primate ovarian tissue and to compare their results in terms of follicular survival and functional preservation. We searched Pubmed and EMBASE for randomized clinical trials or cohort studies comparing CPAs for human and/or primate ovarian vitrification. The highest rate of morphologically normal follicles after cryopreservation was 98% and was obtained with a combination of 27% ethylene glycol (EG) plus 27% glycerol, in addition to non-permeable synthetic polymers. The use of dimethyl sulfoxide (DMSO) in relatively low concentrations combined with EG and other CPAs yielded more than 90% of intact follicles after vitrification. The methods and outcomes varied largely among studies, making it difficult to combine their results. While there is no definite answer to what is the best combination of CPAs for vitrification of human ovarian tissue, the data reviewed here suggest that current vitrification techniques are able to preserve the integrity of most follicles.

Fresh and cryopreserved ovarian tissue from deceased young donors yields viable follicles

OBJECTIVE

Ovarian tissue cryopreservation is one of the crucial options for fertility preservation. Transplantation of cryopreserved ovarian tissue was proven to restore ovarian endocrine function in patients with premature ovarian insufficiency. Ovaries from deceased donors potentially serve as an excellent and readily available tissue for the translational and basic research. In this study, we used ovaries obtained from 5 deceased donors aged 18-26 years, to evaluate the number and quality of ovarian follicles isolated before and after cryopreservation.

DESIGN

Preclinical.

SETTING

Academic biomedical research laboratory.

PATIENTS

De-identified deceased human donors.

INTERVENTIONS

Slow-freeze cryopreservation and thawing.

MAIN OUTCOME MEASURES

Follicle count, follicle density, follicle viability using immunohistochemical staining (TUNEL).

RESULTS

The follicle density negatively correlated with age in both cryopreserved/thawed and fresh group. A total of 2803 follicles from fresh and 1608 follicles from cryopreserved tissues were classified and analyzed using Hematoxylin and eosin staining. There was no significant difference in the percent of morphologically normal follicles between two groups. TUNEL assay indicated no higher DNA damage in the follicles and the stroma cells after cryopreservation. Morphologically normal preantral follicles were enzymatically isolated from both fresh and cryopreserved tissue with 88.51 ± 5.93% (mean ± SD) of the isolated follicles confirmed viable using LIVE/DEAD evaluation.

CONCLUSIONS

Our results indicate the ovarian tissue from deceased donors maintain high quality after long time extracorporeal circulation and transportation from the hospital to the laboratory. High survival rate of follicles at different developmental stages suggested tolerance to the cryopreservation process. Human ovarian tissues obtained from deceased donors is an ample source tissue and can be applied to promoting research and future clinical applications.

Molecular Mechanism and Prevention Strategy of Chemotherapy- and Radiotherapy-Induced Ovarian Damage

Fertility preservation is an emerging discipline, which is of substantial clinical value in the care of young patients with cancer. Chemotherapy and radiation may induce ovarian damage in prepubertal girls and young women. Although many studies have explored the mechanisms implicated in ovarian toxicity during cancer treatment, its molecular pathophysiology is not fully understood. Chemotherapy may accelerate follicular apoptosis and follicle reservoir utilization and damage the ovarian stroma via multiple molecular reactions. Oxidative stress and the radiosensitivity of oocytes are the main causes of gonadal damage after radiation treatment. Fertility preservation options can be differentiated by patient age, desire for conception, treatment regimen, socioeconomic status, and treatment duration. This review will help highlight the importance of multidisciplinary oncofertility strategies for providing high-quality care to young female cancer patients.

Ovarian tissue grafting: Lessons learnt from our experience with 55 grafts

Purpose

Uncertainties remain regarding the clinical efficacy of ovarian tissue cryopreservation and grafting. We report a retrospective analysis of reproductive outcomes and lessons learnt following 55 ovarian tissue transplant procedures at our center from 2006 to 2019.

Methods

We analyzed variables related to graft success such as tissue volume, follicular density, total follicular volume, and age on the duration of graft function.

Results

Follicular density and total follicular volume correlate positively with duration of graft function. All clinical pregnancies in our cohort occurred in women who were aged 35 or less at the time of ovarian tissue cryopreservation.

Conclusion

Graft success, as determined by eventual pregnancy and the longevity of graft function, may be impacted by factors including age at cryopreservation, follicular density, and total follicular volume.

Therapeutic Angiogenesis for Ovarian Transplantation through Ultrasound-Targeted Microbubble Destruction

Timely angiogenesis and effective microcirculation perfusion are essential for the survival and functional recovery of transplanted ovaries. Ultrasound-targeted microbubble destruction (UTMD) can lead to angiogenesis and increase flow perfusion by causing transient inflammation. The purpose of this study was to evaluate the effects of UTMD on transplanted ovarian revascularization and survival. In vitro, for the criteria of cell viability and tube formation capability, the optimal exposure parameters were determined to be a microbubble concentration of 1 × 10⁸/mL, mechanical index of 1 and exposure time of 30 s. After ovarian transplantation, 40 female Sprague Dawley rats were divided into four groups: transplantation alone, ultrasound alone, microbubbles alone and ultrasound and microbubbles (UTMD). At 7 d after transplantation, ovarian perfusion was assessed using qualitative and quantitative methods. The effect of angiogenesis was assessed by contrast-enhanced ultrasound, laser Doppler perfusion imaging and histologic analysis. The results, in which ovarian perfusion was highest in the UTMD group, suggest that UTMD can effectively improve ovarian perfusion. Compared with the other three groups, the number of follicles, microvascular density and rate of Ki-67-positive cells increased significantly in the UTMD group, while apoptosis decreased significantly (p < 0.05). The study indicates that UTMD promoted ovarian re-vascularization after ovarian transplantation and maintained follicular reserve.

Recent advances: fertility preservation and fertility restoration options for males and females

Fertility preservation is the process of saving gametes, embryos, gonadal tissues and/or gonadal cells for individuals who are at risk of infertility due to disease, medical treatments, age, genetics, or other circumstances. Adult patients have the options to preserve eggs, sperm, or embryos that can be used in the future to produce biologically related offspring with assisted reproductive technologies. These options are not available to all adults or to children who are not yet producing mature eggs or sperm. Gonadal cells/tissues have been frozen for several thousands of those patients worldwide with anticipation that new reproductive technologies will be available in the future. Therefore, the fertility preservation medical and research communities are obligated to responsibly develop next-generation reproductive technologies and translate them into clinical practice. We briefly describe standard options to preserve and restore fertility, but the emphasis of this review is on experimental options, including an assessment of readiness for translation to the human fertility clinic.

Potential roles of experimental reproductive technologies in infertile women with diminished ovarian reserve

In assisted reproductive technology treatment, diminished ovarian reserve (DOR) is a condition of utmost clinical and scientific relevance because of its negative influence on patient outcomes. The current methods of infertility treatment may be unsuitable for many women with DOR, which support the need for development of additional approaches to achieve fertility restoration. Various techniques have been tried to improve the quality and increase the quantity of oocytes in DOR patients, including mitochondrial transfer, activation of primordial follicles, in vitro culture of follicles, and regeneration of oocytes from various stem cells. Herein, we review the science behind these experimental reproductive technologies and their potential use to date in clinical studies for infertility treatment in women with DOR.

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.

N-acetylcysteine protects ovarian follicles from ischemia-reperfusion injury in xenotransplanted human ovarian tissue

STUDY QUESTION

Can antioxidant treatment with N-acetylcysteine (NAC) protect ovarian follicles from ischemia-reperfusion injury in xenotransplanted human ovarian tissue?

SUMMARY ANSWER

Daily administration of NAC for 7-12 days post-transplantation reduced ischemia-reperfusion injury and increased follicle survival in human ovarian xenografts by upregulating the antioxidant defense system and exerting anti-inflammatory and antiapoptotic effects.

WHAT IS KNOWN ALREADY

Freezing of human ovarian tissue is performed with high follicular survival rates but up to 70% of follicles appear to be lost due to hypoxia and ischemia-reperfusion injury during ovarian tissue transplantation (OTT). NAC has been demonstrated to possess antioxidant and antiapoptotic properties, and studies in rodents have shown that intraperitoneal administration of NAC reduces ischemia-reperfusion injury and increases follicle survival in autotransplanted murine ovaries.

STUDY DESIGN, SIZE, DURATION

Pieces of frozen-thawed human ovarian tissue from 28 women aged 23-36 years were transplanted to immunodeficient mice in short- and long-term xenograft studies or cultured in vitro. Three short-term xenograft studies (1-week duration) were performed, in which saline or 150 mg/kg NAC was administered for 7 days post-transplantation (n = 12 patients per group). Two long-term xenograft studies (4 weeks of duration) were performed. In one of these studies, saline or 150 mg/kg NAC was administered for 12 days (n = 12 patients per group), while in the other study 50, 150 or 300 mg/kg NAC was administered for 7 days (n = 8 patients per group). In addition, human ovarian tissue (n = 12 pieces from three patients per group) was cultured with increasing concentrations of NAC (0, 5, 25 and 75 mM) for 4 days in vitro.

PARTICIPANTS/MATERIALS, SETTING, METHODS

Donated ovarian tissue was obtained from women who had undergone ovarian tissue cryopreservation for fertility preservation at the University Hospital of Copenhagen. Cortical tissue pieces (5 × 5 × 1 mm) were transplanted subcutaneously to immunodeficient mice and NAC or saline was injected intraperitoneally. Grafts were retrieved after 1 or 4 weeks and follicle density was assessed. Gene expression analysis of antioxidant defense markers (superoxide dismutase; Sod1/SOD1, heme oxygenase-1; Hmox1/HMOX1, catalase; Cat/CAT), proinflammatory cytokines (tumor necrosis factor-alpha; Tnf-α, interleukin-1-beta; Il1-β, interleukin 6; Il6), apoptotic factors (B-cell lymphoma 2; Bcl2/BCL2, Bcl-2-associated X protein; Bax/BAX) and angiogenic factors (vascular endothelial growth factor A; Vegfa/VEGFA, angiopoietin-like 4; Angptl4/ANGPTL4) was performed in 1-week-old human ovarian xenografts and in cultured human ovarian tissue. Grafts retrieved after 4 weeks were histologically processed and analyzed for vascularization by CD31 immunohistochemical staining, fibrosis by Masson's Trichrome staining and apoptosis by immunofluorescence using cleaved caspase-3.

MAIN RESULTS AND THE ROLE OF CHANCE

After 1-week grafting, the relative expression of Sod1, Hmox1 and Cat was significantly higher in the group receiving 150 mg/kg NAC (NAC150-treated group) compared to controls (P = 0.04, P = 0.03, and P = 0.01, respectively), whereas the expression levels of Tnf-α, Il1-β and Il6 were reduced. The Bax/Bcl2 ratio was also significantly reduced in the NAC150-treated group (P < 0.005). In vitro, the relative gene expression of SOD1, HMOX1 and CAT increased significantly in the human ovarian tissue with increasing concentrations of NAC (P < 0.001 for all genes). However, the expression of VEGFA and ANGPTL4 as well as the BAX/BCL2 ratio decreased significantly with increasing concentrations of NAC (P < 0.02, P < 0.001 and P < 0.001, respectively). After 4-week grafting, fibrosis measured by collagen content was similar in the NAC150-treated group compared to controls (control: 56.6% ± 2.2; NAC150: 57.6% ± 1.8), whereas a statistically significant reduction in the CD31-positive vessel area was found (control: 0.69% ± 0.08; NAC150: 0.51% ± 0.07; P < 0.02). Furthermore, a reduced immunoreactivity of cleaved caspase-3 was observed in follicles of the NAC150-treated xenografts compared to controls. Follicle density (follicles/mm3, mean ± SD) was higher in the NAC150-treated group compared to the control group in the 1-week xenografts (control: 19.5 ± 26.3; NAC150: 34.2 ± 53.5) and 4-week xenografts (control: 9.3 ± 11.0; NAC150: 14.4 ± 15.0). Overall, a 2-fold increase in follicle density was observed in the NAC150-group after 1-week grafting where fold changes in follicle density were calculated in relation to grafts from the same patient. Around a 5-fold increase in follicle density was observed in the NAC150 and NAC300 groups after 4-week grafting.

LARGE SCALE DATA

N/A.

LIMITATIONS, REASONS FOR CAUTION

Follicle density in the human ovarian cortex is highly heterogeneous and can vary 100-fold between cortex pieces from the same woman. A high variability in follicle density within and between treatment groups and patients was found in the current study. Thus, solid conclusions cannot be made. While intraperitoneal injections of NAC appeared to reduce ischemia-reperfusion injury in human ovarian xenografts, different administration routes should be investigated in order to optimize NAC for potential clinical use.

WIDER IMPLICATIONS OF THE FINDINGS

This is the first study to demonstrate the antioxidant, anti-inflammatory and antiapoptotic properties of NAC in xenotransplanted human ovarian tissue. Therefore, NAC appears to be a promising candidate for protecting ovarian follicles from ischemia-reperfusion injury. This provides the initial steps toward clinical application of NAC, which could potentially reduce the loss of ovarian follicles following OTT.

STUDY FUNDING/COMPETING INTEREST(S)

We are grateful to the Danish Childhood Cancer Foundation, Hørslev Foundation, Aase and Einar Danielsen's Foundation (grant number: 10-001999), Dagmar Marshalls Foundation, Else and Mogens Wedell-Wedellsborgs Foundation, Knud and Edith Eriksens Mindefond, and Fabrikant Einar Willumsens Mindelegat for funding this study. None of the authors have any competing interests to declare.