Effect of Local Basic Fibroblast Growth Factor and Vascular Endothelial Growth Factor on Subcutaneously Allotransplanted Ovarian Tissue in Ovariectomized Mice

Research progress on mechanism of follicle injury after frozen ovarian tissue transplantation and protective strategies

The iatrogenic ovarian dysfunction caused by cancer treatment have been increasing, along with the age at onset of malignant tumors getting younger, the survival of cancer patients being longer, as well as the delayed childbearing age for females; therefore it becomes a major clinical challenge to preserve the fertility of these patients. Ovarian tissue cryopreservation is the only solution for female cancer patients in prepubertal ages and those who cannot delay gonadotoxic therapy. However, the successful rate of cryopreservation and transplantation of ovarian tissue is still low at present due to the risk of ischemia and hypoxia of grafted tissues. Abnormal activation of primordial follicle and ischemia-reperfusion injury after blood supply recovery also cause massive loss of follicles in grafted ovarian tissues. It has been tried in various studies to reduce the damage of follicles during freezing and transplantation by adding certain drugs, and extend the duration of endocrine and reproductive function in patients with ovarian transplantation. For example, melatonin, N-acetylcysteine, erythropoietin or other antioxidants are used to reduce oxidative stress; mesenchymal stem cells derived from different tissues, basic fibroblast growth factor, vascular endothelial growth factor, angiopoietin 2 and gonadotropin are used to promote revascularization; anti-Müllerian hormone and rapamycin are used to reduce abnormal activation of primordial follicles. This article reviews the research progress on the main mechanisms of follicle loss after ovarian tissue transplantation, including hypoxia, ischemia-reperfusion injury and associated cell death, and abnormal activation of follicles; and explores the methods of reducing graft follicle loss to provide reference for improving the efficiency of ovarian tissue cryopreservation and transplantation.

Effects of needle puncturing on re-vascularization and follicle survival in xenotransplanted human ovarian tissue

BACKGROUND

Ovarian tissue transplantation can restore fertility in young cancer survivors, however the detrimental loss of follicles following transplantation of cryopreserved ovarian tissue is hampering the efficiency of the procedure. This study investigates whether needle puncturing prior to transplantation can enhance revascularization and improve follicle survival in xenotransplanted human ovarian cortex.

METHODS

Cryopreserved human ovarian cortex pieces (N = 36) from 20 women aged 24-36 years were included. During the thawing process, each piece of tissue was cut in halves; one half serving as the untreated control and the other half was punctured approximately 150-200 times with a 29-gauge needle. The cortex pieces were transplanted subcutaneously to immunodeficient mice for 3, 6 and 10 days (N = 8 patients) and for 4 weeks (N = 12 patients). After 3, 6 and 10 days, revascularization of the ovarian xenografts were assessed using immunohistochemical detection of CD31 and gene expression of angiogenic factors (Vegfα, Angptl4, Ang1, and Ang2), and apoptotic factors (BCL2 and BAX) were performed by qPCR. Follicle density and morphology were evaluated in ovarian xenografts after 4 weeks.

RESULTS

A significant increase in the CD31 positive area in human ovarian xenografts was evident from day 3 to 10, but no significant differences were observed between the needle and control group. The gene expression of Vegfα was consistently higher in the needle group compared to control at all three time points, but not statistically significant. The expression of Ang1 and Ang2 increased significantly from day 3 to day 10 in the control group (p < 0.001, p = 0.0023), however, in the needle group this increase was not observed from day 6 to 10 (Ang2 p = 0.027). The BAX/BCL2 ratio was similar in the needle and control groups. After 4-weeks xenografting, follicle density (follicles/mm³, mean ± SEM) was higher in the needle group (5.18 ± 2.24) compared to control (2.36 ± 0.67) (p = 0.208), and a significant lower percentage of necrotic follicles was found in the needle group (19%) compared to control (36%) (p = 0.045).

CONCLUSIONS

Needle puncturing of human ovarian cortex prior to transplantation had no effect on revascularization of ovarian grafts after 3, 6 and 10 days xenotransplantation. However, needle puncturing did affect angiogenic genes and improved follicle morphology.

Improvement of oocyte quality through the SIRT signaling pathway

Background

Oocyte quality is one of the major deciding factors in female fertility competence.

Methods

PubMed database was searched for reviews by using the following keyword "oocyte quality" AND "Sirtuins". The methodological quality of each literature review was assessed using the Preferred Reporting Items for Systematic reviews and Meta-Analyses (PRISMA) 2020 statement.

Main Findings

Oxidative stress has been recognized as the mechanism attenuating oocyte quality. Increasing evidence from animal experiments and clinical studies has confirmed the protective roles of the sirtuin family in improving oocyte quality via an antioxidant effect.

Conclusion

The protective roles in the oocyte quality of the sirtuin family have been increasingly recognized.

Metabolic and secretory recovery of slow frozen-thawed human ovarian tissue in vitro

Within the options available for fertility preservation, cryopreservation of ovarian cortical tissue has become an important technique. Freezing and thawing procedures have been optimized to preserve tissue integrity and viability. However, the improvement of the tissue retransplantation is currently of great interest. Rapid angiogenesis is needed at the retransplantation site to accomplish sufficient blood supply to provide oxygen and nutrients. Many studies address this issue. However, we need to understand the physiology of the thawed tissue to gain further understanding of the complexities of the procedure. As freezing and thawing generally impairs cellular metabolism, we aimed to characterize the changes in metabolic activity and secretion of the angiogenic factor vascular endothelial growth factor-A (VEGF-A) of frozen-thawed ovarian cortical tissue over time. Biopsy punches of ovarian cortical tissue from patients undergoing fertility preservation were maintained in culture without freezing or after a slow-freezing and thawing procedure. VEGF-A secretion was measured after 48 h by ELISA. To examine temporary changes, metabolic activity was assessed for both fresh and frozen-thawed tissue of the same patient. Metabolic activity and VEGF-A secretion were measured at 0, 24 and 48 h in culture. Thawed ovarian cortical tissue secreted significantly less VEGF-A compared to fresh ovarian cortical tissue within 48 h of culture. After thawing, metabolic activity was significantly reduced compared to fresh ovarian cortex but over the course of 48 h, the metabolic activity recovered. Similarly, VEGF-A secretion of thawed tissue increased significantly over 48 h. Here, we have shown that it takes 48 h for ovarian cortical tissue to recover metabolically after thawing, including VEGF-A secretion.

Fertility Preservation for Prepubertal Patients at Risk of Infertility: Present Status and Future Perspectives

The increasing cure rate of cancer has led to a vast population of survivors having to face the late adverse effects of oncological treatments, with fertility impairment being one of the most sensitive issues for patients. Different options to preserve the fertility of adult patients are routinely used in clinical practice. However, fertility preservation strategies for prepubertal patients at risk of infertility are limited to the cryopreservation of immature gonadal tissue. In recent decades, many research efforts have been focused on the future use of cryopreserved gonadal tissue. This review discusses the common status of fertility preservation measures for pediatric patients undergoing gonadotoxic treatment, focusing especially on the challenges that remain to be solved in order to implement this fundamental service.

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.

Si-Wu-Tang facilitates ovarian function through improving ovarian microenvironment and angiogenesis in a mouse model of premature ovarian failure

ETHNOPHARMACOLOGICAL RELEVANCE

Premature ovarian failure (POF) is a severe illness, characterized by premature menopause with a markedly decrease in ovarian function, which leads to infertility. Si-Wu-Tang (SWT), also called "the first prescription of gynecology" by medical experts in China, is widely used as the basic formula in regulating the menstrual cycle and treating infertility. However, the potential effect and underlying mechanisms of action of SWT on the treatment of POF have not yet been elucidated.

PURPOSE

This study aimed to explore the therapeutic effect and underlying molecular mechanism of action of SWT on the treatment of POF in C57BL/6 mice.

MATERIALS AND METHODS

The main compounds of SWT were identified by high-performance liquid chromatography (HPLC). POF model groups were established by a single intraperitoneal injection of cyclophosphamide (Cy, 100 mg/kg). SWT or dehydroepiandrosterone (DHEA) were administered via oral gavage for 28 consecutive days. Ovarian function and pathological changes were evaluated by hormone levels, follicular development, and changes in angiogenesis. Furthermore, statistical analyses of fertility were also performed.

RESULTS

Treatment with SWT significantly improved estrogen levels, the number of follicles, antioxidant defense, and microvascular formation in POF mice. Moreover, SWT significantly activated the Nrf2/HO-1 and STAT3/HIF-1α/VEGF signaling pathways to promote angiogenesis, resulting in a better fertility outcome when compared to the model group.

CONCLUSIONS

Our findings indicated that SWT protected ovarian function of Cy-induced POF mice by improving the antioxidant ability and promoting ovarian angiogenesis, thereby providing scientific evidence for the treatment of POF using SWT.

Effects of Er:YAG laser treatment on re-vascularization and follicle survival in frozen/thawed human ovarian cortex transplanted to immunodeficient mice

PURPOSE

The huge loss of ovarian follicles after transplantation of frozen/thawed ovarian tissue is considered a major drawback on the efficacy of the procedure. Here we investigate whether Er:YAG laser treatment prior to xenotransplantation can improve re-vascularization and subsequently follicle survival in human ovarian tissue.

METHODS

A total of 99 frozen/thawed human ovarian cortex pieces were included of which 72 pieces from 12 woman were transplanted to immunodeficient mice. Tissues from each woman were included in both an 8-day and an 8-week duration study and treated with either full-beam laser (L1) or fractionated laser (L2), or served as untreated controls. Vascularization of the ovarian xenografts were evaluated after 8 days by qPCR and murine Cd31 immunohistochemical analysis. Follicle densities were evaluated histologically 8 weeks after xenografting.

RESULTS

Gene expression of Vegf/VEGF was upregulated after L1 treatment (p=0.002, p=0.07, respectively), whereas Angpt1, Angpt2, Tnf-α, and Il1-β were significantly downregulated. No change in gene expression was found in Cd31/CD31, ANGPT1, ANGPT2, ANGTPL4, XBP1, or LRG1 after any of the laser treatments. The fraction of Cd31 positive cells were significantly reduced after L1 and L2 treatment (p<0.0001; p=0.0003, respectively), compared to controls. An overall negative effect of laser treatment was detected on follicle density (p=0.03).

CONCLUSIONS

Er:YAG laser treatment did not improve re-vascularization or follicle survival in human ovarian xenografts after 8 days and 8 weeks grafting, respectively. However, further studies are needed to fully explore the potential angiogenic effects of controlled tissue damage using different intensities or lasers.

Prevention of chemotherapy-induced premature ovarian insufficiency in mice by scaffold-based local delivery of human embryonic stem cell-derived mesenchymal progenitor cells

BACKGROUND

Premature ovarian insufficiency (POI) is one of the most serious side effects of chemotherapy in young cancer survivors. It may not only reduce fecundity but also affect lifelong health. There is no standard therapy for preserving ovarian health after chemotherapy. Recently, administration of embryonic stem cell-derived mesenchymal progenitor cells (ESC-MPCs) has been considered a new therapeutic option for preventing POI. However, the previous method of directly injecting cells into the veins of patients exhibits low efficacy and safety. This study aimed to develop safe and effective local delivery methods for the prevention of POI using two types of bioinspired scaffolds.

METHODS

Female mice received intraperitoneal cisplatin for 10 days. On day 11, human ESC-MPCs were delivered through systemic administration using intravenous injection or local administration using intradermal injection and intradermal transplantation with a PLGA/MH sponge or hyaluronic acid (HA) gel (GEL) type of scaffold. PBS was injected intravenously as a negative control. Ovarian function and fertility were evaluated 4 weeks after transplantation. Follicle development was observed using hematoxylin and eosin staining. The plasma levels of sex hormones were measured using ELISA. Expression levels of anti-Müllerian hormone (AMH) and ki-67 were detected using immunostaining, and the quality of oocytes and embryos was evaluated after in vitro fertilization. The estrous cycles were observed at 2 months after transplantation.

RESULTS

The local administration of human ESC-MPCs using the bioinspired scaffold to the backs of mice effectively prolonged the cell survival rate in vivo. The HA GEL group exhibited the best recovered ovarian functions, including a significantly increased number of ovarian reserves, estrogen levels, and AMH levels and decreased apoptotic levels. Furthermore, the HA GEL group showed improved quality of oocytes and embryos and estrous cycle regularity.

CONCLUSIONS

HA GEL scaffolds can be used as new delivery platforms for ESC-MPC therapy, and this method may provide a novel option for the clinical treatment of chemotherapy-induced POI.

Follicular development and the expression of BAX and vascular endothelial growth factor in transplanted ovaries in uni- and bilateral ovariectomized mice: An experimental study

Background

Several conflicting results have been reported on the survival and function of transplanted ovaries.

Objective

Evaluation of the follicular development and the expression of vascular endothelial growth factor (VEGF) and Bcl-2-associated X protein (BAX) in ovaries transplanted into uni- and bilaterally ovariectomized mice.

Materials and Methods

In this experimental study, 40 female NMRI mice (21-days-old, 12-15 gr) were ovariectomized uni- and bilaterally (n = 20/ group), while the 8-wk-old mice were considered as intact control group (n = 6). 5 weeks after transplantation at the proestrus stage, the morphology of recovered transplanted ovaries and the proportion of follicles were studied at different developmental stages. The apoptosis cell death by pro-apoptotic protein BAX and the expression of VEGF were evaluated using immunohistochemistry.

Results

In the bilaterally ovariectomized mice, among the 455 counted normal follicles, a lower rate of primordial and primary follicles and a higher rate of preantral and antral follicles were observed (p = 0.002). However, the percentages of preantral and antral follicles, and the corpus luteum were significantly lower in the intact control group (among the 508 counted normal follicles in this group) compared to other transplanted groups (p = 0.002). The number of BAX-positive cells in all groups was not significantly different. The VEGF expression was prominent in vessels of the corpus luteum, and also in the theca layer of large follicles of studied groups.

Conclusion

Early discharge of ovarian reserve was prominent in the bilaterally ovariectomized group but the incidence of apoptotic cells and VEGF expression as angiogenic factor did not differ in both ovariectomized mice. Thus, unilaterally ovariectomy has less side effects on the ovarian reserve compared to bilateral ovariectomy.

Recent Advancements in Engineered Biomaterials for the Regeneration of Female Reproductive Organs

Various gynecologic diseases and chemoradiation or surgery for the management of gynecologic malignancies may damage the uterus and ovaries, leading to clinical problems such as infertility or early menopause. Embryo or oocyte cryopreservation-the standard method for fertility preservation-is not a feasible option for patients who require urgent treatment because the procedure requires ovarian stimulation for at least several days. Hormone replacement therapy (HRT) for patients diagnosed with premature menopause is contraindicated for patients with estrogen-dependent tumors or a history of thrombosis. Furthermore, these methods cannot restore the function of the uterus and ovaries. Although autologous transplantation of cryopreserved ovarian tissue is being attempted, it may re-introduce malignant cells after cancer treatment. With the recent development in regenerative medicine, research on engineered biomaterials for the restoration of female reproductive organs is being actively conducted. The use of engineered biomaterials is a promising option in the field of reproductive medicine because it can overcome the limitations of current therapies. Here, we review the ideal properties of biomaterials for reproductive tissue engineering and the recent advancements in engineered biomaterials for the regeneration of female reproductive organs.

Implications of Nonphysiological Ovarian Primordial Follicle Activation for Fertility Preservation

In recent years, ovarian tissue cryopreservation has rapidly developed as a successful method for preserving the fertility of girls and young women with cancer or benign conditions requiring gonadotoxic therapy, and is now becoming widely recognized as an effective alternative to oocyte and embryo freezing when not feasible. Primordial follicles are the most abundant population of follicles in the ovary, and their relatively quiescent metabolism makes them more resistant to cryoinjury. This dormant pool represents a key target for fertility preservation strategies as a resource for generating high-quality oocytes. However, development of mature, competent oocytes derived from primordial follicles is challenging, particularly in larger mammals. One of the main barriers is the substantial knowledge gap regarding the regulation of the balance between dormancy and activation of primordial follicles to initiate their growing phase. In addition, experimental and clinical factors also affect dormant follicle demise, while the mechanisms involved remain largely to be elucidated. Moreover, most of our basic knowledge of these processes comes from rodent studies and should be extrapolated to humans with caution, considering the differences between species in the reproductive field. Overcoming these obstacles is essential to improving both the quantity and the quality of mature oocytes available for further fertilization, and may have valuable biological and clinical applications, especially in fertility preservation procedures. This review provides an update on current knowledge of mammalian primordial follicle activation under both physiological and nonphysiological conditions, and discusses implications for fertility preservation and priorities for future research.

Heterotopic autotransplantation of ovarian tissue in a large animal model: Effects of cooling and VEGF

Heterotopic and orthotopic ovarian tissue autotransplantation techniques, currently used in humans, will become promising alternative methods for fertility preservation in domestic and wild animals. Thus, this study describes for the first time the efficiency of a heterotopic ovarian tissue autotransplantation technique in a large livestock species (i.e., horses) after ovarian fragments were exposed or not to a cooling process (4°C/24 h) and/or VEGF before grafting. Ovarian fragments were collected in vivo via an ultrasound-guided biopsy pick-up method and surgically autografted in a subcutaneous site in both sides of the neck in each mare. The blood flow perfusion at the transplantation site was monitored at days 2, 4, 6, and 7 post-grafting using color-Doppler ultrasonography. Ovarian grafts were recovered 7 days post-transplantation and subjected to histological analyses. The exposure of the ovarian fragments to VEGF before grafting was not beneficial to the quality of the tissue; however, the cooling process of the fragments reduced the acute hyperemia post-grafting. Cooled grafts compared with non-cooled grafts contained similar values for normal and developing preantral follicles, vessel density, and stromal cell apoptosis; lower collagen type III fibers and follicular density; and higher stromal cell density, AgNOR, and collagen type I fibers. In conclusion, VEGF exposure before autotransplantation did not improve the quality of grafted tissues. However, cooling ovarian tissue for at least 24 h before grafting can be beneficial because satisfactory rates of follicle survival and development, stromal cell survival and proliferation, as well as vessel density, were obtained.

Restoration of estrous cycles by co-transplantation of mouse ovarian tissue with MSCs

This study investigates the effect of bone marrow (BM-MSCs) and visceral peritoneum (VP-MSCs)-derived mesenchymal stem cells on the transplanted ovary. VP-MSCs and BM-MSCs were obtained from green fluorescent protein-expressing mice (GFP⁺). Six- to eight-week-old female NMRI mice were divided into four experimental groups, autograft ovarian tissue fragments (AO), autograft ovarian tissue fragments encapsulated in fibrin-collagen hydrogel (AO-H), autograft ovarian tissue fragments encapsulated in fibrin-collagen hydrogel containing BM-MSCs (AO-HB) and autograft ovarian tissue fragments encapsulated in fibrin-collagen hydrogel containing VP-MSCs (AO-HP). Intact ovary (IO) was the control group. The estrous cycles resumption time was monitored and at the third estrous cycle, the blood samples and grafted ovaries were evaluated using hormonal, histological and gene expression analysis. Onset of estrous cycles, especially at the second cycle, was earlier in AO-HB and AO-HP groups than in the AO-H group (P < 0.05). Moreover, E2 and FSH levels in AO-HB and AO-HP groups were returned to those of the intact group. However, folliculogenesis was still retarded as compared with the IO group. The gene expression of theca (Lhcgr, Cyp17a1, Gli2, Gli3 and Ptch1), granulosa (Amh and Fshr), oocyte (Zp3 and Gdf9), germ cells (Stella and Prdm1), angiogenesis (VEGF and bFGF) and apoptosis (Bax/Bcl2 and Caspase3) markers was similar in both AO-HB and AO-HP groups. Expression of Amh, Fshr, Gdf9 and VEGF increased only in the AO-HP group whereas expression of Ptch1 increased only in the AO-HB group, as compared with the AO group (P < 0.05). In conclusion, BM-MSCs or VP-MSCs can improve ovarian autotransplantation in mice with no superiority over each other.

Effects of Different Vitrification Solutions and Protocol on Follicular Ultrastructure and Revascularization of Autografted Mouse Ovarian Tissue

Objective

Many attempts have been made to preserve fertility by improving the cryopreservation of the ovarian tissue. This current studyaimed to improve of direct cover vitrification (DCV) protocol on follicular preservation and angiogenesis in autografted ovarian tissue.

Materials and Methods

In this experimental study, sixty five female Balb/c mice (5-6 week-old) were anesthetized and their ovaries were dissected. The left ovaries were vitrified by DCV solution, thawed by descending concentrations of sucrose, and then autografted subcutaneously. The right ovaries were autografted with no vitrification procedure prior to transplantation. The animals were sacrificed under anesthesia on the 7thday after transplantation to obtain ovarian tissue. Follicular quality was assessed by histological and ultrastructure observations, and angiogenesis was examined by immunohistochemical staining and real-time polymerase chain reaction (PCR) analysis.

Results

The histological and ultrastructure features of the follicles preserved well after vitrification of the ovarian tissue by 10% ethylene glycol (EG) and 10% dimethyl sulfoxide (DMSO). Revascularizationwas manifested prominently in the DCV1-vitrified/grafted ovaries by von Willebrand factor (vWF) and alpha smooth muscle actin (α-SMA) immunostaining. The ovarian tissue vitrified in DCV1 protocol had higher expression levels of angiopoietin-2 (Ang-2) and vascular endothelial growth factor (VEGF) 7 days after autotransplantation (P<0.01).

Conclusion

These findings suggest that DCV with 10% of both EG and DMSO, is an effective cryopreservation solution for preservation of good quality follicles as well an upregulation of angiogenic factors after ovarian tissue transplantation.

Effect of sustained release of basic fibroblast growth factor using biodegradable gelatin hydrogels on frozen-thawed human ovarian tissue in a xenograft model

AIM

Ovarian tissue cryopreservation before cancer treatment is the only option to preserve fertility under some circumstances. However, tissue ischemia after transplantation while awaiting angiogenesis induces dysfunctional folliculogenesis and reduces ovarian reserve and is one of the disadvantages of frozen-thawed ovarian tissue transplantation. Basic fibroblast growth factor (bFGF) is a major regulator of angiogenesis. However, bFGF rapidly loses biological activity when its free form is injected in vivo. This study investigated whether administration of active bFGF helps establish a nurturing environment for follicular survival.

METHODS

A sheet form of a sustained release drug delivery system for bFGF was developed using biodegradable acidic gelatin hydrogel (bFGF sheet). The bFGF sheets or phosphate-buffered saline sheets, as a negative control, were transplanted with frozen-thawed human ovarian tissues subcutaneously into the backs of severe combined immunodeficient mice. Neovascularization, cell proliferation, fibrosis and follicular survival of ovarian grafts were analyzed at 6 weeks after xenografting.

RESULTS

The bFGF sheets were optimized to release bFGF for at least 10 days. The transplantation of bFGF sheets with frozen-thawed ovarian tissues significantly increased human and mouse CD31-positive areas and stromal and endothelial cell proliferations. The administration of bFGF also significantly decreased the percentage of the fibrotic area in the graft, resulting in a significant increase in primordial and primary follicular density.

CONCLUSION

Local administration of a sustained release of biologically active bFGF induced neovascularization in frozen-thawed ovarian tissue grafts, which could establish the nurturing environment required for follicular survival in heterotopic xenografts.

Fertility Preservation: Current and Future Perspectives for Oncologic Patients at Risk for Iatrogenic Premature Ovarian Insufficiency

Progress in recent years in the efficacy of oncologic treatment and early diagnosis of cancer has determined an increase in life expectance in cancer patients. About 10% of all cancer cases affect women younger than 45 years; therefore nowadays approximately 5-6% of the population in childbearing age consists in cancer survivors. A crucial issue is the high risk of premature ovarian insufficiency due to possible gonadotoxic effects of oncologic treatments. Considering combined chemotherapy, radiation therapy, and bone marrow transplantation, this risk can reach 92-100%, depending on the age and ovarian reserve of the patient, as well as the schedule and type of therapy. International guidelines recommend addressing all the patients diagnosed with a neoplasia treatable with potentially gonadotoxic therapies to fertility preservation. Moreover, fertility preservation also seems to reserve fascinating implications for women who want to delay childbearing for social reasons or women affected with endometriosis, who could receive unexpected opportunities. At present, the most widespread techniques to preserve fertility in adult women are embryo or oocyte cryopreservation, depending on the presence of a partner or according to legislative issues, but these procedures require time for ovarian stimulation. In prepubertal patients or when there is no possibility of delaying chemotherapy, ovarian tissue cryopreservation and subsequent transplantation represent the main strategy.

Effects of vitrification and transplantation on follicular development and expression of EphrinB1 and PDGFA in mouse ovaries

The aim of this study was to assess the follicular development and the patterns of EphrinB1 and PDGFA immunostaining in vitrified mouse ovarian tissue (OT) with and without transplantation. Histological evaluation was performed on fresh and vitrified OTs, whether transplanted or not. RT-PCR was performed on fresh and vitrified ovarian samples (OSs) and vitrified OS graft. Vitrification alone did not significantly reduce the normal primordial, primary, and secondary follicles except antral ones (p > 0.05). However, transplantation decreased all the follicle types. The EphrinB1 immunoexpression showed high intensity in all follicular types in vitrified OT and the significant increased was detected in secondary and antral follicles (p < 0.05). PDGFA protein immunoexpression of primordial and primary follicles was decreased in vitrified OT (p < 0.05). However, the lowest immunoexpression of EphrinB1 and PDGFA was detected after transplantation (p < 0.05). The levels of ephrinb1 and pdgfa mRNA expressions in vitrified OS and vitrified OS grafts were found as comparable to the fresh OS. In conclusion, vitrification has no detrimental effect on the follicles at the different developmental stages, majority of ovarian follicular loss takes place after transplantation rather than vitrification. Overall, vitrification and grafting do not change the ephrinb1 and pdgfa gene expressions. In addition, EphrinB1 and PDGFA are expressed during different stages of folliculogenesis in a different manner in fresh, vitrified, or grafted OTs. Vitrification and/or grafting appear to affect the follicular expression of EphrinB1 and PDGFA. These findings suggest that these proteins could have several functions related to the development of follicles and angiogenesis after transplantation.

Impacts of survivin and caspase-3 on apoptosis and angiogenesis in oral cancer

The present study aimed to investigate the impact of survivin and caspase-3 on apoptosis and angiogenesis in oral cancer. A total of 16 oral leukoplakia cases accompanied by low-moderate epithelial dysplasia, 12 cases of oral leukoplakia accompanied by severe epithelial dysplasia, 17 cases of high-moderate differentiated oral squamous cell carcinoma and 10 cases of normal oral mucosa were selected. Immunohistochemistry was used to detect the expression levels of survivin, caspase-3, and caspase inhibitor factor VIII in lesions from each group. Terminal deoxynucleotidyl transferase 2'-deoxyuridine, 5'-triphosphate nick end labeling was performed to detect the apoptotic index of oral leukoplakia and cancer tissue. Immunohistochemistry revealed increased expression levels of survivin in oral cancer tissues, as compared with the normal mucosa, whereas the expression of Caspase-3 was decreased during malignant transformation. Microvascular density (MVD) was increased from 28.49±11.87 strips/mm² (mean ± standard deviation, normal control group) to 91.98±40.20 strips/mm² (oral cancer group). Therefore, survivin may serve an important role in oral cancer, as its expression was increased in association with a downward trend in caspase-3 expression and apoptotic index, whereas MVD was significantly increased.

Hyaluronic acid-based hydrogel scaffold without angiogenic growth factors enhances ovarian tissue function after autotransplantation in rats

One of the problems encountered during ovarian transplantation is that the number of primordial follicles in the grafts is considerably reduced 2 d after transplantation due to post-transplantation ischemia. This study investigates if the use of hyaluronic acid-based hydrogel (HABH) with and without vascular endothelial growth factor (VEGF) and basic fibroblast growth factor (bFGF) could prevent or minimize ischemia-induced follicle loss during ovarian autotransplantation and thereby restore ovarian tissue function in the rat model. In this study, twenty four female rats were subjected to bilateral ovariectomy and were randomly divided into 3 groups for ovarian tissue autotransplantation. Group A included rats with ovarian tissue without HABH, VEGF and bFGF, group B comprised rats with ovarian tissue encapsulated with HABH and group C had rats with ovarian tissue encapsulated with HABH containing VEGF and bFGF. Three days after transplantation, the grafts were assessed through histological and hormonal analyses. Apoptotic, angiogenic and maturation genes expressions were also analyzed. The mean number of follicles in all developmental stages increased in group B (P  <  0.05). The level of FSH decreased in group B (P  <  0.05) whereas, the expression level of VEGF gene increased in group B (P  <  0.05). No significant changes were observed in the expression levels of maturation and apoptotic genes in all groups. In conclusion, ovarian encapsulation with HABH alone can prevent or minimize ischemia-induced follicle loss, preserve the follicular pool, promote follicular survival, facilitate angiogenesis, and restore hormone levels. However, its efficiency in a clinical setting and in comparison with other hydrogels needs further investigation.

Restoration of ovarian tissue function and estrous cycle in rat after autotransplantation using hyaluronic acid hydrogel scaffold containing VEGF and bFGF

This study investigates the effect of hyaluronic acid (HA) containing VEGF and bFGF on restoration of ovarian function after ovarian autotransplantation. Twenty-four rats were randomly divided into three groups for ovarian autotransplantation: group A (ovaries without HA, VEGF and bFGF), group B (ovaries encapsulated with HA) and group C (ovaries encapsulated with HA containing VEGF and bFGF). The grafts were assessed using vaginal smears, histological, hormonal, and the genes expression analysis. The duration of first estrous cycle was shorter in group C than in group A (p < 0.01). The mean number of primordial follicles was protected in group C. The level of estradiol was higher in group A than in group C (p < 0.01). The expression level of Cellular-Myelocytomatosis (C-Myc) in group C was lower than in group B (p < 0.05). HA containing VEGF and bFGF can ensure follicular survival, decrease apoptosis and recover ovarian function after auto-transplantation.

VEGF and FGF2 Improve Revascularization, Survival, and Oocyte Quality of Cryopreserved, Subcutaneously-Transplanted Mouse Ovarian Tissues

This study was conducted to investigate the effect of the vascular endothelial growth factor (VEGF) and fibroblast growth factor 2 (FGF2) on revascularization, survival, and oocyte quality of cryopreserved, subcutaneously-transplanted mouse ovarian tissue. Autologous subcutaneous transplantation of vitrified-thawed mouse ovarian tissues treated with (experimental group) or without (control group) VEGF and FGF2 was performed. After transplantation to the inguinal region for two or three weeks, graft survival, angiogenesis, follicle development, and oocyte quality were examined after gonadotropin administration. VEGF coupled with FGF2 (VEGF/FGF2) promoted revascularization and significantly increased the survival rate of subcutaneously-transplanted cryopreserved ovarian tissues compared with untreated controls. The two growth factors did not show long-term effects on the ovarian grafts. In contrast to the untreated ovarian grafts, active folliculogenesis was revealed as the number of follicles at various stages and of mature oocytes in antral follicles after gonadotropin administration were remarkably higher in the VEGF/FGF2-treated groups. Although the fertilization rate was similar between the VEGF/FGF2 and control groups, the oocyte quality was much better in the VEGF/FGF2-treated grafts as demonstrated by the higher ratio of blastocyst development. Introducing angiogenic factors, such as VEGF and FGF2, may be a promising strategy to improve revascularization, survival, and oocyte quality of cryopreserved, subcutaneously-transplanted mouse ovarian tissue.

Differential effects of a high-fat diet on serum lipid parameters and ovarian gene expression in young and aged female mice

The aim of this study was to compare serum lipid profiles and ovarian gene expression between aged and younger female mice fed a control or a high-fat diet for 2 months. For this 16 female mice (C57BL/6) of 4 months (Young, n = 8) or 13 months (Old, n = 8) of age were used. The females were divided into four groups: (i) young females fed a normal diet; (ii) young females fed a high-fat diet; (iii) old females fed a normal diet; and (iv) old females fed a high-fat diet. Food intake was reduced (P < 0.05) in mice fed with a high-fat (2.9 ± 0.1 g) diet in comparison with control mice (3.9 ± 0.1 g). Body weight was higher for old females on the high-fat diet (35.1 ± 0.3 g) than for young females on the same diet (23.3 ± 0.4 g; P < 0.05). PON1 activity was lower in the high-fat than control diet group (114.3 ± 5.8 vs. 78.1 ± 6.0 kU/L, respectively) and was higher in older than younger females (85.9 ± 6.4 vs. 106.5 ± 5.3; P < 0.05, respectively). Females fed a high-fat diet had lower expression of Igf1 mRNA (P = 0.04). There was an interaction between age and diet for the expression of Gdf9 and Survivin, with lower expression in older females in both diets and young females that received the high-fat diet (P < 0.05). Concluding, the high-fat diet reduced the expression of ovarian Igf1 mRNA, and Gdf9 and Survivin mRNA in younger females, which can indicate lower fertility rates. High-density lipoprotein concentration and PON1 activity were higher in aged female mice.