Exploring the effect of platelet-rich plasma on vascularization and survival of follicles in xenotransplanted human ovarian tissue.

RESEARCH QUESTION: Do platelet-rich plasma (PRP) products, specifically human platelet lysate (hPL) and umbilical cord plasma, enhance vascularization and follicular survival in human ovarian tissue transplanted to immunodeficient mice? DESIGN: Human ovarian tissue was transplanted to subcutaneous pockets in nude mice, followed by daily injections for 6 days of PRP or saline at the transplantation sites. After a grafting period of 3 and 6 days, vascularization was assessed using CD-31 quantification, and gene expression of angiogenic markers (VEGF/Vegf) together with apoptosis-related genes (BAX/BCL-2), oxidative stress markers (HMOX-1/Hmox-1) and pro-inflammatory markers (Il-1ß/Il-6/Tnf-α) was quantitively analysed. Follicle density was analysed in the grafts after 4 weeks. Additionally, a pilot study was conducted exploring the suitability of ultrasound scanning for assessing survival and vascularization in ovarian tissue xenografted to mice. RESULTS: Although there was a significant increase in the CD-31 area from day 3 to day 6 post-grafting, there were no significant differences between the hPL and control groups. Gene expression analysis revealed significant down-regulation of VEGF from day 3 to day 6 for both the hPL and control groups, and significant up-regulation of BAX/BCL-2 in the hPL group compared with the controls. The follicle density showed no significant differences in the hPL group and UCP groups compared with the controls. Furthermore, ultrasound biomicroscopy provided valuable insights into graft morphology, necrotic areas and blood flow, suggesting its potential as a monitoring tool. CONCLUSIONS: Despite the angiogenic properties of PRP, this study was unable to demonstrate a significant impact of hPL on vascularization or of hPL and UCP on follicular survival in xenotransplanted human ovarian tissue.

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.

Reducing 3D Hydrogel Stiffness, Addition of Oestradiol in a Physiological Concentration and Increasing FSH Concentration Improve In Vitro Growth of Murine Preantral Follicles.

This study aimed to optimise culture conditions for murine preantral follicles to improve their growth and survival. Preantral follicles (diameter 100-130 µm) were isolated from prepubertal NMRI mice and individually cultured within alginate beads for 12 days. Three conditions were evaluated: (1) follicle re-encapsulation on day 6 of culture-reducing alginate concentration (0.5% to 0.25% w/v), (2) the presence of oestradiol (E2), and (3) increased follicle-stimulating hormone (FSH) concentration in the culture medium (from 10 to 100 mIU/mL FSH). Follicle morphology and growth, as well as anti-Müllerian hormone (AMH) production, were evaluated. From day 8, re-embedded follicles had a larger average diameter compared to follicles without alginate re-encapsulation (0.5% and 0.25% groups, p < 0.05). Oestradiol (1 µM) had a significantly positive effect on the mean follicular diameter and antrum formation (p < 0.001). Moreover, follicles cultured with 100 mIU/mL FSH showed faster growth (p < 0.05) and significantly higher antrum formation (p < 0.05) compared to the low FSH group. Nevertheless, AMH production was not affected by any of the culture conditions. In conclusion, the growth and survival of mouse preantral follicles during a 12-day period were improved by altering the alginate concentration midways during culture and adding E2 and FSH to the culture medium.

Concentrations of oocyte secreted GDF9 and BMP15 decrease with MII transition during human IVM.

BACKGROUND: The suggested effects of the oocyte secreted GDF9 and BMP15 growth factors on oocyte maturation are currently based on recombinant proteins, and little is known about native GDF9 and BMP15 in humans. METHODS: Human immature cumulus-oocyte complexes (COCs) obtained in connection with ovarian tissue cryopreservation (OTC) underwent in vitro maturation (IVM). Oocyte-produced GDF9 and BMP15 were detected in COCs using immunofluorescence, and in fresh GV oocytes and in GV and MII oocytes after IVM by western blot. Concentrations of GDF9, BMP15 homodimers, and GDF9/BMP15 heterodimer in spent media after IVM were measured by ELISA. The relative expression of seven genes from the GDF9 and BMP15 signaling pathways (BMPR2, ALK5, ALK6, SMAD1, SMAD2, SMAD3, and SMAD5) was evaluated in fresh cumulus cells (before IVM) and in cumulus cells from GV and MII oocytes after IVM by RT-qPCR. RESULTS: We detected native pro-mature GDF9 and BMP15 in human oocytes with molecular weights (Mw) of 47 kDa and 43 kDa, respectively. Concentrations of GDF9 and BMP15 in spent media after IVM were detected in 99% and 64% of the samples, respectively. The GDF9/BMP15 heterodimer was detected in 76% of the samples. Overall, the concentration of GDF9 was approximately 10-times higher than BMP15. The concentrations of both GDF9 and BMP15 were significantly lower in spent medium from MII oocytes than in media from oocytes that remained at the GV stage. Concentrations of the GDF9/BMP15 heterodimer did not differ between GV and MII oocytes. Furthermore, BMPR2, SMAD3, and SMAD5 were significantly upregulated in cumulus cells from MII oocytes, indicating that both GDF9 and BMP15 signaling were active during oocyte meiotic resumption in vitro. CONCLUSION: These data suggest that the driving mechanisms for oocyte nuclear maturation may involve both GDF9 and BMP15 homodimers, while the role of the GDF9/BMP15 heterodimer is questionable.

Revascularization of human ovarian grafts is equally efficient from both sides of the cortex tissue.

RESEARCH QUESTION: Does revascularization of human ovarian grafts in a mouse model occur with equal efficiency from both sides of the cortex tissue? DESIGN: Twenty-four frozen-thawed ovarian cortex pieces from 12 women were transplanted to immunodeficient mice, for 8 days to analyse graft revascularization using immunohistochemical detection of murine CD31, or for 8 weeks to evaluate follicle density (follicles/mm3). The CD31-positive vessel area and density were quantified using a custom-designed application. Three regions of interest (ROI) were defined in each tissue section: the cortical side, the centre and the medullary side. Vessels were subdivided into three categories according to size: microvessels (<300 µm2), small vessels (300-1000 µm2) and large vessels (>1000-3000 µm2). RESULTS: No significant difference in the mean percentage of the CD31-positive vessel area was found between the three ROI (cortical side: 3.9% ± 0.2%; centre: 3.5% ± 0.2%; medullary side: 4.0% ± 0.3%; P = 0.17), but a significantly lower density of vessels was found in the centre of the human ovarian grafts compared with the cortical and medullary sides (cortical side: 323 ± 14 vessels/mm2; centre: 240 ± 12 vessels/mm2; medullary side: 301 ± 18 vessels/mm2; P < 0.001). Microvessels comprised 89-91% of all vessels in the three ROI. Follicle density in ungrafted cortex pieces was 51.8 ± 17.3 and 14.7 ± 3.7 follicles/mm3 after 8 weeks of xenografting, resulting in a follicle survival rate of 28%. CONCLUSIONS: Host revascularization was established equally efficiently from both sides of transplanted human ovarian cortex, suggesting that transplantation techniques ensuring revascularization from both sides of the ovarian graft could potentially facilitate faster graft revascularization.

Validating Reference Gene Expression Stability in Human Ovarian Follicles, Oocytes, Cumulus Cells, Ovarian Medulla, and Ovarian Cortex Tissue.

Human ovarian cells are phenotypically very different and are often only available in limited amounts. Despite the fact that reference gene (RG) expression stability has been validated in oocytes and other ovarian cells from several animal species, the suitability of a single universal RG in the different human ovarian cells and tissues has not been determined. The present study aimed to validate the expression stability of five of the most used RGs in human oocytes, cumulus cells, preantral follicles, ovarian medulla, and ovarian cortex tissue. The selected genes were glyceraldehyde 3-phosphate dehydrogenase (GAPDH), beta-2-microglobulin (B2M), large ribosomal protein P0 (RPLP0), beta-actin (ACTB), and peptidylprolyl isomerase A (PPIA). Overall, the stability of all RGs differed among ovarian cell types and tissues. NormFinder identified ACTB as the best RG for oocytes and cumulus cells, and B2M for medulla tissue and isolated follicles. The combination of two RGs only marginally increased the stability, indicating that using a single validated RG would be sufficient when the available testing material is limited. For the ovarian cortex, depending on culture conditions, GAPDH or ACTB were found to be the most stable genes. Our results highlight the importance of assessing RGs for each cell type or tissue when performing RT-qPCR analysis.

Organotypic Culture of Testicular Tissue from Infant Boys with Cryptorchidism.

Organotypic culture of human fetal testis has achieved fertilization-competent spermatids followed by blastocysts development. This study focuses on whether the organotypic culture of testicular tissue from infant boys with cryptorchidism could support the development of spermatogonia and somatic cells. Frozen-thawed tissues were cultured in two different media, with or without retinoic acid (RA), for 60 days and evaluated by tissue morphology and immunostaining using germ and somatic cell markers. During the 60-day culture, spermatocytes stained by boule-like RNA-binding protein (BOLL) were induced in biopsies cultured with RA. Increased AR expression (p < 0.001) and decreased AMH expression (p < 0.001) in Sertoli cells indicated advancement of Sertoli cell maturity. An increased number of SOX9-positive Sertoli cells (p < 0.05) was observed, while the percentage of tubules with spermatogonia was reduced (p < 0.001). More tubules with alpha-smooth muscle actin (ACTA, peritubular myoid cells (PTMCs) marker) were observed in an RA-absent medium (p = 0.02). CYP17A1/STAR-positive Leydig cells demonstrated sustained steroidogenic function. Our culture conditions support the initiation of spermatocytes and enhanced maturation of Sertoli cells and PTMCs within infant testicular tissues. This study may be a basis for future studies focusing on maintaining and increasing the number of spermatogonia and identifying different factors and hormones, further advancing in vitro spermatogenesis.

Proteome of fluid from human ovarian small antral follicles reveals insights in folliculogenesis and oocyte maturation.

STUDY QUESTION: Is it possible to identify by mass spectrometry a wider range of proteins and key proteins involved in folliculogenesis and oocyte growth and development by studying follicular fluid (FF) from human small antral follicles (hSAF)? SUMMARY ANSWER: The largest number of proteins currently reported in human FF was identified in this study analysing hSAF where several proteins showed a strong relationship with follicular developmental processes. WHAT IS KNOWN ALREADY: Protein composition of human ovarian FF constitutes the microenvironment for oocyte development. Previous proteomics studies have analysed fluids from pre-ovulatory follicles, where large numbers of plasma constituents are transferred through the follicular basal membrane. This attenuates the detection of low abundant proteins, however, the basal membrane of small antral follicles is less permeable, making it possible to detect a large number of proteins, and thereby offering further insights in folliculogenesis. STUDY DESIGN, SIZE, DURATION: Proteins in FF from unstimulated hSAF (size 6.1 ± 0.4 mm) were characterised by mass spectrometry, supported by high-throughput and targeted proteomics and bioinformatics. The FF protein profiles from hSAF containing oocytes, capable or not of maturing to metaphase II of the second meiotic division during an IVM (n = 13, from 6 women), were also analysed. PARTICIPANTS/MATERIALS, SETTING, METHODS: We collected FF from hSAF of ovaries that had been surgically removed from 31 women (∼28.5 years old) undergoing unilateral ovariectomy for fertility preservation. MAIN RESULTS AND THE ROLE OF CHANCE: In total, 2461 proteins were identified, of which 1108 identified for the first time in FF. Of the identified proteins, 24 were related to follicular regulatory processes. A total of 35 and 65 proteins were down- and up-regulated, respectively, in fluid from hSAF surrounding oocytes capable of maturing (to MII). We found that changes at the protein level occur already in FF from small antral follicles related to subsequent oocyte maturation. LIMITATIONS, REASONS FOR CAUTION: A possible limitation of our study is the uncertainty of the proportion of the sampled follicles that are undergoing atresia. Although the FF samples were carefully aspirated and processed to remove possible contaminants, we cannot ensure the absence of some proteins derived from cellular lysis provoked by technical reasons. WIDER IMPLICATIONS OF THE FINDINGS: This study is, to our knowledge, the first proteomics characterisation of FF from hSAF obtained from women in their natural menstrual cycle. We demonstrated that the analysis by mass spectrometry of FF from hSAF allows the identification of a greater number of proteins compared to the results obtained from previous analyses of larger follicles. Significant differences found at the protein level in hSAF fluid could predict the ability of the enclosed oocyte to sustain meiotic resumption. If this can be confirmed in further studies, it demonstrates that the viability of the oocyte is determined early on in follicular development and this may open up new pathways for augmenting or attenuating subsequent oocyte viability in the pre-ovulatory follicle ready to undergo ovulation. STUDY FUNDING/COMPETING INTEREST(S): The authors thank the financial support from ReproUnion, which is funded by the Interreg V EU programme. No conflict of interest was reported by the authors. TRIAL REGISTRATION NUMBER: N/A.

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-ß, 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-ß 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.

Clusters of smooth endoplasmic reticulum are absent in oocytes from unstimulated women.

RESEARCH QUESTION: What is the frequency of morphological dysmorphisms in immature human oocytes collected ex vivo from small antral follicles and matured in vitro? DESIGN: Human ovaries (n = 56) were excised for ovarian tissue cryopreservation (OTC). None of the patients had received exogenous gonadotrophins prior to the procedure. Immature oocytes released from small antral follicles were collected in connection with isolation of the cortex for OTC. The oocytes' maturation stage and the morphological characteristics of the cytoplasm, zona pellucida, perivitelline space and first polar body were assessed after in-vitro maturation (IVM). RESULTS: A total of 1649 immature oocytes were collected: 30% of oocytes matured to the metaphase II (MII) stage after IVM, while metaphase I (MI), germinal vesicle and degenerated oocytes accounted for 20%, 24% and 26%, respectively. The percentages of oocytes without any dysmorphisms were 53%, 92%, and 97% for the MII, MI and germinal vesicle stage oocytes, respectively. The most frequently observed dysmorphisms among the MII oocytes were first polar body fragmentation (22%), homogeneously distributed cytoplasmic granularity (16%) and an enlarged perivitelline space (14%). Interestingly, none of the oocytes at any stage had clusters of smooth endoplasmic reticulum (SER). CONCLUSIONS: Morphological dysmorphisms are present among in-vitro-matured oocytes at all maturation stages. The incidence of dysmorphisms increases as maturation progresses. The most frequent dysmorphism among MII oocytes after IVM was fragmentation of the first polar body. Clusters of SER were not observed in oocytes from unstimulated patients.

A threshold concentration of FSH is needed during IVM of ex vivo collected human oocytes.

PURPOSE: To investigate the effect of different FSH concentrations on human oocyte maturation in vitro and its impact on gene expression of key factors in the surrounding cumulus cells. METHODS: The study included 32 patients who underwent unilateral oophorectomy for ovarian tissue cryopreservation (OTC) (aged 28 years on average). Immature oocytes were collected from surplus medulla tissue. A total of 587 immature oocytes were divided into three categories according to the size of the cumulus mass: large (L-COCs), small (S-COCs), and naked oocytes (NOs), and submitted to 44-h IVM with one of the following concentrations of recombinant FSH: 0 IU/L, 20 IU/L, 40 IU/L, 70 IU/L, or 250 IU/L. After IVM, oocyte nuclear maturation stage and diameter were recorded. The relative gene expression of FSHR, LHCGR, and CYP19A1 in cumulus cells before (day 0; D0) and after IVM were evaluated. RESULTS: Addition of 70 or 250 IU/L FSH to the IVM medium improved oocyte nuclear maturation compared to 0, 20, and 40 IU/L FSH by upregulating LHCGR and downregulating FSHR in the cumulus cells. CONCLUSION: FSH improved oocyte nuclear maturation at concentrations above 70 IU/L suggesting a threshold for FSH during IVM of ex vivo collected human oocytes from small antral follicles. Moreover, current results for the first time highlight that FSH function in vitro is mediated via cumulus cells by downregulating FSHR and upregulating LHCGR, which was also observed when the immature oocytes progressed in meiosis from the GV to the MII stage.

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-ß 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.

Effect of sphingosine-1-phosphate on activation of dormant follicles in murine and human ovarian tissue.

In vitro activation of resting ovarian follicles, with the use of mechanical stress and/or pharmacological compounds, is an emerging and novel approach for infertility treatment. The aim of this study was to assess the sphingolipid, sphingosine-1-phosphate (S1P), as a potential in vitro activation agent in murine and human ovarian tissues and isolated follicles. Juvenile murine ovaries and donated human ovarian tissues, from 10 women undergoing ovarian tissue cryopreservation for fertility preservation, were incubated with or without 12 µM S1P for 3 h for quantitative PCR analysis, and 12 h for xenotransplantation or culture studies. Gene expression analyses were performed for genes downstream of the Hippo signaling pathway. Murine ovaries and isolated murine and human preantral follicles showed significantly increased mRNA expression levels of Ccn2/CCN2 following S1P treatment compared to controls. This increase was shown to be specific for the Hippo signaling pathway and for the S1P2 receptor, as co-treatment with Hippo-inhibitor, verteporfin and S1PR2 antagonist, JTE-013, reduced the S1P-induced Ccn2 gene expression in murine ovaries. Histological evaluation of human cortical tissues (5 × 5 × 1 mm; n = 30; three pieces per patient) xenografted for 6 weeks and juvenile murine ovaries cultured for 4 days (n = 9) or allografted for 2 weeks (n = 48) showed no differences in the distribution of resting or growing follicles in S1P-treated ovarian tissues compared to controls. Collectively, S1P increased Ccn2/CCN2 gene expression in isolated preantral follicles and ovarian tissue from mice and human, but it did not promote follicle activation or growth in vivo. Thus, S1P does not appear to be a potent in vitro activation agent under these experimental conditions.

Hippo signaling, actin polymerization, and follicle activation in fragmented human ovarian cortex.

The Hippo pathway has been associated with regulation of early follicle growth. Studies of murine ovaries suggest that changes in the actin cytoskeleton, caused by fragmentation, result in inhibition of the Hippo pathway, and in turn, may activate follicle growth. In humans, the connections between fragmentation, the actin cytoskeleton, and follicle activation are yet to be confirmed. In this study, we investigated the impact in vitro fragmentation of a human ovarian cortex on (a) actin polymerization, (b) components of the Hippo pathway, and (c) follicle growth in vivo. The results showed that the ratio between globular and filamentous actin remained unchanged at all timepoints (0, 10, 30, 60, 120, and 240 min) following tissue fragmentation. Neither was the Hippo pathway effector protein YES-associated protein upregulated nor was gene expression of the downstream growth factors CCN2, CCN3, or CCN5 increased at any timepoint in the fragmented cortex. Furthermore, the number of growing follicles was similar in fragmented and intact cortex pieces after 6 weeks' xenotransplantation. However, the total number of surviving follicles was considerably lower in the fragmented cortex compared with intact tissue, suggesting detrimental effects of fragmentation on tissue grafting. These results indicate that fragmentation is likely to be ineffective to activate follicle growth in the human ovarian cortex.

GtxA is a virulence factor that promotes a Th2-like response during Gallibacterium anatis infection in laying hens.

GtxA, a leukotoxic RTX-toxin, has been proposed a main virulence factor of Gallibacterium anatis. To evaluate the impact of GtxA during infection, we experimentally infected laying hens with a G. anatis wild-type (WT) strain and its isogenic gtxA deletion mutant (ΔgtxA), respectively, and monitored the birds during a 6 day period. Birds inoculated with ΔgtxA had significantly reduced gross lesions and microscopic changes compared to the birds inoculated with the WT strain. To assess the host response further, we quantified the expression of pro-inflammatory cytokines and apoptosis genes by RT-qPCR. In the ovarian tissue, the expression levels of IL-4 and TNF-α were significantly lower in the ΔgtxA group compared to the WT group, while IL-6 and IL-10 levels appeared similar in the two groups. In the spleen tissue of ΔgtxA infected chickens, IL-4 expression was also lower compared to the WT infected chickens. The results indicated that GtxA plays a key role in an acute cytokine-mediated Th2-like response against G. anatis infection in the ovary tissue. The pro-inflammatory response in the ovary tissue of birds inoculated with ΔgtxA mutant was thus significantly lower than the wild-type response. This was, at least partly, supported by the apoptosis gene expression levels, which were significantly higher in the ΔgtxA mutant compared to the wild-type infected chickens. In conclusion, GtxA clearly plays an important role in the pathogenesis of G. anatis infections in laying hens. Further investigations into the specific factors regulating the host response is however needed to provide a more complete understanding of the bacteria-host interaction.

Improving the maturation rate of human oocytes collected ex vivo during the cryopreservation of ovarian tissue.

PURPOSE: The aim of the present study was to improve the in vitro maturation (IVM) procedure using oocytes from surplus ovarian tissue after fertility preservation. METHODS: Twenty-five patients aged 17-37 years were included in the study. Maturation was compared between oocytes collected in HEPES-buffered medium or saline, and we determined whether transport on ice prior to oocyte collection affected maturation. Two different IVM media were used that were supplemented with and without recombinant human midkine. Mature oocytes were assessed for aneuploidy using next-generation sequencing (NGS). RESULTS: On average, 36 immature oocytes were collected from each patient (range 7-90, N = 895). Oocytes recovered from HEPES-buffered medium matured at a higher rate than oocytes recovered from saline (36% vs 26%, p < 0.01). Ovarian transportation on ice prior to the procedure negatively affected maturation compared with non-transported samples (42% vs 27%, p < 0.01). The addition of midkine improved maturation rate (34% vs 27%, p < 0.05). On average, 11 MII oocytes were obtained per patient (range 1-30). NGS of 53 MII oocytes and their first polar bodies indicated that 64% were euploid. CONCLUSIONS: The study demonstrated unexpectedly high number of immature oocytes collected from surplus ovarian tissue without any stimulation. The overall MII rate was one in three, resulting in a total number of MII oocytes that was similar to the number obtained after ovarian stimulation. If these MII oocytes prove suitable for IVF, they will provide a substantial improvement in fertility preservation for patients and advance IVM as an interesting platform for further improvements in assisted reproduction.

Ovarian cortical follicle density in infertile women with low anti-Müllerian hormone.

PURPOSE: To evaluate the association between anti-Müllerian hormone (AMH) and follicle density in infertile women with diminished ovarian reserve (DOR) versus women with normal ovarian reserve? METHODS: Case-control study comparing follicle densities in ovarian cortex from 20 infertile women with DOR (AMH ≤ 5 pmol/L) and 100 controls with presumed normal ovarian reserve. RESULTS: For all women > 25 years, the follicle densities correlated positively with AMH levels. For each single picomole per liter increase in AMH the follicle density increased by 6% (95% CI 3.3-8.5%) when adjusted for age. This was similar for women with DOR and controls. The follicle density was 1.8 follicles/mm3 cortical tissue in women with DOR versus 7.0 in age-paired controls (p = 0.04). The women with DOR had a median AMH of 1.8 pmol/L versus 14.4 pmol/L in the age-paired control group (p < 0.001). The ratio of AMH/follicle density was 1:1 (1.8/1.8) in women with DOR and 2:1 (14.4/7.0) in the age-paired controls. Analyses for gonadotropin receptor polymorphisms could not explain the characteristics of women with DOR. The proportion of secondary follicles was higher in women with DOR compared with controls (4.6% versus 1.4%, p = 0.0003). Pooling all patients, the follicle density decreased significantly by 7.7% for every year added (p < 0.0001). The women with DOR had lower follicle densities than the controls, but the slopes were equal in the two cohorts. CONCLUSIONS: Follicle density and AMH concentrations correlate also when AMH is low. However, AMH is only a reliable marker for the true ovarian reserve when age is included in the estimation and women with DOR may have more follicles than their AMH levels imply.

Biopsying, fragmentation and autotransplantation of fresh ovarian cortical tissue in infertile women with diminished ovarian reserve.

STUDY QUESTION: Can ovarian biopsying per se and/or autotransplantation of fragmented ovarian cortical tissue activate dormant follicles and increase the number of recruitable follicles for IVF/ICSI in women with diminished ovarian reserve (DOR)? SUMMARY ANSWER: Ovarian biopsying followed by immediate autotransplantation of fragmented cortical tissue failed to increase the number of recruitable follicles for IVF/ICSI 10 weeks after the procedure either at the graft site or in the biopsied ovary, but 12 of the 20 women subsequently had a clinical pregnancy during the 1-year follow-up. WHAT IS KNOWN ALREADY: Infertile women with DOR constitute a group of patients with poor reproductive outcome mainly due to the low number of mature oocytes available for IVF/ICSI. Recent studies have shown that in vitro activation of residual dormant follicles by both chemical treatment and tissue fragmentation has resulted in return of menstrual cycles and pregnancies in a fraction of amenorrhoeic women with premature ovarian insufficiency. STUDY DESIGN, SIZE, DURATION: This is a prospective clinical cohort study including 20 women with DOR treated at the fertility clinic, Rigshospitalet, Denmark, during April 2016-December 2017. Non-pregnant patients were on average followed for 280 days (range 118-408), while women who conceived were followed until delivery. Study follow-up of non-pregnant patients ended in September 2018. PARTICIPANTS, MATERIALS, SETTING, METHODS: The study included infertile women aged 30-39 years with preserved menstrual cycles, indication for IVF/ICSI and repeated serum measurements of anti-Müllerian hormone (AMH) ≤ 5 pmol/L. Patients were randomized to have four biopsies taken from either the left or the right ovary by laparoscopy followed by fragmentation of the cortical tissue to an approximate size of 1 mm3 and autotransplanted to a peritoneal pocket. The other ovary served as a control. Patients were followed weekly for 10 weeks with recording of hormone profile, antral follicle count (AFC), ovarian volume and assessment for ectopic follicle growth. After 10 weeks, an IVF/ICSI-cycle with maximal ovarian stimulation was initiated. MAIN RESULTS AND THE ROLE OF CHANCE: No difference in the number of mature follicles after ovarian stimulation 10 weeks after the procedure in the biopsied versus the control ovaries was observed (1.0 vs. 0.7 follicles, P = 0.35). In only three patients, growth of four follicles was detected at the graft site 24-268 days after the procedure. From one of these follicles, a metaphase II (MII) oocyte was retrieved and fertilized, but embryonic development failed. Overall AMH levels did not change significantly after the procedure (P = 0.2). The AFC increased by 0.14 (95% CI: 0.06;0.21) per week (P < 0.005), and the biopsied ovary had on average 0.6 (95% CI: 0.3;-0.88) follicles fewer than the control ovary (P = 0.01). Serum levels of androstenedione and testosterone increased significantly by 0.63 nmol/L (95% CI: 0.21;1.04) and 0.11 nmol/L (95% CI: 0.01;0.21) 1 week after the procedure, respectively, and testosterone increased consecutively over the 10 weeks by 0.0095 nmol/L (95% CI: 0.0002;0.0188) per week (P = 0.045). In 7 of the 20 patients, there was a serum AMH elevation 5 to 8 weeks after the procedure. In this group, mean AMH increased from 2.08 pmol/L (range 1.74-2.34) to 3.94 pmol/L (range 3.66-4.29) from Weeks 1-4 to Weeks 5-8. A clinical pregnancy was obtained in 12 of the 20 (60%) patients with and without medically assisted reproduction (MAR) treatments. We report a cumulated live birth rate per started IVF/ICSI cycle of 18.4%. LIMITATIONS, REASON FOR CAUTION: Limitations of the study were the number of patients included and the lack of a non-operated control group. Moreover, 9 of the 20 women had no male partner at inclusion and were treated with donor sperm, but each of these women had an average of 6.8 (range 4-9) unsuccessful MAR treatments with donor sperm prior to inclusion. WIDER IMPLICATIONS OF THE FINDINGS: Although 12 out of 20 patients became pregnant during the follow-up period, the current study does not indicate that biopsying, fragmenting and autotransplanting of ovarian cortical tissue increase the number of recruitable follicles for IVF/ICSI after 10 weeks. However, a proportion of the patients may have a follicular response in Weeks 5-8 after the procedure. It could therefore be relevant to perform a future study on the possible effects of biopsying per se that includes stimulation for IVF/ICSI earlier than week 10. STUDY FUNDING/COMPETING INTEREST(S): This study is part of the ReproUnion collaborative study, co-financed by the European Union, Interreg V ÖKS. The funders had no role in the study design, data collection and interpretation, or decision to submit the work for publication. None of the authors have a conflict of interest. TRIAL REGISTRATION NUMBER: NCT02792569.

Time from referral to ovarian tissue cryopreservation in a cohort of Danish women.

INTRODUCTION: Young women with a cancer diagnosis often have very little time to decide whether or not to commence fertility-preserving strategies before initiating potentially sterilizing cancer treatment. Minimizing the interval from opting for fertility preservation to completion of the procedure will reduce the potential risk of delaying cancer treatment. In the current study, we have evaluated the period of time from referral to ovarian tissue cryopreservation (OTC) to actual freezing of the tissue in a cohort of Danish women. MATERIAL AND METHODS: The study population comprised 277 consecutive patients with both malignant and nonmalignant diseases referred for OTC from four centers in the Danish network. Statistical analysis was conducted to analyze the impact of age, diagnosis, and referring center on the time from OTC-referral to OTC. A literature search for "random start" protocols for controlled ovarian stimulation (COS) for fertility preservation in cancer patients was performed. RESULTS: The time from OTC-referral to OTC was significantly influenced by diagnosis, age, and referring center. Women with malignant diseases other than breast cancer, such as sarcomas, pelvic cancers, and hematological cancers, experienced a significantly shorter interval to OTC (5 days) than women with breast cancer (7 days) and nonmalignant diseases including systemic, ovarian, and hereditary conditions (13-17.5 days). Women over the age of 30 years experienced a significantly longer time to OTC (P < 0.03), and the diagnosis determined the length of the interval (P < 0.001). According to the literature, fertility preservation by oocyte vitrification requires 13-14 days, as the average time for 1 round of COS was 11 days and oocyte collection can be performed 2 days later. CONCLUSIONS: It is in the interest of both cancer patients and clinicians to perform fertility preservation as quickly and safely as possible. In a Danish setting, OTC provides a short interval of around 6 days from the patient choosing this option to completion of the procedure. This is considerably less time than what is needed to perform COS and oocyte vitrification, and therefore OTC might be considered the preferred choice of fertility preservation when urgency is needed.

Transcription profile of the insulin-like growth factor signaling pathway during human ovarian follicular development.

PURPOSE: The IGF signaling cascade exerts important regulatory functions in human ovarian folliculogenesis. The scope of this study was to evaluate the transcription profile of insulin-like growth factor (IGF) genes during human ovarian follicle development and to analyze follicle fluid levels of key IGF proteins. METHODS: Gene expression profiling was performed with microarray gene analysis. The analysis was assessed from ovarian follicles and granulosa cells (GCs) obtained from isolated stage-specific human ovarian follicles, including preantral follicles, small antral follicles, and preovulatory follicles. Numerous genes involved in the IGF signaling pathway was evaluated and key genes were validated by qPCR from GCs. Protein levels of various IGF components of human follicular fluid (FF) were measured by ELISA and time-resolved immunofluorometric assays (TRIFMA). RESULTS: The gene expression levels of PAPPA, IGF2, IGF receptors and intracellular IGF-activated genes increased with increasing follicle size. This was especially prominent in the late preovulatory stage where IGF2 expression peaked. Protein levels of intact IGF binding protein-4 decreased significantly in FF from large preovulatory follicles compared with small antral follicles concomitant with higher protein levels of PAPP-A. The IGF modulators IGF-2 receptor, IGFBPs, stanniocalcins, and IGF-2 mRNA binding proteins were all observed to be expressed in the different follicle stages. CONCLUSIONS: This study confirms and highlights the importance of PAPP-A regulating bioactive IGF levels throughout folliculogenesis and especially for the high rate of granulosa cell proliferation and expression of key ovarian hormones important in the last part of the follicular phase of the menstrual cycle.