Parameters affecting successful transplantation of frozen-thawed human fetal ovaries into immunodeficient mice

OBJECTIVE: To compare the development and survival of human fetal follicles frozen-thawed with dimethylsulfoxide (DMSO) and propandiol (PROH) in immunodeficient mice, to study the effects of host treatment with FSH, and to compare kidney and subcutaneous transplantation. DESIGN: Controlled histologic study. SETTING: Major tertiary care and referral academic center.Twenty-one women undergoing second-trimester pregnancy termination.Microscopic morphometric analysis and immunocytochemistry for proliferating-cell nuclear antigen in human fetal ovaries grafted into immunodeficient mice. RESULTS: Renal grafts that were frozen-thawed with DMSO rather than PROH survived better in the hosts (79.6% compared with 58.8%), but significantly more follicles were identified in grafts frozen-thawed with PROH (P<.001). Follicular development was observed only in FSH-treated hosts, and follicular survival and development was better in the kidney than the subcutaneous site.CONCLUSION(S): This is the first report showing development of human fetal follicles in immunodeficient mice. Freezing-thawing with PROH seems to support development and survival better than with DMSO. The kidney is a better transplantation site than the subcutaneous site, probably because of its superior vascularization. Administration of FSH to the host is essential for follicular development. Follicular development and growth was better in ovarian grafts from older fetuses, as they contained more formed follicles.     

Follicular growth in fresh and cryopreserved human ovarian cortical grafts transplanted to immunodeficient mice.

OBJECTIVE: To investigate follicle growth in fresh and cryopreserved human ovarian cortical grafts transplanted to immunodeficient mice. STUDY DESIGN: Fresh or frozen-thawed human ovarian cortex was grafted subcutaneously or under the kidney capsule of 43 mice (35 nude mice and eight SCID mice), 14 of which were non-stimulated controls, 21 injected intra-peritoneally with gonadotrophins during 2 weeks and eight injected during 3 months. Follicle count was compared by Chi-square. RESULTS: Proportions of primordial follicles were significantly lower in grafts than in the tissue before transplantation in gonadotrophin-stimulated mice (37% versus 79%), but not in non-stimulated mice (51% versus 74%). Proportions of primary and secondary follicles were increased after transplantation indicating early follicular growth. One antral follicle was observed in a graft in a mouse stimulated for 3 months. CONCLUSION: Primordial follicles in fresh or frozen-thawed human ovarian cortex transplanted under the kidney capsule or subcutaneously can grow and are responsive to hormonal stimulation. Condensation: Primordial follicles in fresh and cryopreserved human ovarian cortical grafts can initiate growth after transplantation to immunodeficient mice     

Blastocyst Development After Cryopreservation and Subcutaneous Transplantation of Mouse Ovarian Tissue

Purpose To investigate follicle survival and developmental potential with IVF of cryopreserved, subcutaneously transplanted mouse ovarian tissue.Methods Fresh and frozen mouse ovarian tissue was autologously transplanted into subcutaneous tissue. Two weeks after the transplantation, the morphology and histology of the fresh and frozen grafts were compared. Superovulation and IVF was performed to evaluate the fertility potential of the frozen ovarian graft.Results Both fresh and frozen grafts of ovarian tissue survived in 14 of 16 mice (88%). Morphologically, both types of grafts resembled fresh ovarian tissue and contained follicles at all stages of folliculogenesis. A total of 73% of follicles in fresh grafts and 62% in frozen grafts survived after transplantation compared with fresh ovarian tissue. Sixteen ICR mice underwent superovulation. A total of 56 oocytes from antral follicles were recovered from the subcutaneously transplanted cryopreserved ovarian tissue. Fourteen (25%) oocytes were in metaphase II stage, 6 were fertilized by IVF, and 2 progressed to the blastocyst stage.Conclusions Cryopreservation and subcutaneous transplantation of ovarian tissue provides a possible means of fertility preservation. The main loss of follicles occurred during grafting rather than during freezing and thawing.     

4种冷冻-解冻方法对家兔卵巢组织形态学的影响

目的:探讨适宜的卵巢组织冻存方案。方法:采用PROH(A2组)及DMSO(B2组)慢速程序化冷冻和DMSO+PROH(C2组)及DMSO+EG(D2组)玻璃化冷冻方法,冻存家兔卵巢组织,解冻复苏后,以相应的4组新鲜组织为对照(A1-D1组),做HE染色,行组织形态学分析。结果:A1-D1组始基卵泡的形态正常率分别为90.1%、91.5%、91.8%、92.2%,其相对应的A2-D2组分别下降为67.6%、69.7%、70.5%、80.1%,差异均有统计学意义(P均<0.05)。冷冻组中A2组始基卵泡形态正常率最高,与B2、C2、D2组比,差异有显著性(P<0.05)。C2、D2组间比,差异无显著性(P>0.05)。各冷冻组合并后形态正常率始基卵泡为72.7%,初级卵泡为55.7%,两者比较有统计学差异(P<0.05)。4个冷冻组中均可见卵巢组织结构受损的表现。结论:4种冷冻解冻方法对卵巢皮质中各级卵泡及卵巢组织结构均造成一定程度的损害,使各级卵泡的形态正常率明显下降,卵巢间质细胞连接变得疏松;PROH慢速程序化冷冻法明显优于DMSO法及玻璃化法,较适合卵巢组织中始基卵泡的保存;冻存卵巢组织对初级卵泡的影响大于始基卵泡。     

Beneficial effect of desialylated erythropoietin administration on the frozen-thawed canine ovarian xenotransplantation

Purpose

The main drawback of ovarian cryopreservation followed by transplantation is that a large proportion of follicles are lost after transplantation. Thus, effects of erythropoietin (EPO) and desialylated EPO administration on the frozen-thawed canine ovarian xenotransplantation were examined.

Methods

The protective and survival-promoting effects of EPO and desialylated EPO on the follicles of frozen-thawed canine ovaries after transplantation were examined using NOD-SCID mice. Frozen-thawed dog ovarian tissue with 400 U/kg of EPO or asialo EPO was placed into the ovarian bursa.

Results

At 4 weeks after the transplantation, the ovaries were removed and subjected to histological examination. The survival rate of early primary follicles was 15.2% in the EPO group and 157.6% in the asialo EPO group, in contrast to 10.1% in the untreated group.

Conclusions

These results demonstrate that administration of asialo EPO could be effectively used to enhance the survival of the follicles of transplanted cryopreserved ovaries.     

Heterotopic ovarian transplantation without vascular pedicle in syngeneic Lewis rats: long-term evaluation of effects on ovarian structure and function

OBJECTIVE: To assess the long-term efficacy of intraperitoneal (IP) and subcutaneous (SC) ovarian autotransplantation in rats. DESIGN: Experimental animal study. SETTING: Unit of Experimental Research, Barcelona University School of Medicine. ANIMAL(S): Female syngeneic Lewis rats aged 14 weeks. INTERVENTION(S): Group A, control group undergoing ovariectomy (n = 15); group B, undergoing ovariectomy and IP autologous heterotopic transplant (n = 15); and group C, ovariectomized with SC autologous heterotopic transplant (n = 15). In groups B and C, five animals were killed and their ovaries removed for morphometric analysis at 30 days after transplantation; five additional animals were killed at 180 days, and the remaining five animals were killed at 360 days. MAIN OUTCOME MEASURE(S): Ovarian morphometric analysis and serial measurement of E(2) and FSH serum levels. RESULT(S); The mean number of antral follicles in the control group A was significantly higher than that observed in the ovarian grafts collected and examined 30 days after grafting in rats from groups B and C, but the mean granulosa cell area was significantly higher in both transplantation groups than in controls because of ovarian follicular hyperplasia. Histological examination of ovaries removed at 6 and 12 months after grafting in groups B and C showed increasing degrees of fibrosis, loss of primordial follicles, and the presence of epithelial cysts. In groups B and C, from day 30 after surgery onward, serum E(2) was significantly higher and FSH significantly lower, respectively, than in group A. E(2) and FSH patterns in groups B and C were similar throughout the study period. CONCLUSION(S): Heterotopic ovarian transplantation without vascular pedicle in rats is characterized by follicular hyperplasia endocrinologically functional, followed by progressive loss of follicles in heterotopic ovarian autografts.     

Transplantation of cryopreserved human ovarian tissue results in follicle growth initiation in SCID mice

OBJECTIVE: To determine the long-term survival of frozen-thawed human ovarian tissue as xenografts in severe-combined-immunodeficiency (SCID) mice. DESIGN: Animal study. SETTING: Animal and laboratory facilities at an academic center. PATIENT(s): Ovarian tissue obtained from a 27-year-old woman. INTERVENTION(s): Grafting of frozen-thawed ovarian tissue in SCID mice for 22 weeks. MAIN OUTCOME MEASURE(s): Follicle counts and growth by morphology and PCNA staining in frozen-thawed grafts and fresh controls. RESULT(s): All three grafts were recovered intact after 22 weeks. Their stroma was devoid of necrotic cells and contained healthy follicles. The ratio of primordial-total follicles decreased significantly after grafting (0.94 +/- 0.02 to 0.87 +/- 0. 01, control vs. grafting). Compared with controls, after 22 weeks of grafting, a higher percentage of follicles had initiated growth (5.6 +/- 2.4 vs. 12.5 +/- 1.9), but there was still a significant number of primordial follicles/graft (75 +/- 6.8). Follicle stages were similar between two groups; only primordial and one-layer follicles were seen in the xenografts. In the controls, except for one two-layer follicle, the most advanced follicle was at the one-layer stage. CONCLUSION(s): Human primordial follicles survive freeze-thaw and long-term xenografting procedures and retain their capacity to initiate growth. These findings encourage future attempts for human autologous ovarian transplantation.     

荷人卵巢上皮癌裸鼠冻融卵巢组织移植的效果评价

目的:获取人卵巢上皮癌裸鼠原位移植瘤癌旁正常卵巢组织,经安全筛查并冻融后移植至去势裸鼠体内,探讨移植后效果,为临床应用提供依据。方法:将人卵巢上皮癌OVCAR3细胞种植于裸鼠皮下以获取瘤源,并进行卵巢原位移植,建立卵巢癌原位移植瘤模型,解剖裸鼠获取癌旁正常卵巢组织。癌旁组:取筛选后的癌旁卵巢组织进行玻璃化冷冻,复苏后分别进行皮下及原位移植,各20例;对照组:同龄正常裸鼠卵巢组织,皮下移植及原位移植各20例;去势裸鼠组:20只同龄去势裸鼠;正常卵巢组:20只同龄正常裸鼠。移植12周后,分析各组裸鼠卵巢组织内卵泡形态及激素分泌功能。结果:40只人卵巢上皮癌裸鼠原位移植瘤模型中共获取35份活检正常的癌旁卵巢组织,获取率87.5%(35/40)。玻璃化冷冻前后卵巢组织中卵泡形态及各级卵泡比例均无显著差异(P>0.05),癌旁冷冻组织和癌旁新鲜组织的异常卵泡比例差异无统计学意义(P>0.05),冷冻组织以初级卵泡及次级卵泡等窦前卵泡为主。癌旁组皮下移植组织存活率80%(16/20),对照组皮下移植组织存活率90%(18/20),癌旁组原位移植组织存活率90%(18/20),对照组原位移植组织存活率95%(19/20)。移植后组织内卵泡以次级卵泡及窦状卵泡为主,各级卵泡的形态及构成比和未移植的同龄正常裸鼠卵巢相似(P>0.05);癌旁组卵泡数明显低于对照组(P<0.05)及正常卵巢组(P<0.01);皮下移植和原位移植组织内的各级卵泡数差异无统计学意义(P>0.05)。癌旁组卵泡刺激素水平明显低于去势裸鼠组,而雌二醇水平明显高于去势裸鼠组(P<0.01);癌旁组卵泡刺激素水平明显高于对照组(P<0.05)及正常卵巢组(P<0.01),而雌二醇水平明显低于对照组(P<0.05)及正常卵巢组(P<0.01);皮下移植和原位移植的卵泡刺激素水平和雌二醇水平差异无统计学意义(P>0.05)。结论:癌旁卵巢组织冻融移植后有正常卵泡发育及激素分泌功能;皮下移植和原位移植均可取得较好的效果;癌旁卵巢组织冻融移植有望作为卵巢上皮癌患者治疗后恢复卵巢内分泌功能的有效手段。     

人脐血单个核细胞移植治疗放射性裸鼠卵巢早衰

目的:探讨人脐血单个核细胞(HCMNCs)移植治疗卵巢早衰(POF)的可行性及疗效。方法 :雌性BALB/C裸鼠105只,随机分为空白对照组、POF对照组、POF+人脐血单个核细胞移植组。钴60γ射线照射建立POF模型,聚蔗糖(Ficoll)密度梯度离心法制备HCMNCs悬液,并以5-溴-2′-脱氧尿苷(BrdU)标记。POF造模成功后,移植组双侧卵巢内注入标记的HCMNCs悬液,POF对照组双侧卵巢内注入同等量的达尔伯克改良伊格尔氏低培养基(L-DMEM)培养液,空白对照组未行任何处理。移植后4周,酶联免疫吸附试验(ELISA)法测定血清雌二醇(E2)、卵泡刺激素(FSH)、黄体生成激素(LH)水平变化,并取卵巢组织行苏木素-伊红(HE)染色、BrdU组化染色,观察卵巢卵泡数目变化及移植细胞成活情况。结果:在移植组发现移植的脐血单个核细胞可在早衰的卵巢内存活并参与卵巢功能的修复;血清E2、FSH、LH与POF对照组相比,E2明显升高(P<0.05),FSH和LH明显降低(均P<0.05);卵巢切片HE染色示未闭锁卵泡数目有所增加,并可见各个发育阶段卵泡;免疫组化示移植的人脐血单个核细胞可在裸鼠卵巢内定居并存活。结论:HCMNCs可成功植入裸鼠放射性早衰卵巢内,并能改善其功能。     

Growth of follicles of various animals following ovarian grafting under the kidney capsules of immunodeficient mice

Aim:  Various researchers have studied xenografting ovarian tissues into immunodeficient mice to accelerate the follicular growth of several mammalian species. In this study, the authors focused on the following three points in growing follicles in transplanted ovarian tissues under kidney capsules: the effects of the storage conditions of the donor ovarian tissues, the effects of donor age on the survival rates of grafted mouse ovaries, and the methods used to grow the follicles of xenografted bovine ovaries.
Methods and Results:  When ovaries stored for 0, 6, 12 or 24 h at 4°C and at room temperature were transplanted under the kidney capsules of immunodeficient mice, fewer mouse and rabbit grafts survived following 24 h storage. The survival rates of bovine grafts were relatively low for all storage times. When mouse ovaries were held for 24 h at 4°C or at room temperature, low-temperature storage effectively improved the survival rates of the grafts. Although the survival rates of grafted genital ridges containing premeiotic germ cells from fetuses and grafted ovaries from mice 0, 10, 20, 40 and 80 days after birth were similar among donors of different ages, the cleavage rate of oocytes following insemination was significantly lower in the grafts from the ovaries of 80-day-old mice. Antral follicles formed in surviving bovine ovarian grafts. Cumulus–oocyte complexes were collected from the grafted ovaries of fetuses and calves, and the oocytes reached the metaphase II stage following culture, but they did not develop to the pronuclear stage after in vitro fertilization.
Conclusion:  Our findings provide basic data on xenografting ovarian tissues into immunodeficient mice to accelerate the growth of follicles. (Reprod Med Biol 2008; 7 : 45–54)     

Is transplantation of cryopreserved ovarian tissue from patients with advanced-stage breast cancer safe? A pilot study

Purpose

To assess the safety of reimplantation of cryopreserved ovarian tissue from advanced-stage breast cancer patients.

Methods

Cryopreserved ovarian cortical fragments were obtained from 13 advanced-stage breast cancer patients aged 17–35 years. After thawing, part of the ovarian cortical tissue was grafted to severe combined immunodeficient mice for 6 months. The presence of malignant mammary cells in ovarian tissue was evaluated after thawing as well as after grafting by 1) histology and immunohistochemistry (epithelial membrane antigen, Her2/neu and gross cystic disease fluid protein 15 identification), and 2) detection of the MGB2 gene by qPCR.

Results

No malignant cells were evidenced by histology and immunohistochemistry. None of the mice died during the 6-month grafting period, nor developed macroscopically visible masses. MGB2 gene expression was detected by qPCR and confirmed by sequencing in frozen-thawed ovarian tissue in 4 cases and in grafts in 1 case.

Conclusions

This pilot study is the first to evaluate the risk of contamination of cryopreserved ovarian tissue from advanced-stage breast cancer patients by xenotransplantation for 6 months to immunodeficient mice, associated with more conventional screening methods. Our xenografting results are reassuring, but caution needs to be exercised, as MGB2 gene expression was detected in some cases. Larger numbers of ovarian tissue samples from patients with advanced-stage breast cancer are required to confirm our findings before ovarian tissue transplantation can be contemplated in these patients.     

人胎儿卵巢移植可行性的实验研究

目的 探讨胎儿卵巢能否用于临床移植。方法 取自流产或病理原因水囊引产的胎儿卵巢共４９份。将卵巢切成碎块进行组织培养,培养后观察组织学变化,同时测定培养液中雌二醇（Ｅ２）浓度;取培养前后胎儿卵巢用免疫组化法检测ＦＳＨ－Ｂｉｎｄｉｎｇ、ＬＨ－Ｂｉｎｄｉｎｇ、ＬＨ－Ｒ、ＨＬＡ－ＡＢＣ、ＨＬＡ－ＤＲ抗原含量;观察冷冻保存后卵泡形态发育及Ｅ２分泌。结果 胎儿卵巢在体外培养条件下,能进一步发育,而且能分泌Ｅ２     

Timing of FSH-stimulation and follicular development in cryopreserved human ovarian grafts

Cryopreserved human primordial follicles grafted into immunodeficient hosts are susceptible to gonadotrophic stimulation but the optimal interval between grafting and stimulation has not been determined. The effect of stimulation with FSH at different time intervals after grafting was therefore investigated. Cryopreserved human ovarian cortical grafts from an androgen pre-treated female-to-male transsexual patient were transplanted into four groups of four non-obese, diabetic severe combined immune deficiency (NOD-SCID) mice. Ten, 12, 14 and 17 weeks after grafting, stimulation was started with daily intra-peritoneal injections of 5 IU of recombinant FSH for 14 days. Grafts were recovered and serially sectioned for counting the number of follicles and determining the different stages of development. Significantly more primary and secondary follicles were found in all stimulated groups compared with the non-stimulated control. This progression from the primordial to growing primary and secondary stages was most significant in the 14 weeks interval group. Formation of antral follicles was scarce and was only noticed in the 10 and 17 week groups. Cystic follicles and follicles with structural oocyte abnormalities were encountered in each group. Whether this phenomenon is related to the hormonal state of the tissue donor or to the cryopreservation and transplantation procedures is the subject of further investigation. It is concluded that the interval between grafting of ovarian tissue and the start of gonadotrophic stimulation may be important for an optimal follicular development after grafting.     

Basal lamina characterization in frozen-thawed and long-term grafted human prepubertal ovarian tissue

Research questionAre there differences in the composition and structure of the basal lamina surrounding follicles in prepubertal versus adult human ovarian tissue?DesignFrozen-thawed human ovarian tissue from six prepubertal and seven adult patients was divided into three fragments in each case: two for non-grafted tissue evaluation and one for long-term xenografting to mice. Collagen IV and laminin expression were investigated by immunohistochemistry before and after grafting. The basal lamina was analysed by transmission electron microscopy on frozen-thawed tissue.ResultsIn frozen-thawed tissue, collagen IV was significantly less expressed around prepubertal follicles than around adult follicles (primordial, P = 0.02; intermediate/growing follicles, P = 0.03), while laminin was significantly more expressed (primordial, P = 0.03; intermediate, P = 0.01). Collagen IV expression was significantly higher around prepubertal primordial follicles in grafted tissue than in non-grafted tissue, reaching similar levels to those in adult tissue. Ultrastructure analysis showed the basal lamina around follicles in prepubertal frozen-thawed tissue to be rather patchy and thinner than around adult follicles (primordial/intermediate, P = 0.001; primary, P = 0.02).ConclusionsIn frozen-thawed tissue, the basal lamina around prepubertal follicles is less mature than around adult follicles, but it becomes similar in both prepubertal and adult subjects after grafting. Grafting could therefore induce maturation of the basal lamina around prepubertal follicles.     

Cryopreservation of human ovarian tissue: effect of spontaneous and initiated ice formation

This investigation compared conventional freezing of human ovarian tissue using either spontaneous or initiated ('seeded') ice formation. Biopsies of ovarian tissue were obtained from women with indications for chemotherapy or radiotherapy. Small pieces of experimental tissue were randomly distributed into three groups that were then subjected to different treatments prior to culture in vitro for 16 days: the control group, no treatment, cultured immediately after biopsy (group 1); cryopreservation/thawing with spontaneous ice formation (group 2); and cryopreservation/thawing with initiated ice formation (group 3). Follicle viability and hormonal activity were then evaluated. There was no significant difference between groups regarding the concentration of oestradiol 17-beta in the culture supernatant, whereas progesterone concentration was significantly (P < 0.05) higher in group 1 compared with group 2 or 3. There was a significant (P < 0.05) difference in primordial and primary follicle density between all of the groups (group 1 having the highest and group 2 having the lowest) and group 2 had significantly (P < 0.05) fewer normal grade follicles than the other two groups. For optimal cryopreservation of human ovarian tissue, the protocol of conventional freezing should therefore include a step of initiated ice formation.     

Follicular development,ovulation, and corpus luteum formation in cryopreserved human ovarian tissue after xenotransplantation

OBJECTIVE: To assess the competency of human frozen/thawed ovarian follicles matured in xenografts to form functioning corpora luteae after human chorionic gonadotropin (hCG) administration. DESIGN: Prospective controlled animal study. SETTING: University research laboratory. PATIENT(S): Three women (19, 28, and 36 years) who underwent oophorectomy. ANIMAL(S): Nineteen female severe combined immunodeficient (SCID) mice. INTERVENTION(S): Cryopreserved human ovarian tissues were grafted into the s.c. space of bilaterally oophorectomized SCID mice. All the animals were stimulated with pregnant mare's serum gonadotropin (PMSG) for 4 weeks starting from 16 weeks after transplantation. Twelve animals were injected with hCG at the end of gonadotropin stimulation. MAIN OUTCOME MEASURE(S): [1] The rate of grafts with growing follicles, with antral follicles, and/or with corpora luteae. [2] The histologic assessment of follicles and corpora luteae. [3] The serum progesterone and estradiol level in animals with corpus luteum in the grafts.RESULT(S): [1] The rate of grafts with growing follicles and with corpora luteae was 33% to 100%, and 28% to 50%, respectively. [2] Corpora luteae in xenografts were all morphologically normal. [3] The progesterone levels were all above 3.0 ng/mL. CONCLUSION(S): This study showed that the cryopreserved human ovarian follicles can be matured to a stage at which they can form functioning corpora luteae in the host animal.     

Histologic and ultrastructural evaluation of fresh and frozen-thawed human ovarian xenografts in nude mice

OBJECTIVE: To compare histologic and ultrastructural characteristics of fresh and frozen-thawed human ovarian cortical tissue grafted into nude mice. DESIGN: Experimental prospective study. SETTING: An academic research environment. PATIENT(S): Ovarian biopsy specimens were obtained from 13 women undergoing laparoscopy for tubal ligation or infertility. ANIMAL(S): Forty nude mice. INTERVENTION(S): A minilaparotomy was performed to place fresh and frozen-thawed ovarian grafts subcutaneously (sc) or intraperitoneally (ip). Removal of the ovarian grafts was performed at 24 days. MAIN OUTCOME MEASURE(S): [1] the follicular population, [2] fibrosis, [3] vascularization of the grafted tissue, and [4] ultrastructural evaluation. RESULT(S): A greater fibrosis relative surface area was noted in frozen-thawed transplanted tissue than in fresh transplants. Regardless of this fibrosis, a similar follicular density was observed in fresh and frozen-thawed ovarian tissue 24 days after transplantation. Active angiogenesis was proved by both immunohistochemical study of the vascular endothelial growth factor and morphometric study of the vascular network. Normal ultrastructural characteristics were noted in frozen-thawed ovarian biopsies. CONCLUSION(S): Angiogenesis allows implantation of the graft even if it has been cryopreserved and thawed similarly to implantation of fresh tissue. The greater fibrosis observed in grafts after cryopreservation and implantation does not seem to affect the primordial and primary ovocyte population and their ultrastructural characteristics, but further studies must be conducted to prove that after cryopreservation and transplantation, ovocytes may achieve full maturation and fertilization.     

Restoration of ovarian function after autotransplantation of intact frozen-thawed sheep ovaries with microvascular anastomosis

OBJECTIVE: To test the feasibility of transplanting an intact frozen-thawed ovary with microvascular anastomosis of the ovarian vascular pedicle to the deep inferior epigastric vessels. DESIGN: Chronic survival study. SETTING: Biological Resources Unit, The Cleveland Clinic Foundation. ANIMAL(S): Adult merino ewes. INTERVENTION(S): Bilateral laparoscopic oophorectomy was performed on 17 synchronized ewes. In one group of animals (Group I, n = 11), both ovaries were cryopreserved intact with their vascular pedicles. In another group of animals (Group II, n = 6), ovarian cortical strips were prepared from each ovary and cryopreserved. After thawing, follicular viability and apoptosis rates were assessed using one ovary. The other ovary was transplanted to the abdominal wall with microvascular anastomosis (Group I). In Group II, the ovarian cortical strips were placed in the anterior abdominal wall. Ovaries were harvested after 8-10 days in situ and subjected to histological evaluation. MAIN OUTCOME MEASURE(S): Blood flow, apoptotic signals, follicular viability, serum estradiol (E(2)), follicle-stimulating hormone (FSH), and histology. RESULT(S): No significant differences were found in the mean values of apoptosis (mostly in the atretic and some secondary follicles) and follicular viability in both groups. In Group I, immediate and long-term patency were documented in 100% and 27% (3/11) of the grafts, respectively; and postoperative FSH levels were similar to preoperative values in animals with patent vessels. In Group II, postoperative FSH levels were significantly higher than the preoperative ones (P=.03). CONCLUSION(S): Transplantation of an intact frozen-thawed ovary is technically feasible. Using this approach, immediate restoration of vascular supply and ovarian hormonal functions is possible.     

Expression of inhibitor proteins that control primordial follicle reserve decreases in cryopreserved ovaries after autotransplantation

Purpose

Even with 86 live births reported globally so far, the mechanism of primordial follicle loss following autotransplantation of the frozen-thawed ovarian tissue needs further evaluation. Pten, Tsc1, p27, and Amh are the inhibitor proteins that play crucial roles in suppressing the transition from the primordial follicle to primary state, maintaining the primordial follicle reserve. In this study, we aimed to evaluate whether the expression patterns of these proteins change and it may be related to the global primordial follicle loss after autotransplantation of the frozen-thawed ovarian tissue.

Methods

Four groups were established in rats: fresh-control, frozen/thawed, fresh-transplanted, and frozen/thawed and transplanted. After slow freezing and thawing process, two ovarian pieces were transplanted into the back muscle of the same rat. After 2 weeks, grafts were harvested, fixed, and embedded into the paraffin block. Normal and atretic primordial/growing follicle count was performed in all groups. Ovarian tissues were evaluated for the dynamic expressions of the Pten, Tsc1, p27, and Amh proteins using immunohistochemistry, and H-score analyses were done.

Results

Ovarian tissue cryopreservation does not change the expression patterns of inhibitory proteins that control ovarian reserve. Both in fresh and frozen/thawed autotransplanted groups, the expression of inhibitory proteins and Amh decreased significantly in primordial follicles and in growing follicles, respectively. In control group and in frozen/thawed group, primordial follicle counts were similar but decreased by almost half in both fresh-transplanted and frozen/thawed and transplanted groups.

Conclusions

One of the causes of primordial follicle loss after transplantation of ovarian graft may be decreased expression of the inhibitory proteins that guard the ovarian reserve and transplantation itself seems to be the major cause for disruption of inhibitory molecular signaling. Our findings highlight important molecular aspects for future clinical applications for fertility preservation in humans.