The effect of sperm DNA fragmentation on the incidence and origin of whole and segmental chromosomal aneuploidies in human embryos.

In brief: Whether sperm DNA fragmentation (SDF) affects embryo development and clinical outcomes is still controversial, which limits the utility of SDF testing in assisted reproductive technology management. This study demonstrates that high SDF is associated with the incidence of segmental chromosomal aneuploidy and increased paternal whole chromosomal aneuploidies. Abstract: We aimed to investigate the correlation of sperm DNA fragmentation (SDF) with the incidence and paternal origin of whole and segmental chromosomal aneuploidies of embryos at the blastocyst stage. A retrospective cohort study was conducted with a total of 174 couples (women aged 35 years or younger) who underwent 238 cycles (including 748 blastocysts) of preimplantation genetic testing for monogenic diseases (PGT-M). All subjects were divided into two groups based on the sperm DNA fragmentation index (DFI) level: low DFI (<27%) and high DFI (≥27%). The rates of euploidy, whole chromosomal aneuploidy, segmental chromosomal aneuploidy, mosaicism, parental origin of aneuploidy, fertilization, cleavage, and blastocyst formation were compared between low- and high-DFI groups. We found no significant differences in fertilization, cleavage, or blastocyst formation between the two groups. Compared to that in the low-DFI group, segmental chromosomal aneuploidy rate was significantly higher in the high-DFI group (11.57% vs 5.83%, P = 0.021; OR: 2.32, 95% CI: 1.10-4.89, P = 0.028). The whole chromosomal embryonic aneuploidy of paternal origin was significantly higher in cycles with high DFI than in cycles with low DFI (46.43% vs 23.33%, P = 0.018; OR: 4.32, 95% CI: 1.06-17.66, P = 0.041). However, the segmental chromosomal aneuploidy of paternal origin was not significantly different between the two groups (71.43% vs 78.05%, P = 0.615; OR: 1.01, 95% CI: 0.16-6.40, P = 0.995). In conclusion, our results suggested that high SDF was associated with the incidence of segmental chromosomal aneuploidy and increased paternal whole chromosomal aneuploidies in embryos.

The time interval between oocyte retrieval and frozen embryo transfer does not impact reproductive outcomes.

RESEARCH QUESTION: Does the time interval between oocyte retrieval and frozen embryo transfer (FET) affect pregnancy outcomes after a freeze-all strategy? DESIGN: Retrospective study including a total of 5995 patients who underwent their first FET following a freeze-all cycle between 1 January 2017 and 31 December 2020. Patients were divided into immediate (the interval between oocyte retrieval and the day of first FET ≤40 days), delayed (>40 days but ≤180 days) and overdue groups (>180 days). Pregnancy and neonatal outcomes were analysed, and multivariable regression analysis was used to study the effect of FET timing on the live birth rate (LBR) in the entire cohort and the different subgroups. RESULTS: The LBR was significantly lower in the overdue group than in the delayed group (34.9% versus 42.8%, P = 0.002); however, after adjusting for confounding factors, the difference was not statistically significant. The immediate group had a comparable LBR (36.9%) to the other two groups in both the crude and adjusted analyses. Multivariable regression analysis showed no impact of FET timing on LBR in the whole cohort or in the subgroups according to ovarian stimulation protocol, trigger type, insemination method, reason for freezing all, FET protocol or transferred embryo stage. CONCLUSIONS: The time interval between oocyte retrieval and FET does not impact reproductive outcomes. Unnecessary delays in FET should be avoided to shorten the time to live birth.

The correlation between morphological parameters and the incidence of de novo chromosomal abnormalities in 3238 biopsied blastocysts.

PURPOSE: The aim of this study was to determine the relationship between morphological parameters and the incidence of de novo chromosomal abnormalities. METHODS: This was a retrospective cohort study of 652 patients who underwent 921 cycles with 3238 blastocysts biopsied. The embryo grades were evaluated according to Gardner and Schoolcraft's system. The incidence of euploidy, whole chromosomal aneuploidy (W-aneuploidy), segmental chromosomal aneuploidy (S-aneuploidy), and mosaicism in trophectoderm (TE) cell biopsies was analyzed. RESULTS: The euploidy decreased significantly with maternal age and was positively correlated biopsy day and morphological parameters. The W-aneuploidy increased significantly with maternal age and was negatively correlated biopsy day and morphological parameters. Parental age, TE biopsy day, and morphological parameters were not associated with S-aneuploidy and mosaicism, except that TE grade C blastocysts had significantly higher mosaicism than TE grade A blastocysts. Subanalysis in different female age groups showed that euploidy and W-aneuploidy had a significant correlation with TE biopsy day among women aged ≤ 30 y and 31-35 y, with expansion degree among women aged ≥ 36 y, with ICM grade among women aged ≥ 31 y, and with TE grade among all female age ranges. CONCLUSION: Female age, embryo developmental speed and blastocyst morphological parameters are associated with euploidy and whole chromosomal aneuploidy. The predictive value of these factors varies across female age groups. Parental age, embryo developmental speed, expansion degree, and ICM grade are not associated with the incidence of segmental aneuploidy or mosaicism, but TE grade seemingly has a weak correlation with segmental aneuploidy and mosaicism in embryos.

Age-related changes in human conventional semen parameters and sperm chromatin structure assay-defined sperm DNA/chromatin integrity.

RESEARCH QUESTION: What are the correlations between male age, traditional semen parameters, sperm DNA fragmentation index (DFI) and high DNA stainability (HDS) in a sufficiently large sample size? DESIGN: Retrospective cohort study of 18,441 semen samples, with data divided into seven age groups according to male age: ≤25, 26-30, 31-35, 36-40, 41-45, 46-50 and ≥51 years. RESULTS: Age was negatively correlated with semen volume, total sperm count, motility and HDS, and positively correlated with sperm concentration and DFI (P < 0.001). After 35 years of age, semen volume and total sperm count began to decline. After 30 years of age, motility and HDS decreased consistently. Sperm concentration and DFI increased from 26-30 years of age. DFI was negatively correlated with sperm concentration, total sperm count, motility and normal morphology (P < 0.001) and positively correlated with semen volume and HDS (P < 0.001). HDS was negatively correlated with all parameters (P < 0.001) except semen volume (r = -0.013, P = 0.074) and DFI (r = 0.124, P < 0.001). Patients aged ≥40 years had higher DFI than those aged <40 years in the entire cohort, in the abnormal semen parameters cohort, and in the normal semen parameters cohort (OR 2.145, 2.042, 1.948, respectively, P < 0.001). The ≥40 years age group had a lower HDS than the <40 years age group in the entire cohort and abnormal semen parameters cohort (OR 0.719, 0.677, respectively, P < 0.001). CONCLUSIONS: Ageing is a negative effector of sperm quantity and quality, and routine sperm parameters have weak but significant correlations with sperm DNA/chromatin integrity.

Assessment of growth and metabolism characteristics in offspring of dehydroepiandrosterone-induced polycystic ovary syndrome adults.

Polycystic ovary syndrome (PCOS) is a common reproductive disorder that has many characteristic features including hyperandrogenemia, insulin resistance and obesity, which may have significant implications for pregnancy outcomes and long-term health of women. Daughters born to PCOS mothers constitute a high-risk group for metabolic and reproductive derangements, but no report has described potential growth and metabolic risk factors for such female offspring. Hence, we used a mouse model of dehydroepiandrosterone (DHEA)-induced PCOS to study the mechanisms underlying the pathology of PCOS by investigating the growth, developmental characteristics, metabolic indexes and expression profiles of key genes of offspring born to the models. We found that the average litter size was significantly smaller in the DHEA group, and female offspring had sustained higher body weight, increased body fat and triglyceride content in serum and liver; they also exhibited decreased energy expenditure, oxygen consumption and impaired glucose tolerance. Genes related to glucolipid metabolism such as Pparγ, Acot1/2, Fgf21, Pdk4 and Inhbb were upregulated in the liver of the offspring in DHEA group compared with those in controls, whereas Cyp17a1 expression was significantly decreased. However, the expression of these genes was not detected in male offspring. Our results show that female offspring in DHEA group exhibit perturbed growth and glucolipid metabolism that were not observed in male offspring.

Basic fibroblast growth factor promotes the development of human ovarian early follicles during growth in vitro.

STUDY QUESTION: What is the effect of basic fibroblast growth factor (bFGF) on the growth of individual early human follicles in a three-dimensional (3D) culture system in vitro? SUMMARY ANSWER: The addition of 200 ng bFGF/ml improves human early follicle growth, survival and viability during growth in vitro. WHAT IS KNOWN ALREADY: It has been demonstrated that bFGF enhances primordial follicle development in human ovarian tissue culture. However, the growth and survival of individual early follicles in encapsulated 3D culture have not been reported. STUDY DESIGN, SIZE, DURATION: The maturation in vitro of human ovarian follicles was investigated. Ovarian tissue (n= 11) was obtained from 11 women during laparoscopic surgery for gynecological disease, after obtaining written informed consent. One hundred and fifty-four early follicles were isolated by enzymic digestion and mechanical disruption. They were individually encapsulated into alginate (1% w/v) and randomly assigned to be cultured with 0, 100, 200 or 300 ng bFGF/ml for 8 days. PARTICIPANTS/MATERIALS, SETTING, METHODS: Individual follicles were cultured in minimum essential medium α (αMEM) supplemented with bFGF. Follicle survival and growth were assessed by microscopy. Follicle viability was evaluated under confocal laser scanning microscope following Calcein-AM and Ethidium homodimer-I (Ca-AM/EthD-I) staining. MAIN RESULTS AND THE ROLE OF CHANCE: After 8 days in culture, all 154 follicles had increased in size. The diameter and survival rate of the follicles and the percentage with good viability were significantly higher in the group cultured with 200 ng bFGF/ml than in the group without bFGF (P < 0.05). The percentage of follicles in the pre-antral stage was significantly higher in the 200 ng bFGF/ml group than in the group without bFGF (P < 0.05), while the percentages of primordial and primary follicles were significantly lower (P < 0.05). LIMITATIONS, REASONS FOR CAUTION: The study focuses on the effect of bFGF on the development of individual human early follicles in 3D culture in vitro and has limited ability to reveal the specific effect of bFGF at each different stage. The findings highlight the need to improve the acquisition and isolation of human ovarian follicles. WIDER IMPLICATIONS OF THE FINDINGS: The in vitro 3D culture of human follicles with appropriate dosage of bFGF offers an effective method to investigate their development. Moreover, it allows early follicles to be cultured to an advanced stage and therefore has the potential to become an important source of mature oocytes for assisted reproductive technology; particularly as an option for fertility preservation in women, including patients with cancer. STUDY FUNDING/COMPETING INTEREST(S): This work was supported by the National Basic Research Program of China (2011|CB944504, 2011CB944503) and the National Natural Science Foundation of China (81200470, 81000275, 31230047, 8110197). There are no conflicts of interest to declare.

Improvement in the quality of heterotopic allotransplanted mouse ovarian tissues with basic fibroblast growth factor and fibrin hydrogel.

STUDY QUESTION: Does basic fibroblast growth factor (bFGF) in combination with fibrin hydrogel improve follicle development and revascularization of heterotopically transplanted mouse ovarian tissues? SUMMARY ANSWER: Treatment of transplanted ovarian tissues with higher concentrations (75, 100 and 150 µg/ml), but not lower concentrations (25 and 50 µg/ml), of bFGF significantly improved primordial follicle survival and angiogenesis, while apoptosis of follicles and stromal cells was significantly decreased. WHAT IS KNOWN ALREADY: Use of transplanted ovarian tissues in female fertility preservation is limited by the massive loss of follicles and ischemia-reperfusion injury due to the expected delay in revascularization. STUDY DESIGN, SIZE AND DURATION: Ovarian tissues from 18-day-old ICR mice were encapsulated in fibrin hydrogel mixed with different concentrations of bFGF, then transplanted under the skin of adult female mice for 1 week. The ovarian tissues treated without fibrin hydrogels and bFGF were designated as Control group I, and the ovarian tissues treated with fibrin hydrogels but without bFGF were designated as Control group II. The ovarian tissues treated with 25 and 50 µg/ml bFGF were designated as the lower concentration group, and the ovarian tissues treated with 75, 100 and 150 µg/ml bFGF were designated as the higher concentration group. MATERIALS, SETTING AND METHODS: Assessment of follicular quantity and follicle classification was carried out by histologic analysis. Follicle proliferation was evidenced by immunostaining with proliferating cell nuclear antigen and apoptosis was verified by anti-active caspase-3 staining. Epithelial cells of new blood vessels were stained using CD31 antibody to evaluate neoangiogenesis, and the blood vessel density was analyzed by immunohistochemistry. MAIN RESULTS AND THE ROLE OF CHANCE: The ovarian tissues were recovered 1 week post-transplantation. Compared with the control group, the survival and proliferation of the follicles was significantly increased, the apoptosis of follicles and stromal cells was significantly decreased, and angiogenesis was significantly enhanced when the transplanted ovarian tissues were treated with a higher concentration of bFGF. Treatment with a lower concentration of bFGF did not improve follicle survival and blood revascularization. LIMITATIONS, REASONS FOR CAUTION: The results obtained may not be fully extrapolated to humans because of the physiologic differences between mice and humans. WIDER IMPLICATIONS OF THE FINDINGS: For the first time, the present study investigated the role of bFGF in transplanted ovarian tissues and demonstrated that bFGF might significantly improve the quality of transplanted ovarian tissues by increasing follicle quantity and promoting neoangiogenesis. This study sets the stage for further study and application of ovarian tissue transplantation in clinics, and may eventually benefit females for fertility preservation. STUDY FUNDING/COMPETING INTEREST(S): This work was partially supported by the Ministry of Science and Technology of China Grants (973 Program; 2011CB944503 to Q.J.), the Program for Changjiang Scholars and Innovative Research Team in University of Ministry of Education of China (30825038 to Q.J.), and the National Natural Science Funds for Young Scholar (81200470 to Y.J. and 81000275 to Y.L.Y.). None of the authors have any conflicts of interest.

The impact of fibronectin knockout on invasion and migration of endometrial cell in adenomyosis.

The present study aimed to investigate the potential effect of fibronectin (FN) in adenomyosis progression. Small guide RNAs were designed to knock down FN expression in Ishikawa cells. The impact of FN on the proliferation, apoptosis, migration, and invasion of the cells was assessed. Cell proliferation was detected using a Celigo Imaging Cytometer system; apoptosis was quantified by flow cytometry; and cell migration and invasion were investigated via transwell assays. Cell proliferation was markedly suppressed in the FN knockout (KO) group compared with the control group, while apoptosis significantly increased. The levels of cell migration and invasion in the KO group were significantly decreased compared with the control group. Our study revealed that downregulation of FN expression is likely to restrain cell proliferation, migration, and invasion in endometrial cells in adenomyosis.

Sequential embryo transfer versus double cleavage-stage embryo or double blastocyst transfer in patients with recurrent implantation failure with frozen-thawed embryo transfer cycles: a cohort study.

Background: Recurrent implantation failure (RIF) is more common among patients receiving assisted reproductive treatment. Many efforts have been made to increase the incidence of clinical pregnancy among patients with RIF. The effect of the sequential transfer procedure, a two-step interval transfer of a cleavage-stage embryo followed by a blastocyst in one transfer cycle, on the clinical outcomes of RIF patients remains controversial. Methods: In total, 1774 frozen-thawed embryo transfer (FET) cycles in RIF patients were included. Of these cycles, 302 were sequential embryo transfer (ET) cycles, 979 were double day 3 cleavage-stage ET cycles, and 493 were double blastocyst ET cycles. The primary outcomes were the rates of implantation, clinical pregnancy and multiple pregnancy, and the secondary outcomes were the rates of hCG positive, early miscarriage and ectopic pregnancy. Results: The implantation, hCG positive, and clinical pregnancy rates in the sequential ET group (32.1%, 58.9%, 50.7%) were significantly higher than those in the day 3 cleavage-stage ET group (24.9%, 46.5%, 40.4%) and were similar to those in the blastocyst transfer group (30.1%, 56.4%, 47.1%). The early miscarriage rate in the blastocyst transfer group was significantly higher than that in the cleavage-stage ET group (17.2% vs. 8.1%, P <0.05), while the ectopic pregnancy rate in the blastocyst transfer group was significantly lower than that in the cleavage-stage ET group (0.4% vs. 3.0%, P <0.05). The multiple pregnancy rate in the sequential ET group was significantly lower than that in the cleavage-stage ET group (17.0% vs. 25.5%, P <0.05) and the blastocyst transfer group (17.0% vs. 27.6%, P <0.05). When cycles of blastocyst culture failure were excluded, the clinical pregnancy rate was significantly higher (55.7% vs. 47.1%, P <0.05), and the early miscarriage rate and multiple pregnancy rate were significantly lower (8.5% vs. 17.2%, 17.7% vs. 27.6%; P <0.05, respectively) in the sequential ET group than in the double blastocyst ET group. Conclusions: Sequential embryo transfer in FET cycles could improve the clinical outcomes of patients with RIF.

A retrospective cohort study of geographic differences in the semen of 1,012 sperm donors in China.

Background: Male reproductive health has become a serious public health concern, and semen quality is essential to male reproduction. We aimed to investigate geographical differences in the semen quality of sperm donors from northern and southern China by enrolling donors across the country. Methods: A total of 1,012 sperm donors were enrolled in this study between 2015 and 2019. Donors were first divided into two parts based on their birthplace according to the "Qinling-Huaihe" line, and secondly, by their residential latitude. Finally, donors were re-classified into two groups (typically north and south) which contained 667 samples. Results: Statistically significant differences in sperm concentration were observed among men from different latitudes in China (P=0.04). The sperm concentrations of males from 18° to 27° north latitude were significantly lower than those from 36° to 45° and 45° to 54° [median 131, 134, and 146, respectively, P=0.021 (18° to 27° vs. 36° to 45°) and P=0.01 (18° to 27° vs. 45° to 54°)]. Conclusion: We hypothesize environmental pollution and mental stress due to the increased population size may be the main factors underlying differences in the sperm quality of men in northern and southern China.

An evaluation of the population characteristics, semen quality, and utilization status of autologous sperm cryopreservation and fertility preservation in for 662 patients: a 6-year monocentric retrospective study.

BACKGROUND: Sperm cryopreservation is an effective method of fertility preservation for disease-related and social sperm freezing. In total, 662 subjects (range: 15-65 years-of-age; mean: 33.49 ± 8.79 years-of-age) were included in this study to investigate the population characteristics, semen quality, and usage of autologous sperm preservation patients in Beijing. Of these, 351 were cancer patients (53.02%, 31.14 ± 7.32 years-of-age) and 311 were non-cancer patients (46.98%, 36.14 ± 9.54 years-of-age). RESULTS: We found that the number of preservation cases increased steadily from 2015 to 2019; 89.73% of these had a bachelor's degree or above; 54.83%, 41.54%, and 3.63% were single, married, and divorced, respectively. The cases of cancers and oligozoospermia accounted for 71.30% of all patients; therefore, most patients required fertility preservation due to disease. The cancer group had a significantly lower sperm concentration, rate of progressive sperm after the frozen-thawed test, total progressive motility sperm count after the frozen-thawed test, and recovery rate of progressive motile sperm (RRPM) than the non-cancer group (all P < 0.05). Sperm count-related parameters were significantly affected by testicular cancer, while sperm motility-related parameters and RRPM were significantly affected by leukemia. The utilization rate of preserved sperm was 6.34% after 6 to 78 months of follow-up. In terms of fresh or frozen embryo transfer, the clinical pregnancy rate was 56.76% or 50.00%, and the live birth rate was 24.32% or 21.43%, respectively. CONCLUSION: The need for autologous sperm preservation was dominated by patients with diseases, followed by the need for social sperm freezing. Tumors had a major negative impact on semen quality, and the usage rates of stored semen were at lower level compared to the number of sperm cryopreservation. Medical staff and patients should pay attention to both cognition-action consistency and cost-effectiveness in fertility preservation.

RéSUMé: CONTEXTE: La cryoconservation des spermatozoïdes est une méthode efficace de préservation de la fertilité pour la congélation des spermatozoïdes liée à des causes médicales et aux demandes sociétales. Au total, 662 hommes (entre 15 et 65 ans; moyenne: 33,5 ± 8,8 ans) ont été inclus dans cette étude pour évaluer les caractéristiques de la population, la qualité du sperme et l'utilisation de la préservation autologue de spermatozoïdes réalisée par des patients à Beijing. Parmi ceux-ci, 351 étaient des patients atteints de cancer (53%; 31,1 ± 7,3 ans) et 311 des patients non atteints de cancer (47%; 36,1 ± 9,5 ans). RéSULTATS: Nous avons constaté que le nombre de cas de conservation a augmenté régulièrement de 2015 à 2019; 89,7% d'entre eux avaient un baccalauréat ou plus; 54,8%, 41,5% et 3,6% étaient respectivement célibataires, mariés, ou divorcés. Les cas de cancer et ceux d'oligozoospermie représentaient 71,3% de tous les patients; par conséquent, la plupart des patients avaient besoin d'une préservation de la fertilité pour raison de maladie. Le groupe des hommes atteints de cancer avait significativement une plus faible concentration de spermatozoïdes, un plus faible taux de spermatozoïdes progressifs après le test de congelation-décongelation, un plus faible nombre total de spermatozoïdes de motilité progressive après le test de congelation-décongelation, et un plus faible taux de récupération de spermatozoïdes mobiles progressifs (TRMP) que le groupe de patients non atteints de cancer (tous p < 0,05). Les paramètres liés au nombre de spermatozoïdes ont été significativement affectés par le cancer du testicule, tandis que les paramètres liés à la mobilité des spermatozoïdes et le taux de récupération de spermatozoïdes mobiles progressifs ont été significativement affectés par la leucémie. Le taux d'utilisation des spermatozoïdes conservés était de 6,3% après 6 à 78 mois de suivi. En ce qui concerne le transfert d'embryons frais et congelés, le taux de grossesse clinique était respectivement de 56,8% et 50,0%, et le taux de naissances vivantes respectivement de 24,3% et 21,4%. CONCLUSIONS: Le besoin de conservation autologue des spermatozoïdes était dominé par les patients atteints de maladies, suivi par le besoin social de congélation des spermatozoïdes. Les tumeurs ont eu un impact négatif majeur sur la qualité du sperme, et le taux d'utilisation des spermatozoïdes stockés était à un niveau inférieur à celui du nombre de cryoconservation des spermatozoïdes. Le personnel médical et les patients doivent prêter attention à la fois à la cohérence cognition-action et à la rentabilité de la préservation de la fertilité.

The Roles of Mitochondrial SIRT4 in Cellular Metabolism.

Sirtuins comprise a family of nicotinamide adenine dinucleotide (NAD+)-dependent lysine deacylases that regulate the life span, aging, and metabolism. Seven sirtuin family members (SIRT1-7) have been identified in mammals, including humans. Despite the indispensable role of mitochondrial sirtuin 4 (SIRT4) in metabolic regulation, the primary enzymatic activity of SIRT4 remains enigmatic. SIRT4 possesses ADP-ribosyltransferase, lipoamidase and deacylase activities. Interestingly, the enzymatic activities and substrates of SIRT4 vary in different tissues and cells. SIRT4 inhibits insulin secretion in pancreatic ß cells and regulates insulin sensitivity as a deacylase in the pancreas. SIRT4 represses fatty acid oxidation (FAO) in muscle and liver cells differently. SIRT4 has also been identified as a mitochondrial-localized tumor suppressor. A comprehensive understanding of the enzymology of SIRT4 in metabolism is essential for developing novel therapeutic agents for human metabolic diseases. This review will update the roles of SIRT4 in cellular and organismal metabolic homeostasis.

Impaired oocyte quality induced by dehydroepiandrosterone is partially rescued by metformin treatment.

The present study evaluated the influence of hyperandrogenism on oocyte quality using a murine PCOS model induced by dehydroepiandrosterone (DHEA) and further explored the effect of metformin treatment. Female BALB/c mice were treated with a vehicle control or DHEA (6 mg /100 g body weight) or DHEA plus metformin (50 mg /100 g body weight) for 20 consecutive days. DHEA-induced mice resembled some characters of human PCOS, such as irregular sexual cycles and polycystic ovaries. After the model validation was completed, metaphase II (MII) oocytes were retrieved and subsequent analyses of oocyte quality were performed. DHEA-treated mice yielded fewer MII oocytes, which displayed decreased mtDNA copy number, ATP content, inner mitochondrial membrane potential, excessive oxidative stress and impaired embryo development competence compared with those in control mice. Metformin treatment partially attenuated those damages, as evidenced by the increased fertilization and blastocyst rate, ATP content, GSH concentration and GSH/GSSG ratio, and decreased reactive oxygen species levels. No significant difference in normal spindle assembly was observed among the three groups. During in vitro maturation (IVM), the periods of germinal vesicle breakdown (GVBD) and the first polar body (PB1) extrusion were extended and the maturation rate of GVBD oocytes was decreased in DHEA mice compared with controls. Metformin treatment decreased the time elapsed of GVBD while had no effect on PB1 extrusion. These results indicated that excessive androgen is detrimental to oocyte quality while metformin treatment is, directly or indirectly, beneficial for oocyte quality improvement.

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

OBJECTIVE: One of the major obstacles to ovarian tissue preservation is delayed angiogenesis that leads follicles lost after transplantation. The aim of the present study was to investigate the effects of bFGF and VEGF on heterotopic transplanted ovarian tissue using a mouse model. METHODS: Female mice underwent bilateral ovariectomy. Ovarian tissues encapsulated by fibrin hydrogels were transplanted subcutaneously into recipient mice, in which ovarian hormonal cyclicity was absent. The fibrinogen solution was mixed with bFGF, VEGF, or a mixture of bFGF and VEGF. The grafts were recovered 21 days after transplantation. Follicle morphology and follicle numbers were observed by H&E staining. Blood vessels were observed in transplanted intra-ovarian tissue by CD31 antibody IHC staining. Daily vaginal cytology was performed to determine estrous cycle and functional restoration of transplanted ovarian tissue. Blood was collected weekly and serum FSH levels were measured with a radioimmunoassay kit. Apoptosis analysis was performed by anti-AC-3 staining and survivin mRNA expression. RESULTS: The number of primordial follicles and secondary follicles in the bFGF+VEGF group was significantly higher than in the control group. The vascular density in the bFGF+VEGF groups were significantly higher than in the bFGF and the VEGF groups; there was no significant difference between the bFGF and VEGF groups. Estrous cycle was earlier in the bFGF+VEGF group compared with the control group; all mice in this group restored ovarian function. Serum FSH levels in the bFGF+VEGF group were significantly lower than in the control group by day 14 post-transplantation. The AC-3-positive in control group was significantly higher compared with bFGF group and VEGF group, and in bFGF+VEGF group was significantly lower than bFGF group and VEGF group. Survivin mRNA expression in bFGF+VEGF group was significantly higher than control group. CONCLUSION: The combination of bFGF and VEGF has beneficial effects on follicle survival, angiogenesis, and resumption of estrous cycles.

Ascorbic acid improves pluripotency of human parthenogenetic embryonic stem cells through modifying imprinted gene expression in the Dlk1-Dio3 region.

INTRODUCTION: Human parthenogenetic embryonic stem cells (hpESCs) are generated from artificially activated oocytes, however, the issue of whether hpESCs have equivalent differentiation ability to human fertilized embryonic stem cells remains controversial. METHODS: hpESCs were injected into male severe combined immunodeficiency (SCID) mice and the efficiency of teratoma formation was calculated. Then the gene expression and methylation modification were detected by real time-PCR and bisulfate methods. RESULTS: Comparison of five hpESCs with different differentiation abilities revealed that levels of paternal genes in the Dlk1-Dio3 region on chromosome 14 in the hpESCs with high differentiation potential are enhanced, but strictly methylated and silenced in the hpESCs with lower differentiation potential. Treatment with ascorbic acid, rescued their ability to support teratoma formation and altered the expression profiles of paternally expressed genes in hpESCs that could not form teratoma easily. No differences in the expression of other imprinting genes were evident between hpESCs with higher and lower differentiation potential, except for those in the Dlk1-Dio3 region. CONCLUSIONS: The Dlk1-Dio3 imprinting gene cluster distinguishes the differentiation ability of hpESCs. Moreover, modification by ascorbic acid may facilitate application of hpESCs to clinical settings in the future by enhancing their pluripotency.