The markers of oocyte quality have remained a major controversy in the field of embryology due to the subjectivity of the different methods of oocyte assessment. Various scholars use oocyte quality and oocyte competen...The markers of oocyte quality have remained a major controversy in the field of embryology due to the subjectivity of the different methods of oocyte assessment. Various scholars use oocyte quality and oocyte competence interchangeably. Oocyte quality can be defined as the overall health of an oocyte whereas oocyte competence refers to the ability of an oocyte to be fertilized and develop into a healthy embryo. Diminished oocyte quality is believed to be a result of alterations in oocyte growth and maturation processes that stem from several pelvic and systemic factors before and after oocyte retrieval. In this review, we focus on the morphological and nonmorphological markers of oocyte quality. Strict restrictions that limit the number of oocytes fertilized in various countries have triggered researchers around the world to come up with the most appropriate and noninvasive markers that enhance oocyte selection and optimize IVF outcomes. PubMed, Google Scholar, and the Cochrane Library were used to search for peer-reviewed, original articles about oocyte quality markers. The review was written in accordance with the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines. Morphological markers are commonly used, but they are subjective, and no single marker can be used exclusively to predict oocyte competence and subsequent embryonic development potential. Furthermore, transcriptomics of differentially expressed genes in cumulus cells and assessment of metabolomics and other contents of follicular fluid have shown greater precision. However, their specificity to the different quality determinants needs further research.展开更多
Omega-3 polyunsaturated fatty acids(n-3 PUFAs),particularly docosahexaenoic acid(22:6n-3,DHA),play crucial roles in the reproductive health of vertebrates,including humans.Nevertheless,the underlying mechanism related...Omega-3 polyunsaturated fatty acids(n-3 PUFAs),particularly docosahexaenoic acid(22:6n-3,DHA),play crucial roles in the reproductive health of vertebrates,including humans.Nevertheless,the underlying mechanism related to this phenomenon remains largely unknown.In this study,we employed two zebrafish genetic models,i.e.,elovl2^(-/-)mutant as an endogenous DHAdeficient model and fat1(omega-3 desaturase encoding gene)transgenic zebrafish as an endogenous DHA-rich model,to investigate the effects of DHA on oocyte maturation and quality.Results show that the elovl2^(-/-)mutants had much lower fecundity and poorer oocyte quality than the wild-type controls,while the fat1 zebrafish had higher fecundity and better oocyte quality than wildtype controls.DHA deficiency in elovl2^(-/-)embryos led to defects in egg activation,poor microtubule stability,and reduced pregnenolone levels.Further study revealed that DHA promoted pregnenolone synthesis by enhancing transcription of cyp11a1,which encodes the cholesterol side-chain cleavage enzyme,thereby stabilizing microtubule assembly during oogenesis.In turn,the hypothalamic-pituitary-gonadal axis was enhanced by DHA.In conclusion,using two unique genetic models,our findings demonstrate that endogenously synthesized DHA promotes oocyte maturation and quality by promoting pregnenolone production via transcriptional regulation of cyp11a1.展开更多
Objective:To compare embryonic development,ploidy status and clinical outcomes between fresh and frozen-thawed oocytes.Methods:This retrospective cohort study evaluated 83 fertilization cycles including both fresh and...Objective:To compare embryonic development,ploidy status and clinical outcomes between fresh and frozen-thawed oocytes.Methods:This retrospective cohort study evaluated 83 fertilization cycles including both fresh and frozen oocytes from 79 patients at the HP Fertility Center of Hai Phong International Hospital of Obstetrics and Pediatrics in Vietnam.The patient underwent several ovarian stimulation cycles to accumulate a certain number of oocytes that would be vitrified.In the last oocyte retrieval,all patient’s oocytes including both frozen and fresh would be fertilized.The outcomes included the rates of oocyte survival,cleavage embryo,blastocyst,ploidy status,pregnancy,biochemical pregnancy and clinical pregnancy.Results:The oocyte survival rate after thawing was 96.5%.No statistically significant difference was found when comparing fresh and frozen oocytes regarding fertilization rate(78.1%vs.75.5%,P=0.461),usable cleavage embryo rate(86.9%vs.87.2%,P=0.916)but usable blastocyst rate was found higher statistically in the frozen oocyte group(44.4%vs.54.0%,P=0.049).The percentages of euploid,aneuploid and mosaic embryos between the fresh group and the vitrified group had no significant differences(33.8%vs.31.6%,P=0.682;51.0%vs.54.2%,P=0.569;15.2%vs.12.4%,P=0.787;respectively).The rates of pregnancy,biochemical pregnancy and clinical pregnancy had no statistical difference(68.8%vs.64.8%,P=0.764;12.5%vs.3.6%,P=0.258;37.5%vs.46.4%,P=0.565).17 Mature oocytes are the minimum to have at least one euploid embryo.Conclusions:Oocyte vitrification does not affect embryonic,genetic and clinical results.The number of mature oocytes should be considered for fertilization in some cases.展开更多
Background:Heavy metal cadmium(Cd)is a widespread environmental contaminant with a potential toxicity that might negatively affect female reproduction and fertility.It has been reported that Cd exposure impaired the q...Background:Heavy metal cadmium(Cd)is a widespread environmental contaminant with a potential toxicity that might negatively affect female reproduction and fertility.It has been reported that Cd exposure impaired the quality of oocytes and led to a defective maturation and fertilization,through oxidative stress induction.Resveratrol(Res)is a natural polyphenol with strong antioxidant properties that exhibited protective role in preventing oocyte redox homeostasis disruption and quality decline.Here,we explored whether the addition of Res to in vitro maturation(IVM)medium might act as a protection against Cd-induced toxicity on ovine oocyte maturation and fertilization.Firstly,we evaluated the effect of supplementing IVM medium with two different Res concentrations(1and 2μmol/L)on nuclear maturation and fertilization of oocytes matured under CdCl2(2μmol/L)exposure.Therefore,the concentration of 1μmol/L Res was selected to analyse the effects of this compound on intracellular ROS levels,mitochondrial(mt)distribution and activity,chromatin configuration,cytoskeleton morphology,cortical granules(CGs)distribution and mRNA expression of genes associated with cellular response to oxidative stress(i.e.SIRT1,SOD 1,GPX1,GSR,CAT)in Cd-exposed in vitro matured oocytes.Results:We found that 1μmol/L Res restored the reduced oocyte meiotic competence induced by Cd exposure as well as,Res sustained oocyte ability to be normally fertilized and decreased polyspermic fertilization at both tested concentrations.Moreover,we demonstrated that 1μmol/L Res mitigated Cd-induced alterations of oocyte cytoplasmic maturation by reducing reactive oxygen species(ROS)accumulation,preventing mt dysfunction,maintaining the correct meiotic spindle and cortical F-actin assembly and the normal cortical granule distribution as well as up-regulating SIRT1,SOD1 and GPX1 genes.Conclusions:Taken together,our findings highlighted the beneficial influence exerted by Res in preventing Cdinduced disturbance of nuclear and cytoplasmic maturation and subsequent fertilization in ovine oocytes.Res treatment may help to establish defence strategies counteracting Cd-induced toxicity on the female gamete.展开更多
Background Zearalenone(ZEA)widely exists in moldy grains,which seriously destroys the fertility of females.Isorhamnetin,a natural flavonoid,has extensive of pharmacological activities.However,the beneficial effect and...Background Zearalenone(ZEA)widely exists in moldy grains,which seriously destroys the fertility of females.Isorhamnetin,a natural flavonoid,has extensive of pharmacological activities.However,the beneficial effect and the underlying molecular mechanism of isorhamnetin involvement in ZEA-induced porcine oocyte damage have not been investigated.Methods Oocytes were treated with different concentrations of ZEA(3,5,8 and 10μmol/L)and isorhamnetin(5,10,20 and 30μmol/L)for 44 h at 39℃.ZEA(5μmol/L)and isorhamnetin(10μmol/L)were selected for subsequent studies.Polar body exclusion rate,apoptosis rate and apoptosis related proteins,ROS levels and SOD2 protein,mitochondrial membrane potential and distribution,endoplasmic reticulum distribution and proteins expression,and PI3K,Akt and p-Akt proteins expression of oocytes were detected.In addition,the effect of PI3K antagonist(LY294002)on oocyte nuclear maturation and apoptosis were used to determine the involvement of PI3K/Akt signaling pathway.Results Our findings showed that ZEA exposure damaged oocytes and isorhamnetin therapy restored the developmental capability of porcine oocytes.Isorhamnetin promoted polar body extrusion rate to rescue ZEA-induced meiotic arrest in porcine oocytes.Isorhamnetin alleviated ZEA-induced oxidative stress by stimulating SOD2 protein expression and inhibiting ROS production.Moreover,isorhamnetin enhanced normal mitochondrial distribution and mitochondrial membrane potential to prevent mitochondrial dysfunction induced by ZEA.Changing the expression of endoplasmic reticulum stress-related marker proteins(CHOP,GRP78)and the distribution rate of normal endoplasmic reticulum showed that isorhamnetin relieved ZEA-caused endoplasmic reticulum stress.Mechanistically,isorhamnetin decreased Bax/Bcl-2 protein expression and inhibited ZEA-induced apoptosis through PI3K/Akt signaling pathway.Conclusions Collectively,these results suggest that isorhamnetin protects oocytes from ZEA-caused damage through PI3K/Akt signaling pathway,which enhances meiotic maturation and mitochondrial function,and inhibits early apoptosis,oxidative stress and endoplasmic reticulum stress in porcine oocytes.Our study provides a new strategy for solving the reproductive toxicity induced by ZEA and treating woman infertility.展开更多
Background:Irreversible cryodamage caused by oocyte vitrification limited its wild application in female fertility preservation.Antioxidants were always used to antagonist the oxidative stress caused by vitrification....Background:Irreversible cryodamage caused by oocyte vitrification limited its wild application in female fertility preservation.Antioxidants were always used to antagonist the oxidative stress caused by vitrification.However,the comprehensive mechanism underlying the protective role of antioxidants has not been studied.Procyanidin B2(PCB2)is a potent natural antioxidant and its functions in response to vitrification are still unknown.In this study,the effects of PCB2 on vitrified-thawed oocytes and subsequent embryo development were explored,and the mechanisms underlying the protective role of PCB2 were systematically elucidated.Results:Vitrification induced a marked decline in oocyte quality,while PCB2 could improve oocyte viability and further development after parthenogenetic activation.A subsequent study indicated that PCB2 effectively attenuated vitrification-induced oxidative stress,rescued mitochondrial dysfunction,and improved cell viability.Moreover,PCB2 also acts as a cortical tension regulator apart from strong antioxidant properties.Increased cortical tension caused by PCB2 would maintain normal spindle morphology and promote migration,ensure correct meiosis progression and finally reduce the aneuploidy rate in vitrified oocytes.Further study reveals that ATP biosynthesis plays a crucial role in cortical tension regulation,and PCB2 effectively increased the cortical tension through the electron transfer chain pathway.Additionally,PCB2 would elevate the cortical tension in embryo cells at morula and blastocyst stages and further improve blastocyst quality.What's more,targeted metabolomics shows that PCB2 has a beneficial effect on blastocyst formation by mediating saccharides and amino acids metabolism.Conclusions:Antioxidant PCB2 exhibits multi-protective roles in response to vitrification stimuli through mitochondria-mediated cortical tension regulation.展开更多
Bovine oocytes are one of the indispensable cells in cattle reproduction and have become a research hot spot in cattle reproduction in recent years.The maturation process of oocytes is mainly regulated by enzymes,horm...Bovine oocytes are one of the indispensable cells in cattle reproduction and have become a research hot spot in cattle reproduction in recent years.The maturation process of oocytes is mainly regulated by enzymes,hormones,cytokines,and other molecules.The factors affecting cattle oocyte maturation have been previously studied to clarify the molecular mechanisms of cattle oocyte maturation.In this review article,phospholipid protein-3-kinase/protein kinase B,mitogen-activated protein kinase/extracellular signal-regulated kinase,Janus kinase/signal transducer and activator of transcription,epidermal growth factor receptor/extracellular signal-regulated kinase,and other signaling pathways related to oocyte maturation are discussed.In addition,the molecular mechanisms of some coding genes(JY-1,FGF-10,CDC20,etc.)and non-coding genes(miRNA,lncRNA,and circRNA)regulating oocyte maturation have been reviewed to provide new ideas for high reproductive performance molecular breeding of high-quality cattle.展开更多
With the clinical development and application of intracytoplasmic sperm injection(ICSI)technology in human assisted reproduction,the influence of oocyte quality on embryo development has been paid more and more attent...With the clinical development and application of intracytoplasmic sperm injection(ICSI)technology in human assisted reproduction,the influence of oocyte quality on embryo development has been paid more and more attention.So far,there have been many reports on oocyte morphology affecting embryo development.It has been found in some works that the appearance of smooth endoplasmic reticulum clusters(SERC)in oocytes may affect the fertilization and embryo development of oocytes.However,with the increasing reports of SERC-containing oocytes obtained by in vitro fertilization and healthy offspring in recent years,there is still some controversy on whether to continue to use SERC-containing oocytes for the following assisted reproductive therapy in clinical practice.Based on this,this review aims to review the research progress of SERC in oocytes in recent years.展开更多
Background:Elevated ambient temperature-caused heat stress is a major concern for livestock production due to its negative impact on animal feed intake,growth,reproduction,and health.Particularly,the germ cells are ex...Background:Elevated ambient temperature-caused heat stress is a major concern for livestock production due to its negative impact on animal feed intake,growth,reproduction,and health.Particularly,the germ cells are extremely sensitive to the heat stress.However,the effective approach and strategy regarding how to protect mammalian oocytes from heat stress-induced defects have not been determined.Methods:Germinal vesicle(GV)porcine oocytes were cultured at 41.5℃ for 24 h to induce heat stress,and then cultured at 38.5℃ to the specific developmental stage for subsequent analysis.Nicotinamide mononucleotide(NMN)was dissolved in water to 1 mol/L for a stock solution and further diluted with the maturation medium to the final concentrations of 10μmol/L,20μmol/L,50μmol/L or 100μmol/L,respectively,during heat stress.Immunostaining and fluorescence intensity quantification were applied to assess the effects of heat stress and NMN supplementation on the key processes during the oocyte meiotic maturation.Results:Here,we report that NMN supplementation improves the quality of porcine oocytes under heat stress.Specifically,we found that heat stress resulted in oocyte maturation failure by disturbing the dynamics of meiotic organelles,including the cytoskeleton assembly,cortical granule distribution and mitochondrial function.In addition,heat stress induced the production of excessive reactive oxygen species(ROS)and DNA damage,leading to the occurrence of apoptosis in oocytes and subsequent embryonic development arrest.More importantly,we validated that supplementation of NMN during heat stress restored the meiotic defects during porcine oocyte maturation.Conclusions:Taken together,our study documents that NMN supplementation is an effective approach to improve the quality of oocytes under heat stress by promoting both nuclear and cytoplasmic maturation.展开更多
BACKGROUND The outcomes of the use of commercial in vitro maturation(IVM)medium to culture immature oocytes obtained from conventional ovulation induction,followed by rescue intracytoplasmic sperm injection(RICSI),are...BACKGROUND The outcomes of the use of commercial in vitro maturation(IVM)medium to culture immature oocytes obtained from conventional ovulation induction,followed by rescue intracytoplasmic sperm injection(RICSI),are not ideal.It is thus difficult to widely adopt this approach in clinical practice.Therefore,it is necessary to explore methods for improving the clinical outcome of IVM.AIM To study the effect of sperm on the developmental potential of in vitro-matured oocytes in conventional culture.METHODS This was a retrospective study of patients whose immature oocytes were harvested from conventional oocyte stimulation cycles and underwent ICSI at our hospital between June 2018 and August 2020.RICSI was performed using sperm collected on the day of oocyte harvest(old)and sperm collected on the day of RICSI(fresh)and oocytes matured in vitro after 24 h of culture in conventional medium.The rates of in vitro oocyte maturation,normal fertilization,normal cleavage,day-3 top-quality embryos,and useful blastocyst formation were compared between the two groups.RESULTS In total,102 germinal vesicle(GV)-stage immature oocytes were cultured in the old sperm group.In the fresh sperm group,122 GV-stage immature oocytes were collected and cultured in vitro for 24 h.There were no significant differences in the general conditions of males and females between the two groups(P>0.05).The oocyte maturation,normal fertilization,and normal cleavage rates of the old and fresh groups were 51.0%vs 55.7%,61.5%vs 64.7%,and 93.8%vs 93.2%,respectively.None of the rates differed significantly(P>0.05)between the two groups.However,the day-3 top-quality embryo and useful blastocyst rates of the old and fresh sperm groups were 16.6%vs 63.4%;6.67%vs 34.6%,respectively.The day-3 top-quality embryos and useful blastocyst rates of the old sperm group were significantly lower than those of the fresh group(P<0.05).CONCLUSION In vitro maturation with conventional culture medium combined with the use of fresh sperm collected on the day of RICSI is an easy-to-implement strategy for patients whose oocytes are completely or mostly immature.展开更多
Is there a really need to validate oocyte vitrification technique in an ART laboratory before establishing it in daily practice? Validation of micromanipulationbased technique, in this case oocyte vitrification, is es...Is there a really need to validate oocyte vitrification technique in an ART laboratory before establishing it in daily practice? Validation of micromanipulationbased technique, in this case oocyte vitrification, is essential prior to enlarging its use to routine practice. Oocyte vitrification is a new worldwide used technique and legal recently inFrance. This micromanipulation needs to be performed by a skilled and experienced embryologist and requires an internal assessment in each ART unit before any wide use. We designed a prospective study, from September 2011 to July 2012, using sibling oocytes from women who recovered more than 12 Metaphase II oocytes. A part of freshly recovered oocytes underwent immediate ICSI while the remaining oocytes were vitrified. 87 couples undergoing ICSI were selected based on number of mature oocytes available on the recovery day after denudation. A part of fresh MII oocytes were microinjected and the others were vitrified using an open system (Cryotop?). The major criterion of interest was the number of embryo transferred/ number of Metaphase II ratio for after ICSI on fresh oocytes (42/211) versus vitrified/warmed oocytes (51/204) (p > 0.05). Secondary studied criteria were survival rate (80.5% ± 26.3%), fertilization rate (68.9 ± 33.5) and finally, cumulative pregnancy rate obtained in this study is 40.2%. One of the benefits of such practice is the limitation of embryo freezing. However, the study design delays oocytes warming cycles, due to pregnancies triggered by the transfer of fresh derived oocyte embryos and to the priority to transfer all the frozen embryos before starting oocytes warming. Moreover, no data is available about children’ health. Oocyte vitrification represents not only a change in our daily practice to improve cumulative pregnancy rate but also a promising tool to develop egg banking and donation. Clinical Trials Registration number: 209 R02.展开更多
In Vitro production of swine embryos is a valuable tool to generate clones and genetically modified pigs during a short period of time. However, the efficiency of the existing methods is extremely low and the oocyte q...In Vitro production of swine embryos is a valuable tool to generate clones and genetically modified pigs during a short period of time. However, the efficiency of the existing methods is extremely low and the oocyte quality and quantity represent important obstacles on the success of in Vitro production of embryos. Therefore, the aim of this study was to compare the in Vitro maturation, fertilization and subsequent embryo development rates of oocytes recovered by ovary slicing or follicular aspiration. The oocyte recovery rate (grade 1 COC/ovary) was higher (p = 0.0083) in the slicing group when compared to the aspiration group. No differences were observed between groups regarding in Vitro maturation and early cleavage rates. A higher percentage of oocytes recovered by follicular aspiration reached the blastocyst stage after IVF when compared to the ovary slicing method (p = 0.0395). However, no difference on blastocyst cell number was observed. Although the recovery of oocytes using the slicing technique yielded more grade 1 oocytes per ovary than the aspiration method, the number of oocytes that reached the blastocyst stage after IVF by the slicing method was lower when compared with oocytes obtained by aspiration, as observed by lower blastocyst rates. In conclusion, the follicular aspiration is the method of choice for porcine in Vitro embryo production.展开更多
Fertilization in mammals requires the successful completion of a sequence of steps, starting with the transport of gametes in the reproductive tract and ending with sperm-egg membrane fusion to produce a zygote. Altho...Fertilization in mammals requires the successful completion of a sequence of steps, starting with the transport of gametes in the reproductive tract and ending with sperm-egg membrane fusion to produce a zygote. Although some integrin subunits are known to be associated with the plasma membrane of some mammalian oocytes and spermatozoa, the presence of α6 integrin on bovine oocytes with intact zona pellucida has not been reported. The present study was undertaken to evaluate the expression of α6 integrin subunit in bovine oocyte and to determine if in vitro binding to the zona pellucida and fertilization were affected by treating oocytes with α6 integrin subunit antibody. The α6 integrin subunit was identified on the bovine oocyte by immunocytochemistry. In vitro fertilization was significantly decreased when in vitro matured bovine oocytes were pre-incubated with α6 integrin subunit antibody at concentration 5 and 20 μg/mL, and spermoocyte binding increased. These studies demonstrated the presence of α6 integrin subunit on bovine oocyte, and its importance in fertilization and polyspermy.展开更多
p28, a 28kD protein from toad (Bufo bufo gargarizans) oocytes, was identified by using p13suc1-agaroseaffinity chromatography. Sequence homology analysis of the full-length cDNA of p28 (Gene Bank accessionnumber: AF 3...p28, a 28kD protein from toad (Bufo bufo gargarizans) oocytes, was identified by using p13suc1-agaroseaffinity chromatography. Sequence homology analysis of the full-length cDNA of p28 (Gene Bank accessionnumber: AF 314091) indicated that it encodes a protein containing 224 amino-acids with about 55% iden-tities and more than 70% positives to human, rat or mouse UCH-L1, and contains homological functionaldomains of UCH family. Anti-p28 monoclonal antibody, on injecting into the oocytes, could inhibit theprogesterone-induced resumption of meiotic division in a dose-dependent manner. The recombinant proteinp28 showed similar SDS/PAGE behaviors to the native one, and promoted ubiquitin ethyl ester hydrolysis,a classical catalytic reaction for ubiquitin carboxyl terminai hydrolases (UCHs). The results in this paperreveal that a novel protein, p28, exists in the toad oocytes, is a UCH L1 homolog, was engaged in theprocess of progesterone-induced oocyte maturation possibly through an involvement in protein turnover anddegradation.展开更多
Background: Resveratrol, an important phyto-antioxidant commonly found in grapes, mulberry, and other plants,has a variety of functions including anti-aging, anti-cancer and anti-inflammatory activities. In the curren...Background: Resveratrol, an important phyto-antioxidant commonly found in grapes, mulberry, and other plants,has a variety of functions including anti-aging, anti-cancer and anti-inflammatory activities. In the current study, we investigated the beneficial effects of resveratrol on in vitro porcine oocyte maturation under heat stress(HS). The effect of resveratrol, melatonin and their combination on alleviating HS was compared according to the maturation rate of oocytes and the development competence of embryos after parthenogenetic activation(PA).Results: Supplementation with resveratrol(2.0 μmol/L) not only improved the nuclear maturation but also raised the blastocyst rate of porcine embryos' PA from oocytes that underwent HS by increasing their glutathione(GSH)level, reducing reactive oxygen species(ROS) and up-regulating the expression of Sirtuin 1(SIRT1). It was also found that melatonin(10^(-7)mol/L) and the combination of resveratrol(2.0 μmol/L) plus melatonin(10^(-7)mol/L) exhibited more potent effects than resveratrol alone regarding their protective activities on oocyte maturation under HS.Conclusions: This study compared the efficiencies of resveratrol, melatonin and their combination for protecting porcine oocytes from heat stress. The mechanisms are attributed to the fact that each treatment may have different ability to regulate the synthesis of steroid hormones and the expression of mature related genes.展开更多
Objective: To study oocyte donation in treatment of premature ovarian failure.Methods:Thirty premature ovarian failure patients receiving hormone replacement therapy had un-dergone 54 treatment cycles of in vitro fert...Objective: To study oocyte donation in treatment of premature ovarian failure.Methods:Thirty premature ovarian failure patients receiving hormone replacement therapy had un-dergone 54 treatment cycles of in vitro fertilization with their husbands’ sperm and donors’ oocytes.Ovulation induction was achieved by GnRH-α/HMG/hCG regimen in donors. Embryos transfers were performed in recipients from 15th to 20th day of hormone replacement therapy cycle. Preclinical preg-nancies were defined when serum β-hCG performed on day 14 post embryo transfer >3. 1ng/ml. Clini-cal pregnancies was diagnosed by the presence of a gestation sac with transvaginal ultrasound at six weeks of gestation.Results:Clinical pregnancy rate per embryo transfer cycle was 35- 2% (19/54). The first baby was deliveried on Jan 14, 1994 in premature ovarian failure patient with hormone replacement therapy and oocyte donation in China. Comharison of the results showed a singnificant increase in number of em-bryos transfer, embryo scoring and clinical pregnancy rate (54. 2 % ) in the whole cohort where oocytes were used. The P value was <0.05, <0. 001, <0.05 respectively. However the spontaneous abortion rate(15. 4% ) significantly decreased (P<0.001 ). No difference was found in the embryos scoring and the number of embryos transfer between groups with age less than 3O years or more than 30 years. But clinical pregnancy rate in the younger group (42. 9% ) was significantly higher than in the older group (30. 3%). The endometrium receptivity window of a 2-days embryo was from 15th to 19th day of a 28 days cycle. The highest pregnancy rate was in day 16 to 18 in the 28 days cycle.Conclusion: Hormone replacement therapy and oocyte donation is a effective method of obtaining successful pregnancy for those with premature ovarian failure. The quality of oocyte is an important factor that affects the pregnancy rate and spontaneous abortion rate. The endometrium receptivity ia al-so a major factor affecting the pregnancy rate, which declined with increasing age.展开更多
Background: SIRT1 histone deacetylase acts on many epigenetic and non-epigenetic targets. It is thought that SIRT1 is involved in oocyte maturation;therefore, the importance of the ooplasmic SIRT1 pool for the further...Background: SIRT1 histone deacetylase acts on many epigenetic and non-epigenetic targets. It is thought that SIRT1 is involved in oocyte maturation;therefore, the importance of the ooplasmic SIRT1 pool for the further fate of mature oocytes has been strongly suggested. We hypothesised that SIRT1 plays the role of a signalling molecule in mature oocytes through selected epigenetic and non-epigenetic regulation.Results: We observed SIRT1 re-localisation in mature oocytes and its association with spindle microtubules.In mature oocytes, SIRT1 distribution shows a spindle-like pattern, and spindle-specific SIRT1 action decreasesα-tubulin acetylation. Based on the observation of the histone code in immature and mature oocytes, we suggest that SIRT1 is mostly predestined for an epigenetic mode of action in the germinal vesicles(GVs) of immature oocytes. Accordingly, BML-278-driven trimethylation of lysine K9 in histone H3 in mature oocytes is considered to be a result of GV epigenetic transformation.Conclusions: Taken together, our observations point out the dual spatiotemporal SIRT1 action in oocytes,which can be readily switched from the epigenetic to non-epigenetic mode of action depending on the progress of meiosis.展开更多
The clomiphene citrate (CC), a nonsteroidal triphenylethylene compound, is a first line of medicine used for the induction of ovulation in anovulatory women worldwide. In spite of high ovulation induction with the use...The clomiphene citrate (CC), a nonsteroidal triphenylethylene compound, is a first line of medicine used for the induction of ovulation in anovulatory women worldwide. In spite of high ovulation induction with the use of CC, the pregnancy rate is much lower. Such a discrepancy could be due to the peripheral anti-estrogenic effect of CC, particularly at the level of ovary, endometrium and cervical mucus. CC induces ovulation by binding to the estrogen receptors and generates hypoestrogrnic state in hypothalamus leading to release of pituitary gonadotropins. CC may have a direct effect at the level of ovary but the molecular mechanism remains unclear. Animal studies suggest that the CC induces apoptosis in granulosa cells and results hypoestrogenic state in the ovary. Reduced estradiol 17β level in the ovary affects development and maturation of oocyte leading to oocyte apoptosis. Further, CC increases hydrogen peroxide (H2O2) level and thereby bax protein expression and DNA fragmentation in cumulus-granulosa cells as well as in oocytes. The exogenous supplementation of either estradiol 17β or melatonin reduces H2O2 level in ovary, delays meiotic cell cycle progression in oocyte and protects oocyte apoptosis. Hence, supplementation of estradiol 17β or melatonin along with CC could be beneficial to protect granulosa cell as well as oocyte apoptosis and inhibit deterioration of oocyte quality. Thus, maintenance of oocyte quality may overcome the adverse effect caused due to CC treatment during infertility management.展开更多
Proper chromosome separation in both mitosis and meiosis depends on the correct connection between kinetochores of chromosomes and spindle microtubules. Kinetochore dysfunction can lead to unequal distribution of chro...Proper chromosome separation in both mitosis and meiosis depends on the correct connection between kinetochores of chromosomes and spindle microtubules. Kinetochore dysfunction can lead to unequal distribution of chromosomes during cell division and result in aneuploidy, thus kinetochores are critical for faithful segregation of chromosomes. Centromere protein A(CENP-A) is an important component of the inner kinetochore plate. Multiple studies in mitosis have found that deficiencies in CENP-A could result in structural and functional changes of kinetochores, leading to abnormal chromosome segregation, aneuploidy and apoptosis in cells. Here we report the expression and function of CENP-A during mouse oocyte meiosis. Our study found that microinjection of CENP-A blocking antibody resulted in errors of homologous chromosome segregation and caused aneuploidy in eggs. Thus, our findings provide evidence that CENP-A is critical for the faithful chromosome segregation during mammalian oocyte meiosis.展开更多
Background:Transzonal projections(TZPs)constitute a structural basis for the communication between the oocyte and its surrounding cumulus cells(CCs),which play critical roles in promoting the oocyte maturation.Previou...Background:Transzonal projections(TZPs)constitute a structural basis for the communication between the oocyte and its surrounding cumulus cells(CCs),which play critical roles in promoting the oocyte maturation.Previously we found that heat stress(HS)causes loss of TZPs in porcine cumulus-oocyte complexes(COCs)with decreased density of filamentous actin(F-actin).However,the time-course responses of F-actin and its monomeric actins(β-actin andγ-actin)during the in vitro maturation of oocytes remain unclear.Results:In this study,excised porcine ovaries were exposed to HS at 41.5°C for 1 h before COCs were isolated and matured in vitro for 44 h.HS significantly reduced oocyte quality,characterized by impaired cumulus expansion,delayed meiotic resumption and lower survival rate and polar body extrusion rate,as well as decreased expression of mitochondrial DNA-encoded genes and elevated mitochondrial reactive oxygen species concentration.Expression ofβ-actin andγ-actin in CCs increased gradually with oocytes maturation,which was significantly reduced in HS group,especially at 24 h and/or 44 h of in vitro maturation.By contrast,the number of TZPs and the fluorescence intensity of F-actin in zona pellucida decreased gradually during oocytes maturation,which were significantly reduced by HS at 24 h of in vitro maturation.Moreover,colocalization analyses revealed bothβ-actin andγ-actin contribute to the F-actin formation in porcine TZPs,and the colocalization of F-actin with GJ protein connexin 45 was significantly reduced in heat-exposed COCs.Conclusions:The results indicate that the suppression of actin expressions in CCs,which may lead to the F-actin unstabilization in TZPs,will subsequently contribute to the compromised quality of oocytes under HS.展开更多
文摘The markers of oocyte quality have remained a major controversy in the field of embryology due to the subjectivity of the different methods of oocyte assessment. Various scholars use oocyte quality and oocyte competence interchangeably. Oocyte quality can be defined as the overall health of an oocyte whereas oocyte competence refers to the ability of an oocyte to be fertilized and develop into a healthy embryo. Diminished oocyte quality is believed to be a result of alterations in oocyte growth and maturation processes that stem from several pelvic and systemic factors before and after oocyte retrieval. In this review, we focus on the morphological and nonmorphological markers of oocyte quality. Strict restrictions that limit the number of oocytes fertilized in various countries have triggered researchers around the world to come up with the most appropriate and noninvasive markers that enhance oocyte selection and optimize IVF outcomes. PubMed, Google Scholar, and the Cochrane Library were used to search for peer-reviewed, original articles about oocyte quality markers. The review was written in accordance with the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines. Morphological markers are commonly used, but they are subjective, and no single marker can be used exclusively to predict oocyte competence and subsequent embryonic development potential. Furthermore, transcriptomics of differentially expressed genes in cumulus cells and assessment of metabolomics and other contents of follicular fluid have shown greater precision. However, their specificity to the different quality determinants needs further research.
基金supported by the Strategic Priority Research Program of the Chinese Academy of Sciences(Precision Seed Design and Breeding,XDA24010108)National Natural Science Foundation of China(31972780&31721005)+1 种基金National Key R&D Program of China(2018YFA0801000)State Key Laboratory of Freshwater Ecology and Biotechnology(2019FBZ05)。
文摘Omega-3 polyunsaturated fatty acids(n-3 PUFAs),particularly docosahexaenoic acid(22:6n-3,DHA),play crucial roles in the reproductive health of vertebrates,including humans.Nevertheless,the underlying mechanism related to this phenomenon remains largely unknown.In this study,we employed two zebrafish genetic models,i.e.,elovl2^(-/-)mutant as an endogenous DHAdeficient model and fat1(omega-3 desaturase encoding gene)transgenic zebrafish as an endogenous DHA-rich model,to investigate the effects of DHA on oocyte maturation and quality.Results show that the elovl2^(-/-)mutants had much lower fecundity and poorer oocyte quality than the wild-type controls,while the fat1 zebrafish had higher fecundity and better oocyte quality than wildtype controls.DHA deficiency in elovl2^(-/-)embryos led to defects in egg activation,poor microtubule stability,and reduced pregnenolone levels.Further study revealed that DHA promoted pregnenolone synthesis by enhancing transcription of cyp11a1,which encodes the cholesterol side-chain cleavage enzyme,thereby stabilizing microtubule assembly during oogenesis.In turn,the hypothalamic-pituitary-gonadal axis was enhanced by DHA.In conclusion,using two unique genetic models,our findings demonstrate that endogenously synthesized DHA promotes oocyte maturation and quality by promoting pregnenolone production via transcriptional regulation of cyp11a1.
文摘Objective:To compare embryonic development,ploidy status and clinical outcomes between fresh and frozen-thawed oocytes.Methods:This retrospective cohort study evaluated 83 fertilization cycles including both fresh and frozen oocytes from 79 patients at the HP Fertility Center of Hai Phong International Hospital of Obstetrics and Pediatrics in Vietnam.The patient underwent several ovarian stimulation cycles to accumulate a certain number of oocytes that would be vitrified.In the last oocyte retrieval,all patient’s oocytes including both frozen and fresh would be fertilized.The outcomes included the rates of oocyte survival,cleavage embryo,blastocyst,ploidy status,pregnancy,biochemical pregnancy and clinical pregnancy.Results:The oocyte survival rate after thawing was 96.5%.No statistically significant difference was found when comparing fresh and frozen oocytes regarding fertilization rate(78.1%vs.75.5%,P=0.461),usable cleavage embryo rate(86.9%vs.87.2%,P=0.916)but usable blastocyst rate was found higher statistically in the frozen oocyte group(44.4%vs.54.0%,P=0.049).The percentages of euploid,aneuploid and mosaic embryos between the fresh group and the vitrified group had no significant differences(33.8%vs.31.6%,P=0.682;51.0%vs.54.2%,P=0.569;15.2%vs.12.4%,P=0.787;respectively).The rates of pregnancy,biochemical pregnancy and clinical pregnancy had no statistical difference(68.8%vs.64.8%,P=0.764;12.5%vs.3.6%,P=0.258;37.5%vs.46.4%,P=0.565).17 Mature oocytes are the minimum to have at least one euploid embryo.Conclusions:Oocyte vitrification does not affect embryonic,genetic and clinical results.The number of mature oocytes should be considered for fertilization in some cases.
基金funded by Fondazione Banco di Sardegna,FDS 2016(CUP J86C18000780005 and J86C18000810005)。
文摘Background:Heavy metal cadmium(Cd)is a widespread environmental contaminant with a potential toxicity that might negatively affect female reproduction and fertility.It has been reported that Cd exposure impaired the quality of oocytes and led to a defective maturation and fertilization,through oxidative stress induction.Resveratrol(Res)is a natural polyphenol with strong antioxidant properties that exhibited protective role in preventing oocyte redox homeostasis disruption and quality decline.Here,we explored whether the addition of Res to in vitro maturation(IVM)medium might act as a protection against Cd-induced toxicity on ovine oocyte maturation and fertilization.Firstly,we evaluated the effect of supplementing IVM medium with two different Res concentrations(1and 2μmol/L)on nuclear maturation and fertilization of oocytes matured under CdCl2(2μmol/L)exposure.Therefore,the concentration of 1μmol/L Res was selected to analyse the effects of this compound on intracellular ROS levels,mitochondrial(mt)distribution and activity,chromatin configuration,cytoskeleton morphology,cortical granules(CGs)distribution and mRNA expression of genes associated with cellular response to oxidative stress(i.e.SIRT1,SOD 1,GPX1,GSR,CAT)in Cd-exposed in vitro matured oocytes.Results:We found that 1μmol/L Res restored the reduced oocyte meiotic competence induced by Cd exposure as well as,Res sustained oocyte ability to be normally fertilized and decreased polyspermic fertilization at both tested concentrations.Moreover,we demonstrated that 1μmol/L Res mitigated Cd-induced alterations of oocyte cytoplasmic maturation by reducing reactive oxygen species(ROS)accumulation,preventing mt dysfunction,maintaining the correct meiotic spindle and cortical F-actin assembly and the normal cortical granule distribution as well as up-regulating SIRT1,SOD1 and GPX1 genes.Conclusions:Taken together,our findings highlighted the beneficial influence exerted by Res in preventing Cdinduced disturbance of nuclear and cytoplasmic maturation and subsequent fertilization in ovine oocytes.Res treatment may help to establish defence strategies counteracting Cd-induced toxicity on the female gamete.
基金supported Key Industry Innovation Chain of Shaanxi Province (2018ZDCXL-NY-02-06)。
文摘Background Zearalenone(ZEA)widely exists in moldy grains,which seriously destroys the fertility of females.Isorhamnetin,a natural flavonoid,has extensive of pharmacological activities.However,the beneficial effect and the underlying molecular mechanism of isorhamnetin involvement in ZEA-induced porcine oocyte damage have not been investigated.Methods Oocytes were treated with different concentrations of ZEA(3,5,8 and 10μmol/L)and isorhamnetin(5,10,20 and 30μmol/L)for 44 h at 39℃.ZEA(5μmol/L)and isorhamnetin(10μmol/L)were selected for subsequent studies.Polar body exclusion rate,apoptosis rate and apoptosis related proteins,ROS levels and SOD2 protein,mitochondrial membrane potential and distribution,endoplasmic reticulum distribution and proteins expression,and PI3K,Akt and p-Akt proteins expression of oocytes were detected.In addition,the effect of PI3K antagonist(LY294002)on oocyte nuclear maturation and apoptosis were used to determine the involvement of PI3K/Akt signaling pathway.Results Our findings showed that ZEA exposure damaged oocytes and isorhamnetin therapy restored the developmental capability of porcine oocytes.Isorhamnetin promoted polar body extrusion rate to rescue ZEA-induced meiotic arrest in porcine oocytes.Isorhamnetin alleviated ZEA-induced oxidative stress by stimulating SOD2 protein expression and inhibiting ROS production.Moreover,isorhamnetin enhanced normal mitochondrial distribution and mitochondrial membrane potential to prevent mitochondrial dysfunction induced by ZEA.Changing the expression of endoplasmic reticulum stress-related marker proteins(CHOP,GRP78)and the distribution rate of normal endoplasmic reticulum showed that isorhamnetin relieved ZEA-caused endoplasmic reticulum stress.Mechanistically,isorhamnetin decreased Bax/Bcl-2 protein expression and inhibited ZEA-induced apoptosis through PI3K/Akt signaling pathway.Conclusions Collectively,these results suggest that isorhamnetin protects oocytes from ZEA-caused damage through PI3K/Akt signaling pathway,which enhances meiotic maturation and mitochondrial function,and inhibits early apoptosis,oxidative stress and endoplasmic reticulum stress in porcine oocytes.Our study provides a new strategy for solving the reproductive toxicity induced by ZEA and treating woman infertility.
基金National Key Research and Development Program Topics,Grant/Award Number:2021YFD1200402Chinese Universities Scientific Fund,Grant/Award Number:2021TC061+6 种基金Natural Science Foundation of Hebei province,Grant/Award Number:H2020206254Special Program for Training and Guiding Outstanding Young and Middle-aged Talents,Grant/Award Number:SKLSGIHP2021A01National Natural Science Foundation of China,Grant/Award Number:81901562&31372307Key research and development projects in Hebei province,Grant/Award Number:18226604DProgram of Young and Middle-aged Scientific and technological Innovation Leaders of the Xinjiang Production and Construction Corps,Grant/Award Number:2018CB025Xinghuo program of the First Hospital of Hebei Medical University,Grant/Award Number:XH202005The Central Guidance on Local Science and Technology Development Fund of Hebei Province,Grant/Award Number:226Z7713G。
文摘Background:Irreversible cryodamage caused by oocyte vitrification limited its wild application in female fertility preservation.Antioxidants were always used to antagonist the oxidative stress caused by vitrification.However,the comprehensive mechanism underlying the protective role of antioxidants has not been studied.Procyanidin B2(PCB2)is a potent natural antioxidant and its functions in response to vitrification are still unknown.In this study,the effects of PCB2 on vitrified-thawed oocytes and subsequent embryo development were explored,and the mechanisms underlying the protective role of PCB2 were systematically elucidated.Results:Vitrification induced a marked decline in oocyte quality,while PCB2 could improve oocyte viability and further development after parthenogenetic activation.A subsequent study indicated that PCB2 effectively attenuated vitrification-induced oxidative stress,rescued mitochondrial dysfunction,and improved cell viability.Moreover,PCB2 also acts as a cortical tension regulator apart from strong antioxidant properties.Increased cortical tension caused by PCB2 would maintain normal spindle morphology and promote migration,ensure correct meiosis progression and finally reduce the aneuploidy rate in vitrified oocytes.Further study reveals that ATP biosynthesis plays a crucial role in cortical tension regulation,and PCB2 effectively increased the cortical tension through the electron transfer chain pathway.Additionally,PCB2 would elevate the cortical tension in embryo cells at morula and blastocyst stages and further improve blastocyst quality.What's more,targeted metabolomics shows that PCB2 has a beneficial effect on blastocyst formation by mediating saccharides and amino acids metabolism.Conclusions:Antioxidant PCB2 exhibits multi-protective roles in response to vitrification stimuli through mitochondria-mediated cortical tension regulation.
基金supported by grants from the Key Research and Development Plan Project of Ningxia Hui Autonomous Region(2021BEF02029)the Key Research and Development Plan Project(Talent Introduction Project)of Ningxia Hui Autonomous Region(2020BEB04006)the Introducing Talent Research Startup Project of Ningxia University(030900002254).
文摘Bovine oocytes are one of the indispensable cells in cattle reproduction and have become a research hot spot in cattle reproduction in recent years.The maturation process of oocytes is mainly regulated by enzymes,hormones,cytokines,and other molecules.The factors affecting cattle oocyte maturation have been previously studied to clarify the molecular mechanisms of cattle oocyte maturation.In this review article,phospholipid protein-3-kinase/protein kinase B,mitogen-activated protein kinase/extracellular signal-regulated kinase,Janus kinase/signal transducer and activator of transcription,epidermal growth factor receptor/extracellular signal-regulated kinase,and other signaling pathways related to oocyte maturation are discussed.In addition,the molecular mechanisms of some coding genes(JY-1,FGF-10,CDC20,etc.)and non-coding genes(miRNA,lncRNA,and circRNA)regulating oocyte maturation have been reviewed to provide new ideas for high reproductive performance molecular breeding of high-quality cattle.
基金National Natural Science Foundation of China (No.82072880,81960283)Science and Technology Project of Hainan Province (No.LCYX202102)Key Science and Technology Project of Hainan Province (No.ZDKJ2017007)。
文摘With the clinical development and application of intracytoplasmic sperm injection(ICSI)technology in human assisted reproduction,the influence of oocyte quality on embryo development has been paid more and more attention.So far,there have been many reports on oocyte morphology affecting embryo development.It has been found in some works that the appearance of smooth endoplasmic reticulum clusters(SERC)in oocytes may affect the fertilization and embryo development of oocytes.However,with the increasing reports of SERC-containing oocytes obtained by in vitro fertilization and healthy offspring in recent years,there is still some controversy on whether to continue to use SERC-containing oocytes for the following assisted reproductive therapy in clinical practice.Based on this,this review aims to review the research progress of SERC in oocytes in recent years.
基金supported by the National Natural Science Foundation of China(31900592)the Natural Science Foundation of Jiangsu Province(BK20190526).
文摘Background:Elevated ambient temperature-caused heat stress is a major concern for livestock production due to its negative impact on animal feed intake,growth,reproduction,and health.Particularly,the germ cells are extremely sensitive to the heat stress.However,the effective approach and strategy regarding how to protect mammalian oocytes from heat stress-induced defects have not been determined.Methods:Germinal vesicle(GV)porcine oocytes were cultured at 41.5℃ for 24 h to induce heat stress,and then cultured at 38.5℃ to the specific developmental stage for subsequent analysis.Nicotinamide mononucleotide(NMN)was dissolved in water to 1 mol/L for a stock solution and further diluted with the maturation medium to the final concentrations of 10μmol/L,20μmol/L,50μmol/L or 100μmol/L,respectively,during heat stress.Immunostaining and fluorescence intensity quantification were applied to assess the effects of heat stress and NMN supplementation on the key processes during the oocyte meiotic maturation.Results:Here,we report that NMN supplementation improves the quality of porcine oocytes under heat stress.Specifically,we found that heat stress resulted in oocyte maturation failure by disturbing the dynamics of meiotic organelles,including the cytoskeleton assembly,cortical granule distribution and mitochondrial function.In addition,heat stress induced the production of excessive reactive oxygen species(ROS)and DNA damage,leading to the occurrence of apoptosis in oocytes and subsequent embryonic development arrest.More importantly,we validated that supplementation of NMN during heat stress restored the meiotic defects during porcine oocyte maturation.Conclusions:Taken together,our study documents that NMN supplementation is an effective approach to improve the quality of oocytes under heat stress by promoting both nuclear and cytoplasmic maturation.
基金Supported by Science and Technology Collaborative Innovation Project of Guangzhou,No.201704020217
文摘BACKGROUND The outcomes of the use of commercial in vitro maturation(IVM)medium to culture immature oocytes obtained from conventional ovulation induction,followed by rescue intracytoplasmic sperm injection(RICSI),are not ideal.It is thus difficult to widely adopt this approach in clinical practice.Therefore,it is necessary to explore methods for improving the clinical outcome of IVM.AIM To study the effect of sperm on the developmental potential of in vitro-matured oocytes in conventional culture.METHODS This was a retrospective study of patients whose immature oocytes were harvested from conventional oocyte stimulation cycles and underwent ICSI at our hospital between June 2018 and August 2020.RICSI was performed using sperm collected on the day of oocyte harvest(old)and sperm collected on the day of RICSI(fresh)and oocytes matured in vitro after 24 h of culture in conventional medium.The rates of in vitro oocyte maturation,normal fertilization,normal cleavage,day-3 top-quality embryos,and useful blastocyst formation were compared between the two groups.RESULTS In total,102 germinal vesicle(GV)-stage immature oocytes were cultured in the old sperm group.In the fresh sperm group,122 GV-stage immature oocytes were collected and cultured in vitro for 24 h.There were no significant differences in the general conditions of males and females between the two groups(P>0.05).The oocyte maturation,normal fertilization,and normal cleavage rates of the old and fresh groups were 51.0%vs 55.7%,61.5%vs 64.7%,and 93.8%vs 93.2%,respectively.None of the rates differed significantly(P>0.05)between the two groups.However,the day-3 top-quality embryo and useful blastocyst rates of the old and fresh sperm groups were 16.6%vs 63.4%;6.67%vs 34.6%,respectively.The day-3 top-quality embryos and useful blastocyst rates of the old sperm group were significantly lower than those of the fresh group(P<0.05).CONCLUSION In vitro maturation with conventional culture medium combined with the use of fresh sperm collected on the day of RICSI is an easy-to-implement strategy for patients whose oocytes are completely or mostly immature.
文摘Is there a really need to validate oocyte vitrification technique in an ART laboratory before establishing it in daily practice? Validation of micromanipulationbased technique, in this case oocyte vitrification, is essential prior to enlarging its use to routine practice. Oocyte vitrification is a new worldwide used technique and legal recently inFrance. This micromanipulation needs to be performed by a skilled and experienced embryologist and requires an internal assessment in each ART unit before any wide use. We designed a prospective study, from September 2011 to July 2012, using sibling oocytes from women who recovered more than 12 Metaphase II oocytes. A part of freshly recovered oocytes underwent immediate ICSI while the remaining oocytes were vitrified. 87 couples undergoing ICSI were selected based on number of mature oocytes available on the recovery day after denudation. A part of fresh MII oocytes were microinjected and the others were vitrified using an open system (Cryotop?). The major criterion of interest was the number of embryo transferred/ number of Metaphase II ratio for after ICSI on fresh oocytes (42/211) versus vitrified/warmed oocytes (51/204) (p > 0.05). Secondary studied criteria were survival rate (80.5% ± 26.3%), fertilization rate (68.9 ± 33.5) and finally, cumulative pregnancy rate obtained in this study is 40.2%. One of the benefits of such practice is the limitation of embryo freezing. However, the study design delays oocytes warming cycles, due to pregnancies triggered by the transfer of fresh derived oocyte embryos and to the priority to transfer all the frozen embryos before starting oocytes warming. Moreover, no data is available about children’ health. Oocyte vitrification represents not only a change in our daily practice to improve cumulative pregnancy rate but also a promising tool to develop egg banking and donation. Clinical Trials Registration number: 209 R02.
基金supported financially by Fundacao de Amparo a Pesquisa do Estado de Sao Paulo(FAPESP).
文摘In Vitro production of swine embryos is a valuable tool to generate clones and genetically modified pigs during a short period of time. However, the efficiency of the existing methods is extremely low and the oocyte quality and quantity represent important obstacles on the success of in Vitro production of embryos. Therefore, the aim of this study was to compare the in Vitro maturation, fertilization and subsequent embryo development rates of oocytes recovered by ovary slicing or follicular aspiration. The oocyte recovery rate (grade 1 COC/ovary) was higher (p = 0.0083) in the slicing group when compared to the aspiration group. No differences were observed between groups regarding in Vitro maturation and early cleavage rates. A higher percentage of oocytes recovered by follicular aspiration reached the blastocyst stage after IVF when compared to the ovary slicing method (p = 0.0395). However, no difference on blastocyst cell number was observed. Although the recovery of oocytes using the slicing technique yielded more grade 1 oocytes per ovary than the aspiration method, the number of oocytes that reached the blastocyst stage after IVF by the slicing method was lower when compared with oocytes obtained by aspiration, as observed by lower blastocyst rates. In conclusion, the follicular aspiration is the method of choice for porcine in Vitro embryo production.
文摘Fertilization in mammals requires the successful completion of a sequence of steps, starting with the transport of gametes in the reproductive tract and ending with sperm-egg membrane fusion to produce a zygote. Although some integrin subunits are known to be associated with the plasma membrane of some mammalian oocytes and spermatozoa, the presence of α6 integrin on bovine oocytes with intact zona pellucida has not been reported. The present study was undertaken to evaluate the expression of α6 integrin subunit in bovine oocyte and to determine if in vitro binding to the zona pellucida and fertilization were affected by treating oocytes with α6 integrin subunit antibody. The α6 integrin subunit was identified on the bovine oocyte by immunocytochemistry. In vitro fertilization was significantly decreased when in vitro matured bovine oocytes were pre-incubated with α6 integrin subunit antibody at concentration 5 and 20 μg/mL, and spermoocyte binding increased. These studies demonstrated the presence of α6 integrin subunit on bovine oocyte, and its importance in fertilization and polyspermy.
基金This work is supported by National Natural Sci-ence Fundation of China (Grant 39770370), and National Laboratory of Contraceptives and Devices Re-search affiliated with Shanghai lnstitute of Planned Parenthood Research.
文摘p28, a 28kD protein from toad (Bufo bufo gargarizans) oocytes, was identified by using p13suc1-agaroseaffinity chromatography. Sequence homology analysis of the full-length cDNA of p28 (Gene Bank accessionnumber: AF 314091) indicated that it encodes a protein containing 224 amino-acids with about 55% iden-tities and more than 70% positives to human, rat or mouse UCH-L1, and contains homological functionaldomains of UCH family. Anti-p28 monoclonal antibody, on injecting into the oocytes, could inhibit theprogesterone-induced resumption of meiotic division in a dose-dependent manner. The recombinant proteinp28 showed similar SDS/PAGE behaviors to the native one, and promoted ubiquitin ethyl ester hydrolysis,a classical catalytic reaction for ubiquitin carboxyl terminai hydrolases (UCHs). The results in this paperreveal that a novel protein, p28, exists in the toad oocytes, is a UCH L1 homolog, was engaged in theprocess of progesterone-induced oocyte maturation possibly through an involvement in protein turnover anddegradation.
基金supported by programs for the 973 National Basic Research Program of China (2014CB138505)the Open Foundation of State Key Laboratory of Animal Nutrition (2004DA115184F1415)
文摘Background: Resveratrol, an important phyto-antioxidant commonly found in grapes, mulberry, and other plants,has a variety of functions including anti-aging, anti-cancer and anti-inflammatory activities. In the current study, we investigated the beneficial effects of resveratrol on in vitro porcine oocyte maturation under heat stress(HS). The effect of resveratrol, melatonin and their combination on alleviating HS was compared according to the maturation rate of oocytes and the development competence of embryos after parthenogenetic activation(PA).Results: Supplementation with resveratrol(2.0 μmol/L) not only improved the nuclear maturation but also raised the blastocyst rate of porcine embryos' PA from oocytes that underwent HS by increasing their glutathione(GSH)level, reducing reactive oxygen species(ROS) and up-regulating the expression of Sirtuin 1(SIRT1). It was also found that melatonin(10^(-7)mol/L) and the combination of resveratrol(2.0 μmol/L) plus melatonin(10^(-7)mol/L) exhibited more potent effects than resveratrol alone regarding their protective activities on oocyte maturation under HS.Conclusions: This study compared the efficiencies of resveratrol, melatonin and their combination for protecting porcine oocytes from heat stress. The mechanisms are attributed to the fact that each treatment may have different ability to regulate the synthesis of steroid hormones and the expression of mature related genes.
文摘Objective: To study oocyte donation in treatment of premature ovarian failure.Methods:Thirty premature ovarian failure patients receiving hormone replacement therapy had un-dergone 54 treatment cycles of in vitro fertilization with their husbands’ sperm and donors’ oocytes.Ovulation induction was achieved by GnRH-α/HMG/hCG regimen in donors. Embryos transfers were performed in recipients from 15th to 20th day of hormone replacement therapy cycle. Preclinical preg-nancies were defined when serum β-hCG performed on day 14 post embryo transfer >3. 1ng/ml. Clini-cal pregnancies was diagnosed by the presence of a gestation sac with transvaginal ultrasound at six weeks of gestation.Results:Clinical pregnancy rate per embryo transfer cycle was 35- 2% (19/54). The first baby was deliveried on Jan 14, 1994 in premature ovarian failure patient with hormone replacement therapy and oocyte donation in China. Comharison of the results showed a singnificant increase in number of em-bryos transfer, embryo scoring and clinical pregnancy rate (54. 2 % ) in the whole cohort where oocytes were used. The P value was <0.05, <0. 001, <0.05 respectively. However the spontaneous abortion rate(15. 4% ) significantly decreased (P<0.001 ). No difference was found in the embryos scoring and the number of embryos transfer between groups with age less than 3O years or more than 30 years. But clinical pregnancy rate in the younger group (42. 9% ) was significantly higher than in the older group (30. 3%). The endometrium receptivity window of a 2-days embryo was from 15th to 19th day of a 28 days cycle. The highest pregnancy rate was in day 16 to 18 in the 28 days cycle.Conclusion: Hormone replacement therapy and oocyte donation is a effective method of obtaining successful pregnancy for those with premature ovarian failure. The quality of oocyte is an important factor that affects the pregnancy rate and spontaneous abortion rate. The endometrium receptivity ia al-so a major factor affecting the pregnancy rate, which declined with increasing age.
基金supported by the Charles University Research Fund(Progres Q39)the National Sustainability Programme I(NPU I)Nr.LO1503 provided by the Ministry of Education+5 种基金Youth and Sports of the Czech Republic(MEYS CR)project No.SVV 02690 awarded by MEYS CRthe project No.CZ.02.1.01/0.0/0.0/16_019/0000787 “Fighting Infectious Diseases”awarded by MEYS CR and financed from The European Regional Development Fundsupported by the National Agency of Agriculture Sciences(NAZV QJ1510138)the Czech Ministry of Agriculture(MZe RO 0718)
文摘Background: SIRT1 histone deacetylase acts on many epigenetic and non-epigenetic targets. It is thought that SIRT1 is involved in oocyte maturation;therefore, the importance of the ooplasmic SIRT1 pool for the further fate of mature oocytes has been strongly suggested. We hypothesised that SIRT1 plays the role of a signalling molecule in mature oocytes through selected epigenetic and non-epigenetic regulation.Results: We observed SIRT1 re-localisation in mature oocytes and its association with spindle microtubules.In mature oocytes, SIRT1 distribution shows a spindle-like pattern, and spindle-specific SIRT1 action decreasesα-tubulin acetylation. Based on the observation of the histone code in immature and mature oocytes, we suggest that SIRT1 is mostly predestined for an epigenetic mode of action in the germinal vesicles(GVs) of immature oocytes. Accordingly, BML-278-driven trimethylation of lysine K9 in histone H3 in mature oocytes is considered to be a result of GV epigenetic transformation.Conclusions: Taken together, our observations point out the dual spatiotemporal SIRT1 action in oocytes,which can be readily switched from the epigenetic to non-epigenetic mode of action depending on the progress of meiosis.
文摘The clomiphene citrate (CC), a nonsteroidal triphenylethylene compound, is a first line of medicine used for the induction of ovulation in anovulatory women worldwide. In spite of high ovulation induction with the use of CC, the pregnancy rate is much lower. Such a discrepancy could be due to the peripheral anti-estrogenic effect of CC, particularly at the level of ovary, endometrium and cervical mucus. CC induces ovulation by binding to the estrogen receptors and generates hypoestrogrnic state in hypothalamus leading to release of pituitary gonadotropins. CC may have a direct effect at the level of ovary but the molecular mechanism remains unclear. Animal studies suggest that the CC induces apoptosis in granulosa cells and results hypoestrogenic state in the ovary. Reduced estradiol 17β level in the ovary affects development and maturation of oocyte leading to oocyte apoptosis. Further, CC increases hydrogen peroxide (H2O2) level and thereby bax protein expression and DNA fragmentation in cumulus-granulosa cells as well as in oocytes. The exogenous supplementation of either estradiol 17β or melatonin reduces H2O2 level in ovary, delays meiotic cell cycle progression in oocyte and protects oocyte apoptosis. Hence, supplementation of estradiol 17β or melatonin along with CC could be beneficial to protect granulosa cell as well as oocyte apoptosis and inhibit deterioration of oocyte quality. Thus, maintenance of oocyte quality may overcome the adverse effect caused due to CC treatment during infertility management.
基金supported by the National Natural Science Foundation of China(No.30930065 and No.31271605)
文摘Proper chromosome separation in both mitosis and meiosis depends on the correct connection between kinetochores of chromosomes and spindle microtubules. Kinetochore dysfunction can lead to unequal distribution of chromosomes during cell division and result in aneuploidy, thus kinetochores are critical for faithful segregation of chromosomes. Centromere protein A(CENP-A) is an important component of the inner kinetochore plate. Multiple studies in mitosis have found that deficiencies in CENP-A could result in structural and functional changes of kinetochores, leading to abnormal chromosome segregation, aneuploidy and apoptosis in cells. Here we report the expression and function of CENP-A during mouse oocyte meiosis. Our study found that microinjection of CENP-A blocking antibody resulted in errors of homologous chromosome segregation and caused aneuploidy in eggs. Thus, our findings provide evidence that CENP-A is critical for the faithful chromosome segregation during mammalian oocyte meiosis.
基金This work was supported by the National Key Research and Development Program of China(Grant number 2016YFD0500502)the National Basic Research Program of China(Grant number 2014CB138502)+1 种基金the Priority Academic Program Development of Jiangsu Higher Education Institutionsand the Jiangsu Collaborative Innovation Center of Meat Production and Processing,Quality and Safety Control.
文摘Background:Transzonal projections(TZPs)constitute a structural basis for the communication between the oocyte and its surrounding cumulus cells(CCs),which play critical roles in promoting the oocyte maturation.Previously we found that heat stress(HS)causes loss of TZPs in porcine cumulus-oocyte complexes(COCs)with decreased density of filamentous actin(F-actin).However,the time-course responses of F-actin and its monomeric actins(β-actin andγ-actin)during the in vitro maturation of oocytes remain unclear.Results:In this study,excised porcine ovaries were exposed to HS at 41.5°C for 1 h before COCs were isolated and matured in vitro for 44 h.HS significantly reduced oocyte quality,characterized by impaired cumulus expansion,delayed meiotic resumption and lower survival rate and polar body extrusion rate,as well as decreased expression of mitochondrial DNA-encoded genes and elevated mitochondrial reactive oxygen species concentration.Expression ofβ-actin andγ-actin in CCs increased gradually with oocytes maturation,which was significantly reduced in HS group,especially at 24 h and/or 44 h of in vitro maturation.By contrast,the number of TZPs and the fluorescence intensity of F-actin in zona pellucida decreased gradually during oocytes maturation,which were significantly reduced by HS at 24 h of in vitro maturation.Moreover,colocalization analyses revealed bothβ-actin andγ-actin contribute to the F-actin formation in porcine TZPs,and the colocalization of F-actin with GJ protein connexin 45 was significantly reduced in heat-exposed COCs.Conclusions:The results indicate that the suppression of actin expressions in CCs,which may lead to the F-actin unstabilization in TZPs,will subsequently contribute to the compromised quality of oocytes under HS.
