Background: Ovarian follicular fluids(FFs) contain several kinds of regulatory factors that maintain a suitable micro-environment for oocyte development. Extracellular vesicles(EVs) are among the factors that play ess...Background: Ovarian follicular fluids(FFs) contain several kinds of regulatory factors that maintain a suitable micro-environment for oocyte development. Extracellular vesicles(EVs) are among the factors that play essential roles in regulating follicle and oocyte development through their cargo molecules that include microRNAs(miRNAs). This study aimed to investigate small-EV(s-EV) miRNAs in porcine FFs and their potential association with oocyte quality.Methods: Individual aspirated oocytes were stained with lissamine green B stain(LB), a vital stain for oocyte quality, and each oocyte was classified as high-quality(unstained;HQ) or low-quality(stained;LQ). FFs corresponding to oocytes were pooled together into HQ and LQ groups. Small-EVs were isolated from FFs, characterized, and their miRNA cargo was identified using the Illumina Nova Seq sequencing platform. Additionally, s-EVs from the HQ and LQ groups were utilized to investigate their effect on oocyte development after co-incubation during in vitro maturation.Results: A total of 19 miRNAs(including miR-125b, miR-193a-5p, and miR-320) were significantly upregulated, while 23(including miR-9, miR-206, and miR-6516) were downregulated in the HQ compared to the LQ group. Apoptosis, p53 signaling, and cAMP signaling were among the top pathways targeted by the elevated miRNAs in the HQ group while oocyte meiosis, gap junction, and TGF-beta signaling were among the top pathways targeted by the elevated miRNAs in the LQ group. The supplementation of small-EVs during maturation does not affect the oocyte developmental rates. However, LQ s-EVs increase the proportion of oocytes with homogeneous mitochondrial distribution and decrease the proportion of heterogeneous distribution.Conclusion: Our findings indicated that FF-EVs contain different miRNA cargos associated with oocyte quality and could affect the mitochondrial distribution patterns during oocyte maturation.展开更多
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
Declining female fertility is a health issue that has received broad global attention.Oocyte quality is the key limiting factor of female fertility,and key processes affecting oocyte quality involve the secretion of a...Declining female fertility is a health issue that has received broad global attention.Oocyte quality is the key limiting factor of female fertility,and key processes affecting oocyte quality involve the secretion of and response to hormones,ovarian function,oogenesis,oocyte maturation,and meiosis.However,compared with other species,the research and understanding of human oocyte quality and human reproductive health is limited.This review highlights our current understanding of the physiological factors and pathological factors related to human oocyte quality and discusses potential treatments.In terms of physiology,we discuss the regulation of the hypothalamic-pituitary-gonadal axis,granulosa cells,key subcellular structures,maternal mRNA homeostasis,the extracellular matrix,the maternal microenvironment,and multi-omics resources related to human oocyte quality.In terms of pathology,we review hypothalamic-pituitary-gonadal defects,ovarian dysfunction(including premature ovarian insufficiency and polycystic ovary syndrome),human oocyte development defects,and aging.In terms of the pathological aspects of human oocyte development and quality defects,nearly half of the reported pathogenic genes are involved in meiosis,while the remainder are involved in maternal mRNA regulation,the subcortical maternal complex,zona pellucida formation,ion channels,protein transport,and mitochondrial function.Furthermore,we outline the emerging scientific prospects and challenges for future explorations of the biological mechanisms behind infertility and the development of clinical treatments.This review seeks to deepen our understanding of the mechanisms regulating human oocyte quality and to provide novel insights into clinical female infertility characterized by defects in oocyte quality and oocyte development.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
Fertility disorders have become a growing problem worldwide. It is well known that female fertility decreases with age, previous studies suggested that the age-related decline in female fertility potential was largely...Fertility disorders have become a growing problem worldwide. It is well known that female fertility decreases with age, previous studies suggested that the age-related decline in female fertility potential was largely due to decrease in oocyte quality and mitochondrial dysfunction. Mitochondria play a crucial role during the process of oocyte maturation. Mitochondrial genetic, numerical and structural defects occur in oocyte aging process, mitochondrial abnormalities are believed to contribute to age-related infertility. Improvement of the mitochondrial function can lead to better fertility outcomes, and application of mitochondria replacement strategy or mitochondrial transfer to age-related infertility will be possible in the future. This review paper, we are trying to discuss current understanding about age-related changes in oocyte quality and mitochondrial dysfunction.展开更多
Selecting oocytes that are most likely to develop is crucial for in vitro fertilization and animal cloning. Brilliant cresyl blue （BCB） staining has been used for oocyte selection in large animals, but its wider uti...Selecting oocytes that are most likely to develop is crucial for in vitro fertilization and animal cloning. Brilliant cresyl blue （BCB） staining has been used for oocyte selection in large animals, but its wider utility needs further evaluation. Mouse oocytes were divided into those stained （BCB＋） and those unstained （BCB-） according to their ooplasm BCB coloration. Chromatin configurations, cumulus cell apoptosis, cytoplasmic maturity and developmental competence were compared between the BCB＋ and BCB- oocytes. The effects of oocyte diameter, sexual maturity and gonadotropin stimulation on the competence of BCB＋ oocytes were also analyzed. In the large- and medium-size groups, BCB＋ oocytes were larger and showed more surrounded nucleoli （SN） chromatin configurations and higher frequencies of early atresia, and they also gained better cytoplasmic maturity （determined as the intracellular GSH level and pattern of mitochondrial distribution） and higher developmental potential after in vitro maturation （IVM） than the BCB-oocytes. Adult mice produced more BCB＋ oocytes with higher competence than the prepubertal mice when not primed with PMSG. PMSG priming increased both proportion and developmental potency of BCB＋ oocytes. The BCB＋ oocytes in the large-size group showed more SN chromatin configurations, better cytoplasmic maturity and higher developmental potential than their counterparts in the medium-size group. It is concluded that BCB staining can be used as an efficient method for oocyte selection, but that the competence of the BCB＋ oocytes may vary with oocyte diameter, animal sexual maturity and gonadotropin stimulation. Taken together, the series of criteria described here would allow for better choices in selecting oocytes for better development.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
Amphibians are considered as reliable indicators of environmental quality. In Europe, a general decline of amphibians population parallels a worldwide decline, and some of the factors which are thought to be responsib...Amphibians are considered as reliable indicators of environmental quality. In Europe, a general decline of amphibians population parallels a worldwide decline, and some of the factors which are thought to be responsible to this decline are habitat loss, introduction of exotic species, disease and decreasing water quality. Recent investigations suggest that these eutrophic conditions may be associated with frog reproduction problems. Water quality criteria settled for the different species of amphibians do not currently exist, but in the present paper, the authors report their observation about water phosphate concentrations in association with hipofertility in African clawed frogs （Xenopus laevis）. The study considered two different groups of African clawed frog showing hypofertility （22 patients） hosted in captivity. The animals were visited, and the filtration systems functionality and the water quality were checked, i.e., temperature, pH, ammonia, nitrite, nitrate, phosphates, hardness and alkalinity. In the first group, it was decided to perform ultrasound scans, parasitological tests on fecal samples, and microscopical/macroscopical examination, as well as microbiological analysis on collected oocytes. In the second group, only fecal samples were collected in order to perform parasitologiacal exams. No pathological findings were showed by veterinary tests. Water changes were carried out in both facilities and after two months, the fertility in African clawed frogs improved, evidencing the involvement of phosphates values in the onset of the problem and even more in its resolution. More studies are needed to further define this correlation.展开更多
Objective:The transcriptional profile of cumulus cells(CCs)during oocyte maturation provides information for predicting oocyte developmental competence.Our previous study using a mouse model indicated that there were ...Objective:The transcriptional profile of cumulus cells(CCs)during oocyte maturation provides information for predicting oocyte developmental competence.Our previous study using a mouse model indicated that there were nine different genes related to oocyte development potential expressed in CCs during oocyte maturation.The purpose of this study was to elucidate whether gene expression levels of CCs during oocyte maturation are associated with oocyte developmental competence.Methods:The human CCs collected from each oocyte were divided into two groups after tracking depending on whether or not they developed to the blastocyst stage:(1)the oocytes were developed to blastocyst stage after fertilization(B+)and(2)the oocytes were not developed to blastocyst stage after fertilization(B−).The expression levels of the nine selected genes(ARRB1,ATP2C1,CDH5,CNTNAP1,LGR4,MKLN1,RHOBTB1,SIX2,and SMC2)were examined.CCs were obtained from 29 women who were undergoing intracytoplasmic sperm injection treatment cycles.Quantitative reverse transcriptase-polymerase chain reaction analysis was performed on cumulus masses collected before insemination.Each sample was run three times.Statistically significant differences in mRNA expression of the target genes in independent samples were evaluated by two-tailed Student’s t-test,and P<0.05 was considered significantly different.Results:There were significant differences in the mRNA expression levels of ARRB1(P=0.016),LGR4(P=0.025),and SMC2(P=0.013)between the groups B+and B−.Gene expression of ARRB1,LGR4,and SMC2 in CCs is related to blastocyst development.Conclusions:Analysis of expression of ARRB1,LGR4,and SMC2 genes in CCs as biomarkers may provide predictive information on oocyte developmental competence before insemination and fertilization.展开更多
Objective To explore the effects of electroacupuncture(EA)on pregnancy outcomes after assisted reproduction and mitochondrial function of granulosa cells(GCs)in patients with polycystic ovary syndrome(PCOS)and phlegm-...Objective To explore the effects of electroacupuncture(EA)on pregnancy outcomes after assisted reproduction and mitochondrial function of granulosa cells(GCs)in patients with polycystic ovary syndrome(PCOS)and phlegm-dampness syndrome.Methods In this randomized controlled trial,90 infertile women with PCOS and phlegm-dampness syndrome were recruited between August 2022 and December 2022.Patients were randomly assigned to the EA and control groups using a random sequence of codes in the order of enrolment,with 45 in in each group.Both groups underwent the ovarian stimulation protocol.The patients in the EA group received EA therapy including Zhongwan(CV 12),Qihai(CV 6),bilateral Xuehai(SP 10),Sanyinjiao(SP 6),Yinlingquan(SP 9),Tianshu(ST 25),Zusanli(ST 36),and Fenglong(ST 40),and the patients in the control group was treated with pseudo-acupuncture.The intervention was 25 min twice a week for a total of 6 times until the trigger day after menstruation had ended in the cycle before oocyte retrieval.The primary outcomes were clinical pregnancy rate(CPR)and the number of high-quality embryos.The secondary outcomes were(1)pregnancy-related indicators,including fresh embryo transfer rate(ETR),ovarian hyperstimulation syndrome(OHSS)rate,early pregnancy loss rate(ePLR),ectopic pregnancy rate,live birth rate(LBR),and cumulative CPR;(2)mitochondrial autophagy and mitochondrial membrane potential(MMP)in GCs;and(3)scoring for Chinese medicine syndrome.Adverse events to assess clinical safety were also monitored.Results The cumulative CPR was significantly higher in the EA group(42/45,93.3%)than in the control group(38/45,84.4%,P=0.036).The number of high-quality embryos and fresh ETR in the EA group were higher than those in the control group(3.80±1.65 vs.2.44±1.34,P<0.001;46.7%vs 24.4%,P=0.028).Ectopic pregnancies were not observed in either group.There were no significant differences in the fresh CPR,OHSS rate,ePLR or LBR between the two groups(P>0.05).Compared with the control group,the EA group showed lower expression levels of miR-146a-5p mRNA and P62 protein in GCs and higher levels of MMP and the LC3-II/LC3-I protein ratio(all P<0.01).The phlegm-dampness syndrome scores of the EA group were significantly lower than those of the control group(P<0.01).Conclusions EA significantly improved pregnancy outcomes in patients with PCOS and phlegm dampness syndrome.Mechanistically,this effect may be related to EA in decreasing miR-146a-5p mRNA expression,promoting mitochondrial autophagy in GCs,and improving mitochondrial function,which may contribute to improved oocyte quality.(Trial registration No.ChiCTR2200062915)展开更多
Ovarian reserve is essential for fertility and influences healthy aging in women.Advanced maternal age correlates with the progressive loss of both the quantity and quality of oocytes.The molecular mechanisms and vari...Ovarian reserve is essential for fertility and influences healthy aging in women.Advanced maternal age correlates with the progressive loss of both the quantity and quality of oocytes.The molecular mechanisms and various contributing factors underlying ovarian aging have been uncovered.In this review,we highlight some of critical factors that impact oocyte quantity and quality during aging.Germ cell and follicle reserve at birth de-termines reproductive lifespan and timing the menopause in female mammals.Accelerated diminishing ovarian reserve leads to premature ovarian aging or insufficiency.Poor oocyte quality with increasing age could result from chromosomal cohesion deterioration and misaligned chromosomes,telomere shortening,DNA damage and associated genetic mutations,oxidative stress,mitochondrial dysfunction and epigenetic alteration.We also discuss the intervention strategies to delay ovarian aging.Both the efficacy of senotherapies by antioxidants against reproductive aging and mitochondrial therapy are discussed.Functional oocytes and ovarioids could be rejuvenated from pluripotent stem cells or somatic cells.We propose directions for future interventions.As couples increasingly begin delaying parenthood in life worldwide,understanding the molecular mechanisms during female reproductive aging and potential intervention strategies could benefit women in making earlier choices about their reproductive health.展开更多
Diminished ovarian reserve(DOR)refers to a decrease in the number and/or quality of oocytes in the ovary,accompanied by a decline in reproductive potential,which is generally related to advanced age or ovarian disease...Diminished ovarian reserve(DOR)refers to a decrease in the number and/or quality of oocytes in the ovary,accompanied by a decline in reproductive potential,which is generally related to advanced age or ovarian disease.In in vitro fertilization(IVF)clinical practice,managing patients with DOR remains one of the most challenging tasks.In recent years,increased research on improving ovarian function has provided us with new insights into treating patients with DOR.Many therapeutic options have been proposed to improve the ovarian function of patients with DOR,yet they are not widely utilized in clinical practice because of limited evidence of safety and effectiveness.In this review,we focus on the mechanisms from animal models and clinical trials that have been applied to the treatment of DOR in recent years,intending to improve IVF outcomes in patients with DOR.Furthermore,new insights and perspectives on the molecular and cellular regulation of follicular development and ovarian reserve are emphasized to provide more clues for research on the treatment of DOR.展开更多
基金supported by the Institute of Animal Physiology and Genetics“IAPG-Matoušek Award 2020”Grant number:DRMA-2020-0002the Ministry of Education,Youth and Sports of the Czech Republic,Operational Program Research,Development and Education,the project“EXCELLENCE in molecular aspects of the early development of vertebrates”Grant number:CZ.02.1.01/0.0/0.0/15_003/0000460.
文摘Background: Ovarian follicular fluids(FFs) contain several kinds of regulatory factors that maintain a suitable micro-environment for oocyte development. Extracellular vesicles(EVs) are among the factors that play essential roles in regulating follicle and oocyte development through their cargo molecules that include microRNAs(miRNAs). This study aimed to investigate small-EV(s-EV) miRNAs in porcine FFs and their potential association with oocyte quality.Methods: Individual aspirated oocytes were stained with lissamine green B stain(LB), a vital stain for oocyte quality, and each oocyte was classified as high-quality(unstained;HQ) or low-quality(stained;LQ). FFs corresponding to oocytes were pooled together into HQ and LQ groups. Small-EVs were isolated from FFs, characterized, and their miRNA cargo was identified using the Illumina Nova Seq sequencing platform. Additionally, s-EVs from the HQ and LQ groups were utilized to investigate their effect on oocyte development after co-incubation during in vitro maturation.Results: A total of 19 miRNAs(including miR-125b, miR-193a-5p, and miR-320) were significantly upregulated, while 23(including miR-9, miR-206, and miR-6516) were downregulated in the HQ compared to the LQ group. Apoptosis, p53 signaling, and cAMP signaling were among the top pathways targeted by the elevated miRNAs in the HQ group while oocyte meiosis, gap junction, and TGF-beta signaling were among the top pathways targeted by the elevated miRNAs in the LQ group. The supplementation of small-EVs during maturation does not affect the oocyte developmental rates. However, LQ s-EVs increase the proportion of oocytes with homogeneous mitochondrial distribution and decrease the proportion of heterogeneous distribution.Conclusion: Our findings indicated that FF-EVs contain different miRNA cargos associated with oocyte quality and could affect the mitochondrial distribution patterns during oocyte maturation.
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 National Natural Science Foundation of China(82325021,82288102,32130029,82371662,82422033,and 82271685)the Project of the Shanghai MunicipalScience and Technology Commission(23QA1401800)+1 种基金the Fund ofFudan University and Cao’ejiang Basic Research(24FCB01)the New Cornerstone Science Foundation through the XPLORERPRIZE.Lei Wang is a SANS Exploration Scholar.
文摘Declining female fertility is a health issue that has received broad global attention.Oocyte quality is the key limiting factor of female fertility,and key processes affecting oocyte quality involve the secretion of and response to hormones,ovarian function,oogenesis,oocyte maturation,and meiosis.However,compared with other species,the research and understanding of human oocyte quality and human reproductive health is limited.This review highlights our current understanding of the physiological factors and pathological factors related to human oocyte quality and discusses potential treatments.In terms of physiology,we discuss the regulation of the hypothalamic-pituitary-gonadal axis,granulosa cells,key subcellular structures,maternal mRNA homeostasis,the extracellular matrix,the maternal microenvironment,and multi-omics resources related to human oocyte quality.In terms of pathology,we review hypothalamic-pituitary-gonadal defects,ovarian dysfunction(including premature ovarian insufficiency and polycystic ovary syndrome),human oocyte development defects,and aging.In terms of the pathological aspects of human oocyte development and quality defects,nearly half of the reported pathogenic genes are involved in meiosis,while the remainder are involved in maternal mRNA regulation,the subcortical maternal complex,zona pellucida formation,ion channels,protein transport,and mitochondrial function.Furthermore,we outline the emerging scientific prospects and challenges for future explorations of the biological mechanisms behind infertility and the development of clinical treatments.This review seeks to deepen our understanding of the mechanisms regulating human oocyte quality and to provide novel insights into clinical female infertility characterized by defects in oocyte quality and oocyte development.
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 funding(to China RC)from the Ministry of Science and Technology of China(grants 2017YFC1001601).
文摘Fertility disorders have become a growing problem worldwide. It is well known that female fertility decreases with age, previous studies suggested that the age-related decline in female fertility potential was largely due to decrease in oocyte quality and mitochondrial dysfunction. Mitochondria play a crucial role during the process of oocyte maturation. Mitochondrial genetic, numerical and structural defects occur in oocyte aging process, mitochondrial abnormalities are believed to contribute to age-related infertility. Improvement of the mitochondrial function can lead to better fertility outcomes, and application of mitochondria replacement strategy or mitochondrial transfer to age-related infertility will be possible in the future. This review paper, we are trying to discuss current understanding about age-related changes in oocyte quality and mitochondrial dysfunction.
基金Acknowledgments This study was supported by grants from the China National Natural Science Foundation （Nos. 30430530 and 30571337） and from the Momentous Research Project of the China Ministry of Science and Technology （No. 2006CB944003）.
文摘Selecting oocytes that are most likely to develop is crucial for in vitro fertilization and animal cloning. Brilliant cresyl blue （BCB） staining has been used for oocyte selection in large animals, but its wider utility needs further evaluation. Mouse oocytes were divided into those stained （BCB＋） and those unstained （BCB-） according to their ooplasm BCB coloration. Chromatin configurations, cumulus cell apoptosis, cytoplasmic maturity and developmental competence were compared between the BCB＋ and BCB- oocytes. The effects of oocyte diameter, sexual maturity and gonadotropin stimulation on the competence of BCB＋ oocytes were also analyzed. In the large- and medium-size groups, BCB＋ oocytes were larger and showed more surrounded nucleoli （SN） chromatin configurations and higher frequencies of early atresia, and they also gained better cytoplasmic maturity （determined as the intracellular GSH level and pattern of mitochondrial distribution） and higher developmental potential after in vitro maturation （IVM） than the BCB-oocytes. Adult mice produced more BCB＋ oocytes with higher competence than the prepubertal mice when not primed with PMSG. PMSG priming increased both proportion and developmental potency of BCB＋ oocytes. The BCB＋ oocytes in the large-size group showed more SN chromatin configurations, better cytoplasmic maturity and higher developmental potential than their counterparts in the medium-size group. It is concluded that BCB staining can be used as an efficient method for oocyte selection, but that the competence of the BCB＋ oocytes may vary with oocyte diameter, animal sexual maturity and gonadotropin stimulation. Taken together, the series of criteria described here would allow for better choices in selecting oocytes for better development.
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Amphibians are considered as reliable indicators of environmental quality. In Europe, a general decline of amphibians population parallels a worldwide decline, and some of the factors which are thought to be responsible to this decline are habitat loss, introduction of exotic species, disease and decreasing water quality. Recent investigations suggest that these eutrophic conditions may be associated with frog reproduction problems. Water quality criteria settled for the different species of amphibians do not currently exist, but in the present paper, the authors report their observation about water phosphate concentrations in association with hipofertility in African clawed frogs （Xenopus laevis）. The study considered two different groups of African clawed frog showing hypofertility （22 patients） hosted in captivity. The animals were visited, and the filtration systems functionality and the water quality were checked, i.e., temperature, pH, ammonia, nitrite, nitrate, phosphates, hardness and alkalinity. In the first group, it was decided to perform ultrasound scans, parasitological tests on fecal samples, and microscopical/macroscopical examination, as well as microbiological analysis on collected oocytes. In the second group, only fecal samples were collected in order to perform parasitologiacal exams. No pathological findings were showed by veterinary tests. Water changes were carried out in both facilities and after two months, the fertility in African clawed frogs improved, evidencing the involvement of phosphates values in the onset of the problem and even more in its resolution. More studies are needed to further define this correlation.
基金Supported by The Key Project from Chinese Technology Department(Project No.2017YFC1001601).
文摘Objective:The transcriptional profile of cumulus cells(CCs)during oocyte maturation provides information for predicting oocyte developmental competence.Our previous study using a mouse model indicated that there were nine different genes related to oocyte development potential expressed in CCs during oocyte maturation.The purpose of this study was to elucidate whether gene expression levels of CCs during oocyte maturation are associated with oocyte developmental competence.Methods:The human CCs collected from each oocyte were divided into two groups after tracking depending on whether or not they developed to the blastocyst stage:(1)the oocytes were developed to blastocyst stage after fertilization(B+)and(2)the oocytes were not developed to blastocyst stage after fertilization(B−).The expression levels of the nine selected genes(ARRB1,ATP2C1,CDH5,CNTNAP1,LGR4,MKLN1,RHOBTB1,SIX2,and SMC2)were examined.CCs were obtained from 29 women who were undergoing intracytoplasmic sperm injection treatment cycles.Quantitative reverse transcriptase-polymerase chain reaction analysis was performed on cumulus masses collected before insemination.Each sample was run three times.Statistically significant differences in mRNA expression of the target genes in independent samples were evaluated by two-tailed Student’s t-test,and P<0.05 was considered significantly different.Results:There were significant differences in the mRNA expression levels of ARRB1(P=0.016),LGR4(P=0.025),and SMC2(P=0.013)between the groups B+and B−.Gene expression of ARRB1,LGR4,and SMC2 in CCs is related to blastocyst development.Conclusions:Analysis of expression of ARRB1,LGR4,and SMC2 genes in CCs as biomarkers may provide predictive information on oocyte developmental competence before insemination and fertilization.
基金Supported by National Natural Science Foundation of China(No.81774355)Natural Science Foundation of Shandong Province(No.ZR2022QH033)。
文摘Objective To explore the effects of electroacupuncture(EA)on pregnancy outcomes after assisted reproduction and mitochondrial function of granulosa cells(GCs)in patients with polycystic ovary syndrome(PCOS)and phlegm-dampness syndrome.Methods In this randomized controlled trial,90 infertile women with PCOS and phlegm-dampness syndrome were recruited between August 2022 and December 2022.Patients were randomly assigned to the EA and control groups using a random sequence of codes in the order of enrolment,with 45 in in each group.Both groups underwent the ovarian stimulation protocol.The patients in the EA group received EA therapy including Zhongwan(CV 12),Qihai(CV 6),bilateral Xuehai(SP 10),Sanyinjiao(SP 6),Yinlingquan(SP 9),Tianshu(ST 25),Zusanli(ST 36),and Fenglong(ST 40),and the patients in the control group was treated with pseudo-acupuncture.The intervention was 25 min twice a week for a total of 6 times until the trigger day after menstruation had ended in the cycle before oocyte retrieval.The primary outcomes were clinical pregnancy rate(CPR)and the number of high-quality embryos.The secondary outcomes were(1)pregnancy-related indicators,including fresh embryo transfer rate(ETR),ovarian hyperstimulation syndrome(OHSS)rate,early pregnancy loss rate(ePLR),ectopic pregnancy rate,live birth rate(LBR),and cumulative CPR;(2)mitochondrial autophagy and mitochondrial membrane potential(MMP)in GCs;and(3)scoring for Chinese medicine syndrome.Adverse events to assess clinical safety were also monitored.Results The cumulative CPR was significantly higher in the EA group(42/45,93.3%)than in the control group(38/45,84.4%,P=0.036).The number of high-quality embryos and fresh ETR in the EA group were higher than those in the control group(3.80±1.65 vs.2.44±1.34,P<0.001;46.7%vs 24.4%,P=0.028).Ectopic pregnancies were not observed in either group.There were no significant differences in the fresh CPR,OHSS rate,ePLR or LBR between the two groups(P>0.05).Compared with the control group,the EA group showed lower expression levels of miR-146a-5p mRNA and P62 protein in GCs and higher levels of MMP and the LC3-II/LC3-I protein ratio(all P<0.01).The phlegm-dampness syndrome scores of the EA group were significantly lower than those of the control group(P<0.01).Conclusions EA significantly improved pregnancy outcomes in patients with PCOS and phlegm dampness syndrome.Mechanistically,this effect may be related to EA in decreasing miR-146a-5p mRNA expression,promoting mitochondrial autophagy in GCs,and improving mitochondrial function,which may contribute to improved oocyte quality.(Trial registration No.ChiCTR2200062915)
基金by the National Natural Science Foundation of China(31970667,82230052,91749129,32030033)China National Key R&D Program(2018YFC1003004,2018YFA0107002)。
文摘Ovarian reserve is essential for fertility and influences healthy aging in women.Advanced maternal age correlates with the progressive loss of both the quantity and quality of oocytes.The molecular mechanisms and various contributing factors underlying ovarian aging have been uncovered.In this review,we highlight some of critical factors that impact oocyte quantity and quality during aging.Germ cell and follicle reserve at birth de-termines reproductive lifespan and timing the menopause in female mammals.Accelerated diminishing ovarian reserve leads to premature ovarian aging or insufficiency.Poor oocyte quality with increasing age could result from chromosomal cohesion deterioration and misaligned chromosomes,telomere shortening,DNA damage and associated genetic mutations,oxidative stress,mitochondrial dysfunction and epigenetic alteration.We also discuss the intervention strategies to delay ovarian aging.Both the efficacy of senotherapies by antioxidants against reproductive aging and mitochondrial therapy are discussed.Functional oocytes and ovarioids could be rejuvenated from pluripotent stem cells or somatic cells.We propose directions for future interventions.As couples increasingly begin delaying parenthood in life worldwide,understanding the molecular mechanisms during female reproductive aging and potential intervention strategies could benefit women in making earlier choices about their reproductive health.
基金the National Science Fund for Distinguished Young Scholars(No.81925013 to R.L.)。
文摘Diminished ovarian reserve(DOR)refers to a decrease in the number and/or quality of oocytes in the ovary,accompanied by a decline in reproductive potential,which is generally related to advanced age or ovarian disease.In in vitro fertilization(IVF)clinical practice,managing patients with DOR remains one of the most challenging tasks.In recent years,increased research on improving ovarian function has provided us with new insights into treating patients with DOR.Many therapeutic options have been proposed to improve the ovarian function of patients with DOR,yet they are not widely utilized in clinical practice because of limited evidence of safety and effectiveness.In this review,we focus on the mechanisms from animal models and clinical trials that have been applied to the treatment of DOR in recent years,intending to improve IVF outcomes in patients with DOR.Furthermore,new insights and perspectives on the molecular and cellular regulation of follicular development and ovarian reserve are emphasized to provide more clues for research on the treatment of DOR.
