Inheritance of perturbed methylation and metabolism caused by uterine malnutrition via oocytes.

BACKGROUND: Undernourishment in utero has deleterious effects on the metabolism of offspring, but the mechanism of the transgenerational transmission of metabolic disorders is not well known. In the present study, we found that undernourishment in utero resulted in metabolic disorders of female F1 and F2 in mouse model. RESULTS: Undernutrition in utero induced metabolic disorders of F1 females, which was transmitted to F2 females. The global methylation in oocytes of F1 exposed to undernutrition in utero was decreased compared with the control. KEGG analysis showed that genes with differential methylation regions (DMRs) in promoters were significantly enriched in metabolic pathways. The altered methylation of some DMRs in F1 oocytes located at the promoters of metabolic-related genes were partially observed in F2 tissues, and the expressions of these genes were also changed. Meanwhile, the abnormal DNA methylation of the validated DMRs in F1 oocytes was also observed in F2 oocytes. CONCLUSIONS: These results indicate that DNA methylation may mediate the transgenerational inheritance of metabolic disorders induced by undernourishment in utero via female germline.

Effect of noninvasive embryo viability testing versus conventional IVF on the live birth rate in IVF/ICSI patients: a study protocol for a double-blind, multicenter, randomized controlled trial.

BACKGROUND: Preimplantation genetic testing for aneuploidy (PGT-A) was demonstrated to be superior to conventional IVF in reducing the incidence of miscarriage and abnormal offspring after the first embryo transfer (ET). PGT-A requires several embryo trophectoderm cells, but its negative impacts on embryo development and long-term influence on the health conditions of conceived children have always been a concern. As an alternative, noninvasive PGT-A (niPGT-A) approaches using spent blastocyst culture medium (SBCM) achieved comparable accuracy with PGT-A in several pilot studies. The main objective of this study is to determine whether noninvasive embryo viability testing (niEVT) results in better clinical outcomes than conventional IVF after the first embryo transfer. Furthermore, we further investigated whether niEVT results in higher the live birth rate between women with advanced maternal age (AMA, > 35 years old) and young women or among patients for whom different fertilization protocols are adopted. METHODS: This study will be a double-blind, multicenter, randomized controlled trial (RCT) studying patients of different ages (20-43 years) undergoing different fertilization protocols (in vitro fertilization [IVF] or intracytoplasmic sperm injection [ICSI]). We will enroll 1140 patients at eight reproductive medical centers over 24 months. Eligible patients should have at least two good-quality blastocysts (better than grade 4 CB). The primary outcome will be the live birth rate of the first embryo transfer (ET). Secondary outcomes will include the clinical pregnancy rate, ongoing pregnancy rate, miscarriage rate, cumulative live birth rate, ectopic pregnancy rate, and time to pregnancy. DISCUSSION: In this study, patients who undergo noninvasive embryo viability testing (niEVT) will be compared to women treated by conventional IVF. We will determine the effects on the pregnancy rate, miscarriage rate, and live birth rate and adverse events. We will also investigate whether there is any difference in clinical outcomes among patients with different ages and fertilization protocols (IVF/ICSI). This trial will provide clinical evidence of the effect of noninvasive embryo viability testing on the clinical outcomes of the first embryo transfer. TRIAL REGISTRATION: Chinese Clinical Trial Registry (ChiCTR) Identifier: ChiCTR2100051408. 9 September 2021.

Effects of comprehensive nursing intervention on pressure ulcer after traumatic brain injury surgery: A meta-analysis.

Pressure ulcers (PUs) are a common complication in postoperative patients with traumatic brain injury, and this study used a meta-analysis to assess the effects of comprehensive nursing applied in PUs intervention in postoperative patients with traumatic brain injury. A computerised systematic search of the PubMed, EMBASE, Cochrane Library, China National Knowledge Infrastructure, Chinese Biomedical Literature Database (CBM), VIP and Wanfang databases was performed to collect publicly available articles on randomised controlled trials (RCTs) on the effects of comprehensive nursing interventions in postoperative patients with traumatic brain injury published up to August 2023. Two researchers independently completed the search and screening of the literature, extraction of data and quality assessment of the included literature based on the inclusion and exclusion criteria. Meta-analysis was performed using RevMan 5.4 software. Twenty-eight articles were finally included, for a cumulative count of 2641 patients, of which 1324 were in the intervention group and 1317 in the control group. The results of the meta-analysis showed that, compared with conventional nursing, comprehensive nursing intervention helped to reduce the incidence of PUs in postoperative patients with traumatic brain injury (5.14% vs. 19.67%, odds ratio [OR]: 0.22, 95% confidence interval [CI]: 0.16-0.29, p < 0.00001) and reduced the incidence of postoperative complications (7.87% vs. 25.84%, OR: 0.22, 95% CI: 0.11-0.43, p < 0.0001), while increasing patient satisfaction (96.67% vs. 75.33%, OR: 9.5, 95% CI: 3.63-24.88, p < 0.00001). This study concludes that a comprehensive nursing intervention applied to postoperative patients with traumatic brain injury can significantly reduce the incidence of PUs and postoperative complications as well as improve nursing satisfaction, and it is recommended for clinical promotion. However, due to the limitations of the studies' number and quality, more high-quality, large-sample RCTs are needed to further validate the conclusions of this study.

[Sperm-hyaluronan binding assay in in vitro fertilization and embryo transfer].

OBJECTIVE: To explore the application value of sperm-hyaluronan binding (SHB) assay in in vitro fertilization and embryo transfer (IVF-ET). METHODS: This retrospective study included 163 cases of IVF-ET performed in our hospital from January to August 2019 due to female fallopian tube abnormality-induced infertility. The men were found with normal seminal parameters at semen analysis. According to the SHB rate, we divided the patients into a normal group (n = 126) and an abnormal group (n = 37) and analyzed the general conditions and the rates of normal fertilization, cleavage, available embryos, embryo implantation and clinical pregnancy. RESULTS: Statistically significant differences were observed between the normal and abnormal groups in the rates of SHB, normal fertilization and available embryos (P < 0.01 or P < 0.05), but not in the general conditions or the rates of cleavage, embryo implantation and clinical pregnancy. CONCLUSIONS: The SHB rate is not correlated with sperm concentration or the percentages of progressively motile sperm and morphologically normal sperm. Sperm-hyaluronan binding assay helps predict the outcomes of IVF-ET and embryo quality. An SHB rate of <58.5% indicates low rates of normal fertilization and available embryos, but has no significant correlation with the rates of embryo implantation and clinical pregnancy.

Embryo quality, and not chromosome nondiploidy, affects mitochondrial DNA content in mouse blastocysts.

It has been shown recently that there is premature mitochondria biosynthesis in blastocysts from older women whose egg or embryo quality is poor and that aneuploid blastocysts also have a high number of mitochondrial DNA (mtDNA) copies. Whether nondiploidy/aneuploidy or reduced egg or embryo quality causes premature mitochondrial biosynthesis is not known. This study constructed haploid, diploid, triploid, and tetraploid blastocysts by parthenogenetic activation, intracytoplasmic sperm injection with one or two sperm heads, blastomere electrofusion, respectively, and generated reduced cytoplasm quality embryos from diabetic mouse and in vitro fertilization of aged oocytes, and examined whether nondiploidy or reduced cytoplasm quality causes premature mitochondrial biosynthesis. MtDNA numbers of each blastocyst from different models were tested by absolute quantitative real-time polymerase chain reaction. It was found that mtDNA content in preimplantation embryos was not associated with their chromosome ploidy, while mtDNA copy numbers in embryos with suboptimal quality were increased. Therefore, it might be the reduced cytoplasmic quality, and not chromosome nondiploidy, that causes premature mitochondria biosynthesis in blastocysts.

High-glucose concentrations change DNA methylation levels in human IVM oocytes.

STUDY QUESTION: What are the effects of high-glucose concentrations on DNA methylation of human oocytes? SUMMARY ANSWER: High-glucose concentrations altered DNA methylation levels of Peg3 and Adiponectin in human in vitro maturation oocytes. WHAT IS KNOWN ALREADY: Maternal diabetes has a detrimental influence on oocyte quality including epigenetic modifications, as shown in non-human mammalian species. STUDY DESIGN, SIZE, DURATION: Immature metaphase I (MI) stage oocytes of good quality were retrieved from patients who had normal ovarian potential and who underwent ICSI in the Reproductive Medicine Center of People's Hospital of Zhengzhou University. MI oocytes were cultured in medium with different glucose concentrations (control, 10 mM and 15 mM) in vitro and 48 h later, oocytes with first polar body extrusion were collected to check the DNA methylation levels. PARTICIPANTS/MATERIALS, SETTING, METHODS: MI oocytes underwent in vitro maturation (IVM) at 37°C with 5% mixed gas for 48 h. Then the mature oocytes were treated with bisulfite buffer. Target sequences were amplified using nested or half-nested PCR and the DNA methylation status was tested using combined bisulfite restriction analysis (COBRA) and bisulfite sequencing (BS). MAIN RESULTS AND THE ROLE OF CHANCE: High-glucose concentrations significantly decreased the first polar body extrusion rate. Compared to controls, the DNA methylation levels of Peg3 in human IVM oocytes were significantly higher in 10 mM (P < 0.001) and 15 mM (P < 0.001) concentrations of glucose. But the DNA methylation level of H19 was not affected by high-glucose concentrations in human IVM oocytes. We also found that there was a decrease in DNA methylation levels in the promoter of adiponectin in human IVM oocytes between controls and oocytes exposed to 10 mM glucose (P = 0.028). LARGE SCALE DATA: N/A. LIMITATIONS REASONS FOR CAUTION: It is not clear whether the alterations are beneficial or not for the embryo development and offspring health. The effects of high-glucose concentrations on the whole process of oocyte maturation are still not elucidated. Another issue is that the number of oocytes used in this study was limited. WIDER IMPLICATIONS OF THE FINDINGS: This is the first time that the effects of high-glucose concentration on DNA methylation of human oocytes have been elucidated. Our result indicates that in humans, the high risk of chronic diseases in offspring from diabetic mothers may originate from abnormal DNA modifications in oocytes. STUDY FUNDING/COMPETING INTEREST(S): This work was supported by the fund of National Natural Science Foundation of China (81401198) and Doctor Foundation of Qingdao Agricultural University (1116008).The authors declare that there are no potential conflicts of interest relevant to this article.

Cumulative live birth and surplus embryo incidence after frozen-thaw cycles in PCOS: how many oocytes do we need?

PURPOSE: This study aimed to evaluate the cumulative live birth rate (CLBR) and surplus embryo rate of polycystic ovarian syndrome (PCOS) patients during in vitro fertilization and embryo transfer (IVF-ET) treatment. METHODS: In this retrospective cohort study, we analyzed 1142 PCOS patients who underwent first IVF in our institution between January 2011 and December 2014. All patients were categorized into five groups according to the number of oocytes retrieved. Main outcomes include CLBR and surplus embryo rate. RESULTS: A strong correlation was observed between number of oocytes retrieved and CLBR as well as surplus embryo rate in PCOS patients. CLBR was elevated with the increasing number of oocytes and plateaued when oocyte number was up to ten, whereas the surplus embryo rate steadily increased in line with the increase of oocyte number. Patients transferred with frozen embryos showed higher CLBR and LBR during first ET than patients transferred with fresh embryos. CONCLUSIONS: For PCOS patients, retrieving more than ten oocytes leads to no significant benefit to CLBR but generates surplus embryos. Thus, moderate ovarian stimulation should be reconsidered during IVF treatment.

Oocyte ageing and epigenetics.

It has become a current social trend for women to delay childbearing. However, the quality of oocytes from older females is compromised and the pregnancy rate of older women is lower. With the increased rate of delayed childbearing, it is becoming more and more crucial to understand the mechanisms underlying the compromised quality of oocytes from older women, including mitochondrial dysfunctions, aneuploidy and epigenetic changes. Establishing proper epigenetic modifications during oogenesis and early embryo development is an important aspect in reproduction. The reprogramming process may be influenced by external and internal factors that result in improper epigenetic changes in germ cells. Furthermore, germ cell epigenetic changes might be inherited by the next generations. In this review, we briefly summarise the effects of ageing on oocyte quality. We focus on discussing the relationship between ageing and epigenetic modifications, highlighting the epigenetic changes in oocytes from advanced-age females and in post-ovulatory aged oocytes as well as the possible underlying mechanisms.

Optimum oocyte retrieved and transfer strategy in young women with normal ovarian reserve undergoing a long treatment protocol: a retrospective cohort study.

PURPOSE: This study aimed to investigate the relationship between the number of oocytes retrieved and clinical outcomes in young women with normal ovarian reserve who were undergoing their first in vitro fertilization and embryo transfer (IVF-ET) cycle. The transfer strategy based on yielded oocytes was also discussed in this article. METHODS: A total of 1567 patients who underwent first long protocol of IVF treatment in our reproductive medical center between January 2010 and June 2014 were categorized into five groups based on the retrieved oocyte number, namely, 4∼6, 7∼9, 10∼12, 13∼15, and ≥16. Baseline parameters were similar among the groups. Primary outcome was defined as the cumulative live birth rate (CLBR), and secondary outcomes included the rate of patients with high risks for ovarian hyperstimulation syndrome (OHSS). RESULTS: It was found that the CLBR increased with the number of oocytes, as well as the rate for high risks of OHSS. In fresh cycles, 10∼12 oocyte group demonstrated the highest implantation rate (53.32 %), clinical pregnancy rate (CPR) (73.13 %), and live birth rate (LBR) (61.14 %), with no significant differences. Moreover, both cumulative CPR (CCPR) and CLBR became significantly higher in the 10∼12 oocyte group, compared with 4∼6 and 7∼9 groups. However, when the retrieved oocytes increased to 13∼15 or ≥16, the cumulative results did not have a significant increase. Also, the high risk rate of OHSS was much lower in the 10∼12 group (11.53 %) than that in the 13∼15 group (29.97 %) and ≥16 group (77.30 %). Unconditional multivariate logistic regression analysis showed that when ≥10 oocytes were retrieved, the CLBR increased significantly (P < 0.01). When oocyte number exceeded 16, the CPR of frozen embryo transfer cycle was much higher than that of fresh cycle (P < 0.05). CONCLUSIONS: For young women with normal ovarian reserve, retrieving 10∼12 oocytes might result in optimized pregnancy outcomes in a fresh cycle with low OHSS risk and would not compromise cumulative outcomes. When ≥16 oocytes were retrieved, a "freeze-all" embryo strategy might be preferable.

Maternal diabetes mellitus and the origin of non-communicable diseases in offspring: the role of epigenetics.

Offspring of diabetic mothers are susceptible to the onset of metabolic syndromes, such as type 2 diabetes and obesity at adulthood, and this trend can be inherited between generations. Genetics cannot fully explain how the noncommunicable disease in offspring of diabetic mothers is caused and inherited by the next generations. Many studies have confirmed that epigenetics may be crucial for the detrimental effects on offspring exposed to the hyperglycemic environment. Although the adverse effects on epigenetics in offspring of diabetic mothers may be the result of the poor intrauterine environment, epigenetic modifications in oocytes of diabetic mothers are also affected. Therefore, the present review is focused on the epigenetic alterations in oocytes and embryos of diabetic mothers. Furthermore, we also discuss initial mechanistic insight on maternal diabetes mellitus causing alterations of epigenetic modifications.

Maternal obesity and diabetes may cause DNA methylation alteration in the spermatozoa of offspring in mice.

BACKGROUND: The adverse effects on offspring of diabetic and/or obese mothers can be passed to the next generation. However, the mechanisms behind this are still unclear. Epigenetics may play a key role during this process. METHODS: To confirm the hypothesis, we investigated the DNA methylation of several imprinted genes in spermatozoa of offspring from diabetic and/or obese mothers utilizing streptozotocin (STZ)- and high-fat-diet (HFD)-induced mouse models. RESULTS: We found that the DNA methylation of Peg3 was significantly increased in spermatozoa of offspring of obese mothers compared to that in spermatozoa of offspring of normal mothers. The DNA methylation of H19 was significantly higher in spermatozoa of offspring of diabetic mothers than that in spermatozoa of offspring of non-diabetic mothers. CONCLUSIONS: These results indicate that pre-gestational diabetes and/or obesity can alter DNA methylation in offspring spermatozoa.

The association between female age and pregnancy outcomes in patients receiving first elective single embryo transfer cycle: a retrospective cohort study.

This study aimed to explore the relationship between female age and pregnancy outcomes in patients undergoing their first elective single embryo transfer (eSET) of in vitro fertilization (IVF) cycles. The retrospective cohort study encompassed 7089 IVF/intracytoplasmic sperm injection (ICSI) patients of the Reproductive Medicine Center, Henan Provincial Peoples' Hospital of China, from September 1, 2016, to May 31, 2022. Patients all received the first eSET in their IVF/ICSI cycles. A generalized additive model (GAM) was employed to examine the the dose-response correlation between age and pregnancy outcomes, namely the clinical pregnancy rate (CPR) and ongoing pregnancy rate (OPR). Logistic regression model was employed to ascertain the correlation between the CPR/OPR and age. The study cohort has an average age of 30.74; 3843 patients got clinical pregnancy rate of 61.40% and ongoing pregnancy rate of 54.21%. The multiple pregnancy rate of is 1.24%. For patients aged 34 and above, the CPR decreased by 10% for every 1-year increase in age (adjusted OR 0.90, 95% CI 0.84-0.96, p < 0.0001). Similarly, the OPR decreased by 16% for every 1-year increase in age (adjusted OR 0.84, 95% CI 0.81-0.88, p < 0.0001). Patients aged 35-37 years had an acceptable OPR of 52.4% after eSET, with a low multiple pregnancy rate (1.1%). Pregnancy outcomes were significantly better in blastocyst cycles compared to cleavage embryo cycles, and this trend was more pronounced in older patients. There was a non-linear relationship between female age and pregnancy outcomes in patients undergoing their first eSET cycles. The clinical pregnancy rate and ongoing pregnancy rate decreased significantly with age, especially in women older than 34 years. For patients under 37 years old, single embryo transfer should be prioritized. For patients over 38 years old with available blastocysts, eSET is also recommended.

Fertility preservation in hematological cancer patients.

Among adolescents and young adults, hematological malignancies are the most common malignancies. Although the survival rate of hematological malignancies in young patients has been dramatically improved, due to the continuous improvement and development of tumor diagnosis and treatment options, cytotoxic therapies can significantly reduce a patient's reproductive capacity and cause irreversible infertility. The most two established solutions are embryo cryopreservation and oocyte cryopreservation which can be considered in single female. Sperm or testicular tissue cryopreservation in adult male are feasible approaches that must be considered before gonadotoxic therapy. A comprehensive consultation with reproductive specialists when once diagnosed is a significantly issue which would help those survivors who want to have children. In this article, we review germ cell toxicity, which happens during the treatment of hematological malignancies, and aims to propose safety, efficacy fertility preservation methods in younger patients with hematological malignancies.

Effects of multisuperovulation on the transcription and genomic methylation of oocytes and offspring.

BACKGROUND: Controlled ovarian stimulation is a common skill of assisted reproductive technologies (ARTs). In the clinic, some females would undergo more than one controlled ovarian stimulation cycle. However, few studies have focused on the influence of multi-superovulation on oocytes and offspring. RESULTS: Here, we found that multi-superovulation disrupted the transcriptome of oocytes and that the differentially expressed genes (DEGs) were associated mainly with metabolism and fertilization. The disruption of mRNA degradation via poly (A) size and metabolism might be a reason for the reduced oocyte maturation rate induced by repeated superovulation. Multi-superovulation results in hypo-genomic methylation in oocytes. However, there was an increase in the methylation level of CGIs. The DMRs are not randomly distributed in genome elements. Genes with differentially methylated regions (DMRs) in promoters are enriched in metabolic pathways. With increasing of superovulation cycles, the glucose and insulin tolerance of offspring is also disturbed. CONCLUSIONS: These results suggest that multi-superovulation has adverse effects on oocyte quality and offspring health.

Diabetic uterus environment may play a key role in alterations of DNA methylation of several imprinted genes at mid-gestation in mice.

BACKGROUND: Maternal diabetes mellitus not only has severe deleterious effects on fetal development, but also it affects transmission to the next generation. However, the underlying mechanisms for these effects are still not clear. METHODS: We investigated the methylation patterns and expressions of the imprinted genes Peg3, Snrpn, and H19 in mid-gestational placental tissues and on the whole fetus utilizing the streptozotocin (STZ)-induced hyperglycemic mouse model for quantitative analysis of methylation by PCR and quantitative real-time PCR. The protein expression of Peg3 was evaluated by Western blot. RESULTS: We found that the expression of H19 was significantly increased, while the expression of Peg3 was significantly decreased in dpc10.5 placentas of diabetic mice. We further found that the methylation level of Peg3 was increased and that of H19 was reduced in dpc10.5 placentas of diabetic mice. When pronuclear embryos of normal females were transferred to normal/diabetic (NN/ND) pseudopregnant females, the methylation and expression of Peg3 in placentas was also clearly altered in the ND group compared to the NN group. However, when the pronuclear embryos of diabetic female were transferred to normal pesudopregnant female mice (DN), the methylation and expression of Peg3 and H19 in dpc10.5 placentas was similar between the two groups. CONCLUSIONS: We suggest that the effects of maternal diabetes on imprinted genes may primarily be caused by the adverse uterus environment.

[Study on ovary development in vitrification of embryos born mice and expression of growth differentiation factor 9].

OBJECTIVE: To study ovarian development in vitrification of embryos born mice and expression of growth differentiation factor 9 (GDF-9) in its. METHODS: The vitrification recovery embryos (vitrified-embryo group) and fresh embryos (fresh-embryo group) were transplanted into pseudopregnant mice, respectively. The female offspring mice in two groups were sacrificed on the 3(rd), 7(th), 14(th), 21(st), 28(th) and 60(th) day after birth, the ovarian tissues were taken, 6 mice in each time point of each group. The ovarian development was observed by HE staining, the expression of GDF-9 mRNA and protein at each time point of two groups were detected by reverse transcription (RT)-PCR and western blot. RESULTS: HE staining showed that no abnormal ovarian development was observed in offsprings at two groups. On the 3(rd), 7(th), 14(th), 21(st), 28(th) and 60(th) day after birth, the expression of GDF-9 mRNA in vitrified-embryo group were 0.14 ± 0.07, 0.42 ± 0.16, 1.00 ± 0.24, 1.59 ± 0.28, 2.05 ± 0.32 and 2.23 ± 0.21, respectively, which in fresh-embryo group were 0.13 ± 0.06, 0.45 ± 0.18, 1.00 ± 0.21, 1.56 ± 0.26, 2.01 ± 0.37 and 2.26 ± 0.23, respectively, there was no statistical difference between two groups (P > 0.05); the expression of GDF-9 protein in vitrified-embryo group were 0.040 ± 0.030, 0.120 ± 0.060, 0.170 ± 0.030, 0.250 ± 0.040, 0.320 ± 0.060 and 0.330 ± 0.010, respectively, which in fresh-embryo group were 0.030 ± 0.020, 0.110 ± 0.040, 0.150 ± 0.010, 0.210 ± 0.020, 0.360 ± 0.070 and 0.350 ± 0.030, respectively, there was no statistical difference between two groups (P > 0.05). CONCLUSION: The ovarian morphology in vitrification of embryos born mice and expression of GDF-9 in ovary has no any obvious change.

Infertility treatment for Chinese women with P450 oxidoreductase deficiency: Prospect on clinical management from IVF to FET.

Cytochrome P450 oxidoreductase deficiency (PORD) is a rare recessive disease with multiple clinical manifestations, which is usually diagnosed in neonates and children because of ambiguous genitalia or skeletal malformations. Moreover, the paucity of studies does not allow us to establish whether adult-onset PORD is associated with infertility. Here, we report clinical and laboratory findings in two phenotypically normal women diagnosed with PORD who underwent in vitro fertilization (IVF) and frozen embryo transfer (FET). We modified the gonadotropin stimulation protocol during controlled ovarian hyperstimulation (COH) and suggest the use of the vaginal 17ß-estradiol route for endometrium preparation in hormone replacement therapy (HRT) cycles. We presume that PORD may be associated with infertility in several aspects, including disordered steroidogenesis, endometrium impairment, attenuation of drug metabolism, and the high risk of miscarriage. Our observations will help the early diagnosis and make a tailored approach to infertility management in adult-onset PORD.

Oocytes could rearrange immunoglobulin production to survive over adverse environmental stimuli.

Immunoglobulins are key humoral immune molecules produced and secreted by B lymphocytes at various stages of differentiation. No research has reported whether immunoglobulins are present in the non-proliferative female germ cells-oocytes-and whether they are functionally important for oocyte quality, self-protection, and survival. Herein, we found that IgG was present in the oocytes of immunodeficient mice; the IgG-VDJ regions were highly variable between different oocytes, and H3K27Ac bound and regulated the IgG promoter region. Next, IgG mRNA and protein levels increased in response to LPS, and this increment was mediated by CR2 on the oocyte membrane. Finally, we revealed three aspects of the functional relevance of oocyte IgG: first, oocytes could upregulate IgG to counteract the increased ROS level induced by CSF1; second, oocytes could upregulate IgG in response to injected virus ssRNA to maintain mitochondrial integrity; third, upon bacterial infection, oocytes could secrete IgG, subsequently encompassing the bacteria, thus increasing survival compared to somatic cells. This study reveals for the first time that the female germ cells, oocytes, can independently adjust intrinsic IgG production to survive in adverse environments.

Repeated Superovulation Accelerates Primordial Follicle Activation and Atresia.

For humans, ARTs (assisted reproductive technologies) have become the most effective method to treat subfertility/infertility in clinic. To obtain enough oocytes during ART, ovarian stimulation is performed by exogenous hormones, and some patients undergo several ovarian stimulation cycles. Although some adverse effects of ARTs on women and offspring are reported, few studies are focused on the effects of multiple superovulation on ovarian reserve. In the present study, we found that repeated superovulation significantly reduced primordial follicle number and the serum AMH. Compared to the decreased antral follicle number, the expression of genes related to primordial follicle activation, such as Foxo3, Akt, and Rptor, and the atretic follicle number in ovaries were increased by superovulation times. We further found that repeated superovulation reduced the plasma level of FSH, LH, and estradiol, and increased the expression of genes related to apoptosis (Bax, Casp3 (caspase-3), Casp8, and Casp9) in granulosa cells, providing evidence that repeated superovulation disrupted the balance between survival and death in granulosa cells. In summary, our results suggest that repeated superovulation has adverse effects on folliculogenesis.

Gm364 coordinates MIB2/DLL3/Notch2 to regulate female fertility through AKT activation.

Many integral membrane proteins might act as indispensable coordinators in specific functional microdomains to maintain the normal operation of known receptors, such as Notch. Gm364 is a multi-pass transmembrane protein that has been screened as a potential female fertility factor. However, there have been no reports to date about its function in female fertility. Here, we found that global knockout of Gm364 decreased the numbers of primordial follicles and growing follicles, impaired oocyte quality as indicated by increased ROS and γ-H2AX, decreased mitochondrial membrane potential, decreased oocyte maturation, and increased aneuploidy. Mechanistically, Gm364 directly binds and anchors MIB2, a ubiquitin ligase, on the membrane. Subsequently, membrane MIB2 ubiquitinates and activates DLL3. Next, the activated DLL3 binds and activates Notch2, which is subsequently cleaved within the cytoplasm to produce NICD2, the intracellular active domain of Notch2. Finally, NICD2 can directly activate AKT within the cytoplasm to regulate oocyte meiosis and quality.