Protein phosphatase 4 maintains the survival of primordial follicles by regulating autophagy in oocytes.

In mammalian ovary, the primordial follicle pool serves as the source of developing follicles and fertilizable ova. To maintain the normal length of female reproductive life, the primordial follicles must have adequate number and be kept in a quiescent state before menopause. However, the molecular mechanisms underlying primordial follicle survival are poorly understood. Here, we provide genetic evidence showing that lacking protein phosphatase 4 (PPP4) in oocytes, a member of PP2A-like subfamily, results in infertility in female mice. A large quantity of primordial follicles has been depleted around the primordial follicle pool formation phase and the ovarian reserve is exhausted at about 7 months old. Further investigation demonstrates that depletion of PPP4 causes the abnormal activation of mTOR, which suppresses autophagy in primordial follicle oocytes. The abnormal primordial follicle oocytes are eventually erased by pregranulosa cells in the manner of lysosome invading. These results show that autophagy prevents primordial follicles over loss and PPP4-mTOR pathway governs autophagy during the primordial follicle formation and dormant period.

Research progress of ferroptosis in female infertility.

Ferroptosis is a novel type of programmed cell death dependent on iron and characterized by the accumulation of lipid peroxides in cells and is closely related to various diseases. Female infertility is a global health concern, which is associated with a variety of factors. The etiology remains unknown in many women with infertility. With further investigation into the pathogenesis of infertility, a growing number of studies have demonstrated the close connections between infertility and ferroptosis. Through a literature review, it is found that ferroptosis is closely involved in endometriosis- and polycystic ovarian syndrome (PCOS)-associated infertility and tubal factor infertility. Iron overload increases the resistance to ferroptosis, and ferroptosis in some cells accelerates endometrial lesion growth. Moreover, iron overload may be hazardous to oocytes. This review may shed some light on the diagnosis and treatment of female infertility.

Variants in NLRP2 and ZFP36L2, non-core components of the human subcortical maternal complex, cause female infertility with embryonic development arrest.

The subcortical maternal complex (SCMC), which is vital in oocyte maturation and embryogenesis, consists of core proteins (NLRP5, TLE6, OOEP), non-core proteins (PADI6, KHDC3L, NLRP2, NLRP7), and other unknown proteins that are encoded by maternal effect genes. Some variants of SCMC genes have been linked to female infertility characterized by embryonic development arrest. However, so far, the candidate non-core SCMC components associated with embryonic development need further exploration and the pathogenic variants that have been identified are still limited. In this study, we discovered two novel variants [p.(Ala131Val) and p.(Met326Val)] of NLRP2 in patients with primary infertility displaying embryonic development arrest from large families. In vitro studies using 293T cells and mouse oocytes, respectively, showed that these variants significantly decreased protein expression and caused the phenotype of embryonic development arrest. Additionally, we combined the 'DevOmics' database with the whole exome sequence data of our cohort and screened out a new candidate non-core SCMC gene ZFP36L2. Its variants [p.(Ala241Pro) and p.(Pro291dup)] were found to be responsible for embryonic development arrest. Co-immunoprecipitation experiments in 293T cells, used to demonstrate the interaction between proteins, verified that ZFP36L2 is one of the human SCMC components, and microinjection of ZFP36L2 complementary RNA variants into mouse oocytes affected embryonic development. Furthermore, the ZFP36L2 variants were associated with disrupted stability of its target mRNAs, which resulted in aberrant H3K4me3 and H3K9me3 levels. These disruptions decreased oocyte quality and further developmental potential. Overall, this is the first report of ZFP36L2 as a non-core component of the human SCMC and we found four novel pathogenic variants in the NLRP2 and ZFP36L2 genes in 4 of 161 patients that caused human embryonic development arrest. These findings contribute to the genetic diagnosis of female infertility and provide new insights into the physiological function of SCMC in female reproduction.

The Current Understanding of Molecular Mechanisms in Adenomyosis-Associated Infertility and the Treatment Strategy for Assisted Reproductive Technology.

Adenomyosis, endometriosis of the uterus, is associated with an increased likelihood of abnormal endometrial molecular expressions thought to impair implantation and early embryo development, resulting in disrupted fertility, including the local effects of sex steroid and pituitary hormones, immune responses, inflammatory factors, and neuroangiogenic mediators. In the recent literature, all of the proposed pathogenetic mechanisms of adenomyosis reduce endometrial receptivity and alter the adhesion molecule expression necessary for embryo implantation. The evidence so far has shown that adenomyosis causes lower pregnancy and live birth rates, higher miscarriage rates, as well as adverse obstetric and neonatal outcomes. Both pharmaceutical and surgical treatments for adenomyosis seem to have a positive impact on reproductive outcomes, leading to improved pregnancy and live birth rates. In addition, adenomyosis has negative impacts on reproductive outcomes in patients undergoing assisted reproductive technology. This association appears less significant after patients follow a long gonadotropin-releasing hormone agonist (GnRHa) protocol, which improves implantation rates. The pre-treatment of GnRHa can also be beneficial before engaging in natural conception attempts. This review aims to discover adenomyosis-associated infertility and to provide patient-specific treatment options.

Association between oxidative balance score and female infertility from the national health and nutrition examination survey 2013-2018.

Background: The correlation between oxidative stress and female infertility pathogenesis was established, and the oxidative balance score (OBS) can serve as a measure of overall oxidative stress burden within an individual. Prior reports have not addressed the relationship between OBS and female infertility. This study endeavors to investigate the association between infertility risk in female and OBS. Methods: The analysis focused on data from the National Health and Nutrition Examination Survey 2013-2018. OBS was determined from 16 dietary components and 4 lifestyle components. Multivariate logistic regression was employed to investigate the relationship between OBS and female infertility. Further stratified analysis was conducted to examine the associations across various subgroups. To elucidate the dose-response relationship between infertility risk in female and OBS, a restricted cubic spline function was employed. Results: The study included a total of 1410 participants. Through weighted multivariable logistic regression analysis, we observed a consistent inverse correlation between OBS and the risk of female infertility [OR (95% CI) = 0.97 (0.95, 0.99), p = 0.047]. When participants were segregated into quartiles based on OBS, those in the highest quartile had a 61% [OR (95% CI) = 0.39 (0.2, 0.79), p = 0.01] reduced risk of infertility compared to those in the lowest quartile of OBS. A trend test assessing OBS by quartile also revealed the relationship between OBS and female infertility. This correlation remained constant across both dietary and lifestyle OBS. Additionally, lifestyle OBS and female infertility exhibited a nonlinear association. A sensitivity analysis verified the consistency of our findings. Conclusion: The study found that a higher OBS is associated with a lower prevalence of female infertility. These results emphasized the potential role of oxidative homeostasis in the pathogenesis of infertility and highlighted the importance of follow-up studies and prevention strategies.

Unraveling the molecular pathogenesis of Type 2 Diabetes and its impact on female infertility: A bioinformatics and systems biology approach.

Type 2 diabetes mellitus (T2D) has been linked with female infertility (FI). Nevertheless, our understanding of the molecular hallmarks and underlying mechanisms remains elusive. This research article aimed to find the hub genes, pathways, transcription factors, and miRNA involved. For this study, softwares like cytoscape, string, Enrichr, FFL loop, etc., were utilized. This research article employed differentially expressed genes (DEGs) to identify multiple biological targets to understand the association between T2D and female infertility (FI). Between T2D and FI, we found 3869 differentially expressed genes. We have also analyzed different pathways like thyroid hormone signaling pathways, AGE-RAGE signaling pathways in diabetic complications and ubiquitin-mediated proteolysis through pathway analysis. Moreover, hub genes MED17, PRKCG, THRA, FOXO1, NCOA2, PLCG2, COL1A1, CXCL8, PRPF19, ANAPC5, UBE2I, XIAP and KEAP1 have been identified. Additionally, these hub genes were subjected to identify the miRNA-mRNA regulation network specific to T2D-associated female infertility. In the FFL study (Feed Forward Loop), transcription factor (SP1, NFKB1, RELA and FOX01), miRNA (has-mir-7-5p, has-let-7a-5p, hsa-mir-16-5p, hsa-mir-155-5p, has-mir-122-5p, has-let-7b-5p, has-mir-124-3p, has-mir-34a-5p, has-mir-130a-3p, has-let-7i-5p, and hsa-mir-27a-3p) and six genes (XIAP, THRA, NCOA2, MED17, FOXO1, and COL1A1) among the thirteen key genes were recognized as regulator and inhibitor. Our analysis reveals that these genes can serve as a significant biomarker for female infertility linked with Type 2 Diabetes, through the prioritization of candidate genes. This study gives us insight into the molecular and cellular mechanism of T2D-associated FI. This finding helps in developing novel therapeutic approaches and will improve efficacy and reduce side effects of the treatment. This research requires further experimental investigation of the principal targets.

Differential expression of ion channel coding genes in the endometrium of women experiencing recurrent implantation failures.

Our study probed the differences in ion channel gene expression in the endometrium of women with Recurrent Implantation Failure (RIF) compared to fertile women. We analyzed the relative expression of genes coding for T-type Ca2+, ENaC, CFTR, and KCNQ1 channels in endometrial samples from 20 RIF-affected and 10 control women, aged 22-35, via microarray analysis and quantitative real-time PCR. Additionally, we examined DNA methylation in the regulatory region of KCNQ1 using ChIP real-time PCR. The bioinformatics component of our research included Gene Ontology analysis, protein-protein interaction networks, and signaling pathway mapping to identify key biological processes and pathways implicated in RIF. This led to the discovery of significant alterations in the expression of ion channel genes in RIF women's endometrium, most notably an overexpression of CFTR and reduced expression of SCNN1A, SCNN1B, SCNN1G, CACNA1H, and KCNQ1. A higher DNA methylation level of KCNQ1's regulatory region was also observed in RIF patients. Gene-set enrichment analysis highlighted a significant presence of genes involved with ion transport and membrane potential regulation, particularly in sodium and calcium channel complexes, which are vital for cation movement across cell membranes. Genes were also enriched in broader ion channel and transmembrane transporter complexes, underscoring their potential extensive role in cellular ion homeostasis and signaling. These findings suggest a potential involvement of ion channels in the pathology of implantation failure, offering new insights into the mechanisms behind RIF and possible therapeutic targets.

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Endometriosis (EMT), a common benign gynecological disease, is a leading cause of infertility in women. EMT affects female fertility in various aspects. However, the underlying mechanisms have not been fully elucidated. Mitochondria are known as the "powerhouse" of a cell. They play pivotal roles in the physiological processes of cellular energy metabolism, calcium homeostasis, oxidative stress, autophagy, the regulation of cell cycle, and cell death, and are involved in the pathophysiology of many diseases. Cellular mitochondria are highly dynamic, continuously undergoing cyclic fission and fusion to meet the demands of cellular activities. Balanced mitochondrial dynamics are critical for maintaining normal reproductive function in women. In addition, mitochondria are the major source of reactive oxygen species (ROS). Cell damage, cell death, and fibrosis mediated by the imbalance in the oxidative-antioxidant system in EMT patients lead to decreased oocyte quality and ovarian reserve. Currently, the treatment of EMT-associated infertility remains a challenging and controversial topic. We herein reviewed the latest findings on the role of mitochondrial dysfunction in EMT-associated infertility and the potential therapeutic targets.

The Molecular Link between Obesity and the Endometrial Environment: A Starting Point for Female Infertility.

Female infertility constitutes a growing health problem in developing countries and could be associated with several possible causes including reproductive disorders, congenital malformations, infections and hormonal dysfunction. Nonetheless, a series of additional factors can also negatively impact female fertility and are represented by chronic exposure to environmental pollutants, stress, unhealthy lifestyle choices such as cigarette smoking and, among others, obesity. Excess weight is associated with several chronic diseases, and growing evidence demonstrates that it can compromise reproductive physiology due to its influence on endometrial gene expression and receptivity. Thus, the current review of the literature mainly focused on how obesity can impair uterine receptivity, mostly from a molecular point of view throughout the window of implantation (WOI) period at an endometrial level. It was also highlighted that an obesity-related increase in adipose tissue may lead to a modulation in the expression of multiple pathways, which could cause a hostile endometrial environment with a consequent negative impact on the uterine receptivity and the establishment of pregnancy. Thanks to the use of the endometrial receptivity assay (ERA), a specific microarray that studies the expression of a series of genes, it is now possible to evaluate the endometrial status of patients with infertility problems in a more detailed manner. Moreover, female fertility and endometrial receptivity could be affected by endometriosis, a chronic benign gynecological disease, whose cause-and-effect relationship to obesity is still uncertain. Therefore, further investigations would be required to better elucidate these mechanisms that govern embryo implantation and could be potentially useful for the generation of new strategies to overcome implantation failure and improve the pregnancy rates in obese women.

Deletion of Fbxw7 in oocytes causes follicle loss and premature ovarian insufficiency in mice.

Premature ovarian insufficiency (POI) is one of the important causes of female infertility. Yet the aetiology for POI is still elusive. FBXW7 (F-box with 7 tandem WD) is one of the important components of the Skp1-Cullin1-F-box (SCF) E3 ubiquitin ligase. FBXW7 can regulate cell growth, survival and pluripotency through mediating ubiquitylation and degradation of target proteins via triggering the ubiquitin-proteasome system, and is associated with tumorigenesis, haematopoiesis and testis development. However, evidence establishing the function of FBXW7 in ovary is still lacking. Here, we showed that FBXW7 protein level was significantly decreased in the ovaries of the cisplatin-induced POI mouse model. We further showed that mice with oocyte-specific deletion of Fbxw7 demonstrated POI, characterized with folliculogenic defects, early depletion of follicle reserve, disordered hormonal secretion, ovarian dysfunction and female infertility. Impaired oocyte-GCs communication, manifested as down-regulation of connexin 37, may contribute to follicular development failure in the Fbxw7-mutant mice. Furthermore, single-cell RNA sequencing and in situ hybridization results indicated an accumulation of Clu and Ccl2 transcripts, which may alter follicle microenvironment deleterious to oocyte development and accelerate POI. Our results establish the important role of Fbxw7 in folliculogenesis and ovarian function, and might provide valuable information for understanding POI and female infertility.

Follicular Fluid and Blood Monitorization of Infertility Biomarkers in Women with Endometriosis.

Infertility is recognized globally as a social disease and a growing medical condition, posing a significant challenge to modern reproductive health. Endometriosis, the third-most frequent gynecologic disorder, is one of the most common and intricate conditions that can lead to female infertility. Despite extensive research, the etiology, malignant transformation, and biological therapy of endometriosis remain unknown. Blood and follicular fluid are two matrices that have been carefully studied and can provide insights into women's health. These matrices are clinically significant because they contain metabolites closely associated with women's illness stage and reproductive outcomes. Nowadays, the application of metabolomic analysis in biological matrices may be able to predict the outcome of assisted reproductive technologies with greater precision. From a molecular viewpoint on reproductive health, we evaluate and compare the utilization of human follicular fluid and blood as matrices in analysis for diagnostic and assisted reproductive technology (ART) predictors of success for endometriosis patients. In the follicular fluid (FF), plasma, and serum of endometriosis-affected women, researchers identified dysregulations of oxidative stress, upregulation of several immune factors, and aberrations in energy metabolic pathways. The altered signatures negatively correlate with the overall oocyte and embryo quality and fertilization rate.

Varied cellular abnormalities in thin vs. normal endometrium in recurrent implantation failure by single-cell transcriptomics.

BACKGROUND: Reduced endometrium thickness and receptivity are two important reasons for recurrent implantation failure (RIF). In order to elucidate differences between these two types of endometrial defects in terms of molecular signatures, cellular interactions, and structural changes, we systematically investigated the single-cell transcriptomic atlas across three distinct groups: RIF patients with thin endometrium (≤ 6 mm, TE-RIF), RIF patients with normal endometrium thickness (≥ 8 mm, NE-RIF), and fertile individuals (Control). METHODS: The late proliferative and mid-secretory phases of the endometrium were collected from three individuals in the TE-RIF group, two in the NE-RIF group, and three in the control group. The study employed a combination of advanced techniques. Single-cell RNA sequencing (scRNA-seq) was utilized to capture comprehensive transcriptomic profiles at the single-cell level, providing insights into gene expression patterns within specific cell types. Scanning and transmission electron microscopy were employed to visualize ultrastructural details of the endometrial tissue, while hematoxylin and eosin staining facilitated the examination of tissue morphology and cellular composition. Immunohistochemistry techniques were also applied to detect and localize specific protein markers relevant to endometrial receptivity and function. RESULTS: Through comparative analysis of differentially expressed genes among these groups and KEGG pathway analysis, the TE-RIF group exhibited notable dysregulations in the TNF and MAPK signaling pathways, which are pivotal in stromal cell growth and endometrial receptivity. Conversely, in the NE-RIF group, disturbances in energy metabolism emerged as a primary contributor to reduced endometrial receptivity. Additionally, using CellPhoneDB for intercellular communication analysis revealed aberrant interactions between epithelial and stromal cells, impacting endometrial receptivity specifically in the TE-RIF group. CONCLUSION: Overall, our findings provide valuable insights into the heterogeneous molecular pathways and cellular interactions associated with RIF in different endometrial conditions. These insights may pave the way for targeted therapeutic interventions aimed at improving endometrial receptivity and enhancing reproductive outcomes in patients undergoing ART. Further research is warranted to validate these findings and translate them into clinical applications for personalized fertility treatments. TRIAL REGISTRATION: Not applicable.

The Role of Total Oxidant and Antioxidant Levels in Follicular Fluid in Unexplained Infertility.

BACKGROUND: Unexplained infertility is defined as the absence of any pathology in the basic evaluation performed in couples who cannot achieve pregnancy after 1 year of unprotected sexual intercourse. The results of tests examining the causes of infertility show no identifiable cause in almost 15% of couples. AIM: The aim of this study was to investigate the effects of reactive oxygen species (ROS) on pregnancy and embryos. METHODS: This study included 200 patients, aged between 20-44 years, with unexplained infertility, who had recurrent intrauterine inseminations failures and hence started in vitro fertilization (IVF)/intracytoplasmic sperm injection treatment. Some amounts of waste follicular fluid samples were collected by embryologists from the oocytes of these patients during the ovum pick-up procedure. Next, total antioxidant status (TAS), total oxidant status (TOS), and oxidative stress index (OSI) values were calculated in the biochemistry laboratory. RESULTS: In terms of pregnancy status, both follicular TOS and OSI values were not significantly different in patients with biochemical and clinical pregnancy, whereas TAS values were significantly higher in patients with pregnancy (P < 0.05). In terms of embryo quality, no significant difference was observed in TAS, TOS, and OSI values between grade 1 and 2 embryos, whereas pregnancy rates were significantly higher in patients who received grade 1 embryo transfer (P < 0.05). However, the follicular fluid TAS levels were significantly lower in smoking patients than in those who did not smoke; TOS and OSI levels were significantly higher. CONCLUSION: This study showed that exposure to oxidative stress might be a causative factor for infertility. In addition, ROS decreased the level of TAS by increasing OSI in the follicular fluid; thus, antioxidant supplementation might be a necessity.

Oxidative Imbalance in Endometriosis-Related Infertility-The Therapeutic Role of Antioxidants.

Endometriosis in half of affected women is closely related to problems with fertility. Endometriosis-associated infertility is caused by a wide range of abnormalities affecting the female reproductive tract, from oocyte quality impairment to disturbances in the eutopic endometrium or mechanical abnormalities resulting from disease progression. Since supportive antioxidant therapies, in addition to surgical treatment or assisted reproductive techniques (ARTs), have overall been proven to be effective tools in endometriosis management, the objective of our review was to analyze the role of antioxidant substances, including vitamins, micronutrients, N-acetylcysteine (NAC), curcumin, melatonin, and resveratrol, in endometriosis-related infertility. Most of these substances have been proven to alleviate the systemic oxidant predominance, which has been expressed through decreased oxidative stress (OS) markers and enhanced antioxidative defense. In addition, we demonstrated that the predominant effect of the aforementioned substances is the inhibition of the development of endometriotic lesions as well as the suppression of pro-inflammatory molecules. Although we can undoubtedly conclude that antioxidants are beneficial in fertility support, further studies explaining the detailed pathways of their action are needed.

High coverage of targeted lipidomics revealed lipid changes in the follicular fluid of patients with insulin-resistant polycystic ovary syndrome and a positive correlation between plasmalogens and oocyte quality.

Background: Polycystic ovary syndrome with insulin resistance (PCOS-IR) is the most common endocrine and metabolic disease in women of reproductive age, and low fertility in PCOS patients may be associated with oocyte quality; however, the molecular mechanism through which PCOS-IR affects oocyte quality remains unknown. Methods: A total of 22 women with PCOS-IR and 23 women without polycystic ovary syndrome (control) who underwent in vitro fertilization and embryo transfer were recruited, and clinical information pertaining to oocyte quality was analyzed. Lipid components of follicular fluid (FF) were detected using high-coverage targeted lipidomics, which identified 344 lipid species belonging to 19 lipid classes. The exact lipid species associated with oocyte quality were identified. Results: The number (rate) of two pronuclear (2PN) zygotes, the number (rate) of 2PN cleaved embryos, and the number of high-quality embryos were significantly lower in the PCOS-IR group. A total of 19 individual lipid classes and 344 lipid species were identified and quantified. The concentrations of the 19 lipid species in the normal follicular fluid (control) ranged between 10-3 mol/L and 10-9 mol/L. In addition, 39 lipid species were significantly reduced in the PCOS-IR group, among which plasmalogens were positively correlated with oocyte quality. Conclusions: This study measured the levels of various lipids in follicular fluid, identified a significantly altered lipid profile in the FF of PCOS-IR patients, and established a correlation between poor oocyte quality and plasmalogens in PCOS-IR patients. These findings have contributed to the development of plasmalogen replacement therapy to enhance oocyte quality and have improved culture medium formulations for oocyte in vitro maturation (IVM).

Association between indicators of visceral lipid accumulation and infertility: a cross-sectional study based on U.S. women.

BACKGROUND: Evidence on the association between visceral lipid accumulation and infertility remains limited and controversial. Therefore, the current investigation is the first investigation to unveil this correlation by utilizing novel indicators of visceral lipid accumulation. METHODS: The present study utilized the NHANES 2013-2020 dataset. Researchers utilized multiple logistic regression, smoothed curve fitting, and subgroup analysis to investigate the associations of waist circumference (WC), metabolic score for visceral fat (METS-VF), lipid accumulation product (LAP), visceral adiposity index (VAI) with infertility. Additionally, the eXtreme Gradient Boosting (XGBoost) algorithm model was utilized to evaluate the relative importance of the factors. RESULTS: After adjusting for potential factors that could influence the results, researchers discovered that all these four indicators of visceral lipid accumulation exhibited strong positive correlations with the probability of infertility. The subgroup analysis demonstrated that the correlations remained consistent in the majority of subgroups (P for interaction > 0.05). The results of XGBoost algorithm model indicate that METS-VF is the most meaningful factor in infertility. The ROC curve research revealed that while METS-VF had the greatest AUC values, there was no variation in the AUC value of different markers of visceral fat accumulation (P > 0.05). CONCLUSIONS: The present investigation discovered that increased WC, METS-VF, LAP, and VAI were associated with a heightened prevalence of infertility.

The impact of obesity on reproductive health and metabolism in reproductive-age females.

Obesity is a highly prevalent chronic disease that impacts >40% of reproductive-aged females. The pathophysiology of obesity is complex and can be understood simply as a chronic energy imbalance whereby caloric intake exceeds caloric expenditure with an energy surplus stored in adipose tissue. Obesity may be categorized into degrees of severity as well as different phenotypes on the basis of metabolic health and underlying pathophysiology. Obesity and excess adiposity have a significant impact on fertility and reproductive health, with direct effects on the hypothalamic-pituitary-ovarian axis, the ovary and oocyte, and the endometrium. There are significant adverse pregnancy outcomes related to obesity, and excess weight gain before, during, and after pregnancy that can alter the lifelong risk for metabolically unhealthy obesity. Given the high prevalence and pervasive impact of obesity on reproductive health, there is a need for better and individualized care for reproductive-aged females that considers obesity phenotype, underlying pathophysiology, and effective and sustainable interventions to treat obesity and manage weight gain before, during, and after pregnancy.

Metabolic profile of follicular fluid in patients with ovarian endometriosis undergoing IVF: a pilot study.

RESEARCH QUESTION: What are the metabolic characteristics of follicular fluid in patients with ovarian endometriosis undergoing IVF? DESIGN: This was an exploratory cohort study on endometriosis. In total, 19 infertile patients with ovarian endometriosis diagnosed by laparoscopy, and 23 controls matched in terms of age and body mass index (women with infertility due to male or tubal factors) were enrolled in this study. All patients underwent IVF treatment with a gonadotrophin-releasing hormone antagonist protocol, and follicular fluid was collected at oocyte retrieval. The metabolomics of follicular fluid samples was analysed using an ultra-high-performance liquid chromatography Orbitrap Exploris mass spectrometer (UHPLC-OE-MS). The best combination of biomarkers was selected by performing stepwise logistic regression analysis with backward elimination. RESULTS: Fifteen metabolites were identified as biomarkers associated with endometriosis. A final model containing 8-hydroxy-2-deoxyguanosine, biotin, n-acetyl-L-methionine and n-methylnicotinamide was constructed. Receiver operating characteristic analysis confirmed the value of these parameters in diagnosing endometriosis, with sensitivity of 94.7% and specificity of 95.7%. Enrichment analysis via the Kyoto Encyclopedia of Genes and Genome showed that 15 metabolites were enriched in eight metabolic pathways. CONCLUSION: Metabolomics based on UHPLC-OE-MS effectively characterized the metabolomics analysis of follicular fluid in patients with ovarian endometriosis. These findings may provide a new basis for better understanding of how diseases progress, and for the discovery of new biomarkers.

Loss of function variant in CIP2A associated with female infertility with early embryonic arrest and fragmentation.

BACKGROUND: Early embryonic arrest and fragmentation (EEAF) is a common cause of female infertility, but the genetic causes remain to be largely unknown. CIP2A encodes the cellular inhibitor of PP2A, playing a crucial role in mitosis and mouse oocyte meiosis. METHODS: Exome sequencing and Sanger sequencing were performed to identify candidate causative genes in patients with EEAF. The pathogenicity of the CIP2A variant was assessed and confirmed in cultured cell lines and human oocytes through Western blotting, semi-quantitative RT-PCR, TUNEL staining, and fluorescence localization analysis. FINDINGS: We identified CIP2A (c.1510C > T, p.L504F) as a novel disease-causing gene in human EEAF from a consanguineous family. L504 is highly conserved throughout evolution. The CIP2A variant (c.1510C > T, p.L504F) reduced the expression level of the mutant CIP2A protein, leading to the abnormal aggregation of mutant CIP2A protein and cell apoptosis. Abnormal aggregation of CIP2A protein and chromosomal dispersion occurred in the patient's oocytes and early embryos. We further replicated the patient phenotype by knockdown CIP2A in human oocytes. Additionally, CIP2A deficiency resulted in decreased levels of phosphorylated ERK1/2. INTERPRETATION: We first found that the CIP2A loss-of-function variant associate with female infertility characterized by EEAF. Our findings suggest the uniqueness and importance of CIP2A gene in human oocyte and early embryo development. FUNDING: This work was supported by National Key Research and Development Program of China (2023YFC2706302), the National Natural Science Foundation of China (81000079, 81170165, and 81870959), the HUST Academic Frontier Youth Team (2016QYTD02), and the Key Research of Huazhong University of Science and Technology, Tongji Hospital (2022A20).