Androgen exposure (AE) poses a profound health threat to women, yet its transgenerational impacts on male descendants remain unclear. Here, employing a large-scale mother-child cohort, we show that maternal hyperandrogenism predisposes sons to β-cell dysfunction. Male offspring mice with prenatal AE exhibited hyperglycemia and glucose intolerance across three generations, which were further exacerbated by aging and a high-fat diet. Mechanistically, compromised insulin secretion underlies this transgenerational susceptibility to diabetes. Integrated analyses of methylome and transcriptome revealed differential DNA methylation of β-cell functional genes in AE-F1 sperm, which was transmitted to AE-F2 islets and further retained in AE-F2 sperm, leading to reduced expression of genes related to insulin secretion, including Pdx1, Irs1, Ptprn2, and Cacna1c. The methylation signatures in AE-F1 sperm were corroborated in diabetic humans and the blood of sons with maternal hyperandrogenism. Moreover, caloric restriction and metformin treatments normalized hyperglycemia in AE-F1 males and blocked their inheritance to offspring by restoring the aberrant sperm DNA methylations. Our findings highlight the transgenerational inheritance of impaired glucose homeostasis in male offspring from maternal AE via DNA methylation changes, providing methylation biomarkers and therapeutic strategies to safeguard future generations’ metabolic health.
Oocyte and early embryo competence defects (OECD) represent a recently recognized cause of female infertility with the application of assisted reproductive technology, characterized by impaired oocyte or early embryo development. To investigate the genetic landscape and subtypes of OECD, we performed whole-exome sequencing on 2,140 patients, classifying them into six distinct subtypes. We identified 183 pathogenic/likely pathogenic variants across 28 established genes. Notably, distinct genetic profiles and diagnostic rates emerged across subtypes, with a rate of 53% in the Empty Follicle subtype. Additionally, we identified and validated two potentially causative genes, MLH3 and CENPH. Gene burden analysis, using 2,424 fertile controls, suggested nine potential previously unreported associated genes and offered biological insights into the underlying pathogenic mechanisms of OECD. Collectively, these genetic findings accounted for 12.8-23.1% of OECD cases. This study delineates the genetic architecture of OECD, offering insights that may inform the development of diagnostic genetic screenings and provide a reference for standardized subtyping of patients with OECD.
Biobanks hold a pivotal role in facilitating translational and clinical research endeavors. However, the effects of prolonged storage on frozen blood samples analytes are not well defined yet. The aim of this study was to investigate the long-term stability of the quality of DNA, RNA, and endocrine markers within blood samples amassed from the biobank over the past 11 years. The results show that the overall quality and integrity of DNA remained not significantly influenced. However, RNA integrity and purity displayed substantial deterioration as storage duration increased, to ensure high-quality RNA for downstream analyses, advised to prioritize using blood samples stored within 3 years. Furthermore, the study examined the influence of storage time on endocrine markers. Through repeated measures ANOVA and linear regression analyses, it was evident that storage duration significantly influenced the levels of endocrine markers. This insight aids researchers in selecting appropriate markers for their investigations and augments the precision and dependability of results when dealing with long-term stored samples.
Abstract Background Polycystic ovary syndrome (PCOS) is a common endocrine disorder in premenopausal women, whose etiology remains uncertain, although it is known to be highly heterogeneous and genetically complex. PCOS often presents with hyperandrogenism symptoms. The present study aimed to determine whether polymorphisms in the FK-506 binding protein 5 (FKBP5) gene (androgen target gene) are associated with an association for PCOS and hyperandrogenism. Methods This is a case–control study, and association analyses were conducted. A total of 13 single-nucleotide polymorphisms (SNPs) in the FKBP5 gene were evaluated in 775 PCOS patients who were diagnosed based on the Rotterdam Standard and 783 healthy Chinese Han women. Associations between FKBP5 SNPs and hormone levels were investigated. These 13 SNPs were genotyped using the Sequenom MassARRAY system, and an association analysis between the phenotype and alleles and genotypes were conducted. Results The genotype frequencies for the rs1360780 and rs3800373 SNPs differed significantly between the PCOS cases and healthy controls (p = 0.025, OR is 1.63 (1.05–2.53) and p = 0.029, OR is 1.59 (1.03–2.45) respectively under co-dominant model). Moreover, the genotype frequencies and genetic model analysis for the SNPs rs1360780, rs9470080, rs9296158, rs1043805 and rs7757037 differed significantly between the hyperandrogenism and non-hyperandrogenism groups of PCOS patients. The TT genotype of rs1360780, the TT genotype of rs9470080, the TT genotype of rs1043805 or the GG genotype of rs7705037 (ORs are 2.13 (1.03–4.39), 1.81 (1.03–3.17), 2.94 (1.32–6.53) and 1.72 (1.04–2.84) respectively) were correlated with androgen level of PCOS patients. Conclusion Our study showed that FKBP5 gene polymorphisms are associated with PCOS generally (rs1360780 and rs3800373) and with the hyperandrogenism subtype specifically (rs1360780, rs9470080, rs9296158, rs1043805 and rs7757037).
Mitochondrial DNA (mtDNA) plays a critical role in oocyte maturation, fertilization, and early embryonic development. Defects in mtDNA may determine the alteration of the mitochondrial function, affecting cellular oxidative phosphorylation and ATP supply, leading to impaired oocyte maturation, abnormal fertilization, and low embryonic developmental potential, ultimately leading to female infertility. This case–control study was established to investigate the correlation between mtDNA variations and early embryonic development defects. Peripheral blood was collected for next-generation sequencing from women who suffered the repeated failures of in vitro fertilization (IVF) and/or intracytoplasmic sperm injection (ICSI) cycles due to early embryonic development defects as well as in-house healthy controls, and the sequencing results were statistically analyzed for all subjects. This study found that infertile women with early embryonic development defects carried more mtDNA variants, especially in the d -loop region, ATP6 gene, and CYTB gene. By univariate logistic regression analysis, 16 mtDNA variants were associated with an increased risk of early embryonic development defects (OR > 1, p < 0.05). Furthermore, we identified 16 potentially pathogenic mtDNA variants only in infertile cases. The data proved that mtDNA variations were associated with early embryonic development defects in infertile Chinese women.
Human female fecundity decreases irreversibly as chronological age rises, adversely affecting oocyte quality, consequently worsening pregnancy outcomes and increasing the extent of birth defects. The first-line type 2 diabetes treatment metformin has been associated with delayed aging and reduction of oxidative stress; yet it remains unclear if metformin confers any benefits for oocytes from aged mice, particularly in the context of the assisted human reproductive technology (ART) known as in vitro maturation (IVM). Here, we found that adding metformin into the M16 culture medium of oocytes from aged mice significantly improved both oocyte maturation and early embryonic development. This study showed that metformin reduced the extent of meiotic defects and maintained a normal distribution of cortical granules (CGs). RNA-seq analysis of metformin-treated oocytes revealed genes apparently involved in the reduction of mitochondrial ROS. Further, the results supported that the metformin improved mitochondrial function, reduced apoptosis, increased the extent of autophagy, and reduced mitochondrial ROS via SIRT3-mediated acetylation status of SOD2K68 in oocytes from aged mice. Thus, this finding demonstrated a protective effect for metformin against the decreased quality of oocytes from aged mice to potentially improve ART success rates and illustrated a potential strategy to prevent or delay reproductive aging.
Maternal fertility declines irreversibly with aging, and advanced maternal age is mostly related to impaired oocyte quality. The flavonol compound quercetin is considered to be an anti-aging agent due to its cytoprotective actions as an antioxidant. However, its role and mechanisms on aged oocytes are unclear. In this study, the quercetin promotes in vitro maturation (IVM) and early embryonic development of oocytes from aged mice. It is extended these findings in human oocytes, showing that quercetin promotes the IVM rate by 19.6% and increases the blastocyst formation rate by 15.5% compared to untreated controls. The overall oocyte quality of aged mice is improved by quercetin treatment, assessed as spindle/chromosome morphology and cortical granule distribution. Mitochondria is the primary endogenous source of age-related oxidative stress, and an RNA-seq analysis of quercetin-treated oocytes reveals molecular insights including scavenged mitochondrial-ROS, reduced apoptosis, and improved autophagy. Further, this study demonstrates that quercetin reduces ROS via SIRT3-mediated acetylation of SOD2's K68 residue. Thus, beyond demonstrating that quercetin confers beneficial mitochondria-related impacts in aged oocytes, this study illustrates a potential strategy to prevent or delay oocyte aging and to improve success rates of assisted human reproductive technologies (ART).
Human zygote arrest during in vitro culture is rare and the etiology is unclear. The oocyte-specific gene Zar1 plays an essential role in oocyte-embryo transition, and most embryos from Zar1 knockout female mice arrest at the one-cell stage. This study investigates whether maternal ZAR1 gene variations play a role in human zygote arrest. Sequence analysis of ZAR1 was conducted for 47 women with recurrent uncleaved zygotes in in vitro fertilization/intracytoplasmic sperm injection (IVF/ICSI) cycles (≥ 70% zygotes uncleaved in at least 2 cycles), 93 women from IVF/ICSI cycles with normal uncleaved rate and live birth (control subset I) and 188 women with spontaneous pregnancy and live birth (control subset II). One novel synonymous variation (c.516C>T) and one novel intron variation (c.964-55A>T) of ZAR1 were identified in the zygote arrest group but not in any of the 188 controls. However, the bioinformatics analysis revealed that neither of the mutations in ZAR1 has effect on ZAR1 protein function. Compared with control subset I, the allele frequencies of rare SNPs rs117545505 and rs17609740 were significantly different in patients with zygote arrest (P = 0.047, OR = 3.66). Allele frequencies of these two SNPs were also significantly different between the case group and control subset II (P = 0.024, OR = 3.28). In conclusion, two SNPs in ZAR1 are associated with human zygote arrest, although additional proof is needed for validation.
Variants of tubulin beta 8 class VIII (TUBB8) have been shown to be associated with female infertility characterized by oocyte or embryonic defects. To further investigate the mutational spectrum of TUBB8 and the prevalence of variants, we performed Sanger sequencing of TUBB8 on a total of 115 infertile females who had undergone repeated in vitro fertilization cycles with oocyte or embryonic defects and 200 healthy controls. A total of 31 variants which were absent from the controls were identified in 36 unrelated individuals, accounting for a large proportion of this cohort (31.3%). All of the variants including heterozygous/homozygous missense variants and a heterozygous frameshift insertion variant were at conserved sites and predicted to be deleterious. Besides, these variants had diverse phenotypic effects, including not only oocyte maturation arrest, fertilization failure, and early embryonic arrest, but also multi-pronuclei (MPN) formation, which is a new phenotype associated with TUBB8 variants. Overall, this study reveals a large number of variants of the TUBB8 gene in infertile females with oocyte or embryonic defects. Our results not only broaden the mutational and phenotypic spectra of TUBB8 variants, but also further confirm the critical role of TUBB8 in oocyte maturation, fertilization, and early embryonic development.
A recent genome-wide association study (GWAS) of polycystic ovary syndrome (PCOS) in European cohorts has identified six susceptibility loci mapping to 11q22.1 (YAP1), 2p21 (THADA), 11p14.1 (FSHB), 2q34 (ERBB4), 12q21.2 (KRR1), and 5q31.1 (RAD50). The loci of 11q22.1, 2p21 and 11p14.1 have been confirmed to be associated with PCOS in Chinese; whereas the other three new loci (2q34, 12q21.2, and 5q31.1) still need to be evaluated in Chinese. This study was aimed to determine if the three new loci identified in European PCOS also confer risks for PCOS in Han Chinese. We performed a case-control genetic association study comprising 1500 PCOS cases and 1220 age-matched control subjects. Marker SNPs rs1351592 (2q34, ERBB4), rs1275468 (12q21.2, KRR1) and rs13164856 (5q31.1, RAD50) were genotyped using TaqMan-MGB probe assay. Genotyping analysis showed the allele frequency of rs1351592 in gene ERBB4 was significantly different (P = 1.05E-03) between PCOS cases and control group, and remained significant even after BMI adjustment (P-adjusted = 2.09E-04). However, the allele frequencies of the other two risk variants, rs1275468 (12q21.2, KRR1) and rs13164856 (5q31.1, RAD50), were not significantly different in the replication cohort. Our results demonstrate that ERBB4, with the strongest association in European PCOS, also confers risk for PCOS in Han Chinese.
Objective: To detect ZP (zona pellucida) gene (ZP1-ZP4) mutations in patients with oocyte anomalies.Design: Case-control genetic study.Setting: University-based reproductive medicine center.Patient(s): A total of 92 infertile patients with repeated cycles of oocyte maturation arrest (group I, n = 49) or oocyte morphologic defect (group II, n = 43) as well as 373 healthy controls.Intervention(s): Genomic DNA extracted from peripheral blood and coding regions of ZP genes amplified by polymerase chain reaction and sequenced by a DNA analyzer.Main Outcome Measure(s): Variant prediction of ZP genes with software.Result(s): In group I with oocyte maturation arrest, no novel variants were found. In group II with oocyte morphologic defects, four novel variants, two in the ZP1 gene [c.247T>C (p.W83R) and c.1413G>A (p.W471X)] and two in the ZP2 gene [c.1599G>T (p.R533S) and c. 1696T>C (p.C566R)] were detected in 4 of 43 patients (approximately 9%) but were absent from the controls. Protein alignments showed that the four variants were highly conserved among different species, and all four variants were predicted to be deleterious by gene software predictions.Conclusion(s): ZP gene variants may account for patients with oocyte morphologic abnormalities but not for those with oocyte maturation arrest. (C) 2017 by American Society for Reproductive Medicine.
Zi-Jiang Chen and colleagues report a genome-wide association analysis for polycystic ovary syndrome (PCOS) in Han Chinese. They identify eight new susceptibility loci for PCOS in this population.