The association between vascular function-related genes and age at natural menopause

Identification of Key Genes and Potential New Biomarkers for Ovarian Aging: A Study Based on RNA-Sequencing Data

Ovarian aging leads to reproductive and endocrine dysfunction, causing the disorder of multiple organs in the body and even declined quality of offspring's health. However, few studies have investigated the changes in gene expression profile in the ovarian aging process. Here, we applied integrated bioinformatics to screen, identify, and validate the critical pathogenic genes involved in ovarian aging and uncover potential molecular mechanisms. The expression profiles of GSE84078 were downloaded from the Gene Expression Omnibus (GEO) database, which included the data from ovarian samples of 10 normal C57BL/6 mice, including old (21-22 months old, ovarian failure period) and young (5-6 months old, reproductive bloom period) ovaries. First, we filtered 931 differentially expressed genes (DEGs), including 876 upregulated and 55 downregulated genes through comparison between ovarian expression data from old and young mice. Functional enrichment analysis showed that biological functions of DEGs were primarily immune response regulation, cell-cell adhesion, and phagosome pathway. The most closely related genes among DEGs (Tyrobp, Rac2, Cd14, Zap70, Lcp2, Itgb2, H2-Ab1, and Fcer1g) were identified by constructing a protein-protein interaction (PPI) network and consequently verified using mRNA and protein quantitative detection. Finally, the immune cell infiltration in the ovarian aging process was also evaluated by applying CIBERSORT, and a correlation analysis between hub genes and immune cell type was also performed. The results suggested that plasma cells and naïve CD4+ T cells may participate in ovarian aging. The hub genes were positively correlated with memory B cells, plasma cells, M1 macrophages, Th17 cells, and immature dendritic cells. In conclusion, this study indicates that screening for DEGs and pathways in ovarian aging using bioinformatic analysis could provide potential clues for researchers to unveil the molecular mechanism underlying ovarian aging. These results could be of clinical significance and provide effective molecular targets for the treatment of ovarian aging.

Anti-Müllerian hormone as a marker of premature ovarian aging in autoimmune thyroid disease

There is an increased incidence of autoimmune thyroid disease (AITD) in women with infertility. We hypothesized that serum anti-Müllerian hormone (AMH) levels will be lower in premenopausal women with AITD than controls. We evaluated ovarian reserve in women with AITD (n = 85) and healthy controls (n = 80), all <40 years old. Detailed data on reproductive history were obtained. Gonadotrophins, steroids, AMH, and inhibin B levels were measured during the follicular phase. The number of pregnancies as well as live births was lower in women with AITD (p < 0.01). No difference was observed in terms of FSH, estradiol, and inhibin B. AMH levels were lower in AITD women than in controls (1.16 + 0.17 versus 1.28 + 0.25 ng/ml, mean + SD, p = 0.001). According to the multiple regression analysis, even after age adjustment, AITD was significantly and independently affected AMH levels (t = 2.674, p = 0.008). Women with AITD seem to have a diminished ovarian follicular reserve and measurement of serum AMH level has the potential to be used to predict this comorbidity.

Serum AMH levels in women with a history of preeclampsia suggest a role for vascular factors in ovarian aging

CONTEXT

The association between early menopause and vascular disease as a possible causative factor has recently received attention. Preeclampsia (PE) is associated with future cardiovascular risk factors, and this premature vascular aging potentially modifies the ovarian aging process.

OBJECTIVE

The purpose of this study was to assess whether women with a history of PE have lower anti-Müllerian hormone (AMH) levels than women with normotensive pregnancies.

DESIGN

This was a retrospective cohort study.

SETTING

The study was conducted in a tertiary referral center.

PATIENTS

Clinical data and blood samples of participants in the Preeclampsia Risk EValuation in FEMales study were used (336 women with a history of PE and 329 women after a normotensive pregnancy).

INTERVENTIONS

There were no interventions.

MAIN OUTCOME MEASURES

The relative decrease in AMH levels was assessed after a median follow-up of 10.5 years.

RESULTS

The mean AMH level was 2.00 ± 1.87 μg/L in the PE group compared with 2.26 ± 2.56 μg/L in the reference group. Linear regression analysis with censoring for undetectable AMH levels, adjusted for age, smoking, and hormonal contraceptive use, showed a relative reduction in AMH levels of 20.9% at any age (fold change 0.79, 95% confidence interval, 0.67-0.94).

CONCLUSIONS

We demonstrate that women with a history of PE have significantly lower AMH levels than women with normotensive pregnancies. Calculations based on a reference population indicate advancement of reproductive age of approximately 1.5 years. Because PE is considered a manifestation of impaired vascular health, these results support the hypothesis that compromised vascular health could act as a causative mechanism in early ovarian aging.

ApoE genotypes are associated with age at natural menopause in Chinese females

Ages at natural menarche and menopause are influenced by several genetic factors. This study aimed to investigate the possible relationship between the apolipoprotein E (ApoE) genotype and the age at menarche and natural menopause in Chinese females. In the current study, 398 (elderly group, aged 47-80 years) and 825 (young group, aged 15-25 years) Chinese females were enrolled under informed content. Ages at natural menarche and menopause were obtained by questionnaires. ApoE genotypes were identified by restriction fragment length polymorphism analysis. In the elderly group, the number of pregnancies and live births and breastfeeding were associated with the age at menopause (P = 0.008, P = 0.002, and P = 0.023, respectively). One-way ANOVA analysis revealed that the ApoE genotype was significantly associated with age at natural menopause (ANM; P = 0.010). Compared with ApoE ε3/3 carriers, ApoE ε3/4 females showed a 1.8-year delay in ANM (P = 0.002). Single ApoE allele-positive/allele-negative analysis also showed that the age at menopause of ApoE ε4 carriers was delayed compared with those who were not carriers (P = 0.023). In the young group, no statistical difference was found in the age of menarche between the carriers of ApoE ε3/3 and ε3/4. Single ApoE allele-positive/allele-negative analysis showed that the age at menarche in ApoE ε4 carriers was slightly earlier than in those who were not carriers (P = 0.048). Meanwhile, univariate association analysis revealed that the ApoE genotypes were not significantly associated with the age at menarche using age as a covariate in the pooled group (young + elderly) (P = 0.143). We demonstrated that the ApoE genotype is significantly linked to the age at natural menopause.

Human studies on genetics of the age at natural menopause: a systematic review

BACKGROUND Timing of natural menopause has great implications for fertility and women's health. Age at natural menopause (ANM) is largely influenced by genetic factors. In the past decade, several genetic studies have been conducted to identify genes in ANM, which can help us unravel the biological pathways underlying this trait and the associated infertility and health risks. After providing an overview of the results of the genetic studies performed so far, we give recommendations for future studies in identifying genetic factors involved in determining the variation in timing of natural menopause. METHODS The electronic databases of Pubmed and Embase were systematically searched until September 2009 for genetic studies on ANM, using relevant keywords on the subject. Additional papers identified through hand search were also included. RESULTS Twenty-eight papers emerged from our literature search. A number of genetic regions and variants involved in several possible pathways underlying timing of ANM were identified, including two possible interesting regions (9q21.3 and chromosome 8 at 26 cM) in linkage analyses. Recent genome-wide association studies have identified two genomic regions (19q13.42 and 20p12.3), containing two promising candidate genes (BRKS1 and MCM). In the candidate gene association studies on ANM, very few consistent associations were found. CONCLUSION A number of genetic variants have been discovered in association with ANM, although the overall results have been rather disappointing. We have described possible new strategies for future genetic studies to identify more genetic loci involved in the variation in menopausal age.

Genetic and genomic insights into age at natural menopause

The age at natural menopause shows great variability. It has been proposed that early age at menopause is a risk factor for osteoporosis and cardiovascular disease, whereas later age at menopause is a risk factor for breast cancer. In addition, it is thought that the genetic factors accounting for the genetic variability in age at menopause could also play a role in those diseases, as well as infertility in women. In this minireview we comment on the latest genetics and genomics insights into age at natural menopause.

Ovarian aging: mechanisms and clinical consequences

Menopause is the final step in the process referred to as ovarian ageing. The age related decrease in follicle numbers dictates the onset of cycle irregularity and the final cessation of menses. The parallel decay in oocyte quality contributes to the gradual decline in fertility and the final occurrence of natural sterility. Endocrine changes mainly relate to the decline in the negative feedback from ovarian factors at the hypothalamo-pituitary unit. The declining cohort of antral follicles with age first results in gradually elevated FSH levels, followed by subsequent stages of overt cycle irregularity. The gradual decline in the size of the antral follicle cohort is best represented by decreasing levels of anti-Mullerian hormone. The variability of ovarian ageing among women is evident from the large variation in age at menopause. The identification of women who have severely decreased ovarian reserve for their age is clinically relevant. Ovarian reserve tests have appeared to be fairly accurate in predicting response to ovarian stimulation in the assisted reproductive technology (ART) setting. The capacity to predict the chances for spontaneous pregnancy or pregnancy after ART appears very limited. As menopause and the preceding decline in oocyte quality seem to have a fixed time interval, tests that predict the age at menopause may be useful to assess individual reproductive lifespan. Especially genetic studies, both addressing candidate gene and genome wide association, have identified several interesting loci of small genetic variation that may determine fetal follicle pool development and subsequent wastage of his pool over time. Improved knowledge of the ovarian ageing mechanisms may ultimately provide tools for prediction of menopause and manipulation of the early steps of folliculogenesis for the purpose of contraception and fertility lifespan extension.