Polymorphisms of the CYP1B1 gene may be associated with the onset of natural menopause in Chinese women

Exploring the molecular mechanism of Dioscorea alata L. for the treatment of menstrual disorders using network pharmacology and molecular docking

Menstrual disorders (MDs), including premenstrual syndrome, amenorrhea, and dysmenorrhea, affect women globally. Dioscorea alata L., a traditional yam species, has been used medicinally, but its potential in treating MDs remains understudied. This study employs a network pharmacology approach to examine the effects of D. alata's secondary metabolites on MDs via multi-target mechanisms. Compounds were identified from literature and PubChem, while disease-related targets were gathered from GeneCards, DisGeNET, and CTD databases. Swiss target prediction was used to link compounds to targets. A protein-protein interaction (PPI) network was constructed using STRING, and Gene Ontology (GO) and KEGG enrichment analyses were conducted to predict functional pathways. Eighteen bioactive compounds and 120 therapeutic targets specific to MDs were identified. KEGG analysis revealed 20 significant pathways related to menstrual disturbances. Among the 120 targets, TNF α, PPARG, ESR1, and AKT1 were highlighted as key therapeutic targets. Molecular docking showed strong interactions between Daidzein and ESR1, Diosgenin and TNF α, Alatanin and AKT1, and PPARG. The findings suggest that D. alata's bioactive compounds, such as Diosgenin, Daidzein, Genistin, Cycloartane, and Alatanin, could modulate pathways involved in ovarian follicle formation, hormone regulation, estrogen receptor signaling, and the stress-activated MAP kinase pathway. This study provides new insights into the multi-target potential of D. alata for treating menstrual disorders, supporting further investigation and therapeutic development.

Genes linked with early menopause and the pathogenesis of its associated diseases: a systematic review

Background

Menopause is a biological process when a woman’s reproductive capability is no longer functional. A naturally or artificially caused premenopausal is known as early menopause occurs between the ages 40–45, which substantially impacts fertility and disease influenced by genetic plus environmental factors and their interactions. Women in early menopause are at greater risk of cardiovascular disease, general mortality, neurological disorders, osteoporosis, mental illness, and other problems.

Main body

A PubMed search of the electronic literature database yielded articles on early menopause and disease etiology. Several unique genes were identified, such as ESR1, ESR2, CYP1B1, BRSK1, HK3, andTMEM150B are associated with early menopause, and research focused on case-control, cohort, and cross-sectional studies are finding novel predisposition loci for early menopause.

Conclusion

The current study’s focus is to understand better the genetic aspects of early menopause. This knowledge will help researchers enhance EM etiology and identify biomarkers that may detect early development of the disease, allowing women at risk to begin family planning earlier.

Women's reproductive span: a systematic scoping review

STUDY QUESTION

What is the scope of literature regarding women's reproductive span in terms of definitions, trends and determinants?

SUMMARY ANSWER

The scoping review found a wide variation in definitions, trends and determinants of biological, social and effective women's reproductive span.

WHAT IS KNOWN ALREADY

A woman's reproductive span refers to her childbearing years. Its span influences a woman's reproductive decisions.

STUDY DESIGN SIZE DURATION

A systematic scoping review was conducted. We searched MEDLINE, PubMed, JSTOR, CINAHL, Web of Science and Scopus electronic databases from inception to January 2021 without imposing language or date restrictions. We searched unpublished sources including the Global Burden of Disease, Demographic and Health Surveys, and National Health and Nutrition Examination Surveys. The list of relevant references was searched by hand. Sixty-seven reports on women's reproductive span were included in this review.

PARTICIPANTS/MATERIALS SETTING METHODS

This scoping systematic review followed an established framework. The reporting of this scoping review followed the reporting requirements provided in the Preferred Reporting Items for Systematic Reviews and Meta-Analyses, Extension for Scoping Reviews. Identified records were independently screened and data were extracted. We performed conceptual synthesis by grouping the studies by available concepts of reproductive span and then summarized definitions, measures used, temporal trends, determinants, and broad findings of implications on population demographics and assisted reproduction. Structured tabulation and graphical synthesis were used to show patterns in the data and convey detailed information efficiently, along with a narrative commentary.

MAIN RESULTS AND THE ROLE OF CHANCE

A total of 67 relevant reports on women's reproductive span were published between 1980 and 2020 from 74 countries. Most reports (42/67) were cross-sectional in design. Literature on reproductive span was conceptually grouped as biological (the interval between age at menarche and age at menopause), effective (when a woman is both fertile and engaging in sexual activity) and social (period of exposure to sexual activity). We summarized the working definitions, trends and determinants of each concept. Few articles addressed implications on demographics and assisted reproduction.

LIMITATIONS REASONS FOR CAUTION

A formal assessment of methodological quality of the included studies was not performed because the aim of this review was to provide an overview of the existing evidence base regardless of quality.

WIDER IMPLICATIONS OF THE FINDINGS

The review produced a comprehensive set of possible definitions of women's reproductive span, trends, and potential determinants. Further advancement of these findings will involve collaboration with relevant stakeholders to rate the importance of each definition in relation to demography and fertility care, outline a set of core definitions, identify implications for policy, practice or research and define future research opportunities to explore linkages between reproductive spans, their determinants, and the need for assisted reproduction.

STUDY FUNDING/COMPETING INTERESTS

This work received funding from the UNDP-UNFPA-UNICEF-WHO-World Bank Special Programme of Research, Development and Research Training in Human Reproduction (HRP), a cosponsored programme executed by the World Health Organization (WHO). The authors had no competing interests.

STUDY REGISTRATION NUMBER

N/A.

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.

Cigarettes, genetic background, and menopausal timing: the presence of single nucleotide polymorphisms in cytochrome P450 genes is associated with increased risk of natural menopause in European-American smokers

OBJECTIVE

This study aims to evaluate associations between variations in genes involved in the metabolism of environmental chemicals and steroid hormones and risk of menopause in smokers.

METHODS

Survival analysis was performed on 410 eligible participants from the Penn Ovarian Aging study (ongoing for 14 years), a cohort study of late-reproductive-age women. Single nucleotide polymorphisms at the following loci were studied: COMT Val158Met, CYP1B1*4 Asn452Ser, CYP1B1*3 Leu432Val, and CYP3A4*1B.

RESULTS

Significant interactions between smoking and single nucleotide polymorphisms were observed in European-American carriers of CYP3A4*1B and CYP1B1*3, supporting a greater risk of menopause entry compared with those not carrying these alleles. Among CYP1B1*3 carriers, smokers had a greater risk of menopause entry than nonsmokers (adjusted hazard ratio [HR], 2.26; 95% CI, 1.4-3.67; median time to menopause, 10.42 and 11.07 y, respectively). No association between smoking and menopause was identified in CYP1B1 wild types. Among CYP3A4*1B carriers, smokers were at greater risk for menopause entry than nonsmokers (adjusted HR, 15.1; 95% CI, 3.31-69.2; median time to menopause, 11.36 and 13.91 y, respectively). Risk of menopause entry in CYP3A4 wild types who smoked was far lower (adjusted HR, 1.59; 95% CI, 1.03-2.44). Heavily smoking CYP1B1*3 carriers (adjusted HR, 3.0; 95% CI, 1.54-5.84; median time to menopause, 10.41 y) and heavily smoking CYP3A4*1B carriers (adjusted HR, 17.79; 95% CI, 3.21-98.65; median time to menopause, 5.09 y) had the greatest risk of menopause entry.

CONCLUSIONS

Our finding that the risk of menopause entry in European-American smokers varies depending on genetic background represents a novel gene-environment interaction in reproductive aging.

Meta-analysis of loci associated with age at natural menopause in African-American women

Age at menopause marks the end of a woman's reproductive life and its timing associates with risks for cancer, cardiovascular and bone disorders. GWAS and candidate gene studies conducted in women of European ancestry have identified 27 loci associated with age at menopause. The relevance of these loci to women of African ancestry has not been previously studied. We therefore sought to uncover additional menopause loci and investigate the relevance of European menopause loci by performing a GWAS meta-analysis in 6510 women with African ancestry derived from 11 studies across the USA. We did not identify any additional loci significantly associated with age at menopause in African Americans. We replicated the associations between six loci and age at menopause (P-value < 0.05): AMHR2, RHBLD2, PRIM1, HK3/UMC1, BRSK1/TMEM150B and MCM8. In addition, associations of 14 loci are directionally consistent with previous reports. We provide evidence that genetic variants influencing reproductive traits identified in European populations are also important in women of African ancestry residing in USA.

Genome-wide association studies of age at menarche and age at natural menopause

Genome-wide association studies (GWAS) have been successful in uncovering genetic determinants of age at menarche and age at natural menopause. To date, more than 30 novel genetic loci have been identified in GWAS for age at menarche and 17 for age at natural menopause. These findings have stimulated a plethora of follow-up studies particularly with respect to the functional characterization of these novel loci and how these results can be translated into risk prediction. However, the genetic loci identified so far account for only a small fraction of the overall heritability. This review provides an overview of the current state of our knowledge of the genetic basis of menarche and menopause timing. It emphasizes recent GWAS results and outlines strategies for discovering the missing heritability and strategies to further our understanding of the underlying molecular mechanisms of the observed genetic associations.

Genomic markers of ovarian reserve

Ovarian reserve and its utilization, over a reproductive life span, are determined by genetic, epigenetic, and environmental factors. The establishment of the primordial follicle pool and the rate of primordial follicle activation have been under intense study to determine genetic factors that affect reproductive lifespan. Much has been learned from transgenic animal models about the developmental origins of the primordial follicle pool and mechanisms that lead to primordial follicle activation, folliculogenesis, and the maturation of a single oocyte with each menstrual cycle. Recent genome-wide association studies on the age of human menopause have identified approximately 20 loci, and shown the importance of factors involved in double-strand break repair and immunology. Studies to date from animal models and humans show that many genes determine ovarian aging, and that there is no single dominant allele yet responsible for depletion of the ovarian reserve. Personalized genomic approaches will need to take into account the high degree of genetic heterogeneity, family pedigree, and functional data of the genes critical at various stages of ovarian development to predict women's reproductive life span.

Genetic variation and reproductive timing: African American women from the Population Architecture using Genomics and Epidemiology (PAGE) Study

Age at menarche (AM) and age at natural menopause (ANM) define the boundaries of the reproductive lifespan in women. Their timing is associated with various diseases, including cancer and cardiovascular disease. Genome-wide association studies have identified several genetic variants associated with either AM or ANM in populations of largely European or Asian descent women. The extent to which these associations generalize to diverse populations remains unknown. Therefore, we sought to replicate previously reported AM and ANM findings and to identify novel AM and ANM variants using the Metabochip (n = 161,098 SNPs) in 4,159 and 1,860 African American women, respectively, in the Women's Health Initiative (WHI) and Atherosclerosis Risk in Communities (ARIC) studies, as part of the Population Architecture using Genomics and Epidemiology (PAGE) Study. We replicated or generalized one previously identified variant for AM, rs1361108/CENPW, and two variants for ANM, rs897798/BRSK1 and rs769450/APOE, to our African American cohort. Overall, generalization of the majority of previously-identified variants for AM and ANM, including LIN28B and MCM8, was not observed in this African American sample. We identified three novel loci associated with ANM that reached significance after multiple testing correction (LDLR rs189596789, p = 5×10⁻⁰⁸; KCNQ1 rs79972789, p = 1.9×10⁻⁰⁷; COL4A3BP rs181686584, p = 2.9×10⁻⁰⁷). Our most significant AM association was upstream of RSF1, a gene implicated in ovarian and breast cancers (rs11604207, p = 1.6×10⁻⁰⁶). While most associations were identified in either AM or ANM, we did identify genes suggestively associated with both: PHACTR1 and ARHGAP42. The lack of generalization coupled with the potentially novel associations identified here emphasize the need for additional genetic discovery efforts for AM and ANM in diverse populations.

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.

Polymorphisms in adiposity-related genes are associated with age at menarche and menopause in breast cancer patients and healthy women

STUDY QUESTION

Is there any effect of genetic polymorphisms in adiposity-related genes on the timing of menarche and menopause and the total duration of menstruation among Korean women?

SUMMARY ANSWER

Our results suggest that the adiposity-related genes LEP, LEPR and PPARγ may play a role in the onset and cessation of menstruation, and the total duration of menstruation.

WHAT IS KNOWN AND WHAT THIS PAPER ADDS

Previous candidate-gene approaches have mainly presented the results for genes related to the estrogen metabolism pathway. Most genes of interest that participate in steroid-hormone metabolism, such as estrogen receptor α and estrogen receptor β, have been associated with age at menarche and menopause. This study shows the possibility that adiposity-related genes also influence the duration of menstruation.

PARTICIPANTS AND SETTING

We recruited 400 breast cancer patients and 452 healthy participants from a case-control study at the Center for Breast Cancer, National Cancer Center in Korea. Ten single nucleotide polymorphisms (SNPs) in the leptin (LEP), leptin receptor (LEPR) and peroxisome proliferator-activated receptor gamma (PPARγ) genes were investigated to evaluate their possible effects on menstruation. Associations between SNPs and age at menarche, age at menopause and duration of menstruation were evaluated.

MAIN RESULTS

Four SNPs (rs2167270 of LEP, rs7602 of LEPR and rs4684846 and rs3856806 of PPARγ) were associated with late menarche (≥ 17-year-old). Four SNPs (rs2167270 of LEP and rs1801282, rs2120825, and rs3856806 of PPARγ) were associated with early menopause (<40-year-old) among post-menopausal women. In logistic regression models with covariate adjustment, women with the GG genotype of rs7602 (LEPR) had a higher risk for late menarche [odds ratio (OR) = 1.83, 95% confidence interval (CI) = 1.01-3.31] compared with their counterparts carrying the GA or AA genotypes. In addition, the GG genotype of rs2167270 (LEP) was inversely associated with a duration of menstruation of <30 years (OR = 0.59, 95% CI = 0.31-1.00) compared with the GA or AA genotypes. BIAS, LIMITATIONS AND GENERALIZABILITY TO OTHER POPULATIONS: We obtained information on the age at menarche and menopause from self-administered questionnaires, and some participants might have had difficulty in remembering their age at menarche and menopause. However, this is a non-differential misclassification and should not appreciably affect the interpretation of the results of this study.

A large-scale candidate gene association study of age at menarche and age at natural menopause

Recent genome-wide association (GWA) studies have identified several novel genetic loci associated with age at menarche and age at natural menopause. However, the stringent significance threshold used in GWA studies potentially led to false negatives and true associations may have been overlooked. Incorporating biologically relevant information, we examined whether common genetic polymorphisms in candidate genes of nine groups of biologically plausible pathways and related phenotypes are associated with age at menarche and age at natural menopause. A total of 18,862 genotyped and imputed single nucleotide polymorphisms (SNPs) in 278 genes were assessed for their associations with these two traits among a total of 24,341 women from the Nurses' Health Study (NHS, N = 2,287) and the Women's Genome Health Study (WGHS, N = 22,054). Linear regression was used to assess the marginal association of each SNP with each phenotype. We adjusted for multiple testing within each gene to identify statistically significant SNP associations at the gene level. To evaluate the overall evidence for an excess of statistically significant gene associations over the proportion expected by chance, we applied a one-sample test of proportion to each group of candidate genes. The steroid-hormone metabolism and biosynthesis pathway was found significantly associated with both age at menarche and age at natural menopause (P = 0.040 and 0.011, respectively). In addition, the group of genes associated with precocious or delayed puberty was found significantly associated with age at menarche (P = 0.013), and the group of genes involved in premature ovarian failure with age at menopause (P = 0.025).

ALOX12 gene is associated with the onset of natural menopause in white women

OBJECTIVE

Natural menopause is a key physiological event in a woman's life. Timing of menopause affects risk for many postmenopausal systemic disorders and may thus influence life expectancy. Age at natural menopause (ANM) is largely determined genetically, but a list of candidate genes is far from complete. This study investigated the ALOX12 gene for its possible association with ANM.

METHODS

Six single-nucleotide polymorphisms (SNPs) of the gene (rs9904779, rs2073438, rs11571340, rs434473, rs2307214, and rs312462) were genotyped in a random sample of 210 unrelated white women. The SNPs and common haplotypes were then analyzed for their association with ANM. Smoking, alcohol consumption, and duration of breast-feeding were used as covariates.

RESULTS

Two SNPs, rs9904779 and rs434473 (encodes a replacement of asparagine by serine in the protein), were significantly associated with ANM (P = 0.022 and 0.033, respectively). The minor alleles of both SNPs seem to promote about 1.3- to 1.5-year earlier menopause and confer a 1.6 to 1.8 times higher risk for early menopause. All SNPs indicated significant or nearly significant interactions with alcohol use and duration of breast-feeding. Five common haplotypes were also associated with ANM.

CONCLUSIONS

The ALOX12 gene seems to be associated with the timing of natural menopause in white women.

Multigenic combination of estrogen-related genes is associated with age at natural menopause in a Spanish population

Objective

Age at natural menopause (ANM) can be considered a complex parameter that depends on the interaction of multiple factors. In the present study, the role of interaction between genetic variants within estrogen synthesis and signalling pathways in the ANM in Spanish women is studied.

Material and methods

Nine single nucleotide polymorphisms (SNPs) located at different candidate genes related to the estrogen signalling pathway were analysed in 1980 Spanish postmenopausal women.

Results

Independently, none of the nine markers were significantly associated with early ANM. Only heterozygosis at the NRIP rs2229741 locus could be associated with early menopause; however, this marker does not maintain statistical significance. In contrast, linear regression analysis suggests several epistatic interactions including these markers in relation to ANM, especially between ESR2, NRIP1 and BMP15. The genetic variant that appears most in these interactions is that of the BMP15 rs3897937. It was observed that AA-TC combined genotype for NRIP-BMP15 (rs3897937), respectively, appears to be associated with a lower ANM than other possible combinations of these SNP (46.1±5.9 versus 50.4±3.3; P = 0.002). In the multilocus analysis, the multigenic interaction formed by ESR2 (AA), BMP15 rs3897937 (TC) and NRIP1 (AA) has the lower ANM (45.37±6.8 versus 48.69±5; P = 0.038).

Conclusions

The results suggest that epistatic interactions of estrogen-related alleles may contribute to variance in ANM in Spanish women. Moreover, BMP15 and NRIP1 also appear as attractive candidate genes for premature menopause but require further investigation to confirm them.

Association study of the oestrogen signalling pathway genes in relation to age at natural menopause

Genetic factors play a significant role in influencing the variation of age at natural menopause (AANM). Estrogen receptor beta (ESR2), is an important factor in the mechanism of action of estrogen, while the aromatase gene (CYP19) and the 17-alpha-hydroxylase gene (CYP17) are involved in the biosynthesis of estrogen. We tested whether polymorphisms of ESR2, CYP19 and CYP17 genes are associated with AANM in Caucasian females. A total of 52 SNPs (17 for ESR2, 28 for CYP19, and 7 for CYP17) were successfully genotyped for 229 Caucasian women having experienced natural menopause. Comprehensive statistical analyses focusing on the association of these genes with AANM were conducted. The effects of age, height and age at menarche on AANM were adjusted when conducting association analyses. We found that six SNPs (2, 6-7, 9, 13 and 16) within ESR2 were not significantly associated with AANM after Bonferroni correction. However, two blocks of ESR2 were associated with AANM. For CYP19, two SNPs (24 and 27) were nominally associated with AANM. No significant association was observed between CYP17 and AANM. Our results suggest that genetic variation in the ESR2 and CYP19 genes may influence the variation in AANM in Caucasian women.