The role of AMH and its receptor SNP in the pathogenesis of PCOS

Anti-Müllerian hormone: biology and role in endocrinology and cancers

Anti-Müllerian hormone (AMH) is a peptide belonging to the transforming growth factor beta superfamily and acts exclusively through its receptor type 2 (AMHR2). From the 8th week of pregnancy, AMH is produced by Sertoli cells, and from the 23rd week of gestation, it is produced by granulosa cells of the ovary. AMH plays a critical role in regulating gonadotropin secretion, ovarian tissue responsiveness to pituitary hormones, and the pathogenesis of polycystic ovarian syndrome. It inhibits the transition from primordial to primary follicles and is considered the best marker of ovarian reserve. Therefore, measuring AMH concentration of the hormone is valuable in managing assisted reproductive technologies. AMH was initially discovered through its role in the degeneration of Müllerian ducts in male fetuses. However, due to its ability to inhibit the cell cycle and induce apoptosis, it has also garnered interest in oncology. For example, antibodies targeting AMHR2 are being investigated for their potential in diagnosing and treating various cancers. Additionally, AMH is present in motor neurons and functions as a protective and growth factor. Consequently, it is involved in learning and memory processes and may support the treatment of Alzheimer's disease. This review aims to provide a comprehensive overview of the biology of AMH and its role in both endocrinology and oncology.

Puberty classifications in beef heifers are moderately to highly heritable and associated with candidate genes related to cyclicity and timing of puberty

Introduction: Pubertal attainment is critical to reproductive longevity in heifers. Previously, four heifer pubertal classifications were identified according to attainment of blood plasma progesterone concentrations > 1 ng/ml: 1) Early; 2) Typical; 3) Start-Stop; and 4) Non-Cycling. Early and Typical heifers initiated and maintained cyclicity, Start-Stop started and then stopped cyclicity and Non-Cycling never initiated cyclicity. Start-Stop heifers segregated into Start-Stop-Discontinuous (SSD) or Start-Stop-Start (SSS), with SSD having similar phenotypes to Non-Cycling and SSS to Typical heifers. We hypothesized that these pubertal classifications are heritable, and loci associated with pubertal classifications could be identified by genome wide association studies (GWAS). Methods: Heifers (n = 532; 2017 - 2022) genotyped on the Illumina Bovine SNP50 v2 or GGP Bovine 100K SNP panels were used for variant component estimation and GWAS. Heritability was estimated using a univariate Bayesian animal model. Results: When considering pubertal classifications: Early, Typical, SSS, SSD, and Non-Cycling, pubertal class was moderately heritable (0.38 ± 0.08). However, when heifers who initiated and maintained cyclicity were compared to those that did not cycle (Early+Typical vs. SSD+Non-Cycling) heritability was greater (0.59 ± 0.19). A GWAS did not identify single nucleotide polymorphisms (SNPs) significantly associated with pubertal classifications, indicating puberty is a polygenic trait. A candidate gene approach was used, which fitted SNPs within or nearby a set of 71 candidate genes previously associated with puberty, PCOS, cyclicity, regulation of hormone secretion, signal transduction, and methylation. Eight genes/regions were associated with pubertal classifications, and twenty-two genes/regions were associated with whether puberty was attained during the trial. Additionally, whole genome sequencing (WGS) data on 33 heifers were aligned to the reference genome (ARS-UCD1.2) to identify variants in FSHR, a gene critical to pubertal attainment. Fisher's exact test determined if FSHR SNPs segregated by pubertal classification. Two FSHR SNPs that were not on the bovine SNP panel were selected for additional genotyping and analysis, and one was associated with pubertal classifications and whether they cycled during the trial. Discussion: In summary, these pubertal classifications are moderately to highly heritable and polygenic. Consequently, genomic tools to inform selection/management of replacement heifers would be useful if informed by SNPs associated with cyclicity and early pubertal attainment.

Association of AMH and AMHR2 gene polymorphisms with ovarian response and pregnancy outcomes in Indian women

PURPOSE

To evaluate the association of single-nucleotide polymorphisms (SNPs) in the anti-Müllerian hormone (AMH) and AMH type II receptor (AMHR2) genes with ovarian response and clinical pregnancy outcomes in women undergoing controlled ovarian hyperstimulation.

METHODS

In this prospective study, we genotyped AMH polymorphisms (c. -649 T > C, c. 146 T > G, c. 252 G > A, and c. 303 G > A) in 365 women and AMHR2 polymorphisms (c. -482 A > G, c. 622-6 C > T, c. 4952 G > A, c. 10 A > G) in 80 women undergoing controlled ovarian hyperstimulation for IVF.

RESULTS

Higher doses of exogenous FSH and lower numbers of preovulatory follicles were noted in women having AMH c. -649 T > C and AMH c. -146 T > G polymorphisms, respectively. Overall, we found that the presence of a polymorphic genotype (homozygous or heterozygous) at positions c. -649 T > C, c. 146 T > G, c. 252 G > A, and c. 303 G > A in the AMH gene was associated with higher doses of FSH for ovulation induction (p < 0.001). Interestingly, a higher live birth rate was noted in women with a homozygous polymorphic genotype for all four AMH SNPs investigated while none of the women showing a homozygous polymorphic genotype at all AMHR2 SNPs investigated in this study had a live birth.

CONCLUSION

Our results show that presence of AMHR2 SNPs (c. 482 A > G, c. 622-6 C > T, c. 4952 G > A, and c. 10 A > G) negatively correlate with live birth rate. However, these findings need to be validated by using larger sample size.

An update on polycystic ovary syndrome: A review of the current state of knowledge in diagnosis, genetic etiology, and emerging treatment options

Polycystic ovary syndrome is the most common endocrine disorder in women of reproductive age, which is still incurable. However, the symptoms can be successfully managed with proper medication and lifestyle interventions. Despite its prevalence, little is known about its etiology. In this review article, the up-to-date diagnostic features and parameters recommended on the grounds of evidence-based data and different guidelines are explored. The ambiguity and insufficiency of data when diagnosing adolescent women have been put under special focus. We look at some of the most recent research done to establish relationships between different gene polymorphisms with polycystic ovary syndrome in various populations along with the underestimated impact of environmental factors like endocrine-disrupting chemicals on the reproductive health of these women. Furthermore, the article concludes with existing treatments options and the scopes for advancement in the near future. Various therapies have been considered as potential treatment through multiple randomized controlled studies, and clinical trials conducted over the years are described in this article. Standard therapies ranging from metformin to newly found alternatives based on vitamin D and gut microbiota could shine some light and guidance toward a permanent cure for this female reproductive health issue in the future.

Effect of lncRNA MALAT1 on the Granulosa Cell Proliferation and Pregnancy Outcome in Patients With PCOS

Follicle arrest is one of the main characteristics of polycystic ovary syndrome (PCOS), the most common endocrinological disorder in reproductive-aged women. Increasing evidence proves that high anti-Mullerian hormone (AMH) levels may play an important role in follicular development. Long noncoding RNA (lncRNA) with a length of more than 200 nt is widely involved in the directional differentiation, growth, and development of cells, whereas whether lncRNA is involved in AMH's role in follicular development is unknown. In this study, we analyzed lncRNA expression in ovarian granulosa cells (GCs) collected from women with and without PCOS via high-throughput sequencing. The results showed that a total of 79 noncoding transcripts were differently expressed in GCs of PCOS patients, including upregulated lncRNA MALAT1. The upregulation of MALAT1 was further confirmed by RT-qPCR in GCs from a larger cohort of PCOS patients. Furthermore, knockdown MALAT1 can promote the proliferation of KGN cell in vitro. These data suggested a role for MALAT1 in the development of PCOS. Meanwhile, MALAT1 and phosphorylated SMAD 1/5 (Ser463/465) protein were upregulated in KGN cells after exogenous AMH stimulation, which identified AMH perhaps as a regulator for the expression of MALAT1. We also found that MALAT1 can predict clinical pregnancy outcome to a certain extent by ROC curve analysis (area: 0.771, p = 0.007, 95% CI: 0.617-0.925, sensitivity: 57.1%, specificity: 91.7%). Thus, our findings revealed a role of lncRNA MALAT1 in inhibiting granulosa cell proliferation and may be correlated with pregnancy outcome in PCOS.

Association between polymorphisms rs2228001 and rs2228000 in XPC and genetic susceptibility to preeclampsia: a case control study

BACKGROUND

Xeroderma pigmentosum complementation group C (XPC) is a DNA damage recognition protein that plays an important role in nucleotide excision repair and can reduce oxidative stress, which may be involved in the development of preeclampsia (PE). Therefore, the aim of this study was to explore whether XPC polymorphisms were relevant to the genetic susceptibility to PE in Chinese Han women.

METHOD

A total of 1276 healthy pregnant women were included as the control group and 958 pregnant women with PE as the case group. DNA was extracted from peripheral blood samples to perform genotyping of loci rs2228001 and rs2228000 in XPC through real-time quantitative polymerase chain reaction (PCR). The relationship between XPC and susceptibility to PE was evaluated by comparing the genotypic and allelic frequencies between the two groups of pregnant women.

RESULTS

Polymorphism of rs2228000 may be associated with PE risk and allele T may play a protective role (genotype, χ2 = 38.961, P < 0.001 and allele χ2 = 21.746 P < 0.001, odds ratio (OR) = 0.885, 95% confidence interval (CI) = 0.840-0.932). No significant difference was found between the two groups in rs2228001,(genotype χ2 = 3.148, P = 0.207 and allele χ2 = 0.59, P = 0.442, OR = 1.017, 95% CI = 0.974-1.062). When the frequencies of genotypes and alleles for early- and late-onset PE, mild PE and severe PE were compared with those of controls, the results were consistent with the large clinical sample.

CONCLUSION

Our data suggest that the genetic variant rs2228000 in XPC may be associated with PE risk in Chinese Han women, and that pregnant women with the TT genotype have a reduced risk of PE. Further investigations are needed to confirm these findings in other regions or larger prospective populations.

Anti-Müllerian Hormone in Female Reproduction

Anti-Müllerian hormone (AMH), also called Müllerian inhibiting substance, was shown to be synthesized by the ovary in the 1980s. This article reviews the main findings of the past 20 years on the regulation of the expression of AMH and its specific receptor AMHR2 by granulosa cells, the mechanism of action of AMH, the different roles it plays in the reproductive organs, its clinical utility, and its involvement in the principal pathological conditions affecting women. The findings in respect of regulation tell us that AMH and AMHR2 expression is mainly regulated by bone morphogenetic proteins, gonadotropins, and estrogens. It has now been established that AMH regulates the different steps of folliculogenesis and that it has neuroendocrine effects. On the other hand, the importance of serum AMH as a reliable marker of ovarian reserve and as a useful tool in the prediction of the polycystic ovary syndrome (PCOS) and primary ovarian failure has also been acknowledged. Last but not least, a large body of evidence points to the involvement of AMH in the pathogenesis of PCOS.

Transcriptome Profiling of Oocytes at the Germinal Vesicle Stage from Women from Mongolia with Polycystic Ovary Syndrome

Background

Polycystic ovary syndrome (PCOS) is one of the most common endocrine disorders. Evidence indicates that genetic and environmental factors contribute to the pathogenesis of PCOS. The molecular basis of PCOS is not well understood.

Methods

Whole-genome RNA sequencing was performed on single oocyte at the germinal vesicle (GV) stage from females with normal ovulation and females with PCOS. All subjects were women from Mongolia undergoing intracytoplasmic sperm injection in vitro fertilization (ICSI-IVF) who met the Rotterdam criteria for PCOS. Women with normal ovulation who were undergoing ICSI-IVF owing to male factor infertility were recruited as control subjects.

Results

A total of 1313 differentially expressed genes were found by bio-informatics software in the GV oocytes of PCOS patients and compared with the control group. There were 367 upregulated and 946 downregulated genes (fold change > 2, false discovery rate < 0.01). When compared with the healthy controls, it was shown that the DEGs like VEGF, IGF, FADS1 et al were investigated as potential causes of PCOS oocytes. The DEGs were related to kinase activity, cell proliferation, gene regulation, and the signaling pathways of phosphatidylinositol 3-kinase, Hippo, and ECM-receptor pathway in patients with PCOS. In addition, the interconnected gene co-expression network was constructed by gene bionetwork analysis, indicating that ITGB5, ITGB3, and CAV2 were the core genes in regulating the module expression of DEGs in PCOS.

Conclusion

RNA sequencing analysis demonstrated DEGs were linked to inflammation, cardiovascular disease, and lipid metabolism in the GV oocytes of women with PCOS. We hypothesize that ITGB5, ITGB3, and CAV2 may be involved in metabolic disorders associated with the different phenotypes of PCOS.

Polycystic Ovary Syndrome and Fibrocystic Breast Disease: An Updated Review

Polycystic ovary syndrome (PCOS) is the most common hormonal disorder in women of reproductive age. There is no clear association between PCOS and benign breast disease (BBD). The latter is a frequent benign disorder, affecting women between 20 and 50 years of age. To date, the classification remains controversial, and the risk of developing breast cancer that is associated with these changes is different depending on the histopathological findings. The most frequent changes are breast cysts, which are noted in up to 50% of patients older than 30 years of age. This up-to-date review presents the relationship between PCOS and BBD. In conclusion, there is no clear association between benign breast disease and PCOS. Further studies on a large population with prospectively collected data using updated PCOS criteria are necessary.

Performance characteristics of the Mindray chemiluminescence anti-Müllerian hormone assay

BACKGROUND

The aim of this study was to define the performance characteristics of the Mindray chemiluminescence assay for anti-Müllerian hormone (AMH) detection.

DESIGNS AND METHODS

Intra-assay and total imprecision, analytical sensitivity, linearity, and interference were compared between the Mindray and Roche assays using pools of human serum according to Clinical and Laboratory Standards Institute protocols. Additionally, male and female reference intervals were established using serum specimens collected from otherwise healthy groups and patients with polycystic ovary syndrome (PCOS).

RESULTS

The intra-assay and total imprecision percent coefficients of variation for low and high AMH serum levels were 2.74%/ 3.01% and 5.41%/5.35% respectively. The limits of blank, detection, and quantitation were 0.007, 0.01, and 0.03 ng/ml, respectively. The assay displayed good linearity over the range of 0.01-23 ng/ml. The coefficient of determination (R² ) of the Mindray versus Roche assays was 0.9713 with 411 samples with AMH concentrations ranging from 0.014 to 22.1 ng/ml. The slope and intercept of the regression equation were 0.9687 and 0.3419, respectively. There was no significant interference from triglycerides (up to 3000 mg/dl), bilirubin (up to 50 mg/dl), hemoglobin (up to 500 mg/dl), or total protein (up to 10 g/dl). Reference intervals showed the expected decrease in serum AMH levels with age in healthy women and increased levels in women with PCOS.

CONCLUSION

The Mindray AMH assay demonstrated acceptable analytical performance under routine conditions and is suitable for determining AMH levels in serum samples.

Genetic Susceptibility to Joint Occurrence of Polycystic Ovary Syndrome and Hashimoto's Thyroiditis: How Far Is Our Understanding?

Polycystic ovary syndrome (PCOS) and Hashimoto’s thyroiditis (HT) are endocrine disorders that commonly occur among young women. A higher prevalence of HT in women with PCOS, relative to healthy individuals, is observed consistently. Combined occurrence of both diseases is associated with a higher risk of severe metabolic and reproductive complications. Genetic factors strongly impact the pathogenesis of both PCOS and HT and several susceptibility loci associated with a higher risk of both disorders have been identified. Furthermore, some candidate gene polymorphisms are thought to be functionally relevant; however, few genetic variants are proposed to be causally associated with the incidence of both disorders together.

Administration of a VIP-antagonist in vivo modifies ovarian hormone secretion in a rat model with polycystic ovary syndrome

AIMS

In the cyclic rat in estrus, the vasoactive intestinal peptide (VIP) has an impact on ovarian function, which depends on the endocrine status of the animal. In this work, we aimed to clarify the participation of VIP in the pathophysiological condition of polycystic ovary syndrome (PCOS) using a model of PCOS induced by estradiol valerate (EV-PCOS) in rats.

MAIN METHODS

In the cyclic rat in estrus and in the EV-PCOS model, we analyzed the acute effects of blocking VIP receptors with the use of an antagonist (Ant-VIP) injected into the left or right ovarian bursa on the steroidogenic response and ovarian catecholamine levels.

KEY FINDINGS

In the cyclic animal in estrus, the treatment with Ant-VIP in the left ovarian bursa resulted in a reduction in testosterone serum levels and in ovarian levels of dopamine and 3,4-dihydroxyphenylacetic acid (DOPAC), without changes in 4-hydroxy-3-methoxyphenyl (MHPG) and norepinephrine (NE). When the treatment was applied on the right side, only MHPG levels increased. In the EV-PCOS model, the treatment with Ant-VIP in the left ovarian bursa increased testosterone, estradiol, MHPG, and NE levels. When the treatment was performed on the right side, progesterone levels decreased and estradiol increased, without changes in ovarian catecholamines.

SIGNIFICANCE

The binding of VIP to its receptors differentially regulates steroidogenesis in the cyclic animal in estrus and in the EV-PCOS model. The blocking of VIP signaling produces changes in ovarian catecholamines.

Anti-Müllerian hormone level is associated with vitamin D receptor polymorphisms in women with polycystic ovary syndrome

Objective

Our study aimed to investigate the relationship between polymorphisms (Apa1, Bsm1, Fok1, and Cdx2) in the VDR gene as well as AMH and AMHR2 genes and their influence on AMH and 25(OH)D levels in PCOS women.

Study design

Seventy-five patients with PCOS and 23 control women were included. Serum AMH and 25(OH)D levels in patients and controls were measured by enzyme-linked immunosorbent assay (ELISA). Polymorphisms in VDR gene Fok1 C/T (rs2228587), Bsm1 A/G (rs1544410), Apa1 A/C (rs7975232), and Cdx2 A/G (rs11568820) polymorphisms as well as AMH G/T (rs10407022) and AMHR2 A/G (rs2002555) were analyzed using real-time PCR.

Results

Analysis of the VDR Cdx2 polymorphism showed a significantly higher frequency of the homozygous GG (mutant) genotype in the PCOS group as compared with the control group (p < 0.05). The analysis revealed a statistically significant correlation between the presence of FokI and ApaI polymorphisms and AMH levels in PCOS women (p < 0.05). The presence of mutant genotypes (CT, TT) in the Fok1 and (CA, CC) in the Apa1 polymorphisms were associated with higher AMH level in PCOS women (p < 0.05). No statistically significant correlations between AMH and AMHR2 polymorphisms and AMH level were found. Moreover, there was no correlation between AMH and 25(OH)D levels in the PCOS or in the control group.

Conclusion

It seems that the elevated AMH level is associated with VDR Fokl and Apal polymorphisms, but not with 25(OH)D levels in PCOS women. Further research is needed to determine the role of VDR polymorphism in AMH level in PCOS.

Anti-Müllerian Hormone Expression in Endometrial Cancer Tissue

Anti-Müllerian hormone (AMH) is a commonly known factor secreted by Sertoli cells, responsible for regression of the Müllerian ducts in male fetuses. AMH has also other functions in humans. In vivo and in vitro studies have shown that AMH inhibits cell cycle and induces apoptosis in cancers with AMH receptors. The aim of the study was to assess whether the tissue of pre-cancerous states of endometrium (PCS) and various histopathologic types of endometrial cancer (EC) exhibit the presence of AMH. We aimed to investigate whether the potential presence of the protein concerns menopausal women or those regularly menstruating, and whether is related to cancers with a good or a bad prognosis, as well as what other factors may influence AMH expression. The undertaken analysis was carried out on tissues retrieved from 232 women who underwent surgical treatment for PCS and EC. Tissues were prepared for immunohistochemical assessment with the use of a tissue microarrays method. AMH expression was confirmed in 23 patients with well differentiated endometrioid adenocarcinoma (G1), moderately differentiated endometrioid adenocarcinoma (G2), clear cell carcinoma (CCA) and nonatypical hyperplasia. AMH was not found in EC tissues in regularly menstruating women. An appropriately long mean period of breastfeeding in line with a prolonged period of hormonal activity had a positive effect on AMH expression. Our results may suggest that AMH is a factor which protects the organism against cancer, and should be further investigated as a potential prognosis marker and a therapeutic agent.

Anti-Müllerian Hormone Gene Polymorphism is Associated with Clinical Pregnancy of Fresh IVF Cycles

The aim of this study was to examine the effects of single-nucleotide polymorphisms (SNPs) in the anti-Müllerian hormone (AMH) and AMH type II receptor (AMHRII) genes on in vitro fertilization (IVF) outcomes. In this prospective cohort study, we genotyped the AMH 146 T > G, AMHRII −482 A > G and AMHRII IVS1 +149 T > A variants in 635 women undergoing their first cycle of controlled ovarian stimulation for IVF. DNA was extracted from the peripheral blood of all participants, and the SNPs were genotyped by real-time polymerase chain reaction. The distributions, frequencies of genes, and correlation with clinical pregnancy of IVF were analyzed. The AMH 146 T > G G/G genotype in women was associated with a lower clinical pregnancy rate (T/T: 55.0%, T/G: 51.8%, G/G: 40.0%; p < 0.05). Women with the AMH 146 T > G GG genotype were half as likely to have a clinical pregnancy compared with women with TT genotypes (OR = 0.55, 95% CI: 0.34–0.88, p = 0.014). With multivariate analysis, the AMH 146 T > G GG genotype remains as a significant independent factor to predict clinical pregnancy (p = 0.014). No significant difference was found between AMHRII polymorphisms and clinical pregnancy outcomes of IVF. In conclusion, our results show that AMH 146 T > G seems to be a susceptibility biomarker capable of predicting IVF pregnancy outcomes. Further studies should focus on the mechanism of these associations and the inclusion of other ethnic populations to confirm the findings of this study.

Clinical application of serum anti-Müllerian hormone as an ovarian reserve marker: A review of recent studies

It has been more than 15 years since the measurement of serum anti-Müllerian hormone (AMH) first allowed the quantitative assessment of ovarian reserve. Meanwhile, the clinical implication of serum AMH has been expanding. The measurement of serum AMH has been applied in various clinical fields, including assisted reproduction, menopause, reproductive disorders and assessment of ovarian damage/toxicity. Well-known findings about the usefulness of serum AMH revealed by numerous studies executed in the early era include decline with aging, a good correlation with oocyte yield in assisted reproduction, upregulation in polycystic ovarian syndrome and a decrease on ovarian surgery and toxic treatment. More intensive research, including a meta-analysis, cutting-edge clinical trial and advances in AMH assays, has yielded newer findings and firmer clinical interpretations in serum AMH in the past few years. Variations in the AMH decline trajectory in the general population do not support the accurate prediction of menopause. The ability to predict pregnancy in infertility treatment and natural conception is poor, while a nomogram integrating serum AMH as a stimulation protocol is useful for avoiding poor and/or hyper-responses. On the other hand, improvements in measuring very low concentrations of serum AMH may be capable of distinguishing women with poor ovarian function. Age-independent standardization of AMH values may be helpful for comparing ovarian reserves among women at different ages.

A homozygous mutation of GNRHR in a familial case diagnosed with polycystic ovary syndrome

CONTEXT

PCOS is a heterogeneous condition characterized by hyperandrogenism and chronic anovulation and affects about 10% of women. Its etiology is poorly known, but a dysregulation of gonadotropin secretion is one of its hallmarks.

OBJECTIVE

As the etiology of PCOS is unclear, we have performed a genome-wide analysis of a consanguineous family with three sisters diagnosed with PCOS.

METHODS

Whole-exome sequencing and Sanger sequencing confirmation.

RESULTS

Whole-exome sequencing allowed the detection of the missense variant rs104893836 located in the first coding exon of the GNRHR gene and leading to the p.Gln106Arg (p.Q106R) substitution. Sanger sequencing of all available individuals of the family confirmed that the variant was homozygous in the three affected sisters and heterozygous in both parents.

CONCLUSIONS

This is the first description of a GNRHR gene mutation in patients diagnosed with PCOS. Although we do not exclude a possible interaction of the identified variant with the genetic background and/or the environment, our result suggests that genetic alterations in the hypothalamo-pituitary axis may play role in the pathogenesis of PCOS.