Molecular Mechanisms of AMH Signaling

Dose-dependent role of AMH and AMHR2 signaling in male differentiation and regulation of sex determination in Spotted knifejaw (Oplegnathus punctatus) with X1X1X2X2/X1X2Y chromosome system

Sex determination mechanisms vary significantly across different chromosomal systems and evolutionary contexts. Nonetheless, the regulatory framework governing the multi-sex chromosome system (X1X1X2X2/X1X2Y) remains enigmatic. Through an examination of sex-related genes (dmrt1, hsd11b2, amh, sox9a, sox9b, foxl2, cyp19a), hormonal influences (E2, 11-KT), and histological analyses of gonadal development, we demonstrate that the critical period for sexual differentiation occurs between 35 to 60 days post-hatching (dph). Our multi-omics analysis identified amhr2 as a candidate sex-determining gene, revealing that the males possess three distinct amhr2 transcripts (amhr2ay, amhr2by, amhr2cy), whereas females express only one (amhr2a). In situ hybridization assays demonstrated that amhr2 is predominantly localized to primary spermatocyte and Sertoli cells of male testes. Notably, the specific mRNA expression of amhr2 is significantly enriched in amhr2cy, whose extracellular domain exhibits the highest binding affinity for Amh protein, with sexual expression differences manifesting as early as 5 dph. The outcomes of amhr2 interference (RNAi) experiments indicate that amhr2 knockdown leads to a reduction in the expression of male-related gene (dmrt1, amh, sox9a, sox9b), androgen synthesis genes (hsd11b2, cyp11a), and female-related genes (wnt4, foxl2, cyp19a, cyp19b). Conversely, overexpression of amhr2 yielded contrasting results. Our research supports the role of amhr2 as a pivotal candidate sex-determining gene. Furthermore, the dosage effect of amhr2, reflected in transcript abundance, mRNA expression levels, and binding efficacy, serves as a fundamental mechanism driving male differentiation and regulatory processes in Spotted knifejaw.

A divergent two-domain structure of the anti-Müllerian hormone prodomain

TGFβ family ligands are synthesized as precursors consisting of an N-terminal prodomain and C-terminal growth factor (GF) signaling domain. After proteolytic processing, the prodomain typically remains noncovalently associated with the GF, sometimes forming a high-affinity latent procomplex that requires activation. For the TGFβ family ligand anti-Müllerian hormone (AMH), the prodomain maintains a high-affinity interaction with its GF that does not render it latent. While the prodomain can be displaced by the type II receptor, AMHR2, the nature of the GF:prodomain interaction and the mechanism of prodomain displacement by AMHR2 are currently unknown. We show here that the AMH prodomain exhibits an atypical two-domain structure, containing a dimerizing and a GF-binding domain connected through a flexible linker. Cryo-EM and genomic analyses show that the distinctive GF-binding domain, the result of an exon insertion 450 Mya, comprises a helical bundle and a belt-like structure which interact with the GF at the type II and I receptor binding sites, respectively. The dimerizing domain, which adopts a TGFβ-like propeptide fold, covalently connects two prodomains through intermolecular disulfide bonds. Disease mutations map to both the GF-binding and dimerization domains. Our results support a model where AMHR2 displaces the helical bundle and induces a conformational change in the GF, followed by release of the prodomain and engagement of the type I receptor. Collectively, this study shows that the AMH prodomain has evolved an atypical binding interaction with the GF that favors, without disrupting signaling, the maintenance of a noncovalent complex until receptors are engaged.

Identification of a functional vitamin D response element in the promoter of goose anti-Müllerian hormone gene

Anti-Müllerian hormone (AMH) plays an important role in avian ovarian follicle development. The high mRNA expression of AMH in avian ovarian prehierarchical follicles helps prevent premature granulosa cell differentiation. Vitamin D3 was reported to downregulate AMH mRNA expression in granulosa cells of prehierarchical follicles in hens; however, the underlying molecular mechanism remains unknown. In this study, AMH mRNA expression was investigated in granulosa cells of prehierarchical follicles in geese under vitamin D3 induction. A potential vitamin D response element (VDRE) present in the goose AMH promoter was identified using luciferase activity, electrophoretic mobility shift assay (EMSA), and chromatin immunoprecipitation (ChIP) assays. The results showed that AMH mRNA expressions were downregulated by vitamin D3 in granulosa cells of prehierarchical follicles in geese. A classical VDRE-like sequence was identified in the goose AMH promoter by in silico analyses. Luciferase activity assays revealed that the putative VDRE is a negative regulatory element. Vitamin D receptor (VDR) and retinoic X receptor (RXR) are necessary to decrease the AMH promoter activity induced by vitamin D3. The EMSA and ChIP assays demonstrated that the VDR/RXR complex directly binds to the putative VDRE. These results suggest that vitamin D3 downregulates AMH mRNA expression via a functional VDRE that binds the VDR/RXR heterodimer in goose ovarian prehierarchical follicles. These results provide new insights into the regulatory mechanisms of vitamin D3 in avian ovarian follicular development.

Assessment of ovarian reserve function in patients with adenomyosis and ovarian endometriosis by three-dimensional transvaginal ultrasound and Anti-Müllerian hormone

We evaluated the impact of adenomyosis and ovarian endometriosis on ovarian reserve function through transvaginal three-dimensional ultrasound and anti-mullerian hormone testing. A total of 150 female patients who were admitted to our hospital from January 2023 to May 2024 were selected; 58 cases had adenomyosis (adenomyosis group), 36 had ovarian endometriosis (ovarian endometriosis group), and 56 were healthy (healthy group). There were no statistically significant differences in clinical baseline data among the three groups (all P > 0.05). However, significant overall differences were found in anti-Mullerian hormone levels, antral follicle count, ovarian volume, vascularization index, flow index, and vascularization flow index among the three groups (F values were 90.34, 146.50, 92.61, 63.87, 59.50, 49.36 respectively; all P < 0.001); compared to the healthy group, these indicators were all decreased in the adenomyosis group and ovarian endometriosis group (all P < 0.05). Pearson correlation analysis revealed that serum anti-mullerian hormone levels were positively correlated with antral follicle count, ovarian volume, vascularization index, flow index, and vascularization flow index (r = 0.80, 0.73, 0.50, 0.48, 0.45, respectively; all P < 0.01). These data suggest that adenomyosis and ovarian endometriosis can lead to a decline in ovarian reserve function in women of reproductive age compared to their peers. Also, antral follicle count and ovarian volume are the optimal indicators for evaluating ovarian reserve function in these patients.

PCOS Influences the Expression of AMHRII in the Endometrium of AEH During the Reproductive Age

BACKGROUND

Endometrial proliferative lesions (EPLs) encompass endometrial hyperplasia (EH) and endometrial carcinoma (EC). Atypical endometrial hyperplasia (AEH) is associated with an elevated risk of progression to EC. Patients with polycystic ovarian syndrome (PCOS) exhibit higher serum levels of anti-Müllerian hormone (AMH) and a correspondingly increased incidence of EPLs. AMH has the capacity to inhibit the cell proliferation of EPLs derived from Müllerian duct tissue through the AMH-AMH receptor (AMHR) signaling pathway.

METHODS

Pairs of samples matched by preference scores were randomly selected. Immunohistochemistry was employed to assess the expression levels of AMHR type II (AMHR2) in endometrial tissue. A comparative analysis was performed between tissues from individuals with PCOS and those without, as well as between a normal endometrium and endometrial tissue from individuals with EPLs. This study aimed to elucidate differences in AMHR2 expression among these tissue types. By focusing on AMHR2 expression, the impact of the PCOS-related background on the endometrial AMH-AMHR cascade signaling pathway was initially investigated.

RESULTS

The AMHR2 protein was expressed in the endometrium of both the PCOS group and the non-PCOS group during the reproductive age (20-39 years). The expression of the AMHR2 protein in the AEH endometrium of PCOS patients did not differ significantly from that in the normal endometrium of PCOS patients; however, it was significantly higher than in the AEH endometrium of non-PCOS patients (p = 0.011). Conversely, the expression of the AMHR2 protein in the AEH endometrium of non-PCOS patients was significantly lower than that in the normal endometrium of non-PCOS patients (p = 0.021). Notably, there was no significant difference in AMHR2 protein expression in a normal endometrium between PCOS and non-PCOS patients.

CONCLUSIONS

The involvement of the endometrial AMH-AMHR cascade signaling pathway and its biological effects in the pathogenesis of AEH are evident. The pathophysiological conditions associated with PCOS, such as elevated serum AMH levels and other pathological states, may directly or indirectly influence the AMH-AMHR cascade signaling pathway in the endometrium. This influence could contribute to the progression of AEH.

Role of epigenetic regulation in diminished ovarian reserve

Diminished ovarian reserve (DOR) is characterized by a decrease in the number and quality of oocytes, with its incidence increasing annually. Its pathogenesis remains unclear, making it one of the most challenging problems in the field of assisted reproduction. Epigenetic modification, a molecular mechanism affecting genomic activity and expression without altering the DNA sequence, has been widely studied in reproductive medicine and has attracted considerable attention regarding DOR. This review comprehensively examines the various epigenetic regulatory changes in ovarian granulosa cells (OGCs) and oocytes during DOR. DNA methylation plays a crucial role in regulating granulosa cell function, hormone production, and oocyte development, maturation, and senescence. Histone modifications are involved in regulating follicular activation, while non-coding RNAs, such as long noncoding RNAs (lncRNAs) and microRNAs (miRNAs), regulate granulosa cell function and oocyte development. N6-methyladenosine (m6A) modifications are associated with age-related oocyte senescence. Epigenetic clocks based on DNA methylation show potential in predicting ovarian reserve in DOR. Furthermore, it discusses the potential for utilizing epigenetic mechanisms to better diagnose and manage DOR.

Persistent Müllerian Duct Syndrome with Supernumerary Testicles Due to a Novel Homozygous Variant in the AMHR2 Gene and Literature Review

Introduction: Persistent Müllerian duct syndrome (PMDS) is a rare disorder of sex development (DSD) caused by mutations in the genes coding anti-Müllerian hormone (AMH) or the AMH receptor, characterized by the persistence of Müllerian derivatives, the uterus and/or fallopian tubes, in otherwise normally virilized boys. Testicular regression syndrome is common in PMDS, yet the association with supernumerary testis has been reported in only two patients where genetic testing was not performed. Method: Thus, we report an individual with this particular association caused by a previously unreported homozygous variant in the AMHR2 gene to enable future genotype-phenotype correlations in this rare disorder. In addition, a search of PMDS associated with congenital anomalies reported in the literature was performed to provide a comprehensive overview of this pathology. Results: We present the case of a 13-year-old boy with a history of bilateral cryptorchidism. Two attempts of right orchidopexy were performed at the age of 4 and 5 years. At that time, exploratory laparoscopy identified an intra-abdominal left testicle. In addition, a fibrous structure extending from the left intra-abdominal testicle to the deep inguinal ring (Müllerian duct remnants) and a medially located abdominal mass, bilaterally fixated to the parietal peritoneum (uterine remnant), were detected. The left testicular biopsy revealed immature prepubertal testicular tissue. The uterine remnant was dissected and removed and the left orchidopexy was performed. The karyotype was 46, XY without other numerical or structural chromosomal abnormalities. Reinterventions on the left testicle were performed at the age of 9 and 12 years when a testicular remnant was identified in the left inguinal canal and removed. Three months after left orchidectomy, ultrasound followed by abdominopelvic MRI identified a structure resembling a testis in the left inguinal area. Another surgical exploration was performed, and a mass located outside (lateral) the inguinal canal was found. A biopsy from the suspected mass was performed. The histopathologic examination showed characteristics of immature prepubertal testis. The patient was later referred to our clinic with the suspicion of DSD. Serum AMH and inhibin B were normal. Therefore, the diagnosis of PMDS was suspected. Genetic testing was performed using next-generation sequencing in a gene panel that included AMH and AMHR2 genes. A homozygous variant classified as likely pathogenic in the AMHR2 gene was identified but remains unreported in the literature (NC_000012.11:g.53823315T>C in exon 8 of the AMHR2 gene). Conclusions: A high degree of suspicion and awareness is needed to diagnose this condition in order to avoid iterative surgery. The coexistence of two extremely rare conditions (PMDS and supernumerary testes) has been reported previously in only two patients, yet the association could have a common pathophysiologic background. Our case, reporting a novel AMHR2 variant, highlights the importance of genetic testing in these individuals in order to elucidate a possible genotype-phenotype correlation.

AMH regulates a mosaic population of AMHR2-positive cells in the ovarian surface epithelium

The function and homeostasis of the mammalian ovary depend on complex paracrine interactions between multiple cell types. Using primary mouse tissues and isolated cells, we showed in vitro that ovarian follicles secrete factor(s) that suppresses the growth of ovarian epithelial cells in culture. Most of the growth suppressive activity was accounted for by Anti-Mullerian Hormone/Mullerian Inhibitory Substance (AMH/MIS) secreted by granulosa cells of the follicles, as determined by immune depletion experiments. Additionally, conditioned medium from granulosa cells from wild-type control, but not AMH knockout, suppressed epithelial cell growth. Tracing of the AMH-regulated cells using AMHR2 (AMH receptor 2)-Cre:ROSA26 mutant mice indicated the presence of populations of AMHR2-positive epithelial cells on the ovarian surface and oviduct epithelia. Cells isolated from the mutant mice indicated that a subpopulation of cells marked by AMHR2-Cre:ROSA26 accounted for most cell growth and expansion in ovarian surface epithelial cells, and the AMHR2 lineage-derived cells were regulated by AMH in vitro; whereas, fewer AMHR2-Cre:ROSA26-marked cells accounted for oviduct epithelial cell outgrowth. The results reveal a paracrine pathway in maintaining follicle-epithelial homeostasis in the ovary and support a subpopulation of AMHR2 lineage marked epithelial cells as ovarian epithelial stem/progenitor cells with higher proliferative potential regulatable by follicle-secreted AMH.

Anti-Müllerian hormone type II receptor protein expression in non-small cell lung cancer and the effect of AMH/AMHR2 signaling on cancer cell proliferation

BACKGROUND

Non-small cell lung cancer (NSCLC) is the leading cause of cancer-related deaths worldwide despite advances in cancer therapeutics. In several gynecological cancers, anti-Müllerian hormone receptor type 2 (AMHR2) mediates AMH-induced growth inhibition and is expressed at high levels. Furthermore, 5%-8% of NSCLCs exhibit high AMHR2 expression, suggesting that AMH may inhibit the progression of some lung cancers. However, the clinical relevance of AMHR2 expression and its role in lung cancer is not fully clarified.

METHODS

Immunostaining was performed on 79 surgical specimens of NSCLC. The Cancer Genome Atlas RNA-seq data for lung adenocarcinoma were analyzed, and gene ontology and gene set enrichment analyses were performed. In cellular experiments, AMHR2-overexpressing NSCLC cell lines were established, and the role of the AMH-AMHR2 pathway in cell proliferation with recombinant human AMH protein treatment was examined.

RESULTS

A total of 13 cases (16.5%) were positive for immunostaining in lung adenocarcinoma tissues; no positive signals were detected in lung squamous carcinoma tissues. Gene expression variation analysis using The Cancer Genome Atlas data showed that the expression of genes related to the cell cycle was downregulated in the AMHR2-high group. Cellular experiments showed that activation of the AMH-AMHR2 pathway suppressed cell proliferation.

CONCLUSION

In lung adenocarcinoma tissues with high expression of AMHR2, activation of the AMH-AMHR2 pathway may suppress cell proliferation.

Reduced anti-Müllerian hormone levels in males with inherited bone marrow failure syndromes

Fanconi anemia (FA), dyskeratosis congenita-related telomere biology disorders (DC/TBD), and Diamond-Blackfan anemia (DBA) are inherited bone marrow failure syndromes (IBMFS) with high risks of bone marrow failure, leukemia, and solid tumors. Individuals with FA have reduced fertility. Previously, we showed low levels of anti-Müllerian hormone (AMH), a circulating marker of ovarian reserve, in females with IBMFS. In males, AMH may be a direct marker of Sertoli cell function and an indirect marker of spermatogenesis. In this study, we assessed serum AMH levels in pubertal and postpubertal males with FA, DC/TBD, or DBA and compared this with their unaffected male relatives and unrelated healthy male volunteers. Males with FA had significantly lower levels of AMH (median: 5 ng/mL, range: 1.18-6.75) compared with unaffected male relatives (median: 7.31 ng/mL, range: 3.46-18.82, P = 0.03) or healthy male volunteers (median: 7.66 ng/mL, range: 3.3-14.67, P = 0.008). Males with DC/TBD had lower levels of AMH (median: 3.76 ng/mL, range: 0-8.9) compared with unaffected relatives (median: 5.31 ng/mL, range: 1.2-17.77, P = 0.01) or healthy volunteers (median: 5.995 ng/mL, range: 1.57-14.67, P < 0.001). Males with DBA had similar levels of AMH (median: 3.46 ng/mL, range: 2.32-11.85) as unaffected relatives (median: 4.66 ng/mL, range: 0.09-13.51, P = 0.56) and healthy volunteers (median: 5.81 ng/mL, range: 1.57-14.67, P = 0.10). Our findings suggest a defect in the production of AMH in postpubertal males with FA and DC/TBD, similar to that observed in females. These findings warrant confirmation in larger prospective studies.

Differential effects of follicle-stimulating hormone glycoforms on the transcriptome profile of cultured rat granulosa cells as disclosed by RNA-seq

It has been documented that variations in glycosylation on glycoprotein hormones, confer distinctly different biological features to the corresponding glycoforms when multiple in vitro biochemical readings are analyzed. We here applied next generation RNA sequencing to explore changes in the transcriptome of rat granulosa cells exposed for 0, 6, and 12 h to 100 ng/ml of four highly purified follicle-stimulating hormone (FSH) glycoforms, each exhibiting different glycosylation patterns: a. human pituitary FSH18/21 (hypo-glycosylated); b. human pituitary FSH24 (fully glycosylated); c. Equine FSH (eqFSH) (hypo-glycosylated); and d. Chinese-hamster ovary cell-derived human recombinant FSH (recFSH) (fully-glycosylated). Total RNA from triplicate incubations was prepared from FSH glycoform-exposed cultured granulosa cells obtained from DES-pretreated immature female rats, and RNA libraries were sequenced in a HighSeq 2500 sequencer (2 x 125 bp paired-end format, 10-15 x 106 reads/sample). The computational workflow focused on investigating differences among the four FSH glycoforms at three levels: gene expression, enriched biological processes, and perturbed pathways. Among the top 200 differentially expressed genes, only 4 (0.6%) were shared by all 4 glycoforms at 6 h, whereas 118 genes (40%) were shared at 12 h. Follicle-stimulating hormone glycocoforms stimulated different patterns of exclusive and associated up regulated biological processes in a glycoform and time-dependent fashion with more shared biological processes after 12 h of exposure and fewer treatment-specific ones, except for recFSH, which exhibited stronger responses with more specifically associated processes at this time. Similar results were found for down-regulated processes, with a greater number of processes at 6 h or 12 h, depending on the particular glycoform. In general, there were fewer downregulated than upregulated processes at both 6 h and 12 h, with FSH18/21 exhibiting the largest number of down-regulated associated processes at 6 h while eqFSH exhibited the greatest number at 12 h. Signaling cascades, largely linked to cAMP-PKA, MAPK, and PI3/AKT pathways were detected as differentially activated by the glycoforms, with each glycoform exhibiting its own molecular signature. These data extend previous observations demonstrating glycosylation-dependent distinctly different regulation of gene expression and intracellular signaling pathways triggered by FSH in granulosa cells. The results also suggest the importance of individual FSH glycoform glycosylation for the conformation of the ligand-receptor complex and induced signalling pathways.

Structural Basis of Non-Latent Signaling by the Anti-Müllerian Hormone Procomplex

Most TGFβ family ligands exist as procomplexes consisting of a prodomain noncovalently bound to a growth factor (GF); Whereas some prodomains confer latency, the Anti-Müllerian Hormone (AMH) prodomain maintains a remarkably high affinity for the GF yet remains active. Using single particle EM methods, we show the AMH prodomain consists of two subdomains: a vestigial TGFβ prodomain-like fold and a novel, helical bundle GF-binding domain, the result of an exon insertion 450 million years ago, that engages both receptor epitopes. When associated with the prodomain, the AMH GF is distorted into a strained, open conformation whose closure upon bivalent binding of AMHR2 displaces the prodomain through a conformational shift mechanism to allow for signaling.

Characterization of the molecular mechanisms that govern anti-Müllerian hormone synthesis and activity

The roles of anti-Müllerian hormone (AMH) continue to expand, from its discovery as a critical factor in sex determination, through its identification as a regulator of ovarian folliculogenesis, its use in fertility clinics as a measure of ovarian reserve, and its emerging role in hypothalamic-pituitary function. In light of these actions, AMH is considered an attractive therapeutic target to address diverse reproductive needs, including fertility preservation. Here, we set out to characterize the molecular mechanisms that govern AMH synthesis and activity. First, we enhanced the processing of the AMH precursor to >90% by introducing more efficient proprotein convertase cleavage sites (RKKR or ISSRKKRSVSS [SCUT]). Importantly, enhanced processing corresponded with a dramatic increase in secreted AMH activity. Next, based on species differences across the AMH type II receptor-binding interface, we generated a series of human AMH variants and assessed bioactivity. AMHSCUT potency (EC50 4 ng/mL) was increased 5- or 10-fold by incorporating Gln484 Met/Leu535 Thr (EC50 0.8 ng/mL) or Gln484 Met/Gly533 Ser (EC50 0.4 ng/mL) mutations, respectively. Furthermore, the Gln484 Met/Leu535 Thr double mutant displayed enhanced efficacy, relative to AMHSCUT . Finally, we identified residues within the wrist pre-helix of AMH (Trp494 , Gln496 , Ser497 , and Asp498 ) that likely mediate type I receptor binding. Mutagenesis of these residues generated gain- (Trp494 Phe or Gln496 Leu) or loss- (Ser497 Ala) of function AMH variants. Surprisingly, combining activating type I and type II receptor mutations only led to modest additive increases in AMH potency/efficacy. Our study is the first to characterize AMH residues involved in type I receptor binding and suggests a step-wise receptor-complex assembly mechanism, in which enhancement in the affinity of the ligand for either receptor can increase AMH activity beyond the natural level.

SMAD signaling pathway is disrupted by BPA via the AMH receptor in bovine granulosa cells†

Significant events that determine oocyte competence occur during follicular growth and oocyte maturation. The anti-Mullerian hormone, a positive predictor of fertility, has been shown to be affected by exposure to endocrine disrupting compounds, such as bisphenol A and S. However, the interaction between bisphenols and SMAD proteins, mediators of the anti-Mullerian hormone pathway, has not yet been elucidated. AMH receptor (AMHRII) and downstream SMAD expression was investigated in bovine granulosa cells treated with bisphenol A, bisphenol S, and then competitively with the anti-Mullerian hormone. Here, we show that 24-h bisphenol A exposure in granulosa cells significantly increased SMAD1, SMAD4, and SMAD5 mRNA expression. No significant changes were observed in AMHRII or SMADs protein expression after 24-h treatment. Following 12-h treatments with bisphenol A (alone or with the anti-Mullerian hormone), a significant increase in SMAD1 and SMAD4 mRNA expression was observed, while a significant decrease in SMAD1 and phosphorylated SMAD1 was detected at the protein level. To establish a functional link between bisphenols and the anti-Mullerian hormone signaling pathway, antisense oligonucleotides were utilized to suppress AMHRII expression with or without bisphenol exposure. Initially, transfection conditions were optimized and validated with a 70% knockdown achieved. Our findings show that bisphenol S exerts its effects independently of the anti-Mullerian hormone receptor, while bisphenol A may act directly through the anti-Mullerian hormone signaling pathway providing a potential mechanism by which bisphenols may exert their actions to disrupt follicular development and decrease oocyte competence.

Anti-Müllerian Hormone promotes human osteoblast differentiation and calcification by modulating osteogenic gene expression

OBJECTIVE

To investigate whether the Anti-Müllerian Hormone (AMH), an ovarian hormone belonging to the Transforming Growth Factor β superfamily, may represent a possible candidate for use as a bone anabolic factor.

METHODS

We performed in vitro studies on Human Osteoblasts (HOb) to evaluate the expression and the functionality of AMHRII, the AMH receptor type-2, and investigate the effects of exogenous AMH exposure on osteogenic gene expression and osteoblast functions.

RESULTS

We reported the first evidence for the expression and functionality of AMHRII in HOb cells, thus suggesting that osteoblasts may represent a specific target for exogenous AMH treatment. Furthermore, the exposure to AMH exerted a stimulatory effect on HOb cells leading to the activation of osteogenic genes, including the upregulation of osteoblastic transcription factors such as RUNX and OSX, along with increased deposition of mineralized nodules.

CONCLUSION

Our findings proved interesting clues on the stimulatory effects of AMH on mature osteoblasts expressing its specific receptor, AMHRII. This study may therefore have translation value in opening the perspective that AMH may be an effective candidate to counteract the bone loss in osteoporotic patients by selectively targeting osteoblast with minimal off-target effect.

Endometrial TGFβ signaling fosters early pregnancy development by remodeling the fetomaternal interface

The endometrium is a unique and highly regenerative tissue with crucial roles during the reproductive lifespan of a woman. As the first site of contact between mother and embryo, the endometrium, and its critical processes of decidualization and immune cell recruitment, play a leading role in the establishment of pregnancy, embryonic development, and reproductive capacity. These integral processes are achieved by the concerted actions of steroid hormones and a myriad of growth factor signaling pathways. This review focuses on the roles of the transforming growth factor β (TGFβ) pathway in the endometrium during the earliest stages of pregnancy through the lens of immune cell regulation and function. We discuss how key ligands in the TGFβ family signal through downstream SMAD transcription factors and ultimately remodel the endometrium into a state suitable for embryo implantation and development. We also focus on the key roles of the TGFβ signaling pathway in recruiting uterine natural killer cells and their collective remodeling of the decidua and spiral arteries. By providing key details about immune cell populations and TGFβ signaling within the endometrium, it is our goal to shed light on the intricate remodeling that is required to achieve a successful pregnancy.

Elevated Anti-Müllerian Hormone as a Prognostic Factor for Poor Outcomes of In Vitro Fertilization in Women with Polycystic Ovary Syndrome

Women with polycystic ovary syndrome (PCOS) tend to have elevated anti-Müllerian hormone (AMH) levels, which appear to correlate with disease severity and pregnancy outcomes. This was a retrospective observational study designed to assess the relationship between circulating AMH levels and in vitro fertilization (IVF) outcomes. The study involved 150 women with PCOS who underwent IVF treatments. The women's IVF cycles were allocated into three subgroups according to AMH levels: 'low' (AMH < 3.7 ng/mL; n = 49), 'middle' (AMH 3.7-7.4 ng/mL; n = 94), and 'high' (AMH > 7.4 ng/mL; n = 56). All pregnancy-related outcomes (positive beta human chorionic gonadotropin (βHCG), clinical pregnancy rate, live birth rate, and cumulative live birth rate) were greater in women's IVF cycles with 'low' AMH when compared to those with 'middle' or 'high' AMH (p < 0.05). AMH levels below 3.7 ng/mL were found to be associated with lower oocyte immaturity rate and better pregnancy outcomes, although baseline AMH was not shown to have any significant predictive power for live birth and cumulative live birth in the multivariable logistic regression analysis after adjusting for possible confounders nor in the ROC analyses. In summary, the current study lays the groundwork to validate high AMH levels as a poor prognostic factor for pregnancy outcomes after IVF in women with PCOS.

Differential effects of follicle-stimulating hormone glycoforms on the transcriptome profile of cultured rat granulosa cells as disclosed by RNA-seq

It has been documented that variations in glycosylation on glycoprotein hormones, confer distinctly different biological features to the corresponding glycoforms when multiple in vitro biochemical readings are analyzed. We here applied next generation RNA sequencing to explore changes in the transcriptome of rat granulosa cells exposed for 0, 6, and 12 h to 100 ng/ml of four highly purified follicle-stimulating hormone (FSH) glycoforms, each exhibiting different glycosylation patterns: human pituitary FSH18/21 and equine FSH (eqFSH) (hypo-glycosylated), and human FSH24 and chinese-hamster ovary cell-derived human recombinant FSH (recFSH) (fully-glycosylated). Total RNA from triplicate incubations was prepared from FSH glycoform-exposed cultured granulosa cells obtained from DES-pretreated immature female rats, and RNA libraries were sequenced in a HighSeq 2500 sequencer (2 × 125 bp paired-end format, 10-15 × 106 reads/sample). The computational workflow focused on investigating differences among the four FSH glycoforms at three levels: gene expression, enriched biological processes, and perturbed pathways. Among the top 200 differentially expressed genes, only 4 (0.6%) were shared by all 4 glycoforms at 6 h, whereas 118 genes (40%) were shared at 12 h. Follicle-stimulating hormone glycocoforms stimulated different patterns of exclusive and associated up regulated biological processes in a glycoform and time-dependent fashion with more shared biological processes after 12 h of exposure and fewer treatment-specific ones, except for recFSH, which exhibited stronger responses with more specifically associated processes at this time. Similar results were found for down-regulated processes, with a greater number of processes at 6 h or 12 h, depending on the particular glycoform. In general, there were fewer downregulated than upregulated processes at both 6 h and 12 h, with FSH18/21 exhibiting the largest number of down-regulated associated processes at 6 h while eqFSH exhibited the greatest number at 12 h. Signaling cascades, largely linked to cAMP-PKA, MAPK, and PI3/AKT pathways were detected as differentially activated by the glycoforms, with each glycoform exhibiting its own molecular signature. These data extend previous observations demonstrating glycosylation-dependent differential regulation of gene expression and intracellular signaling pathways triggered by FSH in granulosa cells. The results also suggest the importance of individual FSH glycoform glycosylation for the conformation of the ligand-receptor complex and induced signalling pathways.

ApoC3 is expressed in oocytes and increased expression is associated with PCOS progression

BACKGROUND

Polycystic ovary syndrome (PCOS) is a lifelong metabolic disorder and the most common cause of anovulatory infertility affecting women in reproductive age. Our recent study reported that apolipoprotein C3 (ApoC3) could be a potential diagnostic serum marker for metabolism disturbance in PCOS patients, but whether it is present in the ovaries and what role it plays has not yet been described.

OBJECTIVE

Aimed to investigate ApoC3 expression in ovary of PCOS, and to discuss its potential role in PCOS progression.

METHODS

ApoC3 expression in ovarian tissue samples from 12 PCOS patients along with 12 healthy controls were measured via immunohistochemistry (IHC). Also, the level of ApoC3 in follicular fluid from 14 patients diagnosed with PCOS and 13 control subjects were detected by ELISA. The expression and location of ApoC3 in ovaries of PCOS mice were tested weekly for three consecutive weeks during PCOS formation using real time PCR, Western Blot, IHC and immunofluorescence. The relation of ApoC3 and sex hormones was analyzed in mouse plasma. Additionally, the dynamic changes of ApoC3 level in ovaries of healthy mice during postnatal development was also investigated.

RESULTS

ApoC3 levels in ovarian tissue and follicular fluid were significantly higher in PCOS patients than in controls (33.87 ± 4.11 vs. 27.71 ± 3.65, P < 0.01; 0.87 ± 0.09 vs. 0.51 ± 0.32 ng/mL, P < 0.05), respectively. In ovary, ApoC3 was found to be located in the cytoplasm of oocyte, and its expression gradually increased with PCOS progression (P < 0.05). Furthermore, correlation analysis showed that plasma ApoC3 level was closely associated with luteinizing hormone (r = 0.709, P = 0.001), testosterone (r = 0.627, P = 0.005) and anti-mullerian hormone (r = 0.680, P = 0.002) in PCOS mice. In addition, ApoC3 level in oocyte was physiologically increased and peaked on postnatal age 21 (P21), then decreased following P21 in healthy mice.

CONCLUSIONS

We identified ApoC3 expression in oocyte. It may be involved in PCOS progression and possibly participate in the regulation of oocyte development.

Mechanisms of primordial follicle activation and new pregnancy opportunity for premature ovarian failure patients

Primordial follicles are the starting point of follicular development and the basic functional unit of female reproduction. Primordial follicles are formed around birth, and most of the primordial follicles then enter a dormant state. Since primordial follicles are limited in number and can't be renewed, dormant primordial follicles cannot be reversed once they enter the growing state. Thus, the orderly occurrence of primordial follicles selective activation directly affects the rate of follicle consumption and thus determines the length of female reproductive lifespan. Studies have found that appropriately inhibiting the activation rate of primordial follicles can effectively slow down the rate of follicle consumption, maintain fertility and delay ovarian aging. Based on the known mechanisms of primordial follicle activation, primordial follicle in vitro activation (IVA) technique has been clinically developed. IVA can help patients with premature ovarian failure, middle-aged infertile women, or infertile women due to gynecological surgery treatment to solve infertility problems. The study of the mechanism of selective activation of primordial follicles can contribute to the development of more efficient and safe IVA techniques. In this paper, recent mechanisms of primordial follicle activation and its clinical application are reviewed.

Analysis of cumulative outcomes and influencing factors of patients with discrepancies between age and AMH levels in the early follicular phase prolonged protocol

OBJECTIVE

To explore the cumulative outcomes and influencing factors of patients with discrepancies between age and Anti-Müllerian hormone (AMH) levels in the early follicular phase prolonged protocol.

METHODS

A total of 1282 cycles of in-vitro fertilization (IVF)/intracytoplasmic sperm injection (ICSI) assisted pregnancy with the early follicular phase prolonged protocol in the Reproductive Medicine Center of the Third Affiliated Hospital of Zhengzhou University from September 2015 to December 2020 were retrospectively analyzed. They were divided into the young low-AMH group (n=1076) and the older high-AMH group (n=206). The primary outcomes included cumulative clinical pregnancy rate (CCPR) and cumulative live birth rate (CLBR). Secondary outcomes included the number of oocytes retrieved, number of available embryos, clinical pregnancy rate (CPR), live birth rate (LBR), miscarriage rate (MR), pregnancy complications, and neonatal outcomes.

RESULTS

The CPR (68.7% vs. 59.4%) and the LBR (60.7% vs. 43.1%) in the young low-AMH group were higher than those in the older high-AMH group. In contrast, the number of oocytes retrieved (11 vs. 17), number of available embryos (5 vs. 8), and MR (10.6% vs. 18.3%) in the young low-AMH group were lower. There was no significant difference between the two groups in the CCPR, CLBR, pregnancy complications, and neonatal outcomes. Logistic regression analysis showed that infertility duration, basal follicle-stimulating hormone (FSH), and antral follicle count (AFC) correlated with CCPR, while maternal age, type of infertility, basal FSH, AFC, and infertility duration correlated with CLBR. The area under the receiver operating characteristic curves (ROC) curve for the combined model of infertility duration, AFC, and basal FSH to predict cumulative pregnancy was 0.629 (95%CI:0.592-0.666), while the combined model of maternal age, AFC, basal FSH, infertility duration, and type of infertility to predict cumulative live birth was 0.649 (95%CI:0.615-0.682).

CONCLUSION

Although AMH levels are low by contrast, young patients have a favorable outcome after IVF/ICSI. In patients with discrepancies between age and AMH levels in the early follicular phase prolonged protocol, maternal age correlates better with cumulative live birth. The model that combines maternal age and other factors can help predict cumulative live birth, but its value is limited.

Anti-Mullerian Hormone (AMH) and adenomyosis: Mini-review of literature of the last 5 years

INTRODUCTION

Adenomyosis is a form of endometriosis characterized by the presence of endometrial tissue in the myometrium. The correlation between anti-Mullerian hormone (AMH) expression and adenomyosis is unclear. Few studies investigated this possible correlation with promising results. The aim of this mini-review is to illustrate the potential prognostic and therapeutic role of AMH in adenomyosis.

MATERIALS AND METHODS

A study protocol was completed conforming to the Preferred Reporting Items for Reviews and Meta-Analyses (PRISMA) guidelines for systematic reviews. We performed an electronic databases search from each database's inception from August 2017 to August 2022 for full-text articles and published abstracts. For database searches, the following main keywords were the following text words: "adenomyosis" or "uterine endometriosis" [Mesh] AND "AMH" or "anti-mullerian hormone".

RESULTS

From the literature search, 8 abstracts of studies were retrieved and independently screened for inclusion by three authors. It was found that the most common therapeutic strategies (such as adenomyomectomy and high-intensity focused ultrasound (HIFU) do not alter AMH levels. Moreover, a higher expression of the AMH receptor II was observed in adenomyotic tissue, hence a possible therapeutic use of AMH was hypothesized.

CONCLUSION

The available evidence shows an unclear relationship between adenomyosis and AMH. Probably, women with adenomyosis have lower levels of AMH and the surgical treatment (adenomyomectomy, HIFU) does not alter this characteristic, therefore in all of them, ovarian function is not influenced.