Anti-Mullerian-hormone-dependent regulation of the brain serine-protease inhibitor neuroserpin

Role of Anti-Müllerian Hormone in the Central Regulation of Fertility

In recent years, the expanding roles of anti-Müllerian hormone (AMH) in various aspects of reproductive health have attracted significant attention. Initially recognized for its classical role in male sexual differentiation, AMH is produced postnatally by the Sertoli cells in the male testes and by the granulosa cells in the female ovaries. Traditionally, it was believed to primarily influence gonadal development and function. However, research over the last decade has unveiled novel actions of AMH beyond the gonads, specifically all along the hypothalamic-pituitary-gonadal axis. This review will focus on the emerging roles of AMH within the hypothalamus and discusses its potential implications in reproductive physiology. Additionally, recent preclinical and clinical studies have suggested that elevated levels of AMH may disrupt the hypothalamic network regulating reproduction, which could contribute to the central pathophysiology of polycystic ovary syndrome. These findings underscore the intricate interplay between AMH and the neuroendocrine system, offering new avenues for understanding the mechanisms underlying fertility and reproductive disorders.

iCre recombinase expressed in the anti-Müllerian hormone receptor 2 gene causes global genetic modification in the mouse†

Genetically engineered mice are widely used to study the impact of altered gene expression in vivo. Within the reproductive tract, the Amhr2-IRES-Cre(Bhr) mouse model is used to ablate genes in ovarian granulosa and uterine stromal cells. There are reports of Amhr2-IRES-Cre(Bhr) inducing recombination in non-target tissues. We hypothesized the inefficiency or off-target Cre action in Amhr2-IRES-Cre(Bhr) mice is due to lack of recombination in every cell that expresses Amhr2. To investigate, we created a new targeted knock-in mouse model, Amhr2-iCre(Fjd), by inserting a codon-optimized improved Cre (iCre) into exon 1 of the Amhr2 gene. Amhr2-iCre(Fjd)/+ males were mated with females that contain a lox-stop-lox cassette in the Sun1 gene so when DNA recombination occurs, SUN1-sfGFP fusion protein is expressed in a peri-nuclear pattern. In adult Amhr2-iCre(Fjd)/+ Sun1LsL/+ mice, Amhr2-iCre(Fjd)-mediated genetic recombination was apparent in uterine epithelial, stromal, and myometrial cells, while Amhr2-IRES-Cre(Bhr)/+ Sun1LsL/+ females demonstrated inter-mouse variability of Amhr2-IRES-Cre(Bhr) activity in uterine cells. Fluorescence was observed in Amhr2-iCre(Fjd)-positive mice at post-natal Day 1, indicating global genetic recombination, while fluorescence of individual Amhr2-IRES-Cre(Bhr)-positive pups varied. To determine the developmental stage that genetic recombination first occurs, Sun1LsL/LsL females were super-ovulated and mated with Amhr2-IRES-Cre(Bhr)/+ or Amhr2(iCre/+)Fjd males, then putative zygotes were collected and cultured. In the four-cell embryo, Amhr2-iCre(Fjd) and Amhr2-IRES-Cre(Bhr) activities were apparent in 100% and 25-100% of cells, respectively. In conclusion, Amhr2-IRES-Cre(Bhr) or Amhr2-iCre(Fjd) driven by the Amhr2 promoter is active in the early embryo and can lead to global genetic modification, rendering this transgenic mouse model ineffective.

High-Dose Vitamin C Prevents Secondary Brain Damage After Stroke via Epigenetic Reprogramming of Neuroprotective Genes

Vitamin C has recently been identified as an epigenetic regulator by activating ten-eleven translocases (TETs), enzymes involved in generating DNA hydroxymethylcytosine (5hmC). Currently, we investigated whether high-dose vitamin C promotes neuroprotection through epigenetic modulation of 5hmC, if there are sex-specific differences in outcome, and the therapeutic potential of vitamin C in stroke-related comorbidities in adult mice. Post-stroke treatment with ascorbate (reduced form), but not dehydroascorbate (oxidized form), increased TET3 activity and 5hmC levels and reduced infarct following focal ischemia. Hydroxymethylation DNA immunoprecipitation sequencing showed that ascorbate increased 5hmC across the genome and specifically in promoters of several stroke pathophysiology-related genes, particularly anti-inflammatory genes. Ascorbate also decreased markers of oxidative stress, mitochondrial fragmentation, and apoptosis in cortical peri-infarct neurons and promoted motor and cognitive functional recovery in both sexes via TET3. Furthermore, post-stroke ascorbate treatment reduced infarct volume and improved motor function recovery in aged, hypertensive and diabetic male and female mice. Delayed ascorbate treatment at 6 h of reperfusion was still effective at reducing infarct volume and motor impairments in adult mice. Collectively, this study shows that post-stroke treatment with high-dose ascorbate protects the brain through epigenetic reprogramming and may function as a robust therapeutic against stroke injury.

Anti-Müllerian Hormone and Polycystic Ovary Syndrome in Women and Its Male Equivalent

This article reviews the main findings on anti-Müllerian hormone (AMH) and its involvement in the pathogenesis of polycystic ovary syndrome (PCOS) and its male equivalent. In women, AMH is produced by granulosa cells from the mid-fetal life to menopause and is a reliable indirect marker of ovarian reserve. AMH protects follicles from atresia, inhibits their differentiation in the ovary, and stimulates gonadotrophin-releasing hormone neurons pulsatility. AMH overexpression in women with PCOS likely contributes to the increase of the follicle cohort and of androgen levels, leading to follicular arrest and anovulation. In the male, AMH is synthesized at high levels by Sertoli cells from fetal life to puberty when serum AMH falls to levels similar to those observed in women. AMH is involved in the differentiation of the genital tract during fetal life and plays a role in Sertoli and Leydig cells differentiation and function. Serum AMH is used to assess Sertoli cell function in children with disorders of sex development and various conditions affecting the hypothalamic–pituitary–testicular axis. Although the reproductive function of male relative of women with PCOS has been poorly investigated, adolescents have elevated levels of AMH which could play a detrimental role on their fertility.

Serpin Signatures in Prion and Alzheimer's Diseases

Serpins represent the most broadly distributed superfamily of proteases inhibitors. They contribute to a variety of physiological functions and any alteration of the serpin-protease equilibrium can lead to severe consequences. SERPINA3 dysregulation has been associated with Alzheimer's disease (AD) and prion diseases. In this study, we investigated the differential expression of serpin superfamily members in neurodegenerative diseases. SERPIN expression was analyzed in human frontal cortex samples from cases of sporadic Creutzfeldt-Jakob disease (sCJD), patients at early stages of AD-related pathology, and age-matched controls not affected by neurodegenerative disorders. In addition, we studied whether Serpin expression was dysregulated in two animal models of prion disease and AD.Our analysis revealed that, besides the already observed upregulation of SERPINA3 in patients with prion disease and AD, SERPINB1, SERPINB6, SERPING1, SERPINH1, and SERPINI1 were dysregulated in sCJD individuals compared to controls, while only SERPINB1 was upregulated in AD patients. Furthermore, we analyzed whether other serpin members were differentially expressed in prion-infected mice compared to controls and, together with SerpinA3n, SerpinF2 increased levels were observed. Interestingly, SerpinA3n transcript and protein were upregulated in a mouse model of AD. The SERPINA3/SerpinA3nincreased anti-protease activity found in post-mortem brain tissue of AD and prion disease samples suggest its involvement in the neurodegenerative processes. A SERPINA3/SerpinA3n role in neurodegenerative disease-related protein aggregation was further corroborated by in vitro SerpinA3n-dependent prion accumulation changes. Our results indicate SERPINA3/SerpinA3n is a potential therapeutic target for the treatment of prion and prion-like neurodegenerative diseases.

Anti-Müllerian Hormone Regulation of Synaptic Transmission in the Hippocampus Requires MAPK Signaling and Kv4.2 Potassium Channel Activity

Anti-Müllerian hormone (AMH) is a paracrine factor generated peripherally by the gonads to regulate gonadal function in adult mammals. We recently reported that AMH and AMH-specific receptor Anti-Müllerian hormone receptor 2 (AMHR2) are expressed in the hippocampus, and exogenous AMH protein rapidly increased synaptic transmission and long-term synaptic plasticity at the CA3-CA1 synapses. Here we examined the cell-specific expression of AMHR2 and the cellular mechanism of rapid boosting effect of AMH on synaptic transmission in mouse hippocampus. Immunofluorescence staining showed that AMHR2 was specifically expressed in the soma and dendrites of hippocampal pyramidal neurons, but not glial cells. Electrophysiological recordings on acute hippocampal slices showed that AMH did not affect AMPAR-mediated or N-Methyl-D-aspartic acid receptor (NMDAR)-mediated excitatory postsynaptic currents at the CA3-CA1 synapses. The small-conductance Ca²⁺-activated K⁺ channel (SK2) and A-type K⁺ channel (Kv4.2) contribute to shaping excitatory postsynaptic potentials (EPSPs) at the CA3-CA1 synapses. Bath application of apamin to block SK2 did not alter AMH effect on increasing EPSPs, whereas blocking Kv4.2 channel with 4-aminopyridine, or chelating internal Ca²⁺ with BAPTA occluded the action of AMH on boosting EPSPs. Kv4.2 activity is regulated by p38 mitogen-activated kinase (MAPK). Blocking p38 MAPK with SB203580 occluded the effect of AMH on increasing EPSPs. These results show that Kv4.2 channel contributes to the rapid action of AMH on boosting synaptic transmission in a Ca²⁺- and p38 MAPK-dependent manner. Our findings provide functional evidence that AMH enhances synaptic transmission through Kv4.2 channel in the hippocampus, suggesting a possible role of Kv4.2 channel in AMH-regulated neuronal process underlying learning and memory.

Anti-Müllerian hormone: A function beyond the Müllerian structures

The anti-Müllerian hormone (AMH) is a heterodimeric glycoprotein belonging to the TGFb superfamily implicated in human embryonic development. This hormone was first described as allowing regression of the epithelial embryonic Müllerian structures in males, which would otherwise differentiate into the uterus and fallopian tubes. It activates a signaling pathway mediated by two transmembrane receptors. Binding of AMH to its receptor induces morphological changes leading to the degeneration of Müllerian ducts. Recently, new data has shown the role played by this hormone on structures other than the genital tract. If testicular AMH expression decreases in humans over the course of a lifetime, synthesis may persist in other tissues in adulthood. The mechanisms underlying its production have been unveiled. The aim of this review is to describe the different pathways in which AMH has been identified and plays a pivotal role.

Anti-mullerian hormone attenuates insulin resistance and systemic inflammation in old obese C57BL/6 male mice

Purpose

Epidemiological studies show that Anti-mullerian hormone (AMH) is inversely correlated with age, obesity-related diseases, and all-cause mortality in men. To further investigate the role of AMH in aging and obesity, we studied the effect of AMH treatment on the inflammatory and metabolic parameters and weight in old male C57BL/6 mice.

Method

Thirty-six old male C57BL/6 mice (18 month-old) were either on the High-Fat Diet (HFD) or Normal Diet (ND). When obesity occurred in the HFD group, each group was divided into two subgroups; AMH-treated (ND^+AMH and HFD^+AMH) or controls (ND and HFD). The AMH subgroup received 15 ng/gbw of recombinant AMH injection every 48 h in four weeks. Then, serum AMH, CRP, fasting glucose, fasting insulin, and HOMA-IR were measured and analyzed.

Results

AMH injection decreased CRP level (HFD =622.86±25.73, HFD^+AMH =543.2±24.99 ng/ml, p= 0.003), fasting insulin (HFD=1.50± 0.34, HFD^+AMH =0.8±0.25 ng/ml, p=0.006) and HOMA-IR (HFD=12.76± 2.88, HFD^+AMH =7.06±2.31, p=0.008) in the obese old mice comparison with control. In ND group, just CRP levels dropped following AMH injection (ND=451.24±20.61, ND^+AMH= 326.8±23.76 ng/ml; p=0.001). Accelerated weight gain was observed in HFD^+AMH compared with the HFD subgroup (p<0.05).

Conclusions

In conclusion, increasing the circulating level of AMH could subside the systemic inflammation through decreasing CRP levels regardless of diet type and enhance insulin sensitivity in old obese mice. It can also lead to higher weight gain, without inflammation, in old obese male mice who are on an HFD.

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.

AMH and AMHR2 Involvement in Congenital Disorders of Sex Development

Anti-müllerian hormone (AMH) is 1 of the 2 testicular hormones involved in male development of the genitalia during fetal life. When the testes differentiate, AMH is secreted by Sertoli cells and binds to its specific receptor type II (AMHR2) on the müllerian ducts, inducing their regression. In the female fetus, the lack of AMH allows the müllerian ducts to form the fallopian tubes, the uterus, and the upper part of the vagina. The human AMH gene maps to 19p13.3 and consists of 5 exons and 4 introns spanning 2,764 bp. The AMHR2 gene maps to 12q13.13, consists of 11 exons, and is 7,817 bp long. Defects in the AMH pathway are the underlying etiology of a subgroup of disorders of sex development (DSD) in 46,XY patients. The condition is known as the persistent müllerian duct syndrome (PMDS), characterized by the existence of a uterus and fallopian tubes in a boy with normally virilized external genitalia. Approximately 200 cases of patients with PMDS have been reported to date with clinical, biochemical, and molecular genetic characterization. An updated review is provided in this paper. With highly sensitive techniques, AMH and AMHR2 expression has also been detected in other tissues, and massive sequencing technologies have unveiled variants in AMH and AMHR2 genes in hitherto unsuspected conditions.

New Anti-Müllerian Hormone Target Genes Involved in Granulosa Cell Survival in Women With Polycystic Ovary Syndrome

PURPOSE

A protective effect of anti-Müllerian hormone (AMH) on follicle atresia was recently demonstrated using long-term treatments, but this effect has never been supported by mechanistic studies. This work aimed to gain an insight into the mechanism of action of AMH on follicle atresia and on how this could account for the increased follicle pool observed in women with polycystic ovary syndrome (PCOS).

METHODS

In vivo and in vitro experiments were performed to study the effects of AMH on follicle atresia and on the proliferation and apoptosis of granulosa cells (GCs). RNA-sequencing was carried out to identify new AMH target genes in GCs. The expression of some of these genes in GCs from control and PCOS women was compared using microfluidic real time quantitative RT-PCR.

RESULTS

A short-term AMH treatment prevented follicle atresia in prepubertal mice. Consistent with this result, AMH inhibited apoptosis and promoted proliferation of different models of GCs. Moreover, integrative biology analyses of 965 AMH target genes identified in 1 of these GC models, confirmed that AMH had initiated a gene expression program favoring cell survival and proliferation. Finally, on 43 genes selected among the most up- and down-regulated AMH targets, 8 were up-regulated in GCs isolated from PCOS women, of which 5 are involved in cell survival.

MAIN CONCLUSIONS

Our results provide for the first time cellular and molecular evidence that AMH protects follicles from atresia by controlling GC survival and suggest that AMH could participate in the increased follicle pool of PCOS patients.

The Neuroprotective Role of Neuroserpin in Ischemic and Hemorrhagic Stroke

Tissue plasminogen activator (tPA) is commonly used to treat acute ischemic stroke within an appropriate therapeutic window. Its inhibitor, neuroserpin (NSP), is reported to exhibit neuroprotective effects on stroke. This review aims to summarize, from literature, the available evidence, potential mechanisms, and knowledge limitations regarding the neuroprotective role of NSP in stroke. All the available evidence indicates that the regulation of the inflammatory response may play a key role in the mechanisms of NSP, which involve all the constituents of the neuroimmune axis. The neuroinflammatory response triggered by stroke can be reversed by NSP, with complicated mechanisms such as maintenance and reconstruction of the structure and function of the blood-brain barrier (BBB), protection of the cells in the central nervous system, and suppression of cell death in both ischemic and hemorrhagic stroke. Moreover, available evidence strongly suggests a tPA-independent mechanism is involved in NSP. However, there are many important issues that are still unclear and need further investigation, such as the effects of NSP on hemorrhagic stroke, the role of the tPA-independent neuroprotective mechanisms, and the clinical application prospects of NSP. We believe our work will be helpful to further understand the neuroprotective role of NSP.

The proportion of cleaved anti-Müllerian hormone is higher in serum but not follicular fluid of obese women independently of polycystic ovary syndrome

RESEARCH QUESTION

Does the relative distribution of anti-Müllerian hormone (AMH) isoforms differ between patients depending on their body mass index (BMI) and polycystic ovary syndrome (PCOS) status in serum and follicular fluid?

DESIGN

Obese and normal weight patients (PCOS [n = 70]; non-PCOS [n = 37]) were selected for this case-control study in the serum. Between 2018 and 2019, obese (n = 19) and normal weight (n = 20) women with or without PCOS who were receiving IVF treatment were included in the follicular fluid study. The bio-banked serums and follicular fluid were tested for total AMH (proAMH and AMH_N,C combined) and proAMH using an automatic analyzer. The AMH prohormone index (API = [proAMH]/[total AMH]x 100) was calculated as an inverse marker of conversion of proAMH to AMH_N,C, with only the latter isoform that could bind to the AMH receptor complex.

RESULTS

The API was not significantly different between controls and women with PCOS, whereas obese women had a lower API compared with their normal weight counterparts. Grouping PCOS and controls, a lower API was found in obese versus normal weight women, suggesting a greater conversion of proAMH to AMH_N,C. The API in the serum was significantly correlated with metabolic parameters. In the follicular fluid, API is not different between obese and normal weight women independently of PCOS and is higher than in the concomitant serum.

CONCLUSIONS

The proportion of inactive form of AMH in the serum is higher in normal weight versus obese women but not in the follicular fluid, independently of PCOS. The conversion of proAMH into the cleaved isoform is likely to occur in extra-ovarian tissues and to exacerbate in obese individuals.

New insights into anti-Müllerian hormone role in the hypothalamic-pituitary-gonadal axis and neuroendocrine development

Research into the physiological actions of anti-Müllerian hormone (AMH) has rapidly expanded from its classical role in male sexual differentiation to the regulation of ovarian function, routine clinical use in reproductive health and potential use as a biomarker in the diagnosis of polycystic ovary syndrome (PCOS). During the past 10 years, the notion that AMH could act exclusively at gonadal levels has undergone another paradigm shift as several exciting studies reported unforeseen AMH actions throughout the Hypothalamic–Pituitary–Gonadal (HPG) axis. In this review, we will focus on these findings reporting novel AMH actions across the HPG axis and we will discuss their potential impact and significance to better understand human reproductive disorders characterized by either developmental alterations of neuroendocrine circuits regulating fertility and/or alterations of their function in adult life. Finally, we will summarize recent preclinical studies suggesting that elevated levels of AMH may potentially be a contributing factor to the central pathophysiology of PCOS and other reproductive diseases.

Treatment of Women With Epilepsy

PURPOSE OF REVIEW

This article provides the latest information to guide practitioners in counseling and treating women with epilepsy.

RECENT FINDINGS

There is an increasing body of literature on the multidirectional effects of sex hormones on seizure frequency and severity and of seizures altering areas of the brain involved in neuroendocrine function. Ongoing pregnancy outcome data from pregnancy registries and meta-analysis of observational studies have provided key information on the safety of using antiseizure medications during pregnancy and the risk to the fetus.

SUMMARY

In treating and counseling women with epilepsy from puberty to menopause, it is important to understand the complex interactions of sex hormones, seizures, and antiseizure medications on reproductive health and pregnancy outcomes.

Rapid actions of anti-Müllerian hormone in regulating synaptic transmission and long-term synaptic plasticity in the hippocampus

Anti-Müllerian hormone (Amh) is a peptide factor that is known to regulate sexual differentiation and gonadal function in mammals. Although Amh is also suggested to be associated with cognitive development and function in the postnatal brain, little is known about its expression or direct effects on neuronal activities in the hippocampus. Therefore, we assessed Amh and its receptor expression in the hippocampus of male and female mice using PCR, Western blot, and immunofluorescence staining. While Amh-specific receptor expression was comparable between males and females, mRNA and protein levels of Amh were higher in females than those of males. Electrophysiological recordings on acute hippocampal slices showed that exogenous Amh protein addition increased synaptic transmission and long-term synaptic plasticity at the Cornu Ammonis (CA) 3-CA1 synapses. Amh exposure also increased the excitatory postsynaptic potential at CA1 synapses. Our findings support direct and rapid actions of Amh as a paracrine and/or autocrine factor in regulating hippocampal neuronal activities. Data provide functional evidence of Amh-mediated postsynaptic modulation of synaptic transmission and Amh-regulated long-term synaptic plasticity in the hippocampus. These results suggest a potential role of Amh in learning and memory, and a possible cause of the sex differences in cognitive development and function.

Defective AMH signaling disrupts GnRH neuron development and function and contributes to hypogonadotropic hypogonadism

Congenital hypogonadotropic hypogonadism (CHH) is a condition characterized by absent puberty and infertility due to gonadotropin releasing hormone (GnRH) deficiency, which is often associated with anosmia (Kallmann syndrome, KS). We identified loss-of-function heterozygous mutations in anti-Müllerian hormone (AMH) and its receptor, AMHR2, in 3% of CHH probands using whole-exome sequencing. We showed that during embryonic development, AMH is expressed in migratory GnRH neurons in both mouse and human fetuses and unconvered a novel function of AMH as a pro-motility factor for GnRH neurons. Pathohistological analysis of Amhr2-deficient mice showed abnormal development of the peripheral olfactory system and defective embryonic migration of the neuroendocrine GnRH cells to the basal forebrain, which results in reduced fertility in adults. Our findings highlight a novel role for AMH in the development and function of GnRH neurons and indicate that AMH signaling insufficiency contributes to the pathogenesis of CHH in humans.

GnRH Transactivates Human AMH Receptor Gene via Egr1 and FOXO1 in Gonadotrope Cells

BACKGROUND/OBJECTIVES

Anti-Müllerian hormone (AMH) signaling is critical for sexual differentiation and gonadal function. AMH receptor type 2 (AMHR2) is expressed in extragonadal sites such as brain, and pituitary and emerging evidence indicates that AMH biological action is much broader than initially thought. We recently reported that AMH signaling enhances follicle-stimulating hormone synthesis in pituitary gonadotrope cells. However, mechanisms regulating AMHR2 expression in these extragonadal sites remain to be explored.

METHOD/RESULTS

Here, we demonstrated in perifused murine LβT2 gonadotrope cells that Amhr2 expression is differentially regulated by GnRH pulse frequency with an induction under high GnRH pulsatility. Furthermore, we showed that GnRH transactivates the human AMHR2 promoter in LβT2 cells. Successive deletions of the promoter revealed the importance of a short proximal region (-53/-37 bp) containing an Egr1 binding site. Using site-directed mutagenesis of Egr1 motif and siRNA mediated-knockdown of Egr1, we demonstrated that Egr1 mediates basal and GnRH-dependent activity of the promoter, identifying Egr1 as a new transcription factor controlling hAMHR2 expression. We also showed that SF1 and β-catenin are required for basal promoter activity and demonstrated that both factors contribute to the GnRH stimulatory effect, independently of their respective binding sites. Furthermore, using a constitutively active mutant of FOXO1, we identified FOXO1 as a negative regulator of basal and GnRH-dependent AMHR2 expression in gonadotrope cells.

CONCLUSIONS

This study identifies GnRH as a regulator of human AMHR2 expression, further highlighting the importance of AMH signaling in the regulation of gonadotrope function.

Emerging Roles of Anti-Müllerian Hormone in Hypothalamic-Pituitary Function

Since its initial discovery in the 1940s, research into the physiological actions of anti-Müllerian hormone (AMH), from its eponymous role in male developmental biology to its routine clinical use in female reproductive health, has undergone a paradigm shifting change. With several exciting studies recently reporting hitherto unforeseen AMH actions at all levels in the hypogonadal-pituitary-gonadal axis, the importance of this hormone for both hypothalamic and pituitary reproductive control is finding increasing support and significance. In this review, we will briefly summarize what is known about the traditional roles and biology of AMH and how this could be integrated with new findings of AMH actions at the level of the hypothalamic-pituitary axis. We also synthesize the important findings from these new studies and discuss their potential impact and significance to our understanding of one of the most common reproductive disorders currently affecting women, polycystic ovary syndrome.

Primary Immunoprevention of Epithelial Ovarian Carcinoma by Vaccination against the Extracellular Domain of Anti-Müllerian Hormone Receptor II

Epithelial ovarian carcinoma (EOC) is the most prevalent form of ovarian cancer in the United States, representing approximately 85% of all cases and causing more deaths than any other gynecologic malignancy. We propose that optimized control of EOC requires the incorporation of a vaccine capable of inducing safe and effective preemptive immunity in cancer-free women. In addition, we hypothesize that ovarian-specific self-proteins that are "retired" from autoimmune-inducing expression levels as ovaries age but are expressed at high levels in emerging EOC may serve as vaccine targets for mediating safe and effective primary immunoprevention. Here, we show that expression of the extracellular domain of anti-Müllerian hormone receptor II (AMHR2-ED) in normal tissues is confined exclusively to the human ovary, drops to nonautoimmune inducing levels in postmenopausal ovaries, and is at high levels in approximately 90% of human EOC. We found that AMHR2-ED vaccination significantly inhibits growth of murine EOC and enhances overall survival without inducing oophoritis in aged female mice. The observed inhibition of EOC growth was mediated substantially by induction of AMHR2-ED-specific IgG antibodies that agonize receptor signaling of a Bax/caspase-3-dependent proapoptotic cascade. Our results indicate that AMHR2-ED vaccination may be particularly useful in providing safe and effective preemptive immunity against EOC in women at high genetic or familial risk who have the greatest need for a preventive vaccine and ultimately in cancer-free postmenopausal women who account for 75% of all EOC cases. Cancer Prev Res; 10(11); 612-24. ©2017 AACRSee related editorial by Shoemaker et al., p. 607.

Distant Space Processing is Controlled by tPA-dependent NMDA Receptor Signaling in the Entorhinal Cortex

In humans, spatial cognition and navigation impairments are a frequent situation during physiological and pathological aging, leading to a dramatic deterioration in the quality of life. Despite the discovery of neurons with location-specific activity in rodents, that is, place cells in the hippocampus and later on grid cells in the entorhinal cortex (EC), the molecular mechanisms underlying spatial cognition are still poorly known. Our present data bring together in an unusual combination 2 molecules of primary biological importance: a major neuronal excitatory receptor, N-methyl-D-aspartate receptor (NMDAR), and an extracellular protease, tissue plasminogen activator (tPA), in the control of spatial navigation. By using tPA-deficient mice and a structure-selective pharmacological approach, we demonstrate that the tPA-dependent NMDAR signaling potentiation in the EC plays a key and selective role in the encoding and the subsequent use of distant landmarks during spatial learning. We also demonstrate that this novel function of tPA in the EC is reduced during aging. Overall, these results argue for the concept that encoding of proximal versus distal landmarks is mediated not only by different anatomical pathways but also by different molecular mechanisms, with the tPA-dependent potentiation of NMDAR signaling in the EC that plays an important role.

Effects of neuroserpin on clinical outcomes and inflammatory markers in Chinese patients with acute ischemic stroke

OBJECTIVE

Neuroserpin (NSP) is known for its neuroprotective effects. The aim of this study was to investigate the relationship between NSP level and clinical outcomes and inflammatory markers in Chinese patients with acute ischemic stroke.

METHODS

A total of 133 patients with acute cerebral infarction (ischemia group) and 44 controls were recruited. The modified Rankin Scale (mRS) was used to determine the functional outcome three months after onset. We investigated the relationship between serum NSP levels [on admission and a decrease in NSP levels (10 days after admission versus on admission)] and serum levels of several inflammatory markers.

RESULTS

We confirmed that NSP levels on admission in the ischemia group were significantly higher than those in the control group. NSP levels in patients with good outcomes were significantly higher than those in patients with poor outcomes. NSP levels on admission were associated with having a good outcome in these patients. We found that a larger decrease in NSP levels (on admission vs. 10 days after admission) was correlated with lower serum levels of IL-6, IL-1β, and ICAM-1 10 days after admission.

CONCLUSIONS

A larger decrease in NSP levels related to lower levels of inflammatory marker, while higher NSP levels were associated with lower inflammatory markers and better functional outcomes. Decreasing the infarct size may play a role in this process. These results provide more evidence of the neuroprotective effect of NSP in cerebral ischemic patients. Decrease in the Serum NSP level and NSP level at admission may be considered as potential predictive factors for outcome of acute ischemic stroke.

Anti-Müllerian Hormone Trajectories Are Associated With Cardiovascular Disease in Women: Results From the Doetinchem Cohort Study

BACKGROUND

Earlier age at menopause is widely considered to be associated with an increased risk of cardiovascular disease. However, the underlying mechanisms of this relationship remain undetermined. Indications suggest that anti-Müllerian hormone (AMH), an ovarian reserve marker, plays a physiological role outside of the reproductive system. Therefore, we investigated whether longitudinal AMH decline trajectories are associated with an increased risk of cardiovascular disease (CVD) occurrence.

METHODS

This study included 3108 female participants between 20 and 60 years of age at baseline of the population-based Doetinchem Cohort. Participants completed ≥1 of 5 consecutive quinquennial visits between 1987 and 2010, resulting in a total follow-up time of 20 years. AMH was measured in 8507 stored plasma samples. Information on total CVD, stroke, and coronary heart disease was obtained through a hospital discharge registry linkage. The association of AMH trajectories with CVD was quantified with joint modeling, with adjustment for age, smoking, oral contraceptive use, body mass index, menopausal status, postmenopausal hormone therapy use, diastolic blood pressure, total cholesterol, high-density lipoprotein cholesterol, and glucose levels.

RESULTS

By the end of follow-up, 8.2% of the women had suffered from CVD, 4.9% had suffered from coronary heart disease, and 2.6% had experienced a stroke. After adjustment, each ng/mL lower _logAMH level was associated with a 21% higher risk of CVD (hazard ratio, 1.21; 95% confidence interval, 1.07-1.36) and a 26% higher risk of coronary heart disease (hazard ratio, 1.25; 95% confidence interval, 1.08-1.46). Each additional ng/mL/year decrease of _logAMH was associated with a significantly higher risk of CVD (hazard ratio, 1.46; 95% confidence interval, 1.14-1.87) and coronary heart disease (hazard ratio, 1.56; 95% confidence interval, 1.15-2.12). No association between AMH and stroke was found.

CONCLUSIONS

These results indicate that AMH trajectories in women are independently associated with CVD risk. Therefore, we postulate that the decline of circulating AMH levels may be part of the pathophysiology of the increased cardiovascular risk of earlier menopause. Confirmation of this association and elucidation of its underlying mechanisms are needed to place these results in a clinical perspective.

Expressional changes of AMH signaling system in the quail testis induced by photoperiod

Gonadal sex differentiation proceeds by the interplay of various genes including the transcription factors and secretory factors in a complex network. The sex-differentiating genes are expressed not only during early sex differentiation but also throughout the gonadal development and even in the adult gonads. In addition, the evidence that they actually function in the adult gonads have been accumulated from the studies using the conditional knockout mice. However, many previous studies were focused on one single gene though those genes function in a network. In this study, the expressions of various sex-differentiating genes were analyzed simultaneously in the adult testis of the Japanese quail (Coturnix japonica), whose testicular functions are dramatically changed by altering the photoperiod, to elucidate the roles of them in the adult gonad. Anti-Müllerian hormone (AMH) was significantly upregulated in the regressed testis induced by the short-day condition. The expressions of the transcription factors that promoteAMHexpression in mammals (SF1,SOX9,WT1andGATA4) were also increased in the regressed testis. Moreover, AMH receptor (AMHR2) showed similar expression pattern to its ligand. We also analyzed the expressions of other transforming growth factor beta (TGFB) superfamily members and their receptors. The expressions of the ligands and receptors of TGFB family, and follistatin and betaglycan in addition to inhibin subunits were increased in the regressed testis. These results suggest that AMH is involved in the adult testicular functions of the Japanese quail together with other TGFB superfamily members.

Anti-mullerian hormone is higher in seizure-free women with epilepsy compared to those with ongoing seizures

OBJECTIVE

To determine if anti-mullerian hormone (AMH), a neuroactive peptide hormone and a measure of ovarian reserve, is different between women with epilepsy (WWE) and healthy controls (HC) seeking pregnancy and to evaluate epilepsy-related factors associated with AMH concentrations.

METHODS

Subjects were participants in Women with Epilepsy: Pregnancy Outcomes and Deliveries (WEPOD), a multi-center prospective, observational cohort study evaluating fecundity in WWE compared to HC, ages 18-40 years. WWE were divided into a Sz+ group or a Sz- group, dependent on whether they had seizures within the 9 months prior to enrollment. Serum was collected, and AMH concentrations were measured as an exploratory analysis. Linear and logistic regression models were used to assess associations and control for covariates.

RESULTS

Serum AMH concentrations were measured in 72 out of 90 enrolled WWE and 97 out of 109 HC; the remaining subjects became pregnant before serum was obtained. Thirty WWE were in the Sz+ group and 40 in the Sz- group (retrospective seizure information was missing for two). All AMH concentrations were within the range, however, the normal inverse correlation between age and AMH was present in the HC and in the Sz- groups, but was lacking in the Sz+ group. Mean AMH concentration was higher in the Sz- group (3982pg/ml (SD+/-2452)) compared to the Sz+ group of WWE (2776pg/ml (SD+/-2308)) and HCs (3241 (SD±2647)). All values were within the expected range for age. In WWE, by linear regression, after controlling for age and BMI, seizure occurrence remained associated with AMH (p=0.025). In the prospective phase of the study, AMH concentrations were also associated with seizure occurrence during the menstrual cycle in which the serum sample was obtained (p=0.012). Antiepileptic drugs and other epilepsy factors were not associated with AMH concentrations. When analyzing the Sz- WWE group and the HC group by linear regression with AMH as the dependent variable, after controlling for age and BMI, the association with AMH was also present (p=0.017). AMH concentrations of the Sz+ group and HCs did not differ.

SIGNIFICANCE

In this exploratory analysis, seizure freedom was associated with higher AMH concentrations compared to women with ongoing seizures and to HCs. Future studies should further investigate the mechanism of the association of AMH with seizure occurrence, whether AMH could have a direct seizure-protective neuroactive hormone effect, as well as implications of AMH concentrations as a biomarker for ovarian reserve in women with epilepsy.

Anti-Müllerian hormone: a new actor of sexual dimorphism in pituitary gonadotrope activity before puberty

Anti-Müllerian hormone (AMH) contributes to male sexual differentiation and acts on gonads of both sexes. Identification of AMH receptivity in both pituitary and brain has led to the intriguing idea that AMH participates to the hypothalamic-pituitary control of reproduction, however in vivo experimental evidence is still lacking. We show that AMH stimulates secretion and pituitary gene expression of the gonadotropin FSH in vivo in rats. AMH action is sex-dependent, being restricted to females and occurring before puberty. Accordingly, we report higher levels of pituitary AMH receptor transcripts in immature females. We show that AMH is functionally coupled to the Smad pathway in LβT2 gonadotrope cells and dose-dependently increases Fshb transcript levels. Furthermore, AMH was shown to establish complex interrelations with canonical FSH regulators as it cooperates with activin to induce Fshb expression whereas it reduces BMP2 action. We report that GnRH interferes with AMH by decreasing AMH receptivity in vivo in females. Moreover, AMH specifically regulates FSH and not LH, indicating that AMH is a factor contributing to the differential regulation of gonadotropins. Overall, our study uncovers a new role for AMH in regulating gonadotrope function and suggests that AMH participates in the postnatal elevation of FSH secretion in females.

Novel role for anti-Müllerian hormone in the regulation of GnRH neuron excitability and hormone secretion

Anti-Müllerian hormone (AMH) plays crucial roles in sexual differentiation and gonadal functions. However, the possible extragonadal effects of AMH on the hypothalamic–pituitary–gonadal axis remain unexplored. Here we demonstrate that a significant subset of GnRH neurons both in mice and humans express the AMH receptor, and that AMH potently activates the GnRH neuron firing in mice. Combining in vivo and in vitro experiments, we show that AMH increases GnRH-dependent LH pulsatility and secretion, supporting a central action of AMH on GnRH neurons. Increased LH pulsatility is an important pathophysiological feature in many cases of polycystic ovary syndrome (PCOS), the most common cause of female infertility, in which circulating AMH levels are also often elevated. However, the origin of this dysregulation remains unknown. Our findings raise the intriguing hypothesis that AMH-dependent regulation of GnRH release could be involved in the pathophysiology of fertility and could hold therapeutic potential for treating PCOS.

Anti-Müllerian hormone (AMH) plays a role in sexual differentiation and gonadal function, but extra-gonadal effects of AMH are not known. Here Cimino et al. show that AMH activates a subset of gonadotrophin-releasing hormone (GnRH)-releasing neurons, contributing to luteinizing hormone secretion from the pituitary gland.

Regulation of Murine Ovarian Epithelial Carcinoma by Vaccination against the Cytoplasmic Domain of Anti-Müllerian Hormone Receptor II

Anti-Müllerian hormone receptor, type II (AMHR2), is a differentiation protein expressed in 90% of primary epithelial ovarian carcinomas (EOCs), the most deadly gynecologic malignancy. We propose that AMHR2 may serve as a useful target for vaccination against EOC. To this end, we generated the recombinant 399-amino acid cytoplasmic domain of mouse AMHR2 (AMHR2-CD) and tested its efficacy as a vaccine target in inhibiting growth of the ID8 transplantable EOC cell line in C57BL/6 mice and in preventing growth of autochthonous EOCs that occur spontaneously in transgenic mice. We found that AMHR2-CD immunization of C57BL/6 females induced a prominent antigen-specific proinflammatory CD4+ T cell response that resulted in a mild transient autoimmune oophoritis that resolved rapidly with no detectable lingering adverse effects on ovarian function. AMHR2-CD vaccination significantly inhibited ID8 tumor growth when administered either prophylactically or therapeutically, and protection against EOC growth was passively transferred into naive recipients with AMHR2-CD-primed CD4+ T cells but not with primed B cells. In addition, prophylactic AMHR2-CD vaccination of TgMISIIR-TAg transgenic mice significantly inhibited growth of autochthonous EOCs and provided a 41.7% increase in mean overall survival. We conclude that AMHR2-CD vaccination provides effective immunotherapy of EOC with relatively benign autoimmune complications.

The role of Amh signaling in teleost fish--Multiple functions not restricted to the gonads

This review summarizes the important role of Anti-Müllerian hormone (Amh) during gonad development in fishes. This Tgfβ-domain bearing hormone was named after one of its known functions, the induction of the regression of Müllerian ducts in male mammalian embryos. Later in development it is involved in male and female gonad differentiation and extragonadal expression has been reported in mammals as well. Teleosts lack Müllerian ducts, but they have amh orthologous genes. amh expression is reported from 21 fish species and possible regulatory interactions with further factors like sex steroids and gonadotropic hormones are discussed. The gonadotropin Fsh inhibits amh expression in all fish species studied. Sex steroids show no consistent influence on amh expression. Amh is produced in male Sertoli cells and female granulosa cells and inhibits germ cell proliferation and differentiation as well as steroidogenesis in both sexes. Therefore, Amh might be a central player in gonad development and a target of gonadotropic Fsh. Furthermore, there is evidence that an Amh-type II receptor is involved in germ cell regulation. Amh and its corresponding type II receptor are also present in brain and pituitary, at least in some teleosts, indicating additional roles of Amh effects in the brain-pituitary-gonadal axis. Unraveling Amh signaling is important in stem cell research and for reproduction as well as for aquaculture and in environmental science.

Physiological and pathological roles of tissue plasminogen activator and its inhibitor neuroserpin in the nervous system

Although its roles in the vascular space are most well-known, tissue plasminogen activator (tPA) is widely expressed in the developing and adult nervous system, where its activity is believed to be regulated by neuroserpin, a predominantly brain-specific member of the serpin family of protease inhibitors. In the normal physiological state, tPA has been shown to play roles in the development and plasticity of the nervous system. Ischemic damage, however, may lead to excess tPA activity in the brain and this is believed to contribute to neurodegeneration. In this article, we briefly review the physiological and pathological roles of tPA in the nervous system, which includes neuronal migration, axonal growth, synaptic plasticity, neuroprotection and neurodegeneration, as well as a contribution to neurological disease. We summarize tPA's multiple mechanisms of action and also highlight the contributions of the inhibitor neuroserpin to these processes.

Anti-Müllerian hormone is a gonadal cytokine with two circulating forms and cryptic actions

Anti-Müllerian hormone (AMH) is a multi-faceted gonadal cytokine. It is present in all vertebrates with its original function in phylogeny being as a regulator of germ cells in both sexes, and as a prime inducer of the male phenotype. Its ancient functions appear to be broadly conserved in mammals, but with this being obscured by its overt role in triggering the regression of the Müllerian ducts in male embryos. Sertoli and ovarian follicular cells primarily release AMH as a prohormone (proAMH), which forms a stable complex (AMHN,C) after cleavage by subtilisin/kexin-type proprotein convertases or serine proteinases. Circulating AMH is a mixture of proAMH and AMHN,C, suggesting that proAMH is activated within the gonads and putatively by its endocrine target-cells. The gonadal expression of the cleavage enzymes is subject to complex regulation, and the preliminary data suggest that this influences the relative proportions of proAMH and AMHN,C in the circulation. AMH shares an intracellular pathway with the bone morphogenetic protein (BMP) and growth differentiation factor (GDF) ligands. AMH is male specific during the initial stage of development, and theoretically should produce male biases throughout the body by adding a male-specific amplification of BMP/GDF signalling. Consistent with this, some of the male biases in neuron number and the non-sexual behaviours of mice are dependent on AMH. After puberty, circulating levels of AMH are similar in men and women. Putatively, the function of AMH in adulthood maybe to add a gonadal influence to BMP/GDF-regulated homeostasis.

Vitamin D levels in multiple sclerosis patients: Association with TGF-β2, TGF-βRI, and TGF-βRII expression

AIM

A variety of evidence suggests that vitamin D can prevent the development of multiple sclerosis (MS). TGF-β pathway genes also play important roles in MS. Here, we aim to study whether vitamin D affects TGF-β pathway gene expression and Expanded Disability Status Scale (EDSS) scores in MS patients.

MAIN METHODS

A randomized clinical trial was conducted on 31 relapsing-remitting (RR) MS patients. Using real-time RT-PCR, we tested the levels of TGF-β2, TGF-βRI and TGF-βRII mRNAs in the RRMS patients before and after 8 weeks of supplementation with vitamin D.

KEY FINDINGS

Expression of TGF-β2 mRNA increased 2.84-fold, while TGF-βRI and TGF-βRII mRNA levels did not change after vitamin D treatment. In addition, these results revealed no correlation between the normalized expression of TGF-β2, TGF-βRI, or TGF-βRII and EDSS scores.

SIGNIFICANCE

Here, we demonstrate new evidence for the complex role of vitamin D in the pathogenesis, activity and progression of MS through the TGF-β signaling pathway.

Molecular bases of neuroserpin function and pathology

Serpins build a large and evolutionary widespread protein superfamily, hosting members that are mainly Ser-protease inhibitors. Typically, serpins display a conserved core domain composed of three main β-sheets and 9-10 α-helices, for a total of approximately 350 amino acids. Neuroserpin (NS) is mostly expressed in neurons and in the central and peripheral nervous systems, where it targets tissue-type plasminogen activator. NS activity is relevant for axogenesis, synaptogenesis and synaptic plasticity. Five (single amino acid) NS mutations are associated with severe neurodegenerative disease in man, leading to early onset dementia, epilepsy and neuronal death. The functional aspects of NS protease inhibition are linked to the presence of a long exposed loop (reactive center loop, RCL) that acts as bait for the incoming partner protease. Large NS conformational changes, associated with the cleavage of the RCL, trap the protease in an acyl-enzyme complex. Contrary to other serpins, this complex has a half-life of approximately 10 min. Conformational flexibility is held to be at the bases of NS polymerization leading to Collins bodies intracellular deposition and neuronal damage in the pathological NS variants. Two main general mechanisms of serpin polymerization are currently discussed. Both models require the swapping of the RCL among neighboring serpin molecules. Specific differences in the size of swapped regions, as well as differences in the folding stage at which polymerization can occur, distinguish the two models. The results provided by recent crystallographic and biophysical studies allow rationalization of the functional and pathological roles played by NS based on the analysis of four three-dimensional structures.

Neuroprotective effect of neuroserpin in oxygen-glucose deprivation- and reoxygenation-treated rat astrocytes in vitro

Neuroserpin (NSP) reportedly exerts neuroprotective effects in cerebral ischemic animal models and patients; however, the mechanism of protection is poorly understood. We thus attempted to confirm neuroprotective effects of NSP on astrocytes in the ischemic state and then explored the relative mechanisms. Astrocytes from neonatal rats were treated with oxygen-glucose deprivation (OGD) followed by reoxygenation (OGD/R). To confirm the neuroprotective effects of NSP, we measured the cell survival rate, relative lactate dehydrogenase (LDH) release; we also performed morphological methods, namely Hoechst 33342 staining and Annexin V assay. To explore the potential mechanisms of NSP, the release of nitric oxide (NO) and TNF-α related to NSP administration were measured by enzyme-linked immunosorbent assay. The proteins related to the NF-κB, ERK1/2, and PI3K/Akt pathways were investigated by Western blotting. To verify the cause-and-effect relationship between neuroprotection and the NF-κB pathway, a NF-κB pathway inhibitor sc3060 was employed to observe the effects of NSP-induced neuroprotection. We found that NSP significantly increased the cell survival rate and reduced LDH release in OGD/R-treated astrocytes. It also reduced NO/TNF-α release. Western blotting showed that the protein levels of p-IKKBα/β and P65 were upregulated by the OGD/R treatment and such effects were significantly inhibited by NSP administration. The NSP-induced inhibition could be significantly reversed by administration of the NF-κB pathway inhibitor sc3060, whereas, expressions of p-ERK1, p-ERK2, and p-AKT were upregulated by the OGD/R treatment; however, their levels were unchanged by NSP administration. Our results thus verified the neuroprotective effects of NSP in ischemic astrocytes. The potential mechanisms include inhibition of the release of NO/TNF-α and repression of the NF-κB signaling pathways. Our data also indicated that NSP has little influence on the MAPK and PI3K/Akt pathways.

The polycystic ovary syndrome: a position statement from the European Society of Endocrinology

Polycystic ovary syndrome (PCOS) is the most common ovarian disorder associated with androgen excess in women, which justifies the growing interest of endocrinologists. Great efforts have been made in the last 2 decades to define the syndrome. The presence of three different definitions for the diagnosis of PCOS reflects the phenotypic heterogeneity of the syndrome. Major criteria are required for the diagnosis, which in turn identifies different phenotypes according to the combination of different criteria. In addition, the relevant impact of metabolic issues, specifically insulin resistance and obesity, on the pathogenesis of PCOS, and the susceptibility to develop earlier than expected glucose intolerance states, including type 2 diabetes, has supported the notion that these aspects should be considered when defining the PCOS phenotype and planning potential therapeutic strategies in an affected subject. This paper offers a critical endocrine and European perspective on the debate on the definition of PCOS and summarises all major aspects related to aetiological factors, including early life events, potentially involved in the development of the disorder. Diagnostic tools of PCOS are also discussed, with emphasis on the laboratory evaluation of androgens and other potential biomarkers of ovarian and metabolic dysfunctions. We have also paid specific attention to the role of obesity, sleep disorders and neuropsychological aspects of PCOS and on the relevant pathogenetic aspects of cardiovascular risk factors. In addition, we have discussed how to target treatment choices based according to the phenotype and individual patient's needs. Finally, we have suggested potential areas of translational and clinical research for the future with specific emphasis on hormonal and metabolic aspects of PCOS.

[What's new in 2014 about anti-Müllerian hormone?]

The existence of the anti-Müllerian hormone (AMH) has been postulated by Professor Alfred Jost to explain the regression of the Müllerian ducts during male sexual differentiation. Since then, AMH has been purified, its gene and specific receptor, AMHR-II have been cloned. Further, the signaling pathways were identified and it has been observed that AMH was produced by the granulosa cells of growing follicles. From the 2000s, unexpected roles of AMH have been highlighted, reactivating international research on this hormone. It is now well established that AMH plays a key role in the follicular recruitment and development. Over the past years, serum AMH measurements have been proposed as a marker of the follicular ovarian status, and a predictor of assisted reproductive cycles. AMH is also useful to assess the effectiveness of treatment of some gynecological tumors. This article is a review of the past five years advances on the regulation of the expression of AMH and its specific receptor AMHR-II in female.

Anti-Müllerian hormone recruits BMPR-IA in immature granulosa cells

Anti-Müllerian hormone (AMH) is a member of the TGF-β superfamily secreted by the gonads of both sexes. This hormone is primarily known for its role in the regression of the Müllerian ducts in male fetuses. In females, AMH is expressed in granulosa cells of developing follicles. Like other members of the TGF-β superfamily, AMH transduces its signal through two transmembrane serine/threonine kinase receptors including a well characterized type II receptor, AMHR-II. The complete signalling pathway of AMH involving Smads proteins and the type I receptor is well known in the Müllerian duct and in Sertoli and Leydig cells but not in granulosa cells. In addition, few AMH target genes have been identified in these cells. Finally, while several co-receptors have been reported for members of the TGF-β superfamily, none have been described for AMH. Here, we have shown that none of the Bone Morphogenetic Proteins (BMPs) co-receptors, Repulsive guidance molecules (RGMs), were essential for AMH signalling. We also demonstrated that the main Smad proteins used by AMH in granulosa cells were Smad 1 and Smad 5. Like for the other AMH target cells, the most important type I receptor for AMH in these cells was BMPR-IA. Finally, we have identified a new AMH target gene, Id3, which could be involved in the effects of AMH on the differentiation of granulosa cells and its other target cells.

Premenopausal antimüllerian hormone concentration is associated with subsequent atherosclerosis

OBJECTIVE

The aim of this study was to determine if premenopausal ovarian reserve is associated with susceptibility for atherosclerosis.

METHODS

Female cynomolgus macaques (n = 66, women's equivalent age = 45 y) consumed an atherogenic diet for ∼5 months before the measurement of a marker of ovarian reserve (antimüllerian hormone [AMH]), plasma lipids, follicular phase estradiol, and body weight (BW). Monkeys were then ovariectomized (OVX; n = 17), remained premenopausal (n = 20), or were induced to have reduced ovarian reserve (ROR, n = 29). After 26 additional months consuming the diet, atherosclerosis measurements and risk variables were reassessed.

RESULTS

No differences in baseline AMH, plasma lipids, BW, and estradiol or postdiet lipids and BW were observed among the groups subsequently assigned to the OVX, premenopausal control, or reduced ovarian reserve conditions. Postdiet measurements of atherosclerosis extent did not differ among the groups. However, analysis of plaque size by tertile of baseline AMH revealed that plaques were largest in monkeys that began the experiment with the lowest baseline AMH, followed by those in the middle and high tertiles (plaque extent: low AMH, 0.76 ± 0.12 mm; mid AMH, 0.46 ± 0.1 mm; high AMH, 0.34 ± 0.08 mm; P = 0.02). Baseline AMH and plaque size were also correlated negatively (r = -0.31, P = 0.01). Plasma lipids were also correlated significantly with plaque extent (all P < 0.01) but not with AMH.

CONCLUSIONS

We report for the first time an inverse relationship between a marker of ovarian reserve (AMH) and subsequent atherosclerosis risk.

The male bias in the number of Purkinje cells and the size of the murine cerebellum may require Müllerian inhibiting substance/anti-Müllerian hormone

There is a male bias in the size of the cerebellum, with males, on average, having more Purkinje cells than females. The critical periods in cerebellum development occur when the immature testes secrete Müllerian inhibiting substance (MIS; synonym anti-Müllerian hormone) but only trace levels of testosterone. This suggests that the male bias in the cerebellum is generated by a different mechanism to the testosterone-sensitive reproductive nuclei. Consistent with this, in the present study, we report that Purkinje cells and other cerebella neurones express receptors for MIS, and that MIS(-/-) male mice have female-like numbers of Purkinje cells and a female-like size to other parts of their cerebellum. The size of the cell bodies of Purkinje cells was also dimorphic, although only a minority of this was a result of MIS. This suggests that MIS induces the initial male bias in the cerebellum, which is then refined by pubescent testosterone and/or other sex-specific factors.

Deletions and duplications of developmental pathway genes in 5q31 contribute to abnormal phenotypes

Although copy number changes of 5q31 have been rarely reported, deletions have been associated with some common characteristics, such as short stature, failure to thrive, developmental delay (DD)/intellectual disability (ID), club feet, dislocated hips, and dysmorphic features. We report on three individuals with deletions and two individuals with duplications at 5q31, ranging from 3.6 Mb to 8.1 Mb and 830 kb to 3.4 Mb in size, respectively. All five copy number changes are apparently de novo and involve several genes that are important in developmental pathways, including PITX1, SMAD5, and WNT8A. The individuals with deletions have characteristic features including DD, short stature, club feet, cleft or high palate, dysmorphic features, and skeletal anomalies. Haploinsufficiency of PITX1, a transcription factor important for limb development, is likely the cause for the club feet, skeletal anomalies, and cleft/high palate, while additional genes, including SMAD5 and WNT8A, may also contribute to additional phenotypic features. Two patients with deletions also presented with corneal anomalies. To identify a causative gene for the corneal anomalies, we sequenced candidate genes in a family with apparent autosomal dominant keratoconus with suggestive linkage to 5q31, but no mutations in candidate genes were found. The duplications are smaller than the deletions, and the patients with duplications have nonspecific features. Although development is likely affected by increased dosage of the genes in the region, the developmental disruption appears less severe than that seen with deletion.

The sex bias in novelty preference of preadolescent mouse pups may require testicular Müllerian inhibiting substance

Male mouse pups exhibit elevated preference for novelty relative to their sisters. The testes of pups secrete high levels of Müllerian inhibiting substance (MIS, anti-Müllerian hormone), with neurons being a target of this hormone. We report here that Mis(+/+) male pups exhibit novelty preference, but their Mis(-/-) brothers and Mis(+/+) sisters do not. This suggests that MIS is one of the determinants of "boy"-specific behavior.

Müllerian inhibiting substance is anterogradely transported and does not attenuate avulsion-induced death of hypoglossal motor neurons

Müllerian Inhibiting Substance (MIS, Anti-Müllerian hormone) is a gonadal hormone that contributes to the subtle sex-biases in the nervous system. Mature neurons of both sexes also produce MIS, suggesting that MIS may be a paracrine regulator of adult neural networks. We report here that murine hypoglossal motor neurons produce MIS and its receptors, MISRII and bone morphogenetic protein receptor 1A (BMPR1A, ALK3), but differentially transport them, with only MIS being detectable in axons. The production of MIS and its receptors were rapidly down regulated after axonal damage, which is a characteristic of genes involved in mature neuronal function. MIS is a survival factor for embryonic spinal motor neurons, but the rate of cell loss after hypoglossal nerve avulsion was normal in Mis(-/-) mice and was not attenuated by intraventricular administration of MIS. These observations suggest that MIS may be involved in anterograde rather than autocrine or retrograde regulation of neurons.

Elevated amh gene expression in the brain of male tilapia (Oreochromis niloticus) during testis differentiation

Anti-müllerian hormone (AMH) is expressed in male embryos and represses development of müllerian ducts during testis differentiation in mammals, birds and reptiles. Amh orthologues have been identified in teleosts despite them lacking müllerian ducts. Previously we found sexually dimorphic aromatase activity in tilapia brains before ovarian differentiation. This prompted us to search for further dimorphisms in tilapia brains during sex differentiation and see whether amh is expressed. We cloned the tilapia amh gene and found that it contains 7 exons but no spliced forms. The putative protein presents highest homologies with Amh proteins of pejerrey and medaka as compared to other Perciformes. We analysed amh expression in adult tissues and found elevated levels in testes, ovary and brain. Amh expression was dimorphic with higher levels in XY male brains at 10-15 dpf, when the gonads were still undifferentiated and gonadal amh was not dimorphic. Male brains had 2.7-fold higher amh expression than gonads. Thereafter, amh levels decreased in the brain while they were up-regulated in differentiating testes. Our study indicates that amh is transcribed in male brains already at 10 dpf, suggesting that sexual differentiation may be occurring earlier in tilapia brain than in gonads.

Müllerian inhibiting substance/anti-Müllerian hormone: a potential therapeutic agent for human ovarian and other cancers

According to the 2008 American Cancer Society statistics, cancer remains the second leading cause of death in American today. Early detection, innovative surgery, new drugs and increased public education regarding avoidable risk factors, such as smoking, have had significant impact on the incidence and survival rates of many cancers, while overall death rates from all cancers have declined a modest 5% over the past 50 years. Ovarian cancer statistics, however, have not been as encouraging. Despite recent advances in the management of this disease, 5-year survival has not improved, and the search continues for rationally designed new treatments. Müllerian Inhibiting Substance is a strong candidate because it addresses many of the deficiencies of existing treatments. Namely, Müllerian Inhibiting Substance has little demonstrated toxicity, it complements the activity of known anticancer drugs, it is highly specific against cancers expressing its receptor and it inhibits the proliferation of drug-resistant tumors.