Apolipoprotein D (APOD) is a putative biomarker of androgen receptor function in androgen insensitivity syndrome

Sex-biased human thymic architecture guides T cell development through spatially defined niches

Within the thymus, regulation of the cellular crosstalk directing T cell development depends on spatial interactions within specialized niches. To create a spatially defined map of tissue niches guiding human postnatal T cell development, we employed the multidimensional imaging platform co-detection by indexing (CODEX) as well as cellular indexing of transcriptomes and epitopes sequencing (CITE-seq) and assay for transposase accessible chromatin sequencing (ATAC-seq). We generated age-matched 4- to 5-month-old human postnatal thymus datasets for male and female donors, identifying significant sex differences in both T cell and thymus biology. We demonstrate a possible role for JAG ligands in directing thymic-like dendritic cell development, identify important functions of a population of extracellular matrix (ECM)- fibroblasts, and characterize the medullary niches surrounding Hassall's corpuscles. Together, these data represent an age-matched spatial multiomic resource to investigate how sex-based differences in thymus regulation and T cell development arise, providing an essential resource to understand the mechanisms underlying immune function and dysfunction in males and females.

Classic genetic and hormonal switches during fetal sex development and beyond

Critical genetic and hormonal switches characterize fetal sex development in humans. They are decisive for gonadal sex determination and subsequent differentiation of the genital and somatic sex phenotype. Only at the first glace these switches seem to behave like the dual 0 and 1 system in computer sciences and lead invariably to either typically male or female phenotypes. More recent data indicate that this model is insufficient. In addition, in case of distinct mutations, many of these switches may act variably, causing a functional continuum of alterations of gene functions and -dosages, enzymatic activities, sex hormone levels, and sex hormone sensitivity, giving rise to a broad clinical spectrum of biological differences of sex development (DSD) and potentially diversity of genital and somatic sex phenotypes. The gonadal anlage is initially a bipotential organ that can develop either into a testis or an ovary. Sex-determining region Y (SRY) is the most important upstream switch of gonadal sex determination inducing SOX9 further downstream, leading to testicular Sertoli cell differentiation and the repression of ovarian pathways. If SRY is absent (virtually "switched off"), e. g., in 46,XX females, RSPO1, WNT4, FOXL2, and other factors repress the male pathway and promote ovarian development. Testosterone and its more potent derivative, dihydrotestosterone (DHT) as well as AMH, are the most important upstream hormonal switches in phenotypic sex differentiation. Masculinization of the genitalia, i. e., external genital midline fusion forming the scrotum, growth of the genital tubercle, and Wolffian duct development, occurs in response to testosterone synthesized by steroidogenic cells in the testis. Müllerian ducts will not develop into a uterus and fallopian tubes in males due to Anti-Müllerian-Hormone (AMH) produced by the Sertoli cells. The functionality of these two hormone-dependent switches is ensured by their corresponding receptors, the intracellular androgen receptor (AR) and the transmembrane AMH type II receptor. The absence of high testosterone and high AMH is crucial for anatomically female genital development during fetal life. Recent technological advances, including single-cell and spatial transcriptomics, will likely shed more light on the nature of these molecular switches.

Sex biased human thymic architecture guides T cell development through spatially defined niches

Within the thymus, regulation of the cellular cross-talk directing T cell development is dependent on spatial interactions within specialized niches. To create a holistic, spatially defined map of tissue niches guiding postnatal T cell development we employed the multidimensional imaging platform CO-detection by indEXing (CODEX), as well as CITE-seq and ATAC-seq. We generated age-matched 4-5-month-old postnatal thymus datasets for male and female donors, and identify significant sex differences in both T cell and thymus biology. We demonstrate a crucial role for JAG ligands in directing thymic-like dendritic cell development, reveal important functions of a novel population of ECM- fibroblasts, and characterize the medullary niches surrounding Hassall's corpuscles. Together, these data represent a unique age-matched spatial multiomic resource to investigate how sex-based differences in thymus regulation and T cell development arise, and provide an essential resource to understand the mechanisms underlying immune function and dysfunction in males and females.

What Does Androgen Receptor Signaling Pathway in Sertoli Cells During Normal Spermatogenesis Tell Us?

Androgen receptor signaling pathway is necessary to complete spermatogenesis in testes. Difference between androgen binding location in Sertoli cell classifies androgen receptor signaling pathway into classical signaling pathway and non-classical signaling pathway. As the only somatic cell type in seminiferous tubule, Sertoli cells are under androgen receptor signaling pathway regulation via androgen receptor located in cytoplasm and plasma membrane. Androgen receptor signaling pathway is able to regulate biological processes in Sertoli cells as well as germ cells surrounded between Sertoli cells. Our review will summarize the major discoveries of androgen receptor signaling pathway in Sertoli cells and the paracrine action on germ cells. Androgen receptor signaling pathway regulates Sertoli cell proliferation and maturation, as well as maintain the integrity of blood-testis barrier formed between Sertoli cells. Also, Spermatogonia stem cells achieve a balance between self-renewal and differentiation under androgen receptor signaling regulation. Meiotic and post-meiotic processes including Sertoli cell - Spermatid attachment and Spermatid development are guaranteed by androgen receptor signaling until the final sperm release. This review also includes one disease related to androgen receptor signaling dysfunction named as androgen insensitivity syndrome. As a step further ahead, this review may be conducive to develop therapies which can cure impaired androgen receptor signaling in Sertoli cells.

The Lipocalin Apolipoprotein D Functional Portrait: A Systematic Review

Apolipoprotein D is a chordate gene early originated in the Lipocalin protein family. Among other features, regulation of its expression in a wide variety of disease conditions in humans, as apparently unrelated as neurodegeneration or breast cancer, have called for attention on this gene. Also, its presence in different tissues, from blood to brain, and different subcellular locations, from HDL lipoparticles to the interior of lysosomes or the surface of extracellular vesicles, poses an interesting challenge in deciphering its physiological function: Is ApoD a moonlighting protein, serving different roles in different cellular compartments, tissues, or organisms? Or does it have a unique biochemical mechanism of action that accounts for such apparently diverse roles in different physiological situations? To answer these questions, we have performed a systematic review of all primary publications where ApoD properties have been investigated in chordates. We conclude that ApoD ligand binding in the Lipocalin pocket, combined with an antioxidant activity performed at the rim of the pocket are properties sufficient to explain ApoD association with different lipid-based structures, where its physiological function is better described as lipid-management than by long-range lipid-transport. Controlling the redox state of these lipid structures in particular subcellular locations or extracellular structures, ApoD is able to modulate an enormous array of apparently diverse processes in the organism, both in health and disease. The new picture emerging from these data should help to put the physiological role of ApoD in new contexts and to inspire well-focused future research.

Adolescent Gynecomastia due to Minimal Androgen Resistance Syndrome: A Case Report and Literature Review

A 14-year-old boy with a 46,XY karyotype and persistent breast-3-stage gynecomastia is reported. The reproductive axis was investigated by standard laboratory methods and the androgen receptor (AR) gene was sequenced. Also, a literature review of phenotypes associated with the AR genetic variant p.Pro392Ser was performed. The boy presented with height in the upper normal range (+1.9 SDS) and normal body mass index (-0,3 SDS); pubertal development was PH5/G4 (mean testicular volume 15 mL; 0 SDS). Laboratory findings were normal for age and sex, except aromatization index (0.09; reference range 0.03-0.07). Analysis of the AR gene showed the single nucleotide variant c.1174C>T (p.Pro392Ser) in exon 1, leading to the diagnosis of minimal androgen insensitivity syndrome (AIS). This genetic variant is reported in other 8 patients with AIS and is associated with variable clinical phenotypes ranging from complete to partial and minimal AIS. To the best of our knowledge, this is the first adolescent in whom the p.Pro392Ser mutation is associated with isolated persistent gynecomastia. The underlying reason of phenotypic variability due to this AR mutation remains unknown. Persistent gynecomastia due to minimal AIS has been reported in few additional males with variable AR mutations. Since fertility troubles may occur in adult men with minimal AIS, early diagnosis can allow optimizing the clinical management.

Molecular basis of androgen insensitivity syndromes

Individuals with complete androgen insensitivity syndrome show a female genital phenotype despite 46, XY gonosomes and the presence of androgen producing testes. This clinical observation indicates the resistance of the body and its cells to androgens like testosterone. At the molecular level, this hormone resistance is caused by hemizygous loss of function mutations in the X-chromosomal androgen receptor (AR) gene. Partial forms of androgen insensitivity syndrome (PAIS) show different degrees of virilisation largely depending on the remaining activity of the AR. Nevertheless, the phenotypic outcome can be variable even in presence of the same mutation and in the same kindred indicating the presence of further influencing factors. Importantly, the majority of clinically diagnosed PAIS individuals do not bear a mutation in their AR gene. A recent assay using the androgen regulated gene apolipoprotein D as biomarker is able to detect androgen insensitivity on the cellular level even in absence of an AR gene mutation. Using this assay a class of AIS without an AR-gene mutation was defined as AIS type II and suggests that unidentified cofactors of the AR are responsible for the PAIS phenotype. Here we outline the scientific progress made from the first clinical definition of AIS over biochemical and molecular characterizations to the concept of AIS type II. This review is based on publications in the PubMed database of the National Institutes of Health using the search terms androgen insensitivity syndrome and androgen receptor mutation.

Apolipoprotein D

ApoD is a 25 to 30 kDa glycosylated protein, member of the lipocalin superfamily. As a transporter of several small hydrophobic molecules, its known biological functions are mostly associated to lipid metabolism and neuroprotection. ApoD is a multi-ligand, multi-function protein that is involved lipid trafficking, food intake, inflammation, antioxidative response and development and in different types of cancers. An important aspect of ApoD's role in lipid metabolism appears to involve the transport of arachidonic acid, and the modulation of eicosanoid production and delivery in metabolic tissues. ApoD expression in metabolic tissues has been associated positively and negatively with insulin sensitivity and glucose homeostasis in a tissue dependent manner. ApoD levels rise considerably in association with aging and neuropathologies such as Alzheimer's disease, stroke, meningoencephalitis, moto-neuron disease, multiple sclerosis, schizophrenia and Parkinson's disease. ApoD is also modulated in several animal models of nervous system injury/pathology.

Dihydrotestosterone induces minor transcriptional alterations in genital skin fibroblasts of children with and without androgen insensitivity

Endogenous and exogenous androgens induce masculinization of external genitalia through binding to the androgen receptor (AR). The target genes of androgens in external genitalia remain to be determined, although previous studies have shown that the apolipoprotein D gene (APOD) was significantly upregulated by dihydrotestosterone (DHT), the most potent androgen in humans. In the present study, we performed microarray analysis for genital skin fibroblasts obtained from four boys with buried penis (the control individuals) and a patient with partial androgen insensitivity syndrome (PAIS) due to a hypomorphic mutation in AR (the PAIS patient). We identified 24 transcripts that were upregulated or downregulated by DHT in all samples of control individuals and, to a lesser extent, in the sample of the PAIS patient. Differences between DHT-treated and -untreated samples were small; the results of 24 transcripts did not reach statistical significance. The 24 transcripts included CYP1B1, a gene possibly involved in the development of genital tubercle in mice, and APOD, as well as several genes that have been reported as androgen targets in prostate or other tissues. The results of this study indicate that androgen-mediated masculinization of external genitalia is unlikely to depend on massive transcriptional changes in specific AR target genes. Rather, minor transcriptional changes of several genes, and/or a complex molecular network may play a major role in penile development. Importantly, our data suggest the possible involvement of CYP1B1 in human genital development and confirm the clinical importance of APOD as a biomarker for AR function.

Epigenetic Repression of Androgen Receptor Transcription in Mutation-Negative Androgen Insensitivity Syndrome (AIS Type II)

CONTEXT

Inactivating mutations within the AR gene are present in only ~40% of individuals with clinically and hormonally diagnosed androgen insensitivity syndrome (AIS). Previous studies revealed the existence of an AR gene mutation-negative group of patients with AIS who have compromised androgen receptor (AR) function (AIS type II).

OBJECTIVE

To investigate whether AIS type II can be due to epigenetic repression of AR transcription.

DESIGN

Quantification of AR mRNA and AR proximal promoter CpG methylation levels in genital skin-derived fibroblasts (GFs) derived from patients with AIS type II and control individuals.

SETTING

University hospital endocrine research laboratory.

PATIENTS

GFs from control individuals (n = 11) and patients with AIS type II (n = 14).

MAIN OUTCOME MEASURE(S)

Measurement of AR mRNA and AR promoter CpG methylation as well as activity of AR proximal promoter in vitro.

RESULTS

Fifty-seven percent of individuals with AIS type II (n = 8) showed a reduced AR mRNA expression in their GFs. A significant inverse correlation was shown between AR mRNA abundance and methylation at two consecutive CpGs within the proximal AR promoter. Methylation of a 158-bp-long region containing these CpGs was sufficient to severely reduce reporter gene expression. This region was bound by the runt related transcription factor 1 (RUNX1). Ectopic expression of RUNX1 in HEK293T cells was able to inhibit reporter gene expression through this region.

CONCLUSIONS

Aberrant CpGs methylation within the proximal AR promoter plays an important role in the control of AR gene expression and may result in AIS type II. We suggest that transcriptional modifiers, such as RUNX1, could play roles therein offering new perspectives for understanding androgen-mediated endocrine diseases.

The evaluation and management of the boy with DSD

Atypical genitalia in a boy may have a very wide and diverse aetiology and a definitive diagnosis is often challenging to reach. Detailed clinical evaluation integrated with extensive biochemical and genetic studies play an important role in this process. Such care should be undertaken in highly specialized centres that can also provide access to a multidisciplinary team for optimal long-term care.

A recurrent synonymous mutation in the human androgen receptor gene causing complete androgen insensitivity syndrome

Androgen insensitivity syndrome (AIS) is the most common cause of 46,XY disorders of sex development (46,XY DSD). This syndrome is an X-linked inheritance disease and it is caused by mutations in the human androgen receptor (AR) gene. Non-synonymous point AR mutations are frequently described in this disease, including in the complete phenotype. We present a novel synonymous mutation in the human AR gene (c.1530C > T) in four 46,XY patients from two unrelated families associated with complete androgen insensitivity syndrome (CAIS). The analysis of mRNA from testis showed that synonymous AR mutation changed the natural exon 1 donor splice site, with deletion of the last 92 nucleotides of the AR exon 1 leading to a premature stop codon 12 positions ahead resulting in a truncate AR protein. Linkage analyses suggested a probable founder effect for this mutation. In conclusion, we described the first synonymous AR mutation associated with CAIS phenotype, reinforcing the disease-causing role of synonymous mutations.

[Estimation of the diagnostic potential of APOD, PTOV1, and EPHA4 for prostatic neoplasms]

Prostate cancer is one of the most frequently detected malignancies in men. The gold standard for its diagnosis is morphological examination; at the same time the differential diagnosis of adenocarcinoma, high-grade prostatic intraepithelial neoplasia (HGPIN), and benign conditions that are able to mimic the malignancies is tremendously difficult in a number of cases, this being so, the hyperdiagnosis rate of HGPIN requiring mandatory repeat biopsy is as high as 24%. The currently available differential diagnostic panel of antibodies is imperfect, which necessitates a search for novel markers.

AIM

to estimate the diagnostic and prognostic value of the expression of PTOV1, APOD, and EPHA4 in prostatic neoplasias.

MATERIAL AND METHODS

A total of 90 samples from prostate cancer patients who had undergone radical prostatectomy were examined. The presence of adenocarcinoma and HGPIN was verified by immunohistochemical tests using antibodies to AMACR (P504S) and high molecular weight cytokeratin 34βE12 in serial sections. The latter were also used to immunohistochemically analyze the expression of PTOV1, APOD, and EPHA4.

RESULTS

APOD expression was noted in 76% of cases of both adenocarcinomas and HGPIN, in 4% in only cancer, and in 7% in only HGPIN. All the study samples showed a considerable decrease in PTOV1 expression in cancer and HGPIN compared to morphologically normal glands. Three samples also exhibited no PTOV1 expression in a number of morphologically normal glands. No difference was found in the expression of EPHA4 in morphologically normal glands, HGPIN, or cancer.

CONCLUSION

The high rate of APOD expression in HGPIN and cancer, as well as the absence of its expression in the vast majority of morphologically normal glands allows the use of this protein as an additional marker in the differential diagnosis of prostatic neoplasms. The emerging trends in the difference of PTOV1 expression in morphologically normal prostate tissue, HGPIN, and cancer call for further investigations with a larger sample.

Identification of an AR Mutation-Negative Class of Androgen Insensitivity by Determining Endogenous AR Activity

CONTEXT

Only approximately 85% of patients with a clinical diagnosis complete androgen insensitivity syndrome and less than 30% with partial androgen insensitivity syndrome can be explained by inactivating mutations in the androgen receptor (AR) gene.

OBJECTIVE

The objective of the study was to clarify this discrepancy by in vitro determination of AR transcriptional activity in individuals with disorders of sex development (DSD) and male controls.

DESIGN

Quantification of DHT-dependent transcriptional induction of the AR target gene apolipoprotein D (APOD) in cultured genital fibroblasts (GFs) (APOD assay) and next-generation sequencing of the complete coding and noncoding AR locus.

SETTING

The study was conducted at a university hospital endocrine research laboratory.

PATIENTS

GFs from 169 individuals were studied encompassing control males (n = 68), molecular defined DSD other than androgen insensitivity syndrome (AIS; n = 18), AR mutation-positive AIS (n = 37), and previously undiagnosed DSD including patients with a clinical suspicion of AIS (n = 46).

INTERVENTION(S)

There were no interventions.

MAIN OUTCOME MEASURE(S)

DHT-dependent APOD expression in cultured GF and AR mutation status in 169 individuals was measured.

RESULTS

The APOD assay clearly separated control individuals (healthy males and molecular defined DSD patients other than AIS) from genetically proven AIS (cutoff < 2.3-fold APOD-induction; 100% sensitivity, 93.3% specificity, P < .0001). Of 46 DSD individuals with no AR mutation, 17 (37%) fell below the cutoff, indicating disrupted androgen signaling.

CONCLUSIONS

AR mutation-positive AIS can be reliably identified by the APOD assay. Its combination with next-generation sequencing of the AR locus uncovered an AR mutation-negative, new class of androgen resistance, which we propose to name AIS type II. Our data support the existence of cellular components outside the AR affecting androgen signaling during sexual differentiation with high clinical relevance.

A Recurrent Germline Mutation in the 5'UTR of the Androgen Receptor Causes Complete Androgen Insensitivity by Activating Aberrant uORF Translation

A subset of patients with monogenic disorders lacks disease causing mutations in the protein coding region of the corresponding gene. Here we describe a recurrent germline mutation found in two unrelated patients with complete androgen insensitivity syndrome (CAIS) generating an upstream open reading frame (uORF) in the 5’ untranslated region (5’-UTR) of the androgen receptor (AR) gene. We show in patient derived primary genital skin fibroblasts as well as in cell-based reporter assays that this mutation severely impacts AR function by reducing AR protein levels without affecting AR mRNA levels. Importantly, the newly generated uORF translates into a polypeptide and the expression level of this polypeptide inversely correlates with protein translation from the primary ORF of the AR thereby providing a model for AR-5′UTR mediated translational repression. Our findings not only add a hitherto unrecognized genetic cause to complete androgen insensitivity but also underline the importance of 5′UTR mutations affecting uORFs for the pathogenesis of monogenic disorders in general.

Association between the ABCC11 gene polymorphism and the expression of apolipoprotein D by the apocrine glands in axillary osmidrosis

It has been suggested that the adenosine triphosphate‑binding cassette sub‑family C member 11 (ABCC11) gene polymorphism and apolipoprotein D (ApoD), an odor precursor carrier, may be important in the formation of axillary odor. To date, few studies have examined the potential correlation between these two factors. The present study aimed to investigate the association between a 538 G>A single‑nucleotide polymorphism (SNP) of the ABCC11 gene and the mRNA expression levels of ApoD in the apocrine gland of patients with osmidrosis. The 538 G>A polymorphism genotypes of 33 patients with a clinical diagnosis of osmidrosis were analyzed by polymerase chain reaction (PCR) and a base‑quenched probe method, and they were divided into two groups according to the results. The G allele functions as a dominant gene; therefore, patients with the GG or GA genotype were allocated to Group I (n=28) and patients with the AA genotype to Group II (n=5). The mRNA expression levels of ApoD in the apocrine glands were determined by reverse transcription‑PCR. The results indicated that the mRNA expression levels of ApoD were significantly higher in the apocrine glands of patients in Group I compared with those in Group II (P<0.01). In conclusion, the results indicated that the ABCC11 gene SNP of the 538 G>A allele was associated with a downregulation of the mRNA expression of ApoD in the apocrine glands, which may indicate a role for the ABCC11 gene in the mediation of osmidrosis by enhancing the transition of odor precursors via the ApoD pathway.

Management of disorders of sex development

The medical term disorders of sex development (DSDs) is used to describe individuals with an atypical composition of chromosomal, gonadal and phenotypic sex, which leads to differences in the development of the urogenital tract and reproductive system. A variety of genetic factors have been identified that affect sex development during gonadal differentiation or in specific disorders associated with altered androgen biosynthesis or action. The diagnosis of DSDs in individuals and the subsequent management of patients and their families requires a targeted and structured approach, involving a multidisciplinary team with effective communication between the disciplines. This approach includes distinct clinical, imaging, laboratory and genetic evaluations of patients with DSDs. Although treatment of patients with DSDs can include endocrine and surgical options, many patients have concerns that arise from past incorrect treatments that were founded on the traditional binary concept of the sexes. To dispel these concerns, it is necessary to create centres of expertise for DSDs that include physicians, surgeons, psychologists and specialists in diagnostic procedures to manage patients and their families. Additionally, the inclusion of trained peer support in the multidisciplinary DSD team seems to be integral to the supportive management of patients with DSDs. Most importantly, dealing with DSDs requires acceptance of the fact that deviation from the traditional definitions of gender is not necessarily pathologic.

AR and SRD5A2 gene mutations in a series of 51 Turkish 46,XY DSD children with a clinical diagnosis of androgen insensitivity

46,XY disorders of sex development (DSD) are caused by disorders of gonadal development, androgen biosynthesis and receptor (AR) defects. Although, clinical/biochemical features help in distinguishing specific aetiologies, there are overlaps which necessitate molecular analyses for the definitive diagnosis. To test precision of our clinical diagnosis of androgen insensitivity (AIS) by analysing AR and then SRD5A2 genes, patients were recruited at Marmara University Hospital and molecular analyses were performed at Vall d'Hebron Research Institute. Among 101 46,XY DSD patients, 46 index and five siblings (nine complete, 42 partial) with clinical/biochemical data suggestive of AIS and stimulated T/DHT ratio <25 were selected. AR and then SRD5A2 genes were sequenced. We detected AR mutations in 11 patients [seven index and four siblings (22% of all and 15% of index patients)] and SRD5A2 mutations in six [five index and one sibling (12% of all and 11% of index)]. AR mutation detection rate was 6/9 in all CAIS and 4/7 in the index (67 and 57% respectively) and 5/42 in all PAIS and 3/40 in the index (12 and 7.5% respectively). The eight mutations detected in the AR gene were as follows: p.Q58L, p.P392S, p.R609K, p.R775H, p.R856H, p.A871A, p.V890M and p.F892L, with p.A871A and p.F892L being novel. Further six patients had SRD5A2 mutations which were as follows: p.L73WfsX59, p.Y91H, p.R171S and p.G196S, the first being novel. Hormonal data in those with AR mutations, SRD5A2 mutations and no mutations were not statistically different. In conclusion, a significant proportion of children with presumptive diagnosis of AIS has a normal AR gene. The less severe the phenotype, the less likely is the chance of demonstrating a mutation. Furthermore, a significant number of children with presumptive diagnosis of AIS have mutations in SRD5A2 gene and are clinically and biochemically indistinguishable from AIS.

Androgen receptor function links human sexual dimorphism to DNA methylation

Sex differences are well known to be determinants of development, health and disease. Epigenetic mechanisms are also known to differ between men and women through X-inactivation in females. We hypothesized that epigenetic sex differences may also result from sex hormone functions, in particular from long-lasting androgen programming. We aimed at investigating whether inactivation of the androgen receptor, the key regulator of normal male sex development, is associated with differences of the patterns of DNA methylation marks in genital tissues. To this end, we performed large scale array-based analysis of gene methylation profiles on genomic DNA from labioscrotal skin fibroblasts of 8 males and 26 individuals with androgen insensitivity syndrome (AIS) due to inactivating androgen receptor gene mutations. By this approach we identified differential methylation of 167 CpG loci representing 162 unique human genes. These were significantly enriched for androgen target genes and low CpG content promoter genes. Additional 75 genes showed a significant increase of heterogeneity of methylation in AIS compared to a high homogeneity in normal male controls. Our data show that normal and aberrant androgen receptor function is associated with distinct patterns of DNA-methylation marks in genital tissues. These findings support the concept that transcription factor binding to the DNA has an impact on the shape of the DNA methylome. These data which derived from a rare human model suggest that androgen programming of methylation marks contributes to sexual dimorphism in the human which might have considerable impact on the manifestation of sex-associated phenotypes and diseases.

The differential role of androgens in early human sex development

Sexual development in humans is only partly understood at the molecular level. It is dependent on genetic control primarily induced by the sex chromosomal differences between males and females. This leads to the development of the gonads, whereby afterwards the differentiation of the apparent phenotype is controlled by hormone action. Sex steroids may exert permanent and temporary effects. Their organizational features of inducing permanent changes in phenotype occur through genetic control of downstream genes. In this, androgens are the key elements for the differentiation of male internal and external genitalia as well as other sexual organs and general body composition, acting through a single androgen receptor. The androgen receptor is a nuclear transcription factor modulating DNA transcription of respective target genes and thereby driving development and growth in a stringent manner. The specificity of androgen action seems to be a strictly time-controlled process with the androgen receptor acting in concert with different metabolites and an array of cofactors modulating the cellular response and thereby permanently altering the phenotype of any given individual. For every cell programmed by androgens, a specific 'androgen response index' must be proposed.

Male gender identity in complete androgen insensitivity syndrome

Women and girls with complete androgen insensitivity syndrome (CAIS) invariably have a female typical core gender identity. In this case report, we describe the first case of male gender identity in a CAIS individual raised female leading to complete sex reassignment involving both androgen treatment and phalloplasty. CAIS was diagnosed at age 17, based on an unambiguously female phenotype, a 46,XY karyotype, and a 2660delT androgen receptor (AR) gene mutation, leading to a premature stop in codon 807. Bilateral gonadectomy was performed but a short period of estrogen treatment induced a negative emotional reaction and treatment was stopped. Since the age of 3, childhood-onset cross gender behavior had been noticed. After a period of psychotherapy, persisting male gender identity was confirmed. There was no psychiatric co-morbidity and there was an excellent real life experience. Testosterone substitution was started, however without inducing any of the desired secondary male characteristics. A subcutaneous mastectomy was performed and the patient received phalloplasty by left forearm free flap and scrotoplasty. Testosterone treatment was continued, without inducing virilization, and bone density remained normal. The patient qualifies as female-to-male transsexual and was treated according to the Standards of Care by the World Professional Association for Transgender Health with good outcome. However, we do not believe that female sex of rearing as a standard procedure should be questioned in CAIS. Our case challenges the role of a functional AR pathway in the development of male gender identity.

Increased JNK1 activity contributes to the upregulation of ApoD in the apocrine secretory gland cells from axillary osmidrosis

Axillary osmidrosis is a benign disorder that causes functional and emotional problems in Asian patients. Recently, ApoD has been identified as an axillary odorant binding protein. The present study was designed to compare the expression of ApoD in normal and osmidrosis subjects. Compared with the normal subjects, osmidrosis subjects had a higher expression of AR and ApoD in the apocrine samples, both at mRNA and protein level. Further study showed that, consistent with the increased ApoD and AR, phosphorylated JNK1 was higher in apocrine samples from axillary osmidrosis subjects, while with no obvious differences of the total expression of JNK1. In the cultured apocrine epithelial cells from normal subjects, 5α-dihydrotestosterone (5α-DHT) increased the expression of ApoD in a dose dependent manner, which can be inhibited by the JNK1 inhibitor. In contrast, in the cultured apocrine epithelial cells from axillary osmidrosis subjects, inhibition of JNK1 significantly reduced the expression of ApoD. Taken together, our study here revealed that increased JNK1 activation in the apocrine cells from axillary osmidrosis contributes to the increased ApoD expression, which in turn involved in the process of axillary osmidrosis.

Androgen receptor mutations are associated with altered epigenomic programming as evidenced by HOXA5 methylation

Male external genital differentiation is accompanied by implementation of a long-term, male-specific gene expression pattern indicating androgen programming in cultured genital fibroblasts. We hypothesized the existence of an epigenetic background contributing to this phenomenon. DNA methylation levels in 2 normal scrotal fibroblast strains from 46,XY males compared to 2 labia majora fibroblast strains from 46,XY females with complete androgen insensitivity syndrome (AIS) due to androgen receptor (AR) mutations were analyzed by Illumina GoldenGate methylation arrays®. Results were validated with pyrosequencing in labia majora fibroblast strains from fifteen 46,XY patients and compared to nine normal male scrotal fibroblast strains. HOXA5 showed a significantly higher methylation level in complete AIS. This finding was confirmed by bisulfite pyrosequencing of 14 CpG positions within the HOXA5 promoter in the same strains. Extension of the 2 groups revealed a constant low HOXA5 methylation pattern in the controls in contrast to a highly variable methylation pattern in the AIS patients. HOXA5 represents a candidate gene of androgen-mediated promoter methylation. The constantly low HOXA5 DNA methylation level of normal male scrotal fibroblast strains and the frequently high methylation levels in labia majora fibroblast strains in AIS indicate for the first time that androgen programming in sexual differentiation is not restricted to global gene transcription but also occurs at the epigenetic level.

46,XY disorders of sex development--the undermasculinised male with disorders of androgen action

Insensitivity to the action of androgens is a common cause of undermasculinisation in 46,XY individuals. These disorders are a result of the failure of major androgens to act via the intracellular androgen receptor and, thus, the genomic effects of androgen signalling are disrupted. The phenotype of affected individuals can vary considerably, depending on the dysfunction of the receptor. In childhood, the diagnosis is often complicated due to the lack of sensitive biochemical determinants, whilst during adolescence and in adults, the diagnosis can be readily made because of the striking clinical feminisation and a conclusive laboratory analysis. A variety of mutations in the androgen receptor have been analysed, providing insight into the complex pathways of intracellular processing and signal transduction via the androgen receptor. Endocrine therapy in androgen-insensitivity syndrome is controversial, because till date the special hormonal profiles in androgen insensitivity have not been acknowledged in replacement strategies.