[Show abstract][Hide abstract] ABSTRACT: Lin28 proteins are emerging as important regulators of microRNAs in endocrine systems. Lin28a regulates primordial germ cell development and puberty timing in mice, whereas the related protein LIN28B is associated with age at menarche in genome-wide association studies in humans. Here, we studied expression of LIN28A and LIN28B in early human gonad development. LIN28A increased in the developing ovary between 6 and 9weeks post conception, but not in the developing testis. Immunohistochemistry demonstrated LIN28A in peripheral germ cells. LIN28B was expressed at lower levels in both tissues and did not increase with time. As disruption of Lin28a affects germ cell development in mice, LIN28A was considered a candidate gene for primary ovarian insufficiency (POI) in humans. However, no significant changes were found in 50 women studied. These findings show LIN28A is strongly expressed in germ cells during early human ovary development, but disruption of LIN28A is not a common cause of POI.
[Show abstract][Hide abstract] ABSTRACT: Steroidogenic factor 1 (SF-1, NR5A1) is a key transcriptional regulator of many genes involved in the hypothalamic-pituitary-gonadal axis and mutations in NR5A1 can result in 46,XY disorders of sex development (DSD). Patients with this condition typically present with ambiguous genitalia, partial gonadal dysgenesis, and absent/rudimentary Müllerian structures. In these cases, testosterone is usually low in early infancy, indicating significantly impaired androgen synthesis. Further, Sertoli cell dysfunction is seen (low inhibin B, anti-Müllerian hormone). However, gonadal function at puberty in patients with NR5A1 mutations is unknown.
Clinical assessment, endocrine evaluation, and genetic analysis were performed in one female and one male with 46,XY DSD who showed spontaneous virilization during puberty. The female patient presented at adolescence with clitoral hypertrophy, whereas the male patient presented at birth with severe hypospadias and entered puberty spontaneously. Molecular analysis of NR5A1 was performed followed by in vitro functional analysis of the two novel mutations detected.
Testosterone levels were normal during puberty in both patients. Analysis of NR5A1 revealed two novel heterozygous missense mutations in the ligand-binding domain of SF-1 (patient 1: p.L376F; patient 2: p.G328V). The mutant proteins showed reduced transactivation of the CYP11A promoter in vitro.
Patients with 46,XY DSD and NR5A1 mutations can produce sufficient testosterone for spontaneous virilization during puberty. Phenotypic females (46,XY) with NR5A1 mutations can present with clitoromegaly at puberty, a phenotype similar to other partial defects of androgen synthesis or action. Testosterone production in 46,XY males with NR5A1 mutations can be sufficient for virilization at puberty. As progressive gonadal dysgenesis is likely, gonadal function should be monitored in adolescence and adulthood, and early sperm cryopreservation considered in male patients if possible.
European Journal of Endocrinology 04/2012; 167(1):125-30. DOI:10.1530/EJE-11-0944 · 3.69 Impact Factor
[Show abstract][Hide abstract] ABSTRACT: Steroidogenic factor-1 (SF-1, NR5A1, Ad4BP) is a master regulator of adrenal development and steroidogenesis. Defects in several known targets of SF-1 can cause adrenal disorders in humans.
We aimed to identify novel targets of SF-1 in the human adrenal. These factors could be important regulators of adrenal development and steroidogenesis and potential candidates for adrenal dysfunction.
A gene discovery strategy was developed based on bidirectional manipulation of SF-1. Overexpression or knockdown of SF-1 in NCI-H295R human adrenocortical cells was used to identify a subset of positively-regulated SF-1 targets.
This approach identified well-established SF-1 target genes (STAR, CYP11A) and several novel genes (VSNL1, ZIM2, PEG3, SOAT1, and MTSS1). Given its role in cholesterol metabolism, sterol O-acyltransferase 1 (SOAT1, previously referred to as acyl-Coenzyme A:cholesterol acyltransferase 1, ACAT) was studied further and found to be expressed in the developing human fetal adrenal cortex. We hypothesized that impaired SOAT1 activity could result in adrenal insufficiency through reduced cholesteryl ester reserves or through toxic destruction of the adrenal cells during development. Therefore, mutational analysis of SOAT1 in a cohort of 43 patients with unexplained adrenal insufficiency was performed but failed to reveal significant coding sequence changes.
Our reverse discovery approach led to the identification of novel SF-1 targets and defined SOAT1 as an important factor in human adrenal steroidogenesis. SF-1-dependent up-regulation of SOAT1 may be important for maintaining readily-releasable cholesterol reserves needed for active steroidogenesis and during episodes of recurrent stress.
The Journal of Clinical Endocrinology and Metabolism 02/2011; 96(4):E663-8. DOI:10.1210/jc.2010-2021 · 6.31 Impact Factor
[Show abstract][Hide abstract] ABSTRACT: Human testis development starts from around 42 days post conception with a transient wave of SRY expression followed by up-regulation of testis specific genes and a distinct set of morphological, paracrine and endocrine events. Although anatomical changes in the ovary are less marked, a distinct sub-set of ovary specific genes are also expressed during this time. The furin-domain containing peptide R-spondin1 (RSPO1) has recently emerged as an important regulator of ovary development through up-regulation of the WNT/β-catenin pathway to oppose testis formation. Here, we show that RSPO1 is upregulated in the ovary but not in the testis during critical early stages of gonad development in humans (between 6-9 weeks post conception), whereas the expression of the related genes WNT4 and CTNNB1 (encoding β catenin) is not significantly different between these tissues. Furthermore, reduced R-spondin1 function in the ovotestis of an individual (46,XX) with a RSPO1 mutation leads to reduced β-catenin protein and WNT4 mRNA levels, consistent with down regulation of ovarian pathways. Transfection of wild-type RSPO1 cDNA resulted in weak dose-dependent activation of a β-catenin responsive TOPFLASH reporter (1.8 fold maximum), whereas co-transfection of CTNNB1 (encoding β-catenin) with RSPO1 resulted in dose-dependent synergistic augmentation of this reporter (approximately 10 fold). Furthermore, R-spondin1 showed strong nuclear localization in several different cell lines. Taken together, these data show that R-spondin1 is upregulated during critical stages of early human ovary development and may function as a tissue-specific amplifier of β-catenin signaling to oppose testis determination.
PLoS ONE 01/2011; 6(1):e16366. DOI:10.1371/journal.pone.0016366 · 3.23 Impact Factor
[Show abstract][Hide abstract] ABSTRACT: The nuclear receptor transcription factors DAX-1 (NR0B1) and SF-1 (NR5A1) regulate many aspects of adrenal and reproductive development and function. Disruption of the genes encoding these factors can be associated with pediatric adrenal disease. DAX-1 mutations are classically associated with X-linked adrenal hypoplasia congenita, hypogonadotropic hypogonadism and impaired spermatogenesis. However, other phenotypes are also being reported, such as isolated mineralocorticoid insufficiency, premature sexual development, primary adrenal insufficiency in a 46, XX patient and late-onset X-linked adrenal hypoplasia congenita and/or hypogonadotropic hypogonadism. SF-1 mutations have also been associated with primary adrenal insufficiency, together with 46, XY disorders of sex development. However it is emerging that SF-1 changes are a relatively rare cause of primary adrenal failure in humans, and most individuals with SF-1 mutations have a spectrum of 46, XY disorders of sex development phenotypes. These conditions range from 46, XY females with streak gonads and müllerian structures, through children with ambiguous genitalia and inguinal testes, to severe penoscrotal hypospadias with undescended testes. Therefore, the human gonad appears to be more sensitive than the adrenal gland to loss of SF-1 function. This review will focus on the expanding range of phenotypes associated with DAX-1 and SF-1 mutations.
Endocrine development 01/2011; 20:38-46. DOI:10.1159/000321213
[Show abstract][Hide abstract] ABSTRACT: The nuclear receptor steroidogenic factor-1 (SF-1, NR5A1) is a key regulator of adrenal and gonadal biology. Disruption of SF-1 can lead to disorders of adrenal development, while increased SF-1 dosage has been associated with adrenocortical tumorigenesis. We aimed to identify a novel subset of SF-1 target genes in the adrenal by using chromatin immunoprecipitation (ChIP) microarrays (ChIP-on-chip) combined with systems analysis. SF-1 ChIP-on-chip was performed in NCI-H295R human adrenocortical cells using promoter tiling arrays, leading to the identification of 445 gene loci where SF-1-binding regions were located from 10 kb upstream to 3 kb downstream of a transcriptional start. Network analysis of genes identified as putative SF-1 targets revealed enrichment for angiogenic process networks. A 1.1-kb SF-1-binding region was identified in the angiopoietin 2 (Ang2, ANGPT2) promoter in a highly repetitive region, and SF-1-dependent activation was confirmed in luciferase assays. Angiogenesis is paramount in adrenal development and tumorigenesis, but until now a direct link between SF-1 and vascular remodeling has not been established. We have identified Ang2 as a potentially important novel target of SF-1 in the adrenal gland, indicating that regulation of angiogenesis might be an important additional mechanism by which SF-1 exerts its actions in the adrenal gland.
The FASEB Journal 12/2010; 25(4):1166-75. DOI:10.1096/fj.10-170522 · 5.48 Impact Factor
[Show abstract][Hide abstract] ABSTRACT: Steroidogenic factor-1 (SF-1, Ad4BP, encoded by NR5A1) is a key regulator of adrenal and reproductive development and function. Based upon the features found in Nr5a1 null mice, initial attempts to identify SF-1 changes in humans focused on those rare individuals with primary adrenal failure, a 46,XY karyotype, complete gonadal dysgenesis and Müllerian structures. Although alterations affecting DNA-binding of SF-1 were found in two such cases, disruption of SF-1 is not commonly found in patients with adrenal failure. In contrast, it is emerging that variations in SF-1 can be found in association with a range of human reproductive phenotypes such as 46,XY disorders of sex development (DSD), hypospadias, anorchia, male factor infertility, or primary ovarian insufficiency in women. Overexpression or overactivity of SF-1 is also reported in some adrenal tumors or endometriosis. Therefore, the clinical spectrum of phenotypes associated with variations in SF-1 is expanding and the importance of this nuclear receptor in human endocrine disease is now firmly established.
[Show abstract][Hide abstract] ABSTRACT: One in seven couples worldwide are infertile, and male factor infertility accounts for approximately 30%-50% of these cases. Although many genes are known to be essential for gametogenesis, there are surprisingly few monogenic mutations that have been conclusively demonstrated to cause human spermatogenic failure. A nuclear receptor, NR5A1 (also called steroidogenic factor 1), is a key transcriptional regulator of genes involved in the hypothalamic-pituitary-steroidogenic axis, and it is expressed in the steroidogenic tissue of the developing and adult human gonad. Mutations of NR5A1 have been reported in 46,XY disorders of sex development and in 46,XX primary ovarian insufficiency. To test the hypothesis that mutations in NR5A1 cause male infertility, we sequenced NR5A1 in 315 men with idiopathic spermatogenic failure. We identified seven men with severe spermatogenic failure who carried missense mutations in NR5A1. Functional studies indicated that these mutations impaired NR5A1 transactivational activity. We did not observe these mutations in more than 4000 control alleles, including the entire coding sequence of 359 normospermic men and 370 fertile male controls. NR5A1 mutations are found in approximately 4% of men with otherwise unexplained severe spermatogenic failure.
The American Journal of Human Genetics 09/2010; 87(4):505-12. DOI:10.1016/j.ajhg.2010.09.009 · 10.99 Impact Factor
[Show abstract][Hide abstract] ABSTRACT: Familial glucocorticoid deficiency (FGD) is an autosomal recessive disorder resulting from resistance to the action of ACTH on the adrenal cortex. Affected individuals are deficient in cortisol and, if untreated, are likely to succumb to hypoglycemia and/or overwhelming infection. Mutations of the ACTH receptor (MC2R) and the melanocortin 2 receptor accessory protein (MRAP), FGD types 1 and 2 respectively, account for approximately 45% of cases.
A locus on chromosome 8 has previously been linked to the disease in three families, but no underlying gene defect has to date been identified.
The study design comprised single-nucleotide polymorphism genotyping and mutation detection.
The study was conducted at secondary and tertiary referral centers.
Eighty probands from families referred for investigation of the genetic cause of FGD participated in the study.
There were no interventions.
Analysis by single-nucleotide polymorphism array of the genotype of one individual with FGD previously linked to chromosome 8 revealed a large region of homozygosity encompassing the steroidogenic acute regulatory protein gene, STAR. We identified homozygous STAR mutations in this patient and his affected siblings. Screening of our total FGD patient cohort revealed homozygous STAR mutations in a further nine individuals from four other families.
Mutations in STAR usually cause lipoid congenital adrenal hyperplasia, a disorder characterized by both gonadal and adrenal steroid deficiency. Our results demonstrate that certain mutations in STAR (R192C and the previously reported R188C) can present with a phenotype indistinguishable from that seen in FGD.
The Journal of Clinical Endocrinology and Metabolism 09/2009; 94(10):3865-71. DOI:10.1210/jc.2009-0467 · 6.31 Impact Factor
[Show abstract][Hide abstract] ABSTRACT: Hypospadias is a frequent congenital anomaly but in most cases an underlying cause is not found. Steroidogenic factor 1 (SF-1, NR5A1, Ad4BP) is a key regulator of human sex development and an increasing number of SF-1 (NR5A1) mutations are reported in 46,XY disorders of sex development (DSD). We hypothesized that NR5A1 mutations could be identified in boys with hypospadias.
Mutational analysis of NR5A1 in 60 individuals with varying degrees of hypospadias from the German DSD network.
Heterozygous NR5A1 mutations were found in three out of 60 cases. These three individuals represented the most severe end of the spectrum studied as they presented with penoscrotal hypospadias, variable androgenization of the phallus and undescended testes (three out of 20 cases (15%) with this phenotype). Testosterone was low in all three patients and inhibin B/anti-Müllerian hormone (AMH) were low in two patients. Two patients had a clear male gender assignment. Gender re-assignment to male occurred in the third case. Two patients harbored heterozygous nonsense mutations (p.Q107X/WT, p.E11X/WT). One patient had a heterozygous splice site mutation in intron 2 (c.103-3A/WT) predicted to disrupt the main DNA-binding motif. Functional studies of the nonsense mutants showed impaired transcriptional activation of an SF-1-responsive promoter (Cyp11a). To date, adrenal insufficiency has not occurred in any of the patients.
SF-1 (NR5A1) mutations should be considered in 46,XY individuals with severe (penoscrotal) hypospadias, especially if undescended testes, low testosterone, or low inhibin B/AMH levels are present. SF-1 mutations in milder forms of idiopathic hypospadias are unlikely to be common.
European Journal of Endocrinology 05/2009; 161(2):237-42. DOI:10.1530/EJE-09-0067 · 3.69 Impact Factor
[Show abstract][Hide abstract] ABSTRACT: The genetic causes of nonsyndromic ovarian insufficiency are largely unknown. A nuclear receptor, NR5A1 (also called steroidogenic factor 1), is a key transcriptional regulator of genes involved in the hypothalamic-pituitary-steroidogenic axis. Mutation of NR5A1 causes 46,XY disorders of sex development, with or without adrenal failure, but growing experimental evidence from studies in mice suggests a key role for this factor in ovarian development and function as well.
To test the hypothesis that mutations in NR5A1 cause disorders of ovarian development and function, we sequenced NR5A1 in four families with histories of both 46,XY disorders of sex development and 46,XX primary ovarian insufficiency and in 25 subjects with sporadic ovarian insufficiency. None of the affected subjects had clinical signs of adrenal insufficiency.
Members of each of the four families and 2 of the 25 subjects with isolated ovarian insufficiency carried mutations in the NR5A1 gene. In-frame deletions and frameshift and missense mutations were detected. Functional studies indicated that these mutations substantially impaired NR5A1 transactivational activity. Mutations were associated with a range of ovarian anomalies, including 46,XX gonadal dysgenesis and 46,XX primary ovarian insufficiency. We did not observe these mutations in more than 700 control alleles.
NR5A1 mutations are associated with 46,XX primary ovarian insufficiency and 46,XY disorders of sex development.
New England Journal of Medicine 03/2009; 360(12):1200-10. DOI:10.1056/NEJMoa0806228 · 54.42 Impact Factor
[Show abstract][Hide abstract] ABSTRACT: Disorders of adrenal development result in significant morbidity and mortality. However, the molecular basis of human adrenal development, and many forms of disease, is still poorly understood.
We evaluated the role of two new candidate genes, CBP/p300-interacting transactivator, with Glu/Asp-rich C-terminal domain, 2 (CITED2), and pre-B-cell leukemia transcription factor 1 (PBX1), in human adrenal development and disease.
CITED2 and PBX1 expression in early human fetal adrenal development was assessed using RT-PCR and in situ hybridization. The regulation of CITED2 and PBX1 by steroidogenic factor-1 (SF-1) and dosage-sensitive sex reversal, adrenal hypoplasia congenital, critical region on the X chromosome, gene-1 (DAX1) was evaluated in NCI-H295R human adrenocortical tumor cells by studying promoter regulation. Finally, mutational analysis of CITED2 and PBX1 was performed in patients with primary adrenal disorders.
CITED2 and PBX1 are expressed in the human fetal adrenal gland during early development. Both genes are activated by SF-1 in a dose-dependent manner in NCI-H295R cells, and, surprisingly, PBX1 is synergistically activated by SF-1 and DAX1. Mutational analysis failed to reveal significant coding sequence changes in individuals with primary adrenal disorders.
CITED2 and PBX1 are likely to be important mediators of adrenal development and function in humans, but mutations in these genes are not common causes of adrenal failure in patients in whom a molecular diagnosis remains unknown. The positive interaction between DAX1 and SF-1 in regulating PBX1 may be an important mechanism in this process.
[Show abstract][Hide abstract] ABSTRACT: BACKGROUND Steroidogenic factor 1 (SF1/AdBP4/FTZF1, NR5A1) is a nuclear receptor transcription factor that plays a key role in regulating adrenal and gonadal development, steroidogenesis and reproduction. Recently, haploinsufficiency of SF1 has been described in several 46,XY individuals with mild gonadal dysgenesis and impaired androgenization, but normal adrenal function, suggesting that dosage-sensitive or domain-specific effects of SF1 action are important in human testicular development and function. Our objective was to investigate whether partial defects in SF1 function might be associated with milder male reproductive phenotypes, such as bilateral anorchia ('vanishing testis syndrome') and micropenis. METHODS This study involved mutational analysis of NR5A1 in 24 individuals with bilateral anorchia and micropenis from the French Collaborative Anorchia study, as well as in vitro functional studies of SF1-dependent transcriptional activation and computer modeling. RESULTS A novel heterozygous missense mutation (V355M) in SF1 was found in one boy with a micropenis and testicular regression syndrome. This non-synonymous change was found to affect a highly conserved amino acid within helix 7 of the ligand-binding domain of SF1. This V355M mutation did not affect stability or nuclear localization, but did result in an approximately 50% reduction in SF1 activity in several different assay systems. CONCLUSIONS In conclusion, heterozygous partial loss of function mutations in SF1 may be associated with bilateral anorchia ('vanishing testis syndrome') and micropenis in humans.
Human Reproduction 11/2008; 22(12):3255-61. DOI:10.1093/humrep/dem278 · 4.59 Impact Factor
[Show abstract][Hide abstract] ABSTRACT: Mitochondrial cytochrome P450scc converts cholesterol to pregnenolone in all steroidogenic tissues. Although progesterone production from the fetally-derived placenta is necessary to maintain pregnancy to term, four patients with mutations in the gene encoding P450scc (CYP11A1), have been described, one in a 46,XX female and three in underandrogenized 46,XY individuals, all with primary adrenal failure.
Our aim was to determine whether P450scc mutations might be found in other children and to explore genotype/phenotype correlations.
We performed mutational analysis of CYP11A1 in individuals with 46,XY disorders of sex development and primary adrenal failure, followed by functional studies of P450scc activity and of P450scc RNA splicing.
Among nine 46,XY infants with adrenal failure and disordered sexual differentiation, two infants had compound heterozygous mutations in CYP11A1. One patient harbored the novel P450scc missense mutations L141W and V415E, which retained 38 and 0% activity, respectively. The other carried a CYP11A1 frameshift mutation c835delA (0% activity) and a splice site mutation [IVS3+(2-3)insT] that prevented correct splicing of P450scc mRNA.
P450scc deficiency is a recently recognized disorder that may be more frequent than originally thought. The phenotypic spectrum ranges from severe loss-of-function mutations associated with prematurity, complete underandrogenization, and severe, early-onset adrenal failure, to partial deficiencies found in children born at term with clitoromegaly and later-onset adrenal failure. In contradistinction to congenital lipoid adrenal hyperplasia caused by steroidogenic acute regulatory protein mutations, adrenal hyperplasia has not been reported in any of the six patients with P450scc deficiency.
[Show abstract][Hide abstract] ABSTRACT: Steroidogenic factor 1 (SF1, NR5A1) is a nuclear receptor that regulates multiple genes involved in adrenal and gonadal development, steroidogenesis, and the reproductive axis. Human mutations in SF1 were initially found in two 46,XY female patients with severe gonadal dysgenesis and primary adrenal failure. However, more recent case reports have suggested that heterozygous mutations in SF1 may also be found in patients with 46,XY partial gonadal dysgenesis and underandrogenization but normal adrenal function. We have analyzed the gene encoding SF1 (NR5A1) in a cohort of 27 patients with 46,XY disorders of sex development (DSD) from the German network of DSD. Heterozygous SF1 mutations were found in 5 out of 27 (18.5%) of cases. Four patients with SF1 mutations presented with the similar phenotype of mild gonadal dysgenesis, severe underandrogenization, and absent Müllerian structures. Of these, two patients harbored missense mutations within the DNA-binding region of SF1 (p.C33S, p.R84H), one patient had a nonsense mutation (p.Y138X) and one patient had a frameshift mutation (c.1277dupT) predicted to disrupt RNA stability or protein function. One additional patient ([c.424_427dupCCCA]+[p.G146A]) displayed a more marked phenotype of severe gonadal dysgenesis, normal female external genitalia, and Müllerian structures. Functional studies of the missense mutants (p.C33S, p.R84H) and of one nonsense mutant (p.Y138X) revealed impaired transcriptional activation of SF1-responsive target genes. To date, adrenal insufficiency has not occurred in any of the patients. Thus, SF1 mutations are a relatively frequent cause of 46,XY DSD in humans.
Human Mutation 01/2008; 29(1):59-64. DOI:10.1002/humu.20588 · 5.05 Impact Factor
[Show abstract][Hide abstract] ABSTRACT: Steroidogenic factor 1 (SF1/AdBP4/FTZF1, NR5A1) is a nuclear receptor transcription factor that plays a key role in regulating adrenal and gonadal development, steroidogenesis, and reproduction. Targeted deletion of Nr5a1 (Sf1) in the mouse results in adrenal and gonadal agenesis, XY sex-reversal, and persistent Müllerian structures in males. Consistent with the murine phenotype, human mutations in SF1 were described initially in two 46,XY individuals with female external genitalia, Müllerian structures (uterus), and primary adrenal failure.
Given recent case reports of haploinsufficiency of SF1 affecting testicular function in humans, we aimed to identify SF1 mutations in a cohort of individuals with a phenotypic spectrum of 46,XY gonadal dysgenesis/impaired androgenization (now termed 46,XY disorders of sex development) with normal adrenal function.
The study included mutational analysis of NR5A1 in 30 individuals with 46,XY disorders of sex development, followed by functional studies of SF1 activity.
Heterozygous missense mutations in NR5A1 were found in four individuals (four of 30, 13%) with this phenotype. These mutations (V15M, M78I, G91S, L437Q) were shown to impair transcriptional activation through abnormal DNA binding (V15M, M78I, G91S), altered subnuclear localization (V15M, M78I), or disruption of the putative ligand-binding pocket (L437Q). Two mutations appeared to be de novo or germline changes. The other two mutations appeared to be inherited in a sex-limited dominant manner because the mother is heterozygous for the change.
These studies demonstrate that SF1 mutations are more frequent than previously suspected causes of impaired fetal and postnatal testicular function in 46,XY individuals.