Testicular Stem Cell Dysfunction Due to Environmental Insults Could Be Responsible for Deteriorating Reproductive Health of Men.

Reproductive health of men has declined over time including reduced semen quality specifically sperm count, increased incidence of infertility, and testicular cancers. Our recent findings suggest that these disease states possibly arise as a result of disruption of testicular stem cells biology by perinatal insults including exposure to endocrine disrupting chemicals. Testicular stem cells include relatively quiescent, very small embryonic-like stem cells (VSELs), and actively dividing spermatogonial stem cells (SSCs). Both VSELs and SSCs express estrogen receptors and are directly vulnerable to endocrine disruption. Exposing mice pups to estradiol (20 µg/pup/day on days 5-7) or diethylstilbestrol (2 µg/pup/day on days 1-5) affected spermatogenesis during adult life with reduced numbers of tubules in stage VIII, tetraploid cells and sperm. These mice were infertile and majority of diethylstilbestrol treated mice revealed testicular cancer-like changes. An increase in VSEL numbers, observed by both flow cytometry and qRT-PCR, was associated with marked reduction of c-KIT positive spermatogonial cells. VSELs undergo epigenetic changes due to endocrine disruption that results in blocked differentiation (impaired spermatogenesis) leading to reduced sperm count and infertility, and their excessive self-renewal initiates cancer-like changes in adult life. Thus, testicular dysgenesis syndrome (TDS) has a stem cell rather than a genetic basis.

Clinical Report: Warsaw Breakage Syndrome with small radii and fibulae.

We present two new cases of Warsaw Breakage Syndrome (WABS), an autosomal recessive cohesinopathy, in sisters aged 13 and 11 years who both had compound heterozygous mutations in DDX11. After exclusion of Fanconi anemia, Bloom syndrome and Nijmegen breakage syndrome, whole exome sequencing revealed two novel variants-c.1523T>G, predicting (p.Leu508Arg) and c.1949-1G>A (IVS19-1G>A), that were confirmed with Sanger sequencing in both affected individuals. DDX11 encodes an iron-sulfur-containing DNA helicase, and mutations in this gene have been reported in the five WABS cases previously identified to date. The sisters reported here display the distinguishing clinical features of WABS: pre- and post-natal growth restriction, microcephaly, intellectual disability, sensorineural hearing loss with cochlear abnormalities, and facial dysmorphic features. In addition, our cases had early menarche at 8 and 10 years of age, bilateral small thumbs, and the younger, more severely affected sister had small fibulae. These findings broaden the WABS phenotype and the limb malformations demonstrate further clinical overlap with Fanconi anemia and other cohesinopathies, such as Roberts Syndrome.

Dibutyl phthalate induced testicular dysgenesis originates after seminiferous cord formation in rats.

Administration of dibutyl phthalate (DBP) to pregnant rats causes reproductive disorders in male offspring, resulting from suppression of intratesticular testosterone, and is used as a model for human testicular dysgenesis syndrome (TDS). DBP exposure in pregnancy induces focal dysgenetic areas in fetal testes that appear between e19.5-e21.5, manifesting as focal aggregation of Leydig cells and ectopic Sertoli cells (SC). Our aim was to identify the origins of the ectopic SC. Time-mated female rats were administered 750 mg/kg/day DBP in three different time windows: full window (FW; e13.5-e20.5), masculinisation programming window (MPW; e15.5-e18.5), late window (LW; e19.5-e20.5). We show that DBP-MPW treatment produces more extensive and severe dysgenetic areas, with more ectopic SC and germ cells (GC) than DBP-FW treatment; DBP-LW induces no dysgenesis. Our findings demonstrate that ectopic SC do not differentiate de novo, but result from rupture of normally formed seminiferous cords beyond e20.5. The more severe testis dysgenesis in DBP-MPW animals may result from the presence of basally migrating GC and a weakened basal lamina, whereas GC migration was minimal in DBP-FW animals. Our findings provide the first evidence for how testicular dysgenesis can result after normal testis differentiation/development and may be relevant to understanding TDS in human patients.

New NR5A1 mutations and phenotypic variations of gonadal dysgenesis.

Mutations in NR5A1 have been reported as a frequent cause of 46,XY disorders of sex development (DSD) associated to a broad phenotypic spectrum ranging from infertility, ambiguous genitalia, anorchia to gonadal dygenesis and female genitalia. Here we present the clinical follow up of four 46,XY DSD patients with three novel heterozygous mutations in the NR5A1 gene leading to a p.T40P missense mutation and a p.18DKVSG22del nonframeshift deletion in the DNA-binding domain and a familiar p.Y211Tfs*83 frameshift mutation. Functional analysis of the missense and nonframeshift mutation revealed a deleterious character with loss of DNA-binding and transactivation capacity. Both, the mutations in the DNA-binding domain, as well as the familiar frameshift mutation are associated with highly variable endocrine values and phenotypic appearance. Phenotypes vary from males with spontaneous puberty, substantial testosterone production and possible fertility to females with and without Müllerian structures and primary amenorrhea. Exome sequencing of the sibling's family revealed TBX2 as a possible modifier of gonadal development in patients with NR5A1 mutations.

MAP3K1-related gonadal dysgenesis: Six new cases and review of the literature.

Investigation of disorders of sex development (DSD) has resulted in the discovery of multiple sex-determining genes. MAP3K1 encodes a signal transduction regulator in the sex determination pathway and is emerging as one of the more common genes responsible for 46,XY DSD presenting as complete or partial gonadal dysgenesis. Clinical assessment, endocrine evaluation, and genetic analysis were performed in six individuals from four unrelated families with 46,XY DSD. All six individuals were found to have likely pathogenic MAP3K1 variants. Three of these individuals presented with complete gonadal dysgenesis, characterized by bilateral streak gonads with typical internal and external female genitalia, while the other three presented with partial gonadal dysgenesis, characterized by incomplete testicular development, resulting in clitoral hypertrophy with otherwise typical female external genitalia. Testing for MAP3K1 variants should be considered in patients with 46,XY complete or partial gonadal dysgenesis, particularly in families with multiple members affected with 46,XY DSD. Identification of a MAP3K1 variant should prompt an evaluation for DSD in female siblings of the proband.

Genetics of Reproductive Aging from Gonadal Dysgenesis through Menopause.

Reproduction is essential for the survival of the species and is influenced by external factors such as smoking and exposure to chemotherapy as well as chronic disorders such as obesity and autoimmunity. Reproductive senescence, such as menopause, is also dependent on multiple intrinsic genetic factors. Reproductive aging is not isolated from an overall aging process, and several studies strongly support the link between the early age of menopause and mortality. The extreme form of reproductive aging is primary ovarian insufficiency (POI) with prevalence ranging from 1 to 5% of the female population. POI has been shown to have long-term consequences on overall health. POI and age of menopause have a significant hereditary component. The population-based genome-wide association studies have identified 44 genomic loci to associate with age of menopause, and 29 of 44 loci harbor DNA damage response genes. Recent application of whole exome sequencing on carefully selected families with POI has also revealed a significant contribution of DNA damage response genes. The inability to repair the DNA damage in both somatic and germ cells might be a predisposing factor for the link between reproductive and overall aging in a subset of individuals with POI. The aim of this review is to characterize recent advances in the genetics of POI and its link with overall health.

[Effects of Chronic Irradiation at Low Doses on Morphological Indicators of Reproductive System of Dysgenic Female Drosophila melanogaster].

In this paper the contribution of chronic irradiation at low doses (0.42 mGy/h) and dysgenesis to changing morphological parameters (gonadal atrophy/sterility and ovarian reserve) of the reproductive system of female Drosophild melanogaster is rated. It is shown that the sterilizing effect of dysgenesis is enhanced predominantly by irradiation of the maternal line. The level of ovarian reserve of irradiated females depends on the type of dysgenic system. Unlike I-R females in whom the level of radiation-induced ovarian reserve does not differ from the control, both decrease (in P-M females) and increase (in H-E females) is observed in the ovariole number. The results indicate the important role of mobile genetic elements destabilizing the genome in the modification of reproductive functions of females exposed to chronic-action of low-intensity γ-radiation.

A case of 46,XX dysgenesis and marked tall stature; the need for caution in interpreting array comparative genomic hybridization (CGH).

BACKGROUND: Gonadal dysgenesis with an apparently normal 46,XX karyotype is a rare cause of hypergonadotrophic hypogonadism. Tall stature is not a widely recognized association. CASE REPORT: A 15-year-old girl presented with primary amenorrhoea. Examination showed a non-dysmorphic girl of normal intellect with no breast development (Tanner stage B1P4A1) who was tall compared with her parents: height standard deviation score (SDS) +1.56 vs. midparental height of +0.23 SDS, and slim build (weight -0.13 SDS). Investigations showed a 46,XX karyotype, elevated gonadotropins (FSH 119 and LH 33.7 IU/L), serum estradiol <5 pmol/L, uterine length 3.75 cm with cylindrical shape, and absent ovaries on ultrasound. Initially, a 364055-bp deletion on Xp21.2 was reported on array CGH. However, repeat analysis using BlueGnome CytoChip ISCA 4x180k v2.0 array was normal. With oral ethinyl estradiol induction puberty progressed to B4P4A2 but aged 18.4 years, the patient was remarkably tall with height SDS +2.88, weight SDS +0.97. CONCLUSIONS: Caution is needed in interpreting small changes with array CGH, particularly with the older assays. We postulate that the genetic change causing 46,XX gonadal dysgenesis in our patient may have also resulted in unsuppressed somatic growth. More critical height assessment, including parental height measurement, of future patients with 46,XX gonadal dysgenesis is recommended in order to determine whether or not a true association with tall stature may be present in certain cases.

Reproductive and obstetric outcomes in mosaic Turner's Syndrome: a cross-sectional study and review of the literature.

BACKGROUND: Turner's syndrome (TS) is depicted as a total or partial absence of one X chromosome that results in ovarian dysgenesis. Chances of spontaneous pregnancy in TS are rare and the outcome of the pregnancies is known to be poor with an increased risk of miscarriage and stillbirths. Our aim is to evaluate reproductive and obstetric outcomes of natural conception and in-vitro fertilization (IVF) cycles in mosaic TS patients. METHODS: A total of 22 mosaic TS cases (seventeen 45,X/46,XX and five 45,X/46,XX/47,XXX karyotypes) were evaluated. RESULTS: Live birth and abortion rates were found as 32.7 % and 67.3 %, respectively in 52 pregnancies. Implantation, clinical pregnancy and take home baby rates were detected as 3.7 %, 8.6 % and 5.7 %, respectively per IVF cycle as a result of 35 cycles. Fecundability analysis revealed that 5 % of the cases experienced first pregnancy within 6 months and 8 % within the first 2 years. Mosaicism ratio did not have an effect on the time to the first pregnancy (p = .149). CONCLUSION: Only a small proportion of the mosaic TS patients conceive in the first 2 years of the marriage. Age of menarche and age of marriage appear not to have any impact on the chance of conceiving. Mosaic TS cases should counseled about the low odds of pregnancy and high miscarriage rates.

Live birth after blastocyst transfer following only 2 days of progesterone administration in an agonadal oocyte recipient.

In oocyte donation cycles where hormone replacement is given to recipients, progesterone administration is necessary to induce the luteal phase and synchronize the endometrium with the embryo stage. Most studies suggest that 5-7 days of progesterone are needed to prepare the endometrium for a day-5 embryo transfer and provide optimal implantation rate. This paper reports a case where an agonadal oocyte recipient received only 2 days of progesterone prior to the embryo transfer of a day-5 embryo. She subsequently had a clinical pregnancy and a live birth.

Hypoestrogenism in young women and its influence on bone mass density.

One of the most important hormonal factors responsible for bone health is estradiol. Genetic factors, adequacy of hormonal functioning, nutrition and physical activity may be the markers of bone status and development in young women. During adolescence, women reach peak bone acquisition and develop a skeletal mass. This process is largely regulated by endocrine factors mainly such as adequate levels of gonadal, adrenal and pituitary hormones. The crucial role played by estradiol and its impact on bones are very multiple. Estradiol induces growth factors' activation, receptor activator of nuclear factor kappa B ligand (RANKL) production inhibition and is mainly referred to antiresorptive activity. Clinical situations leading to hypoestrogenism has been linked to decreased bone mineral density leading to osteopenia and osteoporosis. This status both in fertile and perimenopausal women can increase the risk of pathological fractures. Such conditions as hypothalamic-pituitary insufficiency (functional hypothalamic amenorrhea, anorexia nervosa, Kallmann syndrome, hyperprolactinemia), ovarian failure (gonadal dysgenesis, premature ovarian failure) and iatrogenic treatment (surgery, chemotherapy, radiotherapy) can cause hypoestrogenism. The treatment of osteopenia and osteoporosis caused by hypoestrogenism is very essential and multidirectional. The crucial role of the therapy is the achievement of proper serum estradiol concentration and eliminate the causes of hypoestrogenism.

Pure gonadal dysgenesis and spontaneous pregnancy: a case report.

We report a case of pure gonadal dysgenesis with streak gonads in which spontaneous conception occurred 10 years after the diagnosis. Her pregnancy proceeded as normal, and she gave birth to a live baby at term by cesarean section. A lactation period lasting for 1 year and afterwards proceeded as amenorrheic. Gonadotropins measurements in post-lactational period were at the menopausal levels again. To the best of our knowledge, this is the first case of pure gonadal dysgenesis with streak gonads in which spontaneous conception occurred.

Unilateral ovarian and fallopian tube agenesis.

INTRODUCTION: The unilateral agenesis of the ovary and fallopian tube is an extremely uncommon event with only few cases described in literature. CASE REPORT: Here, we report a case of a 30-year-old woman admitted to our Unit for increasing pelvic pain. In the suspect of a corpus luteum hemorrhage, we performed a laparoscopy identifying the rare anomaly. DISCUSSION: Together with the predisposing genetic and/or environmental factor not yet discovered, two are the hypotheses explaining the absence of one or both the adnexes, the mechanical hypothesis, i.e., the asymptomatic torsion of both Fallopian tube and ovary with consequent organs' ischemia and atresia and the embryological hypothesis, i.e., the congenital absence of the adnexes.

The transforming growth factor-beta superfamily in early spermatogenesis: potential relevance to testicular dysgenesis.

Regulated transforming growth factor-beta (TGFbeta) superfamily signalling is an integral part of normal testicular development and the processes that enable the production of fertile sperm. Through shared utilization of receptors, signal transduction components and inhibitors, many ligands in this family exhibit functional overlaps; this facet of their function is critical to understand because these ligands are often co-expressed and, hence, they may compete with or compensate for one another, depending on the specific cellular context. This review describes particular germ cell maturation steps governed by bone morphogenetic proteins, glial cell line-derived neurotrophic factor and activins, focusing on data predominantly from rodent studies that implicate activin and other family members in modulation of gonocyte and spermatogonial stem cell development. We also review knowledge of the TGFbeta superfamily signalling components in the human testis, exploring their potential impact on the processes associated with disrupted gonocyte development and an enhanced risk of testicular cancer.

Role of androgens in fetal testis development and dysgenesis.

This study sought to establish whether reduced androgen levels/action in the fetal rat testis induced by di(n-butyl) phthalate (DBP) contributes to dysgenetic features, namely reduced Sertoli cell number, occurrence of multinucleated gonocytes (MNG), and Leydig cell aggregation. Pregnant rats were administered treatments or cotreatments designed to manipulate testosterone levels [DBP, testosterone propionate (TP)] or action [flutamide, 7,12-dimethyl-benz[a]anthracene (DMBA)]. The aforementioned end points were analyzed and related to intratesticular testosterone (ITT) levels and peripheral androgen action (anogenital distance). Dysgenetic features were also evaluated in mice with inactivation of the androgen receptor (testicular feminized or ARKO mice). Exposure to DBP alone, or combined with flutamide, DMBA, or TP, resulted in reduced Sertoli cell number and ITT levels, as did exposure to TP alone; coadministration of DBP + TP caused the most severe reduction in both parameters. A positive correlation between ITT levels and Sertoli cell number was found (r = 0.791; P = 0.019). Similarly, exposure to DBP alone, or as a cotreatment, significantly increased occurrence of MNG and Leydig cell aggregation, and these were negatively correlated with ITT levels. Exposure to flutamide or DMBA alone had no significant effect on these dysgenetic end points. These findings suggest that reduced ITT decreases fetal Sertoli cell numbers and might be involved in Leydig cell aggregation and MNG. However, of these three end points, only Sertoli cell number was affected significantly in ARKO/testicular feminized mice with absent androgen action. Therefore, induction of MNG and Leydig cell aggregation might result from DBP-induced effects other than suppression of ITT levels.

Phthalate ester toxicity in Leydig cells: developmental timing and dosage considerations.

Humans have significant exposures to phthalates, as these chemical plasticizers are ubiquitously present in flexible plastics. Recent epidemiological evidence indicates that boys born to women exposed to phthalates during pregnancy have an increased incidence of congenital genital malformations and spermatogenic dysfunction, signs of a condition referred to as testicular dysgenesis syndrome (TDS). TDS is thought to develop as a result of environmental factors that cause a testicular disturbance at an early fetal stage with a resultant spectrum of clinical testicular dysfunction, ranging from impaired spermatogenesis and genital malformations to increased risk for development of testicular cancer. Proposed environmental factors in the etiology of TDS include endocrine disrupting compounds such as the phthalates. Leydig cells have been classified as one of the main targets for phthalate ester toxicity in the body based on studies in rodents. In support of this hypothesis, two Leydig cell products - insulin-like growth factor 3 (INSL3) and testosterone (T) - are both suppressed after phthalate exposures. Both fetal and adult generations of Leydig cells are affected by phthalate esters, although their sensitivities may differ. In rodent models, when pregnant dams are exposed to phthalate esters, fetal Leydig cells form enlarged clusters that are retained in the testis even after birth, in contrast to untreated controls. Despite the retention of fetal Leydig cells, however, their numbers and average cell volume of total in exposed males are reduced, as are INSL3 production and steroidogenic competence. These alterations are directly associated with clinical features of TDS, including cryptorchidism and impaired spermatogenesis.

Steroidogenic factor-1 (SF-1) and its relevance to pediatric endocrinology.

Steroidogenic factor-1 (SF-1) (NR5A1) is a member of the nuclear receptor superfamily that is expressed widely throughout the adrenal and reproductive axes during development and plays a central role in the function of these endocrine systems in post-natal and adult life. Much has been learned about the role of this transcription factor since its initial cloning in 1992, largely due to the creation of an Sf-1 (FtzF1) knockout mouse model, in vitro studies of nuclear receptor function and, more recently, following identification and characterization of patients with naturally-occurring SF-1 mutations. In this review, we will summarize how our knowledge of SF-1 in endocrine development and disease evolved to its current state, focusing on the spectrum of phenotypes associated with mutations in this transcription factor in patients who might present to a pediatric endocrinologist.