Role of hormones, genes, and environment in human cryptorchidism

Exomic and Epigenomic Analyses in a Pair of Monozygotic Twins Discordant for Cryptorchidism

Cryptorchidism represents one of the most common human congenital anomalies. In most cases, its etiology remains unclear and seems to be multifactorial. In the present study, a pair of monozygotic twins discordant for cryptorchidism was identified. Twin zygosity was confirmed by microsatellite genotyping. Whole exome sequencing and methylated DNA immunoprecipitation sequencing (MeDIP-Seq) of DNA extract from leucocytes were performed to, respectively, evaluate their exomes and epigenomes. No differences in exome sequencing data were found between the twins after validation. MeDIP-Seq analysis detected 5,410 differentially hypermethylated genes and 2,383 differentially hypomethylated genes. Bioinformatic analysis showed that these genes belonged to several biological processes and signaling pathways, including regulation of actin cytoskeleton, which has been previously implicated in the etiology of cryptorchidism. The findings of the present study suggest that non-genetic factors might contribute to the pathogenesis of cryptorchidism.

Ibuprofen results in alterations of human fetal testis development

Among pregnant women ibuprofen is one of the most frequently used pharmaceutical compounds with up to 28% reporting use. Regardless of this, it remains unknown whether ibuprofen could act as an endocrine disruptor as reported for fellow analgesics paracetamol and aspirin. To investigate this, we exposed human fetal testes (7–17 gestational weeks (GW)) to ibuprofen using ex vivo culture and xenograft systems. Ibuprofen suppressed testosterone and Leydig cell hormone INSL3 during culture of 8–9 GW fetal testes with concomitant reduction in expression of the steroidogenic enzymes CYP11A1, CYP17A1 and HSD17B3, and of INSL3. Testosterone was not suppressed in testes from fetuses younger than 8 GW, older than 10–12 GW, or in second trimester xenografted testes (14–17 GW). Ex vivo, ibuprofen also affected Sertoli cell by suppressing AMH production and mRNA expression of AMH, SOX9, DHH, and COL2A1. While PGE2 production was suppressed by ibuprofen, PGD2 production was not. Germ cell transcripts POU5F1, TFAP2C, LIN28A, ALPP and KIT were also reduced by ibuprofen. We conclude that, at concentrations relevant to human exposure and within a particular narrow ‘early window’ of sensitivity within first trimester, ibuprofen causes direct endocrine disturbances in the human fetal testis and alteration of the germ cell biology.

Cryptorchidism: A practical review for all community healthcare providers

Cryptorchidism is one of the most common congenital anomalies of the male genitalia, occurring in 1% of boys by the age of one year. Even though the etiology of cryptorchidism is multifactorial, management has evolved with the clear recognition that hormonal treatment is not effective and surgery between 6-18 months of age leads to better testicular outcomes. Diagnostic laparoscopy is considered the standard approach for management of non-palpable testes, and can be combined with one or two-stage orchidopexy, with up to 80-90% success rates. This review discusses the natural history of retractile testicles, indications for hormonal treatment and orchidectomy, ultrasound's role as a diagnostic tool, risks of infertility and testicular cancer, and surgical techniques for inguinal and intra-abdominal testes.

Hormonally active agents in the environment: a state-of-the-art review

After the Second World War, infatuation with modern products has exponentially widened the spectrum of chemicals used. Some of them are capable of hijacking the endocrine system by blocking or imitating a hormone and are referred to as hormonally active chemicals or endocrine disruptors. These are chemicals that the body was not designed for evolutionarily and they are present in every matrix of the environment. We are living in a chemical world where the exposures are ubiquitous and take place in combinations that can interact with the endocrine system and some other metabolic activities in unexpected ways. The complexity of interaction of these compounds can be understood by the fact that they interfere with gene expression at extremely low levels, consequently harming an individual life form, its offspring or population. As the endocrine system plays a critical role in many biological or physiological functions, by interfering body's endocrine system, endocrine disrupting compounds (EDCs) have various adverse effects on human health, starting from birth defects to developmental disorders, deadly deseases like cancer and even immunological disorders. Most of these compounds have not been tested yet for safety and their effects cannot be assessed by the available techniques. The establishment of proper exposure measurement techniques and integrating correlation is yet to be achieved to completely understand the impacts at various levels of the endocrine axis.

Genomic copy number variation association study in Caucasian patients with nonsyndromic cryptorchidism

Background

Copy number variation (CNV) is a potential contributing factor to many genetic diseases. Here we investigated the potential association of CNV with nonsyndromic cryptorchidism, the most common male congenital genitourinary defect, in a Caucasian population.

Methods

Genome wide genotyping were performed in 559 cases and 1772 controls (Group 1) using Illumina HumanHap550 v1, HumanHap550 v3 or Human610-Quad platforms and in 353 cases and 1149 controls (Group 2) using the Illumina Human OmniExpress 12v1 or Human OmniExpress 12v1-1. Signal intensity data including log R ratio (LRR) and B allele frequency (BAF) for each single nucleotide polymorphism (SNP) were used for CNV detection using PennCNV software. After sample quality control, gene- and CNV-based association tests were performed using cleaned data from Group 1 (493 cases and 1586 controls) and Group 2 (307 cases and 1102 controls) using ParseCNV software. Meta-analysis was performed using gene-based test results as input to identify significant genes, and CNVs in or around significant genes were identified in CNV-based association test results. Called CNVs passing quality control and signal intensity visualization examination were considered for validation using TaqMan CNV assays and QuantStudio® 3D Digital PCR System.

Results

The meta-analysis identified 373 genome wide significant (p < 5X10⁻⁴) genes/loci including 49 genes/loci with deletions and 324 with duplications. Among them, 17 genes with deletion and 1 gene with duplication were identified in CNV-based association results in both Group 1 and Group 2. Only 2 genes (NUCB2 and UPF2) containing deletions passed CNV quality control in both groups and signal intensity visualization examination, but laboratory validation failed to verify these deletions.

Conclusions

Our data do not support that structural variation is a major cause of nonsyndromic cryptorchidism.

Electronic supplementary material

The online version of this article (doi:10.1186/s12894-016-0180-4) contains supplementary material, which is available to authorized users.

Urine-derived induced pluripotent stem cells as a modeling tool to study rare human diseases

Rare diseases with a low prevalence are a key public health issue because the causes of those diseases are difficult to determine and those diseases lack a clearly established or curative treatment. Thus, investigating the molecular mechanisms that underlie the pathology of rare diseases and facilitating the development of novel therapies using disease models is crucial. Human induced pluripotent stem cells (iPSCs) are well suited to modeling rare diseases since they have the capacity for self-renewal and pluripotency. In addition, iPSC technology provides a valuable tool to generate patient-specific iPSCs. These cells can be differentiated into cell types that have been affected by a disease. These cells would circumvent ethical concerns and avoid immunological rejection, so they could be used in cell replacement therapy or regenerative medicine. To date, human iPSCs could have been generated from multiple donor sources, such as skin, adipose tissue, and peripheral blood. However, these cells are obtained via invasive procedures. In contrast, several groups of researchers have found that urine may be a better source for producing iPSCs from normal individuals or patients. This review discusses urinary iPSC (UiPSC) as a candidate for modeling rare diseases. Cells obtained from urine have overwhelming advantages compared to other donor sources since they are safely, affordably, and frequently obtained and they are readily obtained from patients. The use of iPSC-based models is also discussed. UiPSCs may prove to be a key means of modeling rare diseases and they may facilitate the treatment of those diseases in the future.

Analgesic use - prevalence, biomonitoring and endocrine and reproductive effects

Paracetamol and NSAIDs, in particular acetylsalicylic acid (aspirin) and ibuprofen, are among the most used and environmentally released pharmaceutical drugs. The differences in international trends in the sale and consumption of mild analgesics reflect differences in marketing, governmental policies, habits, accessibility, disease patterns and the age distribution of each population. Biomonitoring indicates ubiquitous and high human exposure to paracetamol and to salicylic acid, which is the main metabolite of acetylsalicylic acid. Furthermore, evidence suggests that analgesics can have endocrine disruptive properties capable of altering animal and human reproductive function from fetal life to adulthood in both sexes. Medical and public awareness about these health concerns should be increased, particularly among pregnant women.

Undescended testis - current trends and guidelines: a review of the literature

The best mode of undescended testis (UDT) treatment remains controversial. However, knowledge gained from randomized controlled studies and meta-analyses allowed different groups of researchers to set out guidelines on management of patients with UDT. The authors reviewed recent literature and came to the following conclusions: (1) Hormonal treatment is not recommended, considering both the immediate results (only 15-20% of retained testes descend) and the possible long-term adverse effects on spermatogenesis. (2) Surgery is the treatment of choice; orchiopexy is successful in about 95% of UDT, with a low rate of complications (about 1%). (3) Orchiopexy should be performed between 12 and 18 months of age, or at first contact if diagnosed later.

Relaxin and insulin-like peptide 3 in the musculoskeletal system: from bench to bedside

Skeletal muscles and bones form a joined functional unit sharing a complex mechanical, biochemical and hormonal crosstalk. A number of factors, including sex hormones, physiologically regulate the musculoskeletal system. Striking gender differences in muscle and bone mass, and function are mainly caused by distinct actions exerted by oestrogens and androgens. However, relaxin and relaxin-related peptides, such as insulin-like peptide 3 (INSL3), might contribute to these sex-associated differences in physiological and pathological conditions (such as osteoporosis and sarcopenia). Relaxin is a 'pregnancy' hormone, but it is also produced from the prostate gland, and has recently attracted attention as a potential drug for cardiovascular disorders and fibrosis. In contrast, INSL3 is a male-specific hormone produced by the Leydig cells of the testis with a fundamental role in testicular descent during fetal life. Recent evidence suggests that both hormones have interesting roles in the musculoskeletal system. Relaxin and INSL3, by finely tuning bone formation and resorption, are involved in bone remodelling processes, and relaxin contributes to the healing of injured ligaments and promotes skeletal muscle regeneration. Here, we review the most recent findings on the effects of relaxin and INSL3 on skeletal muscle and the cell components of bone. In the light of the experimental evidence available and animal models, their clinical implications are also discussed.

LINKED ARTICLES

This article is part of a themed section on Recent Progress in the Understanding of Relaxin Family Peptides and their Receptors. To view the other articles in this section visit http://onlinelibrary.wiley.com/doi/10.1111/bph.v174.10/issuetoc.

A novel mutation in steroidogenic factor (SF1/NR5A1) gene in a patient with 46 XY DSD without adrenal insufficiency

Steroidogenic factor-1 (SF-1), also known as nuclear receptor subfamily 5 group A member 1 (NR5A1), is a member of orphan receptor subfamily and located on chromosome 9 (9q33). In 46, XY individuals with mutation of SF-1 gene, adrenal failure, testis dysgenesis, androgen synthesis defects, hypospadias and anorchia with microphallus, infertility can occur from severe to mild. We report a case of a 20-day-old male who is admitted to our clinic due to ambiguous genitalia. In this report, we describe a novel heterozygous c.814A > C (p. T272P) NR5A1 mutation in a patient with 46, XY DSD without adrenal insufficiency. We describe a novel missense mutation c.814A > C (p. T272P) in NR5A1 gene which had not previously been reported. Also this report highlights that the potential diagnostic utility of next-generation sequencing is an effective strategy versus Sanger sequencing to identify genetic mosaicism in clinical practice.

Spermatogenesis in humans and its affecting factors

Spermatogenesis is an extraordinary complex process. The differentiation of spermatogonia into spermatozoa requires the participation of several cell types, hormones, paracrine factors, genes and epigenetic regulators. Recent researches in animals and humans have furthered our understanding of the male gamete differentiation, and led to clinical tools for the better management of male infertility. There is still much to be learned about this intricate process. In this review, the critical steps of human spermatogenesis are discussed together with its main affecting factors.

Mutational analysis of HOXA10 gene in Chinese patients with cryptorchidism

Cryptorchidism is one of the most common congenital anomalies and affects 2-4% of full-term new born boys. Its aetiology is poorly understood at present. HOXA10 plays a pivotal role in regulation of testicular descent. Male mice mutant for Hoxa10 exhibit unilateral or bilateral cryptorchidism as a result of impaired development of the gubernaculums. In this study, we performed mutation analysis of HOXA10 gene in a cohort of 98 cryptorchid patients. And we found a mutation (N27K) in a boy with unilateral cryptorchidism. The mutation was not detected in 106 healthy controls. Both in silico analyses and functional studies showed that the mutation affected the function of HOXA10. The results demonstrated that mutation in HOXA10 gene contributes to the pathogenesis of cryptorchidism, but may not be a common cause.

Outcomes of Laparoscopic Treatment Modalities for Unilateral Non-palpable Testes

PURPOSE

To date, laparoscopy has gradually become the gold standard for treatment of non-palpable testicles (NPT) with different success and complication rates. In this study, we aimed to evaluate outcomes of laparoscopic approaches for NPT.

MATERIALS AND METHODS

We reviewed data of 82 consecutive patients who underwent laparoscopic treatment for unilateral NPT at two institutions by two high volume surgeons from 2004 January to 2014 December. Laparoscopic-assisted orchidopexy (LAO) and two-stage Fowler-Stephens technique (FST) was performed for 45 and 37 patients, respectively. Age (at surgery), follow-up time, laterality of testes, and postoperative complications were analyzed. Modified Clavien classification system (MCCS) was used for evaluating complications.

RESULTS

The median age (at surgery) and median follow-up time were 18 (range: 6-56) and 60 (range: 9-130) months, respectively. Overall success rate for two laparoscopy techniques was 87.8% during the maximal follow-up time. We observed wound infection in two, hematoma in one, testicular atrophy in five, testicular re-ascending in two patients at follow-up period. There was no statistical difference between two laparoscopic techniques for grade I (five vs. two patients, p = 0.14) and grade IIIb MCCS complications (five vs. two patients, p = 0.44).

CONCLUSION

Our results have shown that two laparoscopic approaches have low complication rates.

Putting the pieces together: cryptorchidism - do we know everything?

Cryptorchidism is one of the most common birth defects in male children, and it has a potential impact on future health. It is the best-characterized risk factor for reduced fertility and testicular cancer. However, the etiology of cryptorchidism remains largely unknown. In the literature, we find different opinions and theories on this topic. Probably, the etiology is multifactorial, and hormonal, genetic and environmental factors may regulate testicular development and descent from intra-abdominal location into the bottom of the scrotum. The descent of the testis is a complex, two-stage process. A critical role in testicular descent has been attributed to androgens, insulin-like hormone 3 (insl3) and anti-Müllerian hormone. It is believed that interaction between Leydig and Sertoli cells may cause impaired spermatogenesis. Based on recent knowledge of germ cell development, it is believed that the best treatment for undescended testis is orchiopexy between 6th and 12th month of life. Long follow-up studies are needed to focus on the effect of this recommendation.

Killer cell immunoglobulin-like receptor gene association with cryptorchidism

Cryptorchidism is a condition where a testis persists in the abdominal cavity. Thus, due to elevated temperature we may expect induction of aberrant immune reactions depending on genetic constitution of individual. This may be reflected by development of anti-sperm antibodies (ASA) in cryptorchid males. Also, natural killer (NK) cells which belong to innate immunity may control adaptive immunity. Therefore, the gene system encoding polymorphic NK cell immunoglobulin receptors (KIRs) has been studied. 109 prepubertal boys with cryptorchidism and 136 ethnically matched young male donors were selected to study NK cell KIRs. DNA was isolated using automatic Maxwell(®) system from the peripheral venous blood drawn onto anticoagulant. Olerup SSP KIR Genotyping kit including Taq polymerase was used for detection of KIR genes. Human leukocyte antigen-C (HLA-C) groups, C1 and C2 were established using a Olerup SSP KIR HLA Ligand kit. KIR2DL2 (killer immunoglobulin-like receptor two-domain long 2) and KIR2DS2 (killer immunoglobulin-like receptor two-domain short 2) genes were less frequent in patients than in control individuals (corrected p values: 0.0110 and 0.0383, respectively). However, no significant differences were observed between ASA-positive and ASA-negative patients, or between bilateral or unilateral cryptorchidism. No association between KIR ligands C1 and C2, alone or together with KIR2DL2, was found. However, the results suggest that KIR2DL2+/KIR2DS2+ genotype may be, to some extent, protective against cryptorchidism.

Pathway analysis supports association of nonsyndromic cryptorchidism with genetic loci linked to cytoskeleton-dependent functions

STUDY QUESTION

What are the genetic loci that increase susceptibility to nonsyndromic cryptorchidism, or undescended testis?

SUMMARY ANSWER

A genome-wide association study (GWAS) suggests that susceptibility to cryptorchidism is heterogeneous, with a subset of suggestive signals linked to cytoskeleton-dependent functions and syndromic forms of the disease.

WHAT IS KNOWN ALREADY

Population studies suggest moderate genetic risk of cryptorchidism and possible maternal and environmental contributions to risk. Previous candidate gene analyses have failed to identify a major associated locus, although variants in insulin-like 3 (INSL3), relaxin/insulin-like family peptide receptor 2 (RXFP2) and other hormonal pathway genes may increase risk in a small percentage of patients.

STUDY DESIGN, SIZE, DURATION

This is a case-control GWAS of 844 boys with nonsyndromic cryptorchidism and 2718 control subjects without syndromes or genital anomalies, all of European ancestry.

PARTICIPANTS/MATERIALS, SETTING, METHODS

All boys with cryptorchidism were diagnosed and treated by a pediatric specialist. In the discovery phase, DNA was extracted from tissue or blood samples and genotyping performed using the Illumina HumanHap550 and Human610-Quad (Group 1) or OmniExpress (Group 2) platform. We imputed genotypes genome-wide, and combined single marker association results in meta-analyses for all cases and for secondary subphenotype analyses based on testis position, laterality and age, and defined genome-wide significance as P = 7 × 10(-9) to correct for multiple testing. Selected markers were genotyped in an independent replication group of European cases (n = 298) and controls (n = 324). We used several bioinformatics tools to analyze top (P < 10(-5)) and suggestive (P < 10(-3)) signals for significant enrichment of signaling pathways, cellular functions and custom gene lists after multiple testing correction.

MAIN RESULTS AND THE ROLE OF CHANCE

In the full analysis, we identified 20 top loci, none reaching genome-wide significance, but one passing this threshold in a subphenotype analysis of proximal testis position (rs55867206, near SH3PXD2B, odds ratio = 2.2 (95% confidence interval 1.7, 2.9), P = 2 × 10(-9)). An additional 127 top loci emerged in at least one secondary analysis, particularly of more severe phenotypes. Cytoskeleton-dependent molecular and cellular functions were prevalent in pathway analysis of suggestive signals, and may implicate loci encoding cytoskeletal proteins that participate in androgen receptor signaling. Genes linked to human syndromic cryptorchidism, including hypogonadotropic hypogonadism, and to hormone-responsive and/or differentially expressed genes in normal and cryptorchid rat gubernaculum, were also significantly overrepresented. No tested marker showed significant replication in an independent population. The results suggest heterogeneous, multilocus and potentially multifactorial susceptibility to nonsyndromic cryptorchidism.

LIMITATIONS, REASONS FOR CAUTION

The present study failed to identify genome-wide significant markers associated with cryptorchidism that could be replicated in an independent population, so further studies are required to define true positive signals among suggestive loci.

WIDER IMPLICATIONS OF THE FINDINGS

As the only GWAS to date of nonsyndromic cryptorchidism, these data will provide a basis for future efforts to understand genetic susceptibility to this common reproductive anomaly and the potential for additive risk from environmental exposures.

STUDY FUNDING/COMPETING INTERESTS

This work was supported by R01HD060769 (the Eunice Kennedy Shriver National Institute for Child Health and Human Development (NICHD)), P20RR20173 (the National Center for Research Resources (NCRR), currently P20GM103464 from the National Institute of General Medical Sciences (NIGMS)), an Institute Development Fund to the Center for Applied Genomics at The Children's Hospital of Philadelphia, and Nemours Biomedical Research. The authors have no competing interests to declare.

Leydig cell tumor in a patient with 49,XXXXY karyotype: a review of literature

49,XXXXY pentasomy or Fraccaro's syndrome is the most severe variant of Klinefelter's syndrome (KS) affecting about 1/85000 male births. The classical presentation is the triad: mental retardation, hypergonadotropic hypogonadism and radio ulnar synostosis. Indeed, the reproductive function of Fraccaro's syndrome is distinguished from KS. Besides, Leydig cell tumors are described in cases of KS, but never documented in the Klinefelter variants.We describe a young adult of 22 years old who presented with hyper gonadotropic hypogonadism, delayed puberty and bilateral micro-cryptorchidism. Chromosomal pentasomy was confirmed since infancy. Bilateral orchidectomy revealed a unilateral well-circumscribed Leydig cell tumor associated with bilateral Leydig cell hyperplasia.Inspired from reporting the first case of Leydig cell tumor in a 49,XXXXY patient, we summarize the particularities of testicular function in 49,XXXXY from one side, and the risk and mechanisms of Leydig cell tumorigenesis in Klinefelter variants on the other side. The histological destructions in 49,XXXXY testes and hypogonadism are more profound than in Klinefelter patients, with early Sertoli, Leydig and germ cell destruction. Furthermore, the risk of Leydigioma development in KS and its variants remains a dilemma. We believe that the risk of Leydigioma is much higher in KS than the general population. By contrast, the risk could be lower in the Klinefelter variants with more than 3 supplementary X chromosomes, owing to an earlier and more profound destruction of Leydig cells rendering them irresponsive to chronic Luteinizing hormone (LH) stimulation.

The variations in the AXIN1 gene and susceptibility to cryptorchidism

BACKGROUND

Cryptorchidism is one of the most common congenital anomalies in newborn boys. Although the mechanism responsible for the pathophysiology of cryptorchidism has not yet been well addressed, the Wnt signaling pathway has been involved in the development of cryptorchidism. Axin1 is a central component of the Wnt signaling pathway and may play a critical role in the development of cryptorchidism.

OBJECTIVE

We assumed that cryptorchidism risk and the AXIN1 gene may have an association. Thus we picked out three tag SNPs (single nucleotide polymorphisms) in the AXIN1 gene and aimed to investigate whether cryptorchidism risk is associated with polymorphisms in the AXIN1 gene.

STUDY DESIGN

The variants were discriminated using polymerase chain reaction restriction fragment length polymorphism (PCR-RFLP) methods. A total of 113 cases and 179 controls were recruited to participate in this study, including 92 unilateral cryptorchidism and 21 bilateral cases. In bilateral cases, the position of the testis was decided by the higher one.

RESULTS

A significantly increased cryptorchidism risk was found to be associated with both the T allele (p = 2e(-4), OR 1.96, 95% CI 1.37-2.78) and T/T genotype (p = 6e(-4), OR 4.00, 95% CI 1.79-9.09) of rs370681 polymorphism, and, compared with the C/C genotype, a significantly increased cryptorchidism risk was associated with the C/T-T/T genotype (p = 4e(-4), OR 2.44, 95% CI 1.47-4.00) of rs370681 polymorphisms.

DISCUSSION

Among the three tag SNPs we have chosen in AXIN1, two SNPs are located in the intron region, the other SNP is located in the synonymous codon region. Evidential research has indicated that introns and other non-protein-coding RNAs may have evolved to function as network control molecules in higher organisms. Therefore, we suspected that the tag SNPs may work as controls influencing the conduct of other genes rather than affecting the structure of the protein by influencing the coding of amino acid. There were limitations in our study. One is that we did not test the expression level of Axin1. Secondly, the number of the study subjects is limited. Finally, the molecular mechanisms by which AXIN1 is involved in susceptibility to cryptorchidism should be characterized.

CONCLUSIONS

We assessed the impact of the genetic variability of the AXIN1 gene on cryptorchidism. We have offered primary evidence that the T allele and T/T genotype of rs370681 polymorphisms and C/T genotype of rs1805105 polymorphisms in AXIN1 gene are more frequent in patients with cryptorchidism.

Mutational screening of NR5A1 gene encoding steroidogenic factor 1 in cryptorchidism and male factor infertility and functional analysis of seven undescribed mutations

OBJECTIVE

To study the role of NR5A1 in cryptorchidism and male factor infertility. Mutations in NR5A1 have been initially associated with primary adrenal insufficiency and 46,XY gonadal dysgenesis and more recently with less severe phenotypes, including preliminary descriptions in severe forms of male factor infertility. Far less clear is the possible involvement of NR5A1 mutations in cryptorchidism.

DESIGN

Retrospective cross-sectional cohort study and functional analysis of mutant proteins.

SETTING

University department.

PATIENT(S)

Nine hundred fifty-nine subjects, including children with cryptorchidism and adults with different semen phenotypes associated or not associated with a history of cryptorchidism.

INTERVENTION(S)

None.

MAIN OUTCOME MEASURE(S)

Mutation screening of NR5A1 by sequencing all exons. Functional analysis of mutant proteins by transactivation assays of CYP11A1 and CYP17A1 promoters.

RESULT(S)

We identified seven undescribed and one previously described missense mutation in subjects with severe spermatogenic impairment, without (4/236, 1.7%) and with (3/85, 3.5%) a history of cryptorchidism. Newborns with cryptorchidism carry NR5A1 mutations at low frequency (0.7%), whereas no mutations were found in milder forms of infertility and normozoospermia, irrespective of the presence of cryptorchidism. The mutant proteins showed impaired transactivation of gonadal promoters. A single nucleotide polymorphism (rs1110061; c.437 G→C; p.Gly146Ala) was also associated with more severe forms of spermatogenic impairment with cryptorchidism.

CONCLUSION(S)

This study, combined with what is already known about NR5A1-associated phenotypes, suggests considering mutations in this gene as a novel genetic cause of more severe forms of male factor infertility, especially when associated with a history of cryptorchidism.

Cord blood insulin-like peptide 3 (INSL3) but not testosterone is reduced in idiopathic cryptorchidism

BACKGROUND

Cryptorchidism, the most frequent congenital malformation in full-term male newborns, increases the risk of hypofertility and testicular cancer. Most cases remain idiopathic but epidemiological and experimental studies have suggested a role of both genetic and environmental factors. Physiological testicular descent is regulated by two major Leydig hormones: insulin-like peptide 3 (INSL3) and testosterone.

OBJECTIVES

To study the endocrine context at birth as a reflection of late pregnancy in isolated idiopathic cryptorchidism and to analyse the possible disruptions of INSL3 and/or testosterone.

METHODS

From a prospective case-control study at Nice University Hospital, we assessed 180 boys born after 34 weeks gestation: 52 cryptorchid (48 unilateral, 4 bilateral; 26 transient, 26 persistent), and 128 controls matched for term, weight and time of birth. INSL3 and testosterone were measured in cord blood and compared in both groups as were other components of the pituitary-gonadic axis: LH, HCG, FSH, AMH and SHBG.

RESULTS

INSL3 was decreased in cryptorchid boys (P = 0·031), especially transient cryptorchid (P = 0·029), while testosterone was unchanged as were the other hormones measured. INSL3 was significantly decreased (P = 0·018) in the group of 20 with nonpalpable testes compared with the group of 21 with palpable testes (15 suprascrotal, five inguinal, one high scrotal) according to Scorer classification. In the whole population, INSL3 correlated positively with LH and negatively with AMH, but with no other measured hormones.

CONCLUSIONS

INSL3 but not testosterone is decreased at birth in idiopathic cryptorchidism, especially in transient forms. This hormonal decrease may contribute to the impaired testicular descent along with genetic and anatomical factors. Whether foetal environment (nutritional and/or toxicological) interferes with INSL3 secretion in humans remains to be confirmed.

Serum Bisphenol A Level in Boys with Cryptorchidism: A Step to Male Infertility?

Cryptorchidism is the most common congenital birth defect in boys and affects about 2-4% full-term male neonates. Its etiology is multifactorial. Purpose. To evaluate the serum bisphenol A (BPA) levels in boys with cryptorchidism and healthy boys and to assess the risk of environmental exposure to BPA using the authors' questionnaire. The data were acquired from a study on boys with cryptorchidism (n = 98) and a control group (n = 57). Prior to surgery, all patients had BPA serum levels evaluated. The size, position, rigidity of the testis, and abnormality of the epididymis of the undescended testis were assessed. Parents also completed a questionnaire on the risks of exposure to BPA in everyday life. Results. The testes in both groups were similar in size. The turgor of the undescended testis in the group of boys with cryptorchidism was decreased. Free serum BPA level in cryptorchid boys and in the control group was not statistically significant (p > 0.05). The conjugated serum BPA level in cryptorchid boys and in the control group was statistically significant (p ≤ 0.05). Total serum BPA level in cryptorchid boys and in the control group was statistically significant (p < 0.05). Serum total BPA level was related with a positive answer about problems with conception (p < 0.02). Conclusion. Our study indicated that high serum BPA was associated with cryptorchidism.

A negative correlation between insulin-like peptide 3 and bisphenol A in human cord blood suggests an effect of endocrine disruptors on testicular descent during fetal development

STUDY QUESTION

Does a relationship exist between insulin-like peptide 3 (INSL3) and selected environmental endocrine disruptors (EEDs) in human cord blood (cb)?

SUMMARY ANSWER

In the whole population (cryptorchid and control boys) cbINSL3 correlated negatively with cb free bisphenol A (BPA) providing indirect evidence for an impact of EEDs on fetal Leydig cell INSL3 production.

WHAT IS KNOWN ALREADY

INSL3 is a major regulator of testicular descent. This hormone has been shown to be decreased in cord blood from boys with idiopathic cryptorchidism, the most frequent male malformation. Fetal exposure to several EEDs has been suspected to be involved in the occurrence of idiopathic cryptorchidism.

STUDY DESIGN, SIZE, DURATION

Correlations between cb INSL3 or testosterone and cb free bioactive BPA and maternal milk polychlorinated biphenyls (PCB153), dichlorodiphenyldichloroethylene (DDE), and monobutyl phthalate (mBP) were assessed in newborn boys in a prospective case-control study. All boys (n = 6246) born after 34 weeks of gestation were systematically screened at birth for cryptorchidism over a 3-year period (2002-2005), and a diagnosis of cryptorchidism confirmed by a senior paediatrician.

PARTICIPANTS/MATERIALS, SETTING, METHODS

We studied 52 cryptorchid (26 transient, 26 persistent) and 128 control boys born at two hospitals in southern France. INSL3 was assayed in CB by a modified validated enzyme-linked immunosorbent assay. Testosterone was measured in CB after diethyl-ether extraction by means of ultra-pressure liquid chromatography-tandem mass spectrometry. Free cbBPA was measured after an extraction step with a radioimmunoassay validated after comparison of values obtained by high-pressure liquid chromatography-mass spectrometry. The xenobiotic analysis in mothers' milk was performed after fat extraction by gas chromatography-mass spectrometry.

MAIN RESULTS AND THE ROLE OF CHANCE

EED concentrations were not increased in the cryptorchid versus control group although a trend for increased mBP (P = 0.09) was observed. In the whole study population, cb levels of BPA correlated negatively with INSL3 (P = 0.01; R² = 0.05) but not with testosterone. No other EED correlated with INSL3 or with testosterone.

LIMITATIONS, REASONS FOR CAUTION

The levels of BPA and INSL3 in cb may not reflect chronic fetal exposure to EEDs. The deleterious impact of EEDs on fetal testicular descent during specific windows of development has yet to be demonstrated.

WIDER IMPLICATIONS OF THE FINDINGS

The negative correlation between cb free BPA and INSL3 provides indirect evidence for an impact of EEDs on human fetal Leydig cell INSL3 production and points to cbINSL3 as a possible target of EED action during fetal testis development.

Similar causes of various reproductive disorders in early life

During the past few decades, scientific evidence has been accumulated concerning the possible adverse effects of the exposure to environmental chemicals on the well-being of wildlife and human populations. One large and growing group of such compounds of anthropogenic or natural origin is referred to as endocrine-disrupting chemicals (EDCs), due to their deleterious action on the endocrine system. This concern was first focused on the control of reproductive function particularly in males, but has later been expanded to include all possible endocrine functions. The present review describes the underlying physiology behind the cascade of developmental events that occur during sexual differentiation of males and the specific role of androgen in the masculinization process and proper organogenesis of the external male genitalia. The impact of the genetic background, environmental exposures and lifestyle factors in the etiology of hypospadias, cryptorchidism and testicular cancer are reviewed and the possible role of EDCs in the development of these reproductive disorders is discussed critically. Finally, the possible direct and programming effects of exposures in utero to widely use therapeutic compounds, environmental estrogens and other chemicals on the incidence of reproductive abnormalities and poor semen quality in humans are also highlighted.

Could androgen receptor gene CAG tract polymorphism affect spermatogenesis in men with idiopathic infertility?

PURPOSE

This study examined whether the AR-CAG repeat length might affect clinical characteristics (testis volume) seminal parameters (sperm count and its mobility) along with hormonal serum profile [FSH, LH, Testosterone (T) and Inhibin B (InhB)] both in idiopathic male infertility (IM) and in infertility due to a previous condition of cryptorchidism (CryM) or to Y chromosome long arm microdeletions (YM).

DESIGN

Observational study without intervention(s).

PATIENTS

One hundred and ten IM patients [90 idiopathic olizoospermic males (IOM) and 20 idiopathic azoospermic males (IAM)], 19 CryM male and 10 YM patients were included. Sixty-one age-matched healthy men who had fathered within 3 years were involved representing the control group (FM).

RESULTS

AR-CAG repeats stretch was significantly longer in IOM (p<0.05), CryM (p<0.05) and YM (p<0.001) than FM. When the AR-CAG repeat tracts were subdivided in three subgroups according to the length of CAG repeats tract assessed in fertile subjects (the one with the middle (n 19-21) belonging to the 25 and 75 % inter-quartile, the ends belonging to the <25 % inter-quartile and >75 % inter-quartile, respectively), there was a statistically significant difference of distribution of AR-CAG tract length among fertile and different groups of infertile men (p=<0.0005; chi-square test). Moreover, the subgroup of AR-CAG repeat stretch with 22-28 triplets was associated with lower levels of InhB both in idiopathic oligozoospermic (Scheffe, Bonferroni and Dunett tests p=<0.01) and azoospermic men (Scheffe, Bonferroni and Dunett test p=<0.05), while, when FM and men with idiopathic infertility were gathered in a single group, both the subgroup of AR- CAG tract with 15-18 repeats and the one with 22-28 repeats are associated with lower testis volume, reduced sperm count and serum InhB levels.

CONCLUSIONS

Our study showed that the outliers of AR-CAG repeat length seem to influence the function of AR, affecting testis volume and Sertoli cell function and consequently sperm production in both fertile and idiopathic infertile men.

Congenital hypogonadotropic hypogonadism and Kallmann syndrome as models for studying hormonal regulation of human testicular endocrine functions

Men with Kallmann syndrome (KS) and those with congenital isolated hypogonadotropic hypogonadism with normal olfaction share a chronic, usually profound deficit, in FSH and LH, the two pituitary gonadotropins. Many studies indicate that this gonadotropin deficiency is already present during fetal life, thus explaining the micropenis, cryptorchidism and marked testicular hypotrophy already present at birth. In addition, neonatal activation of gonadotropin secretion is compromised in boys with severe CHH/Kallmann, preventing the first phase of postnatal testicular activation. Finally, CHH is characterized by the persistence, in the vast majority of cases, of gonadotropin deficiency at the time of puberty and during adulthood. This prevents the normal pubertal testicular reactivation required for physiological sex steroid and testicular peptide production, and for spermatogenesis. CHH/KS thus represents a pathological paradigm that can help to unravel, in vivo, the role of each gonadotropin in human testicular exocrine and endocrine functions at different stages of development. Recombinant gonadotropins with pure LH or FSH activity have been used to stimulate Leydig's cells and Sertoli's cells, respectively, and thereby to clarify their paracrine interaction in vivo. The effects of these pharmacological probes can be assessed by measuring the changes they provoke in circulating testicular hormone concentrations. This review discusses the impact of chronic gonadotropin deficiency on the endocrine functions of the interstitial compartment, which contains testosterone-, estradiol- and INSL3-secreting Leydig's cells. It also examines the regulation of inhibin B and anti-Mullerian hormone (AMH) secretion in the seminiferous tubules, and the insights provided by studies of human testicular stimulation with recombinant gonadotropins, used either individually or in combination.

Cryptorchidism --disease or symptom?

Testes descend to the scrotum normally before birth. When they fail to do so, the boy is cryptorchid and has an increased risk for testicular germ cell cancer and subfertility later in life. Early correction of maldescent by orchiopexy operation improves the spermatogenetic capacity of the testis but does not return the testicular cancer risk to the control level. Testicular descent is regulated by testis-derived hormones testosterone and insulin-like peptide 3. Cryptorchidism can therefore be considered a symptom of impaired testicular function that may also be linked to other testicular diseases, such as germ cell cancer and subfertility. Early orchiopexy can alleviate the effects of cryptorchidism on spermatogenesis, but alertness for testicular cancer should be maintained. In searching the genetic and environmental reasons for these diseases, it is useful to consider their connection with each other.

Ubiquitous presence of paracetamol in human urine: sources and implications

N-acetyl-4-aminophenol (acetaminophen/paracetamol, NA4AP) is one of the most commonly used over-the-counter analgesic and antipyretic drugs. Recent studies have reported anti-androgenic effects of NA4AP in vitro and possible associations between intrauterine exposure to NA4AP and the development of male reproductive disorders in humans. NA4AP is also a major metabolite of aniline (phenylamine), representing 75–86% of the aniline dose excreted in urine. Aniline is an important large-volume intermediate in several industrial processes. Besides individuals in various occupational settings with aniline exposure, the general population is also known to be ubiquitously exposed to aniline. In this article, we provide an overview of the recent literature concerning the intake of NA4AP during pregnancy and the possible anti-androgenic effects of NA4AP as well as literature concerning its known metabolic precursor aniline. We also present new research data, including the first human biomonitoring data on NA4AP excretion in urine, showing ubiquitous NA4AP body burdens in the general population at a wide range of concentrations. We found a small but significant impact of smoking on urinary NA4AP concentrations. We further present preliminary data on NA4AP excretion after therapeutic acetaminophen use, after aniline exposure in an occupational setting, and during a controlled fasting study (excluding oral exposure to both aniline and acetaminophen). Our findings indicate exposure to aniline (or aniline-releasing substances) as well as nutrition (next to the direct use of acetaminophen as medication) as possible sources of internal body burdens of NA4AP.

Role of laparoscopy and ultrasound in the management of "impalpable testis" in children

BACKGROUND

Undescended testes is one of the most common congenital abnormalities in boys. In cases of impalpable testes, ultrasound is often used to find the testis, which frequently provides false-negative results. Recently, laparoscopy has become popular in the management of impalpable testes.

METHODS

Retrospective study of all children with impalpable testes presenting for laparoscopy between August 2007 and July 2011 who had undergone ultrasound examinations without localizing the testes was conducted and the role of laparoscopy in diagnosing impalpable testes was evaluated.

RESULTS

Twenty-three patients presented with impalpable testes for laparoscopy. All patients underwent ultrasound examinations in which the testes could not be identified. Of the 23 patients, Five patients were found to have palpable testes in the superficial inguinal pouch under anesthesia and proceeded to conventional open exploration during which the testes were brought into the scrotum. Eighteen patients were found to have impalpable testes in an evaluation under anesthesia (EUA) and proceeded to laparoscopy. Twelve patients were found to have intra-abdominal testes and underwent laparoscopic-assisted orchidopexy. Three patients underwent a two-stage Fowler-Stephens procedure, and two patients with "vanishing" testes with the vas and atrophic vessels entering a closed internal ring proceeded to open exploration and orchidectomy for atrophic testes. In addition, a teenager with atrophic testes underwent laparoscopic orchidectomy.

CONCLUSIONS

Laparoscopy is superior to ultrasound in the management of impalpable testes when high-resolution ultrasound is not available during the diagnostic process, with respect to both the sensitivity of localizing the testis and being more time and cost effective.

Insulin-like peptide 3 (INSL3) in men with congenital hypogonadotropic hypogonadism/Kallmann syndrome and effects of different modalities of hormonal treatment: a single-center study of 281 patients

CONTEXT

Insulin-like factor 3 (INSL3) is a testicular hormone secreted during fetal life, the neonatal period, and after puberty.

OBJECTIVE

To measure INSL3 levels in a large series of men with congenital hypogonadotropic hypogonadism (CHH)/ Kallmann syndrome (KS), in order to assess its diagnostic value and to investigate its regulation.

PATIENTS

We studied 281 CHH/KS patients (91 untreated, 96 receiving T, and 94 receiving combined gonadotropin therapy [human chorionic gonadotropin, hCG, and FSH]) and 72 age-matched healthy men.

METHODS

Serum INSL3 was immunoassayed with a validated RIA.

RESULTS

Mean (±SD) INSL3 levels (pg/mL) were 659 ± 279 in controls and lower (60 ± 43; P < .001) in untreated CHH/KS patients, with no overlap between the two groups, when the threshold of 250 pg/mL was used. Basal INSL3 levels were lower in both untreated CHH/KS men with cryptorchidism than in those with intrascrotal testes and in patients with testicular volumes below 4 mL. Significant positive correlations between INSL3 and both serum total T and LH levels were observed in untreated CHH/KS. Mean INSL3 levels remained low in T-treated CHH/KS patients and were significantly higher in men receiving combined hCG-FSH therapy (P < .001), but the increase was lower cryptorchid patients. FSH-hCG combination therapy or hCG monotherapy, contrary to T and FSH monotherapies, significantly increased INSL3 levels in CHH/KS.

CONCLUSIONS

INSL3 is as sensitive a marker as T for the evaluation of altered Leydig cell function in CHH/KS patients. INSL3 levels correlate with LH levels in CHH/KS men showing, together with the rise in INSL3 levels during hCG therapy, that INSL3 secretion seems not constitutively secreted during adulthood but is dependence on pituitary LH.

An interesting case of Rathke's cleft cyst presenting as bilateral cryptorchidism

Rathke's cleft cyst (RCC) are benign, epithelium-lined sellar and suprasellar cysts believed to originate from remnants of the Rathke pouch. Here, we report a rare case of entirely suprasellar RCC in a 4.5-year-old child causing hypopituitarism, who presented to us with bilateral cryptorchidism. Subsequently we discuss the distinct rarity of entirely suprasellar RCC presenting in this fashion and the relevant literature is also discussed.

Estrogenic endocrine-disrupting chemicals: molecular mechanisms of actions on putative human diseases

Endocrine-disrupting chemicals (EDC), including phthalates, bisphenol A (BPA), phytoestrogens such as genistein and daidzein, dichlorodiphenyltrichloroethane (DDT), and 2,3,7,8-tetrachlorodibenzo-p-dioxin (TCDD), are associated with a variety of adverse health effects in organisms or progeny by altering the endocrine system. Environmental estrogens, including BPA, phthalates, and phytoestrogens, are the most extensively studied and are considered to mimic the actions of endogenous estrogen, 17β-estradiol (E2). Diverse modes of action of estrogen and estrogen receptors (ERα and ERβ) have been described, but the mode of action of estrogenic EDC is postulated to be more complex and needs to be more clearly elucidated. This review examines the adverse effects of estrogenic EDC on male or female reproductive systems and molecular mechanisms underlying EDC effects that modulate ER-mediated signaling. Mechanisms of action for estrogenic EDC may involve both ER-dependent and ER-independent pathways. Recent findings from systems toxicology of examining estrogenic EDC are also discussed.

Paracetamol, aspirin, and indomethacin induce endocrine disturbances in the human fetal testis capable of interfering with testicular descent

CONTEXT

Masculinization depends on the fetal testis. Exposure of the human fetus during pregnancy to paracetamol and/or to other mild analgesics is associated with an increased risk of cryptorchidism.

OBJECTIVE

We aimed to determine whether mild analgesics disrupted the morphology and endocrine function of the human testis.

DESIGN

We used an in vitro system based on the culture of human fetal testes exposed or not to paracetamol, its metabolite N-(4-hydroxyphenyl)-arachidonoylethanolamide (AM404), aspirin, indomethacin, and ketoconazole at 10(-4) to 10(-7) M.

SETTING

The study was conducted at the University of Rennes I.

PATIENTS/PARTICIPANTS

Human fetal testes were from pregnant women after induced abortion, between 7 and 12 weeks of gestation (GW).

MAIN OUTCOME MEASURES

Testosterone (RIA), anti-Müllerian hormone (ELISA), insulin-like factor 3 (RIA), and prostaglandin (PG) D2 and PGE2 (ELISA) were assayed in the medium. Testicular cells were counted using histology and image analysis. The possible nuclear receptor-mediated activities of the analgesics were investigated using reporter cell lines expressing estrogen, androgen, and peroxisome proliferator-activated γ receptors.

RESULTS

Indomethacin and aspirin stimulated testosterone production, particularly by the younger testes (8-9 GW vs 10-12 GW). Paracetamol, AM404, and ketoconazole decreased insulin-like factor 3 levels. Aspirin stimulated whereas ketoconazole inhibited AMH production. PGE2 levels were inhibited by paracetamol and aspirin in the 7 to 12 GW testes and by indomethacin but only in 7 to 9.86 GW testes. The inhibitory trends seen for PGD2 were not statistically significant.

CONCLUSIONS

Analgesics at concentrations relevant to human exposure cause endocrine disturbances in the fetal testis. We suggest that the fetal human testis displays slight critical age windows for sensitivity to direct exposure to aspirin, indomethacin, and paracetamol. The analgesic-induced inhibition of INSL3 may be the mechanism by which analgesics increase the risk of cryptorchidism. Greater caution is required concerning consumption of analgesics during pregnancy.

Testicular function and bone metabolism--beyond testosterone

Findings in the past few years have advanced understanding of the crosstalk between testis and bone and could contribute to defining an improved clinical approach to the biochemical diagnosis and therapeutic management of hypogonadism and male osteoporosis. This Review focuses on the Leydig cells of the testis. Other than being responsible for steroidogenesis and production of testosterone, the function of these cells is fundamental to bone health in at least two other ways: Leydig cells produce insulin-like 3 (INSL3), which has a role in osteoblast function, and they contribute to 25-hydroxylation of vitamin D. Impairment of testicular function leads to low levels of testosterone, INSL3 and 25-hydroxyvitamin D and consequently to an increased risk of osteopenia and osteoporosis.

Androgen receptor (AR) physiological roles in male and female reproductive systems: lessons learned from AR-knockout mice lacking AR in selective cells

Androgens/androgen receptor (AR) signaling is involved primarily in the development of male-specific phenotypes during embryogenesis, spermatogenesis, sexual behavior, and fertility during adult life. However, this signaling has also been shown to play an important role in development of female reproductive organs and their functions, such as ovarian folliculogenesis, embryonic implantation, and uterine and breast development. The establishment of the testicular feminization (Tfm) mouse model exploiting the X-linked Tfm mutation in mice has been a good in vivo tool for studying the human complete androgen insensitivity syndrome, but this mouse may not be the perfect in vivo model. Mouse models with various cell-specific AR knockout (ARKO) might allow us to study AR roles in individual types of cells in these male and female reproductive systems, although discrepancies are found in results between labs, probably due to using various Cre mice and/or knocking out AR in different AR domains. Nevertheless, no doubt exists that the continuous development of these ARKO mouse models and careful studies will provide information useful for understanding AR roles in reproductive systems of humans and may help us to develop more effective and more specific therapeutic approaches for reproductive system-related diseases.

Clinical review: Anogenital distance or digit length ratio as measures of fetal androgen exposure: relationship to male reproductive development and its disorders

CONTEXT

Male reproductive disorders evident at birth or in young adulthood are remarkably common. They are hypothesized to comprise a testicular dysgenesis syndrome (TDS), with a fetal origin involving mild androgen deficiency.

EVIDENCE ACQUISITION

Testing this hypothesis requires "seeing back in time." Two ways have been proposed: measurement of anogenital distance (AGD), or measurement of the 2:4 digit length ratio. This review assesses the evidence that they reflect fetal androgen exposure and might be used to provide insight into the origin of TDS disorders.

EVIDENCE SYNTHESIS

Supporting evidence for AGD derives from rat experimental studies that identified a fetal masculinization programming window, within which androgen action determines adult reproductive organ size, TDS disorders, and AGD. In humans, AGD is positively correlated to testis size, sperm count/fertility, penis length, and T levels, consistent with rat experimental data. The 2:4 digit ratio also shows associations with these parameters, but inconsistently between studies; evidence that the 2:4 digit ratio accurately reflects fetal androgen exposure is also equivocal.

CONCLUSIONS

AGD appears to provide a reliable guide to fetal androgen exposure, although available data are limited. The next steps are to: standardize AGD measurement; obtain age-specific population data; and use AGD to evaluate the importance of fetal androgens in determining reproductive disorders and variation in testis/penis size and sperm count in the normal population. These studies should identify what, if any, clinical applications of AGD measurement are feasible--for example, its ability to predict adult-onset reproductive function and disorders.

Pivotal role of the muscle-contraction pathway in cryptorchidism and evidence for genomic connections with cardiomyopathy pathways in RASopathies

BACKGROUND

Cryptorchidism is the most frequent congenital disorder in male children; however the genetic causes of cryptorchidism remain poorly investigated. Comparative integratomics combined with systems biology approach was employed to elucidate genetic factors and molecular pathways underlying testis descent.

METHODS

Literature mining was performed to collect genomic loci associated with cryptorchidism in seven mammalian species. Information regarding the collected candidate genes was stored in MySQL relational database. Genomic view of the loci was presented using Flash GViewer web tool (http://gmod.org/wiki/Flashgviewer/). DAVID Bioinformatics Resources 6.7 was used for pathway enrichment analysis. Cytoscape plug-in PiNGO 1.11 was employed for protein-network-based prediction of novel candidate genes. Relevant protein-protein interactions were confirmed and visualized using the STRING database (version 9.0).

RESULTS

The developed cryptorchidism gene atlas includes 217 candidate loci (genes, regions involved in chromosomal mutations, and copy number variations) identified at the genomic, transcriptomic, and proteomic level. Human orthologs of the collected candidate loci were presented using a genomic map viewer. The cryptorchidism gene atlas is freely available online: http://www.integratomics-time.com/cryptorchidism/. Pathway analysis suggested the presence of twelve enriched pathways associated with the list of 179 literature-derived candidate genes. Additionally, a list of 43 network-predicted novel candidate genes was significantly associated with four enriched pathways. Joint pathway analysis of the collected and predicted candidate genes revealed the pivotal importance of the muscle-contraction pathway in cryptorchidism and evidence for genomic associations with cardiomyopathy pathways in RASopathies.

CONCLUSIONS

The developed gene atlas represents an important resource for the scientific community researching genetics of cryptorchidism. The collected data will further facilitate development of novel genetic markers and could be of interest for functional studies in animals and human. The proposed network-based systems biology approach elucidates molecular mechanisms underlying co-presence of cryptorchidism and cardiomyopathy in RASopathies. Such approach could also aid in molecular explanation of co-presence of diverse and apparently unrelated clinical manifestations in other syndromes.

Generation and characterization of human cryptorchid-specific induced pluripotent stem cells from urine

Cryptorchidism is a common congenital birth defect in human beings with the possible complication of infertility. An in vitro model of cryptorchidism might be valuable due to the inaccessibility of human embryos for research purposes. In this study, we reprogrammed urine cells containing genetic variations in insulin-like factor 3, zinc finger (ZNF) 214, and ZNF215 from a cryptorchid patient by introducing human OCT4, SOX2, C-MYC, and KLF4 with lentivirus. The cells were then replated on irradiated mouse embryonic fibroblasts and cultured with the human embryonic stem (ES) cell medium. The compact colonies with well-defined borders were manually picked, and 2 induced pluripotent cell lines were fully characterized. Our results demonstrated that these 2 cell lines were similar to human ES cells in morphological appearance, marker expression, and epigenetic status of the pluripotent cell-specific gene, OCT4. These cells could be differentiated into cells of all 3 germ layers in teratomas and in vitro, including into the VASA-positive germ cell lineage. Both parental urine cells and the reprogrammed cells possessed the normal karyotype and the same short tandem repeat loci, indicating that these 2 cell population share the same genetic identity. This establishment and characterization of human urine-derived cryptorchid-specific induced pluripotent stem cells could present a good human genetic system for future studies investigating the molecular mechanism of cryptorchidism.

Human infertility: are endocrine disruptors to blame?

Over recent decades, epidemiological studies have been reporting worrisome trends in the incidence of human infertility rates. Extensive detection of industrial chemicals in human serum, seminal plasma and follicular fluid has led the scientific community to hypothesise that these compounds may disrupt hormonal homoeostasis, leading to a vast array of physiological impairments. Numerous synthetic and natural substances have endocrine-disruptive effects, acting through several mechanisms. The main route of exposure to these chemicals is the ingestion of contaminated food and water. They may disturb intrauterine development, resulting in irreversible effects and may also induce transgenerational effects. This review aims to summarise the major scientific developments on the topic of human infertility associated with exposure to endocrine disruptors (EDs), integrating epidemiological and experimental evidence. Current data suggest that environmental levels of EDs may affect the development and functioning of the reproductive system in both sexes, particularly in foetuses, causing developmental and reproductive disorders, including infertility. EDs may be blamed for the rising incidence of human reproductive disorders. This constitutes a serious public health issue that should not be overlooked. The exposure of pregnant women and infants to EDs is of great concern. Therefore, precautionary avoidance of exposure to EDs is a prudent attitude in order to protect humans and wildlife from permanent harmful effects on fertility.

Altered infant feeding patterns in boys with acquired nonsyndromic cryptorchidism

BACKGROUND

Genetic and environmental factors likely influence susceptibility to nonsyndromic cryptorchidism, a common disease presenting at birth or in later childhood. We compared cases and controls to define differential risk factors for congenital versus acquired cryptorchidism.

METHODS

We compared questionnaire and clinical data from cases of congenital cryptorchidism (n = 230), acquired cryptorchidism (n = 182) and hernia/hydrocele (n = 104) with a group of healthy male controls (n = 358). Potential predictor variables (p < 0.2 in univariable analysis) were included in stepwise multivariable logistic regression models.

RESULTS

Temporary (odds ratio [OR], 0.5; 95% confidence interval [CI], 0.4-0.8) or exclusive (OR, 0.6; 95% CI, 0.4-0.9) breastfeeding was reduced and soy formula feeding increased (OR, 1.8; 95% CI, 1.2-2.9) in acquired but not congenital or hernia/hydrocele groups. The highest risk estimates were observed for primary soy formula feeding with limited or no breastfeeding (OR 2.5; 95% CI, 1.4-4.3; adjusted OR, 2.7; 95% CI, 1.4-5.4) in the acquired group. Primary feeding risk estimates were equivalent or strengthened when multivariable models were limited to age greater than 2 years, full-term or not small for gestational age, or Caucasian subjects. Pregnancy complications and increased maternal exposure to cosmetic or household chemicals were not consistently associated with either form of cryptorchidism in these models.

CONCLUSIONS

Our data support reduced breastfeeding and soy formula feeding as potential risk factors for acquired cryptorchidism. Although additional studies are needed, hormonally active components of breast milk and soy formula could influence the establishment of normal testis position in the first months of life, leading to apparent ascent of testes in childhood. Birth Defects Research (Part A), 2012.

Unilateral cryptorchidism in mice mutant for Ptgds

The pathophysiology of cryptorchidism, abnormal testicular descent, remains poorly understood. In this study, we show that both heterozygous and homozygous mice deficient for lipocalin-type prostaglandin D(2) (PGD(2) ) synthase (Ptgds) presented unilateral cryptorchidism affecting the second phase of testicular descent in 16% and 24% of cases, respectively. The adult cryptorchid testes show an increase in spermatogonia apoptosis along with a global decrease in the tubule size parameters, whereas the gubernaculum of newborn mutants present some histological abnormalities. Disruption of the inguinoscrotal phase did not present impairment of the androgen pathway but rather a decrease in Rxfp2 mRNA expression in the gubernaculum. These observations led us to investigate the role of the PGD(2) signaling pathway in human testicular migration through PTGDS sequencing of DNA from 29 children with cryptorchidism. However, none of the investigated cases presented mutations in the PTGDS gene. Nevertheless, our results identify the PTGDS enzyme as a novel component in the cryptorchidism puzzle.