Progesterone Receptors in the Developing Genital Tubercle: Implications for the Endocrine Disruptor Hypothesis as the Etiology of Hypospadias

Androgen Receptor-Positive Penile Acrochordon: A Case Report

Acrochordons are polypoid, skin-colored lesions usually present at the site of skin folds. They are extremely rare in the preputial area of the penis and do not tend to grow. To the best of our knowledge, in English literature, this report presents the first case of an androgen receptor-positive penile acrochordon, which is located on the penis and showed rapid growth along with body development during puberty with no underlying causes such as acromegaly, diabetes, obesity, and trauma.

Hormone receptor expression in hypospadias

INTRODUCTION

Sex hormone imbalance in utero is hypothesized to play an important role in the pathogenesis of hypospadias. Due to its easy accessibility, foreskin samples have been used to describe hormone receptor expression in rodents, and both adult and pediatric patients. In this study we conducted a systematic approach to assess hormone receptor expression in pediatric patients with hypospadias compared to healthy controls with a focus on age-matching and differences in severity and degree of hypospadias.

METHODS

Foreskin samples were collected from 35 children during hypospadias operations (18 distal and 17 proximal hypospadias) and compared with ventral foreskin samples of a control group of 32 children during circumcision (15 age-matched and 17 older boys). The samples were stained with H/E, androgen (AR), estrogen (ER) and progesterone receptors (PR). The receptor stainings were blindly evaluated. An Allred score was used to evaluate receptor expression in both the epithelium as well as stroma.

RESULTS

AR was detected in all cases. AR expression in the stroma was more evident than in the epithelium. AR expression in the hypospadias groups was significantly less than the age matched controls (p < 0.05). There was no significant difference between the two hypospadias groups nor between the two control groups. Older control group showed significantly elevated levels of AR expression compared to the hypospadias group (p < 0.05). ER was also detected in all cases. The stroma showed more ER than in epithelium. PR was minimal or negative in all samples.

CONCLUSION

Boys with hypospadias showed significantly weaker expression of androgen receptors than age matched controls. The severity of hypospadias did not influence hormone receptor distribution. AR expression is better observed in the stroma than in the epithelium. There was no difference in ER expression between the hypospadias group (distal or proximal) and age matched normal controls. ER was expressed in larger numbers in normal older preputial tissue. The foreskin of prepubertal boys shows little to no expression of PR.

Is primary adult hypospadiatic prepuce different from healthy prepuce in terms of microvascular density and androgen-estrogen-progesterone receptors?

This study aims to determine the histological data such as microvessel density, nerve density, and the androgen, oestrogen and progesterone receptor density in the prepuce of primary distal hypospadias cases in adulthood, compared to that of healthy individuals in the same age group. Between 2014 and 2019, we prospectively evaluated adult hypospadias and adult circumcision patients. A total of 28 patients were included: Group 1 (18 patients) primary distal hypospadias and Group 2 (10 patients-control group) healthy individuals who had a previous circumcision request for social/religious reasons. The prepuce of healthy individuals that were excised after the circumcision and the excised parts excluded from the prepuce that was used in reconstruction during the repair of hypospadias, were shaped and stored to be able to perform a study by the pathology clinic. Histopathological findings on adult distal hypospadias cases showed that the microvascular density and inflammation in the prepuce with hypospadias were found to be increased compared to the healthy prepuce and the density of androgen and oestrogen receptors was similar in both groups. Unlike childhood studies, in this study with adults, the progesterone receptor was detected in both groups and found to be significantly lower in the hypospadias group.

Contrasting mechanisms of penile urethral formation in mouse and human

This paper addresses the developmental mechanisms of formation of the mouse and human penile urethra and the possibility that two disparate mechanisms are at play. It has been suggested that the entire penile urethra of the mouse forms via direct canalization of the endodermal urethral plate. While this mechanism surely accounts for development of the proximal portion of the mouse penile urethra, we suggest that the distal portion of the mouse penile urethra forms via a series of epithelial fusion events. Through review of the recent literature in combination with new data, it is unlikely that the entire mouse urethra is formed from the endodermal urethral plate due in part to the fact that from E14 onward the urethral plate is not present in the distal aspect of the genital tubercle. Formation of the distal portion of the mouse urethra receives substantial contribution from the preputial swellings that form the preputial-urethral groove and subsequently the preputial-urethral canal, the later of which is subdivided by a fusion event to form the distal portion of the mouse penile urethra. Examination of human penile development also reveals comparable dual morphogenetic mechanisms. However, in the case of human, direct canalization of the urethral plate occurs in the glans, while fusion events are involved in formation of the urethra within the penile shaft, a pattern exactly opposite to that of the mouse. The highest incidence of hypospadias in humans occurs at the junction of these two different developmental mechanisms. The relevance of the mouse as a model of human hypospadias is discussed.

Placental pathology and hypospadias

BACKGROUND

Studies have shown that hypospadias is associated with placenta-mediated pregnancy complication (PMPC). The role of placental lesions is still unclear. We aimed to examine the association between hyposadias and placental pathology, and the effect of PMPC.

METHODS

Using data from the US Collaborative Perinatal Project in 1959-1966, we identified 15,780 male subjects (167 hypospadias) for analysis. Detailed placental examinations were conducted following a standard protocol. Subjects were divided into two groups according to whether they had PMPC, including small-for-gestational-age, pre-eclampsia/eclampsia or placental abruption. Logistic regression models were used to explore the association.

RESULTS

The prevalence of hypospadias was two times higher in subjects with PMPC than those without. Compared to pregnancies with PMPC but no hypospadias, those with both PMPC and hypospadias had significant higher prevalence of placental lesions, such as low placental weight, vascular lesions, villous lesions, and membranous insertion of cord (adjusted odds ratio (OR) ranging from 2.6 to 5.2) after adjusting for potential confounders. In subjects without PMPC, no significant difference of placental pathology was found between those with or without hypospadias.

CONCLUSION

About one third of hypospadias cases were complicated with PMPC and had a higher risk of placental lesions, suggesting heterogeneity of hypospadias etiology and mechanisms.

Do endocrine disruptors cause hypospadias?

Introduction

Endocrine disruptors or environmental agents, disrupt the endocrine system, leading to various adverse effects in humans and animals. Although the phenomenon has been noted historically in the cases of diethylstilbestrol (DES) and dichlorodiphenyltrichloroethane (DDT), the term “endocrine disruptor” is relatively new. Endocrine disruptors can have a variety of hormonal activities such as estrogenicity or anti-androgenicity. The focus of this review concerns on the induction of hypospadias by exogenous estrogenic endocrine disruptors. This has been a particular clinical concern secondary to reported increased incidence of hypospadias. Herein, the recent literature is reviewed as to whether endocrine disruptors cause hypospadias.

Methods

A literature search was performed for studies involving both humans and animals. Studies within the past 5 years were reviewed and categorized into basic science, clinical science, epidemiologic, or review studies.

Results

Forty-three scientific articles were identified. Relevant sentinel articles were also reviewed. Additional pertinent studies were extracted from the reference of the articles that obtained from initial search results. Each article was reviewed and results presented. Overall, there were no studies which definitely stated that endocrine disruptors caused hypospadias. However, there were multiple studies which implicated endocrine disruptors as one component of a multifactorial model for hypospadias.

Conclusions

Endocrine disruption may be one of the many critical steps in aberrant development that manifests as hypospadias.

Diethylstilbestrol-induced mouse hypospadias: "window of susceptibility"

This review presents published and novel results that define the programming window for diethylstilbestrol (DES)-induced abnormal development of the mouse penis. These data indicate that DES has its greatest effect during the period of most intense penile morphogenesis, namely postnatal days 0-15 (P0-P15). Pregnant mice and their neonatal pups were injected subcutaneously with 200 ng/gbw DES every other day from embryonic day 12-18 (DES E12-E18), postnatal day 0-10 (DES P0-P10), embryonic day 12 to postnatal day 10 (DES E12-P10), postnatal day 5-15 (DES P5-P15), and postnatal day 10-20 (DES P10-P20). Aged-matched controls received sesame oil vehicle. After euthanasia at 10, 15, 20 and 60 days, penises were analyzed by gross morphology, histology and morphometry. Penises of all 5 groups of DES-treated mice were reduced in size, which was confirmed by morphometric analysis of internal penile structures. The most profound effects were seen in the DES E12-P10, DES P0-P10, and DES P5-P15 groups, thus defining a DES "programming window". For all parameters, DES treatment from P10 to P20 showed the most mild of effects. Adverse effects of DES on the MUMP cartilage and erectile bodies observed shortly after the last DES injection reverted to normality in the DES P5-P15, but not in the E12-P10 and P0-P10 groups, in which MUMP cartilage and erectile body malformations persisted into adulthood, again emphasizing a "window of susceptibility" in the early neonatal period.

Implications of prenatal steroid perturbations for neurodevelopment, behavior, and autism

The prenatal brain develops under the influence of an ever-changing hormonal milieu that includes endogenous fetal gonadal and adrenal hormones, placental and maternal hormones, and exogenous substances with hormonal activity that can cross the placental barrier. This review discusses the influences of endogenous fetal and maternal hormones on normal brain development and potential consequences of pathophysiological hormonal perturbations to the developing brain, with particular reference to autism. We also consider the effects of hormonal pharmaceuticals used for assisted reproduction, the maintenance of pregnancy, the prevention of congenital adrenal hypertrophy, and hormonal contraceptives continued into an unanticipated pregnancy, among others. These treatments, although in some instances life-saving, may have unintended consequences on the developing fetuses. Additional concern is raised by fetal exposures to endocrine-disrupting chemicals encountered universally by pregnant women from food/water containers, contaminated food, household chemicals, and other sources. What are the potential outcomes of prenatal steroid perturbations on neurodevelopmental and behavioral disorders, including autism-spectrum disorders? Our purposes here are 1) to summarize some consequences of steroid exposures during pregnancy for the development of brain and behavior in the offspring; 2) to summarize what is known about the relationships between exposures and behavior, including autism spectrum disorders; 3) to discuss the molecular underpinnings of such effects, especially molecular epigenetic mechanisms of prenatal steroid manipulations, a field that may explain effects of direct exposures, and even transgenerational effects; and 4) for all of these, to add cautionary notes about their interpretation in the name of scientific rigor.

Androgen receptor is overexpressed in boys with severe hypospadias, and ZEB1 regulates androgen receptor expression in human foreskin cells

INTRODUCTION

ZEB1 is overexpressed in patients with severe hypospadias. We examined the interaction between ZEB1 and the androgen receptor (AR) in vitro and the expression of AR in boys with hypospadias.

RESULTS

ZEB1 and AR colocalize to the nucleus. Estrogen upregulated ZEB1 and AR expression. Chromatin immunoprecipitation (ChIP) demonstrated that ZEB1 binds to an E-box sequence in the AR gene promoter. AR expression is higher in subjects with severe hypospadias than those with mild hypospadias and control subjects (P < 0.05). ZEB1 physically interacts with AR in human foreskin cells.

DISCUSSION

AR is overexpressed in patients with severe hypospadias. Environmental estrogenic compounds may increase the risk of hypospadias by facilitating the interaction between ZEB1 and AR.

METHODS

Hs68 cells, a fibroblast cell line derived from neonatal human foreskin, were exposed to 0, 10, and 100 nmol/l of estrogen, after which the cellular localization of ZEB1 and AR was assessed using immunocytochemistry. To determine if ZEB1 interacted with the AR gene, ChIP was performed using ZEB1 antibody and polymerase chain reaction (PCR) for AR. Second, AR expression was quantified using real-time PCR and western blot in normal subjects (n = 32), and subjects with mild (n = 16) and severe hypospadia (n = 16).

The microvessel density of the hypospadiac prepuce in children

OBJECTIVE

The blood supply of the hypospadiac prepuce is crucial for success in surgery. Although the vascular anatomy of the hypospadiac prepuce has been previously documented, data on microvessel density are missing. It was aimed to document the microvessel density of the normal and hypospadiac prepuce.

METHODS

After ethical approval of the study, prepuces from 24 children with hypospadias undergoing surgical repair and from 9 healthy age-matched controls were stained by immunohistochemical methods using panendothelial cell antigen CD31 in order to assay their microvessel density.

RESULTS

The microvessel density was significantly decreased in hypospadiac children when compared to controls (P<0.05). A gradual decrease in microvessel density was observed as the severity of the condition increased, indicating a significant negative correlation (r=-0.585; P<0.05).

CONCLUSION

Our findings should be taken into account when considering preoperative treatments such as topical testosterone application or operative strategies for hypospadias using prepucial flaps, and also during the postoperative course, especially when it is complicated. Further studies are needed to clarify the role of vascularity in the pathogenesis of hypospadias and its consequences for surgical repair.

Water consumption and use, trihalomethane exposure, and the risk of hypospadias

OBJECTIVES

Hypospadias is a congenital anomaly that affects up to 70 in 10 000 males. Ingestion of drinking-water-disinfection byproducts such as trihalomethanes (THMs) has been associated with hypospadias in a small sample. We examined risk of hypospadias and exposure to THMs through water consumption and use.

METHODS

Between September 2000 and March 2003, we interviewed mothers of 471 boys with hypospadias and 490 controls in southeast England about maternal water consumption, dishwashing, showering, bathing and swimming. We obtained residential THM concentrations from the water companies and linked them by using Geographical Information Systems, which provided data on 468 case-subjects and 485 controls.

RESULTS

THM exposures, except for ingestion of ≥ 6 μg/day of bromodichloromethane (odds ratio [OR]: 1.65 [95% confidence interval (CI): 1.02-2.69]), were not associated with risk of hypospadias. Elevated risk of hypospadias was associated with estimates of consumption of cold tap water at home (OR: 1.71 [95% CI: 1.07-2.76]), total water (OR: 1.70 [95% CI: 1.09-2.67]), bottled water (OR: 1.64 [95% CI: 1.09-2.48]), and total fluid (OR: 1.55 [95% CI: 1.01-2.39]) for the highest versus the lowest categories; the first 2 showed dose-response trends.

CONCLUSIONS

Evidence for an association between maternal water consumption and risk of hypospadias did not seem to be explained by THM exposure. Factors that influence maternal water consumption or other contaminants in tap or bottled water might explain this finding. It is important that women maintain an adequate fluid intake during pregnancy.

Effects of environmental pollutants on the reproduction and welfare of ruminants

Anthropogenic pollutants comprise a wide range of synthetic organic compounds and heavy metals, which are dispersed throughout the environment, usually at low concentrations. Exposure of ruminants, as for all other animals, is unavoidable and while the levels of exposure to most chemicals are usually too low to induce any physiological effects, combinations of pollutants can act additively or synergistically to perturb multiple physiological systems at all ages but particularly in the developing foetus. In sheep, organs affected by pollutant exposure include the ovary, testis, hypothalamus and pituitary gland and bone. Reported effects of exposure include changes in organ weight and gross structure, histology and gene and protein expression but these changes are not reflected in changes in reproductive performance under the conditions tested. These results illustrate the complexity of the effects of endocrine disrupting compounds on the reproductive axis, which make it difficult to extrapolate between, or even within, species. Effects of pollutant exposure on the thyroid gland, immune, cardiovascular and obesogenic systems have not been shown explicitly, in ruminants, but work on other species suggests that these systems can also be perturbed. It is concluded that exposure to a mixture of anthropogenic pollutants has significant effects on a wide variety of physiological systems, including the reproductive system. Although this physiological insult has not yet been shown to lead to a reduction in ruminant gross performance, there are already reports indicating that anthropogenic pollutant exposure can compromise several physiological systems and may pose a significant threat to both reproductive performance and welfare in the longer term. At present, many potential mechanisms of action for individual chemicals have been identified but knowledge of factors affecting the rate of tissue exposure and of the effects of combinations of chemicals on physiological systems is poor. Nevertheless, both are vital for the identification of risks to animal productivity and welfare.