FGF8, FGF10 and FGF receptor 2 in foreskin of children with hypospadias: an analysis of immunohistochemical expression patterns and gene transcription.

INTRODUCTION: Fibroblast growth factors (FGFs) play a crucial role in early embryogenesis of the genital tubercle and are involved in the development of hypospadias, affecting both endo- and ectodermally derived tissues. It was hypothesized that expression of FGFs could be qualitatively or quantitatively altered in skin of children with hypospadias. OBJECTIVE: The objective of the study was to investigate expression patterns and transcription levels of FGF8, FGF10, and FGF Receptor 2 (FGFR2) in patients with hypospadias compared to normal controls. PATIENTS AND METHODS: Skin samples from the ventro-lateral aspect of the foreskin of 32 patients with hypospadias (17 distal and 15 proximal, mean age 25 months) and 10 normal foreskin samples (mean age 77 months) were analyzed by immunohistochemistry. Staining, localization, and distribution of positive cells in epidermis and dermis were categorized independently by two researchers. Complementary DNA (cDNA) samples prepared from messenger RNA (mRNA) isolates of the same samples were analyzed by quantitative polymerase chain reaction (qPCR), comparing expressions of FGF8, FGF10, and FGFR2 with loading controls. RESULTS: Patients with hypospadias consistently showed aberrant immunohistochemical staining patterns for FGF8/FGF10/FGFR2 in epidermis and dermis compared to patients without penile malformation (p < 0.01 for all markers). qPCR displayed no difference in expression levels on mRNA level (FGFR2 p = 0.44, FGF8 p = 0.77, and FGF10 p = 0.17) comparing normal foreskin with foreskin from patients with hypospadias. Figure. DISCUSSION: The results point at an impact of FGF signaling during embryological development of hypospadias on skin, as an ectodermally derived tissue. Similar to the urethral development, this might be a result of mesothelial-epithelial interactions. The differing expression patterns in immunohistochemistry are not matched by a quantitative difference in marker expression on the mRNA level, putatively caused by post-translational modifications or alterations of the downstream pathway. FGFs, particularly FGF10 and FGFR2, are critically involved in wound healing. CONCLUSIONS: There are significant differences in localization and distribution of FGF8, FGF10, and FGFR2 in comparisons of normal foreskin to foreskin of patients with hypospadias, whereas there is no difference in the quantitative expression of these markers on the mRNA level. This confirms the notion that penile skin is affected as well by the embryological aberrations during the embryogenesis of hypospadias.

Tissue-Specific Gene Expression during Productive Human Papillomavirus 16 Infection of Cervical, Foreskin, and Tonsil Epithelium.

Epidemiological data confirm a much higher incidence of high-risk human papillomavirus 16 (HPV16)-mediated carcinogenesis of the cervical epithelium than for other target sites. In order to elucidate tissue-specific responses to virus infection, we compared gene expression changes induced by productive HPV16 infection of cervical, foreskin, and tonsil organotypic rafts. These rafts closely mimic persistent HPV16 infection, long before carcinogenesis sets in. The total number of gene expression changes varied considerably across the tissue types, with only 32 genes being regulated in common. Among them, we confirmed the Kelch-like family protein KLHL35 and the laminin-5 complex to be upregulated and downregulated, respectively, in all the three tissues. HPV16 infection induces upregulation of genes involved in cell cycle control, cell division, mitosis, DNA replication, and DNA damage repair in all the three tissues, indicative of a hyperproliferative environment. In the cervical and tonsil epithelium, we observe significant downregulation of genes involved in epidermis development, keratinocyte differentiation, and extracellular matrix organization. On the other hand, in HPV16-positive foreskin (HPV16 foreskin) tissue, several genes involved in interferon-mediated innate immunity, cytokine signaling, and cellular defenses were downregulated. Furthermore, pathway analysis and experimental validations identified important cellular pathways like STAT1 and transforming growth factor ß (TGF-ß) to be differentially regulated among the three tissue types. The differential modulation of important cellular pathways like TGF-ß1 and STAT1 can explain the sensitivity of tissues to HPV cancer progression.IMPORTANCE Although the high-risk human papillomavirus 16 infects anogenital and oropharyngeal sites, the cervical epithelium has a unique vulnerability to progression of cancer. Host responses during persistent infection and preneoplastic stages can shape the outcome of cancer progression in a tissue-dependent manner. Our study for the first time reports differential regulation of critical cellular functions and signaling pathways during productive HPV16 infection of cervical, foreskin, and tonsil tissues. While the virus induces hyperproliferation in infected cells, it downregulates epithelial differentiation, epidermal development, and innate immune responses, according to the tissue type. Modulation of these biological functions can determine virus fitness and pathogenesis and illuminate key cellular mechanisms that the virus employs to establish persistence and finally initiate disease progression.

Cutaneous myeloid sarcoma of the penile foreskin.

Myeloid sarcoma, considered to herald the onset of a blast crisis in the setting of chronic myeloproliferative neoplasm/dysplasia, typically presents during the course of the disorder. Cutaneous involvement is uncommon and lesions on genital skin are seldom seen. We present a case of a well-differentiated myeloid sarcoma in the penile foreskin in an apparently healthy 29-year-old male presenting with phimosis. The unusual composition of the inflammatory cell infiltrate, and characteristic sparing of dermal blood vessels, nerves and smooth muscle fibres led to the correct diagnosis. Absence of commonly observed changes in the circumcision skin like those of balanitis xerotica was also helpful. Detailed hematological work up revealed a previously undiagnosed chronic myeloid leukemia in chronic phase. The patient also had simultaneous priapism, another rare presentation of chronic myeloid leukemia. One year hence, the patient is in hematological remission with no evidence of extramedullary disease. Although priapism has been described as a rare presenting symptom in chronic myeloid leukemia, the present case is unique as this is the first time a cutaneous myeloid sarcoma has been documented in the penile foreskin.

Keratinized versus non-keratinized preputial flap onlay urethroplasty: does it make any difference in the histological analysis? An experimental study in rabbits

Purpose To compare the histological characteristics of keratinized versus non-keratinized onlay island flaps in an experimental rabbit model. Materials and Methods Sixteen male rabbits were randomly allocated into two experimental groups: keratinized and non-keratinized onlay island flaps. A defect was created in the ventral aspect of the penile urethra. In the keratinized group, a longitudinal island flap was harvested from the external prepuce and rotated to cover the urethral defect. In the non-keratinized group a transverse island flap was harvested from the inner prepuce. The animals were sacrificed after 2, 4, 8 and 12 weeks. Results The flaps were viable in all animals, and no deaths were associated with the procedure. Two urethrocutaneous fistulas were identified, one in each experimental group. A similar pattern of fibrosis was identified in both groups. The keratinized epithelium of the external prepuce kept its histological aspect and keratin production. Both keratinized and non-keratinized groups presented a slight decrease on the epithelial thickness, however without a statistically significant difference between groups. Conclusions In this short-term rabbit model, we observed that the stratified squamous keratinized epithelium from the external prepuce kept its keratin production. There was no statistical influence of the flap type on the mean epithelial thickness. .

Quantitative measurement of the androgen receptor in prepuces of boys with and without hypospadias.

UNLABELLED: WHAT'S KNOWN ON THE SUBJECT? AND WHAT DOES THE STUDY ADD?: Despite diverse anatomical and histological trials in humans and animal models, the aetiology of hypospadias remains unknown and currently there is no clear molecular explanation about the emergence of this disease; however, genetic, endocrine and environmental mechanisms have been suggested. The aim of the present study was to quantify and compare the androgen receptor (AR; mRNA and protein) levels in 40 prepuces of boys with and without hypospadias using quantitative real-time polymerase chain reaction, Western Blot and standardised, automated immunohistochemistry. AR mRNA (P = 0.013) and AR protein (P = 0.014) was significantly elevated in the prepuces of boys with hypospadias compared with boys without hypospadias. Altogether our data indicate that elevated AR mRNA and protein levels can be considered as a biochemical response of an AR signalling defect as an identified cause in boys with hypospadias. Additionally, nuclear staining intensity for AR-protein in specimens of boys with hypospadias was higher than in boys with phimosis. OBJECTIVE: To address the role of the androgen receptor (AR) on mRNA and protein levels in prepuces of boys with and without hypospadias. PATIENTS AND METHODS: Data from 40 foreskin specimens of consecutive circumcised boys (20 with vs 20 without hypospadias) were enrolled in this prospective study. After surgery, samples were fixed in formaldehyde and frozen in liquid nitrogen. Total RNA was isolated from frozen tissue and transcribed to complementary DNA. The amount of AR mRNA was measured by quantitative real-time polymerase chain reaction and Western Blot and standardised, automated immunohistochemistry were used to assess AR protein levels. RESULTS: The mean age at time of surgery was 61.8 and 30.9 months in boys without and with hypospadias, respectively. There was penile, coronal and sine hypospadias in seven (35%), nine (45%), and four (20%) boys, respectively. AR mRNA was significantly elevated in the prepuces of boys with hypospadias compared with boys without hypospadias, at a mean (sd) of 28.33 (5.39) vs 15.31 (1.85) (P = 0.013). Furthermore, the amount of AR protein was higher in boys with, compared with boys without hypospadias, at a mean (sd) of 133.25 (6.17) vs 100 (4.45) (P = 0.014). CONCLUSIONS: Different AR mRNA expression and protein levels seem to be an indication of an AR signalling defect as a cause in boys with hypospadias. Decreased AR DNA binding and functional capability may result in a compensatory up-regulation of both AR mRNA and protein. Further studies are necessary to perform structural analysis of the AR and to corroborate these preliminary findings.

Keratinized versus non-keratinized preputial flap onlay urethroplasty: does it make any difference in the histological analysis? An experimental study in rabbits.

PURPOSE: To compare the histological characteristics of keratinized versus non-keratinized onlay island flaps in an experimental rabbit model. MATERIALS AND METHODS: Sixteen male rabbits were randomly allocated into two experimental groups: keratinized and non-keratinized onlay island flaps. A defect was created in the ventral aspect of the penile urethra. In the keratinized group, a longitudinal island flap was harvested from the external prepuce and rotated to cover the urethral defect. In the non-keratinized group a transverse island flap was harvested from the inner prepuce. The animals were sacrificed after 2, 4, 8 and 12 weeks. RESULTS: The flaps were viable in all animals, and no deaths were associated with the procedure. Two urethrocutaneous fistulas were identified, one in each experimental group. A similar pattern of fibrosis was identified in both groups. The keratinized epithelium of the external prepuce kept its histological aspect and keratin production. Both keratinized and non-keratinized groups presented a slight decrease on the epithelial thickness, however without a statistically significant difference between groups. CONCLUSIONS: In this short-term rabbit model, we observed that the stratified squamous keratinized epithelium from the external prepuce kept its keratin production. There was no statistical influence of the flap type on the mean epithelial thickness.

Structural alterations of foreskin caused by chronic smoking may explain high levels of urethral reconstruction failure using foreskin flaps.

OBJECTIVES: The aim of the present study was to perform a stereological and biochemical analysis of the foreskin of smoker subjects. MATERIALS AND METHODS: Foreskin samples were obtained from 20 young adults (mean = 27.2 years old) submitted to circumcision. Of the patients analyzed, one group (n = 10) had previous history of chronic smoking (a half pack to 3 packs per day for 3 to 13 years (mean = 5.8 ± 3.2). The control group included 10 nonsmoking patients. Masson 's trichrome stain was used to quantify the foreskin vascular density. Weigert's resorcin-fucsin stain was used to assess the elastic system fibers and Picrosirius red stain was applied to study the collagen. Stereological analysis was performed using the Image J software to determine the volumetric densities. For biochemical analysis, the total collagen was determined as µg of hydroxyproline per mg of dry tissue. Means were compared using the unpaired t-test (p < 0.05). RESULTS: Elastic system fibers of smokers was 42.5 % higher than in the control group (p = 0.002). In contrast, smooth muscle fibers (p = 0.42) and vascular density (p = 0.16) did not show any significant variation. Qualitative analysis using Picrosirius red stain with polarized light evidenced the presence of type I and III collagen in the foreskin tissue, without significant difference between the groups. Total collagen concentration also did not differ significantly between smokers and non-smokers (73.1 µg/mg ± 8.0 vs. 69.2 µg/mg ± 5.9, respectively, p = 0.23). CONCLUSIONS: The foreskin tissue of smoking patients had a significant increase of elastic system fibers. Elastic fibers play an important role in this tissue's turnover and this high concentration in smokers possibly causes high extensibility of the foreskin. The structural alterations in smokers' foreskins could possibly explain the poor results in smoking patients submitted to foreskin fasciocutaneous flaps in urethral reconstruction surgery.

Structural alterations of foreskin caused by chronic smoking may explain high levels of urethral reconstruction failure using foreskin flaps

OBJECTIVES: The aim of the present study was to perform a stereological and biochemical analysis of the foreskin of smoker subjects. MATERIALS AND METHODS: Foreskin samples were obtained from 20 young adults (mean = 27.2 years old) submitted to circumcision. Of the patients analyzed, one group (n = 10) had previous history of chronic smoking (a half pack to 3 packs per day for 3 to 13 years (mean = 5.8 ± 3.2). The control group included 10 nonsmoking patients. Masson's trichrome stain was used to quantify the foreskin vascular density. Weigert’s resorcin-fucsin stain was used to assess the elastic system fibers and Picrosirius red stain was applied to study the collagen. Stereological analysis was performed using the Image J software to determine the volumetric densities. For biochemical analysis, the total collagen was determined as µg of hydroxyproline per mg of dry tissue. Means were compared using the unpaired t-test (p < 0.05). RESULTS: Elastic system fibers of smokers was 42.5% higher than in the control group (p = 0.002). In contrast, smooth muscle fibers (p = 0.42) and vascular density (p = 0.16) did not show any significant variation. Qualitative analysis using Picrosirius red stain with polarized light evidenced the presence of type I and III collagen in the foreskin tissue, without significant difference between the groups. Total collagen concentration also did not differ significantly between smokers and non-smokers (73.1µg/mg ± 8.0 vs. 69.2µg/mg ± 5.9, respectively, p = 0.23). CONCLUSIONS: The foreskin tissue of smoking patients had a significant increase of elastic system fibers. Elastic fibers play an important role in this tissue’s turnover and this high concentration in smokers possibly causes high extensibility of the foreskin. The structural alterations in smokers’ foreskins could possibly explain the poor results in smoking patients submitted to foreskin fasciocutaneous flaps in urethral reconstruction surgery.

Antiviral antibodies and T cells are present in the foreskin of simian immunodeficiency virus-infected rhesus macaques.

No information exists regarding immune responses to human immunodeficiency virus (HIV) infection in the foreskin or glans of the human penis, although this is a key tissue for HIV transmission. To address this gap, we characterized antiviral immune responses in foreskin of male rhesus macaques (RMs) inoculated with simian immunodeficiency virus (SIV) strain SIVmac251 by penile foreskin exposure. We found a complete population of immune cells in the foreskin and glans of normal RMs, although B cells were less common than CD4(+) and CD8(+) T cells. IgG-secreting cells were detected by enzyme-linked immunospot (ELISPOT) assay in cell suspensions made from the foreskin. In the foreskin and glans of SIV-infected RMs, although B cells were less common than CD4(+) and CD8(+) T cells, SIV-specific IgG antibody was present in foreskin secretions. In addition, cytokine-secreting SIV-specific CD8(+) T cells were readily found in cell suspensions made from the foreskin. Although potential HIV target cells were found in and under the epithelium covering all penile surfaces, the presence of antiviral effector B and T cells in the foreskin suggests that vaccines may be able to elicit immunity in this critical site to protect men from acquiring HIV.

Expression of estrogen receptor alpha and beta is decreased in hypospadias.

PURPOSE: Estrogenic endocrine disruptors acting via estrogen receptors α and ß have been implicated in the etiology of hypospadias. However, the expression and distribution of estrogen receptors α and ß in normal and hypospadiac human foreskins is unknown. We characterized the location and expression of estrogen receptors α and ß in normal and hypospadiac foreskins. MATERIALS AND METHODS: We prospectively collected excess foreskin from 35 patients undergoing hypospadias repair and 15 patients undergoing elective circumcision. Hypospadias was classified as severe in 18 patients and mild in 17 based on the ectopic position of the meatus. mRNA expression levels in estrogen receptors α and ß were quantified using reverse transcriptase polymerase chain reaction. Receptor location was characterized by immunohistochemical analysis. Additionally immunohistochemical analysis was performed in 4 archived human fetal penises. RESULTS: Mean ± SD ages were similar for the circumcision (9.5±3 months) and hypospadias repair groups (9±3 months, p=0.75). mRNA expression levels in estrogen receptors α and ß were significantly decreased in hypospadiac foreskin cases compared to controls (p<0.001), while no statistically significant differences were seen between foreskins with severe and mild hypospadias. Estrogen receptor ß immunostaining was strong in normal foreskin but weak in hypospadiac foreskin. Estrogen receptor ß immunoreactivity was most intense in the stratum basale and stratum spinosum. Estrogen receptor α immunostaining was weak in normal and mild hypospadias foreskin, and undetectable in severe hypospadias. Fetal penises expressed strong estrogen receptor ß immunopositivity in the urethral plate epithelium, corpus spongiosum, corpora cavernosa and penile skin, while estrogen receptor α immunostaining was not detected. CONCLUSIONS: These data demonstrate a difference in estrogen receptor α and ß expression and location in the foreskin of patients with hypospadias compared to controls. These findings are consistent with aberrant estrogenic effects having a role in the etiology of hypospadias.

Langerhans' cell density and degree of keratinization in foreskins of Chinese preschool boys and adults.

BACKGROUND: Recent epidemiological studies have proposed that male circumcision reduces the relative risk of acquiring HIV-1. Here, we evaluated the density of Langerhans' cell and degree of keratinization in the foreskins of Chinese preschool boys and adults. METHODS: Sixty preschool boys and 20 healthy men without infectious history following male circumcisions were included. The keratin thickness and Langerhans' cells were quantified by using keratin staining, immunohistochemistry, and image analysis. RESULTS: The extent of keratinization was much greater in the inner foreskin than in the outer foreskin in adults and boys with infectious history. It was likely to be less keratinized in boys' foreskins compared with those of adults. The density of Langerhans' cells was higher in the outer foreskin than in the inner foreskin of adults and healthy boys. Furthermore, an increased density of Langerhans' cells of inner foreskin was also found in boys with infectious history compared with healthy boys. There was much higher Langerhans' cell density in boys' foreskin compared with those of adults. CONCLUSIONS: These findings suggest that Chinese men may have a different feature of keratin in the foreskin, and a higher Langerhans' cells density in boys' foreskin may be due to it being less keratinized.

Rapid, high-quality and epidermal-specific isolation of RNA from human skin.

As global transcriptome analyses with a growing demand on layer-specific applications are widely used in cutaneous biology, we investigated the effect of established and optimized dermo-epidermal separation methods on the quality of RNA. We compared enzymatic separation with dispase, chemical separation with 1 M sodium chloride and heat separation to a treatment with 3.8% ammonium thioyanate. The impact of freezing as well as the addition of 10 mM aurintricarboxylic acid was considered in the evaluation of the amount and quality of isolated RNA from dermis and epidermis. Using the low abundant gene kallikrein 12 for real-time PCR analysis, we were able to demonstrate the superior RNA quality after dermo-epidermal separation using 3.8% ammonium thiocyanate. In addition to the time effectiveness this separation technique promises dermal and epidermal purity and is therefore the method of choice for producing high-quality RNA for genome-wide dermal and epidermal transcriptional analysis.