Normal penile development is dependent on testosterone, its conversion via steroid 5 alpha-reductase type 2 to dihydrotestosterone, and a functional androgen receptor (AR). The goal of this study was to investigate the distribution of AR and 5 alpha-reductase type 2 in the developing human fetal external genitalia with special emphasis on urethra formation. Twenty fetal genital specimens from normal human males (12-20 weeks gestation) were sectioned serially and stained by avidin-biotinylated peroxidase complex method with antigen retrieval. Stained sections throughout male genital development documented the expression of AR and 5 alpha-reductase type 2 in the phallus. Between 12 and 14 weeks of gestation, AR was localized to epithelial cells of the urethral plate in the glans, the tubular urethra of the penile shaft, and stromal tissue surrounding the urethral epithelium. In the fetal penis between 16 and 20 weeks gestation, the density of AR expression was greatest in urethral epithelial cells versus the surrounding stromal tissues. There was a characteristic pattern of AR expression in the glandular urethral epithelium between 16 and 20 weeks gestation. AR expression was greater along the ventral aspect of the glandular urethra than along the dorsal aspect of the urethral epithelium. The expression of 5 alpha-reductase type 2 was localized to the stroma surrounding the urethra, especially along the urethral seam area in the ventral portion of the remodeling urethra. These anatomical studies support the hypothesis that androgens are essential for the formation of the ventral portion of the urethra and that abnormalities in either the AR or 5 alpha-reductase type 2 can explain the occurrence of hypospadias.

The Cancer/Testis Antigen (CTA), Prostate-associated Gene 4 (PAGE4), is a stress-response protein that is upregulated in prostate cancer (PCa) especially in precursor lesions that result from inflammatory stress. In cells under stress, translocation of PAGE4 to mitochondria increases while production of reactive oxygen species decreases. Furthermore, PAGE4 is also upregulated in human fetal prostate, underscoring its potential role in development. However, the proteins that interact with PAGE4 and the mechanisms underlying its pleiotropic functions in prostatic development and disease remain unknown. Here, we identified c-Jun as a PAGE4 interacting partner. We show that both PAGE4 and c-Jun are overexpressed in the human fetal prostate; and in cell-based assays, PAGE4 robustly potentiates c-Jun transactivation. Single-molecule Förster resonance energy transfer experiments indicate that upon binding to c-Jun, PAGE4 undergoes conformational changes. However, no interaction is observed in presence of BSA or unilamellar vesicles containing the mitochondrial inner membrane diphosphatidylglycerol lipid marker cardiolipin. Together, our data indicate that PAGE4 specifically interacts with c-Jun and that, conformational dynamics may account for its observed pleiotropic functions. To our knowledge, this is the first report demonstrating crosstalk between a CTA and a proto-oncogene. Disrupting PAGE4/c-Jun interactions using small molecules may represent a novel therapeutic strategy for PCa.

The urinary tract is an outflow system that conducts urine from the kidneys to the bladder via the ureters that propel urine to the bladder via peristalsis. Once in the bladder, the ureteral valve, a mechanism that is not well understood, prevents backflow of urine to the kidney that can cause severe damage and induce end-stage renal disease. The upper and lower urinary tract compartments form independently, connecting at mid-gestation when the ureters move from their primary insertion site in the Wolffian ducts to the trigone, a muscular structure comprising the bladder floor just above the urethra. Precise connections between the ureters and the trigone are crucial for proper function of the ureteral valve mechanism; however, the developmental events underlying these connections and trigone formation are not well understood. According to established models, the trigone develops independently of the bladder, from the ureters, Wolffian ducts or a combination of both; however, these models have not been tested experimentally. Using the Cre-lox recombination system in lineage studies in mice, we find, unexpectedly, that the trigone is formed mostly from bladder smooth muscle with a more minor contribution from the ureter, and that trigone formation depends at least in part on intercalation of ureteral and bladder muscle. These studies suggest that urinary tract development occurs differently than previously thought, providing new insights into the mechanisms underlying normal and abnormal development.

This study catalogs the cellular events underlying the formation of a human testis. These events were identified by immunocytochemistry using antibodies that served as markers for specific cell types, then contrasted with the events occurring in the developing mouse testis. The presence of germ cells in the embryonic gonadal ridge and of coelomic epithelial cells that give rise to Sertoli cells was observed at 7 weeks. This was followed by the appearance of Sertoli cells in testicular tubules and of Leydig cells at 9 weeks and by the appearance of vascular endothelial cells and peritubular myoid cells at 12 weeks. Overall the temporal sequence of events in humans was similar, albeit longer, than what occurs in mice. Notably, Leydig cell differentiation occurs earlier in the sequence of events and germ cell maturation occurs during fetal life. The candidate testis-determining genes, FGF9, GATA4, FOG2, EMX2, and CBX2 were expressed at 7 weeks suggesting a role in early gonadal development, such as that observed in mice. In addition, expression of FGF9 in germ cells following testis determination suggests a role in germ cell maturation.

Although the epithelial lining of much of the mammalian urinary tract is known simply as the urothelium, this epithelium can be divided into at least three lineages of renal pelvis/ureter, bladder/trigone, and proximal urethra based on their embryonic origin, uroplakin content, keratin expression pattern, in vitro growth potential, and propensity to keratinize during vitamin A deficiency. Moreover, these cells remain phenotypically distinct even after they have been serially passaged under identical culture conditions, thus ruling out local mesenchymal influence as the sole cause of their in vivo differences. During vitamin A deficiency, mouse urothelium form multiple keratinized foci in proximal urethra probably originating from scattered K14-positive basal cells, and the keratinized epithelium expands horizontally to replace the surrounding normal urothelium. These data suggest that the urothelium consists of multiple cell lineages, that trigone urothelium is closely related to the urothelium covering the rest of the bladder, and that lineage heterogeneity coupled with cell migration/replacement form the cellular basis for urothelial squamous metaplasia.

We show that the utricle forms as an ingrowth of specialized cells from the dorsal wall of the UGS as the caudal MDs regress.

To our knowledge we report the first immunolocalization of ERalpha in the human fetal prostate and the earliest demonstration of ERbeta expression in the prostate at 7 weeks of gestation. ERbeta expression is intense during ductal morphogenesis, suggesting a role in normal glandular growth and proliferation. The induction of squamous metaplasia in the UGE, distal periurethral ducts and utricle is associated with ERalpha expression in these areas, while the induction of squamous metaplasia in peripheral prostatic acini is associated with peripheral stromal ERalpha expression. This study suggests estrogen signaling pathways in the human fetal prostate via ERalpha that involve epithelial-epithelial and epithelial-stromal interactions.

Strain H2, an attenuated live hepatitis A virus (HAV), was derived from the fecal specimen of a patient with hepatitis A in Hangzhou, China. After isolation and passage in a culture of newborn monkey kidney cells, adaptation to grow in human lung diploid cells (KMB17), and serial passage at a low temperature (32 degrees C) in KMB17 cells, this strain became the master seed virus for H2-strain vaccine. Twelve human volunteers received the experimental vaccine subcutaneously and were closely observed for 20 w. None of the subjects developed any local or systemic reactions, and there were no elevations of serum glutamic-pyruvic transaminase, type 5 isoenzyme of lactate dehydrogenase, or isocitrate dehydrogenase. Seroconversion occurred in all subjects at a mean time of 3 w after inoculation. ELISA competitive test for titer of antibody to HAV showed values ranging from 1:2 to 1:8 with a geometric mean titer of 1:3.48 at 20 w after inoculation. No marked decrease in titer of HAV antibody was found in the subjects tested at 1 y. These antibodies were proved to be neutralizing antibodies.