Female Prostate Development: Morphological Analysis of the Budding Dynamic.

The presence of the prostate in female mammals has long been known. However, pieces of information related to its development are still lacking. The aim of this study was to explore the budding dynamic during the initial prostate development in female gerbils. Pregnant females were timed, the fetuses were euthanized, and the urogenital sinus was dissected out between the embryonic days 20 and 24 (E20-E24 groups). Newborn pups (1-day-old; P1 group) underwent the same procedures. The female prostate development was based on epithelial buds which arose far from the paraurethral mesenchyme (PAM). The epithelial buds reached the PAM at prenatal day 24, crossing a small gap in the smooth muscle layer between the periurethral mesenchyme (PEM) and the PAM. Steroid nuclear receptors such as the androgen receptor and estrogen receptor alpha were localized in the PEM through the urethral wall, although some epithelial labeling was also present in the urogenital sinus epithelium (UGE). P63-positive cells were found only in the UGE, becoming restricted to the basal compartment after the 23rd prenatal day. The results showed that the gerbil female prostate exhibits a distinct budding pattern as compared to the male prostate development.

Heparan sulfate fine-tunes stromal-epithelial communication in the prostate gland.

Several studies reported the concerted and mutual communication between the prostate epithelium and stroma, which determines the final organ architecture and function, but gets awry in cancer. Deciphering the mechanisms involved in this communication is crucial to find new therapeutic strategies. HS sequesters a number of secreted growth factors and cytokines, controlling their bioavailability to the target cells, suggesting that HS is an important regulator of the extracellular matrix (ECM) and a key player in the cell-cell and cell-microenvironment communication during prostate morphogenesis and physiology. We propose that by controlling HS biosynthesis and sulfation pattern, as well as the cleavage of the HS chain and/or the shedding of proteoglycans, epithelial and stromal cells are able to precisely tune the availability of signaling molecules and modulate ligand-receptor interaction and intracellular signal transduction.

Differences between male and female prostates in terms of physiology, sensitivity to chemicals and pathogenesis-A review in a rodent model.

The prostate is a gland that is not exclusively present in males, being also found in females of several mammalian species, including humans. There is evidence that the prostate in both sexes is affected by the same pathologies such as prostatitis, benign alterations and even cancer. In view of the difficulties of manipulating the prostate gland, the Mongolian gerbil (Meriones unguiculatus), a rodent species with high incidence of functional prostates in females, is widely used in studies of the female prostate. However, despite knowing much about the similarities between the female and male prostate, little emphasis has been placed on the differences between them. This review investigates the intersex differences in prostate development, physiology and pathogenesis. The female prostate develops earlier than in males and studies indicate that it is more sensitive to oestrogens than the male prostate, as well as being more sensitive to exposure to xenoestrogens, such as Bisphenol A and methylparaben, with a higher susceptibility to benign lesions in the adult and senile prostate than in males. In addition, the female prostate is impacted by pregnancy and the oestrous cycle, and is also dependent on progesterone. The peculiarities of the female prostate raise concerns about the risk of it undergoing neglected changes as a result of environmental chemicals, since safe dosages are established exclusively for the male prostate.

Short-term exposure to chrysin promotes proliferative responses in the ventral male prostate and female prostate of adult gerbils.

Chrysin (5,7-dihydroxyflavone) is a bioactive compound found in different fruits, vegetables, honey and propolis. This flavone has been suggested for the treatment of reproductive dysfunction, mainly because of its antioxidant and hormonal properties. However, the effects of this polyphenol on the prostate are still poorly understood. The purpose of this study was to evaluate the effects of short-term chrysin exposure on the ventral male and female prostates of adult gerbils. To evaluate the androgenic potential of chrysin, gerbils were also exposed to testosterone. Male and female gerbils were exposed to chrysin (50 mg/kg/day, orally) or testosterone cypionate (1 mg/kg/week, subcutaneously) for 3, 7 and 21 days. Prostates were dissected for morphological, stereological and immunohistochemical analyses. Serum levels of testosterone and 17ß-estradiol were measured by ELISA. Serum testosterone levels were not increased by chrysin supplementation in males or females. However, only females treated with chrysin for 21 days showed an increase in estradiol levels. Increased androgen receptor immunoreactivity, higher proliferation rates and glandular hyperplasia were observed in male and female prostates for all chrysin treatment times. Additionally, increased oestrogen receptor alpha immunoreactivity was observed in all chrysin-treated females. Although chrysin and testosterone promoted similar morphological changes in the gerbil prostate, chrysin supplementation was less deleterious to prostate health, since it resulted in lower incidence of hyperplasia and an absence of neoplastic foci.

Aluminum disrupts the prenatal development of the male and female gerbil prostate (Meriones unguiculatus).

Normal prostate development is highly dependent of an equilibrated hormonal regulation, so that sensible interferences during this period may predispose the gland to lesions during aging. Industrial activities have increased the exposure of this gland to active elements found in environment, such as aluminum (Al). Al presents toxic effect for living beings, having the potential to disrupt the development and growth of several organs and systems. Therefore, the aim of this study was to evaluate whether the prenatal exposure to Al may alter the development and morphophysiology of the gerbil prostate (Meriones unguiculatus). Pregnant females were orally exposed to aluminum chloride (100 mg/kg/day) from 17th to 21th gestational day. Following the birth, the male and female pups were euthanized with 1 (PN1) and 90-days-old (PN90). The prostates were collected for biometrical, three-dimensional reconstruction, morphometrical, stereological, and immunohistochemical analysis. Results indicated that Al decreases the body weight of PN1 males and females, and also reduce the anogenital distance of PN1 females. Moreover, Al changed the prostate developmental patterns of PN1 animals, causing an increase in proliferative status and decreasing androgen receptor immunostaining. The results suggest that Al-promoted changes were permanent, since low androgen receptor frequency, increased serum testosterone levels and high proliferation index were observed in adult gerbils. This study demonstrated that body and prostatic changes were more pronounced in females than in males, and that Al performed as an endocrine-disrupting chemical in gerbils.

Combined oral contraceptives promote androgen receptor and oestrogen receptor alpha upregulation in the female prostate (Skene's paraurethral glands) of adult gerbils (Meriones unguiculatus).

The aim of this study was to evaluate the effects of cyproterone acetate (CPA) and ethinyloestradiol (EE) alone or in combination on the female prostate of adult gerbils. Adult females were exposed for 21 days to daily oral doses of CPA (1mgkg-1), EE (10µgkg-1) or a combination of CPA and EE. Female prostatic complexes were removed, weighed and subjected to morphological, stereological, immunohistochemical and ultrastructural analyses. CPA treatment caused epithelial atrophy and decreased prostate secretory activity. The EE treatment group showed glandular hyperplasia, a high cell-proliferation index and an increase in androgen and oestrogen receptor α (AR and ERα) immunoreactivity. Combined treatment (CPA+EE) caused adverse effects, such as an increase in cell proliferation, higher AR and ERα immunoreactivity, prostatic intraepithelial neoplasia, cell degeneration and aging. In conclusion, the CPA-only treatment promoted antiandrogenic effects on the female gerbil prostate, whereas EE-only had a potent oestrogenic activity. However, when combined, EE overlapped the effects of CPA, changing the pattern of glandular hormonal regulation and stimulating the development of prostatic lesions in female gerbils.

Anabolic effects of chrysin on the ventral male prostate and female prostate of adult gerbils (Meriones unguiculatus).

Chrysin is a bioflavonoid found in fruits, flowers, tea, honey and wine, which has antioxidant, anti-inflammatory, antiallergic and anticarcinogenic properties. This flavone has also been considered as beneficial for reproduction due its testosterone-boosting potential. Thus, the aim of this study was to evaluate the effects of chrysin on the prostate and gonads of male and female adult gerbils. In addition, a comparative analysis of the effects of testosterone on these same organs was conducted. Ninety-day-old male and female gerbils were treated with chrysin (50mgkg-1day-1) or testosterone cypionate (1mgkg-1week-1) for 21 days. The ventral male prostate and female prostate were dissected out for morphological, morphometric-stereological and ultrastructural assays. Testes and ovaries were submitted to morphological and morphometric---stereological analyses. Chrysin treatment caused epithelial hyperplasia and stromal remodelling of the ventral male and female prostate. Ultrastructurally, male and female prostatic epithelial cells in the chrysin group presented marked development of the organelles involved in the biosynthetic-secretory pathway, whereas cellular toxicity was observed only in female glands. Chrysin preserved normal testicular morphology and increased the number of growing ovarian follicles. Comparatively, testosterone treatment was detrimental to the prostate and gonads, since foci of prostatic intraepithelial neoplasia and gonadal degeneration were observed in both sexes. Thus, under the experimental conditions of this study, chrysin was better tolerated than testosterone in the prostate and gonads.

Prepubertal chrysin exposure upregulates either AR in male ventral prostate or AR and ERα in Skene's paraurethral gland of pubertal and adult gerbils.

Chrysin is a plant-derived polyphenol that has the potential to increase endogenous testosterone levels both by inhibiting the aromatase enzyme and by stimulating testicular steroidogenesis. The effects of chrysin on the prostate are unknown, especially during its development and functional maturation. Thus, the aim of this study was to evaluate the effects of chrysin prepubertal exposure on the male and female prostates of both pubertal and adult gerbils. To evaluate the possible androgenic responses of chrysin, gerbils were also exposed to testosterone. Male and female gerbils were exposed to chrysin or to testosterone cypionate from postnatal day 15 to 42. Male and female gerbils were euthanized at either 43days or 90days age. The prostates were collected for biometrical, morphological and immunohistochemical analysis. The results showed that prepubertal exposure to chrysin had differential effects on the prostate of both pubertal and adult animals. The prostates of male and female pubertal gerbils showed no histological alterations, although there was increased frequency of androgen receptor (AR) in males and females, and estrogen receptor alpha (ERα) in females. Adult males and females presented developed prostate glands, with higher cell proliferative rate. In addition, AR and ERα frequency remained high in the prostate of adult animals. These results demonstrated that prepubertal exposure to chrysin disrupts steroid receptors regulation in the prostate, potentiating the response of this gland to the biological effects of endogenous steroids. In this context, excessive consumption of phytoestrogens during the critical stages of development should be considered with caution.

The origin of prostate gland-secreted IgA and IgG.

The prostate secretes immunoglobulin (Ig) A (IgA) and IgG; however, how immunoglobulins reach the secretion, where the plasma cells are located, whether immunoglobulins are antigen-specific and where activation of the adaptive response occurs are still unknown. Immune cells, including CD45RA+ cells, were scattered in the stroma and not organized mucosae-associated lymphoid-tissue. IgA (but not IgG) immunostaining identified stromal plasma cells and epithelial cells in non-immunized rats. Injected tetramethylrhodamine-IgA transcytosed the epithelium along with polymeric immunoglobulin receptor. Oral immunization with ovalbumin/mesopourous SBA-15 silica adjuvant resulted in more stromal CD45RA+/IgA+ cells, increased content of ovalbumin-specific IgA and IgG, and the appearance of intraepithelial CD45RA+/IgG+ cells. An increased number of dendritic cells that cooperate in other sites with transient immunocompetent lymphocytes, and the higher levels of interleukin-1ß, interferon-γ and transforming growth factor-ß, explain the levels of specific antibodies. Nasal immunization produced similar results except for the increase in dendritic cells. This immunomodulatory strategy seems useful to boost immunity against genitourinary infections and, perhaps, cancer.

Desquamation takes center stage at the origin of proliferative inflammatory atrophy, epithelial-mesenchymal transition, and stromal growth in benign prostate hyperplasia.

In this commentary, we propose a relationship between desquamation, initially described as the collective detachment and deletion of epithelial cell in the prostate gland after castration, and proliferative inflammatory atrophy (PIA) and stromal growth in benign prostate hyperplasia (BPH). First, in response to diverse stimuli, including inflammatory mediators, epithelial cells desquamate and leave a large surface of the luminal side of the basement membrane (BM) exposed. Basal cells are activated into intermediate-type cells, which change morphology to cover and remodel the exposed BM (simple atrophy) to a new physiological demand (such as in the hypoandrogen environment, simulated by surgical and/or chemical castration) and/or to support re-epithelialization (under normal androgen levels). In the presence of inflammation (that might be the cause of desquamation), the intermediate-type cells proliferate and characterize PIA. Second, in other circumstances, desquamation is an early step of epithelial-to-mesenchymal transition (EMT), which contributes to stromal growth, as suggested by some experimental models of BPH. The proposed associations correlate unexplored cell behaviors and reveal the remarkable plasticity of the prostate epithelium that might be at the origin of prostate diseases.

Telocytes play a key role in prostate tissue organisation during the gland morphogenesis.

Telocytes are CD34-positive interstitial cells, known to exert several functions, one of which is a role in tissue organisation, previously demonstrated by telocytes in the myocardium. The existence of telocytes in the prostate has recently been reported, however, there is a lack of information regarding the function of these cells in prostate tissue, and information regarding the possible role of these cells in prostatic development. This study used immunofluorescence techniques in prostate tissue and prostatic telocytes in culture to determine the relationship between telocytes and prostate morphogenesis. Furthermore, immunofluorescent labelling of telocytes was performed on prostate tissue at different stages of early postnatal development. Initially, CD34-positive cells are found at the periphery of the developing alveoli, later in the same region, c-kit-positive cells and cells positive for both factors are verified and CD34-positive cells were predominantly observed in the interalveolar stroma and the region surrounding the periductal smooth muscle. Fluorescence assays also demonstrated that telocytes secrete TGF-ß1 and are ER-Beta (ERß) positive. The results suggest that telocytes play a changing role during development, initially supporting the differentiation of periductal and perialveolar smooth muscle, and later, producing dense networks that separate alveoli groups and form a barrier between the interalveolar region and periurethral smooth muscle. We conclude that telocytes play a relevant role in prostate tissue organisation during postnatal development.

Intrauterine exposure to 17ß-oestradiol (E2) impairs postnatal development in both female and male prostate in gerbil.

We employed histological techniques to assess the effects of intrauterine exposure to different dosages of E2 on male and female Mongolian gerbils on the postnatal development of the prostate. E2 promotes alterations this gland branches in the female, but not in males, even at low dosage, at higher dosages, acini of altered aspect are verified in the male and female prostate, as well as a decrease in branching number, reduced cell proliferation and staining for FGF10, simultaneously to the increased labelling for TGFß1, which may account for alterations on branching of the prostate. The sensitivity of the female prostate to intrauterine exposure to E2, which can reflect the E2 dependence of female prostate development. This becomes alarming in view of the occurrence of prostate in female of several mammals and including women, and the possibility that low E2 dosage exposures considered safe to males provoke developmental alterations in female prostate.

Intrauterine exposure to oestradiol promotes sex-specific differential effects on the prostatic development of neonate gerbils.

The effects of intrauterine exposure to 17ß-oestradiol (E2) are well studied for the male prostate and there are accumulating evidences that the exposure to high dosages leads to a hypomorphic development. However, there is a lack of information about the effects of intrauterine exposure to E2 in the prostate of rodent females, and such research becomes relevant in view of the presence of functional prostate in a proportion of women, and the morphophysiological similarities between the prostate of female rodents and the prostate of women. This study uses histochemical, immunohistochemical, immunofluorescence and three-dimensional (3D) reconstruction techniques to evaluate the effects of intrauterine exposure to E2 (500 BW/d) on neonatal prostate development in both male and female gerbils. It was verified that intrauterine exposure to E2 promotes epithelial proliferation and growth of prostatic budding in females, whereas in males the prostatic budding shows hypomorphic growth in the VMP (Ventral Mesenchymal Pad) as well as reduced epithelial proliferation. Together, the data demonstrate that intrauterine exposure to E2 causes different effects on male and female prostates of the gerbil even at the early postnatal development of the gland.

Female prostate: historical, developmental, and morphological perspectives.

The female prostate was first described by Reijnier de Graaf in 1672, and even after several years this gland is still a matter of controversy. Part of this is because the biological function of this female gland is unclear. Moreover, when compared with the male prostate, the existence of this organ in females does not make sense, mainly when we consider that the major function of this gland is to produce a secretion that is responsible for guarantee the sperm survival and assure the reproductive success. However, even under a controversy field, we now have a lot of scientific information which enhances our knowledge of several important biological aspects of this gland. It is clear that this gland is found in some female mammals including humans, rodents, rabbits, bats, and dogs. Several studies with rodents showed that the female prostate is homolog of the male prostate, showing strong macroscopic and microscopic similarities with the ventral lobe of males. Besides these aspects, there are several studies reporting that diseases such as cysts, hyperplasia, and carcinoma may affect the female prostate. Therefore, although diseases involving the female prostate are rare, the susceptibility of this organ to develop lesions must be considered, especially in our recent years in which the exposure to endocrine-disrupting chemicals has greatly increased. Finally, further studies will be necessary to enhance our understanding about this gland, mainly of the developmental, evolutionary, and biological functions.

Endocrine-disrupting effects of methylparaben on the adult gerbil prostate.

Parabens are xenoestrogens widely employed in cosmetics, foodstuffs, and pharmaceutical products. These chemicals are known to disrupt hormone-dependent organs, due to their binding affinity for hormonal receptors. Although recent studies have evaluated the endocrine-disrupting potential of parabens in several reproductive organs, few have investigated the effects of these chemicals in the prostate. The aim of this work was to evaluate the effects of oral exposure to methylparaben (500 mg/kg/day) for 3, 7, and 21 days on male and female adult gerbil prostate. For this purpose, we employed biometrical, morphological, and immunohistochemical analyses. The results showed that methylparaben caused morphological changes in gerbil prostates in all experimental groups. These animals displayed similar alterations such as prostate epithelial hyperplasia, increased cell proliferation, and a higher frequency of AR-positive cells. However, the prostate of the female gerbil showed additional changes such as stromal inflammatory infiltration, intraepithelial neoplasia foci, and an increase in AR-positive frequency. Altogether, these data show that methylparaben was responsible for disrupting estrogenic and androgenic receptors, suggesting that parabens may have estrogenic and antiandrogenic effects in the prostate.

Pubertal exposure to ethinylestradiol promotes different effects on the morphology of the prostate of the male and female gerbil during aging.

In rodents, the final growth and maturation of the prostate occur at puberty, a crucial period for prostate development. The present study is a serological, morphological, morphometric, and immunohistochemical analysis of the effects of exposure to ethinylestradiol (EE) (15 µg/kg/day) during puberty (EE/PUB group) on the male ventral and female prostate in senile gerbils. In the study, male and female gerbils (Meriones unguiculatus) (42 days) received by gavage 15 µg/kg/day of EE (a component of the contraceptive pill), diluted in 100 µL of Nujol® for 1 week (EE/PUB group). In the control group, males and females were not treated. Animals were killed (n = 5) after 12 months in the experimental groups. In the senile male in the EE/PUB group, we observed a reduction in testosterone levels and a decrease in the prostatic epithelial thickness, as well as in the thickness of the muscle layer. In addition, an increase in PIN multiplicity and prostatic inflammation was observed. In the senile female in the EE/PUB group, we observed increased testosterone and estradiol levels, an enhanced prostatic epithelial thickness and an increase in the thickness of the muscle layer. Immunohistochemical analysis revealed an increase in positive cells (%) for AR and PCNA in the male prostate and an increase in positive basal cells for p63 in the female prostate of the EE/PUB group. Exposure to EE during puberty resulted in an inhibitory action on the male ventral prostate and an anabolic effect on the female prostate in senile gerbils. © 2016 Wiley Periodicals, Inc. Environ Toxicol 32: 477-489, 2017.

Prenatal and pubertal testosterone exposure imprint permanent modifications in the prostate that predispose to the development of lesions in old Mongolian gerbils.

The prostate is an accessory sex gland that develops under precise androgenic control. It is known that hormonal imbalance may disrupt its development predisposing this gland to develop diseases during aging. Although the hypothesis regarding earlier origins of prostate diseases was proposed many years ago, the mechanisms underlying this complex phenomenon are poorly understood. Therefore, the aim of this study was to evaluate the prostates of old male gerbils exposed to testosterone during intrauterine and postnatal life using morphological, biometrical, stereological, Kariometric, immunohistochemical, and immunofluorescence analyses. Our findings demonstrate that prenatal and pubertal exposure to testosterone increases the susceptibility to the development of prostate diseases during aging. The presence of a more proliferative gland associated with foci of adenomatous hyperplasia in animals exposed to testosterone during the prenatal and pubertal phase show that the utero life and the pubertal period are important phases for prostatic morphophysiology establishment, which is a determinant for the health of the gland during aging. Therefore, these findings reinforce the idea that prostate disease may result from hormonal disruptions in early events during prostate development, which imprint permanently on the gland predisposing it to develop lesions in later stages of life.

The Expression of the Androgen Receptor and Estrogen Receptor 1 is Related to Sex Dimorphism in the Gerbil Prostate Development.

The development of the prostate gland in females has not yet been clearly elucidated, and the sexual dimorphism associated with such gland development in general is far from being understood. In the present study, we used tridimensional (3D) reconstructions and histochemical and immunohistochemical techniques to describe the sexual dimorphism and its causes in the early postnatal development of the prostate in male and female Mongolian gerbils (Meriones unguiculatus). We observed that the female prostate was smaller, had fewer branches throughout the development, and underwent differentiation earlier than that in males. Also, the expression of the estrogen receptor 1 (ESR1 or ER-alpha) and fibroblast growth factor 10 (FGF10) was decreased in the periductal region, and the expression of the androgen receptor (AR) was increased in the epithelium. All together, these changes decreased proliferation and branching and led to an earlier prematuration of the female prostate. These new data shed light on the underlying mechanisms involved with the sexual dimorphism in the development of the prostate. Anat Rec, 299:1130-1139, 2016. © 2016 Wiley Periodicals, Inc.

Postnatal development of Mongolian gerbil female prostate: An immunohistochemical and 3D modeling study.

The development of the prostate in male rodents, which involves complex epithelial-mesenchymal interactions between the urogenital sinus epithelium (UGE) and the urogenital sinus mesenchyme (UGM), has been deeply studied. In females, however, this process is not very clear. In this study, the postnatal development of the prostate in female Mongolian gerbils employing three-dimensional (3D) reconstructions, histochemical, and immunohistochemical techniques was characterized. It was observed that prostatic branching and differentiation in females was induced by a single mesenchyme localized at a ventrolateral position, which was named as ventrolateral mesenchyme (VLM); furthermore, the canalization of solid buds began on the third postnatal day (P3) and the branching morphogenesis on P5. We observed secretions in the acini at the end of the first month, and, on P45, the acini were completely differentiated. The strong cell proliferation phase in the first week coincided with the mesenchymal expression of estrogen receptor 1 (ESR1). The expression of androgen receptor (AR) paralleled cell differentiation, and, on P30, immunolabelling with p63 was restricted to basal cells. This study serves as a baseline parameter for future research on disruptions that could affect the development of the female prostate.

Prenatal exposure to ethinylestradiol alters the morphologic patterns and increases the predisposition for prostatic lesions in male and female gerbils during ageing.

Ethinylestradiol (EE) is an endocrine disruptor (ED) which acts as an oestrogen agonist; this compound is known as an oral contraceptive. Male and female rodents exposed to EE during critical time points of development, such as in the prenatal period, show alterations in their reproductive tract during adulthood. Few studies have placed an emphasis on the effects of EE during ageing. Thus, this study had as it's objective the analysis of the morphological and immunohistochemical effects of exposure to EE in the prenatal period on ventral male prostate and female prostate of gerbils (Meriones unguiculatus) during ageing. The animals were exposed to EE (15 µg/kg/day) during the 18-22th days of prenatal life (EE/PRE group), and the analyses were performed when the male and female reached 12 months of age. Our results showed an increase in the development of prostatic intraepithelial neoplasia (PIN), which was observed in the male and female prostate of EE/PRE groups. Immunohistochemistry showed a rise in prostatic epithelial and basal cells immunoreactivity, respectively, and to AR and p63 in the male EE/PRE. There were alterations in the morphological pattern of the prostatic glands and increase in predisposition to emergence of prostatic lesions of both sexes during ageing. Despite male and female having been exposed to the same doses of EE, the "exposure to EE promoted modifications" more accentuated in the male prostate. Thus the male gland is more sensitive to the action of this synthetic oestrogen than the female prostate.