Disorders related with ageing in the gerbil female prostate (Skene's paraurethral glands)

Prostatic morphological changes throughout life: Cytochemistry as a tool to reveal tissue aging markers

The prostate undergoes normal or pathological morphological changes throughout life. An understanding of these changes is fundamental for the comprehension of aging-related pathological processes such as benign prostatic hyperplasia (BPH) and cancer. In the present study, we show some of these morphological changes, as well as histochemical techniques like Weigert's resorcin-fuchsin method, Picrosirius Red, and Gömöri's reticulin for use as tools in the study of prostate tissue under light microscopy. For this purpose, prostates of the Mongolian gerbil (n = 9), an experimental model that develops BPH spontaneously, were analyzed at three life stages: young (1 month old), adult (3 months old), and old (15 months old). The results showed that fibrillar components such as collagen, and reticular and elastic fibers, change throughout life. In young animals, the prostate has cuboidal epithelium surrounded by thin layers of smooth muscle, continuous collagen fibers, winding reticular fibers, and sporadic elastic fibers. With adulthood, the epithelium becomes columnar, encircled by compacted muscle cells among slender collagen fibers, elongated reticular fibers, and linear elastic fibers. In aging individuals, the prostate's epithelium stratifies, surrounded by thick muscle layers among dense collagen fibers, disordered reticular fibers, and elastic fibers in different planes. We also identified a few accumulations of lipid droplets and lipofuscin granules in adult animals and high accumulation in old animals evidenced by Oil red O and Gömöri-Halmi techniques, respectively. The histochemical techniques presented here have been demonstrated to be useful and accessible tools in prostate studies. RESEARCH HIGHLIGHTS: Cytochemical techniques to study prostate morphology. The prostate changes with age.

Female Hyperplastic PSA-Positive Prostate Tissue in the Bladder Neck

INTRODUCTION

We report a rare case of Skene's gland hyperplasia where the serum prostate-specific antigen (PSA) level was measurable.

CASE PRESENTATION

The patient was a 91-year-old woman with a suspected bladder mass at the bladder trigone. Cystoscopy revealed a suspected lesion and an obstructed anterior bladder neck with a large mass located from a "7 o'clock" to "11 o'clock" area. The photodynamic diagnosis was negative. Transurethral subtotal resection of the mass was performed. The serum PSA level at the third postoperative day was 0.08 ng/mL. Postoperative cystography showed no contrast media extravasation. Thus, histopathology revealed massive adenomyomatous hyperplasia of the Skene's gland, as well as nondysplastic urothelium and glandular and squamous epithelium. Immunohistochemistry showed strong PSA and NKX3.1 positivity, confirming the diagnosis of "female prostate." FISH analysis showed only green signals that confirm an XX karyotype. In follow-up to 17 months, there was no disease recurrence or need for a urinary catheter.

CONCLUSION

Effective therapeutic strategies for these lesions are unknown due to the absence of reported cases. Given the patient's age, we assumed that bladder neck resection by transurethral resection with a controlled level of serum PSA would be a suitable therapeutic approach.

The complex role of telocytes in female prostate tumorigenesis in a rodent model

The prostate is not an organ exclusive to the male. It is also found in females of several species, including humans, in which part of the Skene gland is homologous to the male prostate. Evidence is accumulating that changes in the stroma are central to tumorigenesis. Equally, telocytes, a recently discovered type of interstitial cell, are essential for the maintenance of stromal organization. However, it is still uncertain whether there are telocytes in the female prostate and if they play a role in tumorigenesis. The present study used ultrastructural and immunofluorescence techniques to investigate the presence of telocytes in the prostate of Mongolian gerbil females, a rodent model that often has a functional prostate in females, as well as to assess the impact of a combination of N-ethyl-N-nitrosourea, testosterone, and estradiol on telocytes. The results point to the presence of telocytes in the female prostate in the perialveolar and interalveolar regions, and reveal that these cells are absent in regions of benign and premalignant lesions in the gland, in which the perialveolar smooth muscle is altered. Additionally, telocytes are also closely associated with infiltrated immune cells in the stroma. Our data suggest that telocytes are important for both the maintenance of smooth muscle and prostatic epithelium integrity, which indicates a protective role against the advancement of tumorigenesis. But telocytes are also associated with immune cells and a proinflammatory/proangiogenic role for these cells cannot be ruled out, implying that telocytes have a complex role in prostatic tumorigenesis in females.

Hormone receptor expression in aging mammary tissue and carcinoma from a rodent model after xenoestrogen disruption

AIMS

Hormone receptors are the main markers applied for prognosis of breast cancer subtypes. Among modulators, exogenous chemical agents known as endocrine disruptors interact with certain receptors, triggering molecular pathways or increasing their expression. Bisphenol A (BPA), a xenoestrogen, interacts with several hormone receptors. Thus, our aim was to characterize the hormone receptor status in the mammary gland (MG) of aged female Mongolian gerbils exposed to BPA in pregnancy and lactation.

METHODS

We evaluated the expression of receptors for estrogens (ERα and ERβ), progesterone (PR), prolactin (PRL-R), HER2/ErbB2, and androgen (AR) in normal and hyperplastic mammary tissue and in carcinomas developed after BPA exposure.

KEY FINDINGS

BPA-exposed MG presented increased ERα, whereas ERβ, PR, and PRL-R showed lower expression. AR and HER2/ErbB2 showed similar expression in normal and hyperplastic tissue from control, vehicle, and BPA groups. Both receptors were found in cytoplasm and nucleus in BPA-induced carcinoma. We demonstrate the presence of EZH2 expression, an epigenetic and epithelial-mesenchymal transition (EMT) marker, with a high H-score in BPA-exposed MG, which was associated with poor prognosis of cancer. Co-localization of ERα and EZH2 was present in normal and carcinoma features, corroborating the installation of ERα-positive mammary cancer associated with the EMT process. Enhanced EZH2 in BPA-exposed mammary tissue could decrease ERβ expression and promote tumorigenesis progress through HER2/ErbB2.

SIGNIFICANCE

The present study proposes the Mongolian gerbil as an experimental model for mammary carcinogenesis studies, based on BPA disruption that triggers a phenotype of increased ERα/HER2 positivity and depletion of ERβ/PR expression.

Inflammatory repercussions in female steroid responsive glands after perinatal exposure to bisphenol A and 17-β estradiol

The mammary gland (MG) and female prostate are plastic reproductive organs which are highly responsive to hormones. Thus, endocrine disruptors, such as bisphenol A (BPA) and exogenous estrogens, negatively affect glandular homeostasis. In addition to previously described alterations, changes in inflammatory markers expression also trigger the development of a microenvironment that contributes to tumor progression. The current work aimed to evaluate the inflammatory responses of the MG and prostate gland to BPA (50 µg/kg) and 17-β estradiol (35 µg/kg) exposure during the perinatal window of susceptibility. The results showed that at 6 months of age there was an increase in the number of phospho-STAT3 (P-STAT3) positive cells in the female prostate from animals perinatally exposed to 50 µg/kg BPA daily. In addition, the number of macrophages increased in these animals in comparison with nonexposed animals, as shown by the F4/80 marker. Despite an increase in the incidence of lobuloalveolar and intraductal hyperplasia, the MG did not show any difference in the expression of the four inflammatory markers evaluated: tumor necrosis factor-α, COX-2, P-STAT3, and F4/80. Analysis of both glands from the same animal led to the conclusion that exposure to endocrine disruptors during the perinatal window of susceptibility leads to different inflammatory responses in different reproductive organs. As the prostate is more susceptible to these inflammatory mechanisms, it is reasonable to affirm that possible neoplastic alterations in this organ are related to changes in the inflammatory pattern of the stroma, a characteristic that is not evident in the MG.

Prenatal and pubertal exposure to 17α-ethinylestradiol cause morphological changes in the prostate of old gerbils

This study evaluated such as exposure to ethinylestradiol during the prenatal (18th-22nd day) and pubertal (42nd-49th day) periods acts on the male ventral prostate and female prostate of 12-month old gerbils. We performed the analysis to serum hormone levels for estradiol and testosterone. The prostates were submitted to morphometric and immunohistochemical analyses. Exposure to ethinylestradiol during these developmental periods decreased the testosterone serum levels in males and increased the estradiol serum levels in females. Morphologically, prostate intraepithelial neoplasia and disorders in the arrangement of the fibrous components were observed in the prostate glands of both sexes of gerbil exposed to ethinylestradiol during development periods. In the male prostate, the ethinylestradiol promoted decreased in the frequency of positive epithelial cell for androgen receptor (AR) and increased the frequency of positive stromal cell for estrogen receptor α. However, in the female prostate, this synthetic estrogen caused AR upregulation and increased cell proliferation. This study shows that the exposure to ethinylestradiol during development phases alters the morphology and the hormonal signaling in the male and female prostates of old gerbils, confirming the action of ethinylestradiol as endocrine disruptor.

Ovariectomy increases the phenotypic plasticity of the female prostate epithelium in the Mongolian gerbil (Meriones unguiculatus)

The female prostate is a reproductive gland that typically presents a morphology similar to that of the male gland and is highly developed in female Mongolian gerbils. Two main cell populations compose the epithelium gland: basal and secretory luminal cells. However, during postnatal development, diverse secretory cell phenotypes are distributed among the typical ones. Prostate homeostasis is under the control of sexual hormones, such as oestrogen and progesterone. After hormonal deprivation the female gland undergoes several morphophysiological changes. The objective of this study was to identify and characterise, structurally and ultrastructurally, the cellular heterogeneity of the female prostate epithelium in normal conditions and after ovariectomy. Histological routine stains, such as haematoxylin-eosin, periodic acid-Schiff and silver impregnation, as well as immunocytochemical techniques were used to enable identification of the different cell types. Some secretory cells types were identified and characterised as mucinous, basophil, clear, ciliated, droplet, spumous and neuroendocrine cells. Population tally data showed that the hormonal suppression caused by ovariectomy resulted in a decrease in the proportions of basophil and clear cells and an increase in spumous cells. Thus, the secretory epithelial cells of the female gerbil prostate are not morphologically and functionally uniform, presenting a phenotypical plasticity according to the hormonal environment in which they operate.

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-β1 and are ER-Beta (ERβ) 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.

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.

Intrauterine exposure to bisphenol A promotes different effects in both neonatal and adult prostate of male and female gerbils (Meriones unguiculatus)

Substances that mimic endogenous hormones may alter the cell signaling that govern prostate development and predispose it to developing lesions in adult and senile life. Bisphenol A is able to mimic estrogens, and studies have demonstrated that low levels of exposure to this compound have caused alterations during prostate development. The aim of this study was to describe the prostate development in both male and female neonatal gerbils in normal conditions and under exposure to BPA during intrauterine life, and also to analyze whether the effects of intrauterine exposure to BPA remain in adulthood. Morphological, stereological, three-dimensional reconstruction, and immunohistochemical methods were employed. The results demonstrated that in 1-day-old normal gerbils, the female paraurethral glands and the male ventral lobe are morphologically similar, although its tissue components-epithelial buds (EB), periurethral mesenchyme (PeM), paraurethral mesenchyme (PaM) or ventral mesenchymal pad (VMP), and smooth muscle (SM)-have presented different immunolabeling pattern for androgen receptor (AR), and for proliferating cell nuclear antigen (PCNA). Moreover, we observed a differential response of male and female prostate to intrauterine BPA exposure. In 1-day-old males, the intrauterine exposure to BPA caused a decrease of AR-positive cells in the PeM and SM, and a decrease of the proliferative status in the EB. In contrast, no morphological alterations were observed in ventral prostate of adult males. In 1-day-old females, BPA exposure promoted an increase of estrogen receptor alpha (ERα) positive cells in PeM and PaM, a decrease of AR-positive cells in EB and PeM, besides a reduction of cell proliferation in EB. Additionally, the adult female prostate of BPA-exposed animals presented an increase of AR- and PCNA-positive cells. These results suggest that the prostate of female gerbils were more susceptible to the intrauterine BPA effects, since they became more proliferative in adult life. © 2015 Wiley Periodicals, Inc. Environ Toxicol 31: 1740-1750, 2016.

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.

Actions of oestradiol and progesterone on the prostate in female gerbils: reversal of the histological effects of castration

The female prostate is a functionally active gland in several mammalian species, including humans and rodents. Investigations of prostate morphophysiology during the phases of the oestrous cycle have shown that the female prostate is influenced by fluctuations in serum concentrations of oestradiol (E2) and progesterone (P4). The aim of the present study was to evaluate the effect of combined prolonged administration of E2 and P4 on the prostate in ovariectomised female gerbils. Ovariectomy caused atrophy and decreased glandular secretory activity. Administration of E2 and P4 (0.1mgkg(-1) diluted in 0.1mL of mineral oil, every 48h over 30 days) resulted in a recovery of overall prostate structure, as evidenced by increased epithelial height, mass and prostatic secretory activity, without leading the appearance of significant lesions. Evaluation of androgen receptor (AR) expression revealed increased immunoreactivity in the E2+P4-treated group. Immunostaining for oestrogen receptor (ER) α was decreased in the castrated groups, but increased in the group subjected to hormone treatment. There were no significant differences in ERβ immunoreactivity among the groups. Assessment of cell proliferation revealed greater immunoreactivity in the treated group. Together, the results indicate that the interaction between E2 and P4 may be responsible for maintaining female prostate gland histophysiology.

Exposure to ethinylestradiol during prenatal development and postnatal supplementation with testosterone causes morphophysiological alterations in the prostate of male and female adult gerbils

Steroids perform significant functions in prostatic development and growth, so that interferences of this equilibrium may predispose the gland to the development of diseases during the life. Embryonic and neonatal exposure to xenoestrogens, many of them with endocrine-disrupting potential, has been related to the induction of disturbances in reproductive system organs. Thus, this study aimed to analyse morphological and immunocytochemical aspects of prostate in both male and female adult gerbils either exposed to ethinylestradiol during the prenatal phase (pregnant females received 10 μg/kg, by gavage) (EE group) or exposed to testosterone (1 mg/kg) during the postnatal period (EE/T group). Serological analysis revealed a rise in estradiol levels in adult males and females of the EE group. A higher incidence of prostatic intraepithelial neoplasia (PIN) was observed in the male and female prostate of the treated groups, besides an increase in collagen and reticular fibres. Immunocytochemistry showed an increase in prostatic epithelial cells immunoreactive to AR and a presence of a smooth muscle layer, evidenced by α actin, in injured regions this way absent in prostatic epithelial buds. These pieces of evidence suggest that the alterations verified in the prostate in adulthood of both sexes may be due to the high oestrogen levels. Either males or females of the EE/T group showed normalized estradiol levels, although prostatic lesions could be observed. While the prostatic gland of male gerbils was more affected than the female prostate, this study showed that the exposure to EE during this critical period of development disrupts the prostate of both sexes in terms of prostatic lesions.