Budding process during the organogenesis of the ventral prostatic lobe in mongolian gerbil

The prostate is a mammalian gland that shows a complex process of organogenesis. Here, a morphological study to characterize the organogenesis of the ventral prostate lobe in male gerbils was conducted. The urogenital sinus (UGS) was dissected out and processed for paraffin embedding. Histological sections were subjected to cytochemical, immunofluorescence, immunohistochemical, and three‐dimensional reconstruction techniques. We found that the first ventral buds emerged from the ventral urethral epithelium between the days 20 and 21 of prenatal life, reaching the ventral mesenchymal pad and initiating the branching process on the first day of postnatal life. The buds presented a V‐shaped elongation, suggesting that the smooth muscle layer (SML) plays an important role during budding events. Indeed, whereas the androgen receptor (AR) was preferentially found in the UGS mesenchyme (UGM), estrogen receptor alpha (ERα) was localized in both the UGM and in the emerging buds. This study characterized the morphological aspects of the budding process in a different rodent from rat and mice, serving as a new model for future studies on developmental biology of the prostate. Microsc. Res. Tech. 77:458–466, 2014. © 2014 Wiley Periodicals, Inc.     

Instructive induction of prostate growth and differentiation by a defined urogenital sinus mesenchyme

Instructive influences of fetal mesenchyme were examined in heterotypic tissue recombinants consisting of urogenital sinus mesenchyme (UGM) from male and female rats and distal ductal tips from adult rat prostate. Tissues were grown under the renal capsule of male hosts for periods up to 28 days. Resultant growths exhibited typical prostate histology. Expression of lobe-specific proteins for the ventral (prostatic steroid binding protein [PSBP]) lateral (seminal vesicle secretion II [SVS II]), and dorsal prostate (secretory transglutaminase [TGase]) were examined by immunocytochemistry. Male or female UGM combined with terminal segments of the ventral or dorsal prostate and immunolabeled with antibodies to lobe-specific proteins demonstrated expression of all three secretory products. The pattern of staining was consistent with a compound inductive response from the UGM. Unique to this study was our ability to use a defined mesenchymal tissue (female ventral mesenchymal pad [VMP]). This tissue is specifically associated with ductal branching morphogenesis and cytodifferentiation of the ventral prostate. Distal ductal tips from the dorsal lobe of the adult male prostate when recombined with female VMP and grown in vivo exhibited transformation of secretory phenotype, and the epithelium expressed mRNAs for PSBP. Immunocytochemistry of serial sections did not demonstrate labeling for TGase in the new epithelial growth. Ultrastructural analysis of the heterotypic recombinants indicated that the epithelium had similar characteristics to those of normal ventral prostate. Early stages of the mesenchymal-epithelial interactions resulted in dedifferentiation of the adult epithelium to solid cords of stratified cells. These findings illustrate the potent instructive capacity of a defined fetal UGM to influence development and cytodifferentiation of adult prostate epithelium. © 1995 Wiley-Liss, Inc.     

Increased androgen receptor and remodeling in the prostatic stroma after the inhibition of 5‐alpha reductase and aromatase in gerbil ventral prostate

Prostate require high levels of steroidogenic enzymes such as 5α‐reductase (5α‐r) and Aromatase (Aro) for the formation of active steroids. Dihydrotestosterone (DHT), the prostate dominant androgen, is converted from testosterone (T) by the action of 5α‐r. Aro provides an alternative pathway for estrogen, via T aromatization. Since prostatic maintenance is dependent on both reciprocal stromal–epithelial interaction and regulation by steroids, this study aimed to elucidate what the absence of 5α‐r and Aro enzymes provokes in the prostate microenvironment after their long‐term inhibition. Data obtained 1 day after the 30 consecutive days of enzymatic inhibition with Finasteride (5α‐r inhibitor) and Letrozole (Aro inhibitor) demonstrated a marked stromal remodeling, with an increased deposition of extracellular matrix (ECM) proteins besides androgen receptor (AR) overexpression in the three phases of postnatal development analyzed. The subepithelial area of acini from ventral prostate presented collagen and reticular fibers accumulation, besides various altered and active fibroblasts. The AR content immunostaining was elevated after enzymatic inhibition therapy, mainly in the nuclei of epithelial cells. Similar data were observed in the ventral prostates even 21 days after the end of treatments. Results obtained following the long‐term inhibition of 5α‐r and Aro are relevant and highlight the actions of these enzymes as crucial not only for the maintenance of tissue architecture and ECM arrangement but also for androgen and AR function. The long‐term absence of their action imposes a novel situation on the prostate from which its normal physiology could not be restored by the conclusion of the treatments. Microsc. Res. Tech., 2009. © 2009 Wiley‐Liss, Inc.     

Microscopic comparative study of the exposure effects of testosterone cypionate and ethinylestradiol during prenatal life on the prostatic tissue of adult gerbils

There is an increasing variety of endocrine disrupting chemicals (EDCs) either with (anti)estrogenic or (anti)androgenic potential widely present in the environment. These xenosteroids may mimic endogenous steroid hormones disrupting the homeostasis of physiological pathways and leading to several disturbances, especially in tissues highly dependent on steroid hormones such as the prostate. Taking this into account, this comparative study aimed to verify the potential of ethinylestradiol (EE) and testosterone acting as ECDs on the prostate of both male and female adult gerbils exposed to these agents during the embryonic phase. Consequently, pregnant gerbils were treated either with 10 μg/kg/day of EE or with a single dose of 1 mg of testosterone cypionate. The pups that were born 6-8 days after testosterone exposure and the pups that were born after 3 days of EE exposure were allowed to grow but were sacrificed within 4 months. Serological, morphological, stereological, and immunohistochemical analyses were used. Overall, the results showed that both sexes exposed to testosterone and EE during gestation had a prostatic gland with an increased stromal and epithelial and a reduced luminal compartment. Moreover, we observed that glands affected with prostatic intraepithelial neoplasia showed intense stromal reshuffling. In conclusion, although these alterations were observed in both sexes, more relevant to this study was the differential responsiveness of males and females exposed to these different drugs. Whereas the EE affected males more, the testosterone was more harmful to the females.     

Morphological alterations in the prostate stroma of rats submitted to chronic nicotine treatment

The stroma plays a fundamental role in the function of different glandular systems. In the prostate, the stroma is responsible for the development and maintenance of the differentiated state of the epithelium. Nicotine induces tobacco dependence and promotes morphological alterations in the epithelial compartment. However, its effects on the prostate stroma are unclear. The objective of this study was to evaluate the morphology of the stromal microenvironment in the ventral prostate lobe of rats submitted to chronic nicotine administration. Twenty rats (Rattus norvegicus) were divided into two groups: 10 animals received subcutaneous nicotine and 10 animals received physiological saline by the same route. After treatment, samples were collected from the ventral prostate lobe, processed and submitted to histology, histochemistry, and ultrastructural analysis by transmission and scanning electron microscopy. The level of circulating testosterone was also analyzed. The results showed a significant increase in the density of type I collagen (56.3% to 85.9%, P < 0.01) and a decrease in the density of type III collagen (43.7% to 14.1%, P < 0.01). In addition, there was a qualitative increase in elastic fibers and in the number of smooth muscle cells with a secretory phenotype. Circulating testosterone levels were significantly reduced (898.3 to 363.1 ng/mL, P < 0.01). The results showed that nicotine modifies different components of the prostate stroma, suggesting that this drug is a risk factor for morphofunctional alterations in the prostate gland.     

Calcifications in prostate cancer: An active phenomenon mediated by epithelial cells with osteoblast‐phenotype

The main aim of this study was to investigate putative correlation between the formation of prostate calcifications and the presence of cancer cells showing the ultrastructural and morphological aspects of osteoblasts. To this end, 40 prostate biopsies of prostate cancer were enrolled and investigated from histological, immunohistochemical, and ultrastructural point of view. To the best of our knowledge, this is the first study to propose a new cell type related to the ectopic calcifications in prostate tissue, the prostate osteoblast‐like cells (POLCs). Although our data require further investigations about the molecular mechanisms of both POLCs Cells generation and calcification formation, this study can open new and interesting prospective in the management of prostate cancer patients. In fact, if our data will be validated in large‐cohort studies, the presence of POLCs Cells and/or prostate calcifications could become a poor negative prognostic marker for cancer occurrence due to the correlation between the presence of POLCs Cells and epithelial to mesenchymal transition phenomenon.     

Early changes induced by short-term low-dose cadmium exposure in rat ventral and dorsolateral prostates

Prostate cancer (PCa) is the most commonly diagnosed cancer in men. The etiology of PCa in humans is multifactorial and includes age, ethnicity, environmental factors, and other unknown causes. Epidemiological and experimental evidence has shown that cadmium is associated with PCa both in humans and rodents. This metal can act as an endocrine disruptor during prostate development, and it induces prostate lesions late in life. In this study, we investigated the effects of low-dose cadmium on rat prostate morphology during puberty. Two-month-old male Wistar rats were randomized into two experimental groups: cadmium-treated and control. The ventral and dorsolateral prostates were dissected, weighed, and immunohistochemically stained with specific antibodies against Ki-67 and the androgen receptor (AR). The concentration of cadmium was measured in the blood and prostate, and testosterone concentration was measured from the plasma. Our results show that cadmium concentration was increased in both the blood and the prostate of cadmium-treated rats, but there were no changes in the prostatic weight, epithelial cell height, or testosterone levels. However, AR immunostaining and epithelial cell proliferation (Ki-67 index) were increased in both prostates with an increase in apoptosis only in the dorsal lobe. Furthermore, atypical hyperplasic proliferative lesions were found in the dorsolateral lobe after cadmium exposure. Cadmium treatment reduced collagen fiber absolute volume in both prostates. Thus, low-doses of cadmium, even for a short period of time, can interfere with prostate epithelium-stroma homeostasis, and this disruption might be an important factor in the onset of prostate lesions late in life.     

Embryological origin of interstitial cells of Cajal

Until recently, the embryological origin of the interstitial cells of Cajal (ICC) within the intestine was unclear. An origin from the neural crest or from the mesenchyme was considered possible because ICC possess some characteristics in common with neural crest-derived cells, and some characteristics in common with cells derived from the mesenchyme. Experiments in both mammalian and avian species, in which segments of embryonic gut were removed prior to the arrival of neural crest cells and grown in organ culture, have now shown that ICC do not arise from the neural crest. It appears that ICC and smooth muscle cells arise from common mesenchymal precursor cells. From mid-embryonic stages, ICC precursors express Kit, which is a receptor tyrosine kinase. Both ICC and many smooth muscle cell precursors initially express Kit, and then the cells destined to become smooth muscle cells down-regulate Kit and up-regulate the synthesis of myofilament proteins, whereas cells destined to differentiate into ICC maintain their expression of Kit. Adult mice with mutations that block the activity of Kit have disrupted arrays of ICC, whereas normal ICC are present until shortly after birth in such mice. It, therefore, appears that the Kit signalling pathway in not necessary for the embryonic development of ICC, but rather the post-natal proliferation of ICC.     

Fibroblast growth factor,estrogen, and prolactin receptor features in different grades of prostatic adenocarcinoma in elderly men

The objective was to characterize and associate the receptor reactivities of fibroblastic growth factor (FGF)‐2, FGF‐7, FGF‐8, epidermal growth factor (EGF), α‐actin and vimentin in relation to the androgen receptor (AR), α and β estrogen receptors (ERα and ERβ), and prolactin receptor in the prostate of elderly men showing low‐ and high‐grade adenocarcinoma. Thirty prostatic samples were taken from 60‐ to 90‐year‐old patients without prostatic lesions and with low‐grade cancer and high‐grade cancer, from the University Hospital, School of Medicine, the State University of Campinas. The results showed that increased FGF‐2, FGF‐7, and FGF‐8 receptor reactivities and decreased AR reactivity were verified in both high‐ and low‐grade cancer. However, the FGF‐8 receptor showed greater involvement at the beginning of the malignancy alterations. Increased EGF receptor (EGFR) reactivity and diminished α‐actin immunohistochemistry were identified in both cancer groups. Also, increased ERα, PR, and vimentin receptors were verified in both cancer groups. To conclude, the ERα involvement in the reactive stroma activation led to a microenvironment, which was favorable to cancer progression, due to maximizing stromal imbalance. The prolactin could be related to cancer progression due to its interaction with ERα action, indicating that this hormone could be a relevant target to prevent the estrogenic effects in the prostatic lesions. Both FGF receptor (FGFR)‐2 and FGFR‐8 play a fundamental role in the early stages of prostate cancer, suggesting that these molecules could be a promising therapeutic target. The differential localization of the fibroblastic factors between the prostatic epithelium and stroma of elderly men, who presented prostate cancer, could indicate a favorable distinction for tumoral progression. Microsc. Res. Tech. 76:321–330, 2013. © 2013 Wiley Periodicals, Inc.     

Adrenomedullin and proadrenomedullin N-terminal 20 peptide in the normal prostate and in prostate carcinoma

There is increasing evidence for the important role played by regulatory peptides in the physiology of the normal and neoplastic prostate. Adrenomedullin (AM) and pro-adrenomedullin N-terminal 20 peptide (PAMP) are recently discovered regulatory peptides widely expressed in the normal prostate and in prostate carcinoma. AM is produced in secretory, stroma, and endothelial cells and in neurons of the prostate ganglia. PAMP is only produced by neuroendocrine cells. The expression of AM mRNA is regulated by androgens in the rat prostate. The number of neuroendocrine cells expressing PAMP is increased in prostate carcinoma after androgen deprivation, which shows that this peptide could regulate androgen-independent prostate tumor growth. However, the roles of AM and PAMP in the normal prostate and in prostate carcinoma are yet to be elucidated.     

Microscopic study of certain age-related structural changes of maxillary sinus lining epithelium in albino rats

Mucociliary clearance is essential to maintain the defense function of the maxillary sinus; however, no literatures described the age changes in its lining epithelium. Therefore, the current work sought to describe the morphological postnatal age-related changes of maxillary sinus lining epithelium in rats using light, transmission, and scanning electron microscopes. Eighteen albino rats were divided into six groups according to their ages: 2-week-old, 1-month-old, 2-month-old, 3-month-old, adults, and senile rats. One-month-old-rats' group was the first to have recognizable maxillary sinus cavities that were lined by either single flat cellular layer or two distinct epithelial layers. These cells were devoid of microvilli and cilia, none of them showed evidence of differentiation into identifiable cell types. In 2- and 3-month-old rats, the mucosa of maxillary sinus started to be lined with pseudostratified epithelium with apparent increase in both microvilli and cilia. The first indication of goblet cell differentiation was observed in 3-month-old-rats. In the adult rats, the sinuses became completely lined by mature respiratory epithelium. However, in senile rats the epithelium exhibited polyps with clumped cilia and some areas of stratification and desquamation. Goblet cells were scanty and degenerating. The impaired mucociliary components (epithelium, cilia, and goblet cells' mucus) found in young and old ages of the current work might be correlated to human to explain predisposition of rhino-sinusitis in these age groups.     

Effects of exposure to estradiol and estradiol plus testosterone on the mongolian gerbil (Meriones unguiculatus) female prostate

The female prostate is a differentiated organ found in several mammal species, including humans and rodents. This gland has been related to important functions on female reproductive biology. Although the factors, which regulate prostate's development and activity are not well known, its functionality has been related to steroid hormones. It is well established that cyclic changes of estradiol and progesterone levels promote histophysiological adaptations of the whole female body. In contrast, only a few is found about those adaptations in female prostate. Thus, this study aimed to evaluate the effect of estradiol and estradiol + testosterone association on gerbil female prostate in order to verify, which hormonal associations are necessary to its homeostasis. For this, adult females had the ovaries surgically removed. After recovering, they received estradiol and estradiol + testosterone doses through 30 days, each 48 h. The prostatic tissue underwent morphological and morphometric‐estereological analysis. Hormonal restriction caused great gland involution and decreased secretory activity, aspects that were reverted by exposure to estradiol and estradiol + testosterone. However, these hormones were not able to re‐establish the normal prostate histoarchitecture. The immunoreaction of steroid receptors (ER‐α, ER‐β, and AR) responded differently among the experimental and control groups, and PCNA assay showed a decrease in epithelial cell proliferation within groups that had hormone privation. Therefore, we conclude that estradiol and testosterone are able to influence prostate morphophysiology and the maintenance of gland homeostasis depends on a balance among these and other hormones. Microsc. Res. Tech. 76:486–495, 2013. © 2013 Wiley Periodicals, Inc.     

Morphology and distribution of antennal sensilla of female Phyllotreta striolata (Fabricius) (Coleoptera: Chrysomelidae)

Phyllotreta striolata (Fabricius) is an important pest of Brassicaceae in Southeast Asia and North America. Using scanning electron microscopy, we observed the external structure, number, and distribution of the antennal sensilla in P. striolata females to discuss the putative function of these sensilla in host location and oviposition behaviors. The antenna of female P. striolata is filiform, composed of a scape, a pedicel, and a flagellum with 9 flagellomeres. Five types of sensilla were identified, including sensilla cheaetica, sensilla trichodea, Böhm bristles, sensilla auricillica, and sensilla basiconica (five subtypes, SB1–SB2). External structure and distribution of antennal sensilla are compared with data from other insect species. In addition, we discuss the possible functions of antennal sensilla based on their characteristics. Microsc. Res. Tech. 79:219–226, 2016. © 2016 Wiley Periodicals, Inc.     

Lobe variation effects of experimental diabetes and insulin replacement on rat prostate

We investigated the impact of diabetes with simultaneous and late insulin replacement on rat prostate growth during puberty, paying special attention to different prostatic lobes. Diabetes was induced by administration of streptozotocin (STZ) in 40-day-old male Wistar rats. A subset of diabetic rats underwent simultaneous insulin replacement (3 days after STZ administration), and another subset underwent a late insulin replacement (20 days after STZ administration). The ventral, dorsolateral, and anterior prostatic lobes were weighed and processed for histological, immunohistochemical, and morphometric analyses. Both diabetic and insulin-treated animals maintained low plasma testosterone (T) concentrations, whereas dihydrotestostenore (DHT) levels were normal. Diabetic animals had a decreased gain in absolute prostatic weight when compared to age-matched controls and insulin replacement animals. However, prostatic lobe weight in the diabetic animals was ～100% higher, even at the beginning of the experiment. Among the lobes, the anterior lobe showed the highest weight gain in diabetic and insulin replacement conditions. Epithelial cell proliferation in all lobes was significantly reduced in diabetic animals and significantly increased in insulin replacement animals, although apoptosis was unaltered. In conclusion, diabetes diminishes, but does not abolish, prostate growth during puberty. Even late insulin administration reduces the adverse effects of this disease on the prostate. In a scenario with both low insulin and T levels, DHT and other factors may play an important role in pubertal prostate growth. The adverse effects of diabetes on the rat prostate show a variation in lobe response, suggesting that diabetes may affect human prostate zones differently.     

Expression of caspase-8 and caspase-9 in rat hippocampus during postnatal development

The role of caspases in the regulation of apoptosis of neurons during development is well established. An emerging body of evidence indicates that caspases may also play significant roles which are nonapoptotic. We have demonstrated previously that the executor caspase-3 exhibited a unique pattern of spatiotemporal expression in the postnatal rat hippocampal subregions, and the activation of caspase-3 in different hippocampal neurons appeared to have distinct roles during postnatal development. In the present study, we examined the expressions of initiator caspases in the hippocampus, using immunofluorescent staining for caspase-8 and caspase-9, and Hoechst 33342 staining for nuclear chromatin to assess caspase-8 and -9 expression in the CA1, CA3, and the dentate gyrus (DG) on postnatal days (P) 0, P2, P4, P7, P14, P21, P28, P56. The results indicate that caspase-8 and caspase-9 were expressed in pyramidal neurons of CA1 and CA3 fields, and granular neurons of the DG during development. Caspase-8 was expressed in a general upward trend while caspase-9 showed a slight downward pattern, but still remained at high levels in the adult hippocampus. The expression profiles of caspases-8 and -9 are distinct from that of the apoptotic cells. These data indicate that caspase-8 may be involved not only in the classical apoptotic function, but also in the cell death of necrosis, and in response to different insults and other nonapoptotic functions. Caspase-9 plays a role in apoptosis during postnatal development, but it may have other functions as well.     

Quantitative analysis of pore patterns on rat prostate nuclei using spatial statistics methods

Spatial statistics methods have been used to analyse the nuclear pore pattern in rat ventral prostate nuclei isolated from adult animals. The observed results show that: (1) pores on prostate nuclear membranes are not randomly distributed; (2) the data sets obtained from different micrographs are consistent with the same statistical model thus suggesting the existence of a typical pore distribution.     

Different expression of caspase-3 in rat hippocampal subregions during postnatal development

Recent studies indicate that caspase-3 has distinct characteristics in postmitotic and neuronal progenitor apoptosis. Pyramidal neurons in CA1 and CA3 of the hippocampus become postmitotic during early postnatal development, whereas granule cells in the dentate gyrus (DG) undergo self-renewal throughout life. The distribution of caspase-3 in the hippocampal subfields during postnatal development is largely unknown. We used immunofluorescent staining for two isoforms of caspase-3 (an active 17 kDa isoform and an inactive 35 kDa precursor) and the Hoechst 33342 staining for nuclear chromatin to assess caspase-3 expression in the CA1, CA3, and DG of rat hippocampus during postnatal development. The expression of active caspase-3 reached a peak at P7 in CA1, at P2 in CA3, and then decreased with age. Whereas in DG, active caspase-3 expression increased slightly after P7, and remained at high levels for the rest of the investigated period. Procaspase-3 immunoreactivity was strong at P2 and decreased gradually to a basal plateau by P21 in the three regions examined. In addition, the number of apoptotic cells in the three regions all reached maximum levels at P7, and then decreased with age. These data indicate that there were specific spatio-temporal patterns of expression of active and precursor caspase-3 in the postnatally developing rat hippocampal subregions, and that the activation of caspase-3 in neuronal progenitor cells of DG and that in the postmitotic neurons of CA1 and CA3 may have distinct roles and mechanisms during postnatal development.     

Neurotrophic control of ovarian development

Substantial evidence now exists indicating that the neurotrophins, a family of growth factors required for the survival, development, and differentiation of various neuronal populations of the nervous system, are also important for the development of nonneuronal tissues. Such a function was first suggested by studies showing the presence of high-affinity neurotrophin receptors in a variety of nonneuronal tissues including those of the cardiovascular, endocrine, immune, and reproductive systems. Within the latter, the gonads appear to be a preferential site of neurotrophin action as suggested by the presence in the mammalian ovary of at least four of the five known neurotrophins and all of the neurotrophin receptors thus far identified. While the various functions that the neurotrophins may have in the ovary are still being elucidated, it is now clear that in addition to recruiting the ovarian innervation, they play a direct role in the regulation of two different maturational periods that are critical for the acquisition of female reproductive function: early follicular development and ovulation. Neurotrophins facilitate the development of newly formed follicles by promoting the initial differentiation and the subsequent growth of primordial follicles. These actions appear to be related to the ability of neurotrophins to sustain the proliferation of both mesenchymal and granulosa cells, and to induce the synthesis of follicle stimulating hormone (FSH) receptors. At the time of the first ovulation, neurotrophins contribute to the ovulatory cascade by increasing prostaglandin E(2) release, reducing gap junction communication, and inducing cell proliferation within the thecal compartment of preovulatory follicles.     

基于水平集的前列腺磁共振图像分割方法研究

基于前列腺磁共振图像(MRI)特征信息及其病变好发特定区域等先验知识,针对前列腺内外轮廓全分割问题,提出基于边缘距离调整水平集演化(DRLSE)的前列腺MRI两步分割方法。在构建统一水平集能量函数的基础上,第1步基于前列腺MR的T1(纵向弛豫时间)图像实现其外轮廓分割,第2步在外轮廓约束限定条件下,基于前列腺MR的T2(横向弛豫时间)图像实现前列腺的内部轮廓分割,进而完成前列腺内外轮廓的全面有效分割。设计了前列腺分割的人机交互界面,对10个前列腺病例MR图像(含正常、增生和癌变共30幅)进行了分割实验研究,并采用Dice相似性系数(DSC)对分割结果进行评价分析,DSC值达到90%以上。实验结果表明,所提出的基于边缘DRLSE的前列腺MRI两步分割方法能够有效地实现前列腺内外轮廓的全面分割,非常接近于临床专家手动分割的理想结果,对前列腺疾病的临床诊断和治疗有较好的参考价值。