Fibrosis-related gene expression in the prostate is modulated by doxazosin treatment

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

Ultrastructural study of the follicular epithelium in oocytes of Pachycondyla (Neoponera) villosa ants (Hymenoptera : Ponerinae)

Insect oocytes are surrounded by the follicular epithelium which is simple and cuboidal, wih the mainly functions of: synthesis of vitellin membrane and chorion and synthesis and transport of hemolymph products (proteins). In Pachycondyla (Neoponera) villosa ants workers aged less than 10 days do not present the formation of ovarian follicles (oocytes, nurse cells and follicular cells) indicating that vitellogenesis starts at approximately 10 days of age. Studies of participation of the follicular epithelium in Pachycondyla (Neoponera) villosa showed that in stage I oocytes the epithelium does not present the opening of intercellular spaces. In stage II these spaces begin to be observed together with separation of the follicular epithelium from the oocyte surface. In stage III two types of material were observed in the intercellular spaces: electrodense material in the basal region and compacted material in apical one as well as follicular epithelium/oocytes interface suggesting that the extraovarian material that reach oocytes undergoes some type of modification during passage through the intercellular spaces. The follicular epithelium spaces in queen are bigger than in workers oocytes.

Ultrastructure of the midgut epithelium of Meliponinae larvae with different developmental stages and diets

The comparative study of the ultrastructure of the midgut epithelium of stingless bee larvae that eat plant protein (pollen) and animal protein (carrion) throughout the larval phase, shows variations in the digestive cells that are only relative to larval aging and not to the type of larval diet. The cells of older larvae present a cytoplasm with empty spaces that result from emptying of lipid and glycogen stocks, and the presence of autophagic vacuoles. These results are discussed in relation to the hypothesis that variations in the digestive tract of insects may be associated with different diets or phylogeny. We conclude that different diets do not determine cell morphology adaptations in the studied species. As the variations in the ultrastructure of the midgut epithelium are the same in all studied species, including the necrophagous species Trigona hypogea, throughout the larval stage, this sequence of changes seems to be due to different physiological state during larval development.

The midgut of Cephalotes ants (Formicidae: Myrmicinae): Ultrastructure of the epithelium and symbiotic bacteria

The ultrastructural analysis of the midgut of Cephalotes atratus. C. clypeatus, and C. pusillus reveled that the midgut epithelium lays on a basal lamina and is composed basically of three cell types: digestive cells, regenerative cells, and goblet cells. In these ants, the rough endoplasmic reticulum, in addition to producing digestive enzymes, is involved in the formation of concretions and ion storage in specialized vacuoles present in the midgut. These concretions are spherocrystals and may contribute to stabilize the pH and to maintain symbiotic bacteria found between microvilli. The ultrastructure analysis of these bacteria revealed the presence of a double envelope typical of gram-negative bacteria. For the three species examined, the ultrastructure similarities are conspicuous, suggesting that this may be the pattern for the genus Cephalotes. Details of the relationship between bacteria and microvilli were examined. (C) 2010 Elsevier Ltd. All rights reserved.

Histology and Histochemistry of the Stomach Epithelium of Pachycondyla (= Neoponera) villosa (Formicidae: Ponerinae)

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

Modulation of smooth muscle cell function: Morphological evidence for a contractile to synthetic transition in the rat ventral prostate after castration

In this study, we evaluated the involvement of rat ventral prostate smooth muscle cells (SMC) in secretory activity and whether this function is modulated after castration. Cell morphology was examined at both light and electron microscopy levels and the organelles involved in secretory function were labeled by the zinc-iodide-osmium (ZIO) method at the ultrastructural level and their volume density was determined by stereology. Castration resulted in marked changes of the SMC, which adopted a spinous aspect and abandoned the layered arrangement observed in the prostates of non-castrated rats. The volume density of ZIO reactive organelles increased progressively after castration, reaching significantly higher levels 21 days after castration, Since previous studies have demonstrated that SMC express SMC markers (even 21 days after castration) and are able to respond to adrenergic stimulation, we concluded that differentiated SMC are able to shift from a predominantly contractile to a more synthetic phenotype without changing their differentiation status. (c) 2005 International Federation for Cell Biology. Published by Elsevier Ltd. All rights reserved.

Apoptosis as a mediator of hyperplastic recovery in human prostate lesions: cytochemical and immunocytochemical evaluation

The present study was carried out to investigate the occurrence of apoptosis in human prostatic lesions with emphasis on nodular hyperplasia and adenocarcinomas, using cytochemistry and immunocytochemistry. The results showed that apoptosis is a common event on nodular hyperplasia but not in adenocarcinomas. This led to the hypothesis that apoptosis may represent an important factor on the localized recovery response of the hyperplastic acini.

Cellular and extracellular behavior in the gerbil (Meriones unguiculatus) ventral prostate following different types of castration and the consequences of testosterone replacement

Mongolian gerbils (Meriones unguiculatus) were grouped into two experimental groups: GEx.01 suffered orchiectomy and after 30 days received doses of testosterone cipionate (T), while GEx.02 received weekly and alternated doses of the anti-androgens cyproterone acetate and flutamide for 30 days, and the animals were then euthanized. Structural evaluation reveals a more intense reduction in epithelial height in GEx.02. Smooth muscle cells (SMC) presented a star-shaped aspect after 30 days of hormonal ablation and basal membrane was shown to be more intensely grooved in GEx.01. In both groups, after hormonal replacement, recovery in epithelial height could be noted and the SMC presented its phenotypes, but an increase in RER was seen, characterizing a modulation from its contractile to secreting phenotype. In conclusion, the prostate presented involution capacity after androgen ablation and the ability to reorganize after hormonal replacement, but events resulting from orchiectomy and subsequent T replacement were shown to be more aggressive to the prostate. (c) 2006 International Federation for Cell Biology. Published by Elsevier Ltd. All rights reserved.

Deletion (1)(q12) and double minutes in a metastatic adenocarcinoma of the prostate

Cytogenetic analysis after short-term cultures were performed on an invasive and moderately-differentiated prostatic adenocarcinoma. The results showed a normal male chromosomal complement in most metaphases examined. Furthermore, several abnormalities were found, including del(1)(q12), double minute and ring chromosomes, acentric fragments, triradial figures, and near-tetraploid cells. (C) Elsevier B.V., 1999. All rights reserved.

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

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

Cellular changes in the prostatic stroma of glucocorticoid-treated rats

Glucocorticoid hormones (GCs) have been widely used for the treatment of prostate cancer because of their inhibitory property against tumour growth. However, their mechanism of action in the prostate has received little attention. Excess GCs can lead to peripheral insulin resistance resulting in hyperglycaemia and hyperinsulinaemia. Insulin plays an important role as a cellular stimulant and high levels are related to low levels of androgens. Our objective has been to describe the effects of insulin resistance induced by dexamethasone treatment on the morphology of rat ventral prostate. Mate adult Wistar rats received daily intraperitoneal injections of dexamethasone or saline for five consecutive days after which the rats were killed and the ventral prostate was removed, weighed and prepared for conventional and transmission electron microscopy (TEM). Dexamethasone treatment resulted in atrophy and decreased proliferative activity of prostatic epithelial cells. TEM analysis revealed changes in the epithelium-stroma interface, with some interruptions in the basement membrane. Fibroblasts showed a secretory phenotype with dilated endoplasmic reticulum. Smooth muscle cells exhibited a contractile pattern with 50% atrophy, an irregular membrane and twisted nuclei. Mitochondrial alterations, such as enlarged size and high electron density in the mitochondrial matrix, were also detected in smooth muscle cells. Insulin resistance induced by dexamethasone is thus associated with epithelial atrophy similar to that described for diabetic rats. However, GCs are responsible for morphological changes in the stromal cell population suggesting the activation of fibroblasts and atrophy of the smooth muscle cells.

Antiestrogen therapies affect tissue homeostasis of the gerbil (Meriones unguiculatus) female prostate and ovaries

Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)

Anatomy of smooth muscle cells in nonmalignant and malignant human prostate tissue

Differently graded areas of human prostate adenocarcinoma were examined after Masson's trichrome staining or immunohistochemistry for smooth muscle alpha-actin, type IV collagen and laminin. In addition, the ultrastructure of the prostatic smooth muscle cells (SMC) during glandular proliferation and epithelial invasion in selected tumors was studied. The SMC formed a thick layer below the epithelial structures in unaffected areas and were closely associated with each other in homotypic interactions. As the tumor grade increased, the SMC gradually lost interactions with each other and became atrophic. With the growth of the epithelial compartment, the SMC initially segregated to the tumor periphery and the intercellular spaces increased. In high grade tumors, the epithelial cancer cells invaded the spaces between the SMC. Immunohistochemical analysis of the basal membrane revealed increased disruption of the usually thick basal membrane, which became thinner and faintly stained with each of the antibodies used. We conclude that most SMC become atrophic following epithelial invasion in human tumors and that degradation of the basal membrane is an important factor in this process. At the ultrastructural level, different SMC phenotypes occur in prostatic tissues during epithelial invasion. Interconversion between these phenotypes is suggested and a probable relationship among them is proposed.

Prenatal testosterone exposure as a model for the study of endocrine-disrupting chemicals on the gerbil prostate

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)