Navegando por Palavras-chave "Sertoli cells"
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- ItemSomente Metadadados17 beta-estradiol induces the translocation of the estrogen receptors ESR1 and ESR2 to the cell membrane, MAPK3/1 phosphorylation and proliferation of cultured immature rat Sertoli cells(Soc Study Reproduction, 2008-01-01) Lucas, Thais Fabiana Gameiro [UNIFESP]; Siu, Erica Rosanna [UNIFESP]; Esteves, Carlos A. [UNIFESP]; Monteiro, Hugo Pequeno [UNIFESP]; Oliveira, Cleida Aparecida de; Porto, Catarina Segreti [UNIFESP]; Lazari, Maria de Fatima Magalhaes [UNIFESP]; Universidade Federal de São Paulo (UNIFESP); Universidade Federal de Minas Gerais (UFMG)The aim of the present study was to determine the mechanisms involved in estrogen actions in cultured rat Sertoli cells. RT-PCR detected transcripts for the estrogen receptors ESR1 and ESR2 in cultured immature Sertoli cells and in the testis of 15-, 28-, and 120-day-old rats. the expression of ESR1 and ESR2 was confirmed in Sertoli cells by immunofluorescence and Western blot. Immunohistochemistry with cryosections of testes from immature and adult rats revealed that ESR1 is present in Sertoli, Leydig, and some peritubular myoid cells, and ESR2 is present in multiple cell types, including germ cells. Treatment of Sertoli cells with 17beta-estradiol (E-2) induced a translocation of ESR1 and ESR2 to the plasma membrane and a, concomitant phosphorylation of MAPK3/1. Both effects reached a maximum after 10 min and were blocked by PP2, an inhibitor of the SRC family of protein tyrosine kinases, and by the antiestrogen ICI 182,780 (10). MAPK3/1 phosphorylation was also decreased in the presence of AG 1478, an inhibitor of the epidermal growth factor receptor (EGFR) kinase, and in the presence of MAP2K1/2 inhibitor UO126. Treatment with 2 for 24 h increased the incorporation of [methyl-H-3]thymidine, which was blocked by ICI. These results indicate that E2 activates an SRC-mediated translocation of estrogen receptors to the plasma membrane, which results in the activation of EGFR and the mitogen-activated protein kinase signaling pathway. in addition, activation of ESR1 and/or ESR2 by E 2 is involved in proliferation of immature Sertoli cells. the estrogen actions in Sertoli cells might be a key step mediating cellular events important for spermatogenesis and fertility.
- ItemSomente Metadadados17Beta-Estradiol Signaling and Regulation of Proliferation and Apoptosis of Rat Sertoli Cells(Soc Study Reproduction, 2012-04-01) Royer, Carine [UNIFESP]; Lucas, Thais Fabiana Gameiro [UNIFESP]; Lazari, Maria de Fatima Magalhaes [UNIFESP]; Porto, Catarina Segreti [UNIFESP]; Universidade Federal de São Paulo (UNIFESP)The aim of the present study was to investigate the intracellular signaling events downstream of the classical estrogen receptors (ESRs) and G protein-coupled estrogen receptor 1 (GPER) involved in regulation of proliferation and apoptosis of rat Sertoli cells, in which we have previously described ESR1, ESR2, and GPER. ESRs play a role in Sertoli cell proliferation, and GPER, but not ESRs, plays a role modulating gene expression involved with apoptosis. the present study shows that 17beta-estradiol (E2) and the GPER-selective agonist G-1 rapidly activate phosphatidylinositol 3-kinase (PIK3)/serine threonine protein kinase (AKT) and cyclic AMP response element-binding (CREB) phosphorylation. E2 and the ESR1-selective agonist 4,4',4 ''-(4-propyl-(1H)-pyrazole-1,3,5-triyl)trisphenol (PPT) increase the expression of cyclin D1 (CCND1), whereas the ESR2-selective agonist 2,3-bis(4-hydroxyphenyl)-propionitrile (DPN) and G-1 do not change the expression of this protein, suggesting that ESR1 is the upstream receptor regulating Sertoli cell proliferation. E2- or PPT-ESR1, through activation of epidermal growth factor receptor (EGFR)/mitogen-activated protein kinase 3/1 (MAPK3/1) and PIK3 pathways, induces upregulation of CCND1. KG-501, the compound that disrupts the phospho-CREB/CREB binding protein (CBP) complex, does not change E2-or PPT-ESR1-mediated CCND1 expression, suggesting that phospho-CREB/cyclic AMP response element/CBP is not involved in the expression of this protein. E2- or G-1-GPER, through activation of EGFR/MAPK3/1 and PIK3 pathways, may be involved in the upregulation of antiapoptotic proteins BCL2 and BCL2L2. E2- or G-1-GPER/EGFR/MAPK3/1/phospho-CREB decreases BAX expression. Taken together, these results show a differential effect of E2-GPER on the CREB-mediated transcription of proapoptotic and antiapoptotic genes of the same BCL2 gene family. ESR1 and GPER can mediate the rapid E2 actions in the Sertoli cells, which in turn can modulate nuclear transcriptional events important for Sertoli cell function and maintenance of normal testis development and homeostasis. Our findings are important to clarify the role of estrogen in a critical period of testicular development, and to direct further studies, which may contribute to better understanding of the causes of male infertility.
- ItemSomente MetadadadosCadmium-induced testicular injury(Elsevier B.V., 2009-08-01) Siu, Erica Rosanna; Mruk, Dolores D.; Porto, Catarina Segreti [UNIFESP]; Cheng, C. Yan; Populat Council; Universidade Federal de São Paulo (UNIFESP)Cadmium (Cd) is an environmental toxicant and an endocrine disrupter in humans and rodents. Several organs (e.g., kidney, liver) are affected by Cd and recent studies have illustrated that the testis is exceedingly sensitive to Cd toxicity. More important, Cd and other toxicants, such as heavy metals (e.g., lead, mercury) and estrogenic-based compounds (e.g., bisphenols) may account for the recent declining fertility in men among developed countries by reducing sperm count and testis function. in this review, we critically discuss recent data in the field that have demonstrated the Cd-induced toxicity to the testis is probably the result of interactions of a complex network of causes. This is likely to involve the disruption of the blood-testis barrier (BTB) via specific signal transduction pathways and signaling molecules, such as p38 mitogen-activated protein kinase (MAPK). We also summarize current studies on factors that confer and/or regulate the testis sensitivity to Cd, such as Cd transporters and metallothioneins, the impact of Cd on the testis as an endocrine disruptor and oxidative stress inducer, and how it may disrupt the Zn(2+) and/or Ca(2+) mediated cellular events. While much work is needed before a unified mechanistic pathway of Cd-induced testicular toxicity emerges, recent studies have helped to identify some of the likely mechanisms and/or events that take place during Cd-induced testis injury. Furthermore, some of the recent studies have shed lights on potential therapeutic or preventive approaches that can be developed in future studies by blocking or minimizing the destructive effects of Cd to testicular function in men. (C) 2009 Elsevier Inc. All rights reserved
- ItemSomente MetadadadosDifferential role of the estrogen receptors ESR1 and ESR2 on the regulation of proteins involved with proliferation and differentiation of Sertoli cells from 15-day-old rats(Elsevier B.V., 2014-01-25) Lucas, Thais Fabiana Gameiro [UNIFESP]; Lazari, Maria de Fatima Magalhaes [UNIFESP]; Porto, Catarina Segreti [UNIFESP]; Universidade Federal de São Paulo (UNIFESP)The aim of the present study was to investigate the role of each estrogen receptors on the regulation of proteins involved with proliferation and differentiation of Sertoli cells from 15-day-old rats. Activation of ESR1 by 17 beta-estradiol (E2) and ESR1-selective agonist PPT increased CCND1 expression, and this effect was dependent on NF-kB activation. E2 and the ESR2-selective agonist DPN, but not PPT, increased, in a PI3K and CREB-dependent manner, the expression of CDKN1B and the transcription factors GATA-1 and DMRT1. Analyzing the expression of ESR1 and ESR2 in different stages of development of Sefton cells, we observed that the ESR1/ESR2 ratio decreased with age, and this ratio seems to be important to determine the end of cell proliferation and the start of cell differentiation. in Sertoli cells from 15-day-old rats, the ESR1/ESR2 ratio favors the effect of ESR1 and the activation of this receptor increased [Methyl-31-I]thymidine incorporation. We propose that in Sertoli cells from 15-day-old rats E2 modulates Sertoli cell proliferation through ESR1/NF-kappa B-mediated increase of CCND1, and cell cycle exit and differentiation through ESR2/CREB-mediated increase of CDKN1B, GATA-1 and DMRT1. the present study reinforces the important role of estrogen for normal testis development. (C) 2013 Elsevier Ireland Ltd. All rights reserved.
- ItemSomente MetadadadosEstudo morfofuncional das células de Sertoli de ratos albinos tratados com etoposide na fase pré-púbere(Universidade Federal de São Paulo (UNIFESP), 2006-12-31) Stumpp, Taiza [UNIFESP]; Miraglia, Sandra Maria [UNIFESP]; Universidade Federal de São Paulo (UNIFESP)Spermatogenesis is a complex and controlled process in which Sertoli cells play a key role. In the testis, endocrine, paracrine and autocrine mechanisms that control spermatogenesis occurrence. The Sertoli cells synthesize substances which are essential for these mechanisms. Among them is transferrin. This protein is an important iron transporter that binds Fe+3 ions and transports them to cells via receptor-mediated endocytosis. It has been demonstrated that testicular transferrin constitutes 5% of all proteins secreted by Sertoli cells. In addition, it is a reliable instrument of investigation of the function and maturity of these cells, both in vitro and in vivo (Holmes et al., 1982; 1984). Tranferrin secreted by Sertoli cells is internalized by germ cell lineage through receptor-mediated endocytosis. It was recently demonstrated that, in addition to transport iron, transferrin exert antiapoptotic activity through Fas/FasL route, shows high antioxidant activity and play important role against reactive oxygen species (ROS). Although the Sertoli cells are considered the most resistant cell in the testis, they can be affected by germ cell damage or death. Studies showed that after apoptotic germ cell death, caused by gamma irradiation, Sertoli cell function is harmed. Apoptosis is responsible for germ cell number in the seminiferous epithelium under normal and adverse conditions. In normal conditions, apoptosis controls the number of germ cells that Sertoli cells are able to support. In addition to radiation, other adverse situations can interfere with germ cell apoptosis frequency. Chemotherapic drugs, e. g., provoke accentuated increase of germ cell apoptosis in the testis. Spermatogonia and primary spermatocytes are the main target of these drugs, because they undergo continuous mitosis and meiosis, respectively. Etoposide is an efficient chemotherapeutic drug administered against a large variety of malignant neoplasms. However, in spite of its beneficial effects against cancer, some reports have emphasized its toxicity, such as myelotoxicity and loss of fertility, on mammal. In fact, this drug might cause germ cell apoptosis and consequent severe depletion of seminiferous epithelium may occur in post-treated patients. Studies have shown that Sertoli cells play key role in etoposide action in the testis, because these cells express MRP1, a protein located in their basal plasma membrane. This protein functions as a bomb, which transports drugs, that entered Sertoli cells, back to the extracellular compartment. Furthermore, in addition to germ cell death, we observed a significant increase of numerical density of the Sertoli cells occurred in 64 day-old rats treated with etoposide in prepubertal phase. This phenomenon was surprising, since etoposide is mainly known to interfere with topoisomerase II, an important enzyme engaged in DNA replication and particularly abundant in cells undergoing rapid division; otherwise, this phenomenon does not normally occur in Sertoli cells at the studied age. Thus, based on Sertoli cell number alteration observed in our recently published work and considering the controversy about the action of the chemotherapeutic drugs on Sertoli cells, we decided to investigate Sertoli cell function and morphology in rats treated with etoposide during the prepubertal phase to assess a possible direct action of etoposide on Sertoli cells. Prepubertal 25 day-old albino Wistar rats were treated with the total dose of 40mg/Kg of etoposide. This dose was fractioned in eight doses of 5mg/Kg/day, which were administered during eight consecutive days. In this study we also investigated a possible cytoprotector action of iron-free transferrin (apotransferrin) on seminiferous epithelium. Thus, three apotransferrin doses were utilized: 0.1mg, 0.5mg and 1.0mg. Apotransferrin was administered: 24h before etoposide treatment beginning (i.e., when rats were 24-day-old), 30 minutes before each etoposide injection and 24h after the last etoposide injection. Thus, the rats were distributed in 14 groups: six treated only with etoposide; five controls treated with 0.9% saline solution; three treated with etoposide + apotranferrin. The control groups and five groups treated only with etoposide were sacrificed in different periods after the end of the treatment: 12h and 13, 32, 95 and 148 days. Each of these groups was composed by 13 rats; the testes of 10 rats were removed, processed for inclusion in paraffin and submitted to intratesticular transferrin labeling and to PAS+H method for Sertoli cell function and morphology, respectively. The testes of the other three rats were perfusion-fixed with 2.0% formaldehyde + 2.5% glutaraldehyde solution for ultrastructural analysis of Sertoli cell morphology under transmission electron microscope (TEM). The last group treated only with etoposide and the groups treated with etoposide + apotransferrin had five rats each and were sacrificed when they were 64-day-old. This age was chosen for transferrin protection investigation because, at this age, the rats showed the most accentuated alterations in the seminiferous epithelium after etoposide treatment. These rats were sacrificed and their testes were processed for paraffin embedding and stained with PAS+H for histopathological and morphometric analyses. In the control groups, accentuated transferrin labeling in the seminiferous epithelium was observed. In general, the etoposide-treated groups showed accentuated reduction of transferrin labeling in the seminiferous epithelium. This reduction caused diminution of volume density of transferrin labeled testicular tissue in all groups, except for the prepubertal. There was no difference in the interstitial tissue transferrin labeling among control and etoposide-treated groups; all groups showed accentuated labeling of this tissue. These data indicate that etoposide provoked alteration of Sertoli cell function, causing reduction of transferrin synthesis by this cell. However etoposide did not affected global transferrin production. During analysis under light microscope, morphological alteration of Sertoli cell nuclei were observed in the etoposide-treated groups; these cells did not show evident nucleoli. Sertoli cell nuclei in the tubular lumen were also observed. The analysis under TEM confirmed that etoposide causes accentuated Sertoli cell morphological alteration in all etoposide-treated groups. Some Sertoli cells showed degenerative characteristics and other cells showed morphological features of immature Sertoli cells, which were not compatible with the studied ages. All the morphological alterations observed in this study suggest the etoposide exert activity directly on Sertoli cell. This study also showed that, under the experimental conditions here utilized, apotransferrin did not protect the seminiferous epithelium against harmful effects of etoposide.
- ItemSomente MetadadadosExpression and Signaling of G Protein-Coupled Estrogen Receptor 1 (GPER) in Rat Sertoli Cells(Soc Study Reproduction, 2010-08-01) Lucas, Thais Fabiana Gameiro [UNIFESP]; Royer, Carine [UNIFESP]; Siu, Erica Rosanna [UNIFESP]; Lazari, Maria de Fatima Magalhaes [UNIFESP]; Porto, Catarina Segreti [UNIFESP]; Universidade Federal de São Paulo (UNIFESP)The aim of the present study was to investigate the expression and signaling of the G protein-coupled estrogen receptor 1 (GPER) in cultured immature rat Sertoli cells-in which we have previously described the classical estrogen receptors (ESR1 and ESR2). Expression of GPER in cultured Sertoli cells from 15-day-old rats was detected by RT-PCR and immunoassays. Gper transcripts also were present in testes from 5-, 15-, and 120-day-old rats. Short-term treatment of Sertoli cells with 17beta-estradiol (E2), the GPER agonist G-1, or the ESR antagonist ICI 182,780 (ICI) rapidly activated MAPK3/1 (ERK1/2), even after down-regulation of ESR1 and ESR2, suggesting a role for GPER in the rapid E2 action in these cells. MAPK3/1 phosphorylation induced by ICI or G-1 was blocked by pertussis toxin, selective inhibitor of the SRC family of protein tyrosine kinases, metalloprotease inhibitor, MAP2K1/2 inhibitor, and epidermal growth factor receptor (EGFR) kinase inhibitor. Furthermore, E2, but not G-1, induced up-regulation of cyclin D1 in the Sertoli cells. This effect was blocked by ICI. E2 and G-1 decreased BAX and increased BCL2 expression and these effects were blocked by MAP2K1/2 inhibitor and EGFR kinase inhibitor. the pretreatment with ICI did not block the effect of E2. Taken together, these results indicate that in Sertoli cells 1) GPER-mediated MAPK3/1 activation occurs via EGFR transactivation through G protein beta gamma subunits that promote SRC-mediated metalloprotease-dependent release of EGFR ligands, which bind to EGFR and lead to MAPK3/1 phosphorylation; 2) E2-ESRs play a role in Sertoli cell proliferation; and 3) E2-GPER may regulate gene expression involved with apoptosis. ESR and GPER may mediate actions important for Sertoli cell function and maintenance of normal testis development and homeostasis.
- ItemSomente MetadadadosHistological characteristics of the gonads of pig fetuses and their relationship with fetal anatomical measurements(Elsevier Sci Ltd, 2018) Pontelo, Thais Preisser; Miranda, Jose Rafael; Felix, Matheus Augusto Rodrigues; Pereira, Barbara Azevedo; Silva, William Eduardo da; Avelar, Gleide Fernandes; Mariano, Flavia Cristina Martins Queiroz [UNIFESP]; Guimaraes, Gregorio Correa; Zangeronimo, Marcio GilbertoThe objective was to evaluate the histomorphometric characteristics of the testis and ovaries of pig fetuses at different gestational ages, as well as their correlation with some fetus measurements. Forty-four fetuses were separated for gender (male and female) and gestational age (50, 80 and 106 days of gestation). After slaughter, fetuses had their body length, head and thoracic perimeters measured and their gonads submitted to histomorphometric analyses. The gonadal characteristics at different gestational ages were statistically compared, correlations with the fetal measurements were performed and equations to predict the gonadal characteristics from the fetal measurements were obtained. The testis weight logarithmically increased along pregnancy, whereas ovary weight increased in a linear manner. The cordonal length and number of Sertoli cells were positively correlated with the fetal measurements, being higher at 106 days gestation, while the nuclear volume of these cells were negatively correlated. The total number of follicles was higher at day 80 and 106 of pregnancy. The number of oogonia decreased along the pregnancy, however, their nucleus size was increased. The number of follicles and volume of oogonia were positively correlated with the fetal measurements, while the number of oogonia was negatively correlated. Equations were obtained for the prediction of gonadal characteristics of fetuses. We concluded that in pigs testis cell proliferation, ovary development and histological organization was more pronounced during the final third of pregnancy. Fetal weight and size were strongly related to gonadal development, and can be used to estimate the histological characteristics of gonads.