Navegando por Palavras-chave "Proliferating cell nuclear antigen"
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- ItemAcesso aberto (Open Access)Immunoexpression of aromatase and estrogen receptors beta in stem spermatogonia of bullfrogs indicates a role of estrogen in the seasonal spermatogonial mitotic activity(Elsevier B.V., 2013-02-01) Caneguim, Breno Henrique [UNIFESP]; Luz, Juliana Silva da; Valentini, Sandro Roberto; Cerri, Paulo Sergio [UNIFESP]; Cerri, Estela Sasso [UNIFESP]; Universidade Federal de São Paulo (UNIFESP); Univ Estadual PaulistaBullfrog stem spermatogonia, also named primordial germ cells (PGCs), show strong testosterone immunolabeling in winter, but no or weak testosterone immunoexpression in summer. Thus, the role of testosterone in these cells needs to be clarified. in this study, we proposed to evaluate whether PGCs express aromatase and estrogen receptors, and verify a possible role of estrogen in PGCs seasonal proliferation. Testes of male adult bullfrogs, collected in winter (WG) and summer (SG), were fixed and embedded in historesin, for quantitative analysis, or paraffin for immunohistochemistry (IHC). the number of haematoxylin/eosin stained PGCs/lobular area was obtained. Proliferating cell nuclear antigen (PCNA), aromatase, estrogen receptor beta (ER beta) and PCNA/ER beta double immunolabeling were detected by IHC. the number of PCNA-positive PGCs and the histological score (HSCORE) of aromatase and ER beta immunolabeled PGCs were obtained. Although the number of PGCs increased significantly in WG, a high number of PCNA-positive PGCs was observed in summer. Moreover, aromatase and ER beta HSCORE was higher in SG than WG. the results indicate that PGCs express a seasonal proliferative activity; the low mitotic activity in winter is related to the maximal limit of germ cells which can be supported in the large lobules. in SG, the increased ER beta and aromatase HSCORE suggests that testosterone is converted into estrogen from winter to summer. Moreover, the parallelism between the high PGCs mitotic activity and ER beta immunoexpression suggest a participation of estrogen in the control of the PGCs seasonal proliferative activity which guarantee the formation of new germ cysts from summer to next autumn. (c) 2012 Elsevier Inc. All rights reserved.
- ItemSomente MetadadadosLineage-Negative Bone Marrow Cells Protect Against Chronic Renal Failure(Alphamed Press, 2009-01-01) Alexandre, Cristianne Silva; Volpini, Rildo Aparecido; Shimizu, Maria Heloisa; Sanches, Talita Rojas; Semedo, Patricia [UNIFESP]; Di Jura, Vera Lucia; Camara, Niels Olsen [UNIFESP]; Seguro, Antonio Carlos; Andrade, Lucia; Universidade de São Paulo (USP); Universidade Federal de São Paulo (UNIFESP)Progressive renal failure continues to be a challenge. the use of bone marrow cells represents a means of meeting that challenge. We used lineage-negative (Lin(-)) cells to test the hypothesis that Lin(-) cell treatment decreases renal injury. Syngeneic Fischer 344 rats were divided into four groups: sham ( laparotomy only, untreated); Nx (five-sixth nephrectomy and untreated); NxLC1 (five-sixth nephrectomy and receiving 2 x 10(6) Lin(-) cells on postnephrectomy day 15); and NxLC3 (five-sixth nephrectomy and receiving 2 x 10(6) Lin(-) cells on postnephrectomy days 15, 30, and 45). On postoperative day 16, renal mRNA expression of interleukin (IL)-1 beta, tumor necrosis factor-alpha, and IL-6 was lower in NxLC rats than in Nx rats. On postnephrectomy day 60, NxLC rats presented less proteinuria, glomerulosclerosis, anemia, renal infiltration of immune cells, and protein expression of monocyte chemoattractant protein-1, as well as decreased interstitial area. Immunostaining for proliferating cell nuclear antigen showed that, in comparison with sham rats, Nx rats presented greater cell proliferation, whereas NxLC1 rats and NxLC3 rats presented less cell proliferation than did Nx rats. Protein expression of the cyclin-dependent kinase inhibitor p21 and of vascular endothelial growth factor increased after nephrectomy and decreased after Lin(-) cell treatment. On postnephrectomy day 120, renal function (inulin clearance) was significantly better in Lin(-) cell-treated rats than in untreated rats. Lin(-) cell treatment significantly improved survival. These data suggest that Lin(-) cell treatment protects against chronic renal failure. STEM CELLS 2009; 27: 682-692
- ItemAcesso aberto (Open Access)Papel de oct4, sox2 e caspase-3 na quiescência dos gonócitos de rato(Universidade Federal de São Paulo (UNIFESP), 2014-10-29) Arantes, Anelise Diniz [UNIFESP]; Teixeira, Taiza Stumpp Teixeira [UNIFESP]; Oliva, Samara Urban de [UNIFESP]; http://lattes.cnpq.br/5886968082690915; http://lattes.cnpq.br/1024329256080770; http://lattes.cnpq.br/0559069185165585; Universidade Federal de São Paulo (UNIFESP)Introduction: The germ cells emerge from the epiblast and migrate to the gonads, where they become gonocytes. The gonocytes are the precursors of the spermatogonial stem cells, but little is known about their differentiation. It is seems that the rigid control of gonocyte proliferation, quiescence and pluripotent marker expression is crucial for germ cell development. Objective: Identify the pre-natal period of male germ cell quiescence in the rat and whether caspase-3 (Casp3) is involved in the process. Methods: Rat embryonic gonads were collected at 15, 17 and 19 days post-coitum (dpc). The expression of pluripotency (SOX2, OCT4) and proliferation (Ki67, phosphorylated Retinoblastoma 1 (pRb1)) markers as well as of cleaved Casp3 was analysed. To address Casp3 role in rat gonocyte quiescence, testes from 19dpc embryos were incubated with Casp3 inhibitor and submitted to the immunolabelling of Ki67, PCNA, Casp3 and NANOG. Results: The number of Ki67 and pRB1-labelled gonocytes reduced from 15dpc to 17dpc reaching zero at 19dpc, indicating that quiescence starts around 15dpc and that they are quiescent at 19dpc. OCT4 labelling followed the same detection pattern, whereas SOX2 was present only at 15dpc. These data suggest that the establishment of the quiescence period involves the downregulation of these pluripotent markers. Casp3 labelling was opposite to OCT4, pRB1 and Ki67 labelling, suggesting that it has a role in rat gonocyte quiescence. Casp3 labelling was maintained after the incubation with Casp3 inhibitor, what was expected since the inhibitor does not induce Casp3 degradation. Ki67 was not detected in the gonads incubated with Casp3 inhibitor, suggesting that Caps3 inhibition does not reactivate the cell cycle. NANOG was detected in the gonocyte cytoplasm at 19dpc and its labelling was identical to that of Casp3, suggesting that it has a role in the control of germ cell cycle in the embryo and may interact with Casp3. PCNA-positive and negative gonocytes were observed in 19dpc gonads before and after culture. However, the number of PCNA-negative gonocytes increased in the gonads incubated with Casp3-inhibitor, suggesting that Casp3 is a positive regulator of PCNA. Conclusion: These results suggest that OCT4 and SOX2 downregulation as well as Casp3 and NANOG expression are involved in rat gonocyte quiescence and that PCNA depend on Casp3 activity in these cells.
- ItemAcesso aberto (Open Access)The role of HER2/neu, BCL2, p53 genes and proliferating cell nuclear protein as molecular prognostic parameters in localized prostate carcinoma(Associação Paulista de Medicina - APM, 2004-05-01) Fonseca, Gilvan Neiva [UNIFESP]; Srougi, Miguel [UNIFESP]; Leite, Kátia Ramos Moreira [UNIFESP]; Nesrallah, Luciano João [UNIFESP]; Ortiz, Valdemar [UNIFESP]; Universidade Federal de São Paulo (UNIFESP); Hospital Sírio LibanêsCONTEXT: Prostate cancer is the most frequent solid genitourinary neoplasm in men. Involvement of several genes has been described in the promotion and progression of prostate carcinoma. OBJECTIVE: To study the expression of the oncogenes HER2/neu and BCL2, tumor suppressor gene p53 and the tumor proliferation rate in 150 radical prostatectomy specimens, in order to define their role as prognostic parameters in localized prostate cancer. TYPE OF STUDY: Prospective study. SETTING: Universidade Federal de São Paulo (UNIFESP) and Hospital Sírio Libanês, São Paulo PARTICIPANTS: One hundred and fifty men who were submitted to radical prostatectomy between August 1997 and August 1998, for localized prostate cancer. MAIN MEASUREMENTS: All specimens underwent evaluation in their entirety, to determine tumor volume percentage, tumor extent and Gleason score. Immunohistochemistry was performed to determine gene expression using anti- HER2/neu, BCL2 and p53 antibodies, and proliferating cell nuclear antigen. The chi-squared test was used for correlation between gene expression, proliferative activity and histological variables. RESULTS: Thirty percent of the cases were p53 positive. There was positive correlation between p53 expression and tumor stage. The p53 expression was 22.9% and 42.6% for pT2 and pT3 tumors, respectively (p = 0.01). Expression of HER2/neu, BCL2 and proliferating cell nuclear antigen was identified in 66%, 23% and 43% of patients, respectively. There was no correlation between these three parameters and tumor volume, Gleason score or tumor stage. CONCLUSION: One-third of prostate adenocarcinomas express p53 protein, and this characteristic is related to tumor stage. HER2/neu is frequently expressed in prostate carcinomas, with no correlation with histological parameters. BCL2 is rarely expressed, and together with proliferative activity has no relationship with prognostic pathological variables in these neoplasms.