Navegando por Palavras-chave "Cellular proliferation"

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    Phytochemical screening of the dichloromethaneethanolic extract of Eriosema campestre var. macrophylum roots and its antiproliferative effect on human peripheral blood lymphocytes.
    (Soc Brasileira Farmacognosia, 2016) Santos, Michaelle G.; Almeida, Valeria G.; Avelar-Freitas, Bethania A.; Grael, Cristiane F. F.; Gregorio, Luiz E. [UNIFESP]; Pereira, Wagner F.; Brito-Melo, Gustavo E. A.
    Eriosema campestre var. macrophylum (Grear) Fortunato, Fabaceae, is a native plant of the Brazilian Cerrado and the decoction of its roots has been used by folk medicine for the therapy of inflammatory diseases. In this study we aimed to investigate the effect of the dichloromethane-ethanolic extract of E. campestre roots on the proliferative response of lymphocytes and to examine the profile of IL-2 production. The effect of dichloromethane-ethanolic extract of E. campestre on the proliferation of phytohemagglutinin-stimulated lymphocytes was evaluated by using flow cytometry and the cell supernatants were assayed for IL-2 concentrations by using an enzyme-linked immunosorbent assay. The phytochemical screening of E. campestre roots was performed to determine the main secondary metabolites through chromogenic and precipitation reactions and by using HPLC-PAD. In addition to the presence of subclasses of flavonoids (flavones and flavonols) in dichloromethaneethanolic extract of E. campestre, we observed that the extract induced a concentration-dependent decrease in IL-2 levels on the supernatant of the cell cultures as well as an antiproliferative effect on T lymphocytes, including CD4+ and CD8+ cells. The anti-inflammatory effects attributed to E. campestre by folk medicine may partly be explained by its antiproliferative action on T lymphocytes. (C) 2016 Sociedade Brasileira de Farmacognosia. Published by Elsevier Editora Ltda.
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    Upregulation of E2F1 in cerebellar neuroprogenitor cells and cell cycle arrest during postnatal brain development
    (Springer, 2011-08-01) Suzuki, Daniela E. [UNIFESP]; Ariza, Carolina B. [UNIFESP]; Porcionatto, Marimelia A. [UNIFESP]; Okamoto, Oswaldo Keith [UNIFESP]; Universidade de São Paulo (USP); Universidade Federal de São Paulo (UNIFESP)
    In the developing cerebellum, proliferation of granular neuroprogenitor (GNP) cells lasts until the early postnatal stages when terminal maturation of the cerebellar cortex occurs. GNPs are considered cell targets for neoplastic transformation, and disturbances in cerebellar GNP cell proliferation may contribute to the development of pediatric medulloblastoma. At the molecular level, proliferation of GNPs is regulated through an orchestrated action of the SHH, NOTCH, and WNT pathways, but the underlying mechanisms still need to be dissected. Here, we report that expression of the E2F1 transcription factor in rat GNPs is inversely correlated with cell proliferation rate during postnatal development, as opposed to its traditional SHH-dependent induction of cell cycle. Proliferation of GNPs peaked at postnatal day 3 (P3), with a subsequent continuing decrease in proliferation rates occurring until P12. Such gradual decline in proliferating neuroprogenitors paralleled the extent of cerebellum maturation confirmed by histological analysis with cresyl violet staining and temporal expression profiling of SHH, NOTCH2, and WNT4 genes. A time course analysis of E2F1 expression in GNPs revealed significantly increased levels at P12, correlating with decreased cell proliferation. Expression of the cell cycle inhibitor p18 (Ink4c) , a target of E2F1, was also significantly higher at P12. Conversely, increased E2F1 expression did not correlate with either SMAC/DIABLO and BCL2 expression profiles or apoptosis of cerebellar cells. Altogether, these results suggest that E2F1 may also be involved in the inhibition of GNP proliferation during rat postnatal development despite its conventional mitogenic effects.