Navegando por Palavras-chave "PKC"

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    Activation of P2Y(1) receptor triggers two calcium signaling pathways in bone marrow erythroblasts
    (Elsevier B.V., 2006-03-18) Paredes-Gamero, E. J.; Craveiro, R. B.; Pesquero, J. B.; Franca, J. P.; Oshiro, MEM; Ferreira, A. T.; Universidade Federal de São Paulo (UNIFESP)
    In this study, we describe the presence of P2 receptor subtypes and Ca2+ signaling in erythroblasts. ATP and ADP produced a biphasic increase of intracellular Ca2+ concentration ([Ca2+],), with an initial transient phase followed by a sustained phase. Reverse transcription polymerase chain reaction (RT-PCR) showed the expression of P2Y(1), P2Y(2) and P2Y(12). the selective P2Y(1) receptor antagonist 2'-deoxy-N-6-methyl-adenosine- 3',5'diphosphate (MRS2179) and the Gi protein inhibitor pertussis toxin blocked Ca2+ increase. the initial transient [Ca2+](i) increase phase was sensitive to the 1,4,5-inositol trisphosphate (IP3) receptor blocker 2-aminoethoxy-diphenylborate (2-APB), while the sustained phase was sensitive to the protein kinase C (PKC) inhibitor 2-[1-(3-dimethylaminopropyl)-1H-indol-3-yl]-3(1H-indol-3-yl)-maleimide (GF109203X) and calcium calmodulin kinase 11 (CaMKII) inhibitor 1-[N,O-bis(5-isoquinolinesulfonyl)-N-methyl-L-tyrosyl]-4-phenylpiperazine (KN-62). in addition, the PKC activator phorbol-12,13-dibutyrate (PDBu) produced increase of [Ca2+](i). Flow cytometry analysis showed the expression of Ca2+-dependent PKC alpha, beta I, gamma and phospho-CaMKII.These results suggest that the activation of the P2Y(1) receptor triggers two different [Ca2+]i increase pathways, one IP3-dependent and the other kinase-dependent. (c) 2006 Elsevier B.V. All rights reserved.
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    Phosphoproteome Reveals an Atlas of Protein Signaling Networks During Osteoblast Adhesion
    (Wiley-Blackwell, 2010-04-01) Milani, Renato; Ferreira, Carmen V.; Granjeiro, Jose M.; Paredes-Gamero, Edgar J. [UNIFESP]; Silva, Rodrigo A.; Justo, Giselle Z. [UNIFESP]; Nader, Helena B. [UNIFESP]; Galembeck, Eduardo; Peppelenbosch, Maikel P.; Aoyama, Hiroshi; Zambuzzi, Willian F.; Universidade Estadual de Campinas (UNICAMP); Universidade Federal Fluminense (UFF); Universidade Federal de São Paulo (UNIFESP); Univ Groningen
    Cell adhesion on surfaces is a fundamental process in the emerging biomaterials field and developmental events as well. However, the mechanisms regulating this biological process in osteoblasts are not fully understood. Reversible phosphorylation catalyzed by kinases is probably the most important regulatory mechanism in eukaryotes. Therefore, the goal of this study is to assess osteoblast adhesion through a molecular prism under a peptide array technology, revealing essential signaling proteins governing adhesion-related events. First, we showed that there are main morphological changes on osteoblast shape during adhesion up to 3 h. Second, besides classical proteins activated upon integrin activation, our results showed a novel network involving signaling proteins such as Rap1A, PKA, PKC, and GSK3 beta during osteoblast adhesion on polystyrene. Third, these proteins were grouped in different signaling cascades including focal adhesion establishment, cytoskeleton rearrangement, and cell-cycle arrest. We have thus provided evidence that a global phosphorylation screening is able to yield a systems-oriented look at osteoblast adhesion, providing new insights for understanding of bone formation and improvement of cell-substratum interactions. Altogether, these statements are necessary means for further intervention and development of new approaches for the progress of tissue engineering. Cell. Biochem. 109: 957-966, 2010. (C) 2010 Wiley-Liss, Inc.
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    Timp1 Promotes Cell Survival by Activating the PDK1 Signaling Pathway in Melanoma
    (Mdpi Ag, 2017) Toricelli, Mariana [UNIFESP]; Melo, Fabiana H. M. [UNIFESP]; Hunger, Aline; Zanatta, Daniela; Strauss, Bryan E.; Jasiulionis, Miriam G. [UNIFESP]
    High TIMP1 expression is associated with poor prognosis in melanoma, where it can bind to CD63 and beta 1 integrin, inducing PI3-kinase pathway and cell survival. Phosphatidylinositol (3,4,5)-trisphosphate (PIP3), generated under phosphatidylinositol-3-kinase (PI3K) activation, enables the recruitment and activation of protein kinase B (PKB/AKT) and phosphoinositide-dependent kinase 1 (PDK1) at the membrane, resulting in the phosphorylation of a host of other proteins. Using a melanoma progression model, we evaluated the impact of Timp1 and AKT silencing, as well as PI3K, PDK1, and protein kinase C (PKC) inhibitors on aggressiveness characteristics. Timp1 downregulation resulted in decreased anoikis resistance, clonogenicity, dacarbazine resistance, and in vivo tumor growth and lung colonization. In metastatic cells, pAKT(Thr308) is highly expressed, contributing to anoikis resistance. We showed that PDK1(Ser241) and PKC beta IISer660 are activated by Timp1 in different stages of melanoma progression, contributing to colony formation and anoikis resistance. Moreover, simultaneous inhibition of Timp1 and AKT in metastatic cells resulted in more effective anoikis inhibition. Our findings demonstrate that Timp1 promotes cell survival with the participation of PDK1 and PKC in melanoma. In addition, Timp1 and AKT act synergistically to confer anoikis resistance in advanced tumor stages. This study brings new insights about the mechanisms by which Timp1 promotes cell survival in melanoma, and points to novel perspectives for therapeutic approaches.