Encontrados 16 documentos, a visualizar página 1 de 2
Signal transduction profile of chemical sensitisers in dendritic cells: an endp...
Neves, BM; Gonçalo, Margarida; Figueiredo, A; Duarte, CB; Lopes, MC; Cruz, MTThe development of non-animal testing methods for the assessment of skin sensitisation potential is an urgent challenge within the framework of existing and forthcoming legislation. Efforts have been made to replace current animal tests, but so far no alternative methods have been developed. It is widely recognised that alternatives to animal testing cannot be accomplished with a single approach, but rather wil...
Effect of lipopolysaccharide, skin sensitizers and irritants on thioredoxin-1 e...
Francisco, V; Neves, BM; Cruz, MT; Gonçalo, Margarida; Figueiredo, A; Duarte, CB; Lopes, MCThioredoxin-1 is a ubiquitous protein involved in phenotypical and functional changes in dendritic cells (DC). We investigated the effect of lipopolysaccharide (LPS), skin sensitizers, and irritants on thioredoxin-1 by Western blot and immunofluorescence and on mRNA by real-time PCR. As DC models, we used a skin DC line and DC derived from human blood monocytes. We observed that all tested chemicals increased t...
Differential modulation of CXCR4 and CD40 protein levels by skin sensitizers an...
Neves, BM; Cruz, MT; Francisco, V; Gonçalo, Margarida; Figueiredo, A; Duarte, CB; Lopes, MCThe development of non-animal methods for skin sensitization testing is an urgent challenge. Some of the most promising in vitro approaches are based on the analysis of phenotypical and functional modifications induced by sensitizers in dendritic cell models. In this work, we evaluated, for the first time, a fetal skin-derived dendritic cell line (FSDC) as a model to discriminate between sensitizers and irritan...
Effect of skin sensitizers on inducible nitric oxide synthase expression and ni...
Cruz, MT; Neves, BM; Gonçalo, Margarida; Figueiredo, A; Duarte, CB; Lopes, MCNitric oxide (NO) is involved in the pathogenesis of acute and chronic inflammatory conditions, namely in allergic contact dermatitis (ACD). However, the mechanism by which NO acts in ACD remains elusive. The present study focuses on the effects of different contact sensitizers (2,4-dinitrofluorbenzene, 1,4-phenylenediamine, nickel sulfate), the inactive analogue of DNFB, 2,4-dichloronitrobenzene, and two irrit...
Contact sensitizers downregulate the expression of the chemokine receptors CCR6...
Cruz, MT; Gonçalo, Margarida; Paiva, A; Morgado, JM; Figueiredo, A; Duarte, CB; Lopes, MCChemokines are involved in the control of dendritic cell (DC) trafficking, which is critical for the immune response, namely in allergic contact dermatitis (ACD). In this work, we investigated by flow cytometry the effect of the contact sensitizers 2,4-dinitrofluorobenzene (DNFB), 1,4-phenylenediamine (PPD) and nickel sulfate (NiSO(4)), on the surface expression of the chemokine receptors CCR6 and CXCR4 in DC. ...
DNFB activates MAPKs and upregulates CD40 in skin-derived dendritic cells
Matos, TJ; Duarte, CB; Gonçalo, Margarida; Lopes, MCBACKGROUND: The intracellular mechanisms involved in the activation of DCs during sensitization in allergic contact dermatitis (ACD) are not known. OBJECTIVE: Here, we investigated the effect of a strong sensitizer, 2,4-dinitrofluorobenzene (DNFB) on the activity of MAPKs in a dendritic cell (DC) line generated from fetal mouse skin (FSDC), and the results were correlated with the expression of a costimulatory ...
Release of IL-1beta via IL-1beta-converting enzyme in a skin dendritic cell lin...
Matos, MT; Jaleco, SP; Gonçalo, Margarida; Duarte, CB; Lopes, MCWe used a mouse fetal skin dendritic cell line (FSDC) to study the effect of the strong allergen 2,4-dinitrofluorobenzene (DNFB) on interleukin (IL)-1beta release and IL-1beta receptor immunoreactivity. Stimulation with DNFB (30 minutes) increased IL-1 release without changing the mRNA levels of the protein. Furthermore, DNFB increased transiently the interleukin-1beta-converting enzyme (ICE) activity, as measu...
Role of oxidative stress in ERK and p38 MAPK activation induced by the chemical...
Matos, MT; Duarte, CB; Gonçalo, Margarida; Lopes, MCThe intracellular mechanisms involved in the early phase of dendritic cell (DC) activation upon contact with chemical sensitizers are not well known. The strong skin sensitizer 2,4-dinitrofluorobenzene (DNFB) was shown to induce the activation of mitogen-activated protein kinases (MAPK) in DC. In the present study, we investigated a putative role for oxidative stress in DNFB-induced MAPK activation and upregula...
The sensitizers nickel sulfate and 2,4-dinitrofluorobenzene increase CD40 and I...
Vital, AL; Gonçalo, Margarida; Cruz, MT; Figueiredo, A; Duarte, CB; Lopes, MCDendritic cells (DCs) are antigen-presenting cells (APCs) capable of capturing haptens and to process and present them to T lymphocytes. In order to sensitize T cells for contact hypersensitivity (CHS), skin DCs suffer a maturation process with modifications on their surface molecules. The aim of this work was to evaluate changes induced by two contact sensitizers, 2,4-dinitrofluorobenzene (DNFB) and nickel sul...
Contact sensitizer nickel sulfate activates the transcription factors NF-kB and...
Cruz, MT; Gonçalo, Margarida; Figueiredo, A; Carvalho, AP; Duarte, CBNuclear factor kappa B (NF-kB) and activating protein-1 (AP-1) transcription factors are ubiquitously expressed signaling molecules known to regulate the transcription of a large number of genes involved in immune responses, namely the inducible isoform of nitric oxide synthase (iNOS). In this study, we demonstrate that a fetal skin-derived dendritic cell line (FSDC) produces nitric oxide (NO) in response to th...
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