Browsing by Author "Francisco, V"
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- Differential modulation of CXCR4 and CD40 protein levels by skin sensitizers and irritants in the FSDC cell linePublication . 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 irritants, through analysis of their effects on CD40 and CXCR4 protein expression. The chemicals concentrations were chosen based on a slight cytotoxicity effect (up to 15%). Protein levels were evaluated by Western blot and immunocytochemistry, after stimulation with the skin sensitizers 2,4-dinitrofluorobenzene (DNFB), 1,4-phenylenediamine (PPD) and nickel sulphate (NiSO(4)), the non-sensitizer 2,4-dichloronitrobenzene (DCNB), and the irritants sodium dodecyl sulphate (SDS) and benzalkonium chloride (BC). All sensitizers tested increased CD40 and CXCR4 levels. In contrast, irritants decreased both proteins levels, with a more pronounced effect on CXCR4. In agreement with these results, dendritic cells derived from human peripheral blood monocytes-derived dendritic cells (MoDC) showed a similar response pattern to the skin sensitizer and irritant tested, PPD and SDS, respectively. In conclusion, evaluation of CD40 and CXCR4 proteins in chemical-treated FSDC may represent a useful tool in a future in vitro test for sensitizing assessment
- Effect of lipopolysaccharide, skin sensitizers and irritants on thioredoxin-1 expression in dendritic cells: relevance of different signalling pathwaysPublication . 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 thioredoxin-1 expression, which is only transient for irritants, being the strongest effect observed for LPS (63 +/- 15%). To address the involvement of thioredoxin-1 in DC maturation, we analysed the effect of an activator of thioredoxin-1 expression, hydrogen peroxide, on CD86 expression, a marker of DC maturation. We found that hydrogen peroxide increases thioredoxin-1 and CD86 expression reinforcing thioredoxin-1 involvement in DC maturation. Because mitogen-activated protein kinases and PI3K are activated upon DC maturation, we also analysed their involvement in thioredoxin-1 modulation. We verified that LPS-induced upregulation of thioredoxin-1 expression was dependent on PI3K pathway.
- Multicentric Genome-Wide Association Study for Primary Spontaneous PneumothoraxPublication . Sousa, I; Abrantes, P; Francisco, V; Teixeira, G; Monteiro, M; Neves, J; Norte, A; Robalo-Cordeiro, C; Moura E Sá, J; Reis, E; Santos, P; Oliveira, M; Sousa, S; Fradinho, M; Malheiro, F; Negrão, L; Feijó, S; Oliveira, SADespite elevated incidence and recurrence rates for Primary Spontaneous Pneumothorax (PSP), little is known about its etiology, and the genetics of idiopathic PSP remains unexplored. To identify genetic variants contributing to sporadic PSP risk, we conducted the first PSP genome-wide association study. Two replicate pools of 92 Portuguese PSP cases and of 129 age- and sex-matched controls were allelotyped in triplicate on the Affymetrix Human SNP Array 6.0 arrays. Markers passing quality control were ranked by relative allele score difference between cases and controls (|RASdiff|), by a novel cluster method and by a combined Z-test. 101 single nucleotide polymorphisms (SNPs) were selected using these three approaches for technical validation by individual genotyping in the discovery dataset. 87 out of 94 successfully tested SNPs were nominally associated in the discovery dataset. Replication of the 87 technically validated SNPs was then carried out in an independent replication dataset of 100 Portuguese cases and 425 controls. The intergenic rs4733649 SNP in chromosome 8 (between LINC00824 and LINC00977) was associated with PSP in the discovery (P = 4.07E-03, ORC[95% CI] = 1.88[1.22-2.89]), replication (P = 1.50E-02, ORC[95% CI] = 1.50[1.08-2.09]) and combined datasets (P = 8.61E-05, ORC[95% CI] = 1.65[1.29-2.13]). This study identified for the first time one genetic risk factor for sporadic PSP, but future studies are warranted to further confirm this finding in other populations and uncover its functional role in PSP pathogenesis.