Poster (Painel)
| 1876-1 | OLE1 AND FAS2 INTERFERES WITH GLUCOSYLCERAMIDE SYNTHESIS AND EXTRACELLULAR VESICLE PRODUCTION IN CANDIDA PARAPSILOSIS. | | Autores: | TAVARES, P.M. (UFRJ - UNIVERSIDADE FEDERAL DO RIO DE JANEIRO) ; CESAR, G.V. (UFRJ - UNIVERSIDADE FEDERAL DO RIO DE JANEIRO) ; BRILHANTE, T.T. (UFRJ - UNIVERSIDADE FEDERAL DO RIO DE JANEIRO) ; NGUYEN, L.N. (AECOM - ALBERT EINSTEIN COLLEGE OF MEDICINE) ; GAZOS LOPES, F. (UTEP - UNIVERSITY OF TEXAS AT EL PASO) ; NOSANCHUK, J.D. (AECOM - ALBERT EINSTEIN COLLEGE OF MEDICINE) ; ALMEIDA, I.C. (UTEP - UNIVERSITY OF TEXAS AT EL PASO) ; NIMRICHTER, L. (UFRJ - UNIVERSIDADE FEDERAL DO RIO DE JANEIRO) |
Resumo The incidence of opportunistic invasive mycoses caused by non-albicans species of Candida has increased proportionally with the population of immunocompromised individuals. Among these species Candida parapsilosis, has emerged as a major nosocomial pathogen. Recent data supports that fatty acid metabolism impacts growth and virulence of this pathogen, although this relationship is poorly understood. In the de novo pathway, yeasts produce and regulate saturated and unsaturated fatty acids species that are required for the generation and maintenance of cell membranes. The same fatty acids are also used as building blocks for glycosphingolipid (GSL) biosynthesis. Glucosylceramide (GlcCer), the main neutral GSL produced by most fungal pathogens, is involved with fungal physiological processes. Recent studies suggest that GlcCer is a major determinant of virulence in Candida albicans and a virulence regulator in Cryptococcus neoformans. GlcCer is also a component of extracellular vesicles (EV) produced by fungal pathogens. In the present study, we utilized C. parapsilosis wild-type (WT), fatty acid desaturase (OLE1) and fatty acid synthase (FAS2) gene deletion mutants to unravel the relationship between fatty acid biosynthesis pathway, GlcCer synthesis and extracellular vesicle production in C. parapsilosis. First, we evaluated the influence of fatty acid biosynthesis during GlcCer biosynthesis. Lipids from WT, OLE1 and FAS2 mutants were extracted with organic solvents and then resolved by Folch’s partition. The GlcCer content was then quantified by densitometry after resolution by thin layer chromatography (TLC). The major species were analyzed through mass spectrometry. We also evaluated the production of EV in the culture supernatant of these strains by dynamic light scattering (DLS) analysis. Our results indicate that GlcCer content is reduced only in Ole1 mutant. In all species investigated GlcCer structure was the same. EV were produced by all strains but their content was decreased in Ole1 supernatant. DLS analysis showed that vesicles from mutants are significant larger than that found in WT strain. These results indicate that lipid biosynthesis could be investigated as alternatives pathways to impair fungal infections.
CNPQ, CAPES, FAPERJ. |