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Melanin in Fonsecaea pedrosoi: a trap for oxidative radicals
BACKGROUND: The pathogenic fungus Fonsecaea pedrosoi constitutively produces the pigment melanin, an important virulence factor in fungi. Melanin is incorporated in the cell wall structure and provides chemical and physical protection for the fungus. We evaluated the production of nitric oxide (NO)...
Autores principales: | , , , , , , , |
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Formato: | Texto |
Lenguaje: | English |
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BioMed Central
2010
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Acceso en línea: | https://www.ncbi.nlm.nih.gov/pmc/articles/PMC2845570/ https://www.ncbi.nlm.nih.gov/pubmed/20233438 http://dx.doi.org/10.1186/1471-2180-10-80 |
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author | Cunha, Marcel ML Franzen, Anderson J Seabra, Sergio H Herbst, Marcelo H Vugman, Ney V Borba, Luana P de Souza, Wanderley Rozental, Sonia |
author_facet | Cunha, Marcel ML Franzen, Anderson J Seabra, Sergio H Herbst, Marcelo H Vugman, Ney V Borba, Luana P de Souza, Wanderley Rozental, Sonia |
author_sort | Cunha, Marcel ML |
collection | PubMed |
description | BACKGROUND: The pathogenic fungus Fonsecaea pedrosoi constitutively produces the pigment melanin, an important virulence factor in fungi. Melanin is incorporated in the cell wall structure and provides chemical and physical protection for the fungus. We evaluated the production of nitric oxide (NO) in macrophages, the oxidative burst and the inducible nitric oxide synthase (i-NOS) activity in interactions between activated murine macrophages and F. pedrosoi. Experiments were carried out with or without tricyclazole (TC) treatment, a selective inhibitor of the dihydroxynaphthalene (DHN)-melanin biosynthesis pathway in F. pedrosoi. The paramagnetisms of melanin and the TC-melanin were analysed by electron spin resonance. The fungal growth responses to H(2)O(2 )and to S-nitroso-N-acetylpenicillamine (SNAP), a nitric oxide donor, were also evaluated. RESULTS: Melanised F. pedrosoi cells were more resistant to both H(2)O(2 )and NO. Nitrite was not detected in the supernatant of macrophages incubated with melanised fungal cells. However, i-NOS expression was unaffected by the presence of either untreated control F. pedrosoi or TC-treated F. pedrosoi. In addition, the inhibition of the DHN-melanin pathway by TC improved the oxidative burst capability of the macrophages. CONCLUSION: The NO-trapping ability of F. pedrosoi melanin is an important mechanism to escape the oxidative burst of macrophages. |
format | Text |
id | pubmed-2845570 |
institution | National Center for Biotechnology Information |
language | English |
publishDate | 2010 |
publisher | BioMed Central |
record_format | MEDLINE/PubMed |
spelling | pubmed-28455702010-03-26 Melanin in Fonsecaea pedrosoi: a trap for oxidative radicals Cunha, Marcel ML Franzen, Anderson J Seabra, Sergio H Herbst, Marcelo H Vugman, Ney V Borba, Luana P de Souza, Wanderley Rozental, Sonia BMC Microbiol Research article BACKGROUND: The pathogenic fungus Fonsecaea pedrosoi constitutively produces the pigment melanin, an important virulence factor in fungi. Melanin is incorporated in the cell wall structure and provides chemical and physical protection for the fungus. We evaluated the production of nitric oxide (NO) in macrophages, the oxidative burst and the inducible nitric oxide synthase (i-NOS) activity in interactions between activated murine macrophages and F. pedrosoi. Experiments were carried out with or without tricyclazole (TC) treatment, a selective inhibitor of the dihydroxynaphthalene (DHN)-melanin biosynthesis pathway in F. pedrosoi. The paramagnetisms of melanin and the TC-melanin were analysed by electron spin resonance. The fungal growth responses to H(2)O(2 )and to S-nitroso-N-acetylpenicillamine (SNAP), a nitric oxide donor, were also evaluated. RESULTS: Melanised F. pedrosoi cells were more resistant to both H(2)O(2 )and NO. Nitrite was not detected in the supernatant of macrophages incubated with melanised fungal cells. However, i-NOS expression was unaffected by the presence of either untreated control F. pedrosoi or TC-treated F. pedrosoi. In addition, the inhibition of the DHN-melanin pathway by TC improved the oxidative burst capability of the macrophages. CONCLUSION: The NO-trapping ability of F. pedrosoi melanin is an important mechanism to escape the oxidative burst of macrophages. BioMed Central 2010-03-16 /pmc/articles/PMC2845570/ /pubmed/20233438 http://dx.doi.org/10.1186/1471-2180-10-80 Text en Copyright ©2010 Cunha et al; licensee BioMed Central Ltd. http://creativecommons.org/licenses/by/2.0 This is an Open Access article distributed under the terms of the Creative Commons Attribution License (http://creativecommons.org/licenses/by/2.0), which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited. |
spellingShingle | Research article Cunha, Marcel ML Franzen, Anderson J Seabra, Sergio H Herbst, Marcelo H Vugman, Ney V Borba, Luana P de Souza, Wanderley Rozental, Sonia Melanin in Fonsecaea pedrosoi: a trap for oxidative radicals |
title | Melanin in Fonsecaea pedrosoi: a trap for oxidative radicals |
title_full | Melanin in Fonsecaea pedrosoi: a trap for oxidative radicals |
title_fullStr | Melanin in Fonsecaea pedrosoi: a trap for oxidative radicals |
title_full_unstemmed | Melanin in Fonsecaea pedrosoi: a trap for oxidative radicals |
title_short | Melanin in Fonsecaea pedrosoi: a trap for oxidative radicals |
title_sort | melanin in fonsecaea pedrosoi: a trap for oxidative radicals |
topic | Research article |
url | https://www.ncbi.nlm.nih.gov/pmc/articles/PMC2845570/ https://www.ncbi.nlm.nih.gov/pubmed/20233438 http://dx.doi.org/10.1186/1471-2180-10-80 |
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