| Texto completo | |
| Autor(es): Mostrar menos - |
Oliveira, Karla A.
;
Torquato, Ricardo J. S.
;
Garcia Lustosa, Daniela C. G.
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Ribeiro, Tales
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Nascimento, Bruno W. L.
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de Oliveira, Lilian C. G.
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Juliano, Maria A.
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Paschoalin, Thaysa
;
Lemos, Virginia S.
;
Araujo, Ricardo N.
;
Pereira, Marcos H.
;
Tanaka, Aparecida S.
Número total de Autores: 12
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| Tipo de documento: | Artigo Científico |
| Fonte: | Journal of Venomous Animals and Toxins including Tropical Diseases; v. 27, p. 12-pg., 2021-03-08. |
| Resumo | |
Background: Triatoma infestans (Hemiptera: Reduviidae) is a hematophagous insect and the main vector of Trypanosoma cruzi (Kinetoplastida: Trypanosomatidae). In the present study, the authors investigated whether a serine protease activity from the saliva of T. infestans has a role in vasomotor modulation, and in the insect-blood feeding by cleaving and activating protease-activated receptors (PARs). Methods: T. infestans saliva was chromatographed as previously reported for purification of triapsin, a serine protease. The cleavage activity of triapsin on PAR peptides was investigated based on FRET technology. Mass spectrometry was used to analyze the sites of PAR-2 peptide cleaved by triapsin. NO measurements were performed using the DAN assay (2,3-diaminonapthalene). The vasorelaxant activity of triapsin was measured in vessels with or without functional endothelium pre-contracted with phenylephrine (3 mu M). Intravital microscopy was used to assess the effect of triapsin on mouse skin microcirculation. Results: Triapsin was able to induce hydrolysis of PAR peptides and showed a higher preference for cleavage of the PAR-2 peptide. Analysis by mass spectrometry confirmed a single cleavage site, which corresponds to the activation site of the PAR-2 receptor. Triapsin induced dose-dependent NO release in cultured human umbilical vein endothelial cells (HUVECs), reaching a maximum effect at 17.58 nM. Triapsin purified by gel-filtration chromatography (10(-16) to 10(-9) M) was applied cumulatively to mouse mesenteric artery rings and showed a potent endothelium-dependent vasodilator effect (EC30 = 10(-12) M). Nitric oxide seems to be partially responsible for this vasodilator effect because L-NAME (L-NG-nitroarginine methyl ester 300 mu M), a nitric oxide synthetase inhibitor, did not abrogate the vasodilation activated by triapsin. Anti-PAR-2 antibody completely inhibited vasodilation observed in the presence of triapsin activity. Triapsin activity also induced an increase in the mouse ear venular diameter. Conclusion: Data from this study suggest a plausible association between triapsin activity mediated PAR-2 activation and vasodilation caused by T. infestans saliva. (AU) | |
| Processo FAPESP: | 12/03657-8 - Inibidores e proteases de ectoparasitas: relação de estrutura-função e identificação do papel dessas moléculas na interação de vetores de doenças e seus agentes etiológicos |
| Beneficiário: | Aparecida Sadae Tanaka |
| Modalidade de apoio: | Auxílio à Pesquisa - Temático |