Characterization of calcineurin in human neutrophils: inhibitory effect of hydrogen peroxide on its enzyme activity and on NF-κB DNA binding
| Autor: | Carballo Álvarez, Modesto, Márquez, Gracia, Conde, Manuel, Martín-Nieto, José, Monteseirín Mateo, Javier, Conde Hernández, José, Pintado Sanjuan, Elizabeth, Sobrino Beneyto, Francisco |
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| Přispěvatelé: | Universidad de Alicante. Departamento de Fisiología, Genética y Microbiología, Universidad de Sevilla. Departamento de Bioquímica Médica y Biología Molecular, Hospital Universitario Virgen Macarena. Servicio Regional de Inmunología y Alergia, Genética Humana y de Mamíferos |
| Jazyk: | angličtina |
| Rok vydání: | 1998 |
| Předmět: | |
| Zdroj: | RUA. Repositorio Institucional de la Universidad de Alicante Universidad de Alicante (UA) |
| Popis: | We describe here a specific calcineurin activity in neutrophil lysates, which is dependent on Ca2+, inhibited by trifluoroperazine, and insensitive to okadaic acid. Immunoblotting experiments using a specific antiserum recognized both the A and B chains of calcineurin. Neutrophils treated with cyclosporin A or FK 506 showed a dose-dependent inhibition of calcineurin activity. The effect of oxidant compounds on calcineurin activity was also investigated. Neutrophils treated with hydrogen peroxide (H2O2), where catalase was inhibited with aminotriazole, exhibited a specific inhibition of calcineurin activity. However, the addition of reducing agents to neutrophil extracts partially reversed the inhibition caused by H2O2. A similar inhibitory effect of H2O2 on calcineurin activity was observed to occur in isolated lymphocytes. This is the first demonstration that redox agents modulate calcineurin activity in a cellular system. In addition, electrophoretic mobility shift assays revealed that lipopolysaccharide-induced activation of NF-κB in human neutrophils is inhibited by cell pretreatment with H2O2 in a dose-dependent manner. These data indicate that calcineurin activity regulates the functional activity of lipopolysaccharide-induced NF-κB/Rel proteins in human neutrophils. These data indicate a role of peroxides in the modulation of calcineurin activity and that the H2O2-dependent NF-κB inactivation in neutrophils occurs in concert with inhibition of calcineurin. This work was supported in part by Fondo Investigaciones Sanitarias Grants 94/1484 and 97/1289 (to F. S.) and Grant 97/207 (to J. C.) and the Fundation of SEAIC of Spain. |
| Databáze: | OpenAIRE |
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