In Vivo and In Vitro Silica Induces Nuclear Factor Egr-1 Activation Mediated by ERK 1/2 in RAW264.7 Cell Line.
Toxicol Mech Methods
; 15(2): 93-9, 2005.
Article
em En
| MEDLINE
| ID: mdl-20021069
ABSTRACT
The transcription factor early growth response gene (Egr-1) is a stress response gene activated by various forms of stress. The effect of silica on transcription and expression of Egr-1 was investigated in rat lung and in RAW264.7 cells. Silica induced the expression of Egr-1 in vivo and was mainly located in alveolar macrophage cells and lung epithelial cells. Furthermore, silica induced Egr-1 mRNA and protein expression in cultured RAW264.7 cells. Immunofluorescence microscopy revealed translocation of Egr-1 to the nucleus in response to silica. The contribution of the extracellular signal-regulated kinase (ERK) pathway to the activation of Egr-1 in response to silica was examined. Exposure to silica resulted in a rapid phosphorylation of ERK 1/2 kinases in RAW264.7 cells. MAP Kinase Kinase (MEK) inhibitor U0126 prevented Egr-1 induction by silica. The results suggest that silica could induce Egr-1 activation in macrophages in vivo and in vitro and that phosphorylated ERK 1/2 may be involved in this action.
Texto completo:
1
Bases de dados:
MEDLINE
Idioma:
En
Revista:
Toxicol Mech Methods
Assunto da revista:
TOXICOLOGIA
Ano de publicação:
2005
Tipo de documento:
Article
País de afiliação:
China