[Sudy on the activation of early growth response factor-1 by silica dioxide and its signal pathway]

Abstract

Objective: To discuss the role of early growth response factor (Egr)-1 and it's upstream signaling pathway in the development of silicosis.

Methods: The expression and localization of Egr-1 were analyzed by immunofluorescence and in-situ hybridization. The activity of Egr-1 was observed in treated cells by using a reporter plasmid and EMSA, the activity of ERK1/2 in RAW264.7 incubated with SiO(2) by using a kinase assay, and further by using a kinase inhibitor assay to investigate the role of upstream kinase in the signal pathway of the activation of Egr-1.

Results: The obvious increase of expression and transcription of Egr-1 was observed shortly after being treated by silica and its activity increased abruptly. There was an increase of the activity of ERK1/2 in RAW264.7 cells treated, which reached a peak at 30 minutes. The expression and transcription of Egr-1 decreased maniferstly after using kinase inhibitors.

Conclusion: Egr-1 expression can be induced by silica dioxide in RAW264.7 cells, and the ERK1/2, p38 kinases may take part in this process which suggest the pathway of SiO(2), ERK1/2, p38 and Egr-1 may play an important role in the development of silicosis.