Background: Early growth response-1 (Egr-1) protein plays an important role in many human fibrotic diseases. Areca nut chewing is the most important risk factor of oral submucous fibrosis (OSF).
Methods: Egr-1 protein expression in OSF was examined using antibody to Egr-1. Arecoline-induced Egr-1 expression and its signaling pathways were assessed by Western blot analyses in human buccal mucosal fibroblasts (BMFs).
Results: Elevated Egr-1 staining was observed in epithelial cells, fibroblast, and inflammatory cells in 7 of 10 OSF cases. Arecoline, a main alkaloid found in the areca nut, stimulated Egr-1 synthesis in BMFs. Pretreatment with antioxidant N-acetyl-L-cysteine, c-Jun NH2-terminal kinase inhibitor SP600125, and extracellular signal-regulated kinase inhibitor PD98059 significantly reduced arecoline-induced Egr-1 synthesis. Epigallocatechin-3-gallate (EGCG) inhibited arecoline-induced Egr-1 synthesis and collagen gel contraction in a dose-responsive manner.
Conclusion: Constitutive Egr-1 expression during areca nut chewing may play a role in the pathogenesis of OSF. EGCG could be a good candidate for prevention or treatment of OSF.
Keywords: arecoline; early growth response-1 (Egr-1); epigallocatechin-3-gallate (EGCG); fibroblast; oral submucous fibrosis.
© 2014 Wiley Periodicals, Inc.