Methods: We immunohistochemically examined the expression of CTGF protein in 20 cases of OSF and treated human buccal fibroblast (HBF) with arecoline, a main alkaloid found in areca nut.
Results: We found positive CTGF staining in fibroblasts and endothelial cells in all OSF cases. Western blot analysis showed that arecoline stimulated CTGF synthesis in a dose- and time- dependent manner in buccal fibroblasts. Pretreatment with NF-kB inhibitor Bay 11-7082, JNK inhibitor SP600125, p38 MAPK inhibitor SB203580 and antioxidant N-acetyl-L-cysteine, but not ERK inhibitor PD98059, significantly reduced arecoline induced CTGF synthesis.
Conclusions:Our study demonstrates, for the first time to our knowledge, that arecoline stimulated CTGF production in HBFs and immunohistochemical staining showed the presence of CTGF in fibroblasts and endothelial cells of OSF tissues. Arecoline induced CTGF synthesis was mediated by reactive oxygen species (ROS), NF-kB, JNK, P38 MAPK pathways. Constitutive overexpression of CTGF during AN chewing may enhance the fibrotic activity in OSF and play a role in the pathogenesis of OSF.