Arecoline activates latent transforming growth factor beta 1 via mitochondrial reactive oxygen species in buccal fibroblasts: Suppression by epigallocatechin-3-gallate

作者：Hsieh Yu Ping; Wu King Jean; Chen Hsin Ming; Deng Yi Ting^*

来源：Journal of the Formosan Medical Association, 2018, 117(6): 527-534.

DOI：10.1016/j/jfma.2017.07.003

• Areca nut chewing
• EGCG
• Fibroblast
• TGF beta
• Oral submucous fibrosis

Background/Purpose: Oral submucous fibrosis (OSF) is a premalignant condition caused by the chewing of areca nut (AN). Transforming growth factor beta (TGF beta) plays a central role in the pathogenesis of OSF. Connective tissue growth factor (CTGF or CCN2) and early growth response-1 (Egr-1) are important mediators in the fibrotic response to TGFB in several fibrotic disorders including OSF. Arecoline, a major AN alkaloid, induced the synthesis of CCN2 and Egr-1 in human buccal mucosal fibroblast (BMFs). The aims of this study were to investigate whether arecoline-induced CCN2 and Egr-1 syntheses are mediated through TGF beta 1 signaling and to inspect the detailed mechanisms involved.
Methods: Western blot and TGF beta 1 E-max (R) ImmunoAssay were used to measure the effect of arecoline on the TGFB signaling pathways. 2',7'-dichlorodihydrofluorescein diacetate and MitoSOX (TM) Red were used to measure the effect of arecoline on the cellular and mitochondrial reactive oxygen species (ROS).
Results: Arecoline induced latent TGF beta 1 activation, Smad2 phosphorylation, and mitochondrial and total cellular ROS in BMFs. TGFB-neutralizing antibody completely inhibited the arecoline-induced synthesis of CCN2 and Egr-1. Mito-TEMPO, a mitochondria-targeted antioxidant, completely suppressed arecoline-induced latent TGF beta 1 activation and mitochondrial and total cellular ROS. Epigallocatechin-3-gallate (EGCG) dose-dependently inhibited arecoline-induced TGF beta 1 activation and mitochondrial ROS in BMFs.
Conclusion: Our results indicated that arecoline-induced mitochondria) ROS plays pivotal roles in the activation of latent TGF beta 1 leading to the initiation of TGF beta 1 signaling and subsequent increase in the synthesis of CCN2 and Egr-1. EGCG can be a useful agent in the chemoprevention and treatment of OSF.

• 出版日期2018-6