Asian Dust Particles Induce TGF-β1 via Reactive Oxygen Species in Bronchial Epithelial Cells

BACKGROUND Asian dust storms can be transported across eastern Asia. In vitro, Asian dust particle-induced inflammation and enhancement of the allergic reaction have been observed. However, the fibrotic effects of Asian dust particles are not clear. Production of transforming growth factor β(1) (TGF-β(1)) and fibronectin were investigated in the bronchial epithelial cells after exposure to Asian dust particulate matter (AD-PM10). METHODS During Asian dust storm periods, air samples were collected. The bronchial epithelial cells were exposed to AD-PM10 with and without the antioxidant, N-acetyl-L-cysteine (NAC). Then TGF-β(1) and fibronectin were detected by Western blotting. The reactive oxygen species (ROS) was detected by the measurement of dicholorodihydrofluorescin (DCF), using a FACScan, and visualized by a confocal microscopy. RESULTS The expression of TGF-β(1), fibronectin and ROS was high after being exposed to AD-PM10, compared to the control. NAC attenuated both TGF-β(1) and fibronectin expression in the AD-PM10-exposed the bronchial epithelial cells. CONCLUSION AD-PM10 may have fibrotic potential in the bronchial epithelial cells and the possible mechanism is AD-PM10-induced intracellular ROS.