Role of Reactive Oxygen Species in Transforming Growth Factor - beta1 - inuduced Fibronectin Secretion and alpha - Smooth Muscle Actin Expression in Human Lung Fibroblasts.
10.4046/trd.2005.58.3.267
- Author:
Hunjoo HA
1
;
Mi Ra YU
;
Soo Taek UH
;
Choon Sik PARK
;
Hi Bahl LEE
Author Information
1. Hyonam Kidney Laboratory, Soon Chun Hyang University, Korea. hblee@hkl.ac.kr
- Publication Type:Original Article
- Keywords:
Pulmonary fibrosis;
Transforming growth factor-beta1;
Reactive oxygen species;
alpha-Smooth muscle actin;
Fibroblast;
Myofibroblast;
Fibronectin;
N-acetylcysteine;
Diphenyleneiodonium
- MeSH:
Acetylcysteine;
Actins*;
Blotting, Western;
Extracellular Matrix;
Fibroblasts*;
Fibronectins*;
Fibrosis;
Humans*;
Lung*;
Muscle, Smooth*;
Myofibroblasts;
NADP;
Pulmonary Fibrosis;
Reactive Oxygen Species*;
Transforming Growth Factor beta1;
Transforming Growth Factors*;
Up-Regulation
- From:Tuberculosis and Respiratory Diseases
2005;58(3):267-275
- CountryRepublic of Korea
- Language:Korean
-
Abstract:
BACKGROUND: The transforming growth factor-beta1 (TGF-beta1) plays a key role in lung fibrosis. However, the mole?cular mechanisms involved in TGF-beta1-induced lung fibrosis are unclear. TGF-beta1 is the key inducer of myofibroblast transdifferentiation via de novo synthesis of alphasmooth muscle actin (alpha-SMA). Since TGF-beta1 signals through reactive oxygen species (ROS) and ROS have been shown to induce accumulation of extracellular matrix (ECM) in various tissues, this study examined if ROS play a role in TGF-beta1-induced fibronectin secretion and alpha-SMA expression in human lung fibroblasts, MRC-5 cells. METHODS: Growth arrested and synchronized MRC-5 cells were stimulated with TGF-beta1 (0.2-10 ng/ml) in the presence or absence of N-acetylcysteine (NAC) or diphenyleneiodonium (DPI) for up to 96 hours. Dichlorofluorescein (DCF)- sensitive cellular ROS were measured by FACScan and secreted fibronectin and cellular alpha-SMA by Western blot analysis. RESULTS: TGF-beta1 increased the level of fibronectin secretion and alpha-SMA expression in MRC-5 cells in a dose- dependent manner. Both NAC (20 and 30 mM) and DPI (1 and 5 microM significantly inhibited TGF-beta1-induced fibronectin and alpha-SMA upregulation. The TGF-beta1-induced cellular ROS level was also significantly reduced by NAC and DPI. CONCLUSIONS: The results suggest that NADPH oxidase-dependent ROS play an important role in TGF-beta1-induced fibronectin secretion and alpha-SMA expression in MRC-5 cells, which leads to myofibroblast transdifferentiation and progressive lung fibrosis.
