Objective To examine the effects of TGF-β1 on epithelial-myofibroblast transition ( EMT) of A549 cells and its relationship with extracellular regulating kinase1/2 ( ERK1/2) signaling system. Methods Cultured A549 cells were divided into one negative control group and four groups incubated with TGF-β1 for 48 hours at different concentration ( 0.05, 0. 5, 5, 10 μg/L, respectively) . The protein expressions of E-cadherin, α-smooth muscle actin ( α-SMA) , vimentin and fibronectin were assessed by indirect immunofluorescence and Western blot. In the other experiment, cultured A549 cells were incubated with TGF-β1 for different time. The protein and mRNA expressions of E-cadherin and α-SMA were assessed by Western blot and RT-PCR. The protein expressions of vimentin, fibronectin, ERK1 /2, and p-ERK1 /2 were detected by Western blot. Results By indirect immunofluorescence, Western blot, and RT-PCR analysis, E-cadherin expression significantly decreased and α-SMA expression significantly increased in A549 cells treated with TGF-β1 compared with negative controls in a time- and concentrationdependent manner ( Plt;0.05 ) . Vimentin and fibronectin protein expressions significantly increased simultaneously ( Plt;0.05) . The concentration of 5 ng/mL of TGF-β1 was most effective. The ratio of p-ERK1 /2 and ERK1/2 was significantly increased in the TGF-β1 treated cells in a time-dependent manner ( P lt;0. 05) . Conclusions TGF-β1 can induced EMT in A549 cells in vitro in a time- and concentrationdependant manner. This effect may involve in upregulation of ERK1/2 signaling system.
Objective To investigate the lung involvement in Chinese patients with systemic sclerosis ( SSc) and its functional impact. Methods 68 patients with SSc were enrolled in Scleroderma study of PUMCH ( Peking Union Medical College Hospital) . All the patients underwent high resolution computed tomography ( HRCT) , pulmonary function testing, 6-minute walk testing, and echocardiography. And 36 patients filled in the Saint George’s Respiratory Questionnaire ( SGRQ) for assessment of healthrelated quality of life. Results HRCT revealed interstitial lung disease ( ILD) in 52 ( 76. 5% ) patients, 20 out of them without respiratory symptoms. Reticular opacification, ground-glass opacity ( GGO) , traction bronchiectasis, and honeycomb were presented respectively in 80.8% , 73.1% , 59.6% , and 30.8% of patients with SSc-ILD. Fibrosis was the predominant HRCT finding, and pure GGO ( in the absence of reticulation or architectural distortion) was only present in 8 ( 15. 7% ) patients. 57 (83.8% ) patients presented with diffusion defect, with most of them having moderate to severe impairent. Reduced FVC or TLC presented in 20 ( 29.4% ) and 28 ( 41.2% ) of patients respectively. The significant correlation was observed between the DLCO and the extent of ILD on HRCT ( rs = -0.476, P =0.000) . DLCO showed significant correlations with all the four components of the SGRQ ( Plt;0.05) . Significant correlations were also observed among the SGRQ scores and SpO2 ( maximum desaturation) or Borg index. Stepwise multiple regression analysis confirmed that the DLCO, SpO2 , and Borg index contributed to the SGRQ. Conclusions Lung involvement in Chinese SSc patients is common and insidious. The HRCT features of SSc-ILD are predominant fibrosis plus GGO, indicating little reversibility. Thus HRCT should be performed routinely in newly diagnosed SSc patients for early screening of lung involvement. The lung function defect of SSc is characterized by reduced diffusing capacity, and DLCO show better correlations with HRCT abnormities or SGRQ than FVC or TLC. Thus DLCO is of great value for early detection or severity assessment of SSc-ILD. SGRQ can be used to examine the health related quality of life of SSc patients and may reflect severity of lung involvement.