Apoptotic and antiapoptotic signal expression in epithelial cells from patients with idiopathic pulmonary fibrosis

Abstract

Objective To investigate the changes and significance of cell apoptosis,P53,P21,Bax and Bcl-2 protein in epithelial cells from patients with idiopathic pulmonary fibrosis (IPF). Methods Cell apoptosis and the expressions of P53,P21,Bax and Bcl-2 protein in lung tissues from 12 patients with IPF (IPF group) and 10 normal controls (control group) were detected by TUNEL(terminal deoxynucleotide transferase-mediated deoxyuridine triphosphate-biotin nick end-labeling) and immunohistochemistry. Results Compared with that of control group,the percentage of apoptosis in alveolar epithelial cells and bronchial cells of IPF group was higher (all U = 0.0, all P＜0.01). The expressions of P53, P21, Bax protein in alveolar epithelial cells of IPF group were higher than those of control group( U = 5.0,25.5,27.0, all P＜0.05); and the expressions in bronchial cells of IPF group were also higher than those of control group( U =5.0,35.5,25.0,all P＜0.01). The expressions of Bcl-2 protein in alveolar epithelial cells and bronchial cells of IPF group were higher than those of control group( U = 12.0,18.0, all P＜0.01 ). There was a significant correlation between the percentage of apoptosis and P53, P21, Bax protein expression ( rs =0. 436-0. 806 ,all P＜0.01). The correlation of the percentage of apoptosis and Bcl-2 protein expression was also significant (rs=0. 715--0. 699,all P＜0.01). Conclusions The apoptosis percentage of epithelial cells and the expression of P53, P21, Bax protein are up-regulated in lung tissues of IPF, the expression of Bcl-2 protein is down-regulated,which may play an important role in the development of the disease. Key words: Pulmonary fibrosis; Apoptosis; Epithelial celIs; Protein P53