Dynamic Changes of IL-28B Expression in Lung Tissues of Mice with Experimental Pulmonary Fibrosis

Objective:To determine the expressions of interleukin(IL)-28B in lung tissues of mice with pulmonary fibrosis (PF) induced by bleomycin and the effect of the cytokine on PF thereof. Methods:Forty eight male mice were randomly divided into two groups : experimental group( n = 24) and control group ( n = 24) . The mice were treated with bleomycin solutions(5 mg/ kg) and saline(0.06-0.07 mL)by intratracheal instillation respectively. On day 7, 14, 21 and 28 after administration, 6 mice of each group were sacrificed and the lung tissues were harvested. The pulmonary inflammation and fibrosis were observed by pathological method in mice of different groups. Hydroxyproline concentrations were examined. The method of Western blot was adopted to detect the protein expression of IL-28B in lung tissue of mice. Results:In experimental group, dynamic changes from alveolitis to pulmonary fibrosis could be observed in the slices by pathological method. Hydroxyproline concentrations were higher in experimental group than those in control group on day 14,21 and 28. The protein expressions of IL-28B were higher in lung tissues of experimental group than those in control group during early periods (P 0.05), and peaked on the 14th day. On the 28th day its level was similar in experimental group to that of the control group. Conclusion:IL-28B protein may contribute to the pathogenesis of pulmonary fibrosis. Detection of IL-28B is helpful to early diagnosis of pulmonary fibrosis.