Dynamic Changes And Effects Of IL-31 In Lung Tissues Of Experimental Mice With Pulmonary Fibrosis

Objective To investigate the IL-31 protein expressions in lung tissues of experimental mice with pulmonary fibrosis(PF) induced by bleomycin in various periods and to study the effects of IL-31 in pulmonary fibrosis.Methods Forty eight male mice were randomly divided into two groups:control group(n = 24) and experimental group(n = 24),and poured respectively by 0.9%NaCl saline and bleomycin solutions(5 mg/kg).6 mice of each group were sacrificed on the 7th,14th,21th,28th day and the lung tissues were harvested respectively.The alkaline hydrolysis method was used to test the content of hydroxyproline. Real-time PCR examined the expression of IL-31 mRNA.Western Blotting method was used to analyse the protein expression of IL-31.Results1.The content of hydroxyproline in lung tissues in experimental group were higher than those in control group on the 14th,21th,28th day(P＜0.05).2.The protein and mRNA expression of IL-31 in lung tissues in experimental group were higher than those in control group(P＜0.05).3.The expression of IL-31 mRNA in lung tissues in experimental group were higher than control group from the 7th day,peaked on the 21th day,and lower on the 28th day.4.The protein expression of IL-31 in lung tissues in experimental group were higher than control group from the 7th day,peaked on the 21th day,and lower on the 28th day.Conclusion The expression of IL-31 were high at different stages of pulmonary fibrosis.It played an important role especially at the middle and late stages in pulmonary fibrosis.