Study Of JNK And Smad Signal Pathways Interaction In Pulmonary Fibrosis In Mice And The Influence On The Expression Of TypeⅠCollagen

Objective:The preparation of the wild type of male health using C57BL/6 mice,use the bleomycin-induced pulmonary fibrosis as a model system to investigate the relationship between JNK and Smad signaling pathway and their effect on the expression of type Ιcollagen.Methods:Ninety-six healthy wild male C57BL/6 mice were randomly divided into four groups,the normal group(N group,n=24),the model group(M group,n=24),the p-Smad3 blocking group(SB group,n=24)and the JNK blocker group(SP group,n=24).M group,SB group and SP group were endotracheal driped by bleomycin(3.5mg/Kg) to pulmonary fibrosis model and then given corresponding drugs,while the N group is given isodose physiological saline.Eight mice in each group were randomly killed on the 7th,14 th,28th.We observed the degree of alveolitis and pulmonary fibrosis by the mice lung tissue pathological in HE staining and Masson staining,detect lung tissue hydroxyproline(Hyp)conte-nt by alkaline hydrolysis method and compare each group’s lung tissue of type I collagen,p-JNK and p-Smad protein content by immunohistochemical determination.Results:The degree of pulmonary alveolitis of M group is obvious on the 7thday after modeling and the fibrosis is reduced significantly on the 28 th.day.The Hyp increasegradually and reached the maximum level on the 28 thday.The pulmonary alveolitis and fibrosis of lung tissue in SB,SP and N group are in a relatively low degree,compare with M group.The Hyp ration of these groups are on a slightly lower level;the expression of type I collage,p-JNK and p-Smad protein are reduced(P<0.05).Conclusions:Pulmonary fibrosis are closely associated with JNK and Smad pathway,JNK and Smad signaling pathway play an important role in TGF-β1 induced excessive accumulation of ECM.The activation of JNK may increase the phosphorylation of Smad3 protein,and the activation of Smad pathway can also be activated to strengthen JNK.This two interrelated pathways will provide new ideas for the step in the treatment of pulmonary fibrosis.