Expression and effect of osteopontin on the pulmonary fibrosis after acute lung injury induced by lipopolysaccharide in rats

doi:10.3969/j.issn.1002-1949.2014.12.018

Abstract：Objective To observe the expression and effect of osteopontin ( OPN) on the pulmonary fibrosis after acute lung injury ( ALI) induced by lipopolysaccharide ( LPS) in rats.Methods One hundred and twenty SD rats were randomly divided into control group , model group and treatment group, with 40 rats in each group .Rats were injected with normal saline in control group , LPS solution in model group and treatment group .Five minutes later , rats in treatment group were injected with anti -OPN antibody , while rats in control group and model group were injected with normal saline in the same way.Ten rats in each group were sacrificed at the 24 th,7 th,14 th and 28 th day, respectively.Alveolitis and pulmonary fibrosis were assessed by HE and Masson staining .The expression of TGF -β1 was measured by immunohistochemistry .OPN protein levels ,hydroxyproline content , typeⅠandⅢcollagen mRNA were determined .Results The changes of pulmonary fibrosis first appeared in model group at 24 h, but it was most obvious at the 28th day.Compared with control group , the degree of pulmonary fibrosis,the expression of TGF -β1 , OPN levels, hydroxyproline content and type Ⅰ and Ⅲ collagen mRNA were increased significantly in model group at the same time point , while all of these changes were attenuated significantly in treatment group compared with model group . Conclusion The expression of OPN in lung tissue was increased significantly in the pulmonary fibrosis after ALI induced by LPS.OPN can aggravate the degree of pulmonary fibrosis caused by ALI , which might be related to promote the expression of TGF-β1 and type ⅠandⅢcollagen .