title: Levels of matrix metalloproteinase-9 and its inhibitor in guinea pig asthma model following ovalbumin challenge.
abstract: Our objective was to investigate the role of matrix metalloproteinase-9 (MMP-9) and tissue inhibitor of matrix metalloproteinase-1 (TIMP-1) and their cellular sources in guinea pig asthma model following ovalbumin (OA) challenge. Twenty guinea pigs were divided into 2 groups: OA-challenged group were sensitized by intraperitoneal injection with OA and exposed to OA while the control group used saline in a similar manner. The positive level index (PLI), defined as the percentage of positive-stained cells x average optical density, was used to assess the expressing levels of MMP-9 and TIMP-1. The levels of MMP-9 from OA-challenged group were significantly higher than those of controls. However, no significant difference of the TIMP-1 levels between the OA-challenged group and controls were found. MMP-9 was expressed strongly in both inflammatory and structural cells while TIMP-1 was expressed weakly in inflammatory cells and structural cells. Our results implied that MMP-9 may contribute to tissue remodeling in asthma and both structural and inflammatory cells within lung tissue are the main cellular sources of MMP-9. Excessive expression of MMP-9 in the early or acute stage of asthma may be associated with the initiation of bronchial injury and inflammatory cells accumulation.
authors.affiliation: The Children's Hospital of Zhejiang University School of Medicine, Hangzhou, China.
authors.forename: Lan Fang
authors.initials: LF
authors.lastname: Tang
authors.forename: Li Zhong
authors.initials: LZ
authors.lastname: Du
authors.forename: Chao Chun
authors.initials: CC
authors.lastname: Zou
authors.forename: Wei Zhong
authors.initials: WZ
authors.lastname: Gu
mesh_terms: D000818:Animals; D001249:Asthma / Q000139:chemically induced / Q000276:immunology / Q000378:metabolism*; D004195:Disease Models, Animal; D005260:Female; D006168:Guinea Pigs; D007150:Immunohistochemistry; D008168:Lung / Q000276:immunology / Q000378:metabolism*; D008214:Lymphocytes / Q000378:metabolism; D008264:Macrophages / Q000378:metabolism; D008297:Male; D020780:Matrix Metalloproteinase 9 / Q000096:biosynthesis*; D010047:Ovalbumin / Q000276:immunology; D019715:Tissue Inhibitor of Metalloproteinase-1 / Q000096:biosynthesis*
chemical_list: D019715:Tissue Inhibitor of Metalloproteinase-1; D010047:Ovalbumin; D020780:Matrix Metalloproteinase 9