title: Possible dual role of decorin in abdominal aortic aneurysm.
abstract: Abdominal aortic aneurysm (AAA) is characterized by chronic inflammation, which leads to pathological remodeling of the extracellular matrix. Decorin, a small leucine-rich repeat proteoglycan, has been suggested to regulate inflammation and stabilize the extracellular matrix. Therefore, the present study investigated the role of decorin in the pathogenesis of AAA. Decorin was localized in the aortic adventitia under normal conditions in both mice and humans. AAA was induced in mice using CaCl2 treatment. Initially, decorin protein levels decreased, but as AAA progressed decorin levels increased in all layers. Local administration of exogenous decorin prevented the development of CaCl2-induced AAA. However, decorin was highly expressed in the degenerative lesions of human AAA walls, and this expression positively correlated with matrix metalloproteinase (MMP)-9 expression. In cell culture experiments, the addition of decorin inhibited secretion of MMP-9 in vascular smooth muscle cells, but had the opposite effect in macrophages. The results suggest that decorin plays a dual role in AAA. Adventitial decorin in normal aorta may protect against the development of AAA, but macrophages expressing decorin in AAA walls may facilitate the progression of AAA by up-regulating MMP-9 secretion.
authors.affiliation: Department of Surgery and Clinical Science, Yamaguchi University Graduate School of Medicine, Ube, 755-8505, Japan.
authors.forename: Koshiro
authors.initials: K
authors.lastname: Ueda
authors.affiliation: Department of Surgery and Clinical Science, Yamaguchi University Graduate School of Medicine, Ube, 755-8505, Japan; Graduate School of Health and Welfare, Yamaguchi Prefectural University, Yamaguchi, 753-8502, Japan.
authors.forename: Koichi
authors.initials: K
authors.lastname: Yoshimura
authors.affiliation: Department of Surgery and Clinical Science, Yamaguchi University Graduate School of Medicine, Ube, 755-8505, Japan.
authors.forename: Osamu
authors.initials: O
authors.lastname: Yamashita
authors.affiliation: Department of Surgery and Clinical Science, Yamaguchi University Graduate School of Medicine, Ube, 755-8505, Japan.
authors.forename: Takasuke
authors.initials: T
authors.lastname: Harada
authors.affiliation: Department of Surgery and Clinical Science, Yamaguchi University Graduate School of Medicine, Ube, 755-8505, Japan.
authors.forename: Noriyasu
authors.initials: N
authors.lastname: Morikage
authors.affiliation: Department of Surgery and Clinical Science, Yamaguchi University Graduate School of Medicine, Ube, 755-8505, Japan.
authors.forename: Kimikazu
authors.initials: K
authors.lastname: Hamano
mesh_terms: D063194:Adventitia / Q000378:metabolism / Q000473:pathology; D000818:Animals; D017544:Aortic Aneurysm, Abdominal / Q000139:chemically induced / Q000378:metabolism* / Q000473:pathology; D002122:Calcium Chloride / Q000633:toxicity; D005786:Gene Expression Regulation / Q000187:drug effects*; D006801:Humans; D008264:Macrophages / Q000378:metabolism* / Q000473:pathology; D008297:Male; D020780:Matrix Metalloproteinase 9 / Q000096:biosynthesis; D051379:Mice; D009131:Muscle, Smooth, Vascular / Q000378:metabolism* / Q000473:pathology; D032389:Myocytes, Smooth Muscle / Q000378:metabolism* / Q000473:pathology; D011241:Prednisone / Q000378:metabolism*
chemical_list: C579270:MMP9 protein, human; D020780:Matrix Metalloproteinase 9; C501830:Mmp9 protein, mouse; D002122:Calcium Chloride; D011241:Prednisone