title: Semicarbazide-sensitive amine oxidase in annulo-aortic ectasia disease: relation to elastic lamellae-associated proteins.
abstract: Lysyl oxidases (Lox), which are members of the amine oxidase family, are involved in the maturation of elastic lamellae and collagen fibers. Modifications of amine oxidases in idiopathic annulo-aortic ectasia disease (IAAED) have never been investigated. Our aim was to examine the expression of several proteins that might interfere with elastic fiber organization in control (n=10) and IAAED (n=18) aortic tissues obtained at surgery. Expression of amine oxidases and semicarbazide-sensitive amine oxidase (SSAO), and cellular phenotypic markers were examined by immunohistopathology and confocal microscopy. The expression of these proteins was assessed in relation to clinical and histomorphological features of the arterial wall. In control aorta, SSAO staining was expressed along elastic lamellae, whereas in aneurysmal areas of IAAED, SSAO was markedly decreased, in association with severe disorganization of elastic lamellae. Smooth muscle myosin heavy chain was also decreased in IAAED compared with controls, indicating smooth muscle cell dedifferentiation. Multiple regression analysis showed that elastic lamellar thickness (ELT) was correlated positively with the SSAO:elastin ratio and negatively with the Lox:elastin ratio, and that the clinical features of IAAED (aneurysm, thoracic aorta diameter, and aortic insufficiency) were positively correlated with ELT but not with SSAO. The relationship between SSAO expression and ELT suggests that this amine oxidase may be involved in elastic fiber organization. However, in advanced IAAED, the deficit in SSAO expression could be secondary to the decrease and fragmentation of elastic fibers and/or to vascular smooth muscle cell dedifferentiation.
authors.affiliation: Inserm U441, Université Victor Segalen Bordeaux 2, avenue du Haut Lévêque, 33600 Pessac, France.
authors.forename: Igor
authors.initials: I
authors.lastname: Sibon
authors.forename: Daniel
authors.initials: D
authors.lastname: Larrieu
authors.forename: Khadija
authors.initials: K
authors.lastname: El Hadri
authors.forename: Nathalie
authors.initials: N
authors.lastname: Mercier
authors.forename: Bruno
authors.initials: B
authors.lastname: Fève
authors.forename: Patrick
authors.initials: P
authors.lastname: Lacolley
authors.forename: Carlos
authors.initials: C
authors.lastname: Labat
authors.forename: Danièle
authors.initials: D
authors.lastname: Daret
authors.forename: Jacques
authors.initials: J
authors.lastname: Bonnet
authors.forename: Jean-Marie Daniel
authors.initials: JM
authors.lastname: Lamazière
mesh_terms: D006631:Amine Oxidase (Copper-Containing) / Q000096:biosynthesis*; D001013:Aorta, Thoracic / Q000201:enzymology / Q000378:metabolism / Q000648:ultrastructure; D017545:Aortic Aneurysm, Thoracic / Q000150:complications / Q000201:enzymology / Q000378:metabolism*; D001022:Aortic Valve Insufficiency / Q000150:complications / Q000201:enzymology / Q000378:metabolism*; D002454:Cell Differentiation; D004549:Elastin / Q000096:biosynthesis*; D005109:Extracellular Matrix / Q000201:enzymology / Q000378:metabolism* / Q000648:ultrastructure; D005260:Female; D006801:Humans; D007150:Immunohistochemistry; D008297:Male; D018613:Microscopy, Confocal; D008875:Middle Aged; D009131:Muscle, Smooth, Vascular / Q000201:enzymology / Q000378:metabolism / Q000648:ultrastructure; D018995:Myosin Heavy Chains / Q000096:biosynthesis; D008249:Protein-Lysine 6-Oxidase / Q000096:biosynthesis*; D012044:Regression Analysis
chemical_list: D004549:Elastin; D008249:Protein-Lysine 6-Oxidase; D006631:Amine Oxidase (Copper-Containing); D018995:Myosin Heavy Chains