Proteomic comparison between abdominal and thoracic aortic aneurysms.

The pathogenesis of abdominal aortic aneurysms (AAAs) and that of thoracic aortic aneurysms (TAAs) is distinct. In this study, to reveal the differences in their biochemical properties, we performed quantitative proteomic analysis of AAAs and TAAs compared with adjacent normal aorta (NA) tissues. The proteomic analysis revealed 176 non-redundant differentially expressed proteins in the AAAs and 189 proteins in the TAAs which were common in at least 5 samples within 7 samples of each. Among the identified proteins, 55 and 68 proteins were unique to the AAAs and TAAs, respectively, whereas 121 proteins were identified in both the AAAs and TAAs. Panther overrepresentation analysis of the unique proteins in the AAAs and TAAs revealed a significant downregulation of the blood coagulation pathway in the AAAs and that of the integrin signaling pathway in the TAAs. On the other hand, Genesis analysis revealed distinct expression patterns of 58 proteins among the 121 proteins. Panther overrepresentation analysis of these 58 proteins revealed that the expression of these proteins in the blood coagulation and the plasminogen activating cascade was decreased in the AAAs, whereas it was increased in the TAAs compared with the NA tissues. On the other hand, the protein expression in the integrin signaling pathway was increased in the AAAs, whereas it was decreased in the TAAs compared with the NA tissues. Thus, the data presented in this study indicate that the proteins that show differential expression patterns in AAAs and TAAs may be involved in the distinct pathogenesis of AAAs and TAAs.