Altered patterns of gene expression distinguishing unruptured abdominal aortic aneurysms from ruptured ones:...

The purpose of this study was to profile altered patterns of gene expression that characterize abdominal aortic aneurysm and to compare these patterns between different conditions, unruptured (URA) and ruptured (RA). Full-thickness aortic wall tissues were obtained from patients during surgical repair of abdominal aortic aneurysm, including unruptured (n=29) and ruptured (n=11). RNA, protein and blood samples were prepared for each specimen, and differential levels of gene expression between unruptured and ruptured abdominal aortic tissues were assessed by immunohistochemistry, RT-qPCR and ELISA assays. Biochemical assay showed that triglyceride (TG), total cholesterol (TC) and low density lipoprotein (LDL) concentration in the peripheral blood of URA and UA patients with large size of aneurysm (>5 cm) was significantly increased compared with those with small size of aneurysm (3-5 cm). Of 7 genes examined, TRPV1, CAM, TNF-α, IL-6, MCP-1 and VCAM were significantly increased in RA patients compared with URA patients, which also showed markedly increased expression in large size of aneurysm, with TRPV1 and CAM exception in RA patients. Only PPARδ expression observed decrease in RA patients with larger size of aneurysm. Taken together, URA and RA exhibit distinct patterns of gene expression, with most alterations being unique to this disease. Abdominal aortic aneurysm arising in different sizes of aneurysm is thus characterized by a high degree of molecular heterogeneity, reflecting different pathophysiologic mechanisms.