Correlation of osteopontin and nuclear factor-κB expression with pathogenesis of abdominal aortic aneurysm in rats

Abstract

Objective To establish rat model of abdominal aortic aneurysm (AAA),observe the expression of osteopontin (OPN) and nuclear factor-κB (NF-κB) and explore the molecular mechanism of AAA.Methods Thirty rats were divided into 3 groups (n =10 each).The rat AAA models were made by perfusing pancreatopeptidase E from hog pancreas into the aorta of rats for 30 min.Aortas were taken out two weeks after perfusion and the diameter of all aortas was measured.Hematoxylin and eosin (HE) staining was used to observe the structural change and elastase staining to observe how the area of elastase altered in the middle tuna of the aorta.Immunohistochemistry and Western blotting were used to detect the expression of OPN,NF-κB and matrix metalloproteinase-2 (MMP-2).Results Rat AAA model was successfully made.As compared with saline group and normal group,the infiltration of inflammatory cells was significantly increased and the quantity of elastase was significantly reduced in experimental group.Immunohistochemistry revealed that the expression of OPN was significantly increased in experimental group (P ＜ 0.05).Western blotting demonstrated that the expression of OPN was also obviously increased in experimental group (P ＜ 0.01).Conclusion OPN may increase the expression of MMP-2 through the NF-κB pathway in rat AAA model,thereby accelerating the degradation of extracellular matrix and eventually leading to occurrence of AAA. Key words: Abdominal aortic aneurysm; Osteopontin; Nuclear factor-κB; Matrix metallo-proteinase-2