Authors: Tomoe Hayashi Eriko Morishita Hiroshi Ohtake Yoshio Oda Hidesaku Asakura Shinji Nakao
Publish Date: 2009/09/16
Volume: 90, Issue: 3, Pages: 336-342
Abstract
Annexin II is a receptor of tissuetype plasminogen activator tPA We have previously identified annexin II by immunolocalization in human atherosclerotic abdominal aortic aneurysms AAAs To investigate possible interactions between annexin II and AAA development we examined annexin II mRNA and protein expression in a rat model of experimental AAA AAAs were induced in rats by transient aortic infusion of elastase The rats were divided into three groups a salinetreated control group a group with 15min elastase infusion and a group with 30min elastase infusion The 15min elastaseinfused group had smaller aneurysms and more preserved media than the 30min elastaseinfused group Immunohistochemistry showed that annexin II expression was increased in the thickened intima and media of AAA rats as compared with the media of control rats Furthermore annexin II was colocalized with macrophages and smooth muscle cells Quantitative realtime polymerase chain reaction showed that annexin II mRNA levels were upregulated only in the smaller aneurysm group compared with the control group In contrast tPA mRNA levels were increased in both the 15 and 30min elastaseinfused groups as compared with the control group These results demonstrate various levels of annexin II expression within the aortic wall of rats with experimental AAAs It has been suggested that alteration of fibrinolytic activity regulated by annexin II within the aortic wall may be associated with aneurysm formation
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