Abstract 13577: Increased Iron Accumulation in Human Abdominal Aortic Aneurysm
Background: Iron is an essential element in the body, while excess iron leads to tissue damages causing by oxidative stress and inflammation. Although inflammation and oxidative stress play critical roles in the pathophysiological mechanism of abdominal aortic aneurysm (AAA), it has not been investigated whether iron play a role in the pathophysiological mechanism of AAA. The aim of this study is to examine iron accumulation in human AAA tissue.
Methods: Aortic tissue samples were collected from 53 patients undergoing cardiovascular surgery (AAA: n=19, Control: n=34). Non aneurysmal control aortic tissue were obtained from patients undergoing aortic valve replacement for aortic valve stenosis or aortic valve regurgitation and extracted from ascending aortas at the time of establishment of cardiopulmonary bypass. Aortic iron content was assessed by atomic absorption spectrometry and berlin blue staining. In addition, immunohistochemical analyses for CD68 and 8-Hydroxydeoxyguanosine (8-OHdG) were performed to evaluate inflammation and oxidative stress in aortic tissue.
Results: The percentage of male patients was higher in AAA than Control (84 vs 38%, p<0.05), while there was no significant difference in medication between two groups. CD68 expression was increased in AAA tissue compared with Control. 8-OHdG expression was also increased in AAA tissue compared with Control. Importantly, aortic iron content was increased in AAA tissue compared with Control (626.1±381.4 vs 154.5±123.3 μg/g, p<0.05). Furthermore, berlin blue staining showed that iron was markedly accumulated in AAA walls. Interestingly, the distribution of iron accumulated area was quite similar to that of CD68 and 8-OHdG positive area. Moreover, the extent of CD68 and 8-OHdG positive area were positively correlated with that of iron accumulated area (R=0.70, R=0.75, p<0.05, respectively).
Conclusion: Iron was markedly accumulated in human AAA tissue and localized with CD68 and 8-OHdG positive area. These results indicate that iron may be involved in the pathophysiology of AAA.
- © 2013 by American Heart Association, Inc.