Related Experiment Videos
Differential expression of prostaglandin E2 and interleukin-6 in occlusive and aneurysmal aortic disease
J M Reilly1, M Miralles, W N Wester
1Department of Surgery, Washington University School of Medicine, John Cochran Veterans Administration Medical Center, St Louis, MO, USA.
Insights
Inflammation plays a role in aortoiliac occlusive disease (AIOD) and abdominal aortic aneurysm (AAA). Both conditions show increased prostaglandin E2 (PGE2), but AIOD has significantly higher interleukin-6 (IL-6) levels than AAA.
Area of Science:
- Vascular Biology
- Immunology
- Biochemistry
Background:
- Aortoiliac occlusive disease (AIOD) and abdominal aortic aneurysm (AAA) are traditionally viewed as atherosclerotic, degenerative conditions.
- Emerging evidence suggests distinct pathophysiological determinants for each, with inflammation implicated in both.
- This study investigates inflammatory cytokines in AIOD and AAA compared to normal aorta.
Purpose of the Study:
- To analyze and compare the expression of inflammatory cytokines, specifically interleukin-6 (IL-6) and prostaglandin E2 (PGE2), in AIOD and AAA.
- To compare cytokine expression in diseased aortas (AIOD and AAA) with that of normal aortic tissue.
Main Methods:
- Aortic tissue samples were obtained from patients undergoing surgery for AAA (n=13) and AIOD (n=14), and from organ donors for normal controls (n=16).
- Whole organ cultures were established, and culture media were collected after 72 hours.
- Enzyme-linked immunosorbent assay (ELISA) quantified PGE2, and a lymphoproliferative assay quantified IL-6. Statistical analysis used paired 2-tail t-tests.
Main Results:
- Both AAA and AIOD tissues exhibited significantly higher prostaglandin E2 (PGE2) levels compared to normal aorta (P < .001 and P < .002, respectively).
- No significant difference in PGE2 levels was observed between AAA and AIOD groups (P = .44).
- Interleukin-6 (IL-6) expression was markedly elevated in both AAA (P = .02) and AIOD (P < .001) compared to normal aorta, with significantly higher IL-6 levels in AIOD than in AAA (P = .03).
Conclusions:
- Abdominal aortic aneurysm (AAA) and aortoiliac occlusive disease (AIOD) are associated with increased expression of proinflammatory cytokines PGE2 and IL-6.
- While PGE2 levels are similar between AAA and AIOD, AIOD demonstrates significantly higher IL-6 expression.
- This differential IL-6 expression may offer insights into the distinct pathogenesis of these two aortic diseases.
Background:
Both aortoiliac occlusive disease (AIOD) and abdominal aortic aneurysm disease (AAA) are traditionally considered degenerative conditions that are caused by atherosclerosis. Although it is becoming apparent that the pathophysiology of each condition has its own determinants, inflammation is thought to play a role in each. The purpose of this study was to analyze the inflammatory cytokines interleukin-6 (IL-6) and prostaglandin E2 (PGE2) in aortic disease and compare AAA with AIOD, as well as to compare both with normal aorta.
Methods:
Aortic tissue was harvested at the time of aortic reconstructive surgery for AAA (n = 13) and AIOD (n = 14) or at time of organ harvest for normal (n = 16) aortic specimens. Whole organ cultures were immediately established, and the culture medium was collected after 72 hours. An enzyme-linked immunosorbent assay was used to assay for PGE2 and a lymphoproliferative assay was used to quantitate IL-6. Statistical analysis was performed using paired 2-tail t tests.
Results:
Normal aorta expressed much less PGE2 (384 +/- 67 ng/mL) than either AAA (11,093 +/- 7,411 ng/mL) (P < .001) or AIOD (13, 719 +/- 3,355 ng/mL) (P < .002). However there was no statistically significant difference in PGE2 expression between the AAA and AIOD groups (P = . 44). The IL-6 assay also showed that normal aorta had very little expression (1,861 +/- 334 U/mL) compared with either AAA (14,329 +/- 4,159 U/mL) (P = . 02) or AIOD (39,805 +/- 8,426) (P < .001). Comparison between AAA and AIOD revealed significantly higher expression of IL-6 by the AIOD cultures (P = .03).
Conclusions:
AAA and AIOD are associated with increased expression of the proinflammatory cytokines PGE2 and IL-6. However, AIOD is associated with a much higher level of IL-6 expression than is AAA, although the level of PGE2 expression is the same. This differential expression of IL-6 may help explain the pathogenesis of these 2 distinct aortic diseases.