Abstract 515: Anti-Inflammatory Cytokine Interleukin-19 Suppresses the Formation and Progression of Experimental Abdominal Aortic Aneurysms

Abstract

Inflammation plays an important role in the progression of abdominal aortic aneurysms (AAAs). Interleukin (IL)-19 is an anti-inflammatory cytokine that have been show to inhibit inflammatory process. However, its pathogenic role in AAAs is unknown. This study evaluated the effect of IL-19 treatment on the formation and progression of AAAs using transient intra-aortic infusion of porcine pancreatic elastase (PPE) in male C57BL/6 mice. Treatment efficacy was analyzed via serial in vivo transabdominal ultrasound measurements of aortic diameters and histology at sacrifice. PPE infusion significantly increased aortic IL-19 message and protein expression as well as aortic diameter through day 14 in mice. In contrast, exogenous IL-19 therapy initiated one day prior to PPE infusion significantly suppressed subsequent aortic enlargement. Additionally, IL-19 treatment initiated four days following PPE infusion limited further progression of existing aneurysms. Exogenous IL-19 treatment, initiated either pre- or post-PPE infusion, was associated with retained medial smooth muscle cellularity and elastin fibers and attenuated mural inflammation (including reduced T & B cell and macrophage infiltration) in developing aneurysms. In conclusion, IL-19 limits the formation and progression of experimental AAAs.