Elevated expression of runt-related transcription factors in human abdominal aortic aneurysm

Abdominal aortic aneurysm (AAA) is a multifactorial disease of unknown etiology. AAA is caused by segmental weakening of the aortic walls and progressive aortic dilation leading to the eventual rupture of the aorta, accompanied by intense inflammation. Additionally, studies have indicated a close relationship between the pathogenesis and progression of AAA and cellular immune responses in aneurysm wall tissue. The Runt-related genes (RUNX) encode multifunctional mediators of the of intracellular signal transduction pathways in vascular remodeling, endothelial function, immune response and inflammation. The aim of this study was to evaluate the expression level of RUNX regulatory genes in AAA tissues and to assess the correlations between them. The study was performed on AAA wall-tissue samples obtained from patients with AAA during open aneurysm repair and normal aortic tissues collected from healthy organ donors. There are no proven clinical management strategies or pharmaco-therapeutics to prevent AAA progression once an AAA has been detected. Moreover, so far no biomarkers have been established to indicate the disease status of AAA. Hence, understanding the pathogenesis of AAA has recently become an increasing priority in basic and translational vascular research. We identified significantly higher mRNA and protein level of all of three Runt-related genes in aneurysmal aorta compared to a normal aorta. Increased expression of RUNX2 was demonstrated for the first time in abdominal aortic aneurysm tissue. Additionally, relationships between the activity of RUNX genes in the pathological tissue were identified. The results of elevated expression of RUNX genes and their relationships in the AAA tissues suggest the involvement of conserved Runt-related genes in the pathophysiology of AAA development.