The role of lysyl oxidase family members in the stabilization of abdominal aortic aneurysms.

Abdominal aortic aneurysms (AAAs) are a major cause of morbidity and mortality in the United States today. We employed a model for AAA development using apolipoprotein E knock out mice fed a high-fat diet and treated with ANG II and β-aminopropionitrile (β-APN) for 4 wk. ANG II induces hypertension and atherosclerotic disease, whereas β-APN inhibits the activity of the lysyl oxidase/ lysyl oxidase-like protein (LOX/LOXL) family members. LOX/LOXL family members crosslink collagen and elastin in the extracellular matrix and therefore contribute to the integrity and stabilization of a healthy vessel wall. In this model, cotreatment with ANG II and β-APN caused a 90% AAA incidence and increased atherosclerotic lesion formation from less than 5% to greater than 25% after 4 wk. In more atheroprotected mouse strains (C57BL/6 and BalbC), cotreatment with ANG II and β-APN caused 50% and 40% AAA incidence, respectively. These data demonstrate the importance of LOX/LOXL to the stability of the vessel wall. Therapeutic strategies to overexpress LOX/LOXL enzymes or to support the crosslinking of soluble matrix proteins in a polymeric scaffold are a promising opportunity to achieve stabilization of AAAs.