Elastin in the Pathogenesis of Abdominal Aortic Aneurysm.

Abdominal aortic aneurysms (AAAs) are progressive, life-threatening vascular disorders characterized by focal dilation of the abdominal aorta due to chronic weakening of the arterial wall. The condition often remains asymptomatic until rupture, which carries mortality rates exceeding 70-85%. Among the various etiological theories of AAA development, degradation of the extracellular matrix (ECM) has emerged as the most widely accepted paradigm, with the breakdown of elastin representing a central and irreversible hallmark event. Elastin, a highly cross-linked and durable structural protein, provides elasticity and recoil to the aortic wall. In human AAA specimens, reduced elastin content, impaired cross-linking, and extensive fiber fragmentation are consistently observed, while experimental studies across multiple animal models confirm that elastin degradation directly correlates with aneurysm initiation, expansion, and rupture risk. Elastin loss is driven by a complex interplay of proteolytic enzymes coupled with inflammatory cell infiltration and oxidative stress. Furthermore, elastin-derived peptides perpetuate immune cell recruitment and matrix degradation, creating a vicious cycle of wall injury. Genetic and epigenetic factors, including variants in ECM regulators and dysregulation of non-coding RNAs, further modulate elastin homeostasis in AAA pathobiology. Clinically, biomarkers of elastin turnover and elastin-targeted molecular imaging techniques are emerging as tools for risk stratification. Therapeutically, novel strategies aimed at stabilizing elastin fibers, enhancing cross-linking, or delivering drugs directly to sites of elastin damage have shown promise in preclinical models and early translational studies. In parallel, regenerative approaches employing stem cells, exosomes, and bioengineered elastin scaffolds are under development to restore structural integrity. Collectively, these advances underscore the pivotal roles of elastin not only as a structural determinant of aneurysm development but also as a diagnostic and therapeutic target. This review summarizes and integrates recent discoveries on elastin biology in AAA, with a particular emphasis on molecular mechanisms of elastin degradation and the translational potential of elastin-centered interventions for the prevention and treatment of AAA.