The function of cathepsins B, D, and X in atherosclerosis.

Cathepsins are proteolytic enzymes typically located within the lysosomes of macrophages. Once released, they can enhance the inflammatory process in atherosclerosis. Cathepsin X aids in the migration of T-lymphocytes and the release of cytokines. Cathepsin D modifies low-density lipoprotein to promote its uptake by macrophages and its subsequent foam cell formation. Furthermore, cathepsin D regulates apoptosis. Cathepsin B degrades the extracellular matrix within the arterial intima. Together, they increase plaque vulnerability. This evidence suggests that cathepsins play an important role in the pathogenesis of atherosclerosis.