Matrix metalloproteinases in critical limb ischemia.

Critical limb ischemia (CLI) is most commonly the result of arterial occlusive disease, specifically atherosclerotic plaque formation and rupture within the infrainguinal arteries. The physiological response to CLI is partial limb reperfusion via the distinct processes of angiogenesis and arteriogenesis. Matrix metalloproteinases (MMPs) are extracellular matrix-remodeling enzymes that play an important role in both the occlusion and reperfusion processes associated with CLI. This article provides a review of the recent literature, summarizing the current understanding of the role of MMPs in both the arterial occlusion and limb reperfusion associated with CLI. Specifically, the functions of MMPs in atherosclerosis, angiogenesis, and arteriogenesis are discussed.