Failure of vascular interventions such as angioplasty, stenting, and bypass surgery remains a common clinical problem resulting in considerable morbidity, mortality, and healthcare expenditures. The most common cause of these failures is a narrowing of the vessel lumen ("restenosis") resulting from excessive thickening of the vessel wall (intimal hyperplasia) and scarring (fibrosis). The response of blood vessels to injury is initiated and potentiated by inflammation. The magnitude of this response, including its temporal and spatial extent, is a primary determinant of the vessel remodeling outcome. Recent studies have suggested that the resolution of inflammation is an active, rather than a passive process, and is mediated by specialized pro-resolving lipid mediators derived from polyunsaturated fatty acids such as eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA). These mediators - termed lipoxins, resolvins, protectins, and maresins - exert potent effects on inflammatory cells to turn off inflammation and promote a return of homeostasis. Recently we and others have identified direct actions of these pro-resolving mediators on vascular cells which suggest they may be important modulators of vascular healing, and candidate therapeutics for vascular disease. In this translational research proposal, we will examine the hypothesis that restenosis is caused by a relative deficit in resolution following vascular injury. We will examine the molecular mechanisms by which one important class of pro-resolving lipid mediators, the D-series resolvins, exerts anti-inflammatory and cytostatic effects on vascular smooth muscle (VSMC) and adventitial cells. We will characterize the endogenous resolution pathways that are operative in the setting of acute arterial injury using an established animal model, and their manipulation by either dietary or local drug delivery interventions. These studies will yield novel insights into the control of vascular healing, and may lead to new therapeutic approaches leveraging the unique pharmacobiology of pro-resolving lipid mediators in cardiovascular diseases.
Recurrent narrowing of arteries (restenosis) following angioplasty, stenting, or bypass surgery for atherosclerosis is a common problem, which stems from excessive inflammation and scarring of the vessel. We propose that restenosis reflects a relative deficit in the resolution of inflammation, a process which has recently been understood to involve specialized mediators derived from polyunsaturated fatty acids (PUFA), particularly the ?-3 PUFAs present in fish oils. In this research program, we will investigate the mechanisms by which these specialized mediators control vascular healing, and test whether nutritional supplementation or localized delivery of these compounds can reduce vessel scarring after angioplasty and improve function.