Aim: Mast cells are versatile innate immune cells and are reported to promote vascular inflammation and neointimal lesion formation, thereby contributing to the development of vascular stenosis and atherosclerosis. However, it is not clear whether mast cells also regulate vascular matrix remodelling in established neointima. This study addressed the hypothesis that perivascular mast cells regul...

BACKGROUND We have previously demonstrated vasculoprotective effects after repeated intravenous administration of recombinant apolipoprotein A-IMilano (apoA-Im)/phospholipid complex. In this study, we sought to determine the effects of local recombinant apoA-Im/1-palmitoyl,2-oleoyl phosphatidylcholine complex (ETC-216) delivered intramurally via the Infiltrator catheter on luminal narrowing in ...

Arterial restenosis frequently develops after open or endovascular surgery due to intimal hyperplasia. Since tissue transglutaminase (TG2) is known to involve in fibrosis, wound healing, and extracellular matrix remodeling, we examined the role of TG2 in the process of intimal hyperplasia using TG2-null mice. The neointimal formation was compared between TG2-null and wild-type (C57BL/6) mice by...

BACKGROUND Extracellular matrix deposition is the main factor inducing stenotic lesions in arterial grafts. Lysyl oxidases (LOX) play a key role in stabilizing collagen and elastin. OBJECTIVE To examine the repair response to arterial allografts in terms of LOX expression and collagen/elastin deposition using LOX inhibitors. METHODS Lewis/Fisher-344 rats were used as donors/recipients. Dono...

This study used optical coherence tomography (OCT) to investigate the effects of systemic methotrexate, in combination with a drug-eluting stent, on in-stent neoatherosclerosis in a rabbit model. Sirolimus-eluting stents were surgically implanted in the right common carotid arteries of 200 male New Zealand White rabbits; the animals received a high-fat diet, beginning one week before stent impl...

OBJECTIVE Arterial injury stimulates remodeling responses that, when excessive, lead to stenosis. These responses are influenced by integrin signaling in vascular smooth muscle cells (VSMCs). Microfibrillar-associated protein 4 (MFAP4) is an integrin ligand localized to extracellular matrix fibers in the vascular wall. The role of MFAP4 in vascular biology is unknown. We aimed to test the hypot...

BACKGROUND Pathological changes in vein grafts begin immediately after arterial circulation is applied to the grafts. Chemical mediator stimulation and mechanical strain induce neointimal hyperplasia and medial thickening of the vein grafts, resulting in their failure. We investigated the inhibitory effect of locally applied cilostazol, an inhibitor of cyclic adenosine monophosphate phosphodies...

OBJECTIVE Vascular injury causes neointimal hypertrophy, which is characterized by redox-mediated matrix degradation and smooth muscle cell (SMC) migration and proliferation. We hypothesized that, as compared to the adjacent medial SMCs, neointimal SMCs produce increased superoxide via NADPH oxidase, which induces redox-sensitive intracellular signaling to activate matrix metalloproteinase-9 (M...

AIMS Histological restenosis models in animals have indicated that stent design has a significant impact on vessel trauma during stent implantation and on the amount of subsequent neointimal tissue proliferation. The impact of different stent designs on intimal hyperplasia in human atherosclerotic coronary arteries has not been determined. METHODS AND RESULTS Angiographic and intravascular ul...

OBJECTIVES We report optical coherence tomography (OCT) findings in 33 patients who presented with very late stent thrombosis (VLST) after either drug-eluting stent (DES) or bare-metal stent (BMS) implantation. BACKGROUND VLST is a potentially life-threatening complication, but the underlying mechanisms remain unclear. METHODS In 33 patients (27 DES- and 6 BMS-treated lesions) with definite...