Effect of Lipids on Vascular Graft Healing

脂质对血管移植物愈合的影响

基本信息

批准号：
8606230
负责人：
Linda M Graham
金额：
$ 44.71万
依托单位：
CLEVELAND CLINIC LERNER COM-CWRU
依托单位国家：
美国
项目类别：
财政年份：
2000
资助国家：
美国
起止时间：
2000-08-01 至 2016-01-31
项目状态：
已结题

来源：
https://reporter.nih.gov/project-details/8606230
关键词：
Address Anastomosis - action Angioplasty Animals Aorta Apolipoprotein A-I Area Arterial Injury Arteries Balloon Angioplasty Blood Vessels Bypass Calcium Calcium Channel Calcium ion Calpain Cardiovascular Diseases Cardiovascular system Carotid Arteries Cell membrane Cell physiology Cell surface Cells Cholesterol Cholesterol Esters Complex Cytoskeletal Proteins Data Deposition Development Diet Disease Endothelial Cells Extracellular Matrix Focal Adhesions Functional disorder Goals Growth Healed High Density Lipoproteins Human Hyperlipidemia Hyperplasia Implant In Vitro Infiltration Inflammatory Inflammatory Response Injury Intervention Ion Channel Lead Lipids Lipoproteins Low Density Lipoprotein oxidation Low-Density Lipoproteins Lysophosphatidylcholines Membrane Fluidity Modeling Movement Mus Myosin Light Chain Kinase Nicotinic Acids Operative Surgical Procedures Oryctolagus cuniculus Outcome Pathway interactions Patients Phospholipase C Phosphotransferases Play Production Property Prosthesis Proteins Reactive Oxygen Species Reconstructive Surgical Procedures Research Role Site Structural Protein Surface Testing Time Vascular Graft atherogenesis base cell motility design graft failure graft function graft healing healing hypercholesterolemia improved improved functioning in vivo inhibitor/antagonist injured macrophage migration mimetics mouse model novel strategies oxidation oxidized lipid oxidized low density lipoprotein prevent protein kinase C-delta public health relevance receptor src-Family Kinases therapy development

项目摘要

DESCRIPTION (provided by applicant): Prosthetic grafts are used widely in vascular reconstructive surgery, but their long-term patency is limited by their thrombogenicity and the development of intimal hyperplasia. Oxidized LDL and lysophosphatidylcholine (lysoPC), a product of LDL oxidation, accumulate in grafts and alter cell function. The long-term goal of our research is to improve the patency of vascular grafts by promoting endothelial cell (EC) healing of graft surfaces. LysoPC inhibits EC migration in vitro, and hypercholesterolemia reduces EC migration into injured arteries and onto grafts. Old and lysoPC increase cellular production of reactive oxygen species, increase cell membrane fluidity, and open ion channels. These effects can inhibit EC migration. Specifically, lysoPC activates a canonical transient receptor potential (TRPC) ion channel, TRPC6, which opens TRPC5 through a unique TRPC activation cascade, leading to a prolonged rise in intracellular free calcium ion concentration ([Ca2+]i). Increased [Ca2+]i inhibits EC migration by activation of calpains that breakdown cytoskeletal proteins essential for migration. This proposal addresses the hypothesis that lipid oxidation products formed within synthetic vascular grafts inhibit their EC migration, in part through activation of TRPC6 and TRPC5 channels, and thereby limit endothelialization of grafts in vivo. The goals of this project are to identify mechanisms by which lipid oxidation products activate TRPC6 and TRPC5 channels and identify ways to counteract this. To accomplish these goals, the mechanism by which lipid oxidation products activate TRPC6, specifically the roles of Src kinases and phospholipase C-31, will be explored. In addition, and the mechanism by which TRPC6 activates TRPC5 will be studied, focusing on the role of intracellular calcium and myosin light chain kinase. The role of reactive oxygen species and changes in membrane fluidity in these actions will also be explored. Finally, the ability of an apoA-I mimetic or HDL, which we have shown to block the TRPC6-TRPC5 activation cascade in vitro, to improve EC migration in areas of arterial injury in mice and onto prosthetic grafts implanted in normal and hypercholesterolemic rabbits will be assessed. The proposed studies will investigate a mechanism by which lipid oxidation products limit EC healing of vascular injuries and synthetic vascular grafts. Studies will also address the ability of HDL to promote EC healing. These studies will lead to a better understanding of the role of lipids in the pathophysiology of graft failure, and provide impetus for development of TRPC6 channel inhibitors or agents that interrupt the TRPC6- TRPC5 activation cascade. These mechanism-based therapies will promote endothelial healing of angioplasty sites and prosthetic grafts to prolong their patency for the benefit of all people undergoing cardiovascular interventions.

描述（由申请人提供）：假体移植物被广泛用于血管重建手术中，但它们的长期通畅受到其血栓形成性和内膜增生的发展的限制。 LDL氧化的产物氧化的LDL和溶物磷脂酰胆碱（LysoPC）积聚在移植物中并改变细胞功能。我们研究的长期目标是通过促进移植物表面的内皮细胞（EC）愈合来提高血管移植物的通畅性。 lysoPC在体外抑制EC迁移，高胆固醇血症降低了EC迁移到受伤的动脉中，并将其迁移到移植物上。旧和lysopc增加了活性氧的细胞产生，增加了细胞膜流动性和开放的离子通道。这些影响可以抑制EC迁移。具体而言，lysOPC激活了规范的瞬态受体电位（TRPC）离子通道TRPC6，该通道通过唯一的TRPC激活级联反应打开TRPC5，从而导致细胞内游离钙离子浓度的延长延长（[[CA2+] I）。增加[Ca2+] I通过激活Calpain的激活来抑制EC的迁移，而Calpain损坏了迁移必不可少的细胞骨架蛋白。该提议解决了以下假设：合成血管移植物中形成的脂质氧化产物抑制了其EC迁移，部分通过TRPC6和TRPC5通道的激活，从而限制了体内移植物的内皮化。该项目的目标是确定脂质氧化产物激活TRPC6和TRPC5通道的机制，并确定解决此问题的方法。为了实现这些目标，将探索脂质氧化产物激活TRPC6的机制，特别是SRC激酶和磷脂酶C-31的作用。另外，将研究TRPC6激活TRPC5的机制，重点是细胞内钙和肌球蛋白轻链激酶的作用。还将探索活性氧种类的作用和膜流动性在这些作用中的变化。最后，将评估APOA-I模拟物或HDL的能力，我们已证明在体外阻止TRPC6-TRPC5激活级联反应，可以评估小鼠动脉损伤区域的EC迁移，并评估植入正常和多胆固醇兔的假体移植物。拟议的研究将研究一种机制，脂质氧化产物限制了血管损伤和合成血管移植物的EC愈合。研究还将解决HDL促进EC康复的能力。这些研究将使人们更好地理解脂质在移植失败的病理生理中的作用，并为中断TRPC6- TRPC5激活级联的TRPC6通道抑制剂的发展提供动力。这些基于机制的疗法将促进血管成形术部位和假肢移植物的内皮愈合，以延长其通畅性，以使所有接受心血管干预措施的人受益。