SMOOTH MUSCLE CELLS AND GRAFT INTIMAL HYPERPLASIA

平滑肌细胞与移植物内膜增生

• 批准号: 2219925
• 负责人: Linda M Graham
• 金额: $ 19.38万
• 依托单位: CASE WESTERN RESERVE UNIVERSITY
• 依托单位国家: 美国
• 财政年份: 1989
• 资助国家: 美国
• 起止时间: 1989-07-01 至 1998-11-30
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/2219925
• 关键词: antisense nucleic acid; aorta; blood vessel prosthesis; blood vessel transplantation; cell migration; dogs; enzyme linked immunosorbent assay; extracellular matrix; fibroblast growth factor; gene induction /repression; growth factor receptors; heparin; human tissue; hyperplasia; immunocytochemistry; mitogens; nonhuman therapy evaluation; northern blottings; platelet derived growth factor; polymerase chain reaction; receptor binding; receptor expression; transforming growth factors; vascular endothelium; vascular smooth muscle

The long-term goal of our research is to improve patency of prosthetic vascular grafts by controlling intimal hyperplasia. Intimal hyperplasia is characterized by smooth muscle cell (SMC) accumulation and matrix deposition, and is most severe adjacent to the anastomoses of prosthetic grafts. Our studies of endothelial cell (EC) seeded grafts demonstrate a time-dependent increase in production of platelet-derived growth factor (PDGF), which is associated with the appearance of SMC in the inner capsule of the graft. Preliminary in vitro studies suggest that graft SMC are significantly modified compared to aortic SMC; graft SMC produce high levels of PDGF, proliferative in minimal serum, and growth is less sensitive to inhibition by heparin compared to aortic SMC. We postulate that SMC that migrate to, and proliferate in, the inner capsule of the graft are modified to produce mitogens to which they respond in an autocrine fashion. Furthermore, we propose that the response of graft SMC to natural growth stimulators and inhibitors is altered, and that the most effective method to inhibit intimal hyperplasia is to block a common pathway between the multiple mitogen receptors and cell division. To test these hypotheses, production and response to growth regulators will be studied. Production of PDGF A-chain, B-chain, basic fibroblast growth factor (bFGF), and transforming growth factor beta (TGFBeta) a bi- directional growth regulator, will be compared in graft and aortic EC and SMC. To determine differences in the capacity of SMC to respond to mitogens, receptor number and affinity of binding of PDGF, bFGF, and TGFBeta will be studied in graft and aortic SMC. In addition, proliferative and migratory responses of graft and arterial SMC to PDGF- AA, AB, -BB; bFGF; TGFBeta; and heparin will be compared. If differences in mitogen or inhibitor production or response are identified between graft and artery SMC in vitro, the level of gene expression will be determined, and differences in mRNA related to variation in gene transcription rates or message stability. To determine if SMC proliferation on grafts can be inhibited by blocking a late common pathway of cell division, the efficacy of antisense to c-myb to inhibit SMC proliferation will be studied in vitro and in vivo. Production of mitogens by SMC lining the graft may be responsible for continued SMC migration and proliferation as well as matrix deposition causing neointimal hyperplasia of grafts. The proposed studies will lead to a better understanding of alterations in mitogen production and response by SMC lining prosthetic vascular grafts, and the ability to suppress proliferation by blocking the common pathway in cell division. Ultimately, this may lead to interventions to inhibit mitogenic responses and control the development of anastomotic intimal hyperplasia.

我们研究的长期目标是提高假肢的通畅率 通过控制内膜增生来进行血管移植。 内膜增生 其特点是平滑肌细胞（SMC）积累和基质 沉积，并且在假体吻合处最严重 移植物。 我们对内皮细胞 (EC) 接种移植物的研究表明 血小板衍生生长因子的产生随时间增加 (PDGF)，与内部SMC的出现有关 移植物的囊。 初步体外研究表明，移植物 与主动脉 SMC 相比，SMC 发生显着改变；接枝SMC生产 高水平的PDGF，在极少量的血清中增殖，并且生长较少 与主动脉 SMC 相比，对肝素的抑制作用敏感。 我们假设 SMC 迁移至细胞内囊并在其中增殖 移植物被修饰以产生有丝分裂原，它们以一种 自分泌时尚。 此外，我们建议移植物的反应 SMC 对自然生长刺激剂和抑制剂的作用发生了改变，并且 抑制内膜增生最有效的方法是阻断常见的 多种有丝分裂原受体和细胞分裂之间的途径。 为了测试这些假设、生产和对生长调节剂的反应 将被研究。 PDGF A链、B链、碱性成纤维细胞的产生 生长因子 (bFGF) 和转化生长因子 β (TGFBeta) 是一种双 定向生长调节剂，将在移植物和主动脉 EC 中进行比较 SMC。 确定 SMC 响应能力的差异 有丝分裂原、PDGF、bFGF 和受体的数量和结合亲和力 TGFBeta 将在移植物和主动脉 SMC 中进行研究。 此外， 移植物和动脉 SMC 对 PDGF 的增殖和迁移反应 AA、AB、-BB；成纤维细胞生长因子； TGFβ；和肝素将进行比较。 如果有差异 在有丝分裂原或抑制剂的产生或反应之间进行鉴定 移植物和动脉 SMC 在体外，基因表达水平将 确定了与基因变异相关的 mRNA 差异 转录率或消息稳定性。 判断SMC是否 可以通过阻断晚期常见细胞来抑制移植物的增殖 细胞分裂途径，c-myb反义蛋白抑制的功效 将在体外和体内研究 SMC 增殖。 移植物内衬 SMC 产生有丝分裂原可能是造成这种情况的原因 持续的 SMC 迁移和增殖以及基质沉积 引起移植物的新内膜增生。 拟议的研究将导致 更好地了解有丝分裂原产生的变化和 SMC 衬里人工血管移植物的反应，以及 通过阻断细胞分裂的共同途径来抑制增殖。 最终，这可能导致抑制促有丝分裂反应的干预措施 并控制吻合口内膜增生的发展。