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 血管移植通过控制内膜增生。 内膜增生 以平滑肌细胞（SMC）的积累和基质为特征 沉积，并且最严重与假肢的吻合 移植物。 我们对内皮细胞（EC）种子移植物的研究表明 血小板衍生生长因子的产生时间依赖性增加 （PDGF），它与内部SMC的外观有关 移植胶囊。 初步的体外研究表明移植物 与主动脉SMC相比，SMC已显着修饰；移植SMC产品 高水平的PDGF，最小血清增殖和生长较少 与主动脉SMC相比，肝素抑制敏感。 我们假设 那个迁移到并扩散的SMC 移植物经过修改以产生有丝分裂剂，它们以此反应 自分泌时尚。 此外，我们提出了移植的反应 SMC对自然生长刺激剂和抑制剂发生了改变，并且 抑制内膜增生的最有效方法是阻止常见 多丝分裂受体和细胞分裂之间的途径。 为了检验这些假设，生产和对增长调节剂的反应 将被研究。 PDGF A链，B链，基本成纤维细胞的生产 生长因子（BFGF）和转化生长因子β（TGFBETA）BI- 方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 PDGF，BFGF和BFGF结合的受体数量和亲和力 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-的增生和迁移反应 aa，ab，-bb; BFGF; tgfbeta;将比较肝素。 如果有差异 在有丝分裂原或抑制剂的产生或反应中 移植物和动脉SMC在体外，基因表达水平将是 确定以及与基因变异有关的mRNA差异 转录率或消息稳定性。 确定SMC是否 通过阻止晚期常见，可以抑制移植物上的增殖 细胞分裂的途径，反义对C-MYB的疗效抑制 将在体外和体内研究SMC增殖。 通过SMC衬里生产促分裂物可能是负责的 持续的SMC迁移和增殖以及基质沉积 引起移植物的新膜增生。 拟议的研究将领导 更好地理解有丝分裂原的改变和 SMC衬里假体血管移植的反应，以及能够 通过阻止细胞分裂中的公共途径来抑制增殖。 最终，这可能会导致抑制有丝分裂反应的干预措施 并控制吻合的内膜增生的发展。