TNF-INHIBITOR GENE THERAPY FOR NEOINTIMAL HYPERPLASIA

在美国，每年大约有500,000名患者接受经皮冠状动脉介入治疗(PCI)和冠状动脉旁路移植手术(CABG)。这两个过程都因血管壁细胞的激活、迁移和增殖而变得复杂，从而导致新生内膜增生(NH)。大量证据表明，这些细胞中的大多数来自血管平滑肌。NH影响约30%的经皮冠状动脉介入治疗患者，约30%的冠脉搭桥术患者需要在两年内再次介入治疗。仅治疗冠状动脉介入治疗再狭窄每年所需的费用就超过20亿美元。经皮冠状动脉介入术和大隐静脉冠状动脉旁路移植术都会导致血管壁损伤，导致内皮功能障碍和单核/巨噬细胞系的血小板、中性粒细胞和循环细胞的黏附。局部释放的细胞因子，如肿瘤坏死因子，与包括血小板衍生生长因子和碱性成纤维细胞生长因子在内的生长因子协同作用，激活损伤血管段的SMC。在体外，肿瘤坏死因子是一种强烈的有丝分裂原，可以与PDGF-BB协同作用，刺激细胞生长。这项工作建议研究肿瘤坏死因子对血管内皮细胞活化的贡献，单独和结合各种生长因子。为此，将检测经肿瘤坏死因子处理和未处理的SMC中丝裂原活化蛋白激酶(MAPK)的激活、DNA合成、增殖、趋化和凋亡。此外，这项建议试图在实验动物模型中验证抑制肿瘤坏死因子可以降低体外SMC激活程度和减少体内新生内膜形成大小的假设。为抑制肿瘤坏死因子，构建了肿瘤坏死因子受体胞外区-小鼠免疫球蛋白重链嵌合体，并将其插入重组腺病毒中。Ad-肿瘤坏死因子-I)。这种病毒将被用来感染体外兔颈静脉，这些静脉将被移植到兔的颈动脉，形成具有良好特征的新生内膜增生模型。旁路移植4周后，对REC.AD-肿瘤坏死因子-I和REC.AD对照感染静脉的新生内膜形成程度进行组织学检测。这将在接受正常饮食的兔子和给予高脂肪饮食的动物身上进行，以检查高脂血症在这种情况下对新生内膜增生的影响。通过抑制肿瘤坏死因子抑制移植静脉新生内膜的增殖可能对人类血管疾病具有重要的治疗意义。

Percutaneous coronary intervention (PCI) and coronary artery bypass graft surgery (CABG) are each performed on approximately 500,000 patients annually in the US. Both procedures are complicated by activation, migration and proliferation of cells in the vascular wall, leading to neointimal hyperplasia (NH). A preponderance of evidence suggests that the majority of these cells are of vascular smooth muscle origin. NH affects about 30 % of all PCI patients and necessitates reintervention in some 30 % of all CABG cases within two years. The annual cost needed to treat PCI restenosis alone exceeds $2 billion. PCI and saphenous vein CABG surgery both lead to significant injury of the underlying vessel wall, causing endothelial dysfunction and adherence of platelets, neutrophils and circulating cells of the monocyte / macrophage lineage. Locally released cytokines, such as tumor necrosis factor (TNF), synergize with growth factors, including platelet derived growth factor (PDGF) and basic fibroblast growth factor (bFGF), to activate SMCs in the injured vessel segment. In vitro TNF is a strong mitogen for SMCs and can act in concert with PDGF-BB, to stimulate cell growth. This work proposes to examine the contribution of TNF to the activation of SMCs, alone and in combination with various growth factors. To this end mitogen activated protein kinase (MAPK) activation, DNA synthesis, proliferation, chemotaxis and apoptosis will be examined in TNF treated and untreated SMCs. In addition, this proposal seeks to test the hypothesis that inhibition of TNF can decrease the degree of SMC activation in vitro and can reduce the size of neointima formation in vivo in an experimental animal model. To inhibit TNF, a chimeric TNF receptor extracellular domain - murine immunoglobulin heavy chain construct (TNF-I) was generated and inserted into a recombinant adenovirus (rec. AD-TNF-I). This virus will be used to infect rabbit jugular veins ex vivo that will be grafted across the rabbit's carotid artery in a well characterized model of neointima hyperplasia. Four weeks after bypass grafting the degree of neointima formation in rec.AD-TNF-I and rec.AD-control infected veins will be measured histologically. This will be done both in rabbits receiving a normal diet and also in animals given a high fat diet to examine the contribution of hyperlipidemia towards the development of neointimal hyperplasia in this setting. Reduction of vein graft neointimal hyperplasia by inhibition of TNF may have significant therapeutic implications for human vascular diseases.