GENE AND STEM CELL THERAPY IN CORONARY ARTERY BYPASS GRAFT

 描述(由申请人提供)：隐静脉(SV)移植失败是接受冠状动脉旁路移植(CABG)手术的患者常见的临床问题。潜在的机制仍不清楚。各种治疗方法的失败，包括靶向基因治疗，可能是由于基因选择不当和/或使用了与人类疾病不同的动物模型。此外，也没有考虑促进内皮细胞的增殖。我们观察到PTEN的失活伴随着人类SV中SMC增殖的增加，而PTEN的过表达限制了细胞的增殖。由于PTEN调控细胞信号传导和细胞生长，因此PTEN转基因在移植血管内膜中的表达可以防止内膜增生的发生。此外，用间充质干细胞(MSCs)修复内皮细胞(ECs)将抑制血栓形成。假设在冠状动脉旁路移植术前，通过PTEN转基因抑制血管内膜增殖，同时通过移植MSCs保护血管内皮细胞，将是维持移植静脉通畅的最佳策略。我们将在我们实验室常规使用的猪动脉粥样硬化模型中进行这些研究，并使用“无接触技术”分离的腹壁浅静脉(SEV)进行冠状动脉搭桥术。目的1：我们的假设是，PTEN转基因在动脉粥样硬化猪冠状动脉移植静脉的SMC中的过表达将阻止搭桥静脉移植后新生内膜的发展。目的：我们的假设是，在动脉粥样硬化猪冠状动脉移植静脉的SMCs中，MSCs与PTEN转基因联合修复内皮细胞可预防搭桥静脉的血栓形成和新生内膜增生，且优于单独PTEN转基因移植的效果。目的：我们的假设是PTEN基因的过表达和MSCs诱导的内皮细胞再生可以减轻炎症，抑制狭窄重塑，抑制冠状动脉移植静脉的新生内膜增生。将自体SEV接种于PTEN载体和MSCs中，然后进行动脉粥样硬化猪的主动脉-冠状动脉移植。EKG和超声心动图监测心功能，冠状动脉造影和最佳相干断层成像量化节段内最小管腔直径、直径狭窄、晚期丢失和内膜增生将检查该疗法的疗效。组织学参数将包括内膜厚度、管腔面积、内膜中层比率、斑块的发展和溃烂、血栓形成、细胞外基质和再闭塞。在切除的静脉移植物中，将检测促炎症、抗炎和促增殖通路的表达，并与新生内膜增生和狭窄重塑的程度相关。这些研究的结果将为我们的假设提供概念上的支持，并使我们能够将我们的研究转化为临床第一阶段研究，使用PTEN工程的自体MSCs治疗并可能治愈CABG后的静脉移植物疾病。

 DESCRIPTION (provided by applicant): Saphenous vein (SV) graft failure is a common clinical problem in patients undergoing coronary artery bypass graft (CABG) surgery. Underlying mechanisms are still unclear. Failure of various therapies, including targeted gene therapy, could be due to the bad choice of the gene and/or the use of animal model dissimilar to human disease. Also, there was no consideration to promote endothelial cell proliferation. We observed inactivation of PTEN with increased proliferation of SMCs in human SV and PTEN overexpression limits cell proliferation. Since PTEN modulates cell signaling and cell growth, PTEN transgene expression in SV graft SMCs would prevent the development of intimal hyperplasia. Also, the repair of endothelial cells (ECs) with mesenchymal stem cells (MSCs) would inhibit thrombosis. The hypothesis is that the inhibition of intimal hyperplasia by PTEN transgene while preserving endothelium with the delivery of MSCs in autologous vein grafts prior to CABG would be the best strategy to maintain vein graft patency. We will do these studies in a well-established and routinely used in our laboratory the swine model of atherosclerosis and perform CABG using superficial epigastric vein (SEV) isolated with "no touch technique". Aim 1: Our hypothesis predicts that the overexpression of PTEN transgene in the SMCs of vein graft in coronary arteries in atherosclerotic swine will prevent the development of neointimal hyperplasia in bypass vein graft. Aim 2: Our hypothesis predicts that the repair of endothelial cells with MSCs together with PTEN transgene in the SMCs of vein graft in coronary arteries of atherosclerotic swine will prevent thrombosis and neointimal hyperplasia in bypass vein graft, and this would be superior to the effect of PTEN transgene alone. Aim 3: Our hypothesis predicts that overexpression of PTEN transgene and MSCs-induced endothelial cell regeneration would reduce inflammation and inhibit constrictive remodeling together with inhibition of neointimal hyperplasia in the vein graft in coronary arteries. The autologous SEV will be exposed to PTEN vector and MSCs followed by aorto-coronary grafting in atherosclerotic swine. EKG and echocardiography to monitor heart function, and coronary angiography and optimal coherence tomography to quantify in-segment minimal luminal diameter, diameter stenosis, late loss and intimal hyperplasia will examine the therapeutic efficacy of this therapy. Histological parameters will include the intimal thickness, lumen area, intima-media ratio, development and ulceration of plaque, thrombosis, extracellular matrix, and re-occlusion. Expression of pro- and anti-inflammatory and pro-hyperplasia pathways will be examined in excised vein graft and correlated with the degree of neointimal hyperplasia and constrictive remodeling. Findings from these studies will provide the conceptual support for our hypothesis, and position us to translate our investigation into a clinical phase 1 study for the use of PTEN-engineered autologous MSCs for the treatment and possibly cure of the vein graft disease following CABG.