转染组织纤溶酶原激活物及内皮型一氧化氮合酶基因的内皮细胞和平滑肌细胞共同种植于人工血管对内膜增生的影响

Neointimal hyperplasia in the vessel grafts after seeding both endothelial cells and smooth muscle cells respectively transfected with tissue plasminogen activator and endothelial nitric oxide synthase

背景:前期研究表明,双层细胞种植能有效提高内皮细胞保留率,将组织纤溶酶原激活物基因转染到内皮细胞中能提高其细胞溶解纤维蛋白的能力。目的:采用双细胞种植及修饰内皮的组织纤溶酶原激活物基因提高内皮细胞保留率和抗栓能力,通过内皮型一氧化氮合酶基因调控平滑肌细胞的增殖,观察对小口径人工血管通畅率的影响。方法:以4种不同组合细胞(内皮细胞+平滑肌细胞SMC,内皮细胞/组织纤溶酶原激活物+平滑肌细胞,内皮细胞+平滑肌细胞/内皮型一氧化氮合酶,内皮细胞/组织纤溶酶原激活物+平滑肌细胞/内皮型一氧化氮合酶)种植在PTFE管腔面。将新西兰大白兔随机分成4组,4种人工血管经旁路分别移植在4组兔的腹主动脉上。结果与结论:移植后60d,种植内皮细胞+平滑肌细胞组和内皮细胞+平滑肌细胞/内皮型一氧化氮合酶组内膜厚度无明显差异(P>0.05)。与内皮细胞/组织纤溶酶原激活物+平滑肌细胞/内皮型一氧化氮合酶组相比,未转染内皮型一氧化氮合酶组(内皮细胞/组织纤溶酶原激活物+平滑肌细胞)内膜明显增厚(P<0.05);未转染组织纤溶酶原激活物组(内皮细胞+平滑肌细胞/内皮型一氧化氮合酶)内膜较薄(P<0.05)。提示组织纤溶酶原激活物基因转染可以促进血管内膜增生导致血管狭窄,但同时转入内皮型一氧化氮合酶基因可以抑制组织纤溶酶原激活物的促进平滑肌细胞增殖及内膜增生的作用。

BACKGROUND：Previous studies have shown that double layer cells implantation improves retention rate of vascular prosthesis endothelial cells.The fibrinolysis ability of endothelial cells（ECs） is improved after transfection with tissue plasminogen activator（tPA）.OBJECTIVE：In order to enhance the antithrombotic ability and adhesion to polytetrafluoroethylene（PTFE） of ECs,tPA gene was introduced into ECs by pseudotyped retroviral vector.And endothelial nitric oxide synthase（eNOS） gene was introduced into smooth muscle cells（SMCs） to research whether eNOS gene transfection can inhibit the proliferation of neointimal hyperplasia with grafted both SMCs and ECs transfected with tPA.METHODS：The SMCs and ECs were implanted in PTFE grafts successively according to the following combination：ECs＋SMCs,ECs/tPA＋SMCs,ECs＋SMCs/eNOS,ECs/tPA＋SMCs/eNOS.Twenty-four adult New Zealand rabbits were randomly divided into 4 groups（n = 6）.The above four types of PTFE covered with ECs and MSCs were transplanted respectively into the abdominal aorta of rabbits in four groups as bypass graft.RESULTS AND CONCLUSION：There was no difference in neointimal thickness between grafts seeded with ECs＋SMCs and grafts seeded with ECs＋SMCs/eNOS（P 0.05）.But compared with the grafts seeded with ECs/tPA＋SMCs/eNOS,the neointimal thickness on grafts seeded with ECs/tPA＋SMCs was significantly thicker（P 0.05）,while the neointimal thickness on grafts seeded with ECs＋SMCs/eNOS was significantly thinner（P 0.05）.tPA gene in ECs can promote neointimal hyperplasia in the vessel graft seeded with ECs＋SMCs,but eNOS gene in SMCs can inhibit this effect.