纳米粒子介导反义mTOR基因转染抑制移植静脉内膜增生

The effect of antisense mTOR gene mediated by nanoparticles on neointimal formation in vein graft in rats

目的观察以纳米粒子为载体的外源性反义雷帕霉素靶蛋白(mTOR)基因局部转染对移植静脉内膜增生的影响。方法应用聚乳酸聚乙醇酸共聚物(PLGA)和聚乙烯醇(PVA)包载mTOR基因,制备纳米级粒子混合物。建立自体静脉移植模型72只,随机分成转基因组(转染以纳米粒子为载体的反义mTOR基因),空载体组(单纯转染纳米粒子包载的空载体)和对照组(不予特殊处理)。分别于术后3,7,14,28d取材。检测mTOR基因的mRNA及蛋白产物表达,以及血管平滑肌细胞(VSMC)凋亡的动态变化。结果转基因组内膜中mTOR基因的mRNA及蛋白产物表达较其他两组明显减少(P<0.05);转基因组内膜增生厚度于7,14,28d较其他组明显减少(P<0.01);转基因组凋亡细胞较其他组明显增高(P<0.05)。结论纳米粒子可以作为转基因载体。反义mTOR基因的表达能有效抑制自体移植静脉内膜的增生及促进VSMC凋亡。

Objective To study the effect of antisense mTOR gene transfection mediated by nanoparticles （ NP ） on intimal perliferation after vein grafting. Methods Nanoparticle antisense roTOR gene complex was prepared with PLGA and PVA. Autogenous vein graft model was established in 72 rats by transplanting internal branch of jugular vein to carotid artery. Three groups were studied ： （ 1 ） antisense mTOR group, antisense mTOR gene mediated by NP was transfected into the veins before anastomosis. （2） Empty vector group, the vein was transfected by empty vector mediated by NP. （3） Control group, no transfection. The grafted veins were harvested 3 days, 1 week, 2 weeks and 4 weeks after operation, respectively. The exogenous mTOR mRNA and protein expression were determined and intimal hyperplasia （ IH ） was observed. The presence of apoptotic VSMC was also detected. Results Antisense mTOR gene transfection mediated by nanoparticle complex inhibited the mRNA and protein expression of mTOR gene （ P 〈 0.05 ） , and the IH was inhibited in the vein graft especially during 7 d - 28 d （ P 〈 0. 01 ）. Conclusions Nanoparticle is an effective gene transfecting carrier, and antisense mTOR gene expression can prevent the IH and promote apoptosis after vein grafting.