gax基因在移植静脉重塑早期过表达对平滑肌细胞转化态的影响

Effects of gax mRNA overexpression transferred by recombinant adeno-associated virus on phecotypic changes of vascular smooth muscle cells in venous autografts

目的 探讨 gax基因在移植静脉重塑早期过表达对平滑肌细胞 (VSMCs)表型转化的影响。方法 48只大鼠随机分为实验组与对照组 ,每组 2 4只 ,均行右颈内静脉移植到同侧颈总动脉显微手术。术后 14d取出移植静脉 ,检测并观察 gax基因、凋亡相关基因及VSMCs的表型转化状态。结果 实验组与对照组比较 :gaxmRNA表达明显增加 (10 6.9± 3 8.7,P <0 .0 1) ,末端脱氧核苷酸转移酶介导的dUTP缺口末端标记 (TUNEL)阳性细胞明显增多 (5 0 .5± 2 0 .4,P <0 .0 1)和增殖细胞核抗原 (PCNA)阳性细胞显著减少 (3 3 .86± 13 .3 8,P <0 .0 1) ;bcl 2表达明显下降 (13 .0±4.6,P <0 .0 1) ;p5 3、bax表达显著增高 (分别为 2 7.0 0± 7.2 5或 2 8.6± 5 .5 ,P均 <0 .0 1)。

Objective To explore the effects of gax gene mRNA overexpression on apoptosis of vascular smooth muscle cells (VSMCs) in venous autografts,and search for an ideal approach for inhibition of intimal hyperplasia (IH) after autogenous vein grafting.Methods Forty-eight Wistar rats weighing 200- 300 g were randomly divided into 2 groups:control group and experimental group (n= 24 in each group).A rat experimental model of autogenouse vein graft was established by transplanting the right internal jugular vein into the right common carotide artery in 48 rats.The transplanted vein in the experimental group was coated using glue gel (Pluronic F127) in which rAAA gax was added just after anastomosis,while the controls were coated only with glue gel without gax gene.The vein grafts were taken at 14th day after operation.Reverse transcription polymerase chain reaction,terminal deoxynucleotidy1 transferase-mediated X-dUTP nick end labiling and immunohistochemical technique were used to detect the expression of gax mRNA,proliferating cell nuclear antigen (PCNA),p53,bcl-2,bax,and apoptosis of VSMCs in vein graft.Results In the experimental group,there were remarkable increases in the expression of gax gene mRNA (106.9± 38.7, P< 0.01), p53 (27.0± 7.2, P< 0.01), bax gene (28.6± 5.5, P< 0.01) and TUNEL (50.5± 20.4, P< 0.01),and significant decreases in the expression of bcl 2 (13.0± 4.6, P< 0.01), PCNA gene (33.86± 13.38, P< 0.01), as acompared with the control group.Conclusion The overexpression of gax mRNA can enhance the apoptosis of VSMCs in autogenous vein after vein grafting.