基质金属蛋白酶抑制物-2基因转移对家兔动脉粥样硬化斑块的影响

目的探讨局部转染金属蛋白酶抑制物(pcDNA3TIMP2)基因对动脉粥样硬化斑块的影响。方法内皮剥脱加高脂饮食建立兔动脉粥样硬化动物模型,基因球囊局部转染pcDNA3TIMP2,RT PCR和Westernblot分别检测动脉粥样硬化斑块局部外源基因转移效果,Zymography检测动脉粥样硬化斑块局部基质金属蛋白酶(MMPs)活性,病变股动脉组织行HE和苦味酸酸性品红染色,全自动图像分析仪行图像处理,测量血管腔面积、胶原成分含量。结果基因转染组术后2周动脉粥样硬化局部TIMP2基因表达即明显高于空白载体对照组(P<0.01),术后4周达高峰;术后2、4、8周TIMP2蛋白表达也明显高于空白载体对照组(P<0.01),MMP2和MMP9活性低于对照组。局部转染TIMP2基因组动物,动脉粥样硬化斑块纤维帽厚度和病变局部胶原含量均明显高于对照组,但病变血管腔面积与对照组差异则无统计学意义。结论动脉粥样硬化局部转移TIMP2基因可明显抑制病变局部MMP2和MMP9活性,增加动脉粥样硬化斑块纤维帽厚度和病变局部胶原含量,但对动脉粥样硬化所致血管腔狭窄程度无明显影响。

Effects of TIMP-2 gene transfer on atherosclerotic plaque in rabbits

ObjectiveTo evaluate the effects of TIMP-2 local gene transfer on atherosclerotic plaque. MethodsAtherosclerosis models were induced by denuding femoral artery endothelium plus high lipid diet in rabbits. TIMP-2 gene was transferred locally by balloons eluted with pcDNA3-TIMP-2. RT-PCR and Western blot were performed to verify exogenous genes transfer. MMPs activity in atherosclerotic plaque was evaluated by zymography. HE and VG staining and automatic image analysis system were used for pathological analysis of atherosclerotic femoral arteries. The lumen area of the vessel and the collagen contents in the atherosclerotic plaque were measured. ResultsThe expression of TIMP-2 gene in pcDNA3-TIMP-2 transferred group was significantly higher than control-vector transferred group at the end of week 2 after operation and reached the peak at the end of week 4. Comparing with the control group, the expression of TIMP-2 protein in treated group was also higher at the end of week 2, 4, and 8 after operation. Correspondingly, the MMP-2 and MMP-9 activities were lower in treated group. The thickness of fibrous cap of atherosclerotic plaque and the amount of collagen of the lesion were increased significantly in treated group compared with the control group, but there were no significant differences in vessel lumen area. Conclusion TIMP-2 gene transfer locally in atherosclerotic plaque could inhibit the activities of MMP-2 and MMP-9 in the lesion, increase the thickness of fibrous cap and the amount of collagen of the lesion, but may have no effect on the degree of the stenosis.