转染金属蛋白酶抑制剂2基因对损伤血管平滑肌细胞核因子-κB和蛋白激酶C的影响

Effect of transfected tissue inhibitor of metalloproteinase-2 on nuclear factor-κB and protein kinase C of the injured rabbit vascular smooth cells

目的 探讨血管平滑肌细胞 (VSMC)损伤后金属蛋白酶 (MMPs)和蛋白激酶C(PKC)、核因子 -κB(NF -κB)表达的变化。 方法 采用脂质体对VSMC转染金属蛋白酶抑制剂 2 (TIMP- 2 )基因进行基因转染 ,并用Westernblot加以鉴定 ,分别用酶谱分析法、凝胶电泳迁移率分析技术(EMSA)、逆转录 -聚合酶链反应 (RT -PCR)和免疫细胞化学检测该细胞克隆MMPs、NF -κB的活性变化和PKCαmRNA、蛋白的表达水平。 结果 体外损伤的VSMC金属蛋白酶显著增加。PKCα、NF -κB在正常VSMC中很少表达 ,但在损伤的VSMC中这种表达非常显著 ,对兔VSMC进行TIMP - 2转染后 ,损伤的VSMCMMP - 2 ,9活性受抑制 ,并且PKCα、NF -κB的表达下调 (P <0 .0 5 )。结论 PKCα和NF -κB在MMPs合成及损伤VSMC迁移中有重要价值 ,TIMP - 2能通过抑制平滑肌细胞PKCα、NF -κB信号途径来防止血管再狭窄。

Objective To study the expression changes of matrix metalloproteinases (MMPs), protein kinase C (PKC) and nuclear factor-κB (NF-κB ) on the injured rabbit vascular smooth muscular cells (VSMC) transfected with tissue inhibitor of metalloproteinase-2 (TIMP-2) vector. Methods Lipofectin method was used to transfect TIMP-2 vector into VSMC, Western blot analysis to detect TIMP-2 peptides and zymography assay to determine MMPs. The activities of MMPs and NF-κB were detected by electrophoretic mobility shift assay (EMSA). The mRNA and protein expressions of PKCα were determined by RT-PCR and immunocytochemistry. Results The injured VSMC showed increased enzyme activity of MMP-2. There was very lower level expressions of PKCα and NF-κB in the normal VSMC but high in the injured VSMC. However, in injured VSMC transfected with TIMP-2 vector, the activity of MMP2/9 was suppressed and the expressions of PKCα and NF-κB decreased (P<0.05). Conclusions PKCα and NF-κB play an important role in synthesis of MMPs and mobility of the injured VSMC.TIMP-2 prevents activation of MMPs and restenosis via blocking expressions of PKCα and NF-κB.