中文摘要：

目的：研究大鼠线粒体融合素基因2（Mfn2）在去除蛋白激酶A（PKA）磷酸化位点后对大鼠血管平滑肌细胞（VSMC）增殖的影响及其相关的信号通路。方法：构建携带去除PKA磷酸化位点的Mfn2重组腺病毒[Adv-Mfn2-PKA（△）]和携带Mfn2的重组腺病毒（Adv-Mfn2）并感染VSMC。Western blot分析法Mfn2-PKA（△）和Mfn2蛋白的表达;激光共聚焦显微镜观察其亚细胞定位;荧光显微镜观察细胞形态变化;四甲基偶氮唑盐（MTT）法比较其对细胞增殖的影响;Western blot法分析磷酸化ERK1/2（p-ERK1/2）蛋白表达变化。结果：激光共聚焦显微镜示Mfn2-PKA（△）与Mfn2蛋白都主要分布于线粒体外膜;荧光显微镜示Mfn2组细胞数较少,而Mfn2-PKA（△）组与对照组相似;MTT示,Mfn2-PKA（△）抑制VSMC增殖作用较Mfn2显著减弱（〈0.01）,与对照组无显著差异;Westernblot结果显示,Mfn2-PKA（△）较Mfn2组p-ERK1/2表达显著升高（〈0.01）,与对照组无明显差异。结论：Mfn2-PKA（△）与Mfn2蛋白一样都定位于线粒体外膜 ，但抑制VSMC增殖的作用消失，对ERK1／2信号通路无抑制作用。表明PKA磷酸化位点是调控Mfn2抗VSMC增殖的重要功能位点。

英文摘要：

Objective：The aim of the study is to investigate the effect of Mfn2 with the removal of PKA phos- phorylation site （Mfn2-PKA（△）） on inhibiting the proliferation of VSMC and related signaling pathway. Meth- ods： VSMC of rat were infected by adenovirus-mediated Mfn2-PKA （ A ） （Adv-Mfn2-PKA （△）） or adenovirusmediated Mfn2（Adv Mfn2）. The abundance of Mfn2-PKA（△） protein and Mfn2 protein were determined by Western blot analysis using Mfn2 antibody. Laser confocal microscopy（LCMS） was used to observe the location of proteins. The number of VSMC was analyzed by fluorescence microscopy. The effect of Adv-Mfn2-PKA（△） on the proliferation of VSMC was explored by MTT. Western blot was used to detect the expression of p-ERK1/2. Results：Both Mfn2-PKA（△） and Mfn2 were located at the out membrane of mitochondria. Fluorescence microsco- py showed the number of VSMC increased remarkably in Mfn2-PKA（△） group comparing with Mfn2 group at 48 hours later. The results of MTT indicated that Mfn2-PKA（△） gene cannot attenuate the effect on inhibiting the proliferation of VSMC （P〈0.01）. Western blot indicated that overexpression of Mfn2-PKA（△） gene could not down regulate the phosphorylation of ERK1/2 （P〈O. 01）. Conclusions： Mfn2-PKA（△） has no effect on suppress- ing the proliferation of VSMC. PKA phosphorylation site plays an important role in regulating the anti-prolifera- tion of Mfn2 gene.