转录因子Foxp1在TGF-β1诱导的VSMC表型转化中的作用

Role of transcription factor Foxp1 in TGF-beta1 induced phenotype switch of vascular smooth muscle cells

目的:研究转录调节因子叉头框蛋白P1(Foxp1)在急性Stanford A型主动脉夹层患者主动脉壁的表达情况并探讨Foxp1在TGF-β1诱导的主动脉血管平滑肌细胞(VSMC)表型转化中的作用。方法:收集急性Stanford A型主动脉夹层手术切除的主动脉标本,通过RT-PCR和Western Blot方法检测标本中Foxp1的mRNA与蛋白表达情况。Foxp1重组质粒转染大鼠主动脉平滑肌细胞,通过荧光显微镜观察其转染结果;将大鼠主动脉平滑肌细胞进行不同处理并分为3组(+TGF-β1、Foxp1质粒转染、Foxp1质粒转染+TGF-β1),以未做处理的大鼠主动脉平滑肌细胞为空白对照,通过RT-PCR和Western Blot方法检测4组细胞中Foxp1、收缩型细胞标志物α-SMA、SM22α以及合成型细胞标志物骨桥蛋白(OPN)的表达情况。结果:在急性Stanford A型主动脉夹层患者主动脉壁中Foxp1的mRNA与蛋白表达显著降低(均P<0.05);荧光显微镜下观察可见大量转染成功的细胞;与空白对照组细胞相比,Foxp1质粒转染组大鼠主动脉平滑肌细胞中Foxp1的mRNA与蛋白表达明显上调(均P<0.05),+TGF-β1组大鼠主动脉平滑肌细胞中α-SMA、SM22α的mRNA与蛋白表达明显下调,OPN的mRNA与蛋白表达明显上调(均P<0.05);与+TGF-β1组相比,Foxp1质粒转染+TGF-β1组中α-SMA、SM22α的mRNA与蛋白表达明显上调,OPN的mRNA与蛋白表达明显下调(均P<0.05)。结论:急性Stanford A型主动脉夹层患者主动脉壁中Foxp1的表达降低;Foxp1能抑制TGF-β1诱导的VSMC表型转化。在急性主动脉夹层的发生进展中,Foxp1的表达降低可能起重要作用。

Objective:To study the expression of forkhead box protein 1(Foxp1)in aortic samples from acute type A aortic dissection patients and the role of Foxp1 in the phenotypic switch of aortic vascular smooth muscle cells(VSMCs)induced by TGF-β1.Methods:Aortic specimens from patients of acute Stanford type A aortic dissection were collected,and the mRNA and protein expression of Foxp1 in the specimens was assayed by RT-PCR and Western Blot.The Foxp1 recombinant plasmid was transfected into rat aortic smooth muscle cells,and the results of the transfection were observed by fluorescence microscope.The rat aortic smooth muscle cells were treated differently and divided into three groups(+TGF-β1,Foxp1 plasmid transfection,and Foxp1 plasmid transfection+TGF-β1).The untreated rat aortic smooth muscle cells were used as a blank control.The expression of Foxp1,α-SMA,SM22α,and OPN in the four groups of cells was detected by RT-PCR and Western Blot.Results:Both mRNA and protein expression levels of Foxp1 in the aortic wall of patients with acute Stanford A aortic dissection were significantly reduced(all P<0.05).A large number of successfully transfected cells can be seen under fluorescence microscope in transfection groups.Compared with that respectively in the blank control group,α-SMA and SM22αexpression was significantly down-regulated,while OPN expression was significantly up-regulated(all P<0.05)in the Foxp1 plasmid transfection group(all P<0.05).Compared with that respectively in the+TGF-β1 group,the expression ofα-SMA and SM22αin the Foxp1 plasmid transfection+TGF-β1 group was significantly up-regulated,while OPN expression was significantly down-regulated(all P<0.05).Conclusion:The expression of Foxp1 in the aortic wall of patients with acute Stanford A aortic dissection is significantly reduced.Foxp1 can inhibit the phenotypic switch of VSMCs induced by TGF-β1.In the occurrence and progression of acute aortic dissection,the decreased expression of Foxp1 may play an important role.