Krohn Regina, Raffetseder Ute, Bot Ilze, Zernecke Alma, Shagdarsuren Erdenechimeg, Liehn Elisa A, van Santbrink Peter J, Nelson Peter J, Biessen Erik A, Mertens Peter R, Weber Christian
Institute for Molecular Cardiovascular Research, University Hospital Aachen, RWTH Aachen University, Aachen, Germany.
Circulation. 2007 Oct 16;116(16):1812-20. doi: 10.1161/CIRCULATIONAHA.107.708016. Epub 2007 Sep 24.
The CC chemokine CCL5/Regulated on Activation, Normal T Cell Expressed and Secreted (RANTES) is upregulated in mononuclear cells or deposited by activated platelets during inflammation and has been implicated in atherosclerosis and neointimal hyperplasia. We investigated the influence of the transcriptional regulator Y-box binding protein (YB)-1 on CCL5 expression and wire-induced neointimal hyperplasia.
Analysis of the CCL5 promoter revealed potential binding sites for YB-1, and interaction of YB-1 with a sequence at position -204/-173 was confirmed by DNA binding assays. Both YB-1 expression and CC chemokine ligand-5 (CCL5) mRNA expression were increased in neointimal versus medial smooth muscle cells, as analyzed by real-time polymerase chain reaction. Overexpression of YB-1 in smooth muscle cells (but not macrophages) enhanced CCL5 transcriptional activity in reporter assays, mRNA and protein expression, and CCL5-mediated monocyte arrest. Carotid arteries of hyperlipidemic apolipoprotein E-deficient mice were subjected to intraluminal transfection with a lentivirus encoding YB-1 short hairpin RNA or empty vector directly after wire injury. Double immunofluorescence revealed YB-1 expression in neointimal smooth muscle cells but not macrophages and colocalization with neointimal CCL5, which was downregulated by YB-1 short hairpin RNA. Neointima formation was decreased significantly after YB-1 knockdown compared with controls and was associated with a diminished content of lesional macrophages. A reduction of lesion formation by YB-1 knockdown was not observed in apolipoprotein E-deficient mice deficient in the CCL5 receptor CCR5 or after treatment with the CCL5 antagonist Met-RANTES, which indicates that YB-1 effects were dependent on CCL5.
The transcriptional regulator YB-1 mediates CCL5 expression in smooth muscle cells and thereby contributes to neointimal hyperplasia, thus representing a novel target with which to limit vascular remodeling.
CC趋化因子CCL5/活化正常T细胞表达和分泌调节因子（RANTES）在炎症期间单核细胞中上调或由活化血小板沉积，并且与动脉粥样硬化和新生内膜增生有关。我们研究了转录调节因子Y盒结合蛋白（YB）-1对CCL5表达和钢丝诱导的新生内膜增生的影响。
对CCL5启动子的分析揭示了YB-1的潜在结合位点，并且通过DNA结合试验证实了YB-1与-204/-173位序列的相互作用。通过实时聚合酶链反应分析，新生内膜平滑肌细胞中YB-1表达和CC趋化因子配体-5（CCL5）mRNA表达均高于中膜平滑肌细胞。在报告基因试验中，YB-1在平滑肌细胞（而非巨噬细胞）中的过表达增强了CCL5转录活性、mRNA和蛋白表达以及CCL5介导的单核细胞滞留。高脂血症载脂蛋白E缺陷小鼠的颈动脉在钢丝损伤后直接用编码YB-1短发夹RNA的慢病毒或空载体进行腔内转染。双重免疫荧光显示新生内膜平滑肌细胞中有YB-1表达，但巨噬细胞中无，且YB-1与新生内膜CCL5共定位，而YB-1短发夹RNA可使其下调。与对照组相比，YB-1敲低后新生内膜形成显著减少，并且与损伤部位巨噬细胞含量减少有关。在缺乏CCL5受体CCR5的载脂蛋白E缺陷小鼠中或用CCL5拮抗剂Met-RANTES治疗后，未观察到YB-1敲低导致的损伤形成减少，这表明YB-1的作用依赖于CCL5。
转录调节因子YB-1介导平滑肌细胞中CCL5的表达，从而促进新生内膜增生，因此是限制血管重塑的一个新靶点。
