Adhesion molecule expression in fibroblasts - Alteration in fibroblast biology after transfection with LOX-1 plasmids
Adhesion molecule expression in fibroblasts - Alteration in fibroblast biology after transfection with LOX-1 plasmids
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DOI：
10.1161/01.hyp.0000179045.95915.b0
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发表时间：
2005-09-01
期刊：
影响因子：
8.3
通讯作者：
Mehta, JL
中科院分区：
文献类型：
--
作者：
Chen, K;Chen, JW;Mehta, JL
内皮凝集素样氧化修饰LDL受体LOX- 1在动脉粥样硬化和心肌缺血的发病机制中起关键作用。Ox- LDL结合LOX- 1导致各种粘附分子的表达，这些粘附分子将单核细胞吸引到内皮细胞，这是动脉粥样硬化的第一步。我们希望研究ox- LDL/ LOX- 1信号通路在天然表达低水平LOX- 1的成纤维细胞中的作用。用巨细胞病毒(CMV)- LOX-1(wt)（氨基酸[aa] 1 ~ 273）或CMV- LOX-1(1 ~ 261)（一种ox- LDL结合阴性突变体，aa 1 ~ 261）质粒转染大鼠心脏成纤维细胞。Western blot结果显示，转染CMV- LOX- 1（wt）或CMV- LOX- 1（1-261）质粒的细胞中LOX- 1蛋白表达显著升高（P < 0.01）。转染CMV- LOX- 1wt的成纤维细胞显示ox- LDL结合，而未转染的成纤维细胞和转染CMV- LOX- 1（1-261）的成纤维细胞不结合ox- LDL。与未转染细胞相比，ox- LDL处理（50 μ g/ mL， 24小时）显著诱导CMV- LOX- 1转染细胞（wt）表达白细胞黏附分子细胞间黏附分子- 1（ICAM- 1）、血管细胞黏附分子- 1(VCAM)- 1和基质金属蛋白酶(MMP)- 1(P < 0.05)，而CMV- LOX- 1转染细胞（1-261）无明显表达。同时，ox- LDL处理增强了CMV- LOX- 1（wt）转染细胞中p38丝裂原活化蛋白激酶（MAPK）的磷酸化（与对照组相比P < 0.05）。这些数据表明，在心脏成纤维细胞中，ox- LDL与LOX- 1结合并激活p38 MAPK，随后表达ICAM- 1， VCAM- 1和MMP- 1。因此，在转染CMV- LOX- 1（wt）和随后暴露于ox- LDL后，成纤维细胞转化为内皮表型。本研究为研究LOX- 1的分子生物学提供了一个有用的模型系统（质粒转染成纤维细胞）。
The endothelial lectinlike, oxidatively ( ox-) modified LDL receptor LOX- 1 is a critical player in the pathogenesis of atherosclerosis and myocardial ischemia. Ox- LDL binding of LOX- 1 results in the expression of various adhesion molecules, which attract monocytes to endothelial cells, an initial step in atherogenesis. We wished to examine the role of the ox- LDL/ LOX- 1 signaling pathway in fibroblasts, which naturally express low levels of LOX- 1. Rat cardiac fibroblasts were transfected with either cytomegalovirus ( CMV)- LOX-1(wt) ( amino acids [ aa] 1 to 273) or CMV- LOX- 1(1-261) ( an ox- LDL - binding negative mutant, aa 1 to 261) plasmid. Western blots showed that LOX- 1 protein expression was increased significantly in cells transfected with CMV- LOX- 1(wt) or CMV- LOX- 1(1-261) plasmid ( P < 0.01 vs control). Fibroblasts transfected with CMV- LOX- 1wt showed ox- LDL binding, whereas fibroblasts without transfection and those transfected with CMV- LOX- 1(1-261) did not bind ox- LDL. Compared with untransfected cells, ox- LDL treatment ( 50 mu g/ mL, 24 hours) markedly induced the expression of the leukocyte adhesion molecules intercellular adhesion molecule- 1 ( ICAM- 1), and vascular cell adhesion molecule- 1 ( VCAM)- 1 as well as matrix metalloproteinase ( MMP)- 1 in cells transfected with CMV- LOX- 1(wt) ( P < 0.05) but not in cells transfected with CMV- LOX- 1(1-261). Concurrently, ox- LDL treatment enhanced the phosphorylation of p38 mitogen- activated protein kinase ( MAPK) ( P < 0.05 vs control) in CMV- LOX- 1(wt) - transfected cells. These data suggest that in cardiac fibroblasts, ox- LDL binds to LOX- 1 and activates p38 MAPK, followed by the expression of ICAM- 1, VCAM- 1, and MMP- 1. Thus, fibroblasts transform into an endothelial phenotype on transfection with CMV- LOX- 1(wt) and subsequent exposure to ox- LDL. This study provides a useful model system ( plasmid- transfected fibroblasts) to study the molecular biology of LOX- 1.