Deficiency of Endothelial Cxcr4 Reduces Reendothelialization and Enhances Neointimal Hyperplasia After Vascular Injury in Atherosclerosis-Prone Mice
Deficiency of Endothelial Cxcr4 Reduces Reendothelialization and Enhances Neointimal Hyperplasia After Vascular Injury in Atherosclerosis-Prone Mice
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DOI：
10.1161/atvbaha.113.302878
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发表时间：
2014-06-01
影响因子：
8.7
通讯作者：
Weber, Christian
中科院分区：
文献类型：
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作者：
Noels, Heidi;Zhou, Baixue;Weber, Christian
目的CXCL12/CXCR4趋化因子配体/受体轴介导血管内皮细胞前体细胞的动员，驱动损伤诱导的新生内膜增生。本研究旨在探讨内皮细胞CXCR4在新生内膜形成中的作用。方法与结果-用骨髓X-激酶(BMX)-Creer(T2)报告小鼠进行半乳糖苷酶染色和双重免疫荧光显示，与BMX-Creer(T2-)CXCR4-Floated载脂蛋白E缺陷(APOE(-/-))小鼠(分别称为CXCR4(EC-KO)ApoE(-/-)和CXCR4(EC-WT)ApoE(-/-))相比，BMX-Creer(T2+)中CXCR4的高效和内皮特异性缺失。内皮细胞CXCR4缺乏显著增加CXCR4(EC-KO)ApoE(-/-)小鼠颈动脉内膜损伤诱导的新生内膜形成。皮损中巨噬细胞数量增多，而平滑肌细胞和胶原含量减少。与CXCR4(EC-WT)ApoE(-/-)对照相比，受损的CXCR4(EC-KO)ApoE(-/-)颈动脉再内皮化和内皮细胞增殖显著减少。此外，在体外划痕实验中，用趋化因子(C-X-C基序)配体12(CXCL12)刺激人主动脉内皮细胞显著增强了它们的伤口愈合能力，这一作用可被CXCR4拮抗剂AMD3100逆转。此外，流式细胞术分析显示血管损伤后CXCR4(EC-KO)ApoE(-/-)小鼠的Sca1(+)Flk1(+)CD31(+)和Lin(-)Sca1(+)祖细胞的动员减少，尽管CXCR4表面的表达没有改变。CXCL12、血管内皮生长因子、1-磷酸鞘氨醇或Flt3(FMS相关酪氨酸激酶3)配体的血浆浓度没有差异，所有这些细胞因子都在祖细胞动员中发挥了既定的作用。然而，双重免疫荧光显示CXCR4(EC-KO)ApoE(-/-)小鼠损伤的颈动脉局部内皮细胞CXCL12染色显著减少。结论内皮细胞CXCR4通过内皮伤口的愈合和增殖以及通过动员Sca1(+)Flk1(+)CD31(+)细胞(通常被称为循环内皮祖细胞)在血管损伤后的有效内皮化中起关键作用。
Objective The Cxcl12/Cxcr4 chemokine ligand/receptor axis mediates the mobilization of smooth muscle cell progenitors, driving injury-induced neointimal hyperplasia. This study aimed to investigate the role of endothelial Cxcr4 in neointima formation.Approach and Results -Galactosidase staining using bone marrow x kinase (Bmx)-CreER(T2) reporter mice and double immunofluorescence revealed an efficient and endothelial-specific deletion of Cxcr4 in Bmx-CreER(T2+) compared with Bmx-CreER(T2-)Cxcr4-floxed apolipoprotein E-deficient (Apoe(-/-)) mice (referred to as Cxcr4(EC-KO)ApoE(-/-) and Cxcr4(EC-WT)ApoE(-/-), respectively). Endothelial Cxcr4 deficiency significantly increased wire injury-induced neointima formation in carotid arteries from Cxcr4(EC-KO)ApoE(-/-) mice. The lesions displayed a higher number of macrophages, whereas the smooth muscle cell and collagen content were reduced. This was associated with a significant reduction in reendothelialization and endothelial cell proliferation in injured Cxcr4(EC-KO)ApoE(-/-) carotids compared with Cxcr4(EC-WT)ApoE(-/-) controls. Furthermore, stimulation of human aortic endothelial cells with chemokine (C-X-C motif) ligand 12 (CXCL12) significantly enhanced their wound-healing capacity in an in vitro scratch assay, an effect that could be reversed with the CXCR4 antagonist AMD3100. Also, flow cytometric analysis showed a reduced mobilization of Sca1(+)Flk1(+)Cd31(+) and of Lin(-)Sca1(+) progenitors in Cxcr4(EC-KO)ApoE(-/-) mice after vascular injury, although Cxcr4 surface expression was unaltered. No differences could be detected in plasma concentrations of Cxcl12, vascular endothelial growth factor, sphingosine 1-phosphate, or Flt3 (fms-related tyrosine kinase 3) ligand, all cytokines with an established role in progenitor cell mobilization. Nonetheless, double immunofluorescence revealed a significant reduction in local endothelial Cxcl12 staining in injured carotids from Cxcr4(EC-KO)ApoE(-/-) mice.Conclusions Endothelial Cxcr4 is crucial for efficient reendothelialization after vascular injury through endothelial wound healing and proliferation, and through the mobilization of Sca1(+)Flk1(+)Cd31(+) cells, often referred to as circulating endothelial progenitor cells.