High urokinase expression contributes to the angiogenic properties of endothelial cells derived from circulating progenitors
High urokinase expression contributes to the angiogenic properties of endothelial cells derived from circulating progenitors
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DOI：
10.1160/th05-07-0511
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发表时间：
2006-04-01
影响因子：
6.7
通讯作者：
Dignat-George, F
中科院分区：
文献类型：
--
作者：
Basire, A;Sabatier, F;Dignat-George, F
内皮祖细胞(EPC)具有独特的修复血管损伤和促进新生血管的能力，但其潜在的分子机制尚不清楚。尿激酶型纤溶酶原激活物(UPA)及其受体(UPAR)通过促进细胞外基质的蛋白分解，在细胞迁移和血管生成中发挥重要作用。本研究的目的是研究人脐血来源的内皮细胞uPA/u-PAR依赖的蛋白水解力，并分析其在体外血管生成中的作用。EPC来源的细胞(EPDC)具有晚期生长内皮细胞的典型特征，与以人脐静脉内皮细胞(HUVEC)为代表的成熟内皮细胞进行比较。应用定量流式细胞术、酶联免疫吸附试验和酶谱分析，我们发现EPDC表达较高水平的uPA和uPAR。在条件培养液中，EPDC的uPA依赖的蛋白水解酶活性也显著增加。这种活性与较高的金属蛋白酶原-2(Pro-MMP2)分泌是平行的。用阻断uPA活性或受体结合的单抗抑制EPDC相关的uPA，可显著减少细胞的增殖、迁移和毛细血管样管的形成。此外，缺血区局部分泌的肿瘤坏死因子-α和血管内皮生长因子分别上调uPA和uPAR的表达，进一步增强EPDC的蛋白分解潜能，EPDC对这些因子的反应比HUVEC更明显。综上所述，这些发现表明EPDC具有高的固有的uPA/uPAR依赖的蛋白分解潜能，这可能有助于其侵袭和血管生成行为。
Endothelial progenitor cells (EPC) display a unique ability to repair vascular injury and promote neovascularization although the underlying molecular mechanisms remain poorly understood. Urokinase-type plasminogen activator (uPA) and its receptor (uPAR) play a critical role in cell migration and angiogenesis by facilitating proteolysis of extracellular matrix. The aim of the present study was to characterize the uPA/u PAR-dependent proteolytic potential of EPC outgrown from human umbilical cord blood and to analyze its contribution to their angiogenic properties in vitro. Cells derived from EPC (EPDC), presenting typical features of late outgrowth endothelial cells, were compared to mature endothelial cells, represented by human umbilical vein endothelial cells (HUVEC). Using quantitative flow cytometry, enzyme-linked immunosorbent assays and zymography, we demonstrated that EPDC displayed higher levels of uPA and uPAR. In conditioned culture media, uPA-dependant proteolytic activity was also found to be significantly increased in EPDC. This activity was paralleled by a higher secretion of pro-metalloproteinase-2 (pro-MMP-2). Inhibition of EPDC-associated uPA by monoclonal antibodies that block either uPA activity or receptor binding, significantly reduced proliferation, migration and capillary like tube formation. Moreover, tumor necrosis factor-alpha and vascular endothelial growth factor, known to be locally secreted in ischemic areas, further increased the proteolytic potential of EPDC by up-regulating uPA and uPAR expression respectively.The EPDC response to these factors was found to be more pronounced than that of HUVEC. In conclusion, these findings indicated that EPDC are characterized by high intrinsic uPA/uPAR-dependent proteolytic potential that could contribute to their invasive and angiogenic behaviour.