Laboratory for Physiology, Institute for Cardiovascular Research, VU University Medical Center Amsterdam, Amsterdam, The Netherlands.
Eur Cytokine Netw. 2009 Dec;20(4):207-19. doi: 10.1684/ecn.2009.0174.
Since the initial discovery of endothelial progenitor cells (EPC), and their promise in increasing angiogenesis and vasculogenesis, a myriad of papers have highlighted their potential application in experimental and clinical neovascularization and in tissue engineering. However, promising reports are contrasted by other studies that could not find a role for EPC in neovascularization. Presently, two types of endothelial progenitor cell populations are recognized. The first population provides early-outgrowth CD34+/VEGFR-2+ cells, or colony-forming unit endothelial cells (CFU-EC), which represent myeloid cells with some endothelial properties, but no ability to form endothelial colonies. They can stimulate neovascularization by paracrine means, but are not incorporated in the endothelial lining themselves. The second population generates the late-outgrowth endothelial colony-forming cells (ECFC) from a very scant blood-derived cell population. ECFC have a very high proliferative potential, can insert into the endothelial lining of new blood vessels, and can also form endothelial tubes by themselves after stimulation with the proper angiogenic stimulus. This review surveys the mobilization of progenitor cells from the bone marrow, the homing of EPC (CFU-EC) to areas of neovascularization, and the participation of EPC (ECFC) in the endothelial lining of newly formed blood vessels. Specific emphasis has been placed on the role of proteases, which include serine proteases, including urokinase, L-cathepsin, and several ADAM- and matrix metalloproteinases. The specific properties of ECFC make them a potential source of cells for tissue engineering applications, but much has to be learned about their nature, origin and properties.
自最初发现内皮祖细胞（EPC）及其在促进血管生成和血管发生方面的潜力以来，大量文献强调了其在实验和临床新生血管形成和组织工程中的潜在应用。然而，有希望的报告与其他研究形成对比，后者无法发现 EPC 在新生血管形成中的作用。目前，已经识别出两种类型的内皮祖细胞群体。第一群体提供早期出现的 CD34+/VEGFR-2+细胞或成血管单位内皮细胞（CFU-EC），它们代表具有一些内皮特性但没有形成内皮集落能力的髓样细胞。它们可以通过旁分泌方式刺激新生血管形成，但本身不整合到内皮衬里中。第二群体从非常稀少的血液衍生细胞群体中产生晚期出现的内皮集落形成细胞（ECFC）。ECFC 具有非常高的增殖潜力，可以插入新血管的内皮衬里，并且在受到适当的血管生成刺激后也可以自行形成内皮管。这篇综述调查了祖细胞从骨髓中的动员、EPC（CFU-EC）向新生血管化区域的归巢以及 EPC（ECFC）在新形成的血管内皮衬里中的参与。特别强调了蛋白酶的作用，包括丝氨酸蛋白酶，包括尿激酶、L-组织蛋白酶和几种 ADAM 和基质金属蛋白酶。ECFC 的特定特性使它们成为组织工程应用的潜在细胞来源，但需要了解更多关于它们的性质、起源和特性。
