Green Linden, Ofstein Richard H, Rapp Brian, Saadatzadeh M Reza, Bhavsar Janak R, Fajardo Andres, Dalsing Michael C, Ingram David A, Murphy Michael P
Health Center for Aortic Disease, Indiana University Health Center for Aortic Disease, Indianapolis, Ind; Department of Cellular and Integrative Physiology, Indiana University Health Center for Aortic Disease, Indianapolis, Ind.
Department of Surgery, Indiana University Health Center for Aortic Disease, Indianapolis, Ind.
J Vasc Surg. 2017 Dec;66(6):1854-1863. doi: 10.1016/j.jvs.2016.11.059. Epub 2017 Jun 24.
Postnatal resident endothelium of blood vessels has been proposed to represent terminally differentiated tissue that does not replicate. We previously isolated endothelial colony-forming cells (ECFCs) from human umbilical cord blood (CB) and term placenta by using colony-forming assays and immunocytochemistry. We showed that ECFCs are highly proliferative and form functioning vessels in vivo, the defining characteristics of a true endothelial progenitor cell. This exploratory investigation was conducted to determine whether the endothelium of healthy adult blood vessels contained resident ECFCs.
The endothelium of great saphenous vein (GSV) obtained from vein stripping procedures was collected with mechanical scraping, and ECFCs were isolated according to established protocols.
GSV ECFCs incorporated acetylated low-density lipoprotein, formed tubules in Matrigel (BD Biosciences, San Jose, Calif) at 24 hours, and expressed endothelial antigens cluster of differentiation (CD) 144, CD31, CD105, and kinase insert domain receptor but not hematopoietic antigen CD45. Using cumulative population doublings and single-cell assays, we demonstrated that GSV ECFCs exhibited comparable proliferative capacities compared with CB ECFCs, including similar numbers of highly proliferative cells. When injected in collagen/fibronectin gels implanted in nonobese diabetic/severe combined immune deficiency mice, GSV ECFCs formed blood vessels with circulating murine red blood cells, demonstrating their vasculogenic potential.
The ECFCs of the GSV contain a hierarchy of progenitor cells with a comparable number of highly proliferative clones as ECFCs of CB. The results of this investigation demonstrate that the adult endothelium contains resident progenitor cells that may have a critical role in vascular homeostasis and repair and could potentially be used as a source of autologous cells for cell therapies focusing on vasculogenesis.
血管的产后常驻内皮被认为代表不进行复制的终末分化组织。我们之前通过集落形成试验和免疫细胞化学从人脐带血（CB）和足月胎盘分离出内皮集落形成细胞（ECFCs）。我们表明，ECFCs具有高度增殖能力，并在体内形成功能性血管，这是真正内皮祖细胞的定义特征。进行这项探索性研究以确定健康成人血管的内皮中是否含有常驻ECFCs。
通过机械刮擦收集从静脉剥脱手术中获取的大隐静脉（GSV）的内皮，并根据既定方案分离ECFCs。
GSV ECFCs摄取乙酰化低密度脂蛋白，在24小时内在基质胶（BD生物科学公司，加利福尼亚州圣何塞）中形成小管，并表达内皮抗原分化簇（CD）144、CD31、CD105和激酶插入结构域受体，但不表达造血抗原CD45。使用累积群体倍增和单细胞试验，我们证明GSV ECFCs与CB ECFCs相比具有相当的增殖能力，包括相似数量的高增殖细胞。当注射到植入非肥胖糖尿病/严重联合免疫缺陷小鼠的胶原/纤连蛋白凝胶中时，GSV ECFCs形成带有循环鼠红细胞的血管，证明了它们的血管生成潜力。
GSV的ECFCs含有祖细胞层级结构，其高增殖克隆数量与CB的ECFCs相当。这项研究结果表明，成人内皮含有常驻祖细胞，这些祖细胞可能在血管稳态和修复中起关键作用，并且有可能用作专注于血管生成的细胞疗法的自体细胞来源。
