Department of Histology and Embryology, Pomeranian Medical University, Szczecin, Poland.
Invest Ophthalmol Vis Sci. 2011 Jan 5;52(1):93-100. doi: 10.1167/iovs.10-5756.
Circulating endothelial cells (CECs) and endothelial progenitor cells (EPCs) may serve as novel markers of endothelial dysfunction. The presence and clinical implications of CECs and the expression of endothelin (ET)-1, one of the most potent vasoconstrictors, have not been evaluated in patients with the neovascular form of age-related macular degeneration (AMD). This study was conducted to determine the different populations of endothelial cells (ECs) in the peripheral blood of AMD patients and to correlate these findings with the expression of ET-1 and the cytokines and growth factors responsible for EC migration and function.
Peripheral blood samples were collected from 29 patients with diagnosed neovascular AMD and from 38 healthy control subjects. CD133(-)CD144(+) CECs and CD34(+)CD133(+)CD144(+) EPCs were counted and analyzed by flow cytometry. The intracellular expression of ET-1 in peripheral blood nuclear cells (PBNCs) was studied by using qRT-PCR, Western blot, and immunocytofluorescence assays, and ET-1, IGF-1, VEGF, SDF-1, and HGF plasma concentrations were measured in enzyme-linked immunosorbent assays.
Increased CECs and EPCs were found in the AMD patients compared with the counts in healthy individuals. The expression of intracellular ET-1 was significantly elevated in PBNCs from the AMD patients compared with the control subjects. In addition a significantly higher plasma concentration of IGF-1 was observed, but a lower SDF-1 level in the group of AMD patients.
These findings suggest that circulating endothelial cells, together with high ET-1 content, may contribute to the development of AMD. Further prospective investigations on the mechanism involved may be relevant to the potential treatment of this disease.
循环内皮细胞（CECs）和内皮祖细胞（EPCs）可作为内皮功能障碍的新型标志物。在新生血管性年龄相关性黄斑变性（AMD）患者中，尚未评估 CEC 的存在及其临床意义，以及内皮素（ET）-1 的表达，ET-1 是最强的血管收缩剂之一。本研究旨在确定 AMD 患者外周血中不同的内皮细胞（EC）群体，并将这些发现与 ET-1 的表达以及负责 EC 迁移和功能的细胞因子和生长因子相关联。
采集 29 名确诊为新生血管性 AMD 患者和 38 名健康对照者的外周血样本。通过流式细胞术计数和分析 CD133(-)CD144(+)CECs 和 CD34(+)CD133(+)CD144(+)EPCs。通过 qRT-PCR、Western blot 和免疫细胞荧光检测研究外周血核细胞（PBNCs）中 ET-1 的细胞内表达，并通过酶联免疫吸附试验测量 ET-1、IGF-1、VEGF、SDF-1 和 HGF 的血浆浓度。
与健康个体相比，AMD 患者的 CECs 和 EPCs 计数增加。与对照组相比，AMD 患者的 PBNCs 中细胞内 ET-1 的表达明显升高。此外，在 AMD 患者组中观察到 IGF-1 的血浆浓度显著升高，而 SDF-1 水平较低。
这些发现表明，循环内皮细胞与高 ET-1 含量一起可能有助于 AMD 的发生。对所涉及机制的进一步前瞻性研究可能与该疾病的潜在治疗相关。
