Comparison of three fluorescence labeling and tracking methods of endothelial progenitor cells in laser-injured retina

AIM： To compare three kinds of fluorescent probes for in vitro labeling and in vivo tracking of endothelial progenitor cells（EPCs） in a mouse model of laser-induced retinal injury.METHODS： EPCs were isolated from human umbilical cord blood mononuclear cells and labeled with three different fluorescent probes： 5-（and-6）-carboxyfluorescein diacetate succinimidyl ester（CFSE）, 1,1′-dilinoleyl-3,3,3′,3′-tetramethylindo-carbocyanine perchlorate linked acetylated low-density lipoprotein（Di I-Ac LDL）, and green fluorescent protein（GFP）. The fluorescent intensity of EPCs was examined by confocal microscopy. Survival rate of labeled EPCs was calculated with trypan blue staining, and their adhesive capability was assessed. A mouse model of retinal injury was induced by laser, and EPCs were injected into the vitreous cavity. Frozen section and fluorescein angiography on flat-mounted retinal samples was employed to track the labeled EPCs in vivo.RESULTS： EPCs labeled with CFSE and Di I-Ac LDL exhibited an intense green and red fluorescence at the beginning; the fluorescence intensity decreased gradually to 20.23% and 49.99% respectively, after 28 d. On the contrary, the florescent intensity of GFP-labeled EPCs increased in a time-dependent manner. All labeled EPCs showed normal morphology and no significant change in survival and adhesive capability. In the mouse model, transplantation of EPCs showed a protective effect against retinal injury. EPCs labeled with CFSE and Di I-Ac LDL were successfully tracked in mice during the development of retinal injury and repair; however, GFP-labeled EPCs were not detected in the laser-injured mouse retina.CONCLUSION： The three fluorescent markers used in this study have their own set of advantages and disadvantages. CFSE and Di I-Ac LDL are suitable for short-term EPClabeling, while GFP should be used for long-term labeling. The choice of fluorescent markers should be guided by the purpose of the study.

民族药珠芽艾麻化学成分研究

目的:对荨麻科艾麻属珠芽艾麻药材进行化学成分研究。方法:经70%乙醇回流提取,通过硅胶柱层析等技术,进行分离纯化,结合理化性质及各种波谱数据分析鉴定其化学结构。结果:从珠芽艾麻的根中分离并鉴定了6个化合物,分别是:β-谷甾醇(1)、β-胡萝卜苷(2)2、2,'-oxy-bis(1-phenylethanol)(3)、1-(2-phenylcarbonyloxy ac-etyl)benzene(4)、亚油酸甲酯(5)和14,-二苯基-14,-丁二酮(6)。结论:所有化合物均为首次从该植物中分离得到,其中化合物3和4为首次报道的天然产物。