Li Wei, Yang Xiaohai, Wang Kemin, Tan Weihong, He Yan, Guo Qiuping, Tang Hongxing, Liu Jianbo
College of Chemistry and Chemical Engineering, Engineering Center for Biomedicine, Key Laboratory for Bio-Nanotechnology and Molecular Engineering of Hunan Province, Hunan University, Changsha 410082, PR China.
Anal Chem. 2008 Jul 1;80(13):5002-8. doi: 10.1021/ac800930q. Epub 2008 Jun 6.
Angiogenin is a potent angiogenic factor that is known to play an important role in tumor angiogenesis. In this paper, we investigate the cellular internalization of angiogenin conjugated with its highly specific aptamer. By using fluorophore-labeled aptamer and confocal laser scanning microscopy, we have developed a novel and simple method by which to visualize the real-time process of angiogenin internalization. Specifically, when aptamer-angiogenin conjugates were added into cell cultures, conjugates could be selectively bound to HUVE cells (human umbilical vein endothelial cells) and MCF-7 cells (human breast cancer cells). Nuclear staining and Z-axis scanning studies demonstrated that the aptamer-angiogenin conjugates were internalized to intracellular organelles, and dynamic confocal imaging studies indicated that the conjugates were quickly internalized. These results provide the first evidence that a fluorophore-labeled aptamer can be used as a fluorescent probe to visualize the spatiotemporal process of protein internalization in real time.
血管生成素是一种强效血管生成因子，已知在肿瘤血管生成中起重要作用。在本文中，我们研究了与其高度特异性适配体结合的血管生成素的细胞内化过程。通过使用荧光团标记的适配体和共聚焦激光扫描显微镜，我们开发了一种新颖且简单的方法来可视化血管生成素内化的实时过程。具体而言，当将适配体 - 血管生成素缀合物添加到细胞培养物中时，缀合物可选择性地结合到人脐静脉内皮细胞（HUVE细胞）和人乳腺癌细胞（MCF - 7细胞）上。细胞核染色和Z轴扫描研究表明，适配体 - 血管生成素缀合物被内化到细胞内细胞器中，动态共聚焦成像研究表明缀合物被快速内化。这些结果提供了首个证据，即荧光团标记的适配体可作为荧光探针实时可视化蛋白质内化的时空过程。
