State Key Laboratory of Chemo/Bio-Sensing and Chemometrics, College of Chemistry and Chemical Engineering, Hunan University , Changsha 410082, P. R. China.
J Am Chem Soc. 2015 Jan 21;137(2):982-9. doi: 10.1021/ja511988w. Epub 2015 Jan 12.
We have developed an aptameric nanosensor for fluorescence activation imaging of cytochrome c (Cyt c). Fluorescence imaging tools that enable visualization of key molecular players in apoptotic signaling are essential for cell biology and clinical theranostics. Cyt c is a major mediator in cell apoptosis. However, fluorescence imaging tools allowing direct visualization of Cyt c translocation in living cells have currently not been realized. We report for the first time the realization of a nanosensor tool that enables direct fluorescence activation imaging of Cyt c released from mitochondria in cell apoptosis. This strategy relies on spatially selective cytosolic delivery of a nanosensor constructed by assembly of a fluorophore-tagged DNA aptamer on PEGylated graphene nanosheets. The cytosolic release of Cyt c is able to dissociate the aptamer from graphene and trigger an activated fluorescence signal. The nanosensor is shown to exhibit high sensitivity and selectivity, rapid response, large signal-to-background ratio for in vitro, and intracellular detection of Cyt c. It also enables real-time visualization of the Cyt c release kinetics and direct identification of the regulators for apoptosis. The developed nanosensor may provide a very valuable tool for apoptotic studies and catalyze the fundamental interrogations of Cyt c-mediated biology.
我们开发了一种适体纳米传感器，用于细胞色素 c（Cyt c）的荧光激活成像。荧光成像工具对于细胞生物学和临床治疗学至关重要，可用于可视化细胞凋亡信号传导中的关键分子。Cyt c 是细胞凋亡的主要介导物。然而，目前还没有实现能够直接可视化活细胞中 Cyt c 易位的荧光成像工具。我们首次报道了一种纳米传感器工具的实现，该工具能够直接荧光激活成像细胞凋亡中从线粒体释放的 Cyt c。该策略依赖于通过将荧光标记的 DNA 适体组装在聚乙二醇化石墨烯纳米片上构建的纳米传感器的空间选择性细胞溶质递送。细胞质中 Cyt c 的释放能够使适体从石墨烯上解离并触发激活的荧光信号。该纳米传感器表现出高灵敏度和选择性、快速响应、体外和细胞内检测 Cyt c 的大信号背景比。它还能够实时可视化 Cyt c 释放动力学，并直接鉴定凋亡的调节剂。所开发的纳米传感器可为凋亡研究提供非常有价值的工具，并促进 Cyt c 介导的生物学的基本研究。
