title: Fluorescence activation imaging of cytochrome c released from mitochondria using aptameric nanosensor.
abstract: 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.
authors.affiliation: State Key Laboratory of Chemo/Bio-Sensing and Chemometrics, College of Chemistry and Chemical Engineering, Hunan University , Changsha 410082, P. R. China.
authors.forename: Ting-Ting
authors.initials: TT
authors.lastname: Chen
authors.forename: Xue
authors.initials: X
authors.lastname: Tian
authors.forename: Chen-Liwei
authors.initials: CL
authors.lastname: Liu
authors.forename: Jia
authors.initials: J
authors.lastname: Ge
authors.forename: Xia
authors.initials: X
authors.lastname: Chu
authors.forename: Yingfu
authors.initials: Y
authors.lastname: Li
mesh_terms: D017209:Apoptosis; D052157:Aptamers, Nucleotide / Q000737:chemistry* / Q000378:metabolism*; D015374:Biosensing Techniques / Q000379:methods*; D002470:Cell Survival; D045304:Cytochromes c / Q000378:metabolism*; D006108:Graphite / Q000737:chemistry; D006367:HeLa Cells; D006801:Humans; D061986:MCF-7 Cells; D008928:Mitochondria / Q000378:metabolism*; D008958:Models, Molecular; D049329:Nanostructures / Q000737:chemistry; D036103:Nanotechnology / Q000295:instrumentation*; D009690:Nucleic Acid Conformation; D061848:Optical Imaging; D010087:Oxides / Q000737:chemistry; D011487:Protein Conformation
chemical_list: D052157:Aptamers, Nucleotide; D010087:Oxides; D006108:Graphite; D045304:Cytochromes c