A Two-Photon Tracer for Glucose Uptake

SCOTfluors: Small, Conjugatable, Orthogonal, and Tunable Fluorophores for In Vivo Imaging of Cell Metabolism

The transport and trafficking of metabolites are critical for the correct functioning of live cells. However, in situ metabolic imaging studies are hampered by the lack of fluorescent chemical structures that allow direct monitoring of small metabolites under physiological conditions with high spatial and temporal resolution. Herein, we describe SCOTfluors as novel small-sized multi-colored fluorophores for real-time tracking of essential metabolites in live cells and in vivo and for the acquisition of metabolic profiles from human cancer cells of variable origin.

A two-photon turn-on probe for glucose uptake

We report a two-photon turn-on probe (AS1) that can be excited by 780 nm femto-second pulses and visualize glucose uptake and the changes in the intracellular glucose concentration in live cells and tissue by two-photon microscopy.

Development of fluorescent glucose bioprobes and their application on real-time and quantitative monitoring of glucose uptake in living cells

We developed a novel fluorescent glucose bioprobe, GB2-Cy3, for the real-time and quantitative monitoring of glucose uptake in living cells. We synthesized a series of fluorescent glucose analogues by adding Cy3 fluorophores to the α-anomeric position of D-glucose through various linkers. Systematic and quantitative analysis of these Cy3-labeled glucose analogues revealed that GB2-Cy3 was the ideal fluorescent glucose bioprobe. The cellular uptake of this probe competed with the cellular uptake of D-glucose in the media and was mediated by a glucose-specific transport system, and not by passive diffusion. Flow cytometry and fluorescence microscopy analyses revealed that GB2-Cy3 is ten times more sensitive than 2-NBDG, a leading fluorescent glucose bioprobe. GB2-Cy3 can also be utilized for the quantitative flow cytometry monitoring of glucose uptake in metabolically active C2C12 myocytes under various treatment conditions. As opposed to a glucose uptake assay performed by using radioisotope-labeled deoxy-D-glucose and a scintillation counter, GB2-Cy3 allows the real-time monitoring of glucose uptake in living cells under various experimental conditions by using fluorescence microscopy or confocal laser scanning microscopy (CLSM). Therefore, we believe that GB2-Cy3 can be utilized in high-content screening (HCS) for the discovery of novel therapeutic agents and for making significant advances in biomedical studies and diagnosis of various diseases, especially metabolic diseases.