title: Investigation of tryptophan-NADH interactions in live human cells using three-photon fluorescence lifetime imaging and Förster resonance energy transfer microscopy.
abstract: A method to investigate the metabolic activity of intracellular tryptophan (TRP) and coenzyme-NADH using three-photon (3P) fluorescence lifetime imaging (FLIM) and Förster resonance energy transfer (FRET) is presented. Through systematic analysis of FLIM data from tumorigenic and nontumorigenic cells, a statistically significant decrease in the fluorescence lifetime of TRP was observed in response to the increase in protein-bound NADH as cells were treated with glucose. The results demonstrate the potential use of 3P-FLIM-FRET as a tool for label-free screening of the change in metabolic flux occurring in human diseases or other clinical conditions.
authors.forename: Vinod
authors.initials: V
authors.lastname: Jyothikumar
authors.forename: Yuansheng
authors.initials: Y
authors.lastname: Sun
authors.forename: Ammasi
authors.initials: A
authors.lastname: Periasamy
mesh_terms: D045744:Cell Line, Tumor; D002467:Cell Nucleus / Q000378:metabolism; D003600:Cytosol / Q000378:metabolism; D003952:Diagnostic Imaging; D031541:Fluorescence Resonance Energy Transfer / Q000379:methods*; D005947:Glucose / Q000737:chemistry; D006367:HeLa Cells; D006801:Humans; D008928:Mitochondria / Q000378:metabolism; D009243:NAD / Q000737:chemistry*; D055095:Optics and Photonics; D017785:Photons; D014364:Tryptophan / Q000737:chemistry*
chemical_list: D009243:NAD; D014364:Tryptophan; D005947:Glucose