title: Increase of reduced nicotinamide adenine dinucleotide fluorescence lifetime precedes mitochondrial dysfunction in staurosporine-induced apoptosis of HeLa cells.
abstract: In vivo noninvasive detection of apoptosis represents a new tool that may yield a more definite diagnosis, a more accurate prognosis, and help improve therapies for human diseases. The intrinsic fluorescence of reduced nicotinamide adenine dinucleotide (NADH) may be a potential optical biomarker for the apoptosis detection because NADH is involved in the respiration for the mitochondrial membrane potential (ΔΨ) formation and adenosine-5'-triphosphate (ATP) synthesis, and the depletion of ΔΨ and ATP level is the hallmark of apoptosis. We have previously observed the NADH fluorescence lifetime change is associated with staurosporine (STS)-induced mitochondria-mediated apoptosis. However, its relationship with mitochondrial functions such as ΔΨ, ATP, and oxygen consumption rate is not clear. In this study, we investigated this relationship. Our results indicate that the NADH fluorescence lifetime increased when ΔΨ and ATP levels were equal to or higher than their values of controls and decreased before the depletion of ΔΨ and ATP, and the oxygen consumption rate did not change. These findings suggest that the increased NADH fluorescence lifetime in STS-induced cell death occurred before the depletion of ΔΨ and ATP and activation of caspase 3, and was not simply caused by cellular metabolic change. Furthermore, the NADH fluorescence lifetime change is associated with the pace of apoptosis.
authors: National Yang-Ming University, Institute of Biophotonics, Taipei, Taiwan.
authors: Jia-Sin
authors: JS
authors: Yu
authors: Han-Wen
authors: HW
authors: Guo
authors: Chih-Hao
authors: CH
authors: Wang
authors: Yau-Huei
authors: YH
authors: Wei
authors: Hsing-Wen
authors: HW
authors: Wang
mesh_terms: D000255:Adenosine Triphosphate / Q000378:metabolism; D017209:Apoptosis / Q000187:drug effects* / Q000502:physiology*; D015415:Biomarkers / Q000378:metabolism; D053148:Caspase 3 / Q000378:metabolism; D004789:Enzyme Activation / Q000187:drug effects; D006367:HeLa Cells; D006801:Humans; D007700:Kinetics; D053078:Membrane Potential, Mitochondrial / Q000187:drug effects / Q000502:physiology; D008856:Microscopy, Fluorescence / Q000379:methods; D008928:Mitochondria / Q000187:drug effects* / Q000378:metabolism*; D009243:NAD / Q000378:metabolism*; D055620:Optical Phenomena; D010101:Oxygen Consumption; D019311:Staurosporine / Q000494:pharmacology
chemical_list: D015415:Biomarkers; D009243:NAD; D000255:Adenosine Triphosphate; C505407:CASP3 protein, human; D053148:Caspase 3; D019311:Staurosporine