The Oxidation-Induced Autofluorescence Hypothesis: Red Edge Excitation and Implications for Metabolic Imaging.
Alexey N SemenovBoris P YakimovAnna A RubekinaDmitry A GorinVladimir P DrachevMikhail P ZarubinAlexander N VelikanovJuergen LademannVictor V FadeevAlexander V PriezzhevMaxim E DarvinEvgeny A ShirshinPublished in: Molecules (Basel, Switzerland) (2020)
Endogenous autofluorescence of biological tissues is an important source of information for biomedical diagnostics. Despite the molecular complexity of biological tissues, the list of commonly known fluorophores is strictly limited. Still, the question of molecular sources of the red and near-infrared excited autofluorescence remains open. In this work we demonstrated that the oxidation products of organic components (lipids, proteins, amino acids, etc.) can serve as the molecular source of such red and near-infrared excited autofluorescence. Using model solutions and cell systems (human keratinocytes) under oxidative stress induced by UV irradiation we demonstrated that oxidation products can contribute significantly to the autofluorescence signal of biological systems in the entire visible range of the spectrum, even at the emission and excitation wavelengths higher than 650 nm. The obtained results suggest the principal possibility to explain the red fluorescence excitation in a large class of biosystems-aggregates of proteins and peptides, cells and tissues-by the impact of oxidation products, since oxidation products are inevitably presented in the tissue. The observed fluorescence signal with broad excitation originated from oxidation products may also lead to the alteration of metabolic imaging results and has to be taken into account.
Keyphrases
- energy transfer
- hydrogen peroxide
- electron transfer
- oxidative stress
- single molecule
- gene expression
- induced apoptosis
- high resolution
- amino acid
- endothelial cells
- dna damage
- minimally invasive
- single cell
- diabetic rats
- visible light
- photodynamic therapy
- stem cells
- nitric oxide
- drinking water
- ischemia reperfusion injury
- radiation therapy
- cell cycle arrest
- mass spectrometry
- endoplasmic reticulum stress
- drug induced
- heat shock