title: Probing metabolic states of differentiating stem cells using two-photon FLIM.
abstract: The ability of stem cells to differentiate into specialized cell types presents a number of opportunities for regenerative medicine, stem cell therapy and developmental biology. Because traditional assessments of stem cells are destructive, time consuming, and logistically intensive, the use of a non-invasive, label-free approach to study of cell differentiation provides a powerful tool for rapid, high-content characterization of cell and tissue cultures. Here, we elucidate the metabolic changes in MSCs during adipogenic differentiation, based on the fluorescence of the metabolic co-factors NADH, NADPH, and FAD using the methods of two-photon fluorescence microscopy combined with FLIM. To estimate the contribution of energy metabolism and lipogenesis in the observed changes of the metabolic profile, a separate analysis of NADH and NADPH is required. In our study we demonstrated, for the first time, an increased contribution of protein-bound NADPH in adipocytes that is associated with lipogenesis. The optical redox ratio FAD/NAD(P)H decreased during adipogenic differentiation, and that this was likely to be explained by the intensive biosynthesis of lipids and the enhanced NADPH production associated with this. Based on the data on the fluorescence lifetime contribution of protein-bound NAD(P)H, we registered a metabolic switch from glycolysis to oxidative phosphorylation in adipocytes.
authors.affiliation: Institute of Biomedical technologies, Nizhny Novgorod State Medical Academy, Minin and Pozharsky Square, 10/1, Nizhny Novgorod, 603005, Russia.|Institute of Biology and Biomedicine, Nizhny Novgorod State University, Gagarin Avenue, 23, Nizhny Novgorod, 603950, Russia.
authors.forename: Aleksandra V
authors.initials: AV
authors.lastname: Meleshina
authors.affiliation: Institute of Biomedical technologies, Nizhny Novgorod State Medical Academy, Minin and Pozharsky Square, 10/1, Nizhny Novgorod, 603005, Russia.|Department of Radiophysics, Nizhny Novgorod State University, Gagarin Avenue, 23, Nizhny Novgorod, 603950, Russia.
authors.forename: Varvara V
authors.initials: VV
authors.lastname: Dudenkova
authors.affiliation: Institute of Biomedical technologies, Nizhny Novgorod State Medical Academy, Minin and Pozharsky Square, 10/1, Nizhny Novgorod, 603005, Russia.|Institute of Biology and Biomedicine, Nizhny Novgorod State University, Gagarin Avenue, 23, Nizhny Novgorod, 603950, Russia.
authors.forename: Marina V
authors.initials: MV
authors.lastname: Shirmanova
authors.affiliation: Becker &Hickl GmbH Nahmitzer Damm 30, Berlin, 12277, Germany.
authors.forename: Vladislav I
authors.initials: VI
authors.lastname: Shcheslavskiy
authors.affiliation: Becker &Hickl GmbH Nahmitzer Damm 30, Berlin, 12277, Germany.
authors.forename: Wolfgang
authors.initials: W
authors.lastname: Becker
authors.affiliation: Institute of Biology and Biomedicine, Nizhny Novgorod State University, Gagarin Avenue, 23, Nizhny Novgorod, 603950, Russia.
authors.forename: Alena S
authors.initials: AS
authors.lastname: Bystrova
authors.affiliation: Institute of Biomedical technologies, Nizhny Novgorod State Medical Academy, Minin and Pozharsky Square, 10/1, Nizhny Novgorod, 603005, Russia.|Institute of Biology and Biomedicine, Nizhny Novgorod State University, Gagarin Avenue, 23, Nizhny Novgorod, 603950, Russia.
authors.forename: Elena I
authors.initials: EI
authors.lastname: Cherkasova
authors.affiliation: Institute of Biomedical technologies, Nizhny Novgorod State Medical Academy, Minin and Pozharsky Square, 10/1, Nizhny Novgorod, 603005, Russia.|Institute of Biology and Biomedicine, Nizhny Novgorod State University, Gagarin Avenue, 23, Nizhny Novgorod, 603950, Russia.
authors.forename: Elena V
authors.initials: EV
authors.lastname: Zagaynova
mesh_terms: D017667:Adipocytes / Q000166:cytology / Q000378:metabolism; D050156:Adipogenesis; D001854:Bone Marrow Cells / Q000166:cytology; D002454:Cell Differentiation; D002478:Cells, Cultured; D005182:Flavin-Adenine Dinucleotide / Q000737:chemistry / Q000378:metabolism; D006019:Glycolysis; D006801:Humans; D059630:Mesenchymal Stem Cells / Q000166:cytology / Q000378:metabolism*; D008856:Microscopy, Fluorescence; D036641:Microscopy, Fluorescence, Multiphoton; D009249:NADP / Q000737:chemistry / Q000378:metabolism; D010084:Oxidation-Reduction; D010085:Oxidative Phosphorylation
chemical_list: D005182:Flavin-Adenine Dinucleotide; D009249:NADP