{"status":"ok","message-type":"work","message-version":"1.0.0","message":{"indexed":{"date-parts":[[2026,11,5]],"date-time":"2026-11-05T01:07:18Z","timestamp":1793840838933,"version":"4.6.1"},"reference-count":93,"publisher":"Frontiers Media SA","license":[{"start":{"date-parts":[[2023,11,28]],"date-time":"2023-11-28T00:00:00Z","timestamp":1701129600000},"content-version":"vor","delay-in-days":0,"URL":"https:\/\/creativecommons.org\/licenses\/by\/4.0\/"}],"content-domain":{"domain":["frontiersin.org"],"crossmark-restriction":true},"short-container-title":["Front. Bioeng. Biotechnol."],"abstract":"<jats:p>Metabolic reprogramming at a cellular level contributes to many diseases including cancer, yet few assays are capable of measuring metabolic pathway usage by individual cells within living samples. Here, autofluorescence lifetime imaging is combined with single-cell segmentation and machine-learning models to predict the metabolic pathway usage of cancer cells. The metabolic activities of MCF7 breast cancer cells and HepG2 liver cancer cells were controlled by growing the cells in culture media with specific substrates and metabolic inhibitors. Fluorescence lifetime images of two endogenous metabolic coenzymes, reduced nicotinamide adenine dinucleotide (NADH) and oxidized flavin adenine dinucleotide (FAD), were acquired by a multi-photon fluorescence lifetime microscope and analyzed at the cellular level. Quantitative changes of NADH and FAD lifetime components were observed for cells using glycolysis, oxidative phosphorylation, and glutaminolysis. Conventional machine learning models trained with the autofluorescence features classified cells as dependent on glycolytic or oxidative metabolism with 90%\u201392% accuracy. Furthermore, adapting convolutional neural networks to predict cancer cell metabolic perturbations from the autofluorescence lifetime images provided improved performance, 95% accuracy, over traditional models trained via extracted features. Additionally, the model trained with the lifetime features of cancer cells could be transferred to autofluorescence lifetime images of T cells, with a prediction that 80% of activated T cells were glycolytic, and 97% of quiescent T cells were oxidative. In summary, autofluorescence lifetime imaging combined with machine learning models can detect metabolic perturbations between glycolysis and oxidative metabolism of living samples at a cellular level, providing a label-free technology to study cellular metabolism and metabolic heterogeneity.<\/jats:p>","DOI":"10.3389\/fbioe.2023.1293268","type":"journal-article","created":{"date-parts":[[2023,11,28]],"date-time":"2023-11-28T10:03:44Z","timestamp":1701165824000},"update-policy":"https:\/\/doi.org\/10.3389\/crossmark-policy","source":"Crossref","is-referenced-by-count":11,"title":["Label-free spatially maintained measurements of metabolic phenotypes in cells"],"prefix":"10.3389","volume":"11","author":[{"given":"Linghao","family":"Hu","sequence":"first","affiliation":[],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Nianchao","family":"Wang","sequence":"additional","affiliation":[],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Joshua D.","family":"Bryant","sequence":"additional","affiliation":[],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Lin","family":"Liu","sequence":"additional","affiliation":[],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Linglin","family":"Xie","sequence":"additional","affiliation":[],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"A. Phillip","family":"West","sequence":"additional","affiliation":[],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Alex J.","family":"Walsh","sequence":"additional","affiliation":[],"role":[{"vocabulary":"crossref","role":"author"}]}],"member":"1965","published-online":{"date-parts":[[2023,11,28]]},"reference":[{"key":"B1","doi-asserted-by":"publisher","first-page":"10451","DOI":"10.1038\/s41598-017-10856-3","article-title":"Investigation of mitochondrial metabolic response to doxorubicin in prostate cancer cells: an NADH, FAD and tryptophan FLIM assay","volume":"7","author":"Alam","year":"2017","journal-title":"Sci. Rep."},{"key":"B2","doi-asserted-by":"publisher","first-page":"046005","DOI":"10.1117\/1.jbo.21.4.046005","article-title":"Label-free identification of macrophage phenotype by fluorescence lifetime imaging microscopy","volume":"21","author":"Alfonso-Garcia","year":"2016","journal-title":"J. Biomed. Opt."},{"key":"B3","doi-asserted-by":"publisher","first-page":"38","DOI":"10.1038\/nbt.4314","article-title":"Dimensionality reduction for visualizing single-cell data using UMAP","volume":"37","author":"Becht","year":"2018","journal-title":"Nat. Biotechnol."},{"key":"B4","doi-asserted-by":"publisher","first-page":"119","DOI":"10.1111\/j.1365-2818.2012.03618.x","article-title":"Fluorescence lifetime imaging--techniques and applications","volume":"247","author":"Becker","year":"2012","journal-title":"J. Microsc."},{"key":"B5","volume-title":"The bh TCSPC Handbook","author":"Becker","year":"2021"},{"key":"B6","doi-asserted-by":"publisher","first-page":"254","DOI":"10.1515\/cdbme-2020-3064","article-title":"Metabolic imaging by simultaneous FLIM of NAD(P)H and FAD","volume":"6","author":"Becker","year":"2020","journal-title":"Curr. Dir. Biomed. Eng."},{"key":"B7","doi-asserted-by":"publisher","first-page":"838","DOI":"10.1242\/jcs.03381","article-title":"Mitochondrial bioenergetics and structural network organization","volume":"120","author":"Benard","year":"2007","journal-title":"J. Cell Sci."},{"key":"B8","doi-asserted-by":"publisher","first-page":"8766","DOI":"10.1158\/0008-5472.can-04-3922","article-title":"Metabolic mapping of MCF10A human breast cells via multiphoton fluorescence lifetime imaging of the coenzyme NADH","volume":"65","author":"Bird","year":"2005","journal-title":"Cancer Res."},{"key":"B9","doi-asserted-by":"publisher","first-page":"47","DOI":"10.1016\/j.atherosclerosis.2020.07.017","article-title":"Two-photon excited fluorescence (TPEF) may be useful to identify macrophage subsets based on their metabolic activity and cellular responses in atherosclerotic plaques","volume":"309","author":"Borowczyk","year":"2020","journal-title":"Atherosclerosis"},{"key":"B10","doi-asserted-by":"publisher","first-page":"110","DOI":"10.1002\/cyto.a.23711","article-title":"Single-cell redox states analyzed by fluorescence lifetime metrics and tryptophan FRET interaction with NAD(P)H","volume":"95","author":"Cao","year":"2019","journal-title":"Cytom. A"},{"key":"B11","doi-asserted-by":"publisher","first-page":"985","DOI":"10.1158\/0008-5472.can-03-1101","article-title":"Energy substrate modulates mitochondrial structure and oxidative capacity in cancer cells","volume":"64","author":"Capaldi","year":"2004","journal-title":"Cancer Res."},{"key":"B12","doi-asserted-by":"publisher","first-page":"497","DOI":"10.1002\/cyto.a.24534","article-title":"Identification of rare cell populations in autofluorescence lifetime image data","volume":"101","author":"Cardona","year":"2022","journal-title":"Cytom. A"},{"key":"B13","doi-asserted-by":"publisher","first-page":"19145","DOI":"10.1038\/srep19145","article-title":"Quantification of the metabolic state in cell-model of Parkinson's disease by fluorescence lifetime imaging microscopy","volume":"6","author":"Chakraborty","year":"2016","journal-title":"Sci. Rep."},{"key":"B14","doi-asserted-by":"publisher","first-page":"44","DOI":"10.3389\/fonc.2016.00044","article-title":"Positron emission tomography imaging of tumor cell metabolism and application to therapy response monitoring","volume":"6","author":"Challapalli","year":"2016","journal-title":"Front. Oncol."},{"key":"B15","doi-asserted-by":"publisher","first-page":"4764","DOI":"10.1016\/s0021-9258(17)30079-0","article-title":"Oxidation-reduction ratio studies of mitochondria in freeze-trapped samples. NADH and flavoprotein fluorescence signals","volume":"254","author":"Chance","year":"1979","journal-title":"J. Biol. Chem."},{"key":"B16","doi-asserted-by":"publisher","first-page":"1239","DOI":"10.1016\/j.cell.2013.05.016","article-title":"Posttranscriptional control of T cell effector function by aerobic glycolysis","volume":"153","author":"Chang","year":"2013","journal-title":"Cell"},{"key":"B17","doi-asserted-by":"publisher","first-page":"153","DOI":"10.1111\/imr.12218","article-title":"Macrophage phenotypes in atherosclerosis","volume":"262","author":"Colin","year":"2014","journal-title":"Immunol. Rev."},{"key":"B18","doi-asserted-by":"publisher","first-page":"8760","DOI":"10.1038\/s41598-017-09206-0","article-title":"Bioenergetic adaptations in chemoresistant ovarian cancer cells","volume":"7","author":"Dar","year":"2017","journal-title":"Sci. Rep."},{"key":"B19","doi-asserted-by":"publisher","first-page":"310","DOI":"10.1038\/s41556-020-0477-0","article-title":"Transcriptional diversity and bioenergetic shift in human breast cancer metastasis revealed by single-cell RNA sequencing","volume":"22","author":"Davis","year":"2020","journal-title":"Nat. Cell Biol."},{"key":"B20","doi-asserted-by":"publisher","first-page":"367ra169","DOI":"10.1126\/scitranslmed.aag2202","article-title":"Imaging mitochondrial dynamics in human skin reveals depth-dependent hypoxia and malignant potential for diagnosis","volume":"8","author":"Dimitra Pouli","year":"2016","journal-title":"Sci. Transl. Med."},{"key":"B21","doi-asserted-by":"publisher","first-page":"086016","DOI":"10.1117\/1.jbo.19.8.086016","article-title":"Multiphoton fluorescence lifetime imaging microscopy reveals free-to-bound NADH ratio changes associated with metabolic inhibition","volume":"19","author":"Drozdowicz-Tomsia","year":"2014","journal-title":"J. Biomed. Opt."},{"key":"B22","doi-asserted-by":"publisher","first-page":"2198","DOI":"10.1016\/j.jacc.2018.08.2150","article-title":"Monocyte and macrophage dynamics in the cardiovascular system: JACC macrophage in CVD series (Part 3)","volume":"72","author":"Fayad","year":"2018","journal-title":"J. Am. Coll. Cardiol."},{"key":"B23","doi-asserted-by":"publisher","first-page":"351","DOI":"10.1146\/annurev-bioeng-071811-150108","article-title":"Optical imaging using endogenous contrast to assess metabolic state","volume":"14","author":"Georgakoudi","year":"2012","journal-title":"Annu. Rev. Biomed. Eng."},{"key":"B24","doi-asserted-by":"publisher","first-page":"e1004063","DOI":"10.1371\/journal.pgen.1004063","article-title":"Anoxia-reoxygenation regulates mitochondrial dynamics through the hypoxia response pathway, SKN-1\/Nrf, and stomatin-like protein STL-1\/SLP-2","volume":"9","author":"Ghose","year":"2013","journal-title":"PLoS Genet."},{"key":"B25","doi-asserted-by":"publisher","first-page":"2724","DOI":"10.1038\/s41598-018-19947-1","article-title":"Novel reversibly switchable fluorescent proteins for RESOLFT and STED nanoscopy engineered from the bacterial photoreceptor YtvA","volume":"8","author":"Gregor","year":"2018","journal-title":"Sci. Rep."},{"key":"B26","doi-asserted-by":"publisher","first-page":"e0125706","DOI":"10.1371\/journal.pone.0125706","article-title":"Enhancement of early cervical cancer diagnosis with epithelial layer analysis of fluorescence lifetime images","volume":"10","author":"Gu","year":"2015","journal-title":"PLoS One"},{"key":"B27","doi-asserted-by":"publisher","first-page":"345","DOI":"10.1083\/jcb.37.2.345","article-title":"Ultrastructural bases for metabolically linked mechanical activity in mitochondria. II. Electron transport-linked ultrastructural transformations in mitochondria","volume":"37","author":"Hackenbrock","year":"1968","journal-title":"J. Cell Biol."},{"key":"B28","doi-asserted-by":"publisher","first-page":"123","DOI":"10.1083\/jcb.51.1.123","article-title":"Oxidative phosphorylation and ultrastructural transformation in mitochondria in the intact ascites tumor cell","volume":"51","author":"Hackenbrock","year":"1971","journal-title":"J. Cell Biol."},{"key":"B29","first-page":"842","article-title":"PET imaging of brain tumor with [methyl-11C] choline","volume":"38","author":"Hara","year":"1997","journal-title":"J. Nucl. Med."},{"key":"B30","doi-asserted-by":"publisher","first-page":"186","DOI":"10.1038\/s41587-020-0651-8","article-title":"Single-cell metabolic profiling of human cytotoxic T cells","volume":"39","author":"Hartmann","year":"2021","journal-title":"Nat. Biotechnol."},{"key":"B31","doi-asserted-by":"publisher","first-page":"5408","DOI":"10.1158\/0008-5472.can-20-0831","article-title":"Autofluorescence imaging of 3D tumor-macrophage microscale cultures resolves spatial and temporal dynamics of macrophage metabolism","volume":"80","author":"Heaster","year":"2020","journal-title":"Cancer Res."},{"key":"B32","doi-asserted-by":"publisher","first-page":"9821","DOI":"10.1002\/anie.201502543","article-title":"Vibrational imaging of glucose uptake activity in live cells and tissues by stimulated Raman scattering","volume":"54","author":"Hu","year":"2015","journal-title":"Angew. Chem. Int. Ed. Engl."},{"key":"B33","doi-asserted-by":"publisher","first-page":"5674","DOI":"10.1364\/boe.401935","article-title":"Fluorescence intensity and lifetime redox ratios detect metabolic perturbations in T cells","volume":"11","author":"Hu","year":"2020","journal-title":"Biomed. Opt. Express"},{"key":"B34","doi-asserted-by":"crossref","DOI":"10.1117\/12.2577004","article-title":"Classification of T cell metabolism from autofluorescence imaging features","author":"Hu","year":"2021"},{"key":"B35","doi-asserted-by":"publisher","first-page":"2811","DOI":"10.1016\/s0006-3495(02)75621-x","article-title":"Two-photon fluorescence spectroscopy and microscopy of NAD(P)H and flavoprotein","volume":"82","author":"Huang","year":"2002","journal-title":"Biophys. J."},{"key":"B36","doi-asserted-by":"publisher","first-page":"518","DOI":"10.1002\/elps.201400451","article-title":"Quantification of riboflavin, flavin mononucleotide, and flavin adenine dinucleotide in mammalian model cells by CE with LED-induced fluorescence detection","volume":"36","author":"Huhner","year":"2015","journal-title":"Electrophoresis"},{"key":"B37","doi-asserted-by":"publisher","first-page":"309","DOI":"10.1128\/mcb.05603-11","article-title":"Mitochondrial fission contributes to mitochondrial dysfunction and insulin resistance in skeletal muscle","volume":"32","author":"Jheng","year":"2012","journal-title":"Mol. Cell Biol."},{"key":"B38","doi-asserted-by":"publisher","first-page":"1271","DOI":"10.1073\/pnas.89.4.1271","article-title":"Fluorescence lifetime imaging of free and protein-bound NADH","volume":"89","author":"Jr","year":"1992","journal-title":"Proc. Natl. Acad. Sci. U. S. A."},{"key":"B39","doi-asserted-by":"publisher","first-page":"5952","DOI":"10.3390\/ijms22115952","article-title":"Bioenergetic alterations of metabolic redox coenzymes as NADH, FAD and FMN by means of fluorescence lifetime imaging techniques","volume":"22","author":"Kalinina","year":"2021","journal-title":"Int. J. Mol. Sci."},{"key":"B40","doi-asserted-by":"publisher","first-page":"361","DOI":"10.20455\/ros.2016.865","article-title":"MitoSOX-based flow Cytometry for detecting mitochondrial ROS","volume":"2","author":"Kauffman","year":"2016","journal-title":"React. Oxyg. Species (Apex)"},{"key":"B41","doi-asserted-by":"publisher","first-page":"875","DOI":"10.1089\/ars.2017.7451","article-title":"Evaluating cell metabolism through autofluorescence imaging of NAD(P)H and FAD","volume":"30","author":"Kolenc","year":"2019","journal-title":"Antioxid. Redox Signal"},{"key":"B42","doi-asserted-by":"publisher","first-page":"9","DOI":"10.1002\/jemt.20866","article-title":"Multiphoton fluorescence lifetime imaging of 3D-stem cell spheroids during differentiation","volume":"74","author":"Konig","year":"2011","journal-title":"Microsc. Res. Tech."},{"key":"B43","doi-asserted-by":"publisher","first-page":"1015","DOI":"10.1007\/s10895-014-1368-1","article-title":"Testing fluorescence lifetime standards using two-photon excitation and time-domain instrumentation: rhodamine B, coumarin 6 and lucifer yellow","volume":"24","author":"Kristoffersen","year":"2014","journal-title":"J. Fluoresc."},{"key":"B44","doi-asserted-by":"crossref","DOI":"10.1007\/978-0-387-46312-4","volume-title":"Principles of fluorescence spectroscopy","author":"Lakowicz","year":"2006"},{"key":"B45","doi-asserted-by":"publisher","first-page":"1271","DOI":"10.1073\/pnas.89.4.1271","article-title":"Fluorescence lifetime imaging of free and protein-bound NADH","volume":"89","author":"Lakowicz","year":"1992","journal-title":"Proc. Natl. Acad. Sci. U. S. A."},{"key":"B46","doi-asserted-by":"publisher","first-page":"110","DOI":"10.1016\/j.cmet.2011.12.009","article-title":"Glucose-independent glutamine metabolism via TCA cycling for proliferation and survival in B cells","volume":"15","author":"Le","year":"2012","journal-title":"Cell Metab."},{"key":"B47","doi-asserted-by":"publisher","first-page":"516","DOI":"10.1038\/s41568-020-0273-y","article-title":"Metabolism of immune cells in cancer","volume":"20","author":"Leone","year":"2020","journal-title":"Nat. Rev. Cancer"},{"key":"B48","doi-asserted-by":"publisher","first-page":"3305","DOI":"10.1364\/ol.32.003305","article-title":"Diagnostic cellular organization features extracted from autofluorescence images","volume":"32","author":"Levitt","year":"2007","journal-title":"Opt. Lett."},{"key":"B49","doi-asserted-by":"publisher","first-page":"6807","DOI":"10.1038\/srep06807","article-title":"Direct visualization of de novo lipogenesis in single living cells","volume":"4","author":"Li","year":"2014","journal-title":"Sci. Rep."},{"key":"B50","doi-asserted-by":"publisher","first-page":"1947","DOI":"10.2967\/jnumed.111.093815","article-title":"PET imaging of glutaminolysis in tumors by 18F-(2S,4R)4-fluoroglutamine","volume":"52","author":"Lieberman","year":"2011","journal-title":"J. Nucl. Med."},{"key":"B51","doi-asserted-by":"publisher","first-page":"271","DOI":"10.1038\/s42003-020-0988-z","article-title":"High-content fluorescence imaging with the metabolic flux assay reveals insights into mitochondrial properties and functions","volume":"3","author":"Little","year":"2020","journal-title":"Commun. Biol."},{"key":"B52","doi-asserted-by":"publisher","first-page":"eaap9302","DOI":"10.1126\/sciadv.aap9302","article-title":"Mapping metabolic changes by noninvasive, multiparametric, high-resolution imaging using endogenous contrast","volume":"4","author":"Liu","year":"2018","journal-title":"Sci. Adv."},{"key":"B53","doi-asserted-by":"publisher","first-page":"2669","DOI":"10.1016\/s0021-9258(17)30124-2","article-title":"Evidence that glutamine, not sugar, is the major energy source for cultured HeLa cells","volume":"254","author":"Lj Reitzer","year":"1979","journal-title":"J. Biol. Chem."},{"key":"B54","doi-asserted-by":"publisher","first-page":"13206","DOI":"10.1038\/s41598-019-48107-2","article-title":"Label-free assessment of pre-implantation embryo quality by the Fluorescence Lifetime Imaging Microscopy (FLIM)-phasor approach","volume":"9","author":"Ma","year":"2019","journal-title":"Sci. Rep."},{"key":"B55","doi-asserted-by":"publisher","first-page":"102","DOI":"10.1038\/s41467-019-13668-3","article-title":"Mitochondrial TCA cycle metabolites control physiology and disease","volume":"11","author":"Martinez-Reyes","year":"2020","journal-title":"Nat. Commun."},{"key":"B56","doi-asserted-by":"publisher","first-page":"100143","DOI":"10.1016\/j.xcrm.2020.100143","article-title":"Targeting mitochondrial complex I overcomes chemoresistance in high OXPHOS pancreatic cancer","volume":"1","author":"Masoud","year":"2020","journal-title":"Cell Rep. Med."},{"key":"B57","doi-asserted-by":"publisher","first-page":"2539S","DOI":"10.1093\/jn\/131.9.2539s","article-title":"Glutamine and cancer","volume":"131","author":"Medina","year":"2001","journal-title":"J. Nutr."},{"key":"B58","doi-asserted-by":"publisher","first-page":"15","DOI":"10.1186\/s13287-017-0484-7","article-title":"Two-photon FLIM of NAD(P)H and FAD in mesenchymal stem cells undergoing either osteogenic or chondrogenic differentiation","volume":"8","author":"Meleshina","year":"2017","journal-title":"Stem Cell Res. Ther."},{"key":"B59","doi-asserted-by":"publisher","first-page":"S236","DOI":"10.1016\/j.nima.2010.11.092","article-title":"Fundamental limits of spatial resolution in PET","volume":"648","author":"Moses","year":"2011","journal-title":"Nucl. Instrum. Methods Phys. Res. A"},{"key":"B60","doi-asserted-by":"publisher","first-page":"5261","DOI":"10.1016\/s0021-9258(19)70779-0","article-title":"Picosecond fluorescence lifetime of the coenzyme of D-amino acid oxidase","volume":"255","author":"Nakashima","year":"1980","journal-title":"J. Biol. Chem."},{"key":"B61","doi-asserted-by":"publisher","first-page":"24","DOI":"10.1186\/s40170-021-00258-5","article-title":"Inhibition of glycolysis and mitochondrial respiration promotes radiosensitisation of neuroblastoma and glioma cells","volume":"9","author":"Nile","year":"2021","journal-title":"Cancer Metab."},{"key":"B62","doi-asserted-by":"publisher","first-page":"28","DOI":"10.1073\/pnas.1107524108","article-title":"Label-free Raman observation of cytochrome c dynamics during apoptosis","volume":"109","author":"Okada","year":"2012","journal-title":"Proc. Natl. Acad. Sci. U. S. A."},{"key":"B63","doi-asserted-by":"publisher","first-page":"4759","DOI":"10.1158\/0008-5472.can-09-2572","article-title":"Optical redox ratio differentiates breast cancer cell lines based on estrogen receptor status","volume":"70","author":"Ostrander","year":"2010","journal-title":"Cancer Res."},{"key":"B64","doi-asserted-by":"publisher","first-page":"977","DOI":"10.1364\/boe.6.000977","article-title":"Detection of urinary bladder cancer cells using redox ratio and double excitation wavelengths autofluorescence","volume":"6","author":"Palmer","year":"2015","journal-title":"Biomed. Opt. Express"},{"key":"B65","doi-asserted-by":"publisher","first-page":"101549","DOI":"10.1016\/j.redox.2020.101549","article-title":"Single cell-based fluorescence lifetime imaging of intracellular oxygenation and metabolism","volume":"34","author":"Penjweini","year":"2020","journal-title":"Redox Biol."},{"key":"B66","doi-asserted-by":"publisher","first-page":"4580","DOI":"10.1038\/s41467-021-24868-1","article-title":"Label-free imaging for quality control of cardiomyocyte differentiation","volume":"12","author":"Qian","year":"2021","journal-title":"Nat. Commun."},{"key":"B67","doi-asserted-by":"publisher","first-page":"248","DOI":"10.1002\/1097-0320(20010401)43:4<248::aid-cyto1057>3.0.co;2-y","article-title":"Fluorescence lifetime imaging: multi-point calibration, minimum resolvable differences, and artifact suppression","volume":"43","author":"Qs","year":"2001","journal-title":"Cytometry"},{"key":"B68","doi-asserted-by":"publisher","first-page":"3432","DOI":"10.1038\/srep03432","article-title":"Quantitative metabolic imaging using endogenous fluorescence to detect stem cell differentiation","volume":"3","author":"Quinn","year":"2013","journal-title":"Sci. Rep."},{"key":"B69","doi-asserted-by":"publisher","first-page":"204","DOI":"10.1016\/j.tibtech.2013.01.008","article-title":"Stem cell metabolic and spectroscopic profiling","volume":"31","author":"Ramm Sander","year":"2013","journal-title":"Trends Biotechnol."},{"key":"B70","doi-asserted-by":"publisher","first-page":"1105648","DOI":"10.3389\/fonc.2023.1105648","article-title":"Flavin fluorescence lifetime and autofluorescence optical redox ratio for improved visualization and classification of brain tumors","volume":"13","author":"Reichert","year":"2023","journal-title":"Front. Oncol."},{"key":"B71","doi-asserted-by":"publisher","first-page":"34755","DOI":"10.1038\/srep34755","article-title":"The phasor-FLIM fingerprints reveal shifts from OXPHOS to enhanced glycolysis in Huntington Disease","volume":"6","author":"Sameni","year":"2016","journal-title":"Sci. Rep."},{"key":"B72","doi-asserted-by":"publisher","first-page":"5456","DOI":"10.1038\/s41598-018-23691-x","article-title":"Protein-bound NAD(P)H lifetime is sensitive to multiple fates of glucose carbon","volume":"8","author":"Sharick","year":"2018","journal-title":"Sci. Rep."},{"key":"B73","doi-asserted-by":"publisher","first-page":"19494","DOI":"10.1073\/pnas.0708425104","article-title":"In vivo multiphoton microscopy of NADH and FAD redox states, fluorescence lifetimes, and cellular morphology in precancerous epithelia","volume":"104","author":"Skala","year":"2007","journal-title":"PNAS"},{"key":"B74","first-page":"1723","article-title":"Quantitation of myocardial fatty acid metabolism using PET","volume":"37","author":"Steven","year":"1996","journal-title":"J. Nucl. Med."},{"key":"B75","doi-asserted-by":"publisher","first-page":"568","DOI":"10.1038\/srep00568","article-title":"Metabolic trajectory of cellular differentiation in small intestine by Phasor Fluorescence Lifetime Microscopy of NADH","volume":"2","author":"Stringari","year":"","journal-title":"Sci. Rep."},{"key":"B76","doi-asserted-by":"publisher","first-page":"e48014","DOI":"10.1371\/journal.pone.0048014","article-title":"Phasor fluorescence lifetime microscopy of free and protein-bound NADH reveals neural stem cell differentiation potential","volume":"7","author":"Stringari","year":"","journal-title":"PLoS One"},{"key":"B77","doi-asserted-by":"publisher","first-page":"25086","DOI":"10.1038\/srep25086","article-title":"In vivo Visualization of Stromal Macrophages via label-free FLIM-based metabolite imaging","volume":"6","author":"Szulczewski","year":"2016","journal-title":"Sci. Rep."},{"key":"B78","doi-asserted-by":"publisher","first-page":"22171","DOI":"10.1038\/s41598-021-00126-8","article-title":"Simultaneous NAD(P)H and FAD fluorescence lifetime microscopy of long UVA-induced metabolic stress in reconstructed human skin","volume":"11","author":"Ung","year":"2021","journal-title":"Sci. Rep."},{"key":"B79","doi-asserted-by":"publisher","first-page":"8858","DOI":"10.1021\/jp020356s","article-title":"Dynamic conformations of flavin adenine dinucleotide: simulated molecular dynamics of the flavin cofactor related to the time-resolved fluorescence characteristics","volume":"106","author":"Van Den Berg","year":"2002","journal-title":"J. Phys. Chem. B"},{"key":"B80","doi-asserted-by":"publisher","first-page":"53424","DOI":"10.3791\/53424","article-title":"Metabolic characterization of polarized M1 and M2 bone marrow-derived macrophages using real-time extracellular flux analysis","author":"Van Den Bossche","year":"2015","journal-title":"J. Vis. Exp."},{"key":"B81","doi-asserted-by":"publisher","first-page":"3067","DOI":"10.1158\/0008-5472.can-13-2713","article-title":"Endogenous two-photon fluorescence imaging elucidates metabolic changes related to enhanced glycolysis and glutamine consumption in precancerous epithelial tissues","volume":"74","author":"Varone","year":"2014","journal-title":"Cancer Res."},{"key":"B82","doi-asserted-by":"publisher","first-page":"79","DOI":"10.1038\/s41598-017-18634-x","article-title":"Segmented cell analyses to measure redox states of autofluorescent NAD(P)H, FAD & Trp in cancer cells by FLIM","volume":"8","author":"Wallrabe","year":"2018","journal-title":"Sci. Rep."},{"key":"B83","doi-asserted-by":"publisher","first-page":"6164","DOI":"10.1158\/0008-5472.can-13-0527","article-title":"Optical metabolic imaging identifies glycolytic levels, subtypes, and early-treatment response in breast cancer","volume":"73","author":"Walsh","year":"2013","journal-title":"Cancer Res."},{"key":"B84","doi-asserted-by":"publisher","first-page":"77","DOI":"10.1038\/s41551-020-0592-z","article-title":"Classification of T-cell activation via autofluorescence lifetime imaging","volume":"5","author":"Walsh","year":"2021","journal-title":"Nat. Biomed. Eng."},{"key":"B85","doi-asserted-by":"publisher","first-page":"907","DOI":"10.1038\/ni.2386","article-title":"Metabolic checkpoints in activated T cells","volume":"13","author":"Wang","year":"2012","journal-title":"Nat. Immunol."},{"key":"B86","doi-asserted-by":"publisher","first-page":"594","DOI":"10.1038\/s42003-021-02113-1","article-title":"Live-cell imaging of glucose-induced metabolic coupling of \u03b2 and \u03b1\u00a0cell metabolism in health and type\u00a02 diabetes","volume":"4","author":"Wang","year":"2021","journal-title":"Commun. Biol."},{"key":"B87","doi-asserted-by":"publisher","first-page":"e201960050","DOI":"10.1002\/jbio.201960050","article-title":"Classifying T cell activity in autofluorescence intensity images with convolutional neural networks","volume":"13","author":"Wang","year":"2020","journal-title":"J. Biophot."},{"key":"B88","doi-asserted-by":"publisher","first-page":"309","DOI":"10.1126\/science.123.3191.309","article-title":"On the origin of cancer cells","volume":"123","author":"Warburg","year":"1956","journal-title":"Science"},{"key":"B89","doi-asserted-by":"publisher","first-page":"427","DOI":"10.1016\/j.tibs.2010.05.003","article-title":"Glutamine addiction: a new therapeutic target in cancer","volume":"35","author":"Wise","year":"2010","journal-title":"Trends Biochem. Sci."},{"key":"B90","doi-asserted-by":"publisher","first-page":"13305","DOI":"10.1021\/acs.analchem.7b03461","article-title":"Raman deuterium isotope probing reveals microbial metabolism at the single-cell level","volume":"89","author":"Xu","year":"2017","journal-title":"Anal. Chem."},{"key":"B91","doi-asserted-by":"publisher","first-page":"322","DOI":"10.1002\/ijc.28992","article-title":"Noninvasive assessment of mitochondrial organization in three-dimensional tissues reveals changes associated with cancer development","volume":"136","author":"Xylas","year":"2015","journal-title":"Int. J. Cancer"},{"key":"B92","doi-asserted-by":"publisher","first-page":"46","DOI":"10.1016\/j.cbpa.2016.05.016","article-title":"Deciphering single cell metabolism by coherent Raman scattering microscopy","volume":"33","author":"Yue","year":"2016","journal-title":"Curr. Opin. Chem. Biol."},{"key":"B93","doi-asserted-by":"publisher","first-page":"1068","DOI":"10.1038\/nprot.2012.048","article-title":"Measuring energy metabolism in cultured cells, including human pluripotent stem cells and differentiated cells","volume":"7","author":"Zhang","year":"2012","journal-title":"Nat. Protoc."}],"container-title":["Frontiers in Bioengineering and Biotechnology"],"original-title":[],"link":[{"URL":"https:\/\/www.frontiersin.org\/articles\/10.3389\/fbioe.2023.1293268\/full","content-type":"unspecified","content-version":"vor","intended-application":"similarity-checking"}],"deposited":{"date-parts":[[2023,11,28]],"date-time":"2023-11-28T10:03:50Z","timestamp":1701165830000},"score":1,"resource":{"primary":{"URL":"https:\/\/www.frontiersin.org\/articles\/10.3389\/fbioe.2023.1293268\/full"}},"subtitle":[],"short-title":[],"issued":{"date-parts":[[2023,11,28]]},"references-count":93,"alternative-id":["10.3389\/fbioe.2023.1293268"],"URL":"https:\/\/doi.org\/10.3389\/fbioe.2023.1293268","relation":{},"ISSN":["2296-4185"],"issn-type":[{"value":"2296-4185","type":"electronic"}],"subject":[],"published":{"date-parts":[[2023,11,28]]},"article-number":"1293268"}}