摘要：SummaryMetabolism is a key regulator of hematopoietic stem cell (HSC) functions. There is a lack of real-time, non-invasive approaches to evaluate metabolism in single HSCs. Using fluorescence lifetime imaging microscopy, we developed a set of metabolic optical biomarkers (MOBs) from the auto-fluorescent properties of metabolic coenzymes NAD(P)H and FAD. The MOBs revealed the enhanced glycolysis, low oxidative metabolism, and distinct mitochondrial localization of HSCs. Importantly, the fluorescence lifetime of enzyme-bound NAD(P)H (τbound) can non-invasively monitor the glycolytic/lactate dehydrogenase activity in single HSCs. As a proof of concept for metabolism-based cell sorting, we further identified HSCs within the Lineage-cKit+Sca1+ (KLS) hematopoietic stem/progenitor population using MOBs and a machine-learning algorithm. Moreover, we revealed the dynamic changes of MOBs, and the association of longer τboundwith enhanced glycolysis under HSC stemness-maintaining conditions during HSC culture. Our work thus provides a new paradigm to identify and track the metabolism of single HSCs non-invasively and in real time.Graphical AbstractDisplay OmittedHighlights•Metabolic optical biomarkers non-invasively distinguish HSCs from early progenitors•NAD(P)H τboundreflects lactate dehydrogenase activity in single fresh/cultured HSCs•pHi correlates with τboundin hematopoietic populations, with HSCs being the highest•Optical biomarkers track metabolic changes and response to drugs in cultured HSCsOptical Imaging; Biological Sciences; Cellular Physiology; Stem Cells Research
