Anna V. Naumova1, Daciana H. Margineantu2, Kareen L. Kreutziger3, Nathan J. Palpant3, James Fugate3, Charles E. Murry3
1Radiology, University of Washington, Seattle, WA, United States; 2Fred Hutchinson Cancer Research Center, Seattle, WA, United States; 3Department of Pathology, University of Washington, Seattle, WA, United States
Despite the literature data demonstrating that anaerobic glycolytic metabolism sufficient for mouse embryonic stem cell homeostasis, we demonstrated that undifferentiated human embryonic stem cells have active mitochondrial metabolism reflected by a high respiratory rate. Our data also demonstrate greater metabolic flexibility of differentiated cardiomyocytes characterized by a quick shift of ATP production from respiration to glycolysis in conditions where mitochondrial ATP production is impaired. Measurement of respiration and glycolysis rates by extracellular flux analysis using Seahorse analyzer and assessment of high energy phosphates by 31P NMR spectroscopy are complementary to each other for evaluation of metabolic activity on live cells.