qNMR-based bioenergetics tracking of C2C12 myoblasts in culture

Here, we used quantitative Nuclear Magnetic Resonance spectroscopy approach ( q NMR) to determine the molar concentrations of glucose, glutamine, lactate, and alanine metabolites in culture-media samples collected from non-differentiated C2C12 myoblasts at three distinct incubation periods, along with identical cell-free medium analyzed as a control. Through this specific metabolic profile, we were able to evaluate the main metabolic fluxes in mM/h by incorporating the temporal dynamics of the measured metabolites. Using logistical mathematical methods, we also overcame the inherent informational discretization of data and provided instantaneous time dependence information about the referred metabolites concentrations that ultimately enabled us to assess the energy metabolism of this cell line as a function of time, and ranking the aerobic and anaerobic routes used by the cells over time. Associating these mathematical models with assumed biochemical reactions, we manage to estimate ATP synthesis dynamics, reconstructing the energy state of the cells over time. We found that the estimated temporal profile of intracellular ATP flux, theoretically described here by a continuous function, revealed distinct metabolic phases along the cultivation timeline, as expected in the literature, thereby reinforcing the robustness of our analytical method, paving a robust path for further studies, for instance, myoblasts in a state of metabolic starvation.