Maximal oxidative capacity of NK/Ly lymphoma cells upon glucose, pyruvate and glutamine oxidation
V. Hreniukh, B. Manko, O. Sidorova, A. Babsky
Ivan Franko National University of Lviv
4, Hrushevskyi St., Lviv 79005, Ukraine
Respiration and oxidative phosphorylation of cancer cells are substantially determined by energy substrates and oxygen availability, as well as by intrinsic mechanisms of metabolism regulation. The aim of the study was to establish the maximal mitochondrial capacity of intact NK/Ly cells to oxidize important exogenous energy substrates – glucose, pyruvate and glutamine. After 15 min of incubation, cells were placed into the respiratory chamber. Oxygen consumption rate was determined using YSI 5300 Biological Oxygen Monitor with Clark oxygen electrode at 37°Ñ. To assess the maximal oxidative capacity of cells the respiration was stimulated with different concentrations of uncoupling agent cyanide-4-(trifluoromethoxy)phenylhydrazone (FCCP, 0.25–2 μM). The maximal stimulation of respiration was achieved with 0.5 or 1 μM FCCP, depending on the oxidative substrate. Glucose or pyruvate significantly and substantially elevated the respiration stimulated with 0.5–1.5 μM FCCP or 0.5–2 μM FCCP, respectively. Respiration rate and maximal oxidative capacity did not change significantly upon glutamine oxidation compared to control. The obtained data suggest that glucose and pyruvate might be an energy fuel for mitochondria of NK/Ly cells, whereas glutamine may be used as a precursor for intensive synthetic processes.
Keywords: lymphoma, mitochondria, glucose, pyruvate, glutamine, maximal oxidative capacity