Modified glutamine catabolism in macrophages of Ucp2 knock-out mice.
Uncoupling protein 2 (UCP2) belongs to a family of transporters of the mitochondrial inner membrane and is reported to uncouple respiration from ATP synthesis. Our observation that the amino acid glutamine specifically induces UCP2 protein expression prompted us to investigate metabolic consequences of a UCP2 knockdown (Ucp2-KO) when glutamine is offered as a substrate. We found that Ucp2-KO macrophages incubated in the presence of glutamine exhibit a lower ammonium release, a decreased respiratory rate, and an intracellular accumulation of aspartate. Therefore, we conclude that UCP2 expression is required for efficient oxidation of glutamine in macrophages. This role of UCP2 in glutamine metabolism appears independent from the uncoupling activity of UCP2.
BIOTRAM, Université Paris Descartes, CNRS UPR9078, Faculté de Médecine Necker-Enfants Malades, 156 rue de Vaugirard 75730 Paris, France.
Tobias
T
Nübel
Yalin
Y
Emre
Daniel
D
Rabier
Bernadette
B
Chadefaux
Daniel
D
Ricquier
Frédéric
F
Bouillaud
D000818:Animals; D002478:Cells, Cultured; D005973:Glutamine / Q000378:metabolism*; D007473:Ion Channels / Q000235:genetics / Q000502:physiology*; D008264:Macrophages / Q000378:metabolism*; D051379:Mice; D018345:Mice, Knockout; D024101:Mitochondrial Proteins / Q000235:genetics / Q000502:physiology*; D000071246:Uncoupling Protein 2
D007473:Ion Channels; D024101:Mitochondrial Proteins; C000604390:Ucp2 protein, mouse; D000071246:Uncoupling Protein 2; D005973:Glutamine