Wagenaars 2014 Abstract IOC 2014-04 Schroecken

Wagenaars J, Willems PHGM, Koopman WJ (2014) Oxygen consumption in OXPHOS-deficient cells. Mitochondr Physiol Network 19.02.

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Wagenaars J, Willems PHGM, Koopman WJ (2014)

Event: IOC88

Mitochondria are crucially involved in cellular Ca2+ and redox homeostasis and apoptosis induction. Maintenance of mitochondrial function and integrity requires an inside-negative potential difference across the mitochondrial inner membrane. This potential is sustained by four complexes (CI-CIV) of the electron-transport chain (ETC). Together with the ATP-generating FoF1-ATPase (complex V or CV) the ETC complexes constitute the oxidative phosphorylation (OXPHOS) system. CI or NADH:ubiquinone oxidoreductase is the first and largest protein complex of the ETC and couples the oxidation of NADH to the reduction of ubiquinone. In my current research I focus on the analysis of primary skin fibroblasts from patients with mitochondrial OXPHOS disorders (including CI deficiency) and myofibers/myoblasts/myotubes from wildtype (WT) and KO animals with CI deficiency (NDUFS4-/- mice). We have observed that intact fibroblasts from patients with a mild CI deficiency display normal routine O2 consumption, whereas patient fibroblasts with a very severe CI deficiency display reduced routine O2 consumption (threshold effect). Furthermore we observed no differences in maximal (FCCP-induced) respiration in fibroblasts from patients with a mild isolated CI deficiency. To stimulate mitochondrial ATP-linked respiration, cells were treated with the hormone bradykinin during O2 consumption measurements. In this type of experiment the magnitude of the bradykinin-stimulated O2 consumption was less in fibroblasts from patients with isolated CI deficiency than in cells from a healthy individual. In this workshop I aim to increase my general knowledge of the Oroboros system and its (im)possibilities. I am particularly interested in strategies that can be applied in intact cells to investigate OXPHOS deficiencies. Moreover, the meaning and relevance of “reserve capacity” in the context of intact cells I find particularly interesting. Cell types: - Primary patient and animal cells - Fibroblasts, myoblasts, myofibers - Intact vs. permeabilized vs. isolated mitochondria

• O2k-Network Lab: NL Nijmegen Koopman WJ

Labels: MiParea: Respiration 

Stress:Mitochondrial disease  Organism: Human, Mouse  Tissue;cell: Skeletal muscle  Preparation: Intact cells, Permeabilized cells, Isolated mitochondria 

HRR: Oxygraph-2k