Sommer 2010 Eur Respir J

From Bioblast
Publications in the MiPMap
Sommer N, Pak O, SchΓΆrner S, Derfuss T, Krug A, Gnaiger E, Ghofrani HA, Schermuly RT, Huckstorf C, Seeger W, Grimminger F, Weissmann N (2010) Mitochondrial cytochrome redox states and respiration in acute pulmonary oxygen sensing.

Β» Eur Respir J 36:1056-66. PMID: 20516051 Open Access

Sommer N, Pak O, Schoerner S, Derfuss T, Krug A, Gnaiger Erich, Ghofrani HA, Schermuly RT, Huckstorf C, Seeger W, Grimminger F, Weissmann N (2010) Eur Respir J

Abstract: Hypoxic pulmonary vasoconstriction (HPV) is an essential mechanism to optimise lung gas exchange. We aimed to decipher the proposed oxygen sensing mechanism of mitochondria in HPV. Cytochrome redox state was assessed by remission spectrophotometry in intact lungs and isolated pulmonary artery smooth muscle cells (PASMC). Mitochondrial respiration was quantified by high-resolution respirometry. Alterations were compared to HPV and hypoxia-induced functional and molecular readouts on the cellular level. Aortic and renal arterial smooth muscle cells (ASMC, RASMC) served as controls. The hypoxia-induced decrease of mitochondrial respiration paralleled HPV in isolated lungs. In PASMC reduction of respiration and mitochondrial cytochrome c and aa3 (complex IV), but not of cytochrome b (complex III) matched an increase in matrix superoxide levels as well as mitochondrial membrane hyperpolarisation with subsequent cytosolic calcium increase. In contrast to PASMC, RASMC displayed a lower decrease in respiration, no rise in superoxide, membrane potential, and intracellular calcium. Pharmacological inhibition of mitochondria revealed analogous kinetics of cytochrome redox state and strength of HPV. Our data suggest inhibition of complex IV as an essential step in mitochondrial oxygen sensing of HPV. Concomitantly, increased superoxide release from complex III and mitochondrial membrane hyperpolarisation may initiate the cytosolic calcium increase underlying HPV.

β€’ O2k-Network Lab: DE Giessen Weissmann N, AT Innsbruck Gnaiger E, AT Innsbruck Oroboros

Cited by

  • KomlΓ³di T, Schmitt S, Zdrazilova L, Donnelly C, Zischka H, Gnaiger E. Oxygen dependence of hydrogen peroxide production in isolated mitochondria and permeabilized cells. MitoFit Preprints (in prep).


Labels: MiParea: Respiration, Instruments;methods 

Stress:Oxidative stress;RONS  Organism: Human  Tissue;cell: Lung;gill, Endothelial;epithelial;mesothelial cell  Preparation: Intact cells 

Regulation: mt-Membrane potential, Oxygen kinetics, Redox state  Coupling state: ROUTINE, ET 

HRR: Oxygraph-2k, O2k-Spectrophotometer 

MitoFit2022Hypoxia, MitoFit 2021 AmR 

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