TY  - JOUR
A1  - Nanadikar, Maithily S.
A1  - Vergel Leon, Ana M.
A1  - Borowik, Sergej
A1  - Hillemann, Annette
A1  - Zieseniss, Anke
A1  - Belousov, Vsevolod V.
A1  - Bogeski, Ivan
A1  - Rehling, Peter
A1  - Dudek, Jan
A1  - Katschinski, Dörthe M.
T1  - O2 affects mitochondrial functionality ex vivo
JF  - Redox Biology
N2  - Mitochondria have originated in eukaryotic cells by endosymbiosis of a specialized prokaryote approximately 2 billion years ago. They are essential for normal cell function by providing energy through their role in oxidizing carbon substrates. Glutathione (GSH) is a major thiol-disulfide redox buffer of the cell including the mitochondrial matrix and intermembrane space. We have generated cardiomyocyte-specific Grx1-roGFP2 GSH redox potential (EGSH) biosensor mice in the past, in which the sensor is targeted to the mitochondrial matrix. Using this mouse model a distinct EGSH of the mitochondrial matrix (−278.9 ± 0.4 mV) in isolated cardiomyocytes is observed. When analyzing the EGSH in isolated mitochondria from the transgenic hearts, however, the EGSH in the mitochondrial matrix is significantly oxidized (−247.7 ± 8.7 mV). This is prevented by adding N-Ethylmaleimide during the mitochondria isolation procedure, which precludes disulfide bond formation. A similar reducing effect is observed by isolating mitochondria in hypoxic (0.1–3% O2) conditions that mimics mitochondrial pO2 levels in cellulo. The reduced EGSH is accompanied by lower ROS production, reduced complex III activity but increased ATP levels produced at baseline and after stimulation with succinate/ADP. Altogether, we demonstrate that oxygenation is an essential factor that needs to be considered when analyzing mitochondrial function ex vivo.
KW  - glutathione redox potential
KW  - hypoxia
KW  - mitochondrial matrix
KW  - Grx1-roGFP
Y1  - 2019
U6  - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-232217
VL  - 22
ER  -