Cardoso 2022 ESCI Bari

Cardoso LHD, Donnelly C, Komlódi T, Gnaiger E (2022) Bioenergetic fingerprinting with coupling and pathway control of coenzyme Q redox state and respiration in permeabilized HEK 293T cells. 56^th Annual Scientific Meeting of the European Society for Clinical Investigation.

Link: 56th Annual Scientific Meeting of the European Society for Clinical Investigation

Cardoso Luiza H D, Donnelly Chris, Komlodi Timea, Gnaiger Erich (2022)

Event: ESCI 2022 Bari IT

Multiple mitochondrial electron transfer (ET) pathways converge at the Q-junction and reduce coenzyme Q, which is oxidized by downstream Complexes III and IV. Diagnostic fingerprinting is challenged with targeting specific segments of pathway and coupling control of oxidative phosphorylation (OXPHOS) [1].

We characterised the Q redox state in pathway and coupling control using the Oroboros NextGen-O2k with the electrochemical Q-Module [2], monitoring simultaneously respiration and the reduced Q-fraction in permeabilized HEK 293T cells. Multiple combinations of substrates (pyruvate, malate, succinate) and inhibitors (rotenone, malonate) were used to interrogate the NADH-pathway (N), succinate-pathway (S), or their combination (NS). Coupling control was analysed in the S-pathway (succinate and rotenone), varying from LEAK respiration to OXPHOS-, and ET-capacity.

The reduced Q-fraction increased proportionally with increasing respiration, from N-, S-, and NS-pathway control. This reflects the variable ET push upstream of the Q-junction. In coupling control, the reduced Q-fraction decreased with an increase of respiration, opposite to pathway control. This is caused by the pull effect of coupling control downstream of the Q-junction: Stimulation of respiration by ADP increases the pull and Q becomes more oxidized.

Combined measurements of respiration and the Q-redox state provide unique diagnostic fingerprinting approaches for in-depth diagnostics of mitochondrial function in health and disease.

• Bioblast editor: Plangger M

Labels:

Affiliations and support

Luiza H.D. Cardoso¹, Chris Donnelly^1,2, Timea Komlódi^{1, Erich Gnaiger¹
Oroboros Instruments, Innsbruck, Austria
Institute of Sport Sciences, University of Lausanne, Switzerland}

This work was part of the NextGen-O2k project, with funding from the European Union’s Horizon 2020 research and innovation programme under grant agreement nº 859770. Chris Donnelly was supported by the Swiss National Science Foundation under grant agreement nº 194964.