|
|
| Line 1: |
Line 1: |
| {{Abstract
| |
| |title=[[File:CardosoLHD.JPG|left|100px|Luiza Cardoso]]Cardoso LHD, Donnelly C, Komlódi T, Gnaiger E (2022) Characterizing electron transfer through the mitochondrial Q-junction from fatty acid oxidation and TCA cycle on HEK 293T cells: correlation with respiration. EBEC 2022.
| |
| |info=[https://ebec2022.org/ EBEC 2022 Conference website]
| |
| |authors=Cardoso Luiza HD, Donnelly Chris, Komlodi Timea, Gnaiger Erich
| |
| |year=2022
| |
| |event=EBEC2022 Marseille FR
| |
| |abstract=Several electron transfer pathways into the Q-junction reduce coenzyme Q. Substrate combinations are used to study the bioenergetics of isolated mitochondria, such as (1) pyruvate & malate providing the CI substrate NADH (N-pathway); (2) succinate as the substrate of CII (S-pathway); and (3) fatty acids & malate to initiate fatty acid oxidation (F-pathway) [1]. In addition, oxidative phosphorylation (OXPHOS) is impacted by coupling control, with electron transfer (ET) maximally stimulated in the presence of uncouplers (ET capacity) or by ADP (OXPHOS capacity), or inhibited in the absence of ADP or by oligomycin (LEAK respiration) [2]. Theoretically, modulating pathway and coupling control upstream or downstream of the Q-junction, respectively, impacts the relation between the Q redox state and O<sub>2</sub> flux in opposite directions. Therefore, our aim was to characterize the influence of pathway and coupling control on these two bioenergetic parameters.
| |
|
| |
|
| We used the NextGen-O2k with Q-Module to measure O<sub>2</sub> flux and the Q redox state simultaneously, using CoQ<sub>2</sub> as a probe [3]. Cryopreserved HEK 293T cells were incubated with digitonin (plasma membrane permeabilization) and combinations of substrates and inhibitors to measure ET capacity in different pathway-control-states. Coupling control was assessed in LEAK and OXPHOS states (absence and presence of 2.5 mM ADP) and ET capacity (CCCP uncoupler titration).
| |
|
| |
| Pathway control exerted a push effect on the Q-junction, as Q became reduced proportional with respiration supported by F-, N-, S-, and combined NS-pathways. Coupling control, contrarily, had a pull effect on the Q-junction: with respiration increasing from LEAK to OXPHOS and ET capacity (S- and F-pathways), Q became increasingly oxidized. Combined measurements of respiration and Q-redox state provide new diagnostic tools based on a deeper understanding of mitochondrial bioenergetics.
| |
| |editor=[[Plangger M]]
| |
| |mipnetlab=AT Innsbruck Oroboros, CH Lausanne Place N, AT Innsbruck Gnaiger E, AT Innsbruck MitoFit
| |
| }}
| |
|
| |
| == Affiliations ==
| |
| ::::Luiza H.D. Cardoso<sup>1</sup>, Chris Donnelly<sup>1,2</sup>, Timea Komlódi<sup>1,3</sup>, Erich Gnaiger<sup>1</sup>
| |
| ::::#Oroboros Instruments, Innsbruck, Austria
| |
| ::::#Institute of Sport Sciences, University of Lausanne, Switzerland
| |
| ::::#Current address: Department of Medical Biochemistry, Semmelweis University, Hungary. - [email protected] | |
|
| |
| == References ==
| |
| ::::#E. Gnaiger E, Mitochondrial pathways and respiratory control. An introduction to OXPHOS analysis, 5th ed. Bioenerg Commun, 2020.2 (2020) 1−112.
| |
| ::::#E. Gnaiger et al ― MitoEAGLE Task Group, Mitochondrial physiology. Bioenerg Commun, 2020.1 (2020) 1−44.
| |
| ::::#T. Komlódi, L.H.D. Cardoso, C. Doerrier, A.L. Moore, P.R. Rich, E. Gnaiger E, Coupling and pathway control of coenzyme Q redox state and respiration in isolated mitochondria. Bioenerg Commun, 2021.3 (2021) 1−28.
| |
|
| |
| == List of abbreviations, terms and definitions - MitoPedia ==
| |
| {{Template:List of abbreviations, terms and definitions - MitoPedia}}
| |
|
| |
| {{Labeling
| |
| |area=Respiration
| |
| |organism=Human
| |
| |tissues=HEK
| |
| |preparations=Permeabilized cells
| |
| |couplingstates=LEAK, OXPHOS, ET
| |
| |pathways=F, N, S, NS
| |
| |instruments=Oxygraph-2k
| |
| }}
| |
