Christen 2013 Abstract MiP2013

Christen F, Desrosiers V, Blier PU (2013) Thermal sensitivity of mitochondria from arctic charr heart: Mitochondrial respiration and ROS production. Mitochondr Physiol Network 18.08.

Link:

Christen F, Desrosiers V, Blier PU (2013)

Event: MiP2013

In the context of climate change, it is of paramount importance to investigate the thermal sensitivity of aquatic ectoterms [1]. Oxidative phosphorylation in mitochondria is one of the key processes of energy production and is known to be influenced by temperature [2,3]. The aim of our study was to shed light on the specific steps of the electron transfer system (ETS) that contribute to the adaptation of fish to temperature changes. For this purpose, we measured oxygen consumption and hydrogen peroxide production at four different temperatures (10, 15, 20 and 25°C) in mitochondria isolated from arctic charr heart (Salvelinus alpinus) raised at 10 °C. Activities of citrate synthase and cytochrome c oxidase (COX) were also measured at the same temperatures. Specifically, respiration rates of Complex I and Complex II in both coupled and uncoupled states were determined separately by adding either pyruvate, malate, ADP and FCCP for Complex I or succinate, ADP and FCCP for Complex II. Moreover, respiration rates were also measured in the presence of pyruvate+malate+succinate+ADP allowing the evaluation of Complexes I+II together.

Our preliminary results showed that the Complex I and Complex II respiration rates (taken together) were higher when measured separately than when both complexes worked simultaneously. However, this difference was only significant at 15 °C. This may concomitantly occur with a higher reactive oxygen species production at elevated temperatures, and potentially a disruption of mitochondrial integrity. Subsequent analyses of hydrogen peroxide production, citrate synthase and COX activity will give us further insights into the thermal sensitivity of arctic charr heart mitochondria.

• O2k-Network Lab: CA Rimouski Blier PU

Labels:

Stress:RONS; Oxidative Stress"RONS; Oxidative Stress" is not in the list (Cell death, Cryopreservation, Ischemia-reperfusion, Permeability transition, Oxidative stress;RONS, Temperature, Hypoxia, Mitochondrial disease) of allowed values for the "Stress" property. 

Tissue;cell: Heart  Preparation: Isolated Mitochondria"Isolated Mitochondria" is not in the list (Intact organism, Intact organ, Permeabilized cells, Permeabilized tissue, Homogenate, Isolated mitochondria, SMP, Chloroplasts, Enzyme, Oxidase;biochemical oxidation, ...) of allowed values for the "Preparation" property.  Enzyme: Marker Enzyme"Marker Enzyme" is not in the list (Adenine nucleotide translocase, Complex I, Complex II;succinate dehydrogenase, Complex III, Complex IV;cytochrome c oxidase, Complex V;ATP synthase, Inner mt-membrane transporter, Marker enzyme, Supercomplex, TCA cycle and matrix dehydrogenases, ...) of allowed values for the "Enzyme" property.  Regulation: Temperature  Coupling state: OXPHOS, ETS"ETS" is not in the list (LEAK, ROUTINE, OXPHOS, ET) of allowed values for the "Coupling states" property. 

HRR: Oxygraph-2k 

Affiliations and author contributions

Dept de biologie, Université du Québec à Rimouski, Canada.

Email: [email protected]

References

1. Pörtner HO, Knust R (2007) Climate change affects marine fishes through the oxygen limitation of thermal tolerance. Science 315: 95.
2. Lemieux H, Tardif JC, Dutil JD, Blier PU (2010) Thermal sensitivity of cardiac mitochondrial metabolism in an ectothermic species from a cold environment, Atlantic wolffish (Anarhichas lupus). J Exp Mar Biol Ecol 384: 113–118.
3. Pichaud N, Chatelain EH, Ballard JWO, Tanguay R, Morrow G, Blier PU (2010) Thermal sensitivity of mitochondrial metabolism in two distinct mitotypes of Drosophila simulans: evaluation of mitochondrial plasticity. J Exp Biol 213: 1665–1675.