A5025109057- Mitochondrial Function and Pathology
- ATP Synthase and ATPases Research
- Cardiovascular Function and Risk Factors
- Advanced MRI Techniques and Applications
- Photosynthetic Processes and Mechanisms
- Adipose Tissue and Metabolism
- Cardiac electrophysiology and arrhythmias
- Cardiac Ischemia and Reperfusion
- Fuel Cells and Related Materials
- Cardiac Imaging and Diagnostics
- Cardiovascular and exercise physiology
- Metabolomics and Mass Spectrometry Studies
- Cardiomyopathy and Myosin Studies
- Lipid metabolism and biosynthesis
- Muscle metabolism and nutrition
- Ion channel regulation and function
- Advanced NMR Techniques and Applications
- Cardiac Arrest and Resuscitation
- Sphingolipid Metabolism and Signaling
- Lipid Membrane Structure and Behavior
- Muscle Physiology and Disorders
- Metabolism and Genetic Disorders
- Electrochemical sensors and biosensors
- Traditional Chinese Medicine Analysis
- Endoplasmic Reticulum Stress and Disease
Electrophysiology and Heart Modeling Institute
2012-2024
Centre National de la Recherche Scientifique
2003-2021
Centre Hospitalier Universitaire de Bordeaux
2016-2021
Inserm
2004-2021
Université de Bordeaux
2002-2021
Centre de Recherche Cardio-Thoracique de Bordeaux
2012-2021
Hôpital Cardiologique du Haut-Lévêque
2018-2021
Bordeaux Population Health
2012
Centre de Résonance Magnétique des Systèmes Biologiques
1998-2011
Université Paris-Sud
1997
Upon induction of permeability transition with different agents (Ca2+, tert-butyl hydroperoxide, atractyloside), mouse hepatocyte mitochondria manifest a disruption outer membrane integrity leading to the release cytochrome c and apoptosis-inducing factor (AIF), two proteins which are involved in programmed cell death (apoptosis). Chelation Ca2+ shortly (within 2 min) after its addition isolated reestablished mitochondrial transmembrane potential (deltapsi(m)), prevented large amplitude...
We previously have shown that Nicotiana sylvestris cytoplasmic male sterile (CMS) mutants I and II present large mtDNA deletions the NAD7 subunit of complex (the main dehydrogenase mitochondrial respiratory chain) is absent in CMS I. Here, we show that, despite a difference size deletion, display similar alterations. Both an impaired development from germination to flowering, with partial sterility becomes complete under low light. Besides NAD7, two other subunits are missing (NAD9...
With aging, most skeletal muscles undergo a progressive loss of mass and strength, process termed sarcopenia. Aging-related defects in mitochondrial energetics have been proposed to be causally involved However, changes muscle oxidative phosphorylation with aging remain highly controversial issue, creating pressing need for integrative approaches determine whether bioenergetics are impaired aged muscle. To address this was first investigated vivo the gastrocnemius adult (6 months) (21 male...
Mitochondrial respiration is the main source of energy in aerobic animal cells and adapted to demand by respiratory coupling. Uncoupling proteins (UCPs) perturb coupling inducing a proton leak through mitochondrial inner membrane. Although this could lead deleterious waste, it may prevent production oxygen radicals when rate phosphorylation ADP into ATP low, whereas substrate availability mitochondria high. The latter conditions are encountered during cardiac reperfusion after ischemia...
Trypanosoma brucei is a parasitic protist responsible for sleeping sickness in humans. The procyclic form of this parasite, transmitted by tsetse flies, considered to be dependent on oxidative phosphorylation ATP production. Indeed, its respiration was 55% inhibited oligomycin, which the most specific inhibitor mitochondrial F0/F1-ATP synthase. However, 10-fold excess compound did not significantly affect intracellular concentration and doubling time parasite only 1.5-fold increased,...
The effects of temperature on the control respiration rate, phosphorylation proton leakage protonmotive force and effective ATP/O ratio were determined in isolated rat liver mitochondria over a range respiratory conditions by applying top-down elasticity analyses. Simultaneous measurements membrane potential, oxidation rates performed under various ATP turnover rates, ranging from state 4 to 3. Although activities three subsystems decreased with (over 30-fold between 37 °C), exhibited...
Findings Here, we demonstrate that OP2113 (5-(4-Methoxyphenyl)-3H-1,2-dithiole-3-thione, CAS 532-11-6), synthesized and used as a drug since 1696, does not act an unspecific antioxidant molecule (i.e., radical scavenger) but unexpectedly decreases mitochondrial reactive oxygen species (ROS/H2O2) production by acting specific inhibitor of ROS at the IQ site complex I respiratory chain. Studies performed on isolated rat heart mitochondria also showed affect oxidative phosphorylation driven or...
By measuring the relationship between protonmotive force and increment in oxygen consumption by mitochondria treated with submaximal amounts of uncoupler, we have experimentally tested four different models imperfect coupling oxidative phosphorylation. The results show that increased rate at high is explained entirely dependence on passive proton leak conductance mitochondrial inner membrane. There no measurable contribution from redox-slip reactions pumps caused force. Neither there any...
The purpose of this study was to test the hypothesis that mitochondrial permeability transition might be implicated in and intact organ dysfunctions associated with damage induced by reperfusion after cold ischaemia. Energetic metabolism assessed continuously 31P-NMR on a model system isolated perfused rat liver; mitochondria were extracted from livers studied using top-down control analysis. During temperature hypothermic normothermic perfusion (from 4 37 °C) ATP content fell rapidly,...
The mitochondrial uncoupling protein of brown adipose tissue (UCP1) was expressed in skeletal muscle and heart transgenic mice at levels comparable with the amount found mitochondria. These have a lower body weight, when related to food intake energy expenditure are increased. A specific reduction mass observed but varied according contractile activity muscles. Heart soleus unaffected, indicating that muscles undergoing regular contractions, therefore continuous ATP production, protected. In...
The mitochondrial uncoupling protein (UCP) is a membranous proton carrier exclusively synthesized in brown adipocytes. cDNA for the rat UCP was placed an expression vector and transfected into mammalian cells. Its tested transiently CHO In these cells detected mitochondria by using antibodies. Permanent of achieved stable transformed cell lines. characterized membranes, antibodies hydroxyapatite purification. expressed displayed functional characteristics adipocyte UCP. It induced...
Microglia are immune cells within the central nervous system. In brain-developing tumors, gliomas able to silence defense and functions of microglia, a phenomenon which strongly contributes tumor progression treatment resistance. Being activated highly motile, microglia infiltrate tumors secrete macrophagic chemoattractant factors. Thereafter, shut down their properties stimulate release growth-promoting The result such modulation is that kind symbiosis occurs between cells, in favor growth....
Trypanosoma brucei is a parasitic protist that undergoes complex life cycle during transmission from its mammalian host (bloodstream forms) to the midgut of insect vector (procyclic form). In both forms, most glycolytic steps take place within specialized peroxisomes, called glycosomes. Here, we studied metabolic adaptations in procyclic trypanosome mutants affected their maintenance glycosomal redox balance. T. can theoretically use three strategies maintain NAD(+)/NADH balance as follows:...
Background Mitochondrial dysfunctions appear strongly implicated in a wide range of pathologies. Therefore, there is growing need the determination normal and pathological integrated response oxidative phosphorylation to cellular ATP demand. The present study intends address this issue by providing method investigate mitochondrial affinity for ADP isolated mitochondria. Methodology/Principal Findings proposed based on simultaneous monitoring substrate oxidation (determined polarographically)...
Changes in mitochondrial matrix volume were studied both on isolated mitochondria and situ CHME 5 human microglia monoblastoid U 937 cells using multiparametric flow cytometric analysis. The use of specific effectors activity (oligomycin KCN) allowed the demonstration, whole cells, a strict correlation between light scattering changes: swelling induced concomitant increase forward scattering, decrease side cell population. technique was applied to study early phases acetyl-ceramide-induced...
The membrane potential in highly coupled potato ( Solanum tuberosum L.) mitochondria, as measured by changes safranine absorbance, was significantly increased addition of bovine serum albumin. Purification mitochondria on Percoll, removing 50% free unsaturated fatty acids, decreased the BSA‐de‐pendent potential. effect added linoleic acid and natural accumulation acids during aging studied. response to albumin appeared be directly correlated amount acids. Aging vitro, releasing respiratory...
Purified and intact mitochondria isolated from potato tuber show a specific concanavalin A (Con A) binding as deduced fluorescence labelling studies in the presence of sugar α‐D‐methylmannose. This also occurs mitoplasts, indicating Con A‐binding sites on inner mitochondrial membrane. In contrast, wheat germ agglutinin appears non‐specific. Flow cytometry with purified enables assessment by individual mitochondria. Thus, three subpopulations were identified their reactivity towards fluorescent A.
Control over oxidative phosphorylation by purified potato mitochondria was determined using the top‐down approach of metabolic control analysis. The respiration rate, proton‐leak rate and proton motive force exerted respiratory chain, reactions leak were measured a range rates from resting (state 4) to maximal 3). These obtained adding different amounts hexokinase in presence glucose, or oligomycin ADP. substrate NADH succinate, both which feed electrons directly ubiquinone. oxygen...