Philippe H Diolez

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We previously have shown that Nicotiana sylvestris cytoplasmic male sterile (CMS) mutants I and II present large mtDNA deletions and that the NAD7 subunit of complex I (the main dehydrogenase of the mitochondrial respiratory chain) is absent in CMS I. Here, we show that, despite a large difference in size in the mtDNA deletion, CMS I and II display similar(More)
TNFR1/Fas engagement results in the cleavage of cytosolic Bid to truncated Bid (tBid), which translocates to mitochondria. We demonstrate that recombinant tBid induces in vitro immediate destabilization of the mitochondrial bioenergetic homeostasis. These alterations result in mild uncoupling of mitochondrial state-4 respiration, associated with an(More)
Upon induction of permeability transition with different agents (Ca2+, tert-butyl hydroperoxide, atractyloside), mouse hepatocyte mitochondria manifest a disruption of outer membrane integrity leading to the release of cytochrome c and apoptosis-inducing factor (AIF), two proteins which are involved in programmed cell death (apoptosis). Chelation of Ca2+(More)
BACKGROUND Our objective was to assess the effects of targeted exercise programs on health-related quality of life compared with usual care based on the ability to perform activities of daily living (ADL) and the Neuropsychiatric Inventory scores in geriatric institutionalized persons. METHODS A randomized controlled trial of 2 exercise programs vs usual(More)
BACKGROUND Mitochondrial respiration is the main source of energy in aerobic animal cells and is adapted to the energy demand by respiratory coupling. Uncoupling proteins (UCPs) perturb respiratory coupling by inducing a proton leak through the mitochondrial inner membrane. Although this could lead to deleterious energy waste, it may prevent the production(More)
S6 kinase (S6K) deletion in metazoans causes small cell size, insulin hypersensitivity, and metabolic adaptations; however, the underlying molecular mechanisms are unclear. Here we show that S6K-deficient skeletal muscle cells have increased AMP and inorganic phosphate levels relative to ATP and phosphocreatine, causing AMP-activated protein kinase (AMPK)(More)
The effects of temperature on the control of respiration rate, phosphorylation rate, proton leakage rate, the protonmotive force and the effective ATP/O ratio were determined in isolated rat liver mitochondria over a range of respiratory conditions by applying top-down elasticity and control analyses. Simultaneous measurements of membrane potential,(More)
Commonly, muscle phosphocreatine (PCr) recovery from exercise has been fitted to a monoexponential function. However, a number of experiments indicate that at low muscle pH, a monoexponential fit is not suitable. We have performed in vivo 31P-MRS measurements of PCr during recovery from high-intensity intermittent exercise where muscle pH dropped below 6.5(More)
The process of skeletal muscle aging is characterized by a progressive loss of muscle mass and functionality. The underlying mechanisms are highly complex and remain unclear. This study was designed to further investigate the consequences of aging on mitochondrial oxidative phosphorylation in rat gastrocnemius muscle, by comparing young (6 months) and aged(More)
Trypanosoma brucei is a parasitic protist responsible for sleeping sickness in humans. The procyclic form of this parasite, transmitted by tsetse flies, is considered to be dependent on oxidative phosphorylation for ATP production. Indeed, its respiration was 55% inhibited by oligomycin, which is the most specific inhibitor of the mitochondrial F0/F1-ATP(More)