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See detailMitochondrial comparative proteomics: Strenghts and Pitfalls
Mathy, Grégory ULg; Sluse, Francis ULg

in Biochimica et Biophysica Acta-Bioenergetics (2008), 1977

In this review, we describe the various techniques available to carry out valid comparative proteomics, their advantages and their disadvantages according to the goal of the research. Two-dimensional ... [more ▼]

In this review, we describe the various techniques available to carry out valid comparative proteomics, their advantages and their disadvantages according to the goal of the research. Two-dimensional electrophoresis and 2D-DIGE are compared to shotgun proteomics and SILE. We give our opinion on the best fields of application in the domain of comparative proteomics. We emphasize the usefulness of these new tools, providing mass data to study physiology and mitochondrial plasticity when faced with a specific mitochondrial insufficiency or exogenic stress. We illustrate the subject with results obtained in our laboratory specifying the importance of an approach of comparative proteomics combined from mitochondria and from the cell, which makes it possible to obtain important information on the status of the mitochondrial function at the cellular level. Finally, we draw attention to the dangers of the extrapolation of proteomic data to metabolic flows which requires the greatest care [less ▲]

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See detailMitochondrial complex I encephalomyopathy and cerebral 5-methyltetrahydrofolate deficiency
RAMAEKERS, Vincent ULg; Wels, J.; Sequeira, J. M. et al

in Neuropediatrics (2007), 38(4), 184-187

Folate transport to the brain depends on ATP-driven folate receptor-mediated transport across choroid plexus epithelial cells. Failure of ATP production in Kearns-Sayre syndrome syndrome provides one ... [more ▼]

Folate transport to the brain depends on ATP-driven folate receptor-mediated transport across choroid plexus epithelial cells. Failure of ATP production in Kearns-Sayre syndrome syndrome provides one explanation for the finding of low spinal fluid (CSF) 5-methyltetrahydrofolate (5MTHF) levels in this condition. Therefore, we suspect the presence of reduced folate transport across the blood-spinal fluid barrier in other mitochondrial encephalopathies. In the present patient with mitochondrial complex I encephalomyopathy a low 5-methyltetrahydrofolate level was found in the CSF. Serum folate receptor autoantibodies were negative and could not explain the low spinal fluid folate levels. The epileptic seizures did not respond to primidone monotherapy, but addition of ubiquinone-10 and radical scavengers reduced seizure frequency. Add-on treatment with folinic acid led to partial clinical improvement including full control of epilepsy, followed by marked recovery from demyelination of the brainstem, thalamus, basal ganglia and white matter. Cerebral folate deficiency is not only present in Kearns-Sayre syndrome but may also be secondary to the failure of mitochondrial ATP production in other mitochondrial encephalopathies. Treatment with folinic acid in addition to supplementation with radical scavengers and cofactors of deficient respiratory enzymes can result in partial clinical improvement and reversal of abnormal myelination patterns on neuro-imaging. © Georg Thieme Verlag KG Stuttgart. [less ▲]

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See detailMitochondrial diseases associated with cerebral folate deficiency
Garcia-Cazorla, A.; Quadros, E. V.; Nascimento, A. et al

in Neurology (2008), 70(16), 1360-1362

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See detailMitochondrial DNA haplogroups and serum levels of proteolytic enzymes in patients with osteoarthritis.
Rego-Perez, I.; Fernandez-Moreno, M.; Deberg, Michelle ULg et al

in Annals of the Rheumatic Diseases (2011), 70(4), 646-52

OBJECTIVE: To analyse the influence of mitochondrial DNA haplogroups, as well as the radiographic grade, on serum levels of proteolytic enzymes in patients with osteoarthritis (OA). METHODS: Serum levels ... [more ▼]

OBJECTIVE: To analyse the influence of mitochondrial DNA haplogroups, as well as the radiographic grade, on serum levels of proteolytic enzymes in patients with osteoarthritis (OA). METHODS: Serum levels of metalloproteinase-1 (MMP-1), MMP-3, MMP-13, myeloperoxidase and cathepsin K were analysed in 73 patients with OA and 77 healthy controls carrying the haplogroups J, U and H, by ELISA. Knee and hip radiographs were classified according to Kellgren and Lawrence (K/L) scoring from grade 0 to grade IV. Non-parametric and multiple regression analyses were performed to test the effects of clinical variables, including gender, age, smoking status, diagnosis, haplogroups and radiological K/L grade on serum levels of these enzymes. RESULTS: A significant influence of the haplogroups on the serum levels of MMP-3 and MMP-13 was detected (p=0.027 and p=0.035, respectively). Patients with OA with haplogroup H showed higher serum levels of MMP-3 than healthy controls. Serum levels of MMP-13 were significantly higher in patients with OA (p<0.001), and carriers of the haplogroup J showed lower levels than H carriers. Besides, levels of MMP-13 were proportionally higher in radiological groups B (K/L grade II and III) and C (K/L grade IV) than in group A (K/L grade 0 and I) (p=0.005). CONCLUSIONS: This study shows that haplogroups have a significant influence on serum levels of MMP-3 and MMP-13. The influence of the haplogroups on serum levels of MMP-3 is clearly dependent on the diagnosis, whereas the influence of the haplogroups on serum levels of MMP-13 is independent of diagnosis. [less ▲]

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See detailMitochondrial DNA haplogroups influence response to Riboflavin in Migraineurs
Di Lorenzo, C.; Coppola, G.; Santorelli, F. et al

in Cephalalgia : An International Journal of Headache (2009, January), 29(1),

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See detailMitochondrial DNA haplogroups influence the therapeutic response to riboflavin in migraineurs.
Di Lorenzo, C.; Pierelli, F.; Coppola, G. et al

in Neurology (2009), 72(18), 1588-94

OBJECTIVES: In migraine, an interictal reduction of mitochondrial energy metabolism and a preventive effect of high-dose riboflavin were reported. To explore the relation between the two, we tested if the ... [more ▼]

OBJECTIVES: In migraine, an interictal reduction of mitochondrial energy metabolism and a preventive effect of high-dose riboflavin were reported. To explore the relation between the two, we tested if the therapeutic response to riboflavin is associated with specific mitochondrial DNA (mtDNA) haplogroups. We focused our attention on haplogroup H, which is known to differ from others in terms of energy metabolism. METHODS: Sixty-four migraineurs completed a 4-month open trial with riboflavin (400 mg QD) and were genotyped blindly for mtDNA haplogroups. RESULTS: Forty patients responded to riboflavin treatment and 24 were nonresponders. The mtDNA haplogroup H was found in 29 subjects (20 migraine without aura, 9 migraine with aura). Riboflavin responders were more numerous in the non-H group (67.5%). Conversely, nonresponders were mostly H (66.7%). The difference between the two groups was significant (chi(2) = 7.07; p = 0.01). The presence of aura had no influence on riboflavin's effectiveness (chi(2) = 0.113; p = 0.74) and was not associated with a particular haplogroup (chi(2) = 0.55; p = 0.46). CONCLUSIONS: In this pharmacogenetic study, riboflavin appears to be more effective in patients with migraine with non-H mitochondrial DNA haplotypes. The underlying mechanisms are unknown, but could be related to the association of haplogroup H with increased activity in complex I, which is a major target for riboflavin. Our results may have ethnic implications, since haplogroup H is chiefly found in the European population. [less ▲]

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See detailMitochondrial DNA haplogroups modulate the serum levels of biomarkers in patients with osteoarthritis.
Rego-Perez, I.; Fernandez-Moreno, M.; Deberg, Michelle ULg et al

in Annals of the Rheumatic Diseases (2010), 69(5), 910-7

OBJECTIVE: To analyse the influence of mitochondrial DNA (mtDNA) haplogroups on serum levels of molecular biomarkers in patients with osteoarthritis (OA). METHODS: Serum levels of molecular biomarkers of ... [more ▼]

OBJECTIVE: To analyse the influence of mitochondrial DNA (mtDNA) haplogroups on serum levels of molecular biomarkers in patients with osteoarthritis (OA). METHODS: Serum levels of molecular biomarkers of cartilage metabolism (collagen type II markers: C-terminal neoepitope generated by the collagenase-mediated cleavage of collagen type II triple helix (C2C), collagen type II (Coll2-1, and its nitrated form, Coll2-1NO(2)), procollagen type II (CPII)), synovial metabolism (hyaluronic acid (HA)) and cartilage and synovial turnover (cartilage glycoprotein 39 (YKL-40)) were analysed in 73 patients with OA and 77 healthy controls using ELISAs. All participants had been previously genotyped for the mtDNA haplogroups J, U and H. Non-parametric and multivariate analysis were performed to test the effects of the clinical variables, including gender, age, smoking status, diagnosis, mtDNA haplogroups and radiological Kellgren and Lawrence (K/L) grade on the serum levels of the molecular markers. RESULTS: Non-parametric analysis found increased serum levels of HA in patients with OA, while the values for C2C and the C2C/CPII ratio were significantly higher in the healthy controls. A multiple regression analysis showed a relationship between the mtDNA haplogroups and serum levels of the typical collagen type II markers. Carriers of the mtDNA haplogroup H had higher levels while carriers of the mtDNA haplogroup J showed lower levels. Statistically significant interactions between mtDNA haplogroups and diagnosis and between mtDNA haplogroups and radiological K/L grade in the serum levels of molecular markers were also found. CONCLUSION: A new role for mtDNA haplogroups emerges from this work. The results suggest that the mtDNA haplogroups interact significantly with the serum levels of OA-related molecular markers, suggesting the possibility of their use as a complementary assay with these molecular markers. [less ▲]

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See detailMitochondrial encephalomyopathy with cytochrome c oxidase deficiency caused by a novel mutation in the MTCO1 gene.
Debray, François-Guillaume ULg; Seneca, Sara; Gonce, Michel et al

in Mitochondrion (2014)

Cytochrome c oxidase (COX) deficiency is one of the most common respiratory chain deficiencies. A woman was presented at the age of 18y with acute loss of consciousness, non-convulsive status epilepticus ... [more ▼]

Cytochrome c oxidase (COX) deficiency is one of the most common respiratory chain deficiencies. A woman was presented at the age of 18y with acute loss of consciousness, non-convulsive status epilepticus, slow neurological deterioration, transient cortical blindness, exercise intolerance, muscle weakness, hearing loss, cataract and cognitive decline. Muscle biopsy revealed ragged-red fibers, COX negative fibers and a significant decreased activity of complex IV in a homogenate. Using next generation massive parallel sequencing of the mtDNA, a novel heteroplasmic mutation was identified in MTCO1, m.7402delC, causing frameshift and a premature termination codon. Single fiber PCR showed co-segregation of high mutant load in COX negative fibers. Mutation in mitochondrially encoded complex IV subunits should be considered in mitochondrial encephalomyopathies and COX negative fibers after the common mtDNA mutations have been excluded. [less ▲]

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See detailMitochondrial function plasticity in Acanthamoeba castellanii during growth in batch culture.
Czarna, M.; Sluse, Francis ULg; jarmuszkiewicz, W.

in Journal of Bioenergetics & Biomembranes (2007), 39

The alterations in mitochondrial bioenergetics during growth in a batch culture of Acanthamoeba castellanii were studied. The capacity of cytochrome pathway-dependent respiration measured in vitro ... [more ▼]

The alterations in mitochondrial bioenergetics during growth in a batch culture of Acanthamoeba castellanii were studied. The capacity of cytochrome pathway-dependent respiration measured in vitro decreased from the intermediary phase, when cell division slowed down. The pattern of the cytochrome pathway capacity changes was paralleled from the intermediary phase by alterations in the amount of total (and reducible) membranous ubiquinone. These changes were accompanied by a decrease in mitochondrial reactive oxygen species production in vitro (when no energy-dissipating system was active), and almost no change in superoxide dismutase activity and protein level, thus indicating an equivalent need for this enzyme in oxidative stress defence in A. castellanii culture. On the other hand, a decrease in the activity and protein level of alternative oxidase and uncoupling protein was observed in vitro, when cells shifted from the exponential growth phase to the stationary phase. It turned out that the contribution of both energy-dissipating systems in the prevention of mitochondrial reactive oxygen species generation in vivo could lead to its constant level throughout the growth cycle of A. castellanii batch culture. Hence, the observed functional plasticity insures survival of high quality cysts of A. castellanii cells. [less ▲]

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See detailMitochondrial genetics
Remacle, Claire ULg; Matagne, René-Fernand ULg

in Rochaix, Jean-David; Goldschmidt-Clermont, Michel; Merchant, Sabeeha (Eds.) The Molecular Biology of Chloroplasts and Mitochondria in Chlamydomonas (1998)

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See detailMitochondrial Genome Transmission in Chlamydomonas Diploids Obtained by Sexual Crosses and Artificial Fusions: Role of the Mating Type and of a 1 Kb Intron
Remacle, Claire ULg; Bovie, C.; Michel-Wolwertz, M. R. et al

in Molecular & General Genetics [=MGG] (1990), 223(2), 180-4

The linear mitochondrial DNAs of the two infertile algal species Chlamydomonas smithii and C. reinhardtii are co-linear with the exception of a 1 kb intron (alpha intron) located in the cytochrome b gene ... [more ▼]

The linear mitochondrial DNAs of the two infertile algal species Chlamydomonas smithii and C. reinhardtii are co-linear with the exception of a 1 kb intron (alpha intron) located in the cytochrome b gene of C. smithii. C. smithii also possesses an additional HpaI restriction site (H marker) located in the COXI gene, about 5 kb from the intron. In reciprocal crosses, C. smithii (H+ alpha +) x C. reinhardtii (H- alpha -), the alpha intron is transmitted to all diploid progeny, whereas the H marker is frequently transmitted either biparentally or paternally depending on whether the C. smithii parent is maternal (mt+) or paternal (mt-). In diploids resulting from artificial fusion between vegetative cells, the absolute transmission of alpha is accompanied by the frequent transmission of the H+ marker, irrespective of the mating type of the parental strains. Finally, in reciprocal crosses between C. smithii (H+ alpha +) and recombinant H- alpha + clones, the transmission of the H marker is predominantly paternal or biparental. These results allow us to conclude that (1) the alpha intron behaves as a group I intron whose unidirectional conversion influences the transmission of the H marker; and (2) the mt- paternal mitochondrial genome is transmitted more often than the mt+. The mating type has no effect in diploids obtained by artificial fusion. [less ▲]

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See detailThe mitochondrial genome
Cardol, Pierre ULg; Remacle, Claire ULg

in Stern, David; Harris, Elizabeth; Witman, George (Eds.) The Chlamydomonas Sourcebook 3-vol set, 1-3 (2009)

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See detailA mitochondrial half-size ABC transporter is involved in cadmium tolerance in Chlamydomonas reinhardtii
Hanikenne, Marc ULg; Motte, Patrick ULg; Wu, Madeline C.S. et al

in Plant Cell and Environment (2005), 28(7), 863-873

Five cadmium-sensitive insertional mutants, all affected at the CDS1 ('cadmium-sensitive 1') locus, have been previously isolated in the unicellular green alga Chlamydomonas reinhardtii. We here describe ... [more ▼]

Five cadmium-sensitive insertional mutants, all affected at the CDS1 ('cadmium-sensitive 1') locus, have been previously isolated in the unicellular green alga Chlamydomonas reinhardtii. We here describe the cloning of the Cds1 gene (8314 bp with 26 introns) and the corresponding cDNA. The Cds1 gene, strongly induced by cadmium, encodes a putative protein (CrCds1) of 1062 amino acid residues that belongs to the ATM/HMT subfamily of half-size ABC transporters. This subfamily includes both vacuolar HMT-type proteins transporting phytochelatin-cadmium complexes from the cytoplasm to the vacuole and mitochondrial ATM-type proteins involved in the maturation of cytosolic Fe/S proteins. Unlike the Delta sphmt1 cadmium-sensitive mutant of Schizosaccharomyces pombe that lacks a vacuolar HMT-type transporter, the cds1 mutant accumulates a high amount of phytochelatin-cadmium complexes. By epitope tagging, the CrCds1 protein was localized in the mitochondria. Even though mitochondria of cds1 do not accumulate important amounts of 'free' iron, the mutant cells are hypersensitive to high iron concentrations. Our data show for the first time that a mitochondrial ATM-like transporter plays a major role in tolerance to cadmium. [less ▲]

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See detailMitochondrial metabolite carrier family, topology, structure and functional properties: an overview.
Sluse, Francis ULg

in Acta Biochimica Polonica. Polish. (1996), 43(2), 349-360

A set of metabolite carriers operates the traffic of numerous molecules consumed or produced in mitochondrial matrix and/or cytosolic compartments. As their existence has been predicted by the ... [more ▼]

A set of metabolite carriers operates the traffic of numerous molecules consumed or produced in mitochondrial matrix and/or cytosolic compartments. As their existence has been predicted by the chemiosmotic theory, the first challenge, in the late sixties, was to prove their presence in the inner mitochondrial membrane and to describe the various transports carried out. The second challenge was to understand their mechanisms by the kinetic approach in intact mitochondria (seventies). The third challenge (late seventies-eighties) was to isolate and to reconstitute the carriers in liposomes in order to characterize the proteins and to establish the concept of a structural and a functional family as well as some structure-function relationship with the help of primary sequences. Genetics, molecular biology and genomic sequencing bring the fourth challenge (nineties): a raising number of putative carriers becomes known only by their primary sequences but their functions have to be discovered. The actual challenge of the future is the elucidation of the ternary structure of carrier proteins that together with site-directed mutagenesis and kinetic mechanism will permit to advance in the understanding of molecular mechanisms of transport processes. [less ▲]

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See detailMitochondrial NADH:ubiquinone oxidoreductase (complex I) in eukaryotes: A highly conserved subunit composition highlighted by mining of protein databases
Cardol, Pierre ULg

in Biochimica et Biophysica Acta-Bioenergetics (2011), 11

Complex I (NADH:ubiquinone oxidoreductase) is the largest enzyme of the mitochondrial respiratory chain. Compared to its bacterial counterpart which encompasses 14-17 subunits, mitochondrial complex I has ... [more ▼]

Complex I (NADH:ubiquinone oxidoreductase) is the largest enzyme of the mitochondrial respiratory chain. Compared to its bacterial counterpart which encompasses 14-17 subunits, mitochondrial complex I has almost tripled its subunit composition during evolution of eukaryotes, by recruitment of so-called accessory subunits, part of them being specific to distinct evolutionary lineages. The increasing availability of numerous broadly sampled eukaryotic genomes now enables the reconstruction of the evolutionary history of this large protein complex. Here, a combination of profile-based sequence comparisons and basic structural properties analyses at the protein level enabled to pinpoint homology relationships between complex I subunits from fungi, mammals or green plants, previously identified as "lineage-specific" subunits. In addition, homologs of at least 40 mammalian complex I subunits are present in representatives of all major eukaryote assemblages, half of them having not been investigated so far (Excavates, Chromalveolates, Amoebozoa). This analysis revealed that complex I was subject to a phenomenal increase in size that predated the diversification of extant eukaryotes, followed by very few lineage-specific additions/losses of subunits. The implications of this subunit conservation for studies of complex I are discussed. [less ▲]

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See detailMitochondrial oxidative phosphorylation : in vitro and in situ effect of EGb 761
Willet, K.; DETRY, Olivier ULg; Evens, A. et al

in Packer, L.; Trabet, Maret G; Xin, Wenjuan (Eds.) Proceedings of the international symposium on natural antioxidants molecular mechanisms and health effects (1996)

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