Life manifests as growth, movement or heat production that occurs thanks to the energy accepted from the outside environment. The basis of energy transduction attracted the Czech researchers since the beginning of the 20th century. It further accelerated after World War II, when the new Institute of Physiology was established in 1954. When it was found that energy is stored in the form of adenosine triphosphate (ATP) that can be used by numerous reactions as energy source and is produced in the process called oxidative phosphorylation localized in mitochondria, the investigation focused on this cellular organelle. Although the Czech scientists had to overcome various obstacles including Communist party leadership, driven by curiosity, boldness, and enthusiasm, they characterized broad spectrum of mitochondrial properties in different tissues in (patho)physiological conditions in collaboration with many world-known laboratories. The current review summarizes the contribution of the Czech scientists to the bioenergetic and mitochondrial research in the global context. Keywords: Mitochondria, Bioenergetics, Chemiosmotic coupling.

• MeSH
• biomedicínský výzkum dějiny   trendy   MeSH
• dějiny 20. století MeSH
• dějiny 21. století MeSH
• energetický metabolismus * MeSH
• lidé MeSH
• mitochondrie * metabolismus   MeSH
• zvířata MeSH
• Check Tag
• dějiny 20. století MeSH
• dějiny 21. století MeSH
• lidé MeSH
• zvířata MeSH
• Publikační typ
• časopisecké články MeSH
• historické články MeSH
• přehledy MeSH
• Geografické názvy
• Česká republika MeSH

INTRODUCTION: Mitochondrial disorders (MD) may manifest in neonates, but early diagnosis is difficult. In this study, clinical and laboratory data were analyzed in 129 patients with neonatal onset of MD to identify any association between specific mitochondrial diseases and their symptoms with the aim of optimizing diagnosis. MATERIALS AND METHODS: Retrospective clinical and laboratory data were evaluated in 461 patients (331 families) with confirmed MD. RESULTS: The neonatal onset of MD was reported in 28% of the patients. Prematurity, intrauterine growth retardation and hypotonia necessitating ventilatory support were present in one-third, cardiomyopathy in 40%, neonatal seizures in 16%, Leigh syndrome in 15%, and elevated lactate level in 87%. Hyperammonemia was observed in 22 out of 52 neonates. Complex I deficiency was identified in 15, complex III in one, complex IV in 23, complex V in 31, combined deficiency of several complexes in 53, and PDH complex deficiency was identified in six patients. Molecular diagnosis was confirmed in 49 cases, including a newborn with a 9134A>G mutation in the MTATP6 gene, which has not been described previously. CONCLUSION: The most significant finding is the high incidence of neonatal cardiomyopathy and hyperammonemia. Based on our experience, we propose a diagnostic flowchart applicable to critically ill neonates suspicious for MD. This tool will allow for the use of direct molecular genetic analyses without the need for muscle biopsies in neonates with Alpers, Barth, MILS and Pearson syndromes, SCO1, SCO2, TMEM70, ATP5E, SUCLG1 gene mutations and PDH complex deficiency.

• MeSH
• hyperamonemie diagnóza   genetika   MeSH
• kardiomyopatie diagnóza   genetika   MeSH
• Leighova nemoc krev   diagnóza   genetika   MeSH
• lidé MeSH
• mitochondriální nemoci krev   diagnóza   genetika   MeSH
• mutace MeSH
• novorozenec nedonošený MeSH
• novorozenec MeSH
• retrospektivní studie MeSH
• růstová retardace plodu krev   diagnóza   genetika   MeSH
• Check Tag
• lidé MeSH
• mužské pohlaví MeSH
• novorozenec MeSH
• ženské pohlaví MeSH
• Publikační typ
• časopisecké články MeSH
• práce podpořená grantem MeSH

BACKGROUND: To strengthen research and differential diagnostics of mitochondrial disorders, we constructed and validated an oligonucleotide microarray (h-MitoArray) allowing expression analysis of 1632 human genes involved in mitochondrial biology, cell cycle regulation, signal transduction and apoptosis. Using h-MitoArray we analyzed gene expression profiles in 9 control and 13 fibroblast cell lines from patients with F1Fo ATP synthase deficiency consisting of 2 patients with mt9205deltaTA microdeletion and a genetically heterogeneous group of 11 patients with not yet characterized nuclear defects. Analysing gene expression profiles, we attempted to classify patients into expected defect specific subgroups, and subsequently reveal group specific compensatory changes, identify potential phenotype causing pathways and define candidate disease causing genes. RESULTS: Molecular studies, in combination with unsupervised clustering methods, defined three subgroups of patient cell lines--M group with mtDNA mutation and N1 and N2 groups with nuclear defect. Comparison of expression profiles and functional annotation, gene enrichment and pathway analyses of differentially expressed genes revealed in the M group a transcription profile suggestive of synchronized suppression of mitochondrial biogenesis and G1/S arrest. The N1 group showed elevated expression of complex I and reduced expression of complexes III, V, and V-type ATP synthase subunit genes, reduced expression of genes involved in phosphorylation dependent signaling along MAPK, Jak-STAT, JNK, and p38 MAP kinase pathways, signs of activated apoptosis and oxidative stress resembling phenotype of premature senescent fibroblasts. No specific functionally meaningful changes, except of signs of activated apoptosis, were detected in the N2 group. Evaluation of individual gene expression profiles confirmed already known ATP6/ATP8 defect in patients from the M group and indicated several candidate disease causing genes for nuclear defects. CONCLUSION: Our analysis showed that deficiency in the ATP synthase protein complex amount is generally accompanied by only minor changes in expression of ATP synthase related genes. It also suggested that the site (mtDNA vs nuclear DNA) and the severity (ATP synthase content) of the underlying defect have diverse effects on cellular gene expression phenotypes, which warrants further investigation of cell cycle regulatory and signal transduction pathways in other OXPHOS disorders and related pharmacological models.

• MeSH
• analýza hlavních komponent MeSH
• buněčné linie MeSH
• fenotyp MeSH
• fibroblasty enzymologie   MeSH
• genom mitochondriální MeSH
• lidé MeSH
• mitochondriální DNA genetika   MeSH
• mitochondriální nemoci klasifikace   diagnóza   enzymologie   genetika   MeSH
• mitochondriální protonové ATPasy nedostatek   genetika   MeSH
• modely genetické MeSH
• sekvenční analýza hybridizací s uspořádaným souborem oligonukleotidů metody   statistika a číselné údaje   MeSH
• sekvenční delece MeSH
• shluková analýza MeSH
• stanovení celkové genové exprese metody   statistika a číselné údaje   MeSH
• Check Tag
• lidé MeSH
• Publikační typ
• časopisecké články MeSH
• práce podpořená grantem MeSH
• validační studie MeSH
• Názvy látek
• F1F0-ATP synthase MeSH Prohlížeč
• mitochondriální DNA MeSH
• mitochondriální protonové ATPasy MeSH

The biogenesis of eukaryotic COX (cytochrome c oxidase) requires several accessory proteins in addition to structural subunits and prosthetic groups. We have analysed the assembly state of COX and SCO2 protein levels in various tissues of six patients with mutations in SCO2 and SURF1. SCO2 is a copper-binding protein presumably involved in formation of the Cu(A) centre of the COX2 subunit. The function of SURF1 is unknown. Immunoblot analysis of native gels demonstrated that COX holoenzyme is reduced to 10-20% in skeletal muscle and brain of SCO2 and SURF1 patients and to 10-30% in heart of SCO2 patients, whereas liver of SCO2 patients' contained normal holoenzyme levels. The steady-state levels of mutant SCO2 protein ranged from 0 to 20% in different SCO2 patient tissues. In addition, eight distinct COX subcomplexes and unassembled subunits were found, some of them identical with known assembly intermediates of the human enzyme. Heart, brain and skeletal muscle of SCO2 patients contained accumulated levels of the COX1.COX4.COX5A subcomplex, three COX1-containing subcomplexes, a COX4.COX5A subcomplex and two subcomplexes composed of only COX4 or COX5A. The accumulation of COX1.COX4.COX5A subcomplex, along with the virtual absence of free COX2, suggests that the lack of the Cu(A) centre may result in decreased stability of COX2. The appearance of COX4.COX5A subcomplex indicates that association of these nucleus-encoded subunits probably precedes their addition to COX1 during the assembly process. Finally, the consequences of SCO2 and SURF1 mutations suggest the existence of tissue-specific functional differences of these proteins that may serve different tissue-specific requirements for the regulation of COX biogenesis.

• MeSH
• fibroblasty enzymologie   MeSH
• játra enzymologie   MeSH
• kojenec MeSH
• kosterní svaly enzymologie   MeSH
• lidé MeSH
• membránové proteiny MeSH
• mitochondriální proteiny MeSH
• molekulární chaperony MeSH
• mozek enzymologie   MeSH
• mutace genetika   MeSH
• myokard enzymologie   MeSH
• orgánová specificita MeSH
• podjednotky proteinů chemie   metabolismus   MeSH
• předškolní dítě MeSH
• proteiny genetika   metabolismus   MeSH
• regulace genové exprese enzymů MeSH
• respirační komplex IV biosyntéza   chemie   metabolismus   MeSH
• transportní proteiny MeSH
• Check Tag
• kojenec MeSH
• lidé MeSH
• předškolní dítě MeSH
• Publikační typ
• časopisecké články MeSH
• práce podpořená grantem MeSH
• Názvy látek
• membránové proteiny MeSH
• mitochondriální proteiny MeSH
• molekulární chaperony MeSH
• podjednotky proteinů MeSH
• proteiny MeSH
• respirační komplex IV MeSH
• SCO2 protein, human MeSH Prohlížeč
• Surf-1 protein MeSH Prohlížeč
• transportní proteiny MeSH

Dysfunction of mitochondrial ATPase (F1F(o)-ATP synthase) due to missense mutations in ATP6 [mtDNA (mitochondrial DNA)-encoded subunit a] is a frequent cause of severe mitochondrial encephalomyopathies. We have investigated a rare mtDNA mutation, i.e. a 2 bp deletion of TA at positions 9205 and 9206 (9205DeltaTA), which affects the STOP codon of the ATP6 gene and the cleavage site between the RNAs for ATP6 and COX3 (cytochrome c oxidase 3). The mutation was present at increasing load in a three-generation family (in blood: 16%/82%/>98%). In the affected boy with severe encephalopathy, a homoplasmic mutation was present in blood, fibroblasts and muscle. The fibroblasts from the patient showed normal aurovertin-sensitive ATPase hydrolytic activity, a 70% decrease in ATP synthesis and an 85% decrease in COX activity. ADP-stimulated respiration and the ADP-induced decrease in the mitochondrial membrane potential at state 4 were decreased by 50%. The content of subunit a was decreased 10-fold compared with other ATPase subunits, and [35S]-methionine labelling showed a 9-fold decrease in subunit a biosynthesis. The content of COX subunits 1, 4 and 6c was decreased by 30-60%. Northern Blot and quantitative real-time reverse transcription-PCR analysis further demonstrated that the primary ATP6--COX3 transcript is cleaved to the ATP6 and COX3 mRNAs 2-3-fold less efficiently. Structural studies by Blue-Native and two-dimensional electrophoresis revealed an altered pattern of COX assembly and instability of the ATPase complex, which dissociated into subcomplexes. The results indicate that the 9205DeltaTA mutation prevents the synthesis of ATPase subunit a, and causes the formation of incomplete ATPase complexes that are capable of ATP hydrolysis but not ATP synthesis. The mutation also affects the biogenesis of COX, which is present in a decreased amount in cells from affected individuals.

• MeSH
• 2D gelová elektroforéza metody   MeSH
• adenin metabolismus   MeSH
• adenosintrifosfát biosyntéza   MeSH
• adenosintrifosfatasy chemie   fyziologie   MeSH
• fibroblasty chemie   enzymologie   metabolismus   patologie   MeSH
• intracelulární membrány chemie   enzymologie   MeSH
• kultivované buňky MeSH
• kůže patologie   MeSH
• lidé MeSH
• membránové potenciály genetika   MeSH
• messenger RNA biosyntéza   MeSH
• mitochondriální DNA biosyntéza   genetika   MeSH
• mitochondriální protonové ATPasy biosyntéza   MeSH
• mitochondrie chemie   enzymologie   MeSH
• mutace genetika   MeSH
• předškolní dítě MeSH
• respirační komplex IV biosyntéza   chemie   metabolismus   fyziologie   MeSH
• sekvenční delece genetika   MeSH
• spotřeba kyslíku genetika   fyziologie   MeSH
• thymidin metabolismus   MeSH
• Check Tag
• lidé MeSH
• mužské pohlaví MeSH
• předškolní dítě MeSH
• Publikační typ
• časopisecké články MeSH
• práce podpořená grantem MeSH
• Názvy látek
• adenin MeSH
• adenosintrifosfát MeSH
• adenosintrifosfatasy MeSH
• messenger RNA MeSH
• mitochondriální DNA MeSH
• mitochondriální protonové ATPasy MeSH
• MT-ATP6 protein, human MeSH Prohlížeč
• respirační komplex IV MeSH
• thymidin MeSH

Oxidation of glycerophosphate (GP) by brown adipose tissue mitochondria in the presence of antimycin A was found to be accompanied by significant production of hydrogen peroxide. GP-dependent hydrogen peroxide production could be detected by p-hydroxyphenylacetate fluorescence changes or as an antimycin A-insensitive oxygen consumption. One-electron acceptor, potassium ferricyanide, highly stimulated the rate of GP-dependent antimycin A-insensitive oxygen uptake, which was prevented by inhibitors of mitochondrial GP dehydrogenase (mGPDH) or by coenzyme Q (CoQ). GP-dependent ferricyanide-induced peroxide production was also determined luminometrically, using mitochondria or partially purified mGPDH. Ferricyanide-induced peroxide production was negligible, when succinate or NADH was used as a substrate. These results indicate that hydrogen peroxide is produced directly by mGPDH and reflect the differences in the transport of reducing equivalents from mGPDH and succinate dehydrogenase to the CoQ pool. The data suggest that more intensive production of reactive oxygen species may be present in mammalian cells with active mGPDH.

• MeSH
• biologické modely MeSH
• ferrikyanidy farmakologie   MeSH
• glycerolfosfátdehydrogenasa antagonisté a inhibitory   izolace a purifikace   metabolismus   MeSH
• glycerolfosfáty metabolismus   MeSH
• hnědá tuková tkáň účinky léků   metabolismus   MeSH
• inhibitory enzymů farmakologie   MeSH
• katalasa metabolismus   farmakologie   MeSH
• křečci praví MeSH
• křeček rodu Mesocricetus MeSH
• luminiscenční měření MeSH
• mitochondrie účinky léků   metabolismus   MeSH
• peroxid vodíku metabolismus   MeSH
• reaktivní formy kyslíku metabolismus   MeSH
• techniky in vitro MeSH
• ubichinon metabolismus   farmakologie   MeSH
• zvířata MeSH
• Check Tag
• křečci praví MeSH
• mužské pohlaví MeSH
• zvířata MeSH
• Publikační typ
• časopisecké články MeSH
• práce podpořená grantem MeSH
• Názvy látek
• ferrikyanidy MeSH
• glycerolfosfátdehydrogenasa MeSH
• glycerolfosfáty MeSH
• inhibitory enzymů MeSH
• katalasa MeSH
• peroxid vodíku MeSH
• potassium ferricyanide MeSH Prohlížeč
• reaktivní formy kyslíku MeSH
• ubichinon MeSH

We have investigated pathogenic effects of the tRNA(Lys) A8344G mutation associated with the syndrome myoclonus epilepsy with ragged-red fibres (MERRF) by using fibroblasts and fibroblast-derived cytoplasmic hybrid cells harbouring different percentages of mutated mitochondrial DNA (mtDNA). The activity of cytochrome c oxidase (COX) in patient fibroblasts with 89% mutated mtDNA was decreased to 20% of the control levels. COX exhibited altered kinetics, with a decreased V(max) for both the low-affinity and high-affinity phases; however, the K(m) values were not significantly changed. The substrate-dependent synthesis of ATP was decreased to 50% of the control. Analysis of the mitochondrial membrane potential, DeltaPsi, in digitonin-treated cells with tetramethylrhodamine methyl ester (TMRM) with the use of flow cytometry showed a 80% decrease in DeltaPsi at state 4 and an increased sensitivity of DeltaPsi to an uncoupler in fibroblasts from the patient. The investigation of transmitochondrial cytoplasmic hybrid clones derived from the patient's fibroblasts enabled us to characterize the relationship between heteroplasmy of the MERRF mutation, COX activity and DeltaPsi. Within the range of 87-73% mutated mtDNA, COX activity was decreased to 5-35% and DeltaPsi was decreased to 6-78%. These results demonstrate that the MERRF mutation affects COX activity and DeltaPsi in different proportions with regard to mutation heteroplasmy and indicate that the biochemical manifestation of the MERRF mutation exerts a very steep threshold of DeltaPsi inhibition.

• MeSH
• adenosintrifosfát biosyntéza   MeSH
• fibroblasty enzymologie   MeSH
• fluorescenční spektrometrie MeSH
• intracelulární membrány fyziologie   MeSH
• kinetika MeSH
• lidé MeSH
• membránové potenciály fyziologie   MeSH
• mutace MeSH
• oxidativní fosforylace MeSH
• průtoková cytometrie MeSH
• respirační komplex IV metabolismus   MeSH
• separace buněk MeSH
• syndrom MERRF enzymologie   genetika   patologie   MeSH
• Check Tag
• lidé MeSH
• Publikační typ
• časopisecké články MeSH
• práce podpořená grantem MeSH
• Názvy látek
• adenosintrifosfát MeSH
• respirační komplex IV MeSH