inner mitochondrial membrane
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Triphenylphosphonium (TPP) derivatives are commonly used to target chemical into mitochondria. We show that alkyl-TPP cause reversible, dose- and hydrophobicity-dependent alterations of mitochondrial morphology and function and a selective decrease of mitochondrial inner membrane proteins including subunits of the respiratory chain complexes, as well as components of the mitochondrial calcium uniporter complex. The treatment with alkyl-TPP resulted in the cleavage of the pro-fusion and cristae organisation regulator Optic atrophy-1. The structural and functional effects of alkyl-TPP were found to be reversible and not merely due to loss of membrane potential. A similar effect was observed with the mitochondria-targeted antioxidant MitoQ.
- MeSH
- antioxidancia * farmakologie MeSH
- kationty metabolismus farmakologie MeSH
- membránové proteiny metabolismus MeSH
- membránový potenciál mitochondrií MeSH
- mitochondriální membrány metabolismus MeSH
- mitochondrie * metabolismus MeSH
- organofosforové sloučeniny farmakologie MeSH
- Publikační typ
- časopisecké články MeSH
- práce podpořená grantem MeSH
Trypanosoma brucei is an important human pathogen. In this study, we have focused on the characterization of FtsH protease, ATP-dependent membrane-bound mitochondrial enzyme important for regulation of protein abundance. We have determined localization and orientation of all six putative T.brucei FtsH homologs in the inner mitochondrial membrane by in silico analyses, by immunofluorescence, and with protease assay. The evolutionary origin of these homologs has been tested by comparative phylogenetic analysis. Surprisingly, some kinetoplastid FtsH proteins display inverted orientation in the mitochondrial membrane compared to related proteins of other examined eukaryotes. Moreover, our data strongly suggest that during evolution the orientation of FtsH protease in T. brucei varied due to both loss and acquisition of the transmembrane domain.
- MeSH
- Arabidopsis klasifikace enzymologie genetika MeSH
- Euglena gracilis klasifikace enzymologie genetika MeSH
- Euglena longa klasifikace enzymologie genetika MeSH
- exprese genu MeSH
- fylogeneze MeSH
- izoenzymy chemie genetika metabolismus MeSH
- konzervovaná sekvence MeSH
- Leishmania major klasifikace enzymologie genetika MeSH
- lidé MeSH
- mitochondriální membrány chemie enzymologie MeSH
- mitochondriální proteiny chemie genetika metabolismus MeSH
- mitochondrie enzymologie genetika MeSH
- molekulární evoluce * MeSH
- myši MeSH
- proteasy chemie genetika metabolismus MeSH
- proteinové domény MeSH
- protozoální proteiny chemie genetika metabolismus MeSH
- Saccharomyces cerevisiae klasifikace enzymologie genetika MeSH
- Trypanosoma brucei brucei klasifikace enzymologie genetika MeSH
- zvířata MeSH
- Check Tag
- lidé MeSH
- myši MeSH
- zvířata MeSH
- Publikační typ
- časopisecké články MeSH
- práce podpořená grantem MeSH
Dysfunction of TMEM70 disrupts the biogenesis of ATP synthase and represents the frequent cause of autosomal recessive encephalocardiomyopathy. We used tagged forms of TMEM70 and demonstrated that it has a hairpin structure with the N- and C-termini oriented towards the mitochondrial matrix. On BN-PAGE TMEM70 was detected in multiple forms including dimers and displayed partial overlap with assembled ATP synthase. Immunoprecipitation studies confirmed mutual interactions between TMEM70 molecules but, together with immunogold electron microscopy, not direct interaction with ATP synthase subunits. This indicates that the biological function of TMEM70 in the ATP synthase biogenesis may be mediated through interaction with other protein(s).
- MeSH
- buněčné linie MeSH
- imunoelektronová mikroskopie MeSH
- imunoprecipitace MeSH
- lidé MeSH
- membránové proteiny metabolismus MeSH
- mitochondriální membrány metabolismus MeSH
- mitochondriální proteiny metabolismus MeSH
- mitochondriální protonové ATPasy metabolismus MeSH
- multimerizace proteinu * MeSH
- Check Tag
- lidé MeSH
- Publikační typ
- časopisecké články MeSH
- práce podpořená grantem MeSH
BACKGROUND: Mitochondrial membrane protein-associated neurodegeneration is an autosomal-recessive disorder caused by C19orf12 mutations and characterized by iron deposits in the basal ganglia. OBJECTIVES: The aim of this study was to quantify iron concentrations in deep gray matter structures using quantitative susceptibility mapping MRI and to characterize metabolic abnormalities in the pyramidal pathway using 1 H MR spectroscopy in clinically manifesting membrane protein-associated neurodegeneration patients and asymptomatic C19orf12 gene mutation heterozygous carriers. METHODS: We present data of 4 clinically affected membrane protein-associated neurodegeneration patients (mean age: 21.0 ± 2.9 years) and 9 heterozygous gene mutation carriers (mean age: 50.4 ± 9.8 years), compared to age-matched healthy controls. MRI assessments were performed on a 7.0 Tesla whole-body system, consisting of whole-brain gradient-echo scans and short echo time, single-volume MR spectroscopy in the white matter of the precentral/postcentral gyrus. Quantitative susceptibility mapping, a surrogate marker for iron concentration, was performed using a state-of-the-art multiscale dipole inversion approach with focus on the globus pallidus, thalamus, putamen, caudate nucleus, and SN. RESULTS AND CONCLUSION: In membrane protein-associated neurodegeneration patients, magnetic susceptibilities were 2 to 3 times higher in the globus pallidus (P = 0.02) and SN (P = 0.02) compared to controls. In addition, significantly higher magnetic susceptibility was observed in the caudate nucleus (P = 0.02). Non-manifesting heterozygous mutation carriers exhibited significantly increased magnetic susceptibility (relative to controls) in the putamen (P = 0.003) and caudate nucleus (P = 0.001), which may be an endophenotypic marker of genetic heterozygosity. MR spectroscopy revealed significantly increased levels of glutamate, taurine, and the combined concentration of glutamate and glutamine in membrane protein-associated neurodegeneration, which may be a correlate of corticospinal pathway dysfunction frequently observed in membrane protein-associated neurodegeneration patients. © 2019 International Parkinson and Movement Disorder Society.
- MeSH
- lidé MeSH
- magnetická rezonanční tomografie metody MeSH
- membránové proteiny genetika MeSH
- mitochondriální membrány metabolismus MeSH
- mitochondriální proteiny genetika MeSH
- mitochondrie metabolismus MeSH
- mozek metabolismus patologie MeSH
- mutace genetika MeSH
- železo metabolismus MeSH
- Check Tag
- lidé MeSH
- Publikační typ
- časopisecké články MeSH
- práce podpořená grantem MeSH
Mitochondrial membrane potential (Deltapsi(m)) plays important roles in the normal function of cells and in pathobiochemical situations. The application of ion-selective electrodes for the measurement of Deltapsi(m) is important for studying normal biological reactions and pathways and mitochondrial diseases. We constructed and optimized a computerized device for real-time monitoring of the Deltapsi(m), which included modification of tetraphenylphosphonium (TPP(+))-selective membrane that improved reproducibility of the TPP(+)-selective electrode. Application of MATLAB software increased the sensitivity of the system. We tested our improved device for membrane potential measurements of isolated mitochondria (in absolute scale of millivolts). In addition, we assessed relative changes of Deltapsi(m) (as changes in TPP(+) concentration) of digitonin-permeabilized cells (hepatocytes, control transmitochondrial cybrids, HeLa G and BSC-40) after addition of substrates, inhibitors, and uncoupler of respiratory chain. Our system can be successfully used for studies of many aspects of the regulation of mitochondrial bioenergetics and as a diagnostic tool for mitochondrial oxidative phosphorylation disorders.
- MeSH
- elektrofyziologie metody přístrojové vybavení MeSH
- financování organizované MeSH
- indikátory a reagencie chemie MeSH
- iontově selektivní elektrody MeSH
- jaterní mitochondrie metabolismus MeSH
- krysa rodu rattus MeSH
- lidé MeSH
- membránové potenciály fyziologie MeSH
- mitochondriální membrány metabolismus MeSH
- nádorové buňky kultivované MeSH
- oniové sloučeniny chemie MeSH
- organofosforové sloučeniny chemie MeSH
- periferní zařízení počítače MeSH
- počítačové systémy MeSH
- potkani Wistar MeSH
- reprodukovatelnost výsledků MeSH
- zvířata MeSH
- Check Tag
- krysa rodu rattus MeSH
- lidé MeSH
- mužské pohlaví MeSH
- zvířata MeSH
- Publikační typ
- hodnotící studie MeSH
Apoptóza je typ programované buněčné smrti (typ I), který je nezbytný pro správný vývoj organizmu a tkáňovou homeostázu. Její průběh může být určen dvěma signálními drahami – vnější (receptorovou) dráhou řízenou receptory smrti a vnitřní (mitochondriální) apoptotickou dráhou, kde klíčovou roli plní mitochondrie. Mitochondrie jsou důležité buněčné organely s nepostradatelnými funkcemi pro život buňky, jako je např. tvorba energie ve formě molekul ATP (adenosintrifosfátu). Mitochondriální buněčná smrt je charakteristická změnou transmembránového potenciálu a permeabilizací vnější mitochondriální membrány. Mitochondrie jsou elektronegativní organely a depolarizace mitochondriální membrány je důležitá pro uvolnění proapoptotických signálů. Narušená regulace mitochondriální buněčné smrti se může podílet na patogenezi různých onemocnění, včetně rakoviny. Mitochondrie jsou také zdrojem reaktivních kyslíkových radikálů, iontů Ca2+ a proteinů ovlivňujících procesy iniciace a progrese nádorů nezávisle na indukci apoptózy. Současné studie se zaměřují na výzkum mitochondriálního membránového potenciálu a kyslíkových radikálů, které modulují různé signální dráhy uvnitř buňky a vymezení jejich významu v kancerogenezi, případně v léčbě onkologických pacientů. Monitorování apoptotických markerů, jako je stav mitochondriálního membránového potenciálu a určení hladiny reaktivních kyslíkových radikálů ve vzorcích nádorových pacientů, má prediktivní hodnotu pro výstup léčebných protokolů.
Apoptosis is type I programmed cell death, a process that is essential for development and tissue homeostasis. It is a prevalent form of cell death and it proceeds via two signaling pathways – external (receptor pathway) triggered by death receptors and intrinsic (mitochondrial) apoptotic pathway with major involvement of mitochondria. Mitochondria are important cellular organelles producing energy stored in molecules of adenosine triphosphate that are essential for cell survival. The mitochondrial cell death is characterized by permeabilization of the mitochondrial outer membrane and dissipation of the transmembrane potential. Mitochondria are electronegative organelles and depolarization of the mitochondrial membrane is important for the release of proapoptotic signals. Aberrant control of the mitochondrial cell death might contribute to several diseases including cancer. Mitochondria are also a source of reactive oxygen species, Ca2+ ions and other proteins that affect processes important for the initiation and progression of tumors independently of apoptosis. Current studies focus on research of mitochondrial membrane potential and reactive oxygen species modulating various signaling pathways within the cell, their importance in carcinogenesis, and in treatment of oncological patients. Monitoring of the apoptotic markers, such as the mitochondrial membrane potential (MMP), and the level of reactive oxygen species in samples of oncological patients has a predictive value for the output of treatment protocols. Key words: mitochondria – flow cytometry – apoptosis – free radicals – mitochondrial membrane potential This work was supported by the European Regional Development Fund and the State Budget of the Czech Republic (RECAMO, CZ.1.05/2.1.00/03.0101) and IntegRECAMO CZ.1.07/2.3.00/20.0097). The authors declare they have no potential conflicts of interest concerning drugs, products, or services used in the study. The Editorial Board declares that the manuscript met the ICMJE “uniform requirements” for biomedical papers. Submitted: 13. 1. 2014 Accepted: 11. 4. 2014
- MeSH
- apoptóza * fyziologie MeSH
- buněčná smrt fyziologie MeSH
- ethidium analogy a deriváty diagnostické užití MeSH
- fluoresceiny diagnostické užití MeSH
- fluorescenční barviva diagnostické užití MeSH
- lidé MeSH
- membránový potenciál mitochondrií * MeSH
- mitochondriální membrány MeSH
- mitochondrie MeSH
- průtoková cytometrie * metody MeSH
- reaktivní formy kyslíku * analýza MeSH
- Check Tag
- lidé MeSH
- Publikační typ
- práce podpořená grantem MeSH
Mitochondrial membrane protein-associated neurodegeneration (MPAN) is an ultraorphan neurogenetic disease from the group of neurodegeneration with brain iron accumulation (NBIA) disorders. Here we report cross-sectional and longitudinal data to define the phenotype, to assess disease progression and to estimate sample sizes for clinical trials. We enrolled patients with genetically confirmed MPAN from the Treat Iron-Related Childhood-Onset Neurodegeneration (TIRCON) registry and cohort study, and from additional sites. Linear mixed-effect modelling (LMEM) was used to calculate annual progression rates for the Unified Parkinson's Disease Rating Scale (UPDRS), Barry-Albright Dystonia (BAD) scale, Schwab and England Activities of Daily Living (SE-ADL) scale and the Pediatric Quality of Life Inventory (PedsQL). We investigated 85 MPAN patients cross-sectionally, with functional outcome data collected in 45. Median age at onset was 9 years and the median diagnostic delay was 5 years. The most common findings were gait disturbance (99%), pyramidal involvement (95%), dysarthria (90%), vision disturbances (82%), with all but dysarthria presenting early in the disease course. After 16 years with the disease, 50% of patients were wheelchair dependent. LMEM showed an annual progression rate of 4.5 points in total UPDRS. The total BAD scale score showed no significant progression over time. The SE-ADL scale and the patient- and parent-reported PedsQL showed a decline of 3.9%, 2.14 and 2.05 points, respectively. No patient subpopulations were identified based on longitudinal trajectories. Our cross-sectional results define the order of onset and frequency of symptoms in MPAN, which will inform the diagnostic process, help to shorten diagnostic delay and aid in counselling patients, parents and caregivers. Our longitudinal findings define the natural history of MPAN, reveal the most responsive outcomes and highlight the need for an MPAN-specific rating approach. Our sample size estimations inform the design of upcoming clinical trials.
- MeSH
- činnosti denního života MeSH
- dítě MeSH
- dysartrie MeSH
- dystonické poruchy * MeSH
- dystonie * MeSH
- fenotyp MeSH
- kohortové studie MeSH
- kvalita života MeSH
- lidé MeSH
- membránové proteiny genetika MeSH
- mitochondriální membrány MeSH
- mutace genetika MeSH
- neurodegenerativní nemoci * genetika MeSH
- opožděná diagnóza MeSH
- průřezové studie MeSH
- Check Tag
- dítě MeSH
- lidé MeSH
- Publikační typ
- časopisecké články MeSH
Values of the calcium retention capacity (CRC) of rat liver mitochondria are highly dependent on the experimental conditions used. When increasing amounts of added calcium chloride are used (1.25-10 nmol), the values of the CRC increase 3-fold. When calcium is added in 75 s intervals, the CRC values increase by 30 % compared with 150 s interval additions. CRC values are not dependent on the calcium/protein ratio in the measured sample in our experimental design. We also show that a more detailed evaluation of the fluorescence curves can provide new information about mitochondrial permeability transition pore opening after calcium is added.
- MeSH
- biologický transport MeSH
- jaterní mitochondrie metabolismus MeSH
- játra metabolismus MeSH
- krysa rodu rattus MeSH
- mitochondriální membrány metabolismus MeSH
- permeabilita MeSH
- přechodový pór mitochondriální permeability metabolismus MeSH
- transportní proteiny mitochondriální membrány metabolismus MeSH
- vápník metabolismus MeSH
- výzkumný projekt MeSH
- zvířata MeSH
- Check Tag
- krysa rodu rattus MeSH
- mužské pohlaví MeSH
- zvířata MeSH
- Publikační typ
- časopisecké články MeSH
- hodnotící studie MeSH
