34080156 OR Measurement of Mitochondrial Respiration in Platelets Dotaz Zobrazit nápovědu
Platelet mitochondria can be used in the study of mitochondrial dysfunction in various complex diseases and can help in finding biological markers for diagnosing the disease, monitoring its course and the effects of treatment. The aim of this chapter was to describe in detail the method of measuring mitochondrial respiration in platelets using high-resolution respirometry. The described method was successfully used for the study of mitochondrial dysfunction in neuropsychiatric diseases.
- MeSH
- buněčné dýchání MeSH
- lidé MeSH
- mitochondrie metabolismus MeSH
- polarografie přístrojové vybavení metody MeSH
- trombocyty metabolismus MeSH
- Check Tag
- lidé MeSH
- Publikační typ
- časopisecké články MeSH
- práce podpořená grantem MeSH
3-hydroxy-3-methylglutaryl-coenzyme A (HMG-CoA) reductase inhibitors (statins) are widely used drugs for lowering blood lipid levels and preventing cardiovascular diseases. However, statins can have serious adverse effects, which may be related to development of mitochondrial dysfunctions. The aim of study was to demonstrate the in vivo effect of high and therapeutic doses of statins on mitochondrial respiration in blood platelets. Model approach was used in the study. Simvastatin was administered to rats at a high dose for 4 weeks. Humans were treated with therapeutic doses of rosuvastatin or atorvastatin for 6 weeks. Platelet mitochondrial respiration was measured using high-resolution respirometry. In rats, a significantly lower physiological respiratory rate was found in intact platelets of simvastatin-treated rats compared to controls. In humans, no significant changes in mitochondrial respiration were detected in intact platelets; however, decreased complex I-linked respiration was observed after statin treatment in permeabilized platelets. We propose that the small in vivo effect of statins on platelet energy metabolism can be attributed to drug effects on complex I of the electron transport system. Both intact and permeabilized platelets can be used as a readily available biological model to study changes in cellular energy metabolism in patients treated with statins.
The objective of the present study was to evaluate platelet mitochondrial oxygen consumption using high-resolution respirometry (HRR) and metabolic flux analysis (MFA) and to verify the effect of advanced age on these parameters. HRR was used to analyze permeabilized and intact platelets, MFA to measure oxygen consumption rates (OCR), extracellular acidification rates (ECAR) and ATP production rate in intact fixed platelets. Two groups of healthy volunteers were included in the study: YOUNG (20-42 years, n=44) and older adults (OLD; 70-89 years; n=15). Compared to YOUNG donors, platelets from group OLD participants displayed significantly lower values of oxygen consumption in the Complex II-linked phosphorylating and uncoupled states and the Complex IV activity in HRR protocols for permeabilized cells and significantly lower resting and uncoupled respirations in intact cells when analyzed by both methods. In addition, mitochondrial ATP production rate was also significantly lower in platelets isolated from older adults. Variables measured by both methods from the same bloods correlated significantly, nevertheless those acquired by MFA were higher than those measured using HRR. In conclusion, the study verifies compromised mitochondrial respiration and oxidative ATP production in the platelets of aged persons and documents good compatibility of the two most widely used methods for determining the global performance of the electron-transporting system, i.e. HRR and MFA.
- MeSH
- adenosintrifosfát metabolismus MeSH
- analýza metabolického toku metody MeSH
- buněčné dýchání MeSH
- dospělí MeSH
- energetický metabolismus * MeSH
- koncentrace vodíkových iontů MeSH
- lidé MeSH
- mitochondrie metabolismus MeSH
- mladý dospělý MeSH
- senioři nad 80 let MeSH
- senioři MeSH
- spotřeba kyslíku MeSH
- stárnutí krev metabolismus MeSH
- trombocyty metabolismus MeSH
- věkové faktory MeSH
- Check Tag
- dospělí MeSH
- lidé MeSH
- mladý dospělý MeSH
- mužské pohlaví MeSH
- senioři nad 80 let MeSH
- senioři MeSH
- ženské pohlaví MeSH
- Publikační typ
- časopisecké články MeSH
- srovnávací studie MeSH
OBJECTIVES: Altered amyloid metabolism and mitochondrial dysfunction play key roles in the development of Alzheimer's disease (AD). We asked whether an association exists between disturbed platelet mitochondrial respiration and the plasma concentrations of Aβ40 and Aβ42 in patients with AD. DESIGN AND METHODS: Plasma Aβ40 and Aβ42 concentrations and mitochondrial respiration in intact and permeabilized platelets were measured in 50 patients with AD, 15 patients with vascular dementia and 25 control subjects. A pilot longitudinal study was performed to monitor the progression of AD in a subgroup 11 patients with AD. RESULTS: The mean Aβ40, Aβ42 and Aβ42/Aβ40 levels were not significantly altered in patients with AD compared with controls. The mitochondrial respiratory rate in intact platelets was significantly reduced in patients with AD compared to controls, particularly the basal respiratory rate, maximum respiratory capacity, and respiratory reserve; however, the flux control ratio for basal respiration was increased. A correlation between the plasma Aβ42 concentration and mitochondrial respiration in both intact and permeabilized platelets differs in controls and patients with AD. CONCLUSIONS: Based on our data, (1) mitochondrial respiration in intact platelets, but not the Aβ level itself, may be included in a panel of biomarkers for AD; (2) dysfunctional mitochondrial respiration in platelets is not explained by changes in plasma Aβ concentrations; and (3) the association between mitochondrial respiration in platelets and plasma Aβ levels differs in patients with AD and controls. The results supported the hypothesis that mitochondrial dysfunction is the primary factor contributing to the development of AD.
- MeSH
- Alzheimerova nemoc krev komplikace diagnóza MeSH
- amyloidní beta-protein krev MeSH
- biologické markery krev MeSH
- buněčné dýchání MeSH
- lidé středního věku MeSH
- lidé MeSH
- mitochondriální nemoci krev komplikace diagnóza MeSH
- mitochondrie metabolismus MeSH
- peptidové fragmenty krev MeSH
- senioři MeSH
- spotřeba kyslíku MeSH
- Check Tag
- lidé středního věku MeSH
- lidé MeSH
- mužské pohlaví MeSH
- senioři MeSH
- ženské pohlaví MeSH
- Publikační typ
- časopisecké články MeSH
OBJECTIVES: The bipolar affective disorder (BAD) pathophysiology is multifactorial and has not been fully clarified. METHOD: We measured selected mitochondrial parameters in peripheral blood components. The analyses were performed for patients suffering from a manic episode during remission and were compared to those performed for healthy controls. BAD was clinically evaluated using well-established diagnostic scales and questionnaires. Mitochondrial respiration was examined in intact and permeabilized blood platelets using high-resolution respirometry. The citrate synthase (CS) and electron transport system (ETS) complex (complex I, II, and IV) activities were examined in platelets. RESULTS: The CS, complex II and complex IV activities were decreased in the BAD patients, complex I activity was increased, and the ratio of complex I to CS was significantly increased. In the intact platelets, respiration after complex I inhibition and residual oxygen consumption were decreased in the BAD patients compared to the healthy controls. In the permeabilized platelets, a decreased ETS capacity was found in the BAD patients. No significant differences were found between BAD patients in mania and remission. CONCLUSION: Increased complex I activity can be a compensatory mechanism for decreased CS and complex II and IV activities. We conclude that complex I and its abnormal activity contribute to defects in cellular energy metabolism during a manic episode and that the deficiency in the complex's functioning, but not the availability of oxidative phosphorylation substrates, seems to be responsible for the decreased ETS capacity in BAD patients. The observed parameters can be further evaluated as 'trait' markers of BAD.
- MeSH
- bipolární porucha komplikace farmakoterapie metabolismus MeSH
- citrátsynthasa metabolismus MeSH
- dospělí MeSH
- elektronový transportní řetězec metabolismus MeSH
- lidé MeSH
- mitochondrie metabolismus MeSH
- trombocytopatie komplikace metabolismus MeSH
- trombocyty metabolismus MeSH
- Check Tag
- dospělí MeSH
- lidé MeSH
- mužské pohlaví MeSH
- ženské pohlaví MeSH
- Publikační typ
- časopisecké články MeSH
- práce podpořená grantem MeSH
Mitochondrial dysfunction is an important cellular hallmark of aging and neurodegeneration. Platelets are a useful model to study the systemic manifestations of mitochondrial dysfunction. To evaluate the age dependence of mitochondrial parameters, citrate synthase activity, respiratory chain complex activity, and oxygen consumption kinetics were assessed. The effect of cognitive impairment was examined by comparing the age dependence of mitochondrial parameters in healthy individuals and those with neuropsychiatric disease. The study found a significant negative slope of age-dependence for both the activity of individual mitochondrial enzymes (citrate synthase and complex II) and parameters of mitochondrial respiration in intact platelets (routine respiration, maximum capacity of electron transport system, and respiratory rate after complex I inhibition). However, there was no significant difference in the age-related changes of mitochondrial parameters between individuals with and without cognitive impairment. These findings highlight the potential of measuring mitochondrial respiration in intact platelets as a means to assess age-related mitochondrial dysfunction. The results indicate that drugs and interventions targeting mitochondrial respiration may have the potential to slow down or eliminate certain aging and neurodegenerative processes. Mitochondrial respiration in platelets holds promise as a biomarker of aging, irrespective of the degree of cognitive impairment.
- Publikační typ
- časopisecké články MeSH
Úvod: Příčiny vzniku bipolární afektivní poruchy (BAP) jsou multifaktoriální a nebyly dosud plně objasněny. Na patofyziologii BAP se mohou podílet také mitochondriální dysfunkce. Metoda: Měřili jsme vybrané mitochondriální parametry v trombocytech izolovaných z periferní krve u pacientů trpících manickou fází BAP, v jejich remisi a u zdravých kontrol. BAP byla klinicky hodnocena pomocí diagnostických škál a dotazníků. Aktivity citrátsyntázy (CS) a elektronového transportního systému (ETS) - komplexů I, II, a IV byly měřeny spektrofotometricky Mitochondriální respirace byla zkoumána v intaktních a permeabilizovaných trombocytech za použití respirometrie s vysokým rozlišením. Výsledky: Aktivity komplexů II, IV a CS byly u pacientů s BAP sníženy, aktivita komplexu I byla zvýšena, a poměr komplexu I k CS byl signifikantně zvýšen. V intaktních trombocytech byly respirace po inhibici komplexu I a reziduální spotřeba kyslíku sníženy u pacientů s BAP ve srovnání se zdravými kontrolami. V permeabilizovaných trombocytech byla prokázána snížená kapacita ETS u pacientů s BAP. Nebyly prokázány signifikantní rozdíly mezi pacienty s manickou fází BAP a pacienty v remisi. Závěr: Pokles kapacity ETS u pacientů s BAP lze vysvětlit nedostatečnou funkcí enzymů citrátového cyklu a enzymových komplexů systému oxidativní fosforylace. Zvýšení aktivity komplexu I by mohl představovat kompenzační mechanismus ke sníženým aktivitám CS a narušené funkci komplexů II a IV. Předpokládáme, že komplex I a změny v jeho aktivitě přispívají k eliminaci poruch buněčného energetického metabolismu při BAP způsobených nedostatečným fungováním komplexů II a IV. Sledované parametry by měly být dále zkoumány jako "trait" markery BAP.
Introduction: The reasons for bipolar affective disorder (BAD) development are multifactorial and have not been fully clarified. Mitochondrial dysfunctions can be implicated in pathophysiology of BAD. Method: We measured selected mitochondrial parameters in blood platelets isolated from peripheral blood. The analyses were performed for patients suffering from a manic episode during remission and were compared to those performed for healthy controls. BAD was clinically evaluated using well-established diagnostic scales and questionnaires. Activities of electron transport system (ETS) complexes - complex I, II, and IV and citrate synthase (CS) were examined spectrophotometrically Mitochondrial respiration was examined in intact and permeabilized blood platelets using high-resolution respirometry. Results: The CS, complex II and complex IV activities were decreased in the BAD patients, complex I activity was increased, and the ratio of complex I to CS was significantly increased. In the intact platelets, respiration after complex I inhibition and residual oxygen consumption were decreased in the BAD patients compared to the healthy controls. In the permeabilized platelets, a decreased ETS capacity was found in the BAD patients. No significant differences were found between BAD patients in mania and remission. Conclusion: Increased complex I activity can be a compensatory mechanism for decreased CS and complex II and IV activities. We conclude that complex I and its abnormal activity contribute to elimination of defects in cellular energy metabolism during a manic episode and that the deficiency in the complex's II and IV functioning. The availability of oxida-tive phosphorylation substrates, seems to be not responsible for the decreased ETS capacity in BAD patients. The observed parameters can be further evaluated as ´trait´ markers of BAD.
Background: Mitochondrial dysfunctions are implicated in the pathophysiology of mood disorders. We measured and examined the following selected mitochondrial parameters: citrate synthase (CS) activity, electron transport system (ETS) complex (complexes I, II, and IV) activities, and mitochondrial respiration in blood platelets. Patients and methods: The analyses were performed for 24 patients suffering from a depressive episode of bipolar affective disorder (BD), compared to 68 patients with MDD and 104 healthy controls. BD and unipolar depression were clinically evaluated using well-established diagnostic scales and questionnaires. Results: The CS, complex II, and complex IV activities were decreased in the depressive episode of BD patients; complex I and complex I/CS ratio were significantly increased compared to healthy controls. We observed significantly decreased complex II and CS activities in patients suffering from MDD compared to controls. Decreased respiration after complex I inhibition and increased residual respiration were found in depressive BD patients compared to controls. Physiological respiration and capacity of the ETS were decreased, and respiration after complex I inhibition was increased in MDD patients, compared to controls. Increased complex I activity can be a compensatory mechanism for decreased CS and complex II and IV activities. Conclusion: We can conclude that complex I and its abnormal activity contribute to the defects in cellular energy metabolism during a depressive episode of BD. The observed parameters could be used in a panel of biomarkers that could selectively distinguish BD depression from MDD and can be easily examined from blood elements.
- Publikační typ
- časopisecké články MeSH
