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Bahire KL, Maļuhins R, Bello F, Upīte J, Makarovs A, Jansone B. Long-Term Region-Specific Mitochondrial Functionality Changes in Both Cerebral Hemispheres after fMCAo Model of Ischemic Stroke. Antioxidants (Basel) 2024; 13:416. [PMID: 38671864 PMCID: PMC11047464 DOI: 10.3390/antiox13040416] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/29/2024] [Revised: 03/24/2024] [Accepted: 03/27/2024] [Indexed: 04/28/2024] Open
Abstract
Cerebral ischemia/reperfusion (I/R) refers to a secondary brain injury that results in mitochondrial dysfunction of variable extent, leading to neuronal cell damage. The impact of this process has mainly been studied in the short term, from the early hours up to one week after blood flow reperfusion, and in the ischemic hemisphere only. The focus of this study was to assess the long-term impacts of I/R on mitochondrial functionality using high-resolution fluorespirometry to evaluate state-dependent activities in both ischemic (ipsilateral) and non-ischemic (contralateral) hemispheres of male mice 60, 90, 120, and 180 days after I/R caused by 60-min-long filament-induced middle cerebral artery occlusion (fMCAo). Our results indicate that in cortical tissues, succinate-supported oxygen flux (Complex I&II OXPHOS state) and H2O2 production (Complex II LEAK state) were significantly decreased in the fMCAo (stroke) group ipsilateral hemisphere compared to measurements in the contralateral hemisphere 60 and 90 days after stroke. In hippocampal tissues, during the Complex I&II ET state, mitochondrial respiration was generally lower in the ipsilateral compared to the contralateral hemisphere 90 days following stroke. An aging-dependent impact on mitochondria oxygen consumption following I/R injury was observed 180 days after surgery, wherein Complex I&II activities were lowest in both hemispheres. The obtained results highlight the importance of long-term studies in the field of ischemic stroke, particularly when evaluating mitochondrial bioenergetics in specific brain regions within and between separately affected cerebral hemispheres.
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Affiliation(s)
- Ksenija Lūcija Bahire
- Department of Pharmacology, Faculty of Medicine, University of Latvia, LV-1586 Riga, Latvia; (R.M.); (F.B.); (J.U.); (A.M.)
| | | | | | | | | | - Baiba Jansone
- Department of Pharmacology, Faculty of Medicine, University of Latvia, LV-1586 Riga, Latvia; (R.M.); (F.B.); (J.U.); (A.M.)
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Muscle Lipid Oxidation Is Not Affected by Obstructive Sleep Apnea in Diabetes and Healthy Subjects. Int J Mol Sci 2023; 24:ijms24065308. [PMID: 36982383 PMCID: PMC10048979 DOI: 10.3390/ijms24065308] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/21/2023] [Revised: 03/05/2023] [Accepted: 03/07/2023] [Indexed: 03/12/2023] Open
Abstract
The molecular mechanisms linking obstructive sleep apnea (OSA) with type 2 diabetes mellitus (T2DM) remain unclear. This study investigated the effect of OSA on skeletal muscle lipid oxidation in nondiabetic controls and in type 2 diabetes (T2DM) patients. Forty-four participants matched for age and adiposity were enrolled: nondiabetic controls (control, n = 14), nondiabetic patients with severe OSA (OSA, n = 9), T2DM patients with no OSA (T2DM, n = 10), and T2DM patients with severe OSA (T2DM + OSA, n = 11). A skeletal muscle biopsy was performed; gene and protein expressions were determined and lipid oxidation was analyzed. An intravenous glucose tolerance test was performed to investigate glucose homeostasis. No differences in lipid oxidation (178.2 ± 57.1, 161.7 ± 22.4, 169.3 ± 50.9, and 140.0 ± 24.1 pmol/min/mg for control, OSA, T2DM, and T2DM+OSA, respectively; p > 0.05) or gene and protein expressions were observed between the groups. The disposition index, acute insulin response to glucose, insulin resistance, plasma insulin, glucose, and HBA1C progressively worsened in the following order: control, OSA, T2DM, and T2DM + OSA (p for trend <0.05). No association was observed between the muscle lipid oxidation and the glucose metabolism variables. We conclude that severe OSA is not associated with reduced muscle lipid oxidation and that metabolic derangements in OSA are not mediated through impaired muscle lipid oxidation.
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Janovska P, Zouhar P, Bardova K, Otahal J, Vrbacky M, Mracek T, Adamcova K, Lenkova L, Funda J, Cajka T, Drahota Z, Stanic S, Rustan AC, Horakova O, Houstek J, Rossmeisl M, Kopecky J. Impairment of adrenergically-regulated thermogenesis in brown fat of obesity-resistant mice is compensated by non-shivering thermogenesis in skeletal muscle. Mol Metab 2023; 69:101683. [PMID: 36720306 PMCID: PMC9922683 DOI: 10.1016/j.molmet.2023.101683] [Citation(s) in RCA: 4] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/11/2023] [Accepted: 01/23/2023] [Indexed: 02/02/2023] Open
Abstract
OBJECTIVE Non-shivering thermogenesis (NST) mediated by uncoupling protein 1 (UCP1) in brown adipose tissue (BAT) can be activated via the adrenergic system in response to cold or diet, contributing to both thermal and energy homeostasis. Other mechanisms, including metabolism of skeletal muscle, may also be involved in NST. However, relative contribution of these energy dissipating pathways and their adaptability remain a matter of long-standing controversy. METHODS We used warm-acclimated (30 °C) mice to characterize the effect of an up to 7-day cold acclimation (6 °C; CA) on thermoregulatory thermogenesis, comparing inbred mice with a genetic background conferring resistance (A/J) or susceptibility (C57BL/6 J) to obesity. RESULTS Both warm-acclimated C57BL/6 J and A/J mice exhibited similar cold endurance, assessed as a capability to maintain core body temperature during acute exposure to cold, which improved in response to CA, resulting in comparable cold endurance and similar induction of UCP1 protein in BAT of mice of both genotypes. Despite this, adrenergic NST in BAT was induced only in C57BL/6 J, not in A/J mice subjected to CA. Cold tolerance phenotype of A/J mice subjected to CA was not based on increased shivering, improved insulation, or changes in physical activity. On the contrary, lipidomic, proteomic and gene expression analyses along with palmitoyl carnitine oxidation and cytochrome c oxidase activity revealed induction of lipid oxidation exclusively in skeletal muscle of A/J mice subjected to CA. These changes appear to be related to skeletal muscle NST, mediated by sarcolipin-induced uncoupling of sarco(endo)plasmic reticulum calcium ATPase pump activity and accentuated by changes in mitochondrial respiratory chain supercomplexes assembly. CONCLUSIONS Our results suggest that NST in skeletal muscle could be adaptively augmented in the face of insufficient adrenergic NST in BAT, depending on the genetic background of the mice. It may provide both protection from cold and resistance to obesity, more effectively than BAT.
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Affiliation(s)
- Petra Janovska
- Laboratory of Adipose Tissue Biology, Institute of Physiology of the Czech Academy of Sciences, Videnska 1083, 142 00, Prague, Czech Republic
| | - Petr Zouhar
- Laboratory of Adipose Tissue Biology, Institute of Physiology of the Czech Academy of Sciences, Videnska 1083, 142 00, Prague, Czech Republic
| | - Kristina Bardova
- Laboratory of Adipose Tissue Biology, Institute of Physiology of the Czech Academy of Sciences, Videnska 1083, 142 00, Prague, Czech Republic
| | - Jakub Otahal
- Laboratory of Developmental Epileptology, Institute of Physiology of the Czech Academy of Sciences, Videnska 1083, 142 20, Prague, Czech Republic
| | - Marek Vrbacky
- Laboratory of Bioenergetics, Institute of Physiology of the Czech Academy of Sciences, Videnska 1083, 142 20, Prague, Czech Republic
| | - Tomas Mracek
- Laboratory of Bioenergetics, Institute of Physiology of the Czech Academy of Sciences, Videnska 1083, 142 20, Prague, Czech Republic
| | - Katerina Adamcova
- Laboratory of Adipose Tissue Biology, Institute of Physiology of the Czech Academy of Sciences, Videnska 1083, 142 00, Prague, Czech Republic
| | - Lucie Lenkova
- Laboratory of Adipose Tissue Biology, Institute of Physiology of the Czech Academy of Sciences, Videnska 1083, 142 00, Prague, Czech Republic
| | - Jiri Funda
- Laboratory of Adipose Tissue Biology, Institute of Physiology of the Czech Academy of Sciences, Videnska 1083, 142 00, Prague, Czech Republic
| | - Tomas Cajka
- Laboratory of Translational Metabolism and Laboratory of Bioactive Lipids, Institute of Physiology of the Czech Academy of Sciences, Videnska 1083, 142 20, Prague, Czech Republic
| | - Zdenek Drahota
- Laboratory of Bioenergetics, Institute of Physiology of the Czech Academy of Sciences, Videnska 1083, 142 20, Prague, Czech Republic
| | - Sara Stanic
- Laboratory of Adipose Tissue Biology, Institute of Physiology of the Czech Academy of Sciences, Videnska 1083, 142 00, Prague, Czech Republic,Department of Physiology, Faculty of Science, Charles University in Prague, Vinicna 7, 128 44, Prague, Czech Republic
| | - Arild C. Rustan
- Section for Pharmacology and Pharmaceutical Biosciences, Department of Pharmacy, University of Oslo, Sem Sælands vei 3, 0371, Oslo, Norway
| | - Olga Horakova
- Laboratory of Adipose Tissue Biology, Institute of Physiology of the Czech Academy of Sciences, Videnska 1083, 142 00, Prague, Czech Republic
| | - Josef Houstek
- Laboratory of Bioenergetics, Institute of Physiology of the Czech Academy of Sciences, Videnska 1083, 142 20, Prague, Czech Republic
| | - Martin Rossmeisl
- Laboratory of Adipose Tissue Biology, Institute of Physiology of the Czech Academy of Sciences, Videnska 1083, 142 00, Prague, Czech Republic
| | - Jan Kopecky
- Laboratory of Adipose Tissue Biology, Institute of Physiology of the Czech Academy of Sciences, Videnska 1083, 142 00, Prague, Czech Republic.
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Brkić BM, Rovčanin B, Stojanović M, Srebro D, Vučković S, Savić Vujović K. Chloroquine Attenuates Oxidative Stress in Gentamicin-Induced Nephrotoxicity in Rats. Dose Response 2022; 20:15593258221119871. [PMID: 36003319 PMCID: PMC9393693 DOI: 10.1177/15593258221119871] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Revised: 07/18/2022] [Accepted: 07/24/2022] [Indexed: 11/25/2022]
Abstract
The wider application of gentamicin is limited by potential adverse effects
(nephrotoxicity and ototoxicity). The goal of our study was to investigate the effects of
chloroquine on biochemical and oxidative stress parameters in gentamicin-induced
nephrotoxicity in rats. Animals were randomly divided into 1 of 5 groups. First was Sham
group (0.9% NaCl) (n = 8); second group received gentamicin (n = 8); while third (n = 8),
fourth (n = 8) and fifth group (n = 8) received gentamicin and chloroquine in a dose of
0.3, 1 and 3 mg/kg, respectively. The urea and creatinine levels were significantly lower
in chloroquine treated groups in doses of 0.3 mg/kg and 1 mg/kg (P <
0.001). Total oxidant status and the oxidative stress index showed significantly lower
values in all chloroquine treated groups (P < 0.001;
P < 0.005). Malondialdehyde was lower in chloroquine treatment in
doses of 0.3 mg/kg (P < 0.005) and 3 mg/kg (P <
0.05). Chloroquine treatment markedly reduced the level of superoxide dismutase in doses
of 1 mg/kg (P < 0.01) and 3 mg/kg (P < 0.05). Our
study showed that chloroquine attenuates gentamicin-induced nephrotoxicity in rats
regarding biochemical and oxidative stress parameters.
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Affiliation(s)
- Branislava Medić Brkić
- Department of Pharmacology, Clinical Pharmacology and Toxicology, Faculty of Medicine, University of Belgrade, Belgrade, Serbia
| | - Branislav Rovčanin
- Centre for Endocrine Surgery, Clinical Centre of Serbia, Faculty of Medicine, University of Belgrade, Belgrade, Serbia
| | - Marko Stojanović
- Department of Pharmacology, Clinical Pharmacology and Toxicology, Faculty of Medicine, University of Belgrade, Belgrade, Serbia
| | - Dragana Srebro
- Department of Pharmacology, Clinical Pharmacology and Toxicology, Faculty of Medicine, University of Belgrade, Belgrade, Serbia
| | - Sonja Vučković
- Department of Pharmacology, Clinical Pharmacology and Toxicology, Faculty of Medicine, University of Belgrade, Belgrade, Serbia
| | - Katarina Savić Vujović
- Department of Pharmacology, Clinical Pharmacology and Toxicology, Faculty of Medicine, University of Belgrade, Belgrade, Serbia
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Hof S, Marcus C, Kuebart A, Schulz J, Truse R, Raupach A, Bauer I, Flögel U, Picker O, Herminghaus A, Temme S. A Toolbox to Investigate the Impact of Impaired Oxygen Delivery in Experimental Disease Models. Front Med (Lausanne) 2022; 9:869372. [PMID: 35652064 PMCID: PMC9149176 DOI: 10.3389/fmed.2022.869372] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/04/2022] [Accepted: 04/25/2022] [Indexed: 12/29/2022] Open
Abstract
Impaired oxygen utilization is the underlying pathophysiological process in different shock states. Clinically most important are septic and hemorrhagic shock, which comprise more than 75% of all clinical cases of shock. Both forms lead to severe dysfunction of the microcirculation and the mitochondria that can cause or further aggravate tissue damage and inflammation. However, the detailed mechanisms of acute and long-term effects of impaired oxygen utilization are still elusive. Importantly, a defective oxygen exploitation can impact multiple organs simultaneously and organ damage can be aggravated due to intense organ cross-talk or the presence of a systemic inflammatory response. Complexity is further increased through a large heterogeneity in the human population, differences in genetics, age and gender, comorbidities or disease history. To gain a deeper understanding of the principles, mechanisms, interconnections and consequences of impaired oxygen delivery and utilization, interdisciplinary preclinical as well as clinical research is required. In this review, we provide a "tool-box" that covers widely used animal disease models for septic and hemorrhagic shock and methods to determine the structure and function of the microcirculation as well as mitochondrial function. Furthermore, we suggest magnetic resonance imaging as a multimodal imaging platform to noninvasively assess the consequences of impaired oxygen delivery on organ function, cell metabolism, alterations in tissue textures or inflammation. Combining structural and functional analyses of oxygen delivery and utilization in animal models with additional data obtained by multiparametric MRI-based techniques can help to unravel mechanisms underlying immediate effects as well as long-term consequences of impaired oxygen delivery on multiple organs and may narrow the gap between experimental preclinical research and the human patient.
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Affiliation(s)
- Stefan Hof
- Department of Anaesthesiology, Medical Faculty and University Hospital Düsseldorf, Heinrich-Heine-University Düsseldorf, Düsseldorf, Germany
| | - Carsten Marcus
- Department of Anaesthesiology, Medical Faculty and University Hospital Düsseldorf, Heinrich-Heine-University Düsseldorf, Düsseldorf, Germany
| | - Anne Kuebart
- Department of Anaesthesiology, Medical Faculty and University Hospital Düsseldorf, Heinrich-Heine-University Düsseldorf, Düsseldorf, Germany
| | - Jan Schulz
- Department of Anaesthesiology, Medical Faculty and University Hospital Düsseldorf, Heinrich-Heine-University Düsseldorf, Düsseldorf, Germany
| | - Richard Truse
- Department of Anaesthesiology, Medical Faculty and University Hospital Düsseldorf, Heinrich-Heine-University Düsseldorf, Düsseldorf, Germany
| | - Annika Raupach
- Department of Anaesthesiology, Medical Faculty and University Hospital Düsseldorf, Heinrich-Heine-University Düsseldorf, Düsseldorf, Germany
| | - Inge Bauer
- Department of Anaesthesiology, Medical Faculty and University Hospital Düsseldorf, Heinrich-Heine-University Düsseldorf, Düsseldorf, Germany
| | - Ulrich Flögel
- Experimental Cardiovascular Imaging, Department of Molecular Cardiology, Medical Faculty and University Hospital Düsseldorf, Heinrich-Heine-University Düsseldorf, Düsseldorf, Germany
| | - Olaf Picker
- Department of Anaesthesiology, Medical Faculty and University Hospital Düsseldorf, Heinrich-Heine-University Düsseldorf, Düsseldorf, Germany
| | - Anna Herminghaus
- Department of Anaesthesiology, Medical Faculty and University Hospital Düsseldorf, Heinrich-Heine-University Düsseldorf, Düsseldorf, Germany
| | - Sebastian Temme
- Department of Anaesthesiology, Medical Faculty and University Hospital Düsseldorf, Heinrich-Heine-University Düsseldorf, Düsseldorf, Germany
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Peng H, Fu S, Wang S, Xu H, Dhanasekaran M, Chen H, Shao C, Yuanzhuo, Ren J. Ablation of FUNDC1-dependent mitophagy renders myocardium resistant to paraquat-induced ferroptosis and contractile dysfunction. Biochim Biophys Acta Mol Basis Dis 2022; 1868:166448. [DOI: 10.1016/j.bbadis.2022.166448] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/22/2022] [Revised: 05/10/2022] [Accepted: 05/12/2022] [Indexed: 02/08/2023]
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Funda J, Villena JA, Bardova K, Adamcova K, Irodenko I, Flachs P, Jedlickova I, Haasova E, Rossmeisl M, Kopecky J, Janovska P. Adipose tissue-specific ablation of PGC-1β impairs thermogenesis in brown fat. Dis Model Mech 2022; 15:dmm049223. [PMID: 35466996 PMCID: PMC9066513 DOI: 10.1242/dmm.049223] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/29/2021] [Accepted: 02/21/2022] [Indexed: 12/12/2022] Open
Abstract
Impaired thermogenesis observed in mice with whole-body ablation of peroxisome proliferator-activated receptor-γ coactivator-1β (PGC-1β; officially known as PPARGC1B) may result from impaired brown fat (brown adipose tissue; BAT) function, but other mechanism(s) could be involved. Here, using adipose-specific PGC-1β knockout mice (PGC-1β-AT-KO mice) we aimed to learn whether specific PGC-1β ablation in adipocytes is sufficient to drive cold sensitivity. Indeed, we found that warm-adapted (30°C) mutant mice were relatively sensitive to acute cold exposure (6°C). When these mice were subjected to cold exposure for 7 days (7-day-CE), adrenergic stimulation of their metabolism was impaired, despite similar levels of thermogenic uncoupling protein 1 in BAT in PGC-1β-AT-KO and wild-type mice. Gene expression in BAT of mutant mice suggested a compensatory increase in lipid metabolism to counteract the thermogenic defect. Interestingly, a reduced number of contacts between mitochondria and lipid droplets associated with low levels of L-form of optic atrophy 1 was found in BAT of PGC-1β-AT-KO mice. These genotypic differences were observed in warm-adapted mutant mice, but they were partially masked by 7-day-CE. Collectively, our results suggest a role for PGC-1β in controlling BAT lipid metabolism and thermogenesis. This article has an associated First Person interview with the first author of the paper.
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Affiliation(s)
- Jiří Funda
- Laboratory of Adipose Tissue Biology, Institute of Physiology of the Czech Academy of Sciences, 142 20 Prague, Czech Republic
- Department of Physiology, Faculty of Science, Charles University in Prague, 128 44 Prague, Czech Republic
| | - Josep A. Villena
- Laboratory of Metabolism and Obesity, Vall d'Hebron-Institut de Recerca, Universitat Autònoma de Barcelona, 08035 Barcelona, Spain
- Centro de Investigación Biomédica en Red de Diabetes y Enfermedades Metabólicas Asociadas, Instituto de Salud Carlos III, 28029 Madrid, Spain
| | - Kristina Bardova
- Laboratory of Adipose Tissue Biology, Institute of Physiology of the Czech Academy of Sciences, 142 20 Prague, Czech Republic
| | - Katerina Adamcova
- Laboratory of Adipose Tissue Biology, Institute of Physiology of the Czech Academy of Sciences, 142 20 Prague, Czech Republic
| | - Illaria Irodenko
- Laboratory of Adipose Tissue Biology, Institute of Physiology of the Czech Academy of Sciences, 142 20 Prague, Czech Republic
| | - Pavel Flachs
- Laboratory of Adipose Tissue Biology, Institute of Physiology of the Czech Academy of Sciences, 142 20 Prague, Czech Republic
| | - Ivana Jedlickova
- Research Unit for Rare Diseases, Department of Paediatrics and Inherited Metabolic Disorders, First Faculty of Medicine, Charles University and General University Hospital, 128 08 Prague, Czech Republic
| | - Eliska Haasova
- Laboratory of Adipose Tissue Biology, Institute of Physiology of the Czech Academy of Sciences, 142 20 Prague, Czech Republic
- Department of Physiology, Faculty of Science, Charles University in Prague, 128 44 Prague, Czech Republic
| | - Martin Rossmeisl
- Laboratory of Adipose Tissue Biology, Institute of Physiology of the Czech Academy of Sciences, 142 20 Prague, Czech Republic
| | - Jan Kopecky
- Laboratory of Adipose Tissue Biology, Institute of Physiology of the Czech Academy of Sciences, 142 20 Prague, Czech Republic
| | - Petra Janovska
- Laboratory of Adipose Tissue Biology, Institute of Physiology of the Czech Academy of Sciences, 142 20 Prague, Czech Republic
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8
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Genetic Complementation of ATP Synthase Deficiency Due to Dysfunction of TMEM70 Assembly Factor in Rat. Biomedicines 2022; 10:biomedicines10020276. [PMID: 35203486 PMCID: PMC8869460 DOI: 10.3390/biomedicines10020276] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/02/2021] [Revised: 01/05/2022] [Accepted: 01/18/2022] [Indexed: 11/17/2022] Open
Abstract
Mutations of the TMEM70 gene disrupt the biogenesis of the ATP synthase and represent the most frequent cause of autosomal recessive encephalo-cardio-myopathy with neonatal onset. Patient tissues show isolated defects in the ATP synthase, leading to the impaired mitochondrial synthesis of ATP and insufficient energy provision. In the current study, we tested the efficiency of gene complementation by using a transgenic rescue approach in spontaneously hypertensive rats with the targeted Tmem70 gene (SHR-Tmem70ko/ko), which leads to embryonic lethality. We generated SHR-Tmem70ko/ko knockout rats expressing the Tmem70 wild-type transgene (SHR-Tmem70ko/ko,tg/tg) under the control of the EF-1α universal promoter. Transgenic rescue resulted in viable animals that showed the variable expression of the Tmem70 transgene across the range of tissues and only minor differences in terms of the growth parameters. The TMEM70 protein was restored to 16–49% of the controls in the liver and heart, which was sufficient for the full biochemical complementation of ATP synthase biogenesis as well as for mitochondrial energetic function in the liver. In the heart, we observed partial biochemical complementation, especially in SHR-Tmem70ko/ko,tg/0 hemizygotes. As a result, this led to a minor impairment in left ventricle function. Overall, the transgenic rescue of Tmem70 in SHR-Tmem70ko/ko knockout rats resulted in the efficient complementation of ATP synthase deficiency and thus in the successful genetic treatment of an otherwise fatal mitochondrial disorder.
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Liang L, Zhang G, Cheng C, Li H, Jin T, Su C, Xiao Y, Bradley J, Peberdy MA, Ornato JP, Mangino MJ, Tang W. High-resolution respirometry for evaluation of mitochondrial function on brain and heart homogenates in a rat model of cardiac arrest and cardiopulmonary resuscitation. Biomed Pharmacother 2021; 142:111935. [PMID: 34467895 DOI: 10.1016/j.biopha.2021.111935] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/10/2020] [Revised: 07/12/2021] [Accepted: 07/14/2021] [Indexed: 10/20/2022] Open
Abstract
The physiology and physiopathology process of mitochondrial function following cardiac arrest remains poorly understood. We aimed to assess mitochondrial respiratory function on the heart and brain homogenates from cardiac arrest rats. The expression level of SIRT1/PGC-1α pathway was measured by immunoblotting. 30 rats were assigned to the CA group and the sham group. Rats of CA were subjected to 6 min of untreated ventricular fibrillation (VF) followed by 8 min of cardiopulmonary resuscitation (CPR). Mitochondrial respiratory function was compromised following CA and I/R injury, as indicated by CIL (451.46 ± 71.48 vs. 909.91 ± 5.51 pmol/min*mg for the heart and 464.14 ± 8.22 vs. 570.53 ± 56.33 pmol/min*mg for the brain), CI (564.04 ± 64.34 vs. 2729.52 ± 347.39 pmol/min*mg for the heart and 726.07 ± 85.78 vs. 1762.82 ± 262.04 pmol/min*mg for the brain), RCR (1.88 ± 0.46 vs. 3.57 ± 0.38 for the heart and 2.05 ± 0.19 vs. 3.49 ± 0.19, for the brain) and OXPHOS coupling efficiency (0.45 ± 0.11 vs. 0.72 ± 0.03 for the heart and 0.52 ± 0.05 vs. 0.71 ± 0.01 for the brain). However, routine respiration was lower in the heart and comparable in the brain after CA. CIV did not change in the heart but was enhanced in the brain. Furthermore, both SIRT1 and PGC-1α were downregulated concurrently in the heart and brain. The mitochondrial respiratory function was compromised following CA and I/R injury, and the major affected respiratory state is complex I-linked respiration. Furthermore, the heart and the brain respond differently to the global I/R injury after CA in mitochondrial respiratory function. Inhibition of the SIRT1/PGC-1α pathway may be a major contributor to the impaired mitochondrial respiratory function.
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Affiliation(s)
- Lian Liang
- Department of Emergency, Sun Yat-sen Memorial Hospital, Sun Yat-sen University, Guangzhou, China; Weil Institute of Emergency and Critical Care Research, Virginia Commonwealth University, Richmond, VA, USA; Institute of Cardiopulmonary Cerebral Resuscitation, Sun Yat-Sen University, Guangzhou, China
| | - Guozhen Zhang
- Weil Institute of Emergency and Critical Care Research, Virginia Commonwealth University, Richmond, VA, USA; Department of Intensive Care Medicine, Tianjin Cancer Hospital Airport Free Trade Zone Hospital, Tianjin, China
| | - Cheng Cheng
- Weil Institute of Emergency and Critical Care Research, Virginia Commonwealth University, Richmond, VA, USA; Department of Intensive Care Medicine, The Second Hospital of Anhui Medical University, Hefei, China
| | - Hui Li
- Weil Institute of Emergency and Critical Care Research, Virginia Commonwealth University, Richmond, VA, USA; Department of Intensive Care Medicine, The Second Hospital of Anhui Medical University, Hefei, China
| | - Tao Jin
- Weil Institute of Emergency and Critical Care Research, Virginia Commonwealth University, Richmond, VA, USA
| | - Chenglei Su
- Weil Institute of Emergency and Critical Care Research, Virginia Commonwealth University, Richmond, VA, USA
| | - Yan Xiao
- Weil Institute of Emergency and Critical Care Research, Virginia Commonwealth University, Richmond, VA, USA
| | - Jennifer Bradley
- Weil Institute of Emergency and Critical Care Research, Virginia Commonwealth University, Richmond, VA, USA
| | - Mary A Peberdy
- Weil Institute of Emergency and Critical Care Research, Virginia Commonwealth University, Richmond, VA, USA; Department of Internal Medicine and Emergency Medicine, Virginia Commonwealth University Health System, Richmond, VA, USA
| | - Joseph P Ornato
- Weil Institute of Emergency and Critical Care Research, Virginia Commonwealth University, Richmond, VA, USA; Department of Emergency Medicine, Virginia Commonwealth University Health System, Richmond, VA, USA
| | - Martin J Mangino
- Weil Institute of Emergency and Critical Care Research, Virginia Commonwealth University, Richmond, VA, USA; Department of Surgery, Virginia Commonwealth University Health System, Richmond, VA, USA
| | - Wanchun Tang
- Weil Institute of Emergency and Critical Care Research, Virginia Commonwealth University, Richmond, VA, USA; Department of Emergency Medicine, Virginia Commonwealth University Health System, Richmond, VA, USA.
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10
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Schulz J, Kramer S, Kanatli Y, Kuebart A, Bauer I, Picker O, Vollmer C, Truse R, Herminghaus A. Sodium Thiosulfate Improves Intestinal and Hepatic Microcirculation Without Affecting Mitochondrial Function in Experimental Sepsis. Front Immunol 2021; 12:671935. [PMID: 34163476 PMCID: PMC8215355 DOI: 10.3389/fimmu.2021.671935] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/24/2021] [Accepted: 05/18/2021] [Indexed: 11/25/2022] Open
Abstract
Introduction In the immunology of sepsis microcirculatory and mitochondrial dysfunction in the gastrointestinal system are important contributors to mortality. Hydrogen sulfide (H2S) optimizes gastrointestinal oxygen supply and mitochondrial respiration predominantly via K(ATP)-channels. Therefore, we tested the hypothesis that sodium thiosulfate (STS), an inducer of endogenous H2S, improves intestinal and hepatic microcirculation and mitochondrial function via K(ATP)-channels in sepsis. Methods In 40 male Wistar rats colon ascendens stent peritonitis (CASP) surgery was performed to establish sepsis. Animals were randomized into 4 groups (1: STS 1 g • kg-1 i.p., 2: glibenclamide (GL) 5 mg • kg-1 i.p., 3: STS + GL, 4: vehicle (VE) i.p.). Treatment was given directly after CASP-surgery and 24 hours later. Microcirculatory oxygenation (µHBO2) and flow (µflow) of the colon and the liver were continuously recorded over 90 min using tissue reflectance spectrophotometry. Mitochondrial oxygen consumption in tissue homogenates was determined with respirometry. Statistic: two-way ANOVA + Dunnett´s and Tukey post - hoc test (microcirculation) and Kruskal-Wallis test + Dunn’s multiple comparison test (mitochondria). p < 0.05 was considered significant. Results STS increased µHbO2 (colon: 90 min: + 10.4 ± 18.3%; liver: 90 min: + 5.8 ± 9.1%; p < 0.05 vs. baseline). Furthermore, STS ameliorated µflow (colon: 60 min: + 51.9 ± 71.1 aU; liver: 90 min: + 22.5 ± 20.0 aU; p < 0.05 vs. baseline). In both organs, µHbO2 and µflow were significantly higher after STS compared to VE. The combination of STS and GL increased colonic µHbO2 and µflow (µHbO2 90 min: + 8.7 ± 11.5%; µflow: 90 min: + 41.8 ± 63.3 aU; p < 0.05 vs. baseline), with significantly higher values compared to VE. Liver µHbO2 and µflow did not change after STS and GL. GL alone did not change colonic or hepatic µHbO2 or µflow. Mitochondrial oxygen consumption and macrohemodynamic remained unaltered. Conclusion The beneficial effect of STS on intestinal and hepatic microcirculatory oxygenation in sepsis seems to be mediated by an increased microcirculatory perfusion and not by mitochondrial respiratory or macrohemodynamic changes. Furthermore, the effect of STS on hepatic but not on intestinal microcirculation seems to be K(ATP)-channel-dependent.
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Affiliation(s)
- Jan Schulz
- Department of Anesthesiology, University Hospital Duesseldorf, Duesseldorf, Germany
| | - Sandra Kramer
- Department of Anesthesiology, University Hospital Duesseldorf, Duesseldorf, Germany
| | - Yasin Kanatli
- Department of Anesthesiology, University Hospital Duesseldorf, Duesseldorf, Germany
| | - Anne Kuebart
- Department of Anesthesiology, University Hospital Duesseldorf, Duesseldorf, Germany
| | - Inge Bauer
- Department of Anesthesiology, University Hospital Duesseldorf, Duesseldorf, Germany
| | - Olaf Picker
- Department of Anesthesiology, University Hospital Duesseldorf, Duesseldorf, Germany
| | - Christian Vollmer
- Department of Anesthesiology, University Hospital Duesseldorf, Duesseldorf, Germany
| | - Richard Truse
- Department of Anesthesiology, University Hospital Duesseldorf, Duesseldorf, Germany
| | - Anna Herminghaus
- Department of Anesthesiology, University Hospital Duesseldorf, Duesseldorf, Germany
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11
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Liang L, Zhang G, Li H, Cheng C, Jin T, Su C, Xiao Y, Bradley J, Peberdy MA, Ornato JP, Mangino MJ, Tang W. Combined Therapy With Polyethylene Glycol-20k and MCC950 Preserves Post-Resuscitated Myocardial Function in a Rat Model of Cardiac Arrest and Cardiopulmonary Resuscitation. J Am Heart Assoc 2021; 10:e019177. [PMID: 33884887 PMCID: PMC8200739 DOI: 10.1161/jaha.120.019177] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 02/07/2023]
Abstract
Background To investigate the therapeutic potential of combined therapy with polyethylene glycol-20k (PEG-20k) and MCC950 on post-resuscitation myocardial function in a rat model of cardiac arrest. Methods and Results Thirty rats were randomized into 5 groups: Sham, Control, PEG-20k, MCC950, PEG-20k+ MCC950. Except for sham, animals were subjected to 6 minutes of ventricular fibrillation followed by 8 minutes cardiopulmonary resuscitation. Two milliliters PEG-20k was administered by intravenous injection coincident with the start of cardiopulmonary resuscitation; MCC950 (10 mg/kg), a highly selective NLRP3 inflammasome inhibitor, was delivered immediately after restoration of spontaneous circulation. Myocardial function, sublingual microcirculation, mitochondrial function, plasma cardiac troponin I, and interleukin-1β, expression of proteins in SIRT1 (sirtuin 1)/PGC-1α (peroxisome proliferator-activated receptor gamma coactivator 1-alpha) and NLRP3 (the NOD-like receptor family protein 3) inflammasome pathways were evaluated. Following cardiopulmonary resuscitation, myocardial function was compromised with a significantly decreased cardiac output, ejection fraction, and increased myocardial performance index, cardiac troponin I. Sublingual microcirculation was disturbed with impaired perfused vessel density and microvascular flow index. Cardiac arrest reduced mitochondrial routine respiration, Complex I-linked respiration, respiratory control rates and oxidative phosphorylation coupling efficiency. PEG-20k or MCC950 alone restored mitochondrial respiratory function, restituted sublingual microcirculation, and preserved myocardial function, whereas a combination of PEG-20k and MCC950 further improved these aspects. PEG-20k restored the expression of SIRT1 and PGC-1α, and blunted activation of NLRP3 inflammasomes. MCC950 suppressed expression of cleaved-caspase-1/pro-caspase-1, ASC (apoptosis-associated speck-like protein), GSDMD [gasdermin d], and interleukin-1β. Conclusions Combined therapy with PEG-20k and MCC950 is superior to either therapy alone for preserving post-resuscitated myocardial function, restituting sublingual microcirculation at restoration of spontaneous circulation at 6 hours. The responsible mechanisms involve upregulated expression of SIRT1/PGC1-α in tandem with inhibition of NLRP3 inflammasomes.
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Affiliation(s)
- Lian Liang
- Department of Emergency Sun Yat-sen Memorial Hospital, Sun Yat-sen University Guangzhou China.,Weil Institute of Emergency and Critical Care Research Virginia Commonwealth University Richmond VA.,Institute of Cardiopulmonary Cerebral Resuscitation Sun Yat-sen University Guangzhou China
| | - Guozhen Zhang
- Weil Institute of Emergency and Critical Care Research Virginia Commonwealth University Richmond VA
| | - Hui Li
- Weil Institute of Emergency and Critical Care Research Virginia Commonwealth University Richmond VA
| | - Cheng Cheng
- Weil Institute of Emergency and Critical Care Research Virginia Commonwealth University Richmond VA
| | - Tao Jin
- Weil Institute of Emergency and Critical Care Research Virginia Commonwealth University Richmond VA
| | - Chenglei Su
- Weil Institute of Emergency and Critical Care Research Virginia Commonwealth University Richmond VA
| | - Yan Xiao
- Weil Institute of Emergency and Critical Care Research Virginia Commonwealth University Richmond VA
| | - Jennifer Bradley
- Weil Institute of Emergency and Critical Care Research Virginia Commonwealth University Richmond VA
| | - Mary A Peberdy
- Weil Institute of Emergency and Critical Care Research Virginia Commonwealth University Richmond VA.,Departments of Internal Medicine and Emergency Medicine Virginia Commonwealth University Health System Richmond VA
| | - Joseph P Ornato
- Weil Institute of Emergency and Critical Care Research Virginia Commonwealth University Richmond VA.,Department of Emergency Medicine Virginia Commonwealth University Health System Richmond VA
| | - Martin J Mangino
- Weil Institute of Emergency and Critical Care Research Virginia Commonwealth University Richmond VA.,Department of Surgery Virginia Commonwealth University Health System Richmond VA
| | - Wanchun Tang
- Weil Institute of Emergency and Critical Care Research Virginia Commonwealth University Richmond VA
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12
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Krishnaswamy VKD, Alugoju P, Periyasamy L. Effect of short-term oral supplementation of crocin on age-related oxidative stress, cholinergic, and mitochondrial dysfunction in rat cerebral cortex. Life Sci 2020; 263:118545. [PMID: 33038382 DOI: 10.1016/j.lfs.2020.118545] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/24/2020] [Revised: 09/25/2020] [Accepted: 09/29/2020] [Indexed: 12/12/2022]
Abstract
BACKGROUND AND AIM Aging is associated with oxidative stress and altered cholinergic and mitochondrial function. Crocin is a carotenoid antioxidant that quenches free radicals and protects cells and tissues from oxidation in biological systems. The aim of the present study is to investigate the effect of oral supplementation of Crocin on age-associated oxidative stress, cholinergic, and mitochondrial function in rat cerebral cortex. MAIN METHODS The middle-aged (15 months old) rats were segregated into three groups (n = 6): Control (ad-libitum fed +0.9% saline as vehicle), Cro 50 (ad-libitum fed + crocin 50 mg/kg/day), Cro 150 (ad-libitum fed + crocin 150 mg/kg/day). The experiment was scheduled for 45 days. The serum and brain parameters were estimated after euthanasia. KEY FINDINGS Crocin supplementation of Cro 50 and Cro 150 displayed a relative decline in body weight gain during the experimental period and significantly reduced age-associated serum triglyceride level over control. In rat cerebral cortex, age-associated macromolecular damage, decline in endogenous antioxidants and an increase in intracellular calcium concentration were significantly reversed due to oral supplementation of Crocin. Cro 150 significantly improved acetylcholine content as a consequence of acetylcholinesterase inhibition. Further, remarkable mitochondrial function was observed in Cro 150 over the control group as determined by citrate synthase and cytochrome C oxidase enzyme activities. SIGNIFICANCE Oral supplementation of Crocin significantly reversed age-associated oxidative stress and neuroinflammatory markers. Meanwhile, Cro 150 remarkably improved cholinergic and mitochondrial function over the control group and facilitated further delay in the aging process due to enhanced cognitive effect.
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Affiliation(s)
- V K D Krishnaswamy
- Department of Biochemistry and Molecular Biology, Pondicherry University, India
| | - Phaniendra Alugoju
- Department of Biochemistry and Molecular Biology, Pondicherry University, India
| | - Latha Periyasamy
- Department of Biochemistry and Molecular Biology, Pondicherry University, India.
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13
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Agil A, Chayah M, Visiedo L, Navarro-Alarcon M, Rodríguez Ferrer JM, Tassi M, Reiter RJ, Fernández-Vázquez G. Melatonin Improves Mitochondrial Dynamics and Function in the Kidney of Zücker Diabetic Fatty Rats. J Clin Med 2020; 9:jcm9092916. [PMID: 32927647 PMCID: PMC7564180 DOI: 10.3390/jcm9092916] [Citation(s) in RCA: 29] [Impact Index Per Article: 7.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/26/2020] [Revised: 09/04/2020] [Accepted: 09/08/2020] [Indexed: 12/13/2022] Open
Abstract
Obesity and associated diabetes (diabesity) impair kidney mitochondrial dynamics by augmenting fission and diminishing fusion, which results in mitochondrial and renal dysfunction. Based on available evidence, the antioxidant activities of melatonin may improve impaired renal mitochondrial function in obese diabetic animals by restoring the imbalanced dynamics through inhibiting fission and promoting fusion. Male Zücker diabetic fatty (ZDF) rats and lean littermates (ZL) were orally treated either with melatonin (10 mg/kg BW/day) (M-ZDF and M-ZL) or vehicle (C-ZDF and C-ZL) for 17 weeks. Kidney function was evaluated by measurement of total urine volume, proteinuria, creatinine clearance, and assessment of kidney mitochondrial dynamics and function. C-ZDF exhibited impaired dynamics and function of kidney mitochondria in comparison to C-ZL. Melatonin improved nephropathy of ZDF rats and modulated their mitochondrial dynamics by reducing expression of Drp1 fission marker and increasing that of fusion markers, Mfn2 and Opa1. Furthermore, melatonin ameliorated mitochondrial dysfunction by increasing respiratory control index and electron transfer chain complex IV activity. In addition, it lowered mitochondrial oxidative status. Our findings show that melatonin supplementation improves nephropathy likely via modulation of the mitochondrial fission/fusion balance and function in ZDF rats.
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Affiliation(s)
- Ahmad Agil
- Department of Pharmacology and Neurosciences Institute, School of Medicine, University of Granada, 18016 Granada, Spain; (M.C.); (L.V.)
- Biosanitary Research Institute of Granada (ibs.GRANADA), University Hospital of Granada, 18016 Granada, Spain
- Correspondence: ; Tel.: +34-625-143-359
| | - Meriem Chayah
- Department of Pharmacology and Neurosciences Institute, School of Medicine, University of Granada, 18016 Granada, Spain; (M.C.); (L.V.)
- Biosanitary Research Institute of Granada (ibs.GRANADA), University Hospital of Granada, 18016 Granada, Spain
| | - Lucia Visiedo
- Department of Pharmacology and Neurosciences Institute, School of Medicine, University of Granada, 18016 Granada, Spain; (M.C.); (L.V.)
- Biosanitary Research Institute of Granada (ibs.GRANADA), University Hospital of Granada, 18016 Granada, Spain
| | - Miguel Navarro-Alarcon
- Department of Nutrition and Bromatology, School of Pharmacy, University of Granada, 18071 Granada, Spain;
| | | | - Mohamed Tassi
- Service of Microscopy, CIBM, University of Granada, 18016 Granada, Spain;
| | - Russel J. Reiter
- Department of Cellular and Structural Biology, University of Texas Health Science at San Antonio, San Antonio, TX 78229, USA;
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14
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Guanosine protects against behavioural and mitochondrial bioenergetic alterations after mild traumatic brain injury. Brain Res Bull 2020; 163:31-39. [PMID: 32681970 DOI: 10.1016/j.brainresbull.2020.07.003] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/16/2020] [Revised: 07/06/2020] [Accepted: 07/08/2020] [Indexed: 12/11/2022]
Abstract
Traumatic brain injury (TBI) constitutes a heterogeneous cerebral insult induced by traumatic biomechanical forces. Mitochondria play a critical role in brain bioenergetics, and TBI induces several consequences related with oxidative stress and excitotoxicity clearly demonstrated in different experimental model involving TBI. Mitochondrial bioenergetics alterations can present several targets for therapeutics which could help reduce secondary brain lesions such as neuropsychiatric problems, including memory loss and motor impairment. Guanosine (GUO), an endogenous neuroprotective nucleoside, affords the long-term benefits of controlling brain neurodegeneration, mainly due to its capacity to activate the antioxidant defense system and maintenance of the redox system. However, little is known about the exact protective mechanism exerted by GUO on mitochondrial bioenergetics disruption induced by TBI. Thus, the aim of this study was to investigate the effects of GUO in brain cortical and hippocampal mitochondrial bioenergetics in the mild TBI model. Additionally, we aimed to assess whether mitochondrial damage induced by TBI may be related to behavioral alterations in rats. Our findings showed that 24 h post-TBI, GUO treatment promotes an adaptive response of mitochondrial respiratory chain increasing oxygen flux which it was able to protect against the uncoupling of oxidative phosphorylation (OXPHOS) induced by TBI, restored the respiratory electron transfer system (ETS) established with an uncoupler. Guanosine treatment also increased respiratory control ratio (RCR), an indicator of the state of mitochondrial coupling, which is related to the mitochondrial functionality. In addition, mitochondrial bioenergetics failure was closely related with locomotor, exploratory and memory impairments. The present study suggests GUO treatment post mild TBI could increase GDP endogenous levels and consequently increasing ATP levels promotes an increase of RCR increasing OXPHOS and in substantial improve mitochondrial respiration in different brain regions, which, in turn, could promote an improvement in behavioral parameters associated to the mild TBI. These findings may contribute to the development of future therapies with a target on failure energetic metabolism induced by TBI.
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15
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High resolution respirometry to assess function of mitochondria in native homogenates of human heart muscle. PLoS One 2020; 15:e0226142. [PMID: 31940313 PMCID: PMC6961865 DOI: 10.1371/journal.pone.0226142] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/04/2019] [Accepted: 11/20/2019] [Indexed: 01/28/2023] Open
Abstract
Impaired myocardial bioenergetics is a hallmark of many cardiac diseases. There is a need of a simple and reproducible method of assessment of mitochondrial function from small human myocardial tissue samples. In this study we adopted high-resolution respirometry to homogenates of fresh human cardiac muscle and compare it with isolated mitochondria. We used atria resected during cardiac surgery (n = 18) and atria and left ventricles from brain-dead organ donors (n = 12). The protocol we developed consisting of two-step homogenization and exposure of 2.5% homogenate in a respirometer to sequential addition of 2.5 mM malate, 15 mM glutamate, 2.5 mM ADP, 10 μM cytochrome c, 10 mM succinate, 2.5 μM oligomycin, 1.5 μM FCCP, 3.5 μM rotenone, 4 μM antimycin and 1 mM KCN or 100 mM Sodium Azide. We found a linear dependency of oxygen consumption on oxygen concentration. This technique requires < 20 mg of myocardium and the preparation of the sample takes <20 min. Mitochondria in the homogenate, as compared to subsarcolemmal and interfibrillar isolated mitochondria, have comparable or better preserved integrity of outer mitochondrial membrane (increase of respiration after addition of cytochrome c is up to 11.7±1.8% vs. 15.7±3.1%, p˂0.05 and 11.7±3.5%, p = 0.99, resp.) and better efficiency of oxidative phosphorylation (Respiratory Control Ratio = 3.65±0.5 vs. 3.04±0.27, p˂0.01 and 2.65±0.17, p˂0.0001, resp.). Results are reproducible with coefficient of variation between two duplicate measurements ≤8% for all indices. We found that whereas atrial myocardium contains less mitochondria than the ventricle, atrial bioenergetic profiles are comparable to left ventricle. In conclusion, high resolution respirometry has been adapted to homogenates of human cardiac muscle and shown to be reliable and reproducible.
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16
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Biochemical thresholds for pathological presentation of ATP synthase deficiencies. Biochem Biophys Res Commun 2020; 521:1036-1041. [DOI: 10.1016/j.bbrc.2019.11.033] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/22/2019] [Accepted: 11/05/2019] [Indexed: 12/11/2022]
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17
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Abstract
Isolated mitochondria are useful to study fundamental processes including mitochondrial respiration, metabolic activity, protein import, membrane fusion, protein complex assembly, as well as interactions of mitochondria with the cytoskeleton, nuclear encoded mRNAs, and other organelles. In addition, studies of the mitochondrial proteome, phosphoproteome, and lipidome are dependent on preparation of highly purified mitochondria (Boldogh, Vojtov, Karmon, & Pon, 1998; Cui, Conte, Fox, Zara, & Winge, 2014; Marc et al., 2002; Meeusen, McCaffery, & Nunnari, 2004; Reinders et al., 2007; Schneiter et al., 1999; Stuart & Koehler, 2007). Most methods to isolate mitochondria rely on differential centrifugation, a two-step centrifugation carried out at low speed to remove intact cells, cell and tissue debris, and nuclei from whole cell extracts followed by high speed centrifugation to concentrate mitochondria and separate them from other organelles. However, methods to disrupt cells and tissue vary. Moreover, density gradient centrifugation or affinity purification of the organelle are used to further purify mitochondria or to separate different populations of the organelle. Here, we describe protocols to isolate mitochondria from different cells and tissues as well as approaches to assess the purity and integrity of isolated organelles.
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18
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Haraux F, Lombès A. Kinetic analysis of ATP hydrolysis by complex V in four murine tissues: Towards an assay suitable for clinical diagnosis. PLoS One 2019; 14:e0221886. [PMID: 31461494 PMCID: PMC6713359 DOI: 10.1371/journal.pone.0221886] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/15/2019] [Accepted: 08/17/2019] [Indexed: 12/12/2022] Open
Abstract
Background ATP synthase, the mitochondrial complex V, plays a major role in bioenergetics and its defects lead to severe diseases. Lack of a consensual protocol for the assay of complex V activity probably explains the under-representation of complex V defect among mitochondrial diseases. The aim of this work was to elaborate a fast, simple and reliable method to check the maximal complex V capacity in samples relevant to clinical diagnosis. Methods Using homogenates from four different murine organs, we tested the use of dodecylmaltoside, stability of the activity, linearity with protein amount, sensitivity to oligomycin and to exogenous inhibitory factor 1 (IF1), influence of freezing, and impact of mitochondrial purification. Results We obtained organ-dependent, reproducible and stable complex V specific activities, similar with fresh and frozen organs. Similar inhibition by oligomycin and exogenous IF1 demonstrated tight coupling between F1 and F0 domains. The Michaelis constant for MgATP had close values for all organs, in the 150–220 μM range. Complex V catalytic turnover rate, as measured in preparations solubilized in detergent using immunotitration and activity measurements, was more than three times higher in extracts from brain or muscle than in extracts from heart or liver. This tissue specificity suggested post-translational modifications. Concomitant measurement of respiratory activities showed only slightly different complex II/complex V ratio in the four organs. In contrast, complex I/complex V ratio differed in brain as compared to the three other organs because of a high complex I activity in brain. Mitochondria purification preserved these ratios, except for brain where selective degradation of complex I occurred. Therefore, mitochondrial purification could introduce a biased enzymatic evaluation. Conclusion Altogether, this work demonstrates that a reliable assay of complex V activity is perfectly possible with very small samples from frozen biopsies, which was confirmed using control and deficient human muscles.
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Affiliation(s)
- Francis Haraux
- Institute for Integrative Biology of the Cell (I2BC), CEA, Gif-sur-Yvette, France.,UMR 9198, CNRS, Gif-sur-Yvette, France.,Université Paris-Sud, Université Paris-Saclay, Gif-sur-Yvette, France
| | - Anne Lombès
- Institut Cochin, Unité U1016, INSERM, Paris, France.,UMR 8104, CNRS, Paris, France.,Université Paris 5, Paris, France
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Kohoutová M, Dejmek J, Tůma Z, Kuncová J. Variability of mitochondrial respiration in relation to sepsis-induced multiple organ dysfunction. Physiol Res 2019; 67:S577-S592. [PMID: 30607965 DOI: 10.33549/physiolres.934050] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/29/2022] Open
Abstract
Ample experimental evidence suggests that sepsis could interfere with any mitochondrial function; however, the true role of mitochondrial dysfunction in the pathogenesis of sepsis-induced multiple organ dysfunction is still a matter of controversy. This review is primarily focused on mitochondrial oxygen consumption in various animal models of sepsis in relation to human disease and potential sources of variability in experimental results documenting decrease, increase or no change in mitochondrial respiration in various organs and species. To date, at least three possible explanations of sepsis-associated dysfunction of the mitochondrial respiratory system and consequently impaired energy production have been suggested: 1. Mitochondrial dysfunction is secondary to tissue hypoxia. 2. Mitochondria are challenged by various toxins or mediators of inflammation that impair oxygen utilization (cytopathic hypoxia). 3. Compromised mitochondrial respiration could be an active measure of survival strategy resembling stunning or hibernation. To reveal the true role of mitochondria in sepsis, sources of variability of experimental results based on animal species, models of sepsis, organs studied, or analytical approaches should be identified and minimized by the use of appropriate experimental models resembling human sepsis, wider use of larger animal species in preclinical studies, more detailed mapping of interspecies differences and organ-specific features of oxygen utilization in addition to use of complex and standardized protocols evaluating mitochondrial respiration.
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Affiliation(s)
- M Kohoutová
- Institute of Physiology, Faculty of Medicine in Plzeň, Charles University, Plzeň, Czech Republic.
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20
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Herminghaus A, Papenbrock H, Eberhardt R, Vollmer C, Truse R, Schulz J, Bauer I, Weidinger A, Kozlov AV, Stiban J, Picker O. Time-related changes in hepatic and colonic mitochondrial oxygen consumption after abdominal infection in rats. Intensive Care Med Exp 2019; 7:4. [PMID: 30623256 PMCID: PMC6325055 DOI: 10.1186/s40635-018-0219-9] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/10/2018] [Accepted: 12/25/2018] [Indexed: 11/18/2022] Open
Abstract
Background Evidence suggests that early adaptive responses of hepatic mitochondria occur in experimentally induced sepsis. Little is known about both colonic mitochondrial function during abdominal infection and long-term changes in mitochondrial function under inflammatory conditions. We hypothesize that hepatic and colonic mitochondrial oxygen consumption changes time-dependently after sterile laparotomy and in the course of abdominal infection. The aim of the present study was to investigate the hepatic and colonic mitochondrial respiration after sterile laparotomy and abdominal infection over up to 96 h. Methods After approval of the local Animal Care and Use Committee, 95 Wistar rats were randomized into 8 groups (n = 11–12): 1–4 sham (laparotomy only) and 5–8 colon ascendens stent peritonitis (CASP). Healthy, unoperated animals served as controls (n = 9). The mitochondrial respiration in colon and liver homogenates was assessed 24, 48, 72, and 96 h after surgery. Mitochondrial oxygen consumption was determined using a Clark-type electrode. State 2 (oxygen consumption in the presence of the substrates for complexes I and II) and state 3 respiration (ADP dependent) were assessed. The respiratory control ratio (RCR state 3/state 2) and ADP/O ratio (ADP added/oxygen consumed) were calculated for both complexes. Data are presented as means ± SD, two-way ANOVA followed by Tukey’s post hoc test. Results Hepatic RCR was initially (after 24 h) elevated in both operated groups; after 48 h only, the septic group was elevated compared to controls. In CASP groups, the hepatic ADP/O ratio for complex I was elevated after 24 h (vs. controls) and after 48 h (vs. sham) but declined after 72 h (vs. controls). The ADP/O ratio for complex II stayed unchanged over the time period until 96 h. The colonic RCR and ADP/O did not change over time after sham or CASP operation. Conclusion Hepatic, but not colonic, mitochondrial respiration is increased in the initial phase (until 48 h) and normalizes in the longer course of time (until 96 h) of abdominal infection. Electronic supplementary material The online version of this article (10.1186/s40635-018-0219-9) contains supplementary material, which is available to authorized users.
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Affiliation(s)
- Anna Herminghaus
- Department of Anaesthesiology, University of Düsseldorf, Moorenstrasse 5, 40225, Düsseldorf, Germany.
| | - Henrike Papenbrock
- Department of Anaesthesiology, University of Düsseldorf, Moorenstrasse 5, 40225, Düsseldorf, Germany
| | - Rebecca Eberhardt
- Department of Anaesthesiology, University of Düsseldorf, Moorenstrasse 5, 40225, Düsseldorf, Germany
| | - Christian Vollmer
- Department of Anaesthesiology, University of Düsseldorf, Moorenstrasse 5, 40225, Düsseldorf, Germany
| | - Richard Truse
- Department of Anaesthesiology, University of Düsseldorf, Moorenstrasse 5, 40225, Düsseldorf, Germany
| | - Jan Schulz
- Department of Anaesthesiology, University of Düsseldorf, Moorenstrasse 5, 40225, Düsseldorf, Germany
| | - Inge Bauer
- Department of Anaesthesiology, University of Düsseldorf, Moorenstrasse 5, 40225, Düsseldorf, Germany
| | - Adelheid Weidinger
- Ludwig Boltzmann Institute for Clinical and Experimental Traumatology, AUVA Research Center, Donaueschingenstraße 13, 1200, Wien, Austria
| | - Andrey V Kozlov
- Ludwig Boltzmann Institute for Clinical and Experimental Traumatology, AUVA Research Center, Donaueschingenstraße 13, 1200, Wien, Austria
| | - Johnny Stiban
- Department of Biology and Biochemistry, Birzeit University, Birzeit, Ramallah, Palestine
| | - Olaf Picker
- Department of Anaesthesiology, University of Düsseldorf, Moorenstrasse 5, 40225, Düsseldorf, Germany
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Pravenec M, Zídek V, Landa V, Mlejnek P, Šilhavý J, Šimáková M, Trnovská J, Škop V, Marková I, Malínská H, Hüttl M, Kazdová L, Bardová K, Tauchmannová K, Vrbacký M, Nůsková H, Mráček T, Kopecký J, Houštěk J. Mutant Wars2 gene in spontaneously hypertensive rats impairs brown adipose tissue function and predisposes to visceral obesity. Physiol Res 2018; 66:917-924. [PMID: 29261326 DOI: 10.33549/physiolres.933811] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/18/2022] Open
Abstract
Brown adipose tissue (BAT) plays an important role in lipid and glucose metabolism in rodents and possibly also in humans. Identification of genes responsible for BAT function would shed light on underlying pathophysiological mechanisms of metabolic disturbances. Recent linkage analysis in the BXH/HXB recombinant inbred (RI) strains, derived from Brown Norway (BN) and spontaneously hypertensive rats (SHR), identified two closely linked quantitative trait loci (QTL) associated with glucose oxidation and glucose incorporation into BAT lipids in the vicinity of Wars2 (tryptophanyl tRNA synthetase 2 (mitochondrial)) gene on chromosome 2. The SHR harbors L53F WARS2 protein variant that was associated with reduced angiogenesis and Wars2 thus represents a prominent positional candidate gene. In the current study, we validated this candidate as a quantitative trait gene (QTG) using transgenic rescue experiment. SHR-Wars2 transgenic rats with wild type Wars2 gene when compared to SHR, showed more efficient mitochondrial proteosynthesis and increased mitochondrial respiration, which was associated with increased glucose oxidation and incorporation into BAT lipids, and with reduced weight of visceral fat. Correlation analyses in RI strains showed that increased activity of BAT was associated with amelioration of insulin resistance in muscle and white adipose tissue. In summary, these results demonstrate important role of Wars2 gene in regulating BAT function and consequently lipid and glucose metabolism.
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Affiliation(s)
- M Pravenec
- Institute of Physiology of the Czech Academy of Sciences, Prague, Czech Republic.
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22
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Uzelac JJ, Stanić M, Krstić D, Čolović M, Djurić D. Effects of homocysteine and its related compounds on oxygen consumption of the rat heart tissue homogenate: the role of different gasotransmitters. Mol Cell Biochem 2017; 444:143-148. [DOI: 10.1007/s11010-017-3238-z] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/01/2017] [Accepted: 11/24/2017] [Indexed: 10/18/2022]
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Pleiotropic Effects of Biguanides on Mitochondrial Reactive Oxygen Species Production. OXIDATIVE MEDICINE AND CELLULAR LONGEVITY 2017; 2017:7038603. [PMID: 28874953 PMCID: PMC5569935 DOI: 10.1155/2017/7038603] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 03/29/2017] [Accepted: 06/13/2017] [Indexed: 11/18/2022]
Abstract
Metformin is widely prescribed as a first-choice antihyperglycemic drug for treatment of type 2 diabetes mellitus, and recent epidemiological studies showed its utility also in cancer therapy. Although it is in use since the 1970s, its molecular target, either for antihyperglycemic or antineoplastic action, remains elusive. However, the body of the research on metformin effect oscillates around mitochondrial metabolism, including the function of oxidative phosphorylation (OXPHOS) apparatus. In this study, we focused on direct inhibitory mechanism of biguanides (metformin and phenformin) on OXPHOS complexes and its functional impact, using the model of isolated brown adipose tissue mitochondria. We demonstrate that biguanides nonspecifically target the activities of all respiratory chain dehydrogenases (mitochondrial NADH, succinate, and glycerophosphate dehydrogenases), but only at very high concentrations (10-2-10-1 M) that highly exceed cellular concentrations observed during the treatment. In addition, these concentrations of biguanides also trigger burst of reactive oxygen species production which, in combination with pleiotropic OXPHOS inhibition, can be toxic for the organism. We conclude that the beneficial effect of biguanides should probably be associated with subtler mechanism, different from the generalized inhibition of the respiratory chain.
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Emmett MJ, Lim HW, Jager J, Richter HJ, Adlanmerini M, Peed LC, Briggs ER, Steger DJ, Ma T, Sims CA, Baur JA, Pei L, Won KJ, Seale P, Gerhart-Hines Z, Lazar MA. Histone deacetylase 3 prepares brown adipose tissue for acute thermogenic challenge. Nature 2017; 546:544-548. [PMID: 28614293 PMCID: PMC5826652 DOI: 10.1038/nature22819] [Citation(s) in RCA: 120] [Impact Index Per Article: 17.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/20/2016] [Accepted: 05/03/2017] [Indexed: 12/18/2022]
Abstract
Brown adipose tissue is a thermogenic organ that dissipates chemical energy as heat to protect animals against hypothermia and to counteract metabolic disease. However, the transcriptional mechanisms that determine the thermogenic capacity of brown adipose tissue before environmental cold are unknown. Here we show that histone deacetylase 3 (HDAC3) is required to activate brown adipose tissue enhancers to ensure thermogenic aptitude. Mice with brown adipose tissue-specific genetic ablation of HDAC3 become severely hypothermic and succumb to acute cold exposure. Uncoupling protein 1 (UCP1) is nearly absent in brown adipose tissue lacking HDAC3, and there is also marked downregulation of mitochondrial oxidative phosphorylation genes resulting in diminished mitochondrial respiration. Remarkably, although HDAC3 acts canonically as a transcriptional corepressor, it functions as a coactivator of oestrogen-related receptor α (ERRα) in brown adipose tissue. HDAC3 coactivation of ERRα is mediated by deacetylation of PGC-1α and is required for the transcription of Ucp1, Ppargc1a (encoding PGC-1α), and oxidative phosphorylation genes. Importantly, HDAC3 promotes the basal transcription of these genes independently of adrenergic stimulation. Thus, HDAC3 uniquely primes Ucp1 and the thermogenic transcriptional program to maintain a critical capacity for thermogenesis in brown adipose tissue that can be rapidly engaged upon exposure to dangerously cold temperature.
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Affiliation(s)
- Matthew J. Emmett
- Institute for Diabetes, Obesity, and Metabolism, Perelman School of Medicine at the University of Pennsylvania, Philadelphia, PA 19104, USA
- Division of Endocrinology, Diabetes, and Metabolism, Department of Medicine, Perelman School of Medicine at the University of Pennsylvania, Philadelphia, PA 19104, USA
| | - Hee-Woong Lim
- Institute for Diabetes, Obesity, and Metabolism, Perelman School of Medicine at the University of Pennsylvania, Philadelphia, PA 19104, USA
- Department of Genetics, Perelman School of Medicine at the University of Pennsylvania, Philadelphia, PA 19104, USA
| | - Jennifer Jager
- Institute for Diabetes, Obesity, and Metabolism, Perelman School of Medicine at the University of Pennsylvania, Philadelphia, PA 19104, USA
- Division of Endocrinology, Diabetes, and Metabolism, Department of Medicine, Perelman School of Medicine at the University of Pennsylvania, Philadelphia, PA 19104, USA
| | - Hannah J. Richter
- Institute for Diabetes, Obesity, and Metabolism, Perelman School of Medicine at the University of Pennsylvania, Philadelphia, PA 19104, USA
- Division of Endocrinology, Diabetes, and Metabolism, Department of Medicine, Perelman School of Medicine at the University of Pennsylvania, Philadelphia, PA 19104, USA
| | - Marine Adlanmerini
- Institute for Diabetes, Obesity, and Metabolism, Perelman School of Medicine at the University of Pennsylvania, Philadelphia, PA 19104, USA
- Division of Endocrinology, Diabetes, and Metabolism, Department of Medicine, Perelman School of Medicine at the University of Pennsylvania, Philadelphia, PA 19104, USA
| | - Lindsey C. Peed
- Institute for Diabetes, Obesity, and Metabolism, Perelman School of Medicine at the University of Pennsylvania, Philadelphia, PA 19104, USA
- Division of Endocrinology, Diabetes, and Metabolism, Department of Medicine, Perelman School of Medicine at the University of Pennsylvania, Philadelphia, PA 19104, USA
| | - Erika R. Briggs
- Institute for Diabetes, Obesity, and Metabolism, Perelman School of Medicine at the University of Pennsylvania, Philadelphia, PA 19104, USA
- Division of Endocrinology, Diabetes, and Metabolism, Department of Medicine, Perelman School of Medicine at the University of Pennsylvania, Philadelphia, PA 19104, USA
| | - David J. Steger
- Institute for Diabetes, Obesity, and Metabolism, Perelman School of Medicine at the University of Pennsylvania, Philadelphia, PA 19104, USA
- Division of Endocrinology, Diabetes, and Metabolism, Department of Medicine, Perelman School of Medicine at the University of Pennsylvania, Philadelphia, PA 19104, USA
| | - Tao Ma
- Section for Metabolic Receptology at the Novo Nordisk Foundation Center for Basic Metabolic Research, and Institute for Neuroscience and Pharmacology, University of Copenhagen, Copenhagen, 2200, DK
| | - Carrie A. Sims
- Institute for Diabetes, Obesity, and Metabolism, Perelman School of Medicine at the University of Pennsylvania, Philadelphia, PA 19104, USA
- The Trauma Center at Penn, Department of Surgery, Perelman School of Medicine at the University of Pennsylvania, Philadelphia, PA 19104
| | - Joseph A. Baur
- Institute for Diabetes, Obesity, and Metabolism, Perelman School of Medicine at the University of Pennsylvania, Philadelphia, PA 19104, USA
- Department of Physiology, Perelman School of Medicine at the University of Pennsylvania, Philadelphia, PA 19104, USA
| | - Liming Pei
- Institute for Diabetes, Obesity, and Metabolism, Perelman School of Medicine at the University of Pennsylvania, Philadelphia, PA 19104, USA
- Center for Mitochondrial and Epigenomic Medicine, Children’s Hospital of Philadelphia, and Department of Pathology and Laboratory Medicine, Perelman School of Medicine at the University of Pennsylvania, Philadelphia, PA 19104, USA
| | - Kyoung-Jae Won
- Institute for Diabetes, Obesity, and Metabolism, Perelman School of Medicine at the University of Pennsylvania, Philadelphia, PA 19104, USA
- Department of Genetics, Perelman School of Medicine at the University of Pennsylvania, Philadelphia, PA 19104, USA
| | - Patrick Seale
- Institute for Diabetes, Obesity, and Metabolism, Perelman School of Medicine at the University of Pennsylvania, Philadelphia, PA 19104, USA
- Department of Cell and Developmental Biology, Perelman School of Medicine at the University of Pennsylvania, Philadelphia, PA 19104, USA
| | - Zachary Gerhart-Hines
- Section for Metabolic Receptology at the Novo Nordisk Foundation Center for Basic Metabolic Research, and Institute for Neuroscience and Pharmacology, University of Copenhagen, Copenhagen, 2200, DK
| | - Mitchell A. Lazar
- Institute for Diabetes, Obesity, and Metabolism, Perelman School of Medicine at the University of Pennsylvania, Philadelphia, PA 19104, USA
- Division of Endocrinology, Diabetes, and Metabolism, Department of Medicine, Perelman School of Medicine at the University of Pennsylvania, Philadelphia, PA 19104, USA
- Department of Genetics, Perelman School of Medicine at the University of Pennsylvania, Philadelphia, PA 19104, USA
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Witt AM, Larsen FS, Bjerring PN. Accumulation of lactate in the rat brain during hyperammonaemia is not associated with impaired mitochondrial respiratory capacity. Metab Brain Dis 2017; 32:461-470. [PMID: 27928693 DOI: 10.1007/s11011-016-9934-7] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/18/2016] [Accepted: 11/29/2016] [Indexed: 01/27/2023]
Abstract
In acute liver failure (ALF) cerebral oedema and high intracranial pressure (ICP) are potentially deadly complications. Astrocytes cultured in ammonia have shown mitochondrial dysfunction and in rat models of liver failure, de novo lactate production in the brain has been observed and has led to a hypothesis of compromised brain metabolism during ALF. In contrast, normal lactate levels are found in cerebral microdialysate of ALF patients and the oxygen: glucose ratio of cerebral metabolic rates remains normal. To investigate this inconsistency we studied the mitochondrial function in brain tissue with respirometry in animal models of hyperammonaemia. Wistar rats with systemic inflammation induced by lipopolysaccharide or liver insufficiency induced by 90% hepatectomy were given ammonium or sodium acetate for 120 min. A cerebral cortex homogenate was studied with respirometry and substrates of the citric acid cycle, uncouplers and inhibitors of the mitochondrial complexes were successively added to investigate the mitochondrial function in detail. In a separate dose-response experiment cortex from healthy rats was incubated for 120 min in ammonium acetate in concentrations up to 80 mM prior to respirometry. Hyperammonaemia was associated with elevated ICP and increased tissue lactate concentration. No difference between groups was found in total respiratory capacity or the function of individual mitochondrial complexes. Ammonium in concentrations of 40 and 80 mM reduced the respiratory capacity in vitro. In conclusion, acute hyperammonaemia leads to elevated ICP and cerebral lactate accumulation. We found no indications of impaired oxidative metabolism in vivo but only in vitro at extreme concentrations of ammonium.
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Affiliation(s)
- Anne Møller Witt
- Department of Hepatology, Rigshospitalet, DK-2100, Copenhagen, Denmark
| | - Fin Stolze Larsen
- Department of Hepatology, Rigshospitalet, DK-2100, Copenhagen, Denmark
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Selective replacement of mitochondrial DNA increases the cardioprotective effect of chronic continuous hypoxia in spontaneously hypertensive rats. Clin Sci (Lond) 2017; 131:865-881. [PMID: 28292971 DOI: 10.1042/cs20170083] [Citation(s) in RCA: 15] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/26/2017] [Revised: 03/08/2017] [Accepted: 03/14/2017] [Indexed: 12/13/2022]
Abstract
Mitochondria play an essential role in improved cardiac ischaemic tolerance conferred by adaptation to chronic hypoxia. In the present study, we analysed the effects of continuous normobaric hypoxia (CNH) on mitochondrial functions, including the sensitivity of the mitochondrial permeability transition pore (MPTP) to opening, and infarct size (IS) in hearts of spontaneously hypertensive rats (SHR) and the conplastic SHR-mtBN strain, characterized by the selective replacement of the mitochondrial genome of SHR with that of the more ischaemia-resistant brown Norway (BN) strain. Rats were adapted to CNH (10% O2, 3 weeks) or kept at room air as normoxic controls. In the left ventricular mitochondria, respiration and cytochrome c oxidase (COX) activity were measured using an Oxygraph-2k and the sensitivity of MPTP opening was assessed spectrophotometrically as Ca2+-induced swelling. Myocardial infarction was analysed in anaesthetized open-chest rats subjected to 20 min of coronary artery occlusion and 3 h of reperfusion. The IS reached 68±3.0% and 65±5% of the area at risk in normoxic SHR and SHR-mtBN strains, respectively. CNH significantly decreased myocardial infarction to 46±3% in SHR. In hypoxic SHR-mtBN strain, IS reached 33±2% and was significantly smaller compared with hypoxic SHR. Mitochondria isolated from hypoxic hearts of both strains had increased detergent-stimulated COX activity and were less sensitive to MPTP opening. The maximum swelling rate was significantly lower in hypoxic SHR-mtBN strain compared with hypoxic SHR, and positively correlated with myocardial infarction in all experimental groups. In conclusion, the mitochondrial genome of SHR modulates the IS-limiting effect of adaptation to CNH by affecting mitochondrial energetics and MPTP sensitivity to opening.
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27
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Djafarzadeh S, Jakob SM. Isolation of Intact Mitochondria from Skeletal Muscle by Differential Centrifugation for High-resolution Respirometry Measurements. J Vis Exp 2017. [PMID: 28362420 DOI: 10.3791/55251] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/26/2023] Open
Abstract
Mitochondria are involved in cellular energy metabolism and use oxygen to produce energy in the form of adenosine triphosphate (ATP). Differential centrifugation at low- and high-speed is commonly used to isolate mitochondria from tissues and cultured cells. Crude mitochondrial fractions obtained by differential centrifugation are used for respirometry measurements. The differential centrifugation technique is based on the separation of organelles according to their size and sedimentation velocity. The isolation of mitochondria is performed immediately after tissue harvesting. The tissue is immersed in an ice-cold homogenization medium, minced using scissors and homogenized in a glass homogenizer with a loose-fitting pestle. The differential centrifugation technique is efficient, fast and inexpensive and the mitochondria obtained by differential centrifugation are pure enough for respirometry assays. Some of the limitations and disadvantages of isolated mitochondria, based on differential centrifugation, are that the mitochondria can be damaged during the homogenization and isolation procedure and that large amounts of the tissue biopsy or cultured cells are required for the mitochondrial isolation.
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Affiliation(s)
- Siamak Djafarzadeh
- Department of Intensive Care Medicine, Inselspital, Bern University Hospital;
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28
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Wang S, Zhu X, Xiong L, Ren J. Ablation of Akt2 prevents paraquat-induced myocardial mitochondrial injury and contractile dysfunction: Role of Nrf2. Toxicol Lett 2017; 269:1-14. [DOI: 10.1016/j.toxlet.2017.01.009] [Citation(s) in RCA: 50] [Impact Index Per Article: 7.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/12/2016] [Revised: 12/30/2016] [Accepted: 01/15/2017] [Indexed: 12/19/2022]
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29
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Haegler P, Grünig D, Berger B, Terracciano L, Krähenbühl S, Bouitbir J. Hepatic Effects of Pharmacological Doses of Hydroxy-Cobalamin[c-lactam] in Mice. PLoS One 2017; 12:e0171026. [PMID: 28135329 PMCID: PMC5279765 DOI: 10.1371/journal.pone.0171026] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/28/2016] [Accepted: 01/13/2017] [Indexed: 12/04/2022] Open
Abstract
The vitamin B12 analog hydroxy-cobalamin[c-lactam] (HCCL) impairs hepatic mitochondrial protein synthesis and function of the electron transport chain in rats. We aimed to establish an in vivo model for mitochondrial dysfunction in mice, which could be used to investigate hepatotoxicity of mitochondrial toxicants. In a first step, we performed a dose-finding study in mice treated with HCCL 0.4 mg/kg and 4 mg/kg i.p. for two to four weeks. The plasma methylmalonate concentration was strongly increased at 4 mg/kg starting at three weeks of treatment. We subsequently treated mice daily with 4 mg/kg HCCL i.p. for three weeks and characterized liver function and histology as well as liver mitochondrial function. We found an increase in liver weight in HCCL-treated mice, which was paralleled by hepatocellular accumulation of triglycerides. In liver homogenate of HCCL-treated mice, the complex I activity of the electron transport chain was reduced, most likely explaining hepatocellular triglyceride accumulation. The activity of CPT1 was not affected by methylmalonyl-CoA in isolated liver mitochondria. Despite impaired complex I activity, mitochondrial superoxide anion production was not increased and the hepatocellular glutathione (GSH) pool was maintained. Finally, the mitochondrial DNA content was not altered with HCCL treatment. In conclusion, treatment of mice with HCCL is associated with increased liver weight explained by hepatocellular triglyceride accumulation. Hepatocellular fat accumulation is most likely a consequence of impaired activity of the mitochondrial electron transport chain. The impairment of complex I activity is not strong enough to result in ROS accumulation and reduction of the GSH stores.
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Affiliation(s)
- Patrizia Haegler
- Division of Clinical Pharmacology & Toxicology, University Hospital, Basel, Switzerland
- Department of Biomedicine, University of Basel, Basel, Switzerland
| | - David Grünig
- Division of Clinical Pharmacology & Toxicology, University Hospital, Basel, Switzerland
- Department of Biomedicine, University of Basel, Basel, Switzerland
| | - Benjamin Berger
- Division of Clinical Pharmacology & Toxicology, University Hospital, Basel, Switzerland
- Department of Biomedicine, University of Basel, Basel, Switzerland
| | - Luigi Terracciano
- Swiss Center of Applied Human Toxicology, SCAHT, Basel, Switzerland
- Department of Molecular Pathology, Institute for Pathology, University Hospital, Basel, Switzerland
| | - Stephan Krähenbühl
- Division of Clinical Pharmacology & Toxicology, University Hospital, Basel, Switzerland
- Department of Biomedicine, University of Basel, Basel, Switzerland
- Swiss Center of Applied Human Toxicology, SCAHT, Basel, Switzerland
- * E-mail:
| | - Jamal Bouitbir
- Division of Clinical Pharmacology & Toxicology, University Hospital, Basel, Switzerland
- Department of Biomedicine, University of Basel, Basel, Switzerland
- Swiss Center of Applied Human Toxicology, SCAHT, Basel, Switzerland
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30
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Mahapatra G, Varughese A, Ji Q, Lee I, Liu J, Vaishnav A, Sinkler C, Kapralov AA, Moraes CT, Sanderson TH, Stemmler TL, Grossman LI, Kagan VE, Brunzelle JS, Salomon AR, Edwards BFP, Hüttemann M. Phosphorylation of Cytochrome c Threonine 28 Regulates Electron Transport Chain Activity in Kidney: IMPLICATIONS FOR AMP KINASE. J Biol Chem 2016; 292:64-79. [PMID: 27758862 DOI: 10.1074/jbc.m116.744664] [Citation(s) in RCA: 36] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/22/2016] [Revised: 09/20/2016] [Indexed: 11/06/2022] Open
Abstract
Mammalian cytochrome c (Cytc) plays a key role in cellular life and death decisions, functioning as an electron carrier in the electron transport chain and as a trigger of apoptosis when released from the mitochondria. However, its regulation is not well understood. We show that the major fraction of Cytc isolated from kidneys is phosphorylated on Thr28, leading to a partial inhibition of respiration in the reaction with cytochrome c oxidase. To further study the effect of Cytc phosphorylation in vitro, we generated T28E phosphomimetic Cytc, revealing superior behavior regarding protein stability and its ability to degrade reactive oxygen species compared with wild-type unphosphorylated Cytc Introduction of T28E phosphomimetic Cytc into Cytc knock-out cells shows that intact cell respiration, mitochondrial membrane potential (ΔΨm), and ROS levels are reduced compared with wild type. As we show by high resolution crystallography of wild-type and T28E Cytc in combination with molecular dynamics simulations, Thr28 is located at a central position near the heme crevice, the most flexible epitope of the protein apart from the N and C termini. Finally, in silico prediction and our experimental data suggest that AMP kinase, which phosphorylates Cytc on Thr28 in vitro and colocalizes with Cytc to the mitochondrial intermembrane space in the kidney, is the most likely candidate to phosphorylate Thr28 in vivo We conclude that Cytc phosphorylation is mediated in a tissue-specific manner and leads to regulation of electron transport chain flux via "controlled respiration," preventing ΔΨm hyperpolarization, a known cause of ROS and trigger of apoptosis.
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Affiliation(s)
- Gargi Mahapatra
- From the Center for Molecular Medicine and Genetics and.,the Departments of Biochemistry and Molecular Biology
| | - Ashwathy Varughese
- From the Center for Molecular Medicine and Genetics and.,the Departments of Biochemistry and Molecular Biology
| | | | - Icksoo Lee
- From the Center for Molecular Medicine and Genetics and.,the College of Medicine, Dankook University, Cheonan-si, Chungcheongnam-do 31116, Republic of Korea
| | - Jenney Liu
- From the Center for Molecular Medicine and Genetics and
| | | | | | - Alexandr A Kapralov
- the Center for Free Radical and Antioxidant Health and the Department of Environmental and Occupational Health, University of Pittsburgh, Pittsburgh, Pennsylvania 15219
| | - Carlos T Moraes
- the Department of Neurology, University of Miami School of Medicine, Miami, Florida 33136, and
| | | | - Timothy L Stemmler
- Pharmaceutical Sciences, Wayne State University, Detroit, Michigan 48201
| | | | - Valerian E Kagan
- the Center for Free Radical and Antioxidant Health and the Department of Environmental and Occupational Health, University of Pittsburgh, Pittsburgh, Pennsylvania 15219
| | - Joseph S Brunzelle
- the Life Sciences Collaborative Access Team, Northwestern University, Center for Synchrotron Research, Argonne, Illinois 60439
| | - Arthur R Salomon
- the MCB Department, Brown University, Providence, Rhode Island 02912
| | | | - Maik Hüttemann
- From the Center for Molecular Medicine and Genetics and .,the Departments of Biochemistry and Molecular Biology
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31
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Salin K, Villasevil EM, Auer SK, Anderson GJ, Selman C, Metcalfe NB, Chinopoulos C. Simultaneous measurement of mitochondrial respiration and ATP production in tissue homogenates and calculation of effective P/O ratios. Physiol Rep 2016; 4:e13007. [PMID: 27798358 PMCID: PMC5099967 DOI: 10.14814/phy2.13007] [Citation(s) in RCA: 19] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/22/2016] [Accepted: 09/23/2016] [Indexed: 01/30/2023] Open
Abstract
The use of tissue homogenate has greatly aided the study of the functioning of mitochondria. However, the amount of ATP produced per oxygen molecule consumed, that is, the effective P/O ratio, has never been measured directly in tissue homogenate. Here we combine and refine existing methods previously used in permeabilized cells and isolated mitochondria to simultaneously measure mitochondrial ATP production (JATP) and oxygen consumption (JO2) in tissue homogenate. A major improvement over existing methods is in the control of ATPases that otherwise interfere with the ATP assay: our modified technique facilitates simultaneous measurement of the rates of "uncorrected" ATP synthesis and of ATP hydrolysis, thus minimizing the amount of tissue and time needed. Finally, we develop a novel method of calculating effective P/O ratios which corrects measurements of JATP and JO2 for rates of nonmitochondrial ATP hydrolysis and respiration, respectively. Measurements of JATP and JO2 in liver homogenates from brown trout (Salmo trutta) were highly reproducible, although activity declined once homogenates were 2 h old. We compared mitochondrial properties from fed and food-deprived animals to demonstrate that the method can detect mitochondrial flexibility in P/O ratios in response to nutritional state. This method simplifies studies examining the mitochondrial bioenergetics of tissue homogenates, obviating the need for differential centrifugation or chemical permeabilization and avoiding the use of nonmitochondrial ATPase inhibitors. We conclude that our approach for characterizing effective P/O ratio opens up new possibilities in the study of mitochondrial function in very small samples, where the use of other methods is limited.
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Affiliation(s)
- Karine Salin
- Institute of Biodiversity, Animal Health and Comparative Medicine, University of Glasgow, Glasgow, UK
| | - Eugenia M Villasevil
- Institute of Biodiversity, Animal Health and Comparative Medicine, University of Glasgow, Glasgow, UK
| | - Sonya K Auer
- Institute of Biodiversity, Animal Health and Comparative Medicine, University of Glasgow, Glasgow, UK
| | - Graeme J Anderson
- Institute of Biodiversity, Animal Health and Comparative Medicine, University of Glasgow, Glasgow, UK
| | - Colin Selman
- Institute of Biodiversity, Animal Health and Comparative Medicine, University of Glasgow, Glasgow, UK
| | - Neil B Metcalfe
- Institute of Biodiversity, Animal Health and Comparative Medicine, University of Glasgow, Glasgow, UK
| | - Christos Chinopoulos
- Department of Medical Biochemistry, Semmelweis University, Budapest, Hungary
- MTA-SE Lendület Neurobiochemistry Research Group, Budapest, Hungary
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32
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Melenovsky V, Petrak J, Mracek T, Benes J, Borlaug BA, Nuskova H, Pluhacek T, Spatenka J, Kovalcikova J, Drahota Z, Kautzner J, Pirk J, Houstek J. Myocardial iron content and mitochondrial function in human heart failure: a direct tissue analysis. Eur J Heart Fail 2016; 19:522-530. [PMID: 27647766 DOI: 10.1002/ejhf.640] [Citation(s) in RCA: 174] [Impact Index Per Article: 21.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/20/2016] [Revised: 05/13/2016] [Accepted: 07/29/2016] [Indexed: 11/08/2022] Open
Abstract
AIMS Iron replacement improves clinical status in iron-deficient patients with heart failure (HF), but the pathophysiology is poorly understood. Iron is essential not only for erythropoiesis, but also for cellular bioenergetics. The impact of myocardial iron deficiency (MID) on mitochondrial function, measured directly in the failing human heart, is unknown. METHODS AND RESULTS Left ventricular samples were obtained from 91 consecutive HF patients undergoing transplantation and 38 HF-free organ donors (controls). Total myocardial iron content, mitochondrial respiration, citric acid cycle and respiratory chain enzyme activities, respiratory chain components (complex I-V), and protein content of reactive oxygen species (ROS)-protective enzymes were measured in tissue homogenates to quantify mitochondrial function. Myocardial iron content was lower in HF compared with controls (156 ± 41 vs. 200 ± 38 µg·g-1 dry weight, P < 0.001), independently of anaemia. MID (the lowest iron tercile in HF) was associated with more extensive coronary disease and less beta-blocker usage compared with non-MID HF patients. Compared with controls, HF patients displayed reduced myocardial oxygen2 respiration and reduced activity of all examined mitochondrial enzymes (all P < 0.001). MID in HF was associated with preserved activity of respiratory chain enzymes but reduced activity of aconitase and citrate synthase (by -26% and -15%, P < 0.05) and reduced expression of catalase, glutathione peroxidase, and superoxide dismutase 2. CONCLUSION Myocardial iron content is decreased and mitochondrial functions are impaired in advanced HF. MID in HF is associated with diminished citric acid cycle enzyme activities and decreased ROS-protecting enzymes. MID may contribute to altered myocardial substrate use and to worsening of mitochondrial dysfunction that exists in HF.
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Affiliation(s)
- Vojtech Melenovsky
- Department of Cardiology and Cardiac Surgery, Institute of Clinical and Experimental Medicine-IKEM, Prague, Czech Republic
| | - Jiri Petrak
- Department of Pathological Physiology and BIOCEV, First Faculty of Medicine, Charles University, Prague, Czech Republic
| | - Tomas Mracek
- Department of Bioenergetics, Institute of Physiology, Academy of Sciences, Prague, Czech Republic
| | - Jan Benes
- Department of Cardiology and Cardiac Surgery, Institute of Clinical and Experimental Medicine-IKEM, Prague, Czech Republic
| | - Barry A Borlaug
- Department of Cardiovascular Diseases, Mayo Clinic, Rochester, MN, USA
| | - Hana Nuskova
- Department of Bioenergetics, Institute of Physiology, Academy of Sciences, Prague, Czech Republic
| | - Tomas Pluhacek
- Department of Analytical Chemistry and RCPTM, Faculty of Science, Palacky University, Olomouc, Czech Republic
| | - Jaroslav Spatenka
- Department of Transplantation and Tissue Bank, University Hospital in Motol, Prague, Czech Republic
| | - Jana Kovalcikova
- Department of Bioenergetics, Institute of Physiology, Academy of Sciences, Prague, Czech Republic
| | - Zdenek Drahota
- Department of Bioenergetics, Institute of Physiology, Academy of Sciences, Prague, Czech Republic
| | - Josef Kautzner
- Department of Cardiology and Cardiac Surgery, Institute of Clinical and Experimental Medicine-IKEM, Prague, Czech Republic
| | - Jan Pirk
- Department of Cardiology and Cardiac Surgery, Institute of Clinical and Experimental Medicine-IKEM, Prague, Czech Republic
| | - Josef Houstek
- Department of Bioenergetics, Institute of Physiology, Academy of Sciences, Prague, Czech Republic
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Sobotka O, Endlicher R, Drahota Z, Kučera O, Rychtrmoc D, Raad M, Hakeem K, Červinková Z. Impaired mitochondrial functions contribute to 3-bromopyruvate toxicity in primary rat and mouse hepatocytes. J Bioenerg Biomembr 2016; 48:363-73. [PMID: 27530389 DOI: 10.1007/s10863-016-9674-8] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/28/2016] [Accepted: 08/07/2016] [Indexed: 01/22/2023]
Abstract
A compound with promising anticancer properties, 3-bromopyruvate (3-BP) is a synthetic derivative of a pyruvate molecule; however, its toxicity in non-malignant cells has not yet been fully elucidated. Therefore, we elected to study the effects of 3-BP on primary hepatocytes in monolayer cultures, permeabilized hepatocytes and isolated mitochondria. After a 1-h treatment with 100 μM 3-BP cell viability of rat hepatocytes was decreased by 30 % as measured by the WST-1 test (p < 0.001); after 3-h exposure to ≥200 μM 3-BP lactate dehydrogenase leakage was increased (p < 0.001). Reactive oxygen species production was increased in the cell cultures after a 1-h treatment at concentrations ≥100 μmol/l (p < 0.01), and caspase 3 activity was increased after a 20-h incubation with 150 μM and 200 μM 3-BP (p < 0.001). This toxic effect of 3-BP was also proved using primary mouse hepatocytes. In isolated mitochondria, 3-BP induced a dose- and time-dependent decrease of mitochondrial membrane potential during a 10-min incubation both with Complex I substrates glutamate + malate or Complex II substrate succinate, although this decrease was more pronounced with the latter. We also measured the effect of 3-BP on respiration of isolated mitochondria. ADP-activated respiration was inhibited by 20 μM 3-BP within 10 min. Similar effects were also found in permeabilized hepatocytes of both species.
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Affiliation(s)
- Ondřej Sobotka
- Department of Physiology, Faculty of Medicine in Hradec Kralove, Charles University in Prague, Hradec Kralove, Czech Republic
| | - René Endlicher
- Department of Physiology, Faculty of Medicine in Hradec Kralove, Charles University in Prague, Hradec Kralove, Czech Republic
- Department of Anatomy, Faculty of Medicine in Hradec Kralove, Charles University in Prague, Hradec Kralove, Czech Republic
| | - Zdeněk Drahota
- Department of Physiology, Faculty of Medicine in Hradec Kralove, Charles University in Prague, Hradec Kralove, Czech Republic
- Institute of Physiology, The Czech Academy of Sciences, Prague, Czech Republic
| | - Otto Kučera
- Department of Physiology, Faculty of Medicine in Hradec Kralove, Charles University in Prague, Hradec Kralove, Czech Republic
| | - David Rychtrmoc
- Department of Physiology, Faculty of Medicine in Hradec Kralove, Charles University in Prague, Hradec Kralove, Czech Republic
| | - Marjan Raad
- Department of Physiology, Faculty of Medicine in Hradec Kralove, Charles University in Prague, Hradec Kralove, Czech Republic
| | - Khurum Hakeem
- Department of Physiology, Faculty of Medicine in Hradec Kralove, Charles University in Prague, Hradec Kralove, Czech Republic
| | - Zuzana Červinková
- Department of Physiology, Faculty of Medicine in Hradec Kralove, Charles University in Prague, Hradec Kralove, Czech Republic.
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Jiroutková K, Krajčová A, Žiak J, Fric M, Gojda J, Džupa V, Kalous M, Tůmová J, Trnka J, Duška F. Mitochondrial Function in an In Vitro Model of Skeletal Muscle of Patients With Protracted Critical Illness and Intensive Care Unit-Acquired Weakness. JPEN J Parenter Enteral Nutr 2016; 41:1213-1221. [PMID: 27358332 DOI: 10.1177/0148607116657649] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/20/2022]
Abstract
BACKGROUND Functional mitochondria in skeletal muscle of patients with protracted critical illness and intensive care unit-acquired weakness are depleted, but remaining mitochondria have increased functional capacities of respiratory complexes II and III. This can be an adaptation to relative abundancy of fatty acid over glucose caused by insulin resistance. We hypothesized that the capacity of muscle mitochondria to oxidize fatty acid is increased in protracted critical illness. METHODS We assessed fatty acid oxidation (FAO) and mitochondrial functional indices in vitro by using extracellular flux analysis in cultured myotubes obtained by isolating and culturing satellite cells from vastus lateralis muscle biopsy samples from patients with ICU-acquired weakness (n = 6) and age-matched healthy controls (n = 7). Bioenergetic measurements were performed at baseline and after 6 days of exposure to free fatty acids (FFAs). RESULTS Mitochondrial density in myotubes from ICU patients was 69% of healthy controls ( P = .051). After adjustment to mitochondrial content, there were no differences in adenosine triphosphate (ATP) synthesis or the capacity and coupling of the respiratory chain. FAO capacity in ICU patients was 157% of FAO capacity in controls ( P = .015). In myotubes of ICU patients, unlike healthy controls, the exposure to FFA significantly ( P = .009) increased maximum respiratory chain capacity. CONCLUSION In an in vitro model of skeletal muscle of patients with protracted critical illness, we have shown signs of adaptation to increased FAO. Even in the presence of glucose and insulin, elevation of FFAs in the extracellular environment increased maximal capacity of the respiratory chain.
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Affiliation(s)
- Kateřina Jiroutková
- 1 Laboratory of Bioenergetics, Third Faculty of Medicine, Charles University in Prague, Prague, Czech Republic.,2 Anaesthesiology and Resuscitation Department, Cardiology Centre, Institute for Clinical and Experimental Medicine, Prague, Czech Republic
| | - Adéla Krajčová
- 1 Laboratory of Bioenergetics, Third Faculty of Medicine, Charles University in Prague, Prague, Czech Republic.,3 Department of Internal Medicine II, Kralovske Vinohrady University Hospital, Prague, Czech Republic
| | - Jakub Žiak
- 1 Laboratory of Bioenergetics, Third Faculty of Medicine, Charles University in Prague, Prague, Czech Republic
| | - Michal Fric
- 4 Department of Anaesthesia and Intensive Care Medicine, Královské Vinohrady University Hospital and Third Faculty of Medicine, Charles University, Prague, Czech Republic
| | - Jan Gojda
- 3 Department of Internal Medicine II, Kralovske Vinohrady University Hospital, Prague, Czech Republic
| | - Valér Džupa
- 5 Department of Orthopaedic Surgeries, Kralovske Vinohrady University Hospital, Prague, Czech Republic
| | - Martin Kalous
- 6 Department of Cell Biology, Faculty of Science, Charles University in Prague, Prague, Czech Republic
| | - Jana Tůmová
- 1 Laboratory of Bioenergetics, Third Faculty of Medicine, Charles University in Prague, Prague, Czech Republic
| | - Jan Trnka
- 1 Laboratory of Bioenergetics, Third Faculty of Medicine, Charles University in Prague, Prague, Czech Republic
| | - František Duška
- 1 Laboratory of Bioenergetics, Third Faculty of Medicine, Charles University in Prague, Prague, Czech Republic.,4 Department of Anaesthesia and Intensive Care Medicine, Královské Vinohrady University Hospital and Third Faculty of Medicine, Charles University, Prague, Czech Republic
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35
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Heinonen JA, Schramko AA, Skrifvars MB, Litonius E, Backman JT, Mervaala E, Rosenberg PH. The effects of intravenous lipid emulsion on hemodynamic recovery and myocardial cell mitochondrial function after bupivacaine toxicity in anesthetized pigs. Hum Exp Toxicol 2016; 36:365-375. [DOI: 10.1177/0960327116650010] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
Local anesthetic toxicity is thought to be mediated partly by inhibition of cardiac mitochondrial function. Intravenous (i.v.) lipid emulsion may overcome this energy depletion, but doses larger than currently recommended may be needed for rescue effect. In this randomized study with anesthetized pigs, we compared the effect of a large dose, 4 mL/kg, of i.v. 20% Intralipid® ( n = 7) with Ringer’s acetate ( n = 6) on cardiovascular recovery after a cardiotoxic dose of bupivacaine. We also examined mitochondrial respiratory function in myocardial cell homogenates analyzed promptly after needle biopsies from the animals. Bupivacaine plasma concentrations were quantified from plasma samples. Arterial blood pressure recovered faster and systemic vascular resistance rose more rapidly after Intralipid than Ringer’s acetate administration ( p < 0.0001), but Intralipid did not increase cardiac index or left ventricular ejection fraction. The lipid-based mitochondrial respiration was stimulated by approximately 30% after Intralipid ( p < 0.05) but unaffected by Ringer’s acetate. The mean (standard deviation) area under the concentration–time curve (AUC) of total bupivacaine was greater after Intralipid (105.2 (13.6) mg·min/L) than after Ringer’s acetate (88.1 (7.1) mg·min/L) ( p = 0.019). After Intralipid, the AUC of the lipid-un-entrapped bupivacaine portion (97.0 (14.5) mg·min/L) was 8% lower than that of total bupivacaine ( p < 0.0001). To conclude, 4 mL/kg of Intralipid expedited cardiovascular recovery from bupivacaine cardiotoxicity mainly by increasing systemic vascular resistance. The increased myocardial mitochondrial respiration and bupivacaine entrapment after Intralipid did not improve cardiac function.
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Affiliation(s)
- JA Heinonen
- Department of Anesthesiology and Intensive Care Medicine, University of Helsinki and Helsinki University Hospital, Helsinki, Finland
| | - AA Schramko
- Department of Anesthesiology and Intensive Care Medicine, University of Helsinki and Helsinki University Hospital, Helsinki, Finland
| | - MB Skrifvars
- Department of Anesthesiology and Intensive Care Medicine, University of Helsinki and Helsinki University Hospital, Helsinki, Finland
| | - E Litonius
- Department of Anesthesia and Perioperative Care, University of California, San Francisco, CA, USA
| | - JT Backman
- Department of Clinical Pharmacology, University of Helsinki and Helsinki University Hospital, Helsinki, Finland
| | - E Mervaala
- Department of Pharmacology, University of Helsinki, Helsinki, Finland
| | - PH Rosenberg
- Department of Anesthesiology and Intensive Care Medicine, University of Helsinki and Helsinki University Hospital, Helsinki, Finland
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Pravenec M, Mlejnek P, Zídek V, Landa V, Šimáková M, Šilhavý J, Strnad H, Eigner S, Eigner Henke K, Škop V, Malínská H, Trnovská J, Kazdová L, Drahota Z, Mráček T, Houštěk J. Autocrine effects of transgenic resistin reduce palmitate and glucose oxidation in brown adipose tissue. Physiol Genomics 2016; 48:420-7. [PMID: 27113533 DOI: 10.1152/physiolgenomics.00122.2015] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/23/2015] [Accepted: 04/06/2016] [Indexed: 12/23/2022] Open
Abstract
Resistin has been originally identified as an adipokine that links obesity to insulin resistance in mice. In our previous studies in spontaneously hypertensive rats (SHR) expressing a nonsecreted form of mouse resistin (Retn) transgene specifically in adipose tissue (SHR-Retn), we have observed an increased lipolysis and serum free fatty acids, ectopic fat accumulation in muscles, and insulin resistance. Recently, brown adipose tissue (BAT) has been suggested to play an important role in the pathogenesis of metabolic disturbances. In the current study, we have analyzed autocrine effects of transgenic resistin on BAT glucose and lipid metabolism and mitochondrial function in the SHR-Retn vs. nontransgenic SHR controls. We observed that interscapular BAT isolated from SHR-Retn transgenic rats compared with SHR controls showed a lower relative weight (0.71 ± 0.05 vs. 0.91 ± 0.08 g/100 g body wt, P < 0.05), significantly reduced both basal and insulin stimulated incorporation of palmitate into BAT lipids (658 ± 50 vs. 856 ± 45 and 864 ± 47 vs. 1,086 ± 35 nmol/g/2 h, P ≤ 0.01, respectively), and significantly decreased palmitate oxidation (37.6 ± 4.5 vs. 57 ± 4.1 nmol/g/2 h, P = 0.007) and glucose oxidation (277 ± 34 vs. 458 ± 38 nmol/g/2 h, P = 0.001). In addition, in vivo microPET imaging revealed significantly reduced (18)F-FDG uptake in BAT induced by exposure to cold in SHR-Retn vs. control SHR (232 ± 19 vs. 334 ± 22 kBq/ml, P < 0.05). Gene expression profiles in BAT identified differentially expressed genes involved in skeletal muscle and connective tissue development, inflammation and MAPK and insulin signaling. These results provide evidence that autocrine effects of resistin attenuate differentiation and activity of BAT and thus may play a role in the pathogenesis of insulin resistance in the rat.
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Affiliation(s)
- Michal Pravenec
- Institute of Physiology, Czech Academy of Sciences, Prague, Czech Republic;
| | - Petr Mlejnek
- Institute of Physiology, Czech Academy of Sciences, Prague, Czech Republic
| | - Václav Zídek
- Institute of Physiology, Czech Academy of Sciences, Prague, Czech Republic
| | - Vladimír Landa
- Institute of Physiology, Czech Academy of Sciences, Prague, Czech Republic
| | - Miroslava Šimáková
- Institute of Physiology, Czech Academy of Sciences, Prague, Czech Republic
| | - Jan Šilhavý
- Institute of Physiology, Czech Academy of Sciences, Prague, Czech Republic
| | - Hynek Strnad
- Institute of Molecular Genetics, Czech Academy of Sciences, Prague, Czech Republic
| | - Sebastian Eigner
- Nuclear Physics Institute, Czech Academy of Sciences, Husinec-Řež, Czech Republic, Faculty of Pharmacy, Charles University in Prague, Hradec Králové, Czech Republic
| | | | - Vojtěch Škop
- Institute for Clinical and Experimental Medicine, Prague, Czech Republic
| | - Hana Malínská
- Institute for Clinical and Experimental Medicine, Prague, Czech Republic
| | - Jaroslava Trnovská
- Institute for Clinical and Experimental Medicine, Prague, Czech Republic
| | - Ludmila Kazdová
- Institute for Clinical and Experimental Medicine, Prague, Czech Republic
| | - Zdeněk Drahota
- Institute of Physiology, Czech Academy of Sciences, Prague, Czech Republic
| | - Tomáš Mráček
- Institute of Physiology, Czech Academy of Sciences, Prague, Czech Republic
| | - Josef Houštěk
- Institute of Physiology, Czech Academy of Sciences, Prague, Czech Republic
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Margulies SS, Kilbaugh T, Sullivan S, Smith C, Propert K, Byro M, Saliga K, Costine BA, Duhaime AC. Establishing a Clinically Relevant Large Animal Model Platform for TBI Therapy Development: Using Cyclosporin A as a Case Study. Brain Pathol 2016; 25:289-303. [PMID: 25904045 DOI: 10.1111/bpa.12247] [Citation(s) in RCA: 41] [Impact Index Per Article: 5.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/29/2015] [Accepted: 02/05/2015] [Indexed: 11/26/2022] Open
Abstract
We have developed the first immature large animal translational treatment trial of a pharmacologic intervention for traumatic brain injury (TBI) in children. The preclinical trial design includes multiple doses of the intervention in two different injury types (focal and diffuse) to bracket the range seen in clinical injury and uses two post-TBI delays to drug administration. Cyclosporin A (CsA) was used as a case study in our first implementation of the platform because of its success in multiple preclinical adult rodent TBI models and its current use in children for other indications. Tier 1 of the therapy development platform assessed the short-term treatment efficacy after 24 h of agent administration. Positive responses to treatment were compared with injured controls using an objective effect threshold established prior to the study. Effective CsA doses were identified to study in Tier 2. In the Tier 2 paradigm, agent is administered in a porcine intensive care unit utilizing neurological monitoring and clinically relevant management strategies, and intervention efficacy is defined as improvement in longer term behavioral endpoints above untreated injured animals. In summary, this innovative large animal preclinical study design can be applied to future evaluations of other agents that promote recovery or repair after TBI.
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38
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Sex difference in the sensitivity of cardiac mitochondrial permeability transition pore to calcium load. Mol Cell Biochem 2015; 412:147-54. [PMID: 26715132 DOI: 10.1007/s11010-015-2619-4] [Citation(s) in RCA: 28] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/29/2015] [Accepted: 12/08/2015] [Indexed: 12/18/2022]
Abstract
Most of the experimental studies have revealed that female heart is more tolerant to ischemia/reperfusion (I/R) injury as compared with the male myocardium. It is widely accepted that mitochondrial dysfunction, and particularly mitochondrial permeability transition pore (MPTP) opening, plays a major role in determining the extent of cardiac I/R injury. The aim of the present study was, therefore, to analyze (i) whether calcium-induced swelling of cardiac mitochondria is sex-dependent and related to the degree of cardiac tolerance to I/R injury and (ii) whether changes in MPTP components-cyclophilin D (CypD) and ATP synthase-can be involved in this process. We have observed that in mitochondria isolated from rat male and female hearts the MPTP has different sensitivity to the calcium load. Female mitochondria are more resistant both in the extent and in the rate of the mitochondrial swelling at higher calcium concentration (200 µM). At low calcium concentration (50 µM) no differences were observed. Our data further suggest that sex-dependent specificity of the MPTP is not the result of different amounts of ATP synthase and CypD, or their respective ratio in mitochondria isolated from male and female hearts. Our results indicate that male and female rat hearts contain comparable content of MPTP and its regulatory protein CypD; parallel immunodetection revealed also the same contents of adenine nucleotide translocator or voltage-dependent anion channel. Increased resistance of female heart mitochondria thus cannot be explained by changes in putative components of MPTP, and rather reflects regulation of MPTP function.
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Jiroutková K, Krajčová A, Ziak J, Fric M, Waldauf P, Džupa V, Gojda J, Němcova-Fürstová V, Kovář J, Elkalaf M, Trnka J, Duška F. Mitochondrial function in skeletal muscle of patients with protracted critical illness and ICU-acquired weakness. CRITICAL CARE : THE OFFICIAL JOURNAL OF THE CRITICAL CARE FORUM 2015; 19:448. [PMID: 26699134 PMCID: PMC4699339 DOI: 10.1186/s13054-015-1160-x] [Citation(s) in RCA: 30] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 09/08/2015] [Accepted: 12/06/2015] [Indexed: 11/10/2022]
Abstract
BACKGROUND Mitochondrial damage occurs in the acute phase of critical illness, followed by activation of mitochondrial biogenesis in survivors. It has been hypothesized that bioenergetics failure of skeletal muscle may contribute to the development of ICU-acquired weakness. The aim of the present study was to determine whether mitochondrial dysfunction persists until protracted phase of critical illness. METHODS In this single-centre controlled-cohort ex vivo proof-of-concept pilot study, we obtained vastus lateralis biopsies from ventilated patients with ICU-acquired weakness (n = 8) and from age and sex-matched metabolically healthy controls (n = 8). Mitochondrial functional indices were measured in cytosolic context by high-resolution respirometry in tissue homogenates, activities of respiratory complexes by spectrophotometry and individual functional capacities were correlated with concentrations of electron transport chain key subunits from respiratory complexes II, III, IV and V measured by western blot. RESULTS The ability of aerobic ATP synthesis (OXPHOS) was reduced to ~54% in ICU patients (p<0.01), in correlation with the depletion of complexes III (~38% of control, p = 0.02) and IV (~26% of controls, p<0.01) and without signs of mitochondrial uncoupling. When mitochondrial functional indices were adjusted to citrate synthase activity, OXPHOS and the activity of complexes I and IV were not different, whilst the activities of complexes II and III were increased in ICU patients 3-fold (p<0.01) respectively 2-fold (p<0.01). CONCLUSIONS Compared to healthy controls, in ICU patients we have demonstrated a ~50% reduction of the ability of skeletal muscle to synthetize ATP in mitochondria. We found a depletion of complex III and IV concentrations and relative increases in functional capacities of complex II and glycerol-3-phosphate dehydrogenase/complex III.
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Affiliation(s)
- Kateřina Jiroutková
- Laboratory of Bioenergetics, Third Faculty of Medicine, Charles University in Prague, Ruská 87, Prague, 100 00, Prague 10, Czech Republic.
| | - Adéla Krajčová
- Laboratory of Bioenergetics, Third Faculty of Medicine, Charles University in Prague, Ruská 87, Prague, 100 00, Prague 10, Czech Republic. .,Department of Internal Medicine II, Kralovske Vinohrady University Hospital, Prague, Czech Republic.
| | - Jakub Ziak
- Laboratory of Bioenergetics, Third Faculty of Medicine, Charles University in Prague, Ruská 87, Prague, 100 00, Prague 10, Czech Republic.
| | - Michal Fric
- Department of Anaesthesia and Intensive Care, Kralovske Vinohrady University Hospital, Prague, Czech Republic.
| | - Petr Waldauf
- Department of Anaesthesia and Intensive Care, Kralovske Vinohrady University Hospital, Prague, Czech Republic.
| | - Valér Džupa
- Department of Orthopaedic Surgery, Kralovske Vinohrady University Hospital, Prague, Czech Republic.
| | - Jan Gojda
- Department of Internal Medicine II, Kralovske Vinohrady University Hospital, Prague, Czech Republic.
| | - Vlasta Němcova-Fürstová
- Department of Cell and Molecular Biology & Center for Research of Diabetes, Metabolism and Nutrition, Third Faculty of Medicine, Charles University in Prague, Prague, Czech Republic.
| | - Jan Kovář
- Department of Cell and Molecular Biology & Center for Research of Diabetes, Metabolism and Nutrition, Third Faculty of Medicine, Charles University in Prague, Prague, Czech Republic.
| | - Moustafa Elkalaf
- Laboratory of Bioenergetics, Third Faculty of Medicine, Charles University in Prague, Ruská 87, Prague, 100 00, Prague 10, Czech Republic.
| | - Jan Trnka
- Laboratory of Bioenergetics, Third Faculty of Medicine, Charles University in Prague, Ruská 87, Prague, 100 00, Prague 10, Czech Republic.
| | - František Duška
- Laboratory of Bioenergetics, Third Faculty of Medicine, Charles University in Prague, Ruská 87, Prague, 100 00, Prague 10, Czech Republic. .,Adult Intensive Care Unit, Queen's Medical Centre, Nottingham University Hospital NHS Trust, Nottingham, UK.
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40
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Simultaneous evaluation of substrate-dependent oxygen consumption rates and mitochondrial membrane potential by TMRM and safranin in cortical mitochondria. Biosci Rep 2015; 36:e00286. [PMID: 26647379 PMCID: PMC4725245 DOI: 10.1042/bsr20150244] [Citation(s) in RCA: 23] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/28/2015] [Accepted: 12/04/2015] [Indexed: 12/03/2022] Open
Abstract
Simultaneous evaluation of two mitochondrial bioenergetics parameters, respiration rates and mitochondrial membrane potential (mtMP) can be useful to determine the mitochondrial dysfunction under various pathological conditions including neurodegenerative diseases and diabetes. Mitochondrial membrane potential (mtMP) is critical for maintaining the physiological function of the respiratory chain to generate ATP. The present study characterized the inter-relationship between mtMP, using safranin and tetramethyl rhodamine methyl ester (TMRM), and mitochondrial respiratory activity and established a protocol for functional analysis of mitochondrial bioenergetics in a multi-sensor system. Coupled respiration was decreased by 27 and 30–35% in the presence of TMRM and safranin respectively. Maximal respiration was higher than coupled with Complex I- and II-linked substrates in the presence of both dyes. Safranin showed decreased maximal respiration at a higher concentration of carbonyl cyanide-4-(trifluoromethoxy)phenylhydrazone (FCCP) compared with TMRM. FCCP titration revealed that maximal respiration in the presence of glutamate and malate was not sustainable at higher FCCP concentrations as compared with pyruvate and malate. Oxygen consumption rate (OCR) and mtMP in response to mitochondrial substrates were higher in isolated mitochondria compared with tissue homogenates. Safranin exhibited higher sensitivity to changes in mtMP than TMRM. This multi-sensor system measured mitochondrial parameters in the brain of transgenic mice that model Alzheimer's disease (AD), because mitochondrial dysfunction is believed to be a primary event in the pathogenesis of AD. The coupled and maximal respiration of electron transport chain were decreased in the cortex of AD mice along with the mtMP compared with age-matched controls. Overall, these data demonstrate that safranin and TMRM are suitable for the simultaneous evaluation of mtMP and respiratory chain activity using isolated mitochondria and tissue homogenate. However, certain care should be taken concerning the selection of appropriate substrates and dyes for specific experimental circumstances.
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Kilbaugh TJ, Sutton RM, Karlsson M, Hansson MJ, Naim MY, Morgan RW, Bratinov G, Lampe JW, Nadkarni VM, Becker LB, Margulies SS, Berg RA. Persistently Altered Brain Mitochondrial Bioenergetics After Apparently Successful Resuscitation From Cardiac Arrest. J Am Heart Assoc 2015; 4:e002232. [PMID: 26370446 PMCID: PMC4599507 DOI: 10.1161/jaha.115.002232] [Citation(s) in RCA: 30] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/17/2022]
Abstract
BACKGROUND Although advances in cardiopulmonary resuscitation have improved survival from cardiac arrest (CA), neurologic injury persists and impaired mitochondrial bioenergetics may be critical for targeted neuroresuscitation. The authors sought to determine if excellent cardiopulmonary resuscitation and postresuscitation care and good traditional survival rates result in persistently disordered cerebral mitochondrial bioenergetics in a porcine pediatric model of asphyxia-associated ventricular fibrillation CA. METHODS AND RESULTS After 7 minutes of asphyxia, followed by ventricular fibrillation, 5 female 1-month-old swine (4 sham) received blood pressure-targeted care: titration of compression depth to systolic blood pressure of 90 mm Hg and vasopressor administration to a coronary perfusion pressure >20 mm Hg. All animals received protocol-based vasopressor support after return of spontaneous circulation for 4 hours before they were killed. The primary outcome was integrated mitochondrial electron transport system (ETS) function. CA animals displayed significantly decreased maximal, coupled oxidative phosphorylating respiration (OXPHOSCI + CII) in cortex (P<0.02) and hippocampus (P<0.02), as well as decreased phosphorylation and coupling efficiency (cortex, P<0.05; hippocampus, P<0.05). Complex I- and complex II-driven respiration were both significantly decreased after CA (cortex: OXPHOSCI P<0.01, ETSCII P<0.05; hippocampus: OXPHOSCI P<0.03, ETSCII P<0.01). In the hippocampus, there was a significant decrease in maximal uncoupled, nonphosphorylating respiration (ETSCI + CII), as well as a 30% reduction in citrate synthase activity (P<0.04). CONCLUSIONS Mitochondria in both the cortex and hippocampus displayed significant alterations in respiratory function after CA despite excellent cardiopulmonary resuscitation and postresuscitation care in asphyxia-associated ventricular fibrillation CA. Analysis of integrated ETS function identifies mitochondrial bioenergetic failure as a target for goal-directed neuroresuscitation after CA. IACUC Protocol: IAC 13-001023.
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Affiliation(s)
- Todd J Kilbaugh
- Department of Anesthesiology and Critical Care Medicine, The Children's Hospital of Philadelphia, University of Pennsylvania Perelman School of Medicine, Philadelphia, PA (T.J.K., R.M.S., M.Y.N., R.W.M., G.B., V.M.N., R.A.B.)
| | - Robert M Sutton
- Department of Anesthesiology and Critical Care Medicine, The Children's Hospital of Philadelphia, University of Pennsylvania Perelman School of Medicine, Philadelphia, PA (T.J.K., R.M.S., M.Y.N., R.W.M., G.B., V.M.N., R.A.B.)
| | - Michael Karlsson
- Mitochondrial Medicine, Department of Clinical Sciences, Lund University, Lund, Sweden (M.K., M.J.H.)
| | - Magnus J Hansson
- Mitochondrial Medicine, Department of Clinical Sciences, Lund University, Lund, Sweden (M.K., M.J.H.)
| | - Maryam Y Naim
- Department of Anesthesiology and Critical Care Medicine, The Children's Hospital of Philadelphia, University of Pennsylvania Perelman School of Medicine, Philadelphia, PA (T.J.K., R.M.S., M.Y.N., R.W.M., G.B., V.M.N., R.A.B.)
| | - Ryan W Morgan
- Department of Anesthesiology and Critical Care Medicine, The Children's Hospital of Philadelphia, University of Pennsylvania Perelman School of Medicine, Philadelphia, PA (T.J.K., R.M.S., M.Y.N., R.W.M., G.B., V.M.N., R.A.B.)
| | - George Bratinov
- Department of Anesthesiology and Critical Care Medicine, The Children's Hospital of Philadelphia, University of Pennsylvania Perelman School of Medicine, Philadelphia, PA (T.J.K., R.M.S., M.Y.N., R.W.M., G.B., V.M.N., R.A.B.)
| | - Joshua W Lampe
- Department of Emergency Medicine, The Hospital of the University of Pennsylvania, University of Pennsylvania Perelman School of Medicine, Philadelphia, PA (J.W.L., L.B.B.)
| | - Vinay M Nadkarni
- Department of Anesthesiology and Critical Care Medicine, The Children's Hospital of Philadelphia, University of Pennsylvania Perelman School of Medicine, Philadelphia, PA (T.J.K., R.M.S., M.Y.N., R.W.M., G.B., V.M.N., R.A.B.)
| | - Lance B Becker
- Department of Emergency Medicine, The Hospital of the University of Pennsylvania, University of Pennsylvania Perelman School of Medicine, Philadelphia, PA (J.W.L., L.B.B.)
| | - Susan S Margulies
- Department of Bioengineering, School of Engineering and Applied Science, University of Pennsylvania, Philadelphia, PA (S.S.M.)
| | - Robert A Berg
- Department of Anesthesiology and Critical Care Medicine, The Children's Hospital of Philadelphia, University of Pennsylvania Perelman School of Medicine, Philadelphia, PA (T.J.K., R.M.S., M.Y.N., R.W.M., G.B., V.M.N., R.A.B.)
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42
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Salin K, Auer SK, Rey B, Selman C, Metcalfe NB. Variation in the link between oxygen consumption and ATP production, and its relevance for animal performance. Proc Biol Sci 2015; 282:20151028. [PMID: 26203001 PMCID: PMC4528520 DOI: 10.1098/rspb.2015.1028] [Citation(s) in RCA: 160] [Impact Index Per Article: 17.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/30/2015] [Accepted: 06/24/2015] [Indexed: 12/17/2022] Open
Abstract
It is often assumed that an animal's metabolic rate can be estimated through measuring the whole-organism oxygen consumption rate. However, oxygen consumption alone is unlikely to be a sufficient marker of energy metabolism in many situations. This is due to the inherent variability in the link between oxidation and phosphorylation; that is, the amount of adenosine triphosphate (ATP) generated per molecule of oxygen consumed by mitochondria (P/O ratio). In this article, we describe how the P/O ratio can vary within and among individuals, and in response to a number of environmental parameters, including diet and temperature. As the P/O ratio affects the efficiency of cellular energy production, its variability may have significant consequences for animal performance, such as growth rate and reproductive output. We explore the adaptive significance of such variability and hypothesize that while a reduction in the P/O ratio is energetically costly, it may be associated with advantages in terms of somatic maintenance through reduced production of reactive oxygen species. Finally, we discuss how considering variation in mitochondrial efficiency, together with whole-organism oxygen consumption, can permit a better understanding of the relationship between energy metabolism and life history for studies in evolutionary ecology.
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Affiliation(s)
- Karine Salin
- Institute of Biodiversity, Animal Health and Comparative Medicine, College of Medical, Veterinary and Life Sciences, University of Glasgow, Glasgow, UK
| | - Sonya K Auer
- Institute of Biodiversity, Animal Health and Comparative Medicine, College of Medical, Veterinary and Life Sciences, University of Glasgow, Glasgow, UK
| | - Benjamin Rey
- Laboratoire de Biométrie et Biologie Évolutive, UMR 5558, CNRS, Université de Lyon 1, Lyon, France Brain Function Research Group, School of Physiology, Faculty of Health Sciences, University of the Witwatersrand, Johannesburg, South Africa
| | - Colin Selman
- Institute of Biodiversity, Animal Health and Comparative Medicine, College of Medical, Veterinary and Life Sciences, University of Glasgow, Glasgow, UK
| | - Neil B Metcalfe
- Institute of Biodiversity, Animal Health and Comparative Medicine, College of Medical, Veterinary and Life Sciences, University of Glasgow, Glasgow, UK
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43
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Mitochondrial ATP synthasome: Expression and structural interaction of its components. Biochem Biophys Res Commun 2015; 464:787-93. [PMID: 26168732 DOI: 10.1016/j.bbrc.2015.07.034] [Citation(s) in RCA: 23] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/26/2015] [Accepted: 07/07/2015] [Indexed: 11/20/2022]
Abstract
Mitochondrial ATP synthase, ADP/ATP translocase (ANT), and inorganic phosphate carrier (PiC) are supposed to form a supercomplex called ATP synthasome. Our protein and transcript analysis of rat tissues indicates that the expression of ANT and PiC is transcriptionally controlled in accordance with the biogenesis of ATP synthase. In contrast, the content of ANT and PiC is increased in ATP synthase deficient patients' fibroblasts, likely due to a post-transcriptional adaptive mechanism. A structural analysis of rat heart mitochondria by immunoprecipitation, blue native/SDS electrophoresis, immunodetection and MS analysis revealed the presence of ATP synthasome. However, the majority of PiC and especially ANT did not associate with ATP synthase, suggesting that most of PiC, ANT and ATP synthase exist as separate entities.
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44
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Kilbaugh TJ, Karlsson M, Byro M, Bebee A, Ralston J, Sullivan S, Duhaime AC, Hansson MJ, Elmér E, Margulies SS. Mitochondrial bioenergetic alterations after focal traumatic brain injury in the immature brain. Exp Neurol 2015; 271:136-44. [PMID: 26028309 DOI: 10.1016/j.expneurol.2015.05.009] [Citation(s) in RCA: 42] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/13/2015] [Revised: 05/12/2015] [Accepted: 05/13/2015] [Indexed: 12/30/2022]
Abstract
Traumatic brain injury (TBI) is one of the leading causes of death in children worldwide. Emerging evidence suggests that alterations in mitochondrial function are critical components of secondary injury cascade initiated by TBI that propogates neurodegeneration and limits neuroregeneration. Unfortunately, there is very little known about the cerebral mitochondrial bioenergetic response from the immature brain triggered by traumatic biomechanical forces. Therefore, the objective of this study was to perform a detailed evaluation of mitochondrial bioenergetics using high-resolution respirometry in a high-fidelity large animal model of focal controlled cortical impact injury (CCI) 24h post-injury. This novel approach is directed at analyzing dysfunction in electron transport, ADP phosphorylation and leak respiration to provide insight into potential mechanisms and possible interventions for mitochondrial dysfunction in the immature brain in focal TBI by delineating targets within the electron transport system (ETS). Development and application of these methodologies have several advantages, and adds to the interpretation of previously reported techniques, by having the added benefit that any toxins or neurometabolites present in the ex-vivo samples are not removed during the mitochondrial isolation process, and simulates the in situ tricarboxylic acid (TCA) cycle by maximizing key substrates for convergent flow of electrons through both complexes I and II. To investigate alterations in mitochondrial function after CCI, ipsilateral tissue near the focal impact site and tissue from the corresponding contralateral side were examined. Respiration per mg of tissue was also related to citrate synthase activity (CS) and calculated flux control ratios (FCR), as an attempt to control for variability in mitochondrial content. Our biochemical analysis of complex interdependent pathways of electron flow through the electron transport system, by most measures, reveals a bilateral decrease in complex I-driven respiration and an increase in complex II-driven respiration 24h after focal TBI. These alterations in convergent electron flow though both complex I and II-driven respiration resulted in significantly lower maximal coupled and uncoupled respiration in the ipsilateral tissue compared to the contralateral side, for all measures. Surprisingly, increases in complex II and complex IV activities were most pronounced in the contralateral side of the brain from the focal injury, and where oxidative phosphorylation was increased significantly compared to sham values. We conclude that 24h after focal TBI in the immature brain, there are significant alterations in cerebral mitochondrial bioenergetics, with pronounced increases in complex II and complex IV respiration in the contralateral hemisphere. These alterations in mitochondrial bioenergetics present multiple targets for therapeutic intervention to limit secondary brain injury and support recovery.
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Affiliation(s)
- Todd J Kilbaugh
- Perelman School of Medicine at the University of Pennsylvania, Anesthesiology and Critical Care Medicine, Children's Hospital of Philadelphia, 34th & Civic Center Blvd., Philadelphia, PA 19104, USA.
| | - Michael Karlsson
- Mitochondrial Medicine, Department of Clinical Sciences, Lund University, BMC A13, SE-221 84 Lund, Sweden.
| | - Melissa Byro
- Department of Bioengineering, University of Pennsylvania, 210 South 33rd Street, Philadelphia, PA 19104, USA.
| | - Ashley Bebee
- Department of Bioengineering, University of Pennsylvania, 210 South 33rd Street, Philadelphia, PA 19104, USA.
| | - Jill Ralston
- Department of Bioengineering, University of Pennsylvania, 210 South 33rd Street, Philadelphia, PA 19104, USA.
| | - Sarah Sullivan
- Department of Bioengineering, University of Pennsylvania, 210 South 33rd Street, Philadelphia, PA 19104, USA.
| | - Ann-Christine Duhaime
- Department of Neurosurgery, Massachusetts General Hospital, 15 Parkman Street, Boston, MA 02114, USA.
| | - Magnus J Hansson
- Mitochondrial Medicine, Department of Clinical Sciences, Lund University, BMC A13, SE-221 84 Lund, Sweden.
| | - Eskil Elmér
- Mitochondrial Medicine, Department of Clinical Sciences, Lund University, BMC A13, SE-221 84 Lund, Sweden.
| | - Susan S Margulies
- Department of Bioengineering, University of Pennsylvania, 210 South 33rd Street, Philadelphia, PA 19104, USA.
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Chu MJJ, Hickey AJR, Jiang Y, Petzer A, Bartlett ASJR, Phillips ARJ. Mitochondrial dysfunction in steatotic rat livers occurs because a defect in complex i makes the liver susceptible to prolonged cold ischemia. Liver Transpl 2015; 21:396-407. [PMID: 25312517 DOI: 10.1002/lt.24024] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/05/2014] [Accepted: 10/06/2014] [Indexed: 01/12/2023]
Abstract
Steatotic livers are susceptible to cold ischemia, which is thought to be secondary to mitochondrial dysfunction. Ischemic preconditioning (IPC) has been reported to improve liver function in the setting of warm ischemia/reperfusion injury, but the effect of IPC on steatotic liver mitochondrial function (MF) with cold ischemia has not been previously evaluated. We aimed to evaluate MF with various severities of hepatic steatosis after various durations of cold ischemia storage with or without IPC. Male Sprague-Dawley rats were fed a normal diet or a high-fat/high-sucrose diet for 1, 2, or 4 weeks to induce mild (<30%), moderate (30%-60%), or severe (>60%) macrovesicular steatosis, respectively. Liver MF was tested with high-resolution respirometry after 1.5, 4, 8, 12, 18, and 24 hours of cold ischemia. Rats in each group (n = 10) underwent 10 minutes of IPC or no IPC before cold ischemia. The baseline (time 0) respiration was similar for lean and severely steatotic livers despite decreased mitochondrial complex I (C-I) activity in severely steatotic livers. Hepatic steatosis was associated with increased C-I-mediated leaks and decreased respiratory control ratios (RCRs) after cold ischemia. Mildly, moderately, and severely steatotic livers showed significantly lower RCRs after 8, 1.5, and 1.5 hours of cold ischemia, respectively, in comparison with lean livers. IPC restored RCRs in mildly steatotic livers to levels comparable to those in lean livers for up to 24 hours of cold ischemia via the attenuation of C-I-mediated leaks, but it had no beneficial effect on moderately and severely steatotic livers. In conclusion, steatotic livers exhibited apparent mitochondrial dysfunction through an alteration in C-I activity, and this made them more susceptible to prolonged cold ischemia. The clinically based IPC protocol used here restored MF in cases of mild hepatic steatosis by attenuating C-I-mediated leaks after prolonged cold ischemia, but it did work not in livers with moderate or severe steatosis.
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Affiliation(s)
- Michael J J Chu
- Department of Surgery, University of Auckland, Auckland, New Zealand
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46
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Ziak J, Krajcova A, Jiroutkova K, Nemcova V, Dzupa V, Duska F. Assessing the function of mitochondria in cytosolic context in human skeletal muscle: adopting high-resolution respirometry to homogenate of needle biopsy tissue samples. Mitochondrion 2015; 21:106-12. [PMID: 25701243 DOI: 10.1016/j.mito.2015.02.002] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/27/2014] [Revised: 01/11/2015] [Accepted: 02/09/2015] [Indexed: 10/24/2022]
Abstract
Using skeletal muscle homogenates for respirometry has many advantages, but the main challenge is avoiding the damage to outer mitochondrial membrane (OMM) and complex I. By optimising the amount of muscle and careful titration of substrates and inhibitors we developed a new protocol and compared it to isolated mitochondria. We found acceptable damage to OMM (~10-15% increment of oxygen flux after addition of cytochrome c) and to complex I (~70% of electron flux). Homogenate retained ~90% of phosphorylation capacity of isolated mitochondria. The use of fresh homogenate was crucial as mitochondrial function declined rapidly after 2-3h of cold storage.
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Affiliation(s)
- Jakub Ziak
- Laboratory of Bioenergetics, 3rd Faculty of Medicine, Charles University in Prague, Czech Republic
| | - Adela Krajcova
- Laboratory of Bioenergetics, 3rd Faculty of Medicine, Charles University in Prague, Czech Republic
| | - Katerina Jiroutkova
- Laboratory of Bioenergetics, 3rd Faculty of Medicine, Charles University in Prague, Czech Republic
| | - Vlasta Nemcova
- Department of Molecular Biology, 3rd Faculty of Medicine, Charles University in Prague, Czech Republic
| | - Valer Dzupa
- Department of Orthopaedic Surgery, Kralovske Vinohrady University Hospital in Prague, Czech Republic
| | - Frantisek Duska
- Laboratory of Bioenergetics, 3rd Faculty of Medicine, Charles University in Prague, Czech Republic.
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47
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Duan MH, Xu WJ, Yao XH, Zhang DY, Zhang YH, Fu YJ, Zu YG. Homogenate-assisted negative pressure cavitation extraction of active compounds from Pyrola incarnata Fisch. and the extraction kinetics study. INNOV FOOD SCI EMERG 2015. [DOI: 10.1016/j.ifset.2014.12.008] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
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48
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Zhang DY, Yao XH, Duan MH, Luo M, Zhao CJ, Zu YG, Fu YJ. An effective homogenate-assisted negative pressure cavitation extraction for the determination of phenolic compounds in pyrola by LC-MS/MS and the evaluation of its antioxidant activity. Food Funct 2015; 6:3323-33. [DOI: 10.1039/c5fo00727e] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
A novel extraction method was designed for the extraction and determination of the main phenolic compounds of Pyrola incarnata Fisch.
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Affiliation(s)
- Dong-Yang Zhang
- College of Biotechonlogy and Sericultural Research Institute
- Jiangsu University of Science and Technology
- Zhenjiang
- PR China
| | - Xiao-Hui Yao
- College of Biotechonlogy and Sericultural Research Institute
- Jiangsu University of Science and Technology
- Zhenjiang
- PR China
| | - Ming-Hui Duan
- State Engineering Laboratory for Bio-Resource Eco-Utilization
- Northeast Forestry University
- Harbin 150040
- PR China
| | - Meng Luo
- State Engineering Laboratory for Bio-Resource Eco-Utilization
- Northeast Forestry University
- Harbin 150040
- PR China
| | - Chun-Jian Zhao
- State Engineering Laboratory for Bio-Resource Eco-Utilization
- Northeast Forestry University
- Harbin 150040
- PR China
| | - Yuan-Gang Zu
- State Engineering Laboratory for Bio-Resource Eco-Utilization
- Northeast Forestry University
- Harbin 150040
- PR China
| | - Yu-Jie Fu
- State Engineering Laboratory for Bio-Resource Eco-Utilization
- Northeast Forestry University
- Harbin 150040
- PR China
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49
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Jiroutkova K, Ziak J, Krajcova A, Fric M, Dzupa V, Duska F. 0520. The role of mitochondrial dysfunction in the pathophysiology of icu-acquired weakness. Intensive Care Med Exp 2014. [PMCID: PMC4797754 DOI: 10.1186/2197-425x-2-s1-p29] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022] Open
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50
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Jiroutkova K, Ziak J, Krajcova A, Fric M, Dzupa V, Duska F. The role of mitochondrial dysfunction in the pathophysiology of ICU-acquired weakness. Nutrition 2014. [DOI: 10.1016/j.nut.2014.07.019] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/24/2022]
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