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Chang JK, Teo G, Pewzner-Jung Y, Cuthbertson DJ, Futerman AH, Wenk MR, Choi H, Torta F. Q-RAI data-independent acquisition for lipidomic quantitative profiling. Sci Rep 2023; 13:19281. [PMID: 37935746 PMCID: PMC10630469 DOI: 10.1038/s41598-023-46312-8] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/31/2023] [Accepted: 10/30/2023] [Indexed: 11/09/2023] Open
Abstract
Untargeted lipidomics has been increasingly adopted for hypothesis generation in a biological context or discovery of disease biomarkers. Most of the current liquid chromatography mass spectrometry (LC-MS) based untargeted methodologies utilize a data dependent acquisition (DDA) approach in pooled samples for identification and MS-only acquisition for semi-quantification in individual samples. In this study, we present for the first time an untargeted lipidomic workflow that makes use of the newly implemented Quadrupole Resolved All-Ions (Q-RAI) acquisition function on the Agilent 6546 quadrupole time-of-flight (Q-TOF) mass spectrometer to acquire MS2 spectra in data independent acquisition (DIA) mode. This is followed by data processing and analysis on MetaboKit, a software enabling DDA-based spectral library construction and extraction of MS1 and MS2 peak areas, for reproducible identification and quantification of lipids in DIA analysis. This workflow was tested on lipid extracts from human plasma and showed quantification at MS1 and MS2 levels comparable to multiple reaction monitoring (MRM) targeted analysis of the same samples. Analysis of serum from Ceramide Synthase 2 (CerS2) null mice using the Q-RAI DIA workflow identified 88 lipid species significantly different between CerS2 null and wild type mice, including well-characterized changes previously associated with this phenotype. Our results show the Q-RAI DIA as a reliable option to perform simultaneous identification and reproducible relative quantification of lipids in exploratory biological studies.
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Affiliation(s)
- Jing Kai Chang
- Precision Medicine Translational Research Programme and Department of Biochemistry, Yong Loo Lin School of Medicine, National University of Singapore, Singapore, Singapore
- SLING, Singapore Lipidomics Incubator, Life Sciences Institute, National University of Singapore, Singapore, Singapore
| | - Guoshou Teo
- Department of Medicine, Yong Loo Lin School of Medicine, National University of Singapore, Singapore, Singapore
| | - Yael Pewzner-Jung
- Department of Biomolecular Sciences, Weizmann Institute of Science, Rehovot, Israel
| | | | - Anthony H Futerman
- Department of Biomolecular Sciences, Weizmann Institute of Science, Rehovot, Israel
| | - Markus R Wenk
- Precision Medicine Translational Research Programme and Department of Biochemistry, Yong Loo Lin School of Medicine, National University of Singapore, Singapore, Singapore
- SLING, Singapore Lipidomics Incubator, Life Sciences Institute, National University of Singapore, Singapore, Singapore
| | - Hyungwon Choi
- Precision Medicine Translational Research Programme and Department of Biochemistry, Yong Loo Lin School of Medicine, National University of Singapore, Singapore, Singapore
- Department of Medicine, Yong Loo Lin School of Medicine, National University of Singapore, Singapore, Singapore
| | - Federico Torta
- Precision Medicine Translational Research Programme and Department of Biochemistry, Yong Loo Lin School of Medicine, National University of Singapore, Singapore, Singapore.
- SLING, Singapore Lipidomics Incubator, Life Sciences Institute, National University of Singapore, Singapore, Singapore.
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2
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Marcheggiani F, Cirilli I, Orlando P, Silvestri S, Vogelsang A, Knott A, Blatt T, Weise JM, Tiano L. Modulation of Coenzyme Q 10 content and oxidative status in human dermal fibroblasts using HMG-CoA reductase inhibitor over a broad range of concentrations. From mitohormesis to mitochondrial dysfunction and accelerated aging. Aging (Albany NY) 2020; 11:2565-2582. [PMID: 31076563 PMCID: PMC6535058 DOI: 10.18632/aging.101926] [Citation(s) in RCA: 24] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/09/2019] [Accepted: 04/04/2019] [Indexed: 12/27/2022]
Abstract
Coenzyme Q10 (CoQ10) is an endogenous lipophilic quinone, ubiquitous in biological membranes and endowed with antioxidant and bioenergetic properties, both crucial to the aging process. In fact, coenzyme Q10 synthesis is known to decrease with age in different tissues including skin. Moreover, synthesis can be inhibited by 3-hydroxy-3-methyl-glutaryl-coenzyme A (HMG-CoA) reductase inhibitors such as statins, that are widely used hypocholesterolemic drugs. They target a key enzymatic step along the mevalonate pathway, involved in the synthesis of both cholesterol and isoprenylated compounds including CoQ10.In the present study, we show that pharmacological CoQ10 deprivation at concentrations of statins > 10000 nM triggers intracellular oxidative stress, mitochondrial dysfunction and generates cell death in human dermal fibroblasts (HDF). On the contrary, at lower statin concentrations, cells and mainly mitochondria, are able to partially adapt and prevent oxidative imbalance and overt mitochondrial toxicity. Importantly, our data demonstrate that CoQ10 decrease promotes mitochondrial permeability transition and bioenergetic dysfunction leading to premature aging of human dermal fibroblasts in vitro.
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Affiliation(s)
- Fabio Marcheggiani
- Department of Life and Environmental Sciences, Polytechnic University of Marche, Ancona, Italy
| | - Ilenia Cirilli
- Department of Clinical and Dental Sciences, Polytechnic University of Marche, Ancona, Italy
| | - Patrick Orlando
- Department of Life and Environmental Sciences, Polytechnic University of Marche, Ancona, Italy
| | - Sonia Silvestri
- Department of Life and Environmental Sciences, Polytechnic University of Marche, Ancona, Italy
| | | | - Anja Knott
- Research and Development, Beiersdorf AG, Hamburg, Germany
| | - Thomas Blatt
- Research and Development, Beiersdorf AG, Hamburg, Germany
| | - Julia M Weise
- Research and Development, Beiersdorf AG, Hamburg, Germany
| | - Luca Tiano
- Department of Life and Environmental Sciences, Polytechnic University of Marche, Ancona, Italy
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Bauerova K, Kucharska J, Ponist S, Slovak L, Svik K, Jakus V, Muchova J. The Role of Endogenous Antioxidants in the Treatment of Experimental Arthritis. Antioxidants (Basel) 2019. [DOI: 10.5772/intechopen.85568] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/16/2022] Open
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4
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Fallah M, Askari G, Soleimani A, Feizi A, Asemi Z. Clinical Trial of the Effects of Coenzyme Q10 Supplementation on Biomarkers of Inflammation and Oxidative Stress in Diabetic Hemodialysis Patients. Int J Prev Med 2019; 10:12. [PMID: 30774846 PMCID: PMC6360842 DOI: 10.4103/ijpvm.ijpvm_418_18] [Citation(s) in RCA: 15] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/10/2018] [Accepted: 11/01/2018] [Indexed: 11/04/2022] Open
Abstract
Background The aim of the study was to determine the effects of coenzyme Q10 (CoQ10) supplementation on biomarkers of inflammation and oxidative stress among diabetic hemodialysis (HD) patients. Methods Sixty diabetic HD patients participated in the randomized, double blind, placebo-controlled clinical trial. They were randomly assigned into two groups to intake either 60 mg CoQ10 supplements (n = 30) or placebo (n = 30) twice a day for 12 weeks. Results After 12 weeks of intervention, CoQ10 supplementation significantly increased total antioxidant (TAC) (54.921 ± 26.437 vs. -126.781 ± 26.437, P < 0.001) and nitric oxide (NO) levels (4.121 ± 1.314 vs. -1.427 ± 1.314, P = 0.006) and decreased C-reactive protein (CRP) (-1.302 ± 0.583 vs. 0.345 ± 0.583, 0.042) levels compared with the placebo. We did not observe any significant effect of CoQ10 supplementation on malondialdehyde (MDA) and glutathione (GSH) levels compared with the placebo. Conclusions Overall, our study showed that CoQ10 supplementation to diabetic HD patients for 12 weeks was associated with increased levels of TAC and NO levels and decreased level of high-sensitivity CRP (hs-CRP) levels, but did not have any beneficial effects on MDA and GSH.
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Affiliation(s)
- Melika Fallah
- Department of Community Nutrition, School of Nutrition and Food Science, Food Security Research Center, Isfahan University of Medical Sciences, Isfahan, Iran
| | - Gholamreza Askari
- Department of Community Nutrition, School of Nutrition and Food Science, Food Security Research Center, Isfahan University of Medical Sciences, Isfahan, Iran
| | - Alireza Soleimani
- Department of Internal Medicine, Kashan University of Medical Sciences, Kashan, Iran
| | - Awat Feizi
- Isfahan Endocrine and Metabolism Research Center, Isfahan, Iran.,Department of Biostatistics and Epidemiology, School of Public Health, Isfahan University of Medical Sciences, Isfahan, Iran
| | - Zatollah Asemi
- Research Center for Biochemistry and Nutrition in Metabolic Diseases, Kashan University of Medical Sciences, Kashan, Iran
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5
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Zahedi H, Eghtesadi S, Seifirad S, Rezaee N, Shidfar F, Heydari I, Golestan B, Jazayeri S. Effects of CoQ10 Supplementation on Lipid Profiles and Glycemic Control in Patients with Type 2 Diabetes: a randomized, double blind, placebo-controlled trial. J Diabetes Metab Disord 2014; 13:81. [PMID: 26413493 PMCID: PMC4583053 DOI: 10.1186/s40200-014-0081-6] [Citation(s) in RCA: 37] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/07/2014] [Accepted: 07/13/2014] [Indexed: 01/06/2023]
Abstract
Background Low grade inflammation and oxidative stress are the key factors in the pathogenesis and development of diabetes and its complications. Coenzyme Q10 (CoQ10) is known as an antioxidant and has a vital role in generation of cellular energy providing. This study was undertaken to evaluate the effects of CoQ10 supplementation on lipid profiles and glycemic controls in patients with diabetes. Methods Fifty patients with diabetes were randomly allocated into two groups to receive either 150 mg CoQ10 or placebo daily for 12 weeks. Before and after supplementation, fasting venous blood samples were collected and lipid profiles containing triglyceride, total cholesterol, low-density lipoprotein cholesterol (LDL-C) and high-density lipoprotein cholesterol (HDL-C) and glycemic indices comprising of fasting plasma glucose (FPG), insulin and hemoglobin A1C (HbA1C) were measured. Insulin resistance was calculated using HOMA-IR index. Results Forty patients completed the study. After intervention FPG and HbA1C were significantly lower in the CoQ10 group compared to the placebo group, but there were no significant differences in serum insulin and HOMA-IR between the two groups. Although total cholesterol did not change in the Q10 group after supplementation, triglyceride and HDL-C significantly decreased and LDL-C significantly increased in the CoQ10 group. Conclusion The present study showed that treatment with Q10 may improve glycemic control with no favorable effects on lipid profiles in type 2 patients with diabetes. Trial registration IRCT registry number: IRCT138806102394N1
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Affiliation(s)
- Hoda Zahedi
- Obesity and Eating Habits Research Center, Endocrinology and Metabolism Molecular -Cellular Sciences Institute, Tehran University of Medical Sciences, Tehran, Iran
| | - Shahryar Eghtesadi
- Department of Nutrition, School of Public Health, Iran University of Medical Sciences, Tehran, Iran
| | - Soroush Seifirad
- Endocrinology and Metabolism Research Center, Endocrinology and Metabolism Clinical Sciences Institute, Tehran University of Medical Sciences, Tehran, Iran
| | - Neshat Rezaee
- Department of Nutrition, School of Public Health, Iran University of Medical Sciences, Tehran, Iran
| | - Farzad Shidfar
- Department of Nutrition, School of Public Health, Iran University of Medical Sciences, Tehran, Iran
| | - Iraj Heydari
- Institute of Endocrinology and Metabolism, Firouzgar Hospital, Iran University of Medical Sciences, Tehran, Iran
| | - Banafsheh Golestan
- Department of Epidemiology and Biostatistics, School of Public Health, Tehran University of Medical Sciences, Tehran, Iran
| | - Shima Jazayeri
- Department of Nutrition, School of Public Health, Iran University of Medical Sciences, Tehran, Iran
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Seibenhener ML, Zhao T, Du Y, Calderilla-Barbosa L, Yan J, Jiang J, Wooten MW, Wooten MC. Behavioral effects of SQSTM1/p62 overexpression in mice: support for a mitochondrial role in depression and anxiety. Behav Brain Res 2013; 248:94-103. [PMID: 23591541 DOI: 10.1016/j.bbr.2013.04.006] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/14/2013] [Revised: 04/01/2013] [Accepted: 04/06/2013] [Indexed: 11/18/2022]
Abstract
Affective spectrum and anxiety disorders have come to be recognized as the most prevalently diagnosed psychiatric disorders. Among a suite of potential causes, changes in mitochondrial energy metabolism and function have been associated with such disorders. Thus, proteins that specifically change mitochondrial functionality could be identified as molecular targets for drugs related to treatment for affective spectrum disorders. Here, we report generation of transgenic mice overexpressing the scaffolding and mitophagy related protein Sequestosome1 (SQSTM1/p62) or a single point mutant (P392L) in the UBA domain of SQSTM1/p62. We show that overexpression of SQSTM1/p62 increases mitochondrial energy output and improves transcription factor import into the mitochondrial matrix. These elevated levels of mitochondrial functionality correlate directly with discernible improvements in mouse behaviors related to affective spectrum and anxiety disorders. We also describe how overexpression of SQSTM1/p62 improves spatial learning and long term memory formation in these transgenic mice. These results suggest that SQSTM1/p62 provides an attractive target for therapeutic agents potentially suitable for the treatment of anxiety and affective spectrum disorders.
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Affiliation(s)
- M Lamar Seibenhener
- Dept. Biological Sciences, Auburn University, 331 Funchess Hall, Auburn, AL 36832, USA.
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7
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Genova ML, Lenaz G. New developments on the functions of coenzyme Q in mitochondria. Biofactors 2011; 37:330-54. [PMID: 21989973 DOI: 10.1002/biof.168] [Citation(s) in RCA: 52] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/04/2011] [Accepted: 04/06/2011] [Indexed: 12/12/2022]
Abstract
The notion of a mobile pool of coenzyme Q (CoQ) in the lipid bilayer has changed with the discovery of respiratory supramolecular units, in particular the supercomplex comprising complexes I and III; in this model, the electron transfer is thought to be mediated by tunneling or microdiffusion, with a clear kinetic advantage on the transfer based on random collisions. The CoQ pool, however, has a fundamental function in establishing a dissociation equilibrium with bound quinone, besides being required for electron transfer from other dehydrogenases to complex III. The mechanism of CoQ reduction by complex I is analyzed regarding recent developments on the crystallographic structure of the enzyme, also in relation to the capacity of complex I to generate superoxide. Although the mechanism of the Q-cycle is well established for complex III, involvement of CoQ in proton translocation by complex I is still debated. Some additional roles of CoQ are also examined, such as the antioxidant effect of its reduced form and the capacity to bind the permeability transition pore and the mitochondrial uncoupling proteins. Finally, a working hypothesis is advanced on the establishment of a vicious circle of oxidative stress and supercomplex disorganization in pathological states, as in neurodegeneration and cancer.
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Wang J, Yang J, Yang B, Sun JQ, Yang T. Alternative Synthesis of 5-Chloromethyl-2,3-Dimethoxy-6-Methyl-1,4-Benzoquinone: A Key Intermediate for Preparing Coenzyme Q Analogues. JOURNAL OF CHEMICAL RESEARCH 2010. [DOI: 10.3184/030823410x12857507693464] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/17/2022]
Abstract
The title compound, a key intermediate for preparing Coenzyme Qn family, was prepared in high yield by a reaction sequence starting from the commercially available 3, 4, 5-trimethoxy-benzadehyde via Wolff–Kishner reduction, Vilsmeier–Haack reaction, Blanc chloromethylation reaction, Dakin reaction and oxidation.
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Affiliation(s)
- Jin Wang
- Faculty of Life Science and Technology, Kunming University of Science and Technology, Kunming 650224, P. R. China
| | - Jian Yang
- Faculty of Life Science and Technology, Kunming University of Science and Technology, Kunming 650224, P. R. China
| | - Bo Yang
- Faculty of Life Science and Technology, Kunming University of Science and Technology, Kunming 650224, P. R. China
| | - Jia-Qiang Sun
- Faculty of Life Science and Technology, Kunming University of Science and Technology, Kunming 650224, P. R. China
| | - Tao Yang
- Faculty of Life Science and Technology, Kunming University of Science and Technology, Kunming 650224, P. R. China
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Scientific Opinion on the substantiation of health claims related to coenzyme Q10 and contribution to normal energy-yielding metabolism (ID 1508, 1512, 1720, 1912, 4668), maintenance of normal blood pressure (ID 1509, 1721, 1911), protection of DNA, prote. EFSA J 2010. [DOI: 10.2903/j.efsa.2010.1793] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/05/2023] Open
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10
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Zhou H, Yue Y, Liu G, Li Y, Zhang J, Yan Z, Duan M. Characterisation and Skin Distribution of Lecithin-Based Coenzyme Q10-Loaded Lipid Nanocapsules. NANOSCALE RESEARCH LETTERS 2010; 5:1561-9. [PMID: 21076708 PMCID: PMC2956036 DOI: 10.1007/s11671-010-9677-z] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 03/10/2010] [Accepted: 06/29/2010] [Indexed: 05/30/2023]
Abstract
The purpose of this study was to investigate the influence of the inner lipid ratio on the physicochemical properties and skin targeting of surfactant-free lecithin-based coenzyme Q10-loaded lipid nanocapsules (CoQ10-LNCs). The smaller particle size of CoQ10-LNCs was achieved by high pressure and a lower ratio of CoQ10/GTCC (Caprylic/capric triglyceride); however, the zeta potential of CoQ10-LNCs was above /- 60 mV/ with no distinct difference among them at different ratios of CoQ10/GTCC. Both the crystallisation point and the index decreased with the decreasing ratio of CoQ10/GTCC and smaller particle size; interestingly, the supercooled state of CoQ10-LNCs was observed at particle size below about 200 nm, as verified by differential scanning calorimetry (DSC) in one heating-cooling cycle. The lecithin monolayer sphere structure of CoQ10-LNCs was investigated by cryogenic transmission electron microscopy (Cryo-TEM). The skin penetration results revealed that the distribution of Nile red-loaded CoQ10-LNCs depended on the ratio of inner CoQ10/GTCC; moreover, epidermal targeting and superficial dermal targeting were achieved by the CoQ10-LNCs application. The highest fluorescence response was observed at a ratio of inner CoQ10/GTCC of 1:1. These observations suggest that lecithin-based LNCs could be used as a promising topical delivery vehicle for lipophilic compounds.
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Affiliation(s)
- Huafeng Zhou
- State-key Laboratory of Biomembrane and Membrane Biotechnology, School of Life Sciences, Tsinghua University, 100084, Beijing, China
- Jiangsu Longliqi Bioscience Co., Ltd., 215555, Suzhou, China
| | - Yang Yue
- State-key Laboratory of Biomembrane and Membrane Biotechnology, School of Life Sciences, Tsinghua University, 100084, Beijing, China
| | - Guanlan Liu
- State-key Laboratory of Biomembrane and Membrane Biotechnology, School of Life Sciences, Tsinghua University, 100084, Beijing, China
| | - Yan Li
- State-key Laboratory of Biomembrane and Membrane Biotechnology, School of Life Sciences, Tsinghua University, 100084, Beijing, China
| | - Jing Zhang
- State-key Laboratory of Biomembrane and Membrane Biotechnology, School of Life Sciences, Tsinghua University, 100084, Beijing, China
| | - Zemin Yan
- Jiangsu Longliqi Bioscience Co., Ltd., 215555, Suzhou, China
| | - Mingxing Duan
- State-key Laboratory of Biomembrane and Membrane Biotechnology, School of Life Sciences, Tsinghua University, 100084, Beijing, China
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Pepe S, Marasco SF, Haas SJ, Sheeran FL, Krum H, Rosenfeldt FL. Coenzyme Q10 in cardiovascular disease. Mitochondrion 2007; 7 Suppl:S154-67. [PMID: 17485243 DOI: 10.1016/j.mito.2007.02.005] [Citation(s) in RCA: 98] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/01/2006] [Revised: 02/06/2007] [Accepted: 02/10/2007] [Indexed: 12/26/2022]
Abstract
In this review we summarise the current state of knowledge of the therapeutic efficacy and mechanisms of action of CoQ(10) in cardiovascular disease. Our conclusions are: 1. There is promising evidence of a beneficial effect of CoQ(10) when given alone or in addition to standard therapies in hypertension and in heart failure, but less extensive evidence in ischemic heart disease. 2. Large scale multi-centre prospective randomised trials are indicated in all these areas but there are difficulties in funding such trials. 3. Presently, due to the notable absence of clinically significant side effects and likely therapeutic benefit, CoQ(10) can be considered a safe adjunct to standard therapies in cardiovascular disease.
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Affiliation(s)
- Salvatore Pepe
- CJOB Department of Cardiothoracic Surgery, Alfred Hospital, Melbourne, Australia
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12
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Marriage BJ, Clandinin MT, Macdonald IM, Glerum DM. Cofactor treatment improves ATP synthetic capacity in patients with oxidative phosphorylation disorders. Mol Genet Metab 2004; 81:263-72. [PMID: 15059613 DOI: 10.1016/j.ymgme.2003.12.008] [Citation(s) in RCA: 66] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/29/2003] [Revised: 12/18/2003] [Accepted: 12/18/2003] [Indexed: 11/29/2022]
Abstract
Marked progress has been made over the past 15 years in defining the specific biochemical defects and underlying molecular mechanisms of oxidative phosphorylation disorders, but limited information is currently available on the development and evaluation of effective treatment approaches. Metabolic therapies that have been reported to produce a positive effect include coenzyme Q(10) (ubiquinone), other antioxidants such as ascorbic acid and vitamin E, riboflavin, thiamine, niacin, vitamin K (phylloquinone and menadione), and carnitine. The goal of these therapies is to increase mitochondrial ATP production, and to slow or arrest the progression of clinical symptoms. In the present study, we demonstrate for the first time that there is a significant increase in ATP synthetic capacity in lymphocytes from patients undergoing cofactor treatment. We also examined in vitro cofactor supplementation in control lymphocytes in order to determine the effect of the individual components of the cofactor treatment on ATP synthesis. A dose-dependent increase in ATP synthesis with CoQ(10) incubation was demonstrated, which supports the proposal that CoQ(10) may have a beneficial effect in the treatment of oxidative phosphorylation (OXPHOS) disorders.
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Affiliation(s)
- Barbara J Marriage
- Department of Medicine, University of Alberta, Edmonton, Alberta, Canada.
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13
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Zhou Q, Chowbay B. Effect of coenzyme Q10 on the disposition of doxorubicin in rats. Eur J Drug Metab Pharmacokinet 2002; 27:185-92. [PMID: 12365200 DOI: 10.1007/bf03190456] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
Abstract
The effect of exogenous coenzyme Q10 (CoQ10) on the pharmacokinetic profiles and biliary excretion of doxorubicin and its main metabolites, doxorubicinol and doxorubicinolone, was investigated in rats. No statistically significant changes in the pharmacokinetic parameters of doxorubicin was observed following the intravenous bolus administration of 10 mg/kg doxorubicin to rats during a 6-day oral regimen of CoQ10 (20 mg/kg daily). Treatment with CoQ10 did not affect the formation of the doxorubicinol, but produced a 75% increase (P < 0.05) in the AUC of doxorubicinolone. Correspondingly, CoQ10 had no apparent effect on the biliary excretion of doxorubicin and formation clearance of doxorubicinol, whereas the formation clearance of doxorubicinolone was significantly increased by 69% in CoQ10-pretreated rats (P < 0.05). Overall, the results suggest that CoQ10 treatment has no significant effect on the pharmacokinetics of doxorubicin and the formation of the cytotoxic metabolite, doxorubicinol.
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Affiliation(s)
- Qingyu Zhou
- Clinical Pharmacology Unit, Division of Clinical Trials & Epidemiological Sciences, National Cancer Centre, 11 Hospital Drive, Singapore 169610, Republic of Singapore
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14
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Lyon W, Van den Brink O, Pepe S, Wowk M, Marasco S, Rosenfeldt FL. Similar therapeutic serum levels attained with emulsified and oil-based preparations of coenzyme Q10. Asia Pac J Clin Nutr 2002; 10:212-5. [PMID: 11708311 DOI: 10.1046/j.1440-6047.2001.00244.x] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
Abstract
Studies of the therapeutic efficacy of coenzyme Q10 (CoQ10) have been confounded by the variable bioavailability of numerous CoQ10 preparations. The aims of the present study were to determine the early serum levels attained by two different preparations of CoQ10, a soybean oil-based preparation and a complex micelle emulsion and to assess whether these preparations of oral CoQ10 influence plasma lipid profiles. Twelve healthy individuals received 300 mg CoQ10 daily of either preparation for 7 days in a double-blind cross-over design with a 21-day washout period. Blood samples to determine serum levels of CoQ10 and lipids were taken at baseline, after 24 h and 7 days. Both preparations induced significant increases in serum CoQ10 levels at 24 h and 7 days. These were for soy oil: baseline 0.27 +/- 0.03 mol/L, 24 h 0.50 +/- 0.04 mol/L (180%) and 7 days 0.80 +/- 0.05 mol/L (291%), mean +/- SEM: for emulsion: baseline 0.29 +/- 0.03 mol/L, 24 h 0.45 +/- 0.03 mol/L (150%) and 7 days 0.79 +/- 0.06 mol/L (270%). There were no significant differences between CoQ10 levels for the two preparations at either time point. There was no change in any of the serum lipids following the 7 days treatment. We conclude that administration of either a soy oil suspension or a complex emulsion of CoQ10 increases serum levels to the therapeutic range within 1 week.
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Affiliation(s)
- W Lyon
- Cardiac Surgical Research Unit, Alfred Hospital and Baker Medical Research Institute, Melbourne, Victoria, Australia
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15
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Zhou S, Chan E. Effect of ubidecarenone on warfarin anticoagulation and pharmacokinetics of warfarin enantiomers in rats. DRUG METABOLISM AND DRUG INTERACTIONS 2001; 18:99-122. [PMID: 11460879 DOI: 10.1515/dmdi.2001.18.2.99] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/15/2022]
Abstract
Interaction between the antioxidant ubidecarenone and the oral anticoagulant warfarin enantiomers was investigated in rats. The decreased hypoprothrombinemic response, assessed by means of percent changes of prothrombin complex activity and clotting factor VII activity, to warfarin, was observed following oral administration of 1.5 mg/kg racemic warfarin to rats during an 8-day oral regimen (10 mg/kg daily) of ubidecarenone. The antioxidant had no apparent effect on the in vitro rat serum protein binding of warfarin enantiomers. Treatment with ubidecarenone did not affect the absorption and distribution of the S- and R-enantiomers of warfarin, but produced a significant increase in the total serum clearance values of both R- and S-warfarin in rats. This effect was more pronounced with R-warfarin than with S-warfarin. The increased clearance values are attributable to acceleration of certain metabolic pathways and renal excretion of the warfarin enantiomers.
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Affiliation(s)
- S Zhou
- Department of Pharmacy, National University of Singapore, Republic of Singapore
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16
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Sole MJ, Jeejeebhoy KN. Conditioned nutritional requirements and the pathogenesis and treatment of myocardial failure. Curr Opin Clin Nutr Metab Care 2000; 3:417-24. [PMID: 11085825 DOI: 10.1097/00075197-200011000-00001] [Citation(s) in RCA: 39] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/25/2022]
Abstract
The majority of symptomatic patients with congestive heart failure have been shown to be significantly malnourished. Myocardial and skeletal muscle energy reserves are also diminished. Total daily energy expenditure in these patients is less than that in control individuals, and high protein-calorie feeds do not reverse the abnormalities; thus, the wasting that occurs in patients with congestive heart failure is metabolic rather than because of negative protein-calorie balance. Several specific deficiencies have been found in the failing myocardium: a reduction in the content of L-carnitine, coenzyme Q10, creatine and thiamine, nutrient cofactors that are important for myocardial energy production; a relative deficiency of taurine, an amino acid that is integral to the modulation of intracellular calcium levels; and an increase in myocardial oxidative stress, and a reduction of both endogenous and exogenous antioxidant defences. In addition, these processes may influence skeletal muscle metabolism and function. Cellular nutritional requirements conditioned by metabolic abnormalities in heart failure are important considerations in the pathogenesis of the skeletal and cardiac muscle dysfunction. A comprehensive restoration of adequate myocyte nutrition would seem to be essential to any therapeutic strategy designed to benefit patients suffering from this disease.
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Affiliation(s)
- M J Sole
- Division of Cardiology, Department of Medicine, University of Toronto, Toronto, Ontario, Canada
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17
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Barogi S, Baracca A, Cavazzoni M, Parenti Castelli G, Lenaz G. Effect of the oxidative stress induced by adriamycin on rat hepatocyte bioenergetics during ageing. Mech Ageing Dev 2000; 113:1-21. [PMID: 10708246 DOI: 10.1016/s0047-6374(99)00089-5] [Citation(s) in RCA: 21] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/07/2023]
Abstract
We have investigated the effect of ageing and of adriamycin treatment on the bioenergetics of isolated rat hepatocytes. Ageing per se, whilst being associated with a striking increase of hydrogen peroxide in the cells, induces only minor changes on mitochondrial functions. The adriamycin treatment induces a decrease of the mitochondrial membrane potential in situ and a consistent increase of the superoxide anion cellular content independently of the donor's age, whilst the hydrogen peroxide is significantly higher in aged than in adult rat hepatocytes. Kinetic studies in isolated mitochondria show that the mitochondrial respiratory chain activity (NADH --> O2) of 50 microM adriamycin-treated hepatocytes is lowered both in adult and aged rats. The same adriamycin concentration induces a slight decrease of the maximal rate of ATP hydrolysis in both young and aged rats, without affecting the Km for the substrate. However, at drug concentrations lower than 50 microM, both ATPase and NADH oxidation activities decrease significantly in aged rats only. The results suggest that free radicals increase during ageing in rat hepatocytes but are unable to induce major modifications of mitochondrial bioenergetics. This contrasts with the damaging effect of adriamycin, suggesting that some effects of the drug may be due to other reasons besides oxidative stress.
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Affiliation(s)
- S Barogi
- Dipartimento di Biochimica G. Moruzzi, Università di Bologna, Italy
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18
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Arroyo A, Kagan VE, Tyurin VA, Burgess JR, de Cabo R, Navas P, Villalba JM. NADH and NADPH-dependent reduction of coenzyme Q at the plasma membrane. Antioxid Redox Signal 2000; 2:251-62. [PMID: 11229530 DOI: 10.1089/ars.2000.2.2-251] [Citation(s) in RCA: 27] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/12/2022]
Abstract
High affinity for NADH, and low affinity for NADPH, for reduction of endogenous coenzyme Q10 (CoQ10) by pig liver plasma membrane is reported in the present work. CoQ reduction in plasma membrane is carried out, in addition to other mechanisms, by plasma membrane coenzyme Q reductase (PMQR). We show that PMQR-catalyzed reduction of CoQ0 by both NADH and NADPH is accompanied by generation of CoQ0 semiquinone radicals in a superoxide-dependent reaction. In the presence of a water-soluble vitamin E homologue, Trolox, this reduction leads to quenching of the Trolox phenoxyl radicals. The involvement of PMQR versus DT-diaphorase under the conditions of vitamin E and selenium sufficiency and deficiency was evaluated for CoQ reduction by plasma membranes. The data presented here suggest that both nucleotides (NADH and NADPH) can be accountable for CoQ reduction by PMQR on the basis of their physiological concentrations within the cell. The enzyme is primarily responsible for CoQ reduction in plasma membrane under normal (nonoxidative stress-associated) conditions.
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Affiliation(s)
- A Arroyo
- Departamento de Biología Celular, Fisiología e Immunología, Facultad de Ciencias, Universidad de Córdoba, Spain
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19
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Lenaz G, Fato R, Di Bernardo S, Jarreta D, Costa A, Genova ML, Parenti Castelli G. Localization and mobility of coenzyme Q in lipid bilayers and membranes. Biofactors 1999; 9:87-93. [PMID: 10416019 DOI: 10.1002/biof.5520090202] [Citation(s) in RCA: 61] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
Abstract
We have studied the mobility of coenzyme Q (CoQ) in lipid bilayers and mitochondrial membranes in relation to the control of electron transfer activities. A molecular dynamics computer simulation in the vacuum yielded a folded structure for CoQ10, with a length of only 21 A. Using this information we were able to calculate diffusion coefficients in the range of 10(-6) cm2/s in good agreement with those found experimentally by fluorescence quenching of pyrene derivatives. To investigate if CoQ diffusion may represent the rate-limiting step of electron transfer, we reconstituted complexes I and III and assayed the resulting NADH-cytochrome c reductase activity in presence of different CoQ10 levels and at different distances between complexes; the experimental turnovers were higher than the collision frequencies calculated using diffusion coefficients of 10(-9) cm2/s but compatible with values found by us by fluorescence quenching. Since the experimental turnovers are independent of the distance between complexes, we conclude that CoQ diffusion is not rate-limiting for electron transfer.
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Affiliation(s)
- G Lenaz
- Dipartimento di Biochimica G. Moruzzi, Università di Bologna, Italy.
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20
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Rauchová H, Fato R, Drahota Z, Lenaz G. Steady-state kinetics of reduction of coenzyme Q analogs by glycerol-3-phosphate dehydrogenase in brown adipose tissue mitochondria. Arch Biochem Biophys 1997; 344:235-41. [PMID: 9244403 DOI: 10.1006/abbi.1997.0150] [Citation(s) in RCA: 26] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/04/2023]
Abstract
We have undertaken a study of the role of coenzyme Q (CoQ) in glycerol-3-phosphate oxidation in mitochondrial membranes from hamster brown adipose tissue, using either quinone homologs, as CoQ1 and CoQ2, or the analogs duroquinone and decylubiquinone as artificial electron acceptors. We have found that the most suitable electron acceptor for glycerol-3-phosphate:CoQ reductase activity in situ in the mitochondrial membrane is the homolog CoQ1 yielding the highest rate of enzyme activity (225 +/- 41 nmol x min(-1) x mg(-1) protein). With all acceptors tested the quinone reduction rates were completely insensitive to Complex III inhibitors, indicating that all acceptors were easily accessible to the quinone-binding site of the dehydrogenase preferentially with respect to the endogenous CoQ pool, in such a way that Complex III was kept in the oxidized state. We have also experimentally investigated the saturation kinetics of endogenous CoQ (1.35 nmol/mg protein of a mixture of 70% CoQ9 and 30% CoQ10) by stepwise pentane extraction of brown adipose tissue mitochondria and found a K(m) of the integrated activity of glycerol-3-phosphate cytochrome c reductase for endogenous CoQ of 0.22 nmol/mg protein, indicating that glycerol-3-phosphate-supported respiration is over 80% of V(max) with respect to the CoQ pool. A similar K(m) of 0.19 nmol CoQ/mg protein was found in glycerol-3-phosphate cytochrome c reductase in cockroach flight muscle mitochondria.
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Affiliation(s)
- H Rauchová
- Institute of Physiology, Academy of Sciences of the Czech Republic, Vídenská, Praha
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21
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Estornell E, Tormo JR, Barber T. A deficiency in respiratory complex I in heart mitochondria from vitamin A-deficient rats is counteracted by an increase in coenzyme Q. Biochem Biophys Res Commun 1997; 233:451-4. [PMID: 9144556 DOI: 10.1006/bbrc.1997.6480] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/04/2023]
Abstract
Defects of NADH:coenzyme Q oxidoreductase (complex I) of mitochondria have been described in many congenital and acquired diseases. Administration of coenzyme Q (CoQ, ubiquinone) has been shown to benefit patients with some of these diseases. However, the mechanisms by which CoQ exerts the therapeutic effects are not clearly understood. A reason could be the lack of saturation of CoQ, in kinetic terms, for complex I activity. However, this hypothesis has not been proved in vivo because of the difficulty to incorporate CoQ into the mitochondrial membranes. We have found a deficiency in respiratory complex I in heart mitochondria from vitamin A-deficient rats which was accompanied by high CoQ content. The defect in complex I activity was compensated by the increase in CoQ to maintain the mitochondrial electron transfer rate. This finding supports, for the first time in an in vivo experimental approach, the kinetic hypothesis to explain the short-term therapeutic effects of CoQ.
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Affiliation(s)
- E Estornell
- Departament de Bioquímica i Biologia Molecular, Facultat de Farmàcia,Universitat de València, Burjassot, Spain.
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22
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Lenaz G, Parenti Castelli G, D'Aurelio M, Bovina C, Formiggini G, Marchetti M, Estornell E, Rauchova H. Coenzyme Q deficiency in mitochondria: kinetic saturation versus physical saturation. Mol Aspects Med 1997; 18 Suppl:S25-31. [PMID: 9266503 DOI: 10.1016/s0098-2997(97)00029-0] [Citation(s) in RCA: 23] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/05/2023]
Abstract
The coenzyme Q (CoQ) concentration in the inner membrane of beef heart mitochondria is not kinetically saturating for NADH oxidation inasmuch as the K(m) of NADH oxidation for endogenous CoQ10 is in the mM range in membrane lipids. Using CoQ1 as an electron acceptor from complex I, we have found additional evidence that the high Km of NADH oxidase for CoQ is not an artifact due to the use of organic solvents in reconstitution studies. We have also obtained experimental evidence that CoQ concentration may be rendered more rate-limiting for NADH oxidation either by a decrease of CoQ content (as in liver regeneration or under an acute oxidative stress), or by a possible increase of the Km for CoQ, as in some mitochondrial diseases and ageing. The possibility of enhancing the rate of NADH oxidation by CoQ therapy is hindered by the fact that the CoQ concentration in mitochondria appears to be regulated by its mixability with the membrane phospholipids. Nevertheless CoQ10 incorporated into heart submitochondrial particles by sonication enhances NADH oxidation (but not succinate oxidation) up to twofold. Nontoxic CoQ homologs and analogs having shorter side-chains with respect to CoQ10 can be incorporated in the mitochondrial membrane without sonication, supporting an enhancement of NADH oxidation rate above 'physiological' values. It is worth investigating whether this approach can have a therapeutical value in vivo in mitochondrial bioenergetic disorders.
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Affiliation(s)
- G Lenaz
- Department of Biochemistry G. Moruzzi, Bologna, Italy
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23
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Beyer RE, Segura-Aguilar J, di Bernardo S, Cavazzoni M, Fato R, Fiorentini D, Galli MC, Setti M, Landi L, Lenaz G. The two-electron quinone reductase DT-diaphorase generates and maintains the antioxidant (reduced) form of coenzyme Q in membranes. Mol Aspects Med 1997; 18 Suppl:S15-23. [PMID: 9266502 DOI: 10.1016/s0098-2997(97)00043-5] [Citation(s) in RCA: 29] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/05/2023]
Abstract
The experiments reported here were undertaken to test the hypothesis that the antioxidative, reduced form of hydrophobic phase coenzyme Q (CoQ) may be generated and maintained by the two-electron quinone reductase, DT-diaphorase [NAD(P)H:(quinone-acceptor) oxidoreductase, EC 1.6.99.2] by catalyzing formation of the hydroquinone form of CoQ. This enzyme was isolated and purified from rat liver cytosol and its reduction of several CoQ homologs incorporated into large unilamellar vesicles (LUVETs) was demonstrated. The addition of NADH and DT-diaphorase to LUVETs and to multilamellar vesicles (MLVs) containing CoQ homologs, including CoQ9 and CoQ10, resulted in essentially complete reduction of the CoQ. Incorporation of either CoQ9H2 or CoQ10H2 and the lipophylic radical generator 2,2'-azobis(2,4-dimethylvaleronitrile) (AMVN) into MLVs in the presence of DT-diaphorase and NADH maintained the reduced state of CoQ and inhibited lipid peroxidation. The reaction between DT-diaphorase and CoQ was also demonstrated in isolated rat liver hepatocytes in which incorporation of CoQ10 provided protection from adriamycin (adr)-induced mitochondrial membrane damage. The role of DT-diaphorase in the antioxidant activity of CoQ was demonstrated by the co-incorporation of dicoumarol (dic), a potent inhibitor of DT-diaphorase, resulting in a loss of protection by incorporated CoQ10. These results support the antioxidant function of DT-diaphorase in both artificial and natural membrane systems by acting as a two-electron CoQ reductase which forms and maintains CoQ in the reduced state.
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Affiliation(s)
- R E Beyer
- Department of Biology, University of Michigan, Ann Arbor 48105-1737, USA
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24
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Langsjoen PH, Langsjoen A, Willis R, Folkers K. Treatment of hypertrophic cardiomyopathy with coenzyme Q10. Mol Aspects Med 1997; 18 Suppl:S145-51. [PMID: 9266516 DOI: 10.1016/s0098-2997(97)00006-x] [Citation(s) in RCA: 41] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/05/2023]
Abstract
Hypertrophic cardiomyopathy (HCM) is manifested by severe thickening of the left ventricle with significant diastolic dysfunction. Previous observations on the improvement in diastolic function and left ventricular wall thickness through the therapeutic administration of coenzyme Q10 (CoQ10) in patients with hypertensive heart disease prompted the investigation of its utility in HCM. Seven patients with HCM, six non-obstructive and one obstructive, were treated with an average of 200 mg/day of CoQ10 with mean treatment whole blood CoQ10 level of 2.9 micrograms/ml. Echocardiograms were obtained in all seven patients at baseline and again 3 or more months post-treatment. All patients noted improvement in symptoms of fatigue and dyspnea with no side effects noted. The mean interventricular septal thickness improved significantly from 1.51 +/- 0.17 cm to 1.14 +/- 0.13 cm, a 24% reduction (P < 0.002). The mean posterior wall thickness improved significantly from 1.37 +/- 0.13 cm to 1.01 +/- 0.15 cm, a 26% reduction (P < 0.005). Mitral valve inflow slope by pulsed wave Doppler (EF slope) showed a non-significant trend towards improvement, 1.55 +/- 0.49 m/sec2 to 2.58 +/- 1.18 m/sec2 (P < 0.08). The one patient with subaortic obstruction showed an improvement in resting pressure gradient after CoQ10 treatment (70 mmHg to 30 mmHg).
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25
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Plásek J, Sigler K. Slow fluorescent indicators of membrane potential: a survey of different approaches to probe response analysis. JOURNAL OF PHOTOCHEMISTRY AND PHOTOBIOLOGY. B, BIOLOGY 1996; 33:101-24. [PMID: 8691353 DOI: 10.1016/1011-1344(96)07283-1] [Citation(s) in RCA: 131] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 02/07/2023]
Abstract
Basic tenets related to the use of three main classes of potentiometric redistribution fluorescent dyes (carbocyanines, oxonols, and rhodamines) are discussed in detail. They include the structure/function relationship, formation of nonfluorescent (H-type) and fluorescent (J-type) dimers and higher aggregates, probe partitioning between membranes and medium and binding to membranes and intracellular components (with attendant changes in absorption and emission spectra, fluorescence quantum yield and lifetime). The crucial importance of suitable probe-to-cell concentration ratio and selection of optimum monitored fluorescence wavelength is illustrated in schematic diagrams and possible artifacts or puzzling results stemming from faulty experimental protocol are pointed out. Special attention is paid to procedures used for probe-response calibration (potential clamping by potassium in the presence of valinomycin, use of gramicidin D in combination with N-methylglucamine, activation of Ca-dependent K-channels by A23187, the null-point technique). Among other problems treated are dye toxicity, interaction with mitochondria and other organelles, and possible effects of intracellular pH and the quantity of cytosolic proteins and/or RNA on probe response. Individual techniques using redistribution dyes (fluorescence measurements in cuvettes, flow cytometry and microfluorimetry of individual cells including fluorescence confocal microscopy) are discussed in terms of reliability, limitations and drawbacks, and selection of suitable probes. Up-to-date examples of application of slow dyes illustrate the broad range of problems in which these probes can be used.
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Affiliation(s)
- J Plásek
- Institute of Physics, Charles University, Prague, Czech Republic. ,cz
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26
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Beyer RE, Segura-Aguilar J, Di Bernardo S, Cavazzoni M, Fato R, Fiorentini D, Galli MC, Setti M, Landi L, Lenaz G. The role of DT-diaphorase in the maintenance of the reduced antioxidant form of coenzyme Q in membrane systems. Proc Natl Acad Sci U S A 1996; 93:2528-32. [PMID: 8637908 PMCID: PMC39831 DOI: 10.1073/pnas.93.6.2528] [Citation(s) in RCA: 222] [Impact Index Per Article: 7.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/01/2023] Open
Abstract
The experiments reported here were designed to test the hypothesis that the two-electron quinone reductase DT-diaphorase [NAD(P)H:(quinone-acceptor) oxidoreductase, EC 1.6.99.2] functions to maintain membrane-bound coenzyme Q (CoQ) in its reduced antioxidant state, thereby providing protection from free radical damage. DT-diaphorase was isolated and purified from rat liver cytosol, and its ability to reduce several CoQ homologs incorporated into large unilamellar vesicles was demonstrated. Addition of NADH and DT-diaphorase to either large unilamellar or multilamellar vesicles containing homologs of CoQ, including CoQ9 and CoQ10, resulted in the essentially complete reduction of the CoQ. The ability of DT-diaphorase to maintain the reduced state of CoQ and protect membrane components from free radical damage as lipid peroxidation was tested by incorporating either reduced CoQ9 or CoQ10 and the lipophylic azoinitiator 2,2'-azobis(2,4-dimethylvaleronitrile) into multilamellar vesicles in the presence of NADH and DT-diaphorase. The presence of DT-diaphorase prevented the oxidation of reduced CoQ and inhibited lipid peroxidation. The interaction between DT-diaphorase and CoQ was also demonstrated in an isolated rat liver hepatocyte system. Incubation with adriamycin resulted in mitochondrial membrane damage as measured by membrane potential and the release of hydrogen peroxide. Incorporation of CoQ10 provided protection from adriamycin-induced mitochondrial membrane damage. The incorporation of dicoumarol, a potent inhibitor of DT-diaphorase, interfered with the protection provided by CoQ. The results of these experiments provide support for the hypothesis that DT-diaphorase functions as an antioxidant in both artificial membrane and natural membrane systems by acting as a two-electron CoQ reductase that forms and maintains the antioxidant form of CoQ. The suggestion is offered that DT-diaphorase was selected during evolution to perform this role and that its conversion of xenobiotics and other synthetic molecules is secondary and coincidental.
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Affiliation(s)
- R E Beyer
- Laboratory of Chemical Biology, Department of Biology, University of Michigan, Ann Arbor 48109, USA
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