1
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Abdillah AM, Yun JW. Capsaicin induces ATP-dependent thermogenesis via the activation of TRPV1/β3-AR/α1-AR in 3T3-L1 adipocytes and mouse model. Arch Biochem Biophys 2024; 755:109975. [PMID: 38531438 DOI: 10.1016/j.abb.2024.109975] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/18/2023] [Revised: 03/22/2024] [Accepted: 03/22/2024] [Indexed: 03/28/2024]
Abstract
Capsaicin (CAP) is a natural bioactive compound in chili pepper that activates the transient receptor potential vanilloid subfamily 1 (TRPV1) and is known to stimulate uncoupling protein 1 (UCP1)-dependent thermogenesis. However, its effect on ATP-dependent thermogenesis remains unknown. In this study, we employed qRT-PCR, immunoblot, staining method, and assay kit to investigate the role of CAP on ATP-dependent thermogenesis and its modulatory roles on the TRPV1, β3-adrenergic receptor (β3-AR), and α1-AR using in vitro and in vivo models. The studies showed that CAP treatment in high-fat diet-induced obese mice resulted in lower body weight gain and elevated ATP-dependent thermogenic effectors' protein and gene expression through ATP-consuming calcium and creatine futile cycles. In both in vitro and in vivo experiments, CAP treatment elevated the protein and gene expressions of sarcoendoplasmic/endoplasmic reticulum calcium ATPase 2 (SERCA2), ryanodine receptor 2 (RYR2), creatine kinase B (CKB), and creatine kinase mitochondrial 2 (CKMT2) mediated by the activation of β3-AR, α1-AR, and TRPV1. Our study showed that CAP increased intracellular Ca2+ levels and the expression of voltage-dependent anion channel (VDAC) and mitochondrial calcium uniporter (MCU) which indicates that increased mitochondrial Ca2+ levels lead to increased expression of oxidative phosphorylation protein complexes as a result of ATP-futile cycle activation. A mechanistic study in 3T3-L1 adipocytes revealed that CAP induces UCP1- and ATP-dependent thermogenesis mediated by the β3-AR/PKA/p38MAPK/ERK as well as calcium-dependent α1-AR/TRPV1/CaMKII/AMPK/SIRT1 pathway. Taken together, we identified CAP's novel functional and modulatory roles in UCP1- and ATP-dependent thermogenesis, which is important for developing therapeutic strategies for combating obesity and metabolic diseases.
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Affiliation(s)
- Alfin Mohammad Abdillah
- Department of Biotechnology, Daegu University, Gyeongsan, Gyeongbuk, 38453, Republic of Korea
| | - Jong Won Yun
- Department of Biotechnology, Daegu University, Gyeongsan, Gyeongbuk, 38453, Republic of Korea.
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2
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Nesci S. Proton leak through the UCPs and ANT carriers and beyond: A breath for the electron transport chain. Biochimie 2023; 214:77-85. [PMID: 37336388 DOI: 10.1016/j.biochi.2023.06.008] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/03/2023] [Accepted: 06/16/2023] [Indexed: 06/21/2023]
Abstract
Mitochondria produce heat as a result of an ineffective H+ cycling of mitochondria respiration across the inner mitochondrial membrane (IMM). This event present in all mitochondria, known as proton leak, can decrease protonmotive force (Δp) and restore mitochondrial respiration by partially uncoupling the substrate oxidation from the ADP phosphorylation. During impaired conditions of ATP generation with F1FO-ATPase, the Δp increases and IMM is hyperpolarized. In this bioenergetic state, the respiratory complexes support H+ transport until the membrane potential stops the H+ pump activity. Consequently, the electron transfer is stalled and the reduced form of electron carriers of the respiratory chain can generate O2∙¯ triggering the cascade of ROS formation and oxidative stress. The physiological function to attenuate the production of O2∙¯ by Δp dissipation can be attributed to the proton leak supported by the translocases of IMM.
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Affiliation(s)
- Salvatore Nesci
- Department of Veterinary Medical Sciences, University of Bologna, Ozzano Emilia, 40064, BO, Italy.
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3
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Qi X, Rusch NJ, Fan J, Mora CJ, Xie L, Mu S, Rabinovitch PS, Zhang H. Mitochondrial proton leak in cardiac aging. GeroScience 2023; 45:2135-2143. [PMID: 36856945 PMCID: PMC10651624 DOI: 10.1007/s11357-023-00757-x] [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: 01/10/2023] [Accepted: 02/16/2023] [Indexed: 03/02/2023] Open
Abstract
Age-associated diseases are becoming progressively more prevalent, reflecting the increased lifespan of the world's population. However, the fundamental mechanisms of physiologic aging are poorly understood, and in particular, the molecular pathways that mediate cardiac aging and its associated dysfunction are unclear. Here, we focus on certain ion flux abnormalities of the mitochondria that may contribute to cardiac aging and age-related heart failure. Using oxidative phosphorylation, mitochondria pump protons from the matrix to the intermembrane space to generate a proton gradient across the inner membrane. The protons are returned to the matrix by the ATPase complex within the membrane to generate ATP. However, a portion of protons leak back to the matrix and do not drive ATP production, and this event is called proton leak or uncoupling. Accumulating evidence suggests that mitochondrial proton leak is increased in the cardiac myocytes of aged hearts. In this mini-review, we discuss the measurement methods and major sites of mitochondrial proton leak with an emphasis on the adenine nucleotide transporter 1 (ANT1), and explore the possibility of inhibiting augmented mitochondrial proton leak as a therapeutic intervention to mitigate cardiac aging.
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Affiliation(s)
- Xingyun Qi
- Department of Biology, Rutgers University, Camden, USA
| | - Nancy J Rusch
- Department of Pharmacology and Toxicology, University of Arkansas for Medical Sciences, Little Rock, USA
| | - Jiaojiao Fan
- Department of Pharmacology and Toxicology, University of Arkansas for Medical Sciences, Little Rock, USA
| | - Christoph J Mora
- Department of Pharmacology and Toxicology, University of Arkansas for Medical Sciences, Little Rock, USA
| | - Lixin Xie
- Department of Pharmacology and Toxicology, University of Arkansas for Medical Sciences, Little Rock, USA
| | - Shengyu Mu
- Department of Pharmacology and Toxicology, University of Arkansas for Medical Sciences, Little Rock, USA
| | - Peter S Rabinovitch
- Department of Laboratory Medicine and Pathology, University of Washington, Seattle, USA.
| | - Huiliang Zhang
- Department of Pharmacology and Toxicology, University of Arkansas for Medical Sciences, Little Rock, USA.
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4
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Oflaz FE, Koshenov Z, Hirtl M, Bachkoenig OA, Graier WF, Gottschalk B. Synergy of Uncoupling Proteins (1 and 2) with Mitochondrial Ca2+ Uptake Machinery Potentiate Mitochondrial Uncoupling. Cell Calcium 2023; 112:102736. [PMID: 37031662 DOI: 10.1016/j.ceca.2023.102736] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/06/2023] [Revised: 03/30/2023] [Accepted: 04/04/2023] [Indexed: 04/07/2023]
Abstract
Mitochondrial uncoupling proteins UCP1 and UCP2 have a structural homology of app. 60%. They execute their mitochondria uncoupling function through different molecular mechanisms. Non-shivering thermogenesis by UCP1 is mediated through a transmembrane dissipation of the proton motive force to create heat during sympathetic stimulation. UCP2, on the other hand, modulates through the interaction with methylated MICU1 the permeability of the cristae junction, which acts as an isolator for the cristae-located mitochondrial membrane potential. In this mini-review, we discuss and compare the recently described molecular mechanism of UCP1 in brown adipose tissue and UCP2 in aged and cancer non-excitable cells that contribute to mitochondrial uncoupling, and the synergistic effects of both UCPs with the mitochondrial Ca2+ uptake machinery.
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Affiliation(s)
- Furkan E Oflaz
- Gottfried Schatz Research Center: Molecular Biology and Biochemistry, Medical University of Graz, Neue Stiftingtalstraße 6/4, Graz, 8010 Austria
| | - Zhanat Koshenov
- Gottfried Schatz Research Center: Molecular Biology and Biochemistry, Medical University of Graz, Neue Stiftingtalstraße 6/4, Graz, 8010 Austria
| | - Martin Hirtl
- Gottfried Schatz Research Center: Molecular Biology and Biochemistry, Medical University of Graz, Neue Stiftingtalstraße 6/4, Graz, 8010 Austria
| | - Olaf A Bachkoenig
- Gottfried Schatz Research Center: Molecular Biology and Biochemistry, Medical University of Graz, Neue Stiftingtalstraße 6/4, Graz, 8010 Austria
| | - Wolfgang F Graier
- Gottfried Schatz Research Center: Molecular Biology and Biochemistry, Medical University of Graz, Neue Stiftingtalstraße 6/4, Graz, 8010 Austria; BioTechMed, Graz, Austria.
| | - Benjamin Gottschalk
- Gottfried Schatz Research Center: Molecular Biology and Biochemistry, Medical University of Graz, Neue Stiftingtalstraße 6/4, Graz, 8010 Austria
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5
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Somnay YR, Wang A, Griffiths KK, Levy RJ. Altered Brown Adipose Tissue Mitochondrial Function in Newborn Fragile X Syndrome Mice. Mitochondrion 2022; 65:1-10. [DOI: 10.1016/j.mito.2022.04.003] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/04/2021] [Revised: 03/21/2022] [Accepted: 04/27/2022] [Indexed: 10/18/2022]
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6
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Li Y, Fromme T. Uncoupling Protein 1 Does Not Produce Heat without Activation. Int J Mol Sci 2022; 23:2406. [PMID: 35269549 PMCID: PMC8910648 DOI: 10.3390/ijms23052406] [Citation(s) in RCA: 9] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/27/2022] [Revised: 02/16/2022] [Accepted: 02/18/2022] [Indexed: 12/21/2022] Open
Abstract
Mitochondrial uncoupling protein 1 (UCP1) is the crucial mechanistic component of heat production in classical brown fat and the newly identified beige or brite fat. Thermogenesis inevitably comes at a high energetic cost and brown fat, ultimately, is an energy-wasting organ. A constrained strategy that minimizes brown fat activity unless obligate will have been favored during natural selection to safeguard metabolic thriftiness. Accordingly, UCP1 is constitutively inhibited and is inherently not leaky without activation. It follows that increasing brown adipocyte number or UCP1 abundance genetically or pharmacologically does not lead to an automatic increase in thermogenesis or subsequent metabolic consequences in the absence of a plausible route of concomitant activation. Despite its apparent obviousness, this tenet is frequently ignored. Consequently, incorrect conclusions are often drawn from increased BAT or brite/beige depot mass, e.g., predicting or causally linking beneficial metabolic effects. Here, we highlight the inherently inactive nature of UCP1, with a particular emphasis on the molecular brakes and releases of UCP1 activation under physiological conditions. These controls of UCP1 activity represent potential targets of therapeutic interventions to unlock constraints and efficiently harness the energy-expending potential of brown fat to prevent and treat obesity and associated metabolic disorders.
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Affiliation(s)
- Yongguo Li
- Chair for Molecular Nutritional Medicine, TUM School of Life Sciences, Technical University of Munich, Gregor-Mendel-Str. 2, 85354 Freising, Germany
| | - Tobias Fromme
- Chair for Molecular Nutritional Medicine, TUM School of Life Sciences, Technical University of Munich, Gregor-Mendel-Str. 2, 85354 Freising, Germany
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7
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Abstract
Mitochondria of all tissues convert various metabolic substrates into two forms of energy: ATP and heat. Historically, the primary focus of research in mitochondrial bioenergetics was on the mechanisms of ATP production, while mitochondrial thermogenesis received significantly less attention. Nevertheless, mitochondrial heat production is crucial for the maintenance of body temperature, regulation of the pace of metabolism, and prevention of oxidative damage to mitochondria and the cell. In addition, mitochondrial thermogenesis has gained significance as a pharmacological target for treating metabolic disorders. Mitochondria produce heat as the result of H+ leak across their inner membrane. This review provides a critical assessment of the current field of mitochondrial H+ leak and thermogenesis, with a focus on the molecular mechanisms involved in the function and regulation of uncoupling protein 1 and the ADP/ATP carrier, the two proteins that mediate mitochondrial H+ leak.
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Affiliation(s)
- Ambre M. Bertholet
- Department of Physiology, University of California San Francisco, 600 16 Street, San Francisco, CA 94158, USA,Department of Physiology, David Geffen School of Medicine at UCLA, 10833 Le Conte Avenue, Los Angeles, CA 90095, USA,Corresponding authors: ,
| | - Yuriy Kirichok
- Department of Physiology, University of California, San Francisco, California, USA;
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8
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Brownstein AJ, Veliova M, Acin-Perez R, Liesa M, Shirihai OS. ATP-consuming futile cycles as energy dissipating mechanisms to counteract obesity. Rev Endocr Metab Disord 2022; 23:121-131. [PMID: 34741717 PMCID: PMC8873062 DOI: 10.1007/s11154-021-09690-w] [Citation(s) in RCA: 33] [Impact Index Per Article: 16.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Accepted: 09/24/2021] [Indexed: 12/25/2022]
Abstract
Obesity results from an imbalance in energy homeostasis, whereby excessive energy intake exceeds caloric expenditure. Energy can be dissipated out of an organism by producing heat (thermogenesis), explaining the long-standing interest in exploiting thermogenic processes to counteract obesity. Mitochondrial uncoupling is a process that expends energy by oxidizing nutrients to produce heat, instead of ATP synthesis. Energy can also be dissipated through mechanisms that do not involve mitochondrial uncoupling. Such mechanisms include futile cycles described as metabolic reactions that consume ATP to produce a product from a substrate but then converting the product back into the original substrate, releasing the energy as heat. Energy dissipation driven by cellular ATP demand can be regulated by adjusting the speed and number of futile cycles. Energy consuming futile cycles that are reviewed here are lipolysis/fatty acid re-esterification cycle, creatine/phosphocreatine cycle, and the SERCA-mediated calcium import and export cycle. Their reliance on ATP emphasizes that mitochondrial oxidative function coupled to ATP synthesis, and not just uncoupling, can play a role in thermogenic energy dissipation. Here, we review ATP consuming futile cycles, the evidence for their function in humans, and their potential employment as a strategy to dissipate energy and counteract obesity.
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Affiliation(s)
- Alexandra J Brownstein
- Metabolism Theme, David Geffen School of Medicine, University of California, Los Angeles, CA, 90095, USA
- Molecular Cellular Integrative Physiology Interdepartmental Program, University of California, Los Angeles, CA, 90095, USA
| | - Michaela Veliova
- Metabolism Theme, David Geffen School of Medicine, University of California, Los Angeles, CA, 90095, USA
- Department of Molecular and Medical Pharmacology, David Geffen School of Medicine, University of California, Los Angeles, CA, 90095, USA
- Department of Medicine, Division of Endocrinology, David Geffen School of Medicine, University of California, Los Angeles, CA, 90095, USA
| | - Rebeca Acin-Perez
- Metabolism Theme, David Geffen School of Medicine, University of California, Los Angeles, CA, 90095, USA
- Department of Medicine, Division of Endocrinology, David Geffen School of Medicine, University of California, Los Angeles, CA, 90095, USA
| | - Marc Liesa
- Metabolism Theme, David Geffen School of Medicine, University of California, Los Angeles, CA, 90095, USA
- Molecular Cellular Integrative Physiology Interdepartmental Program, University of California, Los Angeles, CA, 90095, USA
- Department of Molecular and Medical Pharmacology, David Geffen School of Medicine, University of California, Los Angeles, CA, 90095, USA
- Department of Medicine, Division of Endocrinology, David Geffen School of Medicine, University of California, Los Angeles, CA, 90095, USA
- Molecular Biology Institute, University of California, Los Angeles, CA, 90095, USA
| | - Orian S Shirihai
- Metabolism Theme, David Geffen School of Medicine, University of California, Los Angeles, CA, 90095, USA.
- Molecular Cellular Integrative Physiology Interdepartmental Program, University of California, Los Angeles, CA, 90095, USA.
- Department of Molecular and Medical Pharmacology, David Geffen School of Medicine, University of California, Los Angeles, CA, 90095, USA.
- Department of Medicine, Division of Endocrinology, David Geffen School of Medicine, University of California, Los Angeles, CA, 90095, USA.
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9
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Figueira TR, Francisco A, Ronchi JA, Dos Santos GRRM, Santos WD, Treberg JR, Castilho RF. NADPH supply and the contribution of NAD(P) + transhydrogenase (NNT) to H 2O 2 balance in skeletal muscle mitochondria. Arch Biochem Biophys 2021; 707:108934. [PMID: 34043997 DOI: 10.1016/j.abb.2021.108934] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/26/2020] [Revised: 04/27/2021] [Accepted: 05/19/2021] [Indexed: 10/21/2022]
Abstract
H2O2 is endogenously generated and its removal in the matrix of skeletal muscle mitochondria (SMM) is dependent on NADPH likely provided by NAD(P)+ transhydrogenase (NNT) and isocitrate dehydrogenase (IDH2). Importantly, NNT activity is linked to mitochondrial protonmotive force. Here, we demonstrate the presence of NNT function in detergent-solubilized and intact functional SMM isolated from rats and wild type (Nnt+/+) mice, but not in SMM from congenic mice carrying a mutated NNT gene (Nnt-/-). Further comparisons between SMM from both Nnt mouse genotypes revealed that the NADPH supplied by NNT supports up to 600 pmol/mg/min of H2O2 removal under selected conditions. Surprisingly, SMM from Nnt-/- mice removed exogenous H2O2 at wild-type levels and exhibited a maintained or even decreased net emission of endogenous H2O2 when substrates that support Krebs cycle reactions were present (e.g., pyruvate plus malate or palmitoylcarnitine plus malate). These results may be explained by a compensation for the lack of NNT, since the total activities of concurrent NADP+-reducing enzymes (IDH2, malic enzymes and glutamate dehydrogenase) were ~70% elevated in Nnt-/- mice. Importantly, respiratory rates were similar between SMM from both Nnt genotypes despite differing NNT contributions to H2O2 removal and their implications for an evolving concept in the literature are discussed. We concluded that NNT is capable of meaningfully sustaining NADPH-dependent H2O2 removal in intact SMM. Nonetheless, if the available substrates favor non-NNT sources of NADPH, the H2O2 removal by SMM is maintained in Nnt-/- mice SMM.
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Affiliation(s)
- Tiago R Figueira
- Department of Pathology, Faculty of Medical Sciences, University of Campinas (UNICAMP), Rua Tessália Vieira de Camargo, 126, 13083-887, Campinas, SP, Brazil.
| | - Annelise Francisco
- Department of Pathology, Faculty of Medical Sciences, University of Campinas (UNICAMP), Rua Tessália Vieira de Camargo, 126, 13083-887, Campinas, SP, Brazil
| | - Juliana A Ronchi
- Department of Pathology, Faculty of Medical Sciences, University of Campinas (UNICAMP), Rua Tessália Vieira de Camargo, 126, 13083-887, Campinas, SP, Brazil
| | - Guilherme R R M Dos Santos
- Department of Pathology, Faculty of Medical Sciences, University of Campinas (UNICAMP), Rua Tessália Vieira de Camargo, 126, 13083-887, Campinas, SP, Brazil
| | - William Dos Santos
- Department of Biological Sciences, University of Manitoba, General Office 212B Bio-Sci Bldg., R3T 2N2, Winnipeg, MB, Canada
| | - Jason R Treberg
- Department of Biological Sciences, University of Manitoba, General Office 212B Bio-Sci Bldg., R3T 2N2, Winnipeg, MB, Canada; Centre on Aging, University of Manitoba, Winnipeg, MB, Canada
| | - Roger F Castilho
- Department of Pathology, Faculty of Medical Sciences, University of Campinas (UNICAMP), Rua Tessália Vieira de Camargo, 126, 13083-887, Campinas, SP, Brazil
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10
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Nicholls DG. Mitochondrial proton leaks and uncoupling proteins. BIOCHIMICA ET BIOPHYSICA ACTA-BIOENERGETICS 2021; 1862:148428. [PMID: 33798544 DOI: 10.1016/j.bbabio.2021.148428] [Citation(s) in RCA: 58] [Impact Index Per Article: 19.3] [Reference Citation Analysis] [Abstract] [Key Words] [Subscribe] [Scholar Register] [Received: 01/27/2021] [Revised: 03/15/2021] [Accepted: 03/25/2021] [Indexed: 01/02/2023]
Abstract
Non-shivering thermogenesis in brown adipose tissue is mediated by uncoupling protein 1 (UCP1), which provides a carefully regulated proton re-entry pathway across the mitochondrial inner membrane operating in parallel to the ATP synthase and allowing respiration, and hence thermogenesis, to be released from the constraints of respiratory control. In the 40 years since UCP1 was first described, an extensive, and frequently contradictory, literature has accumulated, focused on the acute physiological regulation of the protein by fatty acids, purine nucleotides and possible additional factors. The purpose of this review is to examine, in detail, the experimental evidence underlying these proposed mechanisms. Emphasis will be placed on the methodologies employed and their relation to the physiological constraints under which the protein functions in the intact cell. The nature of the endogenous, UCP1-independent, proton leak will also be discussed. Finally, the troubled history of the putative novel uncoupling proteins, UCP2 and UCP3, will be evaluated.
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11
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Smith CD, Schmidt CA, Fisher-Wellman KH, Neufer PD. Reply to Figueira et al.: Can NAD(P) + transhydrogenase (NNT) mediate a physiologically meaningful increase in energy expenditure by mitochondria during H 2O 2 removal? J Biol Chem 2021; 296:100378. [PMID: 33837732 PMCID: PMC7988312 DOI: 10.1016/j.jbc.2021.100378] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/02/2021] [Accepted: 02/02/2021] [Indexed: 11/28/2022] Open
Affiliation(s)
- Cody D Smith
- East Carolina Diabetes and Obesity Institute, East Carolina University, Greenville, North Carolina, USA; Department of Physiology, Brody School of Medicine, East Carolina University, Greenville, North Carolina, USA
| | - Cameron A Schmidt
- East Carolina Diabetes and Obesity Institute, East Carolina University, Greenville, North Carolina, USA; Department of Physiology, Brody School of Medicine, East Carolina University, Greenville, North Carolina, USA
| | - Kelsey H Fisher-Wellman
- East Carolina Diabetes and Obesity Institute, East Carolina University, Greenville, North Carolina, USA; Department of Physiology, Brody School of Medicine, East Carolina University, Greenville, North Carolina, USA
| | - P Darrell Neufer
- East Carolina Diabetes and Obesity Institute, East Carolina University, Greenville, North Carolina, USA; Department of Physiology, Brody School of Medicine, East Carolina University, Greenville, North Carolina, USA.
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12
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Figueira TR, Francisco A, Treberg JR, Castilho RF. Can NAD(P) + transhydrogenase (NNT) mediate a physiologically meaningful increase in energy expenditure by mitochondria during H 2O 2 removal? J Biol Chem 2021; 296:100377. [PMID: 33837731 PMCID: PMC7948320 DOI: 10.1016/j.jbc.2021.100377] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/07/2020] [Revised: 02/02/2021] [Accepted: 02/02/2021] [Indexed: 11/22/2022] Open
Affiliation(s)
- Tiago R Figueira
- School of Physical Education and Sport of Ribeirão Preto, University of São Paulo (USP), Ribeirão Preto, Brazil; Department of Pathology, Faculty of Medical Sciences, University of Campinas (UNICAMP), Campinas, Brazil.
| | - Annelise Francisco
- Department of Pathology, Faculty of Medical Sciences, University of Campinas (UNICAMP), Campinas, Brazil
| | - Jason R Treberg
- Department of Biological Sciences, University of Manitoba, Winnipeg, Manitoba, Canada; Centre on Aging, University of Manitoba, Winnipeg, Manitoba, Canada
| | - Roger F Castilho
- Department of Pathology, Faculty of Medical Sciences, University of Campinas (UNICAMP), Campinas, Brazil
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13
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Hass DT, Barnstable CJ. Uncoupling proteins in the mitochondrial defense against oxidative stress. Prog Retin Eye Res 2021; 83:100941. [PMID: 33422637 DOI: 10.1016/j.preteyeres.2021.100941] [Citation(s) in RCA: 47] [Impact Index Per Article: 15.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/21/2020] [Revised: 12/28/2020] [Accepted: 01/03/2021] [Indexed: 02/06/2023]
Abstract
Oxidative stress is a major component of most major retinal diseases. Many extrinsic anti-oxidative strategies have been insufficient at counteracting one of the predominant intrinsic sources of reactive oxygen species (ROS), mitochondria. The proton gradient across the inner mitochondrial membrane is a key driving force for mitochondrial ROS production, and this gradient can be modulated by members of the mitochondrial uncoupling protein (UCP) family. Of the UCPs, UCP2 shows a widespread distribution and has been shown to uncouple oxidative phosphorylation, with concomitant decreases in ROS production. Genetic studies using transgenic and knockout mice have documented the ability of increased UCP2 activity to provide neuroprotection in models of a number of diseases, including retinal diseases, indicating that it is a strong candidate for a therapeutic target. Molecular studies have identified the structural mechanism of action of UCP2 and have detailed the ways in which its expression and activity can be controlled at the transcriptional, translational and posttranslational levels. These studies suggest a number of ways in control of UCP2 expression and activity can be used therapeutically for both acute and chronic conditions. The development of such therapeutic approaches will greatly increase the tools available to combat a broad range of serious retinal diseases.
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Affiliation(s)
- Daniel T Hass
- Department of Biochemistry, The University of Washington, Seattle, WA, 98109, USA
| | - Colin J Barnstable
- Department of Neural and Behavioral Sciences, The Pennsylvania State University, Hershey, PA, 17033, USA.
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14
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Thermogenic adipocytes: lineage, function and therapeutic potential. Biochem J 2020; 477:2071-2093. [PMID: 32539124 PMCID: PMC7293110 DOI: 10.1042/bcj20200298] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/20/2020] [Revised: 05/13/2020] [Accepted: 05/15/2020] [Indexed: 12/12/2022]
Abstract
Metabolic inflexibility, defined as the inability to respond or adapt to metabolic demand, is now recognised as a driving factor behind many pathologies associated with obesity and the metabolic syndrome. Adipose tissue plays a pivotal role in the ability of an organism to sense, adapt to and counteract environmental changes. It provides a buffer in times of nutrient excess, a fuel reserve during starvation and the ability to resist cold-stress through non-shivering thermogenesis. Recent advances in single-cell RNA sequencing combined with lineage tracing, transcriptomic and proteomic analyses have identified novel adipocyte progenitors that give rise to specialised adipocytes with diverse functions, some of which have the potential to be exploited therapeutically. This review will highlight the common and distinct functions of well-known adipocyte populations with respect to their lineage and plasticity, as well as introducing the most recent members of the adipocyte family and their roles in whole organism energy homeostasis. Finally, this article will outline some of the more preliminary findings from large data sets generated by single-cell transcriptomics of mouse and human adipose tissue and their implications for the field, both for discovery and for therapy.
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15
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Rodríguez-Cano MM, González-Gómez MJ, Sánchez-Solana B, Monsalve EM, Díaz-Guerra MJM, Laborda J, Nueda ML, Baladrón V. NOTCH Receptors and DLK Proteins Enhance Brown Adipogenesis in Mesenchymal C3H10T1/2 Cells. Cells 2020; 9:cells9092032. [PMID: 32899774 PMCID: PMC7565505 DOI: 10.3390/cells9092032] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/25/2020] [Revised: 08/27/2020] [Accepted: 09/03/2020] [Indexed: 12/26/2022] Open
Abstract
The NOTCH family of receptors and ligands is involved in numerous cell differentiation processes, including adipogenesis. We recently showed that overexpression of each of the four NOTCH receptors in 3T3-L1 preadipocytes enhances adipogenesis and modulates the acquisition of the mature adipocyte phenotype. We also revealed that DLK proteins modulate the adipogenesis of 3T3-L1 preadipocytes and mesenchymal C3H10T1/2 cells in an opposite way, despite their function as non-canonical inhibitory ligands of NOTCH receptors. In this work, we used multipotent C3H10T1/2 cells as an adipogenic model. We used standard adipogenic procedures and analyzed different parameters by using quantitative-polymerase chain reaction (qPCR), quantitative reverse transcription-polymerase chain reaction (qRT-PCR), luciferase, Western blot, and metabolic assays. We revealed that C3H10T1/2 multipotent cells show higher levels of NOTCH receptors expression and activity and lower Dlk gene expression levels than 3T3-L1 preadipocytes. We found that the overexpression of NOTCH receptors enhanced C3H10T1/2 adipogenesis levels, and the overexpression of NOTCH receptors and DLK (DELTA-like homolog) proteins modulated the conversion of cells towards a brown-like adipocyte phenotype. These and our prior results with 3T3-L1 preadipocytes strengthen the idea that, depending on the cellular context, a precise and highly regulated level of global NOTCH signaling is necessary to allow adipogenesis and determine the mature adipocyte phenotype.
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Affiliation(s)
- María-Milagros Rodríguez-Cano
- Departamento de Química Inorgánica, Laboratorio de Bioquímica y Biología Molecular, Facultad de Farmacia/CRIB/Unidad de Biomedicina, Orgánica y Bioquímica, Universidad de Castilla-La Mancha/CSIC, C/Almansa 14, 02008 Albacete, Spain; (M.-M.R.-C.); (M.-J.G.-G.)
| | - María-Julia González-Gómez
- Departamento de Química Inorgánica, Laboratorio de Bioquímica y Biología Molecular, Facultad de Farmacia/CRIB/Unidad de Biomedicina, Orgánica y Bioquímica, Universidad de Castilla-La Mancha/CSIC, C/Almansa 14, 02008 Albacete, Spain; (M.-M.R.-C.); (M.-J.G.-G.)
| | - Beatriz Sánchez-Solana
- National Institutes of Health, Laboratory of Cellular Oncology, Center for Cancer Research, National Cancer Institute, Bethesda, MD 20892, USA;
| | - Eva-María Monsalve
- Departamento de Química Inorgánica, Laboratorio de Bioquímica y Biología Molecular, Facultad de Medicina de Albacete/CRIB/Unidad de Biomedicina, Orgánica y Bioquímica, Universidad de Castilla-La Mancha/CSIC, C/Almansa 14, 02008 Albacete, Spain; (E.-M.M.); (M.-J.M.D.-G.)
| | - María-José M. Díaz-Guerra
- Departamento de Química Inorgánica, Laboratorio de Bioquímica y Biología Molecular, Facultad de Medicina de Albacete/CRIB/Unidad de Biomedicina, Orgánica y Bioquímica, Universidad de Castilla-La Mancha/CSIC, C/Almansa 14, 02008 Albacete, Spain; (E.-M.M.); (M.-J.M.D.-G.)
| | - Jorge Laborda
- Departamento de Química Inorgánica, Laboratorio de Bioquímica y Biología Molecular, Facultad de Farmacia/CRIB/Unidad de Biomedicina, Orgánica y Bioquímica, Universidad de Castilla-La Mancha/CSIC, C/Almansa 14, 02008 Albacete, Spain; (M.-M.R.-C.); (M.-J.G.-G.)
- Correspondence: (J.L.); (M.-L.N.); (V.B.); Tel.: +34-967-599-200 (ext. 2926) (V.B.); Fax: +34-967-599-327 (V.B.)
| | - María-Luisa Nueda
- Departamento de Química Inorgánica, Laboratorio de Bioquímica y Biología Molecular, Facultad de Farmacia/CRIB/Unidad de Biomedicina, Orgánica y Bioquímica, Universidad de Castilla-La Mancha/CSIC, C/Almansa 14, 02008 Albacete, Spain; (M.-M.R.-C.); (M.-J.G.-G.)
- Correspondence: (J.L.); (M.-L.N.); (V.B.); Tel.: +34-967-599-200 (ext. 2926) (V.B.); Fax: +34-967-599-327 (V.B.)
| | - Victoriano Baladrón
- Departamento de Química Inorgánica, Laboratorio de Bioquímica y Biología Molecular, Facultad de Medicina de Albacete/CRIB/Unidad de Biomedicina, Orgánica y Bioquímica, Universidad de Castilla-La Mancha/CSIC, C/Almansa 14, 02008 Albacete, Spain; (E.-M.M.); (M.-J.M.D.-G.)
- Correspondence: (J.L.); (M.-L.N.); (V.B.); Tel.: +34-967-599-200 (ext. 2926) (V.B.); Fax: +34-967-599-327 (V.B.)
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Berry BJ, Wojtovich AP. Mitochondrial light switches: optogenetic approaches to control metabolism. FEBS J 2020; 287:4544-4556. [PMID: 32459870 DOI: 10.1111/febs.15424] [Citation(s) in RCA: 14] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/28/2020] [Revised: 05/11/2020] [Accepted: 05/20/2020] [Indexed: 02/06/2023]
Abstract
Developing new technologies to study metabolism is increasingly important as metabolic disease prevalence increases. Mitochondria control cellular metabolism and dynamic changes in mitochondrial function are associated with metabolic abnormalities in cardiovascular disease, cancer, and obesity. However, a lack of precise and reversible methods to control mitochondrial function has prevented moving from association to causation. Recent advances in optogenetics have addressed this challenge, and mitochondrial function can now be precisely controlled in vivo using light. A class of genetically encoded, light-activated membrane channels and pumps has addressed mechanistic questions that promise to provide new insights into how cellular metabolism downstream of mitochondrial function contributes to disease. Here, we highlight emerging reagents-mitochondria-targeted light-activated cation channels or proton pumps-to decrease or increase mitochondrial activity upon light exposure, a technique we refer to as mitochondrial light switches, or mtSWITCH . The mtSWITCH technique is broadly applicable, as energy availability and metabolic signaling are conserved aspects of cellular function and health. Here, we outline the use of these tools in diverse cellular models of disease. We review the molecular details of each optogenetic tool, summarize the results obtained with each, and outline best practices for using optogenetic approaches to control mitochondrial function and downstream metabolism.
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Affiliation(s)
- Brandon J Berry
- Department of Pharmacology and Physiology, University of Rochester Medical Center, NY, USA
| | - Andrew P Wojtovich
- Department of Anesthesiology and Perioperative Medicine, University of Rochester Medical Center, NY, USA
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17
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Johnson JM, Verkerke ARP, Maschek JA, Ferrara PJ, Lin CT, Kew KA, Neufer PD, Lodhi IJ, Cox JE, Funai K. Alternative splicing of UCP1 by non-cell-autonomous action of PEMT. Mol Metab 2020; 31:55-66. [PMID: 31918922 PMCID: PMC6889607 DOI: 10.1016/j.molmet.2019.10.007] [Citation(s) in RCA: 9] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/16/2019] [Revised: 10/14/2019] [Accepted: 10/30/2019] [Indexed: 12/12/2022] Open
Abstract
OBJECTIVE Phosphatidylethanolamine methyltransferase (PEMT) generates phosphatidylcholine (PC), the most abundant phospholipid in the mitochondria and an important acyl chain donor for cardiolipin (CL) biosynthesis. Mice lacking PEMT (PEMTKO) are cold-intolerant when fed a high-fat diet (HFD) due to unclear mechanisms. The purpose of this study was to determine whether PEMT-derived phospholipids are important for the function of uncoupling protein 1 (UCP1) and thus for maintenance of core temperature. METHODS To test whether PEMT-derived phospholipids are important for UCP1 function, we examined cold-tolerance and brown adipose (BAT) mitochondria from PEMTKO mice with or without HFD feeding. We complemented these studies with experiments on mice lacking functional CL due to tafazzin knockdown (TAZKD). We generated several conditional mouse models to study the tissue-specific roles of PEMT, including mice with BAT-specific knockout of PEMT (PEMT-BKO). RESULTS Chow- and HFD-fed PEMTKO mice completely lacked UCP1 protein in BAT, despite a lack of difference in mRNA levels, and the mice were accordingly cold-intolerant. While HFD-fed PEMTKO mice exhibited reduced mitochondrial CL content, this was not observed in chow-fed PEMTKO mice or TAZKD mice, indicating that the lack of UCP1 was not attributable to CL deficiency. Surprisingly, the PEMT-BKO mice exhibited normal UCP1 protein levels. Knockout of PEMT in the adipose tissue (PEMT-AKO), liver (PEMT-LKO), or skeletal muscle (PEMT-MKO) also did not affect UCP1 protein levels, suggesting that lack of PEMT in other non-UCP1-expressing cells communicates to BAT to suppress UCP1. Instead, we identified an untranslated UCP1 splice variant that was triggered during the perinatal period in the PEMTKO mice. CONCLUSIONS PEMT is required for UCP1 splicing that yields functional protein. This effect is derived by PEMT in nonadipocytes that communicates to BAT during embryonic development. Future research will focus on identifying the non-cell-autonomous PEMT-dependent mechanism of UCP1 splicing.
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Affiliation(s)
- Jordan M Johnson
- Diabetes & Metabolism Research Center, University of Utah, 15 N. 2030 E, Salt Lake City, UT, 84112, USA; Department of Nutrition & Integrative Physiology, University of Utah, 250 S. 1850 E., RM 214, Salt Lake City, UT, 84112, USA; Department of Physical Therapy & Athletic Training, University of Utah, 520 Wakara Way, Salt Lake City, UT, 84108, USA; East Carolina Diabetes & Obesity Institute, East Carolina University, 115 Heart Drive, 4101 ECHI, Greenville, NC, 27834, USA
| | - Anthony R P Verkerke
- Diabetes & Metabolism Research Center, University of Utah, 15 N. 2030 E, Salt Lake City, UT, 84112, USA; Department of Nutrition & Integrative Physiology, University of Utah, 250 S. 1850 E., RM 214, Salt Lake City, UT, 84112, USA; Department of Physical Therapy & Athletic Training, University of Utah, 520 Wakara Way, Salt Lake City, UT, 84108, USA; East Carolina Diabetes & Obesity Institute, East Carolina University, 115 Heart Drive, 4101 ECHI, Greenville, NC, 27834, USA
| | - J Alan Maschek
- Diabetes & Metabolism Research Center, University of Utah, 15 N. 2030 E, Salt Lake City, UT, 84112, USA; Metabolomics Core Research Facility, University of Utah, 15 N. Medical Dr. East RM A306, Salt Lake City, UT, 84112, USA; Department of Biochemistry, University of Utah, 15 N. Medical Dr. East RM 4100, Salt Lake City, UT, 84112, USA
| | - Patrick J Ferrara
- Diabetes & Metabolism Research Center, University of Utah, 15 N. 2030 E, Salt Lake City, UT, 84112, USA; Department of Nutrition & Integrative Physiology, University of Utah, 250 S. 1850 E., RM 214, Salt Lake City, UT, 84112, USA; Department of Physical Therapy & Athletic Training, University of Utah, 520 Wakara Way, Salt Lake City, UT, 84108, USA; East Carolina Diabetes & Obesity Institute, East Carolina University, 115 Heart Drive, 4101 ECHI, Greenville, NC, 27834, USA
| | - Chien-Te Lin
- East Carolina Diabetes & Obesity Institute, East Carolina University, 115 Heart Drive, 4101 ECHI, Greenville, NC, 27834, USA
| | - Kimberly A Kew
- East Carolina Diabetes & Obesity Institute, East Carolina University, 115 Heart Drive, 4101 ECHI, Greenville, NC, 27834, USA; Department of Chemistry, East Carolina University, Greenville, NC, 27858, USA
| | - P Darrell Neufer
- East Carolina Diabetes & Obesity Institute, East Carolina University, 115 Heart Drive, 4101 ECHI, Greenville, NC, 27834, USA
| | - Irfan J Lodhi
- Division of Endocrinology, Metabolism and Lipid Research, Washington University School of Medicine, 660 S. Euclid Ave, St. Louis, MO, 63110, USA
| | - James E Cox
- Diabetes & Metabolism Research Center, University of Utah, 15 N. 2030 E, Salt Lake City, UT, 84112, USA; Metabolomics Core Research Facility, University of Utah, 15 N. Medical Dr. East RM A306, Salt Lake City, UT, 84112, USA; Department of Biochemistry, University of Utah, 15 N. Medical Dr. East RM 4100, Salt Lake City, UT, 84112, USA
| | - Katsuhiko Funai
- Diabetes & Metabolism Research Center, University of Utah, 15 N. 2030 E, Salt Lake City, UT, 84112, USA; Department of Nutrition & Integrative Physiology, University of Utah, 250 S. 1850 E., RM 214, Salt Lake City, UT, 84112, USA; Department of Physical Therapy & Athletic Training, University of Utah, 520 Wakara Way, Salt Lake City, UT, 84108, USA; East Carolina Diabetes & Obesity Institute, East Carolina University, 115 Heart Drive, 4101 ECHI, Greenville, NC, 27834, USA; Molecular Medicine Program, University of Utah, 15 N. 2030 E. RM 4145, Salt Lake City, UT, 84112, USA.
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Novel discovery of Averrhoa bilimbi ethanolic leaf extract in the stimulation of brown fat differentiation program in combating diet-induced obesity. Altern Ther Health Med 2019; 19:243. [PMID: 31488120 PMCID: PMC6727514 DOI: 10.1186/s12906-019-2640-3] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/07/2018] [Accepted: 08/14/2019] [Indexed: 01/06/2023]
Abstract
BACKGROUND Brown adipocytes are known to promote energy expenditure and limit weight gain to combat obesity. Averrhoa bilimbi, locally called belimbing buluh (DBB), is mainly used as an ethnomedicine in the treatment of metabolic disorders including diabetes mellitus, hypertension and obesity. The present study aims to investigate the browning activity on white adipocytes by A. bilimbi leaf extract and to evaluate the potential mechanisms. METHODS Ethanolic leaf extract of A. bilimbi was exposed to Myf5 lineage precursor cells to stimulate adipocyte differentiation. Protein expressions of brown adipocyte markers were determined through high content screening analysis and validated through western blotting. Mito Stress Test assay was conducted to evaluate the cellular oxygen consumption rate upon A. bilimbi treatment. RESULTS A. bilimbi ethanolic leaf extract exhibited an adipogenesis effect similar to a PPARgamma agonist. It also demonstrated brown adipocyte differentiation in myoblastic Myf5-positive precursor cells. Expression of UCP1 and PRDM16 were induced. The basal metabolic rate and respiratory capacity of mitochondria were increased upon A. bilimbi treatment. CONCLUSIONS The findings suggest that Averrhoa bilimbi ethanolic leaf extract induces adipocyte browning through PRDM16 activation and enhances mitochondria activity due to UCP1 up-regulation.
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19
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Park KA, Jin Z, An HS, Lee JY, Jeong EA, Choi EB, Kim KE, Shin HJ, Lee JE, Roh GS. Effects of caloric restriction on the expression of lipocalin-2 and its receptor in the brown adipose tissue of high-fat diet-fed mice. THE KOREAN JOURNAL OF PHYSIOLOGY & PHARMACOLOGY : OFFICIAL JOURNAL OF THE KOREAN PHYSIOLOGICAL SOCIETY AND THE KOREAN SOCIETY OF PHARMACOLOGY 2019; 23:335-344. [PMID: 31496871 PMCID: PMC6717793 DOI: 10.4196/kjpp.2019.23.5.335] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 05/02/2019] [Revised: 06/25/2019] [Accepted: 07/09/2019] [Indexed: 01/15/2023]
Abstract
Obesity causes inflammation and impairs thermogenic functions in brown adipose tissue (BAT). The adipokine lipocalin 2 (LCN2) has been implicated in inflammation and obesity. Herein, we investigated the protective effects of caloric restriction (CR) on LCN2-mediated inflammation and oxidative stress in the BAT of high-fat diet (HFD)-fed mice. Mice were fed a HFD for 20 weeks and then either continued on the HFD or subjected to CR for the next 12 weeks. CR led to the browning of the white fat-like phenotype in HFD-fed mice. Increased expressions of LCN2 and its receptor in the BAT of HFD-fed mice were significantly attenuated by CR. Additionally, HFD+CR-fed mice had fewer neutrophils and macrophages expressing LCN2 and iron-positive cells than HFD-fed mice. Further, oxidative stress and mitochondrial fission induced by a HFD were also significantly attenuated by CR. Our findings indicate that the protective effects of CR on inflammation and oxidative stress in the BAT of obese mice may be associated with regulation of LCN2.
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Affiliation(s)
- Kyung-Ah Park
- Department of Anatomy and Convergence Medical Science, Bio Anti-Aging Medical Research Center, Institute of Health Sciences, College of Medicine, Gyeongsang National University, Jinju 52727, Korea
| | - Zhen Jin
- Department of Anatomy and Convergence Medical Science, Bio Anti-Aging Medical Research Center, Institute of Health Sciences, College of Medicine, Gyeongsang National University, Jinju 52727, Korea
| | - Hyeong Seok An
- Department of Anatomy and Convergence Medical Science, Bio Anti-Aging Medical Research Center, Institute of Health Sciences, College of Medicine, Gyeongsang National University, Jinju 52727, Korea
| | - Jong Youl Lee
- Department of Anatomy and Convergence Medical Science, Bio Anti-Aging Medical Research Center, Institute of Health Sciences, College of Medicine, Gyeongsang National University, Jinju 52727, Korea
| | - Eun Ae Jeong
- Department of Anatomy and Convergence Medical Science, Bio Anti-Aging Medical Research Center, Institute of Health Sciences, College of Medicine, Gyeongsang National University, Jinju 52727, Korea
| | - Eun Bee Choi
- Department of Anatomy and Convergence Medical Science, Bio Anti-Aging Medical Research Center, Institute of Health Sciences, College of Medicine, Gyeongsang National University, Jinju 52727, Korea
| | - Kyung Eun Kim
- Department of Anatomy and Convergence Medical Science, Bio Anti-Aging Medical Research Center, Institute of Health Sciences, College of Medicine, Gyeongsang National University, Jinju 52727, Korea
| | - Hyun Joo Shin
- Department of Anatomy and Convergence Medical Science, Bio Anti-Aging Medical Research Center, Institute of Health Sciences, College of Medicine, Gyeongsang National University, Jinju 52727, Korea
| | - Jung Eun Lee
- Department of Thoracic and Cardiovascular Surgery, Institute of Health Sciences, College of Medicine, Gyeongsang National University, Jinju 52727, Korea
| | - Gu Seob Roh
- Department of Anatomy and Convergence Medical Science, Bio Anti-Aging Medical Research Center, Institute of Health Sciences, College of Medicine, Gyeongsang National University, Jinju 52727, Korea
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Tews D, Pula T, Funcke JB, Jastroch M, Keuper M, Debatin KM, Wabitsch M, Fischer-Posovszky P. Elevated UCP1 levels are sufficient to improve glucose uptake in human white adipocytes. Redox Biol 2019; 26:101286. [PMID: 31382214 PMCID: PMC6692062 DOI: 10.1016/j.redox.2019.101286] [Citation(s) in RCA: 28] [Impact Index Per Article: 5.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/06/2019] [Revised: 07/08/2019] [Accepted: 07/26/2019] [Indexed: 01/02/2023] Open
Abstract
Brown adipose tissue (BAT) has been considered beneficial for metabolic health by participating in the regulation of glucose homoeostasis. The browning factors that improve glucose uptake beyond normal levels are still unknown but glucose uptake is not affected in UCP1 knockout mice. Here, we demonstrate in human white adipocytes that basal/resting glucose uptake is improved by solely elevating UCP1 protein levels. Generating human white Simpson-Golabi-Behmel syndrome (SGBS) adipocytes with a stable knockout and overexpression of UCP1, we discovered that UCP1 overexpressing adipocytes significantly improve glucose uptake by 40%. Mechanistically, this is caused by higher glycolytic flux, seen as increased oxygen consumption, extracellular acidification and lactate secretion rates. The improvements in glucose handling are comparable to white-to-brown transitions, as judged by, for the first time, directly comparing in vitro differentiated mouse brown vs white adipocytes. Although no adipogenic, metabolic and mitochondrial gene expressions were significantly altered in SGBS cells, pharmacological inhibition of GLUT1 completely abrogated differences between UCP1+ and control cells, thereby uncovering GLUT1-mediated uptake as permissive gatekeeper. Collectively, our data demonstrate that elevating UCP1 levels is sufficient to improve human white adipocytes as a glucose sink without adverse cellular effects, thus not requiring the adrenergic controlled, complex network of browning which usually hampers translational efforts. Basal glucose uptake in human adipocytes is improved by solely elevating UCP1 levels. Adipogenic, metabolic and mitochondrial gene expressions were not affected by UCP1 overexpression. UCP1-driven increase in glucose uptake is mediated by GLUT1.
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Affiliation(s)
- D Tews
- Division of Pediatric Endocrinology and Diabetes, Department of Pediatrics and Adolescent Medicine, Ulm University Medical Center, Ulm, Germany.
| | - T Pula
- Division of Pediatric Endocrinology and Diabetes, Department of Pediatrics and Adolescent Medicine, Ulm University Medical Center, Ulm, Germany
| | - J B Funcke
- Division of Pediatric Endocrinology and Diabetes, Department of Pediatrics and Adolescent Medicine, Ulm University Medical Center, Ulm, Germany
| | - M Jastroch
- Department of Molecular Biosciences, The Wenner-Gren Institute, Stockholm University, SE-106 91 Stockholm, Sweden
| | - M Keuper
- Department of Molecular Biosciences, The Wenner-Gren Institute, Stockholm University, SE-106 91 Stockholm, Sweden
| | - K M Debatin
- Department of Pediatrics and Adolescent Medicine, Ulm University Medical Center, Ulm, Germany
| | - M Wabitsch
- Division of Pediatric Endocrinology and Diabetes, Department of Pediatrics and Adolescent Medicine, Ulm University Medical Center, Ulm, Germany
| | - P Fischer-Posovszky
- Division of Pediatric Endocrinology and Diabetes, Department of Pediatrics and Adolescent Medicine, Ulm University Medical Center, Ulm, Germany
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Brandao CFC, de Carvalho FG, Souza ADO, Junqueira-Franco MVM, Batitucci G, Couto-Lima CA, Fett CA, Papoti M, Freitas ECD, Alberici LC, Marchini JS. Physical training, UCP1 expression, mitochondrial density, and coupling in adipose tissue from women with obesity. Scand J Med Sci Sports 2019; 29:1699-1706. [PMID: 31282585 DOI: 10.1111/sms.13514] [Citation(s) in RCA: 21] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/30/2018] [Revised: 06/10/2019] [Accepted: 06/28/2019] [Indexed: 12/11/2022]
Abstract
BACKGROUND Exercise training may improve energy expenditure, thermogenesis, and oxidative capacities. Therefore, we hypothesized that physical training enhances white adipose tissue mitochondrial oxidative capacity from obese women. OBJECTIVE To evaluate mitochondrial respiratory capacity, mitochondrial content, and UCP1 gene expression in white adipose tissue from women with obesity before and after the physical training program. METHODS Women (n = 14, BMI 33 ± 3 kg/m2 , 35 ± 6 years, mean ± SD) were submitted to strength and aerobic exercises (75%-90% maximum heart rate and multiple repetitions), 3 times/week during 8 weeks. All evaluated subjects were paired, before and after training for resting metabolic rate (RMR), substrate oxidation (lipid and carbohydrate) by indirect calorimeter, deuterium oxide body composition, and aerobic maximum velocity (Vmax ) test. At the beginning and at the ending of the protocol, abdominal subcutaneous adipose tissue was collected to measure the mitochondrial respiration by high-resolution respirometry, mitochondrial content by citrate synthase (CS) activity, and UCP1 gene expression by RT-qPCR. RESULTS Combined physical training increased RMR, lipid oxidation, and Vmax but did not change body weight/composition. In WAT, exercise increased CS activity, decreased mitochondrial uncoupled respiration and mRNA of UCP1. RMR was positively correlated with fat-free mass. CONCLUSION Physical training promotes an increase in mitochondrial content without changing tissue respiratory capacity, a reduction in mitochondrial uncoupling degree and UCP1 mRNA expression in WAT. Finally, it improved the resting metabolic rate, lipid oxidation and physical performance, independent of the body changing free, or fat mass in obese women.
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Affiliation(s)
| | - Flavia Giolo de Carvalho
- School of Physical Education and Sports of Ribeirão Preto, University of São Paulo, Ribeirão Preto, Brazil
| | | | | | - Gabriela Batitucci
- School of Physical Education and Sports of Ribeirão Preto, University of São Paulo, Ribeirão Preto, Brazil.,Department of Food and Nutrition, School of Pharmaceutical Sciences of Araraquara, State University of Sao Paulo, Araraquara, Brazil
| | - Carlos Antonio Couto-Lima
- School of Pharmaceutical Sciences of Ribeirão Preto, University of São Paulo, Ribeirão Preto, Brazil
| | | | - Marcelo Papoti
- School of Physical Education and Sports of Ribeirão Preto, University of São Paulo, Ribeirão Preto, Brazil
| | - Ellen Cristini de Freitas
- School of Physical Education and Sports of Ribeirão Preto, University of São Paulo, Ribeirão Preto, Brazil.,Department of Food and Nutrition, School of Pharmaceutical Sciences of Araraquara, State University of Sao Paulo, Araraquara, Brazil
| | - Luciane Carla Alberici
- School of Pharmaceutical Sciences of Ribeirão Preto, University of São Paulo, Ribeirão Preto, Brazil
| | - Julio Sergio Marchini
- Nutrology, Ribeirão Preto Medical School, University of São Paulo, Ribeirão Preto, Brazil
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Zhao RZ, Jiang S, Zhang L, Yu ZB. Mitochondrial electron transport chain, ROS generation and uncoupling (Review). Int J Mol Med 2019; 44:3-15. [PMID: 31115493 PMCID: PMC6559295 DOI: 10.3892/ijmm.2019.4188] [Citation(s) in RCA: 427] [Impact Index Per Article: 85.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/24/2019] [Accepted: 04/19/2019] [Indexed: 12/18/2022] Open
Abstract
The mammalian mitochondrial electron transport chain (ETC) includes complexes I-IV, as well as the electron transporters ubiquinone and cytochrome c. There are two electron transport pathways in the ETC: Complex I/III/IV, with NADH as the substrate and complex II/III/IV, with succinic acid as the substrate. The electron flow is coupled with the generation of a proton gradient across the inner membrane and the energy accumulated in the proton gradient is used by complex V (ATP synthase) to produce ATP. The first part of this review briefly introduces the structure and function of complexes I-IV and ATP synthase, including the specific electron transfer process in each complex. Some electrons are directly transferred to O2 to generate reactive oxygen species (ROS) in the ETC. The second part of this review discusses the sites of ROS generation in each ETC complex, including sites IF and IQ in complex I, site IIF in complex II and site IIIQo in complex III, and the physiological and pathological regulation of ROS. As signaling molecules, ROS play an important role in cell proliferation, hypoxia adaptation and cell fate determination, but excessive ROS can cause irreversible cell damage and even cell death. The occurrence and development of a number of diseases are closely related to ROS overproduction. Finally, proton leak and uncoupling proteins (UCPS) are discussed. Proton leak consists of basal proton leak and induced proton leak. Induced proton leak is precisely regulated and induced by UCPs. A total of five UCPs (UCP1-5) have been identified in mammalian cells. UCP1 mainly plays a role in the maintenance of body temperature in a cold environment through non-shivering thermogenesis. The core role of UCP2-5 is to reduce oxidative stress under certain conditions, therefore exerting cytoprotective effects. All diseases involving oxidative stress are associated with UCPs.
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Affiliation(s)
- Ru-Zhou Zhao
- Department of Aerospace Physiology, Fourth Military Medical University, Xi'an, Shaanxi 710032, P.R. China
| | - Shuai Jiang
- Department of Aerospace Physiology, Fourth Military Medical University, Xi'an, Shaanxi 710032, P.R. China
| | - Lin Zhang
- Department of Aerospace Physiology, Fourth Military Medical University, Xi'an, Shaanxi 710032, P.R. China
| | - Zhi-Bin Yu
- Department of Aerospace Physiology, Fourth Military Medical University, Xi'an, Shaanxi 710032, P.R. China
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Abstract
Brown and beige adipocytes can catabolize stored energy to generate heat, and this distinct capacity for thermogenesis could be leveraged as a therapy for metabolic diseases like obesity and type 2 diabetes. Thermogenic adipocytes drive heat production through close coordination of substrate supply with the mitochondrial oxidative machinery and effectors that control the rate of substrate oxidation. Together, this apparatus affords these adipocytes with tremendous capacity to drive thermogenesis. The best characterized thermogenic effector is uncoupling protein 1 (UCP1). Importantly, additional mechanisms for activating thermogenesis beyond UCP1 have been identified and characterized to varying extents. Acute regulation of these thermogenic pathways has been an active area of study, and numerous regulatory factors have been uncovered in recent years. Here we will review the evidence for regulators of heat production in thermogenic adipocytes in the context of the thermodynamic and kinetic principles that govern their therapeutic utility.
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Affiliation(s)
- Edward T Chouchani
- Department of Cancer Biology, Dana-Farber Cancer Institute, Boston, MA, USA; Department of Cell Biology, Harvard Medical School, Boston, MA, USA.
| | - Lawrence Kazak
- Goodman Cancer Research Centre, McGill University, Montreal, QC, Canada; Department of Biochemistry, McGill University, Montreal, QC, Canada.
| | - Bruce M Spiegelman
- Department of Cancer Biology, Dana-Farber Cancer Institute, Boston, MA, USA; Department of Cell Biology, Harvard Medical School, Boston, MA, USA.
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Cadenas S. Mitochondrial uncoupling, ROS generation and cardioprotection. BIOCHIMICA ET BIOPHYSICA ACTA-BIOENERGETICS 2018; 1859:940-950. [DOI: 10.1016/j.bbabio.2018.05.019] [Citation(s) in RCA: 238] [Impact Index Per Article: 39.7] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/22/2018] [Revised: 05/11/2018] [Accepted: 05/29/2018] [Indexed: 12/31/2022]
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Dard L, Bellance N, Lacombe D, Rossignol R. RAS signalling in energy metabolism and rare human diseases. BIOCHIMICA ET BIOPHYSICA ACTA-BIOENERGETICS 2018; 1859:845-867. [PMID: 29750912 DOI: 10.1016/j.bbabio.2018.05.003] [Citation(s) in RCA: 35] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/07/2018] [Revised: 04/12/2018] [Accepted: 05/03/2018] [Indexed: 02/07/2023]
Abstract
The RAS pathway is a highly conserved cascade of protein-protein interactions and phosphorylation that is at the heart of signalling networks that govern proliferation, differentiation and cell survival. Recent findings indicate that the RAS pathway plays a role in the regulation of energy metabolism via the control of mitochondrial form and function but little is known on the participation of this effect in RAS-related rare human genetic diseases. Germline mutations that hyperactivate the RAS pathway have been discovered and linked to human developmental disorders that are known as RASopathies. Individuals with RASopathies, which are estimated to affect approximately 1/1000 human birth, share many overlapping characteristics, including cardiac malformations, short stature, neurocognitive impairment, craniofacial dysmorphy, cutaneous, musculoskeletal, and ocular abnormalities, hypotonia and a predisposition to developing cancer. Since the identification of the first RASopathy, type 1 neurofibromatosis (NF1), which is caused by the inactivation of neurofibromin 1, several other syndromes have been associated with mutations in the core components of the RAS-MAPK pathway. These syndromes include Noonan syndrome (NS), Noonan syndrome with multiple lentigines (NSML), which was formerly called LEOPARD syndrome, Costello syndrome (CS), cardio-facio-cutaneous syndrome (CFC), Legius syndrome (LS) and capillary malformation-arteriovenous malformation syndrome (CM-AVM). Here, we review current knowledge about the bioenergetics of the RASopathies and discuss the molecular control of energy homeostasis and mitochondrial physiology by the RAS pathway.
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Affiliation(s)
- L Dard
- Bordeaux University, 33000 Bordeaux, France; INSERM U1211, 33000 Bordeaux, France
| | - N Bellance
- Bordeaux University, 33000 Bordeaux, France; INSERM U1211, 33000 Bordeaux, France
| | - D Lacombe
- Bordeaux University, 33000 Bordeaux, France; INSERM U1211, 33000 Bordeaux, France; CHU de Bordeaux, Service de Génétique Médicale, F-33076 Bordeaux, France
| | - R Rossignol
- Bordeaux University, 33000 Bordeaux, France; INSERM U1211, 33000 Bordeaux, France; CELLOMET, CGFB-146 Rue Léo Saignat, Bordeaux, France.
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26
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Berry BJ, Trewin AJ, Amitrano AM, Kim M, Wojtovich AP. Use the Protonmotive Force: Mitochondrial Uncoupling and Reactive Oxygen Species. J Mol Biol 2018; 430:3873-3891. [PMID: 29626541 DOI: 10.1016/j.jmb.2018.03.025] [Citation(s) in RCA: 103] [Impact Index Per Article: 17.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/31/2018] [Revised: 03/21/2018] [Accepted: 03/26/2018] [Indexed: 02/06/2023]
Abstract
Mitochondrial respiration results in an electrochemical proton gradient, or protonmotive force (pmf), across the mitochondrial inner membrane. The pmf is a form of potential energy consisting of charge (∆ψm) and chemical (∆pH) components, that together drive ATP production. In a process called uncoupling, proton leak into the mitochondrial matrix independent of ATP production dissipates the pmf and energy is lost as heat. Other events can directly dissipate the pmf independent of ATP production as well, such as chemical exposure or mechanisms involving regulated mitochondrial membrane electrolyte transport. Uncoupling has defined roles in metabolic plasticity and can be linked through signal transduction to physiologic events. In the latter case, the pmf impacts mitochondrial reactive oxygen species (ROS) production. Although capable of molecular damage, ROS also have signaling properties that depend on the timing, location, and quantity of their production. In this review, we provide a general overview of mitochondrial ROS production, mechanisms of uncoupling, and how these work in tandem to affect physiology and pathologies, including obesity, cardiovascular disease, and immunity. Overall, we highlight that isolated bioenergetic models-mitochondria and cells-only partially recapitulate the complex link between the pmf and ROS signaling that occurs in vivo.
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Affiliation(s)
- Brandon J Berry
- Department of Pharmacology and Physiology, University of Rochester Medical Center, Box 711/604, 575 Elmwood Ave., Rochester, NY 14642, USA.
| | - Adam J Trewin
- Department of Anesthesiology and Perioperative Medicine, University of Rochester Medical Center, Box 711/604, 575 Elmwood Ave., Rochester, NY 14642, USA.
| | - Andrea M Amitrano
- Department of Pathology, University of Rochester Medical Center, Box 609, 601 Elmwood Ave., Rochester, NY 14642, USA; Department of Microbiology and Immunology, University of Rochester Medical Center, Box 609, 601 Elmwood Ave., Rochester, NY 14642, USA.
| | - Minsoo Kim
- Department of Pharmacology and Physiology, University of Rochester Medical Center, Box 711/604, 575 Elmwood Ave., Rochester, NY 14642, USA; Department of Pathology, University of Rochester Medical Center, Box 609, 601 Elmwood Ave., Rochester, NY 14642, USA; Department of Microbiology and Immunology, University of Rochester Medical Center, Box 609, 601 Elmwood Ave., Rochester, NY 14642, USA.
| | - Andrew P Wojtovich
- Department of Pharmacology and Physiology, University of Rochester Medical Center, Box 711/604, 575 Elmwood Ave., Rochester, NY 14642, USA; Department of Anesthesiology and Perioperative Medicine, University of Rochester Medical Center, Box 711/604, 575 Elmwood Ave., Rochester, NY 14642, USA.
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Abstract
Adipose tissue plays an important role in whole body metabolism, and its dysfunction results in poor metabolic health and is associated with a diverse set of disorders, such as obesity, cardiovascular disease, hypertension, cancer, and type 2 diabetes. The search for cellular processes that can be targeted to activate adipose oxidative metabolism is thought to hold promise for combating these diseases, and so the analysis of adipose bioenergetics is crucial toward this end. A description is provided here for the preparation of mitochondria and primary adipocytes from adipose tissue to be used for bioenergetics profiling.
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Affiliation(s)
- Lawrence Kazak
- Dana-Faber Cancer Institute, Harvard Medical School, Cancer Biology CLS 111146, 3 Blackfan Circle, Boston, MA, 02115, USA.
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28
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The conserved regulation of mitochondrial uncoupling proteins: From unicellular eukaryotes to mammals. BIOCHIMICA ET BIOPHYSICA ACTA-BIOENERGETICS 2016; 1858:21-33. [PMID: 27751905 DOI: 10.1016/j.bbabio.2016.10.003] [Citation(s) in RCA: 37] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Abstract] [Key Words] [Subscribe] [Scholar Register] [Received: 06/27/2016] [Revised: 09/29/2016] [Accepted: 10/13/2016] [Indexed: 12/19/2022]
Abstract
Uncoupling proteins (UCPs) belong to the mitochondrial anion carrier protein family and mediate regulated proton leak across the inner mitochondrial membrane. Free fatty acids, aldehydes such as hydroxynonenal, and retinoids activate UCPs. However, there are some controversies about the effective action of retinoids and aldehydes alone; thus, only free fatty acids are commonly accepted positive effectors of UCPs. Purine nucleotides such as GTP inhibit UCP-mediated mitochondrial proton leak. In turn, membranous coenzyme Q may play a role as a redox state-dependent metabolic sensor that modulates the complete activation/inhibition of UCPs. Such regulation has been observed for UCPs in microorganisms, plant and animal UCP1 homologues, and UCP1 in mammalian brown adipose tissue. The origin of UCPs is still under debate, but UCP homologues have been identified in all systematic groups of eukaryotes. Despite the differing levels of amino acid/DNA sequence similarities, functional studies in unicellular and multicellular organisms, from amoebae to mammals, suggest that the mechanistic regulation of UCP activity is evolutionarily well conserved. This review focuses on the regulatory feedback loops of UCPs involving free fatty acids, aldehydes, retinoids, purine nucleotides, and coenzyme Q (particularly its reduction level), which may derive from the early stages of evolution as UCP first emerged.
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29
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Diolez P, Bourdel-Marchasson I, Calmettes G, Pasdois P, Detaille D, Rouland R, Gouspillou G. Hypothesis on Skeletal Muscle Aging: Mitochondrial Adenine Nucleotide Translocator Decreases Reactive Oxygen Species Production While Preserving Coupling Efficiency. Front Physiol 2015; 6:369. [PMID: 26733871 PMCID: PMC4679911 DOI: 10.3389/fphys.2015.00369] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/31/2015] [Accepted: 11/19/2015] [Indexed: 01/07/2023] Open
Abstract
Mitochondrial membrane potential is the major regulator of mitochondrial functions, including coupling efficiency and production of reactive oxygen species (ROS). Both functions are crucial for cell bioenergetics. We previously presented evidences for a specific modulation of adenine nucleotide translocase (ANT) appearing during aging that results in a decrease in membrane potential - and therefore ROS production-but surprisingly increases coupling efficiency under conditions of low ATP turnover. Careful study of the bioenergetic parameters (oxidation and phosphorylation rates, membrane potential) of isolated mitochondria from skeletal muscles (gastrocnemius) of aged and young rats revealed a remodeling at the level of the phosphorylation system, in the absence of alteration of the inner mitochondrial membrane (uncoupling) or respiratory chain complexes regulation. We further observed a decrease in mitochondrial affinity for ADP in aged isolated mitochondria, and higher sensitivity of ANT to its specific inhibitor atractyloside. This age-induced modification of ANT results in an increase in the ADP concentration required to sustain the same ATP turnover as compared to young muscle, and therefore in a lower membrane potential under phosphorylating-in vivo-conditions. Thus, for equivalent ATP turnover (cellular ATP demand), coupling efficiency is even higher in aged muscle mitochondria, due to the down-regulation of inner membrane proton leak caused by the decrease in membrane potential. In the framework of the radical theory of aging, these modifications in ANT function may be the result of oxidative damage caused by intra mitochondrial ROS and may appear like a virtuous circle where ROS induce a mechanism that reduces their production, without causing uncoupling, and even leading in improved efficiency. Because of the importance of ROS as therapeutic targets, this new mechanism deserves further studies.
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Affiliation(s)
- Philippe Diolez
- INSERM U1045 - Centre de Recherche Cardio-Thoracique de Bordeaux and LIRYC, Institut de Rythmologie et Modélisation Cardiaque, Université de Bordeaux, CHU de Bordeaux Pessac, France
| | - Isabelle Bourdel-Marchasson
- CHU de Bordeaux, Pôle de Gérontologie CliniqueBordeaux, France; Résonance Magnétique des Systèmes Biologiques, UMR 5536 Centre National de la Recherche Scientifique, Université de BordeauxBordeaux, France
| | - Guillaume Calmettes
- Division of Cardiology, Department of Medicine, David Geffen School of Medicine, University of California, Los Angeles Los Angeles, CA, USA
| | - Philippe Pasdois
- INSERM U1045 - Centre de Recherche Cardio-Thoracique de Bordeaux and LIRYC, Institut de Rythmologie et Modélisation Cardiaque, Université de Bordeaux, CHU de Bordeaux Pessac, France
| | - Dominique Detaille
- INSERM U1045 - Centre de Recherche Cardio-Thoracique de Bordeaux and LIRYC, Institut de Rythmologie et Modélisation Cardiaque, Université de Bordeaux, CHU de Bordeaux Pessac, France
| | - Richard Rouland
- Résonance Magnétique des Systèmes Biologiques, UMR 5536 Centre National de la Recherche Scientifique, Université de Bordeaux Bordeaux, France
| | - Gilles Gouspillou
- Département des Sciences de l'activité Physique, Université du Québec À Montréal Montréal, QC, Canada
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Akhmedov AT, Rybin V, Marín-García J. Mitochondrial oxidative metabolism and uncoupling proteins in the failing heart. Heart Fail Rev 2015; 20:227-49. [PMID: 25192828 DOI: 10.1007/s10741-014-9457-4] [Citation(s) in RCA: 92] [Impact Index Per Article: 10.2] [Reference Citation Analysis] [Abstract] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 02/07/2023]
Abstract
Despite significant progress in cardiovascular medicine, myocardial ischemia and infarction, progressing eventually to the final end point heart failure (HF), remain the leading cause of morbidity and mortality in the USA. HF is a complex syndrome that results from any structural or functional impairment in ventricular filling or blood ejection. Ultimately, the heart's inability to supply the body's tissues with enough blood may lead to death. Mechanistically, the hallmarks of the failing heart include abnormal energy metabolism, increased production of reactive oxygen species (ROS) and defects in excitation-contraction coupling. HF is a highly dynamic pathological process, and observed alterations in cardiac metabolism and function depend on the disease progression. In the early stages, cardiac remodeling characterized by normal or slightly increased fatty acid (FA) oxidation plays a compensatory, cardioprotective role. However, upon progression of HF, FA oxidation and mitochondrial oxidative activity are decreased, resulting in a significant drop in cardiac ATP levels. In HF, as a compensatory response to decreased oxidative metabolism, glucose uptake and glycolysis are upregulated, but this upregulation is not sufficient to compensate for a drop in ATP production. Elevated mitochondrial ROS generation and ROS-mediated damage, when they overwhelm the cellular antioxidant defense system, induce heart injury and contribute to the progression of HF. Mitochondrial uncoupling proteins (UCPs), which promote proton leak across the inner mitochondrial membrane, have emerged as essential regulators of mitochondrial membrane potential, respiratory activity and ROS generation. Although the physiological role of UCP2 and UCP3, expressed in the heart, has not been clearly established, increasing evidence suggests that these proteins by promoting mild uncoupling could reduce mitochondrial ROS generation and cardiomyocyte apoptosis and ameliorate thereby myocardial function. Further investigation on the alterations in cardiac UCP activity and regulation will advance our understanding of their physiological roles in the healthy and diseased heart and also may facilitate the development of novel and more efficient therapies.
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Affiliation(s)
- Alexander T Akhmedov
- The Molecular Cardiology and Neuromuscular Institute, 75 Raritan Avenue, Highland Park, NJ, 08904, USA
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31
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Wang R, MoYung KC, Zhang MH, Poon K. UCP2- and non-UCP2-mediated electric current in eukaryotic cells exhibits different properties. ENVIRONMENTAL SCIENCE AND POLLUTION RESEARCH INTERNATIONAL 2015; 22:19618-19631. [PMID: 26276275 DOI: 10.1007/s11356-015-5155-6] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/21/2015] [Accepted: 08/04/2015] [Indexed: 06/04/2023]
Abstract
Using live eukaryotic cells, including cancer cells, MCF-7 and HCT-116, normal hepatocytes and red blood cells in anode and potassium ferricyanide in cathode of MFC could generate bio-based electric current. Electrons and protons generated from the metabolic reaction in both cytosol and mitochondria contributing to the leaking would mediate the generation of electric current. Both resveratrol (RVT) and 2,4-dinitrophenol (DNP) used to induce proton leak in mitochondria were found to promote electric current production in all cells except red blood cells without mitochondria. Proton leak might be important for electric current production by bringing the charge balance in cells to enhance the further electron leak. The induced electric current by RVT can be blocked by Genipin, an inhibitor of UCP2-mediated proton leak, while that induced by DNP cannot. RVT could reduce reactive oxygen species (ROS) level in cells better than that of DNP. In addition, RVT increased mitochondrial membrane potential (MMP), while DNP decreased it. Results highly suggested the existence of at least two types of electric current that showed different properties. They included UCP2-mediated and non-UCP2-mediated electric current. UCP2-mediated electric current exhibited higher reactive oxygen species (ROS) reduction effect per unit electric current production than that of non-UCP2-mediated electric current. Higher UCP2-mediated electric current observed in cancer cells might contribute to the mechanism of drug resistence. Correlation could not be established between electric current production with either ROS and MMP without distinguishing the types of electric current.
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Affiliation(s)
- Ruihua Wang
- Department of Gastroenterology, Shanghai Jiao Tong University Affiliated Sixth People's Hospital South Campus, 6600 Nanfeng Road, Fengxian District, Shanghai, China, 201499.
| | - K C MoYung
- Program of Food Science and Technology, Division of Science and Technology, BNU-HKBU United International College, 28 Jinfeng Road, Tangjiawan, Zhuhai, Guangdong, China, 519085.
| | - M H Zhang
- Program of Food Science and Technology, Division of Science and Technology, BNU-HKBU United International College, 28 Jinfeng Road, Tangjiawan, Zhuhai, Guangdong, China, 519085
| | - Karen Poon
- Program of Food Science and Technology, Division of Science and Technology, BNU-HKBU United International College, 28 Jinfeng Road, Tangjiawan, Zhuhai, Guangdong, China, 519085.
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32
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Zhao XY, Zhang JY, Cao J, Zhao ZJ. Oxidative Damage Does Not Occur in Striped Hamsters Raising Natural and Experimentally Increased Litter Size. PLoS One 2015; 10:e0141604. [PMID: 26505889 PMCID: PMC4624642 DOI: 10.1371/journal.pone.0141604] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/25/2015] [Accepted: 10/09/2015] [Indexed: 12/21/2022] Open
Abstract
Life-history theory assumes that animals can balance the allocation of limited energy or resources to the competing demands of growth, reproduction and somatic maintenance, while consequently maximizing their fitness. However, somatic damage caused by oxidative stress in reproductive female animals is species-specific or is tissue dependent. In the present study, several markers of oxidative stress (hydrogen peroxide, H2O2 and malonadialdehyde, MDA) and antioxidant (catalase, CAT and total antioxidant capacity, T-AOC) were examined in striped hamsters during different stages of reproduction with experimentally manipulated litter size. Energy intake, resting metabolic rate (RMR), and mRNA expression of uncoupling protein 1 (UCP1) in brown adipose tissue (BAT) and UCP3 in skeletal muscle were also examined. H2O2 and MDA levels did not change in BAT and liver, although they significantly decreased in skeletal muscle in the lactating hamsters compared to the non-reproductive group. However, H2O2 levels in the brain were significantly higher in lactating hamsters than non-reproductive controls. Experimentally increasing litter size did not cause oxidative stress in BAT, liver and skeletal muscle, but significantly elevated H2O2 levels in the brain. CAT activity of liver decreased, but CAT and T-AOC activity of BAT, skeletal muscle and the brain did not change in lactating hamsters compared to non-reproductive controls. Both antioxidants did not change with the experimentally increasing litter size. RMR significantly increased, but BAT UCP1 mRNA expression decreased with the experimentally increased litter size, suggesting that it was against simple positive links between metabolic rate, UCP1 expression and free radicals levels. It may suggest that the cost of reproduction has negligible effect on oxidative stress or even attenuates oxidative stress in some active tissues in an extensive range of animal species. But the increasing reproductive effort may cause oxidative stress in the brain, indicating that oxidative stress in response to reproduction is tissue dependent. These findings provide partial support for the life-history theory.
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Affiliation(s)
- Xiao-Ya Zhao
- College of Life and Environmental Science, Wenzhou University, Wenzhou 325035, China
| | - Ji-Ying Zhang
- College of Life and Environmental Science, Wenzhou University, Wenzhou 325035, China
| | - Jing Cao
- College of Life and Environmental Science, Wenzhou University, Wenzhou 325035, China
| | - Zhi-Jun Zhao
- College of Life and Environmental Science, Wenzhou University, Wenzhou 325035, China
- * E-mail:
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33
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Anderson CM, Kazantzis M, Wang J, Venkatraman S, Goncalves RLS, Quinlan CL, Ng R, Jastroch M, Benjamin DI, Nie B, Herber C, Van AAN, Park MJ, Yun D, Chan K, Yu A, Vuong P, Febbraio M, Nomura DK, Napoli JL, Brand MD, Stahl A. Dependence of brown adipose tissue function on CD36-mediated coenzyme Q uptake. Cell Rep 2015; 10:505-15. [PMID: 25620701 DOI: 10.1016/j.celrep.2014.12.048] [Citation(s) in RCA: 60] [Impact Index Per Article: 6.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/03/2014] [Revised: 11/13/2014] [Accepted: 12/19/2014] [Indexed: 02/05/2023] Open
Abstract
Brown adipose tissue (BAT) possesses the inherent ability to dissipate metabolic energy as heat through uncoupled mitochondrial respiration. An essential component of the mitochondrial electron transport chain is coenzyme Q (CoQ). While cells synthesize CoQ mostly endogenously, exogenous supplementation with CoQ has been successful as a therapy for patients with CoQ deficiency. However, which tissues depend on exogenous CoQ uptake as well as the mechanism by which CoQ is taken up by cells and the role of this process in BAT function are not well understood. Here, we report that the scavenger receptor CD36 drives the uptake of CoQ by BAT and is required for normal BAT function. BAT from mice lacking CD36 displays CoQ deficiency, impaired CoQ uptake, hypertrophy, altered lipid metabolism, mitochondrial dysfunction, and defective nonshivering thermogenesis. Together, these data reveal an important new role for the systemic transport of CoQ to BAT and its function in thermogenesis.
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Affiliation(s)
- Courtney M Anderson
- Nutritional Sciences and Toxicology Department, University of California Berkeley, Berkeley, CA 94720, USA
| | - Melissa Kazantzis
- Nutritional Sciences and Toxicology Department, University of California Berkeley, Berkeley, CA 94720, USA
| | - Jinshan Wang
- Nutritional Sciences and Toxicology Department, University of California Berkeley, Berkeley, CA 94720, USA
| | - Subramaniam Venkatraman
- Department of Electrical Engineering and Computer Sciences, University of California Berkeley, Berkeley, CA 94720, USA
| | | | - Casey L Quinlan
- The Buck Institute for Research on Aging, Novato, CA 94945, USA
| | - Ryan Ng
- The Buck Institute for Research on Aging, Novato, CA 94945, USA
| | - Martin Jastroch
- The Buck Institute for Research on Aging, Novato, CA 94945, USA
| | - Daniel I Benjamin
- Nutritional Sciences and Toxicology Department, University of California Berkeley, Berkeley, CA 94720, USA
| | - Biao Nie
- Nutritional Sciences and Toxicology Department, University of California Berkeley, Berkeley, CA 94720, USA
| | - Candice Herber
- Nutritional Sciences and Toxicology Department, University of California Berkeley, Berkeley, CA 94720, USA
| | - An-Angela Ngoc Van
- Nutritional Sciences and Toxicology Department, University of California Berkeley, Berkeley, CA 94720, USA
| | - Michael J Park
- Nutritional Sciences and Toxicology Department, University of California Berkeley, Berkeley, CA 94720, USA
| | - Dawee Yun
- Nutritional Sciences and Toxicology Department, University of California Berkeley, Berkeley, CA 94720, USA
| | - Karen Chan
- Nutritional Sciences and Toxicology Department, University of California Berkeley, Berkeley, CA 94720, USA
| | - Angela Yu
- Nutritional Sciences and Toxicology Department, University of California Berkeley, Berkeley, CA 94720, USA
| | - Peter Vuong
- Nutritional Sciences and Toxicology Department, University of California Berkeley, Berkeley, CA 94720, USA
| | - Maria Febbraio
- Faculty of Medicine and Dentistry, University of Alberta, Edmonton, AB T6G 2R3, Canada
| | - Daniel K Nomura
- Nutritional Sciences and Toxicology Department, University of California Berkeley, Berkeley, CA 94720, USA
| | - Joseph L Napoli
- Nutritional Sciences and Toxicology Department, University of California Berkeley, Berkeley, CA 94720, USA
| | - Martin D Brand
- The Buck Institute for Research on Aging, Novato, CA 94945, USA
| | - Andreas Stahl
- Nutritional Sciences and Toxicology Department, University of California Berkeley, Berkeley, CA 94720, USA.
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34
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Li Y, Fromme T, Schweizer S, Schöttl T, Klingenspor M. Taking control over intracellular fatty acid levels is essential for the analysis of thermogenic function in cultured primary brown and brite/beige adipocytes. EMBO Rep 2014; 15:1069-76. [PMID: 25135951 DOI: 10.15252/embr.201438775] [Citation(s) in RCA: 117] [Impact Index Per Article: 11.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022] Open
Abstract
Thermogenesis in brown adipocytes, conferred by mitochondrial uncoupling protein 1 (UCP1), is receiving great attention because metabolically active brown adipose tissue may protect humans from metabolic diseases. In particular, the thermogenic function of brown-like adipocytes in white adipose tissue, known as brite (or beige) adipocytes, is currently of prime interest. A valid procedure to quantify the specific contribution of UCP1 to thermogenesis is thus of vital importance. Adrenergic stimulation of lipolysis is a common way to activate UCP1. We here report, however, that in this frequently applied setup, taking control over intracellular fatty acid levels is essential for the analysis of thermogenic function in cultured brown and brite adipocytes. By the application of these findings, we demonstrate that UCP1 is functionally thermogenic in intact brite adipocytes and adrenergic UCP1 activation is largely dependent on adipose triglyceride lipase (ATGL) rather than hormone sensitive lipase (HSL).
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Affiliation(s)
- Yongguo Li
- Molecular Nutritional Medicine, Else Kröner Fresenius Center for Nutritional Medicine, Technische Universität München, Freising, Germany
| | - Tobias Fromme
- Molecular Nutritional Medicine, Else Kröner Fresenius Center for Nutritional Medicine, Technische Universität München, Freising, Germany
| | - Sabine Schweizer
- Molecular Nutritional Medicine, Else Kröner Fresenius Center for Nutritional Medicine, Technische Universität München, Freising, Germany
| | - Theresa Schöttl
- Molecular Nutritional Medicine, Else Kröner Fresenius Center for Nutritional Medicine, Technische Universität München, Freising, Germany
| | - Martin Klingenspor
- Molecular Nutritional Medicine, Else Kröner Fresenius Center for Nutritional Medicine, Technische Universität München, Freising, Germany
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35
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Kim GW, Lin JE, Blomain ES, Waldman SA. Antiobesity pharmacotherapy: new drugs and emerging targets. Clin Pharmacol Ther 2013; 95:53-66. [PMID: 24105257 DOI: 10.1038/clpt.2013.204] [Citation(s) in RCA: 132] [Impact Index Per Article: 12.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/03/2013] [Accepted: 09/18/2013] [Indexed: 02/07/2023]
Abstract
Obesity is a growing pandemic, and related health and economic costs are staggering. Pharmacotherapy, partnered with lifestyle modifications, forms the core of current strategies to reduce the burden of this disease and its sequelae. However, therapies targeting weight loss have a significant history of safety risks, including cardiovascular and psychiatric events. Here, evolving strategies for developing antiobesity therapies, including targets, mechanisms, and developmental status, are highlighted. Progress in this field is underscored by Belviq (lorcaserin) and Qsymia (phentermine/topiramate), the first agents in more than 10 years to achieve regulatory approval for chronic weight management in obese patients. On the horizon, novel insights into metabolism and energy homeostasis reveal guanosine 3',5'-cyclic monophosphate (cGMP) signaling circuits as emerging targets for antiobesity pharmacotherapy. These innovations in molecular discovery may elegantly align with practical off-the-shelf approaches, leveraging existing approved drugs that modulate cGMP levels for the management of obesity.
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Affiliation(s)
- G W Kim
- Department of Pharmacology and Experimental Therapeutics, Thomas Jefferson University, Philadelphia, Pennsylvania, USA
| | - J E Lin
- Department of Pharmacology and Experimental Therapeutics, Thomas Jefferson University, Philadelphia, Pennsylvania, USA
| | - E S Blomain
- Department of Pharmacology and Experimental Therapeutics, Thomas Jefferson University, Philadelphia, Pennsylvania, USA
| | - S A Waldman
- Department of Pharmacology and Experimental Therapeutics, Thomas Jefferson University, Philadelphia, Pennsylvania, USA
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36
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Adjeitey CNK, Mailloux RJ, Dekemp RA, Harper ME. Mitochondrial uncoupling in skeletal muscle by UCP1 augments energy expenditure and glutathione content while mitigating ROS production. Am J Physiol Endocrinol Metab 2013; 305:E405-15. [PMID: 23757405 PMCID: PMC3742851 DOI: 10.1152/ajpendo.00057.2013] [Citation(s) in RCA: 36] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/16/2022]
Abstract
Enhancement of proton leaks in muscle tissue represents a potential target for obesity treatment. In this study, we examined the bioenergetic and physiological implications of increased proton leak in skeletal muscle. To induce muscle-specific increases in proton leak, we used mice that selectively express uncoupling protein-1 (UCP1) in skeletal muscle tissue. UCP1 expression in muscle mitochondria was ∼13% of levels in brown adipose tissue (BAT) mitochondria and caused increased GDP-sensitive proton leak. This was associated with an increase in whole body energy expenditure and a decrease in white adipose tissue content. Muscle UCP1 activity had divergent effects on mitochondrial ROS emission and glutathione levels compared with BAT. UCP1 in muscle increased total mitochondrial glutathione levels ∼7.6 fold. Intriguingly, unlike in BAT mitochondria, leak through UCP1 in muscle controlled mitochondrial ROS emission. Inhibition of UCP1 with GDP in muscle mitochondria increased ROS emission ∼2.8-fold relative to WT muscle mitochondria. GDP had no impact on ROS emission from BAT mitochondria from either genotype. Collectively, these findings indicate that selective induction of UCP1-mediated proton leak in muscle can increase whole body energy expenditure and decrease adiposity. Moreover, ectopic UCP1 expression in skeletal muscle can control mitochondrial ROS emission, while it apparently plays no such role in its endogenous tissue, brown fat.
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Affiliation(s)
- Cyril Nii-Klu Adjeitey
- Department of Biochemistry, Microbiology and Immunology, Faculty of Medicine, University of Ottawa, Ottawa, Ontario, Canada
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37
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Perrino C, Schiattarella GG, Sannino A, Pironti G, Petretta MP, Cannavo A, Gargiulo G, Ilardi F, Magliulo F, Franzone A, Carotenuto G, Serino F, Altobelli GG, Cimini V, Cuocolo A, Lombardi A, Goglia F, Indolfi C, Trimarco B, Esposito G. Genetic deletion of uncoupling protein 3 exaggerates apoptotic cell death in the ischemic heart leading to heart failure. J Am Heart Assoc 2013; 2:e000086. [PMID: 23688674 PMCID: PMC3698767 DOI: 10.1161/jaha.113.000086] [Citation(s) in RCA: 42] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/15/2023]
Abstract
BACKGROUND Uncoupling protein 3 (ucp3) is a member of the mitochondrial anion carrier superfamily of proteins uncoupling mitochondrial respiration. In this study, we investigated the effects of ucp3 genetic deletion on mitochondrial function and cell survival under low oxygen conditions in vitro and in vivo. METHODS AND RESULTS To test the effects of ucp3 deletion in vitro, murine embryonic fibroblasts and adult cardiomyocytes were isolated from wild-type (WT, n=67) and ucp3 knockout mice (ucp3(-/-), n=70). To test the effects of ucp3 genetic deletion in vivo, myocardial infarction (MI) was induced by permanent coronary artery ligation in WT and ucp3(-/-) mice. Compared with WT, ucp3(-/-) murine embryonic fibroblasts and cardiomyocytes exhibited mitochondrial dysfunction and increased mitochondrial reactive oxygen species generation and apoptotic cell death under hypoxic conditions in vitro (terminal deoxynucleotidyl transferase-dUTP nick end labeling-positive nuclei: WT hypoxia, 70.3 ± 1.2%; ucp3(-/-) hypoxia, 85.3 ± 0.9%; P<0.05). After MI, despite similar areas at risk in the 2 groups, ucp3(-/-) hearts demonstrated a significantly larger infarct size compared with WT (infarct area/area at risk: WT, 48.2 ± 3.7%; ucp3(-/-), 65.0 ± 2.9%; P<0.05). Eight weeks after MI, cardiac function was significantly decreased in ucp3(-/-) mice compared with WT (fractional shortening: WT MI, 42.7 ± 3.1%; ucp3(-/-) MI, 24.4 ± 2.9; P<0.05), and this was associated with heightened apoptotic cell death (terminal deoxynucleotidyl transferase-dUTP nick end labeling-positive nuclei: WT MI, 0.7 ± 0.04%; ucp3(-/-) MI, 1.1 ± 0.09%, P<0.05). CONCLUSIONS Our data indicate that ucp3 levels regulate reactive oxygen species levels and cell survival during hypoxia, modulating infarct size in the ischemic heart.
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Affiliation(s)
- Cinzia Perrino
- Department of Advanced Biomedical Sciences, Federico II University, Naples, Italy (C.P., G.G.S., A.S., G.P., M.P.P., A.C., G.G., F.I., F.M., A.F., G.C., F.S., G.G.A., V.C., A.C., B.T., G.E.)
| | - Gabriele G. Schiattarella
- Department of Advanced Biomedical Sciences, Federico II University, Naples, Italy (C.P., G.G.S., A.S., G.P., M.P.P., A.C., G.G., F.I., F.M., A.F., G.C., F.S., G.G.A., V.C., A.C., B.T., G.E.)
| | - Anna Sannino
- Department of Advanced Biomedical Sciences, Federico II University, Naples, Italy (C.P., G.G.S., A.S., G.P., M.P.P., A.C., G.G., F.I., F.M., A.F., G.C., F.S., G.G.A., V.C., A.C., B.T., G.E.)
| | - Gianluigi Pironti
- Department of Advanced Biomedical Sciences, Federico II University, Naples, Italy (C.P., G.G.S., A.S., G.P., M.P.P., A.C., G.G., F.I., F.M., A.F., G.C., F.S., G.G.A., V.C., A.C., B.T., G.E.)
| | - Maria Piera Petretta
- Department of Advanced Biomedical Sciences, Federico II University, Naples, Italy (C.P., G.G.S., A.S., G.P., M.P.P., A.C., G.G., F.I., F.M., A.F., G.C., F.S., G.G.A., V.C., A.C., B.T., G.E.)
| | - Alessandro Cannavo
- Department of Advanced Biomedical Sciences, Federico II University, Naples, Italy (C.P., G.G.S., A.S., G.P., M.P.P., A.C., G.G., F.I., F.M., A.F., G.C., F.S., G.G.A., V.C., A.C., B.T., G.E.)
| | - Giuseppe Gargiulo
- Department of Advanced Biomedical Sciences, Federico II University, Naples, Italy (C.P., G.G.S., A.S., G.P., M.P.P., A.C., G.G., F.I., F.M., A.F., G.C., F.S., G.G.A., V.C., A.C., B.T., G.E.)
| | - Federica Ilardi
- Department of Advanced Biomedical Sciences, Federico II University, Naples, Italy (C.P., G.G.S., A.S., G.P., M.P.P., A.C., G.G., F.I., F.M., A.F., G.C., F.S., G.G.A., V.C., A.C., B.T., G.E.)
| | - Fabio Magliulo
- Department of Advanced Biomedical Sciences, Federico II University, Naples, Italy (C.P., G.G.S., A.S., G.P., M.P.P., A.C., G.G., F.I., F.M., A.F., G.C., F.S., G.G.A., V.C., A.C., B.T., G.E.)
| | - Anna Franzone
- Department of Advanced Biomedical Sciences, Federico II University, Naples, Italy (C.P., G.G.S., A.S., G.P., M.P.P., A.C., G.G., F.I., F.M., A.F., G.C., F.S., G.G.A., V.C., A.C., B.T., G.E.)
| | - Giuseppe Carotenuto
- Department of Advanced Biomedical Sciences, Federico II University, Naples, Italy (C.P., G.G.S., A.S., G.P., M.P.P., A.C., G.G., F.I., F.M., A.F., G.C., F.S., G.G.A., V.C., A.C., B.T., G.E.)
| | - Federica Serino
- Department of Advanced Biomedical Sciences, Federico II University, Naples, Italy (C.P., G.G.S., A.S., G.P., M.P.P., A.C., G.G., F.I., F.M., A.F., G.C., F.S., G.G.A., V.C., A.C., B.T., G.E.)
| | - Giovanna G. Altobelli
- Department of Advanced Biomedical Sciences, Federico II University, Naples, Italy (C.P., G.G.S., A.S., G.P., M.P.P., A.C., G.G., F.I., F.M., A.F., G.C., F.S., G.G.A., V.C., A.C., B.T., G.E.)
| | - Vincenzo Cimini
- Department of Advanced Biomedical Sciences, Federico II University, Naples, Italy (C.P., G.G.S., A.S., G.P., M.P.P., A.C., G.G., F.I., F.M., A.F., G.C., F.S., G.G.A., V.C., A.C., B.T., G.E.)
| | - Alberto Cuocolo
- Department of Advanced Biomedical Sciences, Federico II University, Naples, Italy (C.P., G.G.S., A.S., G.P., M.P.P., A.C., G.G., F.I., F.M., A.F., G.C., F.S., G.G.A., V.C., A.C., B.T., G.E.)
| | - Assunta Lombardi
- Department of Biology, Federico II University, Naples, Italy (A.L.)
| | - Fernando Goglia
- Department of Biology Sciences, Geology and Environment, Sannio University, Benevento, Italy (F.G.)
| | - Ciro Indolfi
- Department of Cardiology, Magna Graecia University, Catanzaro, Italy (C.I.)
| | - Bruno Trimarco
- Department of Advanced Biomedical Sciences, Federico II University, Naples, Italy (C.P., G.G.S., A.S., G.P., M.P.P., A.C., G.G., F.I., F.M., A.F., G.C., F.S., G.G.A., V.C., A.C., B.T., G.E.)
| | - Giovanni Esposito
- Department of Advanced Biomedical Sciences, Federico II University, Naples, Italy (C.P., G.G.S., A.S., G.P., M.P.P., A.C., G.G., F.I., F.M., A.F., G.C., F.S., G.G.A., V.C., A.C., B.T., G.E.)
- Correspondence to: Giovanni Esposito, MD, PhD, or Cinzia Perrino, MD, PhD, Division of Cardiology, Federico II University, Via Pansini 5, 80131 Naples, Italy. E‐mail: ,
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Pichaud N, Garratt M, Ballard JWO, Brooks RC. Physiological adaptations to reproduction. II. Mitochondrial adjustments in livers of lactating mice. ACTA ACUST UNITED AC 2013; 216:2889-95. [PMID: 23619407 DOI: 10.1242/jeb.082685] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/08/2023]
Abstract
Reproduction imposes significant costs and is characterized by an increased energy demand. As a consequence, individuals adjust their cellular structure and function in response to this physiological constraint. Because mitochondria are central to energy production, changes in their functional properties are likely to occur during reproduction. Such changes could cause adjustments in reactive oxygen species (ROS) production and consequently in oxidative stress levels. In this study, we investigated several mechanisms involved in energy production, including mitochondrial respiration at different steps of the electron transport system (ETS) and related the results to citrate synthase activity in the liver of non-reproductive and reproductive (two and eight pups) female house mice at peak lactation. Whereas we did not find differences between females having different litter sizes, liver mitochondria of reproductive females showed lower ETS activity and an increase in mitochondrial density when compared with the non-reproductive females. Although it is possible that these changes were due to combined processes involved in reproduction and not to the relative investment in lactation, we propose that the mitochondrial adjustment in liver might help to spare substrates and therefore energy for milk production in the mammary gland. Moreover, our results suggest that these changes lead to an increase in ROS production that subsequently upregulates antioxidant defence activity and decreases oxidative stress.
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Affiliation(s)
- Nicolas Pichaud
- Evolution and Ecology Research Centre and School of Biological, Earth and Environmental Sciences, The University of New South Wales, Sydney, New South Wales 2052, Australia.
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Liesa M, Shirihai OS. Mitochondrial dynamics in the regulation of nutrient utilization and energy expenditure. Cell Metab 2013; 17:491-506. [PMID: 23562075 PMCID: PMC5967396 DOI: 10.1016/j.cmet.2013.03.002] [Citation(s) in RCA: 941] [Impact Index Per Article: 85.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/24/2022]
Abstract
Mitochondrial fusion, fission, and mitophagy form an essential axis of mitochondrial quality control. However, quality control might not be the only task carried out by mitochondrial dynamics. Recent studies link mitochondrial dynamics to the balance between energy demand and nutrient supply, suggesting changes in mitochondrial architecture as a mechanism for bioenergetic adaptation to metabolic demands. By favoring either connected or fragmented architectures, mitochondrial dynamics regulates bioenergetic efficiency and energy expenditure. Placement of bioenergetic adaptation and quality control as competing tasks of mitochondrial dynamics might provide a new mechanism, linking excess nutrient environment to progressive mitochondrial dysfunction, common to age-related diseases.
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Affiliation(s)
- Marc Liesa
- Department of Medicine, Obesity and Nutrition Section, Mitochondria ARC, Evans Biomedical Research Center, Boston University School of Medicine, 650 Albany Street, Boston, MA 02118, USA
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40
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Divakaruni AS, Humphrey DM, Brand MD. Fatty acids change the conformation of uncoupling protein 1 (UCP1). J Biol Chem 2012; 287:36845-53. [PMID: 22952235 DOI: 10.1074/jbc.m112.381780] [Citation(s) in RCA: 40] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/02/2023] Open
Abstract
UCP1 catalyzes proton leak across the mitochondrial inner membrane to disengage substrate oxidation from ATP production. It is well established that UCP1 is activated by fatty acids and inhibited by purine nucleotides, but precisely how this regulation occurs remains unsettled. Although fatty acids can competitively overcome nucleotide inhibition in functional assays, fatty acids have little effect on purine nucleotide binding. Here, we present the first demonstration that fatty acids induce a conformational change in UCP1. Palmitate dramatically changed the binding kinetics of 2'/3'-O-(N-methylanthraniloyl)-GDP, a fluorescently labeled nucleotide analog, for UCP1. Furthermore, palmitate accelerated the rate of enzymatic proteolysis of UCP1. The altered kinetics of both processes indicate that fatty acids change the conformation of UCP1, reconciling the apparent discrepancy between existing functional and ligand binding data. Our results provide a framework for how fatty acids and nucleotides compete to regulate the activity of UCP1.
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Affiliation(s)
- Ajit S Divakaruni
- Medical Research Council Mitochondrial Biology Unit, Cambridge CB2 0XY, United Kingdom.
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41
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Jastroch M, Hirschberg V, Klingenspor M. Functional characterization of UCP1 in mammalian HEK293 cells excludes mitochondrial uncoupling artefacts and reveals no contribution to basal proton leak. BIOCHIMICA ET BIOPHYSICA ACTA-BIOENERGETICS 2012; 1817:1660-70. [PMID: 22676960 DOI: 10.1016/j.bbabio.2012.05.014] [Citation(s) in RCA: 44] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/10/2012] [Revised: 05/22/2012] [Accepted: 05/28/2012] [Indexed: 02/02/2023]
Abstract
Mechanistic studies on uncoupling proteins (UCPs) not only are important to identify their cellular function but also are pivotal to identify potential drug targets to manipulate mitochondrial energy transduction. So far, functional and comparative studies of uncoupling proteins in their native environment are hampered by different mitochondrial, cellular and genetic backgrounds. Artificial systems such as yeast ectopically expressing UCPs or liposomes with reconstituted UCPs were employed to address crucial mechanistic questions but these systems also produced inconsistencies with results from native mitochondria. We here introduce a novel mammalian cell culture system (Human Embryonic Kidney 293 - HEK293) to study UCP1 function. Stably transfected HEK293 cell lines were derived that contain mouse UCP1 at concentrations comparable to tissue mitochondria. In this cell-based test system UCP1 displays native functional behaviour as it can be activated with fatty acids (palmitate) and inhibited with purine nucleotides guanosine-diphosphate (GDP). The catalytic centre activity of the UCP1 homodimer in HEK293 is comparable to activities in brown adipose tissue supporting functionality of UCP1. Importantly, at higher protein levels than in yeast mitochondria, UCP1 in HEK293 cell mitochondria is fully inhibitable and does not contribute to basal proton conductance, thereby emphasizing the requirement of UCP1 activation for therapeutic purposes. These findings and resulting analysis on UCP1 characteristics demonstrate that the mammalian HEK293 cell system is suitable for mechanistic and comparative functional studies on UCPs and provides a non-confounding mitochondrial, cellular and genetic background.
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Affiliation(s)
- Martin Jastroch
- Institute for Diabetes and Obesity, Helmholtz Zentrum Munich, Neuherberg, Germany.
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42
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Divakaruni AS, Brand MD. The regulation and physiology of mitochondrial proton leak. Physiology (Bethesda) 2011; 26:192-205. [PMID: 21670165 DOI: 10.1152/physiol.00046.2010] [Citation(s) in RCA: 279] [Impact Index Per Article: 21.5] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/22/2023] Open
Abstract
Mitochondria couple respiration to ATP synthesis through an electrochemical proton gradient. Proton leak across the inner membrane allows adjustment of the coupling efficiency. The aim of this review is threefold: 1) introduce the unfamiliar reader to proton leak and its physiological significance, 2) review the role and regulation of uncoupling proteins, and 3) outline the prospects of proton leak as an avenue to treat obesity, diabetes, and age-related disease.
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Affiliation(s)
- Ajit S Divakaruni
- Medical Research Council Mitochondrial Biology Unit, Wellcome Trust/MRC Building, Cambridge, United Kingdom
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43
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Mailloux RJ, Adjeitey CNK, Xuan JY, Harper ME. Crucial yet divergent roles of mitochondrial redox state in skeletal muscle vs. brown adipose tissue energetics. FASEB J 2011; 26:363-75. [PMID: 21940996 DOI: 10.1096/fj.11-189639] [Citation(s) in RCA: 51] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
Abstract
Reduced glutathione (GSH) is the major determinant of redox balance in mitochondria and as such is fundamental in the control of cellular bioenergetics. GSH is also the most important nonprotein antioxidant molecule in cells. Surprisingly, the effect of redox environment has never been examined in skeletal muscle and brown adipose tissue (BAT), two tissues that have exceptional dynamic range and that are relevant to the development of obesity and related diseases. Here, we show that the redox environment plays crucial, yet divergent, roles in modulating mitochondrial bioenergetics in skeletal muscle and BAT. Skeletal muscle mitochondria were found to naturally have a highly reduced environment (GSH/GSSG≈46), and this was associated with fairly high (∼40%) rates of state 4 (nonphosphorylating) respiration and decreased reactive oxygen species (ROS) emission. The deglutathionylation of uncoupling protein 3 (UCP3) following an increase in the reductive potential of mitochondria results in a further increase in nonphosphorylating respiration (∼20% in situ). BAT mitochondria were found to have a much more oxidized status (GSH/GSSG≈13) and had basal reactive oxygen species emission that was higher (∼250% increase in ROS generation) than that in skeletal muscle mitochondria. When redox status was subsequently increased (i.e., more reduced), UCP1-mediated uncoupling was more sensitive to GDP inhibition. Surprisingly, BAT was found to be devoid of glutaredoxin-2 (Grx2) expression, while there was abundant expression in skeletal muscle. Taken together, these findings reveal the importance of redox environment in controlling bioenergetic functions in both tissues, and the highly unique characteristics of BAT in this regard.
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Affiliation(s)
- Ryan J Mailloux
- University of Ottawa, Department of Biochemistry, Microbiology, and Immunology, Ottawa, ON, Canada
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44
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Mookerjee SA, Brand MD. Characteristics of the turnover of uncoupling protein 3 by the ubiquitin proteasome system in isolated mitochondria. BIOCHIMICA ET BIOPHYSICA ACTA-BIOENERGETICS 2011; 1807:1474-81. [PMID: 21820402 DOI: 10.1016/j.bbabio.2011.07.011] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/13/2011] [Revised: 07/12/2011] [Accepted: 07/21/2011] [Indexed: 11/18/2022]
Abstract
Uncoupling protein 3 (UCP3) is implicated in mild uncoupling and the regulation of mitochondrial ROS production. We previously showed that UCP3 turns over rapidly in C2C12 myoblasts, with a half-life of 0.5-4h, and that turnover can be reconstituted in vitro. We show here that rapid degradation of UCP3 in vitro in isolated brown adipose tissue mitochondria required the 26S proteasome, ubiquitin, ATP, succinate to generate a high membrane potential, and a pH of 7.4 or less. Ubiquitin containing lysine-48 was both necessary and sufficient to support UCP3 degradation, implying a requirement for polyubiquitylation at this residue. The 20S proteasome did not support degradation. UCP3 degradation was prevented by simultaneously blocking matrix ATP generation and import, showing that ATP in the mitochondrial matrix was required. Degradation did not appear to require a transmembrane pH gradient, but was very sensitive to membrane potential: degradation was halved when membrane potential decreased 10-20mV from its resting value, and was not significant below about 120mV. We propose that matrix ATP and a high membrane potential are needed for UCP3 to be polyubiquitylated through lysine-48 of ubiquitin and exported to the cytosolic 26S proteasome, where it is de-ubiquitylated and degraded.
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Garcia-Cazarin ML, Gamboa JL, Andrade FH. Rat diaphragm mitochondria have lower intrinsic respiratory rates than mitochondria in limb muscles. Am J Physiol Regul Integr Comp Physiol 2011; 300:R1311-5. [PMID: 21389333 DOI: 10.1152/ajpregu.00203.2010] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/14/2023]
Abstract
The mitochondrial content of skeletal muscles is proportional to activity level, with the assumption that intrinsic mitochondrial function is the same in all muscles. This may not hold true for all muscles. For example, the diaphragm is a constantly active muscle; it is possible that its mitochondria are intrinsically different compared with other muscles. This study tested the hypothesis that mitochondrial respiration rates are greater in the diaphragm compared with triceps surae (TS, a limb muscle). We isolated mitochondria from diaphragm and TS of adult male Sprague Dawley rats. Mitochondrial respiration was measured by polarography. The contents of respiratory complexes, uncoupling proteins 1, 2, and 3 (UCP1, UCP2, and UCP3), and voltage-dependent anion channel 1 (VDAC1) were determined by immunoblotting. Complex IV activity was measured by spectrophotometry. Mitochondrial respiration states 3 (substrate and ADP driven) and 5 (uncoupled) were 27 ± 8% and 24 ± 10%, respectively, lower in diaphragm than in TS (P < 0.05 for both comparisons). However, the contents of respiratory complexes III, IV, and V, UCP1, and VDAC1 were higher in diaphragm mitochondria (23 ± 6, 30 ± 8, 25 ± 8, 36 ± 15, and 18 ± 8% respectively, P ≤ 0.04 for all comparisons). Complex IV activity was 64 ± 16% higher in diaphragm mitochondria (P ≤ 0.01). Mitochondrial UCP2 and UCP3 content and complex I activity were not different between TS and diaphragm. These data indicate that diaphragm mitochondria respire at lower rates, despite a higher content of respiratory complexes. The results invalidate our initial hypothesis and indicate that mitochondrial content is not the only determinant of aerobic capacity in the diaphragm. We propose that UCP1 and VDAC1 play a role in regulating diaphragm aerobic capacity.
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Hirschberg V, Fromme T, Klingenspor M. Test systems to study the structure and function of uncoupling protein 1: a critical overview. Front Endocrinol (Lausanne) 2011; 2:63. [PMID: 22654819 PMCID: PMC3356129 DOI: 10.3389/fendo.2011.00063] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/31/2011] [Accepted: 10/12/2011] [Indexed: 01/06/2023] Open
Abstract
The discovery of active brown adipose tissue (BAT) in healthy adult humans has renewed interest in the biology of this organ. BAT is capable of distributing nutrient energy in the form of heat allowing small mammals to efficiently defend their body temperature when acutely exposed to the cold. On the other hand BAT might be a target for the treatment of obesity and related diseases, as its pharmacological activation could allow release of excess energy stored in white adipose tissue depots. Energy dissipation in BAT depends on the activity of uncoupling protein 1 (UCP1), therefore a BAT-based obesity therapy requires a detailed understanding of structure and function of UCP1. Although UCP1 has been in the focus of research since its discovery, central questions concerning its mechanistic function and regulation are not yet resolved. They have been addressed in native mitochondria but also in several test systems, which are generally used to lower inter-experimental variability and to simplify analysis conditions. Different test systems have contributed to our current knowledge about UCP1 but of course all of them have certain limitations. We here provide an overview about research on UCP1 structure and function in test systems. So far, these have nearly exclusively been employed to study rodent and not human UCP1. Considering that the amino acid sequence of mouse and human UCP1 is only 79% identical, it will be essential to test whether the human version has a similarly high catalytic activity, allowing a relevant amount of energy dissipation in human BAT. Besides the issue of comparable mechanistic function a sufficiently high expression level of human UCP1 is a further prerequisite for anti-obesity therapeutic potential. Treatments which induce BAT hyperplasia and UCP1 expression in humans might therefore be equally important to discover as mere activators of the thermogenic process.
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Affiliation(s)
- Verena Hirschberg
- Molecular Nutritional Medicine, Else Kröner-Fresenius Zentrum, Technische Universität MünchenFreising, Germany
- *Correspondence: Verena Hirschberg, Molecular Nutritional Medicine, Else Kröner-Fresenius Zentrum, Technische Universität München, Gregor-Mendel-Str. 2, 85350 Freising-Weihenstephan, Germany e-mail:
| | - Tobias Fromme
- Molecular Nutritional Medicine, Else Kröner-Fresenius Zentrum, Technische Universität MünchenFreising, Germany
| | - Martin Klingenspor
- Molecular Nutritional Medicine, Else Kröner-Fresenius Zentrum, Technische Universität MünchenFreising, Germany
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Abstract
Mitochondrial proton and electron leak have a major impact on mitochondrial coupling efficiency and production of reactive oxygen species. In the first part of this chapter, we address the molecular nature of the basal and inducible proton leak pathways, and their physiological importance. The basal leak is unregulated, and a major proportion can be attributed to mitochondrial anion carriers, whereas the proton leak through the lipid bilayer appears to be minor. The basal proton leak is cell-type specific and correlates with metabolic rate. The inducible leak through the ANT (adenine nucleotide translocase) and UCPs (uncoupling proteins) can be activated by fatty acids, superoxide or lipid peroxidation products. The physiological role of inducible leak through UCP1 in mammalian brown adipose tissue is heat production, whereas the roles of non-mammalian UCP1 and its paralogous proteins, in particular UCP2 and UCP3, are not yet resolved. The second part of the chapter focuses on the electron leak that occurs in the mitochondrial electron transport chain. Exit of electrons prior to the reduction of oxygen to water at cytochrome c oxidase causes superoxide production. As the mechanisms of electron leak are crucial to understanding their physiological relevance, we summarize the mechanisms and topology of electron leak from complexes I and III in studies using isolated mitochondria. We also highlight recent progress and challenges of assessing electron leak in the living cell. Finally, we emphasize the importance of proton and electron leak as therapeutic targets in body mass regulation and insulin secretion.
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48
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Shabalina IG, Ost M, Petrovic N, Vrbacky M, Nedergaard J, Cannon B. Uncoupling protein-1 is not leaky. BIOCHIMICA ET BIOPHYSICA ACTA-BIOENERGETICS 2010; 1797:773-84. [PMID: 20399195 DOI: 10.1016/j.bbabio.2010.04.007] [Citation(s) in RCA: 74] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/17/2010] [Revised: 03/23/2010] [Accepted: 04/08/2010] [Indexed: 10/19/2022]
Abstract
The activity of uncoupling protein-1 (UCP1) is rate-limiting for nonshivering thermogenesis and diet-induced thermogenesis. Characteristically, this activity is inhibited by GDP experimentally and presumably mainly by cytosolic ATP within brown-fat cells. The issue as to whether UCP1 has a residual proton conductance even when fully saturated with GDP/ATP (as has recently been suggested) has not only scientific but also applied interest, since a residual proton conductance would make overexpressed UCP1 weight-reducing even without physiological/pharmacological activation. To examine this question, we have here established optimal conditions for studying the bioenergetics of wild-type and UCP1-/- brown-fat mitochondria, analysing UCP1-mediated differences in parallel preparations of brown-fat mitochondria from both genotypes. Comparing different substrates, we find that pyruvate (or palmitoyl-L-carnitine) shows the largest relative coupling by GDP. Comparing albumin concentrations, we find the range 0.1-0.6% optimal; higher concentrations are inhibitory. Comparing basic medium composition, we find 125 mM sucrose optimal; an ionic medium (50-100 mM KCl) functions for wild-type but is detrimental for UCP1-/- mitochondria. Using optimal conditions, we find no evidence for a residual proton conductance (not a higher post-GDP respiration, a lower membrane potential or an altered proton leak at highest common potential) with either pyruvate or glycerol-3-phosphate as substrates, nor by a 3-4-fold alteration of the amount of UCP1. We could demonstrate that certain experimental conditions, due to respiratoty inhibition, could lead to the suggestion that UCP1 possesses a residual proton conductance but find that under optimal conditions our experiments concur with implications from physiological observations that in the presence of inhibitory nucleotides, UCP1 is not leaky.
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Affiliation(s)
- Irina G Shabalina
- The Wenner-Gren Institute, Stockholm University, SE-106 91 Stockholm, Sweden
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Multi-site control and regulation of mitochondrial energy production. BIOCHIMICA ET BIOPHYSICA ACTA-BIOENERGETICS 2010; 1797:698-709. [PMID: 20226160 DOI: 10.1016/j.bbabio.2010.02.030] [Citation(s) in RCA: 84] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/09/2009] [Revised: 02/19/2010] [Accepted: 02/24/2010] [Indexed: 12/21/2022]
Abstract
With the extraordinary progress of mitochondrial science and cell biology, novel biochemical pathways have emerged as strategic points of bioenergetic regulation and control. They include mitochondrial fusion, fission and organellar motility along microtubules and microfilaments (mitochondrial dynamics), mitochondrial turnover (biogenesis and degradation), and mitochondrial phospholipids synthesis. Yet, much is still unknown about the mutual interaction between mitochondrial energy state, biogenesis, dynamics and degradation. Meanwhile, clinical research into metabolic abnormalities in tumors as diverse as renal carcinoma, glioblastomas, paragangliomas or skin leiomyomata, has designated new genes, oncogenes and oncometabolites involved in the regulation of cellular and mitochondrial energy production. Furthermore, the examination of rare neurological diseases such as Charcot-Marie Tooth type 2a, Autosomal Dominant Optic Atrophy, Lethal Defect of Mitochondrial and Peroxisomal Fission, or Spastic Paraplegia suggested involvement of MFN2, OPA1/3, DRP1 or Paraplegin, in the auxiliary control of mitochondrial energy production. Lastly, advances in the understanding of mitochondrial apoptosis have suggested a supplementary role for Bcl2 or Bax in the regulation of mitochondrial respiration and dynamics, which has fostered the investigation of alternative mechanisms of energy regulation. In this review, we discuss the regulatory mechanisms of cellular and mitochondrial energy production, and we emphasize the importance of the study of rare neurological diseases in addition to more common disorders such as cancer, for the fundamental understanding of cellular and mitochondrial energy production.
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Azzu V, Jastroch M, Divakaruni AS, Brand MD. The regulation and turnover of mitochondrial uncoupling proteins. BIOCHIMICA ET BIOPHYSICA ACTA-BIOENERGETICS 2010; 1797:785-91. [PMID: 20211596 DOI: 10.1016/j.bbabio.2010.02.035] [Citation(s) in RCA: 92] [Impact Index Per Article: 6.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/21/2009] [Revised: 02/23/2010] [Accepted: 02/25/2010] [Indexed: 12/15/2022]
Abstract
Uncoupling proteins (UCP1, UCP2 and UCP3) are important in regulating cellular fuel metabolism and as attenuators of reactive oxygen species production through strong or mild uncoupling. The generic function and broad tissue distribution of the uncoupling protein family means that they are increasingly implicated in a range of pathophysiological processes including obesity, insulin resistance and diabetes mellitus, neurodegeneration, cardiovascular disease, immunity and cancer. The significant recent progress describing the turnover of novel uncoupling proteins, as well as current views on the physiological roles and regulation of UCPs, is outlined.
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Affiliation(s)
- Vian Azzu
- Medical Research Council Mitochondrial Biology Unit, Hills Road, Cambridge CB2 0XY, UK.
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