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Antos-Krzeminska N, Kicinska A, Nowak W, Jarmuszkiewicz W. Acanthamoeba castellanii Uncoupling Protein: A Complete Sequence, Activity, and Role in Response to Oxidative Stress. Int J Mol Sci 2023; 24:12501. [PMID: 37569876 PMCID: PMC10419851 DOI: 10.3390/ijms241512501] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/26/2023] [Revised: 08/01/2023] [Accepted: 08/04/2023] [Indexed: 08/13/2023] Open
Abstract
Uncoupling proteins (UCPs) are mitochondrial inner membrane transporters that mediate free-fatty-acid-induced, purine-nucleotide-inhibited proton leak into the mitochondrial matrix, thereby uncoupling respiratory substrate oxidation from ATP synthesis. The aim of this study was to provide functional evidence that the putative Acucp gene of the free-living protozoan amoeba, A. castellanii, encodes the mitochondrial protein with uncoupling activity characteristic of UCPs and to investigate its role during oxidative stress. We report the sequencing and cloning of a complete Acucp coding sequence, its phylogenetic analysis, and the heterologous expression of AcUCP in the S. cerevisiae strain InvSc1. Measurements of mitochondrial respiratory activity and membrane potential indicate that the heterologous expression of AcUCP causes AcUCP-mediated uncoupling activity. In addition, in a model of oxidative stress with increased reactive oxygen species levels (superoxide dismutase 1 knockout yeasts), AcUCP expression strongly promotes cell survival and growth. The level of superoxide anion radicals is greatly reduced in the ΔSOD1 strain expressing AcUCP. These results suggest that AcUCP targeted to yeast mitochondria causes uncoupling and may act as an antioxidant system. Phylogenetic analysis shows that the A. castellanii UCP diverges very early from other UCPs, but clearly locates within the UCP subfamily rather than among other mitochondrial anion carrier proteins.
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Affiliation(s)
- Nina Antos-Krzeminska
- Department of Bioenergetics, Faculty of Biology, Adam Mickiewicz University, Uniwersytetu Poznanskiego 6, 61-614 Poznan, Poland; (A.K.); (W.J.)
| | - Anna Kicinska
- Department of Bioenergetics, Faculty of Biology, Adam Mickiewicz University, Uniwersytetu Poznanskiego 6, 61-614 Poznan, Poland; (A.K.); (W.J.)
| | - Witold Nowak
- Molecular Biology Techniques Laboratory, Faculty of Biology, Adam Mickiewicz University, Uniwersytetu Poznanskiego 6, 61-614 Poznan, Poland;
| | - Wieslawa Jarmuszkiewicz
- Department of Bioenergetics, Faculty of Biology, Adam Mickiewicz University, Uniwersytetu Poznanskiego 6, 61-614 Poznan, Poland; (A.K.); (W.J.)
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Lima RPM, Nunes-Laitz AV, Arcuri MDLC, Campos FG, Joca TAC, Monteiro GC, Kushima H, Lima GPP, de Almeida LFR, Barreto P, de Godoy Maia I. The double knockdown of the mitochondrial uncoupling protein isoforms reveals partial redundant roles during Arabidopsis thaliana vegetative and reproductive development. PLANT SCIENCE : AN INTERNATIONAL JOURNAL OF EXPERIMENTAL PLANT BIOLOGY 2022; 322:111365. [PMID: 35779675 DOI: 10.1016/j.plantsci.2022.111365] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/24/2022] [Revised: 06/22/2022] [Accepted: 06/24/2022] [Indexed: 06/15/2023]
Abstract
Mitochondrial uncoupling proteins (UCPs) are specialized proteins capable of dissipating the proton electrochemical gradient generated in respiration independent of ATP synthesis. Three UCP coding genes with distinct expression patterns have been identified in Arabidopsis thaliana (namely UCP1, UCP2 and UCP3). Here, we generated T-DNA double-insertion mutants (ucp1 ucp2, ucp1 ucp3 and ucp2 ucp3) to investigate the functionality of the Arabidopsis UCP isoforms. A strong compensatory effect of the wild-type UCP gene was found in the double-knockdown lines. Higher levels of reactive oxygen species (ROS) were observed in vegetative and reproductive organs of double mutant plants. This exacerbated oxidative stress in plants also increased lipid peroxidation but was not compensated by the activation of the antioxidant system. Alterations in O2 consumption and ADP/ATP ratio were also observed, suggesting a change in mitochondrial energy-generating processes. Deficiencies in double-mutants were not limited to mitochondria and also changed photosynthetic efficiency and redox state. Our results indicate that UCP2 and UCP3 have complementary function with UCP1 in plant reproductive and vegetative organ/tissues, as well as in stress adaptation. The partial redundancy between the UCP isoforms suggests that they could act separately or jointly on mitochondrial homeostasis during A. thaliana development.
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Affiliation(s)
- Rômulo Pedro Macêdo Lima
- Departamento de Ciências Químicas e Biológicas (Setor Genética), Instituto de Biociências, UNESP, CEP 18618-689 Botucatu, SP, Brazil
| | | | - Mariana de Lara Campos Arcuri
- Departamento de Ciências Químicas e Biológicas (Setor Genética), Instituto de Biociências, UNESP, CEP 18618-689 Botucatu, SP, Brazil
| | - Felipe Girotto Campos
- Departamento de Bioestatística, Biologia Vegetal, Parasitologia e Zoologia (Setor Botânica), Instituto de Biociências, UNESP, CEP 18618-689 Botucatu, SP, Brazil
| | - Thaís Arruda Costa Joca
- Departamento de Bioestatística, Biologia Vegetal, Parasitologia e Zoologia (Setor Botânica), Instituto de Biociências, UNESP, CEP 18618-689 Botucatu, SP, Brazil
| | - Gean Charles Monteiro
- Departamento de Ciências Químicas e Biológicas (Setor de Química e Bioquímica), Instituto de Biociências, UNESP, CEP 18618-689 Botucatu, SP, Brazil
| | - Hélio Kushima
- Departamento de Biofísica e Farmacologia (Setor Farmacologia), Instituto de Biociências, UNESP, CEP 18618-689 Botucatu, SP, Brazil
| | - Giuseppina Pace Pereira Lima
- Departamento de Ciências Químicas e Biológicas (Setor de Química e Bioquímica), Instituto de Biociências, UNESP, CEP 18618-689 Botucatu, SP, Brazil
| | - Luiz Fernando Rolim de Almeida
- Departamento de Bioestatística, Biologia Vegetal, Parasitologia e Zoologia (Setor Botânica), Instituto de Biociências, UNESP, CEP 18618-689 Botucatu, SP, Brazil
| | - Pedro Barreto
- Departamento de Ciências Químicas e Biológicas (Setor Genética), Instituto de Biociências, UNESP, CEP 18618-689 Botucatu, SP, Brazil
| | - Ivan de Godoy Maia
- Departamento de Ciências Químicas e Biológicas (Setor Genética), Instituto de Biociências, UNESP, CEP 18618-689 Botucatu, SP, Brazil.
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Arcuri MDLC, Nunes-Laitz AV, Lima RPM, Barreto P, Marinho AN, Arruda P, Maia IG. Knockdown of Mitochondrial Uncoupling Proteins 1 and 2 (AtUCP1 and 2) in Arabidopsis thaliana Impacts Vegetative Development and Fertility. PLANT & CELL PHYSIOLOGY 2021; 62:1630-1644. [PMID: 34314506 DOI: 10.1093/pcp/pcab117] [Citation(s) in RCA: 9] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/21/2021] [Revised: 07/20/2021] [Accepted: 07/27/2021] [Indexed: 06/13/2023]
Abstract
Mitochondrial uncoupling proteins (UCPs) are mitochondrial inner membrane proteins that dissipate the proton electrochemical gradient generated by the respiratory chain complexes. In plants, these proteins are crucial for maintaining mitochondrial reactive oxygen species (ROS) homeostasis. In this study, single T-DNA insertion mutants for two (AtUCP1 and AtUCP2) out of the three UCP genes present in Arabidopsis thaliana were employed to elucidate their potential roles in planta. Our data revealed a significant increase in the Adenosine triphosphate (ATP)/Adenosine diphosphate (ADP) ratios of both mutants, indicating clear alterations in energy metabolism, and a reduced respiratory rate in atucp2. Phenotypic characterization revealed that atucp1 and atucp2 plants displayed reduced primary root growth under normal and stressed conditions. Moreover, a reduced fertility phenotype was observed in both mutants, which exhibited an increased number of sterile siliques and a lower seed yield compared with wild-type plants. Reciprocal crosses demonstrated that both male fertility and female fertility were compromised in atucp1, while such effect was exclusively observed in the male counterpart in atucp2. Most strikingly, a pronounced accumulation of hydrogen peroxide in the reproductive organs was observed in all mutant lines, indicating a disturbance in ROS homeostasis of mutant flowers. Accordingly, the atucp1 and atucp2 mutants exhibited higher levels of ROS in pollen grains. Further, alternative oxidase 1a was highly induced in mutant flowers, while the expression profiles of transcription factors implicated in gene regulation during female and male reproductive organ/tissue development were perturbed. Overall, these data support the important role for AtUCP1 and AtUCP2 in flower oxidative homeostasis and overall plant fertility.
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Affiliation(s)
- Mariana de Lara Campos Arcuri
- Departamento de Ciências Químicas e Biológicas, Instituto de Biociências de Botucatu, UNESP, R. Prof. Dr. Antônio Celso Wagner Zanin, 250, Botucatu, SP 18618-689, Brazil
| | - Alessandra Vasconcellos Nunes-Laitz
- Departamento de Ciências Químicas e Biológicas, Instituto de Biociências de Botucatu, UNESP, R. Prof. Dr. Antônio Celso Wagner Zanin, 250, Botucatu, SP 18618-689, Brazil
- Instituto Federal de Educação, Ciência e Tecnologia de Rondônia, Campus Colorado do Oeste, Colorado do Oeste, Brazil
| | - Rômulo Pedro Macêdo Lima
- Departamento de Ciências Químicas e Biológicas, Instituto de Biociências de Botucatu, UNESP, R. Prof. Dr. Antônio Celso Wagner Zanin, 250, Botucatu, SP 18618-689, Brazil
| | - Pedro Barreto
- UNICAMP, Centro de Biologia Molecular e Engenharia Genética, Av. Cândido Rondon, 400, Campinas, SP 13083-875, Brazil
| | - Andressa Nagatani Marinho
- Departamento de Ciências Químicas e Biológicas, Instituto de Biociências de Botucatu, UNESP, R. Prof. Dr. Antônio Celso Wagner Zanin, 250, Botucatu, SP 18618-689, Brazil
| | - Paulo Arruda
- UNICAMP, Centro de Biologia Molecular e Engenharia Genética, Av. Cândido Rondon, 400, Campinas, SP 13083-875, Brazil
| | - Ivan G Maia
- Departamento de Ciências Químicas e Biológicas, Instituto de Biociências de Botucatu, UNESP, R. Prof. Dr. Antônio Celso Wagner Zanin, 250, Botucatu, SP 18618-689, Brazil
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Cerrato CP, Kivijärvi T, Tozzi R, Lehto T, Gestin M, Langel Ü. Intracellular delivery of therapeutic antisense oligonucleotides targeting mRNA coding mitochondrial proteins by cell-penetrating peptides. J Mater Chem B 2020; 8:10825-10836. [PMID: 33174901 DOI: 10.1039/d0tb01106a] [Citation(s) in RCA: 9] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/21/2022]
Abstract
Cell-penetrating peptides are a promising therapeutic strategy for a wide variety of degenerative diseases, ageing, and cancer. Among the multitude of cell-penetrating peptides, PepFect14 has been preferentially used in our laboratory for oligonucleotide delivery into cells and in vivo mouse models. However, this activity has mainly been reported towards cytoplasm and nuclei, while the mentioned disorders have been linked to mitochondrial defects. Here, we report a library generated from a combinatorial covalent fusion of a mitochondrial-penetrating peptide, mtCPP1, and PepFect14 in order to deliver therapeutic biomolecules to influence mitochondrial protein expression. The non-covalent complexation of these peptides with oligonucleotides resulted in nano-complexes affecting biological functions in the cytoplasm and on mitochondria. This delivery system proved to efficiently target mitochondrial genes, providing a framework for the development of mitochondrial peptide-based oligonucleotide technologies with the potential to be used as a treatment for patients with mitochondrial disorders.
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Affiliation(s)
- Carmine Pasquale Cerrato
- Department of Biochemistry and Biophysics, The Arrhenius Laboratories for Natural Sciences, Stockholm University, Svante Arrhenius väg 16B, SE-10691 Stockholm, Sweden.
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Barreto P, Couñago RM, Arruda P. Mitochondrial uncoupling protein-dependent signaling in plant bioenergetics and stress response. Mitochondrion 2020; 53:109-120. [DOI: 10.1016/j.mito.2020.05.001] [Citation(s) in RCA: 14] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/20/2019] [Revised: 04/06/2020] [Accepted: 05/14/2020] [Indexed: 12/15/2022]
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Braganza A, Corey CG, Santanasto AJ, Distefano G, Coen PM, Glynn NW, Nouraie SM, Goodpaster BH, Newman AB, Shiva S. Platelet bioenergetics correlate with muscle energetics and are altered in older adults. JCI Insight 2019; 5:128248. [PMID: 31120438 DOI: 10.1172/jci.insight.128248] [Citation(s) in RCA: 38] [Impact Index Per Article: 7.6] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/03/2023] Open
Abstract
BACKGROUND Physical function decreases with age, and though bioenergetic alterations contribute to this decline, the mechanisms by which mitochondrial function changes with age remains unclear. This is partially because human mitochondrial studies require highly invasive procedures, such as muscle biopsies, to obtain live tissue with functional mitochondria. However, recent studies demonstrate that circulating blood cells are potentially informative in identifying systemic bioenergetic changes. Here, we hypothesize that human platelet bioenergetics reflect bioenergetics measured in muscle biopsies. METHODS & RESULTS We demonstrate that maximal and ATP-linked respiratory rate measured in isolated platelets from older adults (86-93 years) correlates significantly with maximal respiration (r = 0.595; P = 0.003) measured by muscle biopsy respirometry and maximal ATP production (r = 0.643; P = 0.004) measured by 31P-MRS respectively, in the same individuals. Comparison of platelet bioenergetics in this aged cohort to platelets from younger adults (18-35 years) shows aged adults demonstrate lower basal and ATP-linked respiration. Platelets from older adults also show enhanced proton leak, which is likely due to increased protein levels of uncoupling protein 2, and correlates with increased gate speed in this cohort (r = 0.58; P = 0.0019). While no significant difference in glycolysis was observed in older adults compared to younger adults, platelet glycolytic rate correlated with fatigability (r = 0.44; P = 0.016). CONCLUSIONS These data advance the mechanistic understanding of age-related changes in mitochondrial function. Further, they suggest that measuring platelet bioenergetics provides a potential supplement or surrogate for muscle biopsy measurement and may be a valuable tool to study mitochondrial involvement in age-related decline of physical function.
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Affiliation(s)
| | | | | | | | | | | | - Seyed-Mehdi Nouraie
- Vascular Medicine Institute.,Division of Pulmonary, Allergy, and Critical Care, Department of Medicine
| | | | | | - Sruti Shiva
- Vascular Medicine Institute.,Department of Pharmacology and Chemical Biology.,Center for Metabolism and Mitochondrial Medicine, University of Pittsburgh School of Medicine, Pittsburgh, Pennsylvania, USA
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Kerbler SM, Taylor NL, Millar AH. Cold sensitivity of mitochondrial ATP synthase restricts oxidative phosphorylation in Arabidopsis thaliana. THE NEW PHYTOLOGIST 2019; 221:1776-1788. [PMID: 30281799 DOI: 10.1111/nph.15509] [Citation(s) in RCA: 24] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/07/2018] [Accepted: 09/20/2018] [Indexed: 05/03/2023]
Abstract
The combined action of the electron transport chain (ETC) and ATP synthase is essential in determining energy efficiency in plants, and so is important for cellular biosynthesis, growth and development. Owing to the sessile nature of plants, mitochondria must operate over a wide temperature range in the environment, necessitating a broad temperature tolerance of their biochemical reactions. We investigated the temperature response of mitochondrial respiratory processes in isolated mitochondria and intact plants of Arabidopsis thaliana and considered the effect of instantaneous responses to temperature and acclimation responses to low temperatures. We show that at 4°C the plant mitochondrial ATP synthase is differentially inhibited compared with other elements of the respiratory pathway, leading to decreased ADP : oxygen ratios and a limitation to the rate of ATP synthesis. This effect persists in vivo and cannot be overcome by cold-temperature acclimation of plants. This mechanism adds a new element to the respiratory acclimation model and provides a direct means of temperature perception by plant mitochondria. This also provides an alternative explanation for non-phosphorylating ETC bypass mechanisms, like the alternative oxidase to maintain respiratory rates, albeit at lower ATP synthesis efficiency, in response to the sensitivity of ATP synthase to the prevailing temperature.
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Affiliation(s)
- Sandra M Kerbler
- Australian Research Council Centre of Excellence in Plant Energy Biology, School of Molecular Sciences, The University of Western Australia, Crawley, WA, 6009, Australia
| | - Nicolas L Taylor
- Australian Research Council Centre of Excellence in Plant Energy Biology, School of Molecular Sciences, The University of Western Australia, Crawley, WA, 6009, Australia
- The Institute of Agriculture, The University of Western Australia, Crawley, WA, 6009, Australia
| | - A Harvey Millar
- Australian Research Council Centre of Excellence in Plant Energy Biology, School of Molecular Sciences, The University of Western Australia, Crawley, WA, 6009, Australia
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Sreedhar A, Zhao Y. Uncoupling protein 2 and metabolic diseases. Mitochondrion 2017; 34:135-140. [PMID: 28351676 PMCID: PMC5477468 DOI: 10.1016/j.mito.2017.03.005] [Citation(s) in RCA: 53] [Impact Index Per Article: 7.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/23/2017] [Revised: 03/22/2017] [Accepted: 03/24/2017] [Indexed: 02/06/2023]
Abstract
Mitochondria are fascinating organelles involved in various cellular-metabolic activities that are integral for mammalian development. Although they perform diverse, yet interconnected functions, mitochondria are remarkably regulated by complex signaling networks. Therefore, it is not surprising that mitochondrial dysfunction is involved in plethora of diseases, including neurodegenerative and metabolic disorders. One of the many factors that lead to mitochondrial-associated metabolic diseases is the uncoupling protein-2, a family of mitochondrial anion proteins present in the inner mitochondrial membrane. Since their discovery, uncoupling proteins have attracted considerable attention due to their involvement in mitochondrial-mediated oxidative stress and energy metabolism. This review attempts to provide a summary of recent developments in the field of uncoupling protein 2 relating to mitochondrial associated metabolic diseases.
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Affiliation(s)
- Annapoorna Sreedhar
- Department of Pharmacology, Toxicology & Neuroscience, LSU Health Sciences Center in Shreveport, Shreveport, LA 71130, USA
| | - Yunfeng Zhao
- Department of Pharmacology, Toxicology & Neuroscience, LSU Health Sciences Center in Shreveport, Shreveport, LA 71130, USA.
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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: 32] [Impact Index Per Article: 4.0] [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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Thyroid Hormones, Oxidative Stress, and Inflammation. Mediators Inflamm 2016; 2016:6757154. [PMID: 27051079 PMCID: PMC4802023 DOI: 10.1155/2016/6757154] [Citation(s) in RCA: 257] [Impact Index Per Article: 32.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/31/2015] [Revised: 02/14/2016] [Accepted: 02/15/2016] [Indexed: 12/26/2022] Open
Abstract
Inflammation and oxidative stress (OS) are closely related processes, as well exemplified in obesity and cardiovascular diseases. OS is also related to hormonal derangement in a reciprocal way. Among the various hormonal influences that operate on the antioxidant balance, thyroid hormones play particularly important roles, since both hyperthyroidism and hypothyroidism have been shown to be associated with OS in animals and humans. In this context, the nonthyroidal illness syndrome (NTIS) that typically manifests as reduced conversion of thyroxine (T4) to triiodothyronine (T3) in different acute and chronic systemic conditions is still a debated topic. The pathophysiological mechanisms of this syndrome are reviewed, together with the roles of deiodinases, the enzymes responsible for the conversion of T4 to T3, in both physiological and pathological situations. The presence of OS indexes in NTIS supports the hypothesis that it represents a condition of hypothyroidism at the tissue level and not only an adaptive mechanism to diseases.
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Oliveira MG, Mazorra LM, Souza AF, Silva GMC, Correa SF, Santos WC, Saraiva KDC, Teixeira AJ, Melo DF, Silva MG, Silva MAP, Arrabaça JDC, Costa JH, Oliveira JG. Involvement of AOX and UCP pathways in the post-harvest ripening of papaya fruits. JOURNAL OF PLANT PHYSIOLOGY 2015; 189:42-50. [PMID: 26513459 DOI: 10.1016/j.jplph.2015.10.001] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/29/2015] [Revised: 09/25/2015] [Accepted: 10/01/2015] [Indexed: 06/05/2023]
Abstract
Enhanced respiration during ripening in climacteric fruits is sometimes associated with an uncoupling between the ATP synthesis and the mitochondrial electron transport chain. While the participation of two energy-dissipating systems, one of which is mediated by the alternative oxidase (AOX) and the other mediated by the uncoupling protein (UCP), has been linked to fruit ripening, the relation between the activation of both mitochondrial uncoupling systems with the transient increase of ethylene synthesis (ethylene peak) remains unclear. To elucidate this question, ethylene emission and the two uncoupling (AOX and UCP) pathways were monitored in harvested papaya fruit during the ripening, from green to fully yellow skin. The results confirmed the typical climacteric behavior for papaya fruit: an initial increase in endogenous ethylene emission which reaches a maximum (peak) in the intermediate ripening stage, before finally declining to a basal level in ripe fruit. Respiration of intact fruit also increased and achieved higher levels at the end of ripening. On the other hand, in purified mitochondria extracted from fruit pulp the total respiration and respiratory control decrease while an increase in the participation of AOX and UCP pathways was markedly evident during papaya ripening. There was an increase in the AOX capacity during the transition from green fruit to the intermediate stage that accompanied the transient ethylene peak, while the O2 consumption triggered by UCP activation increased by 80% from the beginning to end stage of fruit ripening. Expression analyses of AOX (AOX1 and 2) and UCP (UCP1-5) genes revealed that the increases in the AOX and UCP capacities were linked to a higher expression of AOX1 and UCP (mainly UCP1) genes, respectively. In silico promoter analyses of both genes showed the presence of ethylene-responsive cis-elements in UCP1 and UCP2 genes. Overall, the data suggest a differential activation of AOX and UCP pathways in regulation related to the ethylene peak and induction of specific genes such as AOX1 and UCP1.
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Affiliation(s)
- M G Oliveira
- Laboratório de Melhoramento Genético Vegetal, Centro de Ciências e Tecnologias Agropecuárias, Universidade Estadual do Norte Fluminense, Campos dos Goytacazes, RJ 28013602, Brazil
| | - L M Mazorra
- Laboratório de Melhoramento Genético Vegetal, Centro de Ciências e Tecnologias Agropecuárias, Universidade Estadual do Norte Fluminense, Campos dos Goytacazes, RJ 28013602, Brazil
| | - A F Souza
- Laboratório de Melhoramento Genético Vegetal, Centro de Ciências e Tecnologias Agropecuárias, Universidade Estadual do Norte Fluminense, Campos dos Goytacazes, RJ 28013602, Brazil
| | - G M C Silva
- Laboratório de Melhoramento Genético Vegetal, Centro de Ciências e Tecnologias Agropecuárias, Universidade Estadual do Norte Fluminense, Campos dos Goytacazes, RJ 28013602, Brazil
| | - S F Correa
- Laboratório de Ciências Físicas, Universidade Estadual no Norte Fluminense, Campos dos Goytacazes, RJ 28013602, Brazil
| | - W C Santos
- Laboratório de Ciências Físicas, Universidade Estadual no Norte Fluminense, Campos dos Goytacazes, RJ 28013602, Brazil
| | - K D C Saraiva
- Departamento de Bioquímica e Biologia Molecular, Universidade Federal do Ceará, Fortaleza, CE 60455760, Brazil
| | - A J Teixeira
- Laboratório de Melhoramento Genético Vegetal, Centro de Ciências e Tecnologias Agropecuárias, Universidade Estadual do Norte Fluminense, Campos dos Goytacazes, RJ 28013602, Brazil
| | - D F Melo
- Departamento de Bioquímica e Biologia Molecular, Universidade Federal do Ceará, Fortaleza, CE 60455760, Brazil
| | - M G Silva
- Laboratório de Ciências Físicas, Universidade Estadual no Norte Fluminense, Campos dos Goytacazes, RJ 28013602, Brazil
| | - M A P Silva
- Departamento de Biologia Vegetal, Universidade Federal de Viçosa, Viçosa, MG 36570000, Brazil
| | - J D C Arrabaça
- Faculdade de Ciências, Universidade de Lisboa, Lisboa 1749016, Portugal
| | - J H Costa
- Departamento de Bioquímica e Biologia Molecular, Universidade Federal do Ceará, Fortaleza, CE 60455760, Brazil
| | - J G Oliveira
- Laboratório de Melhoramento Genético Vegetal, Centro de Ciências e Tecnologias Agropecuárias, Universidade Estadual do Norte Fluminense, Campos dos Goytacazes, RJ 28013602, Brazil.
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12
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Laitz AVN, Acencio ML, Budzinski IGF, Labate MTV, Lemke N, Ribolla PEM, Maia IG. Transcriptome response signatures associated with the overexpression of a mitochondrial uncoupling protein (AtUCP1) in tobacco. PLoS One 2015; 10:e0130744. [PMID: 26106890 PMCID: PMC4479485 DOI: 10.1371/journal.pone.0130744] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/20/2014] [Accepted: 05/23/2015] [Indexed: 11/30/2022] Open
Abstract
Mitochondrial inner membrane uncoupling proteins (UCP) dissipate the proton electrochemical gradient established by the respiratory chain, thus affecting the yield of ATP synthesis. UCP overexpression in plants has been correlated with oxidative stress tolerance, improved photosynthetic efficiency and increased mitochondrial biogenesis. This study reports the main transcriptomic responses associated with the overexpression of an UCP (AtUCP1) in tobacco seedlings. Compared to wild-type (WT), AtUCP1 transgenic seedlings showed unaltered ATP levels and higher accumulation of serine. By using RNA-sequencing, a total of 816 differentially expressed genes between the investigated overexpressor lines and the untransformed WT control were identified. Among them, 239 were up-regulated and 577 were down-regulated. As a general response to AtUCP1 overexpression, noticeable changes in the expression of genes involved in energy metabolism and redox homeostasis were detected. A substantial set of differentially expressed genes code for products targeted to the chloroplast and mainly involved in photosynthesis. The overall results demonstrate that the alterations in mitochondrial function provoked by AtUCP1 overexpression require important transcriptomic adjustments to maintain cell homeostasis. Moreover, the occurrence of an important cross-talk between chloroplast and mitochondria, which culminates in the transcriptional regulation of several genes involved in different pathways, was evidenced.
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Affiliation(s)
| | - Marcio Luis Acencio
- UNESP, Instituto de Biociências, Departamento de Física e Biofísica, Botucatu, SP, Brazil
| | - Ilara G. F. Budzinski
- USP, Departamento de Genética, Escola Superior de Agricultura Luiz de Queiroz, Piracicaba, SP, Brazil
| | - Mônica T. V. Labate
- USP, Departamento de Genética, Escola Superior de Agricultura Luiz de Queiroz, Piracicaba, SP, Brazil
| | - Ney Lemke
- UNESP, Instituto de Biociências, Departamento de Física e Biofísica, Botucatu, SP, Brazil
| | | | - Ivan G. Maia
- UNESP, Instituto de Biociências, Departamento de Genética, Botucatu, SP, Brazil
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13
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Li W, Zhang C, Jackson K, Shen X, Jin R, Li G, Kevil CG, Gu X, Shi R, Zhao Y. UCP2 knockout suppresses mouse skin carcinogenesis. Cancer Prev Res (Phila) 2015; 8:487-91. [PMID: 25784177 DOI: 10.1158/1940-6207.capr-14-0297-t] [Citation(s) in RCA: 19] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/09/2014] [Accepted: 03/09/2015] [Indexed: 12/18/2022]
Abstract
Mitochondrial uncoupling (uncouples electron transport from ATP production) has recently been proposed as a novel survival mechanism for cancer cells, and reduction in free radical generation is the accepted mechanism of action. However, there is no direct evidence supporting that uncoupling proteins promote carcinogenesis. Herein, we examined whether mitochondrial uncoupling affects mouse skin carcinogenesis using uncoupling protein 2 (UCP2) homozygous knockout and wild-type mice. The results indicate that knockout of Ucp2 significantly reduced the formation of both benign (papilloma) and malignant (squamous cell carcinoma) tumors. UCP2 knockout did not cause increases in apoptosis during skin carcinogenesis. The rates of oxygen consumption were decreased only in the carcinogen-treated UCP2 knockout mice, whereas glycolysis was increased only in the carcinogen-treated wild-type mice. Finally, the levels of metabolites pyruvate, malate, and succinate showed different trends after carcinogen treatments between the wild-type and UCP2 knockout mice. Our study is the first to demonstrate that Ucp2 knockout suppresses carcinogenesis in vivo. Together with early studies showing that UCP2 is overexpressed in a number of human cancers, UCP2 could be a potential target for cancer prevention and/or therapy. Cancer Prev Res; 8(6); 487-91. ©2015 AACR.
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Affiliation(s)
- Wenjuan Li
- Department of Pharmacology, Toxicology and Neuroscience, LSU Health Sciences Center in Shreveport, Shreveport, Louisiana. School of Basic Medicine, Hebei University, Baoding, Hebei, China
| | - Chunjing Zhang
- Department of Pharmacology, Toxicology and Neuroscience, LSU Health Sciences Center in Shreveport, Shreveport, Louisiana. School of Basic Medicine, Qiqihar Medical University, Qiqihar, Heilongjiang, China
| | - Kasey Jackson
- Department of Pharmacology, Toxicology and Neuroscience, LSU Health Sciences Center in Shreveport, Shreveport, Louisiana
| | - Xingui Shen
- Department of Pathology, LSU Health Sciences Center in Shreveport, Shreveport, Louisiana
| | - Rong Jin
- Department of Neurosurgery, LSU Health Sciences Center in Shreveport, Shreveport, Louisiana
| | - Guohong Li
- Department of Neurosurgery, LSU Health Sciences Center in Shreveport, Shreveport, Louisiana
| | - Christopher G Kevil
- Department of Pathology, LSU Health Sciences Center in Shreveport, Shreveport, Louisiana
| | - Xin Gu
- Department of Pathology, LSU Health Sciences Center in Shreveport, Shreveport, Louisiana
| | - Runhua Shi
- Feist-Weiller Cancer Center, LSU Health Sciences Center in Shreveport, Shreveport, Louisiana
| | - Yunfeng Zhao
- Department of Pharmacology, Toxicology and Neuroscience, LSU Health Sciences Center in Shreveport, Shreveport, Louisiana.
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14
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Alves-Bezerra M, Cosentino-Gomes D, Vieira LP, Rocco-Machado N, Gondim KC, Meyer-Fernandes JR. Identification of uncoupling protein 4 from the blood-sucking insect Rhodnius prolixus and its possible role on protection against oxidative stress. INSECT BIOCHEMISTRY AND MOLECULAR BIOLOGY 2014; 50:24-33. [PMID: 24746771 DOI: 10.1016/j.ibmb.2014.03.011] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/18/2013] [Revised: 03/14/2014] [Accepted: 03/24/2014] [Indexed: 06/03/2023]
Abstract
Uncoupling proteins (UCPs) play a critical role in the control of the mitochondrial membrane potential (ΔΨm) due to their ability to dissipate the proton gradient, which results in the uncoupling of mitochondrial respiration from ATP production. Most reactive oxygen species generation in mitochondria occurs in complex III, due to an increase of semiquinone (Q(-)) half-life. When active, UCPs can account as a potential antioxidant system by decreasing ΔΨm and increasing mitochondrial respiration, thus reducing Q(-) life time. The hematophagous insect Rhodnius prolixus, a vector of Chagas disease, is exposed to a huge increase in oxidative stress after a blood meal because of the hydrolysis of hemoglobin and the release of the cytotoxic heme molecule. Although some protective mechanisms were already described for this insect and other hematophagous arthropods, the putative role of UCP proteins as antioxidants in this context has not been explored. In this report, two genes encoding UCP proteins (RpUcp4 and RpUcp5) were identified in the R. prolixus genome. RpUcp4 is the predominant transcript in most analyzed organs, and both mRNA and protein expression are upregulated (13- and 3-fold increase, respectively) in enterocytes the first day after the blood feeding. The increase in UCP4 expression is coincident with the decrease in hydrogen peroxide (H2O2) generation by midgut cells. Furthermore, in mitochondria isolated from enterocytes, the modulation of UCP activity by palmitic acid and GDP resulted in altered ΔΨm, as well as modulation of H2O2 generation rates. These results indicate that R. prolixus UCP4 may function in an antioxidation mechanism to protect the midgut cells against oxidative damage caused by blood digestion.
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Affiliation(s)
- Michele Alves-Bezerra
- Instituto de Bioquímica Médica Leopoldo de Meis, Universidade Federal do Rio de Janeiro, Rio de Janeiro, Brazil
| | - Daniela Cosentino-Gomes
- Instituto de Bioquímica Médica Leopoldo de Meis, Universidade Federal do Rio de Janeiro, Rio de Janeiro, Brazil
| | - Lisvane P Vieira
- Instituto de Bioquímica Médica Leopoldo de Meis, Universidade Federal do Rio de Janeiro, Rio de Janeiro, Brazil
| | - Nathália Rocco-Machado
- Instituto de Bioquímica Médica Leopoldo de Meis, Universidade Federal do Rio de Janeiro, Rio de Janeiro, Brazil
| | - Katia C Gondim
- Instituto de Bioquímica Médica Leopoldo de Meis, Universidade Federal do Rio de Janeiro, Rio de Janeiro, Brazil; Instituto Nacional de Ciência e Tecnologia em Entomologia Molecular, Brazil
| | - José R Meyer-Fernandes
- Instituto de Bioquímica Médica Leopoldo de Meis, Universidade Federal do Rio de Janeiro, Rio de Janeiro, Brazil; Instituto Nacional de Ciência e Tecnologia de Biologia Estrutural e Bioimagem, Brazil.
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15
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Woyda-Ploszczyca AM, Jarmuszkiewicz W. Sensitivity of the aldehyde-induced and free fatty acid-induced activities of plant uncoupling protein to GTP is regulated by the ubiquinone reduction level. PLANT PHYSIOLOGY AND BIOCHEMISTRY : PPB 2014; 79:109-116. [PMID: 24705332 DOI: 10.1016/j.plaphy.2014.03.012] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/05/2014] [Accepted: 03/13/2014] [Indexed: 06/03/2023]
Abstract
Using isolated potato tuber mitochondria possessing uncoupling protein (StUCP), we found that, under non-phosphorylating conditions, the sensitivity of aldehyde (all trans-retinal or 4-hydroxy-2-nonenal)-induced and fatty acid (linoleic acid)-induced StUCP-mediated proton leaks to GTP is controlled by the endogenous ubiquinone (Q) reduction level. The action of StUCP activators was abolished by GTP only when Q was sufficiently oxidized, but no inhibitory effect was observed when Q was highly reduced. Thus, the Q reduction level-dependent regulation of StUCP inhibition functions independently of the type of UCP activation and could be an important physiological factor affecting the efficiency of UCP-catalyzed uncoupling in plant mitochondria.
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Affiliation(s)
| | - Wieslawa Jarmuszkiewicz
- Laboratory of Bioenergetics, Adam Mickiewicz University, Umultowska 89, 61-614 Poznan, Poland.
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16
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Physiological aspects of fruit ripening: the mitochondrial connection. Mitochondrion 2014; 17:1-6. [PMID: 24769052 DOI: 10.1016/j.mito.2014.04.010] [Citation(s) in RCA: 28] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/05/2013] [Revised: 04/08/2014] [Accepted: 04/14/2014] [Indexed: 11/23/2022]
Abstract
Fruit ripening is a genetically programmed process which leads to an assortment of physiological and metabolic changes that irreversibly alter its characteristics. Depending on the species, fruit maturation can be either climacteric or non-climacteric. In both cases there is a metabolic shift from normal development conditions toward the fully mature state, but climacteric fruit is characterized by a sharp increase in respiration. In non-climacteric fruit, that generally does not display this feature, respiration changes can be affected by processes related to postharvest storage. This review describes some of the many ways in which mitochondrial metabolism is implicated in this crucial reproductive stage, such as the connection between ethylene production and respiration rate, the involvement of alternative oxidase (AOX) and plant uncoupling mitochondrial protein (PUMP) during the ripening and the common alterations of this organelle in fruits affected by different stress conditions.
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17
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Fanciullino AL, Bidel LPR, Urban L. Carotenoid responses to environmental stimuli: integrating redox and carbon controls into a fruit model. PLANT, CELL & ENVIRONMENT 2014; 37:273-89. [PMID: 23777240 DOI: 10.1111/pce.12153] [Citation(s) in RCA: 67] [Impact Index Per Article: 6.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/20/2013] [Revised: 06/05/2013] [Accepted: 06/06/2013] [Indexed: 05/20/2023]
Abstract
Carotenoids play an important role in plant adaptation to fluctuating environments as well as in the human diet by contributing to the prevention of chronic diseases. Insights have been gained recently into the way individual factors, genetic, environmental or developmental, control the carotenoid biosynthetic pathway at the molecular level. The identification of the rate-limiting steps of carotenogenesis has paved the way for programmes of breeding, and metabolic engineering, aimed at increasing the concentration of carotenoids in different crop species. However, the complexity that arises from the interactions between the different factors as well as from the coordination between organs remains poorly understood. This review focuses on recent advances in carotenoid responses to environmental stimuli and discusses how the interactions between the modulation factors and between organs affect carotenoid build-up. We develop the idea that reactive oxygen species/redox status and sugars/carbon status can be considered as integrated factors that account for most effects of the major environmental factors influencing carotenoid biosynthesis. The discussion highlights the concept of carotenoids or carotenoid-derivatives as stress signals that may be involved in feedback controls. We propose a conceptual model of the effects of environmental and developmental factors on carotenoid build-up in fruits.
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Affiliation(s)
- A L Fanciullino
- UR 1115 Plantes et Systèmes de Culture Horticoles, INRA, Avignon, Cedex, 9, France
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18
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Peixoto PM, Kim HJ, Sider B, Starkov A, Horvath TL, Manfredi G. UCP2 overexpression worsens mitochondrial dysfunction and accelerates disease progression in a mouse model of amyotrophic lateral sclerosis. Mol Cell Neurosci 2013; 57:104-10. [PMID: 24141050 PMCID: PMC3891658 DOI: 10.1016/j.mcn.2013.10.002] [Citation(s) in RCA: 30] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/12/2013] [Revised: 08/26/2013] [Accepted: 10/04/2013] [Indexed: 12/24/2022] Open
Abstract
Mitochondrial dysfunction leading to deficits in energy production, Ca(2+) uptake capacity, and free radical generation has been implicated in the pathogenesis of familial amyotrophic lateral sclerosis (ALS) caused by mutations in Cu,Zn superoxide dismutase (SOD1). Numerous studies link UCP2, a member of the uncoupling protein family, to protection of neurons from mitochondrial dysfunction and oxidative damage in various mouse models of acute stress and neurodegeneration, including Parkinson's disease. Here, we tested the potential neuroprotective effects of UCP2 and its ability to modulate mitochondrial function, in the G93A mutant SOD1 mouse model of familial ALS. Disease phenotype, mitochondrial bioenergetics, and Ca(2+) uptake capacity were investigated in the central nervous system of double transgenic mice, expressing both human mutant G93A SOD1 and human UCP2 (hUCP2). Unexpectedly, hUCP2 expression accelerated the disease course of SOD1 mutant mice. In addition, we did not observe a classical uncoupling effect of hUCP2 in G93A brain mitochondria, although we did detect a decrease in reactive oxygen species (ROS) production from mitochondria challenged with the respiratory chain inhibitors rotenone and antimycin A. We also found that mitochondrial Ca(2+) uptake capacity was decreased in the double transgenic mice, as compared to G93A mice. In summary, our results indicate that the neuroprotective role of UCP2 in neurodegeneration is disease-specific and that, while a mild uncoupling by UCP2 in brain mitochondria may protect against neurodegeneration in some injury paradigms, the mitochondrial damage and the disease caused by mutant SOD1 cannot be ameliorated by UCP2 overexpression.
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Affiliation(s)
- Pablo M Peixoto
- Brain and Mind Research Institute, Weill Cornell Medical College, 407 East 61 St, New York, NY, 10065
- Department of Natural Sciences, Baruch College, City University of New York (CUNY), 17 Lexington Avenue, New York, NY, 10010
| | - Hyun-Jeong Kim
- Brain and Mind Research Institute, Weill Cornell Medical College, 407 East 61 St, New York, NY, 10065
| | - Brittany Sider
- Brain and Mind Research Institute, Weill Cornell Medical College, 407 East 61 St, New York, NY, 10065
| | - Anatoly Starkov
- Brain and Mind Research Institute, Weill Cornell Medical College, 407 East 61 St, New York, NY, 10065
| | - Tamas L Horvath
- Department of Neurobiology, Yale University School of Medicine and Kavli Institute for Neuroscience, 310 Cedar St, New Haven, CT, 06520
| | - Giovanni Manfredi
- Brain and Mind Research Institute, Weill Cornell Medical College, 407 East 61 St, New York, NY, 10065
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19
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Shi K, Fu LJ, Zhang S, Li X, Liao YWK, Xia XJ, Zhou YH, Wang RQ, Chen ZX, Yu JQ. Flexible change and cooperation between mitochondrial electron transport and cytosolic glycolysis as the basis for chilling tolerance in tomato plants. PLANTA 2013; 237:589-601. [PMID: 23229059 DOI: 10.1007/s00425-012-1799-3] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/19/2012] [Accepted: 10/26/2012] [Indexed: 06/01/2023]
Abstract
To find if cytosolic glycolysis dynamical metabolism plays a role in mediating respiration homeostasis and its relationship with mitochondrial electron transport chain (miETC) flexibility, we selected two tomato genotypes that differ in chilling tolerance and compared the responses of miETC, cytosolic glycolysis and respiratory homeostasis at 7 °C. Our results showed that the transcripts of both classical and bypass component genes for miETC and glycolysis were comparable for both genotypes when grown at 25 °C. However, there was a rapid global increase in the expression of most respiratory genes in response to chilling at 7 °C for both genotypes. When normally grown plant was set as the control for each genotype, the transcripts of most COX family members, ATP synthase, AOX1b, and UCP are highly up-regulated in chilling-tolerant Zhefen No. 208 plants in contrast to the sensitive Zhefen No. 212 plants. Both genotypes mobilized the energy-saving sucrose synthase pathway for sucrose degradation by cytosolic glycolysis, but this mechanism is evidently more effective in tolerant Zhefen No. 208 plants. Furthermore, only Zhefen No. 208 plants were able to partially switch from low-energy efficiency pathways to ATP conserving pathways to carry out fructose-6-phosphate conversion and pyruvate production. This metabolic flexibility in miETC and cytosolic glycolysis were coupled to higher ATP synthesis and lower ROS accumulation, which may be essential for sustaining the higher leaf respiration and homeostasis of chilling-tolerant plants.
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Affiliation(s)
- Kai Shi
- Department of Horticulture, Zijingang Campus, Zhejiang University, 866 Yuhangtang Road, Hangzhou, People's Republic of China.
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20
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Danne JC, Gornik SG, Macrae JI, McConville MJ, Waller RF. Alveolate mitochondrial metabolic evolution: dinoflagellates force reassessment of the role of parasitism as a driver of change in apicomplexans. Mol Biol Evol 2012; 30:123-39. [PMID: 22923466 DOI: 10.1093/molbev/mss205] [Citation(s) in RCA: 49] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/19/2022] Open
Abstract
Mitochondrial metabolism is central to the supply of ATP and numerous essential metabolites in most eukaryotic cells. Across eukaryotic diversity, however, there is evidence of much adaptation of the function of this organelle according to specific metabolic requirements and/or demands imposed by different environmental niches. This includes substantial loss or retailoring of mitochondrial function in many parasitic groups that occupy potentially nutrient-rich environments in their metazoan hosts. Infrakingdom Alveolata comprises a well-supported alliance of three disparate eukaryotic phyla-dinoflagellates, apicomplexans, and ciliates. These major taxa represent diverse lifestyles of free-living phototrophs, parasites, and predators and offer fertile territory for exploring character evolution in mitochondria. The mitochondria of apicomplexan parasites provide much evidence of loss or change of function from analysis of mitochondrial protein genes. Much less, however, is known of mitochondrial function in their closest relatives, the dinoflagellate algae. In this study, we have developed new models of mitochondrial metabolism in dinoflagellates based on gene predictions and stable isotope labeling experiments. These data show that many changes in mitochondrial gene content previously only known from apicomplexans are found in dinoflagellates also. For example, loss of the pyruvate dehydrogenase complex and changes in tricarboxylic acid (TCA) cycle enzyme complement are shared by both groups and, therefore, represent ancestral character states. Significantly, we show that these changes do not result in loss of typical TCA cycle activity fueled by pyruvate. Thus, dinoflagellate data show that many changes in alveolate mitochondrial metabolism are independent of the major lifestyle changes seen in these lineages and provide a revised view of mitochondria character evolution during evolution of parasitism in apicomplexans.
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Affiliation(s)
- Jillian C Danne
- School of Botany, University of Melbourne, Victoria, Australia
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21
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Woyda-Ploszczyca AM, Jarmuszkiewicz W. Hydroxynonenal, a lipid peroxidation end product, stimulates uncoupling protein activity in Acanthamoeba castellanii mitochondria; the sensitivity of the inducible activity to purine nucleotides depends on the membranous ubiquinone redox state. J Bioenerg Biomembr 2012; 44:525-38. [PMID: 22798183 DOI: 10.1007/s10863-012-9456-x] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/18/2012] [Accepted: 06/19/2012] [Indexed: 01/06/2023]
Abstract
We studied the influence of exogenously generated superoxide and exogenous 4-hydroxy-2-nonenal (HNE), a lipid peroxidation end product, on the activity of the Acanthamoeba castellanii uncoupling protein (AcUCP). The superoxide-generating xanthine/xanthine oxidase system was insufficient to induce mitochondrial uncoupling. In contrast, exogenously added HNE induced GTP-sensitive AcUCP-mediated mitochondrial uncoupling. In non-phosphorylating mitochondria, AcUCP activation by HNE was demonstrated by increased oxygen consumption accompanied by a decreased membrane potential and ubiquinone (Q) reduction level. The HNE-induced GTP-sensitive proton conductance was similar to that observed with linoleic acid. In phosphorylating mitochondria, the HNE-induced AcUCP-mediated uncoupling decreased the yield of oxidative phosphorylation. We demonstrated that the efficiency of GTP to inhibit HNE-induced AcUCP-mediated uncoupling was regulated by the endogenous Q redox state. A high Q reduction level activated AcUCP by relieving the inhibition caused by GTP while a low Q reduction level favoured the inhibition. We propose that the regulation of UCP activity involves a rapid response through the endogenous Q redox state that modulates the inhibition of UCP by purine nucleotides, followed by a late response through lipid peroxidation products resulting from an increase in the formation of reactive oxygen species that modulate the UCP activation.
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22
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Cabrera JA, Ziemba EA, Colbert R, Kelly RF, Kuskowski M, Arriaga EA, Sluiter W, Duncker DJ, Ward HB, McFalls EO. Uncoupling protein-2 expression and effects on mitochondrial membrane potential and oxidant stress in heart tissue. Transl Res 2012; 159:383-90. [PMID: 22500511 PMCID: PMC3328031 DOI: 10.1016/j.trsl.2011.11.001] [Citation(s) in RCA: 28] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/14/2011] [Revised: 11/01/2011] [Accepted: 11/03/2011] [Indexed: 10/14/2022]
Abstract
Myocardial uncoupling protein (UCP)-2 is increased with chronic peroxisome proliferator-activated receptor γ (PPARγ) stimulation, but the effect on membrane potential and superoxide is unclear. Wild-type (WT) and UCP-2 knockout (KO) mice were given a 3-week diet of control (C) or the PPARγ agonist pioglitazone (PIO; 50 μg/g-chow per day). In isolated mitochondria, UCP-2 content by Western blots, membrane potential (ΔΨm) by tetraphenylphosphonium (TPP), and relative superoxide levels by dihydroethidium (DHE) were measured. Oxygen respiration was determined at baseline and after 10 min anoxia-reoxygenation. PIO induced a 2-fold increase in UCP-2 and nuclear-bound PGC1α in WT mice with no UCP-2 expression in KO mice. Mitochondrial ΔΨm from WT mice on C and PIO diets was -166±4 mV and -147±6 mV, respectively (P<0.05). These values were lower than in UCP-2 KO mice on C and PIO (-180±4 mV and -180±4 mV, respectively; P<0.05). Maximal complex III inhibitable superoxide from WT mice on C and PIO diets was 22.5±1.3 and 17.8±1.1 AU, respectively (P<0.05), and were lower than UCP-2 KO on C and PIO (32.9±2.3 and 29.2±1.9 AU, respectively; P<0.05). Postanoxia, the respiratory control index (RCI) in mitochondria from WT mice with and without PIO was 2.5±0.3 and 2.4±0.2, respectively, and exceeded that of UCP-2 KO mice on C and PIO (1.2±0.1 and 1.4±0.1, respectively; P<0.05). In summary, chronic PPARγ stimulation leads to depolarization of the inner membrane and reduced superoxide of isolated heart mitochondria, which was critically dependent on increased expression of UCP-2. Thus, UCP-2 expression affords resistance to brief anoxia-reoxygenation.
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Affiliation(s)
- Jesús A Cabrera
- Department of Cardiology & Cardiac Surgery Sections, VA Medical Center, University of Minnesota, Minneapolis, MN 55417, USA
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Physiological uncoupling of mitochondrial oxidative phosphorylation. Studies in different yeast species. J Bioenerg Biomembr 2011; 43:323-31. [PMID: 21556887 DOI: 10.1007/s10863-011-9356-5] [Citation(s) in RCA: 26] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/22/2022]
Abstract
Under non-phosphorylating conditions a high proton transmembrane gradient inhibits the rate of oxygen consumption mediated by the mitochondrial respiratory chain (state IV). Slow electron transit leads to production of reactive oxygen species (ROS) capable of participating in deleterious side reactions. In order to avoid overproducing ROS, mitochondria maintain a high rate of O(2) consumption by activating different exquisitely controlled uncoupling pathways. Different yeast species possess one or more uncoupling systems that work through one of two possible mechanisms: i) Proton sinks and ii) Non-pumping redox enzymes. Proton sinks are exemplified by mitochondrial unspecific channels (MUC) and by uncoupling proteins (UCP). Saccharomyces. cerevisiae and Debaryomyces hansenii express highly regulated MUCs. Also, a UCP was described in Yarrowia lipolytica which promotes uncoupled O(2) consumption. Non-pumping alternative oxido-reductases may substitute for a pump, as in S. cerevisiae or may coexist with a complete set of pumps as in the branched respiratory chains from Y. lipolytica or D. hansenii. In addition, pumps may suffer intrinsic uncoupling (slipping). Promising models for study are unicellular parasites which can turn off their aerobic metabolism completely. The variety of energy dissipating systems in eukaryote species is probably designed to control ROS production in the different environments where each species lives.
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Identification and characterization of uncoupling protein 4 in fat body and muscle mitochondria from the cockroach Gromphadorhina cocquereliana. J Bioenerg Biomembr 2011; 43:717-27. [PMID: 21997226 DOI: 10.1007/s10863-011-9385-0] [Citation(s) in RCA: 22] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/28/2011] [Accepted: 09/13/2011] [Indexed: 12/23/2022]
Abstract
We have identified and characterized an uncoupling protein in mitochondria isolated from leg muscle and from fat body, an insect analogue tissue of mammalian liver and adipose tissue, of the cockroach Gromphadorhina coquereliana (GcUCP). This is the first functional characterization of UCP activity in isolated insect mitochondria. Bioenergetic studies clearly indicate UCP function in both insect tissues. In resting (non-phosphorylating) mitochondria, cockroach GcUCP activity was stimulated by the addition of micromolar concentrations of palmitic acid and inhibited by the purine nucleotide GTP. Moreover, in phosphorylating mitochondria, GcUCP activity was able to divert energy from oxidative phosphorylation. Functional studies indicate a higher activity of GcUCP-mediated uncoupling in cockroach muscle mitochondria compared to fat body mitochondria. GcUCP activation by palmitic acid resulted in a decrease in superoxide anion production, suggesting that protection against mitochondrial oxidative stress may be a physiological role of UCPs in insects. GcUCP protein was immunodetected using antibodies raised against human UCP4 as a single band of around 36 kDa. GcUCP protein expression in cockroach muscle mitochondria was significantly higher compared to mitochondria isolated from fat body. LC-MS/MS analyses revealed 100% sequence identities for peptides obtained from GcUCP to UCP4 isoforms from D. melanogaster (the highest homology), human, rat or other insect mitochondria. Therefore, it can be proposed that cockroach GcUCP corresponds to the UCP4 isoforms of other animals.
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Grabel’nykh OI, Pobezhimova TP, Pavlovskaya NS, Koroleva NA, Borovik OA, Lyubushkina IV, Voinikov VK. Antioxidant function of alternative oxidase in mitochondria of winter wheat during cold hardening. BIOCHEMISTRY MOSCOW SUPPLEMENT SERIES A-MEMBRANE AND CELL BIOLOGY 2011. [DOI: 10.1134/s1990747811040040] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/23/2022]
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26
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New aspects of mitochondrial Uncoupling Proteins (UCPs) and their roles in tumorigenesis. Int J Mol Sci 2011; 12:5285-93. [PMID: 21954358 PMCID: PMC3179165 DOI: 10.3390/ijms12085285] [Citation(s) in RCA: 50] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/26/2011] [Revised: 08/09/2011] [Accepted: 08/10/2011] [Indexed: 01/17/2023] Open
Abstract
Uncoupling proteins (UCPs) belong to a family of mitochondrial carrier proteins that are present in the mitochondrial inner membrane. UCP1 was first identified followed by its two homologs, UCP2 and UCP3. The physiological functions of UCP include lowering mitochondrial membrane potential and dissipating metabolic energy as heat. However, UCP can be dysregulated and may contribute to the pathogenesis of metabolic disorders and obesity. Recent studies suggest that UCP also plays a role in neurodegenerative diseases and atherosclerosis. In addition, the widely expressed UCP, UCP2, has been shown to be upregulated in a number of aggressive human cancers. One mechanism of UCP2 upregulation in these cancers is due to oxidative stress, and elevated UCP2 in turn reduces oxidative stress, which provides a growth advantage for these cancers. Nevertheless, new studies suggest UCP2 may interact with oncogenes and tumor suppressor genes, providing a potential new mechanism of how UCP2 contributes to cancer development. In this review, the evidence supporting the role of UCPs in diseases other than diabetes and obesity, the reports on how UCP is regulated in cancer cells, and how UCP may regulate p53 will be discussed.
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Role of Trypanosoma cruzi peroxiredoxins in mitochondrial bioenergetics. J Bioenerg Biomembr 2011; 43:419-24. [DOI: 10.1007/s10863-011-9365-4] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/11/2011] [Accepted: 06/10/2011] [Indexed: 10/18/2022]
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Arabidopsis thaliana Uncoupling Proteins (AtUCPs): insights into gene expression during development and stress response and epigenetic regulation. J Bioenerg Biomembr 2011; 43:71-9. [DOI: 10.1007/s10863-011-9336-9] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/15/2022]
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Vendelbo MH, Nair KS. Mitochondrial longevity pathways. BIOCHIMICA ET BIOPHYSICA ACTA-MOLECULAR CELL RESEARCH 2011; 1813:634-44. [PMID: 21295080 DOI: 10.1016/j.bbamcr.2011.01.029] [Citation(s) in RCA: 60] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/29/2010] [Revised: 01/18/2011] [Accepted: 01/19/2011] [Indexed: 12/31/2022]
Abstract
Average lifespan has increased over the last centuries, as a consequence of medical and environmental factors, but maximal life span remains unchanged. Better understanding of the underlying mechanisms of aging and determinants of life span will help to reduce age-related morbidity and facilitate healthy aging. Extension of maximal life span is currently possible in animal models with measures such as genetic manipulations and caloric restriction (CR). CR appears to prolong life by reducing oxidative damage. Reactive oxygen species (ROS) have been proposed to cause deleterious effects on DNA, proteins, and lipids, and generation of these highly reactive molecules takes place in the mitochondria. But ROS is positively implicated in cellular stress defense mechanisms and formation of ROS a highly regulated process controlled by a complex network of intracellular signaling pathways. There are endogenous anti-oxidant defense systems that have the potential to partially counteract ROS impact. In this review, we will describe pathways contributing to the regulation of the age-related decline in mitochondrial function and their impact on longevity. This article is part of a Special Issue entitled Mitochondria: the deadly organelle.
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Affiliation(s)
- M H Vendelbo
- Division of endocrinology, Endocrine research Unit, The Mayo Clinic, 200 1st Street SW Joseph 5-194, Rochester, MN 55905, USA
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Wang F, Fu X, Chen X, Chen X, Zhao Y. Mitochondrial uncoupling inhibits p53 mitochondrial translocation in TPA-challenged skin epidermal JB6 cells. PLoS One 2010; 5:e13459. [PMID: 20976134 PMCID: PMC2956637 DOI: 10.1371/journal.pone.0013459] [Citation(s) in RCA: 22] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/10/2010] [Accepted: 09/25/2010] [Indexed: 12/02/2022] Open
Abstract
The tumor suppressor p53 is known to be able to trigger apoptosis in response to DNA damage, oncogene activation, and certain chemotherapeutic drugs. In addition to its transcriptional activation, a fraction of p53 translocates to mitochondria at the very early stage of apoptosis, which eventually contributes to the loss of mitochondrial membrane potential, generation of reactive oxygen species (ROS), cytochrome c release, and caspase activation. However, the mitochondrial events that affect p53 translocation are still unclear. Since mitochondrial uncoupling has been suggested to contribute to cancer development, herein, we studied whether p53 mitochondrial translocation and subsequent apoptosis were affected by mitochondrial uncoupling using chemical protonophores, and further verified the results using a siRNA approach in murine skin epidermal JB6 cells. Our results showed that mitochondrial uncoupling blocked p53 mitochondrial translocation induced by 12-O-tetradecanoylphorbol 13-acetate (TPA), a known tumor promoter to induce p53-mediated apoptosis in skin carcinogenesis. This blocking effect, in turn, led to preservation of mitochondrial functions, and eventually suppression of caspase activity and apoptosis. Moreover, uncoupling protein 2 (UCP2), a potential suppressor of ROS in mitochondria, is important for TPA-induced cell transformation in JB6 cells. UCP2 knock down cells showed enhanced p53 mitochondrial translocation, and were less prone to form colonies in soft agar after TPA treatment. Altogether, our data suggest that mitochondrial uncoupling may serve as an important regulator of p53 mitochondrial translocation and p53-mediated apoptosis during early tumor promotion. Therefore, targeting mitochondrial uncoupling may be considered as a novel treatment strategy for cancer.
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Affiliation(s)
- Fei Wang
- Department of Pharmacology, Toxicology and Neuroscience, LSU Health Sciences Center in Shreveport, Shreveport, Louisiana, United States of America
- College of Life Science, Jilin University, Changchun, People's Republic of China
| | - Xueqi Fu
- College of Life Science, Jilin University, Changchun, People's Republic of China
| | - Xia Chen
- College of Life Science, Jilin University, Changchun, People's Republic of China
| | - Xinbin Chen
- Department of Surgical and Radiological Sciences, University of California Davis, Davis, California, United States of America
| | - Yunfeng Zhao
- Department of Pharmacology, Toxicology and Neuroscience, LSU Health Sciences Center in Shreveport, Shreveport, Louisiana, United States of America
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Slocinska MB, Almsherqi ZAM, Sluse FE, Navet R, Deng Y. Identification and characterization of uncoupling protein in heart and muscle mitochondria of canary birds. J Bioenerg Biomembr 2010; 42:345-53. [DOI: 10.1007/s10863-010-9303-x] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/24/2010] [Accepted: 06/16/2010] [Indexed: 01/21/2023]
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Affiliation(s)
- Shu-Sen Liu
- State Key Laboratory of Biomembrane and Membrane Biotechnology, Institute of Zoology, Chinese Academy of Sciences, Beijing, China.
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Rey B, Roussel D, Romestaing C, Belouze M, Rouanet JL, Desplanches D, Sibille B, Servais S, Duchamp C. Up-regulation of avian uncoupling protein in cold-acclimated and hyperthyroid ducklings prevents reactive oxygen species production by skeletal muscle mitochondria. BMC PHYSIOLOGY 2010; 10:5. [PMID: 20426850 PMCID: PMC2867930 DOI: 10.1186/1472-6793-10-5] [Citation(s) in RCA: 47] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 07/30/2009] [Accepted: 04/28/2010] [Indexed: 12/13/2022]
Abstract
Background Although identified in several bird species, the biological role of the avian homolog of mammalian uncoupling proteins (avUCP) remains extensively debated. In the present study, the functional properties of isolated mitochondria were examined in physiological or pharmacological situations that induce large changes in avUCP expression in duckling skeletal muscle. Results The abundance of avUCP mRNA, as detected by RT-PCR in gastrocnemius muscle but not in the liver, was markedly increased by cold acclimation (CA) or pharmacological hyperthyroidism but was down-regulated by hypothyroidism. Activators of UCPs, such as superoxide with low doses of fatty acids, stimulated a GDP-sensitive proton conductance across the inner membrane of muscle mitochondria from CA or hyperthyroid ducklings. The stimulation was much weaker in controls and not observed in hypothyroid ducklings or in any liver mitochondrial preparations. The production of endogenous mitochondrial reactive oxygen species (ROS) was much lower in muscle mitochondria from CA and hyperthyroid ducklings than in the control or hypothyroid groups. The addition of GDP markedly increased the mitochondrial ROS production of CA or hyperthyroid birds up to, or above, the level of control or hypothyroid ducklings. Differences in ROS production among groups could not be attributed to changes in antioxidant enzyme activities (superoxide dismutase or glutathione peroxidase). Conclusion This work provides the first functional in vitro evidence that avian UCP regulates mitochondrial ROS production in situations of enhanced metabolic activity.
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Affiliation(s)
- Benjamin Rey
- Université de Lyon, F-69000, Lyon; Laboratoire de Physiologie Intégrative, Cellulaire et Moléculaire, CNRS - UMR 5123 Université Lyon 1, 43 Bvd 11 Novembre 1918, F-69622 Villeurbanne Cedex, France.
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Mitochondrial ion transport pathways: role in metabolic diseases. BIOCHIMICA ET BIOPHYSICA ACTA-BIOENERGETICS 2010; 1797:832-8. [PMID: 20044972 DOI: 10.1016/j.bbabio.2009.12.017] [Citation(s) in RCA: 41] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/30/2009] [Revised: 12/16/2009] [Accepted: 12/21/2009] [Indexed: 12/22/2022]
Abstract
Mitochondria are the central coordinators of energy metabolism and alterations in their function and number have long been associated with metabolic disorders such as obesity, diabetes and hyperlipidemias. Since oxidative phosphorylation requires an electrochemical gradient across the inner mitochondrial membrane, ion channels in this membrane certainly must play an important role in the regulation of energy metabolism. However, in many experimental settings, the relationship between the activity of mitochondrial ion transport and metabolic disorders is still poorly understood. This review briefly summarizes some aspects of mitochondrial H+ transport (promoted by uncoupling proteins, UCPs), Ca2+ and K+ uniporters which may be determinant in metabolic disorders.
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Chan SL, Wei Z, Chigurupati S, Tu W. Compromised respiratory adaptation and thermoregulation in aging and age-related diseases. Ageing Res Rev 2010; 9:20-40. [PMID: 19800420 DOI: 10.1016/j.arr.2009.09.006] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/18/2009] [Revised: 09/22/2009] [Accepted: 09/23/2009] [Indexed: 02/04/2023]
Abstract
Mitochondrial dysfunction and reactive oxygen species (ROS) production are at the heart of the aging process and are thought to underpin age-related diseases. Mitochondria are not only the primary energy-generating system but also the dominant cellular source of metabolically derived ROS. Recent studies unravel the existence of mechanisms that serve to modulate the balance between energy metabolism and ROS production. Among these is the regulation of proton conductance across the inner mitochondrial membrane that affects the efficiency of respiration and heat production. The field of mitochondrial respiration research has provided important insight into the role of altered energy balance in obesity and diabetes. The notion that respiration and oxidative capacity are mechanistically linked is making significant headway into the field of aging and age-related diseases. Here we review the regulation of cellular energy and ROS balance in biological systems and survey some of the recent relevant studies that suggest that respiratory adaptation and thermodynamics are important in aging and age-related diseases.
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Rasmusson AG, Fernie AR, van Dongen JT. Alternative oxidase: a defence against metabolic fluctuations? PHYSIOLOGIA PLANTARUM 2009; 137:371-82. [PMID: 19558416 DOI: 10.1111/j.1399-3054.2009.01252.x] [Citation(s) in RCA: 45] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/04/2023]
Abstract
An increasing number of oscillating or fluctuating cellular systems have been recently described following the adaptation of fluorescent technology. In diverse organisms, these variously involve signalling factors, heat production, central metabolism and reactive oxygen species (ROS). In response to many plant stresses and primarily via the influence of ROS, changes in mRNA and protein levels or in vivo activity of alternative oxidase are often observed. However, in several investigations, a lack of correlation between the mRNA, protein and in vivo activity has been evident. This discrepancy has made it questionable whether the induction of alternative oxidase has importance in regulating alternative pathway activity in vivo, or being diagnostic for a role of alternative oxidase in stress tolerance and ROS avoidance. Here, we suggest a role of alternative oxidase in counteracting deleterious short-term metabolic fluctuations, especially under stress conditions. This model emphasizes the importance of peak activity for establishing protein levels and allows an amalgamation of the present status of physiological, cellular and molecular knowledge.
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Affiliation(s)
- Allan G Rasmusson
- Department of Cell and Organism Biology, Lund University, Sölvegatan 35B, SE-22362 Lund, Sweden.
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37
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Dietrich MO, Horvath TL. The role of mitochondrial uncoupling proteins in lifespan. Pflugers Arch 2009; 459:269-75. [PMID: 19760284 DOI: 10.1007/s00424-009-0729-0] [Citation(s) in RCA: 44] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/12/2009] [Accepted: 08/26/2009] [Indexed: 11/27/2022]
Abstract
The increased longevity in modern societies raised the attention to biological interventions that could promote a healthy aging. Mitochondria are main organelles involved in the production of adenosine triphosphate (ATP), the energetic substrate for cellular biochemical reactions. The production of ATP occurs through the oxidative phosphorylation of intermediate substrates derived from the breakdown of lipids, sugars, and proteins. This process is coupled to production of oxygen reactive species (ROS) that in excess will have a deleterious role in cellular function. The damage promoted by ROS has been emphasized as one of the main processes involved in senescence. In the last decades, the discovery of specialized proteins in the mitochondrial inner membrane that promote the uncoupling of proton flux (named uncoupling proteins-UCPs) from the ATP synthase shed light on possible mechanisms implicated in the buffering of ROS and consequently in the process of aging. UCPs are responsible for a physiological uncoupling that leads to decrease in ROS production inside the mitochondria. Thus, induction of uncoupling through UCPs could decrease the cellular damage that occurs during aging due to excess of ROS. This review will focus on the evidence supporting these mechanisms.
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Affiliation(s)
- Marcelo O Dietrich
- Section of Comparative Medicine, Yale University School of Medicine, New Haven, CT 06520, USA
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38
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Kowaltowski AJ, de Souza-Pinto NC, Castilho RF, Vercesi AE. Mitochondria and reactive oxygen species. Free Radic Biol Med 2009; 47:333-43. [PMID: 19427899 DOI: 10.1016/j.freeradbiomed.2009.05.004] [Citation(s) in RCA: 778] [Impact Index Per Article: 51.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/19/2009] [Revised: 04/29/2009] [Accepted: 05/06/2009] [Indexed: 01/02/2023]
Abstract
Mitochondria are a quantitatively relevant source of reactive oxygen species (ROS) in the majority of cell types. Here we review the sources and metabolism of ROS in this organelle, including the conditions that regulate the production of these species, such as mild uncoupling, oxygen tension, respiratory inhibition, Ca2+ and K+ transport, and mitochondrial content and morphology. We discuss substrate-, tissue-, and organism-specific characteristics of mitochondrial oxidant generation. Several aspects of the physiological and pathological roles of mitochondrial ROS production are also addressed.
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Affiliation(s)
- Alicia J Kowaltowski
- Departamento de Bioquímica, Instituto de Química, Universidade de São Paulo, São Paulo, Brazil
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Abstract
The effects of inorganic phosphate (Pi), the main intracellular membrane permeable anion capable of altering mitochondrial pH gradients (Delta pH), were measured on mitochondrial H2O2 release. As expected, Pi decreased Delta pH and increased the electric membrane potential (Delta Psi). Mitochondrial H2O2 release was stimulated by Pi and also by its structural analogue arsenate. However, acetate, another membrane-permeable anion, did not stimulate mitochondrial H2O2 release. The stimulatory effect promoted by Pi was prevented by CCCP, which decreases transport of Pi across the inner mitochondrial membrane, indicating that Pi must be in the mitochondrial matrix to stimulate H2O2 release. In conclusion, we found that Pi and arsenate stimulate mitochondrial reactive oxygen release, an effect that may contribute towards oxidative stress under conditions such as ischemia/reperfusion, in which high-energy phosphate bonds are hydrolyzed.
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Affiliation(s)
- Graciele A Oliveira
- Departamento de Bioquímica, Instituto de Química, Universidade de São Paulo, SP, Brazil
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40
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Jezek P, Zácková M, Kosarová J, Rodrigues ET, Madeira VM, Vicente JA. Occurrence of plant-uncoupling mitochondrial protein (PUMP) in diverse organs and tissues of several plants. J Bioenerg Biomembr 2009; 32:549-61. [PMID: 15254369 DOI: 10.1023/a:1005648226431] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022]
Abstract
The presence of plant-uncoupling mitochondrial protein (PUMP), previously described by Vercesi et al. (1995), was screened in mitochondria of various organs or tissues of several plant species. This was done functionally, by monitoring purine nucleotide-sensitive linoleic acid-induced uncoupling, or by Western blots. The following findings were established: (1) PUMP was found in most of the higher plants tested; (2) since ATP inhibition of linoleic acid-induced membrane potential decrease varied, PUMP content might differ in different plant tissues, as observed with mitochondria from maize roots, maize seeds, spinach leaves, wheat shoots, carrot roots, cauliflower, broccoli, maize shoots, turnip root, and potato calli. Western blots also indicated PUMP presence in oat shoots, carnation petals, onion bulbs, red beet root, green cabbage, and Sedum leaves. (3) PUMP was not detected in mushrooms. We conclude that PUMP is likely present in the mitochondria of organs and tissues of all higher plants.
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Affiliation(s)
- P Jezek
- Department of Membrane Transport Biophysics, Institute of Physiology, Academy of Sciences, Prague, Czech Republic.
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41
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Petrussa E, Casolo V, Peresson C, Krajnáková J, Macrì F, Vianello A. Activity of a KATP+ channel in Arum spadix mitochondria during thermogenesis. JOURNAL OF PLANT PHYSIOLOGY 2008; 165:1360-9. [PMID: 18177980 DOI: 10.1016/j.jplph.2007.10.012] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/04/2007] [Accepted: 10/06/2007] [Indexed: 05/19/2023]
Abstract
This report demonstrates that mitochondria isolated from thermogenic Arum spadices possess an ATP-sensitive potassium channel--responsible for electrical potential (DeltaPsi) collapse and mitochondrial swelling--whose characteristics are similar to those previously described in pea and wheat mitochondria. In order to study the relationship between this K(ATP)(+) channel and the uncoupled respiration, linked to thermogenesis, K(+) transport activities were compared with those of mitochondria that were isolated from pea stems, soybean suspension cell cultures and Arum tubers. The channel from Arum spadices is highly active and its major features are (i) potassium flux is performed primarily in an inward-rectifying manner; (ii) the influx of K(+) is associated with a matrix volume increase in both energized and non-energized mitochondria; and (iii) its activity depends on the redox state of electron transport chain (ETC) and oxygen availability. In particular, this paper shows that the K(ATP)(+) channel is inwardly activated in parallel with the alternative oxidase (AO). The activation is linked to an ETC-oxidized state and to high oxygen consumption. The putative role of this K(ATP)(+) channel is discussed in relation to flowering of thermogenic Arum spadices.
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Affiliation(s)
- Elisa Petrussa
- Department of Biology and Plant Protection, Section of Plant Biology, University of Udine, Udine, Italy
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42
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Trono D, Soccio M, Mastrangelo AM, De Simone V, Di Fonzo N, Pastore D. The transcript levels of two plant mitochondrial uncoupling protein (pUCP)-related genes are not affected by hyperosmotic stress in durum wheat seedlings showing an increased level of pUCP activity. Biosci Rep 2007; 26:251-61. [PMID: 16855867 DOI: 10.1007/s10540-006-9020-1] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/24/2022] Open
Abstract
Etiolated early seedlings of durum wheat submitted to moderate and severe salt (NaCl) and osmotic (mannitol) stress showed no relevant increase of both transcript levels of two plant uncoupling protein (pUCP)-related genes and maximal pUCP activity in purified mitochondria (which estimates protein level); contrarily, pUCP functioning due to endogenous free fatty acids strongly increased. These results show that pUCP activation under hyperosmotic stress may be due to modulation of pUCP reaction rather than to an increased protein synthesis. Finally, a properly developed method, based on a single membrane potential measurement, to evaluate both pUCP maximal activity and functioning, is reported.
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Affiliation(s)
- Daniela Trono
- Istituto Sperimentale per la Cerealicoltura-CRA, S.S. 16 Km 675, 71100, Foggia, Italy.
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Busi MV, Maliandi MV, Valdez H, Clemente M, Zabaleta EJ, Araya A, Gomez-Casati DF. Deficiency of Arabidopsis thaliana frataxin alters activity of mitochondrial Fe-S proteins and induces oxidative stress. THE PLANT JOURNAL : FOR CELL AND MOLECULAR BIOLOGY 2006; 48:873-82. [PMID: 17092311 DOI: 10.1111/j.1365-313x.2006.02923.x] [Citation(s) in RCA: 52] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/12/2023]
Abstract
Frataxin, a protein crucial for the biogenesis of mitochondria in different organisms, was recently identified in Arabidopsis thaliana. To investigate the role of frataxin in higher plants, we analyze two knock-out and one knock-down T-DNA insertion mutants. The knock-out mutants present an embryo-lethal phenotype, indicating an essential role for frataxin. The knock-down mutant has reduced frataxin mRNA and protein levels. This mutant also presents retarded growth, reduced fresh weight of fruits and reduced number of seeds per fruit. Surprisingly, transcription of aconitase and the Fe-S subunit of succinate dehydrogenase (SDH2-1) are increased in mutant plants; however, the activity of these proteins is reduced, indicating a role for frataxin in Fe-S cluster assembly or insertion of Fe-S clusters into proteins. Mutant plants also have increased CO(2) assimilation rates, exhibit increased formation of reactive oxygen species (ROS) and have increased levels of transcripts for proteins known to be involved in the ROS stress responses. These results indicate that frataxin is an essential protein in plants, required for full activity of mitochondrial Fe-S proteins and playing a protective role against oxidative damage.
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Affiliation(s)
- Maria V Busi
- Instituto de Investigaciones Biotecnológicas-Instituto Tecnológico de Chascomús (IIB-INTECH) CONICET/UNSAM, Camino Circunvalación Km 6, 7130 Chascomús, Argentina
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Degasperi GR, Velho JA, Zecchin KG, Souza CT, Velloso LA, Borecký J, Castilho RF, Vercesi AE. Role of mitochondria in the immune response to cancer: a central role for Ca2+. J Bioenerg Biomembr 2006; 38:1-10. [PMID: 16779655 DOI: 10.1007/s10863-006-9000-y] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/28/2005] [Accepted: 01/08/2006] [Indexed: 02/03/2023]
Abstract
This study demonstrates that Ca2+ stimulates mitochondrial energy metabolism during spleen lymphocyte activation in response to the ascitic Walker 256 tumor in rats. Intracellular Ca2+ concentrations, phosphorylated protein kinase C (pPKC) levels, Bcl-2 protein contents, interleukin-2 (IL-2) levels, mitochondrial uncoupling protein-2 (UCP-2) contents and reactive oxygen species (ROS) were significantly elevated in these activated lymphocytes. Mitochondria of activated lymphocytes exhibited high free Ca2+ concentrations in the matrix and enhanced oligomycin-sensitive oxygen consumption, indicating an increased rate of oxidative phosphorylation. The production of ROS was largely decreased by diphenylene iodinium in the activated lymphocytes, suggesting that NADPH oxidase is the prevalent source of these species. Accumulation of UCP-2 and the anti-apoptotic protein Bcl-2 is probably important to prevent mitochondrial dysfunction and cell death elicited by the sustained high levels of intracellular Ca2+ and ROS and may explain the observed higher resistance from activated lymphocytes against the opening of the mitochondrial membrane permeability pore (MPT). All these changes were blocked by pretreatment of the rats with verapamil, an L-type Ca2+ channel antagonist. These data demonstrate a central role of Ca2+ in the control of mitochondrial bioenergetics in spleen lymphocytes during the immune response to cancer.
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Affiliation(s)
- Giovanna R Degasperi
- Departamento de Patologia Clínica, Faculdade de Ciências Médicas, Universidade Estadual de Campinas (UNICAMP), Campinas, SP 13083-970, Brazil
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45
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Rhoads DM, Umbach AL, Subbaiah CC, Siedow JN. Mitochondrial reactive oxygen species. Contribution to oxidative stress and interorganellar signaling. PLANT PHYSIOLOGY 2006; 141:357-66. [PMID: 16760488 PMCID: PMC1475474 DOI: 10.1104/pp.106.079129] [Citation(s) in RCA: 155] [Impact Index Per Article: 8.6] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/17/2006] [Revised: 03/24/2006] [Accepted: 03/27/2006] [Indexed: 05/10/2023]
Affiliation(s)
- David M Rhoads
- School of Life Sciences, Arizona State University, Tempe, 85287-4501, USA.
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46
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Navet R, Mouithys-Mickalad A, Douette P, Sluse-Goffart CM, Jarmuszkiewicz W, Sluse FE. Proton leak induced by reactive oxygen species produced during in vitro anoxia/reoxygenation in rat skeletal muscle mitochondria. J Bioenerg Biomembr 2006; 38:23-32. [PMID: 16733628 DOI: 10.1007/s10863-006-9002-9] [Citation(s) in RCA: 22] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/24/2022]
Abstract
Superoxide anion generation and the impairment of oxidative phosphorylation yield were studied in rat skeletal muscle mitochondria submitted to anoxia/reoxygenation in vitro. Production of superoxide anion was detected after several cycles of anoxia/reoxygenation. Concomitantly, a decrease of state 3 respiration and phosphorylation yield (ADP/O) were observed. The latter resulted from a proton leak. The presence of palmitic acid during anoxia/reoxygenation cycles led to a dose-dependent inhibition of superoxide anion production together with a partial protection of the ADP/O ratio measured after anoxia/reoxygenation. The ADP/O decrease was shown to be due to a permeability transition pore-sustained proton leak, as it was suppressed by cyclosporine A. The permeability transition pore activation was induced during anoxia/reoxygenation by superoxide anion, as it was cancelled by the spin trap (POBN), which scavenges superoxide anion and by palmitic acid, which induces mitochondrial uncoupling. It can be proposed that the palmitic acid-induced proton leak cancels the production of superoxide anion by mitochondria during anoxia/reoxygenation and therefore prevents the occurrence of the superoxide anion-induced permeability transition pore-mediated proton leak after anoxia/reoxygenation.
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Affiliation(s)
- Rachel Navet
- Laboratory of Bioenergetics, Oxygen Biochemistry Centre, University of Liege, Sart Tilman B6c, 4000 Liege, Belgium
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47
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Dlasková A, Spacek T, Skobisová E, Santorová J, Jezek P. Certain aspects of uncoupling due to mitochondrial uncoupling proteins in vitro and in vivo. BIOCHIMICA ET BIOPHYSICA ACTA-BIOENERGETICS 2006; 1757:467-73. [PMID: 16781660 DOI: 10.1016/j.bbabio.2006.05.005] [Citation(s) in RCA: 17] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/11/2006] [Revised: 04/21/2006] [Accepted: 05/05/2006] [Indexed: 01/12/2023]
Abstract
Thermogenic uncoupling has been proven only for UCP1 in brown adipose tissue. All other isoforms of UCPs are potentially acting in suppression of mitochondrial reactive oxygen species (ROS) production. In this contribution we show that BAT mitochondria can be uncoupled by lauric acid in the range of approximately 100 nM when endogenous fatty acids are combusted by carnitine cycle and beta-oxidation is properly separated from the uncoupling effect. Respiration increased up to 3 times when related to the lowest fatty acid content (BSA present plus carnitine cycle). We also illustrated that any effect leading to more coupled states leads to enhanced H2O2 generation and any effect resulting in uncoupling gives reduced H2O2 generation in BAT mitochondria. Finally, we report doubling of plant UCP transcript in cells as well as amount of protein detected by 3H-GTP-binding sites in mitochondria of shoots and roots of maize seedlings subjected to the salt stress.
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Affiliation(s)
- Andrea Dlasková
- Department No.75, Membrane Transport Biophysics, Institute of Physiology, Academy of Sciences of the Czech Republic, Vídenská 1083, 14220 Prague 4, Czech Republic
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Ascensão A, Magalhães J, Soares JMC, Ferreira R, Neuparth MJ, Marques F, Oliveira PJ, Duarte JA. Endurance training limits the functional alterations of heart rat mitochondria submitted to in vitro anoxia-reoxygenation. Int J Cardiol 2006; 109:169-78. [PMID: 16019086 DOI: 10.1016/j.ijcard.2005.06.003] [Citation(s) in RCA: 37] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/17/2005] [Revised: 04/08/2005] [Accepted: 06/04/2005] [Indexed: 01/29/2023]
Abstract
BACKGROUND Studies analysing the effect of endurance training on heart mitochondrial function submitted to in vitro anoxia-reoxygenation (A-R) are missing. The present study aimed to investigate the effect of moderate endurance treadmill training (14 weeks) against rat heart mitochondrial dysfunction induced by in vitro A-R. METHODS Respiratory parameters (state 3, state 4, ADP/O and respiratory control ratio-RCR) and oxidative damage markers (carbonyl groups and malondialdehyde) were determined in isolated mitochondria before and after 1 min anoxia followed by 4 min reoxygenation. Levels of heat shock protein 60 kDa (HSP60) and 70 kDa (HSP70) were measured before A-R in mitochondria and whole muscle homogenate, respectively. RESULTS A-R significantly impaired the rate of state 3 and state 4 respiration, as well as the RCR and ADP/O in the sedentary group. However, mitochondrial state 3 respiration was significantly higher in trained than in the sedentary group both before and after A-R. The impairments in RCR, ADP/O ratio and state 4 induced by A-R in sedentary group were significantly attenuated in endurance-trained group. The inhibition of state 4 induced by GDP was significantly higher in trained than in sedentary group. Oxidative modifications of mitochondrial proteins and phospholipids were found in sedentary group after A-R, although limited in trained group. Increased levels of mitochondrial HSP60 and tissue HSP70 accompanied the lower decrease in the respiratory function after A-R observed in trained group. CONCLUSION We therefore concluded that endurance training limited the impairments on rat heart mitochondria caused by the oxidant insult inflicted by in vitro A-R.
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Affiliation(s)
- António Ascensão
- Department of Sport Biology, Faculty of Sport Sciences, University of Porto, Portugal.
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Fávaro RD, Borecký J, Colombi D, Maia IG. ZmPUMP encodes a fully functional monocot plant uncoupling mitochondrial protein whose affinity to fatty acid is increased with the introduction of a His pair at the second matrix loop. Biochem Biophys Res Commun 2006; 344:194-9. [PMID: 16603126 DOI: 10.1016/j.bbrc.2006.03.132] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/14/2006] [Accepted: 03/20/2006] [Indexed: 11/25/2022]
Abstract
Uncoupling proteins (UCPs) are specialized mitochondrial transporter proteins that uncouple respiration from ATP synthesis. In this study, cDNA encoding maize uncoupling protein (ZmPUMP) was expressed in Escherichia coli and recombinant ZmPUMP reconstituted in liposomes. ZmPUMP activity was associated with a linoleic acid (LA)-mediated H(+) efflux with K(m) of 56.36+/-0.27microM and V(max) of 66.9micromolH(+)min(-1)(mgprot)(-1). LA-mediated H(+) fluxes were sensitive to ATP inhibition with K(i) of 2.61+/-0.36mM (at pH 7.2), a value similar to those for dicot UCPs. ZmPUMP was also used to investigate the importance of a histidine pair present in the second matrix loop of mammalian UCP1 and absent in plant UCPs. ZmPUMP with introduced His pair (Lys155His and Ala157His) displayed a 1.55-fold increase in LA-affinity while its activity remained unchanged. Our data indicate conserved properties of plant UCPs and suggest an enhancing but not essential role of the histidine pair in proton transport mechanism.
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Borecky J, Nogueira FTS, de Oliveira KAP, Maia IG, Vercesi AE, Arruda P. The plant energy-dissipating mitochondrial systems: depicting the genomic structure and the expression profiles of the gene families of uncoupling protein and alternative oxidase in monocots and dicots. JOURNAL OF EXPERIMENTAL BOTANY 2006; 57:849-64. [PMID: 16473895 DOI: 10.1093/jxb/erj070] [Citation(s) in RCA: 39] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/06/2023]
Abstract
The simultaneous existence of alternative oxidases and uncoupling proteins in plants has raised the question as to why plants need two energy-dissipating systems with apparently similar physiological functions. A probably complete plant uncoupling protein gene family is described and the expression profiles of this family compared with the multigene family of alternative oxidases in Arabidopsis thaliana and sugarcane (Saccharum sp.) employed as dicot and monocot models, respectively. In total, six uncoupling protein genes, AtPUMP1-6, were recognized within the Arabidopsis genome and five (SsPUMP1-5) in a sugarcane EST database. The recombinant AtPUMP5 protein displayed similar biochemical properties as AtPUMP1. Sugarcane possessed four Arabidopsis AOx1-type orthologues (SsAOx1a-1d); no sugarcane orthologue corresponding to Arabidopsis AOx2-type genes was identified. Phylogenetic and expression analyses suggested that AtAOx1d does not belong to the AOx1-type family but forms a new (AOx3-type) family. Tissue-enriched expression profiling revealed that uncoupling protein genes were expressed more ubiquitously than the alternative oxidase genes. Distinct expression patterns among gene family members were observed between monocots and dicots and during chilling stress. These findings suggest that the members of each energy-dissipating system are subject to different cell or tissue/organ transcriptional regulation. As a result, plants may respond more flexibly to adverse biotic and abiotic conditions, in which oxidative stress is involved.
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Affiliation(s)
- Jirí Borecky
- Centro de Biologia Molecular e Engenharia Genética, Universidade Estadual de Campinas, UNICAMP, CP 6109, 13083-970, Campinas, SP, Brazil
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