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Relationships between Uncoupling Protein Genes UCP1, UCP2 and UCP3 and Irisin Levels in Residents of the Coldest Region of Siberia. Genes (Basel) 2022; 13:genes13091612. [PMID: 36140780 PMCID: PMC9498418 DOI: 10.3390/genes13091612] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/17/2022] [Revised: 09/07/2022] [Accepted: 09/07/2022] [Indexed: 11/16/2022] Open
Abstract
Currently, it is known that irisin can participate in the processes of thermoregulation and browning of adipose tissue, and, therefore, it is possible that it is involved in the microevolutionary mechanisms of adaptation to a cold. The aim of this study is to investigate the relationship between the uncoupling protein genes (UCP1, UCP2, UCP3) and the irisin levels in the residents of the coldest region of Siberia. The sample consisted of 279 Yakut people (185 females, 94 males, average age 19.8 ± 2.03 years). The females plasma irisin concentration was 8.33 ± 2.74 mcg/mL and the males was 7.76 ± 1.86 mcg/mL. Comparative analysis of irisin levels with the genotypes of six studied SNP-markers in females revealed a significant association of irisin with rs1800849-UCP3. The TT genotype of rs1800849 was associated with elevated levels of irisin (p = 0.01). It was also found that this TT genotype in females was associated with reduced weight and height (p = 0.03). We searched for natural selection signals for the T-allele rs1800849-UCP3; as a result of which, it was found that this allele has a significantly high frequency of distribution in northern (45%, CI: 0.42–0.484) compared with southern Asian populations (28%, CI: 0.244–0.316) (p = 0.01). The results obtained indicate the probable involvement of irisin and the UCP3 gene in thermoregulation, and the spread of its allelic variants is probably related to adaptation to a cold climate.
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Hoffman JM, Valencak TG. Sex differences and aging: Is there a role of brown adipose tissue? Mol Cell Endocrinol 2021; 531:111310. [PMID: 33989715 PMCID: PMC8195864 DOI: 10.1016/j.mce.2021.111310] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/26/2021] [Revised: 03/31/2021] [Accepted: 04/28/2021] [Indexed: 12/12/2022]
Abstract
In every population across the world, women live significantly longer than men; however, the underlying physiological processes that drive these sex differences in age-specific mortality are largely unknown. Recently, the role of adipose tissue in aging and longevity has been a focus of biomedical research in both humans and rodent models. Specifically, brown adipose tissue, a thermoregulatory tissue originally thought to not exist past infancy in humans, has been shown to potentially play a role in health throughout the lifespan. Females have larger adult brown adipose depots that are not just larger in size but also more efficient in non-shivering thermogenesis. This improved functioning of the brown adipose tissue may potentially lead to improved female health, and we hypothesize that this advantage may be of even bigger significance in the older population. Here, we briefly review what is known about sex differences in aging and how sex differences in brown adipose tissue may be contributing to the female lifespan advantage. These questions have usually been addressed in large experimental studies in rodents as a translational model of human aging. Overall, we propose that a better understanding of the thermogenesis-metabolism nexus is necessary in biomedical research, and sex differences in these factors may contribute to the female longevity bias seen in human populations.
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Affiliation(s)
- Jessica M Hoffman
- Department of Biology, University of Alabama at Birmingham, 1300 University Blvd., CH464, Birmingham, AL, 35294, USA.
| | - Teresa G Valencak
- College of Animal Sciences, Zhejiang University, Zijingang Campus, 866 Yuhangtang Road, 310058, Hangzhou, PR China.
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Bal NC, Periasamy M. Uncoupling of sarcoendoplasmic reticulum calcium ATPase pump activity by sarcolipin as the basis for muscle non-shivering thermogenesis. Philos Trans R Soc Lond B Biol Sci 2020; 375:20190135. [PMID: 31928193 DOI: 10.1098/rstb.2019.0135] [Citation(s) in RCA: 50] [Impact Index Per Article: 12.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/06/2023] Open
Abstract
Thermogenesis in endotherms relies on both shivering and non-shivering thermogenesis (NST). The role of brown adipose tissue (BAT) in NST is well recognized, but the role of muscle-based NST has been contested. However, recent studies have provided substantial evidence for the importance of muscle-based NST in mammals. This review focuses primarily on the role of sarcoplasmic reticulum (SR) Ca2+-cycling in muscle NST; specifically, it will discuss recent data showing how uncoupling of sarcoendoplasmic reticulum calcium ATPase (SERCA) (inhibition of Ca2+ transport but not ATP hydrolysis) by sarcolipin (SLN) results in futile SERCA pump activity, increased ATP hydrolysis and heat production contributing to muscle NST. It will also critically examine how activation of muscle NST can be an important factor in regulating metabolic rate and whole-body energy homeostasis. In this regard, SLN has emerged as a powerful signalling molecule to promote mitochondrial biogenesis and oxidative metabolism in muscle. Furthermore, we will discuss the functional interplay between BAT and muscle, especially with respect to how reduced BAT function in mammals could be compensated by muscle-based NST. Based on the existing data, we argue that SLN-mediated thermogenesis is an integral part of muscle NST and that muscle NST potentially contributed to the evolution of endothermy within the vertebrate clade. This article is part of the theme issue 'Vertebrate palaeophysiology'.
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Affiliation(s)
- Naresh C Bal
- KIIT School of Biotechnology, KIIT University, Bhubaneswar, Odisha 751021, India
| | - Muthu Periasamy
- Burnett School of Biomedical Sciences, College of Medicine, University of Central Florida, Orlando, FL 32827, USA
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Hilse KE, Kalinovich AV, Rupprecht A, Smorodchenko A, Zeitz U, Staniek K, Erben RG, Pohl EE. The expression of UCP3 directly correlates to UCP1 abundance in brown adipose tissue. BIOCHIMICA ET BIOPHYSICA ACTA 2016; 1857:72-78. [PMID: 26518386 PMCID: PMC7115856 DOI: 10.1016/j.bbabio.2015.10.011] [Citation(s) in RCA: 46] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 08/24/2015] [Revised: 10/16/2015] [Accepted: 10/25/2015] [Indexed: 01/14/2023]
Abstract
UCP1 and UCP3 are members of the uncoupling protein (UCP) subfamily and are localized in the inner mitochondrial membrane. Whereas UCP1's central role in non-shivering thermogenesis is acknowledged, the function and even tissue expression pattern of UCP3 are still under dispute. Because UCP3 properties regarding transport of protons are qualitatively identical to those of UCP1, its expression in brown adipose tissue (BAT) alongside UCP1 requires justification. In this work, we tested whether any correlation exists between the expression of UCP1 and UCP3 in BAT by quantification of protein amounts in mouse tissues at physiological conditions, in cold-acclimated and UCP1 knockout mice. Quantification using recombinant UCP3 revealed that the UCP3 amount in BAT (0.51ng/(μg total tissue protein)) was nearly one order of magnitude higher than that in muscles and heart. Cold-acclimated mice showed an approximate three-fold increase in UCP3 abundance in BAT in comparison to mice in thermoneutral conditions. Surprisingly, we found a significant decrease of UCP3 in BAT of UCP1 knockout mice, whereas the protein amount in skeletal and heart muscles remained constant. UCP3 abundance decreased even more in cold-acclimated UCP1 knockout mice. Protein quantification in UCP3 knockout mice revealed no compensatory increase in UCP1 or UCP2 expression. Our results do not support the participation of UCP3 in thermogenesis in the absence of UCP1 in BAT, but clearly demonstrate the correlation in abundance between both proteins. The latter is important for understanding UCP3's function in BAT.
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Affiliation(s)
- Karolina E Hilse
- Institute of Physiology, Pathophysiology and Biophysics, Department of Biomedical Sciences, University of Veterinary Medicine, Vienna, Austria
| | - Anastasia V Kalinovich
- Department of Molecular Biosciences, The Wenner-Gren Institute, Stockholm University, Stockholm, Sweden
| | - Anne Rupprecht
- Institute of Physiology, Pathophysiology and Biophysics, Department of Biomedical Sciences, University of Veterinary Medicine, Vienna, Austria
| | - Alina Smorodchenko
- Institute of Physiology, Pathophysiology and Biophysics, Department of Biomedical Sciences, University of Veterinary Medicine, Vienna, Austria
| | - Ute Zeitz
- Institute of Physiology, Pathophysiology and Biophysics, Department of Biomedical Sciences, University of Veterinary Medicine, Vienna, Austria
| | - Katrin Staniek
- Institute of Pharmacology and Toxicology, Department of Biomedical Sciences, University of Veterinary Medicine, Vienna, Austria
| | - Reinhold G Erben
- Institute of Physiology, Pathophysiology and Biophysics, Department of Biomedical Sciences, University of Veterinary Medicine, Vienna, Austria
| | - Elena E Pohl
- Institute of Physiology, Pathophysiology and Biophysics, Department of Biomedical Sciences, University of Veterinary Medicine, Vienna, Austria.
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A novel SP1/SP3 dependent intronic enhancer governing transcription of the UCP3 gene in brown adipocytes. PLoS One 2013; 8:e83426. [PMID: 24391766 PMCID: PMC3877035 DOI: 10.1371/journal.pone.0083426] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/06/2013] [Accepted: 11/05/2013] [Indexed: 11/19/2022] Open
Abstract
Uncoupling protein (UCP) 3 is a mitochondrial inner membrane protein implicated in lipid handling and metabolism of reactive oxygen species. Its transcription is mainly regulated by peroxisome proliferator-activated receptors (PPAR), a family of nuclear hormone receptors. Employing bandshift assays, RNA interference and reporter gene assays we examine an intronic region in the UCP3 gene harboring a cis-element essential for expression in brown adipocytes. We demonstrate binding of SP1 and SP3 to this element which is adjacent to a direct repeat 1 element mediating activation of UCP3 expression by PPARγ agonists. Transactivation mediated by these elements is interdependent and indispensable for UCP3 expression. Systematic deletion uncovered a third binding element, a putative NF1 site, in close proximity to the SP1/3 and PPARγ binding elements. Data mining demonstrated binding of MyoD and Myogenin to this third element in C2C12 cells, and, furthermore, revealed recruitment of p300. Taken together, this intronic region is the main enhancer driving UCP3 expression with SP1/3 and PPARγ as the core factors required for expression.
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Shabalina IG, Hoeks J, Kramarova TV, Schrauwen P, Cannon B, Nedergaard J. Cold tolerance of UCP1-ablated mice: a skeletal muscle mitochondria switch toward lipid oxidation with marked UCP3 up-regulation not associated with increased basal, fatty acid- or ROS-induced uncoupling or enhanced GDP effects. BIOCHIMICA ET BIOPHYSICA ACTA-BIOENERGETICS 2010; 1797:968-80. [PMID: 20227385 DOI: 10.1016/j.bbabio.2010.02.033] [Citation(s) in RCA: 69] [Impact Index Per Article: 4.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/12/2010] [Revised: 02/24/2010] [Accepted: 02/27/2010] [Indexed: 02/04/2023]
Abstract
Mice lacking the thermogenic mitochondrial membrane protein UCP1 (uncoupling protein 1)--and thus all heat production from brown adipose tissue--can still adapt to a cold environment (4 degrees C) if successively transferred to the cold. The mechanism behind this adaptation has not been clarified. To examine possible adaptive processes in the skeletal muscle, we isolated mitochondria from the hind limb muscles of cold-acclimated wild-type and UCP1(-/-) mice and examined their bioenergetic chracteristics. We observed a switch in metabolism, from carbohydrate towards lipid catabolism, and an increased total mitochondrial complement, with an increased total ATP production capacity. The UCP1(-/-) muscle mitochondria did not display a changed state-4 respiration rate (no uncoupling) and were less sensitive to the uncoupling effect of fatty acids than the wild-type mitochondria. The content of UCP3 was increased 3-4 fold, but despite this, endogenous superoxide could not invoke a higher proton leak, and the small inhibitory effect of GDP was unaltered, indicating that it was not mediated by UCP3. Double mutant mice (UCP1(-/-) plus superoxide dismutase 2-overexpression) were not more cold sensitive than UCP1(-/-), bringing into question an involvement of reactive oxygen species (ROS) in activation of any alternative thermogenic mechanism. We conclude that there is no evidence for an involvement of UCP3 in basal, fatty-acid- or superoxide-stimulated oxygen consumption or in GDP sensitivity. The adaptations observed did not imply any direct alternative process for nonshivering thermogenesis but the adaptations observed would be congruent with adaptation to chronically enhanced muscle activity caused by incessant shivering in these mice.
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Affiliation(s)
- Irina G Shabalina
- The Wenner-Gren Institute, Stockholm University, SE-106 91 Stockholm, Sweden
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Cioffi F, Senese R, de Lange P, Goglia F, Lanni A, Lombardi A. Uncoupling proteins: a complex journey to function discovery. Biofactors 2009; 35:417-28. [PMID: 19626697 DOI: 10.1002/biof.54] [Citation(s) in RCA: 49] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
Abstract
Since their discovery, uncoupling proteins have aroused great interest due to the crucial importance of energy-dissipating system for cellular physiology. The uncoupling effect and the physiological role of UCP1 (the first-described uncoupling protein) are well established. However, the reactions catalyzed by UCP1 homologues (UCPs), and their physiological roles are still under debate, with the literature containing contrasting results. Current hypothesis propose several physiological functions for novel UCPs, such as: (i) attenuation of reactive oxygen species production and protection against oxidative damage, (ii) thermogenic function, although UCPs do not generally seem to affect thermogenesis, UCP3 can be thermogenic under certain conditions, (iii) involvement in fatty acid handling and/or transport, although recent experimental evidence argues against the previously hypothesized role for UCPs in the export of fatty acid anions, (iv) fatty acid hydroperoxide export, although this function, due to the paucity of the experimental evidence, remains hypothetical, (v) Ca(2+) uptake, although results for and against a role in Ca(2+) uptake are still emerging, (vi) a signaling role in pancreatic beta cells, where it attenuates glucose-induced insulin secretion. From the above, it is evident that more research will be needed to establish universally accepted functions for UCPs.
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Affiliation(s)
- Federica Cioffi
- Dipartimento di Scienze della Vita, Seconda Università degli Studi di Napoli, Caserta, Italy
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Fromme T, Hoffmann C, Nau K, Rozman J, Reichwald K, Utting M, Platzer M, Klingenspor M. An intronic single base exchange leads to a brown adipose tissue-specific loss of Ucp3 expression and an altered body mass trajectory. Physiol Genomics 2009; 38:54-62. [PMID: 19383623 DOI: 10.1152/physiolgenomics.00249.2007] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022] Open
Abstract
Uncoupling protein 3 (Ucp3) is a transport protein of the inner mitochondrial membrane and presumably is implicated in the maintenance or tolerance of high lipid oxidation rates. Ucp3 is predominantly expressed in skeletal muscle and brown adipose tissue and is regulated by a transcription factor complex involving peroxisome proliferator-activated receptor-alpha, MyoD, and COUP transcription factor II. By analysis of a mutant Djungarian hamster model lacking Ucp3 transcription specifically in brown adipose tissue, we identified a putative transcription factor-binding site that confers tissue specificity. A naturally occurring intronic point mutation disrupting this site leads to brown adipose tissue-specific loss of Ucp3 expression and an altered body weight trajectory. Our findings provide insight into tissue-specific Ucp3 regulation and, for the first time, unambiguously demonstrate that changes in Ucp3 expression can interfere with body weight regulation.
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Affiliation(s)
- Tobias Fromme
- Molecular Nutritional Medicine, ZIEL Research Center for Nutrition and Food Sciences, Technische Universität München, Freising, Germany.
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Nau K, Fromme T, Meyer CW, von Praun C, Heldmaier G, Klingenspor M. Brown adipose tissue specific lack of uncoupling protein 3 is associated with impaired cold tolerance and reduced transcript levels of metabolic genes. J Comp Physiol B 2007; 178:269-77. [PMID: 17987299 DOI: 10.1007/s00360-007-0219-7] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/03/2007] [Revised: 10/09/2007] [Accepted: 10/11/2007] [Indexed: 11/29/2022]
Abstract
Uncoupling protein 3 (Ucp3) is located within the mitochondrial inner membrane of brown adipose tissue and skeletal muscle. It is thought to be implicated in lipid metabolism and defense against reactive oxygen species. We previously reported on a mutation in our breeding colony of Djungarian hamsters (Phodopus sungorus) that leads to brown adipose tissue specific lack of Ucp3 expression. In this study we compared wildtype with mutant hamsters on a broad genetic background. Hamsters lacking Ucp3 in brown adipose tissue displayed a reduced cold tolerance due to impaired nonshivering thermogenesis. This phenotype is associated with a global decrease in expression of metabolic genes but not of uncoupling protein 1. These data implicate that Ucp3 is necessary to sustain high metabolic rates in brown adipose tissue.
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Affiliation(s)
- Kerstin Nau
- Department of Animal Physiology, Faculty of Biology, Philipps Universität Marburg, Marburg, Germany
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Fromme T, Reichwald K, Platzer M, Li XS, Klingenspor M. Chicken ovalbumin upstream promoter transcription factor II regulates uncoupling protein 3 gene transcription in Phodopus sungorus. BMC Mol Biol 2007; 8:1. [PMID: 17204145 PMCID: PMC1779797 DOI: 10.1186/1471-2199-8-1] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/07/2006] [Accepted: 01/04/2007] [Indexed: 12/19/2022] Open
Abstract
BACKGROUND Ucp3 is an integral protein of the inner mitochondrial membrane with a role in lipid metabolism preventing deleterious effects of fatty acids in states of high lipid oxidation. Ucp3 is expressed in brown adipose tissue and skeletal muscle and controlled by a transcription factor complex including PPARalpha, MyoD and the histone acetyltransferase p300. Several studies have demonstrated interaction of these factors with chicken ovalbumin upstream promoter transcription factor II (Coup-TFII). This nuclear receptor is involved in organogenesis and other developmental processes including skeletal muscle development, but also co-regulates a number of metabolic genes. In this study we in silico analyzed the upstream region of Ucp3 of the Djungarian hamster Phodopus sungorus and identified several putative response elements for Coup-TFII. We therefore investigated whether Coup-TFII is a further player in the transcriptional control of the Ucp3 gene in rodents. RESULTS By quantitative PCR we demonstrated a positive correlation of Coup-TFII and Ucp3 mRNA expression in skeletal muscle and brown adipose tissue in response to food deprivation and cold exposure, respectively. In reporter gene assays Coup-TFII enhanced transactivation of the Ucp3 promoter conveyed by MyoD, PPARalpha, RXRalpha and/or p300. Using deletions and mutated constructs, we identified a Coup-TFII enhancer element 816-840 bp upstream of the transcriptional start site. Binding of Coup-TFII to this upstream enhancer was confirmed in electrophoretic mobility shift and supershift assays. CONCLUSION Transcriptional regulation of the Coup-TFII gene in response to starvation and cold exposure seems to be the regulatory mechanism of Ucp3 mRNA expression in brown adipose and skeletal muscle tissue determining the final appropriate rate of transcript synthesis. These findings add a crucial component to the complex transcriptional machinery controlling expression of Ucp3. Given the substantial evidence for a function of Ucp3 in lipid metabolism, Coup-TFII may not only be a negative regulator of glucose responsive genes but also transactivate genes involved in lipid metabolism.
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Affiliation(s)
- Tobias Fromme
- Department of Animal Physiology, Faculty of Biology, Philipps-University, D-35043 Marburg, Germany
| | - Kathrin Reichwald
- Genome Analysis, Leibniz-Institute for Age Research – Fritz Lipmann Institute, D-07745 Jena, Germany
| | - Matthias Platzer
- Genome Analysis, Leibniz-Institute for Age Research – Fritz Lipmann Institute, D-07745 Jena, Germany
| | - Xing-Sheng Li
- Department of Animal Physiology, Faculty of Biology, Philipps-University, D-35043 Marburg, Germany
| | - Martin Klingenspor
- Department of Animal Physiology, Faculty of Biology, Philipps-University, D-35043 Marburg, Germany
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Bézaire V, Seifert EL, Harper ME. Uncoupling protein-3: clues in an ongoing mitochondrial mystery. FASEB J 2007; 21:312-24. [PMID: 17202247 DOI: 10.1096/fj.06-6966rev] [Citation(s) in RCA: 105] [Impact Index Per Article: 6.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/27/2023]
Abstract
Uncoupling protein (UCP) 3 (UCP3) is a mitochondrial anion carrier protein with highly selective expression in skeletal muscle. Despite a great deal of interest, to date neither its molecular mechanism nor its biochemical and physiological functions are well understood. Based on its high degree of homology to the original UCP (UCP1), early studies examined a role for UCP3 in thermogenesis. However, evidence for such a function is lacking. Recent studies have focused on two distinct, but not mutually exclusive, hypotheses: 1) UCP3 mitigates reactive oxygen species (ROS) production, and 2) UCP3 is somehow involved in fatty acid (FA) translocation. While supportive evidence exists for both hypotheses, the interpretation of the corresponding evidence has created some controversy. Mechanistic studies examining mitigated ROS production have been largely conducted in vitro, and the physiological significance of the findings is questioned. Conversely, while physiological evidence exists for FA translocation hypotheses, the evidence is largely correlative, leaving causal relationships unexplored. This review critically assesses evidence for the hypotheses and attempts to link the outcomes from mechanistic studies to physiological implications. Important directions for future studies, using current and novel approaches, are discussed.
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Affiliation(s)
- Véronic Bézaire
- Department of Biochemistry, Microbiology and Immunology, Faculty of Medicine, University of Ottawa, 451 Smyth Rd., Ottawa, ON, Canada K1H 8M5
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Cannon B, Shabalina IG, Kramarova TV, Petrovic N, Nedergaard J. Uncoupling proteins: a role in protection against reactive oxygen species--or not? BIOCHIMICA ET BIOPHYSICA ACTA-BIOENERGETICS 2006; 1757:449-58. [PMID: 16806053 DOI: 10.1016/j.bbabio.2006.05.016] [Citation(s) in RCA: 134] [Impact Index Per Article: 7.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Received: 01/13/2006] [Revised: 04/28/2006] [Accepted: 05/10/2006] [Indexed: 10/24/2022]
Abstract
A physiological function of the original uncoupling protein, UCP1, is well established: UCP1 is the molecular background for nonshivering thermogenesis. The functions of the "novel" UCPs, UCP2 and UCP3, are still not established. Recent discussions imply that all UCPs may play a role in protection against reactive oxygen species (ROS). Here we examine critically the evidence that UCP1, UCP2 and UCP3 are stimulated by ROS (superoxide) or ROS products (4-hydroxy-2-nonenal), and that the UCPs actually diminish oxidative damage. We conclude that, concerning UCP1, it is unlikely that it has such a role; concerning UCP2/UCP3, most evidence for physiologically significant roles in this respect is still circumstantial.
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Affiliation(s)
- Barbara Cannon
- The Wenner-Gren Institute, The Arrhenius Laboratories F3, Stockholm University, SE-106 91 Stockholm, Sweden.
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Loli D, Bicudo JEPW. Control and Regulatory Mechanisms Associated with Thermogenesis in Flying Insects and Birds. Biosci Rep 2005; 25:149-80. [PMID: 16283551 DOI: 10.1007/s10540-005-2883-8] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/22/2022] Open
Abstract
Most insects and birds are able to fly. The chitin made exoskeleton of insects poses them several constraints, and this is one the reasons they are in general small sized animals. On the other hand, because birds possess an endoskeleton made of bones they may grow much larger when compared to insects. The two taxa are quite different with regards to their general “design” platform, in particular with respect to their respiratory and circulatory systems. However, because they fly, they may share in common several traits, namely those associated with the control and regulatory mechanisms governing thermogenesis. High core temperatures are essential for animal flight irrespective of the taxa they belong to. Birds and insects have thus evolved mechanisms which allowed them to control and regulate high rates of heat fluxes. This article discusses possible convergent thermogenic control and regulatory mechanisms associated with flight in insects and birds.
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Affiliation(s)
- Denise Loli
- Departamento de Fisiologia, Instituto de Biociências, Universidade de São Paulo, 05508-900 São Paulo, SP, Brazil
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