101
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Lustig A, Weeraratna AT, Wood WW, Teichberg D, Bertak D, Carter A, Poosala S, Firman J, Becker KG, Zonderman AB, Longo DL, Taub DD. Transcriptome analysis of age-, gender- and diet-associated changes in murine thymus. Cell Immunol 2007; 245:42-61. [PMID: 17499630 PMCID: PMC2271048 DOI: 10.1016/j.cellimm.2007.03.008] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/20/2007] [Revised: 03/25/2007] [Accepted: 03/27/2007] [Indexed: 01/18/2023]
Abstract
The loss of thymic function with age may be due to diminished numbers of T-cell progenitors and the loss of critical mediators within the thymic microenvironment. To assess the molecular changes associated with this loss, we examined transcriptomes of progressively aging mouse thymi, of different sexes and on caloric-restricted (CR) vs. ad libitum (AL) diets. Genes involved in various biological and molecular processes including transcriptional regulators, stress response, inflammation and immune function significantly changed during thymic aging. These differences depended on variables such as sex and diet. Interestingly, many changes associated with thymic aging are either muted or almost completely reversed in mice on caloric-restricted diets. These studies provide valuable insight into the molecular mechanisms associated with thymic aging and emphasize the need to account for biological variables such as sex and diet when elucidating the genomic correlates that influence the molecular pathways responsible for thymic involution.
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Affiliation(s)
- Ana Lustig
- Laboratory of Immunology, National Institute on Aging-Intramural Research Program, National Institutes of Health, 5600 Nathan Shock Drive, Baltimore, MD 21224, USA
| | - Ashani T. Weeraratna
- Laboratory of Immunology, National Institute on Aging-Intramural Research Program, National Institutes of Health, 5600 Nathan Shock Drive, Baltimore, MD 21224, USA
| | - William W. Wood
- The Research Resources Branch, National Institute on Aging-Intramural Research Program, National Institutes of Health, Baltimore, MD 21224, USA
| | - Diane Teichberg
- The Research Resources Branch, National Institute on Aging-Intramural Research Program, National Institutes of Health, Baltimore, MD 21224, USA
| | - Dorothy Bertak
- Laboratory of Immunology, National Institute on Aging-Intramural Research Program, National Institutes of Health, 5600 Nathan Shock Drive, Baltimore, MD 21224, USA
| | - Arnell Carter
- Laboratory of Immunology, National Institute on Aging-Intramural Research Program, National Institutes of Health, 5600 Nathan Shock Drive, Baltimore, MD 21224, USA
| | - Suresh Poosala
- The Research Resources Branch, National Institute on Aging-Intramural Research Program, National Institutes of Health, Baltimore, MD 21224, USA
| | - Jeffrey Firman
- The Research Resources Branch, National Institute on Aging-Intramural Research Program, National Institutes of Health, Baltimore, MD 21224, USA
| | - Kevin G. Becker
- The Research Resources Branch, National Institute on Aging-Intramural Research Program, National Institutes of Health, Baltimore, MD 21224, USA
| | - Alan B. Zonderman
- The Research Resources Branch, National Institute on Aging-Intramural Research Program, National Institutes of Health, Baltimore, MD 21224, USA
| | - Dan L. Longo
- Laboratory of Immunology, National Institute on Aging-Intramural Research Program, National Institutes of Health, 5600 Nathan Shock Drive, Baltimore, MD 21224, USA
| | - Dennis D. Taub
- Laboratory of Immunology, National Institute on Aging-Intramural Research Program, National Institutes of Health, 5600 Nathan Shock Drive, Baltimore, MD 21224, USA
- Corresponding author. Fax: +1 410 558 8284. E-mail address: (D.D. Taub)
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102
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Varady KA, Roohk DJ, Hellerstein MK. Dose effects of modified alternate-day fasting regimens on in vivo cell proliferation and plasma insulin-like growth factor-1 in mice. J Appl Physiol (1985) 2007; 103:547-51. [PMID: 17495119 DOI: 10.1152/japplphysiol.00209.2007] [Citation(s) in RCA: 29] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022] Open
Abstract
Reduced cell proliferation is associated with lower cancer risk. Alternate-day fasting (ADF), defined as alternating 24-h periods of ad libitum feeding and fasting, decreases cell proliferation. The effect of modified regimens of ADF on cell proliferation, however, has not been examined. This study measured the effects of modified ADF regimens on prostate and splenic T-cell proliferation and circulating insulin-like growth factor-1 (IGF-1) levels in mice. In a 4-wk study, 24 male C57BL/6J mice were randomized to one of four interventions: 1) ADF-25% [25% calorie restriction (CR) on fast day], 2) ADF-50% (50% CR on fast day), 3) ADF-100% (100% CR on fast day), and 4) control. Body weight of the ADF-100% group was less (P < 0.005) than that of the ADF-25% and ADF-50% groups posttreatment. On the feast day, the ADF-100% and ADF-50% groups ate 85% and 45% more food, respectively, than controls, indicating a hyperphagic response to fasting. Proliferation rates of T-cells were 6% and 30% lower (P < 0.05) in the ADF-50% and ADF-100% groups, respectively, relative to controls. Prostate cell proliferation was reduced (P < 0.05) by 49% in the ADF-100% group, relative to controls, but did not change in the other groups. IGF-1 levels were reduced (P < 0.05) by 40%, relative to controls, in the ADF-100% group. These findings confirm the beneficial effects of ADF-100% on cancer risk by decreasing cell proliferation and IGF-1 levels and suggest that modified ADF regimens comprising 25-50% CR on the fast day do not replicate these effects.
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Affiliation(s)
- Krista A Varady
- Department of Nutritional Sciences and Toxicology, University of California at Berkeley, Berkeley, California 94720-3104, USA.
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103
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King KL, Young ME, Kerner J, Huang H, O'Shea KM, Alexson SEH, Hoppel CL, Stanley WC. Diabetes or peroxisome proliferator-activated receptor alpha agonist increases mitochondrial thioesterase I activity in heart. J Lipid Res 2007; 48:1511-7. [PMID: 17438340 DOI: 10.1194/jlr.m600364-jlr200] [Citation(s) in RCA: 36] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
Peroxisome proliferator-activated receptor alpha (PPAR alpha) is a transcriptional regulator of the expression of mitochondrial thioesterase I (MTE-I) and uncoupling protein 3 (UCP3), which are induced in the heart at the mRNA level in response to diabetes. Little is known about the regulation of protein expression of MTE-I and UCP3 or about MTE-I activity; thus, we investigated the effects of diabetes and treatment with a PPAR alpha agonist on these parameters. Rats were either made diabetic with streptozotocin (55 mg/kg ip) and maintained for 10-14 days or treated with the PPAR alpha agonist fenofibrate (300 mg/kg/day) for 4 weeks. MTE-I and UCP3 protein expression, MTE-1 activity, palmitate export, and oxidative phosphorylation were measured in isolated cardiac mitochondria. Diabetes and fenofibrate increased cardiac MTE-I mRNA, protein, and activity ( approximately 4-fold compared with controls). This increase in activity was matched by a 6-fold increase in palmitate export in fenofibrate-treated animals, despite there being no effect in either group on UCP3 protein expression. Both diabetes and fenofibrate caused significant decreases in state III respiration of isolated mitochondria with pyruvate + malate as the substrate, but only diabetes reduced state III rates with palmitoylcarnitine. Both diabetes and specific PPAR alpha activation increased MTE-I protein, activity, and palmitate export in the heart, with little effect on UCP3 protein expression.
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Affiliation(s)
- Kristen L King
- Department of Physiology and Biophysics, Case Western Reserve University, Cleveland, OH 44106, USA
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104
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Colom B, Alcolea MP, Valle A, Oliver J, Roca P, García-Palmer FJ. Skeletal muscle of female rats exhibit higher mitochondrial mass and oxidative-phosphorylative capacities compared to males. Cell Physiol Biochem 2007; 19:205-12. [PMID: 17310114 DOI: 10.1159/000099208] [Citation(s) in RCA: 63] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 10/16/2006] [Indexed: 01/26/2023] Open
Abstract
The effect of gender and caloric restriction on mitochondrial content and oxidative-phosphorylative capacities has been investigated in rat gastrocnemius muscle. Muscle protein, mitochondrial protein and DNA contents, enzymatic activities of mitochondrial oxidative and phosphorylative system, mitochondrial antioxidant enzymes, protein levels of complex IV (subunit I and IV) and ATPase, and the gene and protein expression of mitochondrial transcription factor A (TFAM), involved in mitochondrial replication and transcription, were measured in rats of both genders fed ad libitum and subjected to three months of 40% caloric restriction. Compared to males, gastrocnemius muscle of female rats showed higher mitochondrial DNA and protein contents, TFAM protein level, oxidative and phosphorylative machinery and activities, and glutathione peroxidase activity. In conclusion, the present data show a clear gender dimorphism in rat muscle mitochondrial features, which could explain the higher facility of females to adapt to altered metabolic energy situations.
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Affiliation(s)
- Bartomeu Colom
- Grup de Metabolisme Energètic i Nutrició. Departament de Biología Fonamental i Ciències de la Salut. Institut Universitari d'Investigació en Ciències de la Salut (IUNICS). Universitat de les Illes Balears, E-07122 Palma de Mallorca, Spain
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105
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Civitarese AE, Carling S, Heilbronn LK, Hulver MH, Ukropcova B, Deutsch WA, Smith SR, Ravussin E. Calorie restriction increases muscle mitochondrial biogenesis in healthy humans. PLoS Med 2007; 4:e76. [PMID: 17341128 PMCID: PMC1808482 DOI: 10.1371/journal.pmed.0040076] [Citation(s) in RCA: 539] [Impact Index Per Article: 31.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/27/2006] [Accepted: 01/04/2007] [Indexed: 01/04/2023] Open
Abstract
BACKGROUND Caloric restriction without malnutrition extends life span in a range of organisms including insects and mammals and lowers free radical production by the mitochondria. However, the mechanism responsible for this adaptation are poorly understood. METHODS AND FINDINGS The current study was undertaken to examine muscle mitochondrial bioenergetics in response to caloric restriction alone or in combination with exercise in 36 young (36.8 +/- 1.0 y), overweight (body mass index, 27.8 +/- 0.7 kg/m(2)) individuals randomized into one of three groups for a 6-mo intervention: Control, 100% of energy requirements; CR, 25% caloric restriction; and CREX, caloric restriction with exercise (CREX), 12.5% CR + 12.5% increased energy expenditure (EE). In the controls, 24-h EE was unchanged, but in CR and CREX it was significantly reduced from baseline even after adjustment for the loss of metabolic mass (CR, -135 +/- 42 kcal/d, p = 0.002 and CREX, -117 +/- 52 kcal/d, p = 0.008). Participants in the CR and CREX groups had increased expression of genes encoding proteins involved in mitochondrial function such as PPARGC1A, TFAM, eNOS, SIRT1, and PARL (all, p < 0.05). In parallel, mitochondrial DNA content increased by 35% +/- 5% in the CR group (p = 0.005) and 21% +/- 4% in the CREX group (p < 0.004), with no change in the control group (2% +/- 2%). However, the activity of key mitochondrial enzymes of the TCA (tricarboxylic acid) cycle (citrate synthase), beta-oxidation (beta-hydroxyacyl-CoA dehydrogenase), and electron transport chain (cytochrome C oxidase II) was unchanged. DNA damage was reduced from baseline in the CR (-0.56 +/- 0.11 arbitrary units, p = 0.003) and CREX (-0.45 +/- 0.12 arbitrary units, p = 0.011), but not in the controls. In primary cultures of human myotubes, a nitric oxide donor (mimicking eNOS signaling) induced mitochondrial biogenesis but failed to induce SIRT1 protein expression, suggesting that additional factors may regulate SIRT1 content during CR. CONCLUSIONS The observed increase in muscle mitochondrial DNA in association with a decrease in whole body oxygen consumption and DNA damage suggests that caloric restriction improves mitochondrial function in young non-obese adults.
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Affiliation(s)
- Anthony E Civitarese
- Pennington Biomedical Research Center, Baton Rouge, Louisiana, United States of America.
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106
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Fernström M, Bakkman L, Tonkonogi M, Shabalina IG, Rozhdestvenskaya Z, Mattsson CM, Enqvist JK, Ekblom B, Sahlin K. Reduced efficiency, but increased fat oxidation, in mitochondria from human skeletal muscle after 24-h ultraendurance exercise. J Appl Physiol (1985) 2007; 102:1844-9. [PMID: 17234801 DOI: 10.1152/japplphysiol.01173.2006] [Citation(s) in RCA: 47] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022] Open
Abstract
The hypothesis that ultraendurance exercise influences muscle mitochondrial function has been investigated. Athletes in ultraendurance performance performed running, kayaking, and cycling at 60% of their peak O(2) consumption for 24 h. Muscle biopsies were taken preexercise (Pre-Ex), postexercise (Post-Ex), and after 28 h of recovery (Rec). Respiration was analyzed in isolated mitochondria during state 3 (coupled to ATP synthesis) and state 4 (noncoupled respiration), with fatty acids alone [palmitoyl carnitine (PC)] or together with pyruvate (Pyr). Electron transport chain activity was measured with NADH in permeabilized mitochondria. State 3 respiration with PC increased Post-Ex by 39 and 41% (P < 0.05) when related to mitochondrial protein and to electron transport chain activity, respectively. State 3 respiration with Pyr was not changed (P > 0.05). State 4 respiration with PC increased Post-Ex but was lower than Pre-Ex at Rec (P < 0.05 vs. Pre-Ex). Mitochondrial efficiency [amount of added ADP divided by oxygen consumed during state 3 (P/O ratio)] decreased Post-Ex by 9 and 6% (P < 0.05) with PC and PC + Pyr, respectively. P/O ratio remained reduced at Rec. Muscle uncoupling protein 3, measured with Western blotting, was not changed Post-Ex but tended to decrease at Rec (P = 0.07 vs. Pre-Ex). In conclusion, extreme endurance exercise decreases mitochondrial efficiency. This will increase oxygen demand and may partly explain the observed elevation in whole body oxygen consumption during standardized exercise (+13%). The increased mitochondrial capacity for PC oxidation indicates plasticity in substrate oxidation at the mitochondrial level, which may be of advantage during prolonged exercise.
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Affiliation(s)
- Maria Fernström
- Department of Physiology, Karolinska Institute, Stockholm, Sweden
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107
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de la Maza MP, Olivares D, Hirsch S, Sierralta W, Gattás V, Barrera G, Bunout D, Leiva L, Fernández M. Weight increase and overweight are associated with DNA oxidative damage in skeletal muscle. Clin Nutr 2006; 25:968-76. [PMID: 16687193 DOI: 10.1016/j.clnu.2006.02.008] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/22/2005] [Revised: 01/31/2006] [Accepted: 02/14/2006] [Indexed: 11/16/2022]
Abstract
BACKGROUND AND AIMS Weight maintenance within normal standards is recommended for prevention of conditions associated with oxidative injury. To compare oxidative damage in a post mitotic tissue, between adults differing in long-term energy balance. METHODS During hernia surgery, a sample of skeletal muscle was obtained in 17 non-obese adults. Subjects were divided into two groups according to their self-reported weight change: weight maintainers (WM) reported <4kg increase, and weight gainers (WG) reported >5kg increment. Muscle immunohistochemistry for 8-hydroxy-deoxyguanosine (8OHdG), 4-Hydroxy-2-nonenal (4HNE), and TNF-alpha, as markers of oxidative injury and inflammation, were performed. As known positive controls for oxidative injury, we included 10 elderly subjects (66-101yr). Anthropometric measures and blood samples for clinical laboratory and serum cytokines (TNF-alpha and IL-6) were obtained. RESULTS 8OHdG was higher in WG compared with WM (149.1+/-16.2 versus 117.8+/-29.5, P=0.03), and was associated with anthropometric indicators of fat accumulation. 4HNE was similar in WG compared with WM (10.9+/-7.6 versus 9.8+/-6.3) but noticeably higher in elderly subjects (21.5+/-15.3, P=0.059). TNF-alpha protein in WG was higher compared with WM (114.0+/-41.7 versus 70.1+/-23.3, P=0.025), and was associated with weight increase. CONCLUSIONS Moderate self-reported weight increase, and body fat accumulation, suggesting long-term positive energy balance is associated with muscle DNA oxidative injury and inflammation.
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Affiliation(s)
- María-Pía de la Maza
- Institute of Nutrition and Food Technology (INTA), University of Chile, Macul 5540, P.O. Box 138-11, Santiago, Chile.
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108
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Anderson RM, Weindruch R. Calorie restriction: progress during mid-2005-mid-2006. Exp Gerontol 2006; 41:1247-9. [PMID: 17125949 PMCID: PMC1831833 DOI: 10.1016/j.exger.2006.10.019] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/07/2005] [Revised: 10/27/2006] [Accepted: 10/27/2006] [Indexed: 10/23/2022]
Affiliation(s)
- Rozalyn M Anderson
- University of Wisconsin Madison, GRECC VA Hospital, 2500 Overlook Terrace, Madison, WI 53705, USA.
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109
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Lesnefsky EJ, Hoppel CL. Oxidative phosphorylation and aging. Ageing Res Rev 2006; 5:402-33. [PMID: 16831573 DOI: 10.1016/j.arr.2006.04.001] [Citation(s) in RCA: 124] [Impact Index Per Article: 6.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/27/2006] [Revised: 04/01/2006] [Accepted: 04/04/2006] [Indexed: 10/24/2022]
Abstract
This review addresses the data that support the presence and contribution of decreased mitochondrial oxidative phosphorylation during aging to impaired cellular metabolism. Aging impairs substrate oxidation, decreases cellular energy production and increases the production of reactive intermediates that are toxic to the cell. First, the basic principles of mitochondrial oxidative physiology are briefly reviewed. Second, the focus on the relationship of altered mitochondrial respiration to the increased production of reactive oxygen species that are employed by the "rate of living" and the "uncoupling to survive" theories of aging are discussed. Third, the impairment of function of respiration in aging is reviewed using an organ-based approach in mammalian systems. Fourth, the current state of knowledge regarding aging-induced alterations in the composition and function of key mitochondrial constituents is addressed. Model organisms, including C. elegans and D. melanogaster are included where pertinent. Fifth, these defects are related to knowledge regarding the production of reactive oxygen species from specific sites of the electron transport chain.
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Affiliation(s)
- Edward J Lesnefsky
- Department of Medicine, Division of Cardiology, Case Western Reserve University, Cleveland, OH, USA
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110
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Johnson G, Roussel D, Dumas JF, Douay O, Malthièry Y, Simard G, Ritz P. Influence of intensity of food restriction on skeletal muscle mitochondrial energy metabolism in rats. Am J Physiol Endocrinol Metab 2006; 291:E460-7. [PMID: 16621897 DOI: 10.1152/ajpendo.00258.2005] [Citation(s) in RCA: 15] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
Variable durations of food restriction (FR; lasting weeks to years) and variable FR intensities are applied to animals in life span-prolonging studies. A reduction in mitochondrial proton leak is suggested as a putative mechanism linking such diet interventions and aging retardation. Early mechanisms of mitochondrial metabolic adaptation induced by FR remain unclear. We investigated the influence of different degrees of FR over 3 days on mitochondrial proton leak and mitochondrial energy metabolism in rat hindlimb skeletal muscle. Animals underwent 25, 50, and 75% and total FR compared with control rats. Proton leak kinetics and mitochondrial functions were investigated in two mitochondrial subpopulations, intermyofibrillar (IMF) and subsarcolemmal (SSM) mitochondria. Regardless of the degree of restriction, skeletal muscle mass was not affected by 3 days of FR. Mitochondrial basal proton conductance was significantly decreased in 50% restricted rats in both mitochondrial subpopulations (46 and 40% for IMF and SSM, respectively) but was unaffected in other groups compared with controls. State 3 and uncoupled state 3 respiration rates were decreased in SSM mitochondria only for 50% restricted rats when pyruvate + malate was used as substrate (-34.5 and -38.9% compared with controls, P < 0.05). IMF mitochondria respiratory rates remained unchanged. Three days of FR, particularly at 50% FR, were sufficient to lower mitochondria energetic metabolism in both mitochondrial populations. Our study highlights an early step in mitochondrial adaptation to FR and the influence of the severity of restriction on this adaptation. This step may be involved in an aging-retardation process.
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Affiliation(s)
- Gyasi Johnson
- Institut National de la Santé et de la Recherche Médicale, Unité 694, Université d'Angers, F-49033 Angers Cedex 01, France
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111
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Barger JL, Barnes BM, Boyer BB. Regulation of UCP1 and UCP3 in arctic ground squirrels and relation with mitochondrial proton leak. J Appl Physiol (1985) 2006; 101:339-47. [PMID: 16782837 DOI: 10.1152/japplphysiol.01260.2005] [Citation(s) in RCA: 38] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022] Open
Abstract
Uncoupling protein (UCP) 1 (UCP1) catalyzes a proton leak in brown adipose tissue (BAT) mitochondria that results in nonshivering thermogenesis (NST), but the extent to which UCP homologs mediate NST in other tissues is controversial. To clarify the role of UCP3 in mediating NST in a hibernating species, we measured Ucp3 expression in skeletal muscle of arctic ground squirrels in one of three activity states (not hibernating, not hibernating and fasted for 48 h, or hibernating) and housed at 5°C or −10°C. We then compared Ucp3 mRNA levels in skeletal muscle with Ucp1 mRNA and UCP1 protein levels in BAT in the same animals. Ucp1 mRNA and UCP1 protein levels were increased on cold exposure and decreased with fasting, with the highest UCP1 levels in thermogenic hibernators. In contrast, Ucp3 mRNA levels were not affected by temperature but were increased 10-fold during fasting and >3-fold during hibernation. UCP3 protein levels were increased nearly fivefold in skeletal muscle mitochondria isolated from fasted squirrels compared with nonhibernators, but proton leak kinetics in the presence of BSA were unchanged. Proton leak in BAT mitochondria also did not differ between fed and fasted animals but did show classical inhibition by the purine nucleotide GDP. Levels of nonesterified fatty acids were highest during hibernation, and tissue temperatures during hibernation were related to Ucp1, but not Ucp3, expression. Taken together, these results do not support a role for UCP3 as a physiologically relevant mediator of NST in muscle.
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Affiliation(s)
- Jamie L Barger
- 311 Irving I Bldg., Institute of Arctic Biology and Department of Biology and Wildlife, University of Alaska Fairbanks, Fairbanks, Alaska 99775, USA
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112
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Ramsey JJ, Hagopian K. Energy expenditure and restriction of energy intake: could energy restriction alter energy expenditure in companion animals? J Nutr 2006; 136:1958S-1966S. [PMID: 16772468 DOI: 10.1093/jn/136.7.1958s] [Citation(s) in RCA: 28] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
Abstract
The treatment of obesity in companion animals frequently focuses on restriction of energy intake. One important question with this treatment is whether dietary energy restriction (ER) produces a sustained decrease in mass-adjusted energy expenditure (EE), which prevents further weight loss and promotes rapid regain of body weight during lapses in dietary ER. This review summarizes studies that investigated the effects of dietary ER on EE at the whole-animal, organ, and cellular level. Whole-animal studies indicate that long-term dietary ER either decreases or does not affect mass-adjusted EE. The reason for this discrepancy between studies is not entirely clear, although analysis of data pooled from multiple studies suggests that a reduction in mass-adjusted EE with long-term ER would be observed if the sample size were sufficiently large and appropriate methods were used to adjust EE for body size. At the organ level, attempts were made to determine whether alterations in organ mass can entirely explain changes in EE with dietary ER. However, these studies were not conclusive, and it remains to be determined whether changes in EE exceed those that would be predicted from ER-induced alterations in organ mass. At the cellular level, there is evidence that dietary ER may induce sustained decreases in substrate oxidation, mitochondrial proton, and Na+-K+-ATPase activity in at least some tissues. These results are consistent with the idea that dietary ER may induce decreases in cellular EE. However, future studies integrating measurements at the whole-animal, organ, and cellular level will be required to determine definitively whether dietary ER produces sustained decreases in tissue or cellular EE.
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Affiliation(s)
- Jon J Ramsey
- Department of Molecular Biosciences, School of Veterinary Medicine, University of California, Davis, CA 95616, USA.
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113
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Costford SR, Chaudhry SN, Salkhordeh M, Harper ME. Effects of the presence, absence, and overexpression of uncoupling protein-3 on adiposity and fuel metabolism in congenic mice. Am J Physiol Endocrinol Metab 2006; 290:E1304-12. [PMID: 16434555 DOI: 10.1152/ajpendo.00401.2005] [Citation(s) in RCA: 50] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
Uncoupling protein-3 (UCP3) is a poorly understood mitochondrial inner membrane protein expressed predominantly in skeletal muscle. The aim of this study was to examine the effects of the absence or constitutive physiological overexpression of UCP3 on whole body energy metabolism, glucose tolerance, and muscle triglyceride content. Congenic male UCP3 knockout mice (Ucp3-/-), wild-type, and transgenic UCP3 overexpressing (UCP3Tg) mice were fed a 10% fat diet for 4 or 8 mo after they were weaned. UCP3Tg mice had lower body weights and were less metabolically efficient than wild-type or Ucp3-/- mice, but they were not hyperphagic. UCP3Tg mice had smaller epididymal white adipose tissue and brown adipose tissue (BAT) depots; however, there were no differences in muscle weights. Glucose and insulin tolerance tests revealed that both UCP3Tg and Ucp3-/- mice were protected from development of impaired glucose tolerance and were more sensitive to insulin. 2-Deoxy-D-[1-3H]glucose tracer studies showed increased uptake of glucose into BAT and increased storage of liver glycogen in Ucp3-/- mice. Assessments of intramuscular triglyceride (IMTG) revealed decreases in quadriceps of UCP3Tg mice compared with wild-type and Ucp3-/- mice. When challenged with a 45% fat diet, Ucp3-/- mice showed increased accumulation of IMTG compared with wild-type mice, which in turn had greater IMTG than UCP3Tg mice. Results are consistent with a role for UCP3 in preventing accumulation of triglyceride in both adipose tissue and muscle.
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Affiliation(s)
- Sheila R Costford
- Dept. of Biochemistry, Microbiology and Immunology, Faculty of Medicine, Univ. of Ottawa, 451 Smyth Rd., Ottawa, ON, Canada K1H 8M5
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114
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Hunt ND, Hyun DH, Allard JS, Minor RK, Mattson MP, Ingram DK, de Cabo R. Bioenergetics of aging and calorie restriction. Ageing Res Rev 2006; 5:125-43. [PMID: 16644290 DOI: 10.1016/j.arr.2006.03.006] [Citation(s) in RCA: 39] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/23/2006] [Accepted: 03/07/2006] [Indexed: 01/25/2023]
Abstract
Aging is a physiological process that involves a multi-factorial set of deleterious changes. These alterations are caused by an exponential increase in damage to macromolecules. This process is likely due to the cumulative effects of oxidative stress over time. One area of ongoing research in gerontology has focused on determining why there is an age-dependent decrease in cellular bioenergetics. The aim of this review is to summarize the recent findings on the effects of aging and calorie restriction on energy metabolism. The effect of calorie restriction on age-associated changes in bioenergetic parameters will be examined.
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Affiliation(s)
- Nicole D Hunt
- Laboratory of Experimental Gerontology, NIA, NIH, Gerontology Research Center, Box 10, 5600 Nathan Shock Drive, Baltimore, MD 21224-6825, USA
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115
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Abstract
Oxidative stress over time leads to the accumulation of damaged macromolecules and to profound physiological changes that are associated with several age-related diseases. The plasma membrane redox system (PMRS) appears to attenuate oxidative stress acting as a compensatory mechanism during the aging process. The PMRS appears to play a protective role during mitochondrial dysfunction to provide cells with a survival mechanism by lowering oxidative stress. The PMRS accomplishes this by producing more NAD(+) for glycolytic ATP production via transfer of electrons from intracellular reducing equivalents to extracelluar acceptors. Ubiquinone and alpha-tocopherol are key antioxidant molecules in the plasma membrane that are affected by aging and can be up-regulated by dietary interventions such as calorie restriction (CR). Up-regulation of PMRS activity leads to cell survival and membrane homeostasis under stress conditions and during calorie restriction. Further studies of the PMRS may provide not only additional information on the mechanisms involved in aging and CR, but may provide therapeutic targets for the prevention and treatment of age-related diseases.
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Affiliation(s)
- Dong-Hoon Hyun
- Laboratory of Neurosciences, National Institute on Aging, National Institutes of Health, Baltimore, MD 21224, USA
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116
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Heilbronn LK, de Jonge L, Frisard MI, DeLany JP, Meyer DEL, Rood J, Nguyen T, Martin CK, Volaufova J, Most MM, Greenway FL, Smith SR, Williamson DA, Deutsch WA, Ravussin E. Effect of 6-month calorie restriction on biomarkers of longevity, metabolic adaptation, and oxidative stress in overweight individuals: a randomized controlled trial. JAMA 2006; 295:1539-48. [PMID: 16595757 PMCID: PMC2692623 DOI: 10.1001/jama.295.13.1539] [Citation(s) in RCA: 638] [Impact Index Per Article: 35.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/14/2022]
Abstract
CONTEXT Prolonged calorie restriction increases life span in rodents. Whether prolonged calorie restriction affects biomarkers of longevity or markers of oxidative stress, or reduces metabolic rate beyond that expected from reduced metabolic mass, has not been investigated in humans. OBJECTIVE To examine the effects of 6 months of calorie restriction, with or without exercise, in overweight, nonobese (body mass index, 25 to <30) men and women. DESIGN, SETTING, AND PARTICIPANTS Randomized controlled trial of healthy, sedentary men and women (N = 48) conducted between March 2002 and August 2004 at a research center in Baton Rouge, La. INTERVENTION Participants were randomized to 1 of 4 groups for 6 months: control (weight maintenance diet); calorie restriction (25% calorie restriction of baseline energy requirements); calorie restriction with exercise (12.5% calorie restriction plus 12.5% increase in energy expenditure by structured exercise); very low-calorie diet (890 kcal/d until 15% weight reduction, followed by a weight maintenance diet). MAIN OUTCOME MEASURES Body composition; dehydroepiandrosterone sulfate (DHEAS), glucose, and insulin levels; protein carbonyls; DNA damage; 24-hour energy expenditure; and core body temperature. RESULTS Mean (SEM) weight change at 6 months in the 4 groups was as follows: controls, -1.0% (1.1%); calorie restriction, -10.4% (0.9%); calorie restriction with exercise, -10.0% (0.8%); and very low-calorie diet, -13.9% (0.7%). At 6 months, fasting insulin levels were significantly reduced from baseline in the intervention groups (all P<.01), whereas DHEAS and glucose levels were unchanged. Core body temperature was reduced in the calorie restriction and calorie restriction with exercise groups (both P<.05). After adjustment for changes in body composition, sedentary 24-hour energy expenditure was unchanged in controls, but decreased in the calorie restriction (-135 kcal/d [42 kcal/d]), calorie restriction with exercise (-117 kcal/d [52 kcal/d]), and very low-calorie diet (-125 kcal/d [35 kcal/d]) groups (all P<.008). These "metabolic adaptations" (~ 6% more than expected based on loss of metabolic mass) were statistically different from controls (P<.05). Protein carbonyl concentrations were not changed from baseline to month 6 in any group, whereas DNA damage was also reduced from baseline in all intervention groups (P <.005). CONCLUSIONS Our findings suggest that 2 biomarkers of longevity (fasting insulin level and body temperature) are decreased by prolonged calorie restriction in humans and support the theory that metabolic rate is reduced beyond the level expected from reduced metabolic body mass. Studies of longer duration are required to determine if calorie restriction attenuates the aging process in humans. TRIAL REGISTRATION ClinicalTrials.gov Identifier: NCT00099151.
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Affiliation(s)
- Leonie K Heilbronn
- Pennington Biomedical Research Center, Baton Rouge, LA, 70808
- Garvan Institute for Medical Research, Darlinghurst, NSW, AUSTRALIA, 2010
| | - Lilian de Jonge
- Pennington Biomedical Research Center, Baton Rouge, LA, 70808
| | | | - James P. DeLany
- Pennington Biomedical Research Center, Baton Rouge, LA, 70808
| | | | - Jennifer Rood
- Pennington Biomedical Research Center, Baton Rouge, LA, 70808
| | - Tuong Nguyen
- Pennington Biomedical Research Center, Baton Rouge, LA, 70808
| | - Corby K Martin
- Pennington Biomedical Research Center, Baton Rouge, LA, 70808
| | - Julia Volaufova
- Pennington Biomedical Research Center, Baton Rouge, LA, 70808
| | - Marlene M Most
- Pennington Biomedical Research Center, Baton Rouge, LA, 70808
| | | | - Steven R Smith
- Pennington Biomedical Research Center, Baton Rouge, LA, 70808
| | | | | | - Eric Ravussin
- Pennington Biomedical Research Center, Baton Rouge, LA, 70808
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117
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López-Lluch G, Hunt N, Jones B, Zhu M, Jamieson H, Hilmer S, Cascajo MV, Allard J, Ingram DK, Navas P, de Cabo R. Calorie restriction induces mitochondrial biogenesis and bioenergetic efficiency. Proc Natl Acad Sci U S A 2006; 103:1768-73. [PMID: 16446459 PMCID: PMC1413655 DOI: 10.1073/pnas.0510452103] [Citation(s) in RCA: 502] [Impact Index Per Article: 27.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/21/2022] Open
Abstract
Age-related accumulation of cellular damage and death has been linked to oxidative stress. Calorie restriction (CR) is the most robust, nongenetic intervention that increases lifespan and reduces the rate of aging in a variety of species. Mechanisms responsible for the antiaging effects of CR remain uncertain, but reduction of oxidative stress within mitochondria remains a major focus of research. CR is hypothesized to decrease mitochondrial electron flow and proton leaks to attenuate damage caused by reactive oxygen species. We have focused our research on a related, but different, antiaging mechanism of CR. Specifically, using both in vivo and in vitro analyses, we report that CR reduces oxidative stress at the same time that it stimulates the proliferation of mitochondria through a peroxisome proliferation-activated receptor coactivator 1 alpha signaling pathway. Moreover, mitochondria under CR conditions show less oxygen consumption, reduce membrane potential, and generate less reactive oxygen species than controls, but remarkably they are able to maintain their critical ATP production. In effect, CR can induce a peroxisome proliferation-activated receptor coactivator 1 alpha-dependent increase in mitochondria capable of efficient and balanced bioenergetics to reduce oxidative stress and attenuate age-dependent endogenous oxidative damage.
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Affiliation(s)
- G. López-Lluch
- *Centro Andaluz de Biología del Desarrollo, Universidad Pablo de Olavide, 41013 Sevilla, Spain
| | - N. Hunt
- Laboratory of Experimental Gerontology, National Institute on Aging, National Institutes of Health, 5600 Nathan Shock Drive, Baltimore, MD 21224-6825
| | - B. Jones
- Laboratory of Experimental Gerontology, National Institute on Aging, National Institutes of Health, 5600 Nathan Shock Drive, Baltimore, MD 21224-6825
| | - M. Zhu
- Laboratory of Experimental Gerontology, National Institute on Aging, National Institutes of Health, 5600 Nathan Shock Drive, Baltimore, MD 21224-6825
| | - H. Jamieson
- Centre for Education and Research on Aging, University of Sydney, Concord Hospital, Concord NSW 2139, Australia; and
- Departments of Aged Care and Clinical Pharmacology, Royal North Shore Hospital, St. Leonards NSW 2069, Australia
| | - S. Hilmer
- Centre for Education and Research on Aging, University of Sydney, Concord Hospital, Concord NSW 2139, Australia; and
- Departments of Aged Care and Clinical Pharmacology, Royal North Shore Hospital, St. Leonards NSW 2069, Australia
| | - M. V. Cascajo
- *Centro Andaluz de Biología del Desarrollo, Universidad Pablo de Olavide, 41013 Sevilla, Spain
| | - J. Allard
- Laboratory of Experimental Gerontology, National Institute on Aging, National Institutes of Health, 5600 Nathan Shock Drive, Baltimore, MD 21224-6825
| | - D. K. Ingram
- Laboratory of Experimental Gerontology, National Institute on Aging, National Institutes of Health, 5600 Nathan Shock Drive, Baltimore, MD 21224-6825
| | - P. Navas
- *Centro Andaluz de Biología del Desarrollo, Universidad Pablo de Olavide, 41013 Sevilla, Spain
| | - R. de Cabo
- Laboratory of Experimental Gerontology, National Institute on Aging, National Institutes of Health, 5600 Nathan Shock Drive, Baltimore, MD 21224-6825
- To whom correspondence should be addressed. E-mail:
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118
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Amen-Ra N. Humans are evolutionarily adapted to caloric restriction resulting from ecologically dictated dietary deprivation imposed during the Plio-Pleistocene period. Med Hypotheses 2006; 66:978-84. [PMID: 16406387 DOI: 10.1016/j.mehy.2005.11.013] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/29/2005] [Accepted: 11/03/2005] [Indexed: 01/15/2023]
Abstract
Humans are evolutionarily adapted to chronic undernutrition as a consequence of ecologically dictated dietary restriction. Increased aridity, cooler temperatures and increased climatic oscillation effected an alteration of the quantity and quality of vegetation upon which hominids depended for food during the Plio-Pleistocene period. Hominids responded physiologically to climate-induced caloric curtailment in the same way organisms respond to experimentally imposed caloric restriction: by reducing the rate and/or altering the manner in which they metabolized fuel. Such metabolic alterations are mediated principally by the hypothalamus and it is herein hypothesized that the human hypothalamus was subjected to substantial selective pressure, promoting an energetically conservative hypometabolic state. Moreover, the most salient phenotypic characteristics typifying the human species - long lifespan, low reproductive potential, lengthy development and high brain/bodyweight ratio - are effectuated in organisms undergoing caloric restriction. These phenotypic/physiological characteristics - herein termed the quadripartite complex - can be modulated by metabolic rate, which is, in turn, modulated by the hypothalamus. An appreciable alteration in climate occurred between 2.0 and 1.5 million years ago, a juncture at which one hominid lineage (Paranthropus) went extinct. Paranthropus was characterized by such external adaptations as robust cranio-facial morphology and pronounced enamel deposition, indicative of subsistence on tough, low-quality vegetal foods. Conversely, the Homo lineage responded to its marginal dietary repertoire through internal means, centering on metabolic suppression. It is herein hypothesized that this adaptive metabolic alteration, enacted in response to ecologically imposed caloric restriction, produced the defining morphologic attributes of Homo and enabled the evolutionary success of the human species. Among the implications of this line of thinking is that modern humans may be particularly sensitive to the deleterious effects of excess energy intake and, concomitantly, particularly amenable to the ameliorative effects of caloric restriction.
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119
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Stuart JA, Brown MF. Energy, quiescence and the cellular basis of animal life spans. Comp Biochem Physiol A Mol Integr Physiol 2006; 143:12-23. [PMID: 16377223 DOI: 10.1016/j.cbpa.2005.11.002] [Citation(s) in RCA: 31] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/30/2005] [Revised: 11/02/2005] [Accepted: 11/03/2005] [Indexed: 01/11/2023]
Abstract
Animals are routinely faced with harsh environmental conditions in which insufficient energy is available to grow and reproduce. Many animals adapt to this challenge by entering a dormant, or quiescent state. In some animals, such as the nematode Caenorhabditis elegans, quiescence is coincident with increased stress resistance and longevity. Here we review evidence that the rules of life span extension established in C. elegans may be generally true of most animals. That is, that the rate of animal aging correlates inversely with cellular resistance to physiological stress, particularly oxidative stress, and that stress resistance is co-regulated with the quiescence adaptation (where the latter occurs). We discuss evidence for highly conserved intracellular signalling pathways involved in energy sensing that are sensitive to aspects of mitochondrial energy transduction and can be modulated in response to energetic flux. We provide a broad overview of the current knowledge of the relationships between energy, metabolism and life span.
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Affiliation(s)
- Jeffrey A Stuart
- Department of Biological Sciences, Brock University, St. Catharines, Ontario, Canada L2S 3A1.
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