451
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Carlucci A, Lignitto L, Feliciello A. Control of mitochondria dynamics and oxidative metabolism by cAMP, AKAPs and the proteasome. Trends Cell Biol 2008; 18:604-13. [PMID: 18951795 DOI: 10.1016/j.tcb.2008.09.006] [Citation(s) in RCA: 100] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/11/2008] [Revised: 09/27/2008] [Accepted: 09/29/2008] [Indexed: 12/29/2022]
Abstract
Mitochondria are highly specialized organelles and major players in fundamental aspects of cell physiology. In yeast, energy metabolism and coupling of mitochondrial activity to growth and survival is controlled by the protein kinase A pathway. In higher eukaryotes, modulation of the so-called A-kinase anchor protein (AKAP) complex regulates mitochondrial dynamics and activity, adapting the oxidative machinery and the metabolic pathway to changes in physiological demand. Protein kinases and phosphatases are assembled by AKAPs within transduction units, providing a mechanism to control signaling events at mitochondria and other target organelles. Ubiquitin-mediated proteolysis of signal transducers and effectors provides an additional layer of complexity in the regulation of mitochondria homeostasis. Genetic evidence indicates that alteration of one or more components of these biochemical pathways leads to mitochondrial dysfunction and human diseases. In this review, we focus on the emerging role of AKAP scaffolds and the proteasome pathway in the control of oxidative metabolism, organelle dynamics and the mitochondrial signaling network. These aspects are crucial elements for maintaining a proper energy balance and cellular lifespan.
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Affiliation(s)
- Annalisa Carlucci
- Dipartimento di Biologia e Patologia Molecolare e Cellulare, Università Federico II, Naples, Italy
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452
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Petrosillo G, Fattoretti P, Matera M, Ruggiero FM, Bertoni-Freddari C, Paradies G. Melatonin Prevents Age-Related Mitochondrial Dysfunction in Rat Brain Via Cardiolipin Protection. Rejuvenation Res 2008; 11:935-43. [DOI: 10.1089/rej.2008.0772] [Citation(s) in RCA: 46] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/08/2023] Open
Affiliation(s)
- Giuseppe Petrosillo
- Department of Biochemistry and Molecular Biology CNR Institute of Biomembranes and Bioenergetics University of Bari, Bari Italy
| | | | - Mariagiuseppa Matera
- Department of Biochemistry and Molecular Biology CNR Institute of Biomembranes and Bioenergetics University of Bari, Bari Italy
| | - Francesca M. Ruggiero
- Department of Biochemistry and Molecular Biology CNR Institute of Biomembranes and Bioenergetics University of Bari, Bari Italy
| | | | - Giuseppe Paradies
- Department of Biochemistry and Molecular Biology CNR Institute of Biomembranes and Bioenergetics University of Bari, Bari Italy
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453
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Derumeaux G, Ichinose F, Raher MJ, Morgan JG, Coman T, Lee C, Cuesta JM, Thibault H, Bloch KD, Picard MH, Scherrer-Crosbie M. Myocardial alterations in senescent mice and effect of exercise training: a strain rate imaging study. Circ Cardiovasc Imaging 2008; 1:227-34. [PMID: 19808547 DOI: 10.1161/circimaging.107.745919] [Citation(s) in RCA: 30] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
BACKGROUND Aging is accompanied by an alteration in myocardial contractility. However, its noninvasive detection is difficult. The effect of chronic exercise on this decrease is unknown. Murine models of senescence are increasingly used to test therapies in aging. We tested whether strain rate imaging detected left ventricular (LV) systolic dysfunction in aging mice and was able to assess a potential improvement after exercise. METHODS AND RESULTS Young (3 weeks), adult (2 to 3 months), and old (6 to 18 months) C57BL6 male mice underwent echocardiograms with strain rate imaging, either in sedentary conditions or before, 2 weeks and 4 weeks after chronic swimming. Hemodynamic parameters of LV function including maximal and end-systolic elastance were obtained before euthanizing. LV fibrosis was measured using Sirius red staining. Conventional echocardiography was unable to detect LV systolic dysfunction in old mice, whereas both systolic strain rate and load-independent hemodynamic parameters such as preload recruitable stroke work and end-systolic elastance were significantly decreased. Both strain rate and load-independent hemodynamic parameters normalized after 4 weeks of exercise. Both endocardial and epicardial fibrosis were increased in the LV of aging mice. Endocardial fibrosis decreased in exercised aged mice. CONCLUSIONS Strain rate noninvasively detects LV systolic dysfunction associated with aging in mice, whereas conventional echocardiography does not. Chronic exercise normalizes LV systolic function and decreases fibrosis in old mice. Strain rate imaging in mice may be a useful tool to monitor the effect of new therapeutic strategies preventing the myocardial dysfunction associated with aging.
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454
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Comim CM, Rezin GT, Scaini G, Di-Pietro PB, Cardoso MR, Petronilho FC, Ritter C, Streck EL, Quevedo J, Dal-Pizzol F. Mitochondrial respiratory chain and creatine kinase activities in rat brain after sepsis induced by cecal ligation and perforation. Mitochondrion 2008; 8:313-8. [DOI: 10.1016/j.mito.2008.07.002] [Citation(s) in RCA: 53] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/15/2008] [Revised: 06/27/2008] [Accepted: 07/02/2008] [Indexed: 10/21/2022]
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455
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Camello-Almaraz C, Gomez-Pinilla PJ, Pozo MJ, Camello PJ. Age-related alterations in Ca2+ signals and mitochondrial membrane potential in exocrine cells are prevented by melatonin. J Pineal Res 2008; 45:191-8. [PMID: 18318704 DOI: 10.1111/j.1600-079x.2008.00576.x] [Citation(s) in RCA: 27] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/11/2023]
Abstract
Information regarding age-induced Ca(2+) signal alterations in nonexcitable cells is limited. In addition, little evidence exists on the ability of melatonin to palliate the effects of aging on Ca(2+) signals and mitochondrial potential, a parameter involved in both Ca(2+) signaling and aging. We studied the ability of melatonin to prevent the effects of aging on intracellular Ca(2+) homeostasis and mitochondrial potential in exocrine cells. Pancreatic acinar cells were obtained from adult (3 months old) and aged (22-24 months old) mice by collagenase dispersion. Ca(2+) signals, in situ mitochondrial potential and in vitro amylase secretion were determined. Secretion in response to increasing levels of the secretagogues, acetylcholine and cholecystokinin (CCK), were impaired in aged pancreatic acini. This decrease was accompanied by an inhibition in the amplitude of the peak response to maximal concentrations of the agonists, and by a decrease in the pattern of Ca(2+) oscillations induced by postprandial levels of CCK. Both the size of the calcium pools, assessed by low levels of ionomycin, and capacitative calcium entry, induced by depletion of the stores with thapsigargin, were diminished in aged cells. These changes in Ca(2+) homeostasis were associated with depolarization of intracellular mitochondria. Oral administration of melatonin for 3 months to aged mice restored the secretory response, the amplitude and frequency of Ca(2+) responses, the size of intracellular calcium pools, the capacitative calcium entry, and the mitochondrial potential. In conclusion, melatonin restores secretory function, Ca(2+) signals and mitochondrial potential of aged exocrine cells.
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Affiliation(s)
- Cristina Camello-Almaraz
- Department of Physiology, Faculty of Veterinary Science, Nursing School and RETICEF, University of Extremadura, Caceres, Spain
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456
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Valle A, Guevara R, García-Palmer FJ, Roca P, Oliver J. Caloric restriction retards the age-related decline in mitochondrial function of brown adipose tissue. Rejuvenation Res 2008; 11:597-604. [PMID: 18593277 DOI: 10.1089/rej.2007.0626] [Citation(s) in RCA: 41] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/23/2023] Open
Abstract
Caloric restriction (CR) has been shown to prevent the age-associated loss of mitochondrial function and biogenesis in several tissues such as liver, heart, and skeletal muscle. However, little is known about the effects of CR on a tissue in which the mitochondria have no adenosine triphosphate (ATP)-producing purpose but show a high degree of uncoupling, namely brown adipose tissue (BAT). Hence, the aim of the present study was to analyze the effect of long-term CR on BAT mitochondrial function and biogenesis. BAT mitochondria obtained from 24-month-old male and female rats previously subjected to 40% CR for 12 months were compared with mitochondria from old (24 months) and young (6 months) ad libitum fed rats. Old restricted rats compared to old ad libitum fed ones showed a reduction in BAT size with respect to fat content and adipocyte number. Mitochondrial DNA content in BAT increased with age and even more so in restricted rats, indicating a summative effect of age and CR on mitochondrial proliferation. CR induced resistance to lose total and mitochondrial protein, COX activity, and uncoupling capacity with advancing age, in relation with a lower decrease of mitochondrial transcription factor A (TFAM). In summary, our results demonstrate CR prevents the age-associated decline in mitochondrial function in BAT, probably in relation with a lower impairment of mitochondrial biogenesis.
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Affiliation(s)
- Adamo Valle
- Grup de Metabolisme Energètic i Nutrició, Departament de Biologia Fonamental i Ciències de la Salut, Universitat de les Illes Balears, Palma de Mallorca, Ciber Fisiopatología Obesidad y Nutrición (CB06/03) Instituto Salud Carlos III, Spain
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457
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de Cavanagh EMV, Flores I, Ferder M, Inserra F, Ferder L. Renin-angiotensin system inhibitors protect against age-related changes in rat liver mitochondrial DNA content and gene expression. Exp Gerontol 2008; 43:919-28. [PMID: 18765277 DOI: 10.1016/j.exger.2008.08.007] [Citation(s) in RCA: 25] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/30/2008] [Revised: 07/14/2008] [Accepted: 08/08/2008] [Indexed: 02/07/2023]
Abstract
Chronic renin-angiotensin system inhibition protects against liver fibrosis, ameliorates age-associated mitochondrial dysfunction and increases rodent lifespan. We hypothesized that life-long angiotensin-II-mediated stimulation of oxidant generation might participate in mitochondrial DNA "common deletion" formation, and the resulting impairment of bioenergetic capacity. Enalapril (10 mg/kg/d) or losartan (30 mg/kg/d) administered during 16.5 months were unable to prevent the age-dependent accumulation of rat liver mitochondrial DNA "common deletion", but attenuated the decrease of mitochondrial DNA content. This evidence - together with the enhancement of NRF-1 and PGC-1 mRNA contents - seems to explain why enalapril and losartan improved mitochondrial functioning and lowered oxidant production, since both the absolute number of mtDNA molecules and increased NRF-1 and PGC-1 transcription are positively related to mitochondrial respiratory capacity, and PGC-1 protects against increases in ROS production and damage. Oxidative stress evoked by abnormal respiratory function contributes to the pathophysiology of mitochondrial disease and human aging. If the present mitochondrial actions of renin-angiotensin system inhibitors are confirmed in humans they may modify the therapeutic significance of that strategy.
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Affiliation(s)
- Elena M V de Cavanagh
- Institute of Cardiovascular Pathophysiology (INFICA), School of Medicine, University of Buenos Aires, Buenos Aires, Argentina
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458
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Schönfeld P, Wojtczak L. Fatty acids as modulators of the cellular production of reactive oxygen species. Free Radic Biol Med 2008; 45:231-41. [PMID: 18482593 DOI: 10.1016/j.freeradbiomed.2008.04.029] [Citation(s) in RCA: 314] [Impact Index Per Article: 19.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 02/05/2008] [Revised: 04/16/2008] [Accepted: 04/22/2008] [Indexed: 12/17/2022]
Abstract
Long-chain nonesterified ("free") fatty acids (FFA) and some of their derivatives and metabolites can modify intracellular production of reactive oxygen species (ROS), in particular O(2)(-) and H(2)O(2). In mitochondria, FFA exert a dual effect on ROS production. Because of slowing down the rate of electron flow through Complexes I and III of the respiratory chain due to interaction within the complex subunit structure, and between Complexes III and IV due to release of cytochrome c from the inner membrane, FFA increase the rate of ROS generation in the forward mode of electron transport. On the other hand, due to their protonophoric action on the inner mitochondrial membrane ("mild uncoupling effect"), FFA strongly decrease ROS generation in the reverse mode of electron transport. In the plasma membrane of phagocytic neutrophils and a number of other types of cells, polyunsaturated FFA stimulate O(2)(-) generation by NADPH oxidase. These effects of FFA can modulate signaling functions of ROS and be, at least partly, responsible for their proapoptotic effects in several types of cells.
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Affiliation(s)
- Peter Schönfeld
- Institute of Biochemistry and Cell Biology, Otto von Guericke University, Leipziger Str. 44, 39120 Magdeburg, Germany.
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459
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Wang H, Xue Z, Wang Q, Feng X, Shen Z. Propofol Protects Hepatic L02 Cells from Hydrogen Peroxide-Induced Apoptosis via Activation of Extracellular Signal-Regulated Kinases Pathway. Anesth Analg 2008; 107:534-40. [DOI: 10.1213/ane.0b013e3181770be9] [Citation(s) in RCA: 42] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/14/2022]
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460
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López-Lluch G, Irusta PM, Navas P, de Cabo R. Mitochondrial biogenesis and healthy aging. Exp Gerontol 2008; 43:813-9. [PMID: 18662766 DOI: 10.1016/j.exger.2008.06.014] [Citation(s) in RCA: 256] [Impact Index Per Article: 16.0] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/23/2008] [Accepted: 06/26/2008] [Indexed: 02/09/2023]
Abstract
Aging is associated with an overall loss of function at the level of the whole organism that has origins in cellular deterioration. Most cellular components, including mitochondria, require continuous recycling and regeneration throughout the lifespan. Mitochondria are particularly susceptive to damage over time as they are the major bioenergetic machinery and source of oxidative stress in cells. Effective control of mitochondrial biogenesis and turnover, therefore, becomes critical for the maintenance of energy production, the prevention of endogenous oxidative stress and the promotion of healthy aging. Multiple endogenous and exogenous factors regulate mitochondrial biogenesis through the peroxisome proliferator-activated receptor gamma coactivator-1alpha (PGC-1alpha). Activators of PGC-1alpha include nitric oxide, CREB and AMPK. Calorie restriction (CR) and resveratrol, a proposed CR mimetic, also increase mitochondrial biogenesis through activation of PGC-1alpha. Moderate exercise also mimics CR by inducing mitochondrial biogenesis. Negative regulators of PGC-1alpha such as RIP140 and 160MBP suppress mitochondrial biogenesis. Another mechanism involved in mitochondrial maintenance is mitochondrial fission/fusion and this process also involves an increasing number of regulatory proteins. Dysfunction of either biogenesis or fission/fusion of mitochondria is associated with diseases of the neuromuscular system and aging, and a greater understanding of the regulation of these processes should help us to ultimately control the aging process.
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Affiliation(s)
- Guillermo López-Lluch
- Centro Andaluz de Biología del Desarrollo, Universidad Pablo de Olavide-CSIC, Carretera de Utrera Km 1, 41013 Sevilla, Spain
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461
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Niklison Chirou M, Bellomio A, Dupuy F, Arcuri B, Minahk C, Morero R. Microcin J25 induces the opening of the mitochondrial transition pore and cytochrome c release through superoxide generation. FEBS J 2008; 275:4088-96. [PMID: 18616579 DOI: 10.1111/j.1742-4658.2008.06550.x] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
Microcin J25, an antimicrobial lasso-structure peptide, induces the opening of mitochondrial permeability transition pores and the subsequent loss of cytochrome c. The microcin J25 effect is mediated by the stimulation of superoxide anion overproduction. An increased uptake of calcium is also involved in this process. Additional studies with superoxide dismutase, ascorbic acid and different specific inhibitors, such as ruthenium red, cyclosporin A and Mn(2+), allowed us to establish a time sequence of events starting with the binding of microcin J25, followed by superoxide anion overproduction, opening of mitochondrial permeability transition pores, mitochondrial swelling and the concomitant leakage of cytochrome c.
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Affiliation(s)
- María Niklison Chirou
- Departamento de Bioquímica de la Nutrición, Instituto Superior de Investigaciones Biológicas, Instituto de Química Biológica, Dr Bernabe Bloj, San Miguel de Tucumán, Argentina
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462
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Siegenthaler MM, Ammon DL, Keirstead HS. Myelin pathogenesis and functional deficits following SCI are age-associated. Exp Neurol 2008; 213:363-71. [PMID: 18644369 DOI: 10.1016/j.expneurol.2008.06.015] [Citation(s) in RCA: 29] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/04/2008] [Revised: 06/17/2008] [Accepted: 06/18/2008] [Indexed: 11/25/2022]
Abstract
Most spinal cord injuries (SCI) occur in young adults. In the past few decades however, the average age at time of SCI and the percentage of injuries in persons over the age of 60 have increased. Studies have shown that there is an age-associated delay in the rate of remyelination following toxin-induced demyelination of the spinal cord, suggesting that there may be an age-associated difference in regenerative efficiency. Here we examine for the first time locomotor recovery, bladder recovery, and myelin pathology in young (3 months), aged (12 months), and geriatric (24 months) female rats following contusion SCI. Our assessments indicate that aged and geriatric rats have a delayed rate of locomotor recovery following contusion SCI as compared to young rats. Additionally, aged and geriatric rats have significantly slower bladder recovery as compared to young rats. Examination of myelin pathology reveals that aged and geriatric rats have significantly greater area of pathology and amount of demyelination, as well as significantly less remyelination as compared to young rats following contusion SCI. These data are the first to indicate that there is an age-associated decline in the rate and extent of both locomotor and bladder recovery following contusion SCI, and that age adversely affects the degree of general pathology, demyelination, and remyelination that accompanies contusion SCI.
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Affiliation(s)
- Monica M Siegenthaler
- Reeve-Irvine Research Center, Sue and Bill Gross Stem Cell Research Center, Department of Anatomy and Neurobiology, School of Medicine, University of California at Irvine, Irvine, CA 92697-4292, USA
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463
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Pardo Andreu GL, Inada NM, Vercesi AE, Curti C. Uncoupling and oxidative stress in liver mitochondria isolated from rats with acute iron overload. Arch Toxicol 2008; 83:47-53. [PMID: 18560806 DOI: 10.1007/s00204-008-0322-x] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/04/2008] [Accepted: 05/21/2008] [Indexed: 12/17/2022]
Abstract
One hypothesis for the etiology of cell damage arising from iron overload is that its excess selectively affects mitochondria. Here we tested the effects of acute iron overload on liver mitochondria isolated from rats subjected to a single dose of i.p. 500 mg/kg iron-dextran. The treatment increased the levels of iron in mitochondria (from 21 +/- 4 to 130 +/- 7 nmol/mg protein) and caused both lipid peroxidation and glutathione oxidation. The mitochondria of iron-treated rats showed lower respiratory control ratio in association with higher resting respiration. The mitochondrial uncoupling elicited by iron-treatment did not affect the phosphorylation efficiency or the ATP levels, suggesting that uncoupling is a mitochondrial protective mechanism against acute iron overload. Therefore, the reactive oxygen species (ROS)/H+ leak couple, functioning as a mitochondrial redox homeostatic mechanism could play a protective role in the acutely iron-loaded mitochondria.
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Affiliation(s)
- G L Pardo Andreu
- Departamento de Investigaciones Biomédicas, Centro de Química Farmacéutica, Calle 200, Esq. 21, Playa, CP 11600, Ciudad de La Habana, Cuba.
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464
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Kilbride SM, Telford JE, Davey GP. Age-related changes in H2O2 production and bioenergetics in rat brain synaptosomes. BIOCHIMICA ET BIOPHYSICA ACTA-BIOENERGETICS 2008; 1777:783-8. [PMID: 18515065 DOI: 10.1016/j.bbabio.2008.05.445] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/08/2008] [Revised: 05/21/2008] [Accepted: 05/22/2008] [Indexed: 10/22/2022]
Abstract
Detrimental changes to mitochondrial function have been shown to occur with age. In this study we examined the levels of H(2)O(2) production, in situ mitochondrial membrane potential (Deltapsi(m)), oxygen consumption (JO(2)) and electron transport chain (ETC) enzyme activities in synaptosomes isolated from rats of two age groups, 6 and 18 months. The rate of H(2)O(2) production in synaptosomes was found to be higher in the 18-month old group compared to that of 6-month old. Deltapsi(m) was found to be significantly lower in synaptosomes from the older rats, which also correlated with a reduction in JO(2). Measurement of the individual electron transport chain enzyme activities revealed that reduced complex II/III and complex IV activities were the possible contributors to the reduced bioenergetic function in synaptosomes from the older rats. These data suggest that ageing may lead to increased nerve terminal H(2)O(2) production while simultaneous deleterious effects on bioenergetic function occur in in situ synaptosomal mitochondria. In addition, Ca(2+)-independent glutamate release was found to be increased at lower levels of complex I inhibition in the synaptosomes from older rats, suggesting that reduction of mitochondrial function may potentiate excitotoxic conditions in the ageing brain.
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Affiliation(s)
- Seán M Kilbride
- School of Biochemistry and Immunology and Trinity College Institute of Neuroscience, Trinity College Dublin, Ireland
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465
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Betik AC, Hepple RT. Determinants of VO2 max decline with aging: an integrated perspective. Appl Physiol Nutr Metab 2008; 33:130-40. [PMID: 18347663 DOI: 10.1139/h07-174] [Citation(s) in RCA: 95] [Impact Index Per Article: 5.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/14/2022]
Abstract
Aging is associated with a progressive decline in the capacity for physical activity. Central to this decline is a reduction in the maximal rate of oxygen utilization, or VO2 max. This critical perspective examines the roles played by the factors that determine the rate of muscle oxygen delivery versus those that determine the utilization of oxygen by muscle as a means of probing the reasons for VO2 max decline with aging. Reductions in muscle oxygen delivery, principally due to reduced cardiac output and perhaps also a maldistribution of cardiac output, appear to play the dominant role up until late middle age. On the other hand, there is a decline in skeletal muscle oxidative capacity with aging, due in part to mitochondrial dysfunction, which appears to play a particularly important role in extreme old age (senescence) where skeletal muscle VO2 max is observed to decline by approximately 50% even under conditions of similar oxygen delivery as young adult muscle. It is noteworthy that at least the structural aspects of the capillary bed do not appear to be reduced in a manner that would compromise the capacity for muscle oxygen diffusion even in senescence.
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Affiliation(s)
- Andrew C Betik
- Faculty of Kinesiology, University of Calgary, 2500 University Dr. NW, Calgary, AB T2N 1N4
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466
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Puche JE, García-Fernández M, Muntané J, Rioja J, González-Barón S, Castilla Cortazar I. Low doses of insulin-like growth factor-I induce mitochondrial protection in aging rats. Endocrinology 2008; 149:2620-7. [PMID: 18276748 DOI: 10.1210/en.2007-1563] [Citation(s) in RCA: 86] [Impact Index Per Article: 5.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/29/2023]
Abstract
Serum IGF-I levels decline with age. We have recently reported that in aging rats the exogenous administration of IGF-I restores IGF-I circulating levels and age related-changes, improving glucose and lipid metabolisms, increasing testosterone levels and serum total antioxidant capability, and reducing oxidative damage in the brain and liver associated with a normalization of antioxidant enzyme activities. Understanding that mitochondria are one of the most important cellular targets of IGF-I, the aims of this study were to characterize mitochondrial dysfunction and study the effect of IGF-I therapy on mitochondria, leading to cellular protection in the following experimental groups: young controls, untreated old rats, and aging rats treated with IGF-I. Compared with young controls, untreated aging rats showed an increase of oxidative damage in isolated mitochondria with a mitochondrial dysfunction characterized by: depletion of membrane potential with increased proton leak rates and intramitochondrial free radical production, and a significant reduction of ATPase and complex IV activities. In addition, mitochondrial respiration from untreated aging rats was atractyloside insensitive, suggesting that the adenine nucleotide translocator was uncoupled. The adenine nucleotide translocator has been shown to be one of the most sensitive locations for pore opening. Accordingly, untreated aging rats showed a significant overexpression of the active fragment of caspases 3 and 9. IGF-I therapy corrected these parameters of mitochondrial dysfunction and reduced caspase activation. In conclusion, these results show that the cytoprotective effect of IGF-I is closely related to a mitochondrial protection, leading to reduce free radical production, oxidative damage, and apoptosis, and to increased ATP production.
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Affiliation(s)
- Juan E Puche
- Department of Medical Physiology, School of Medicine, University CEU-Universidad San Pablo, Boadilla del Monte, 28668, Madrid, Spain
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467
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Kamboj SS, Kumar V, Kamboj A, Sandhir R. Mitochondrial Oxidative Stress and Dysfunction in Rat Brain Induced by Carbofuran Exposure. Cell Mol Neurobiol 2008; 28:961-9. [DOI: 10.1007/s10571-008-9270-5] [Citation(s) in RCA: 52] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/10/2007] [Accepted: 02/19/2008] [Indexed: 01/19/2023]
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468
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Nordgaard CL, Karunadharma PP, Feng X, Olsen TW, Ferrington DA. Mitochondrial proteomics of the retinal pigment epithelium at progressive stages of age-related macular degeneration. Invest Ophthalmol Vis Sci 2008; 49:2848-55. [PMID: 18344451 DOI: 10.1167/iovs.07-1352] [Citation(s) in RCA: 134] [Impact Index Per Article: 8.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/21/2022] Open
Abstract
PURPOSE Age-related macular degeneration (AMD) is the leading cause of vision loss in individuals over the age of 65. Histopathological changes become evident in the retinal pigment epithelium (RPE), a monolayer that provides metabolic support for the overlying photoreceptors, even at the earliest stages of AMD that precede vision loss. In a previous global RPE proteome analysis, changes were identified in the content of several mitochondrial proteins associated with AMD. In this study, the subproteome of mitochondria isolated from human donor RPE graded with the Minnesota Grading System (MGS) was analyzed. METHODS Human donor eye bank eyes were categorized into one of four progressive stages (MGS 1-4) based on the clinical features of AMD. After dissection of the RPE, mitochondrial proteins were isolated and separated by two-dimensional gel electrophoresis based on their charge and mass. Protein spot densities were compared between the four MGS stages. Peptides from spots that changed significantly with MGS stage were extracted and analyzed by using mass spectrometry to identify the protein. RESULTS Western blot analyses verified that mitochondria were consistently enriched between MGS stages. The densities of eight spots increased or decreased significantly as a function of MGS stage. These spots were identified as the alpha-, beta-, and delta-ATP synthase subunits, subunit VIb of the cytochrome c oxidase complex, mitofilin, mtHsp70, and the mitochondrial translation factor Tu. CONCLUSIONS The results are consistent with the hypothesis that mitochondrial dysfunction is associated with AMD and further suggest specific pathophysiological mechanisms involving altered mitochondrial translation, import of nuclear-encoded proteins, and ATP synthase activity.
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Affiliation(s)
- Curtis L Nordgaard
- Department of Ophthalmology, University of Minnesota, Minneapolis, Minnesota, USA
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469
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Aging-induced alterations in gene transcripts and functional activity of mitochondrial oxidative phosphorylation complexes in the heart. Mech Ageing Dev 2008; 129:304-12. [PMID: 18400259 DOI: 10.1016/j.mad.2008.02.010] [Citation(s) in RCA: 91] [Impact Index Per Article: 5.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/29/2007] [Revised: 02/09/2008] [Accepted: 02/15/2008] [Indexed: 01/15/2023]
Abstract
Aging is associated with progressive decline in energetic reserves compromising cardiac performance and tolerance to injury. Although deviations in mitochondrial functions have been documented in senescent heart, the molecular bases for the decline in energy metabolism are only partially understood. Here, high-throughput transcription profiles of genes coding for mitochondrial proteins in ventricles from adult (6-months) and aged (24-months) rats were compared using microarrays. Out of 614 genes encoding for mitochondrial proteins, 94 were differentially expressed with 95% downregulated in the aged. The majority of changes affected genes coding for proteins involved in oxidative phosphorylation (39), substrate metabolism (14) and tricarboxylic acid cycle (6). Compared to adult, gene expression changes in aged hearts translated into a reduced mitochondrial functional capacity, with decreased NADH-dehydrogenase and F(0)F(1) ATPase complex activities and capacity for oxygen-utilization and ATP synthesis. Expression of genes coding for transcription co-activator factors involved in the regulation of mitochondrial metabolism and biogenesis were downregulated in aged ventricles without reduction in mitochondrial density. Thus, aging induces a selective decline in activities of oxidative phosphorylation complexes I and V within a broader transcriptional downregulation of mitochondrial genes, providing a substrate for reduced energetic efficiency associated with senescence.
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470
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Vaanholt L, Speakman J, Garland Jr. T, Lobley G, Visser G. Protein Synthesis and Antioxidant Capacity in Aging Mice: Effects of Long‐Term Voluntary Exercise. Physiol Biochem Zool 2008; 81:148-57. [DOI: 10.1086/525289] [Citation(s) in RCA: 28] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/04/2022]
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471
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Bustamante J, Czerniczyniec A, Cymeryng C, Lores-Arnaiz S. Age Related Changes from Youth to Adulthood in Rat Brain Cortex: Nitric Oxide Synthase and Mitochondrial Respiratory Function. Neurochem Res 2008; 33:1216-23. [DOI: 10.1007/s11064-007-9570-z] [Citation(s) in RCA: 28] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/01/2007] [Accepted: 12/12/2007] [Indexed: 10/22/2022]
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472
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Changes in dihydrolipoamide dehydrogenase expression and activity during postnatal development and aging in the rat brain. Mech Ageing Dev 2008; 129:282-90. [PMID: 18316113 DOI: 10.1016/j.mad.2008.01.006] [Citation(s) in RCA: 31] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/14/2007] [Revised: 12/19/2007] [Accepted: 01/23/2008] [Indexed: 02/06/2023]
Abstract
Brain energy metabolism is increased during postnatal development and diminished in neurodegenerative diseases linked to senescence. The objective of this study was to determine if these conditions could involve postnatal or senescence-related shifts in activity or expression of dihydrolipoamide dehydrogenase (DLDH), a key mitochondrial oxidoreductase. Rats ranging from 10 to 60 days of age were used in studies of postnatal development, whereas rats aged 5 or 30 months were used in the aging studies. The expression of DLDH was determined by Western blot analysis using anti-DLDH antibodies and DLDH diaphorase activity was measured by an in-gel activity staining method using nitroblue tetrazolium (NBT)/NADH. Activity of DLDH dehydrogenase was measured as NAD+ oxidation of dihydrolipoamide. When these measures were considered in separate groups of 10-, 20-, 30-, or 60-day-old rats, all three showed an increase between 10 and 20 days of age. However, dehydrogenase activity of DLDH showed a further, progressive increase from 20 days to adulthood, in the absence of any further change in DLDH expression or diaphorase activity. No age-related decline in DLDH activity or expression was evident over the period from 5 to 30 months of age. Moreover, aging did not render DLDH more susceptible to oxidative inactivation by mitochondria-generated reactive oxygen species (ROS). Taken together, results of the present study indicate that (1) brain DLDH expression and activity undergo independent postnatal maturational increases; (2) senescence does not confer any detectable change in the activity of DLDH or its susceptibility to inactivation by mitochondrial oxidative stress.
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473
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Serviddio G, Sastre J, Bellanti F, Viña J, Vendemiale G, Altomare E. Mitochondrial involvement in non-alcoholic steatohepatitis. Mol Aspects Med 2008; 29:22-35. [PMID: 18061659 DOI: 10.1016/j.mam.2007.09.014] [Citation(s) in RCA: 75] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/03/2007] [Accepted: 09/28/2007] [Indexed: 02/06/2023]
Abstract
Non-alcoholic steatohepatitis (NASH) is an increasing recognized condition that may progress to end-stage liver disease. There are consistent evidences that mitochondrial dysfunction plays a central role in NASH whatever its origin. Mitochondria are the key controller of fatty acids removal and this is part of an intensive gene program that modifies hepatocytes to counteract the excessive fat storage. Mitochondrial dysfunction participates at different levels in NASH pathogenesis since it impairs fatty liver homeostasis and induces overproduction of ROS that in turn trigger lipid peroxidation, cytokines release and cell death. In this review we briefly recall the role of mitochondria in fat metabolism and energy homeostasis and focus on the role of mitochondrial impairment and uncoupling proteins in the pathophysiology of NASH progression. We suggest that mitochondrial respiratory chain, UCP2 and redox balance cooperate in a common pathway that permits to set down the mitochondrial redox pressure, limits the risk of oxidative damage, and allows the maximal rate of fat removal. When the environmental conditions change and high energy supply occurs, hepatocytes are unable to replace their ATP store and steatosis progress to NASH and cirrhosis. The beneficial effects of some drugs on mitochondrial function are also discussed.
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Affiliation(s)
- Gaetano Serviddio
- Department of Medical and Occupational Sciences, University of Foggia, v.le Pinto 1, 71100 Foggia, Italy.
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474
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Boveris A, Navarro A. Systemic and mitochondrial adaptive responses to moderate exercise in rodents. Free Radic Biol Med 2008; 44:224-9. [PMID: 18191758 DOI: 10.1016/j.freeradbiomed.2007.08.015] [Citation(s) in RCA: 108] [Impact Index Per Article: 6.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/19/2007] [Revised: 08/22/2007] [Accepted: 08/24/2007] [Indexed: 11/22/2022]
Abstract
The systemic and nonmuscular adaptive response to moderate exercise is reviewed and compared with muscle responses to moderate and exhaustive exercise. Rats participating in voluntary wheel running and mice subjected to treadmill exercise on a lifelong basis showed 10-19% increased median life span. Mice also showed improved neurological functions, such as better (35-216%) neuromuscular coordination (tightrope test) and better (11-27%) exploratory activity (T maze). These effects are consistent with the systemic effects of moderate exercise lowering hyperglycemia, hypercholesterolemia, and hypertension. Mitochondria isolated from brain, liver, heart, and kidney of exercised mice show a 12-32% selectively increased complex IV activity, with a significant correlation between complex IV activity and performance in the tightrope test. Chronic exercise decreases (10-20%) the mitochondrial content of TBARS and protein carbonyls in the four organs after 24 weeks of training. Protein carbonyls were linearly and negatively related to complex IV activity. Exercise increased the levels of nNOSmu in human muscle and of nNOS in mouse brain. It is concluded that chronic moderate exercise exerts a whole-body beneficial effect that exceeds muscle adaptation, likely through mechanosensitive afferent nerves and beta-endorphin release to brain and plasma that promote mitochondrial biogenesis in distant organs.
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Affiliation(s)
- Alberto Boveris
- School of Pharmacy and Biochemistry, University of Buenos Aires, C1113AAD Buenos Aires, Argentina
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475
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476
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Abstract
Aging is due to the accumulation of damage over time that affects the function and survival of the organism; however, it has proven difficult to infer the relative importance of the many processes that contribute to aging. To address this, here we outline an approach that may prove useful in analyzing aging. In this approach, the function of the organism is described as a set of interacting physiological systems. Degradation of their outputs leads to functional decline and death as a result of aging. In turn, degradation of the system outputs is attributable to changes at the next hierarchical level down, the cell, through changes in cell number or function, which are in turn a consequence of the metabolic history of the cell. Within this framework, we then adapt the methods of metabolic control analysis (MCA) to determine which modifications are important for aging. This combination of a hierarchical framework and the methodologies of MCA may prove useful both for thinking about aging and for analyzing it experimentally.
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Affiliation(s)
- Michael P. Murphy
- Medical Research Council, Dunn Human Nutrition Unit, Cambridge CB2 0XY, United Kingdom;
| | - Linda Partridge
- Centre for Research on Aging, University College London, Department of Biology, London WC1E 6BT, United Kingdom;
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477
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Navarro A, López-Cepero JM, Bández MJ, Sánchez-Pino MJ, Gómez C, Cadenas E, Boveris A. Hippocampal mitochondrial dysfunction in rat aging. Am J Physiol Regul Integr Comp Physiol 2007; 294:R501-9. [PMID: 18077512 DOI: 10.1152/ajpregu.00492.2007] [Citation(s) in RCA: 71] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/17/2022]
Abstract
Hippocampus mitochondrial dysfunction with impaired electron transfer and increased oxidative damage was observed upon rat aging. Hippocampal mitochondria of aged (12 mo) and senescent (20 mo) rats showed, compared with young (4 mo) rats, marked decreases in the rate of state 3 respiration with NAD-dependent substrates (32-51%) and in the activities of mitochondrial complexes I (57-73%) and IV (33-54%). The activity of mitochondrial nitric oxide synthase was also decreased, 53-66%, with age. These losses in enzymatic activity were more marked in the hippocampus than in brain cortex or in whole brain. The histochemical assay of mitochondrial complex IV in the hippocampus showed decreased staining upon aging. Oxidative damage, determined as the mitochondrial content of thiobarbituric-acid reactive substances (TBARS) and protein carbonyls, increased in aged and senescent hippocampus (66-74% in TBARS and 48-96% in carbonyls). A significant statistical correlation was observed between mitochondrial oxidative damage and enzymatic activity. Mitochondrial dysfunction with shortage of energy supply is considered a likely cause of dysfunction in aged hippocampus.
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Affiliation(s)
- Ana Navarro
- Departamento de Bioquímica y Biología Molecular, Facultad de Medicina, Plaza Fragela 9, 11003-Cádiz, Spain.
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478
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Siegenthaler MM, Berchtold NC, Cotman CW, Keirstead HS. Voluntary running attenuates age-related deficits following SCI. Exp Neurol 2007; 210:207-16. [PMID: 18164294 DOI: 10.1016/j.expneurol.2007.10.019] [Citation(s) in RCA: 30] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/24/2007] [Revised: 10/26/2007] [Accepted: 10/27/2007] [Indexed: 11/26/2022]
Abstract
Over the past few decades, the average age at time of spinal cord injury (SCI) has increased. Here we examined locomotor recovery and myelin pathology in both young and aged adult rats following contusion SCI. Our assessment indicates that the rate of locomotor recovery following SCI is significantly delayed in aged rats as compared to young rats, and is associated with a greater degree of pathology and demyelination. Additionally, we examined the effect of voluntary exercise, pre- and post-injury, on locomotor recovery and myelin pathology following contusion SCI. Our data indicate that exercise improves the locomotor recovery of injured aged rats such that it is comparable to the recovery rate of injured young rats, and is associated with a decreased area of pathology and amount of demyelination. Interestingly, the rate of locomotor recovery and myelin pathology in the aged exercised rats was similar to that of the young sedentary rats after injury, indicating that exercise attenuates the delayed recovery of function and associated histopathology in aged rats. These data indicate that there is an age-related delay in locomotor recovery following SCI, and an age-related increase in histopathology following SCI. Importantly, our data indicate that exercise attenuates these age-related deficits following SCI.
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Affiliation(s)
- Monica M Siegenthaler
- Reeve-Irvine Research Center, Department of Anatomy and Neurobiology, School of Medicine, University of California at Irvine, Irvine, CA 92697-4292, USA
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479
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Victor EG, Zanette F, Aguiar MR, Aguiar CS, Cardoso DC, Cristiano MP, Streck EL, Paula MMS. Effect of ruthenium complexes on the activities of succinate dehydrogenase and cytochrome oxidase. Chem Biol Interact 2007; 170:59-66. [PMID: 17707358 DOI: 10.1016/j.cbi.2007.07.001] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/26/2007] [Revised: 07/04/2007] [Accepted: 07/05/2007] [Indexed: 11/17/2022]
Abstract
In this article, we report the effects of acute administration of ruthenium complexes, trans-[RuCl(2)(nic)(4)] (nic=3-pyridinecarboxylic acid) 180.7 micromol/kg (complex I), trans-[RuCl(2)(i-nic)(4)] (i-nic=4-pyridinecarboxylic acid) 13.6 micromol/kg (complex II), trans-[RuCl(2)(dinic)(4)] (dinic=3,5-pyridinedicarboxylic acid) 180.7 micromol/kg (complex III) and trans-[RuCl(2)(i-dinic)(4)]Cl (i-dinic=3,4-pyridinedicarboxylic acid) 180.7 micromol/kg (complex IV) on succinate dehydrogenase (SDH) and cytochrome oxidase (COX) activities in brain (hippocampus, striatum and cerebral cortex), heart, skeletal muscle, liver and kidney of rats. Our results showed that complex I inhibited SDH activity in hippocampus, cerebral cortex, heart and liver; and inhibited COX in heart and kidney. Complex II inhibited SDH in heart and hippocampus; COX was inhibited in hippocampus, heart, liver and kidney. SDH activity was inhibited by complex III in heart, muscle, liver and kidney. However, COX activity was increased in hippocampus, striatum, cerebral cortex and kidney. Complex IV inhibited SDH activity in muscle and liver; COX activity was inhibited in kidney and increased in hippocampus, striatum and cerebral cortex. In a general manner, the complexes tested in this work decrease the activities of SDH and COX in heart, skeletal muscle, liver and kidney. In brain, complexes I and II were shown to be inhibitors and complexes III and IV activators of these enzymes. In vitro studies showed that the ruthenium complexes III and IV did not alter COX activity in kidney, but activated the enzyme in hippocampus, striatum and cerebral cortex, suggesting that these complexes present a direct action on COX in brain.
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Affiliation(s)
- Eduardo G Victor
- Laboratório de Síntese de Complexos Multifuncionais, Universidade do Extremo Sul Catarinense, 88806-000, Criciúma, SC, Brazil
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480
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Swerdlow RH. Treating neurodegeneration by modifying mitochondria: potential solutions to a "complex" problem. Antioxid Redox Signal 2007; 9:1591-603. [PMID: 17663643 DOI: 10.1089/ars.2007.1676] [Citation(s) in RCA: 52] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/21/2022]
Abstract
Mitochondria function differently in aged brains than they do in young brains. Consistently reported changes include reduced electron transport chain (ETC) enzyme activities, reduced phosphorylation of ADP, and increased reactive oxygen species (ROS) production. Various neurodegenerative diseases are also associated with changes in mitochondrial function, and these changes both recapitulate and extend those seen in "normal" aging. Unfortunately, attempts to treat neurodegenerative diseases by treating mitochondria-related pathology have thus far minimally impacted affected patients. A better understanding of how mitochondrial function changes in aging and neurodegenerative diseases, though, now suggests new approaches to mitochondrial therapy may prove more efficacious. Increasing ETC capacity, increasing oxidative phosphorylation, or decreasing mitochondrial ROS may yet prove useful for the treatment of brain aging and neurodegenerative diseases, and accomplishing this seems increasingly feasible. This review will discuss the role of mitochondrial function and dysfunction in aging and neurodegenerative diseases, and will focus on potential treatment strategies.
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Affiliation(s)
- Russell H Swerdlow
- Department of Neurology, University of Virginia School of Medicine, Charlottesville, Virginia 22908, USA.
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481
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Leuner K, Hauptmann S, Abdel-Kader R, Scherping I, Keil U, Strosznajder JB, Eckert A, Müller WE. Mitochondrial dysfunction: the first domino in brain aging and Alzheimer's disease? Antioxid Redox Signal 2007; 9:1659-75. [PMID: 17867931 DOI: 10.1089/ars.2007.1763] [Citation(s) in RCA: 146] [Impact Index Per Article: 8.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/12/2022]
Abstract
With the increasing average life span of humans and with decreasing cognitive function in elderly individuals, age-related cognitive disorders including dementia have become a major health problem in society. Aging-related mitochondrial dysfunction underlies many common neurodegenerative disorders diseases, including Alzheimer's disease (AD). AD is characterized by two major histopathological hallmarks, initially intracellular and with the progression of the disease extracellular accumulation of oligomeric and fibrillar beta-amyloid (Abeta) peptides and intracellular neurofibrillary tangles (NFT) composed of hyperphosphorylated tau protein. In this review, the authors focus on the latest findings in AD animal models indicating that these histopathological alterations induce deficits in the function of the complexes of the respiratory chain and therefore consecutively result in mitochondrial dysfunction. This parameter is intrinsically tied to oxidative stress. Both are early events in aging and especially in the pathogenesis of aging-related severe neurodegeneration. Ginkgo biloba extract seems to be of therapeutic benefit in the treatment of mild to moderate dementia of different etiology, although the data are quite heterogeneous. Herein, the authors suggest that mitochondrial protection and subsequent reduction of oxidative stress are important components of the neuroprotective activity of Ginkgo biloba extract.
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Affiliation(s)
- Kristina Leuner
- Department of Pharmacology, Zafes, Biocenter, University of Frankfurt, Germany.
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482
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Abstract
Advanced age is a strong independent predictor for death, disability, and morbidity in patients with structural heart disease. With the projected increase in the elderly population and the prevalence of age-related cardiovascular disabilities worldwide, the need to understand the biology of the aging heart, the mechanisms for age-mediated cardiac vulnerability, and the development of strategies to limit myocardial dysfunction in the elderly have never been more urgent. Experimental evidence in animal models indicate attenuation in cardioprotective pathways with aging, yet limited information is available regarding age-related changes in the human heart. Human cardiac aging generates a complex phenotype, only partially replicated in animal models. Here, we summarize current understanding of the aging heart stemming from clinical and experimental studies, and we highlight targets for protection of the vulnerable senescent myocardium. Further progress mandates assessment of human tissue to dissect specific aging-associated genomic and proteomic dynamics, and their functional consequences leading to increased susceptibility of the heart to injury, a critical step toward designing novel therapeutic interventions to limit age-related myocardial dysfunction and promote healthy aging.
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Affiliation(s)
- Arshad Jahangir
- Marriott Heart Disease Research Program, Division of Cardiovascular Diseases, and Department of Medicine, Mayo Clinic College of Medicine, Rochester, MN 55905, USA.
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483
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Lê KA, Tappy L, D'Alessio DA. Mitochondrial dysfunction and insulin resistance: a matter of lifestyle? Curr Opin Clin Nutr Metab Care 2007; 10:494-7. [PMID: 17563469 DOI: 10.1097/mco.0b013e3281e72abf] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/30/2022]
Affiliation(s)
- Kim-Anne Lê
- Department of Physiology, Lausanne University School of Biology and Medicine, Lausanne Switzerland
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