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Faissner S, Plemel JR, Gold R, Yong VW. Progressive multiple sclerosis: from pathophysiology to therapeutic strategies. Nat Rev Drug Discov 2019; 18:905-922. [PMID: 31399729 DOI: 10.1038/s41573-019-0035-2] [Citation(s) in RCA: 246] [Impact Index Per Article: 49.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 07/04/2019] [Indexed: 02/07/2023]
Abstract
Multiple sclerosis (MS) is a chronic inflammatory disease of the central nervous system that involves demyelination and axonal degeneration. Although substantial progress has been made in drug development for relapsing-remitting MS, treatment of the progressive forms of the disease, which are characterized clinically by the accumulation of disability in the absence of relapses, remains unsatisfactory. This unmet clinical need is related to the complexity of the pathophysiological mechanisms involved in MS progression. Chronic inflammation, which occurs behind a closed blood-brain barrier with activation of microglia and continued involvement of T cells and B cells, is a hallmark pathophysiological feature. Inflammation can enhance mitochondrial damage in neurons, which, consequently, develop an energy deficit, further reducing axonal health. The growth-inhibitory and inflammatory environment of lesions also impairs remyelination, a repair process that might protect axons from degeneration. Moreover, neurodegeneration is accelerated by the altered expression of ion channels on denuded axons. In this Review, we discuss the current understanding of these disease mechanisms and highlight emerging therapeutic strategies based on these insights, including those targeting the neuroinflammatory and degenerative aspects as well as remyelination-promoting approaches.
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Affiliation(s)
- Simon Faissner
- Department of Neurology, St. Josef-Hospital, Ruhr-University Bochum, Bochum, Germany. .,Hotchkiss Brain Institute and Department of Clinical Neurosciences, University of Calgary, Calgary, Alberta, Canada.
| | - Jason R Plemel
- Department of Medicine, University of Alberta, Edmonton, Alberta, Canada
| | - Ralf Gold
- Department of Neurology, St. Josef-Hospital, Ruhr-University Bochum, Bochum, Germany
| | - V Wee Yong
- Hotchkiss Brain Institute and Department of Clinical Neurosciences, University of Calgary, Calgary, Alberta, Canada.
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2
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Wang L, Wang Z, Yang K, Shu G, Wang S, Gao P, Zhu X, Xi Q, Zhang Y, Jiang Q. Epigallocatechin Gallate Reduces Slow-Twitch Muscle Fiber Formation and Mitochondrial Biosynthesis in C2C12 Cells by Repressing AMPK Activity and PGC-1α Expression. JOURNAL OF AGRICULTURAL AND FOOD CHEMISTRY 2016; 64:6517-6523. [PMID: 27420899 DOI: 10.1021/acs.jafc.6b02193] [Citation(s) in RCA: 24] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/06/2023]
Abstract
Epigallocatechin gallate (EGCG) is a major active compound in green tea polyphenols. EGCG acts as an antioxidant to prevent the cell damage caused by free radicals and their derivatives. In skeletal muscle, exercise causes the accumulation of intracellular reactive oxygen species (ROS) and promotes the formation of slow-type muscle fiber. To determine whether EGCG, as a ROS scavenger, has any effect on skeletal muscle fiber type, we applied different concentrations (0, 5, 25, and 50 μM) of EGCG in the culture medium of differentiated C2C12 cells for 2 days. The fiber-type composition, mitochondrial biogenesis-related gene expression, antioxidant and glucose metabolism enzyme activity, and ROS levels in C2C12 cells were then detected. According to our results, 5 μM EGCG significantly decreased the cellular activity of SDH, 25 μM EGCG significantly downregulated the MyHC I, PGC-1α, NRF-1, and p-AMPK levels and SDH activity while enhancing the CAT and GSH-Px activity and decreasing the intracellular ROS levels, and 50 μM EGCG significantly downregulated MyHC I, PGC-1α, and NRF-1 expression and HK and SDH activity while increasing LDH activity. Furthermore, 300 μM H2O2 and 0.5 mM AMPK agonist (AICAR) improved the expression of MyHC I, PGC-1α, and p-AMPK, which were all reversed by 25 μM EGCG. In conclusion, the effect of EGCG on C2C12 cells may occur through the reduction of the ROS level, thereby decreasing both AMPK activity and PGC-1α expression and eventually reducing slow-twitch muscle fiber formation and mitochondrial biosynthesis.
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Affiliation(s)
- Lina Wang
- College of Animal Science and National Engineering Research Center for Breeding Swine Industry, South China Agricultural University , Guangzhou, Guangdong 510640, People's Republic of China
| | - Zhen Wang
- College of Animal Science and National Engineering Research Center for Breeding Swine Industry, South China Agricultural University , Guangzhou, Guangdong 510640, People's Republic of China
| | - Kelin Yang
- College of Animal Science and National Engineering Research Center for Breeding Swine Industry, South China Agricultural University , Guangzhou, Guangdong 510640, People's Republic of China
| | - Gang Shu
- College of Animal Science and National Engineering Research Center for Breeding Swine Industry, South China Agricultural University , Guangzhou, Guangdong 510640, People's Republic of China
| | - Songbo Wang
- College of Animal Science and National Engineering Research Center for Breeding Swine Industry, South China Agricultural University , Guangzhou, Guangdong 510640, People's Republic of China
| | - Ping Gao
- College of Animal Science and National Engineering Research Center for Breeding Swine Industry, South China Agricultural University , Guangzhou, Guangdong 510640, People's Republic of China
| | - Xiaotong Zhu
- College of Animal Science and National Engineering Research Center for Breeding Swine Industry, South China Agricultural University , Guangzhou, Guangdong 510640, People's Republic of China
| | - Qianyun Xi
- College of Animal Science and National Engineering Research Center for Breeding Swine Industry, South China Agricultural University , Guangzhou, Guangdong 510640, People's Republic of China
| | - Yongliang Zhang
- College of Animal Science and National Engineering Research Center for Breeding Swine Industry, South China Agricultural University , Guangzhou, Guangdong 510640, People's Republic of China
| | - Qingyan Jiang
- College of Animal Science and National Engineering Research Center for Breeding Swine Industry, South China Agricultural University , Guangzhou, Guangdong 510640, People's Republic of China
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Braconi D, Millucci L, Ghezzi L, Santucci A. Redox proteomics gives insights into the role of oxidative stress in alkaptonuria. Expert Rev Proteomics 2014; 10:521-35. [PMID: 24206226 DOI: 10.1586/14789450.2013.858020] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/04/2023]
Abstract
Alkaptonuria (AKU) is an ultra-rare metabolic disorder of the catabolic pathway of tyrosine and phenylalanine that has been poorly characterized at molecular level. As a genetic disease, AKU is present at birth, but its most severe manifestations are delayed due to the deposition of a dark-brown pigment (ochronosis) in connective tissues. The reasons for such a delayed manifestation have not been clarified yet, though several lines of evidence suggest that the metabolite accumulated in AKU sufferers (homogentisic acid) is prone to auto-oxidation and induction of oxidative stress. The clarification of the pathophysiological molecular mechanisms of AKU would allow a better understanding of the disease, help find a cure for AKU and provide a model for more common rheumatic diseases. With this aim, we have shown how proteomics and redox proteomics might successfully overcome the difficulties of studying a rare disease such as AKU and the limitations of the hitherto adopted approaches.
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Affiliation(s)
- Daniela Braconi
- Dipartimento di Biotecnologie, Chimica e Farmacia, via Fiorentina 1, Università degli Studi di Siena, 53100 Siena, Italy
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Takamura H, Koyama Y, Matsuzaki S, Yamada K, Hattori T, Miyata S, Takemoto K, Tohyama M, Katayama T. TRAP1 controls mitochondrial fusion/fission balance through Drp1 and Mff expression. PLoS One 2012; 7:e51912. [PMID: 23284813 PMCID: PMC3527369 DOI: 10.1371/journal.pone.0051912] [Citation(s) in RCA: 29] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/29/2012] [Accepted: 11/07/2012] [Indexed: 11/18/2022] Open
Abstract
Mitochondria are dynamic organelles that change in response to extracellular stimuli. These changes are essential for normal mitochondrial/cellular function and are controlled by a tight balance between two antagonistic pathways that promote fusion and fission. Although some molecules have been identified to mediate the mitochondrial fusion and fission process, the underlying mechanisms remain unclear. Tumor necrosis factor receptor-associated protein 1 (TRAP1) is a mitochondrial molecule that regulates a variety of mitochondrial functions. Here, we examined the role of TRAP1 in the regulation of morphology. Stable TRAP1 knockdown cells showed abnormal mitochondrial morphology, and we observed significant decreases in dynamin-related protein 1 (Drp1) and mitochondrial fission factor (Mff), mitochondrial fission proteins. Similar results were obtained by transient knockdown of TRAP1 in two different cell lines, SH-SY5Y neuroblastoma cells and KNS-42 glioma cells. However, TRAP1 knockdown did not affect expression levels of fusion proteins. The reduction in Drp1 and Mff protein levels was rescued following treatment with the proteasome inhibitor MG132. These results suggest that TRAP1 regulates the expression of fission proteins and controls mitochondrial fusion/fission, which affects mitochondrial/cellular function.
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Affiliation(s)
- Hironori Takamura
- Molecular Research Center for Children's Mental Development, United Graduate School of Child Development, Osaka University, Suita, Osaka, Japan.
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Voos W. Chaperone-protease networks in mitochondrial protein homeostasis. BIOCHIMICA ET BIOPHYSICA ACTA-MOLECULAR CELL RESEARCH 2012; 1833:388-99. [PMID: 22705353 DOI: 10.1016/j.bbamcr.2012.06.005] [Citation(s) in RCA: 145] [Impact Index Per Article: 12.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/05/2012] [Revised: 05/31/2012] [Accepted: 06/05/2012] [Indexed: 12/22/2022]
Abstract
As essential organelles, mitochondria are intimately integrated into the metabolism of a eukaryotic cell. The maintenance of the functional integrity of the mitochondrial proteome, also termed protein homeostasis, is facing many challenges both under normal and pathological conditions. First, since mitochondria are derived from bacterial ancestor cells, the proteins in this endosymbiotic organelle have a mixed origin. Only a few proteins are encoded on the mitochondrial genome, most genes for mitochondrial proteins reside in the nuclear genome of the host cell. This distribution requires a complex biogenesis of mitochondrial proteins, which are mostly synthesized in the cytosol and need to be imported into the organelle. Mitochondrial protein biogenesis usually therefore comprises complex folding and assembly processes to reach an enzymatically active state. In addition, specific protein quality control (PQC) processes avoid an accumulation of damaged or surplus polypeptides. Mitochondrial protein homeostasis is based on endogenous enzymatic components comprising a diverse set of chaperones and proteases that form an interconnected functional network. This review describes the different types of mitochondrial proteins with chaperone functions and covers the current knowledge of their roles in protein biogenesis, folding, proteolytic removal and prevention of aggregation, the principal reactions of protein homeostasis. This article is part of a Special Issue entitled: Protein Import and Quality Control in Mitochondria and Plastids.
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Affiliation(s)
- Wolfgang Voos
- Institut für Biochemie und Molekularbiologie IBMB, Universität Bonn, Nussallee 11, 53115 Bonn, Germany.
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6
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Larade K, Storey KB. Living without Oxygen: Anoxia-Responsive Gene Expression and Regulation. Curr Genomics 2011; 10:76-85. [PMID: 19794879 PMCID: PMC2699829 DOI: 10.2174/138920209787847032] [Citation(s) in RCA: 28] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/03/2009] [Revised: 02/15/2009] [Accepted: 02/18/2009] [Indexed: 02/05/2023] Open
Abstract
Many species of marine mollusks demonstrate exceptional capacities for long term survival without oxygen. Analysis of gene expression under anoxic conditions, including the subsequent translational responses, allows examination of the functional mechanisms that support and regulate natural anaerobiosis and permit noninjurious transitions between aerobic and anoxic states. Identification of stress-specific gene expression can provide important insights into the metabolic adaptations that are needed for anoxia tolerance, with potential applications to anoxia-intolerant systems. Various methods are available to do this, including high throughput microarray screening and construction and screening of cDNA libraries. Anoxia-responsive genes have been identified in mollusks; some have known functions in other organisms but were not previously linked with anoxia survival. In other cases, completely novel anoxia-responsive genes have been discovered, some that show known motifs or domains that hint at function. Selected genes are expressed at different times over an anoxia-recovery time course with their transcription and translation being actively regulated to ensure protein expression at the optimal time. An examination of transcript status over the course of anoxia exposure and subsequent aerobic recovery identifies genes, and the proteins that they encode, that enhance cell survival under oxygen-limited conditions. Analysis of data generated from non-mainstream model systems allows for insight into the response by cells to anoxia stress.
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Affiliation(s)
- Kevin Larade
- Institute of Biochemistry and Department of Biology, Carleton University, 1125 Colonel By Drive, Ottawa, Ontario, K1S 5B6, Canada
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7
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Takemoto K, Miyata S, Takamura H, Katayama T, Tohyama M. Mitochondrial TRAP1 regulates the unfolded protein response in the endoplasmic reticulum. Neurochem Int 2011; 58:880-7. [DOI: 10.1016/j.neuint.2011.02.015] [Citation(s) in RCA: 41] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/29/2010] [Revised: 01/27/2011] [Accepted: 02/14/2011] [Indexed: 10/18/2022]
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8
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Two-dimensional gel electrophoresis in proteomics: Past, present and future. J Proteomics 2010; 73:2064-77. [PMID: 20685252 DOI: 10.1016/j.jprot.2010.05.016] [Citation(s) in RCA: 288] [Impact Index Per Article: 20.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/26/2010] [Revised: 05/20/2010] [Accepted: 05/25/2010] [Indexed: 12/14/2022]
Abstract
Two-dimensional gel electrophoresis has been instrumental in the birth and developments of proteomics, although it is no longer the exclusive separation tool used in the field of proteomics. In this review, a historical perspective is made, starting from the days where two-dimensional gels were used and the word proteomics did not even exist. The events that have led to the birth of proteomics are also recalled, ending with a description of the now well-known limitations of two-dimensional gels in proteomics. However, the often-underestimated advantages of two-dimensional gels are also underlined, leading to a description of how and when to use two-dimensional gels for the best in a proteomics approach. Taking support of these advantages (robustness, resolution, and ability to separate entire, intact proteins), possible future applications of this technique in proteomics are also mentioned.
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Aguilera-Aguirre L, Bacsi A, Saavedra-Molina A, Kurosky A, Sur S, Boldogh I. Mitochondrial dysfunction increases allergic airway inflammation. THE JOURNAL OF IMMUNOLOGY 2009; 183:5379-87. [PMID: 19786549 DOI: 10.4049/jimmunol.0900228] [Citation(s) in RCA: 187] [Impact Index Per Article: 12.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 02/07/2023]
Abstract
The prevalence of allergies and asthma among the world's population has been steadily increasing due to environmental factors. It has been described that exposure to ozone, diesel exhaust particles, or tobacco smoke exacerbates allergic inflammation in the lungs. These environmental oxidants increase the levels of cellular reactive oxygen species (ROS) and induce mitochondrial dysfunction in the airway epithelium. In this study, we investigated the involvement of preexisting mitochondrial dysfunction in the exacerbation of allergic airway inflammation. After cellular oxidative insult induced by ragweed pollen extract (RWE) exposure, we have identified nine oxidatively damaged mitochondrial respiratory chain-complex and associated proteins. Out of these, the ubiquinol-cytochrome c reductase core II protein (UQCRC2) was found to be implicated in mitochondrial ROS generation from respiratory complex III. Mitochondrial dysfunction induced by deficiency of UQCRC2 in airway epithelium of sensitized BALB/c mice prior the RWE challenge increased the Ag-induced accumulation of eosinophils, mucin levels in the airways, and bronchial hyperresponsiveness. Deficiency of UQCRC1, another oxidative damage-sensitive complex III protein, did not significantly alter cellular ROS levels or the intensity of RWE-induced airway inflammation. These observations suggest that preexisting mitochondrial dysfunction induced by oxidant environmental pollutants is responsible for the severe symptoms in allergic airway inflammation. These data also imply that mitochondrial defects could be risk factors and may be responsible for severe allergic disorders in atopic individuals.
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Affiliation(s)
- Leopoldo Aguilera-Aguirre
- Department of Microbiology and Immunology, University of Texas Medical Branch at Galveston, Galveston, TX 77555, USA
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Dalla Libera L, Ravara B, Gobbo V, Tarricone E, Vitadello M, Biolo G, Vescovo G, Gorza L. A transient antioxidant stress response accompanies the onset of disuse atrophy in human skeletal muscle. J Appl Physiol (1985) 2009; 107:549-57. [PMID: 19478193 DOI: 10.1152/japplphysiol.00280.2009] [Citation(s) in RCA: 59] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022] Open
Abstract
It is presently unknown whether oxidative stress increases in disused skeletal muscle in humans. Markers of oxidative stress were investigated in biopsies from the vastus lateralis muscle, collected from healthy subjects before [time 0 (T0)], after 1 wk (T8), and after 5 wk (T35) of bed rest. An 18% decrease in fiber cross-sectional area was detected in T35 biopsies (P<0.05). Carbonylation of muscle proteins significantly increased about twofold at T35 (P<0.02) and correlated positively with the decrease in fiber cross-sectional area (P=0.04). Conversely, T8 biopsies showed a significant increase in protein levels of heme oxygenase-1 and glucose-regulated protein-75 (Grp75)/mitochondrial heat shock protein-70, two stress proteins involved in the antioxidant defense (P<0.05). Heme oxygenase-1 increase, which involved a larger proportion of slow fibers compared with T0, appeared blunted in T35 biopsies. Grp75 protein level increased threefold in T8 biopsies and localized especially in slow fibers (P<0.025), to decrease significantly in T35 biopsies (P<0.05). Percent change in Grp75 levels positively correlated with fiber cross-sectional area (P=0.01). Parallel investigations on rat soleus muscles, performed after 1-15 days of hindlimb suspension, showed that Grp75 protein levels significantly increased after 24 h of unloading (P = 0.02), i.e., before statistically significant evidence of muscle atrophy, to decrease thereafter in relation to the degree of muscle atrophy (P=0.03). Therefore, in humans as in rodents, disuse muscle atrophy is characterized by increased protein carbonylation and by the blunting of the antioxidant stress response evoked by disuse.
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Affiliation(s)
- Luciano Dalla Libera
- Consiglio Nazionale delle Ricerche-Institute for Neuroscience, Department of Biomedical Sciences, University of Padova, Viale G. Colombo 3, 35121 Padova, Italy
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11
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Witte ME, Bø L, Rodenburg RJ, Belien JA, Musters R, Hazes T, Wintjes LT, Smeitink JA, Geurts JJG, De Vries HE, van der Valk P, van Horssen J. Enhanced number and activity of mitochondria in multiple sclerosis lesions. J Pathol 2009; 219:193-204. [DOI: 10.1002/path.2582] [Citation(s) in RCA: 155] [Impact Index Per Article: 10.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/05/2023]
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Xu L, Voloboueva LA, Ouyang Y, Emery JF, Giffard RG. Overexpression of mitochondrial Hsp70/Hsp75 in rat brain protects mitochondria, reduces oxidative stress, and protects from focal ischemia. J Cereb Blood Flow Metab 2009; 29:365-74. [PMID: 18985056 PMCID: PMC3676940 DOI: 10.1038/jcbfm.2008.125] [Citation(s) in RCA: 127] [Impact Index Per Article: 8.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Abstract
Mitochondria are known to be central to the cell's response to ischemia, because of their role in energy generation, in free radical generation, and in the regulation of apoptosis. Heat shock protein 75 (Hsp75/Grp75/mortalin/TRAP1) is a member of the HSP70 chaperone family, which is targeted to mitochondria. Overexpression of Hsp75 was achieved in rat brain by DNA transfection, and expression was observed in both astrocytes and neurons. Rats were subjected to 100 mins middle cerebral artery occlusion followed by assessment of infarct volume, neurological score, mitochondrial function, and levels of oxidative stress at 24 h reperfusion. Overexpression of Hsp75 reduced infarct area from 44.6%+/-21.1% to 25.7%+/-12.1% and improved neurological outcome significantly. This was associated with improved mitochondrial function as shown by protection of complex IV activity, marked reduction of free radical generation detected by hydroethidine fluorescence, reduction of lipid peroxidation detected by 4-hydroxy-2-nonenol immunoreactivity, and increased preservation of ATP levels. This suggests that targeting mitochondria for protection may be a useful strategy to reduce ischemic brain injury.
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Affiliation(s)
- Lijun Xu
- Department of Anesthesia, Stanford University School of Medicine, Stanford, California 94305-5117, USA
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Irrcher I, Ljubicic V, Hood DA. Interactions between ROS and AMP kinase activity in the regulation of PGC-1alpha transcription in skeletal muscle cells. Am J Physiol Cell Physiol 2008; 296:C116-23. [PMID: 19005163 DOI: 10.1152/ajpcell.00267.2007] [Citation(s) in RCA: 275] [Impact Index Per Article: 17.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
Reactive oxygen species (ROS) play an important role in cellular function via the activation of signaling cascades. ROS have been shown to affect mitochondrial biogenesis, morphology, and function. Their beneficial effects are likely mediated via the upregulation of transcriptional regulators such as peroxisome proliferator-activated receptor-gamma coactivator-1 protein-alpha (PGC-1alpha). However, the ROS signals that regulate PGC-1alpha transcription in skeletal muscle are not understood. Here we examined the effect of H2O2 on the regulation of PGC-1alpha expression, and its relationship to AMPK activation. We demonstrate that 24 h of exogenous H2O2 treatment increased PGC-1alpha promoter activity and mRNA expression. Both effects were blocked with the addition of N-acetylcysteine, a ROS scavenger. These effects were mediated, in part, via upstream stimulatory factor-1/Ebox DNA binding and involved 1) interactions with downstream sequences and 2) the activation of AMPK. Elevated ROS led to the activation of AMPK, likely via a decline in ATP levels. The activation of AMPK using 5-aminoimidazole-4-carboxamide-1-beta-d-ribofuranoside increased PGC-1alpha promoter activity and mRNA levels but reduced ROS production. Thus the net effect of AMPK activation on PGC-1alpha expression was a result of increased transcriptional activation, counterbalanced by reduced ROS production. The effects of H2O2 on PGC-1alpha expression differed depending on the level of ROS within the cell. Low levels of ROS result in reduced PGC-1alpha mRNA in the absence of an effect on PGC-1alpha promoter activation. In contrast, elevated levels of H2O2 induce PGC-1alpha transcription indirectly, via AMPK activation. These data identify unique interactions between ROS and AMPK activation on the expression of PGC-1alpha in muscle cells.
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Affiliation(s)
- Isabella Irrcher
- School of Kinesiology and Health Science, Rm. 302, Farquharson Life Sciences Bldg., York University, 4700 Keele St., Toronto, ON, Canada M3J 1P3
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Felitsyn N, McLeod C, Shroads AL, Stacpoole PW, Notterpek L. The heme precursor delta-aminolevulinate blocks peripheral myelin formation. J Neurochem 2008; 106:2068-79. [PMID: 18665889 DOI: 10.1111/j.1471-4159.2008.05552.x] [Citation(s) in RCA: 22] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/24/2022]
Abstract
Delta-aminolevulinic acid (delta-ALA) is a heme precursor implicated in neurological complications associated with porphyria and tyrosinemia type I. Delta-ALA is also elevated in the urine of animals and patients treated with the investigational drug dichloroacetate (DCA). We postulated that delta-ALA may be responsible, in part, for the peripheral neuropathy observed in subjects receiving DCA. To test this hypothesis, myelinating cocultures of Schwann cells and sensory neurons were exposed to delta-ALA (0.1-1 mM) and analyzed for the expression of neural proteins and lipids and markers of oxidative stress. Exposure of myelinating samples to delta-ALA is associated with a pronounced reduction in the levels of myelin-associated lipids and proteins, including myelin protein zero and peripheral myelin protein 22. We also observed an increase in protein carbonylation and the formation of hydroxynonenal and malondialdehyde after treatment with delta-ALA. Studies of isolated Schwann cells and neurons indicate that glial cells are more vulnerable to this pro-oxidant than neurons, based on a selective decrease in the expression of mitochondrial respiratory chain proteins in glial, but not in neuronal, cells. These results suggest that the neuropathic effects of delta-ALA are attributable, at least in part, to its pro-oxidant properties which damage myelinating Schwann cells.
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Affiliation(s)
- Natalia Felitsyn
- Department of Neuroscience, College of Medicine, McKnight Brain Institute, University of Florida, Gainesville, Florida 32610-0244, USA
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Beigel J, Fella K, Kramer PJ, Kroeger M, Hewitt P. Genomics and proteomics analysis of cultured primary rat hepatocytes. Toxicol In Vitro 2007; 22:171-81. [PMID: 17768030 DOI: 10.1016/j.tiv.2007.06.019] [Citation(s) in RCA: 42] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/22/2007] [Revised: 06/02/2007] [Accepted: 06/27/2007] [Indexed: 11/27/2022]
Abstract
The use of animal models in pharmaceutical research is a costly and sometimes misleading method of generating toxicity data and hence predicting human safety. Therefore, in vitro test systems, such as primary rat hepatocytes, and the developing genomics and proteomics technologies, are playing an increasingly important role in toxicological research. Gene and protein expression analysis were investigated in a time series (up to 5 days) of primary rat hepatocytes cultured on collagen coated dishes. Especially after 24h, a significant down-regulation of many important Phase I and Phase II enzymes (e.g., cytochrome P450's, glutathione-S-transferases, sulfotransferases) involved in xenobiotic metabolism, and antioxidative enzymes (e.g., catalase, superoxide dismutase, glutathione peroxidase) was observed. Acute-phase-response enzymes were frequently up-regulated (e.g., LPS binding protein, alpha-2-macro-globulin, ferritin, serine proteinase inhibitor B, haptoglobin), which is likely to be a result of cellular stress caused by the cell isolation procedure (perfusion) itself. A parallel observation was the increased expression of several structural genes (e.g., beta-actin, alpha-tubulin, vimentin), possibly caused by other proliferating cell types in the culture, such as fibroblasts or alternatively by hepatocyte dedifferentiation. In conclusion, the careful interpretation of data derived from this in vitro system indicates that primary hepatocytes can be successfully used for short-term toxicity studies up to 24h. However, culturing conditions need to be further optimized to reduce the massive changes of gene and protein expression of long-term cultured hepatocytes to allow practical applications as a long-term toxicity test system.
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Affiliation(s)
- Juergen Beigel
- Molecular Toxicology, Institute of Toxicology, Merck KGaA, 64271 Darmstadt, Germany
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Chang J, Cornell JE, Van Remmen H, Hakala K, Ward WF, Richardson A. Effect of aging and caloric restriction on the mitochondrial proteome. J Gerontol A Biol Sci Med Sci 2007; 62:223-34. [PMID: 17389719 DOI: 10.1093/gerona/62.3.223] [Citation(s) in RCA: 28] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
Abstract
The rat mitochondrial proteome was analyzed using two-dimensional polyacrylamide gel electrophoresis (2-D PAGE), and proteins altered by age or caloric restriction (CR) were identified using mass spectrometry. Of 2061 mitochondrial proteins analyzed in the three tissues, a significant change with age occurred in 25 liver proteins (19 increased, 6 decreased), 3 heart proteins (1 increased, 2 decreased), and 5 skeletal muscle proteins (all increased). CR prevented the age-related change in the level of one liver mitochondrial protein, altered the levels of four proteins (one increased, three decreased) from heart, and one protein (decreased) from skeletal muscle. Identification of the proteins that changed with age or CR revealed that they were varied among the three tissues, that is, not one mitochondrial protein was changed, in common, by age or CR in any tissue studied. Thus, the effect of age on the mitochondrial proteome appears to be tissue-specific, and CR has a minor effect on age-related protein changes.
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Affiliation(s)
- Jinsook Chang
- Department of Physiology, The University of Texas Health Science Center at San Antonio, San Antonio, TX 78229-3900, USA
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Kaul SC, Deocaris CC, Wadhwa R. Three faces of mortalin: a housekeeper, guardian and killer. Exp Gerontol 2006; 42:263-74. [PMID: 17188442 DOI: 10.1016/j.exger.2006.10.020] [Citation(s) in RCA: 197] [Impact Index Per Article: 10.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/01/2006] [Revised: 10/05/2006] [Accepted: 10/24/2006] [Indexed: 11/23/2022]
Abstract
Mortalin was first cloned as a mortality factor that existed in the cytoplasmic fractions of normal, but not in immortal, mouse fibroblasts. A decade of efforts have expanded its persona from a house keeper protein involved in mitochondrial import, energy generation and chaperoning of misfolded proteins, to a guardian of stress that has multiple binding partners and to a killer protein that contributes to carcinogenesis on one hand and to old age disorders on the other. Being proved to be an attractive target for cancer therapy, it also warrants attention from the perspectives of management of old age diseases and healthy aging.
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Affiliation(s)
- Sunil C Kaul
- National Institute of Advanced Industrial Science and Technology, Tsukuba, Central 4, 1-1-1 Higashi, Tsukuba, Ibaraki 305 8562, Japan
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18
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Joyner-Matos J, Downs CA, Julian D. Increased expression of stress proteins in the surf clam Donax variabilis following hydrogen sulfide exposure. Comp Biochem Physiol A Mol Integr Physiol 2006; 145:245-57. [PMID: 16890466 DOI: 10.1016/j.cbpa.2006.06.033] [Citation(s) in RCA: 29] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/08/2006] [Revised: 06/21/2006] [Accepted: 06/22/2006] [Indexed: 11/21/2022]
Abstract
Endogenous free radical production and resulting oxidative damage may result from exposure to hypoxia, hyperoxia, or hydrogen sulfide. Previous investigations of sulfide-induced oxidative damage have produced conflicting results, perhaps because these studies utilized species presumably adapted to sulfide. We examined the effects of sulfide, hypoxia and hyperoxia on the surf clam Donax variabilis to test whether these stressors induce a cellular response to oxidative stress. These clams inhabit high-energy sandy beaches and are unlikely to have specific adaptations to these stressors. In duplicate flow-through experiments performed in fall and spring, clams were exposed to normoxia (22 kPa P(O(2))), hypoxia (10 kPa), hyperoxia (37 kPa), or sulfide with normoxia ( approximately 100 mumol L(-1), 22 kPa respectively) for 24 h. We quantified whole-animal expression of three antioxidants (Cu/Zn and Mn superoxide dismutases, glutathione peroxidase), a lipid peroxidation marker (4-hydroxy-2E-nonenol-adducted protein), a DNA repair enzyme (OGG1-m), four heat shock proteins (small Hsp, Hsp60, Hsp70, and mitochondrial Hsp70), ubiquitin, and actin. Clams exposed to sulfide showed upregulation of the greatest number of stress proteins and the pattern was consistent with a cellular response to oxidative stress. Furthermore, there was a marked seasonality, with greater stress protein expression in clams from the spring.
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19
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Stacchiotti A, Ricci F, Rezzani R, Li Volti G, Borsani E, Lavazza A, Bianchi R, Rodella LF. Tubular stress proteins and nitric oxide synthase expression in rat kidney exposed to mercuric chloride and melatonin. J Histochem Cytochem 2006; 54:1149-57. [PMID: 16801527 PMCID: PMC3957807 DOI: 10.1369/jhc.6a6932.2006] [Citation(s) in RCA: 30] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/09/2023] Open
Abstract
Stress proteins such as HSP70 members (HSP72 and GRP75) and metallothionein (MT) protect the kidney against oxidative damage and harmful metals, whereas inducible nitric oxide synthase (iNOS) regulates tubular functions. A single dose of mercuric chloride (HgCl(2)) can cause acute renal failure in rats, its main target being the proximal tubule. Oxidative damage has been proposed as one of its pathogenic mechanisms. In this study we tested whether melatonin (MEL), a powerful antioxidant compound, is effective against HgCl(2) nephrotoxicity. Rats were treated with saline, HgCl(2) (3.5 mg/kg), MEL (5 mg/kg), and MEL + HgCl(2) and examined after 24 hr for HSP72, GRP75, MT, and iNOS by immunohistochemistry and immunoblotting. Tubular effects of the treatment were then characterized by ultrastructure. In the HgCl(2) group, all markers were overexpressed in convoluted proximal tubules and sometimes in distal tubules. In the MEL + HgCl(2) group, GRP75 and iNOS decreased in convoluted and straight proximal tubules, whereas HSP72 and MT persisted more than the saline and MEL-only groups. Tubular damage and mitochondrial morphometry were improved by MEL pretreatment. In conclusion, the beneficial effect of MEL against HgCl(2) nephrotoxicity was outlined morphologically and by the reduction of the tubular expression of stress proteins and iNOS. These markers could represent sensitive recovery index against mercury damage.
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Affiliation(s)
- Alessandra Stacchiotti
- Division of Human Anatomy, Department of Biomedical Sciences and Biotechnology, University of Brescia, Viale Europa 11, I-25123 Brescia, Italy.
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20
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Lee CF, Chen YC, Liu CY, Wei YH. Involvement of protein kinase C delta in the alteration of mitochondrial mass in human cells under oxidative stress. Free Radic Biol Med 2006; 40:2136-46. [PMID: 16785027 DOI: 10.1016/j.freeradbiomed.2006.02.008] [Citation(s) in RCA: 24] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/05/2005] [Revised: 01/15/2006] [Accepted: 02/13/2006] [Indexed: 11/26/2022]
Abstract
Alteration of mitochondrial mass of human 143B osteosarcoma cells upon exposure to hydrogen peroxide (H(2)O(2)) was investigated. We found that mitochondrial mass and the intracellular level of H(2)O(2) were increased by exogenous H(2)O(2), which was accompanied with up-regulation of functional PKCdelta. To investigate the role of PKCdelta in H(2)O(2)-induced increase of mitochondrial mass, we treated 143B cells with PKCdelta activator, bistratene A, and PKCdelta inhibitor, rottlerin, respectively. The results show that bistratene A caused an increase of mitochondrial mass and that the H(2)O(2)-induced increase of mitochondrial mass was completely suppressed by rottlerin. Furthermore, we found that activation of PKCdelta by bistratene A increased the intracellular levels of H(2)O(2) and MnSOD protein expression. By contrast, suppression of PKCdelta by rottlerin decreased the intracellular levels of H(2)O(2) and MnSOD protein expression. Moreover, we noted that MnSOD expression was highly correlated with the expression of p53, which was controlled by PKCdelta. Finally, we demonstrated that PKCdelta was overexpressed in skin fibroblasts of patients with MERRF syndrome. Taken together, we conclude that PKCdelta is involved in the regulation of mitochondrial mass and intracellular H(2)O(2) in human cells and may play a key role in the overproliferation of mitochondria in the affected tissues of patients with mitochondrial diseases such as MERRF syndrome.
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Affiliation(s)
- Cheng-Feng Lee
- Department of Biochemistry and Molecular Biology, National Yang-Ming University, Taipei 112, Taiwan
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21
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Chen HB, Chan YT, Hung AC, Tsai YC, Sun SH. Elucidation of ATP-stimulated stress protein expression of RBA-2 type-2 astrocytes: ATP potentiate HSP60 and Cu/Zn SOD expression and stimulates pI shift of peroxiredoxin II. J Cell Biochem 2006; 97:314-26. [PMID: 16178011 DOI: 10.1002/jcb.20547] [Citation(s) in RCA: 16] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/01/2023]
Abstract
ATP has been shown to mediate stress responses in the brain. The present study examined the ATP-stimulated stress protein expression of RBA-2 type-2 astrocytes. Our results revealed that ATP stimulated HSP60 expression in a dose- and time-dependent manner. The stimulation requires a minimal ATP concentration of 500 microM and high concentration of extracellular ATP (1 mM) stimulated a significant increase of HSP60 expression from 2 to 24 h. In addition, the ATP-stimulated HSP60 expressions were inhibited by inhibitors for protein kinase C (PKC) and phospholipase D (PLD), and by antioxidants, resveratrol, and catalase. Furthermore, ATP stimulated the expression of Cu/Zn superoxide dismutase (SOD). In addition, ATP and P2X7 receptor selective agonist BzATP also decreased mitochondria membrane potential measured by flow cytometry. To further examine the proteins involving in ATP-mediated stress responses, we conducted proteomic analysis. We found that RBA-2 astrocytes possess abundant peroxiredoxin II (Prx II), an antioxidant enzyme. ATP and exogenous H2O2 stimulated Prx II shifting from oxidized form to reduced form. Thus, we concluded that ATP potentiated the expression of HSP60 and Cu/Zn SOD, and decreased mitochondria membrane potential. In addition, RBA-2 astrocytes expressed Prx II that might also serve as a protective mechanism to control the concentration of reactive oxygen species.
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Affiliation(s)
- Hammer B Chen
- Institute of Neuroscience, National Yang Ming University and Brain Research Center, University System of Taiwan, Taipei, Taiwan, Republic of China
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22
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Koopman WJH, Verkaart S, van Emst-de Vries SE, Grefte S, Smeitink JAM, Willems PHGM. Simultaneous quantification of oxidative stress and cell spreading using 5-(and-6)-chloromethyl-2′,7′-dichlorofluorescein. Cytometry A 2006; 69:1184-92. [PMID: 17066472 DOI: 10.1002/cyto.a.20348] [Citation(s) in RCA: 41] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/28/2023]
Abstract
BACKGROUND Mitochondrial dysfunction may lead to increased oxidative stress and consequent changes in cell spreading. Here, we describe and validate a novel method for simultaneous quantification of these two parameters. METHODS Human skin fibroblasts were loaded with 5-(and-6)-chloromethyl-2',7'-dichlorodihydrofluorescein (CM-H(2)DCF), and its oxidative conversion into CM-DCF was monitored as a function of time by video-rate confocal microscopy and real-time image averaging. Cell size was determined after binarization of the acquired images. RESULTS At the lowest practical laser output, CM-DCF formation occurred with zero order kinetics, indicating that [CM-H(2)DCF] was not rate-limiting and that the rate of [CM-DCF] formation (V(CM-DCF)) was a function of the cellular oxidant level. Analysis of fibroblasts of a healthy control subject and a patient with a deficiency of NADH:ubiquinone oxidoreductase, the first complex of the oxidative phosphorylation system, revealed a significant increase in cellular oxidant level in the latter cells that was, however, not accompanied by a change in cell spreading. Conversely, chronic treatment with 6-hydroxy-2,5,7,8-tetramethylchroman-2-carboxylic acid (Trolox), a derivative of vitamin E, markedly decreased the oxidant level and cell spreading in both control and patient fibroblasts. CONCLUSIONS We present a reliable method for simultaneous quantification of oxidant levels and cell spreading in living cells.
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Affiliation(s)
- Werner J H Koopman
- Department of Membrane Biochemistry, Nijmegen Centre for Molecular Life Sciences, Radboud University Nijmegen Medical Centre, Nijmegen, The Netherlands
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23
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Rezzani R, Buffoli B, Rodella L, Stacchiotti A, Bianchi R. Protective role of melatonin in cyclosporine A-induced oxidative stress in rat liver. Int Immunopharmacol 2005; 5:1397-405. [PMID: 15953566 DOI: 10.1016/j.intimp.2005.03.021] [Citation(s) in RCA: 59] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/16/2005] [Revised: 03/03/2005] [Accepted: 03/14/2005] [Indexed: 11/20/2022]
Abstract
Cyclosporine A (CsA) is the most widely used immunosuppressive drug for preventing graft rejection and autoimmune disease. However, the therapeutic treatment induces several side effects such as nephrotoxicity, cardiotoxicity, hypertension and hepatotoxicity. Among possible mechanisms of CsA-induced hepatic damage, oxidative stress has been suggested. Melatonin (Mel) has been successfully used as a potent antioxidant against many pathophysiological states. This experimental study was performed to test, during CsA treatment, the alterations of some heat shock proteins (HSP) and the Mel antioxidant properties against CsA-induced injury. Rats were divided into four groups, which were treated respectively with olive oil, Mel alone, CsA and CsA plus Mel for 30 days. At the end of the treatments, the animals were killed and hepatic tissue was treated for morphological (haematoxylin-eosin), biochemical (reduced glutathione, GSH and malondialdehyde, MDA) and immunohistochemical (HSP60, HSP72, GRP75 and MT) analyses. The results indicate that CsA-induced hepatotoxicity was characterised by morphological alterations in tissue architecture, changes in GSH and MDA levels and increase in stress protein expression. In conclusion, our data suggest that the imbalance between production of free oxygen radicals and antioxidant defence systems, due to CsA administration, is a mechanism responsible for oxidative stress. Moreover, we show that Mel plays a protective action against CsA-induced oxidative stress, as supported by biochemical and immunohistochemical results.
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Affiliation(s)
- Rita Rezzani
- Department of Biomedical Sciences and Biotechnology, Division of Human Anatomy, University of Brescia, 25123 Brescia, Italy.
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24
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Taylor NL, Heazlewood JL, Day DA, Millar AH. Differential impact of environmental stresses on the pea mitochondrial proteome. Mol Cell Proteomics 2005; 4:1122-33. [PMID: 15914488 DOI: 10.1074/mcp.m400210-mcp200] [Citation(s) in RCA: 152] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
Exposure to adverse environmental conditions causes oxidative stress in many organisms, leading either to disease and debilitation or to response and tolerance. Mitochondria are a key site of oxidative stress and of cellular response and play important roles in cell survival. We analyzed the response of mitochondria in pea (Pisum sativum) plants to the common stresses associated with drought, cold, and herbicides. These treatments all altered photosynthetic and respiratory rates of pea leaves to various extents, but only herbicides significantly increased lipid peroxidation product accumulation. Mitochondria isolated from the stressed pea plants maintained their electron transport chain activity, but changes were evident in the abundance of uncoupling proteins, non-phosphorylating respiratory pathways, and oxidative modification of lipoic acid moieties on mitochondrial proteins. These data suggest that herbicide treatment placed a severe oxidative stress on mitochondria, whereas chilling and particularly drought were milder stresses. Detailed analysis of the soluble proteome of mitochondria by gel electrophoresis and mass spectrometry revealed differential degradation of key matrix enzymes during treatments with chilling being significantly more damaging than drought. Differential induction of heat shock proteins and specific losses of other proteins illustrated the diversity of response to these stresses at the protein level. Cross-species matching was required for mass spectrometry identification of nine proteins because only a limited number of pea cDNAs have been sequenced, and the full pea genome is not available. Blue-native separation of intact respiratory chain complexes revealed little if any change in response to environmental stresses. Together these data suggest that although many of the molecular events identified by chemical stresses of mitochondria from a range of model eukaryotes are also apparent during environmental stress of plants, their extent and significance can vary substantially.
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Affiliation(s)
- Nicolas L Taylor
- The Plant Molecular Biology Group, Biochemistry and Molecular Biology, School of Biomedical and Chemical Sciences, The University of Western Australia, 35 Stirling Highway, Crawley 6009, Western Australia, Australia
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25
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Frye SR, Yee A, Eskin SG, Guerra R, Cong X, McIntire LV. cDNA microarray analysis of endothelial cells subjected to cyclic mechanical strain: importance of motion control. Physiol Genomics 2005; 21:124-30. [PMID: 15632272 DOI: 10.1152/physiolgenomics.00029.2003] [Citation(s) in RCA: 31] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022] Open
Abstract
Microarrays were utilized to determine gene expression of vascular endothelial cells (ECs) subjected to mechanical stretch for insight into the role of strain in vascular pathophysiology. Over 4,000 genes were screened for expression changes resulting from cyclic strain (10%, 1 Hz) of human umbilical vein ECs for 6 and 24 h. Comparison of t-statistics and adjusted P values identified genes having significantly different expression between strained and static cells but not between strained and motion control. Relative to static, 6 h of cyclic stretch upregulated two genes and downregulated two genes, whereas 24 h of cyclic stretch upregulated eight genes but downregulated no genes. However, incorporating the motion control revealed that fluid agitation over the cells, rather than strain, is the primary regulator of differential expression. Furthermore, no gene exceeded a threefold change when comparing cyclic strain to either static or motion control. Quantitative real-time polymerase chain reaction confirmed the dominance of fluid agitation in gene regulation with the exception of heat shock protein 10 at 24 h and plasminogen activator inhibitor 1 at 6 h. Taken together, the small number of differentially expressed genes and their low fold expression levels indicate that cyclic strain is a weak inducer of gene regulation in ECs. However, many of the differentially expressed genes possess antioxidant properties, suggesting that oxidative mechanisms direct EC adaptation to cyclic stretch.
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Affiliation(s)
- Stacie R Frye
- Department of Bioengineering, Rice University, Houston, Texas, USA
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26
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Koopman WJH, Verkaart S, Visch HJ, van der Westhuizen FH, Murphy MP, van den Heuvel LWPJ, Smeitink JAM, Willems PHGM. Inhibition of complex I of the electron transport chain causes O2-. -mediated mitochondrial outgrowth. Am J Physiol Cell Physiol 2005; 288:C1440-50. [PMID: 15647387 DOI: 10.1152/ajpcell.00607.2004] [Citation(s) in RCA: 221] [Impact Index Per Article: 11.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/13/2023]
Abstract
Recent evidence indicates that oxidative stress is central to the pathogenesis of a wide variety of degenerative diseases, aging, and cancer. Oxidative stress occurs when the delicate balance between production and detoxification of reactive oxygen species is disturbed. Mammalian cells respond to this condition in several ways, among which is a change in mitochondrial morphology. In the present study, we have used rotenone, an inhibitor of complex I of the respiratory chain, which is thought to increase mitochondrial O(2)(-)* production, and mitoquinone (MitoQ), a mitochondria-targeted antioxidant, to investigate the relationship between mitochondrial O(2)(-)* production and morphology in human skin fibroblasts. Video-rate confocal microscopy of cells pulse loaded with the mitochondria-specific cation rhodamine 123, followed by automated analysis of mitochondrial morphology, revealed that chronic rotenone treatment (100 nM, 72 h) significantly increased mitochondrial length and branching without changing the number of mitochondria per cell. In addition, this treatment caused a twofold increase in lipid peroxidation as determined with C11-BODIPY(581/591). Finally, digital imaging microscopy of cells loaded with hydroethidine, which is oxidized by O(2)(-)* to yield fluorescent ethidium, revealed that chronic rotenone treatment caused a twofold increase in the rate of O(2)(-)* production. MitoQ (10 nM, 72 h) did not interfere with rotenone-induced ethidium formation but abolished rotenone-induced outgrowth and lipid peroxidation. These findings show that increased mitochondrial O(2)(-)* production as a consequence of, for instance, complex I inhibition leads to mitochondrial outgrowth and that MitoQ acts downstream of this O(2)(-)* to prevent alterations in mitochondrial morphology.
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Affiliation(s)
- Werner J H Koopman
- Microscopal Imaging Center, Department of Biochemistry, Nijmegen Center for Molecular Life Sciences, Radboud University Medical Center, PO Box 9101, NL-6500 HB Nijmegen, The Netherlands
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27
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Orsini F, Migliaccio E, Moroni M, Contursi C, Raker VA, Piccini D, Martin-Padura I, Pelliccia G, Trinei M, Bono M, Puri C, Tacchetti C, Ferrini M, Mannucci R, Nicoletti I, Lanfrancone L, Giorgio M, Pelicci PG. The life span determinant p66Shc localizes to mitochondria where it associates with mitochondrial heat shock protein 70 and regulates trans-membrane potential. J Biol Chem 2004; 279:25689-95. [PMID: 15078873 DOI: 10.1074/jbc.m401844200] [Citation(s) in RCA: 219] [Impact Index Per Article: 11.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
P66Shc regulates life span in mammals and is a critical component of the apoptotic response to oxidative stress. It functions as a downstream target of the tumor suppressor p53 and is indispensable for the ability of oxidative stress-activated p53 to induce apoptosis. The molecular mechanisms underlying the apoptogenic effect of p66Shc are unknown. Here we report the following three findings. (i) The apoptosome can be properly activated in vitro in the absence of p66Shc only if purified cytochrome c is supplied. (ii) Cytochrome c release after oxidative signals is impaired in the absence of p66Shc. (iii) p66Shc induces the collapse of the mitochondrial trans-membrane potential after oxidative stress. Furthermore, we showed that a fraction of cytosolic p66Shc localizes within mitochondria where it forms a complex with mitochondrial Hsp70. Treatment of cells with ultraviolet radiation induced the dissociation of this complex and the release of monomeric p66Shc. We propose that p66Shc regulates the mitochondrial pathway of apoptosis by inducing mitochondrial damage after dissociation from an inhibitory protein complex. Genetic and biochemical evidence suggests that mitochondria regulate life span through their effects on the energetic metabolism (mitochondrial theory of aging). Our data suggest that mitochondrial regulation of apoptosis might also contribute to life span determination.
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Affiliation(s)
- Francesca Orsini
- Department of Experimental Oncology, European Institute of Oncology, Via Ripamonti 435, 20141 Milan, Italy
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28
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Abstract
Mitochondrial dysfunction and mutations in mitochondrial DNA have been frequently reported in cancer cells. Mitochondrial gene-expression signatures of transformed cells have been identified; however, the phenotypic effects of these genetic alterations remain to be established. Identification of mitochondrial proteins that are aberrantly expressed in cancer cells has been made possible by the recent development of mitochondrial functional proteomics and could identify new markers for early detection and risk assessment, as well as targets for therapeutic intervention.
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Affiliation(s)
- Mukesh Verma
- Cancer Biomarkers Research Group, Division of Cancer Prevention, National Cancer Institute, Bethesda, Maryland 20892, USA
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29
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Tryoen-Tóth P, Richert S, Sohm B, Mine M, Marsac C, Van Dorsselaer A, Leize E, Florentz C. Proteomic consequences of a human mitochondrial tRNA mutation beyond the frame of mitochondrial translation. J Biol Chem 2003; 278:24314-23. [PMID: 12714596 DOI: 10.1074/jbc.m301530200] [Citation(s) in RCA: 24] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
Numerous severe neurodegenerative and neuromuscular disorders, characterized biochemically by strong perturbations in energy metabolism, are correlated with single point mutations in mitochondrial genes coding for transfer RNAs. Initial comparative proteomics performed on wild-type and Myoclonic Epilepsy and Ragged Red Fibers (MERRF) mitochondria from sibling human cybrid cell lines revealed the potential of this approach. Here a quantitative analysis of several hundred silver-stained spots separated by two-dimensional gel electrophoresis was performed in the specific case of a couple of mitochondria, containing or not mutation A8344G in the gene for mitochondrial tRNALys, correlated with MERRF syndrome. Computer-assisted analysis allowed us to detect 38 spots with significant quantitative variations, of which 20 could be assigned by mass spectrometry. These include nuclear encoded proteins located in mitochondria such as respiratory chain subunits, metabolic enzymes, a protein of the mitochondrial translation machinery, and cytosolic contaminants. Furthermore, Western blotting combined with mass spectrometry revealed the occurrence of numerous isoforms of pyruvate dehydrogenase subunits, with subtle changes in post-translational modifications. This comparative proteomic approach gives the first insight for nuclear encoded proteins that undergo the largest quantitative changes, and pinpoints new potential molecular partners involved in the cascade of events that connect genotype to phenotype.
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Affiliation(s)
- Petra Tryoen-Tóth
- UPR 9002, Institut de Biologie Moléculaire et Cellulaire du CNRS, 15 Rue René Descartes 67084 Strasbourg Cedex, France
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30
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Kario K, McEwen BS, Pickering TG. Disasters and the heart: a review of the effects of earthquake-induced stress on cardiovascular disease. Hypertens Res 2003; 26:355-67. [PMID: 12887126 DOI: 10.1291/hypres.26.355] [Citation(s) in RCA: 151] [Impact Index Per Article: 7.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022]
Abstract
There is growing evidence that stress contributes to cardiovascular disease. Chronic stress contributes to the atherosclerotic process through increased allostatic load, which is mediated by the neuroendocrine and immune systems (sympathetic nervous system and hypothalamus-pituitary adrenal axis) and related chronic risk factors (insulin resistance syndrome, hypertension, diabetes, and hyperlipidemia). In addition, acute stress can trigger cardiovascular events predominantly through sympathetic nervous activation and potentiation of acute risk factors (blood pressure increase, endothelial cell dysfunction, increased blood viscosity, and platelet and hemostatic activation). Earthquakes provide a good example of naturally occurring acute and chronic stress, and in this review we focus mainly on the effects of the Hanshin-Awaji earthquake on the cardiovascular system. The Hanshin-Awaji earthquake resulted in a 3-fold increase of myocardial infarctions in people living close to the epicenter, particularly in women, with most of the increase occurring in nighttime-onset events. There was also a near doubling in the frequency of strokes. These effects may be mediated by changes in hemostatic factors, as demonstrated by an increase of D-dimer, von Willebrand factor, and tissue-type plasminogen activator (tPA) antigen. Blood pressure also increased after the earthquake, and was prolonged for several weeks in patients with microalbuminuria.
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Affiliation(s)
- Kazuomi Kario
- Department of Cardiology, Jichi Medical School, Tochigi, Japan.
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31
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Gromov P, Skovgaard GL, Palsdottir H, Gromova I, Østergaard M, Celis JE. Protein profiling of the human epidermis from the elderly reveals up-regulation of a signature of interferon-gamma-induced polypeptides that includes manganese-superoxide dismutase and the p85beta subunit of phosphatidylinositol 3-kinase. Mol Cell Proteomics 2003; 2:70-84. [PMID: 12644569 DOI: 10.1074/mcp.m200051-mcp200] [Citation(s) in RCA: 36] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
Aging of the human skin is a complex process that consists of chronological and extrinsic aging, the latter caused mainly by exposure to ultraviolet radiation (photoaging). Here we present studies in which we have used proteomic profiling technologies and two-dimensional (2D) PAGE database resources to identify proteins whose expression is deregulated in the epidermis of the elderly. Fresh punch biopsies from the forearm of 20 pairs of young and old donors (21-30 and 75-92 years old, respectively) were dissected to yield an epidermal fraction that consisted mainly of differentiated cells. One- to two-mm3 epidermal pieces were labeled with [35S]methionine for 18 h, lysed, and subjected to 2D PAGE (isoelectric focusing and non-equilibrium pH gradient electrophoresis) and phosphorimage autoradiography. Proteins were identified by matching the gels with the master 2D gel image of human keratinocytes (proteomics.cancer.dk). In selected cases 2D PAGE immunoblotting and/or mass spectrometry confirmed the identity. Quantitative analysis of 172 well focused and abundant polypeptides showed that the level of most proteins (148) remains unaffected by the aging process. Twenty-two proteins were consistently deregulated by a factor of 1.5 or more across the 20 sample pairs. Among these we identified a group of six polypeptides (Mx-A, manganese-superoxide dismutase, tryptophanyl-tRNA synthetase, the p85beta subunit of phosphatidylinositol 3-kinase, and proteasomal proteins PA28-alpha and SSP 0107) that is induced by interferon-gamma in primary human keratinocytes and that represents a specific protein signature for the effect of this cytokine. Changes in the expression of the eukaryotic initiation factor 5A, NM23 H2, cyclophilin A, HSP60, annexin I, and plasminogen activator inhibitor 2 were also observed. Two proteins exhibited irregular behavior from individual to individual. Besides arguing for a role of interferon-gamma in the aging process, the biological activities associated with the deregulated proteins support the contention that aging is linked with increased oxidative stress that could lead to apoptosis in vivo.
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Affiliation(s)
- Pavel Gromov
- Department of Medical Biochemistry and Danish Centre for Molecular Gerontology, The University of Aarhus, Ole Worms Allé, build. 170, DK-8000 Aarhus C, Denmark.
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32
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Chang J, Van Remmen H, Cornell J, Richardson A, Ward WF. Comparative proteomics: characterization of a two-dimensional gel electrophoresis system to study the effect of aging on mitochondrial proteins. Mech Ageing Dev 2003; 124:33-41. [PMID: 12618004 DOI: 10.1016/s0047-6374(02)00167-7] [Citation(s) in RCA: 38] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/27/2022]
Abstract
To study the effect of aging and anti-aging strategies on mitochondria, we have characterized a two-dimensional polyacrylamide gel electrophoresis (2-D PAGE) system to analyze the profile of mitochondrial proteins. We have optimized the separation of proteins by 2-D PAGE and established the linearity and reproducibility of the system with mitochondria isolated from skeletal muscle of mice. Using total mitochondria protein ranging from 10 to 200 microg, we found that 74% of the proteins resolved by 2-D PAGE had coefficient of determination (R2) values greater than 0.8, showing a linear increase in fluorescence with increasing protein concentration. The coefficient of variation (CV) was less than 50% for at least 93% of the 424 spots analyzed for both gel-to-gel variance and animal-to-animal variance. Using mitochondrial protein fractions prepared from skeletal muscle of 18-month-old mice, we show that 10 animals will be sufficient to detect a 100% difference in the 97% (i.e. 505) of the proteins resolved by 2-D PAGE. Thus, 2-D PAGE provides a sensitive and reliable technique for analysis of protein expression in mitochondria.
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Affiliation(s)
- Jinsook Chang
- Department of Physiology, 7703 Floyd Curl Drive, MSC 7756, University of Texas Health Science Center at San Antonio, San Antonio, TX 78229-3900, USA
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Larade K, Storey KB. A Profile of the Metabolic Responses to Anoxia in Marine Invertebrates. CELL AND MOLECULAR RESPONSE TO STRESS 2002. [DOI: 10.1016/s1568-1254(02)80005-5] [Citation(s) in RCA: 53] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
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