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Amidfar M, Garcez ML, Kim YK. The shared molecular mechanisms underlying aging of the brain, major depressive disorder, and Alzheimer's disease: The role of circadian rhythm disturbances. Prog Neuropsychopharmacol Biol Psychiatry 2023; 123:110721. [PMID: 36702452 DOI: 10.1016/j.pnpbp.2023.110721] [Citation(s) in RCA: 8] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/21/2022] [Revised: 01/07/2023] [Accepted: 01/19/2023] [Indexed: 01/24/2023]
Abstract
An association with circadian clock function and pathophysiology of aging, major depressive disorder (MDD), and Alzheimer's disease (AD) is well established and has been proposed as a factor in the development of these diseases. Depression and changes in circadian rhythm have been increasingly suggested as the two primary overlapping and interpenetrating changes that occur with aging. The relationship between AD and depression in late life is not completely understood and probably is complex. Patients with major depression or AD suffer from disturbed sleep/wake cycles and altered rhythms in daily activities. Although classical monoaminergic hypotheses are traditionally proposed to explain the pathophysiology of MDD, several clinical and preclinical studies have reported a strong association between circadian rhythm and mood regulation. In addition, a large body of evidence supports an association between disruption of circadian rhythm and AD. Some clock genes are dysregulated in rodent models of depression. If aging, AD, and MDD share a common biological basis in pathophysiology, common therapeutic tools could be investigated for their prevention and treatment. Nitro-oxidative stress (NOS), for example, plays a fundamental role in aging, as well as in the pathogenesis of AD and MDD and is associated with circadian clock disturbances. Thus, development of therapeutic possibilities with these NOS-related conditions is advisable. This review describes recent findings that link disrupted circadian clocks to aging, MDD, and AD and summarizes the experimental evidence that supports connections between the circadian clock and molecular pathologic factors as shared common pathophysiological mechanisms underlying aging, AD, and MDD.
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Affiliation(s)
- Meysam Amidfar
- Department of Neuroscience, Shahroud University of Medical Sciences, Shahroud, Iran
| | - Michelle Lima Garcez
- Laboratory of Translational Neuroscience, Department of Biochemistry, Federal University of Santa Catarina (UFSC), Florianópolis, Santa Catarina, Brazil
| | - Yong-Ku Kim
- Department of Psychiatry, College of Medicine, Korea University, Seoul, South Korea.
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2
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Di Sanzo S, Spengler K, Leheis A, Kirkpatrick JM, Rändler TL, Baldensperger T, Dau T, Henning C, Parca L, Marx C, Wang ZQ, Glomb MA, Ori A, Heller R. Mapping protein carboxymethylation sites provides insights into their role in proteostasis and cell proliferation. Nat Commun 2021; 12:6743. [PMID: 34795246 PMCID: PMC8602705 DOI: 10.1038/s41467-021-26982-6] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/04/2020] [Accepted: 10/29/2021] [Indexed: 12/19/2022] Open
Abstract
Posttranslational mechanisms play a key role in modifying the abundance and function of cellular proteins. Among these, modification by advanced glycation end products has been shown to accumulate during aging and age-associated diseases but specific protein targets and functional consequences remain largely unexplored. Here, we devise a proteomic strategy to identify sites of carboxymethyllysine modification, one of the most abundant advanced glycation end products. We identify over 1000 sites of protein carboxymethylation in mouse and primary human cells treated with the glycating agent glyoxal. By using quantitative proteomics, we find that protein glycation triggers a proteotoxic response and indirectly affects the protein degradation machinery. In primary endothelial cells, we show that glyoxal induces cell cycle perturbation and that carboxymethyllysine modification reduces acetylation of tubulins and impairs microtubule dynamics. Our data demonstrate the relevance of carboxymethyllysine modification for cellular function and pinpoint specific protein networks that might become compromised during aging.
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Affiliation(s)
- Simone Di Sanzo
- grid.418245.e0000 0000 9999 5706Leibniz Institute on Aging – Fritz Lipmann Institute (FLI), 07745 Jena, Germany
| | - Katrin Spengler
- grid.275559.90000 0000 8517 6224Institute of Molecular Cell Biology, Center for Molecular Biomedicine, Jena University Hospital, 07743 Jena, Germany
| | - Anja Leheis
- grid.275559.90000 0000 8517 6224Institute of Molecular Cell Biology, Center for Molecular Biomedicine, Jena University Hospital, 07743 Jena, Germany
| | - Joanna M. Kirkpatrick
- grid.418245.e0000 0000 9999 5706Leibniz Institute on Aging – Fritz Lipmann Institute (FLI), 07745 Jena, Germany ,grid.451388.30000 0004 1795 1830Present Address: Proteomics Science Technology Platform, The Francis Crick Institute, MW1 1AT London, UK
| | - Theresa L. Rändler
- grid.275559.90000 0000 8517 6224Institute of Molecular Cell Biology, Center for Molecular Biomedicine, Jena University Hospital, 07743 Jena, Germany
| | - Tim Baldensperger
- grid.9018.00000 0001 0679 2801Institute of Chemistry, Food Chemistry, Martin-Luther-University Halle-Wittenberg, 06120 Halle/Saale, Germany
| | - Therese Dau
- grid.418245.e0000 0000 9999 5706Leibniz Institute on Aging – Fritz Lipmann Institute (FLI), 07745 Jena, Germany
| | - Christian Henning
- grid.9018.00000 0001 0679 2801Institute of Chemistry, Food Chemistry, Martin-Luther-University Halle-Wittenberg, 06120 Halle/Saale, Germany
| | - Luca Parca
- grid.413503.00000 0004 1757 9135Bioinformatics Unit, IRCCS Casa Sollievo della Sofferenza, S. Giovanni Rotondo, Italy
| | - Christian Marx
- grid.418245.e0000 0000 9999 5706Leibniz Institute on Aging – Fritz Lipmann Institute (FLI), 07745 Jena, Germany
| | - Zhao-Qi Wang
- grid.418245.e0000 0000 9999 5706Leibniz Institute on Aging – Fritz Lipmann Institute (FLI), 07745 Jena, Germany ,grid.9613.d0000 0001 1939 2794Faculty of Biological Sciences, Friedrich-Schiller-University of Jena, Jena, Germany
| | - Marcus A. Glomb
- grid.9018.00000 0001 0679 2801Institute of Chemistry, Food Chemistry, Martin-Luther-University Halle-Wittenberg, 06120 Halle/Saale, Germany
| | - Alessandro Ori
- Leibniz Institute on Aging - Fritz Lipmann Institute (FLI), 07745, Jena, Germany.
| | - Regine Heller
- Institute of Molecular Cell Biology, Center for Molecular Biomedicine, Jena University Hospital, 07743, Jena, Germany.
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Female Mice Reaching Exceptionally High Old Age Have Preserved 20S Proteasome Activities. Antioxidants (Basel) 2021; 10:antiox10091397. [PMID: 34573029 PMCID: PMC8472714 DOI: 10.3390/antiox10091397] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/28/2021] [Revised: 08/18/2021] [Accepted: 08/28/2021] [Indexed: 01/09/2023] Open
Abstract
Oxidized, damaged and misfolded proteins accumulate during aging and contribute to impaired cell function and tissue homeodynamics. Damaged proteins are degraded by cellular clearance mechanisms like the 20S proteasome. Aging relates to low 20S proteasome function, whereas long-lived species show high levels. However, contradictory results exist depending on the tissue or cell type and it is unknown how the 20S proteasome functions in exceptionally old mice. The aim of this study was to investigate two proteasome activities (caspase-like and chymotrypsin-like) in several tissues (lung, heart, axillary lymph nodes, liver, kidney) and cells (peritoneal leukocytes) from adult (28 ± 4 weeks, n = 12), old (76 ± 4 weeks, n = 9) and exceptionally old (128 ± 4 weeks, n = 9) BALB/c female mice. The results show different age-related changes depending on the tissue and the activity considered, so there is no universal decline in proteasome function with age in female mice. Interestingly, exceptionally old mice displayed better maintained proteasome activities, suggesting that preserved 20S proteasome is associated with successful aging.
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Mechanisms That Activate 26S Proteasomes and Enhance Protein Degradation. Biomolecules 2021; 11:biom11060779. [PMID: 34067263 PMCID: PMC8224753 DOI: 10.3390/biom11060779] [Citation(s) in RCA: 9] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/19/2021] [Revised: 05/11/2021] [Accepted: 05/12/2021] [Indexed: 02/07/2023] Open
Abstract
Although ubiquitination is widely assumed to be the only regulated step in the ubiquitin–proteasome pathway, recent studies have demonstrated several important mechanisms that regulate the activities of the 26S proteasome. Most proteasomes in cells are inactive but, upon binding a ubiquitinated substrate, become activated by a two-step mechanism requiring an association of the ubiquitin chain with Usp14 and then a loosely folded protein domain with the ATPases. The initial activation step is signaled by Usp14’s UBL domain, and many UBL-domain-containing proteins (e.g., Rad23, Parkin) also activate the proteasome. ZFAND5 is a distinct type of activator that binds ubiquitin conjugates and the proteasome and stimulates proteolysis during muscle atrophy. The proteasome’s activities are also regulated through subunit phosphorylation. Agents that raise cAMP and activate PKA stimulate within minutes Rpn6 phosphorylation and enhance the selective degradation of short-lived proteins. Likewise, hormones, fasting, and exercise, which raise cAMP, activate proteasomes and proteolysis in target tissues. Agents that raise cGMP and activate PKG also stimulate 26S activities but modify different subunit(s) and stimulate also the degradation of long-lived cell proteins. Both kinases enhance the selective degradation of aggregation-prone proteins that cause neurodegenerative diseases. These new mechanisms regulating proteolysis thus have clear physiological importance and therapeutic potential.
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Kirana AN, Prafiantini E, Hardiany NS. Protein intake and loss of proteostasis in the eldery. UKRAINIAN BIOCHEMICAL JOURNAL 2021. [DOI: 10.15407/ubj93.01.030] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/17/2022] Open
Abstract
Ageing is a process of declining bodily function and a major risk factor of chronic diseases. The declining bodily function in ageing can cause loss of proteostasis (protein homeostasis), which is a balance between protein synthesis, folding, modification and degradation. For the elderly, adequate protein intake is necessary to prevent sarcopenia, frailty, fracture and osteoporosis as well as reduced resistance to infection. However, increasing the protein intake can enhance the risk of oxidized protein formation, loss of proteostasis and degenerative disorder occurrence. On the other hand, several studies show that protein restriction would increase longevity. The aim of this review was to explain the importance of determining the right amount and composition of protein intake for the elderly. Oxidative stress and molecular mechanism of proteostasis loss in ageing cells as well as its suppression pathway by protein restriction are discussed in this review. Keywords: ageing, dietary proteins, mTOR, oxidative stress, proteostasis loss
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Kodavanti PRS, Valdez M, Richards JE, Agina-Obu DI, Phillips PM, Jarema KA, Kodavanti UP. Ozone-induced changes in oxidative stress parameters in brain regions of adult, middle-age, and senescent Brown Norway rats. Toxicol Appl Pharmacol 2021; 410:115351. [PMID: 33249117 PMCID: PMC7775355 DOI: 10.1016/j.taap.2020.115351] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/25/2020] [Revised: 11/19/2020] [Accepted: 11/23/2020] [Indexed: 12/16/2022]
Abstract
A critical part of community based human health risk assessment following chemical exposure is identifying sources of susceptibility. Life stage is one such susceptibility. A prototypic air pollutant, ozone (O3) induces dysfunction of the pulmonary, cardiac, and nervous systems. Long-term exposure may cause oxidative stress (OS). The current study explored age-related and subchronic O3-induced changes in OS in brain regions of rats. To build a comprehensive assessment of OS-related effects of O3, a tripartite approach was implemented focusing on 1) the production of reactive oxygen species (ROS) [NADPH Quinone oxidoreductase 1, NADH Ubiquinone reductase] 2) antioxidant homeostasis [total antioxidant substances, superoxide dismutase, γ-glutamylcysteine synthetase] and 3) an assessment of oxidative damage [total aconitase and protein carbonyls]. Additionally, a neurobehavioral evaluation of motor activity was compared to these OS measures. Male Brown Norway rats (4, 12, and 24 months of age) were exposed to air or O3 (0.25 or 1 ppm) via inhalation for 6 h/day, 2 days per week for 13 weeks. A significant decrease in horizontal motor activity was noted only in 4-month old rats. Results on OS measures in frontal cortex (FC), cerebellum (CB), striatum (STR), and hippocampus (HIP) indicated life stage-related increases in ROS production, small decreases in antioxidant homeostatic mechanisms, a decrease in aconitase activity, and an increase in protein carbonyls. The effects of O3 exposure were brain area-specific, with the STR being more sensitive. Regarding life stage, the effects of O3 were greater in 4-month-old rats, which correlated with horizontal motor activity. These results indicate that OS may be increased in specific brain regions after subchronic O3 exposure, but the interactions between age and exposure along with their consequences on the brain require further investigation.
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Affiliation(s)
- Prasada Rao S Kodavanti
- Neurological and Endocrine Toxicology Branch, Public Health and Integrated Toxicology Division, CPHEA, ORD, U.S. Environmental Protection Agency, Research Triangle Park, NC 27711, USA.
| | - Matthew Valdez
- Neurological and Endocrine Toxicology Branch, Public Health and Integrated Toxicology Division, CPHEA, ORD, U.S. Environmental Protection Agency, Research Triangle Park, NC 27711, USA
| | - Judy E Richards
- Cardiopulmonary and Immunotoxicology Branch, Public Health and Integrated Toxicology Division, CPHEA, ORD, U.S. Environmental Protection Agency, Research Triangle Park, NC 27711, USA
| | - Datonye I Agina-Obu
- Neurological and Endocrine Toxicology Branch, Public Health and Integrated Toxicology Division, CPHEA, ORD, U.S. Environmental Protection Agency, Research Triangle Park, NC 27711, USA
| | - Pamela M Phillips
- Neurological and Endocrine Toxicology Branch, Public Health and Integrated Toxicology Division, CPHEA, ORD, U.S. Environmental Protection Agency, Research Triangle Park, NC 27711, USA
| | - Kimberly A Jarema
- Neurological and Endocrine Toxicology Branch, Public Health and Integrated Toxicology Division, CPHEA, ORD, U.S. Environmental Protection Agency, Research Triangle Park, NC 27711, USA
| | - Urmila P Kodavanti
- Cardiopulmonary and Immunotoxicology Branch, Public Health and Integrated Toxicology Division, CPHEA, ORD, U.S. Environmental Protection Agency, Research Triangle Park, NC 27711, USA.
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Effect of Antioxidants on the Fibroblast Replicative Lifespan In Vitro. OXIDATIVE MEDICINE AND CELLULAR LONGEVITY 2020; 2020:6423783. [PMID: 33029282 PMCID: PMC7530501 DOI: 10.1155/2020/6423783] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Subscribe] [Scholar Register] [Received: 07/12/2020] [Revised: 09/04/2020] [Accepted: 09/12/2020] [Indexed: 12/20/2022]
Abstract
Replicative senescence is an unalterable growth arrest of primary cells in the culture system. It has been reported that aging in vivo is related to the limited replicative capacity that normal somatic cells show in vitro. If oxidative damage contributes to the lifespan limitation, antioxidants are expected to extend the replicative lifespan of fibroblasts. This article critically reviews the results of experiments devoted to this problem performed within the last decades under conditions of in vitro culture. The results of studied are heterogeneous, some papers showing no effects of antioxidants; most finding limited enhancement of reproductive capacity of fibroblasts, some reporting a significant extension of replicative lifespan (RLS). Both natural and synthetic antioxidants were found to extend the RLS of fibroblasts, either by a direct antioxidant effect or, indirectly, by activation of signaling pathways and activation of proteasomes or hormetic effects. Most significant prolongation of RLS was reported so far for nicotinamide, N-hydroxylamines, carnosine and Methylene Blue. These results may be of importance for the design of skin-protecting cosmetics.
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Mild depolarization of the inner mitochondrial membrane is a crucial component of an anti-aging program. Proc Natl Acad Sci U S A 2020; 117:6491-6501. [PMID: 32152094 PMCID: PMC7104298 DOI: 10.1073/pnas.1916414117] [Citation(s) in RCA: 100] [Impact Index Per Article: 25.0] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/24/2022] Open
Abstract
The mitochondria, organelles that produce the largest amounts of ATP and reactive oxygen species (mROS) in living cells, are equipped with a universal mechanism that can completely prevent mROS production. This mechanism consists of mild depolarization of the inner mitochondrial membrane to decrease the membrane potential to a level sufficient to form ATP but insufficient to generate mROS. In short-lived mice, aging is accompanied by inactivation of the mild depolarization mechanism, resulting in chronic poisoning of the organism with mROS. However, mild depolarization still functions for many years in long-lived naked mole rats and bats. The mitochondria of various tissues from mice, naked mole rats (NMRs), and bats possess two mechanistically similar systems to prevent the generation of mitochondrial reactive oxygen species (mROS): hexokinases I and II and creatine kinase bound to mitochondrial membranes. Both systems operate in a manner such that one of the kinase substrates (mitochondrial ATP) is electrophoretically transported by the ATP/ADP antiporter to the catalytic site of bound hexokinase or bound creatine kinase without ATP dilution in the cytosol. One of the kinase reaction products, ADP, is transported back to the mitochondrial matrix via the antiporter, again through an electrophoretic process without cytosol dilution. The system in question continuously supports H+-ATP synthase with ADP until glucose or creatine is available. Under these conditions, the membrane potential, ∆ψ, is maintained at a lower than maximal level (i.e., mild depolarization of mitochondria). This ∆ψ decrease is sufficient to completely inhibit mROS generation. In 2.5-y-old mice, mild depolarization disappears in the skeletal muscles, diaphragm, heart, spleen, and brain and partially in the lung and kidney. This age-dependent decrease in the levels of bound kinases is not observed in NMRs and bats for many years. As a result, ROS-mediated protein damage, which is substantial during the aging of short-lived mice, is stabilized at low levels during the aging of long-lived NMRs and bats. It is suggested that this mitochondrial mild depolarization is a crucial component of the mitochondrial anti-aging system.
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Valdez JM, Johnstone AFM, Richards JE, Schmid JE, Royland JE, Kodavanti PRS. Interaction of Diet and Ozone Exposure on Oxidative Stress Parameters within Specific Brain Regions of Male Brown Norway Rats. Int J Mol Sci 2018; 20:ijms20010011. [PMID: 30577502 PMCID: PMC6337237 DOI: 10.3390/ijms20010011] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/02/2018] [Revised: 11/29/2018] [Accepted: 12/18/2018] [Indexed: 12/18/2022] Open
Abstract
Oxidative stress (OS) contributes to the neurological and cardio/pulmonary effects caused by adverse metabolic states and air pollutants such as ozone (O3). This study explores the interactive effects of O3 and diet (high-fructose (FRUC) or high–fat (FAT)) on OS in different rat brain regions. In acute exposure, there was a decrease in markers of reactive oxygen species (ROS) production in some brain regions by diet and not by O3. Total antioxidant substances (TAS) were increased in the cerebellum (CER) and frontal cortex (FC) and decreased in the striatum (STR) by both diets irrespective of O3 exposure. Protein carbonyls (PC) and total aconitase decreased in some brain regions irrespective of exposure. Following subacute exposure, an increase in markers of ROS was observed in both diet groups. TAS was increased in the FC (FAT only) and there was a clear O3 effect where TAS was increased in the FC and STR. Diet increased PC formation within the CER in the FAT group, while the hippocampus showed a decrease in PC after O3 exposure in controls. In general, these results indicate that diet/O3 did not have a global effect on brain OS parameters, but showed some brain region- and OS parameter-specific effects by diets.
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Affiliation(s)
- Joseph M Valdez
- Neurotoxicology Branch, Toxicity Assessment Division, NHEERL/ORD, U.S. Environmental Protection Agency, Research Triangle Park, NC 27711, USA.
| | - Andrew F M Johnstone
- Neurotoxicology Branch, Toxicity Assessment Division, NHEERL/ORD, U.S. Environmental Protection Agency, Research Triangle Park, NC 27711, USA.
| | - Judy E Richards
- Environmental Public Health Division, NHEERL/ORD, U.S. Environmental Protection Agency, Research Triangle Park, NC 27711, USA.
| | - Judith E Schmid
- Neurotoxicology Branch, Toxicity Assessment Division, NHEERL/ORD, U.S. Environmental Protection Agency, Research Triangle Park, NC 27711, USA.
| | - Joyce E Royland
- Integrated Systems Toxicology Division, NHEERL/ORD, U.S. Environmental Protection Agency, Research Triangle Park, NC 27711, USA.
| | - Prasada Rao S Kodavanti
- Neurotoxicology Branch, Toxicity Assessment Division, NHEERL/ORD, U.S. Environmental Protection Agency, Research Triangle Park, NC 27711, USA.
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Nitric oxide contributes to protein homeostasis by S-nitrosylations of the chaperone HSPA8 and the ubiquitin ligase UBE2D. Redox Biol 2018; 20:217-235. [PMID: 30368041 PMCID: PMC6202877 DOI: 10.1016/j.redox.2018.10.002] [Citation(s) in RCA: 24] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/28/2018] [Revised: 09/25/2018] [Accepted: 10/02/2018] [Indexed: 02/06/2023] Open
Abstract
Upregulations of neuronal nitric oxide synthase (nNOS) in the rodent brain have been associated with neuronal aging. To address underlying mechanisms we generated SH-SY5Y neuronal cells constitutively expressing nNOS at a level similar to mouse brain (nNOS+ versus MOCK). Initial experiments revealed S-nitrosylations (SNO) of key players of protein homeostasis: heat shock cognate HSC70/HSPA8 within its nucleotide-binding site, and UBE2D ubiquitin conjugating enzymes at the catalytic site cysteine. HSPA8 is involved in protein folding, organelle import/export and chaperone-mediated LAMP2a-dependent autophagy (CMA). A set of deep redox and full proteome analyses, plus analysis of autophagy, CMA and ubiquitination with rapamycin and starvation as stimuli confirmed the initial observations and revealed a substantial increase of SNO modifications in nNOS+ cells, in particular targeting protein networks involved in protein catabolism, ubiquitination, carbohydrate metabolism and cell cycle control. Importantly, NO-independent reversible oxidations similarly occurred in both cell lines. Functionally, nNOS caused an accumulation of proteins, including CMA substrates and loss of LAMP2a. UBE2D activity and proteasome activity were impaired, resulting in dysregulations of cell cycle checkpoint proteins. The observed changes of protein degradation pathways caused an expansion of the cytoplasm, large lysosomes, slowing of the cell cycle and suppression of proliferation suggesting a switch of the phenotype towards aging, supported by downregulations of neuronal progenitor markers but increase of senescence-associated proteins. Hence, upregulation of nNOS in neuronal cells imposes aging by SNOing of key players of ubiquitination, chaperones and of substrate proteins leading to interference with crucial steps of protein homeostasis.
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Carracedo J, Ramírez-Carracedo R, Martínez de Toda I, Vida C, Alique M, De la Fuente M, Ramírez-Chamond R. Protein Carbamylation: A Marker Reflecting Increased Age-Related Cell Oxidation. Int J Mol Sci 2018; 19:ijms19051495. [PMID: 29772765 PMCID: PMC5983744 DOI: 10.3390/ijms19051495] [Citation(s) in RCA: 22] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/20/2018] [Revised: 05/14/2018] [Accepted: 05/15/2018] [Indexed: 12/30/2022] Open
Abstract
Carbamylation is a post-translational modification of proteins that may partake in the oxidative stress-associated cell damage, and its increment has been recently proposed as a “hallmark of aging”. The molecular mechanisms associated with aging are related to an increased release of free radicals. We have studied whether carbamylated proteins from the peripheral blood of healthy subjects are related to oxidative damage and aging, taking into account the gender and the immune profile of the subjects. The study was performed in healthy human volunteers. The detection of protein carbamylation and malondialdehyde (MDA) levels was evaluated using commercial kits. The immune profile was calculated using parameters of immune cell function. The results show that the individuals from the elderly group (60–79 years old) have increased carbamylated protein and MDA levels. When considered by gender, only men between 60 and 79 years old showed significantly increased carbamylated proteins and MDA levels. When those subjects were classified by their immune profile, the carbamylated protein levels were higher in those with an older immune profile. In conclusion, the carbamylation of proteins in peripheral blood is related to age-associated oxidative damage and to an aging functional immunological signature. Our results suggest that carbamylated proteins may play an important role at the cellular level in the aging process.
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Affiliation(s)
- Julia Carracedo
- Department of Genetics, Physiology, and Microbiology, Faculty of Biology, Complutense University/Instituto de Investigación Sanitaria Hospital 12 de Octubre (imas12), 28040 Madrid, Spain.
| | - Rafael Ramírez-Carracedo
- Cardiovascular Joint Research Unit, Francisco de Vitoria University/Hospital Ramon y Cajal Research Unit (IRYCIS), 28223 Madrid, Spain.
| | - Irene Martínez de Toda
- Department of Genetics, Physiology, and Microbiology, Faculty of Biology, Complutense University/Instituto de Investigación Sanitaria Hospital 12 de Octubre (imas12), 28040 Madrid, Spain.
| | - Carmen Vida
- Department of Genetics, Physiology, and Microbiology, Faculty of Biology, Complutense University/Instituto de Investigación Sanitaria Hospital 12 de Octubre (imas12), 28040 Madrid, Spain.
| | - Matilde Alique
- Biology Systems Department, Physiology, Alcala University, Alcala de Henares, 28805 Madrid, Spain.
| | - Mónica De la Fuente
- Department of Genetics, Physiology, and Microbiology, Faculty of Biology, Complutense University/Instituto de Investigación Sanitaria Hospital 12 de Octubre (imas12), 28040 Madrid, Spain.
| | - Rafael Ramírez-Chamond
- Biology Systems Department, Physiology, Alcala University, Alcala de Henares, 28805 Madrid, Spain.
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Skulachev VP, Holtze S, Vyssokikh MY, Bakeeva LE, Skulachev MV, Markov AV, Hildebrandt TB, Sadovnichii VA. Neoteny, Prolongation of Youth: From Naked Mole Rats to “Naked Apes” (Humans). Physiol Rev 2017; 97:699-720. [DOI: 10.1152/physrev.00040.2015] [Citation(s) in RCA: 81] [Impact Index Per Article: 11.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/17/2022] Open
Abstract
It has been suggested that highly social mammals, such as naked mole rats and humans, are long-lived due to neoteny (the prolongation of youth). In both species, aging cannot operate as a mechanism facilitating natural selection because the pressure of this selection is strongly reduced due to 1) a specific social structure where only the “queen” and her “husband(s)” are involved in reproduction (naked mole rats) or 2) substituting fast technological progress for slow biological evolution (humans). Lists of numerous traits of youth that do not disappear with age in naked mole rats and humans are presented and discussed. A high resistance of naked mole rats to cancer, diabetes, cardiovascular and brain diseases, and many infections explains why their mortality rate is very low and almost age-independent and why their lifespan is more than 30 years, versus 3 years in mice. In young humans, curves of mortality versus age start at extremely low values. However, in the elderly, human mortality strongly increases. High mortality rates in other primates are observed at much younger ages than in humans. The inhibition of the aging process in humans by specific drugs seems to be a promising approach to prolong our healthspan. This might be a way to retard aging, which is already partially accomplished via the natural physiological phenomenon neoteny.
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Affiliation(s)
- Vladimir P. Skulachev
- Lomonosov Moscow State University, Belozersky Institute of Physico-Chemical Biology, Moscow, Russia; Lomonosov Moscow State University, Institute of Mitoengineering, Moscow, Russia; Leibniz Institute for Zoo and Wildlife Research, Berlin, Germany; Lomonosov Moscow State University, Biological Faculty, Moscow, Russia; Lomonosov Moscow State University, Faculty of Mechanics and Mathematics, Moscow, Russia
| | - Susanne Holtze
- Lomonosov Moscow State University, Belozersky Institute of Physico-Chemical Biology, Moscow, Russia; Lomonosov Moscow State University, Institute of Mitoengineering, Moscow, Russia; Leibniz Institute for Zoo and Wildlife Research, Berlin, Germany; Lomonosov Moscow State University, Biological Faculty, Moscow, Russia; Lomonosov Moscow State University, Faculty of Mechanics and Mathematics, Moscow, Russia
| | - Mikhail Y. Vyssokikh
- Lomonosov Moscow State University, Belozersky Institute of Physico-Chemical Biology, Moscow, Russia; Lomonosov Moscow State University, Institute of Mitoengineering, Moscow, Russia; Leibniz Institute for Zoo and Wildlife Research, Berlin, Germany; Lomonosov Moscow State University, Biological Faculty, Moscow, Russia; Lomonosov Moscow State University, Faculty of Mechanics and Mathematics, Moscow, Russia
| | - Lora E. Bakeeva
- Lomonosov Moscow State University, Belozersky Institute of Physico-Chemical Biology, Moscow, Russia; Lomonosov Moscow State University, Institute of Mitoengineering, Moscow, Russia; Leibniz Institute for Zoo and Wildlife Research, Berlin, Germany; Lomonosov Moscow State University, Biological Faculty, Moscow, Russia; Lomonosov Moscow State University, Faculty of Mechanics and Mathematics, Moscow, Russia
| | - Maxim V. Skulachev
- Lomonosov Moscow State University, Belozersky Institute of Physico-Chemical Biology, Moscow, Russia; Lomonosov Moscow State University, Institute of Mitoengineering, Moscow, Russia; Leibniz Institute for Zoo and Wildlife Research, Berlin, Germany; Lomonosov Moscow State University, Biological Faculty, Moscow, Russia; Lomonosov Moscow State University, Faculty of Mechanics and Mathematics, Moscow, Russia
| | - Alexander V. Markov
- Lomonosov Moscow State University, Belozersky Institute of Physico-Chemical Biology, Moscow, Russia; Lomonosov Moscow State University, Institute of Mitoengineering, Moscow, Russia; Leibniz Institute for Zoo and Wildlife Research, Berlin, Germany; Lomonosov Moscow State University, Biological Faculty, Moscow, Russia; Lomonosov Moscow State University, Faculty of Mechanics and Mathematics, Moscow, Russia
| | - Thomas B. Hildebrandt
- Lomonosov Moscow State University, Belozersky Institute of Physico-Chemical Biology, Moscow, Russia; Lomonosov Moscow State University, Institute of Mitoengineering, Moscow, Russia; Leibniz Institute for Zoo and Wildlife Research, Berlin, Germany; Lomonosov Moscow State University, Biological Faculty, Moscow, Russia; Lomonosov Moscow State University, Faculty of Mechanics and Mathematics, Moscow, Russia
| | - Viktor A. Sadovnichii
- Lomonosov Moscow State University, Belozersky Institute of Physico-Chemical Biology, Moscow, Russia; Lomonosov Moscow State University, Institute of Mitoengineering, Moscow, Russia; Leibniz Institute for Zoo and Wildlife Research, Berlin, Germany; Lomonosov Moscow State University, Biological Faculty, Moscow, Russia; Lomonosov Moscow State University, Faculty of Mechanics and Mathematics, Moscow, Russia
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13
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Ott C, König J, Höhn A, Jung T, Grune T. Reduced autophagy leads to an impaired ferritin turnover in senescent fibroblasts. Free Radic Biol Med 2016; 101:325-333. [PMID: 27789294 DOI: 10.1016/j.freeradbiomed.2016.10.492] [Citation(s) in RCA: 26] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/23/2016] [Revised: 10/12/2016] [Accepted: 10/20/2016] [Indexed: 01/18/2023]
Abstract
Changes in the two main intracellular degradation systems, the Ubiquitin-Proteasome System and the Autophagy-Lysosome pathway (ALP) are widely discussed as a hallmark of the aging process. To follow the age-related behavior of both degradation systems we examined their impact on ferritin, known to be degradable by both. Ferritin H was analyzed in young and senescent human fibroblasts, revealing a higher steady-state level in the senescent cells. By blocking both proteolytic systems, we confirmed that particularly the ALP plays a crucial role in ferritin H turnover. However, an unexpected increase in lysosomal activity in the senescent cells, suggests a dysregulation in the autophagy pathway. To further investigate the impaired ferritin H turnover, confocal microscopic colocalization studies of ferritin H with lysosomal-associated membrane protein 2a (Lamp2a) and monodansylcadaverine (MDC) were performed and clearly revealed the degradation of ferritin by macroautophagy. By induction of autophagy via inhibition of mTOR using rapamycin an increase of ferritin H turnover was obtained in senescent cells, demonstrating a mTOR dependent reduction of autophagy in senescent human fibroblasts.
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Affiliation(s)
- Christiane Ott
- Department of Molecular Toxicology, German Institute of Human Nutrition, Potsdam-Rehbruecke, Germany.
| | - Jeannette König
- Department of Molecular Toxicology, German Institute of Human Nutrition, Potsdam-Rehbruecke, Germany.
| | - Annika Höhn
- Department of Molecular Toxicology, German Institute of Human Nutrition, Potsdam-Rehbruecke, Germany; German Center for Diabetes Research (DZD), 85764 München-Neuherberg, Germany.
| | - Tobias Jung
- Department of Molecular Toxicology, German Institute of Human Nutrition, Potsdam-Rehbruecke, Germany; German Center for Cardiovascular Research (DZHK), 10117 Berlin, Germany.
| | - Tilman Grune
- Department of Molecular Toxicology, German Institute of Human Nutrition, Potsdam-Rehbruecke, Germany; German Center for Diabetes Research (DZD), 85764 München-Neuherberg, Germany; German Center for Cardiovascular Research (DZHK), 10117 Berlin, Germany.
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14
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Roberts JH, Liu F, Karnuta JM, Fitzgerald MC. Discovery of Age-Related Protein Folding Stability Differences in the Mouse Brain Proteome. J Proteome Res 2016; 15:4731-4741. [PMID: 27806573 DOI: 10.1021/acs.jproteome.6b00927] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
Abstract
Described here is the application of thermodynamic stability measurements to study age-related differences in the folding and stability of proteins in a rodent model of aging. Thermodynamic stability profiles were generated for 809 proteins in brain cell lysates from mice, aged 6 (n = 7) and 18 months (n = 9) using the Stability of Proteins from Rates of Oxidation (SPROX) technique. The biological variability of the protein stability measurements was low and within the experimental error of SPROX. A total of 83 protein hits were detected with age-related stability differences in the brain samples. Remarkably, the large majority of the brain protein hits were destabilized in the old mice, and the hits were enriched in proteins that have slow turnover rates (p < 0.07). Furthermore, 70% of the hits have been previously linked to aging or age-related diseases. These results help validate the use of thermodynamic stability measurements to capture relevant age-related proteomic changes and establish a new biophysical link between these proteins and aging.
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Affiliation(s)
- Julia H Roberts
- Department of Chemistry, Duke University , Durham, North Carolina 27708, United States
| | - Fang Liu
- Department of Chemistry, Duke University , Durham, North Carolina 27708, United States
| | - Jaret M Karnuta
- Department of Chemistry, Duke University , Durham, North Carolina 27708, United States
| | - Michael C Fitzgerald
- Department of Chemistry, Duke University , Durham, North Carolina 27708, United States
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15
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Abstract
The field of engineering has made substantial strides in nanotechnology, in the realm of materials science and construction of nanoscale devices. Nanomedicine encompasses application of cutting edge engineered nanostructures to biological systems and development of novel strategies for disease intervention. In the current review, we discuss the pharmacological application of nanoparticles as free radical scavengers and the capacity of nanoparticles to promote cell and organismal longevity.
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Affiliation(s)
- Beverly A Rzigalinski
- Virginia College of Osteopathic Medicine and Virginia Polytechnic and State University, Department of Pharmacology, Blacksburg, 24060, USA.
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16
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Essential role of proteasomes in maintaining self-renewal in neural progenitor cells. Sci Rep 2016; 6:19752. [PMID: 26804982 PMCID: PMC4726439 DOI: 10.1038/srep19752] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/14/2015] [Accepted: 12/17/2015] [Indexed: 11/29/2022] Open
Abstract
Protein turnover and homeostasis are regulated by the proteasomal system, which is critical for cell function and viability. Pluripotency of stem cells also relies on normal proteasomal activity that mitigates senescent phenotypes induced by intensive cell replications, as previously demonstrated in human bone marrow stromal cells. In this study, we investigated the role of proteasomes in self-renewal of neural progenitor cells (NPCs). Through both in vivo and in vitro analyses, we found that the expression of proteasomes was progressively decreased during aging. Likewise, proliferation and self-renewal of NPCs were also impaired in aged mice, suggesting that the down-regulation of proteasomes might be responsible for this senescent phenotype. Lowering proteasomal activity by loss-of-function manipulations mimicked the senescence of NPCs both in vitro and in vivo; conversely, enhancing proteasomal activity restored and improved self-renewal in aged NPCs. These results collectively indicate that proteasomes work as a key regulator in promoting self-renewal of NPCs. This potentially provides a promising therapeutic target for age-dependent neurodegenerative diseases.
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17
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Kodavanti PRS, Royland JE, Moore-Smith DA, Besas J, Richards JE, Beasley TE, Evansky P, Bushnell PJ. Acute and subchronic toxicity of inhaled toluene in male Long-Evans rats: Oxidative stress markers in brain. Neurotoxicology 2015; 51:10-9. [PMID: 26343380 DOI: 10.1016/j.neuro.2015.09.001] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/18/2015] [Revised: 08/31/2015] [Accepted: 09/01/2015] [Indexed: 10/23/2022]
Abstract
The effects of exposure to volatile organic compounds (VOCs), which are of concern to the EPA, are poorly understood, in part because of insufficient characterization of how human exposure duration impacts VOC effects. Two inhalation studies with multiple endpoints, one acute and one subchronic, were conducted to seek effects of the VOC, toluene, in rats and to compare the effects between acute and subchronic exposures. Adult male Long-Evans rats were exposed to toluene vapor (n=6 per group) at a concentration of 0 or 1019 ± 14 ppm for 6h in the acute study and at 0 ± 0, 10 ± 1.4, 97 ± 7, or 995 ± 43 ppm for 6h/d, 5d/week for 13 weeks in the subchronic study. For the acute study, brains were dissected on ice within 30 min of the end of exposure, while for the subchronic study, brains were dissected 18 h after the last exposure. Frontal cortex, hippocampus, cerebellum, and striatum were assayed for a variety of oxidative stress (OS) parameters including total aconitase (TA), protein carbonyls, glutathione peroxidase (GPX), glutathione reductase (GRD), glutathione transferase (GST), γ-glutamylcysteine synthetase (GCS), superoxide dismutase (SOD), total antioxidants (TAS), NADPH quinone oxidoreductase-1 (NQO1), and NADH ubiquinone reductase (UBIQ-RD) activities using commercially available kits. Following acute exposure, UBIQ-RD, GCS and GRD were increased significantly only in the cerebellum, while TAS was increased in frontal cortex. On the other hand, subchronic exposure affected several OS markers including increases in NQO1 and UBIQ-RD. The effect of subchronic toluene exposure on SOD and TAS was greater in the striatum than in the other brain regions. TA activity (involved in maintaining iron homeostasis and an indicator of DNA damage) was inhibited in striatum and cerebellum, increased in hippocampus, and unchanged in frontal cortex. Protein carbonyls increased significantly in both the frontal cortex and cerebellum. In general, the results showed that acute exposure to toluene affected OS parameters to a lesser extent than did subchronic exposure. These results suggest that toluene exposure induces OS in the brain and this may be a component of an adverse outcome pathway for some of the neurotoxic effects reported following toluene exposure.
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Affiliation(s)
- Prasada Rao S Kodavanti
- Neurotoxicology Branch, NHEERL, ORD, U.S. Environmental Protection Agency, Research Triangle Park, NC, USA.
| | - Joyce E Royland
- Genetic and Cellular Toxicology Branch, NHEERL, ORD, U.S. Environmental Protection Agency, Research Triangle Park, NC, USA
| | - Debra A Moore-Smith
- Neurotoxicology Branch, NHEERL, ORD, U.S. Environmental Protection Agency, Research Triangle Park, NC, USA
| | - Jonathan Besas
- Neurotoxicology Branch, NHEERL, ORD, U.S. Environmental Protection Agency, Research Triangle Park, NC, USA
| | - Judy E Richards
- Cardiopulmonary and Immunotoxicology Branch, NHEERL, ORD, U.S. Environmental Protection Agency, Research Triangle Park, NC, USA
| | - Tracey E Beasley
- Neurotoxicology Branch, NHEERL, ORD, U.S. Environmental Protection Agency, Research Triangle Park, NC, USA
| | - Paul Evansky
- Inhalation Toxicology Facility, NHEERL, ORD, U.S. Environmental Protection Agency, Research Triangle Park, NC, USA
| | - Philip J Bushnell
- Neurotoxicology Branch, NHEERL, ORD, U.S. Environmental Protection Agency, Research Triangle Park, NC, USA
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Chakraborty J, Rajamma U, Jana N, Mohanakumar K. Quercetin improves the activity of the ubiquitin-proteasomal system in 150Q mutated huntingtin-expressing cells but exerts detrimental effects on neuronal survivability. J Neurosci Res 2015; 93:1581-91. [DOI: 10.1002/jnr.23618] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/05/2014] [Revised: 06/02/2015] [Accepted: 06/19/2015] [Indexed: 12/20/2022]
Affiliation(s)
- J. Chakraborty
- Division of Cell Biology and Physiology; Laboratory of Clinical and Experimental Neuroscience, CSIR-Indian Institute of Chemical Biology; Kolkata India
| | - U. Rajamma
- Manovikas Biomedical Research and Diagnostic Centre; Kolkata India
| | - N. Jana
- National Brain Research Centre; Gurgaon Haryana India
| | - K.P. Mohanakumar
- Division of Cell Biology and Physiology; Laboratory of Clinical and Experimental Neuroscience, CSIR-Indian Institute of Chemical Biology; Kolkata India
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19
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Achilli C, Ciana A, Minetti G. The discovery of methionine sulfoxide reductase enzymes: An historical account and future perspectives. Biofactors 2015; 41:135-52. [PMID: 25963551 DOI: 10.1002/biof.1214] [Citation(s) in RCA: 54] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 02/23/2015] [Accepted: 04/19/2015] [Indexed: 01/26/2023]
Abstract
L-Methionine (L-Met) is the only sulphur-containing proteinogenic amino acid together with cysteine. Its importance is highlighted by it being the initiator amino acid for protein synthesis in all known living organisms. L-Met, free or inserted into proteins, is sensitive to oxidation of its sulfide moiety, with formation of L-Met sulfoxide. The sulfoxide could not be inserted into proteins, and the oxidation of L-Met in proteins often leads to the loss of biological activity of the affected molecule. Key discoveries revealed the existence, in rats, of a metabolic pathway for the reduction of free L-Met sulfoxide and, later, in Escherichia coli, of the enzymatic reduction of L-Met sulfoxide inserted in proteins. Upon oxidation, the sulphur atom becomes a new stereogenic center, and two stable diastereoisomers of L-Met sulfoxide exist. A fundamental discovery revealed the existence of two unrelated families of enzymes, MsrA and MsrB, whose members display opposite stereospecificity of reduction for the two sulfoxides. The importance of Msrs is additionally emphasized by the discovery that one of the only 25 selenoproteins expressed in humans is a Msr. The milestones on the road that led to the discovery and characterization of this group of antioxidant enzymes are recounted in this review.
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Affiliation(s)
- Cesare Achilli
- Laboratories of Biochemistry, Department of Biology and Biotechnology, University of Pavia, Pavia, Italy
| | - Annarita Ciana
- Laboratories of Biochemistry, Department of Biology and Biotechnology, University of Pavia, Pavia, Italy
| | - Giampaolo Minetti
- Laboratories of Biochemistry, Department of Biology and Biotechnology, University of Pavia, Pavia, Italy
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20
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Choi SI, Maeng YS, Kim TI, Lee Y, Kim YS, Kim EK. Lysosomal trafficking of TGFBIp via caveolae-mediated endocytosis. PLoS One 2015; 10:e0119561. [PMID: 25853243 PMCID: PMC4390356 DOI: 10.1371/journal.pone.0119561] [Citation(s) in RCA: 23] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/06/2014] [Accepted: 01/10/2015] [Indexed: 11/18/2022] Open
Abstract
Transforming growth factor-beta-induced protein (TGFBIp) is ubiquitously expressed in the extracellular matrix (ECM) of various tissues and cell lines. Progressive accumulation of mutant TGFBIp is directly involved in the pathogenesis of TGFBI-linked corneal dystrophy. Recent studies reported that mutant TGFBIp accumulates in cells; however, the trafficking of TGFBIp is poorly understood. Therefore, we investigated TGFBIp trafficking to determine the route of its internalization and secretion and to elucidate its roles in the pathogenesis of granular corneal dystrophy type 2 (GCD2). Our data indicate that newly synthesized TGFBIp was secreted via the endoplasmic reticulum/Golgi-dependent secretory pathway, and this secretion was delayed in the corneal fibroblasts of patients with GCD2. We also found that TGFBIp was internalized by caveolae-mediated endocytosis, and the internalized TGFBIp accumulated after treatment with bafilomycin A1, an inhibitor of lysosomal degradation. In addition, the proteasome inhibitor MG132 inhibits the endocytosis of TGFBIp. Co-immunoprecipitation revealed that TGFBIp interacted with integrin αVβ3. Moreover, treatment with arginine-glycine-aspartic acid (RGD) tripeptide suppressed the internalization of TGFBIp. These insights on TGFBIp trafficking could lead to the identification of novel targets and the development of new therapies for TGFBI-linked corneal dystrophy.
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Affiliation(s)
- Seung-il Choi
- Department of Ophthalmology, Corneal Dystrophy Research Institute, Yonsei University College of Medicine, Seoul, South Korea
| | - Yong-Sun Maeng
- Department of Ophthalmology, Corneal Dystrophy Research Institute, Yonsei University College of Medicine, Seoul, South Korea
| | - Tae-im Kim
- Department of Ophthalmology, Corneal Dystrophy Research Institute, Yonsei University College of Medicine, Seoul, South Korea
- Institute of Vision Research, Severance Biomedical Science Institute, Brain Korea 21 Plus Project for Medical Science, Yonsei University College of Medicine, Seoul, South Korea
| | - Yangsin Lee
- Department of Integrated Omics for Biomedical Science, Graduate School, Yonsei University, Seoul, South Korea
| | - Yong-Sun Kim
- Ilsong Institute of Life Science, Hallym University, Anyang, South Korea
- Department of Microbiology, College of Medicine, Hallym University, Chuncheon, South Korea
| | - Eung Kweon Kim
- Department of Ophthalmology, Corneal Dystrophy Research Institute, Yonsei University College of Medicine, Seoul, South Korea
- Institute of Vision Research, Severance Biomedical Science Institute, Brain Korea 21 Plus Project for Medical Science, Yonsei University College of Medicine, Seoul, South Korea
- * E-mail:
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21
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Bozaykut P, Ozer NK, Karademir B. Regulation of protein turnover by heat shock proteins. Free Radic Biol Med 2014; 77:195-209. [PMID: 25236750 DOI: 10.1016/j.freeradbiomed.2014.08.012] [Citation(s) in RCA: 66] [Impact Index Per Article: 6.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 02/25/2014] [Revised: 08/11/2014] [Accepted: 08/11/2014] [Indexed: 12/19/2022]
Abstract
Protein turnover reflects the balance between synthesis and degradation of proteins, and it is a crucial process for the maintenance of the cellular protein pool. The folding of proteins, refolding of misfolded proteins, and also degradation of misfolded and damaged proteins are involved in the protein quality control (PQC) system. Correct protein folding and degradation are controlled by many different factors, one of the most important of which is the heat shock protein family. Heat shock proteins (HSPs) are in the class of molecular chaperones, which may prevent the inappropriate interaction of proteins and induce correct folding. On the other hand, these proteins play significant roles in the degradation pathways, including endoplasmic reticulum-associated degradation (ERAD), the ubiquitin-proteasome system, and autophagy. This review focuses on the emerging role of HSPs in the regulation of protein turnover; the effects of HSPs on the degradation machineries ERAD, autophagy, and proteasome; as well as the role of posttranslational modifications in the PQC system.
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Affiliation(s)
- Perinur Bozaykut
- Genetic and Metabolic Diseases Research and Investigation Center, Department of Biochemistry, Faculty of Medicine, Marmara University, 34854 Maltepe, Istanbul, Turkey
| | - Nesrin Kartal Ozer
- Genetic and Metabolic Diseases Research and Investigation Center, Department of Biochemistry, Faculty of Medicine, Marmara University, 34854 Maltepe, Istanbul, Turkey
| | - Betul Karademir
- Genetic and Metabolic Diseases Research and Investigation Center, Department of Biochemistry, Faculty of Medicine, Marmara University, 34854 Maltepe, Istanbul, Turkey.
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22
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Methylation of histone H4 at aspartate 24 by protein L-isoaspartate O-methyltransferase (PCMT1) links histone modifications with protein homeostasis. Sci Rep 2014; 4:6674. [PMID: 25327473 PMCID: PMC4202215 DOI: 10.1038/srep06674] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/01/2014] [Accepted: 09/16/2014] [Indexed: 11/08/2022] Open
Abstract
Histone modifications play crucial roles in modulating chromatin function and transcriptional activity. Due to their long half-life, histones can, in addition to post-translational modifications, also accumulate spontaneous chemical alterations, which can affect their functionality and require either protein repair or degradation. One of the major sources of such protein damage or ageing is the conversion of aspartate into isoaspartate residues that can then be methylated. Here, we characterize a novel histone modification, the methylation of histone H4 at aspartate 24 (H4D24me). We generated H4D24me specific antibodies and showed that H4D24me is ubiquitously present in different mouse and human cells. Our in vitro and in vivo data identified PCMT1 (Protein L-isoaspartate O-methyltransferase), an enzyme involved in protein repair, as a novel H4D24 specific histone methyltransferase. Furthermore, we demonstrated that VprBP (HIV-1 viral protein R (Vpr)-binding protein), a chromo domain-containing protein, specifically recognizes H4D24me potentially implicating H4D24me in H4 degradation. Thus, this work links for the first time a histone modification with histone protein aging and histone homeostasis, suggesting novel functions for histone modifications beyond transcriptional regulation.
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23
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Skulachev MV, Skulachev VP. New data on programmed aging — slow phenoptosis. BIOCHEMISTRY (MOSCOW) 2014; 79:977-93. [DOI: 10.1134/s0006297914100010] [Citation(s) in RCA: 29] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/24/2022]
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24
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Leak RK. Heat shock proteins in neurodegenerative disorders and aging. J Cell Commun Signal 2014; 8:293-310. [PMID: 25208934 DOI: 10.1007/s12079-014-0243-9] [Citation(s) in RCA: 113] [Impact Index Per Article: 11.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/19/2014] [Accepted: 09/01/2014] [Indexed: 12/20/2022] Open
Abstract
Many members of the heat shock protein family act in unison to refold or degrade misfolded proteins. Some heat shock proteins also directly interfere with apoptosis. These homeostatic functions are especially important in proteinopathic neurodegenerative diseases, in which specific proteins misfold, aggregate, and kill cells through proteotoxic stress. Heat shock protein levels may be increased or decreased in these disorders, with the direction of the response depending on the individual heat shock protein, the disease, cell type, and brain region. Aging is also associated with an accrual of proteotoxic stress and modulates expression of several heat shock proteins. We speculate that the increase in some heat shock proteins in neurodegenerative conditions may be partly responsible for the slow progression of these disorders, whereas the increase in some heat shock proteins with aging may help delay senescence. The protective nature of many heat shock proteins in experimental models of neurodegeneration supports these hypotheses. Furthermore, some heat shock proteins appear to be expressed at higher levels in longer-lived species. However, increases in heat shock proteins may be insufficient to override overwhelming proteotoxic stress or reverse the course of these conditions, because the expression of several other heat shock proteins and endogenous defense systems is lowered. In this review we describe a number of stress-induced changes in heat shock proteins as a function of age and neurodegenerative pathology, with an emphasis on the heat shock protein 70 (Hsp70) family and the two most common proteinopathic disorders of the brain, Alzheimer's and Parkinson's disease.
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Affiliation(s)
- Rehana K Leak
- Division of Pharmaceutical Sciences, Duquesne University, 600 Forbes Ave, Pittsburgh, PA, 15282, USA,
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25
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Abstract
The activity of the ubiquitin-proteasome system, UPS, declines during aging in several multicellular organisms. The reason behind this decline remains elusive. Here, using yeast as a model system, we show that while the level and potential capacity of the 26S proteasome is maintained in replicatively aged cells, the UPS is not functioning properly in vivo. As a consequence cytosolic UPS substrates, such as ΔssCPY* are stabilized, accumulate, and form inclusions. By integrating a pGPD-HSP104 recombinant gene into the genome, we were able to constitutively elevate protein disaggregase activity, which diminished the accumulation of protein inclusions during aging. Remarkably, this elevated disaggregation restored degradation of a 26S proteasome substrate in aged cells without elevating proteasome levels, demonstrating that age-associated aggregation obstructs UPS function. The data supports the existence of a negative feedback loop that accelerates aging by exacerbating proteostatic decline once misfolded and aggregation-prone proteins reach a critical level.
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26
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Dasuri K, Zhang L, Keller JN. Oxidative stress, neurodegeneration, and the balance of protein degradation and protein synthesis. Free Radic Biol Med 2013; 62:170-185. [PMID: 23000246 DOI: 10.1016/j.freeradbiomed.2012.09.016] [Citation(s) in RCA: 257] [Impact Index Per Article: 23.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/01/2012] [Revised: 09/05/2012] [Accepted: 09/11/2012] [Indexed: 12/12/2022]
Abstract
Oxidative stress occurs in a variety of disease settings and is strongly linked to the development of neuron death and neuronal dysfunction. Cells are equipped with numerous pathways to prevent the genesis, as well as the consequences, of oxidative stress in the brain. In this review we discuss the various forms and sources of oxidative stress in the brain and briefly discuss some of the complexities in detecting the presence of oxidative stress. We then focus the review on the interplay between the diverse cellular proteolytic pathways and their roles in regulating oxidative stress in the brain. Additionally, we discuss the involvement of protein synthesis in regulating the downstream effects of oxidative stress. Together, these components of the review demonstrate that the removal of damaged proteins by effective proteolysis and the synthesis of new and protective proteins are vital in the preservation of brain homeostasis during periods of increased levels of reactive oxygen species. Last, studies from our laboratory and others have demonstrated that protein synthesis is intricately linked to the rates of protein degradation, with impairment of protein degradation sufficient to decrease the rates of protein synthesis, which has important implications for successfully responding to periods of oxidative stress. Specific neurodegenerative diseases, including Alzheimer disease, Parkinson disease, amyotrophic lateral sclerosis, and stroke, are discussed in this context. Taken together, these findings add to our understanding of how oxidative stress is effectively managed in the healthy brain and help elucidate how impairments in proteolysis and/or protein synthesis contribute to the development of neurodegeneration and neuronal dysfunction in a variety of clinical settings.
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Affiliation(s)
- Kalavathi Dasuri
- Pennington Biomedical Research Center, Baton Rouge, LA 70808, USA
| | - Le Zhang
- Pennington Biomedical Research Center, Baton Rouge, LA 70808, USA
| | - Jeffrey N Keller
- Pennington Biomedical Research Center, Baton Rouge, LA 70808, USA.
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27
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Baraibar MA, Gueugneau M, Duguez S, Butler-Browne G, Bechet D, Friguet B. Expression and modification proteomics during skeletal muscle ageing. Biogerontology 2013; 14:339-52. [PMID: 23624703 DOI: 10.1007/s10522-013-9426-7] [Citation(s) in RCA: 39] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/08/2013] [Accepted: 04/17/2013] [Indexed: 12/17/2022]
Abstract
Skeletal muscle ageing is characterized by a progressive and dramatic loss of muscle mass and strength leading to decreased muscular function resulting in muscle weakness which is often referred to as sarcopenia. Following the standardisation of "omics" approaches to study the genome (genomics) and the transcriptome (transcriptomics), the study of the proteins encoded by the genome, referred to as proteomics, is a tremendous challenge. Unlike the genome, the proteome varies in response to many physiological or pathological factors. In addition, the proteome is orders of magnitude more complex than the transcriptome due to post-translational modifications, protein oxidation and limited protein degradation. Proteomic studies, including the analysis of protein abundance as well as post-translational modified proteins have been shown to provide valuable information to unravel the key molecular pathways implicated in complex biological processes, such as tissue and organ ageing. In this article, we will describe proteomic approaches for the analysis of protein abundance as well as the specific protein targets for oxidative damage upon oxidative stress and/or during skeletal muscle ageing.
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Affiliation(s)
- Martin A Baraibar
- Laboratoire de Biologie Cellulaire du Vieillissement, UR4, UPMC Paris 6 University, 4 place Jussieu, 75252, Paris Cedex 05, France
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28
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Bansode SB, Chougale AD, Joshi RS, Giri AP, Bodhankar SL, Harsulkar AM, Kulkarni MJ. Proteomic analysis of protease resistant proteins in the diabetic rat kidney. Mol Cell Proteomics 2012; 12:228-36. [PMID: 23118466 DOI: 10.1074/mcp.m112.020651] [Citation(s) in RCA: 27] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022] Open
Abstract
Glycation induced protein aggregation has been implicated in the development of diabetic complications and neurodegenerative diseases. These aggregates are known to be resistant to proteolytic digestion. Here we report the identification of protease resistant proteins from the streptozotocin induced diabetic rat kidney, which included enzymes in glucose metabolism and stress response proteins. These protease resistant proteins were characterized to be advanced glycation end products modified and ubiquitinated by immunological and mass spectrometry analysis. Further, diabetic rat kidney exhibited significantly impaired proteasomal activity. The functional analysis of identified physiologically important enzymes showed that their activity was reduced in diabetic condition. Loss of functional activity of these proteins was compensated by enhanced gene expression. Aggregation prone regions were predicted by in silico analysis and compared with advanced glycation end products modification sites. These findings suggested that the accumulation of protein aggregates is an inevitable consequence of impaired proteasomal activity and protease resistance due to advanced glycation end products modification.
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Affiliation(s)
- Sneha B Bansode
- Proteomics Facility, Division of Biochemical Sciences, CSIR-National Chemical Laboratory, Pune-411008, India
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Kästle M, Reeg S, Rogowska-Wrzesinska A, Grune T. Chaperones, but not oxidized proteins, are ubiquitinated after oxidative stress. Free Radic Biol Med 2012; 53:1468-77. [PMID: 22683819 DOI: 10.1016/j.freeradbiomed.2012.05.039] [Citation(s) in RCA: 37] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 02/09/2012] [Revised: 04/17/2012] [Accepted: 05/24/2012] [Indexed: 01/05/2023]
Abstract
After oxidative stress, proteins that are oxidatively modified are degraded by the 20S proteasome. However, several studies have documented an enhanced ubiquitination of yet unknown proteins. Because ubiquitination is a prerequisite for degradation by the 26S proteasome in an ATP-dependent manner this raises the question whether these proteins are also oxidized and, if not, what proteins need to be ubiquitinated and degraded after oxidative conditions. By determination of oxidized and ubiquitinated proteins we demonstrate here that most oxidized proteins are not preferentially ubiquitinated. However, we were able to confirm an increase in ubiquitinated proteins 16 h after oxidative stress. Therefore, we isolated ubiquitinated proteins from hydrogen peroxide-treated cells, as well as from control cells and cells treated with lactacystin, an irreversible proteasome inhibitor, and identified some of these proteins by MALDI tandem mass spectrometry. As a result we obtained 24 different proteins that can be categorized into the following groups: chaperones, energy metabolism, cytoskeleton/intermediate filaments, and protein translation/ribosome biogenesis. The special set of identified, ubiquitinated proteins confirms the thesis that ubiquitination upon oxidative stress is not a random process to degrade the mass of oxidized proteins, but concerns a special group of functional proteins.
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Affiliation(s)
- Marc Kästle
- Department of Nutritional Toxicology, Institute of Nutrition, Friedrich-Schiller University Jena, 07743 Jena, Germany
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Abstract
Ageing leads to a functional deterioration of many brain systems, including the circadian clock--an internal time-keeping system that generates ∼24-hour rhythms in physiology and behaviour. Numerous clinical studies have established a direct correlation between abnormal circadian clock functions and the severity of neurodegenerative and sleep disorders. Latest data from experiments in model organisms, gene expression studies and clinical trials imply that dysfunctions of the circadian clock contribute to ageing and age-associated pathologies, thereby suggesting a functional link between the circadian clock and age-associated decline of brain functions. Potential molecular mechanisms underlying this link include the circadian control of physiological processes such as brain metabolism, reactive oxygen species homeostasis, hormone secretion, autophagy and stem cell proliferation.
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Changes of the Proteasomal System During the Aging Process. PROGRESS IN MOLECULAR BIOLOGY AND TRANSLATIONAL SCIENCE 2012; 109:249-75. [DOI: 10.1016/b978-0-12-397863-9.00007-9] [Citation(s) in RCA: 51] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/21/2023]
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Abstract
The ubiquitin-proteasomal system is an essential element of the protein quality control machinery in cells. The central part of this system is the 20S proteasome. The proteasome is a barrel-shaped multienzyme complex, containing several active centers hidden at the inner surface of the hollow cylinder. So, the regulation of the substrate entry toward the inner proteasomal surface is a key control mechanism of the activity of this protease. This chapter outlines the knowledge on the structure of the subunits of the 20S proteasome, the binding and structure of some proteasomal regulators and inducible proteasomal subunits. Therefore, this chapter imparts the knowledge on proteasomal structure which is required for the understanding of the following chapters.
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Powell SR, Herrmann J, Lerman A, Patterson C, Wang X. The ubiquitin-proteasome system and cardiovascular disease. PROGRESS IN MOLECULAR BIOLOGY AND TRANSLATIONAL SCIENCE 2012; 109:295-346. [PMID: 22727426 DOI: 10.1016/b978-0-12-397863-9.00009-2] [Citation(s) in RCA: 70] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/14/2022]
Abstract
Over the past decade, the role of the ubiquitin-proteasome system (UPS) has been the subject of numerous studies to elucidate its role in cardiovascular physiology and pathophysiology. There have been many advances in this field including the use of proteomics to achieve a better understanding of how the cardiac proteasome is regulated. Moreover, improved methods for the assessment of UPS function and the development of genetic models to study the role of the UPS have led to the realization that often the function of this system deviates from the norm in many cardiovascular pathologies. Hence, dysfunction has been described in atherosclerosis, familial cardiac proteinopathies, idiopathic dilated cardiomyopathies, and myocardial ischemia. This has led to numerous studies of the ubiquitin protein (E3) ligases and their roles in cardiac physiology and pathophysiology. This has also led to the controversial proposition of treating atherosclerosis, cardiac hypertrophy, and myocardial ischemia with proteasome inhibitors. Furthering our knowledge of this system may help in the development of new UPS-based therapeutic modalities for mitigation of cardiovascular disease.
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Affiliation(s)
- Saul R Powell
- Center for Heart and Lung Research, The Feinstein Institute for Medical Research, Manhasset, New York, USA
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Decreased proteasomal activity causes age-related phenotypes and promotes the development of metabolic abnormalities. THE AMERICAN JOURNAL OF PATHOLOGY 2011; 180:963-972. [PMID: 22210478 DOI: 10.1016/j.ajpath.2011.11.012] [Citation(s) in RCA: 134] [Impact Index Per Article: 10.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/10/2011] [Revised: 10/14/2011] [Accepted: 11/04/2011] [Indexed: 11/21/2022]
Abstract
The proteasome is a multicatalytic enzyme complex responsible for the degradation of both normal and damaged proteins. An age-related decline in proteasomal activity has been implicated in various age-related pathologies. The relevance of decreased proteasomal activity to aging and age-related diseases remains unclear, however, because suitable animal models are not available. In the present study, we established a transgenic (Tg) mouse model with decreased proteasomal chymotrypsin-like activity. Tg mice exhibited a shortened life span and developed age-related phenotypes. In Tg mice, polyubiquitinated and oxidized proteins accumulated, and the expression levels of cellular proteins such as Bcl-xL and RNase L were altered. When Tg mice were fed a high-fat diet, they developed more pronounced obesity and hepatic steatosis than did wild-type mice. Consistent with its role in lipid droplet formation, the expression of adipose differentiation-related protein (ADRP) was elevated in the livers of Tg mice. Of note, obesity and hepatic steatosis induced by a high-fat diet were more pronounced in aged than in young wild-type mice, and aged wild-type mice had elevated levels of ADRP, suggesting that the metabolic abnormalities present in Tg mice mimic those in aged mice. Our results provide the first in vivo evidence that decreased proteasomal chymotrypsin-like activity affects longevity and aggravates age-related metabolic disorders, such as obesity and hepatic steatosis.
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Dasuri K, Zhang L, Ebenezer P, Fernandez-Kim SO, Bruce-Keller AJ, Szweda LI, Keller JN. Proteasome alterations during adipose differentiation and aging: links to impaired adipocyte differentiation and development of oxidative stress. Free Radic Biol Med 2011; 51:1727-35. [PMID: 21871954 PMCID: PMC3378646 DOI: 10.1016/j.freeradbiomed.2011.08.001] [Citation(s) in RCA: 26] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/22/2011] [Revised: 07/29/2011] [Accepted: 08/02/2011] [Indexed: 02/07/2023]
Abstract
Intracellular proteins are degraded by a number of proteases, including the ubiquitin-proteasome pathway (UPP). Impairments in the UPP occur during the aging of a variety of tissues, although little is known in regards to age-related alterations to the UPP during the aging of adipose tissue. The UPP is known to be involved in regulating the differentiation of a variety of cell types, although the potential changes in the UPP during adipose differentiation have not been fully elucidated. How the UPP is altered in aging adipose tissue and adipocyte differentiation and the effects of proteasome inhibition on adipocyte homeostasis and differentiation are critical issues to elucidate experimentally. Adipogenesis continues throughout the life of adipose tissue, with continual differentiation of preadipocytes essential to maintaining tissue function during aging, and UPP alterations in mature adipocytes are likely to directly modulate adipose function during aging. In this study we demonstrate that aging induces alterations in the activity and expression of principal components of the UPP. Additionally, we show that multiple changes in the UPP occur during the differentiation of 3T3-L1 cells into adipocytes. In vitro data link observed UPP alterations to increased levels of oxidative stress and altered adipose biology relevant to both aging and differentiation. Taken together, these data demonstrate that changes in the UPP occur in response to adipose aging and adipogenesis and strongly suggest that proteasome inhibition is sufficient to decrease adipose differentiation, as well as increasing oxidative stress in mature adipocytes, both of which probably promote deleterious effects on adipose aging.
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Affiliation(s)
- Kalavathi Dasuri
- Pennington Biomedical Research Center, Louisiana State University System, Baton Rouge Louisiana 70808
| | - Le Zhang
- Pennington Biomedical Research Center, Louisiana State University System, Baton Rouge Louisiana 70808
| | - Philip Ebenezer
- Pennington Biomedical Research Center, Louisiana State University System, Baton Rouge Louisiana 70808
| | - Sun Ok Fernandez-Kim
- Pennington Biomedical Research Center, Louisiana State University System, Baton Rouge Louisiana 70808
| | - Annadora J. Bruce-Keller
- Pennington Biomedical Research Center, Louisiana State University System, Baton Rouge Louisiana 70808
| | - Luke I. Szweda
- Free Radical Biology and Aging Program, Oklahoma Medical Research Foundation, Oklahoma City, Oklahoma, USA
| | - Jeffrey N. Keller
- Pennington Biomedical Research Center, Louisiana State University System, Baton Rouge Louisiana 70808
- Address correspondence to: Dr Jeffrey N Keller, Pennington Biomedical Research Center, 6400 Perkins Road, Baton Rouge Louisiana 70808, (P) 225-763-3190 (E)
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Grune T, Catalgol B, Licht A, Ermak G, Pickering A, Ngo JK, Davies KJA. HSP70 mediates dissociation and reassociation of the 26S proteasome during adaptation to oxidative stress. Free Radic Biol Med 2011; 51:1355-64. [PMID: 21767633 PMCID: PMC3172204 DOI: 10.1016/j.freeradbiomed.2011.06.015] [Citation(s) in RCA: 166] [Impact Index Per Article: 12.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/19/2011] [Revised: 06/01/2011] [Accepted: 06/07/2011] [Indexed: 01/28/2023]
Abstract
We report an entirely new role for the HSP70 chaperone in dissociating 26S proteasome complexes (into free 20S proteasomes and bound 19S regulators), preserving 19S regulators, and reconstituting 26S proteasomes in the first 1-3h after mild oxidative stress. These responses, coupled with direct 20S proteasome activation by poly(ADP ribose) polymerase in the nucleus and by PA28αβ in the cytoplasm, instantly provide cells with increased capacity to degrade oxidatively damaged proteins and to survive the initial effects of stress exposure. Subsequent adaptive (hormetic) processes (3-24h after stress exposure), mediated by several signal transduction pathways and involving increased transcription/translation of 20S proteasomes, immunoproteasomes, and PA28αβ, abrogate the need for 26S proteasome dissociation. During this adaptive period, HSP70 releases its bound 19S regulators, 26S proteasomes are reconstituted, and ATP-stimulated proteolysis is restored. The 26S proteasome-dependent, and ATP-stimulated, turnover of ubiquitinylated proteins is essential for normal cell metabolism, and its restoration is required for successful stress adaptation.
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Affiliation(s)
- Tilman Grune
- Institute of Nutrition, Department of Nutritional Toxicology, Friedrich Schiller University, D-07740Jena, Germany
| | - Betül Catalgol
- Institute of Nutrition, Department of Nutritional Toxicology, Friedrich Schiller University, D-07740Jena, Germany
| | - Anke Licht
- Institute of Nutrition, Department of Nutritional Toxicology, Friedrich Schiller University, D-07740Jena, Germany
| | - Gennady Ermak
- Ethel Percy Andrus Gerontology Center of the Davis School of Gerontology; and Division of Molecular & Computational Biology, Department of Biological Sciences of the Dornsife College of Letters, Arts & Sciences: the University of Southern California, Los Angeles, California 90089-0191, U.S.A
| | - Andrew Pickering
- Ethel Percy Andrus Gerontology Center of the Davis School of Gerontology; and Division of Molecular & Computational Biology, Department of Biological Sciences of the Dornsife College of Letters, Arts & Sciences: the University of Southern California, Los Angeles, California 90089-0191, U.S.A
| | - Jenny K. Ngo
- Ethel Percy Andrus Gerontology Center of the Davis School of Gerontology; and Division of Molecular & Computational Biology, Department of Biological Sciences of the Dornsife College of Letters, Arts & Sciences: the University of Southern California, Los Angeles, California 90089-0191, U.S.A
| | - Kelvin J. A. Davies
- Ethel Percy Andrus Gerontology Center of the Davis School of Gerontology; and Division of Molecular & Computational Biology, Department of Biological Sciences of the Dornsife College of Letters, Arts & Sciences: the University of Southern California, Los Angeles, California 90089-0191, U.S.A
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Affiliation(s)
- Kelvin J A Davies
- Ethel Percy Andrus Gerontology Center of the Davis School of Gerontology, Los Angeles, CA 90089, USA
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Proctor CJ, Lorimer IAJ. Modelling the role of the Hsp70/Hsp90 system in the maintenance of protein homeostasis. PLoS One 2011; 6:e22038. [PMID: 21779370 PMCID: PMC3137010 DOI: 10.1371/journal.pone.0022038] [Citation(s) in RCA: 50] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/18/2011] [Accepted: 06/14/2011] [Indexed: 12/20/2022] Open
Abstract
Neurodegeneration is an age-related disorder which is characterised by the accumulation of aggregated protein and neuronal cell death. There are many different neurodegenerative diseases which are classified according to the specific proteins involved and the regions of the brain which are affected. Despite individual differences, there are common mechanisms at the sub-cellular level leading to loss of protein homeostasis. The two central systems in protein homeostasis are the chaperone system, which promotes correct protein folding, and the cellular proteolytic system, which degrades misfolded or damaged proteins. Since these systems and their interactions are very complex, we use mathematical modelling to aid understanding of the processes involved. The model developed in this study focuses on the role of Hsp70 (IPR00103) and Hsp90 (IPR001404) chaperones in preventing both protein aggregation and cell death. Simulations were performed under three different conditions: no stress; transient stress due to an increase in reactive oxygen species; and high stress due to sustained increases in reactive oxygen species. The model predicts that protein homeostasis can be maintained during short periods of stress. However, under long periods of stress, the chaperone system becomes overwhelmed and the probability of cell death pathways being activated increases. Simulations were also run in which cell death mediated by the JNK (P45983) and p38 (Q16539) pathways was inhibited. The model predicts that inhibiting either or both of these pathways may delay cell death but does not stop the aggregation process and that eventually cells die due to aggregated protein inhibiting proteasomal function. This problem can be overcome if the sequestration of aggregated protein into inclusion bodies is enhanced. This model predicts responses to reactive oxygen species-mediated stress that are consistent with currently available experimental data. The model can be used to assess specific interventions to reduce cell death due to impaired protein homeostasis.
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Affiliation(s)
- Carole J Proctor
- Centre for Integrated Systems Biology of Ageing and Nutrition, Institute for Ageing and Health, Newcastle University, Newcastle upon Tyne, United Kingdom.
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Graikou K, Kapeta S, Aligiannis N, Sotiroudis G, Chondrogianni N, Gonos E, Chinou I. Chemical analysis of Greek pollen - Antioxidant, antimicrobial and proteasome activation properties. Chem Cent J 2011; 5:33. [PMID: 21699688 PMCID: PMC3135496 DOI: 10.1186/1752-153x-5-33] [Citation(s) in RCA: 86] [Impact Index Per Article: 6.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/11/2011] [Accepted: 06/23/2011] [Indexed: 03/24/2023] Open
Abstract
Background Pollen is a bee-product known for its medical properties from ancient times. In our days is increasingly used as health food supplement and especially as a tonic primarily with appeal to the elderly to ameliorate the effects of ageing. In order to evaluate the chemical composition and the biological activity of Greek pollen which has never been studied before, one sample with identified botanical origin from sixteen different common plant taxa of Greece has been evaluated. Results Three different extracts of the studied sample of Greek pollen, have been tested, in whether could induce proteasome activities in human fibroblasts. The water extract was found to induce a highly proteasome activity, showing interesting antioxidant properties. Due to this activity the aqueous extract was further subjected to chemical analysis and seven flavonoids have been isolated and identified by modern spectral means. From the methanolic extract, sugars, lipid acids, phenolic acids and their esters have been also identified, which mainly participate to the biosynthetic pathway of pollen phenolics. The total phenolics were estimated with the Folin-Ciocalteau reagent and the total antioxidant activity was determined by the DPPH method while the extracts and the isolated compounds were also tested for their antimicrobial activity by the dilution technique. Conclusions The Greek pollen is rich in flavonoids and phenolic acids which indicate the observed free radical scavenging activity, the effects of pollen on human fibroblasts and the interesting antimicrobial profile.
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Affiliation(s)
- Konstantia Graikou
- University of Athens, School of Pharmacy, Division of Pharmacognosy and Chemistry of Natural Products, Zografou Campus, 15771, Athens, Greece.
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Toluene effects on oxidative stress in brain regions of young-adult, middle-age, and senescent Brown Norway rats. Toxicol Appl Pharmacol 2011; 256:386-98. [PMID: 21549141 DOI: 10.1016/j.taap.2011.04.012] [Citation(s) in RCA: 26] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/01/2011] [Revised: 04/12/2011] [Accepted: 04/17/2011] [Indexed: 01/24/2023]
Abstract
The influence of aging on susceptibility to environmental contaminants is not well understood. To extend knowledge in this area, we examined effects in rat brain of the volatile organic compound, toluene. The objective was to test whether oxidative stress (OS) plays a role in the adverse effects caused by toluene exposure, and if so, if effects are age-dependent. OS parameters were selected to measure the production of reactive oxygen species (NADPH Quinone oxidoreductase 1 (NQO1), NADH Ubiquinone reductase (UBIQ-RD)), antioxidant homeostasis (total antioxidant substances (TAS), superoxide dismutase (SOD), γ-glutamylcysteine synthetase (γ-GCS), glutathione transferase (GST), glutathione peroxidase (GPX), glutathione reductase (GRD)), and oxidative damage (total aconitase and protein carbonyls). In this study, Brown Norway rats (4, 12, and 24 months) were dosed orally with toluene (0, 0.65 or 1g/kg) in corn oil. Four hours later, frontal cortex, cerebellum, striatum, and hippocampus were dissected, quick frozen on dry ice, and stored at -80°C until analysis. Some parameters of OS were found to increase with age in select brain regions. Toluene exposure also resulted in increased OS in select brain regions. For example, an increase in NQO1 activity was seen in frontal cortex and cerebellum of 4 and 12 month old rats following toluene exposure, but only in the hippocampus of 24 month old rats. Similarly, age and toluene effects on glutathione enzymes were varied and brain-region specific. Markers of oxidative damage reflected changes in oxidative stress. Total aconitase activity was increased by toluene in frontal cortex and cerebellum at 12 and 24 months, respectively. Protein carbonyls in both brain regions and in all age groups were increased by toluene, but step-down analyses indicated toluene effects were statistically significant only in 12month old rats. These results indicate changes in OS parameters with age and toluene exposure resulted in oxidative damage in frontal cortex and cerebellum of 12 month old rats. Although increases in oxidative damage are associated with increases in horizontal motor activity in older rats, further research is warranted to determine if these changes in OS parameters are related to neurobehavioral and neurophysiological effects of toluene in animal models of aging.
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Abstract
Abstract The immune system of an organism is an essential component of the defense mechanism aimed at combating pathogenic stress. Age-associated immune dysfunction, also dubbed "immune senescence," manifests as increased susceptibility to infections, increased onset and progression of autoimmune diseases, and onset of neoplasia. Over the years, extensive research has generated consensus in terms of the phenotypic and functional defects within the immune system in various organisms, including humans. Indeed, age-associated alterations such as thymic involution, T cell repertoire skewing, decreased ability to activate naïve T cells and to generate robust memory responses, have been shown to have a causative role in immune decline. Further, understanding the molecular mechanisms underlying the generation of proteotoxic stress, DNA damage response, modulation of ubiquitin proteasome pathway, and regulation of transcription factor NFκB activation, in immune decline, have paved the way to delineating signaling pathways that cross-talk and impact immune senescence. Given the role of the immune system in combating infections, its effectiveness with age may well be a marker of health and a predictor of longevity. It is therefore believed that a better understanding of the mechanisms underlying immune senescence will lead to an effective interventional strategy aimed at improving the health span of individuals. Antioxid. Redox Signal. 14, 1551-1585.
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Affiliation(s)
- Subramaniam Ponnappan
- Department of Geriatrics, University of Arkansas for Medical Sciences, 4301 W. Markham, Little Rock, AR 72205, USA
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Grimm S, Ernst L, Grötzinger N, Höhn A, Breusing N, Reinheckel T, Grune T. Cathepsin D is one of the major enzymes involved in intracellular degradation of AGE-modified proteins. Free Radic Res 2011; 44:1013-26. [PMID: 20560835 DOI: 10.3109/10715762.2010.495127] [Citation(s) in RCA: 40] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/08/2023]
Abstract
Oxidized and cross-linked modified proteins are known to accumulate in ageing. Little is known about whether the accumulation of proteins modified by advanced glycation end products (AGEs) is due to an affected intracellular degradation. Therefore, this study was designed to determine whether the intracellular enzymes cathepsin B, cathepsin D and the 20S proteasome are able to degrade AGE-modified proteins in vitro. It shows that AGE-modified albumin is degraded by cathepsin D, while cathepsin B was less effective in the degradation of aldehyde-modified albumin and the 20S proteasome was completely unable to degrade them. Mouse primary embryonic fibroblasts isolated from a cathepsin D knockout animals were found to have an extensive intracellular AGE-accumulation, mainly in lysosomes, and a reduction of AGE-modified protein degradation compared to cells isolated from wild type animals. In summary, it can be assumed that cathepsin D plays a significant role in the removal of AGE-modified proteins.
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Affiliation(s)
- Stefanie Grimm
- Institute of Biological Chemistry and Nutrition, University of Hohenheim, Stuttgart, Germany
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Methylglyoxal alters the function and stability of critical components of the protein quality control. PLoS One 2010; 5:e13007. [PMID: 20885985 PMCID: PMC2945773 DOI: 10.1371/journal.pone.0013007] [Citation(s) in RCA: 40] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/22/2010] [Accepted: 09/06/2010] [Indexed: 12/30/2022] Open
Abstract
BACKGROUND Increased production and accumulation of methylglyoxal (MGO), as well as increased modification of proteins by glycoxidation, are hallmarks of aging and diabetes. MGO was shown to modify proteins and to contribute to the accumulation of damaged proteins that can be toxic to cells. However, the effect of MGO on the cell systems responsible for repairing or degrading damaged proteins is still unclear. In this study, the effect of MGO on the function of the ubiquitin-proteasome system (UPS) and on molecular chaperones, two cooperative mechanisms associated with protein quality control, was investigated. PRINCIPAL FINDINGS In this work it is shown that treatment of cells with MGO leads to accumulation of ubiquitin conjugates and depletion of free ubiquitin. Moreover, MGO significantly decreases the proteolytic activity of the 20S proteasome. Data further shows that MGO decreases the levels of the molecular chaperones Hsc70 and Hsp90 and leads to accumulation of CHIP-, Hsp40- and ubiquitin-containing aggregates. The formation of large aggregates containing CHIP is a consequence of its binding to misfolded proteins and to molecular chaperones. Moreover, dysfunction of the chaperones/CHIP/UPS axis is associated with accumulation of oxidized and argpyrimidine-modified proteins, which is likely to be associated with decreased cell viability. Interestingly, data further shows that MGO-induced stress induces the activation of heat shock factor-1 (Hsf-1), the main transcription factor involved in the regulation of the expression of heat shock proteins (HSPs) and cell response to stress. CONCLUSIONS The data obtained in this work suggests that MGO impairs both the UPS and the protein quality control dependent on CHIP and molecular chaperones, leading to accumulation of toxic aggregates and increased cell death. However, these MGO-induced changes appear to elicit a response from the Hsf-1 system, which is crucial to help cells to cope with cellular stress and to re-establish homeostasis.
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Grimm S, Hoehn A, Davies KJ, Grune T. Protein oxidative modifications in the ageing brain: consequence for the onset of neurodegenerative disease. Free Radic Res 2010; 45:73-88. [PMID: 20815785 DOI: 10.3109/10715762.2010.512040] [Citation(s) in RCA: 79] [Impact Index Per Article: 5.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/20/2022]
Abstract
The free radical theory of ageing proposes the accumulation of altered, less active and toxic molecules of DNA, RNA, proteins and lipids caused by reactive oxygen species and reactive nitrogen species. Neurodegenerative disorders are characterized by an abnormal accumulation of oxidatively damaged macromolecules inside cells and in the extracellular space. Proteins involved in the formation of aggregates are β-amyloid, tau, α-synuclein, parkin, prion proteins and proteins containing polyglutamine. These abnormal aggregated proteins influence normal cellular metabolism. Additionally, deposition of abnormal proteins induces oxidative stress and proteasomal as well as mitochondrial dysfunction that ultimately lead to neuronal cell death. This review focuses on the impact of oxidative and nitrative stress in the ageing brain and, consequently, on the generation of modified proteins, as these post-translational modifications are assumed to play an important role in the development of neurodegenerative diseases.
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Affiliation(s)
- Stefanie Grimm
- Institute of Nutrition, Friedrich Schiller University Jena, Dornburger Straße 24, 07743 Jena, Germany
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Anti-ageing and rejuvenating effects of quercetin. Exp Gerontol 2010; 45:763-71. [PMID: 20619334 DOI: 10.1016/j.exger.2010.07.001] [Citation(s) in RCA: 135] [Impact Index Per Article: 9.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/20/2010] [Revised: 05/31/2010] [Accepted: 07/01/2010] [Indexed: 12/22/2022]
Abstract
Homeostasis is a key feature of the cellular lifespan. Its maintenance influences the rate of ageing and it is determined by several factors, including efficient proteolysis. The proteasome is the major cellular proteolytic machinery responsible for the degradation of both normal and damaged proteins. Alterations of proteasome function have been recorded in various biological phenomena including ageing and replicative senescence. Proteasome activities and function are decreased upon replicative senescence, whereas proteasome activation confers enhanced survival against oxidative stress, lifespan extension and maintenance of the young morphology longer in human primary fibroblasts. Several natural compounds possess anti-ageing/anti-oxidant properties. In this study, we have identified quercetin (QUER) and its derivative, namely quercetin caprylate (QU-CAP) as a proteasome activator with anti-oxidant properties that consequently influence cellular lifespan, survival and viability of HFL-1 primary human fibroblasts. Moreover, when these compounds are supplemented to already senescent fibroblasts, a rejuvenating effect is observed. Finally, we show that these compounds promote physiological alterations when applied to cells (i.e. whitening effect). In summary, these data demonstrate the existence of naturally occurring anti-ageing products that can be effectively used through topical application.
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Abstract
Continuous renewal of intracellular components is required to preserve cellular functionality. In fact, failure to timely turnover proteins and organelles leads often to cell death and disease. Different pathways contribute to the degradation of intracellular components in lysosomes or autophagy. In this review, we focus on chaperone-mediated autophagy (CMA), a selective form of autophagy that modulates the turnover of a specific pool of soluble cytosolic proteins. Selectivity in CMA is conferred by the presence of a targeting motif in the cytosolic substrates that, upon recognition by a cytosolic chaperone, determines delivery to the lysosomal surface. Substrate proteins undergo unfolding and translocation across the lysosomal membrane before reaching the lumen, where they are rapidly degraded. Better molecular characterization of the different components of this pathway in recent years, along with the development of transgenic models with modified CMA activity and the identification of CMA dysfunction in different severe human pathologies and in aging, are all behind the recent regained interest in this catabolic pathway.
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Caplan GA, Kvelde T, Lai C, Yap SL, Lin C, Hill MA. Cerebrospinal fluid in long-lasting delirium compared with Alzheimer's dementia. J Gerontol A Biol Sci Med Sci 2010; 65:1130-6. [PMID: 20530241 DOI: 10.1093/gerona/glq090] [Citation(s) in RCA: 42] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/19/2022] Open
Abstract
BACKGROUND Delirium is a common syndrome affecting older people in hospital, whose pathophysiology is poorly understood, but sequelae of increased cognitive and functional impairment suggest neuronal loss. METHODS Cohort study comparing cerebrospinal fluid, blood, and clinical markers of delirium and neuronal cell death in 20 older hospitalized patients with delirium and 20 outpatients with Alzheimer's dementia. RESULTS Compared with participants with dementia, patients with delirium demonstrated higher CSF lactate (1.87 vs 1.48 mmol/L, p < .001) and protein levels (0.62 vs 0.44 g/L, p = .036) and lower levels of neuron-specific enolase (4.84 vs 8.98 ng/mL, p < .001) but no difference in S100B. The changes correlated with clinical indices and outcomes. CONCLUSION Older patients with delirium experience significant metabolic disturbance in the brain, which requires further investigation.
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Affiliation(s)
- Gideon A Caplan
- 1 Department of Geriatric Medicine, Prince of Wales Hospital, Sydney, Australia.
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Ghosh S, Thakur MK. Interaction of estrogen receptor-alpha ligand binding domain with nuclear proteins of aging mouse brain. J Neurosci Res 2009; 87:2591-600. [PMID: 19326447 DOI: 10.1002/jnr.22068] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
Abstract
After the interaction of estrogen with the ligand binding domain (LBD) of mouse estrogen receptor-alpha (mERalpha) and hormone-responsive elements of target genes, many nuclear proteins are recruited to regulate the expression of specific genes. Because it is not known which brain proteins interact with LBD or whether these proteins vary with age and sex, we used pull-down assay and far Western blotting to detect five nuclear proteins of 160, 140, 87, 60, and 46 kD in the mouse brain. These interacting proteins were identified as PELP1, RIP140, PGC1alpha, BAF60, and ADA3, respectively. The level of PELP1, RIP140, PGC1alpha, and BAF60 decreased drastically in old compared with adult male mice, whereas the ADA3 level showed no significant change. PELP1, PGC1alpha, and BAF60 levels were lower in old male compared with female mice. Thus we report the identification and interaction of five nuclear proteins with mERalpha-LBD, indicating their role in estrogen signaling and brain functions during aging.
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Affiliation(s)
- Swati Ghosh
- Biochemistry and Molecular Biology Laboratory, Department of Zoology, Banaras Hindu University, Varanasi, India
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Wang H, Brozoski TJ, Turner JG, Ling L, Parrish JL, Hughes LF, Caspary DM. Plasticity at glycinergic synapses in dorsal cochlear nucleus of rats with behavioral evidence of tinnitus. Neuroscience 2009; 164:747-59. [PMID: 19699270 DOI: 10.1016/j.neuroscience.2009.08.026] [Citation(s) in RCA: 146] [Impact Index Per Article: 9.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/15/2009] [Revised: 07/21/2009] [Accepted: 08/12/2009] [Indexed: 02/01/2023]
Abstract
Fifteen percent to 35% of the United States population experiences tinnitus, a subjective "ringing in the ears". Up to 10% of those afflicted report severe and disabling symptoms. Tinnitus was induced in rats using unilateral, 1 h, 17 kHz-centered octave-band noise (116 dB SPL) and assessed using a gap-startle method. The dorsal cochlear nucleus (DCN) is thought to undergo plastic changes suggestive of altered inhibitory function during tinnitus development. Exposed rats showed near pre-exposure auditory brainstem response (ABR) thresholds for clicks and all tested frequencies 16 weeks post-exposure. Sound-exposed rats showed significantly worse gap detection at 24 and 32 kHz 16 weeks following sound exposure, suggesting the development of chronic, high frequency tinnitus. Message and protein levels of alpha(1-3,) and beta glycine receptor subunits (GlyRs), and the anchoring protein, gephyrin, were measured in DCN fusiform cells 4 months following sound exposure. Rats with evidence of tinnitus showed significant GlyR alpha(1) protein decreases in the middle and high frequency regions of the DCN while alpha(1) message levels were paradoxically increased. Gephyrin levels showed significant tinnitus-related increases in sound-exposed rats suggesting intracellular receptor trafficking changes following sound exposure. Consistent with decreased alpha(1) subunit protein levels, strychnine binding studies showed significant tinnitus-related decreases in the number of GlyR binding sites, supporting tinnitus-related changes in the number and/or composition of GlyRs. Collectively, these findings suggest the development of tinnitus is likely associated with functional GlyR changes in DCN fusiform cells consistent with previously described behavioral and neurophysiologic changes. Tinnitus related GlyR changes could provide a unique receptor target for tinnitus pharmacotherapy or blockade of tinnitus initiation.
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Affiliation(s)
- H Wang
- Department of Pharmacology, Southern Illinois University School of Medicine, PO Box 19629, Springfield, IL 62794-9629, USA
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Balantinou E, Trougakos IP, Chondrogianni N, Margaritis LH, Gonos ES. Transcriptional and posttranslational regulation of clusterin by the two main cellular proteolytic pathways. Free Radic Biol Med 2009; 46:1267-74. [PMID: 19353783 DOI: 10.1016/j.freeradbiomed.2009.01.025] [Citation(s) in RCA: 30] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
Abstract
Clusterin/apolipoprotein J (CLU) is a secreted glycoprotein associated with many severe physiological disturbances that represent states of increased oxidative stress, such as aging, cancer, atherosclerosis, diabetes, and renal and neurodegenerative diseases. The aim of our work was to examine the effect of proteasome and lysosome inhibition on CLU expression and to determine whether those proteolytic pathways are implicated in CLU gene regulation and protein degradation. To this end we used two different model systems, namely the U-2 OS osteosarcoma cell line and the WI38 primary human embryonic lung fibroblasts. We report that proteasome inhibition promotes both heat-shock factor 1 (HSF-1)-dependent CLU gene expression induction and protein accumulation due to reduced degradation. In contrast, lysosome inhibition results in elevated levels of CLU protein but does not affect the CLU mRNA levels. We also provide direct evidence that both the intracellular precursor, psCLU, and the mature secreted, sCLU, isoforms constitute proteolytic substrates of the proteasome and the lysosome. Overall our findings indicate that CLU overexpression after proteasome inhibition relates to both positive gene transcriptional regulation by HSF-1 and posttranslational protein accumulation due to reduced proteasomal and lysosomal degradation.
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Affiliation(s)
- Eirini Balantinou
- National Hellenic Research Foundation, Institute of Biological Research and Biotechnology, 48 Vas. Constantinou Avenue, Athens, Greece
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