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Lou Z, Li P, Sun X, Yang S, Wang B, Han K. A fluorescent probe for rapid detection of thiols and imaging of thiols reducing repair and H2O2 oxidative stress cycles in living cells. Chem Commun (Camb) 2012. [PMID: 23187935 DOI: 10.1039/c2cc36839k] [Citation(s) in RCA: 100] [Impact Index Per Article: 8.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/23/2022]
Abstract
A diselenide containing fluorescent probe based on a fluorescein scaffold for thiols was developed. The fluorescent probe exhibited rapid response, high selectivity and reversibility. Confocal fluorescence microscopy was used to visualize the redox changes mediated by thiols and reactive oxygen species in living HeLa cells.
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Affiliation(s)
- Zhangrong Lou
- State Key Laboratory of Molecular Reaction Dynamics, Dalian Institute of Chemical Physics (DICP), Chinese Academy of Sciences (CAS), 457 Zhongshan Road, Dalian 116023, PR China
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102
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Gounder SS, Kannan S, Devadoss D, Miller CJ, Whitehead KS, Odelberg SJ, Firpo MA, Paine R, Hoidal JR, Abel ED, Rajasekaran NS. Impaired transcriptional activity of Nrf2 in age-related myocardial oxidative stress is reversible by moderate exercise training. PLoS One 2012; 7:e45697. [PMID: 23029187 PMCID: PMC3454427 DOI: 10.1371/journal.pone.0045697] [Citation(s) in RCA: 115] [Impact Index Per Article: 9.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/18/2012] [Accepted: 08/22/2012] [Indexed: 01/31/2023] Open
Abstract
Aging promotes accumulation of reactive oxygen/nitrogen species (ROS/RNS) in cardiomyocytes, which leads to contractile dysfunction and cardiac abnormalities. These changes may contribute to increased cardiovascular disease in the elderly. Inducible antioxidant pathways are regulated by nuclear erythroid 2 p45-related factor 2 (Nrf2) through antioxidant response cis-elements (AREs) and are impaired in the aging heart. Whereas acute exercise stress (AES) activates Nrf2 signaling and promotes myocardial antioxidant function in young mice (∼2 months), aging mouse (>23 months) hearts exhibit significant oxidative stress as compared to those of the young. The purpose of this study was to investigate age-dependent regulation of Nrf2-antioxidant mechanisms and redox homeostasis in mouse hearts and the impact of exercise. Old mice were highly susceptible to oxidative stress following high endurance exercise stress (EES), but demonstrated increased adaptive redox homeostasis after moderate exercise training (MET; 10m/min, for 45 min/day) for ∼6 weeks. Following EES, transcription and protein levels for most of the ARE-antioxidants were increased in young mice but their induction was blunted in aging mice. In contrast, 6-weeks of chronic MET promoted nuclear levels of Nrf2 along with its target antioxidants in the aging heart to near normal levels as seen in young mice. These observations suggest that enhancing Nrf2 function and endogenous cytoprotective mechanisms by MET, may combat age-induced ROS/RNS and protect the myocardium from oxidative stress diseases.
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Affiliation(s)
- Sellamuthu S. Gounder
- Divisions of Cardiology and Pulmonary, Department of Internal Medicine, University of Utah Health Sciences Center, Salt Lake City, Utah, United States of America
| | - Sankaranarayanan Kannan
- Department of Pediatric Research, University of Texas M. D. Anderson Cancer Center, Houston, Texas, United States of America
| | - Dinesh Devadoss
- Divisions of Cardiology and Pulmonary, Department of Internal Medicine, University of Utah Health Sciences Center, Salt Lake City, Utah, United States of America
| | - Corey J. Miller
- Divisions of Cardiology and Pulmonary, Department of Internal Medicine, University of Utah Health Sciences Center, Salt Lake City, Utah, United States of America
| | - Kevin S. Whitehead
- Divisions of Cardiology and Pulmonary, Department of Internal Medicine, University of Utah Health Sciences Center, Salt Lake City, Utah, United States of America
| | - Shannon J. Odelberg
- Divisions of Cardiology and Pulmonary, Department of Internal Medicine, University of Utah Health Sciences Center, Salt Lake City, Utah, United States of America
| | - Matthew A. Firpo
- Department of General Surgery, University of Utah Health Sciences Center, Salt Lake City, Utah, United States of America
| | - Robert Paine
- Division of Pulmonary, Department of Internal Medicine, University of Utah Health Sciences Center, Salt Lake City, Utah, United States of America
| | - John R. Hoidal
- Division of Pulmonary, Department of Internal Medicine, University of Utah Health Sciences Center, Salt Lake City, Utah, United States of America
| | - E. Dale Abel
- Division of Endocrinology, Department of Internal Medicine, University of Utah Health Sciences Center, Salt Lake City, Utah, United States of America
| | - Namakkal S. Rajasekaran
- Divisions of Cardiology and Pulmonary, Department of Internal Medicine, University of Utah Health Sciences Center, Salt Lake City, Utah, United States of America
- * E-mail:
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103
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Christians ES, Ishiwata T, Benjamin IJ. Small heat shock proteins in redox metabolism: implications for cardiovascular diseases. Int J Biochem Cell Biol 2012; 44:1632-45. [PMID: 22710345 DOI: 10.1016/j.biocel.2012.06.006] [Citation(s) in RCA: 47] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/17/2012] [Revised: 06/02/2012] [Accepted: 06/07/2012] [Indexed: 10/28/2022]
Abstract
A timely review series on small heat shock proteins has to appropriately examine their fundamental properties and implications in the cardiovascular system since several members of this chaperone family exhibit robust expression in the myocardium and blood vessels. Due to energetic and metabolic demands, the cardiovascular system maintains a high mitochondrial activity but irreversible oxidative damage might ensue from increased production of reactive oxygen species. How equilibrium between their production and scavenging is achieved becomes paramount for physiological maintenance. For example, heat shock protein B1 (HSPB1) is implicated in maintaining this equilibrium or redox homeostasis by upholding the level of glutathione, a major redox mediator. Studies of gain or loss of function achieved by genetic manipulations have been highly informative for understanding the roles of those proteins. For example, genetic deficiency of several small heat shock proteins such as HSPB5 and HSPB2 is well-tolerated in heart cells whereas a single missense mutation causes human pathology. Such evidence highlights both the profound genetic redundancy observed among the multigene family of small heat shock proteins while underscoring the role proteotoxicity plays in driving disease pathogenesis. We will discuss the available data on small heat shock proteins in the cardiovascular system, redox metabolism and human diseases. From the medical perspective, we envision that such emerging knowledge of the multiple roles small heat shock proteins exert in the cardiovascular system will undoubtedly open new avenues for their identification and possible therapeutic targeting in humans. This article is part of a Directed Issue entitled: Small HSPs in physiology and pathology.
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Affiliation(s)
- Elisabeth S Christians
- Laboratory of Cardiac Disease, Redox Signaling and Cell Regeneration, Division of Cardiology, University of Utah School of Medicine, Salt Lake City, UT 84132, USA.
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104
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Disruption of Nrf2/ARE signaling impairs antioxidant mechanisms and promotes cell degradation pathways in aged skeletal muscle. Biochim Biophys Acta Mol Basis Dis 2012; 1822:1038-50. [DOI: 10.1016/j.bbadis.2012.02.007] [Citation(s) in RCA: 103] [Impact Index Per Article: 8.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/15/2011] [Revised: 01/31/2012] [Accepted: 02/08/2012] [Indexed: 11/21/2022]
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105
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Genetic ablation of Nrf2/antioxidant response pathway in Alexander disease mice reduces hippocampal gliosis but does not impact survival. PLoS One 2012; 7:e37304. [PMID: 22693571 PMCID: PMC3365053 DOI: 10.1371/journal.pone.0037304] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/26/2012] [Accepted: 04/20/2012] [Indexed: 12/22/2022] Open
Abstract
In Alexander disease (AxD) the presence of mutant glial fibrillary acidic protein (GFAP), the major intermediate filament of astrocytes, triggers protein aggregation, with marked induction of a stress response mediated by the transcription factor, Nrf2. To clarify the role of Nrf2 in AxD, we have crossed Gfap mutant and transgenic mouse models into an Nrf2 null background. Deletion of Nrf2 eliminates the phase II stress response normally present in mouse models of AxD, but causes no change in body weight or lifespan, even in a severe lethal model. AxD astrocytes without Nrf2 retain features of reactivity, such as expression of the endothelin-B receptor, but have lower Gfap levels, a decrease in p62 protein and reduced iron accumulation, particularly in hippocampus. Microglial activation, indicated by Iba1 expression, is also diminished. Although the Nrf2 response is generally considered beneficial, these results show that in the context of AxD, loss of the antioxidant pathway has no obvious negative effects, while actually decreasing Gfap accumulation and pathology. Given the attention Nrf2 is receiving as a potential therapeutic target in AxD and other neurodegenerative diseases, it will be interesting to see whether induction of Nrf2, beyond the endogenous response, is beneficial or not in these same models.
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106
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Fumarate is cardioprotective via activation of the Nrf2 antioxidant pathway. Cell Metab 2012; 15:361-71. [PMID: 22405071 PMCID: PMC3314920 DOI: 10.1016/j.cmet.2012.01.017] [Citation(s) in RCA: 198] [Impact Index Per Article: 16.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/18/2011] [Revised: 12/08/2011] [Accepted: 01/18/2012] [Indexed: 12/29/2022]
Abstract
The citric acid cycle (CAC) metabolite fumarate has been proposed to be cardioprotective; however, its mechanisms of action remain to be determined. To augment cardiac fumarate levels and to assess fumarate's cardioprotective properties, we generated fumarate hydratase (Fh1) cardiac knockout (KO) mice. These fumarate-replete hearts were robustly protected from ischemia-reperfusion injury (I/R). To compensate for the loss of Fh1 activity, KO hearts maintain ATP levels in part by channeling amino acids into the CAC. In addition, by stabilizing the transcriptional regulator Nrf2, Fh1 KO hearts upregulate protective antioxidant response element genes. Supporting the importance of the latter mechanism, clinically relevant doses of dimethylfumarate upregulated Nrf2 and its target genes, hence protecting control hearts, but failed to similarly protect Nrf2-KO hearts in an in vivo model of myocardial infarction. We propose that clinically established fumarate derivatives activate the Nrf2 pathway and are readily testable cytoprotective agents.
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107
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Muthusamy VR, Kannan S, Sadhaasivam K, Gounder SS, Davidson CJ, Boeheme C, Hoidal JR, Wang L, Rajasekaran NS. Acute exercise stress activates Nrf2/ARE signaling and promotes antioxidant mechanisms in the myocardium. Free Radic Biol Med 2012; 52:366-76. [PMID: 22051043 PMCID: PMC3800165 DOI: 10.1016/j.freeradbiomed.2011.10.440] [Citation(s) in RCA: 214] [Impact Index Per Article: 17.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/28/2011] [Revised: 10/08/2011] [Accepted: 10/13/2011] [Indexed: 01/12/2023]
Abstract
Oxidative stress has been implicated in the pathogenesis of cardiovascular diseases, including myocardial hypertrophy and infarction. Although impairment of antioxidant defense mechanisms has been thought to provoke oxidative stress-induced myocardial dysfunction, it has been difficult to clearly demonstrate. Nuclear erythroid 2 p45-related factor 2 (Nrf2) is a redox-sensitive, basic leucine zipper protein that regulates the transcription of several antioxidant genes. We previously reported that sustained activation of Nrf2 upregulates transcription of a number of endogenous antioxidants in the heart. Here, we show that acute exercise stress (AES) results in activation of Nrf2/ARE (antioxidant response element) signaling and subsequent enhancement of antioxidant defense pathways in wild-type (WT) mouse hearts, while oxidative stress, along with blunted defense mechanisms, was observed in Nrf2-/- mice. We also find that AES is associated with increased trans-activation of ARE-containing genes in exercised animals when compared to age-matched sedentary WT mice. However, enhanced oxidative stress in response to AES was observed in Nrf2-/- mice due to lower basal expression and marked attenuation of the transcriptional induction of several antioxidant genes. Thus, AES induces ROS and promotes Nrf2 function, but disruption of Nrf2 increases susceptibility of the myocardium to oxidative stress. Our findings suggest the basis for a nonpharmacological approach to activate Nrf2/ARE signaling, which might be a potential therapeutic target to protect the heart from oxidative stress-induced cardiovascular complications.
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Affiliation(s)
- Vasanthi R. Muthusamy
- Division of Cardiology & Pulmonary, Department of Internal Medicine, University of Utah Health Sciences Center, Salt Lake City, UT 84132, USA
| | - Sankaranarayanan Kannan
- Department of Pediatric Research, University of Texas M. D. Anderson Cancer Center, Houston, TX 77030, USA
| | - Kamal Sadhaasivam
- Division of Cardiology & Pulmonary, Department of Internal Medicine, University of Utah Health Sciences Center, Salt Lake City, UT 84132, USA
| | - Sellamuthu S. Gounder
- Division of Cardiology & Pulmonary, Department of Internal Medicine, University of Utah Health Sciences Center, Salt Lake City, UT 84132, USA
| | - Christopher J. Davidson
- Division of Cardiology & Pulmonary, Department of Internal Medicine, University of Utah Health Sciences Center, Salt Lake City, UT 84132, USA
| | - Christoph Boeheme
- EPR Facility, Department of Physics, University of Utah Health Sciences Center, Salt Lake City, UT 84112, USA
| | - John R. Hoidal
- Division of Pulmonary, Department of Internal Medicine, University of Utah Health Sciences Center, Salt Lake City, UT 84132, USA
| | - Li Wang
- Division of Gastroenterology, Department of Internal Medicine, University of Utah Health Sciences Center, Salt Lake City, UT 84132, USA
| | - Namakkal Soorappan Rajasekaran
- Division of Cardiology & Pulmonary, Department of Internal Medicine, University of Utah Health Sciences Center, Salt Lake City, UT 84132, USA
- Corresponding author at: Room 4A100, School of Medicine Building, Divisions of Cardiology & Pulmonary, Department of Internal Medicine, University of Utah Health Science Center, Salt Lake City, UT 84132., Fax: +1 801 5857734., (N.S. Rajasekaran)
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108
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Abstract
Force-generating contractile cells of the myocardium must achieve and maintain their primary function as an efficient mechanical pump over the life span of the organism. Because only half of the cardiomyocytes can be replaced during the entire human life span, the maintenance strategy elicited by cardiac cells relies on uninterrupted renewal of their components, including proteins whose specialized functions constitute this complex and sophisticated contractile apparatus. Thus cardiac proteins are continuously synthesized and degraded to ensure proteome homeostasis, also termed "proteostasis." Once synthesized, proteins undergo additional folding, posttranslational modifications, and trafficking and/or become involved in protein-protein or protein-DNA interactions to exert their functions. This includes key transient interactions of cardiac proteins with molecular chaperones, which assist with quality control at multiple levels to prevent misfolding or to facilitate degradation. Importantly, cardiac proteome maintenance depends on the cellular environment and, in particular, the reduction-oxidation (REDOX) state, which is significantly different among cardiac organelles (e.g., mitochondria and endoplasmic reticulum). Taking into account the high metabolic activity for oxygen consumption and ATP production by mitochondria, it is a challenge for cardiac cells to maintain the REDOX state while preventing either excessive oxidative or reductive stress. A perturbed REDOX environment can affect protein handling and conformation (e.g., disulfide bonds), disrupt key structure-function relationships, and trigger a pathogenic cascade of protein aggregation, decreased cell survival, and increased organ dysfunction. This review covers current knowledge regarding the general domain of REDOX state and protein folding, specifically in cardiomyocytes under normal-healthy conditions and during disease states associated with morbidity and mortality in humans.
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Affiliation(s)
- Elisabeth S Christians
- Laboratory of Cardiac Disease, Redox Signaling and Cell Regeneration, Division of Cardiology, University of Utah School of Medicine, Salt Lake City, USA
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