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Downs CA, Kreiner L, Zhao XM, Trac P, Johnson NM, Hansen JM, Brown LA, Helms MN. Oxidized glutathione (GSSG) inhibits epithelial sodium channel activity in primary alveolar epithelial cells. Am J Physiol Lung Cell Mol Physiol 2015; 308:L943-52. [PMID: 25713321 PMCID: PMC4888545 DOI: 10.1152/ajplung.00213.2014] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/01/2014] [Accepted: 02/15/2015] [Indexed: 11/22/2022] Open
Abstract
Amiloride-sensitive epithelial Na(+) channels (ENaC) regulate fluid balance in the alveoli and are regulated by oxidative stress. Since glutathione (GSH) is the predominant antioxidant in the lungs, we proposed that changes in glutathione redox potential (Eh) would alter cell signaling and have an effect on ENaC open probability (Po). In the present study, we used single channel patch-clamp recordings to examine the effect of oxidative stress, via direct application of glutathione disulfide (GSSG), on ENaC activity. We found a linear decrease in ENaC activity as the GSH/GSSG Eh became less negative (n = 21; P < 0.05). Treatment of 400 μM GSSG to the cell bath significantly decreased ENaC Po from 0.39 ± 0.06 to 0.13 ± 0.05 (n = 8; P < 0.05). Likewise, back-filling recording electrodes with 400 μM GSSG reduced ENaC Po from 0.32 ± 0.08 to 0.17 ± 0.05 (n = 10; P < 0.05), thus implicating GSSG as an important regulatory factor. Biochemical assays indicated that oxidizing potentials promote S-glutathionylation of ENaC and irreversible oxidation of cysteine residues with N-ethylmaleimide blocked the effects of GSSG on ENaC Po. Additionally, real-time imaging studies showed that GSSG impairs alveolar fluid clearance in vivo as opposed to GSH, which did not impair clearance. Taken together, these data show that glutathione Eh is an important determinant of alveolar fluid clearance in vivo.
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Affiliation(s)
- Charles A Downs
- Nell Hodgson Woodruff School of Nursing, Emory University, Atlanta, Georgia
| | - Lisa Kreiner
- Department Pediatrics, School of Medicine, Emory University, Atlanta, Georgia
| | - Xing-Ming Zhao
- Department of Computer Science, School of Electronics and Information Engineering, Tongji University, Shanghai, China
| | - Phi Trac
- Department Pediatrics, School of Medicine, Emory University, Atlanta, Georgia
| | - Nicholle M Johnson
- Department Pediatrics, School of Medicine, Emory University, Atlanta, Georgia
| | - Jason M Hansen
- Department Pediatrics, School of Medicine, Emory University, Atlanta, Georgia; Center for Cystic Fibrosis and Airways Disease Research at Children's Healthcare of Atlanta Hospital, Atlanta, Georgia; and
| | - Lou Ann Brown
- Department Pediatrics, School of Medicine, Emory University, Atlanta, Georgia; Center for Cystic Fibrosis and Airways Disease Research at Children's Healthcare of Atlanta Hospital, Atlanta, Georgia; and
| | - My N Helms
- Department Pediatrics, School of Medicine, Emory University, Atlanta, Georgia; Center for Cystic Fibrosis and Airways Disease Research at Children's Healthcare of Atlanta Hospital, Atlanta, Georgia; and
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Vir P, Gupta D, Agarwal R, Verma I. Interaction of alveolar epithelial cells with CFP21, a mycobacterial cutinase-like enzyme. Mol Cell Biochem 2014; 396:187-99. [PMID: 25091806 DOI: 10.1007/s11010-014-2154-8] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/22/2014] [Accepted: 07/14/2014] [Indexed: 12/17/2022]
Abstract
Mycobacterium tuberculosis (M. tb), an intracellular pathogen, has the ability to infect alveolar epithelial cells (AEC) also in addition to alveolar macrophages. The virulence of M. tb is attributed to proteins encoded by genomic regions of deletion (RD) and till date 16 such regions (RD1-RD16) have been identified. Culture filtrate protein 21 (CFP21), a RD2 secretory protein, is a cutinase-like enzyme that possesses esterase and lipolytic activity. It is hypothesized that CFP21 could be playing a role in M. tb virulence by disrupting the host cell integrity. In this study, recombinant CFP21 was expressed and purified. The in vitro exposure of type I (WI26) and type II (A549) AEC to CFP21 resulted in a significant decline in their cellular viability by inducing cell apoptosis. However, the cytotoxic effects were more pronounced in WI26 cells than in A549 cells. The analysis of immune responses in CFP21-treated AEC exhibited significant production of reactive oxygen species and anti-inflammatory cytokine TGF-β which indicated oxidative stress-mediated cell death. These results show that CFP21 could play an important role in M. tb pathogenesis by disrupting the host alveolar barrier and thereby facilitating mycobacterial dissemination.
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Affiliation(s)
- Pooja Vir
- Department of Biochemistry, Postgraduate Institute of Medical Education and Research, Sector-12, Chandigarh, 160012, India
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Deprem T, Yıldız SE, Sari EK, Bingol SA, Tasci SK, Aslan S, Sozmen M, Nur G. Distribution of glutathione peroxidase 1 in liver tissues of healthy and diabetic rats treated with capsaisin. Biotech Histochem 2014; 90:1-7. [PMID: 24867493 DOI: 10.3109/10520295.2014.919024] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022] Open
Abstract
We investigated the immunohistochemical localization of glutathione peroxidase 1 (GPx 1) and the structural changes that occur in the livers of healthy and diabetic rats that were treated with capsaisin (CAP). Fifty female rats were divided into five groups: group 1, sham; group 2, untreated control; group 3, CAP-treated; group 4, streptozotocin (STZ) diabetic; group 5, STZ diabetic + CAP-treated. STZ was administered to groups 4 and 5; after verifying diabetes, CAP was administered daily for 2 weeks to groups 3 and 5. Diffuse, microvesicular and some macrovesicular fatty degeneration were observed in the cytoplasms of hepatocytes in the livers of the diabetic group. In the CAP-treated diabetic group, fat degeneration in the livers decreased slightly by day 7. Irregularity of the external contours of nuclei of the hepatocytes, swelling of the nuclei, and slight anisocytosis and anisokaryosis were observed in the hepatocytes of the diabetic group. In the CAP-treated diabetic groups, the severity of anisocytosis and anisokaryosis decreased slightly by day 7. In all groups, GPx 1 showed similar immunolocalization, but in the diabetic and diabetic + CAP groups, GPx 1 immunoreactivity was less than in the other groups. GPx 1 immunoreactivity in the CAP-treated diabetic group was weaker than in the diabetic group. In all groups, GPx 1 immunoreactivity was diffusely cytoplasmic in some of the hepatocytes, and diffusely cytoplasmic and diffusely nuclear in other hepatocytes. Also, GPx 1 immunoreactivity in the liver was more intense in the hepatocytes around Kiernan's space. We found that CAP caused a decrease in GPx 1.
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Affiliation(s)
- T Deprem
- Department of Histology-Embryology, Faculty of Veterinary Medicine, University of Kafkas
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Pandey A, Chakraborty S, Datta A, Chakraborty N. Proteomics approach to identify dehydration responsive nuclear proteins from chickpea (Cicer arietinum L.). Mol Cell Proteomics 2007; 7:88-107. [PMID: 17921517 DOI: 10.1074/mcp.m700314-mcp200] [Citation(s) in RCA: 153] [Impact Index Per Article: 9.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/15/2023] Open
Abstract
Dehydration or water-deficit is one of the most important environmental stress factors that greatly influences plant growth and development and limits crop productivity. Plants respond and adapt to such stress by altering their cellular metabolism and activating various defense machineries. Mechanisms that operate signal perception, transduction, and downstream regulatory events provide valuable information about the underlying pathways involved in environmental stress responses. The nuclear proteins constitute a highly organized, complex network that plays diverse roles during cellular development and other physiological processes. To gain a better understanding of dehydration response in plants, we have developed a comparative nuclear proteome in a food legume, chickpea (Cicer arietinum L.). Three-week-old chickpea seedlings were subjected to progressive dehydration by withdrawing water and the changes in the nuclear proteome were examined using two-dimensional gel electrophoresis. Approximately 205 protein spots were found to be differentially regulated under dehydration. Mass spectrometry analysis allowed the identification of 147 differentially expressed proteins, presumably involved in a variety of functions including gene transcription and replication, molecular chaperones, cell signaling, and chromatin remodeling. The dehydration responsive nuclear proteome of chickpea revealed a coordinated response, which involves both the regulatory as well as the functional proteins. This study, for the first time, provides an insight into the complex metabolic network operating in the nucleus during dehydration.
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Affiliation(s)
- Aarti Pandey
- National Institute for Plant Genome Research, Aruna Asaf Ali Marg, New Delhi 110067, India
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Lewis W, Day BJ, Copeland WC. Mitochondrial toxicity of NRTI antiviral drugs: an integrated cellular perspective. Nat Rev Drug Discov 2003; 2:812-22. [PMID: 14526384 DOI: 10.1038/nrd1201] [Citation(s) in RCA: 353] [Impact Index Per Article: 16.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/15/2022]
Abstract
Highly active antiretroviral therapy (HAART) regimes based on nucleoside reverse transcriptase inhibitors (NRTIs) have revolutionized the treatment of AIDS in recent years. Although HAART can successfully suppress viral replication in the long term, it is not without significant toxicity, which can seriously compromise treatment effectiveness. A major toxicity that has been recognized for more than a decade is NRTI-related mitochondrial toxicity, which manifests as serious side effects such as hepatic failure and lactic acidosis. However, a lack of understanding of the mechanisms underlying mitochondrial toxicity has hampered efforts to develop novel drugs with better side-effect profiles. This review characterizes the pharmacological mechanisms and pathways that are involved in mitochondrial dysfunction caused by NRTIs, and suggests opportunities for future pharmacological research.
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Affiliation(s)
- William Lewis
- Emory University, Department of Pathology, 1639 Pierce Drive, Room 7117, Atlanta, Georgia 30322, USA
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Aoshiba K, Nagai A. Oxidative Stress, Cell Death, and Other Damage to Alveolar Epithelial Cells Induced by Cigarette Smoke. Tob Induc Dis 2003. [PMCID: PMC2669562 DOI: 10.1186/1617-9625-1-21] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/07/2022] Open
Abstract
Cigarette smoking is a major risk factor in the development of various lung diseases, including pulmonary emphysema, pulmonary fibrosis, and lung cancer. The mechanisms of these diseases include alterations in alveolar epithelial cells, which are essential in the maintenance of normal alveolar architecture and function. Following cigarette smoking, alterations in alveolar epithelial cells induce an increase in epithelial permeability, a decrease in surfactant production, the inappropriate production of inflammatory cytokines and growth factors, and an increased risk of lung cancer. However, the most deleterious effect of cigarette smoke on alveolar epithelial cells is cell death, i.e., either apoptosis or necrosis depending on the magnitude of cigarette smoke exposure. Cell death induced by cigarette smoke exposure can largely be accounted for by an enhancement in oxidative stress. In fact, cigarette smoke contains and generates many reactive oxygen species that damage alveolar epithelial cells. Whether apoptosis and/or necrosis in alveolar epithelial cells is enhanced in healthy cigarette smokers is presently unclear. However, recent evidence indicates that the apoptosis of alveolar epithelial cells and alveolar endothelial cells is involved in the pathogenesis of pulmonary emphysema, an important cigarette smoke-induced lung disease characterized by the loss of alveolar structures. This review will discuss oxidative stress, cell death, and other damage to alveolar epithelial cells induced by cigarette smoke.
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Affiliation(s)
- K Aoshiba
- First Department of Medicine, Tokyo Women's Medical University, Tokyo, Japan
| | - A Nagai
- First Department of Medicine, Tokyo Women's Medical University, Tokyo, Japan
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Aoshiba K, Nagai A. Oxidative stress, cell death, and other damage to alveolar epithelial cells induced by cigarette smoke. Tob Induc Dis 2003; 1:219-26. [PMID: 19570263 PMCID: PMC2671551 DOI: 10.1186/1617-9625-1-3-219] [Citation(s) in RCA: 71] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/10/2022] Open
Abstract
Cigarette smoking is a major risk factor in the development of various lung diseases, including pulmonary emphysema, pulmonary fibrosis, and lung cancer. The mechanisms of these diseases include alterations in alveolar epithelial cells, which are essential in the maintenance of normal alveolar architecture and function. Following cigarette smoking, alterations in alveolar epithelial cells induce an increase in epithelial permeability, a decrease in surfactant production, the inappropriate production of inflammatory cytokines and growth factors, and an increased risk of lung cancer. However, the most deleterious effect of cigarette smoke on alveolar epithelial cells is cell death, i.e., either apoptosis or necrosis depending on the magnitude of cigarette smoke exposure. Cell death induced by cigarette smoke exposure can largely be accounted for by an enhancement in oxidative stress. In fact, cigarette smoke contains and generates many reactive oxygen species that damage alveolar epithelial cells. Whether apoptosis and/or necrosis in alveolar epithelial cells is enhanced in healthy cigarette smokers is presently unclear. However, recent evidence indicates that the apoptosis of alveolar epithelial cells and alveolar endothelial cells is involved in the pathogenesis of pulmonary emphysema, an important cigarette smoke-induced lung disease characterized by the loss of alveolar structures. This review will discuss oxidative stress, cell death, and other damage to alveolar epithelial cells induced by cigarette smoke.
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Affiliation(s)
- K Aoshiba
- First Department of Medicine, Tokyo Women's Medical University, Tokyo, Japan.
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Lewis W. Mitochondrial DNA replication, nucleoside reverse-transcriptase inhibitors, and AIDS cardiomyopathy. Prog Cardiovasc Dis 2003; 45:305-18. [PMID: 12638094 DOI: 10.1053/pcad.2003.3b] [Citation(s) in RCA: 32] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/05/2023]
Abstract
Nucleoside reverse-transcriptase inhibitors (NRTIs) in combination with other antiretrovirals (HAART) are the cornerstones of current AIDS therapy, but extensive use brought mitochondrial side effects to light. Clinical experience, pharmacological, cell, and molecular biological evidence links altered mitochondrial (mt-) DNA replication to the toxicity of NRTIs in many tissues, and conversely, mtDNA replication defects and mtDNA depletion in target tissues are observed. Organ-specific pathological changes or diverse systemic effects result from and are frequently attributed to HAART in which NRTIs are included. The shared features of mtDNA depletion and energy depletion became key observations and related the clinical and in vivo experimental findings to inhibition of mtDNA replication by NRTI triphosphates in vitro. Subsequent to those findings, other observations suggested that mitochondrial energy deprivation is concomitant with or the result of mitochondrial oxidative stress in AIDS (from HIV, for example) or from NRTI therapy itself.
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Affiliation(s)
- William Lewis
- Department of Pathology, Emory University Atlanta, GA 30322, USA.
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Lewis W, Copeland WC, Day BJ. Mitochondrial dna depletion, oxidative stress, and mutation: mechanisms of dysfunction from nucleoside reverse transcriptase inhibitors. J Transl Med 2001; 81:777-90. [PMID: 11406640 DOI: 10.1038/labinvest.3780288] [Citation(s) in RCA: 116] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022] Open
Affiliation(s)
- W Lewis
- Department of Pathology, Emory University, Atlanta, Georgia 30322, USA.
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Juurlink BH. Management of oxidative stress in the CNS: the many roles of glutathione. Neurotox Res 1999; 1:119-40. [PMID: 12835108 DOI: 10.1007/bf03033276] [Citation(s) in RCA: 40] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/15/2022]
Abstract
An outline is given of mechanisms that generate oxidative stress and inflammation. Considered are the metabolic mechanisms that give rise to peroxides, the source of strong oxidants; the production of dicarbonyls that interact with macromolecules to form advanced glycation endproducts; and the role that activation of the transcription factor NF(Kappa)B has in the expression of pro-inflammatory genes. Management of oxidative stress is considered by outlining the central role of reduced glutathione (GSH) in peroxide scavenging, dicarbonyl scavenging and activation of NF(Kappa)B. Cellular GSH levels are dictated by the balance between consumption, oxidation of GSH, reduction of oxidized-glutathione, and synthesis. The rate-limiting enzyme in GSH synthesis is L-gamma-glutamyl-L-cysteine synthase, a phase II enzyme. Phase II enzyme inducers are found in many fruits and vegetables. It is suggested that dietary phase II enzyme inducers be investigated for their potential for preventing or retarding the development of degenerative diseases that have an underlying oxidative stress and inflammatory component.
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Affiliation(s)
- B H Juurlink
- Department of Anatomy and Cell Biology, The Cameco Multiple Sclerosis and Neuroscience Research Centre, College of Medicine, University of Saskatchewan, 107 Wiggins Rd., Saskatoon, SK, S7N 5E5 Canada.
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Lindenau J, Noack H, Asayama K, Wolf G. Enhanced cellular glutathione peroxidase immunoreactivity in activated astrocytes and in microglia during excitotoxin induced neurodegeneration. Glia 1998. [DOI: 10.1002/(sici)1098-1136(199810)24:2<252::aid-glia10>3.0.co;2-z] [Citation(s) in RCA: 61] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
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