151
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Redox signaling and cancer: The role of “labile” iron. Cancer Lett 2008; 266:21-9. [DOI: 10.1016/j.canlet.2008.02.038] [Citation(s) in RCA: 223] [Impact Index Per Article: 13.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/31/2008] [Revised: 01/31/2008] [Accepted: 02/11/2008] [Indexed: 01/26/2023]
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152
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Luo J, Yang L. Role of nicotinamide adenine dinucleotide phosphate-oxidase family in liver fibrogenesis. Shijie Huaren Xiaohua Zazhi 2008; 16:1768-1773. [DOI: 10.11569/wcjd.v16.i16.1768] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 02/06/2023] Open
Abstract
NADPH oxidase (nicotinamide adenine dinucleotide phosphate-oxidase, NOX) is a multi-protein complex producing reactive oxygen species (ROS), present both in phagocytes, being essential in host defense and in non-phagocytic cells, regulating intracellular signaling. In liver, NADPH oxidase plays a central role in fibrogenesis. A functionally active form of NADPH oxidase is expressed not only in Kupffer cells (phagocytic cell type) but also in hepatic stellate cells (HSCs) (non-phagocytic cell type), suggestive of its role the non-phagocytic NADPH oxidase in HSCs activation. This paper reviewed effects of NOX in liver fibrogenesis.
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153
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Expression of NADPH oxidases and enhanced H(2)O(2)-generating activity in human coronary artery endothelial cells upon induction with tumor necrosis factor-alpha. Int Immunopharmacol 2008; 8:1377-85. [PMID: 18687299 DOI: 10.1016/j.intimp.2008.05.004] [Citation(s) in RCA: 53] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/06/2008] [Revised: 05/05/2008] [Accepted: 05/06/2008] [Indexed: 11/21/2022]
Abstract
Tumor necrosis factor (TNF)-alpha, which potentiates reactive oxygen species (ROS) generation, is crucial for the development of coronary arteritis and aneurysm in Kawasaki disease. We hypothesized that vascular NADPH oxidase (Nox) enzymes participate in the TNF-alpha-triggered endothelial damage through elevating ROS generation. Thus, we herein examine the expression of Nox enzymes in human coronary artery endothelial cells (HCAEC) and the effects of TNF-alpha on Nox-mediated ROS generation. We show that HCAEC in culture spontaneously generate H(2)O(2) at basal level (0.53 nmol/min/mg protein). In searching for Nox components responsible for the H(2)O(2) generation, two distinct isoforms of Nox4 are found expressed in HCAEC: the prototype Nox4A and the shorter Nox4B, respectively in the postnuclear supernatant and the nuclear fractions. Other expressed Nox family components are: as mRNAs, Nox4C, Nox4D, Nox1, p51(nox), and Racs; as mRNAs and proteins, Nox2, p22(phox), p47(phox), and p67(phox). The H(2)O(2)-generating activity increases up to three-fold upon inclusion of TNF-alpha in culture, concomitantly with augmented expressions of Nox4A, p22(phox), p47(phox) and p67(phox) proteins. Together, these results suggest that Nox2 and Nox4A enzymes are induced by TNF-alpha endowing HCAEC with enhanced ROS-generating activity, which may play a role in the initial endothelial dysfunction through oxidative stress.
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154
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Nox enzymes and oxidative stress in the immunopathology of the gastrointestinal tract. Semin Immunopathol 2008; 30:315-27. [PMID: 18521607 DOI: 10.1007/s00281-008-0124-5] [Citation(s) in RCA: 71] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/29/2008] [Accepted: 05/08/2008] [Indexed: 02/07/2023]
Abstract
Chronic inflammation caused by Helicobacter pylori infection or inflammatory bowel disease (IBD) is closely linked to cancer development. Innate immune abnormalities and enhanced production of reactive oxygen species through a phagocyte NADPH oxidase (Nox2) are key issues in understanding the pathogenesis of inflammation-dependent carcinogenesis. Besides Nox2, functionally distinct homologues (Nox1, Nox3, Nox4, Nox5, Duox1, and Duox2) have been identified. Nox1 and Duox2 are highly expressed in the gastrointestinal tract. Although the functional roles of Nox/Duox in the gastrointestinal tract are still unclear, we will review their potential roles in the gastrointestinal immunopathology, particularly in H. pylori-induced inflammation, IBD, and malignancy.
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155
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Sumimoto H. Structure, regulation and evolution of Nox-family NADPH oxidases that produce reactive oxygen species. FEBS J 2008; 275:3249-77. [PMID: 18513324 DOI: 10.1111/j.1742-4658.2008.06488.x] [Citation(s) in RCA: 511] [Impact Index Per Article: 31.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
NADPH oxidases of the Nox family exist in various supergroups of eukaryotes but not in prokaryotes, and play crucial roles in a variety of biological processes, such as host defense, signal transduction, and hormone synthesis. In conjunction with NADPH oxidation, Nox enzymes reduce molecular oxygen to superoxide as a primary product, and this is further converted to various reactive oxygen species. The electron-transferring system in Nox is composed of the C-terminal cytoplasmic region homologous to the prokaryotic (and organelle) enzyme ferredoxin reductase and the N-terminal six transmembrane segments containing two hemes, a structure similar to that of cytochrome b of the mitochondrial bc(1) complex. During the course of eukaryote evolution, Nox enzymes have developed regulatory mechanisms, depending on their functions, by inserting a regulatory domain (or motif) into their own sequences or by obtaining a tightly associated protein as a regulatory subunit. For example, one to four Ca(2+)-binding EF-hand motifs are present at the N-termini in several subfamilies, such as the respiratory burst oxidase homolog (Rboh) subfamily in land plants (the supergroup Plantae), the NoxC subfamily in social amoebae (the Amoebozoa), and the Nox5 and dual oxidase (Duox) subfamilies in animals (the Opisthokonta), whereas an SH3 domain is inserted into the ferredoxin-NADP(+) reductase region of two Nox enzymes in Naegleria gruberi, a unicellular organism that belongs to the supergroup Excavata. Members of the Nox1-4 subfamily in animals form a stable heterodimer with the membrane protein p22(phox), which functions as a docking site for the SH3 domain-containing regulatory proteins p47(phox), p67(phox), and p40(phox); the small GTPase Rac binds to p67(phox) (or its homologous protein), which serves as a switch for Nox activation. Similarly, Rac activates the fungal NoxA via binding to the p67(phox)-like protein Nox regulator (NoxR). In plants, on the other hand, this GTPase directly interacts with the N-terminus of Rboh, leading to superoxide production. Here I describe the regulation of Nox-family oxidases on the basis of three-dimensional structures and evolutionary conservation.
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Affiliation(s)
- Hideki Sumimoto
- Medical Institute of Bioregulation, Kyushu University, Fukuoka CREST, Japan Science and Technology Agency, Tokyo, Japan.
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156
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Ogier-Denis E, Mkaddem SB, Vandewalle A. NOX enzymes and Toll-like receptor signaling. Semin Immunopathol 2008; 30:291-300. [PMID: 18493762 DOI: 10.1007/s00281-008-0120-9] [Citation(s) in RCA: 79] [Impact Index Per Article: 4.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/30/2008] [Accepted: 04/24/2008] [Indexed: 12/20/2022]
Abstract
Invading microorganisms are recognized by the host innate immune system through pattern recognition receptors. Among these receptors, Toll-like receptors (TLRs) are able to sense the molecular signatures of microbial pathogens, protozoa, fungi, and virus and activate proinflammatory signaling cascades. In addition to their role in bacterial killing by phagocytes, reactive oxygen species generated by NADPH oxidase (NOX) homologues also play key roles in signaling and host defense in a variety of cell types. Recent studies have demonstrated a link between TLR activation and NOX homologues following microbial recognition highlighting their important role in the innate immune response and host defense.
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Affiliation(s)
- Eric Ogier-Denis
- INSERM, U773, Centre de Recherche Biomédicale Bichat Beaujon, CRB3, BP 416, 75018 Paris, France.
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157
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Gianni D, Bohl B, Courtneidge SA, Bokoch GM. The involvement of the tyrosine kinase c-Src in the regulation of reactive oxygen species generation mediated by NADPH oxidase-1. Mol Biol Cell 2008; 19:2984-94. [PMID: 18463161 DOI: 10.1091/mbc.e08-02-0138] [Citation(s) in RCA: 100] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/07/2023] Open
Abstract
NADPH oxidase (Nox) family enzymes are one of the main sources of cellular reactive oxygen species (ROS), which have been shown to function as second messenger molecules. To date, seven members of this family have been reported, including Nox1-5 and Duox1 and -2. With the exception of Nox2, the regulation of the Nox enzymes is still poorly understood. Nox1 is highly expressed in the colon, and it requires two cytosolic regulators, NoxO1 and NoxA1, as well as the binding of Rac1 GTPase, for its activity. In this study, we investigate the role of the tyrosine kinase c-Src in the regulation of ROS formation by Nox1. We show that c-Src induces Nox1-mediated ROS generation in the HT29 human colon carcinoma cell line through a Rac-dependent mechanism. Treatment of HT29 cells with the Src inhibitor PP2, expression of a kinase-inactive form of c-Src, and c-Src depletion by small interfering RNA (siRNA) reduce both ROS generation and the levels of active Rac1. This is associated with decreased Src-mediated phosphorylation and activation of the Rac1-guanine nucleotide exchange factor Vav2. Consistent with this, Vav2 siRNA that specifically reduces endogenous Vav2 protein is able to dramatically decrease Nox1-dependent ROS generation and abolish c-Src-induced Nox1 activity. Together, these results establish c-Src as an important regulator of Nox1 activity, and they may provide insight into the mechanisms of tumor formation in colon cancers.
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Affiliation(s)
- Davide Gianni
- Departments of Immunology and Cell Biology, The Scripps Research Institute, La Jolla, CA 92037, USA
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158
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Nauseef WM. Nox enzymes in immune cells. Semin Immunopathol 2008; 30:195-208. [DOI: 10.1007/s00281-008-0117-4] [Citation(s) in RCA: 65] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/20/2008] [Accepted: 04/02/2008] [Indexed: 01/08/2023]
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159
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Monteiro HP, Arai RJ, Travassos LR. Protein tyrosine phosphorylation and protein tyrosine nitration in redox signaling. Antioxid Redox Signal 2008; 10:843-89. [PMID: 18220476 DOI: 10.1089/ars.2007.1853] [Citation(s) in RCA: 124] [Impact Index Per Article: 7.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/05/2023]
Abstract
Reversible phosphorylation of protein tyrosine residues by polypeptide growth factor-receptor protein tyrosine kinases is implicated in the control of fundamental cellular processes including the cell cycle, cell adhesion, and cell survival, as well as cell proliferation and differentiation. During the last decade, it has become apparent that receptor protein tyrosine kinases and the signaling pathways they activate belong to a large signaling network. Such a network can be regulated by various extracellular cues, which include cell adhesion, agonists of G protein-coupled receptors, and oxidants. It is well documented that signaling initiated by receptor protein tyrosine kinases is directly dependent on the intracellular production of oxidants, including reactive oxygen and nitrogen species. Accumulated evidence indicates that the intracellular redox environment plays a major role in the mechanisms underlying the actions of growth factors. Oxidation of cysteine thiols and nitration of tyrosine residues on signaling proteins are described as posttranslational modifications that regulate, positively or negatively, protein tyrosine phosphorylation (PTP). Early observations described the inhibition of PTP activities by oxidants, resulting in increased levels of proteins phosphorylated on tyrosine. Therefore, a redox circuitry involving the increasing production of intracellular oxidants associated with growth-factor stimulation/cell adhesion, oxidative reversible inhibition of protein tyrosine phosphatases, and the activation of protein tyrosine kinases can be delineated.
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Affiliation(s)
- Hugo P Monteiro
- Department of Biochemistry/Molecular Biology and CINTERGEN, Universidade Federal de São Paulo, São Paulo, Brazil.
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160
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Nakano Y, Longo-Guess CM, Bergstrom DE, Nauseef WM, Jones SM, Bánfi B. Mutation of the Cyba gene encoding p22phox causes vestibular and immune defects in mice. J Clin Invest 2008; 118:1176-85. [PMID: 18292807 DOI: 10.1172/jci33835] [Citation(s) in RCA: 67] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/05/2007] [Accepted: 12/05/2007] [Indexed: 02/03/2023] Open
Abstract
In humans, hereditary inactivation of either p22(phox) or gp91(phox) leads to chronic granulomatous disease (CGD), a severe immune disorder characterized by the inability of phagocytes to produce bacteria-destroying ROS. Heterodimers of p22(phox) and gp91(phox) proteins constitute the superoxide-producing cytochrome core of the phagocyte NADPH oxidase. In this study, we identified the nmf333 mouse strain as what we believe to be the first animal model of p22(phox) deficiency. Characterization of nmf333 mice revealed that deletion of p22(phox) inactivated not only the phagocyte NADPH oxidase, but also a second cytochrome in the inner ear epithelium. As a consequence, mice of the nmf333 strain exhibit a compound phenotype consisting of both a CGD-like immune defect and a balance disorder caused by the aberrant development of gravity-sensing organs. Thus, in addition to identifying a model of p22(phox)-dependent immune deficiency, our study indicates that a clinically identifiable patient population with an otherwise cryptic loss of gravity-sensor function may exist. Thus, p22(phox) represents a shared and essential component of at least 2 superoxide-producing cytochromes with entirely different biological functions. The site of p22(phox) expression in the inner ear leads us to propose what we believe to be a novel mechanism for the control of vestibular organogenesis.
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Affiliation(s)
- Yoko Nakano
- Department of Anatomy and Cell Biology, Inflammation Program, University of Iowa, Iowa City, Iowa, USA
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161
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Abstract
Important roles for reactive oxygen species (ROS) in physiology and pathophysiology have been increasingly recognized. Under normal conditions, ROS serve as signaling molecules in the regulation of cellular functions. However, enhanced ROS production as a result of the activation of nicotinamide adenine dinucleotide phosphate (NADPH) oxidase contributes significantly to the pathogeneses of vascular diseases. Although it has become evident that increased ROS is associated with erectile dysfunction (ED), the sources of ROS in the penis remain largely unknown. In recent years, emergent evidence suggests the possible role of NADPH oxidase in inducing ED. In this review, we examine the relationship between ROS and ED in different disease models and discuss the current evidence basis for NADPH oxidase-derived ROS in ED.
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Affiliation(s)
- Liming Jin
- Department of Internal Medicine, University of California, Davis, CA 95616, USA.
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162
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Abstract
According to the free radical theory of aging proposed by Denham Harman more than 50 years ago, oxidatively modified cellular components accumulate continuously in the cells during the organism's lifespan leading to progressive decline of cellular functions. Since then, it has been shown that proteins, lipids, nucleic acids and other cell components undergo reversible and/or irreversible oxidative modifications during aging. Moreover, oxidized cell components can undergo further oxidative modifications leading to formation of products that cell degradation systems are incapable of removing. Accumulation of such non-degradable aggregates further inhibits the functionality of degradation systems, thus aggravating the effects and leading to a vicious cycle. In this presentation, we propose that the availability of intracellular iron in its redox active form (labile iron) represents the main catalyst that mediates extensive oxidative modifications of cellular components and ultimately leads to their accumulation and consequent cellular dysfunction. It is tempting to speculate that regulated restriction of labile iron may have positive effects on health in general and aging in particular.
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Affiliation(s)
- Dimitrios Galaris
- Laboratory of Biological Chemistry, University of Ioannina Medical School, Ioannina, Greece.
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163
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Ginnan R, Guikema BJ, Halligan KE, Singer HA, Jourd’heuil D. Regulation of smooth muscle by inducible nitric oxide synthase and NADPH oxidase in vascular proliferative diseases. Free Radic Biol Med 2008; 44:1232-45. [PMID: 18211830 PMCID: PMC2390910 DOI: 10.1016/j.freeradbiomed.2007.12.025] [Citation(s) in RCA: 39] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/16/2007] [Revised: 12/11/2007] [Accepted: 12/11/2007] [Indexed: 10/22/2022]
Abstract
Inflammation plays a critical role in promoting smooth muscle migration and proliferation during vascular diseases such as postangioplasty restenosis and atherosclerosis. Another common feature of many vascular diseases is the contribution of reactive oxygen (ROS) and reactive nitrogen (RNS) species to vascular injury. Primary sources of ROS and RNS in smooth muscle are several isoforms of NADPH oxidase (Nox) and the cytokine-regulated inducible nitric oxide (NO) synthase (iNOS). One important example of the interaction between NO and ROS is the reaction of NO with superoxide to yield peroxynitrite, which may contribute to the pathogenesis of hypertension. In this review, we discuss the literature that supports an alternate possibility: Nox-derived ROS modulate NO bioavailability by altering the expression of iNOS. We highlight data showing coexpression of iNOS and Nox in vascular smooth muscle demonstrating the functional consequences of iNOS and Nox during vascular injury. We describe the relevant literature demonstrating that the mitogen-activated protein kinases are important modulators of proinflammatory cytokine-dependent expression of iNOS. A central hypothesis discussed is that ROS-dependent regulation of the serine/threonine kinase protein kinase Cdelta is essential to understanding how Nox may regulate signaling pathways leading to iNOS expression. Overall, the integration of nonphagocytic NADPH oxidase with cytokine signaling in general and in vascular smooth muscle in particular is poorly understood and merits further investigation.
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Affiliation(s)
| | | | | | | | - David Jourd’heuil
- To whom correspondence should be addressed: Albany Medical College, Center for Cardiovascular Sciences, 47 New Scotland Avenue (MC8), Albany, NY 12208; Tel: (518) 262 8104; Fax: (518) 262 8101; E-mail:
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164
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de Carvalho DD, Sadok A, Bourgarel-Rey V, Gattacceca F, Penel C, Lehmann M, Kovacic H. Nox1 downstream of 12-lipoxygenase controls cell proliferation but not cell spreading of colon cancer cells. Int J Cancer 2008; 122:1757-64. [PMID: 18076063 DOI: 10.1002/ijc.23300] [Citation(s) in RCA: 49] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/03/2023]
Abstract
The catalytic subunit of the NADPH oxidase complex, Nox1 (homologue of gp91phox/Nox2), expressed mainly in intestinal epithelial and vascular smooth muscle cells, functions in innate immune defense and cell proliferation. The molecular mechanisms underlying these functions, however, are not completely understood. We measured Nox1-dependent O2- production during cell spreading on Collagen IV (Coll IV) in colon carcinoma cell lines. Knocking down Nox1 by shRNA, we showed that Nox1-dependent O2- production is activated during cell spreading after 4 hr of adhesion on Collagen IV. Nox1 activation during cell spreading relies on Rac1 activation and arachidonic metabolism. Our results showed that manoalide (a secreted phospholipase A2 inhibitor) and cinnamyl-3,4-dihydroxy-alpha-cyanocinnamate (a 12-lipoxygenase inhibitor) inhibit O2- production, cell spreading and cell proliferation in these colonic epithelial cells. 12-Lipoxygenase inhibition of ROS production and cell spreading can be reversed by adding 12-HETE, a 12-lipoxygenase product, supporting the specific effect observed with cinnamyl-3,4-dihydroxy-alpha-cyanocinnamate. In contrast, Nox1 shRNA and DPI (NADPH oxidase inhibitor) weakly affect cell spreading while inhibiting O2- production and cell proliferation. These results suggest that the 12-lipoxygenase pathway is upstream of Nox1 activation and controls cell spreading and proliferation, while Nox1 specifically affects cell proliferation.
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Affiliation(s)
- Daniela D de Carvalho
- CNRS FRE 2737, Cytosquelette et Intégration des Signaux du Microenvironnement Tumoral (CISMET), Aix-Marseille Université, France
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165
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Manea A, Manea SA, Gafencu AV, Raicu M, Simionescu M. AP-1-dependent transcriptional regulation of NADPH oxidase in human aortic smooth muscle cells: role of p22phox subunit. Arterioscler Thromb Vasc Biol 2008; 28:878-85. [PMID: 18309110 DOI: 10.1161/atvbaha.108.163592] [Citation(s) in RCA: 84] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
OBJECTIVE NADPH oxidase (NADPHox) is the major source of reactive oxygen species in vascular diseases; the mechanisms of enzyme activation are not completely elucidated. AP-1 controls the expression of many genes linked to vascular smooth muscle cells (SMCs) dysfunction. In this study we searched for the role of AP-1 in the regulation of NADPHox expression and function in human aortic SMCs exposed to proinflammatory conditions. METHODS AND RESULTS Cultured SMCs were exposed to either angiotensin II (Ang II) or tumor necrosis factor (TNF)-alpha. The lucigenin-enhanced chemiluminescence assay and real-time polymerase chain reaction analysis revealed that AP-1 and mitogen-activated protein kinase inhibitors reduced both Ang II or TNF-alpha-dependent upregulation of NADPHox activity and mRNA expression (NOX1, NOX4, p67(phox), p47(phox), p22(phox)). Inhibitors of AP-1 significantly diminished the Ang II or TNF-alpha-stimulated p22(phox) promoter activity and protein level. Transient overexpression of c-Jun/c-Fos upregulated p22(phox) promoter activity. Transcription factor pull-down assay and chromatin immunoprecipitation demonstrated the physical interaction of c-Jun protein with predicted AP-1-binding sites in the p22(phox) gene promoter. CONCLUSIONS In SMCs exposed to Ang II or TNF-alpha, inhibition of AP-1-related pathways reduces NADPHox expression and the O(2)(-) production. The physical interaction of AP-1 with p22(phox) gene promoter facilitates NADPHox regulation.
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Affiliation(s)
- Adrian Manea
- Institute of Cellular Biology and Pathology Nicolae Simionescu, 8 B.P. Hasdeu Street, Bucharest, P.O. Box 35-14, Romania
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166
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Chiera F, Meccia E, Degan P, Aquilina G, Pietraforte D, Minetti M, Lambeth D, Bignami M. Overexpression of human NOX1 complex induces genome instability in mammalian cells. Free Radic Biol Med 2008; 44:332-42. [PMID: 17963706 DOI: 10.1016/j.freeradbiomed.2007.09.018] [Citation(s) in RCA: 37] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/25/2007] [Revised: 09/05/2007] [Accepted: 09/05/2007] [Indexed: 11/18/2022]
Abstract
The production of reactive oxygen species (ROS) in mammalian cells is tightly regulated because of their potential to damage macromolecules, including DNA. To investigate possible links between high ROS levels, oxidative DNA damage, and genomic instability in mammalian cells, we established a novel model of chronic oxidative stress by coexpressing the NADPH oxidase human (h) NOX1 gene together with its cofactors NOXO1 and NOXA1. Transfectants of mismatch repair (MMR)-proficient HeLa cells or MMR-defective Msh2(-/-) mouse embryo fibroblasts overexpressing the hNOX1 complex displayed increased intracellular ROS levels. In one HeLa clone in which ROS were particularly elevated, reactive nitrogen species were also increased and nitrated proteins were identified with an anti-3-nitrotyrosine antibody. Overexpression of the hNOX1 complex increased the steady-state levels of DNA 8-oxo-7,8-dihydroguanine and caused a threefold increase in the HPRT mutation rate in HeLa cells. In contrast, additional oxidatively generated damage did not affect the constitutive mutator phenotype of the Msh2(-/-) fibroblasts. Because no significant changes in the expression of several DNA repair enzymes for oxidative DNA damage were identified, we suggest that chronic oxidative stress can saturate the cell's DNA repair capacity and cause significant genomic instability.
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Affiliation(s)
- Federica Chiera
- Department of Environment and Primary Prevention, Istituto Superiore di Sanità, 00161 Roma, Italy
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167
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Valente AJ, Zhou Q, Lu Z, He W, Qiang M, Ma W, Li G, Wang L, Banfi B, Steger K, Krause KH, Clark RA, Li S. Regulation of NOX1 expression by GATA, HNF-1alpha, and Cdx transcription factors. Free Radic Biol Med 2008; 44:430-43. [PMID: 18005670 DOI: 10.1016/j.freeradbiomed.2007.10.035] [Citation(s) in RCA: 27] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/21/2007] [Revised: 10/05/2007] [Accepted: 10/06/2007] [Indexed: 11/20/2022]
Abstract
NOX1, a member of the NOX family of NADPH oxidases, is expressed primarily in colon epithelium, where it may function in host defense and growth regulation. We investigated factors responsible for its transcriptional regulation in vitro and its expression in vivo. Analysis of promoter constructs in the CaCo2 cell line identified a complex element between -422 and -291 critical for promoter activity. This element contained four sites that bound GATA-4, -5, and -6 in vitro with varied affinities. One site also bound the caudal-related homeodomain proteins Cdx1 and Cdx2, whereas another also bound hepatocyte nuclear factor-1alpha (HNF-1alpha). GATA-6, HNF-1alpha, and Cdx2 also bound to this region in the intact chromatin of CaCo2 cells. These factors demonstrated cooperativity when transactivating the NOX1 promoter. NOX1 mRNA was detected in human colon epithelial cells along the crypt-villus axis. A gradient of NOX1 mRNA expression was seen in the colons of normal as well as germ-free mice, with significantly higher levels in distal compared with proximal segments. The expression gradients of NOX1 mRNA in the colon paralleled those of GATA-6, HNF-1alpha, and Cdx1. These data indicate that developmental, tissue-restricted transcription factors play a key role in NOX1 regulation in vivo.
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Affiliation(s)
- Anthony J Valente
- Department of Medicine, University of Texas Health Science Center, San Antonio, TX 78229-3900, USA.
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168
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Tateishi Y, Sasabe E, Ueta E, Yamamoto T. Ionizing irradiation induces apoptotic damage of salivary gland acinar cells via NADPH oxidase 1-dependent superoxide generation. Biochem Biophys Res Commun 2008; 366:301-7. [DOI: 10.1016/j.bbrc.2007.11.039] [Citation(s) in RCA: 53] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/09/2007] [Accepted: 11/10/2007] [Indexed: 10/22/2022]
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169
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Tominaga K, Kawahara T, Sano T, Toida K, Kuwano Y, Sasaki H, Kawai T, Teshima-Kondo S, Rokutan K. Evidence for cancer-associated expression of NADPH oxidase 1 (Nox1)-based oxidase system in the human stomach. Free Radic Biol Med 2007; 43:1627-38. [PMID: 18037128 DOI: 10.1016/j.freeradbiomed.2007.08.029] [Citation(s) in RCA: 59] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/27/2007] [Revised: 08/03/2007] [Accepted: 08/29/2007] [Indexed: 01/13/2023]
Abstract
Helicobacter pylori infection has been suggested to stimulate expression of the NADPH oxidase 1 (Nox1)-based oxidase system in guinea pig gastric epithelium, whereas Nox1 mRNA expression has not yet been documented in the human stomach. PCR of human stomach cDNA libraries showed that Nox1 and Nox organizer 1 (NOXO1) messages were absent from normal stomachs, while they were specifically coexpressed in intestinal- and diffuse-type adenocarcinomas including signet-ring cell carcinoma. Immunohistochemistry showed that Nox1 and NOXO1 proteins were absent from chronic atrophic gastritis (15 cases), adenomas (4 cases), or surrounding tissues of adenocarcinomas (45 cases). In contrast, Nox1 and its partner proteins were expressed in intestinal-type adenocarcinomas (19/21 cases), diffuse-type adenocarcinomas (15/15 cases), and signet-ring cell carcinomas (9/9 cases). Confocal microscopy revealed that Nox1, NOXO1, Nox activator 1, and p22(phox) were predominantly associated with Golgi apparatus in these cancer cells, while diffuse-type adenocarcinomas also contained cancer cells having Nox1 and its partner proteins in their nuclei. Nox1-expressing cancer cells exhibited both gastric and intestinal phenotypes, as assessed by expression of mucin core polypeptides. Thus, the Nox1-base oxidase may be a potential marker of neoplastic transformation and play an important role in oxygen radical- and inflammation-dependent carcinogenesis in the human stomach.
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MESH Headings
- Adaptor Proteins, Signal Transducing
- Adaptor Proteins, Vesicular Transport/genetics
- Adaptor Proteins, Vesicular Transport/metabolism
- Adenocarcinoma/enzymology
- Adenocarcinoma/genetics
- Adenoma/enzymology
- Adenoma/genetics
- Animals
- Carcinoma, Signet Ring Cell/enzymology
- Carcinoma, Signet Ring Cell/genetics
- Free Radicals/metabolism
- Gastric Mucosa/enzymology
- Gastritis, Atrophic/enzymology
- Gastritis, Atrophic/genetics
- Gene Expression Regulation, Enzymologic
- Gene Expression Regulation, Neoplastic
- Guinea Pigs
- Helicobacter Infections/complications
- Helicobacter pylori/pathogenicity
- Humans
- Immunohistochemistry
- NADPH Oxidase 1
- NADPH Oxidases/genetics
- NADPH Oxidases/metabolism
- RNA, Messenger/genetics
- RNA, Messenger/metabolism
- RNA, Neoplasm/genetics
- RNA, Neoplasm/metabolism
- Stomach Neoplasms/enzymology
- Stomach Neoplasms/etiology
- Stomach Neoplasms/genetics
- Stomach Neoplasms/pathology
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Affiliation(s)
- Kumiko Tominaga
- Department of Stress Science, Institute of Health Biosciences, University of Tokushima Graduate School, 3-18-15 Kuramoto-cho, Tokushima 770-8503, Japan
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170
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Choi H, Leto TL, Hunyady L, Catt KJ, Bae YS, Rhee SG. Mechanism of angiotensin II-induced superoxide production in cells reconstituted with angiotensin type 1 receptor and the components of NADPH oxidase. J Biol Chem 2007; 283:255-267. [PMID: 17981802 DOI: 10.1074/jbc.m708000200] [Citation(s) in RCA: 51] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
The mechanism of angiotensin II (Ang II)-induced superoxide production was investigated with HEK293 or Chinese hamster ovary cells reconstituted with the angiotensin type 1 receptor (AT(1)R) and NADPH oxidase (either Nox1 or Nox2) along with a pair of adaptor subunits (either NOXO1 with NOXA1 or p47(phox) with p67(phox)). Ang II enhanced the activity of both Nox1 and Nox2 supported by either adaptor pair, with more effective activation of Nox1 in the presence of NOXO1 and NOXA1 and of Nox2 in the presence of p47(phox) and p67(phox). Expression of several AT(1)R mutants showed that interaction of the receptor with G proteins but not that with beta-arrestin or with other proteins (Jak2, phospholipase C-gamma1, SH2 domain-containing phosphatase 2) that bind to the COOH-terminal region of AT(1)R, was necessary for Ang II-induced superoxide production. The effects of constitutively active alpha subunits of G proteins and of various pharmacological agents implicated signaling by a pathway comprising AT(1)R, Galpha(q/11), phospholipase C-beta, and protein kinase C as largely, but not exclusively, responsible for Ang II-induced activation of Nox1 and Nox2 in the reconstituted cells. A contribution of Galpha(12/13), phospholipase D, and phosphatidyl-inositol 3-kinase to Ang II-induced superoxide generation was also suggested, whereas Src and the epidermal growth factor receptor did not appear to participate in this effect of Ang II. In reconstituted cells stimulated with Ang II, Nox2 exhibited a more sensitive response than Nox1 to the perturbation of protein kinase C, phosphatidylinositol 3-kinase, or the small GTPase Rac1.
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Affiliation(s)
- Hyun Choi
- Division of Life and Pharmaceutical Sciences, Ewha Womans University, Seoul 120-750, Korea
| | - Thomas L Leto
- Laboratory of Host Defenses, NIAID, National Institutes of Health, Bethesda, Maryland 20892
| | - László Hunyady
- Department of Physiology, Semmelweis University, H-1088 Budapest, Hungary
| | - Kevin J Catt
- Endocrinology and Reproduction Research Branch, NICHD, National Institutes of Health, Bethesda, Maryland 20892
| | - Yun Soo Bae
- Division of Life and Pharmaceutical Sciences, Ewha Womans University, Seoul 120-750, Korea.
| | - Sue Goo Rhee
- Division of Life and Pharmaceutical Sciences, Ewha Womans University, Seoul 120-750, Korea.
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171
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Kim JS, Diebold BA, Babior BM, Knaus UG, Bokoch GM. Regulation of Nox1 activity via protein kinase A-mediated phosphorylation of NoxA1 and 14-3-3 binding. J Biol Chem 2007; 282:34787-800. [PMID: 17913709 DOI: 10.1074/jbc.m704754200] [Citation(s) in RCA: 78] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
Nox activator 1 (NoxA1) is a homologue of p67(phox) that acts in conjunction with Nox organizer 1 (NoxO1) to regulate reactive oxygen species (ROS) production by the NADPH oxidase Nox1. The phosphorylation of cytosolic regulatory components by multiple kinases plays important roles in assembly and activity of the phagocyte NADPH oxidase (Nox2) system, but little is known about regulation by phosphorylation in the Nox1 system. Here we identify Ser(172) and Ser(461) of NoxA1 as phosphorylation sites for protein kinase A (PKA). A consequence of this phosphorylation was the enhancement of NoxA1 complex formation with 14-3-3 proteins. Using both a transfected human embryonic kidney 293 cell Nox1 model system and endogenous Nox1 in colon cell lines, we showed that the elevation of cAMP inhibits, whereas the inhibition of PKA enhances, Nox1-dependent ROS production through effects on NoxA1. Inhibition of Nox1 activity was intensified by the availability of 14-3-3zeta protein, and this regulatory interaction was dependent on PKA-phosphorylatable sites at Ser(172) and Ser(461) in NoxA1. We showed that phosphorylation and 14-3-3 binding induce the dissociation of NoxA1 from the Nox1 complex at the plasma membrane, suggesting a mechanism for the inhibitory effect on Nox1 activity. Our data establish that PKA-phosphorylated NoxA1 is a new binding partner of 14-3-3 protein(s) and that this forms the basis of a novel mechanism regulating the formation of ROS by Nox1 and, potentially, other NoxA1-regulated Nox family members.
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Affiliation(s)
- Jun-Sub Kim
- Department of Immunology, The Scripps Research Institute, La Jolla, California 92037, USA
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172
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Manea A, Manea SA, Gafencu AV, Raicu M. Regulation of NADPH oxidase subunit p22(phox) by NF-kB in human aortic smooth muscle cells. Arch Physiol Biochem 2007; 113:163-72. [PMID: 18158642 DOI: 10.1080/13813450701531235] [Citation(s) in RCA: 91] [Impact Index Per Article: 5.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 10/22/2022]
Abstract
Accumulating evidence demonstrates the involvement of oxidative stress in the pathophysiology of cardiovascular diseases. The molecular mechanisms accountable for the increased production of reactive oxygen species remain uncertain. Among others, NADPH oxidase is one of the most important sources of superoxide in vascular cells. Here we investigate the role of NF-kB in the regulation of p22(phox) subunit and NADPH oxidase activity, in human aortic smooth muscle cells. Overexpression of p65/RelA or IKKbeta up-regulated p22(phox) gene promoter activity. Transcription factor pull-down assays demonstrated the physical interaction of p65/RelA protein with predicted NF-kB binding sites. Real time PCR and Western blotting analysis showed that p22(phox) mRNA and protein expression are significantly down-regulated by NF-kB decoy oligodeoxynucleotides and N-alpha-tosyl-l-phenylalanine chloromethyl ketone (TPCK). Lucigenin-enhanced chemiluminescence assay revealed that NF-kB inhibitors reduce the NADPH-dependent superoxide production. Regulation of NADPH oxidase by NF-kB may represent a possible mechanism whereby pro-inflammatory factors induce oxidative stress in atherosclerosis, hypertension, diabetes, stroke or heart failure.
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Affiliation(s)
- A Manea
- Nicolae Simionescu Institute of Cellular Biology and Pathology, 8 B.P. Hadeu Street, Bucharest, Romania
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173
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Kawahara T, Lambeth JD. Molecular evolution of Phox-related regulatory subunits for NADPH oxidase enzymes. BMC Evol Biol 2007; 7:178. [PMID: 17900370 PMCID: PMC2121648 DOI: 10.1186/1471-2148-7-178] [Citation(s) in RCA: 76] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/16/2007] [Accepted: 09/27/2007] [Indexed: 05/17/2023] Open
Abstract
Background The reactive oxygen-generating NADPH oxidases (Noxes) function in a variety of biological roles, and can be broadly classified into those that are regulated by subunit interactions and those that are regulated by calcium. The prototypical subunit-regulated Nox, Nox2, is the membrane-associated catalytic subunit of the phagocyte NADPH-oxidase. Nox2 forms a heterodimer with the integral membrane protein, p22phox, and this heterodimer binds to the regulatory subunits p47phox, p67phox, p40phox and the small GTPase Rac, triggering superoxide generation. Nox-organizer protein 1 (NOXO1) and Nox-activator 1 (NOXA1), respective homologs of p47phox and p67phox, together with p22phox and Rac, activate Nox1, a non-phagocytic homolog of Nox2. NOXO1 and p22phox also regulate Nox3, whereas Nox4 requires only p22phox. In this study, we have assembled and analyzed amino acid sequences of Nox regulatory subunit orthologs from vertebrates, a urochordate, an echinoderm, a mollusc, a cnidarian, a choanoflagellate, fungi and a slime mold amoeba to investigate the evolutionary history of these subunits. Results Ancestral p47phox, p67phox, and p22phox genes are broadly seen in the metazoa, except for the ecdysozoans. The choanoflagellate Monosiga brevicollis, the unicellular organism that is the closest relatives of multicellular animals, encodes early prototypes of p22phox, p47phox as well as the earliest known Nox2-like ancestor of the Nox1-3 subfamily. p67phox- and p47phox-like genes are seen in the sea urchin Strongylocentrotus purpuratus and the limpet Lottia gigantea that also possess Nox2-like co-orthologs of vertebrate Nox1-3. Duplication of primordial p47phox and p67phox genes occurred in vertebrates, with the duplicated branches evolving into NOXO1 and NOXA1. Analysis of characteristic domains of regulatory subunits suggests a novel view of the evolution of Nox: in fish, p40phox participated in regulating both Nox1 and Nox2, but after the appearance of mammals, Nox1 (but not Nox2) became independent of p40phox. In the fish Oryzias latipes, a NOXO1 ortholog retains an autoinhibitory region that is characteristic of mammalian p47phox, and this was subsequently lost from NOXO1 in later vertebrates. Detailed amino acid sequence comparisons identified both putative key residues conserved in characteristic domains and previously unidentified conserved regions. Also, candidate organizer/activator proteins in fungi and amoeba are identified and hypothetical activation models are suggested. Conclusion This is the first report to provide the comprehensive view of the molecular evolution of regulatory subunits for Nox enzymes. This approach provides clues for understanding the evolution of biochemical and physiological functions for regulatory-subunit-dependent Nox enzymes.
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Affiliation(s)
- Tsukasa Kawahara
- Department of Pathology and Laboratory Medicine, Emory University School of Medicine, Atlanta, Georgia, 30322, USA
| | - J David Lambeth
- Department of Pathology and Laboratory Medicine, Emory University School of Medicine, Atlanta, Georgia, 30322, USA
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174
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Sumimoto H, Kamakura S, Ito T. Structure and Function of the PB1 Domain, a Protein Interaction Module Conserved in Animals, Fungi, Amoebas, and Plants. ACTA ACUST UNITED AC 2007; 2007:re6. [PMID: 17726178 DOI: 10.1126/stke.4012007re6] [Citation(s) in RCA: 100] [Impact Index Per Article: 5.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/02/2022]
Abstract
Proteins containing the PB1 domain, a protein interaction module conserved in animals, fungi, amoebas, and plants, participate in diverse biological processes. The PB1 domains adopt a ubiquitin-like beta-grasp fold, containing two alpha helices and a mixed five-stranded beta sheet, and are classified into groups harboring an acidic OPCA motif (type I), the invariant lysine residue on the first beta strand (type II), or both (type I/II). The OPCA motif of a type I PB1 domain forms salt bridges with basic residues, especially the conserved lysine, of a type II PB1 domain, thereby mediating a specific PB1-PB1 heterodimerization, whereas additional contacts contribute to high affinity and specificity of the modular interaction. The canonical PB1 dimerization is required for the formation of complexes between p40(phox) and p67(phox) (for activation of the NADPH oxidase crucial for mammalian host defense), between the scaffold Bem1 and the guanine nucleotide exchange factor Cdc24 (for polarity establishment in yeasts), and between the polarity protein Par6 and atypical protein kinase C (for cell polarization in animal cells), as well as for the interaction between the mitogen-activated protein kinase kinase kinases MEKK2 or MEKK3 and the downstream target mitogen-activated protein kinase kinase MEK5 (for early cardiovascular development in mammals). PB1 domains can also mediate interactions with other protein domains. For example, an intramolecular interaction between the PB1 and PX domains of p40(phox) regulates phagosomal targeting of the microbicidal NADPH oxidase; the PB1 domain of MEK5 is likely responsible for binding to the downstream kinase ERK5, which lacks a PB1 domain; and the scaffold protein Nbr1 associates through a PB1-containing region with titin, a sarcomere protein without a PB1 domain. This Review describes various aspects of PB1 domains at the molecular and cellular levels.
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Affiliation(s)
- Hideki Sumimoto
- Medical Institute of Bioregulation, Kyushu University, Maidashi, Higashi-ku, Fukuoka, Japan.
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175
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Lambeth JD, Kawahara T, Diebold B. Regulation of Nox and Duox enzymatic activity and expression. Free Radic Biol Med 2007; 43:319-31. [PMID: 17602947 PMCID: PMC1989153 DOI: 10.1016/j.freeradbiomed.2007.03.028] [Citation(s) in RCA: 400] [Impact Index Per Article: 23.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 02/28/2007] [Revised: 03/26/2007] [Accepted: 03/27/2007] [Indexed: 11/18/2022]
Abstract
In recent years, it has become clear that reactive oxygen species (ROS, which include superoxide, hydrogen peroxide, and other metabolites) are produced in biological systems. Rather than being simply a by-product of aerobic metabolism, it is now recognized that specific enzymes--the Nox (NADPH oxidase) and Duox (Dual oxidase) enzymes--seem to have the sole function of generating ROS in a carefully regulated manner, and key roles in signal transduction, immune function, hormone biosynthesis, and other normal biological functions are being uncovered. The prototypical Nox is the respiratory burst oxidase or phagocyte oxidase, which generates large amounts of superoxide and other reactive species in the phagosomes of neutrophils and macrophages, playing a central role in innate immunity by killing microbes. This enzyme system has been extensively studied over the past two decades, and provides a basis for comparison with the more recently described Nox and Duox enzymes, which generate ROS in a variety of cells and tissues. This review first considers the structure and regulation of the respiratory burst oxidase, and then reviews recent studies relating to the regulation of the activity of the novel Nox/Duox enzymes. The regulation of Nox and Duox expression in tissues and by specific stimuli is also considered here. An accompanying review considers biological and pathological roles of the Nox family of enzymes.
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Affiliation(s)
- J David Lambeth
- Department of Pathology and Laboratory Medicine, 148 Whitehead Biomedical Research Building, Emory University, 615 Michael Street, Atlanta, GA 30322, USA.
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176
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Kim YS, Morgan MJ, Choksi S, Liu ZG. TNF-induced activation of the Nox1 NADPH oxidase and its role in the induction of necrotic cell death. Mol Cell 2007; 26:675-87. [PMID: 17560373 DOI: 10.1016/j.molcel.2007.04.021] [Citation(s) in RCA: 410] [Impact Index Per Article: 24.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/20/2006] [Revised: 03/09/2007] [Accepted: 04/27/2007] [Indexed: 12/21/2022]
Abstract
Tumor necrosis factor (TNF) is an important cytokine in immunity and inflammation and induces many cellular responses, including apoptosis and necrosis. TNF signaling enables the generation of superoxide in phagocytic and vascular cells through the activation of the NADPH oxidase Nox2/gp91. Here we show that TNF also activates the Nox1 NADPH oxidase in mouse fibroblasts when cells undergo necrosis. TNF treatment induces the formation of a signaling complex containing TRADD, RIP1, Nox1, and the small GTPase Rac1. TNF-treated RIP1-deficient fibroblasts fail to form such a complex, indicating that RIP1 is essential for Nox1 recruitment. Moreover, the prevention of TNF-induced superoxide generation with dominant-negative mutants of TRADD or Rac1, as well as knockdown of Nox1 using siRNA, inhibits necrosis. Thus our study suggests that activation of Nox1 through forming a complex with TNF signaling components plays a key role in TNF-induced necrotic cell death.
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Affiliation(s)
- You-Sun Kim
- Cell and Cancer Biology Branch, Center for Cancer Research, National Cancer Institute, National Institutes of Health, Bethesda, MD 20892, USA
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177
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Molecular evolution of the reactive oxygen-generating NADPH oxidase (Nox/Duox) family of enzymes. BMC Evol Biol 2007; 7:109. [PMID: 17612411 PMCID: PMC1940245 DOI: 10.1186/1471-2148-7-109] [Citation(s) in RCA: 242] [Impact Index Per Article: 14.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/07/2007] [Accepted: 07/06/2007] [Indexed: 02/07/2023] Open
Abstract
Background NADPH-oxidases (Nox) and the related Dual oxidases (Duox) play varied biological and pathological roles via regulated generation of reactive oxygen species (ROS). Members of the Nox/Duox family have been identified in a wide variety of organisms, including mammals, nematodes, fruit fly, green plants, fungi, and slime molds; however, little is known about the molecular evolutionary history of these enzymes. Results We assembled and analyzed the deduced amino acid sequences of 101 Nox/Duox orthologs from 25 species, including vertebrates, urochordates, echinoderms, insects, nematodes, fungi, slime mold amoeba, alga and plants. In contrast to ROS defense enzymes, such as superoxide dismutase and catalase that are present in prokaryotes, ROS-generating Nox/Duox orthologs only appeared later in evolution. Molecular taxonomy revealed seven distinct subfamilies of Noxes and Duoxes. The calcium-regulated orthologs representing 4 subfamilies diverged early and are the most widely distributed in biology. Subunit-regulated Noxes represent a second major subdivision, and appeared first in fungi and amoeba. Nox5 was lost in rodents, and Nox3, which functions in the inner ear in gravity perception, emerged the most recently, corresponding to full-time adaptation of vertebrates to land. The sea urchin Strongylocentrotus purpuratus possesses the earliest Nox2 co-ortholog of vertebrate Nox1, 2, and 3, while Nox4 first appeared somewhat later in urochordates. Comparison of evolutionary substitution rates demonstrates that Nox2, the regulatory subunits p47phox and p67phox, and Duox are more stringently conserved in vertebrates than other Noxes and Nox regulatory subunits. Amino acid sequence comparisons identified key catalytic or regulatory regions, as 68 residues were highly conserved among all Nox/Duox orthologs, and 14 of these were identical with those mutated in Nox2 in variants of X-linked chronic granulomatous disease. In addition to canonical motifs, the B-loop, TM6-FAD, VXGPFG-motif, and extreme C-terminal regions were identified as important for Nox activity, as verified by mutational analysis. The presence of these non-canonical, but highly conserved regions suggests that all Nox/Duox may possess a common biological function remained in a long history of Nox/Duox evolution. Conclusion This report provides the first comprehensive analysis of the evolution and conserved functions of Nox and Duox family members, including identification of conserved amino acid residues. These results provide a guide for future structure-function studies and for understanding the evolution of biological functions of these enzymes.
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178
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Abstract
Angiogenesis is a key process involved in normal development and wound repair, as well as ischemic heart and limb diseases, and atherosclerosis. Vascular endothelial growth factor (VEGF), a potent angiogenesis factor, stimulates proliferation, migration, and tube formation of endothelial cells (ECs), primarily through the VEGF receptor type2 (VEGFR2). Reactive oxygen species (ROS) function as signaling molecules to mediate biological responses. In ECs, NADPH oxidase is one of the major sources of ROS and consists of catalytic subunits (Nox1, Nox2, and Nox4), p22phox, p47phox, p67phox, and the small GTPase Rac1. VEGF stimulates ROS production via activation of gp91phox (Nox2)-based NADPH oxidase, and ROS are involved in VEGFR2-mediated signaling linked to EC migration and proliferation. Moreover, ROS derived from NADPH oxidase are involved in postnatal angiogenesis. Localizing NADPH oxidase and its regulators at the specific subcellular compartment is an important mechanism for activating specific redox signaling events. This review focuses on a role of NADPH oxidase-derived ROS in angiogenesis and critical regulators involved in generation of spatially and temporally restricted ROS-dependent VEGF signaling at leading edge, focal adhesions/complexes, caveolae/lipid rafts, and cell-cell junctions in ECs. Understanding these mechanisms should facilitate the development of new therapeutic strategies to modulate new blood vessel formation.
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Affiliation(s)
- Masuko Ushio-Fukai
- Department of Pharmacology and Center for Lung and Vascular Biology, University of Illinois at Chicago, Chicago, Illinois 60612, USA.
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179
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Miyano K, Sumimoto H. Role of the small GTPase Rac in p22phox-dependent NADPH oxidases. Biochimie 2007; 89:1133-44. [PMID: 17583407 DOI: 10.1016/j.biochi.2007.05.003] [Citation(s) in RCA: 70] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/11/2006] [Accepted: 05/08/2007] [Indexed: 11/25/2022]
Abstract
The superoxide-producing phagocyte NADPH oxidase gp91(phox)/Nox2 and the non-phagocytic oxidases Nox1 and Nox3 each form a complex in the membrane with p22(phox), which provides both stabilization and a docking site for organizer proteins. The p22(phox)-complexed Nox2 and Nox1 are dormant on their own, and their activation requires soluble supportive proteins such as a Nox organizer (p47(phox) or Noxo1) and a Nox activator (p67(phox) or Noxa1). The small GTPase Rac directly binds to the activators, and thus plays an essential role in the Nox2-based oxidase containing p47(phox) and p67(phox) or a positive role in Nox1 activity supported by Noxo1 and Noxa1. Although Nox3 complexed with p22(phox) constitutively produce superoxide, the production can be enhanced by supportive proteins. Here we compare the roles of Rac in these p22(phox)-dependent oxidases using the organizer and activator in different combinations. Expression of constitutively active Rac1(Q61L) is essential for activation of the Nox2- or Nox1-based oxidase containing the organizer p47(phox) and either p67(phox) or Noxa1. When these oxidases use Noxo1 as an organizer instead of p47(phox), they produce a small but significant amount of superoxide without expression of Rac1(Q61L), although the production is enhanced by Rac1(Q61L). Thus p47(phox) is likely related to strict dependence on Rac. The Nox3-based oxidase has a similar tendency in the change of the dependence: Rac plays a positive role in Nox3 activation in the presence of p47(phox) and either p67(phox) or Noxa1, whereas Rac fails to upregulate Nox3 activity when p47(phox) is replaced with Noxo1. We also demonstrate that, in the Nox3-based oxidase containing solely p67(phox) as supportive protein, expression of Rac1(Q61L) enhances not only superoxide production but also membrane translocation of p67(phox). Since the enhancements are not observed with a mutant p67(phox) defective in binding to Rac, this GTPase appear to directly recruit p67(phox) to the membrane.
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Affiliation(s)
- Kei Miyano
- Medical Institute of Bioregulation, Kyushu University, 3-1-1 Maidashi, Higashi-ku, Fukuoka 812-8582, Japan
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180
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Nakano Y, Banfi B, Jesaitis A, Dinauer M, Allen LA, Nauseef W. Critical roles for p22phox in the structural maturation and subcellular targeting of Nox3. Biochem J 2007; 403:97-108. [PMID: 17140397 PMCID: PMC1828898 DOI: 10.1042/bj20060819] [Citation(s) in RCA: 65] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/17/2022]
Abstract
Otoconia are small biominerals in the inner ear that are indispensable for the normal perception of gravity and motion. Normal otoconia biogenesis requires Nox3, a Nox (NADPH oxidase) highly expressed in the vestibular system. In HEK-293 cells (human embryonic kidney cells) transfected with the Nox regulatory subunits NoxO1 (Nox organizer 1) and NoxA1 (Nox activator 1), functional murine Nox3 was expressed in the plasma membrane and exhibited a haem spectrum identical with that of Nox2, the electron transferase of the phagocyte Nox. In vitro Nox3 cDNA expressed an approximately 50 kDa primary translation product that underwent N-linked glycosylation in the presence of canine microsomes. RNAi (RNA interference)-mediated reduction of endogenous p22phox, a subunit essential for stabilization of Nox2 in phagocytes, decreased Nox3 activity in reconstituted HEK-293 cells. p22phox co-precipitated not only with Nox3 and NoxO1 from transfectants expressing all three proteins, but also with NoxO1 in the absence of Nox3, indicating that p22phox physically associated with both Nox3 and with NoxO1. The plasma membrane localization of Nox3 but not of NoxO1 required p22phox. Moreover, the glycosylation and maturation of Nox3 required p22phox expression, suggesting that p22phox was required for the proper biosynthesis and function of Nox3. Taken together, these studies demonstrate critical roles for p22phox at several distinct points in the maturation and assembly of a functionally competent Nox3 in the plasma membrane.
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Affiliation(s)
- Yoko Nakano
- *Inflammation Program, University of Iowa and Veterans Affairs Medical Center, Iowa City, IA 52241, U.S.A
- †Department of Medicine, University of Iowa and Veterans Affairs Medical Center, Iowa City, IA 52241, U.S.A
| | - Botond Banfi
- *Inflammation Program, University of Iowa and Veterans Affairs Medical Center, Iowa City, IA 52241, U.S.A
- ‡Department of Anatomy and Cell Biology, University of Iowa and Veterans Affairs Medical Center, Iowa City, IA 52241, U.S.A
| | | | - Mary C. Dinauer
- ∥Wells Center for Pediatric Research, Department of Pediatrics (Hematology/Oncology), Microbiology/Immunology, and Medical and Molecular Genetics, Indiana University School of Medicine, Indianapolis, IN 46202, U.S.A
| | - Lee-Ann H. Allen
- *Inflammation Program, University of Iowa and Veterans Affairs Medical Center, Iowa City, IA 52241, U.S.A
- †Department of Medicine, University of Iowa and Veterans Affairs Medical Center, Iowa City, IA 52241, U.S.A
| | - William M. Nauseef
- *Inflammation Program, University of Iowa and Veterans Affairs Medical Center, Iowa City, IA 52241, U.S.A
- †Department of Medicine, University of Iowa and Veterans Affairs Medical Center, Iowa City, IA 52241, U.S.A
- To whom correspondence should be addressed, at Inflammation Program, Department of Medicine, University of Iowa, D160 MTF, 2501 Crosspark Road, Coralville, IA 52241, U.S.A. (email )
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181
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De Minicis S, Brenner DA. NOX in liver fibrosis. Arch Biochem Biophys 2007; 462:266-72. [PMID: 17531188 PMCID: PMC2727549 DOI: 10.1016/j.abb.2007.04.016] [Citation(s) in RCA: 120] [Impact Index Per Article: 7.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/12/2007] [Revised: 04/10/2007] [Accepted: 04/11/2007] [Indexed: 12/13/2022]
Abstract
NADPH oxidase is a multi-protein complex producing reactive oxygen species (ROS) both in phagocytic cells, being essential in host defense, and in non-phagocytic cells, regulating intracellular signalling. In the liver, NADPH oxidase plays a central role in fibrogenesis. A functionally active form of the NADPH oxidase is expressed not only in Kupffer cells (phagocytic cell type) but also in hepatic stellate cells (HSCs) (non-phagocytic cell type), suggesting a role of the non-phagocytic NADPH oxidase in HSC activation. Consistent with this concept, profibrogenic agonists such as Angiotensin II (Ang II) and platelet derived growth factor (PDGF), or apoptotic bodies exert their activity through NADPH oxidase-activation in HSCs. Both pharmacological inhibition with DPI and genetic studies using p47(phox) knockout mice provided evidence for a central role of NADPH oxidase in the regulation of HSC-activity and liver fibrosis. In addition to the p47(phox) component, only Rac1 has been identified as a functional active component of the NADPH oxidase complex in HSCs.
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Affiliation(s)
- Samuele De Minicis
- Department of Medicine, Columbia University, College of Physicians and Surgeons, New York, NY 10026
| | - David A. Brenner
- Department of Medicine, Columbia University, College of Physicians and Surgeons, New York, NY 10026
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182
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Shinohara M, Shang WH, Kubodera M, Harada S, Mitsushita J, Kato M, Miyazaki H, Sumimoto H, Kamata T. Nox1 redox signaling mediates oncogenic Ras-induced disruption of stress fibers and focal adhesions by down-regulating Rho. J Biol Chem 2007; 282:17640-8. [PMID: 17435218 DOI: 10.1074/jbc.m609450200] [Citation(s) in RCA: 85] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/22/2023] Open
Abstract
Generation of reactive oxygen species (ROS) by Ras oncogene-induced NADPH oxidase (Nox) 1 is required for Ras transformation phenotypes including anchorage-independent growth, morphological transformation, and tumorigenesity, but the signaling mechanism downstream of Nox1 remains elusive. Rho is known to be a critical regulator of actin stress fiber formation. Nonetheless, Rho was reported to no longer couple to loss of actin stress fibers in Ras-transformed Swiss3T3 cells despite the elevation of Rho activity. In this study, however, we demonstrate that Rho is inactivated in K-Ras-transformed normal rat kidney cells, and that abrogation of Nox1-generated ROS by Nox1 small interference RNAs or diphenyleneiodonium restores Rho activation, suggesting that Nox1-generated oxidants mediate down-regulation of the Rho activity. This down-regulation involves oxidative inactivation of the low molecular weight protein-tyrosine phosphatase by Nox1-generated ROS and a subsequent elevation in the tyrosine-phosphorylated active form of p190RhoGAP, the direct target of the phosphatase. Furthermore, the decreased Rho activity leads to disruption of both actin stress fibers and focal adhesions in Ras-transformed cells. As for Rac1, Rac1 also appears to participate in the down-regulation of Rho via Nox1. Our discovery defines a mediating role of Nox1-redox signaling for Ras oncogene-induced actin cytoskeletal changes.
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Affiliation(s)
- Masahiro Shinohara
- Department of Molecular Biology and Biochemistry, Shinshu University Graduate School of Medicine, Matsumoto, Nagano 390-8621, Japan
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183
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Benedyk M, Sopalla C, Nacken W, Bode G, Melkonyan H, Banfi B, Kerkhoff C. HaCaT keratinocytes overexpressing the S100 proteins S100A8 and S100A9 show increased NADPH oxidase and NF-kappaB activities. J Invest Dermatol 2007; 127:2001-11. [PMID: 17429438 DOI: 10.1038/sj.jid.5700820] [Citation(s) in RCA: 75] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Abstract
The calcium- and arachidonic acid (AA)-binding proteins S100A8 and S100A9 are involved in nicotinamide adenine dinucleotide phosphate (NADPH) oxidase activation in phagocytes. They are specifically expressed in myeloid cells, and are also found in epithelial cells in various (patho)physiological conditions. We have investigated the consequences of S100A8/A9 overexpression in epithelial cell lines on reactive oxygen species (ROS) generation and downstream signaling. Epithelial carcinoma HeLa cells, which exclusively express Nox2, showed dramatically increased activation of NADPH oxidase by phorbol 12-myristate 13-acetate after S100A8/A9 gene transfection. HaCaT keratinocytes overexpressing S100A8/A9 showed enhanced, transient ROS generation in response to the calcium ionophore A23187 compared to mock-transfected cells. Polymerase chain reaction analysis revealed mRNA transcripts for Nox1, Nox2, and Nox5 in HaCaT keratinocytes. Detailed transfection studies confirmed that NADPH oxidase activities in Nox1- and Nox5-transfected HeLa cells were enhanced after S100A8/A9 gene complementation. Furthermore, mutational analysis revealed that AA binding and Thr113 phosphorylation are important for S100A8/A9-enhanced activation of NADPH oxidase. Nuclear factor-kappaB (NF-kappaB) activation and interleukin-8 mRNA levels were increased in S100A8/A9-HaCaT keratinocytes, consistent with the view that NF-kappaB is a redox-sensitive transcription factor. Because they are expressed in epithelia under specific conditions, S100A8 and S100A9 might be involved in skin pathogenesis by modulating aspects of downstream signaling.
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Affiliation(s)
- Malgorzata Benedyk
- Institute of Experimental Dermatology, University of Münster, Münster, Germany
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184
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Kochel B, Vocks A, Arnhold J. Chemiluminescent picture of diphenyleneiodonium-inhibited NADPH oxidase: a bimodal process and its logistic-exponential model-based description. LUMINESCENCE 2007; 22:275-93. [PMID: 17373025 DOI: 10.1002/bio.961] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/07/2022]
Abstract
A chemiluminescence (CL) study of diphenyleneiodonium-inhibited NADPH oxidase was performed on a cellular system containing neutrophils stimulated by phorbol myristate acetate, indicating a complex bimodal structure of CL processes corresponding to different stages of the inhibition. The complex structure of these processes was described by a superposition of two logistic-exponential (LE) models, characterizing these processes as bimodal ones. To determine the mechanistic foundation of the LE model-described processes, a generalized form of the second-order dynamic system of CL reactions, the solution to which corresponds to the LE model, was constructed. The diphenyleneiodonium effects on neutrophil NADPH oxidase were separated from the total bimodal CL of the whole measurement system by the use of difference CL processes. These difference processes were also found to be bimodal; thus, inhibitor-induced reduction of CL could be described by a second-order dynamic system. The rate constants and initial concentrations in this dynamic system were determined by the least squares method applied to numerical solutions approximating the difference processes. Using interrelations between the parameters of the dynamic system, cooperative effects in the inhibitor reactions with NADPH oxidase were found and described quantitatively. Other evidences of cooperativity were obtained from integral characteristics of the CL reduction process, i.e. dose-response and progress curves, determined by numerical integration of the LE models constituting the superposition. On this basis, it was also possible to detect a specific binding of the inhibitor to the enzyme. Finally, putative reaction mechanisms suggested by the model obtained were considered and compared with those known at present.
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Affiliation(s)
- Bonawentura Kochel
- Department of Toxicology, Wroclaw Medical University, Traugutta 57/59, PL-50417 Wroclaw, Poland.
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185
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Abstract
Studies in Chronic Granulomatous Disease showed two breakthroughs during this past decade. First, the discovery of 7 Nox/Duox family proteins, Noxo1 and Noxa1 (homologues of gp91(phox), p47(phox) and p67(phox)) may clarify novel physiological mechanisms for superoxide regulation in various organs, such as the regulation of blood pressure, mucosal defense system in respiratory/digestive tract and nephron. Secondly, the success in bone marrow transplantation and gene therapy for CGD should facilitate treatment for other genetic diseases as well.
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Affiliation(s)
- Hiroyuki Nunoi
- Department of Reproductive and Developmental Medicine, Faculty of Medicne University of Miyazaki
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186
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Kobayashi M, Ohura I, Kawakita K, Yokota N, Fujiwara M, Shimamoto K, Doke N, Yoshioka H. Calcium-dependent protein kinases regulate the production of reactive oxygen species by potato NADPH oxidase. THE PLANT CELL 2007; 19:1065-80. [PMID: 17400895 PMCID: PMC1867354 DOI: 10.1105/tpc.106.048884] [Citation(s) in RCA: 431] [Impact Index Per Article: 25.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/13/2006] [Revised: 02/20/2007] [Accepted: 03/13/2007] [Indexed: 05/14/2023]
Abstract
Reactive oxygen species (ROS) are implicated in plant innate immunity. NADPH oxidase (RBOH; for Respiratory Burst Oxidase Homolog) plays a central role in the oxidative burst, and EF-hand motifs in the N terminus of this protein suggest possible regulation by Ca(2+). However, regulatory mechanisms are largely unknown. We identified Ser-82 and Ser-97 in the N terminus of potato (Solanum tuberosum) St RBOHB as potential phosphorylation sites. An anti-phosphopeptide antibody (pSer82) indicated that Ser-82 was phosphorylated by pathogen signals in planta. We cloned two potato calcium-dependent protein kinases, St CDPK4 and St CDPK5, and mass spectrometry analyses showed that these CDPKs phosphorylated only Ser-82 and Ser-97 in the N terminus of St RBOHB in a calcium-dependent manner. Ectopic expression of the constitutively active mutant of St CDPK5, St CDPK5VK, provoked ROS production in Nicotiana benthamiana leaves. The CDPK-mediated ROS production was disrupted by knockdown of Nb RBOHB in N. benthamiana. The loss of function was complemented by heterologous expression of wild-type potato St RBOHB but not by a mutant (S82A/S97A). Furthermore, the heterologous expression of St CDPK5VK phosphorylated Ser-82 of St RBOHB in N. benthamiana. These results suggest that St CDPK5 induces the phosphorylation of St RBOHB and regulates the oxidative burst.
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Affiliation(s)
- Michie Kobayashi
- Plant Pathology Laboratory, Graduate School of Bioagricultural Sciences, Nagoya University, Chikusa, Nagoya 464-8601, Japan
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187
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Block K, Gorin Y, Hoover P, Williams P, Chelmicki T, Clark RA, Yoneda T, Abboud HE. NAD(P)H Oxidases Regulate HIF-2α Protein Expression. J Biol Chem 2007; 282:8019-26. [PMID: 17200123 DOI: 10.1074/jbc.m611569200] [Citation(s) in RCA: 97] [Impact Index Per Article: 5.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/15/2023] Open
Abstract
Biallelic inactivation of the von Hippel-Lindau tumor suppressor gene (VHL) is linked to the development of hereditary and sporadic renal cell carcinoma (RCC). In the absence of VHL, the alpha subunits of heterodimeric hypoxia-inducible transcription factors (HIF-1alpha and HIF-2alpha) are stabilized. Reactive oxygen species, generated by NAD(P)H oxidases, are involved in signaling cascades of malignant growth. We show that in VHL-deficient cells p22phox, Nox4 protein levels and NADPH-dependent superoxide generation are increased. Reintroduction of VHL into the VHL-deficient cells down-regulates the expression of p22phox and NADPH-dependent superoxide generation. Inhibition of the 26 S proteasome in VHL-expressing cells increased p22phox protein levels, which correlated with an increase of NADPH-dependent superoxide generation. We also show that p22phox co-immunoprecipitates with VHL in vivo. Moreover, p22phox is a target of ubiquitination. Importantly, in VHL-deficient cells, diphenyleneiodonium chloride (DPI), an inhibitor of Nox oxidases, decreased the expression of HIF-2alpha. Down-regulation of Nox1, Nox4, and p22phox expression by small interfering RNA also decreased HIF-2alpha protein expression and inhibited Akt and 4E-BP1 phosphorylation, suggesting that a translational mechanism is involved in maintaining HIF-2alpha in VHL-deficient cells. Colony formation by RCC 786-O in soft agar was markedly inhibited by DPI. Moreover, DPI significantly inhibited RCC 786-O tumor formation in athymic mice. Collectively, the data demonstrate that VHL protein exerts its tumor suppressor action, at least partially, via inhibition of p22phox-based Nox4/Nox1 NADPH oxidase-dependent reactive oxygen species generation.
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Affiliation(s)
- Karen Block
- Division of Nephrology, Department of Medicine, George O'Brien Kidney Research Center, University of Texas Health Science Center, San Antonio, Texas 78229-3900, USA.
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188
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Bedard K, Krause KH. The NOX family of ROS-generating NADPH oxidases: physiology and pathophysiology. Physiol Rev 2007; 87:245-313. [PMID: 17237347 DOI: 10.1152/physrev.00044.2005] [Citation(s) in RCA: 4902] [Impact Index Per Article: 288.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022] Open
Abstract
For a long time, superoxide generation by an NADPH oxidase was considered as an oddity only found in professional phagocytes. Over the last years, six homologs of the cytochrome subunit of the phagocyte NADPH oxidase were found: NOX1, NOX3, NOX4, NOX5, DUOX1, and DUOX2. Together with the phagocyte NADPH oxidase itself (NOX2/gp91(phox)), the homologs are now referred to as the NOX family of NADPH oxidases. These enzymes share the capacity to transport electrons across the plasma membrane and to generate superoxide and other downstream reactive oxygen species (ROS). Activation mechanisms and tissue distribution of the different members of the family are markedly different. The physiological functions of NOX family enzymes include host defense, posttranlational processing of proteins, cellular signaling, regulation of gene expression, and cell differentiation. NOX enzymes also contribute to a wide range of pathological processes. NOX deficiency may lead to immunosuppresion, lack of otoconogenesis, or hypothyroidism. Increased NOX activity also contributes to a large number or pathologies, in particular cardiovascular diseases and neurodegeneration. This review summarizes the current state of knowledge of the functions of NOX enzymes in physiology and pathology.
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Affiliation(s)
- Karen Bedard
- Biology of Ageing Laboratories, University of Geneva, Geneva, Switzerland
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189
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Opitz N, Drummond GR, Selemidis S, Meurer S, Schmidt HHHW. The 'A's and 'O's of NADPH oxidase regulation: a commentary on "Subcellular localization and function of alternatively spliced Noxo1 isoforms". Free Radic Biol Med 2007; 42:175-9. [PMID: 17189823 DOI: 10.1016/j.freeradbiomed.2006.11.003] [Citation(s) in RCA: 52] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/01/2006] [Revised: 12/30/1899] [Accepted: 11/02/2006] [Indexed: 11/25/2022]
Affiliation(s)
- Nils Opitz
- Department of Pharmacology & Centre for Vascular Health, Monash University, Clayton, Victoria, Australia
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190
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Ueyama T, Lekstrom K, Tsujibe S, Saito N, Leto TL. Subcellular localization and function of alternatively spliced Noxo1 isoforms. Free Radic Biol Med 2007; 42:180-90. [PMID: 17189824 PMCID: PMC1868414 DOI: 10.1016/j.freeradbiomed.2006.08.024] [Citation(s) in RCA: 33] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/08/2006] [Revised: 08/02/2006] [Accepted: 08/30/2006] [Indexed: 02/07/2023]
Abstract
Nox organizer 1 (Noxo1), a p47(phox) homolog, is produced as four isoforms with unique N-terminal PX domains derived by alternative mRNA splicing. We compared the subcellular distribution of these isoforms or their isolated PX domains produced as GFP fusion proteins, as well as their ability to support Nox1 activity in several transfected models. Noxo1alpha, beta, gamma, and delta show different subcellular localization patterns, determined by their PX domains. In HEK293 cells, Noxo1beta exhibits prominent plasma membrane binding, Noxo1gamma shows plasma membrane and nuclear associations, and Noxo1alpha and delta localize primarily on intracellular vesicles or cytoplasmic aggregates, but not the plasma membrane. Nox1 activity correlates with Noxo1 plasma membrane binding in HEK293 cells, since Noxo1beta supports the highest activity and Noxo1gamma and Noxo1alpha support moderate or low activities, respectively. In COS-7 cells, where Noxo1alpha localizes on the plasma membrane, the activities supported by the three isoforms (alpha, beta, and gamma) do not differ significantly. The PX domains of beta and gamma bind the same phospholipids, including phosphatidic acid. These results indicate that the variant PX domains are unique determinants of Noxo1 localization and Nox1 function. Finally, the overexpressed Noxo1 isoforms do not affect p22(phox) localization, although Nox1 is needed to transport p22(phox) to the plasma membrane.
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Affiliation(s)
- Takehiko Ueyama
- Molecular Defenses Section, Laboratory of Host Defenses, National Institute of Allergy and Infectious Diseases, National Institutes of Health, Bethesda 20892, MD, USA
- Laboratory of Molecular Pharmacology, Biosignal Research Center, Kobe University, Kobe 657-8501, Japan
- ‡Address correspondence to: Thomas L. Leto, NIH, NIAID, Twinbrook II, Room 203, 12441 Parklawn Dr., Bethesda 20852, MD, USA, Tel: 301-402-5120, Fax: 301-480-1731, E-mail: . Takehiko Ueyama, Laboratory of Molecular Pharmacology, Biosignal Research Center, Kobe University, 1-1 Rokkodai-cho, Nada-ku, Kobe 657-8501, Japan, Tel: +81-78-803-5962, Fax: +81-78-803-5971, E-mail:
| | - Kristen Lekstrom
- Molecular Defenses Section, Laboratory of Host Defenses, National Institute of Allergy and Infectious Diseases, National Institutes of Health, Bethesda 20892, MD, USA
| | - Satoshi Tsujibe
- Laboratory of Molecular Pharmacology, Biosignal Research Center, Kobe University, Kobe 657-8501, Japan
| | - Naoaki Saito
- Laboratory of Molecular Pharmacology, Biosignal Research Center, Kobe University, Kobe 657-8501, Japan
| | - Thomas L. Leto
- Molecular Defenses Section, Laboratory of Host Defenses, National Institute of Allergy and Infectious Diseases, National Institutes of Health, Bethesda 20892, MD, USA
- ‡Address correspondence to: Thomas L. Leto, NIH, NIAID, Twinbrook II, Room 203, 12441 Parklawn Dr., Bethesda 20852, MD, USA, Tel: 301-402-5120, Fax: 301-480-1731, E-mail: . Takehiko Ueyama, Laboratory of Molecular Pharmacology, Biosignal Research Center, Kobe University, 1-1 Rokkodai-cho, Nada-ku, Kobe 657-8501, Japan, Tel: +81-78-803-5962, Fax: +81-78-803-5971, E-mail:
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191
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Jagnandan D, Church JE, Banfi B, Stuehr DJ, Marrero MB, Fulton DJR. Novel mechanism of activation of NADPH oxidase 5. calcium sensitization via phosphorylation. J Biol Chem 2006; 282:6494-507. [PMID: 17164239 DOI: 10.1074/jbc.m608966200] [Citation(s) in RCA: 163] [Impact Index Per Article: 9.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
In contrast to other Nox isoforms, the activity of Nox5 does not require the presence of accessory proteins and is entirely dependent on the elevation of intracellular calcium. Previous studies have shown that the EC(50) of Nox5 for calcium is relatively high and raises the question of whether Nox5 can be sufficiently activated in cells that do not experience extreme elevations of intracellular calcium. In the current study, we have identified a novel mechanism governing the activity of Nox5. Exposure of cells expressing Nox5 to phorbol 12-myristate 13-acetate (PMA) resulted in a slow and sustained increase in ROS, which was markedly different from the rapid response to ionomycin. PMA greatly potentiated the activity of Nox5 in response to low concentrations of ionomycin. The ability of PMA to increase Nox5 activity was abolished by calcium chelation and was a direct effect on enzyme activity, since PMA increased the calcium sensitivity of Nox5 in a cell-free assay. PMA stimulated the time-dependent phosphorylation of Nox5 on Thr(494) and Ser(498). Mutation of these residues to alanine abolished both PMA-dependent phosphorylation and calcium sensitization. Conversely, mutation of Thr(494) and Ser(498) to glutamic acid produced a gain of function mutant that had increased activity at low concentrations of ionomycin. Within the cell, Nox5 was detected in detergent-resistant microdomains of the endoplasmic reticulum. In summary, the phosphorylation of Nox5 at key residues facilitates enzyme activation at lower levels of intracellular calcium and may provide an avenue for enzyme activation in response to a greater variety of extracellular stimuli.
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Affiliation(s)
- Davin Jagnandan
- Department of Pharmacology and the Vascular Biology Center, Medical College of Georgia, Augusta, Georgia 30912-2500, USA
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192
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Yamamoto A, Kami K, Takeya R, Sumimoto H. Interaction between the SH3 domains and C-terminal proline-rich region in NADPH oxidase organizer 1 (Noxo1). Biochem Biophys Res Commun 2006; 352:560-5. [PMID: 17126813 DOI: 10.1016/j.bbrc.2006.11.060] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/06/2006] [Accepted: 11/14/2006] [Indexed: 10/23/2022]
Abstract
NADPH oxidase organizer 1 (Noxo1), harboring a PX domain, two SH3 domains, and a proline-rich region (PRR), participates in activation of superoxide-producing Nox-family NADPH oxidases. Here, we show that Noxo1 supports superoxide production in a cell-free system for gp91(phox)/Nox2 activation by arachidonic acid. This lipid enhances an SH3-mediated binding of Noxo1 to p22(phox), a protein complexed with Nox oxidases; the binding is known to be required for Nox activation. We also demonstrate that the bis-SH3 domain directly interacts with the Noxo1 PRR. The interaction appears to prevent the bis-SH3 domain and PRR from binding to their target proteins; disruption of the intramolecular interaction facilitates Noxo1 binding to p22(phox) and also allows the PRR to associate with the Nox activator Noxa1, which association is crucial for Nox activation as well. These findings suggest that Nox activation involves a conformational change leading to disruption of the bis-SH3-PRR interaction in Noxo1.
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Affiliation(s)
- Asataro Yamamoto
- Medical Institute of Bioregulation, Kyushu University, 3-1-1 Maidashi, Fukuoka 812-8582, Japan
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193
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Abstract
Neovascularization, the natural physiological process of formation of new blood vessels, is extremely important for ameliorating the function of the heart that undergoes ischemic stress. This process is potentially important for the treatment of ischemic heart and limb diseases, which includes formation of capillaries (angiogenesis) and collateral arteries. Ischemia or coronary artery occlusion induces vascular endothelial growth factor (VEGF) in the experimental rat myocardial infarction model, and this molecule encourages development of coronary collateral circulation and retention of the blood supply to the ischemic area. Restoration of the blood supply to the ischemic area prevents cardiomyocyte death and cardiac remodeling. Among the various triggers and enhancers of angiogenesis, hypoxic or ischemic preconditioning, as well as pharmacologic agents such as statin and resveratrol, have been identified as important stimuli for the induction of new vessel growth. It has already been demonstrated that the VEGF family and its receptor system is the fundamental regulator in the redox cell signaling of angiogenesis. This review article will focus on the role of reactive oxygen species in the process of myocardial angiogenesis.
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Affiliation(s)
- Nilanjana Maulik
- Molecular Cardiology and Angiogenesis Laboratory, Department of Surgery, University of Connecticut Medical Center, Farmington, Connecticut 06030-1110, USA.
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194
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Takeya R, Taura M, Yamasaki T, Naito S, Sumimoto H. Expression and function of Noxo1gamma, an alternative splicing form of the NADPH oxidase organizer 1. FEBS J 2006; 273:3663-77. [PMID: 16911517 DOI: 10.1111/j.1742-4658.2006.05371.x] [Citation(s) in RCA: 14] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
Activation of the superoxide-producing NADPH oxidase Nox1 requires both the organizer protein Noxo1 and the activator protein Noxa1. Here we describe an alternative splicing form of Noxo1, Noxo1gamma, which is expressed in the testis and fetal brain. The Noxo1gamma protein contains an additional five amino acids in the N-terminal PX domain, a phosphoinositide-binding module; the domain plays an essential role in supporting superoxide production by NADPH oxidase (Nox) family oxidases including Nox1, gp91(phox)/Nox2, and Nox3, as shown in this study. The PX domain isolated from Noxo1gamma shows a lower affinity for phosphoinositides than that from the classical splicing form Noxo1beta. Consistent with this, in resting cells, Noxo1gamma is poorly localized to the membrane, and thus less effective in activating Nox1 than Noxo1beta, which is constitutively present at the membrane. On the other hand, cell stimulation with phorbol 12-myristate 13-acetate (PMA), an activator of Nox1-3, facilitates membrane translocation of Noxo1gamma; as a result, Noxo1gamma is equivalent to Noxo1beta in Nox1 activation in PMA-stimulated cells. The effect of the five-amino-acid insertion in the Noxo1 PX domain appears to depend on the type of Nox; in activation of gp91(phox)/Nox2, Noxo1gamma is less active than Noxo1beta even in the presence of PMA, whereas Noxo1gamma and Noxo1beta support the superoxide-producing activity of Nox3 to the same extent in a manner independent of cell stimulation.
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Affiliation(s)
- Ryu Takeya
- Medical Institute of Bioregulation, Kyushu University, Fukuoka, Japan
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195
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Lyle AN, Griendling KK. Modulation of vascular smooth muscle signaling by reactive oxygen species. Physiology (Bethesda) 2006; 21:269-80. [PMID: 16868316 DOI: 10.1152/physiol.00004.2006] [Citation(s) in RCA: 178] [Impact Index Per Article: 9.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/07/2023] Open
Abstract
Modulation of signaling in vascular cells by reactive oxygen species (ROS) affects many aspects of cellular function, including growth, migration, and contraction. NADPH oxidases, important sources of ROS, regulate many growth-specific and migration-related signaling pathways. Identifying the precise intracellular targets of ROS enhances understanding of their role in cardiovascular physiology and pathophysiology.
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Affiliation(s)
- Alicia N Lyle
- Department of Medicine, Division of Cardiology, Emory University, Atlanta, Georgia, USA
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196
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Jiang H, Sha SH, Schacht J. Rac/Rho pathway regulates actin depolymerization induced by aminoglycoside antibiotics. J Neurosci Res 2006; 83:1544-51. [PMID: 16521128 PMCID: PMC1525046 DOI: 10.1002/jnr.20833] [Citation(s) in RCA: 32] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022]
Abstract
Stress stimuli can lead to remodeling of the actin cytoskeleton and subsequent alteration of cell adhesion and permeation as well as cell functions and cell fate. We investigated redox-dependent Rho GTPase-linked pathways controlling the actin cytoskeleton in the inner ear of the CBA mouse, by using aminoglycoside antibiotics as a noxious stimulus that causes loss of sensory cells via the formation of reactive oxygen species. Kanamycin treatment in vivo interfered with the formation of F-actin, disturbed the arrangement of beta-actin in the stereocilia of outer hair cells, and altered the intermittent adherens junction/tight junction complexes between outer hair cells and supporting cells. The drug treatment also activated Rac1 and promoted the formation of the complex of Rac1 and p67phox while decreasing the activity of RhoA and reducing the formation of the RhoA/p140mDia complex. In inner-ear-derived cell lines, expression of mutated Rac1 changed the structural arrangement of F-actin and diminished the immunoreactivity of p140mDia. These findings suggest that actin depolymerization induced by kanamycin is mediated by Rac1 activation, followed by the formation of superoxide by NADPH oxidase. These changes will ultimately contribute to aminoglycoside-induced loss of hair cells.
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Affiliation(s)
| | | | - Jochen Schacht
- *Correspondence to: Jochen Schacht, Kresge Hearing Research Institute, Department of Otolaryngology, University of Michigan, Ann Arbor, MI 48109-0506. E-mail:
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197
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Ranjan P, Anathy V, Burch PM, Weirather K, Lambeth JD, Heintz NH. Redox-dependent expression of cyclin D1 and cell proliferation by Nox1 in mouse lung epithelial cells. Antioxid Redox Signal 2006; 8:1447-59. [PMID: 16987002 DOI: 10.1089/ars.2006.8.1447] [Citation(s) in RCA: 89] [Impact Index Per Article: 4.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/13/2022]
Abstract
NADPH oxidases produce reactive oxygen species (ROS) that serve as co-stimulatory signals for cell proliferation. In mouse lung epithelial cells that express Nox1, Nox2, Nox4, p22(phox), p47(phox), p67(phox), and Noxo1, overexpression of Nox1 delayed cell cycle withdrawal by maintaining AP-1-dependent expression of cyclin D1 in low serum conditions. In cycling cells, the effects of Nox1 were dose dependent: levels of Nox1 that induced 3- to 10-fold increases in ROS promoted phosphorylation of ERK1/2 and expression of cyclin D1, whereas expression of Nox1 with Noxo1 and Noxa1 (or expression of Nox4 alone) that induced substantial increases in intracellular ROS inhibited cyclin D1 and proliferation. Catalase reversed the effects of Nox1 on cyclin D1 and cell proliferation. Diphenylene iodonium, an inhibitor of NADPH oxidase activity, did not affect dosedependent responses of ERK1/2 or Akt to serum, but markedly inhibited the sequential expression of c-Fos and Fra-1 required for induction of cyclin D1 during cell cycle re-entry. These results indicate that Nox1 stimulates cell proliferation in actively cycling cells by reducing the requirement for growth factors to maintain expression of cyclin D1, whereas during cell cycle re-entry, NADPH oxidase activity is required for transcriptional activation of Fos family genes during the immediate early gene response.
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Affiliation(s)
- Priya Ranjan
- Department of Pathology and Vermont Cancer Center, University of Vermont College of Medicine, Burlington, 05405, USA
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198
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Abstract
There is growing experimental evidence that the production of intracellular reactive oxygen species (ROS) represents a tightly regulated process. In particular, numerous observations have suggested a role for the Ras superfamily of small GTPases in redox regulation. This article reviews the evidence that ROS can serve as important downstream effectors for both Ras and Rac proteins. Given the prominent role these proteins play in regulating growth, senescence, and transformation, understanding the role of the small GTPase family in redox regulation may significantly alter our current concepts as to how free radicals contribute to diverse processes from aging to cancer.
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Affiliation(s)
- Toren Finkel
- Cardiology Branch, National Heart Lungs and Blood Institute, National Institutes of Health, Bethesda, Maryland 20892-1454, USA.
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199
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Rokutan K, Kawahara T, Kuwano Y, Tominaga K, Sekiyama A, Teshima-Kondo S. NADPH oxidases in the gastrointestinal tract: a potential role of Nox1 in innate immune response and carcinogenesis. Antioxid Redox Signal 2006; 8:1573-82. [PMID: 16987012 DOI: 10.1089/ars.2006.8.1573] [Citation(s) in RCA: 75] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/20/2022]
Abstract
The gastrointestinal epithelium functions as physical and innate immune barriers against commensal or pathogenic microbes. NADPH oxidase 1 (Nox1) and dual oxidase 2 (Duox2), highly expressed in the colon, are suggested to play a potential role in host defense. Guinea-pig gastric pit cells and human colonic epithelial cells (T84 cells) express Nox1. With regard to activation of Nox1, the gastric epithelial cells are primed with Helicobacter pylori lipopolysaccharide, whereas T84 cells preferentially use the Toll-like receptor (TLR) 5, rather than TLR4, against Salmonella enteritidis infection. Thus, gastric and colonic epithelial cells may use different TLR members to discern pathogenicities among bacteria, depending on their environments and to activate Nox1 appropriately for host defense. Nox1-derived reactive oxygen species (ROS) have been implicated in the pathogenesis of inflammation-associated tumor development. The human stomach does not express Nox1. Helicobacter pylori infection alone does not induce it, whereas Nox1 is specifically expressed in gastric adenocarcinomas. In the human colon, Nox1 is differentiation-dependently expressed, and its expression is upregulated in adenomas and well-differentiated adenocarcinomas. Although Nox1 expression may not be directly linked to mitogenic activity, Nox1-derived ROS may exert a cancer-promoting effect by increasing resistance to programmed cell death of tumor cells.
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Affiliation(s)
- Kazuhito Rokutan
- Department of Stress Science, Institute of Health Biosciences, The University of Tokushima Graduate School, Tokushima, Japan.
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200
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Abstract
The phagocytic NADPH oxidase is recognized as a critical component of innate immunity, responsible for generation of microbicidal reactive oxygen species (ROS). This enzyme is one representative of the Nox family of oxidases (Nox1-Nox5, Duox1, and Duox2) that exhibit diverse expression patterns and appear to serve a variety of functions related to ROS generation. Mounting evidence now suggests that several of these novel oxidases also serve in host defense, particularly those showing high expression along epithelial surfaces exposed to the external environment. Within these sites, Nox enzymes tend to be located on apical cell surfaces and release ROS into extracellular environments, where they can be used by known antimicrobial peroxidases. Moreover, microbial factors were shown in several cases to cause higher ROS production, either by direct oxidase activation or by inducing higher oxidase expression. Several oxidases are also induced by immune cytokines, including interferon-gamma, interleukin (IL)-4, and IL-13. Although most of the evidence supporting host defense roles for mammalian nonphagocytic oxidases remains circumstantial, recent evidence indicates that Drosophila Duox plays a role in host resistance to infection. Finally, oxidative defense against invading pathogens appears to be an ancient protective mechanism, because related oxidases are known to participate in disease resistance in plants.
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Affiliation(s)
- Thomas L Leto
- Molecular Defenses Section, Laboratory of Host Defenses, National Institute of Allergy and Infectious Diseases, National Institutes of Health, Rockville, Maryland 20852, USA.
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