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Molecular Mechanisms of Hypertensive Nephropathy: Renoprotective Effect of Losartan through Hsp70. Cells 2021; 10:cells10113146. [PMID: 34831368 PMCID: PMC8619557 DOI: 10.3390/cells10113146] [Citation(s) in RCA: 35] [Impact Index Per Article: 11.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/30/2021] [Revised: 10/28/2021] [Accepted: 11/02/2021] [Indexed: 02/06/2023] Open
Abstract
Hypertensive nephrosclerosis is the second most common cause of end-stage renal disease after diabetes. For years, hypertensive kidney disease has been focused on the afferent arterioles and glomeruli damage and the involvement of the renin angiotensin system (RAS). Nonetheless, in recent years, novel evidence has demonstrated that persistent high blood pressure injures tubular cells, leading to epithelial–mesenchymal transition (EMT) and tubulointerstitial fibrosis. Injury primarily determined at the glomerular level by hypertension causes changes in post-glomerular peritubular capillaries that in turn induce endothelial damage and hypoxia. Microvasculature dysfunction, by inducing hypoxic environment, triggers inflammation, EMT with epithelial cells dedifferentiation and fibrosis. Hypertensive kidney disease also includes podocyte effacement and loss, leading to disruption of the filtration barrier. This review highlights the molecular mechanisms and histologic aspects involved in the pathophysiology of hypertensive kidney disease incorporating knowledge about EMT and tubulointerstitial fibrosis. The role of the Hsp70 chaperone on the angiotensin II–induced EMT after angiotensin II type 1 receptor (AT1R) blockage, as a possible molecular target for therapeutic strategy against hypertensive renal damage is discussed.
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Vallés PG, Bocanegra V, Costantino VV, Gil Lorenzo AF, Benardon ME, Cacciamani V. The renal antioxidative effect of losartan involves heat shock protein 70 in proximal tubule cells. Cell Stress Chaperones 2020; 25:753-766. [PMID: 32447546 PMCID: PMC7479660 DOI: 10.1007/s12192-020-01119-8] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/23/2019] [Revised: 04/30/2020] [Accepted: 05/06/2020] [Indexed: 02/07/2023] Open
Abstract
Angiotensin II exerts a cardinal role in the pathogenesis of hypertension and renal injury via action of angiotensin II type 1 (AT1) receptors. Local renin-angiotensin system (RAS) activity is essential for the mechanisms mediating pathophysiological functions. Proximal tubular angiotensinogen and tubular AT1 receptors are augmented by intrarenal angiotensin II. Caveolin 1 plays an important role as a regulatory molecule for the compartmentalization of redox signaling events through angiotensin II-induced NADPH oxidase activation in the kidney. A role for the renin-angiotensin system in the development and/or maintenance of hypertension has been demonstrated in spontaneously hypertensive rats (SHRs). Many effects of angiotensin II are dependent on the AT1 stimulation of reactive oxygen species (ROS) production by NADPH oxidase. Angiotensin II upregulation stimulates oxidative stress in proximal tubules from SHR. The NADPH oxidase 4 (Nox4) is abundantly expressed in kidney proximal tubule cells. Induction of the stress response includes synthesis of heat shock protein 70, a molecular chaperone that has a critical role in the recovery of cells from stress and in cytoprotection, guarding cells from subsequent insults. HSP70 chaperones function in part by driving the molecular triage decision, which determines whether proteins enter the productive folding pathway or result in client substrate ubiquitination and proteasomal degradation. This review examines regulation of losartan-mediated antioxidative stress responses by the chaperone HSP70 in proximal tubule cells of spontaneously hypertensive rats.
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Affiliation(s)
- Patricia G Vallés
- Área de Fisiopatología, Departamento de Patología, Facultad de Ciencias Médicas, Universidad Nacional de Cuyo, Mendoza, Argentina.
- IMBECU CONICET (National Council of Scientific and Technical Research of Argentina), Mendoza, Argentina.
| | - Victoria Bocanegra
- IMBECU CONICET (National Council of Scientific and Technical Research of Argentina), Mendoza, Argentina
| | - Valeria V Costantino
- IMBECU CONICET (National Council of Scientific and Technical Research of Argentina), Mendoza, Argentina
| | - Andrea F Gil Lorenzo
- Área de Fisiopatología, Departamento de Patología, Facultad de Ciencias Médicas, Universidad Nacional de Cuyo, Mendoza, Argentina
| | - María Eugenia Benardon
- Área de Fisiopatología, Departamento de Patología, Facultad de Ciencias Médicas, Universidad Nacional de Cuyo, Mendoza, Argentina
| | - Valeria Cacciamani
- IMBECU CONICET (National Council of Scientific and Technical Research of Argentina), Mendoza, Argentina
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González R, Molina-Ruiz FJ, Bárcena JA, Padilla CA, Muntané J. Regulation of Cell Survival, Apoptosis, and Epithelial-to-Mesenchymal Transition by Nitric Oxide-Dependent Post-Translational Modifications. Antioxid Redox Signal 2018; 29:1312-1332. [PMID: 28795583 DOI: 10.1089/ars.2017.7072] [Citation(s) in RCA: 25] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/16/2022]
Abstract
SIGNIFICANCE Nitric oxide (NO) is a physiopathological messenger generating different reactive nitrogen species (RNS) according to hypoxic, acidic and redox conditions. Recent Advances: RNS and reactive oxygen species (ROS) promote relevant post-translational modifications, such as nitrosation, nitration, and oxidation, in critical components of cell proliferation and death, epithelial-to-mesenchymal transition, and metastasis. CRITICAL ISSUES The pro- or antitumoral properties of NO are dependent on local concentration, redox state, cellular status, duration of exposure, and compartmentalization of NO generation. The increased expression of NO synthase has been associated with cancer progression. However, the experimental strategies leading to high intratumoral NO generation have been shown to exert antitumoral properties. The effect of NO and ROS on cell signaling is critically altered by factors modulating tumor progression such as oxygen content, metabolism, and inflammatory response. The review describes the alteration of key components involved in cell survival and death, metabolism, and metastasis induced by RNS- and ROS-related post-translational modifications. FUTURE DIRECTIONS The identification of the molecular targets affected by nitrosation, nitration, and oxidation, as well as their interactions with other post-translational modifications, will improve the understanding on the complex signaling and cell fate decision in cancer. The therapeutic NO-based strategies have to address the complex crosstalk among NO and ROS with regard to critical components affecting tumor cell survival, metabolism, and metastasis in the progression of cancer, as well as close interaction with ionizing radiation and chemotherapy.
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Affiliation(s)
- Raúl González
- 1 Institute of Biomedicine of Seville (IBiS), IBiS/"Virgen del Rocío" University Hospital/CSIC/University of Seville , Seville, Spain
| | - Francisco J Molina-Ruiz
- 1 Institute of Biomedicine of Seville (IBiS), IBiS/"Virgen del Rocío" University Hospital/CSIC/University of Seville , Seville, Spain
| | - J Antonio Bárcena
- 2 Department of Biochemistry and Molecular Biology, Maimonides Biomedical Research Institute of Córdoba (IMIBIC), University of Córdoba , Córdoba, Spain
| | - C Alicia Padilla
- 2 Department of Biochemistry and Molecular Biology, Maimonides Biomedical Research Institute of Córdoba (IMIBIC), University of Córdoba , Córdoba, Spain
| | - Jordi Muntané
- 3 Department of General Surgery, "Virgen del Rocío" University Hospital/IBiS/CSIC/University of Seville , Seville, Spain .,4 Centro de Investigación Biomédica en Red de Enfermedades Hepáticas y Digestivas (CIBERehd) , Madrid, Spain
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Masoud R, Bizouarn T, Houée-Levin C. Cholesterol: A modulator of the phagocyte NADPH oxidase activity - A cell-free study. Redox Biol 2014; 3:16-24. [PMID: 25462061 PMCID: PMC4221629 DOI: 10.1016/j.redox.2014.10.001] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/07/2014] [Revised: 10/02/2014] [Accepted: 10/12/2014] [Indexed: 01/26/2023] Open
Abstract
The NADPH oxidase Nox2, a multi-subunit enzyme complex comprising membrane and cytosolic proteins, catalyzes a very intense production of superoxide ions O2•−, which are transformed into other reactive oxygen species (ROS). In vitro, it has to be activated by addition of amphiphiles like arachidonic acid (AA). It has been shown that the membrane part of phagocyte NADPH oxidase is present in lipid rafts rich in cholesterol. Cholesterol plays a significant role in the development of cardio-vascular diseases that are always accompanied by oxidative stress. Our aim was to investigate the influence of cholesterol on the activation process of NADPH oxidase. Our results clearly show that, in a cell-free system, cholesterol is not an efficient activator of NADPH oxidase like arachidonic acid (AA), however it triggers a basal low superoxide production at concentrations similar to what found in neutrophile. A higher concentration, if present during the assembly process of the enzyme, has an inhibitory role on the production of O2•−. Added cholesterol acts on both cytosolic and membrane components, leading to imperfect assembly and decreasing the affinity of cytosolic subunits to the membrane ones. Added to the cytosolic proteins, it retains their conformations but still allows some conformational change induced by AA addition, indispensable to activation of NADPH oxidase. Natural cholesterol is important for the NADPH oxidase function. Added cholesterol alone activates slightly the NADPH oxidase. Cholesterol addition lowers the AA dependent activity of NADPH oxidase. Added cholesterol acts on both cytosolic and membrane components.
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Affiliation(s)
- Rawand Masoud
- Laboratoire de chimie physique, UMR 8000, Université Paris Sud-CNRS, Orsay 91405, France
| | - Tania Bizouarn
- Laboratoire de chimie physique, UMR 8000, Université Paris Sud-CNRS, Orsay 91405, France
| | - Chantal Houée-Levin
- Laboratoire de chimie physique, UMR 8000, Université Paris Sud-CNRS, Orsay 91405, France.
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Gil Lorenzo AF, Bocanegra V, Benardon ME, Cacciamani V, Vallés PG. Hsp70 regulation on Nox4/p22phox and cytoskeletal integrity as an effect of losartan in vascular smooth muscle cells. Cell Stress Chaperones 2014; 19:115-34. [PMID: 23761196 PMCID: PMC3857436 DOI: 10.1007/s12192-013-0439-6] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/19/2013] [Revised: 05/24/2013] [Accepted: 05/29/2013] [Indexed: 02/07/2023] Open
Abstract
A series of signaling cascades are activated after angiotensin II binds to angiotensin II type I receptor (AT1R), a peptide that is an important mediator of oxidative stress. Hsp70 regulates a diverse set of signaling pathways through interactions with proteins. Here, we tested the hypothesis of angiotensin II AT1R inhibition effect on Hsp70 interaction with Nox4/p22phox complex and Hsp70 leading to actin cytoskeleton modulation in spontaneously hypertensive rats (SHR) vascular smooth muscle cells (VSMCs). SHR and Wistar-Kyotto rats (VSMCs from 8 to 10 weeks) were stimulated with angiotensin II (100 nmol/L) for 15 min (AII), treated with losartan (100 nmol/L) for 90 min (L), and with losartan for 90 min plus angiotensin in the last 15 min (L + AII). Whereas SHR VSMCs exposure to angiotensin II overexpressed AT1R and Nox4 nicotinamide-adenine dinucleotide phosphate (NADPH) oxidase and slightly downregulated caveolin-1 expression, losartan decreased AT1R protein levels and increased caveolin-1 and Hsp70 expression in SHR VSMC membranes. Immunoprecipitation and immunofluorescence confocal microscopy proved interaction and colocalization of membrane translocated Hsp70 and Nox4/p22phox. Increased levels of Hsp70 contrast with the decreased immunoprecipitation of Nox4/p22phox and RhoA in membranes from SHR VSMCs (L) vs SHR VSMCs (AII). Hsp72 depletion resulted in higher Nox4 expression and increased NADPH oxidase activity in VSMCs (L + AII) from SHR when contrasted with nontransfected VSMCs (L + AII). After Hsp72 knockdown in SHR VSMCs, losartan could not impair angiotensin II-enhanced stress fiber formation and focal adhesion assembly. In conclusion, our data showing a negative regulation of Hsp70 on Nox4/p22phox demonstrates a possible mechanism in explaining the antioxidative function joined to cytoskeletal integrity modulation within the effects of losartan in VSMCs from SHR.
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MESH Headings
- Angiotensin II/pharmacology
- Animals
- Antihypertensive Agents/pharmacology
- Caveolin 1/metabolism
- Cells, Cultured
- Cytoskeleton/drug effects
- Cytoskeleton/metabolism
- HSP70 Heat-Shock Proteins/metabolism
- HSP72 Heat-Shock Proteins/antagonists & inhibitors
- HSP72 Heat-Shock Proteins/genetics
- HSP72 Heat-Shock Proteins/metabolism
- Losartan/pharmacology
- Male
- Muscle, Smooth, Vascular/cytology
- Muscle, Smooth, Vascular/drug effects
- Muscle, Smooth, Vascular/metabolism
- NADPH Oxidase 4
- NADPH Oxidases/metabolism
- Rats
- Rats, Inbred SHR
- Rats, Inbred WKY
- Rats, Wistar
- Receptor, Angiotensin, Type 1/chemistry
- Receptor, Angiotensin, Type 1/metabolism
- rhoA GTP-Binding Protein/metabolism
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Affiliation(s)
| | - Victoria Bocanegra
- />IMBECU-CONICET (National Council of Scientific and Technical Research of Argentina), Mendoza, Argentina
| | - María Eugenia Benardon
- />Área de Fisiología Patológica, Departamento de Patología, Facultad de Ciencias Médicas, Universidad Nacional de Cuyo, Centro Universitario, 5500 Mendoza, Argentina
| | - Valeria Cacciamani
- />Área de Fisiología Patológica, Departamento de Patología, Facultad de Ciencias Médicas, Universidad Nacional de Cuyo, Centro Universitario, 5500 Mendoza, Argentina
| | - Patricia G. Vallés
- />IMBECU-CONICET (National Council of Scientific and Technical Research of Argentina), Mendoza, Argentina
- />Área de Fisiología Patológica, Departamento de Patología, Facultad de Ciencias Médicas, Universidad Nacional de Cuyo, Centro Universitario, 5500 Mendoza, Argentina
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Snaar-Jagalska BE, Cambi A, Schmidt T, de Keijzer S. Single-molecule imaging technique to study the dynamic regulation of GPCR function at the plasma membrane. Methods Enzymol 2013; 521:47-67. [PMID: 23351733 DOI: 10.1016/b978-0-12-391862-8.00003-x] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/22/2023]
Abstract
The lateral diffusion of a G-protein-coupled receptor (GPCR) in the plasma membrane determines its interaction capabilities with downstream signaling molecules and critically modulates its function. Mechanisms that control GPCR mobility, like compartmentalization, enable a cell to fine-tune its response through local changes in the rate, duration, and extent of signaling. These processes are known to be highly dynamic and tightly regulated in time and space, usually not completely synchronized in time. Therefore, bulk studies such as protein biochemistry or conventional confocal microscopy will only yield information on the average properties of the interactions and are compromised by poor time resolution. Single-particle tracking (SPT) in living cells is a key approach to directly monitor the function of a GPCR within its natural environment and to obtain unprecedented detailed information about receptor mobility, binding kinetics, aggregation states, and domain formation. This review provides a detailed description on how to perform single GPCR tracking experiments.
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Affiliation(s)
- B E Snaar-Jagalska
- Cell Biology, Leiden Institute of Biology, Leiden University, Leiden, The Netherlands
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Li PL, Zhang Y. Cross talk between ceramide and redox signaling: implications for endothelial dysfunction and renal disease. Handb Exp Pharmacol 2013:171-97. [PMID: 23563657 DOI: 10.1007/978-3-7091-1511-4_9] [Citation(s) in RCA: 34] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/07/2023]
Abstract
Recent studies have demonstrated that cross talk between ceramide and redox signaling modulates various cell activities and functions and contributes to the development of cardiovascular diseases and renal dysfunctions. Ceramide triggers the generation of reactive oxygen species (ROS) and increases oxidative stress in many mammalian cells and animal models. On the other hand, inhibition of ROS-generating enzymes or treatment of antioxidants impairs sphingomyelinase activation and ceramide production. As a mechanism, ceramide-enriched signaling platforms, special cell membrane rafts (MR) (formerly lipid rafts), provide an important microenvironment to mediate the cross talk of ceramide and redox signaling to exert a corresponding regulatory role on cell and organ functions. In this regard, activation of acid sphingomyelinase and generation of ceramide mediate the formation of ceramide-enriched membrane platforms, where transmembrane signals are transmitted or amplified through recruitment, clustering, assembling, or integration of various signaling molecules. A typical such signaling platform is MR redox signaling platform that is centered on ceramide production and aggregation leading to recruitment and assembling of NADPH oxidase to form an active complex in the cell plasma membrane. This redox signaling platform not only conducts redox signaling or regulation but also facilitates a feedforward amplification of both ceramide and redox signaling. In addition to this membrane MR redox signaling platform, the cross talk between ceramide and redox signaling may occur in other cell compartments. This book chapter focuses on the molecular mechanisms, spatial-temporal regulations, and implications of this cross talk between ceramide and redox signaling, which may provide novel insights into the understanding of both ceramide and redox signaling pathways.
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Affiliation(s)
- Pin-Lan Li
- Department of Pharmacology and Toxicology, Virginia Commonwealth University, Richmond, VA 23298, USA.
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Valente AJ, Yoshida T, Murthy SN, Sakamuri SSVP, Katsuyama M, Clark RA, Delafontaine P, Chandrasekar B. Angiotensin II enhances AT1-Nox1 binding and stimulates arterial smooth muscle cell migration and proliferation through AT1, Nox1, and interleukin-18. Am J Physiol Heart Circ Physiol 2012; 303:H282-96. [PMID: 22636674 DOI: 10.1152/ajpheart.00231.2012] [Citation(s) in RCA: 71] [Impact Index Per Article: 5.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/31/2023]
Abstract
The redox-sensitive transcription factors NF-κB and activator protein-1 (AP-1) are critical mediators of ANG II signaling. The promitogenic and promigratory factor interleukin (IL)-18 is an NF-κB- and AP-1-responsive gene. Therefore, we investigated whether ANG II-mediated smooth muscle cell (SMC) migration and proliferation involve IL-18. ANG II induced rat carotid artery SMC migration and proliferation and IL-18 and metalloproteinase (MMP)-9 expression via ANG II type 1 (AT(1)) receptor. ANG II-induced superoxide generation, NF-κB and AP-1 activation, and IL-18 and MMP-9 induction were all markedly attenuated by losartan, diphenyleneiodonium chloride (DPI), and Nox1 knockdown. Similar to ANG II, addition of IL-18 also induced superoxide generation, activated NF-κB and AP-1, and stimulated SMC migration and proliferation, in part via Nox1, and both ANG II and IL-18 induced NOX1 transcription in an AP-1-dependent manner. AT(1) physically associates with Nox1 in SMC, and ANG II enhanced this binding. Interestingly, exogenous IL-18 neither induced AT(1) binding to Nox1 nor enhanced the ANG II-induced increase in AT(1)/Nox1 binding. Importantly, IL-18 knockdown, or pretreatment with IL-18 neutralizing antibodies, or IL-18 binding protein, all attenuated the migratory and mitogenic effects of ANG II. Continuous infusion of ANG II for 7 days induced carotid artery hyperplasia in rats via AT(1) and was associated with increased AT(1)/Nox1 binding (despite lower AT(1) levels); increased DPI-inhibitable superoxide production; increased phospho-IKKβ, JNK, p65, and c-Jun; and induction of IL-18 and MMP-9 in endothelium-denuded carotid arteries. These results indicate that IL-18 amplifies the ANG II-induced, redox-dependent inflammatory cascades by activating similar promitogenic and promigratory signal transduction pathways. The ANG II/Nox1/IL-18 pathway may be critical in hyperplastic vascular diseases, including atherosclerosis and restenosis.
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Affiliation(s)
- Anthony J Valente
- Medicine, University of Texas Health Science Center, San Antonio, USA
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9
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Jin S, Zhou F, Katirai F, Li PL. Lipid raft redox signaling: molecular mechanisms in health and disease. Antioxid Redox Signal 2011; 15:1043-83. [PMID: 21294649 PMCID: PMC3135227 DOI: 10.1089/ars.2010.3619] [Citation(s) in RCA: 90] [Impact Index Per Article: 6.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/20/2022]
Abstract
Lipid rafts, the sphingolipid and cholesterol-enriched membrane microdomains, are able to form different membrane macrodomains or platforms upon stimulations, including redox signaling platforms, which serve as a critical signaling mechanism to mediate or regulate cellular activities or functions. In particular, this raft platform formation provides an important driving force for the assembling of NADPH oxidase subunits and the recruitment of other related receptors, effectors, and regulatory components, resulting, in turn, in the activation of NADPH oxidase and downstream redox regulation of cell functions. This comprehensive review attempts to summarize all basic and advanced information about the formation, regulation, and functions of lipid raft redox signaling platforms as well as their physiological and pathophysiological relevance. Several molecular mechanisms involving the formation of lipid raft redox signaling platforms and the related therapeutic strategies targeting them are discussed. It is hoped that all information and thoughts included in this review could provide more comprehensive insights into the understanding of lipid raft redox signaling, in particular, of their molecular mechanisms, spatial-temporal regulations, and physiological, pathophysiological relevances to human health and diseases.
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Affiliation(s)
- Si Jin
- Department of Pharmacology, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, Hubei, China.
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Zhuo JL, Li XC. New insights and perspectives on intrarenal renin-angiotensin system: focus on intracrine/intracellular angiotensin II. Peptides 2011; 32:1551-65. [PMID: 21699940 PMCID: PMC3137727 DOI: 10.1016/j.peptides.2011.05.012] [Citation(s) in RCA: 111] [Impact Index Per Article: 8.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/28/2011] [Revised: 05/05/2011] [Accepted: 05/09/2011] [Indexed: 02/06/2023]
Abstract
Although renin, the rate-limiting enzyme of the renin-angiotensin system (RAS), was first discovered by Robert Tigerstedt and Bergman more than a century ago, the research on the RAS still remains stronger than ever. The RAS, once considered to be an endocrine system, is now widely recognized as dual (circulating and local/tissue) or multiple hormonal systems (endocrine, paracrine and intracrine). In addition to the classical renin/angiotensin I-converting enzyme (ACE)/angiotensin II (Ang II)/Ang II receptor (AT₁/AT₂) axis, the prorenin/(Pro)renin receptor (PRR)/MAP kinase axis, the ACE2/Ang (1-7)/Mas receptor axis, and the Ang IV/AT₄/insulin-regulated aminopeptidase (IRAP) axis have recently been discovered. Furthermore, the roles of the evolving RAS have been extended far beyond blood pressure control, aldosterone synthesis, and body fluid and electrolyte homeostasis. Indeed, novel actions and underlying signaling mechanisms for each member of the RAS in physiology and diseases are continuously uncovered. However, many challenges still remain in the RAS research field despite of more than one century's research effort. It is expected that the research on the expanded RAS will continue to play a prominent role in cardiovascular, renal and hypertension research. The purpose of this article is to review the progress recently being made in the RAS research, with special emphasis on the local RAS in the kidney and the newly discovered prorenin/PRR/MAP kinase axis, the ACE2/Ang (1-7)/Mas receptor axis, the Ang IV/AT₄/IRAP axis, and intracrine/intracellular Ang II. The improved knowledge of the expanded RAS will help us better understand how the classical renin/ACE/Ang II/AT₁ receptor axis, extracellular and/or intracellular origin, interacts with other novel RAS axes to regulate blood pressure and cardiovascular and kidney function in both physiological and diseased states.
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Affiliation(s)
- Jia L Zhuo
- Laboratory of Receptor and Signal Transduction, Department of Pharmacology and Toxicology, the University of Mississippi Medical Center, Jackson, MS 39216-4505, USA.
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Sardina JL, López-Ruano G, Sánchez-Sánchez B, Llanillo M, Hernández-Hernández A. Reactive oxygen species: are they important for haematopoiesis? Crit Rev Oncol Hematol 2011; 81:257-74. [PMID: 21507675 DOI: 10.1016/j.critrevonc.2011.03.005] [Citation(s) in RCA: 51] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/17/2010] [Revised: 03/15/2011] [Accepted: 03/22/2011] [Indexed: 02/07/2023] Open
Abstract
The production of reactive oxygen species (ROS) has traditionally been related to deleterious effects for cells. However, it is now widely accepted that ROS can play an important role in regulating cellular signalling and gene expression. NADPH oxidase ROS production seems to be especially important in this regard. Some lines of evidence suggest that ROS may be important modulators of cell differentiation, including haematopoietic differentiation, in both physiologic and pathologic conditions. Here we shall review how ROS can regulate cell signalling and gene expression. We shall also focus on the importance of ROS for haematopoietic stem cell (HSC) biology and for haematopoietic differentiation. We shall review the involvement of ROS and NADPH oxidases in cancer, and in particular what is known about the relationship between ROS and haematological malignancies. Finally, we shall discuss the use of ROS as cancer therapeutic targets.
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Affiliation(s)
- José L Sardina
- Department of Biochemistry and Molecular Biology, University of Salamanca, Salamanca, Spain
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Shanmugam P, Valente AJ, Prabhu SD, Venkatesan B, Yoshida T, Delafontaine P, Chandrasekar B. Angiotensin-II type 1 receptor and NOX2 mediate TCF/LEF and CREB dependent WISP1 induction and cardiomyocyte hypertrophy. J Mol Cell Cardiol 2011; 50:928-38. [PMID: 21376054 DOI: 10.1016/j.yjmcc.2011.02.012] [Citation(s) in RCA: 52] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/13/2011] [Revised: 02/17/2011] [Accepted: 02/21/2011] [Indexed: 02/02/2023]
Abstract
Angiotensin-II (Ang-II) plays a key role in myocardial hypertrophy, remodeling and failure. We investigated whether Ang-II-induced cardiomyocyte hypertrophy is dependent on WNT1 inducible signaling pathway protein 1 (WISP1), a pro growth factor. Ang-II induced hypertrophy and WISP1 expression in neonatal rat cardiomyocytes (NRCM), effects that were significantly inhibited by pre-treatment with the AT1 antagonist losartan and by WISP1 knockdown. Further, Ang-II induced WISP1 was superoxide-dependent, and inhibited by DPI, an inhibitor of NADPH oxidases, and by knockdown of NOX2. AT1 was physically associated with NOX2 both in vitro and in vivo, and Ang-II increased this interaction in vivo. Ang-II induced WISP1 expression via superoxide/Akt/GSK3β/β-catenin/TCF/LEF and by Akt-dependent CREB activation. Further, Ang-II also activated CREB via superoxide-mediated p38 MAPK and ERK activation. Continuous infusion of Ang-II for 7days induced myocardial hypertrophy in rats, and was associated with increased Akt, p-Akt, p-p38 MAPK, p-ERK1/2, and WISP1 expression. These results demonstrate that Ang-II induced cardiomyocyte hypertrophy is mediated through AT1, NOX2 and the induction of WISP1, and may involve the direct interaction of AT1 with NOX2. Thus targeting both WISP1 and NOX2 may have a therapeutic potential in improving cardiomyocyte survival and growth following myocardial injury and remodeling. This article is part of a Special Issue entitled 'Possible Editorial'.
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de Keijzer S, Galloway J, Harms GS, Devreotes PN, Iglesias PA. Disrupting microtubule network immobilizes amoeboid chemotactic receptor in the plasma membrane. BIOCHIMICA ET BIOPHYSICA ACTA-BIOMEMBRANES 2011; 1808:1701-8. [PMID: 21334306 DOI: 10.1016/j.bbamem.2011.02.009] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/19/2010] [Revised: 01/08/2011] [Accepted: 02/09/2011] [Indexed: 11/29/2022]
Abstract
Signaling cascades are initiated in the plasma membrane via activation of one molecule by another. The interaction depends on the mutual availability of the molecules to each other and this is determined by their localization and lateral diffusion in the cell membrane. The cytoskeleton plays a very important role in this process by enhancing or restricting the possibility of the signaling partners to meet in the plasma membrane. In this study we explored the mode of diffusion of the cAMP receptor, cAR1, in the plasma membrane of Dictyostelium discoideum cells and how this is regulated by the cytoskeleton. Single-particle tracking of fluorescently labeled cAR1 using Total Internal Reflection Microscopy showed that 70% of the cAR1 molecules were mobile. These receptors showed directed motion and we demonstrate that this is not because of tracking along the actin cytoskeleton. Instead, destabilization of the microtubules abolished cAR1 mobility in the plasma membrane and this was confirmed by Fluorescence Recovery after Photobleaching. As a result of microtubule stabilization, one of the first downstream signaling events, the jump of the PH domain of CRAC, was decreased. These results suggest a role for microtubules in cAR1 dynamics and in the ability of cAR1 molecules to interact with their signaling partners.
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Affiliation(s)
- S de Keijzer
- Department of Cell Biology, Johns Hopkins University School of Medicine, Baltimore, MD 21218, USA.
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14
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Zou T, Yang W, Hou Z, Yang J. Homocysteine enhances cell proliferation in vascular smooth muscle cells: role of p38 MAPK and p47phox. Acta Biochim Biophys Sin (Shanghai) 2010; 42:908-15. [PMID: 21068125 DOI: 10.1093/abbs/gmq102] [Citation(s) in RCA: 31] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/10/2023] Open
Abstract
Elevation of blood homocysteine levels (hyperhomocysteinemia) is a risk factor for cardiovascular disorders. One of the mechanisms by which homocysteine induces atherosclerosis is to promote the proliferation of vascular smooth muscle cells (VSMCs) in a reactive oxygen species (ROS)-dependent manner. It has been shown that homocysteine induces the production of ROS through the activation of NAD(P)H oxidases in VSMCs. In this study, we investigated the signal transduction pathways involved in the activation of NAD(P)H oxidases. Homocysteine promoted DNA synthesis in VSMCs. Inhibition of ROS by N-acetyl-L-cysteine (an antioxidant) and apocynin (an inhibitor of NAD(P)H oxidases) significantly blocked homocysteine-induced proliferation in VSMCs. Homocysteine induced a rapid increase in the phosphorylation of p38-mitogen-activated protein kinase (p38 MAPK). p38 MAPK in turn activated NAD(P)H oxidases by inducing the phosphorylation of p47phox, resulting in the generation of ROS. ROS induced the phosphorylation of Akt, which was probably responsible for proliferation in VSMCs. These findings demonstrate that homocysteine induces an increase in the activity of NAD(P)H oxidases in VSMCs by activating p38 MAPK and enhancing the phosphorylation of p47phox.
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Affiliation(s)
- Tong Zou
- Department of Cardiology, Beijing Hospital, China
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15
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Chudinova EM, Nadezhdina ES, Ivanov PA. Is the microtubule disruption-induced alteration of peroxide concentration a factor inhibiting the assembly of ribonucleoprotein stress granules? Biophysics (Nagoya-shi) 2010. [DOI: 10.1134/s000635091005012x] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/23/2022] Open
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16
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Li H, Yu P, Sun Y, Felder RA, Periasamy A, Jose PA. Actin cytoskeleton-dependent Rab GTPase-regulated angiotensin type I receptor lysosomal degradation studied by fluorescence lifetime imaging microscopy. JOURNAL OF BIOMEDICAL OPTICS 2010; 15:056003. [PMID: 21054097 PMCID: PMC2966490 DOI: 10.1117/1.3484751] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/04/2009] [Revised: 07/19/2010] [Accepted: 07/20/2010] [Indexed: 05/30/2023]
Abstract
The dynamic regulation of the cellular trafficking of human angiotensin (Ang) type 1 receptor (AT1R) is not well understood. Therefore, we investigated the cellular trafficking of AT1R-enhanced green fluorescent protein (EGFP) (AT1R-EGFP) heterologously expressed in HEK293 cells by determining the change in donor lifetime (AT1R-EGFP) in the presence or absence of acceptor(s) using fluorescence lifetime imaging-fluorescence resonance energy transfer (FRET) microscopy. The average lifetime of AT1R-EGFP in our donor-alone samples was ∼2.33 ns. The basal state lifetime was shortened slightly in the presence of Rab5 (2.01±0.10 ns) or Rab7 (2.11±0.11 ns) labeled with Alexa 555, as the acceptor fluorophore. A 5-min Ang II treatment markedly shortened the lifetime of AT1R-EGFP in the presence of Rab5-Alexa 555 (1.78±0.31 ns) but was affected minimally in the presence of Rab7-Alexa 555 (2.09±0.37 ns). A 30-min Ang II treatment further decreased the AT1R-EGFP lifetime in the presence of both Rab5- and Rab7-Alexa 555. Latrunculin A but not nocodazole pretreatment blocked the ability of Ang II to shorten the AT1R-EGFP lifetime. The occurrence of FRET between AT1R-EGFP (donor) and LAMP1-Alexa 555 (acceptor) with Ang II stimulation was impaired by photobleaching the acceptor. These studies demonstrate that Ang II-induced AT1R lysosomal degradation through its association with LAMP1 is regulated by Rab5/7 via mechanisms that are dependent on intact actin cytoskeletons.
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Affiliation(s)
- Hewang Li
- Children's Research Institute, Children's National Medical Center, Center for Molecular Physiology Research, Washington, DC 20010, USA
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17
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Caveolin-1 and Hsp70 interaction in microdissected proximal tubules from spontaneously hypertensive rats as an effect of Losartan. J Hypertens 2010; 28:143-55. [DOI: 10.1097/hjh.0b013e328332b778] [Citation(s) in RCA: 28] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/29/2022]
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18
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Abstract
Both Ras and Nox represent ancient gene families which control a broad range of cellular responses. Both families mediate signals governing motility, differentiation, and proliferation, and both inhabit overlapping subcellular microdomains. Yet little is known of the precise functional relationship between these two ubiquitous families. In this review, we examine the interface where these two large fields meet.
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Affiliation(s)
| | - Lance S. Terada
- Correspondence to: Lance S. Terada; Pulmonary and Critical Care Medicine, University of Texas Southwestern Medical Center, 5323 Harry Hines Blvd., Dallas, TX 75390. Fax: 214-648-9104. E-mail:
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Li XC, Hopfer U, Zhuo JL. AT1 receptor-mediated uptake of angiotensin II and NHE-3 expression in proximal tubule cells through a microtubule-dependent endocytic pathway. Am J Physiol Renal Physiol 2009; 297:F1342-52. [PMID: 19726542 DOI: 10.1152/ajprenal.90734.2008] [Citation(s) in RCA: 53] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/04/2023] Open
Abstract
Angiotensin II (ANG II) is taken up by proximal tubule (PT) cells via AT1 (AT1a) receptor-mediated endocytosis, but the underlying cellular mechanisms remain poorly understood. The present study tested the hypothesis that the microtubule- rather than the clathrin-dependent endocytic pathway regulates AT1-mediated uptake of ANG II and ANG II-induced sodium and hydrogen exchanger-3 (NHE-3) expression in PT cells. The expression of AT1 receptors, clathrin light (LC) and heavy chain (HC) proteins, and type 1 microtubule-associated proteins (MAPs; MAP-1A and MAP-1B) in PT cells were knocked down by their respective small interfering (si) RNAs before AT1-mediated FITC-ANG II uptake and ANG II-induced NHE-3 expression were studied. AT1 siRNAs inhibited AT1 expression and blocked ANG II-induced NHE-3 expression in PT cells, as expected (P < 0.01). Clathrin LC or HC siRNAs knocked down their respective proteins by approximately 90% with a peak response at 24 h, and blocked the clathrin-dependent uptake of Alexa Fluor 594-transferrin (P < 0.01). However, neither LC nor HC siRNAs inhibited AT1-mediated uptake of FITC-ANG II or affected ANG II-induced NHE-3 expression. MAP-1A or MAP-1B siRNAs markedly knocked down MAP-1A or MAP-1B proteins in a time-dependent manner with peak inhibitions at 48 h (>76.8%, P < 0.01). MAP protein knockdown resulted in approximately 52% decreases in AT1-mediated FITC-ANG II uptake and approximately 66% decreases in ANG II-induced NHE-3 expression (P < 0.01). These effects were associated with threefold decreases in ANG II-induced MAP kinases ERK 1/2 activation (P < 0.01), but not with altered AT1 expression or clathrin-dependent transferrin uptake. Both losartan and AT1a receptor deletion in mouse PT cells completely abolished the effects of MAP-1A knockdown on ANG II-induced NHE-3 expression and activation of MAP kinases ERK1/2. Our findings suggest that the alternative microtubule-dependent endocytic pathway, rather than the canonical clathrin-dependent pathway, plays an important role in AT1 (AT1a)-mediated uptake of extracellular ANG II and ANG II-induced NHE-3 expression in PT cells.
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Affiliation(s)
- Xiao C Li
- Laboratory of Receptor and Signal Transduction, Division of Hypertension and Vascular Research, Department of Internal Medicine, Henry Ford Hospital, Detroit, Michigan 48202, USA
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20
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Shin EY, Lee CS, Park MH, Kim DJ, Kwak SJ, Kim EG. Involvement of betaPIX in angiotensin II-induced migration of vascular smooth muscle cells. Exp Mol Med 2009; 41:387-96. [PMID: 19322025 DOI: 10.3858/emm.2009.41.6.044] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/08/2023] Open
Abstract
Angiotensin II (Ang II) stimulates migration of vascular smooth muscle cell (VSMC) in addition to its contribution to contraction and hypertrophy. It is well established that Rho GTPases regulate cellular contractility and migration by reorganizing the actin cytoskeleton. Ang II activates Rac1 GTPase, but its upstream guanine nucleotide exchange factor (GEF) remains elusive. Here, we show that Ang II-induced VSMC migration occurs in a betaPIX GEF-dependent manner. betaPIX-specific siRNA treatment significantly inhibited Ang II-induced VSMC migration. Ang II activated the catalytic activity of betaPIX towards Rac1 in dose- and time-dependent manners. Activity reached a peak at 10 min and declined close to a basal level by 30 min following stimulation. Pharmacological inhibition with specific kinase inhibitors revealed the participation of protein kinase C, Src family kinase, and phosphatidylinositol 3-kinase (PI3-K) upstream of betaPIX. Both p21-activated kinase and reactive oxygen species played key roles in cytoskeletal reorganization downstream of betaPIX-Rac1. Taken together, our results suggest that betaPIX is involved in Ang II-induced VSMC migration.
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Affiliation(s)
- Eun Young Shin
- Department of Biochemistry and Signaling Disorder Research CenterCollege of Medicine, Chungbuk National University, Cheongju 361-763, Korea
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21
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Abstract
PURPOSE OF REVIEW G protein-coupled receptor (GPCR) signaling machinery can serve as a direct target of reactive oxygen species (ROS), including superoxide (O2-), hydrogen peroxide (H2O2) as well as reactive nitrogen species, including nitric oxide and S-nitrosothiols (SNOs). Nicotinamide adenine dinucleotide phosphate (NADPH) oxidase is one of the major sources of O2- produced following GPCR activation in vasculature. Nitric oxide is generated by three isoforms of nitric oxide synthase (NOS). This review will summarize the recent progress on GPCR signaling modulation by NADPH oxidase-derived ROS and NOS-derived SNOs. RECENT FINDINGS ROS and reactive nitrogen species play an important role in GPCR signaling involved in various physiological functions such as cell growth, migration, gene expression as well as pathophysiologies. NADPH oxidase-derived ROS activate specific redox signaling events involved in cardiovascular diseases. SNOs can modulate GPCR signaling and internalization through S-nitrosylation of the scaffolding protein beta-arrestin, the GPCR kinases, and dynamin, a guanosine triphosphatase responsible for endocytosis. SUMMARY NADPH oxidase-derived ROS and NOS-derived SNOs are now recognized as important second messengers to regulate GPCR signaling, thereby contributing to various biological and pathophysiological functions. Understanding the molecular mechanism of how ROS, nitric oxide, and SNOs might modulate GPCR signaling is essential for development of novel therapeutic approaches.
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Abstract
Reactive oxygen species (ROS) are generated in response to growth factors, cytokines, G protein-coupled receptor agonists, or shear stress, and function as signaling molecules in nonphagocytes. However, it is poorly understood how freely diffusible ROS can activate specific signaling, so-called "redox signaling." NADPH oxidases are a major source of ROS and now recognized to have specific subcellular localizations, and this targeting to specific compartments is required for localized ROS production. One important mechanism may involve the interaction of oxidase subunits with various targeting proteins localized in lamellipodial leading edge and focal adhesions/complexes. ROS are believed to inactivate protein tyrosine phosphatases, thereby establishing a positive-feedback system that promotes activation of specific redox signaling pathways involved in various functions. Additionally, ROS production may be localized through interactions of NADPH oxidase with signaling platforms associated with caveolae/lipid rafts, endosomes, and nucleus. These indicate that the specificity of ROS-mediated signal transduction may be modulated by the localization of Nox isoforms and their regulatory subunits within specific subcellular compartments. This review summarizes the recent progress on compartmentalization of redox signaling via activation of NADPH oxidase, which is implicated in cell biology and pathophysiologies.
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Affiliation(s)
- Masuko Ushio-Fukai
- Department of Pharmacology, Center for Lung and Vascular Biology, Center for Cardiovascular Research, University of Illinois at Chicago, Chicago, Illinois 60612, USA.
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Li H, Han W, Villar VAM, Keever LB, Lu Q, Hopfer U, Quinn MT, Felder RA, Jose PA, Yu P. D1-like receptors regulate NADPH oxidase activity and subunit expression in lipid raft microdomains of renal proximal tubule cells. Hypertension 2009; 53:1054-61. [PMID: 19380616 DOI: 10.1161/hypertensionaha.108.120642] [Citation(s) in RCA: 31] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/11/2023]
Abstract
NADPH oxidase (Nox)-dependent reactive oxygen species production is implicated in the pathogenesis of cardiovascular diseases, including hypertension. We tested the hypothesis that oxidase subunits are differentially regulated in renal proximal tubules from normotensive and spontaneously hypertensive rats. Basal Nox2 and Nox4, but not Rac1, in immortalized renal proximal tubule cells and brush border membranes were greater in hypertensive than in normotensive rats. However, more Rac1 was expressed in lipid rafts in cells from hypertensive rats than in cells from normotensive rats; the converse was observed with Nox4, whereas Nox2 expression was similar. The D(1)-like receptor agonist fenoldopam decreased Nox2 and Rac1 protein in lipid rafts to a greater extent in hypertensive than in normotensive rats. Basal oxidase activity was 3-fold higher in hypertensive than in normotensive rats but was inhibited to a greater extent by fenoldopam in normotensive (58+/-3.3%) than in hypertensive rats (31+/-5.2%; P<0.05; n=6 per group). Fenoldopam decreased the amount of Nox2 that coimmunoprecipitated with p67(phox) in cells from normotensive rats. D(1)-like receptors may decrease oxidase activity by disrupting the distribution and assembly of oxidase subunits in cell membrane microdomains. The cholesterol-depleting reagent methyl-beta-cyclodextrin decreased oxidase activity and cholesterol content to a greater extent in hypertensive than in normotensive rats. The greater basal levels of Nox2 and Nox4 in cell membranes and Nox2 and Rac1 in lipid rafts in hypertensive rats than in normotensive rats may explain the increased basal oxidase activity in hypertensive rats.
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Affiliation(s)
- Hewang Li
- Center for Molecular Physiology Research, Children's National Medical Center, Washington, DC 20010, USA
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24
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Bartoli M, Al-Shabrawey M, Labazi M, Behzadian MA, Istanboli M, El-Remessy AB, Caldwell RW, Marcus DM, Caldwell RB. HMG-CoA reductase inhibitors (statin) prevents retinal neovascularization in a model of oxygen-induced retinopathy. Invest Ophthalmol Vis Sci 2008; 50:4934-40. [PMID: 19098312 DOI: 10.1167/iovs.08-2158] [Citation(s) in RCA: 38] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/15/2022] Open
Abstract
PURPOSE Retinal neovascularization (RNV) is a primary cause of blindness and involves the dysfunction of retinal capillaries. Recent studies have emphasized the beneficial effects of inhibitors of HMG-CoA reductase (statins) in preventing vascular dysfunction. In the present study, the authors characterized the therapeutic effects of statins on RNV. METHODS Statin treatment (10 mg/kg/d fluvastatin) was tested in a mouse model of oxygen-induced retinopathy. Morphometric analysis was conducted to determine the extent of capillary growth. Pimonidazole hydrochloride was used to assess retinal ischemia. Western blot and immunohistochemical analyses were used to assess protein expression levels and immunolocalization. Lipid peroxidation and superoxide radical formation were determined to assess oxidative changes. RESULTS Fluvastatin treatment significantly reduced the area of the capillary-free zone (P < 0.01), decreased the formation of neovascular tufts (P < 0.01), and ameliorated retinal ischemia. These morphologic and functional changes were associated with statin effects in preventing the upregulation of VEGF, HIF-1 alpha, phosphorylated STAT3, and vascular expression of the inflammatory mediator ICAM-1 (P < 0.01). Superoxide production and lipid peroxidation in the ischemic retina were also reduced by statin treatment (P < 0.01). CONCLUSIONS These data suggest the beneficial effects of statin treatment in preventing retinal neovascularization. These beneficial effects appear to result from the anti-oxidant and anti-inflammatory properties of statins.
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Affiliation(s)
- Manuela Bartoli
- Department of Ophthalmology, University of South Carolina School of Medicine, Columbia, South Carolina 29203, USA.
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25
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Tsuchioka M, Takebayashi M, Hisaoka K, Maeda N, Nakata Y. Serotonin (5-HT) induces glial cell line-derived neurotrophic factor (GDNF) mRNA expression via the transactivation of fibroblast growth factor receptor 2 (FGFR2) in rat C6 glioma cells. J Neurochem 2008; 106:244-57. [DOI: 10.1111/j.1471-4159.2008.05357.x] [Citation(s) in RCA: 56] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
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26
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Han W, Li H, Villar VAM, Pascua AM, Dajani MI, Wang X, Natarajan A, Quinn MT, Felder RA, Jose PA, Yu P. Lipid rafts keep NADPH oxidase in the inactive state in human renal proximal tubule cells. Hypertension 2008; 51:481-7. [PMID: 18195159 DOI: 10.1161/hypertensionaha.107.103275] [Citation(s) in RCA: 71] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/11/2023]
Abstract
Recent studies have indicated the importance of cholesterol-rich membrane lipid rafts (LRs) in oxidative stress-induced signal transduction. Reduced nicotinamide-adenine dinucleotide phosphate (NADPH) oxidases, the major sources of reactive oxygen species, are implicated in cardiovascular diseases, including hypertension. We tested the hypothesis that NADPH oxidase subunits and activity are regulated by LRs in human renal proximal tubule cells. We report that a high proportion of p22(phox) and the small GTPase Rac1 are expressed in LRs in human renal proximal tubule cells. The D(1)-like receptor agonist, fenoldopam (1 micromol/L per 20 minutes) dispersed Nox subunits within LRs and non-LRs and decreased oxidase activity (30.7+/-3.3%). In contrast, cholesterol depletion (2% methyl-beta-cyclodextrin [beta CD]) translocated NADPH oxidase subunits out of LRs and increased oxidase activity (154.0+/-10.5% versus control, 103.1+/-3.4%), which was reversed by cholesterol repletion (118.9+/-9.9%). Moreover, NADPH oxidase activation by beta CD (145.5+/-9.0%; control: 98.6+/-1.6%) was also abrogated by the NADPH oxidase inhibitors apocynin (100.4+/-3.2%) and diphenylene iodonium (9.5+/-3.3%). Furthermore, beta CD-induced reactive oxygen species production was reversed by knocking down either Nox2 (81.0+/-5.1% versus beta CD: 162.0+/-2.0%) or Nox4 (108.0+/-10.8% versus beta CD: 152.0+/-9.8%). We have demonstrated for the first time that disruption of LRs results in NADPH oxidase activation that is abolished by antioxidants and silencing of Nox2 or Nox4. Therefore, in human renal proximal tubule cells, LRs maintain NADPH oxidase in an inactive state.
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Affiliation(s)
- Weixing Han
- Department of Pediatrics, Georgetown University School of Medicine, Washington, DC, USA
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Alexandre J, Hu Y, Lu W, Pelicano H, Huang P. Novel Action of Paclitaxel against Cancer Cells: Bystander Effect Mediated by Reactive Oxygen Species. Cancer Res 2007; 67:3512-7. [PMID: 17440056 DOI: 10.1158/0008-5472.can-06-3914] [Citation(s) in RCA: 288] [Impact Index Per Article: 16.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
Generation of reactive oxygen species (ROS) has been observed in cancer cells treated with paclitaxel, but the underlying mechanisms and therapeutic implications remain unclear. In the present study, we showed that paclitaxel promoted ROS generation through enhancing the activity of NADPH oxidase (NOX) associated with plasma membranes. Treatment of breast cancer cells caused an increased translocation of Rac1, a positive regulatory protein of NOX, to the membrane fraction. The paclitaxel-induced ROS generation occurred rapidly within several hours of drug exposure, with O(2)(-) and H(2)O(2) accumulation mainly outside the cells while the intracellular ROS remained unchanged. Importantly, the increase in extracellular ROS caused lethal damage to the bystander cancer cells not exposed to paclitaxel, as shown by two different methods using coculture systems where the bystander cells were differentiated from the paclitaxel-treated cells by fluorescent or radioactive labeling. This cytotoxic bystander effect was also observed with other microtubule-targeted agents vincristine and taxotere but not with 5-fluorouracil or doxorubicin. This toxic bystander effect was enhanced by CuZnSOD that converts O(2)(-) to H(2)O(2) and was abolished by a catalase that eliminates H(2)O(2). Furthermore, paclitaxel was able to induce an almost complete inhibition of proliferation of the bystander cells in the coculture system. Our study revealed a novel mechanism by which paclitaxel induces toxic bystander effect through generation of extracellular H(2)O(2) from the membrane-associated NOX. This may contribute to the potent anticancer activity of paclitaxel and provide a novel basis to improve the clinical use of this important drug.
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Affiliation(s)
- Jérôme Alexandre
- Department of Molecular Pathology, The University of Texas M. D. Anderson Cancer Center, Houston, TX 77054, USA
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28
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Callera GE, Montezano AC, Yogi A, Tostes RC, Touyz RM. Vascular signaling through cholesterol-rich domains: implications in hypertension. Curr Opin Nephrol Hypertens 2007; 16:90-104. [PMID: 17293683 DOI: 10.1097/mnh.0b013e328040bfbd] [Citation(s) in RCA: 37] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/07/2023]
Abstract
PURPOSE OF REVIEW Lipid rafts are emerging as key players in the integration of cellular responses. Alterations in these highly regulated signaling cascades are important in structural, mechanical and functional abnormalities that underlie vascular pathological processes. The present review focuses on recent advances in signal transduction through caveolae/lipid rafts, implicated in hypertensive processes. RECENT FINDINGS Caveolae/lipid rafts function as sites of dynamic regulatory events in receptor-induced signal transduction. Mediators of vascular function, including G-protein coupled receptors, Src family tyrosine kinases, receptor tyrosine kinases, protein phosphatases and nitric oxide synthase, are concentrated within these microdomains. The assembly of functionally active nicotinamide adenine dinucleotide phosphate oxidase and subsequent reactive oxygen species production are also dependent on interactions within the caveolae/lipid rafts. Recent findings have also demonstrated the importance of actin-cytoskeleton and focal adhesion sites for protein interactions with caveolae/lipid raft. SUMMARY Many vascular signaling processes are altered in hypertension. Whether these events involve lipid rafts/caveolae remains unclear. A better understanding of how signaling molecules compartmentalize in lipid rafts/caveolae will provide further insights into molecular mechanisms underlying vascular damage in cardiovascular disease.
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Affiliation(s)
- Glaucia E Callera
- Kidney Research Centre, Ottawa Health Research Institute, University of Ottawa, Ottawa, Canada.
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Manrique C, Lastra G, Habibi J, Wei Y, Morris EM, Stump CS, Sowers JR. Methods in the evaluation of cardiovascular renin angiotensin aldosterone activation and oxidative stress. METHODS IN MOLECULAR MEDICINE 2007; 139:163-79. [PMID: 18287671 DOI: 10.1007/978-1-59745-571-8_10] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/18/2022]
Abstract
Renin angiotensin aldosterone system (RAAS) activation plays an essential role in the development of cardiovascular disease (CVD). Multiple pathophysiologic processes are able to activate RAAS, among which hypertension, obesity, diabetes mellitus 2, and chronic kidney disease deserve special attention, because they are the main contributors to CVD. Adding to the well-known effects of RAAS overactivity on the vasculature and water and electrolyte balance, current evidence links abnormal activation of the RAAS to increased production of reactive oxygen species (ROS) and oxidative stress. This association is mediated at least partially through interaction of angiotensin II (Ang II) with its receptor angiotensin receptor 1 (AT1R) in cardiovascular tissue, and subsequent activation of the nicotinamide adenine dinucleotide phosphate (NADPH) enzymatic complex, which finally leads to increased ROS production. This resulting state of enhanced oxidative stress contributes largely to generalized atherosclerosis and finally to CVD. The generation of animal models of increased RAAS and Ang II expression, in particular the Ren2 rodent model, provides important opportunities to better characterize the relationship between this system and the production of ROS. This chapter describes methods to evaluate, characterize, and quantify the activity of the RAAS and NADPH oxidase, as well as the production of ROS production in animal model of RAAS.
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Affiliation(s)
- Camila Manrique
- University of Missouri, Harry S. Truman VA Hospital, Columbia, Missouri, USA
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Krishna SB, Alfonso LF, Thekkumkara TJ, Abbruscato TJ, Bhat GJ. Angiotensin II induces phosphorylation of glucose-regulated protein-75 in WB rat liver cells. Arch Biochem Biophys 2006; 457:16-28. [PMID: 17109810 PMCID: PMC2577571 DOI: 10.1016/j.abb.2006.10.011] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/02/2006] [Revised: 10/06/2006] [Accepted: 10/12/2006] [Indexed: 01/19/2023]
Abstract
Studies in vascular smooth muscle cells suggest that, angiotensin II (Ang II)-mediated cellular response requires transactivation of epidermal growth factor receptor (EGF-R), and involves tyrosine phosphorylation of caveolin-1. Here we demonstrate that, exposure of WB rat liver cells to Ang II does not cause transactivation of EGF-R, but did rapidly activate p42/p44 mitogen-activated protein (MAP) kinases suggesting that it activates MAP kinases independent of EGF-R transactivation. We observed that the phospho-specific anti-caveolin-1 antibody detected a tyrosine phosphorylated, 75kDa protein in Ang II-treated cells which we identified as glucose regulated protein-75 (GRP-75). Phosphoamino acid analysis showed that Ang II induced its phosphorylation at tyrosine, serine and threonine residues and was localized to the cytoplasm. The ability of Ang-II to induce GRP-75 phosphorylation suggests that it may play a role in the protection of cytoplasmic proteins from the damaging effect of oxidative stress known to be produced during Ang-II induced signaling.
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Affiliation(s)
| | | | | | | | - G. Jayarama Bhat
- * To whom correspondence should be addressed. G. Jayarama Bhat, Ph.D., Associate Professor, Department of Pharmaceutical Sciences, Texas Tech University Health Sciences Center, 1300 Coulter Drive, Amarillo, TX 79106, Tel: (806) 356-4015 ext 249, Fax: (806) 356-4034, E-mail:
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31
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Ushio-Fukai M, Alexander RW. Caveolin-dependent angiotensin II type 1 receptor signaling in vascular smooth muscle. Hypertension 2006; 48:797-803. [PMID: 17015782 DOI: 10.1161/01.hyp.0000242907.70697.5d] [Citation(s) in RCA: 52] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
MESH Headings
- Animals
- Caveolins/metabolism
- Caveolins/physiology
- Humans
- Muscle, Smooth, Vascular/cytology
- Muscle, Smooth, Vascular/metabolism
- Muscle, Smooth, Vascular/physiology
- Reactive Oxygen Species/metabolism
- Receptor, Angiotensin, Type 1/metabolism
- Receptor, Angiotensin, Type 1/physiology
- Signal Transduction/physiology
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Affiliation(s)
- Masuko Ushio-Fukai
- Department of Medicine, Emory University School of Medicine, Atlanta, GA, USA.
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Ohtsu H, Suzuki H, Nakashima H, Dhobale S, Frank GD, Motley ED, Eguchi S. Angiotensin II Signal Transduction Through Small GTP-Binding Proteins. Hypertension 2006; 48:534-40. [PMID: 16923993 DOI: 10.1161/01.hyp.0000237975.90870.eb] [Citation(s) in RCA: 81] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Affiliation(s)
- Haruhiko Ohtsu
- Cardiovascular Research Center and Department of Physiology, Temple University School of Medicine, Philadelphia, PA 19140, USA
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Abstract
Reactive oxygen species (ROS) function as signaling molecules to mediate various biological responses, including cell migration, growth, and gene expression. ROS are diffusible and short-lived molecules. Thus, localizing the ROS signal at the specific subcellular compartment is essential for activating redox signaling events after receptor activation. NADPH (nicotinamide adenine dinucleotide phosphate) oxidase is one of the major sources of ROS in vasculature; it consists of a catalytic subunit (Nox1, Nox2, Nox3, Nox4, or Nox5), p22phox, p47phox, p67phox, and the small guanosine triphosphatase Rac1. Targeting of NADPH oxidase to focal complexes in lamellipodia and membrane ruffles through the interaction of p47phox with the scaffold proteins TRAF4 and WAVE1 provides a mechanism for achieving localized ROS production, which is required for directed cell migration. ROS are believed to inactivate protein tyrosine phosphatases, which concentrate in specific subcellular compartments, thereby establishing a positive feedback system that activates redox signaling pathways to promote cell movement. Additionally, ROS production may be localized through interactions of NADPH oxidase with signaling platforms associated with lipid rafts and caveolae, as well as with endosomes. There is also evidence that NADPH oxidase is found in the nucleus, indicating its involvement in redox-responsive gene expression. This review focuses on targeting of NADPH oxidase to discrete subcellular compartments as a mechanism of localizing ROS and activation of downstream redox signaling events that mediate various cell functions.
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Affiliation(s)
- Masuko Ushio-Fukai
- Department of Pharmacology and Center for Lung and Vascular Biology, University of Illinois College of Medicine, Chicago, IL 60612, USA.
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Abstract
Although reactive oxidants have long been stigmatized as unwanted metabolic byproducts, the expression of oxidases specifically functioning to produce these same molecules in a regulated fashion is surprisingly pervasive throughout metazoan and plant evolution. Although the involvement of oxidants in many signaling pathways is well documented, the cellular strategies for conferring pathway specificity to such reactive molecules have remained more recondite. Recent studies now suggest that cells may spatially restrict oxidant production to allow microdomain-specific signaling.
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Affiliation(s)
- Lance S Terada
- Department of Medicine, University of Texas Southwestern Medical Center, Dallas, TX 75390, USA.
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Clempus RE, Griendling KK. Reactive oxygen species signaling in vascular smooth muscle cells. Cardiovasc Res 2006; 71:216-25. [PMID: 16616906 PMCID: PMC1934427 DOI: 10.1016/j.cardiores.2006.02.033] [Citation(s) in RCA: 263] [Impact Index Per Article: 14.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/13/2006] [Revised: 02/22/2006] [Accepted: 02/27/2006] [Indexed: 02/07/2023] Open
Abstract
Reactive oxygen species (ROS) have been shown to function as important signaling molecules in the cardiovascular system. Vascular smooth muscle cells (VSMCs) contain several sources of ROS, among which the NADPH oxidases are predominant. In VSMCs, ROS mediate many pathophysiological processes, such as growth, migration, apoptosis and secretion of inflammatory cytokines, as well as physiological processes, such as differentiation, by direct and indirect effects at multiple signaling levels. Therefore, it becomes critical to understand the different roles ROS play in the physiology and pathophysiology of VSMCs.
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Affiliation(s)
- Roza E. Clempus
- Department of Medicine, Division of Cardiology, Emory University, 319 WMB, 1639 Pierce Dr. Atlanta, GA 30322, United States
| | - Kathy K. Griendling
- Department of Medicine, Division of Cardiology, Emory University, 319 WMB, 1639 Pierce Dr. Atlanta, GA 30322, United States
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Hoshijima M. Mechanical stress-strain sensors embedded in cardiac cytoskeleton: Z disk, titin, and associated structures. Am J Physiol Heart Circ Physiol 2006; 290:H1313-25. [PMID: 16537787 PMCID: PMC3241960 DOI: 10.1152/ajpheart.00816.2005] [Citation(s) in RCA: 188] [Impact Index Per Article: 10.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/11/2022]
Abstract
Cardiac muscle is equipped with intricate intrinsic mechanisms to regulate adaptive remodeling. Recent and extensive experimental findings powered by novel strategies for screening protein-protein interactions, improved imaging technologies, and versatile transgenic mouse methodologies reveal that Z disks and titin filaments possess unexpectedly complicated sensory and modulatory mechanisms for signal reception and transduction. These mechanisms employ molecules such as muscle-enriched LIM domain proteins, PDZ-LIM domain proteins, myozenin gene family members, titin-associated ankyrin repeat family proteins, and muscle-specific ring finger proteins, which have been identified as potential molecular sensor components. Moreover, classic transmembrane signaling processes, including mitogen-activated kinase, protein kinase C, and calcium signaling, also involve novel interactions with the Z disk/titin network. This compartmentalization of signaling complexes permits alteration of receptor-dependent transcriptional regulation by direct sensing of intrinsic stress. Newly identified mechanical stress sensors are not limited to Z-disk region and to I-band and M-band regions of titin but are also embedded in muscle-specific membrane systems such as the costamere, intercalated disks, and caveolae-like microdomains. This review summarizes current knowledge of this rapidly developing area with focus on how the heart adjusts physiological remodeling process to meet with mechanical demands and how this process fails in cardiac pathologies.
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Affiliation(s)
- Masahiko Hoshijima
- Department of Medicine, University of California, San Diego, La Jolla, CA 92093-0734, USA.
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Abstract
Over the last decade, the Rho family GTPases have gained considerable recognition as powerful regulators of actin cytoskeletal organization. As with many high profile signal transducers, these molecules soon attracted the attention of the cardiovascular research community. Shortly thereafter, two prominent members known as RhoA and Rac1 were linked to agonist-induced gene expression and myofilament organization using the isolated cardiomyocyte cell model. Subsequent creation of transgenic mouse lines provided evidence for more complex roles of RhoA and Rac1 signaling. Clues from in vitro and in vivo studies suggest the involvement of numerous downstream targets of RhoA and Rac1 signaling including serum response factor, NF-kappaB, and other transcription factors, myofilament proteins, ion channels, and reactive oxygen species generation. Which of these contribute to the observed phenotypic effects of enhanced RhoA and Rac activation in vivo remain to be determined. Current research efforts with a more translational focus have used statins or Rho kinase blockers to assess RhoA and Rac1 as targets for interventional approaches to blunt hypertrophy or heart failure. Generally, salutary effects on remodeling and ischemic damage are observed, but the broad specificity and multiple cellular targets for these drugs within the myocardium demands caution in interpretation. In this review, we assess the evolution of knowledge related to Rac1 and RhoA in the context of hypertrophy and heart failure and highlight the direction that future exploration will lead.
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Affiliation(s)
- Joan Heller Brown
- Department of Pharmacology, University of California, San Diego, USA
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Chen J, Mehta JL. Interaction of oxidized low-density lipoprotein and the renin-angiotensin system in coronary artery disease. Curr Hypertens Rep 2006; 8:139-43. [PMID: 16672147 DOI: 10.1007/s11906-006-0010-2] [Citation(s) in RCA: 17] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/23/2022]
Abstract
Hyperlipidemia and hypertension are frequently observed in patients with coronary artery disease. It has been proposed that an interaction between low-density lipoprotein, especially its oxidized form (ox-LDL), and renin-angiotensin system (RAS) activation is a major determinant of atherogenesis. Ox-LDL accumulation in the blood vessels enhances the expression and activation of RAS components; on the other hand, activation of RAS stimulates the accumulation of LDL and its oxidation into ox-LDL in the blood vessels. Individually ox-LDL and RAS activation induce oxidative stress and inflammatory cascade, whereas their combination exerts a synergistic effect. This concept of cross-talk between ox-LDL/hyperlipidemia and RAS activation has been proven in laboratory animals. Clinical trials also suggest that blockade of hyperlipidemia and RAS may have a synergistic salutary effect on the outcome of patients with hypertension and/or manifestations of atherosclerosis. This concept needs to be evaluated further in large clinical studies.
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Affiliation(s)
- Jiawei Chen
- Division of Cardiovascular Medicine, University of Arkansas for Medical Sciences, 4301 W. Markham Street, Slot 532, Little Rock, AR 72205, USA
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Li XC, Carretero OA, Navar LG, Zhuo JL. AT1 receptor-mediated accumulation of extracellular angiotensin II in proximal tubule cells: role of cytoskeleton microtubules and tyrosine phosphatases. Am J Physiol Renal Physiol 2006; 291:F375-83. [PMID: 16478976 PMCID: PMC2276851 DOI: 10.1152/ajprenal.00405.2005] [Citation(s) in RCA: 54] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/18/2023] Open
Abstract
Long-term angiotensin II (ANG II) administration is associated with increased ANG II accumulation in the kidney, but intrarenal compartment(s) involved in this response remains to be determined. We tested the hypothesis that 1) extracellular ANG II is taken up by proximal tubule cells (PTCs) through AT(1) receptor-mediated endocytosis, 2) this process is regulated by cytoskeleton microtubule- and tyrosine phosphatase-dependent mechanisms, and 3) AT(1) receptor-mediated endocytosis of ANG II has a functional relevance by modulating intracellular cAMP signaling. In cultured PTCs, [(125)I]Tyr-labeled ANG II and fluorescein labeled-ANG II were internalized in a time-dependent manner and colocalized with the endosome marker Alexa Fluor 594-transferrin. Endocytosis of extracellular ANG II was inhibited by the AT(1) receptor blocker losartan (16.5 +/- 4.6%, P < 0.01 vs. ANG II, 78.3 +/- 6.2%) and by the tyrosine phosphatase inhibitor phenylarsine oxide (PAO; 30.0 +/- 3.5%, P < 0.05 vs. ANG II). Intracellular ANG II levels were increased by approximately 58% (basal, 229.8 +/- 11.4 vs. ANG II, 361.3 +/- 11.8 pg ANG II/mg protein, P < 0.01), and the responses were blocked by losartan (P < 0.01), the cytoskeleton microtubule inhibitor colchicine (P < 0.05), and PAO (P < 0.01), whereas depletion of clathrin-coated pits with hyperosmotic sucrose had no effect (356.1 +/- 25.5 pg ANG II/mg protein, not significant). ANG II accumulation was associated with significant inhibition of both basal (control, 15.5 +/- 2.8 vs. ANG II, 9.1 +/- 2.4 pmol/mg protein, P < 0.05) and forskolin-stimulated cAMP signaling (forskolin, 68.7 +/- 8.6 vs. forskolin + ANG II, 42.8 +/- 13.8 pmol/mg protein, P < 0.01). These effects were blocked by losartan and PAO. We conclude that extracellular ANG II is internalized in PTCs through AT(1) receptor-mediated endocytosis and that internalized ANG II may play a functional role in proximal tubule cells by inhibiting intracellular cAMP signaling.
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MESH Headings
- Angiotensin II/metabolism
- Angiotensin II/pharmacology
- Angiotensin II Type 1 Receptor Blockers/pharmacology
- Animals
- Arsenicals/pharmacology
- Cells, Cultured
- Colchicine/pharmacology
- Colforsin/pharmacology
- Cyclic AMP/physiology
- Cytoskeleton/drug effects
- Cytoskeleton/metabolism
- Endocytosis/physiology
- Enzyme Inhibitors/pharmacology
- Gene Expression Regulation/physiology
- Imidazoles/pharmacology
- Kidney Tubules, Proximal/cytology
- Kidney Tubules, Proximal/metabolism
- Losartan/pharmacology
- Microtubules/drug effects
- Microtubules/metabolism
- Protein Tyrosine Phosphatase, Non-Receptor Type 1
- Protein Tyrosine Phosphatases/antagonists & inhibitors
- Protein Tyrosine Phosphatases/physiology
- Pyridines/pharmacology
- Rabbits
- Receptor, Angiotensin, Type 1/drug effects
- Receptor, Angiotensin, Type 1/genetics
- Receptor, Angiotensin, Type 1/physiology
- Receptor, Angiotensin, Type 2/analysis
- Receptor, Angiotensin, Type 2/drug effects
- Receptor, Angiotensin, Type 2/genetics
- Receptor, Angiotensin, Type 2/physiology
- Signal Transduction/physiology
- Sucrose/pharmacology
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Affiliation(s)
- Xiao C Li
- Laboratory of Receptor and Signal Transduction, Division of Hypertension and Vascular Research, Henry Ford Hospital, Detroit 48202, USA
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Touyz RM, Yao G, Quinn MT, Pagano PJ, Schiffrin EL. p47phox Associates With the Cytoskeleton Through Cortactin in Human Vascular Smooth Muscle Cells. Arterioscler Thromb Vasc Biol 2005; 25:512-8. [PMID: 15618548 DOI: 10.1161/01.atv.0000154141.66879.98] [Citation(s) in RCA: 133] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/07/2023]
Abstract
OBJECTIVE We tested the hypothesis that p47phox associates with the actin cytoskeleton, enabling site-directed activation of NAD(P)H oxidase, and assessed whether these actions influence reactive oxygen species (ROS) generation and signaling by angiotensin II (Ang II) in vascular smooth muscle cells (VSMCs) from human resistance and coronary arteries. METHODS AND RESULTS Electroporation of anti-p47phox antibody into VSMCs abrogated Ang II-mediated O2 generation, establishing the requirement for p47phox in this response. Immunfluorescence confocal microscopy demonstrated a cytosolic distribution of p47phox in basal conditions. After Ang II stimulation, p47phox rearranged in a linear fashion, colocalizing with F-actin. Co-immunoprecipitation studies confirmed an association between p47phox and actin and demonstrated an interaction with the actin-binding protein cortactin. Cytoskeletal disruption with cytochalasin prevented p47phox:actin interaction and attenuated ROS formation and p38MAP kinase and Akt phosphorylation by Ang II. Intracellular ROS generation in response to LY83583 (O2 generator) or exogenous H2O2 and Ang II-induced ERK1/2 activation were unaltered by cytochalasin. CONCLUSIONS The p47phox:actin interaction, through cortactin, plays an important role in Ang II-mediated site-directed assembly of functionally active NAD(P)H oxidase, ROS generation, and activation of redox-sensitive p38MAP kinase and Akt, but not ERK1/2. These findings demonstrate the importance of an intact actin-cytoskeleton in NAD(P)H oxidase regulation and redox signaling by Ang II in human VSMCs.
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Affiliation(s)
- R M Touyz
- Multidisciplinary Research Group on Hypertension, Clinical Research Institute of Montreal, University of Montreal, Canada.
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