51
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Hernandez VJ, Weng J, Ly P, Pompey S, Dong H, Mishra L, Schwarz M, Anderson RGW, Michaely P. Cavin-3 dictates the balance between ERK and Akt signaling. eLife 2013; 2:e00905. [PMID: 24069528 PMCID: PMC3780650 DOI: 10.7554/elife.00905] [Citation(s) in RCA: 51] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/04/2013] [Accepted: 08/14/2013] [Indexed: 12/22/2022] Open
Abstract
Cavin-3 is a tumor suppressor protein of unknown function. Using both in vivo and in vitro approaches, we show that cavin-3 dictates the balance between ERK and Akt signaling. Loss of cavin-3 increases Akt signaling at the expense of ERK, while gain of cavin-3 increases ERK signaling at the expense Akt. Cavin-3 facilitates signal transduction to ERK by anchoring caveolae to the membrane skeleton of the plasma membrane via myosin-1c. Caveolae are lipid raft specializations that contain an ERK activation module and loss of the cavin-3 linkage reduces the abundance of caveolae, thereby separating this ERK activation module from signaling receptors. Loss of cavin-3 promotes Akt signaling through suppression of EGR1 and PTEN. The in vitro consequences of the loss of cavin-3 include induction of Warburg metabolism (aerobic glycolysis), accelerated cell proliferation, and resistance to apoptosis. The in vivo consequences of cavin-3 knockout are increased lactate production and cachexia. DOI:http://dx.doi.org/10.7554/eLife.00905.001.
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Affiliation(s)
- Victor J Hernandez
- Department of Cell Biology , University of Texas Southwestern Medical Center , Dallas , United States
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52
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Di Lorenzo A, Lin MI, Murata T, Landskroner-Eiger S, Schleicher M, Kothiya M, Iwakiri Y, Yu J, Huang PL, Sessa WC. eNOS-derived nitric oxide regulates endothelial barrier function through VE-cadherin and Rho GTPases. J Cell Sci 2013; 126:5541-52. [PMID: 24046447 DOI: 10.1242/jcs.115972] [Citation(s) in RCA: 102] [Impact Index Per Article: 8.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/29/2022] Open
Abstract
Transient disruption of endothelial adherens junctions and cytoskeletal remodeling are responsible for increases in vascular permeability induced by inflammatory stimuli and vascular endothelial growth factor (VEGF). Nitric oxide (NO) produced by endothelial NO synthase (eNOS) is crucial for VEGF-induced changes in permeability in vivo; however, the molecular mechanism by which endogenous NO modulates endothelial permeability is not clear. Here, we show that the lack of eNOS reduces VEGF-induced permeability, an effect mediated by enhanced activation of the Rac GTPase and stabilization of cortical actin. The loss of NO increased the recruitment of the Rac guanine-nucleotide-exchange factor (GEF) TIAM1 to adherens junctions and VE-cadherin (also known as cadherin 5), and reduced Rho activation and stress fiber formation. In addition, NO deficiency reduced VEGF-induced VE-cadherin phosphorylation and impaired the localization, but not the activation, of c-Src to cell junctions. The physiological role of eNOS activation is clear given that VEGF-, histamine- and inflammation-induced vascular permeability is reduced in mice bearing a non-phosphorylatable knock-in mutation of the key eNOS phosphorylation site S1176. Thus, NO is crucial for Rho GTPase-dependent regulation of cytoskeletal architecture leading to reversible changes in vascular permeability.
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Affiliation(s)
- Annarita Di Lorenzo
- Department of Pharmacology and Vascular Biology and Therapeutics Program, Yale University School of Medicine, New Haven, CT 06520, USA
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53
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Lin AL, Zheng W, Halloran JJ, Burbank RR, Hussong SA, Hart MJ, Javors M, Shih YYI, Muir E, Solano Fonseca R, Strong R, Richardson AG, Lechleiter JD, Fox PT, Galvan V. Chronic rapamycin restores brain vascular integrity and function through NO synthase activation and improves memory in symptomatic mice modeling Alzheimer's disease. J Cereb Blood Flow Metab 2013; 33:1412-21. [PMID: 23801246 PMCID: PMC3764385 DOI: 10.1038/jcbfm.2013.82] [Citation(s) in RCA: 176] [Impact Index Per Article: 14.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/09/2012] [Revised: 04/04/2013] [Accepted: 04/23/2013] [Indexed: 12/14/2022]
Abstract
Vascular pathology is a major feature of Alzheimer's disease (AD) and other dementias. We recently showed that chronic administration of the target-of-rapamycin (TOR) inhibitor rapamycin, which extends lifespan and delays aging, halts the progression of AD-like disease in transgenic human (h)APP mice modeling AD when administered before disease onset. Here we demonstrate that chronic reduction of TOR activity by rapamycin treatment started after disease onset restored cerebral blood flow (CBF) and brain vascular density, reduced cerebral amyloid angiopathy and microhemorrhages, decreased amyloid burden, and improved cognitive function in symptomatic hAPP (AD) mice. Like acetylcholine (ACh), a potent vasodilator, acute rapamycin treatment induced the phosphorylation of endothelial nitric oxide (NO) synthase (eNOS) and NO release in brain endothelium. Administration of the NOS inhibitor L-NG-Nitroarginine methyl ester reversed vasodilation as well as the protective effects of rapamycin on CBF and vasculature integrity, indicating that rapamycin preserves vascular density and CBF in AD mouse brains through NOS activation. Taken together, our data suggest that chronic reduction of TOR activity by rapamycin blocked the progression of AD-like cognitive and histopathological deficits by preserving brain vascular integrity and function. Drugs that inhibit the TOR pathway may have promise as a therapy for AD and possibly for vascular dementias.
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Affiliation(s)
- Ai-Ling Lin
- Research Imaging Institute, San Antonio, TX, USA
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Cubbon RM, Mercer BN, Sengupta A, Kearney MT. Importance of insulin resistance to vascular repair and regeneration. Free Radic Biol Med 2013; 60:246-63. [PMID: 23466555 DOI: 10.1016/j.freeradbiomed.2013.02.028] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/29/2012] [Revised: 02/22/2013] [Accepted: 02/23/2013] [Indexed: 01/14/2023]
Abstract
Metabolic insulin resistance is apparent across a spectrum of clinical disorders, including obesity and diabetes, and is characterized by an adverse clustering of cardiovascular risk factors related to abnormal cellular responses to insulin. These disorders are becoming increasingly prevalent and represent a major global public health concern because of their association with significant increases in atherosclerosis-related mortality. Endogenous repair mechanisms are thought to retard the development of vascular disease, and a growing evidence base supports the adverse impact of the insulin-resistant phenotype upon indices of vascular repair. Beyond the impact of systemic metabolic changes, emerging data from murine studies also provide support for abnormal insulin signaling at the level of vascular cells in retarding vascular repair. Interrelated pathophysiological factors, including reduced nitric oxide bioavailability, oxidative stress, altered growth factor activity, and abnormal intracellular signaling, are likely to act in conjunction to impede vascular repair while also driving vascular damage. Understanding of these processes is shaping novel therapeutic paradigms that aim to promote vascular repair and regeneration, either by recruiting endogenous mechanisms or by the administration of cell-based therapies.
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Affiliation(s)
- Richard M Cubbon
- Multidisciplinary Cardiovascular Research Centre, LIGHT Laboratories, The University of Leeds, Leeds LS2 9JT, UK.
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55
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Tanigaki K, Vongpatanasin W, Barrera JA, Atochin DN, Huang PL, Bonvini E, Shaul PW, Mineo C. C-reactive protein causes insulin resistance in mice through Fcγ receptor IIB-mediated inhibition of skeletal muscle glucose delivery. Diabetes 2013; 62:721-31. [PMID: 23069625 PMCID: PMC3581204 DOI: 10.2337/db12-0133] [Citation(s) in RCA: 39] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/04/2023]
Abstract
Elevations in C-reactive protein (CRP) are associated with an increased risk of insulin resistance. Whether CRP plays a causal role is unknown. Here we show that CRP transgenic mice and wild-type mice administered recombinant CRP are insulin resistant. Mice lacking the inhibitory Fcγ receptor IIB (FcγRIIB) are protected from CRP-induced insulin resistance, and immunohistochemistry reveals that FcγRIIB is expressed in skeletal muscle microvascular endothelium and is absent in skeletal muscle myocytes, adipocytes, and hepatocytes. The primary mechanism in glucose homeostasis disrupted by CRP is skeletal muscle glucose delivery, and CRP attenuates insulin-induced skeletal muscle blood flow. CRP does not impair skeletal muscle glucose delivery in FcγRIIB(-/-) mice or in endothelial nitric oxide synthase knock-in mice with phosphomimetic modification of Ser1176, which is normally phosphorylated by insulin signaling to stimulate nitric oxide-mediated skeletal muscle blood flow and glucose delivery and is dephosphorylated by CRP/FcγRIIB. Thus, CRP causes insulin resistance in mice through FcγRIIB-mediated inhibition of skeletal muscle glucose delivery.
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MESH Headings
- Animals
- C-Reactive Protein/genetics
- C-Reactive Protein/metabolism
- Endothelium, Vascular/cytology
- Endothelium, Vascular/metabolism
- Glucose/metabolism
- Humans
- Immunohistochemistry
- Insulin/genetics
- Insulin/metabolism
- Insulin Resistance
- Male
- Mice
- Mice, Inbred C57BL
- Mice, Transgenic
- Microvessels/cytology
- Microvessels/metabolism
- Muscle, Skeletal/blood supply
- Muscle, Skeletal/cytology
- Muscle, Skeletal/metabolism
- Nitric Oxide Synthase Type III/antagonists & inhibitors
- Nitric Oxide Synthase Type III/genetics
- Nitric Oxide Synthase Type III/metabolism
- Organ Specificity
- Phosphorylation
- Protein Processing, Post-Translational
- Receptors, IgG/antagonists & inhibitors
- Receptors, IgG/genetics
- Receptors, IgG/metabolism
- Recombinant Proteins/metabolism
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Affiliation(s)
- Keiji Tanigaki
- Division of Pulmonary and Vascular Biology, Department of Pediatrics, University of Texas Southwestern Medical Center, Dallas, Texas
| | - Wanpen Vongpatanasin
- Hypertension Section, Cardiology Division, Department of Internal Medicine, University of Texas Southwestern Medical Center, Dallas, Texas
| | - Jose A. Barrera
- Division of Pulmonary and Vascular Biology, Department of Pediatrics, University of Texas Southwestern Medical Center, Dallas, Texas
| | - Dmitriy N. Atochin
- Cardiovascular Research Center and Cardiology Division, Department of Medicine, Massachusetts General Hospital and Harvard Medical School, Boston, Massachusetts
| | - Paul L. Huang
- Cardiovascular Research Center and Cardiology Division, Department of Medicine, Massachusetts General Hospital and Harvard Medical School, Boston, Massachusetts
| | | | - Philip W. Shaul
- Division of Pulmonary and Vascular Biology, Department of Pediatrics, University of Texas Southwestern Medical Center, Dallas, Texas
| | - Chieko Mineo
- Division of Pulmonary and Vascular Biology, Department of Pediatrics, University of Texas Southwestern Medical Center, Dallas, Texas
- Corresponding author: Chieko Mineo,
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56
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Kashiwagi S, Atochin DN, Li Q, Schleicher M, Pong T, Sessa WC, Huang PL. eNOS phosphorylation on serine 1176 affects insulin sensitivity and adiposity. Biochem Biophys Res Commun 2013; 431:284-90. [PMID: 23291238 DOI: 10.1016/j.bbrc.2012.12.110] [Citation(s) in RCA: 35] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/09/2012] [Accepted: 12/13/2012] [Indexed: 12/13/2022]
Abstract
Phosphorylation of endothelial nitric oxide synthase (eNOS) is an important regulator of its enzymatic activity. We generated knockin mice expressing phosphomimetic (SD) and unphosphorylatable (SA) eNOS mutations at S1176 to study the role of eNOS phosphorylation. The single amino acid SA mutation is associated with hypertension and decreased vascular reactivity, while the SD mutation results in increased basal and stimulated endothelial NO production. In addition to these vascular effects, modulation of the S1176 phosphorylation site resulted in unanticipated effects on metabolism. The eNOS SA mutation results in insulin resistance, hyperinsulinemia, adiposity, and increased weight gain on high fat. In contrast, the eNOS SD mutation is associated with decreased insulin levels and resistance to high fat-induced weight gain. These results demonstrate the importance of eNOS in regulation of insulin sensitivity, energy metabolism, and bodyweight regulation, and suggest eNOS phosphorylation as a novel target for the treatment of obesity and insulin resistance.
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Affiliation(s)
- Satoshi Kashiwagi
- Cardiovascular Research Center, Cardiology Division, Massachusetts General Hospital and Harvard Medical School, Boston, MA 02114, USA
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57
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eNOS Gene Variant in Patients with Coronary Artery Disease. J Biomark 2012; 2013:403783. [PMID: 26317015 PMCID: PMC4437368 DOI: 10.1155/2013/403783] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/04/2012] [Revised: 10/21/2012] [Accepted: 10/27/2012] [Indexed: 11/27/2022] Open
Abstract
Subject & Aim. Endothelial nitric oxide synthase (eNOS) is one of the most important candidate genes in CAD. A functional polymorphism within eNOS gene is a 27 bp VNTR on its intron 4 which has been shown to be associated with various diseases. In this study we investigated eNOS VNTR polymorphism in addition to eNOS gene expression profile in patients with CAD. Material and Methods. The study comprised patients with angiographically confirmed CAD (CAD+) and individuals with normal coronary as CAD−. eNOS VNTR polymorphism frequencies were determined in both groups. In addition eNOS gene expression profile was examined using a quantitative real-time PCR. Results. We have found that aa genotype was significantly increasing the risk of CAD in our patients (aa versus ab + bb, P = 0.02, OR = 3.5; 95% CI: = 0.98 to 16.2). The differences in eNOS expression were not significant between patients and normal group; however in CAD+ patients eNOS expression was higher than the expression level of patients carrying other genotypes (P = 0.16). Conclusion. We have observed that eNOS gene polymorphism was associated with CAD in angiography-confirmed patients. However, the difference in eNOS gene expression was not statistically significant between patients and control which might be due to the contribution of other confounding factors which require further investigations.
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58
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Gentile C, Muise-Helmericks RC, Drake CJ. VEGF-mediated phosphorylation of eNOS regulates angioblast and embryonic endothelial cell proliferation. Dev Biol 2012; 373:163-75. [PMID: 23103584 DOI: 10.1016/j.ydbio.2012.10.020] [Citation(s) in RCA: 26] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/07/2012] [Revised: 10/04/2012] [Accepted: 10/16/2012] [Indexed: 10/27/2022]
Abstract
To evaluate potential roles of nitric oxide (NO) in the regulation of the endothelial lineage and neovascular processes (vasculogenesis and angiogenesis) we evaluated endothelial nitric oxide synthase (eNOS) and phosphorylated eNOS (p-eNOS) expression in 7.2-8.5 days post-coitum (dpc) mouse embryos. Analysis revealed that p-eNOS((S1177)) but not P-eNOS((S617)) or P-eNOS((T495)) was expressed in a subpopulation of angioblasts (TAL-1(+)/Flk-1(+)/CD31(-)/CD34(-)/VE-Cadherin(-)) at 7.2 dpc. A role of the VEGF/Akt1/eNOS signaling pathway in the regulation of the endothelial cell (EC) lineage was suggested by the strong correlation observed between cell division and p-eNOS((S1177)) expression in both angioblasts and embryonic endothelial cells (EECs, TAL-1(+)/Flk-1(+)/CD31(+)/CD34(+)/VE-Cadherin(+)). Our studies using Akt1 null mouse embryos show a reduction in p-eNOS((S1177)) expression in angioblast and EECs that is correlated with a decrease in endothelial cell proliferation and results in changes in VEGF-induced vascular patterning. Further, we show that VEGF-mediated cell proliferation in Flk-1(+) cells in allantoic cultures is decreased by pharmacological inhibitors of the VEGF/Akt1/eNOS signaling pathways. Taken together, our findings suggest that VEGF-mediated eNOS phosphorylation on Ser1177 regulates angioblast and EEC division, which underlies the formation of blood vessels and vascular networks.
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Affiliation(s)
- Carmine Gentile
- Department of Regenerative Medicine and Cell Biology, Medical University of South Carolina, Charleston, SC 29425, USA
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59
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Acute exercise induce endothelial nitric oxide synthase phosphorylation via Akt and AMP-activated protein kinase in aorta of rats: Role of reactive oxygen species. Int J Cardiol 2012; 167:2983-8. [PMID: 22989604 DOI: 10.1016/j.ijcard.2012.08.050] [Citation(s) in RCA: 26] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/19/2012] [Accepted: 08/31/2012] [Indexed: 02/02/2023]
Abstract
BACKGROUND Acute exercise increases reactive oxygen species (ROS) levels, including hydrogen peroxide (H2O2). H2O2 promotes endothelial nitric oxide synthase (eNOS) activation and phosphorylation in endothelial cells. With this in mind, the present study was designed to evaluate ex vivo eNOS phosphorylation in rat aortas incubated with H2O2 and to test this hypothesis in vivo in the aortas of rats submitted to acute exercise. METHODS For ex vivo studies, six groups of aortic tissue were formed: control, H2O2, N-acetylcysteine (NAC), LY294002, compound C, and LY294002 plus compound C. While incubation with H2O2 increased Akt, AMPK and eNOS phosphorylation, pre-incubation with NAC strongly reduced the phosphorylation of these enzymes. For in vivo studies, male Wistar rats were divided into four groups: control, cont+NAC, exercise, and exer+NAC. After a 3h swimming session, animals were decapitated and aortas were excised for biochemical and immunoblotting analysis. RESULTS Acute exercise increased superoxide levels and dichlorofluorescein (DCF) concentrations, and this increase was related to phosphorylation of Akt, AMPK and eNOS. On the other hand, use of NAC reduced superoxide levels and DCF concentration. Reduced superoxide levels and DCF in the exer+NAC group were associated with decreased Akt, AMPK and eNOS phosphorylation. These results appear to be connected with vascular function because VASP phosphorylation increased in acute exercise and decreased in exer+NAC. CONCLUSION Our results indicate that ROS induced by acute exercise play the important role of activating eNOS, a process apparently mediated by Akt and AMPK.
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60
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Imrie H, Viswambharan H, Sukumar P, Abbas A, Cubbon RM, Yuldasheva N, Gage M, Smith J, Galloway S, Skromna A, Rashid ST, Futers TS, Xuan S, Gatenby VK, Grant PJ, Channon KM, Beech DJ, Wheatcroft SB, Kearney MT. Novel role of the IGF-1 receptor in endothelial function and repair: studies in endothelium-targeted IGF-1 receptor transgenic mice. Diabetes 2012; 61:2359-68. [PMID: 22733797 PMCID: PMC3425420 DOI: 10.2337/db11-1494] [Citation(s) in RCA: 51] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/02/2022]
Abstract
We recently demonstrated that reducing IGF-1 receptor (IGF-1R) numbers in the endothelium enhances nitric oxide (NO) bioavailability and endothelial cell insulin sensitivity. In the present report, we aimed to examine the effect of increasing IGF-1R on endothelial cell function and repair. To examine the effect of increasing IGF-1R in the endothelium, we generated mice overexpressing human IGF-1R in the endothelium (human IGF-1R endothelium-overexpressing mice [hIGFREO]) under direction of the Tie2 promoter enhancer. hIGFREO aorta had reduced basal NO bioavailability (percent constriction to N(G)-monomethyl-l-arginine [mean (SEM) wild type 106% (30%); hIGFREO 48% (10%)]; P < 0.05). Endothelial cells from hIGFREO had reduced insulin-stimulated endothelial NO synthase activation (mean [SEM] wild type 170% [25%], hIGFREO 58% [3%]; P = 0.04) and insulin-stimulated NO release (mean [SEM] wild type 4,500 AU [1,000], hIGFREO 1,500 AU [700]; P < 0.05). hIGFREO mice had enhanced endothelium regeneration after denuding arterial injury (mean [SEM] percent recovered area, wild type 57% [2%], hIGFREO 47% [5%]; P < 0.05) and enhanced endothelial cell migration in vitro. The IGF-1R, although reducing NO bioavailability, enhances in situ endothelium regeneration. Manipulating IGF-1R in the endothelium may be a useful strategy to treat disorders of vascular growth and repair.
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Affiliation(s)
- Helen Imrie
- Division of Cardiovascular and Diabetes Research, Multidisciplinary Cardiovascular Research Centre, University of Leeds, Leeds, U.K
| | - Hema Viswambharan
- Division of Cardiovascular and Diabetes Research, Multidisciplinary Cardiovascular Research Centre, University of Leeds, Leeds, U.K
| | - Piruthivi Sukumar
- Division of Cardiovascular and Diabetes Research, Multidisciplinary Cardiovascular Research Centre, University of Leeds, Leeds, U.K
| | - Afroze Abbas
- Division of Cardiovascular and Diabetes Research, Multidisciplinary Cardiovascular Research Centre, University of Leeds, Leeds, U.K
| | - Richard M. Cubbon
- Division of Cardiovascular and Diabetes Research, Multidisciplinary Cardiovascular Research Centre, University of Leeds, Leeds, U.K
| | - Nadira Yuldasheva
- Division of Cardiovascular and Diabetes Research, Multidisciplinary Cardiovascular Research Centre, University of Leeds, Leeds, U.K
| | - Matthew Gage
- Division of Cardiovascular and Diabetes Research, Multidisciplinary Cardiovascular Research Centre, University of Leeds, Leeds, U.K
| | - Jessica Smith
- Division of Cardiovascular and Diabetes Research, Multidisciplinary Cardiovascular Research Centre, University of Leeds, Leeds, U.K
| | - Stacey Galloway
- Division of Cardiovascular and Diabetes Research, Multidisciplinary Cardiovascular Research Centre, University of Leeds, Leeds, U.K
| | - Anna Skromna
- Division of Cardiovascular and Diabetes Research, Multidisciplinary Cardiovascular Research Centre, University of Leeds, Leeds, U.K
| | - Sheik Taqweer Rashid
- Division of Cardiovascular and Diabetes Research, Multidisciplinary Cardiovascular Research Centre, University of Leeds, Leeds, U.K
| | - T. Simon Futers
- Division of Cardiovascular and Diabetes Research, Multidisciplinary Cardiovascular Research Centre, University of Leeds, Leeds, U.K
| | - Shouhong Xuan
- Department of Genetics and Development, Columbia University, New York, New York
| | - V. Kate Gatenby
- Division of Cardiovascular and Diabetes Research, Multidisciplinary Cardiovascular Research Centre, University of Leeds, Leeds, U.K
| | - Peter J. Grant
- Division of Cardiovascular and Diabetes Research, Multidisciplinary Cardiovascular Research Centre, University of Leeds, Leeds, U.K
| | - Keith M. Channon
- University of Oxford British Heart Foundation Centre of Research Excellence, Oxford, U.K
| | - David J. Beech
- Division of Cardiovascular and Diabetes Research, Multidisciplinary Cardiovascular Research Centre, University of Leeds, Leeds, U.K
| | - Stephen B. Wheatcroft
- Division of Cardiovascular and Diabetes Research, Multidisciplinary Cardiovascular Research Centre, University of Leeds, Leeds, U.K
| | - Mark T. Kearney
- Division of Cardiovascular and Diabetes Research, Multidisciplinary Cardiovascular Research Centre, University of Leeds, Leeds, U.K
- Corresponding author: Mark T. Kearney,
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61
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Lima MHM, Caricilli AM, de Abreu LL, Araújo EP, Pelegrinelli FF, Thirone ACP, Tsukumo DM, Pessoa AFM, dos Santos MF, de Moraes MA, Carvalheira JBC, Velloso LA, Saad MJA. Topical insulin accelerates wound healing in diabetes by enhancing the AKT and ERK pathways: a double-blind placebo-controlled clinical trial. PLoS One 2012; 7:e36974. [PMID: 22662132 PMCID: PMC3360697 DOI: 10.1371/journal.pone.0036974] [Citation(s) in RCA: 149] [Impact Index Per Article: 11.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/27/2011] [Accepted: 04/15/2012] [Indexed: 02/07/2023] Open
Abstract
BACKGROUND Wound healing is impaired in diabetes mellitus, but the mechanisms involved in this process are virtually unknown. Proteins belonging to the insulin signaling pathway respond to insulin in the skin of rats. OBJECTIVE The purpose of this study was to investigate the regulation of the insulin signaling pathway in wound healing and skin repair of normal and diabetic rats, and, in parallel, the effect of a topical insulin cream on wound healing and on the activation of this pathway. RESEARCH DESIGN AND METHODS We investigated insulin signaling by immunoblotting during wound healing of control and diabetic animals with or without topical insulin. Diabetic patients with ulcers were randomized to receive topical insulin or placebo in a prospective, double-blind and placebo-controlled, randomized clinical trial (NCT 01295177) of wound healing. RESULTS AND CONCLUSIONS Expression of IR, IRS-1, IRS-2, SHC, ERK, and AKT are increased in the tissue of healing wounds compared to intact skin, suggesting that the insulin signaling pathway may have an important role in this process. These pathways were attenuated in the wounded skin of diabetic rats, in parallel with an increase in the time of complete wound healing. Upon topical application of insulin cream, the wound healing time of diabetic animals was normalized, followed by a reversal of defective insulin signal transduction. In addition, the treatment also increased expression of other proteins, such as eNOS (also in bone marrow), VEGF, and SDF-1α in wounded skin. In diabetic patients, topical insulin cream markedly improved wound healing, representing an attractive and cost-free method for treating this devastating complication of diabetes. TRIAL REGISTRATION ClinicalTrials.gov NCT01295177.
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Affiliation(s)
- Maria H. M. Lima
- Department of Nursing, FCM, University of Campinas, Campinas, São Paulo, Brazil
| | - Andréa M. Caricilli
- Department of Internal Medicine, FCM, University of Campinas, Campinas, São Paulo, Brazil
| | - Lélia L. de Abreu
- Department of Nursing, FCM, University of Campinas, Campinas, São Paulo, Brazil
| | - Eliana P. Araújo
- Department of Nursing, FCM, University of Campinas, Campinas, São Paulo, Brazil
| | | | - Ana C. P. Thirone
- Department of Internal Medicine, FCM, University of Campinas, Campinas, São Paulo, Brazil
| | - Daniela M. Tsukumo
- Department of Internal Medicine, FCM, University of Campinas, Campinas, São Paulo, Brazil
| | - Ana Flávia M. Pessoa
- Department of Cell and Developmental Biology, University of São Paulo, São Paulo, Brazil
| | | | - Maria A. de Moraes
- Department of Internal Medicine, FCM, University of Campinas, Campinas, São Paulo, Brazil
| | - José B. C. Carvalheira
- Department of Internal Medicine, FCM, University of Campinas, Campinas, São Paulo, Brazil
| | - Lício A. Velloso
- Department of Internal Medicine, FCM, University of Campinas, Campinas, São Paulo, Brazil
| | - Mario J. A. Saad
- Department of Internal Medicine, FCM, University of Campinas, Campinas, São Paulo, Brazil
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Förstermann U, Sessa WC. Nitric oxide synthases: regulation and function. Eur Heart J 2012; 33:829-37, 837a-837d. [PMID: 21890489 PMCID: PMC3345541 DOI: 10.1093/eurheartj/ehr304] [Citation(s) in RCA: 2854] [Impact Index Per Article: 219.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/07/2011] [Revised: 07/14/2011] [Accepted: 07/28/2011] [Indexed: 02/06/2023] Open
Abstract
Nitric oxide (NO), the smallest signalling molecule known, is produced by three isoforms of NO synthase (NOS; EC 1.14.13.39). They all utilize l-arginine and molecular oxygen as substrates and require the cofactors reduced nicotinamide-adenine-dinucleotide phosphate (NADPH), flavin adenine dinucleotide (FAD), flavin mononucleotide (FMN), and (6R-)5,6,7,8-tetrahydrobiopterin (BH(4)). All NOS bind calmodulin and contain haem. Neuronal NOS (nNOS, NOS I) is constitutively expressed in central and peripheral neurons and some other cell types. Its functions include synaptic plasticity in the central nervous system (CNS), central regulation of blood pressure, smooth muscle relaxation, and vasodilatation via peripheral nitrergic nerves. Nitrergic nerves are of particular importance in the relaxation of corpus cavernosum and penile erection. Phosphodiesterase 5 inhibitors (sildenafil, vardenafil, and tadalafil) require at least a residual nNOS activity for their action. Inducible NOS (NOS II) can be expressed in many cell types in response to lipopolysaccharide, cytokines, or other agents. Inducible NOS generates large amounts of NO that have cytostatic effects on parasitic target cells. Inducible NOS contributes to the pathophysiology of inflammatory diseases and septic shock. Endothelial NOS (eNOS, NOS III) is mostly expressed in endothelial cells. It keeps blood vessels dilated, controls blood pressure, and has numerous other vasoprotective and anti-atherosclerotic effects. Many cardiovascular risk factors lead to oxidative stress, eNOS uncoupling, and endothelial dysfunction in the vasculature. Pharmacologically, vascular oxidative stress can be reduced and eNOS functionality restored with renin- and angiotensin-converting enzyme-inhibitors, with angiotensin receptor blockers, and with statins.
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Affiliation(s)
- Ulrich Förstermann
- Department of Pharmacology, Johannes Gutenberg University Medical Center, 55101 Mainz, Germany.
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Saber R, Zadeh M, Pakanati KC, Bere P, Klaenhammer T, Mohamadzadeh M. Lipoteichoic acid-deficient Lactobacillus acidophilus regulates downstream signals. Immunotherapy 2012; 3:337-47. [PMID: 21395377 DOI: 10.2217/imt.10.119] [Citation(s) in RCA: 28] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022] Open
Abstract
The trillions of microbes residing within the intestine induce critical signals that either regulate or stimulate host immunity via their bacterial products. To better understand the immune regulation elicited by lipoteichoic acid (LTA)-deficient Lactobacillus acidophilus NCFM in steady state and induced inflammation, we deleted phosphoglycerol transferase gene, which synthesizes LTA in L. acidophilus NCFM. In vitro and in vivo experiments were conducted in order to compare the immune regulatory properties of the L. acidophilus strain deficient in LTA (NCK2025) with its wild-type parent (NCK56) in C57BL/6, C57BL/6 recombination-activation gene 1-deficient (Rag1 (-/-)) and C57BL/6 Rag1(-/-)IL-10(-/-) mice. We demonstrate that NCK2025 significantly activates the phosphorylation of Erk1/2 but downregulates the phosphorylation of Akt1, cytosolic group IV PLA2 and p38 in mouse dendritic cells. Similarly, mice treated orally with NCK2025 exhibit decreased phosphorylation of inflammatory signals (Akt1, cytosolic group IV PLA2 or P38) but upregulate Erk1/2-phosphorylation in colonic epithelial cells in comparison with mice treated with NCK56. In addition, regulation of pathogenic CD4+ T cell induced colitis by NCK2025 was observed in Rag1 (-/-) but not Rag1(-/-)IL-10 (-/-) mice suggests a critical role of IL-10 that may be tightly regulated by Erk1/2 signaling. These data highlight the immunosuppressive properties of NCK2025 to deliver regulatory signals in innate cells, which results in the mitigation of T-cell-induced colitis in vivo.
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Affiliation(s)
- Rana Saber
- Northwestern University, Feinberg School of Medicine, Chicago, IL 60611, USA
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In vivo cardioprotection by pitavastatin from ischemic-reperfusion injury through suppression of IKK/NF-κB and upregulation of pAkt-e-NOS. J Cardiovasc Pharmacol 2011; 58:199-206. [PMID: 21654332 DOI: 10.1097/fjc.0b013e31822002a6] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/30/2022]
Abstract
Recent studies have uncovered the beneficial effects of statin in cardiovascular diseases; however, the role of pitavastatin in ischemia-reperfusion (IR)-induced apoptosis and myocardial damage is not established. Therefore, in this study, we aim to investigate whether pitavastatin treatment attenuates myocardial IR injury via regulating oxidative stress, inflammation, apoptosis, and phosphorylated protein kinase B (pAkt) endothelial nitric oxide synthase (e-NOS) pathways. After the 14-day treatment with pitavastatin (0.16-0.64 mg·kg·d, po) or saline, rats were subjected to 45 minutes of ischemia by occluding the left anterior descending coronary artery and to 60 minutes of reperfusion to induce myocardial damage. Pitavastatin at a dose of 0.32 and 0.64 mg/kg significantly improved cardiac function as evidenced by the normalization of the mean arterial pressure, heart rate, ±LVdP/dtmax, and left ventricular end-diastolic pressure as compared with the IR control. Additionally, pitavastatin dose-dependently normalized myocardial antioxidants, lactate dehydrogenase, and thiobarbituric acid reactive substances along with decreased serum tumor necrosis factor-α level and creatine kinase isoenzyme-MB activity. Furthermore, pitavastatin enhanced pAkt, (p) e-NOS, Bcl-2, and suppressed IκB kinase/nuclear factor-kappa B, nitrotyrosine (NO inactivation product), Bax, and capases-3 protein expression in the heart. Morphological assessments of the IR-challenged myocardium showed that 0.32 and 0.64 mg/kg of pitavastatin decrease myocardial necrosis and inflammatory changes. Thus, pitavastatin reduced IR-induced infarction and dysfunction via the augmentation of endogenous antioxidant, suppression of IκB kinase/nuclear factor-kappa B, activation of pAkt-e-NOS, and/or decreased NO inactivation and apoptosis.
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Spradley FT, Ho DH, Kang KT, Pollock DM, Pollock JS. Changing standard chow diet promotes vascular NOS dysfunction in Dahl S rats. Am J Physiol Regul Integr Comp Physiol 2011; 302:R150-8. [PMID: 22031779 DOI: 10.1152/ajpregu.00482.2011] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/13/2023]
Abstract
We hypothesized that vascular nitric oxide synthase (NOS) function and expression is differentially regulated in adult Dahl salt-sensitive rats maintained on Teklad or American Institutes of Nutrition (AIN)-76A standard chow diets from 3 to 16 wk old. At 16 wk old, acetylcholine (ACh)-mediated vasorelaxation and phenylephrine (PE)-mediated vasoconstriction in the presence and absence of NOS inhibitor, N(ω)-nitro-L-arginine methyl ester (L-NAME), was assessed in small-resistance mesenteric arteries and aortas. Rats maintained on either diet throughout the study had similar responses to ACh and PE in the presence or absence of L-NAME in both vascular preparations. We reasoned that changing from one diet to another as adults may induce vascular NOS dysfunction. In the absence of L-NAME, small arteries from Teklad-fed rats switched to AIN-76 diet and vice versa had similar responses to ACh and PE. Small-arterial NOS function was maintained in rats switched to AIN-76A from Teklad diet, whereas NOS function in response to ACh and PE was lost in the small arteries from rats changed to Teklad from AIN-76A diet. This loss of NOS function was echoed by reduced expression of NOS3, as well as phosphorylated NOS3. The change in NOS phenotype in the small arteries was observed without changes in blood pressure. Aortic responses to ACh or PE in the presence or absence of L-NAME were similar in all diet groups. These data indicate that changing standard chow diets leads to small arterial NOS dysfunction and reduced NOS signaling, predisposing Dahl salt-sensitive rats to vascular disease.
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Affiliation(s)
- Frank T Spradley
- Section of Experimental Medicine, Department of Medicine, Medical College of Georgia, Georgia Health Sciences University, Augusta, 30912, USA
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Priming of hypoxia-inducible factor by neuronal nitric oxide synthase is essential for adaptive responses to severe anemia. Proc Natl Acad Sci U S A 2011; 108:17544-9. [PMID: 21976486 DOI: 10.1073/pnas.1114026108] [Citation(s) in RCA: 55] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/01/2023] Open
Abstract
Cells sense and respond to changes in oxygen concentration through gene regulatory processes that are fundamental to survival. Surprisingly, little is known about how anemia affects hypoxia signaling. Because nitric oxide synthases (NOSs) figure prominently in the cellular responses to acute hypoxia, we defined the effects of NOS deficiency in acute anemia. In contrast to endothelial NOS or inducible NOS deficiency, neuronal NOS (nNOS)(-/-) mice demonstrated increased mortality during anemia. Unlike wild-type (WT) animals, anemia did not increase cardiac output (CO) or reduce systemic vascular resistance (SVR) in nNOS(-/-) mice. At the cellular level, anemia increased expression of HIF-1α protein and HIF-responsive mRNA levels (EPO, VEGF, GLUT1, PDK1) in the brain of WT, but not nNOS(-/-) mice, despite comparable reductions in tissue PO(2). Paradoxically, nNOS(-/-) mice survived longer during hypoxia, retained the ability to regulate CO and SVR, and increased brain HIF-α protein levels and HIF-responsive mRNA transcripts. Real-time imaging of transgenic animals expressing a reporter HIF-α(ODD)-luciferase chimeric protein confirmed that nNOS was essential for anemia-mediated increases in HIF-α protein stability in vivo. S-nitrosylation effects the functional interaction between HIF and pVHL. We found that anemia led to nNOS-dependent S-nitrosylation of pVHL in vivo and, of interest, led to decreased expression of GSNO reductase. These findings identify nNOS effects on the HIF/pVHL signaling pathway as critically important in the physiological responses to anemia in vivo and provide essential mechanistic insight into the differences between anemia and hypoxia.
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67
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Endothelial nitric oxide synthase controls the expression of the angiogenesis inhibitor thrombospondin 2. Proc Natl Acad Sci U S A 2011; 108:E1137-45. [PMID: 21949402 DOI: 10.1073/pnas.1104357108] [Citation(s) in RCA: 50] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/18/2022] Open
Abstract
Injury- and ischemia-induced angiogenesis is critical for tissue repair and requires nitric oxide (NO) derived from endothelial nitric oxide synthase (eNOS). We present evidence that NO induces angiogenesis by modulating the level of the angiogenesis inhibitor thrombospondin 2 (TSP2). TSP2 levels were higher than WT in eNOS KO tissues in hind-limb ischemia and cutaneous wounds. In vitro studies confirmed that NO represses TSP2 promoter activity. Moreover, double-eNOS/TSP2 KO mice were generated and found to rescue the phenotype of eNOS KO mice. Studies in mice with knock-in constitutively active or inactive eNOS on the Akt-1 KO background showed that eNOS activity correlates with TSP2 levels. Our observations of NO-mediated regulation of angiogenesis via the suppression of TSP2 expression provide a description of improved eNOS KO phenotype by means other than restoring NO signaling.
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68
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Ha JM, Kim YW, Lee DH, Yun SJ, Kim EK, Hye Jin I, Kim JH, Kim CD, Shin HK, Bae SS. Regulation of arterial blood pressure by Akt1-dependent vascular relaxation. J Mol Med (Berl) 2011; 89:1253-60. [PMID: 21842346 DOI: 10.1007/s00109-011-0798-3] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/27/2011] [Revised: 07/22/2011] [Accepted: 07/27/2011] [Indexed: 12/14/2022]
Abstract
Endothelial cell-dependent vascular relaxation plays an important role in the regulation of blood pressure. Here, we show that stimulation of vascular endothelial cells with platelet-derived growth factor (PDGF) results in vascular relaxation through Akt1-dependent activation of endothelial nitric oxide synthase (eNOS) and nitric oxide (NO) production. Stimulation of both human umbilical artery endothelial cells and abdominal aortic vessels with PDGF induced NO production. PDGF-dependent production of NO was completely abolished by inhibition of phosphatidylinositol 3-kinase with wortmannin (100 nM). Stimulation of aortic vessels with PDGF resulted in the activation of Akt phosphorylation and eNOS phosphorylation: however, eNOS phosphorylation and production of NO were abolished in aortic vessels of mice lacking Akt1. PDGF strongly induced vascular relaxation in the presence of endothelium, and inhibition of NO production by N-nitro-L: -arginine-methyl ester completely blocked PDGF-dependent vascular relaxation. In addition, PDGF-dependent relaxation was completely abolished by inhibition of PI3K with wortmannin (100 nM). Furthermore, vessels from Akt1 heterozygotes showed normal relaxation after PDGF stimulation, whereas vessels from Akt1 knockout littermates did not respond to PDGF stimulation. Finally, administration of PDGF (5 ng/ml) significantly lowered blood pressure in Akt1 heterozygotes, whereas a blood pressure-lowering effect was not observed in Akt1 knockout littermates. These results suggest that Akt1 regulates blood pressure through regulation of vascular relaxation by eNOS phosphorylation and subsequent production of NO.
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Affiliation(s)
- Jung Min Ha
- MRC for Ischemic Tissue Regeneration and Department of Pharmacology, Pusan National University School of Medicine, Bumeo-ri, Mulgeum-eup, Yangsan-si, Kyungnam, Republic of Korea
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Olson N, van der Vliet A. Interactions between nitric oxide and hypoxia-inducible factor signaling pathways in inflammatory disease. Nitric Oxide 2011; 25:125-37. [PMID: 21199675 PMCID: PMC3090692 DOI: 10.1016/j.niox.2010.12.010] [Citation(s) in RCA: 103] [Impact Index Per Article: 7.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/08/2010] [Revised: 12/22/2010] [Accepted: 12/29/2010] [Indexed: 02/06/2023]
Abstract
Induction and activation of nitric oxide (NO) synthases (NOS) and excessive production of NO are common features of almost all diseases associated with infection and acute or chronic inflammation, although the contribution of NO to the pathophysiology of these diseases is highly multifactorial and often still a matter of controversy. Because of its direct impact on tissue oxygenation and cellular oxygen (O(2)) consumption and re-distribution, the ability of NO to regulate various aspects of hypoxia-induced signaling has received widespread attention. Conditions of tissue hypoxia and the activation of hypoxia-inducible factors (HIF) have been implicated in hypoxia or in cancer biology, but are also being increasingly recognized as important features of acute and chronic inflammation. Thus, the activation of HIF transcription factors has been increasingly implicated in inflammatory diseases, and recent studies have indicated its critical importance in regulating phagocyte function, inflammatory mediator production, and regulation of epithelial integrity and repair processes. Finally, HIF also appears to contribute to important features of tissue fibrosis and epithelial-to-mesenchymal transition, processes that are associated with tissue remodeling in various non-malignant chronic inflammatory disorders. In this review, we briefly summarize the current state of knowledge with respect to the general mechanisms involved in HIF regulation and the impact of NO on HIF activation. Secondly, we will summarize the major recent findings demonstrating a role for HIF signaling in infection, inflammation, and tissue repair and remodeling, and will address the involvement of NO. The growing interest in hypoxia-induced signaling and its relation with NO biology is expected to lead to further insights into the complex roles of NO in acute or chronic inflammatory diseases and may point to the importance of HIF signaling as key feature of NO-mediated events during these disorders.
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Affiliation(s)
- Nels Olson
- Department of Pathology, College of Medicine, University of Vermont, Burlington, VT 05405, U.S.A
| | - Albert van der Vliet
- Department of Pathology, College of Medicine, University of Vermont, Burlington, VT 05405, U.S.A
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Abbas A, Imrie H, Viswambharan H, Sukumar P, Rajwani A, Cubbon RM, Gage M, Smith J, Galloway S, Yuldeshava N, Kahn M, Xuan S, Grant PJ, Channon KM, Beech DJ, Wheatcroft SB, Kearney MT. The insulin-like growth factor-1 receptor is a negative regulator of nitric oxide bioavailability and insulin sensitivity in the endothelium. Diabetes 2011; 60:2169-78. [PMID: 21677284 PMCID: PMC3142083 DOI: 10.2337/db11-0197] [Citation(s) in RCA: 69] [Impact Index Per Article: 4.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 02/15/2011] [Accepted: 05/15/2011] [Indexed: 12/19/2022]
Abstract
OBJECTIVE In mice, haploinsufficiency of the IGF-1 receptor (IGF-1R(+/-)), at a whole-body level, increases resistance to inflammation and oxidative stress, but the underlying mechanisms are unclear. We hypothesized that by forming insulin-resistant heterodimers composed of one IGF-1Rαβ and one insulin receptor (IR), IRαβ complex in endothelial cells (ECs), IGF-1R reduces free IR, which reduces EC insulin sensitivity and generation of the antioxidant/anti-inflammatory signaling radical nitric oxide (NO). RESEARCH DESIGN AND METHODS Using a number of complementary gene-modified mice with reduced IGF-1R at a whole-body level and specifically in EC, and complementary studies in EC in vitro, we examined the effect of changing IGF-1R/IR stoichiometry on EC insulin sensitivity and NO bioavailability. RESULTS IGF-1R(+/-) mice had enhanced insulin-mediated glucose lowering. Aortas from these mice were hypocontractile to phenylephrine (PE) and had increased basal NO generation and augmented insulin-mediated NO release from EC. To dissect EC from whole-body effects we generated mice with EC-specific knockdown of IGF-1R. Aortas from these mice were also hypocontractile to PE and had increased basal NO generation. Whole-body and EC deletion of IGF-1R reduced hybrid receptor formation. By reducing IGF-1R in IR-haploinsufficient mice we reduced hybrid formation, restored insulin-mediated vasorelaxation in aorta, and insulin stimulated NO release in EC. Complementary studies in human umbilical vein EC in which IGF-1R was reduced using siRNA confirmed that reducing IGF-1R has favorable effects on NO bioavailability and EC insulin sensitivity. CONCLUSIONS These data demonstrate that IGF-1R is a critical negative regulator of insulin sensitivity and NO bioavailability in the endothelium.
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Affiliation(s)
- Afroze Abbas
- Division of Cardiovascular and Diabetes Research, Leeds Multidisciplinary Cardiovascular Research Centre, University of Leeds, Leeds, U.K
| | - Helen Imrie
- Division of Cardiovascular and Diabetes Research, Leeds Multidisciplinary Cardiovascular Research Centre, University of Leeds, Leeds, U.K
| | - Hema Viswambharan
- Division of Cardiovascular and Diabetes Research, Leeds Multidisciplinary Cardiovascular Research Centre, University of Leeds, Leeds, U.K
| | - Piruthivi Sukumar
- Division of Cardiovascular and Diabetes Research, Leeds Multidisciplinary Cardiovascular Research Centre, University of Leeds, Leeds, U.K
| | - Adil Rajwani
- Division of Cardiovascular and Diabetes Research, Leeds Multidisciplinary Cardiovascular Research Centre, University of Leeds, Leeds, U.K
| | - Richard M. Cubbon
- Division of Cardiovascular and Diabetes Research, Leeds Multidisciplinary Cardiovascular Research Centre, University of Leeds, Leeds, U.K
| | - Matthew Gage
- Division of Cardiovascular and Diabetes Research, Leeds Multidisciplinary Cardiovascular Research Centre, University of Leeds, Leeds, U.K
| | - Jessica Smith
- Division of Cardiovascular and Diabetes Research, Leeds Multidisciplinary Cardiovascular Research Centre, University of Leeds, Leeds, U.K
| | - Stacey Galloway
- Division of Cardiovascular and Diabetes Research, Leeds Multidisciplinary Cardiovascular Research Centre, University of Leeds, Leeds, U.K
| | - Nadira Yuldeshava
- Division of Cardiovascular and Diabetes Research, Leeds Multidisciplinary Cardiovascular Research Centre, University of Leeds, Leeds, U.K
| | - Matthew Kahn
- Division of Cardiovascular and Diabetes Research, Leeds Multidisciplinary Cardiovascular Research Centre, University of Leeds, Leeds, U.K
| | - Shouhong Xuan
- Department of Genetics and Development, Columbia University, New York, New York
| | - Peter J. Grant
- Division of Cardiovascular and Diabetes Research, Leeds Multidisciplinary Cardiovascular Research Centre, University of Leeds, Leeds, U.K
| | - Keith M. Channon
- British Heart Foundation Centre of Research Excellence, University of Oxford, Oxford, U.K
| | - David J. Beech
- Division of Cardiovascular and Diabetes Research, Leeds Multidisciplinary Cardiovascular Research Centre, University of Leeds, Leeds, U.K
| | - Stephen B. Wheatcroft
- Division of Cardiovascular and Diabetes Research, Leeds Multidisciplinary Cardiovascular Research Centre, University of Leeds, Leeds, U.K
| | - Mark T. Kearney
- Division of Cardiovascular and Diabetes Research, Leeds Multidisciplinary Cardiovascular Research Centre, University of Leeds, Leeds, U.K
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Gangopahyay A, Oran M, Bauer EM, Wertz JW, Comhair SA, Erzurum SC, Bauer PM. Bone morphogenetic protein receptor II is a novel mediator of endothelial nitric-oxide synthase activation. J Biol Chem 2011; 286:33134-40. [PMID: 21808054 DOI: 10.1074/jbc.m111.274100] [Citation(s) in RCA: 68] [Impact Index Per Article: 4.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/12/2023] Open
Abstract
Activation of bone morphogenetic protein (BMP) receptor II (BMPRII) promotes pulmonary artery endothelial cell (PAEC) survival, proliferation, and migration. Mutations to BMPRII are associated with the development of pulmonary arterial hypertension (PAH). Endothelial dysfunction, including decreased endothelial nitric-oxide synthase (eNOS) activity and loss of bioactive nitric oxide (NO), plays a prominent role in the development of PAH. We hypothesized that stimulation of BMPRII promotes normal PAEC function by activating eNOS. We report that BMPRII ligands, BMP2 and BMP4, (i) stimulate eNOS phosphorylation at a critical regulatory site, (ii) increase eNOS activity, and (iii) result in canonical changes in eNOS protein-protein interactions. The stimulation of eNOS activity by BMPRII ligands was largely dependent on protein kinase A (PKA) activation, as demonstrated using the PKA inhibitors H89 and myristoylated PKI(6-22) amide. PAEC migration stimulated by BMP2 and BMP4 was inhibited by the NOS inhibitor l-nitroarginine methyl ester, providing functional evidence of eNOS activation. Furthermore, BMP2 and BMP4 failed to stimulate eNOS phosphorylation when BMPRII was knocked down by siRNA. Most important to the pathophysiology of the disease, BMP2 and BMP4 failed to stimulate eNOS phosphorylation in PAECs isolated from patients with mutations in the BMPR2 gene. These data demonstrate a new action of BMPs/BMPRII in the pulmonary endothelium and provide novel mechanistic insight into the pathogenesis of PAH.
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Affiliation(s)
- Archana Gangopahyay
- Department of Surgery, University of Pittsburgh School of Medicine, Pittsburgh, Pennsylvania 15261, USA
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72
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Zhang P, Hu X, Xu X, Chen Y, Bache RJ. Dimethylarginine dimethylaminohydrolase 1 modulates endothelial cell growth through nitric oxide and Akt. Arterioscler Thromb Vasc Biol 2011; 31:890-7. [PMID: 21212404 PMCID: PMC3064458 DOI: 10.1161/atvbaha.110.215640] [Citation(s) in RCA: 36] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/04/2010] [Accepted: 12/21/2010] [Indexed: 11/16/2022]
Abstract
OBJECTIVE Dimethylarginine dimethylaminohydrolase 1 (DDAH1) modulates NO production by degrading the endogenous nitric oxide (NO) synthase (NOS) inhibitors asymmetrical dimethylarginine (ADMA) and L-NG-monomethyl arginine (L-NMMA). This study examined whether, in addition to degrading ADMA, DDAH1 exerts ADMA-independent effects that influence endothelial function. METHODS AND RESULTS Using selective gene silencing of DDAH1 with small interfering RNA and overexpression of DDAH1 in human umbilical vein endothelial cells, we found that DDAH1 acts to promote endothelial cell proliferation, migration, and tube formation by Akt phosphorylation, as well as through the traditional role of degrading ADMA. Incubation of human umbilical vein endothelial cells with the NOS inhibitors l-NG-nitro-arginine methyl ester (L-NAME) or ADMA, the soluble guanylyl cyclase inhibitor 1H-(1,2,4)oxadiazolo-(4,3-2)quinoxalin-1-one, or the cGMP analog 8-(4-Chlorophenylthio)-cGMP had no effect on phosphorylated (p)-Akt(Ser473), indicating that the increase in p-Akt(Ser473) produced by DDAH1 was independent of the NO-cGMP signaling pathway. DDAH1 formed a protein complex with Ras, and DDAH1 overexpression increased Ras activity. The Ras inhibitor manumycin-A or dominant-negative Ras significantly attenuated the DDAH1-induced increase in p-Akt(Ser473). Furthermore, DDAH1 knockout impaired endothelial sprouting from cultured aortic rings, and overexpression of constitutively active Akt or DDAH1 rescued endothelial sprouting in the aortic rings from these mice. CONCLUSIONS DDAH1 exerts a unique role in activating Akt that affects endothelial function independently of degrading endogenous NOS inhibitors.
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Affiliation(s)
- Ping Zhang
- Division of Cardiology, University of Minnesota Medical School, Minneapolis, MN 55455, USA
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73
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Yu HS, Kim SH, Park HG, Kim YS, Ahn YM. Activation of Akt signaling in rat brain by intracerebroventricular injection of ouabain: a rat model for mania. Prog Neuropsychopharmacol Biol Psychiatry 2010; 34:888-94. [PMID: 20403403 DOI: 10.1016/j.pnpbp.2010.04.010] [Citation(s) in RCA: 28] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/01/2010] [Revised: 04/06/2010] [Accepted: 04/13/2010] [Indexed: 11/17/2022]
Abstract
Intracerebroventricular (ICV) injection of ouabain, a specific Na-K ATPase inhibitor, induces behavioral changes in rats resembling the manic phenotypes of bipolar disorder. The binding of ouabain to the Na-K ATPase affects signal events in vitro including Akt, a possible molecular target of mood disorders. However, the effects of ouabain on Akt in the brain need further clarification. In this study, we investigated changes in the phosphorylation state of Akt in the rat brain after ICV injection of ouabain. Consistent with our previous report, the locomotor activity of rats within 30 min after ouabain ICV injection changed according to the dose with higher doses of ouabain, 0.5 and 1 mM, inducing significant hyperactivity. In addition, ouabain administration induced a dose-dependent increase in the immunoreactivity of p-Akt (Ser473) in the frontal cortex, striatum, and hippocampus after 30 min, and reached statistical significance with 1mM of ouabain. Phosphorylation of GSK-3beta (Ser9), FOXO1 (Ser256), and eNOS (Ser1177), which are downstream molecules of Akt, was also increased in a dose-dependent manner within the same brain regions. Moreover, hyperactivity was seen for 8h after a single 1mM injection of ouabain and increased phosphorylation of Akt (Ser473), GSK-3beta (Ser9), FOXO1 (Ser256), and eNOS (Ser1177) was also observed in the cortex, striatum, and hippocampus. Thus, intrabrain injection of ouabain induces activation of Akt signaling accompanied by hyperactivity, suggesting the possible role of Akt in ouabain rat model of mania.
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Affiliation(s)
- Hyun-Sook Yu
- Department of Biomedical Sciences, Seoul National University College of Medicine, Seoul, Republic of Korea
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74
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Atochin DN, Huang PL. Endothelial nitric oxide synthase transgenic models of endothelial dysfunction. Pflugers Arch 2010; 460:965-74. [PMID: 20697735 DOI: 10.1007/s00424-010-0867-4] [Citation(s) in RCA: 113] [Impact Index Per Article: 7.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/14/2010] [Revised: 07/24/2010] [Accepted: 07/25/2010] [Indexed: 10/19/2022]
Abstract
Endothelial production of nitric oxide is critical to the regulation of vascular responses, including vascular tone and regional blood flow, leukocyte-endothelial interactions, platelet adhesion and aggregation, and vascular smooth muscle cell proliferation. A relative deficiency in the amount of bioavailable vascular NO results in endothelial dysfunction, with conditions that are conducive to the development of atherosclerosis: thrombosis, inflammation, neointimal proliferation, and vasoconstriction. This review focuses on mouse models of endothelial dysfunction caused by direct genetic modification of the endothelial nitric oxide synthase (eNOS) gene. We first describe the cardiovascular phenotypes of eNOS knockout mice, which are a model of total eNOS gene deficiency and thus the ultimate model of endothelial dysfunction. We then describe S1177A and S1177D eNOS mutant mice as mouse models with altered eNOS phosphorylation and therefore varying degrees of endothelial dysfunction. These include transgenic mice that carry the eNOS S1177A and S1177D transgenes, as well as knockin mice in which the endogenous eNOS gene has been mutated to carry the S1177A and S1177D mutations. Together, eNOS knockout mice and eNOS S1177 mutant mice are useful tools to study the effects of total genetic deficiency of eNOS as well as varying degrees of endothelial dysfunction caused by eNOS S1177 phosphorylation.
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Affiliation(s)
- Dmitriy N Atochin
- Cardiovascular Research Center and Cardiology Division, Department of Medicine, Massachusetts General Hospital and Harvard Medical School, Boston, MA 02114, USA
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76
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Weng L, Enomoto A, Ishida-Takagishi M, Asai N, Takahashi M. Girding for migratory cues: roles of the Akt substrate Girdin in cancer progression and angiogenesis. Cancer Sci 2010; 101:836-42. [PMID: 20132219 PMCID: PMC11159251 DOI: 10.1111/j.1349-7006.2009.01487.x] [Citation(s) in RCA: 55] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/21/2022] Open
Abstract
Cell migration is a fundamental aspect of a multitude of physiological and pathological processes, including embryonic development, inflammation, angiogenesis, and cancer progression. A variety of proteins are essential for cell migration, but context-specific signaling pathways and promigratory proteins must now be identified for our understanding of cancer biology to continue to advance. In this review, we focus on the emerging roles of Girdin (also designated KIAA1212, APE, GIV, and HkRP1), a novel component of the phosphatidylinositol 3-kinase (PI3-K)/Akt signaling pathway that is a core-signaling transduction pathway in cancer progression. Girdin is expressed in some types of cancer cells and immature endothelial cells, and is therefore at the crossroads of multiple intracellular processes, including reorganization of the actin cytoskeleton, endocytosis, and modulation of Akt activity, which ultimately lead to cancer invasion and angiogenesis. It also acts as a nonreceptor guanine nucleotide exchange factor (GEF) for Galphai proteins. A significant observation is that Girdin, although vital for cancer progression and postnatal vascular remodelling, is dispensable for cell migratory events during embryonic development. These findings suggest that Girdin and its interacting proteins are potential pharmaceutical targets for cancer therapies and pathological anigiogenesis, including tumor angiogenesis.
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Affiliation(s)
- Liang Weng
- Department of Pathology, Nagoya University Graduate School of Medicine, Showa-ku, Nagoya, Japan
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Affiliation(s)
- R Daniel Rudic
- Department of Pharmacology and Toxicology, Medical College of Georgia, Augusta, GA 30912, USA.
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