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Shin WS, Berkowitz DE, Ryoo SW. Increased arginase II activity contributes to endothelial dysfunction through endothelial nitric oxide synthase uncoupling in aged mice. Exp Mol Med 2013; 44:594-602. [PMID: 22854495 PMCID: PMC3490081 DOI: 10.3858/emm.2012.44.10.068] [Citation(s) in RCA: 42] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/24/2022] Open
Abstract
The incidence of cardiovascular disease is predicted to increase as the population ages. There is accumulating evidence that arginase upregulation is associated with impaired endothelial function. Here, we demonstrate that arginase II (ArgII) is upregulated in aortic vessels of aged mice and contributes to decreased nitric oxide (NO) generation and increased reactive oxygen species (ROS) production via endothelial nitric oxide synthase (eNOS) uncoupling. Inhibiting ArgII with small interfering RNA technique restored eNOS coupling to that observed in young mice and increased NO generation and decreased ROS production. Furthermore, enhanced vasoconstrictor responses to U46619 and attenuated vasorelaxation responses to acetylcholine in aged vasculature were markedly improved following siRNA treatment against ArgII. These results might be associated with increased L-arginine bioavailability. Collectively, these results suggest that ArgII may be a valuable target in age-dependent vascular diseases.
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Affiliation(s)
- Woo Sung Shin
- Department of Biology College of Natural Sciences Kangwon National University Chuncheon 200-701, Korea
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52
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Abstract
Arginase metabolizes the semi-essential amino acid l-arginine to l-ornithine and urea. There are two distinct isoforms of arginase, arginase I and II, which are encoded by separate genes and display differences in tissue distribution, subcellular localization, and molecular regulation. Blood vessels express both arginase I and II but their distribution appears to be cell-, vessel-, and species-specific. Both isoforms of arginase are induced by numerous pathologic stimuli and contribute to vascular cell dysfunction and vessel wall remodeling in several diseases. Clinical and experimental studies have documented increases in the expression and/or activity of arginase I or II in blood vessels following arterial injury and in pulmonary and arterial hypertension, aging, and atherosclerosis. Significantly, pharmacological inhibition or genetic ablation of arginase in animals ameliorates abnormalities in vascular cells and normalizes blood vessel architecture and function in all of these pathological states. The detrimental effect of arginase in vascular remodeling is attributable to its ability to stimulate vascular smooth muscle cell and endothelial cell proliferation, and collagen deposition by promoting the synthesis of polyamines and l-proline, respectively. In addition, arginase adversely impacts arterial remodeling by directing macrophages toward an inflammatory phenotype. Moreover, the proliferative, fibrotic, and inflammatory actions of arginase in the vasculature are further amplified by its capacity to inhibit nitric oxide (NO) synthesis by competing with NO synthase for substrate, l-arginine. Pharmacologic or molecular approaches targeting specific isoforms of arginase represent a promising strategy in treating obstructive fibroproliferative vascular disease.
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Affiliation(s)
- William Durante
- Department of Medical Pharmacology and Physiology, University of Missouri-Columbia Columbia, MO, USA
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53
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Bratt JM, Zeki AA, Last JA, Kenyon NJ. Competitive metabolism of L-arginine: arginase as a therapeutic target in asthma. J Biomed Res 2013; 25:299-308. [PMID: 23554705 PMCID: PMC3596726 DOI: 10.1016/s1674-8301(11)60041-9] [Citation(s) in RCA: 22] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/25/2011] [Revised: 06/24/2011] [Accepted: 07/21/2011] [Indexed: 12/20/2022] Open
Abstract
Exhaled breath nitric oxide (NO) is an accepted asthma biomarker. Lung concentrations of NO and its amino acid precursor, L-arginine, are regulated by the relative expressions of the NO synthase (NOS) and arginase isoforms. Increased expression of arginase I and NOS2 occurs in murine models of allergic asthma and in biopsies of asthmatic airways. Although clinical trials involving the inhibition of NO-producing enzymes have shown mixed results, small molecule arginase inhibitors have shown potential as a therapeutic intervention in animal and cell culture models. Their transition to clinical trials is hampered by concerns regarding their safety and potential toxicity. In this review, we discuss the paradigm of arginase and NOS competition for their substrate L-arginine in the asthmatic airway. We address the functional role of L-arginine in inflammation and the potential role of arginase inhibitors as therapeutics.
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Affiliation(s)
- Jennifer M Bratt
- Department of Internal Medicine, Division of Pulmonary and Critical Care and Sleep Medicine, University of California, Davis, CA 95616, USA
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54
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Carnicer R, Crabtree MJ, Sivakumaran V, Casadei B, Kass DA. Nitric oxide synthases in heart failure. Antioxid Redox Signal 2013; 18:1078-99. [PMID: 22871241 PMCID: PMC3567782 DOI: 10.1089/ars.2012.4824] [Citation(s) in RCA: 122] [Impact Index Per Article: 11.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/30/2012] [Accepted: 08/07/2012] [Indexed: 12/22/2022]
Abstract
SIGNIFICANCE The regulation of myocardial function by constitutive nitric oxide synthases (NOS) is important for the maintenance of myocardial Ca(2+) homeostasis, relaxation and distensibility, and protection from arrhythmia and abnormal stress stimuli. However, sustained insults such as diabetes, hypertension, hemodynamic overload, and atrial fibrillation lead to dysfunctional NOS activity with superoxide produced instead of NO and worse pathophysiology. RECENT ADVANCES Major strides in understanding the role of normal and abnormal constitutive NOS in the heart have revealed molecular targets by which NO modulates myocyte function and morphology, the role and nature of post-translational modifications of NOS, and factors controlling nitroso-redox balance. Localized and differential signaling from NOS1 (neuronal) versus NOS3 (endothelial) isoforms are being identified, as are methods to restore NOS function in heart disease. CRITICAL ISSUES Abnormal NOS signaling plays a key role in many cardiac disorders, while targeted modulation may potentially reverse this pathogenic source of oxidative stress. FUTURE DIRECTIONS Improvements in the clinical translation of potent modulators of NOS function/dysfunction may ultimately provide a powerful new treatment for many hearts diseases that are fueled by nitroso-redox imbalance.
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Affiliation(s)
- Ricardo Carnicer
- Department of Cardiovascular Medicine, John Radcliffe Hospital, University of Oxford, Oxford, United Kingdom
| | - Mark J. Crabtree
- Department of Cardiovascular Medicine, John Radcliffe Hospital, University of Oxford, Oxford, United Kingdom
| | - Vidhya Sivakumaran
- Division of Cardiology, Department of Medicine, Johns Hopkins University Medical Institutions, Baltimore, Maryland
| | - Barbara Casadei
- Department of Cardiovascular Medicine, John Radcliffe Hospital, University of Oxford, Oxford, United Kingdom
| | - David A. Kass
- Division of Cardiology, Department of Medicine, Johns Hopkins University Medical Institutions, Baltimore, Maryland
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55
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Raber P, Ochoa AC, Rodríguez PC. Metabolism of L-arginine by myeloid-derived suppressor cells in cancer: mechanisms of T cell suppression and therapeutic perspectives. Immunol Invest 2013; 41:614-34. [PMID: 23017138 DOI: 10.3109/08820139.2012.680634] [Citation(s) in RCA: 211] [Impact Index Per Article: 19.2] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/08/2023]
Abstract
Patients with cancer have an impaired T cell response that can decrease the potential therapeutic benefit of cancer vaccines and other forms of immunotherapy. The establishment of a chronic inflammatory environment in patients with cancer plays a critical role in the induction of T cell dysfunction. The accumulation of myeloid-derived suppressor cells (MDSC) in tumor bearing hosts is a hallmark of malignancy-associated inflammation and a major mediator of the induction of T cell suppression in cancer. Recent findings in tumor bearing mice and cancer patients indicate that the increased metabolism of L-Arginine (L-Arg) by MDSC producing Arginase I inhibits T cell lymphocyte responses. Here, we discuss some of the most recent concepts of how MDSC expressing Arginase I may regulate T cell function in cancer and suggest possible therapeutic interventions to overcome this inhibitory effect.
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Affiliation(s)
- Patrick Raber
- Department of Microbiology, Immunology and Parasitology, Louisiana State University Health Sciences Center, NewOrleans, Louisiana, USA.
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Pernow J, Jung C. Arginase as a potential target in the treatment of cardiovascular disease: reversal of arginine steal? Cardiovasc Res 2013; 98:334-43. [DOI: 10.1093/cvr/cvt036] [Citation(s) in RCA: 204] [Impact Index Per Article: 18.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/01/2023] Open
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Khong SML, Andrews KL, Huynh NN, Venardos K, Aprico A, Michell DL, Zarei M, Moe KT, Dusting GJ, Kaye DM, Chin-Dusting JPF. Arginase II inhibition prevents nitrate tolerance. Br J Pharmacol 2012; 166:2015-23. [PMID: 22288373 DOI: 10.1111/j.1476-5381.2012.01876.x] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/29/2023] Open
Abstract
BACKGROUND AND PURPOSE Nitrate tolerance, the loss of vascular responsiveness with continued use of nitrates, remains incompletely understood and is a limitation of these therapeutic agents. Vascular superoxide, generated by uncoupled endothelial NOS (eNOS), may play a role. As arginase competes with eNOS for L-arginine and may exacerbate the production of reactive oxygen species (ROS), we hypothesized that arginase inhibition might reduce nitrate tolerance. EXPERIMENTAL APPROACH Vasodilator responses were measured in aorta from C57Bl/6 and arginase II knockout (argII -/-) mice using myography. Uncoupling of eNOS, determined as eNOS monomer : dimer ratio, was assessed using low-temperature SDS-PAGE and ROS levels were measured using L-012 and lucigenin-enhanced chemiluminescence. KEY RESULTS Repeated application of glyceryl trinitrate (GTN) on aorta isolated from C57Bl/6 mice produced a 32-fold rightward shift of the concentration-response curve. However this rightward shift (or resultant tolerance) was not observed in the presence of the arginase inhibitor (s)-(2-boronethyl)-L-cysteine HCl (BEC; 100 µM) nor in aorta isolated from argII -/- mice. Similar findings were obtained after inducing nitrate tolerance in vivo. Repeated administration of GTN in human umbilical vein endothelial cells induced uncoupling of eNOS from its dimeric state and increased ROS levels, which were reduced with arginase inhibition and exogenous L-arginine. Aortae from GTN tolerant C57Bl/6 mice exhibited increased arginase activity and ROS production, whereas vessels from argII -/- mice did not. CONCLUSION AND IMPLICATIONS Arginase II removal prevents nitrate tolerance. This may be due to decreased uncoupling of eNOS and consequent ROS production.
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Affiliation(s)
- S M L Khong
- Baker IDI Heart and Diabetes Institute, Melbourne, Australia
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58
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Nikolaeva S, Bachteeva V, Fock E, Herterich S, Lavrova E, Borodkina A, Gambaryan S, Parnova R. Frog urinary bladder epithelial cells express TLR4 and respond to bacterial LPS by increase of iNOS expression andl-arginine uptake. Am J Physiol Regul Integr Comp Physiol 2012; 303:R1042-52. [DOI: 10.1152/ajpregu.00045.2012] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
As in mammals, epithelium of the amphibian urinary bladder forms a barrier to pathogen entry and is a first line of defense against penetrating microorganisms. We investigated the effect of Escherichia coli LPS on generation of nitric oxide (NO), a critically important mediator during infectious processes, by primary cultured frog ( Rana temporaria) urinary bladder epithelial cells (FUBEC). It was found that FUBEC constitutively express Toll-like receptor 4 (TLR4), a receptor of LPS, and respond to LPS (10 μg/ml) by stimulation of inducible nitric oxide synthase (iNOS) mRNA/protein expression and NOS activity measured by nitrite produced in the culture medium and by citrulline assay. We characterized uptake of l-arginine, a precursor in NO synthesis, by FUBEC and showed that it is mediated mainly by the y+ cationic amino acid transport system. LPS stimulated l-arginine uptake, and this effect was blocked by the iNOS inhibitor 1400W. Arginase II was found to be expressed in FUBEC. Inhibition of arginase activity by (S)-(boronoethyl)-l-cysteine increased generation of NO, suggesting contribution of arginase to NO production via competing with NOS for the substrate. LPS altered neither total arginase activity nor arginase II expression. Among epithelial cells, phagocytic macrophage-like cells were observed, but they did not contribute to LPS-induced NO production. These data demonstrate that amphibian urinary bladder epithelial cells recognize LPS and respond to it by increased generation of NO via stimulation of iNOS expression and l-arginine uptake, which appears to be essential for the regulation of the innate immune response and the inflammation in bladder epithelium.
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Affiliation(s)
- Svetlana Nikolaeva
- I. M. Sechenov Institute of Evolutionary Physiology and Biochemistry of the Russian Academy of Sciences, St. Petersburg, Russia; and
| | - Vera Bachteeva
- I. M. Sechenov Institute of Evolutionary Physiology and Biochemistry of the Russian Academy of Sciences, St. Petersburg, Russia; and
| | - Ekaterina Fock
- I. M. Sechenov Institute of Evolutionary Physiology and Biochemistry of the Russian Academy of Sciences, St. Petersburg, Russia; and
| | - Sabine Herterich
- Institute of Clinical Biochemistry and Pathobiochemistry, University of Wurzburg, Wurzburg, Germany
| | - Elena Lavrova
- I. M. Sechenov Institute of Evolutionary Physiology and Biochemistry of the Russian Academy of Sciences, St. Petersburg, Russia; and
| | - Alexandra Borodkina
- I. M. Sechenov Institute of Evolutionary Physiology and Biochemistry of the Russian Academy of Sciences, St. Petersburg, Russia; and
| | - Stepan Gambaryan
- I. M. Sechenov Institute of Evolutionary Physiology and Biochemistry of the Russian Academy of Sciences, St. Petersburg, Russia; and
- Institute of Clinical Biochemistry and Pathobiochemistry, University of Wurzburg, Wurzburg, Germany
| | - Rimma Parnova
- I. M. Sechenov Institute of Evolutionary Physiology and Biochemistry of the Russian Academy of Sciences, St. Petersburg, Russia; and
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59
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Lucas R, Yang G, Gorshkov BA, Zemskov EA, Sridhar S, Umapathy NS, Jezierska-Drutel A, Alieva IB, Leustik M, Hossain H, Fischer B, Catravas JD, Verin AD, Pittet JF, Caldwell RB, Mitchell TJ, Cederbaum SD, Fulton DJ, Matthay MA, Caldwell RW, Romero MJ, Chakraborty T. Protein kinase C-α and arginase I mediate pneumolysin-induced pulmonary endothelial hyperpermeability. Am J Respir Cell Mol Biol 2012; 47:445-53. [PMID: 22582175 DOI: 10.1165/rcmb.2011-0332oc] [Citation(s) in RCA: 48] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/25/2022] Open
Abstract
Antibiotics-induced release of the pore-forming virulence factor pneumolysin (PLY) in patients with pneumococcal pneumonia results in its presence days after lungs are sterile and is a major factor responsible for the induction of permeability edema. Here we sought to identify major mechanisms mediating PLY-induced endothelial dysfunction. We evaluated PLY-induced endothelial hyperpermeability in human lung microvascular endothelial cells (HL-MVECs) and human lung pulmonary artery endothelial cells in vitro and in mice instilled intratracheally with PLY. PLY increases permeability in endothelial monolayers by reducing stable and dynamic microtubule content and modulating VE-cadherin expression. These events, dependent upon an increased calcium influx, are preceded by protein kinase C (PKC)-α activation, perturbation of the RhoA/Rac1 balance, and an increase in myosin light chain phosphorylation. At later time points, PLY treatment increases the expression and activity of arginase in HL-MVECs. Arginase inhibition abrogates and suppresses PLY-induced endothelial barrier dysfunction by restoring NO generation. Consequently, a specific PKC-α inhibitor and the TNF-derived tonoplast intrinsic protein peptide, which blunts PLY-induced PKC-α activation, are able to prevent activation of arginase in HL-MVECs and to reduce PLY-induced endothelial hyperpermeability in mice. Arginase I (AI)(+/-)/arginase II (AII)(-/-) C57BL/6 mice, displaying a significantly reduced arginase I expression in the lungs, are significantly less sensitive to PLY-induced capillary leak than their wild-type or AI(+/+)/AII(-/-) counterparts, indicating an important role for arginase I in PLY-induced endothelial hyperpermeability. These results identify PKC-α and arginase I as potential upstream and downstream therapeutic targets in PLY-induced pulmonary endothelial dysfunction.
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Affiliation(s)
- Rudolf Lucas
- Vascular Biology Center and Dept. of Pharmacology and Toxicology, Georgia Health Sciences University, 1459 Laney-Walker Blvd., Augusta, GA 30912-2500, USA.
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60
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Kolluru GK, Bir SC, Kevil CG. Endothelial dysfunction and diabetes: effects on angiogenesis, vascular remodeling, and wound healing. Int J Vasc Med 2012; 2012:918267. [PMID: 22611498 PMCID: PMC3348526 DOI: 10.1155/2012/918267] [Citation(s) in RCA: 319] [Impact Index Per Article: 26.6] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/17/2011] [Accepted: 10/18/2011] [Indexed: 02/06/2023] Open
Abstract
Diabetes mellitus (DM) is a chronic metabolic disorder characterized by inappropriate hyperglycemia due to lack of or resistance to insulin. Patients with DM are frequently afflicted with ischemic vascular disease or wound healing defect. It is well known that type 2 DM causes amplification of the atherosclerotic process, endothelial cell dysfunction, glycosylation of extracellular matrix proteins, and vascular denervation. These complications ultimately lead to impairment of neovascularization and diabetic wound healing. Therapeutic angiogenesis remains an attractive treatment modality for chronic ischemic disorders including PAD and/or diabetic wound healing. Many experimental studies have identified better approaches for diabetic cardiovascular complications, however, successful clinical translation has been limited possibly due to the narrow therapeutic targets of these agents or the lack of rigorous evaluation of pathology and therapeutic mechanisms in experimental models of disease. This paper discusses the current body of evidence identifying endothelial dysfunction and impaired angiogenesis during diabetes.
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Affiliation(s)
| | | | - Christopher G. Kevil
- Department of Pathology, LSU Health Sciences Center-Shreveport, 1501 Kings Highway, Shreveport, LA 71130, USA
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61
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Eryilmaz OG, Aksakal FN, Cicek N, Eyi EG, Avci A. L-arginine pathway in neonates with meconium-stained amniotic fluid. Eur J Obstet Gynecol Reprod Biol 2012; 161:26-9. [PMID: 22239939 DOI: 10.1016/j.ejogrb.2011.12.020] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/19/2011] [Revised: 11/13/2011] [Accepted: 12/18/2011] [Indexed: 11/19/2022]
Abstract
OBJECTIVE To study the arginase, nitric oxide synthase and nitric oxide pathways associated with passage of meconium. STUDY DESIGN Cord blood samples were collected from 20 newborns with meconium-stained amniotic fluid (MSAF) and from 23 newborns with clear amniotic fluid. Cord blood pH, arginase, nitric oxide synthase and nitric oxide levels were compared between the groups. RESULT The differences between the arginase and nitric oxide measurements of the newborns with MSAF and those with clear amniotic fluid were significant. In the MSAF group arginase levels were significantly lower (p=0.007) and nitric oxide levels were significantly higher (p=0.032) than the clear amniotic fluid group. CONCLUSION Hypoxia may be involved in the pathogenesis of meconium passage due to decreased arginase and increased nitric oxide levels.
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Affiliation(s)
- Ozlem Gun Eryilmaz
- Zekai Tahir Burak Women Education and Research Hospital, Obstetrics and Gynecology, Ankara, Turkey.
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62
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Romero MJ, Iddings JA, Platt DH, Ali MI, Cederbaum SD, Stepp DW, Caldwell RB, Caldwell RW. Diabetes-induced vascular dysfunction involves arginase I. Am J Physiol Heart Circ Physiol 2011; 302:H159-66. [PMID: 22058149 DOI: 10.1152/ajpheart.00774.2011] [Citation(s) in RCA: 67] [Impact Index Per Article: 5.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/12/2023]
Abstract
Arginase can cause vascular dysfunction by competing with nitric oxide synthase for l-arginine and by increasing cell proliferation and collagen formation, which promote vascular fibrosis/stiffening. We have shown that increased arginase expression/activity contribute to vascular endothelial cell (EC) dysfunction. Here, we examined the roles of the two arginase isoforms, arginase I and II (AI and AII, respectively), in this process. Experiments were performed using streptozotocin-induced diabetic mice: wild-type (WT) mice and knockout mice lacking the AII isoform alone (AI(+/+)AII(-/-)) or in combination with partial deletion of AI (AI(+/-)AII (-/-)). EC-dependent vasorelaxation of aortic rings and arterial fibrosis and stiffness were assessed in relation to arginase activity and expression. Diabetes reduced mean EC-dependent vasorelaxation markedly in diabetic WT and AI(+/+)AII(-/-) aortas (53% and 44% vs. controls, respectively) compared with a 27% decrease in AI(+/-)AII (-/-) vessels. Coronary fibrosis was also increased in diabetic WT and AI(+/+)AII(-/-) mice (1.9- and 1.7-fold vs. controls, respectively) but was not altered in AI(+/-)AII (-/-) diabetic mice. Carotid stiffness was increased by 142% in WT diabetic mice compared with 51% in AI(+/+)AII(-/-) mice and 19% in AI(+/-)AII (-/-) mice. In diabetic WT and AI(+/+)AII(-/-) mice, aortic arginase activity and AI expression were significantly increased compared with control mice, but neither parameter was altered in AI(+/-)AII (-/-) mice. In summary, AI(+/-)AII (-/-) mice exhibit better EC-dependent vasodilation and less vascular stiffness and coronary fibrosis compared with diabetic WT and AI(+/+)AII(-/-) mice. These data indicate a major involvement of AI in diabetes-induced vascular dysfunction.
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Affiliation(s)
- Maritza J Romero
- Department of Pharmacology and Toxicology, Georgia Health Sciences University, Augusta, 30912, USA
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63
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Fu H, Khan A, Coe D, Zaher S, Chai JG, Kropf P, Müller I, Larkin DFP, George AJT. Arginine depletion as a mechanism for the immune privilege of corneal allografts. Eur J Immunol 2011; 41:2997-3005. [PMID: 21805470 PMCID: PMC3378701 DOI: 10.1002/eji.201141683] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/18/2011] [Revised: 06/20/2011] [Accepted: 07/20/2011] [Indexed: 12/11/2022]
Abstract
The cornea is an immune privileged tissue. Since arginase has been found to modulate T-cell function by depleting arginine, we investigated the expression of arginase in the cornea and its possible role in immune privilege using a murine transplant model. We found that both the endothelium and epithelium of murine corneas express functional arginase I, capable of down-regulating T-cell proliferation in an in vitro culture system. The administration of the specific arginase inhibitor N-hydroxy-nor-L-Arg to recipient mice resulted in an accelerated rejection of allogeneic C57BL/6 (B6) corneal grafts. In contrast, in vivo blockade of arginase activity had no effect in altering the course of rejection of primary skin grafts that express little, if any, arginase. In addition, the inhibition of arginase did not alter systemic T-cell proliferation. These data show that arginase is functional in the cornea and contributes to the immune privilege of the eye, and that modulation of arginase contributes to graft survival.
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Affiliation(s)
- Hongmei Fu
- Section of Immunobiology, Faculty of Medicine, Imperial College London, Hammersmith Hospital, London, UK
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64
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Prati C, Berthelot A, Wendling D, Demougeot C. Endothelial dysfunction in rat adjuvant-induced arthritis: Up-regulation of the vascular arginase pathway. ACTA ACUST UNITED AC 2011; 63:2309-17. [DOI: 10.1002/art.30391] [Citation(s) in RCA: 25] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022]
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65
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Shin W, Cuong TD, Lee JH, Min B, Jeon BH, Lim HK, Ryoo S. Arginase Inhibition by Ethylacetate Extract of Caesalpinia sappan Lignum Contributes to Activation of Endothelial Nitric Oxide Synthase. THE KOREAN JOURNAL OF PHYSIOLOGY & PHARMACOLOGY : OFFICIAL JOURNAL OF THE KOREAN PHYSIOLOGICAL SOCIETY AND THE KOREAN SOCIETY OF PHARMACOLOGY 2011; 15:123-8. [PMID: 21860589 DOI: 10.4196/kjpp.2011.15.3.123] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/05/2011] [Revised: 05/16/2011] [Accepted: 05/30/2011] [Indexed: 01/05/2023]
Abstract
Caesalpinia sappan (C. sappan) is a medicinal plant used for promoting blood circulation and removing stasis. During a screening procedure on medicinal plants, the ethylacetate extract of the lignum of C. sappan (CLE) showed inhibitory activity on arginase which has recently been reported as a novel therapeutic target for the treatment of cardiovascular diseases such as atherosclerosis. CLE inhibited arginase II activity prepared from kidney lysate in a dose-dependent manner. In HUVECs, inhibition of arginase activity by CLE reciprocally increased NOx production through enhancement of eNOS dimer stability without any significant changes in the protein levels of eNOS and arginase II expression. Furthermore, CLE-dependent arginase inhibition resulted in increase of NO generation and decrease of superoxide production on endothelium of isolated mice aorta. These results indicate that CLE augments NO production on endothelium through inhibition of arginase activity, and may imply their usefulness for the treatment of cardiovascular diseases associated with endothelial dysfunction.
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Affiliation(s)
- Woosung Shin
- Department of Biology, Kangwon National University, Chuncheon 200-701, Korea
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66
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Jiang J, George SC. TGF-β2 reduces nitric oxide synthase mRNA through a ROCK-dependent pathway in airway epithelial cells. Am J Physiol Lung Cell Mol Physiol 2011; 301:L361-7. [PMID: 21685242 DOI: 10.1152/ajplung.00464.2010] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/15/2023] Open
Abstract
Exhaled NO (eNO) is a potential noninvasive biomarker of inflammation in asthma. The significant intersubject variability of eNO within clinically similar patients has contributed to its limited clinical application. Arginase and NO synthase (NOS) utilize the same substrate (l-arginine) and contribute to the fibrotic and inflammatory features of asthma, respectively. Interestingly, TGF-β(2) can increase the expression of arginase, stimulates fibrosis, and is overexpressed in asthma. We hypothesized that TGF-β(2)-enhanced arginase activity would decrease gas phase NO release from lung epithelial cells by limiting l-arginine availability for NOS. Our results show that TGF-β(2) (5 ng/ml) significantly enhances total arginase activity up to two- to threefold in both primary small airway epithelial cells (SAECs) and the A549 cell line. Preincubation with TGF-β(2) prior to cytokine (IL-1β, TNF-α, and IFN-γ, 10 ng/ml each) stimulation decreases gas phase NO release to baseline levels (from 1.66 ± 0.52 to 0.30 ± 0.12 pl·s(-1)·cm(-2) and from 0.27 ± 0.03 pl·s(-1)·cm(-2) to near zero in SAEC and A549 cells, respectively). Addition of arginase inhibitor (N(ω)-hydroxy-nor-l-arginine) or small interfering RNA only partly reverses the reduction. In contrast, Rho-kinase (ROCK) pathway inhibitor (Y-27632) completely recovers the cytokine-induced NO flux in the present of TGF-β(2). Inducible NO synthase (iNOS) mRNA and protein levels change in a similar trend as NO release from the cells. We conclude that TGF-β(2) impacts cytokine-induced NO production in airway epithelial cells by reducing iNOS mRNA and protein levels through a ROCK-dependent pathway.
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Affiliation(s)
- Jingjing Jiang
- Dept. of Biomedical Engineering, 2420 Engineering Hall, Univ. of California, Irvine, Irvine, CA 92697-2730, USA
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67
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Jiang J, George SC. Modeling gas phase nitric oxide release in lung epithelial cells. Nitric Oxide 2011; 25:275-81. [PMID: 21550413 DOI: 10.1016/j.niox.2011.04.010] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/26/2011] [Revised: 04/21/2011] [Accepted: 04/23/2011] [Indexed: 10/18/2022]
Abstract
Nitric oxide (NO) is present in exhaled breath and is generally considered to be a noninvasive marker of airway inflammation, and is thus of particular relevance to monitoring asthma. NO is produced when L-arginine is converted to L-citrulline by NO synthase (NOS); however, L-arginine is also the substrate for arginase and both enzymes are upregulated in asthma. Recent reports have speculated that enhanced expression of one or both enzymes could lead to a limitation in substrate availability, and hence impact downstream targets or markers such as exhaled NO. The non-linear nature and vastly different kinetics of the enzymes make predictions difficult, particularly over the wide range of enzyme activity between baseline and inflammation. In this study, we developed a steady state model of L-arginine transmembrane transport, NO production, diffusion, and gas phase NO release from lung epithelial cells. We validated our model with experimental results of gas phase NO release and intracellular l-arginine concentration in A549 cells, and then performed a sensitivity analysis to determine relative impact of each enzyme on NO production. Our model predicts intracellular L-arginine and gas phase NO release over a wide range of initial extracellular L-arginine concentrations following stimulation with cytomix (10ng/ml TNF-α, IL-1β, and INF-γ). Relative sensitivity analysis demonstrates that enhanced arginase activity has little impact on l-arginine bioavailability for NOS. In addition, NOS activity is the dominant parameter which impacts gas phase NO release.
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Affiliation(s)
- Jingjing Jiang
- Department of Biomedical Engineering, University of California, Irvine, CA 92697, USA
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68
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Wang W, Hein TW, Zhang C, Zawieja DC, Liao JC, Kuo L. Oxidized low-density lipoprotein inhibits nitric oxide-mediated coronary arteriolar dilation by up-regulating endothelial arginase I. Microcirculation 2011; 18:36-45. [PMID: 21166924 DOI: 10.1111/j.1549-8719.2010.00066.x] [Citation(s) in RCA: 34] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/03/2023]
Abstract
Oxidized low-density lipoprotein (OxLDL) causes impairment of endothelium-dependent, nitric oxide (NO)-mediated vasodilation involving l-arginine deficiency. However, the underlying mechanism remains elusive. Since arginase and endothelial NO synthase (eNOS) share the substrate l-arginine, we hypothesized that OxLDL may reduce l-arginine availability to eNOS for NO production, and thus vasodilation, by up-regulating arginase. To test this hypothesis, porcine subepicardial arterioles (70-130 μm) were isolated for vasomotor study and for immunohistochemical detection of arginase and eNOS expressions. The coronary arterioles dilated dose-dependently to the endothelium-dependent NO-mediated vasodilator serotonin. This vasodilation was inhibited in the same manner by NOS inhibitor N(G)-nitro-l-arginine methyl ester and by lumenal OxLDL (0.5 mg protein/mL). The inhibitory effect of OxLDL was reversed after treating the vessels with either l-arginine (3 mM) or arginase inhibitor difluoromethylornithine (DFMO; 0.4 mM). Consistent with vasomotor alterations, OxLDL inhibited serotonin-induced NO release from coronary arterioles and this inhibition was reversed by DFMO. Vascular arginase activity was significantly elevated by OxLDL. Immunohistochemical analysis indicated that OxLDL increased arginase I expression in the vascular wall without altering eNOS expression. Taken together, these results suggest that OxLDL up-regulates arginase I, which contributes to endothelial dysfunction by reducing l-arginine availability to eNOS for NO production and thus vasodilation.
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Affiliation(s)
- Wei Wang
- Department of Systems Biology and Translational Medicine, College of Medicine, Texas A&M Health Science Center, Temple, Texas 76504, USA
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69
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Chicoine LG, Chicione LG, Stenger MR, Cui H, Calvert A, Evans RJ, English BK, Liu Y, Nelin LD. Nitric oxide suppression of cellular proliferation depends on cationic amino acid transporter activity in cytokine-stimulated pulmonary endothelial cells. Am J Physiol Lung Cell Mol Physiol 2011; 300:L596-604. [PMID: 21239536 DOI: 10.1152/ajplung.00029.2010] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022] Open
Abstract
Inducible nitric oxide (NO) synthase (iNOS) is a stress response protein upregulated in inflammatory conditions, and NO may suppress cellular proliferation. We hypothesized that preventing L-arginine (L-arg) uptake in endothelial cells would prevent lipopolysaccharide/tumor necrosis factor-α (LPS/TNF)-induced, NO-mediated suppression of cellular proliferation. Bovine pulmonary arterial endothelial cells (bPAEC) were treated with LPS/TNF or vehicle (control), and either 10 mM L-leucine [L-leu; a competitive inhibitor of L-arg uptake by the cationic amino acid transporter (CAT)] or its vehicle. In parallel experiments, iNOS or arginase II were overexpressed in bPAEC using an adenoviral vector (AdiNOS or AdArgII, respectively). LPS/TNF treatment increased the expression of iNOS, arginase II, CAT-1, and CAT-2 mRNA in bPAEC, resulting in greater NO and urea production than in control bPAEC, which was prevented by L-leu. LPS/TNF treatment resulted in fewer viable cells than in controls, and LPS/TNF-stimulated bPAEC treated with L-leu had more viable cells than LPS/TNF treatment alone. LPS/TNF treatment resulted in cleaved caspase-3 and cleaved poly(ADP-ribose) polymerase expression, which was attenuated by L-leu. AdiNOS reduced viable cell number, and treatment of AdiNOS transfected bPAEC with L-leu preserved cell number. AdArgII increased viable cell number, and treatment of AdArgII transfected bPAEC with L-leu prevented the increase in cell number. These data demonstrate that iNOS expression in pulmonary endothelial cells leads to decreased cellular proliferation, which can be attenuated by preventing cellular L-arg uptake. We speculate that CAT activity may represent a novel therapeutic target in inflammatory lung diseases characterized by NO overproduction.
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Affiliation(s)
- Louis G Chicoine
- Department of Pediatrics, The Ohio State University, Columbus, Ohio, USA
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70
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Sahin G, Klimek L, Mullol J, Hörmann K, Walther L, Pfaar O. Nitric Oxide: A Promising Methodological Approach in Airway Diseases. Int Arch Allergy Immunol 2011; 156:352-61. [DOI: 10.1159/000324678] [Citation(s) in RCA: 22] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/19/2022] Open
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71
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Woo A, Min B, Ryoo S. Piceatannol-3'-O-beta-D-glucopyranoside as an active component of rhubarb activates endothelial nitric oxide synthase through inhibition of arginase activity. Exp Mol Med 2010; 42:524-32. [PMID: 20543547 DOI: 10.3858/emm.2010.42.7.053] [Citation(s) in RCA: 34] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/19/2023] Open
Abstract
Arginase competitively inhibits nitric oxide synthase (NOS) via use of the common substrate L-arginine. Arginase II has recently reported as a novel therapeutic target for the treatment of cardiovascular diseases such as atherosclerosis. Here, we demonstrate that piceatannol-3'-O-beta-D-glucopyranoside (PG), a potent component of stilbenes, inhibits the activity of arginase I and II prepared from mouse liver and kidney lysates, respectively, in a dose-dependent manner. In human umbilical vein endothelial cells, incubation of PG markedly blocked arginase activity and increased NOx production, as measured by Griess assay. The PG effect was associated with increase of eNOS dimer ratio, although the protein levels of arginase II or eNOS were not changed. Furthermore, isolated mice aortic rings treated with PG showed inhibited arginase activity that resulted in increased nitric oxide (NO) production upto 78%, as measured using 4-amino-5-methylamino-2',7'-difluorescein (DAF-FM) and a decreased superoxide anions up to 63%, as measured using dihydroethidine (DHE) in the intact endothelium. PG showed IC((50)) value of 11.22 microM and 11.06 microM against arginase I and II, respectively. PG as an arginase inhibitor, therefore, represents a novel molecule for the therapy of cardiovascular diseases derived from endothelial dysfunction and may be used for the design of pharmaceutical compounds.
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Affiliation(s)
- Ainieng Woo
- Department of Biology, College of Natural Sciences, Kangwon National University, Chuncheon 200-701, Korea
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72
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Ryoo S, Bhunia A, Chang F, Shoukas A, Berkowitz DE, Romer LH. OxLDL-dependent activation of arginase II is dependent on the LOX-1 receptor and downstream RhoA signaling. Atherosclerosis 2010; 214:279-87. [PMID: 21130456 DOI: 10.1016/j.atherosclerosis.2010.10.044] [Citation(s) in RCA: 92] [Impact Index Per Article: 6.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/09/2010] [Revised: 10/17/2010] [Accepted: 10/27/2010] [Indexed: 01/01/2023]
Abstract
AIMS Arginase II regulates NOS activity by competing for the substrate l-arginine. Oxidized LDL (OxLDL) is a proatherogenic molecule that activates arginase II. We tested the hypotheses that OxLDL-dependent arginase II activation occurs through a specific receptor, and via a Rho GTPase effector mechanism that is inhibited by statins. METHODS AND RESULTS Arginase II activation by OxLDL was attenuated following preincubation with the LOX-1 receptor-blocking antibody JTX92. This also prevented the dissociation of arginase II from microtubules. LOX-1(-/-) mice failed to exhibit the increased arginase II activity seen in WT mice fed a high cholesterol diet. Furthermore, endothelium from LOX-1(-/-) mice failed to demonstrate the diet-dependent reduction in NO and increase in ROS that were observed in WT mice. OxLDL induced Rho translocation to the membrane and Rho activation, and these effects were inhibited by pretreatment with JTX92 or statins. Transfection with siRNA for RhoA, or inhibition of ROCK both decreased OxLDL-stimulated arginase II activation. Preincubation with simvastatin or lovastatin blocked OxLDL-induced dissociation of arginase II from microtubules and prevented microtubule depolymerization. CONCLUSIONS This study provides a new focus for preventive therapy for atherosclerotic disease by delineating a clearer path from OxLDL through the endothelial cell LOX-1 receptor, RhoA, and ROCK, to the activation of arginase II, downregulation of NO, and vascular dysfunction.
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Affiliation(s)
- Sungwoo Ryoo
- Department of Anesthesiology and Critical Care Medicine, The Johns Hopkins Medical Institutions, Baltimore, MD 21287-4904, United States
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73
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Toque HA, Tostes RC, Yao L, Xu Z, Webb RC, Caldwell RB, Caldwell RW. Arginase II deletion increases corpora cavernosa relaxation in diabetic mice. J Sex Med 2010; 8:722-33. [PMID: 21054801 DOI: 10.1111/j.1743-6109.2010.02098.x] [Citation(s) in RCA: 48] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
INTRODUCTION Diabetes-induced erectile dysfunction involves elevated arginase (Arg) activity and expression. Because nitric oxide (NO) synthase and Arg share and compete for their substrate L-arginine, NO production is likely linked to regulation of Arg. Arg is highly expressed and implicated in erectile dysfunction. AIM It was hypothesized that Arg-II isoform deletion enhances relaxation function of corpora cavernosal (CC) smooth muscle in a streptozotocin (STZ) diabetic model. METHODS Eight weeks after STZ-induced diabetes, vascular functional studies, Arg activity assay, and protein expression levels of Arg and constitutive NOS (using Western blots) were assessed in CC tissues from nondiabetic wild type (WT), diabetic (D) WT (WT + D), Arg-II knockout (KO), and Arg-II KO+D mice (N = 8-10 per group). MAIN OUTCOME MEASURES Inhibition or lack of arginase results in facilitation of CC relaxation in diabetic CC. RESULTS Strips of CC from Arg-II KO mice exhibited an enhanced maximum endothelium-dependent relaxation (from 70 + 3% to 84 + 4%) and increased nitrergic relaxation (by 55%, 71%, 42%, 42%, and 24% for 1, 2, 4, 8 and 16 Hz, respectively) compared with WT mice. WT + D mice showed a significant reduction of endothelium-dependent maximum relaxation (44 + 8%), but this impairment of relaxation was significantly prevented in Arg-II KO+D mice (69 + 4%). Sympathetic-mediated and alpha-adrenergic agent-induced contractile responses also were increased in CC strips from D compared with non-D controls. Contractile responses were significantly lower in Arg-II KO control and D versus the WT groups. WT + D mice increased Arg activity (1.5-fold) and Arg-II protein expression and decreased total and phospho-eNOS at Ser-1177, and nNOS levels. These alterations were not seen in Arg-II KO mice. Additionally, the Arg inhibitor BEC (50 µM) enhanced nitrergic and endothelium-dependent relaxation in CC of WT + D mice. CONCLUSION These studies show for the first time that Arg-II deletion improves CC relaxation in type 1 diabetes.
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Affiliation(s)
- Haroldo A Toque
- Medical College of Georgia, Department of Pharmacology and Toxicology, Augusta, GA 30912-2300, USA.
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Vascular arginase contributes to arteriolar endothelial dysfunction in a rat model of hemorrhagic shock. ACTA ACUST UNITED AC 2010; 69:384-91. [PMID: 20699748 DOI: 10.1097/ta.0b013e3181e771a3] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/20/2022]
Abstract
BACKGROUND Hemorrhagic shock causes hypoperfusion of peripheral tissues and promotes endothelial dysfunction, which may lead to further tissue injury. Trauma increases extrahepatic activity of arginase, an enzyme which competes for l-arginine with nitric oxide synthase, and plays a key role in the development of endothelial dysfunction during aging, hypertension, and diabetes. However, the role of arginase in hemorrhage-induced endothelial dysfunction has not been studied. This study tests the hypothesis that arginase inhibition improves endothelial function after hemorrhage. METHODS Male Sprague-Dawley rats were implanted with indwelling arterial catheters for blood pressure measurements and blood removal. Awake animals were subjected to a 45% fixed volume controlled hemorrhage and blood pressure was monitored. Unbled rats served as controls. Skeletal muscle arterioles were isolated 24 hours after hemorrhage and cannulated in a pressure myograph system. To study endothelial function, arterioles were exposed to constant midpoint, but altered endpoint pressures, to establish graded levels of luminal flow and internal diameter was measured. RESULTS Hemorrhage lowered mean arterial pressure that spontaneously recovered to 78% and 88% of baseline in 2 hours and 20 hours, respectively. Vascular arginase II and blood glucose levels were elevated, whereas hemoglobin and insulin levels were decreased 24 hours after blood loss. In posthemorrhage arterioles, flow-induced dilation was abolished. Acute in vitro treatment with an inhibitor of arginase, N-hydroxy-nor-l-arginine, restored flow-induced dilation to unbled control levels. Similarly, the arginase and nitric oxide synthase substrate, l-arginine, but not the inactive isomer, d-arginine, restored flow-induced dilation. CONCLUSIONS These results indicate that arginase contributes to endothelial dysfunction in resistance vessels after significant hemorrhage.
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Eleftheriadis T, Liakopoulos V, Antoniadi G, Stefanidis I, Galaktidou G. Arginase type I as a marker of coronary heart disease in hemodialysis patients. Int Urol Nephrol 2010; 43:1187-94. [DOI: 10.1007/s11255-010-9842-4] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/25/2010] [Accepted: 08/27/2010] [Indexed: 11/24/2022]
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Jin Y, Calvert TJ, Chen B, Chicoine LG, Joshi M, Bauer JA, Liu Y, Nelin LD. Mice deficient in Mkp-1 develop more severe pulmonary hypertension and greater lung protein levels of arginase in response to chronic hypoxia. Am J Physiol Heart Circ Physiol 2010; 298:H1518-28. [PMID: 20173047 DOI: 10.1152/ajpheart.00813.2009] [Citation(s) in RCA: 39] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/21/2022]
Abstract
The mitogen-activated protein (MAP) kinases are involved in cellular responses to many stimuli, including hypoxia. MAP kinase signaling is regulated by a family of phosphatases that include MAP kinase phosphatase-1 (MKP-1). We hypothesized that mice lacking the Mkp-1 gene would have exaggerated chronic hypoxia-induced pulmonary hypertension. Wild-type (WT) and Mkp-1(-/-) mice were exposed to either 4 wk of normoxia or hypobaric hypoxia. Following chronic hypoxia, both genotypes demonstrated elevated right ventricular pressures, right ventricular hypertrophy as demonstrated by the ratio of the right ventricle to the left ventricle plus septum weights [RV(LV + S)], and greater vascular remodeling. However, the right ventricular systolic pressures, the RV/(LV + S), and the medial wall thickness of 100- to 300-microm vessels was significantly greater in the Mkp-1(-/-) mice than in the WT mice following 4 wk of hypobaric hypoxia. Chronic hypoxic exposure caused no detectable change in eNOS protein levels in the lungs in either genotype; however, Mkp-1(-/-) mice had lower levels of eNOS protein and lower lung NO production than did WT mice. No iNOS protein was detected in the lungs by Western blotting in any condition in either genotype. Both arginase I and arginase II protein levels were greater in the lungs of hypoxic Mkp-1(-/-) mice than those in hypoxic WT mice. Lung levels of proliferating cell nuclear antigen were greater in hypoxic Mkp-1(-/-) than in hypoxic WT mice. These data are consistent with the concept that MKP-1 acts to restrain hypoxia-induced arginase expression and thereby reduces vascular remodeling and the severity of pulmonary hypertension.
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Affiliation(s)
- Yi Jin
- The Research Institute at Nationwide Children's Hospital, 700 Children's Drive, Columbus, OH 43205, USA
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Toby IT, Chicoine LG, Cui H, Chen B, Nelin LD. Hypoxia-induced proliferation of human pulmonary microvascular endothelial cells depends on epidermal growth factor receptor tyrosine kinase activation. Am J Physiol Lung Cell Mol Physiol 2010; 298:L600-6. [PMID: 20139181 DOI: 10.1152/ajplung.00122.2009] [Citation(s) in RCA: 44] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022] Open
Abstract
We hypothesized that hypoxia would activate epidermal growth factor receptor (EGFR) tyrosine kinase, leading to increased arginase expression and resulting in proliferation of human pulmonary microvascular endothelial cell (hPMVEC). To test this hypothesis, hPMVEC were incubated in normoxia (20% O(2), 5% CO(2)) or hypoxia (1% O(2), 5% CO(2)). Immunoblotting for EGFR and proliferating cell nuclear antigen was done, and protein levels of both total EGFR and proliferating cell nuclear antigen were greater in hypoxic hPMVEC than in normoxic hPMVEC. Furthermore, hypoxic hPMVEC had greater levels of EGFR activity than did normoxic hPMVEC. Hypoxic hPMVEC had a twofold greater level of proliferation compared with normoxic controls, and this increase in proliferation was prevented by the addition of AG-1478 (a pharmacological inhibitor of EGFR). Immunoblotting for arginase I and arginase II demonstrated a threefold induction in arginase II protein levels in hypoxia, with little change in arginase I protein levels. The hypoxic induction of arginase II protein was prevented by treatment with AG-1478. Proliferation assays were performed in the presence of arginase inhibitors, and hypoxia-induced proliferation was also prevented by arginase inhibition. Finally, treatment with an EGFR small interfering RNA prevented hypoxia-induced proliferation and urea production. These findings demonstrate that hypoxia activates EGFR tyrosine kinase, leading to arginase expression and thereby promoting proliferation in hPMVEC.
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Affiliation(s)
- Inimary T Toby
- Pulmonary Hypertension Group, Center for Perinatal Research, Research Institute at Nationwide Children's Hospital, and Department of Pediatrics, Ohio State University, Columbus, Ohio, USA
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Moss MB, Siqueira MA, Mann GE, Brunini TMC, Mendes-Ribeiro AC. Platelet aggregation in arterial hypertension: Is there a nitric oxide-urea connection? Clin Exp Pharmacol Physiol 2010; 37:167-72. [DOI: 10.1111/j.1440-1681.2009.05247.x] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/27/2022]
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79
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Chen B, Calvert AE, Cui H, Nelin LD. Hypoxia promotes human pulmonary artery smooth muscle cell proliferation through induction of arginase. Am J Physiol Lung Cell Mol Physiol 2009; 297:L1151-9. [PMID: 19801451 DOI: 10.1152/ajplung.00183.2009] [Citation(s) in RCA: 72] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022] Open
Abstract
Vascular remodeling and smooth muscle cell proliferation are hallmark pathogenic features of pulmonary artery hypertension (PAH). Alterations in the metabolism of l-arginine via arginase and nitric oxide synthase play a critical role in the endothelial dysfunction seen in PAH. l-arginine metabolism by arginase produces l-ornithine and urea. l-ornithine is a precursor for polyamine and proline synthesis, ultimately leading to an increase in cellular proliferation. Given the integral role of the smooth muscle layer in the pathogenesis of hypoxia-induced PAH, we hypothesized that hypoxia would increase cellular proliferation via arginase induction in human pulmonary artery smooth muscle cells (hPASMC). We found that arginase II mRNA and protein expression were significantly increased in cultured hPASMC exposed to 1% O(2) for 24 and 48 h, which coincided with an increase in arginase activity at 48 h. There were no hypoxia-induced changes in levels of arginase I mRNA or protein in cultured hPASMC. Exposure to hypoxia resulted in more than one and a half times as many viable cells after 120 h than normoxic exposure. The addition of the arginase inhibitor, S-(2-boronoethyl)-l-cysteine, completely prevented both the hypoxia-induced increase in arginase activity and proliferation in hPASMC. Furthermore, transfection of small interfering RNA (siRNA) targeting arginase II in hPASMC resulted in knockdown of arginase II protein levels and complete prevention of the hypoxia-induced cellular proliferation. These data support our hypothesis that hypoxia increases proliferation of hPASMC through the induction of arginase II.
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Affiliation(s)
- Bernadette Chen
- Center for Perinatal Research, The Research Institute at Nationwide Children's Hospital, Department of Pediatrics, The Ohio State University College of Medicine, Columbus, USA.
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Kim JH, Bugaj LJ, Oh YJ, Bivalacqua TJ, Ryoo S, Soucy KG, Santhanam L, Webb A, Camara A, Sikka G, Nyhan D, Shoukas AA, Ilies M, Christianson DW, Champion HC, Berkowitz DE. Arginase inhibition restores NOS coupling and reverses endothelial dysfunction and vascular stiffness in old rats. J Appl Physiol (1985) 2009; 107:1249-57. [PMID: 19661445 PMCID: PMC2763842 DOI: 10.1152/japplphysiol.91393.2008] [Citation(s) in RCA: 188] [Impact Index Per Article: 12.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/17/2008] [Accepted: 07/28/2009] [Indexed: 01/01/2023] Open
Abstract
There is increasing evidence that upregulation of arginase contributes to impaired endothelial function in aging. In this study, we demonstrate that arginase upregulation leads to endothelial nitric oxide synthase (eNOS) uncoupling and that in vivo chronic inhibition of arginase restores nitroso-redox balance, improves endothelial function, and increases vascular compliance in old rats. Arginase activity in old rats was significantly increased compared with that shown in young rats. Old rats had significantly lower nitric oxide (NO) and higher superoxide (O2(-)) production than young. Acute inhibition of both NOS, with N(G)-nitro-l-arginine methyl ester, and arginase, with 2S-amino- 6-boronohexanoic acid (ABH), significantly reduced O2(-) production in old rats but not in young. In addition, the ratio of eNOS dimer to monomer in old rats was significantly decreased compared with that shown in young rats. These results suggest that eNOS was uncoupled in old rats. Although the expression of arginase 1 and eNOS was similar in young and old rats, inducible NOS (iNOS) was significantly upregulated. Furthermore, S-nitrosylation of arginase 1 was significantly elevated in old rats. These findings support our previously published finding that iNOS nitrosylates and activates arginase 1 (Santhanam et al., Circ Res 101: 692-702, 2007). Chronic arginase inhibition in old rats preserved eNOS dimer-to-monomer ratio and significantly reduced O2(-) production and enhanced endothelial-dependent vasorelaxation to ACh. In addition, ABH significantly reduced vascular stiffness in old rats. These data indicate that iNOS-dependent S-nitrosylation of arginase 1 and the increase in arginase activity lead to eNOS uncoupling, contributing to the nitroso-redox imbalance, endothelial dysfunction, and vascular stiffness observed in vascular aging. We suggest that arginase is a viable target for therapy in age-dependent vascular stiffness.
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Affiliation(s)
- Jae Hyung Kim
- Anesthesiology, Tower 711, Johns Hopkins Hospital, 600 N. Wolfe St., Baltimore, MD 21287, USA
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81
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Vascular dysfunction in retinopathy-an emerging role for arginase. Brain Res Bull 2009; 81:303-9. [PMID: 19737603 DOI: 10.1016/j.brainresbull.2009.08.025] [Citation(s) in RCA: 33] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/16/2009] [Revised: 07/23/2009] [Accepted: 08/30/2009] [Indexed: 12/29/2022]
Abstract
Retinal neovascularization is a leading cause of visual disability. Retinal diseases involving neovascularization all follow the same progression, beginning with vascular inflammatory reactions and injury of the vascular endothelium and ending with neovascularization, fibrosis and retinal detachment. Understanding the mechanisms underlying this process is critical for its prevention and treatment. Research using retinopathy models has revealed that the NOX2 NADPH oxidase has a key role in inducing production of reactive oxygen species and angiogenic cytokines and causing vascular inflammatory reactions and neovascularization. This prospective review addresses the potential role of the urea/ornithine pathway enzyme arginase in this process. Studies of peripheral vessels isolated from diabetic animals have shown that increased arginase activity causes vascular endothelial cell dysfunction by decreasing availability of l-arginine to endothelial cell nitric oxide synthase which decreases nitric oxide bioavailability and increases oxidative stress. Increasing arginase activity also increases formation of polyamines and proline, which can induce cell growth and fibrosis. Studies in models of retinopathy show that increases in oxidative stress and signs of vascular inflammation are correlated with increases in arginase activity and arginase 1 expression and that decreasing arginase expression or inhibiting its activity blocks these effects. Furthermore, the induction of arginase during retinopathy is blocked by knocking out NOX2 or inhibiting NADPH oxidase activity. These observations suggest that NADPH oxidase-induced activation of the arginase pathway has a key role in causing retinal vascular dysfunction during retinopathy. Limiting the actions of arginase could provide a new strategy for treating this potentially blinding condition.
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Scalera F, Closs EI, Flick E, Martens-Lobenhoffer J, Boissel JP, Lendeckel U, Heimburg A, Bode-Böger SM. Paradoxical effect of l-arginine: Acceleration of endothelial cell senescence. Biochem Biophys Res Commun 2009; 386:650-5. [DOI: 10.1016/j.bbrc.2009.06.091] [Citation(s) in RCA: 30] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/16/2009] [Accepted: 06/17/2009] [Indexed: 02/05/2023]
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Huynh NN, Andrews KL, Head GA, Khong SML, Mayorov DN, Murphy AJ, Lambert G, Kiriazis H, Xu Q, Du XJ, Chin-Dusting JPF. Arginase II knockout mouse displays a hypertensive phenotype despite a decreased vasoconstrictory profile. Hypertension 2009; 54:294-301. [PMID: 19546381 DOI: 10.1161/hypertensionaha.108.121731] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
Arginase upregulation is associated with aging and cardiovascular diseases. In this study we report on the cardiovascular phenotype of the arginase II knockout (KO) mouse. We demonstrate that vascular sensitivity and reactivity altered over time in these animals such that no influence on responses to vasoconstrictor activity was observed in 7-week-old KO mice, but dampened responses to norepinephrine and phenylephrine were observed by 10 and 15 weeks with Rho kinase influencing these effects in the 15-week-old animals. Despite these dampened vasoconstrictory responses, KO mice demonstrated increased mean arterial pressure from 8 weeks old. This hypertensive phenotype was associated with an increase in left ventricular weight, left ventricular systolic pressure, and diminished diastolic function. KO mice also show enhanced plasma norepinephrine turnover, suggesting an increased sympathetic outflow. In conclusion, our data suggest that global loss of arginase II activity results in hypertension. We suggest that this strain of mouse warrants further investigation as a potentially novel model of hypertension.
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Affiliation(s)
- Ngan N Huynh
- Vascular Pharmacology, Baker IDI Heart and Diabetes Institute, PO Box 6492 St Kilda Rd Central, Victoria, 8008 Australia
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Morris SM. Recent advances in arginine metabolism: roles and regulation of the arginases. Br J Pharmacol 2009; 157:922-30. [PMID: 19508396 DOI: 10.1111/j.1476-5381.2009.00278.x] [Citation(s) in RCA: 343] [Impact Index Per Article: 22.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022] Open
Abstract
As arginine can serve as precursor to a wide range of compounds, including nitric oxide, creatine, urea, polyamines, proline, glutamate and agmatine, there is considerable interest in elucidating mechanisms underlying regulation of its metabolism. It is now becoming apparent that the two isoforms of arginase in mammals play key roles in regulation of most aspects of arginine metabolism in health and disease. In particular, work over the past several years has focused on the roles and regulation of the arginases in vascular disease, pulmonary disease, infectious disease, immune cell function and cancer. As most of these topics have been considered in recent review articles, this review will focus more closely on results of recent studies on expression of the arginases in endothelial and vascular smooth muscle cells, post-translational modulation of arginase activity and applications of arginase inhibitors in vivo.
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Affiliation(s)
- Sidney M Morris
- Department of Microbiology and Molecular Genetics, University of Pittsburgh, Pittsburgh, PA 15261, USA.
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85
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Huynh NN, Harris EE, Chin-Dusting JFP, Andrews KL. The vascular effects of different arginase inhibitors in rat isolated aorta and mesenteric arteries. Br J Pharmacol 2009; 156:84-93. [PMID: 19133993 DOI: 10.1111/j.1476-5381.2008.00036.x] [Citation(s) in RCA: 31] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022] Open
Abstract
BACKGROUND AND PURPOSE Arginase and nitric oxide (NO) synthase share the common substrate L-arginine, and arginase inhibition is proposed to increase NO production by increasing intracellular levels of L-arginine. Many different inhibitors are used, and here we have examined the effects of these inhibitors on vascular tissue. EXPERIMENTAL APPROACH Each arginase inhibitor was assessed by its effects on isolated rings of aorta and mesenteric arteries from rats by: (i) their ability to preserve the tolerance to repeated applications of the endothelium-dependent agonist acetylcholine (ACh); and (ii) their direct vasorelaxant effect. KEY RESULTS In both vessel types, tolerance (defined as a reduced response upon second application) to ACh was reversed with addition of L-arginine, (S)-(2-boronethyl)-L-cysteine HCl (BEC) or N(G)-Hydroxy-L-arginine (L-NOHA). On the other hand, N(omega)-hydroxy-nor-L-arginine (nor-NOHA) significantly augmented the response to ACh, an effect that was partially reversed with L-arginine. No effect on tolerance to ACh was observed with L-valine, nor-valine or D,L, alpha-difluoromethylornithine (DFMO). BEC, L-NOHA and nor-NOHA elicited endothelium-independent vasorelaxation in both endothelium intact and denuded aorta while L-valine, DFMO and nor-valine did not. CONCLUSIONS AND IMPLICATIONS BEC and L-NOHA, but not nor-NOHA, L-valine, DFMO or nor-valine, significantly reversed tolerance to ACh possibly conserving L-arginine levels and therefore increasing NO bioavailability. However, both BEC and L-NOHA caused endothelium-independent vasorelaxation in rat aorta, suggesting that these inhibitors have a role beyond arginase inhibition alone. Our data thus questions the interpretation of many studies using these antagonists as specific arginase inhibitors in the vasculature, without verification with other methods.
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Affiliation(s)
- N N Huynh
- Vascular Pharmacology Laboratory, Baker IDI Heart and Diabetes Institute, Melbourne, Vic., Australia
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86
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Bagnost T, André C, Thomassin M, Berthelot A, Demougeot C, Guillaume YC. A molecular chromatographic approach to analyze the cell diffusion of arginase inhibitors. J Chromatogr B Analyt Technol Biomed Life Sci 2009; 877:1599-602. [PMID: 19375985 DOI: 10.1016/j.jchromb.2009.03.032] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/07/2009] [Revised: 03/20/2009] [Accepted: 03/21/2009] [Indexed: 11/15/2022]
Abstract
Our group demonstrated that arginase inhibition reduces endothelial dysfunction in spontaneously hypertensive rats [C. Demougeot, A. Prigent-Tessier, C. Marie, A. Berthelot, J. Hypertens. 23 (2005) 971; C. Demougeot, A. Prigent-Tessier, T. Bagnost, C. Andre, Y. Guillaume, M. Bouhaddi, C. Marie, A. Berthelot, Life Sci. 80 (2007) 1128] which opens perspectives in the development of drugs against hypertension. In previous papers [T. Bagnost, Y.C. Guillaume, M. Thomassin, J.F. Robert, A. Berthelot, A. Xicluna, C. Andre, J. Chromatogr. B: Analyt. Technol. Biomed. Life Sci. 856 (2007) 113; T. Bagnost, Y.C. Guillaume, M. Thomassin, A. Berthelot, C. Demougeot, C. Andre, J. Chromatogr. B: Analyt. Technol. Biomed. Life Sci. 873 (2008) 37], we developed a biochromatographic column for studying the binding of an arginase inhibitor with this enzyme and the effect of magnesium on this binding. In this paper, the interaction of arginase inhibitors with an immobilized artificial membrane (IAM) has been studied using a biochromatographic approach. This IAM provided a biophysical model system to study the inhibitor passive transport across cells. It was demonstrated that more the inhibitor cross the cell membrane by passive diffusion more it is potent. As well, an analysis of the thermodynamics of the interaction of the arginase inhibitors with the IAM showed that van der Waals, hydrogen and ionic bonds were the main forces between the arginase inhibitors and the polar head groups of the IAM surface.
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Affiliation(s)
- Teddy Bagnost
- Faculté de Médecine et de Pharmacie, Equipe Sciences Séparatives Biologiques et Pharmaceutiques, CHU Jean Minjoz, Université de Franche-Comté, Place Saint-Jacques, Besançon Cedex, France
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87
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Rodríguez PC, Ochoa AC, Rodríguez PC. Arginine regulation by myeloid derived suppressor cells and tolerance in cancer: mechanisms and therapeutic perspectives. Immunol Rev 2009; 222:180-91. [PMID: 18364002 DOI: 10.1111/j.1600-065x.2008.00608.x] [Citation(s) in RCA: 525] [Impact Index Per Article: 35.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/20/2022]
Abstract
Patients with cancer have an impaired T-cell response that can decrease the potential therapeutic benefit of cancer vaccines and other forms of immunotherapy. L-arginine (L-Arg) is a conditionally essential amino acid that is fundamental for the function of T lymphocytes. Recent findings in tumor-bearing mice and cancer patients indicate that increased metabolism of L-Arg by myeloid derived suppressor cells (MDSCs) producing arginase I inhibits T-lymphocyte responses. Here we discuss some of the most recent concepts how MDSC expressing arginase I may regulate T-cell function in cancer and other chronic inflammatory diseases and suggest possible therapeutic interventions to overcome this inhibitory effect.
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Affiliation(s)
- Paulo C Rodríguez
- Department of Genetics, Louisiana State University Health Sciences Center, New Orleans, LA, USA
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88
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Nagai A, Imamura M, Watanabe T, Azuma H. Involvement of altered arginase activity, arginase I expression and NO production in accelerated intimal hyperplasia following cigarette smoke extract. Life Sci 2008; 83:453-9. [PMID: 18722385 DOI: 10.1016/j.lfs.2008.07.016] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/11/2008] [Revised: 06/17/2008] [Accepted: 07/18/2008] [Indexed: 12/16/2022]
Abstract
In the present experiments, we tried to elucidate whether changes in arginase activity, protein expression of arginase-I and -II, and NO production are involved in accelerating the intimal hyperplasia following administration of cigarette smoke extract (CSE). The intimal hyperplasia was caused by removing endothelial cells with the aid of balloon embolectomy catheter in the right carotid artery of the male rabbit. The left carotid artery underwent sham operation and served as control. CSE was prepared by bubbling a stream of cigarette smoke into phosphate buffered saline. Rabbits were given subcutaneously with CSE once a day for 5 weeks from 1 week before to 4 weeks after the surgery. The specimens were assessed histologically and the intima/media ratio (%) was evaluated as an index of the intimal hyperplasia. The accelerated intimal hyperplasia with CSE was accompanied by the augmentation of the impaired cyclic GMP production, enhanced overall arginase activity and up-regulation of arginase-I. Pearson's correlation coefficient analyses revealed the close relationships among the arginase activities in endothelial cells and smooth muscle layer, the intimal/media ratio and cyclic GMP production. These results suggest that the enhanced arginase activity together with facilitated up-regulation of arginase-I with CSE, which was associated with the augmented impairment of NO production, shed a new light on the processes associated with accelerating the intimal hyperplasia in rabbit carotid arteries following CSE.
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Affiliation(s)
- Akiko Nagai
- Department of Inorganic Materials, Institute of Biomaterials and Bioengineering, Tokyo Medical and Dental University, Tokyo, Japan
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89
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Zharikov S, Krotova K, Hu H, Baylis C, Johnson RJ, Block ER, Patel J. Uric acid decreases NO production and increases arginase activity in cultured pulmonary artery endothelial cells. Am J Physiol Cell Physiol 2008; 295:C1183-90. [PMID: 18784379 DOI: 10.1152/ajpcell.00075.2008] [Citation(s) in RCA: 175] [Impact Index Per Article: 10.9] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/30/2022]
Abstract
Elevated levels of serum uric acid (UA) are commonly associated with primary pulmonary hypertension but have generally not been thought to have any causal role. Recent experimental studies, however, have suggested that UA may affect various vasoactive mediators. We therefore tested the hypothesis that UA might alter nitric oxide (NO) levels in pulmonary arterial endothelial cells (PAEC). In isolated porcine pulmonary artery segments (PAS), UA (7.5 mg/dl) inhibits acetylcholine-induced vasodilation. The incubation of PAEC with UA caused a dose-dependent decrease in NO and cGMP production stimulated by bradykinin or Ca(2+)-ionophore A23187. We explored cellular mechanisms by which UA might cause reduced NO production focusing on the effects of UA on the l-arginine-endothelial NO synthase (eNOS) and l-arginine-arginase pathways. Incubation of PAEC with different concentrations of UA (2.5-15 mg/dl) for 24 h did not affect l-[(3)H]arginine uptake or activity/expression of eNOS. However, PAEC incubated with UA (7.5 mg/dl; 24 h) released more urea in culture media than control PAEC, suggesting that arginase activation might be involved in the UA effect. Kinetic analysis of arginase activity in PAEC lysates and rat liver and kidney homogenates demonstrated that UA activated arginase by increasing its affinity for l-arginine. An inhibitor of arginase (S)-(2-boronoethyl)-l-cysteine prevented UA-induced reduction of A23187-stimulated cGMP production by PAEC and abolished UA-induced inhibition of acetylcholine-stimulated vasodilation in PAS. We conclude that UA-induced arginase activation is a potential mechanism for reduction of NO production in PAEC.
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Affiliation(s)
- Sergey Zharikov
- SB Rm. M452, Div. of Pulmonary, Critical Care, and Sleep Medicine, Dept. of Medicine, Univ. of Florida, Gainesville, FL 32610, USA.
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90
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Chang R, Chicoine LG, Cui H, Kanagy NL, Walker BR, Liu Y, English BK, Nelin LD. Cytokine-induced arginase activity in pulmonary endothelial cells is dependent on Src family tyrosine kinase activity. Am J Physiol Lung Cell Mol Physiol 2008; 295:L688-97. [PMID: 18621907 DOI: 10.1152/ajplung.00504.2007] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022] Open
Abstract
We hypothesized that the Src family tyrosine kinases (STKs) are involved in the upregulation of arginase and inducible nitric oxide synthase (iNOS) expression in response to inflammatory stimuli in pulmonary endothelial cells. Treatment of bovine pulmonary arterial endothelial cells (bPAEC) with lipopolysaccharide and tumor necrosis factor-alpha (L/T) resulted in increased urea and nitric oxide (NO) production, and this increase in urea and NO production was inhibited by the STK inhibitor PP1 (10 microM). The STK inhibitors PP2 (10 microM) and herbimycin A (10 microM) also prevented the L/T-induced expression of both arginase II and iNOS mRNA in bPAEC. Together, the data demonstrate a central role of STK in the upregulation of both arginase II and iNOS in bPAEC in response to L/T treatment. To identify the specific kinase(s) required for the induction of urea and NO production, we studied human pulmonary microvascular endothelial cells (hPMVEC) so that short interfering RNA (siRNA) techniques could be employed. We found that hPMVEC express Fyn, Yes, c-Src, Lyn, and Blk and that the protein expression of Fyn, Yes, c-Src, and Lyn could be inhibited with specific siRNA. The siRNA targeting Fyn prevented the cytokine-induced increase in urea and NO production, whereas siRNAs specifically targeting Yes, c-Src, and Lyn had no appreciable effect on cytokine-induced urea and NO production. These findings support our hypothesis that inflammatory stimuli lead to increased urea and NO production through a STK-mediated pathway. Furthermore, these results indicate that the STK Fyn plays a critical role in this process.
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Affiliation(s)
- Rossana Chang
- Center for Perinatal Research, Columbus, OH 43205, USA
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91
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92
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Treatment with the arginase inhibitor N ω-hydroxy-nor-L-arginine improves vascular function and lowers blood pressure in adult spontaneously hypertensive rat. J Hypertens 2008; 26:1110-8. [DOI: 10.1097/hjh.0b013e3282fcc357] [Citation(s) in RCA: 82] [Impact Index Per Article: 5.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/05/2023]
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93
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Marinova GV, Loyaga-Rendon RY, Obayashi S, Ishibashi T, Kubota T, Imamura M, Azuma H. Possible involvement of altered arginase activity, arginase type I and type II expressions, and nitric oxide production in occurrence of intimal hyperplasia in premenopausal human uterine arteries. J Pharmacol Sci 2008; 106:385-93. [PMID: 18319562 DOI: 10.1254/jphs.fp0072275] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/22/2022] Open
Abstract
In the present experiments, we tried to elucidate whether changes in arginase activity and protein expression of arginase I and II are involved in the occurrence of intimal hyperplasia in premenopausal human uterine arteries. They were obtained from thirty-four patients undergoing total abdominal hysterectomy with informed consent for the present study. All specimens were assessed histologically and the intima/media ratio (%) was evaluated as an index of the intimal hyperplasia. Thirteen patients out of 34 had histologically normal arteries (intima/media ratio = 18.1 +/- 0.7%), whereas the remaining 21 patients had various degrees of intimal hyperplasia (intima/media ratio = 32.7 +/- 2.3%), and these specimens were categorized as hyperplasic. Intimal hyperplasia was accompanied by impaired cyclic GMP production, enhanced overall arginase activity, and up-regulations of arginase I and II in endothelial cells and of arginase II in the smooth muscle layer. Pearson's correlation coefficient analyses revealed the close relationships among the arginase activities in endothelial cells and smooth muscle layer, the intimal/media ratio, and cyclic GMP production. These results suggest that the enhanced arginase activity and expressions of two arginase subtypes shed new light on the processes associated with the occurrence of intimal hyperplasia in premenopausal human uterine arteries.
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Affiliation(s)
- Galina Vasileva Marinova
- Comprehensive Reproductive Medicine, Graduate School, Tokyo Medical and Dental University, Japan
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94
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Tuning adenosine A1 and A2A receptors activation mediates l-citrulline-induced inhibition of [3H]-acetylcholine release depending on nerve stimulation pattern. Neurochem Int 2008; 52:834-45. [DOI: 10.1016/j.neuint.2007.09.016] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/08/2007] [Revised: 09/20/2007] [Accepted: 09/24/2007] [Indexed: 11/21/2022]
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95
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Belik J, Shehnaz D, Pan J, Grasemann H. Developmental changes in arginase expression and activity in the lung. Am J Physiol Lung Cell Mol Physiol 2008; 294:L498-504. [PMID: 18192591 DOI: 10.1152/ajplung.00242.2007] [Citation(s) in RCA: 24] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022] Open
Abstract
Arginases compete with nitric oxide (NO) synthases for L-arginine as common substrate. Pulmonary vascular and airway diseases in which arginase activity is increased are associated with decreased NO production and reduced smooth muscle relaxation. The developmental patterns of arginase activity and type I and II isoforms expression in the lung have not been previously evaluated. Hypothesizing that lung arginase activity is developmentally regulated and highest in the fetus, we measured the expression of both arginase isoforms and total arginase activity in fetal, newborn, and adult rat lung, pulmonary artery, and bronchial tissue. In addition, intrapulmonary arterial muscle force generation was evaluated in the absence and presence of the arginase inhibitor Nomega-hydroxy-nor-L-arginine (nor-NOHA). Arginase II content, as well as total arginase activity, was highest in fetal rat lung, bronchi, and pulmonary arterial tissue and decreased with age (P<0.05), and its lung cell expression was developmentally regulated. In the presence of nor-NOHA, pulmonary arterial force generation was significantly reduced in fetus and newborn (P<0.01). No significant change in force generation was noted in bronchial tissue following arginase inhibition. In conclusion, arginase II is regulated developmentally, and both expression and activity are maximal during fetal life. We speculate that the maintenance of a high pulmonary vascular resistance and decreased lung NO production prenatally may, in part, be dependent on increased arginase expression and/or activity.
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Affiliation(s)
- Jaques Belik
- Department of Pediatrics, Physiology and Experimental Medicine, The Hospital for Sick Children Research Institute, and University of Toronto, 555 University Ave., Toronto, Ontario, M5G 1X8 Canada.
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96
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Abstract
PURPOSE OF REVIEW L-Arginine is the precursor for nitric oxide synthesis. In the brain, nitric oxide acts as a neurotransmitter; in the immune system, nitric oxide acts as a mediator of host defense; in the cardiovascular system, nitric oxide mediates the protective effects of the intact endothelium, acting as an endogenous antiatherogenic molecule. RECENT FINDINGS About 5 g of L-arginine is taken up each day. L-Arginine plasma levels are not significantly reduced in most diseases, except end-stage renal failure during hemodialysis treatment. Nonetheless, intravenous or oral administration of L-arginine results in enhanced nitric oxide elaboration in subjects with impaired endothelial function. In clinical trials short to medium-term administration of L-arginine improved the symptoms of cardiovascular disease. In other trials, however, L-arginine was not beneficial and in one recent long-term study higher mortality of subjects receiving L-arginine than those receiving placebo was reported. These contradictory results were not understood for a long time. The endogenous inhibitor of nitric oxide synthase, asymmetric dimethylarginine, may determine a subject's response to L-arginine. L-Arginine appears to exert no effect in subjects with low asymmetric dimethylarginine levels, whereas in subjects with high asymmetric dimethylarginine levels L-arginine restores the L-arginine/asymmetric dimethylarginine ratio to normal and normalizes endothelial function. SUMMARY The effects of L-arginine supplementation on human physiology appear to be multicausal and dose related. Criteria need to be developed to define patients who benefit from L-arginine supplementation.
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Affiliation(s)
- Rainer H Böger
- Clinical Pharmacology Unit, Institute of Experimental and Clinical Pharmacology, University Hospital Hamburg-Eppendorf, Germany.
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97
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Romero MJ, Platt DH, Tawfik HE, Labazi M, El-Remessy AB, Bartoli M, Caldwell RB, Caldwell RW. Diabetes-induced coronary vascular dysfunction involves increased arginase activity. Circ Res 2007; 102:95-102. [PMID: 17967788 DOI: 10.1161/circresaha.107.155028] [Citation(s) in RCA: 285] [Impact Index Per Article: 16.8] [Reference Citation Analysis] [Abstract] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/08/2023]
Abstract
Increases in arginase activity have been reported in a variety of disease conditions characterized by vascular dysfunction. Arginase competes with NO synthase for their common substrate arginine, suggesting a cause and effect relationship. We tested this concept by experiments with streptozotocin diabetic rats and high glucose (HG)-treated bovine coronary endothelial cells (BCECs). Our studies showed that diabetes-induced impairment of vasorelaxation to acetylcholine was correlated with increases in reactive oxygen species and arginase activity and arginase I expression in aorta and liver. Treatment of diabetic rats with simvastatin (5 mg/kg per day, subcutaneously) or L-citrulline (50 mg/kg per day, orally) blunted these effects. Acute treatment of diabetic coronary arteries with arginase inhibitors also reversed the impaired vasodilation to acetylcholine. Treatment of BCECs with HG (25 mmol/L, 24 hours) also increased arginase activity. This effect was blocked by treatment with simvastatin (0.1 micromol/L), the Rho kinase inhibitor Y-27632 (10 micromol/L), or L-citrulline (1 mmol/L). Superoxide and active RhoA levels also were elevated in HG-treated BCECs. Furthermore, HG significantly diminished NO production in BCECs. Transfection of BCECs with arginase I small interfering RNA prevented the rise in arginase activity in HG-treated cells and normalized NO production, suggesting a role for arginase I in reduced NO production with HG. These results indicate that increased arginase activity in diabetes contributes to vascular endothelial dysfunction by decreasing L-arginine availability to NO synthase.
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Affiliation(s)
- Maritza J Romero
- Department of Pharmacology and Toxicology, Medical College of Georgia, Augusta, GA 30912, USA
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98
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Durante W, Johnson FK, Johnson RA. Arginase: a critical regulator of nitric oxide synthesis and vascular function. Clin Exp Pharmacol Physiol 2007; 34:906-11. [PMID: 17645639 PMCID: PMC1955221 DOI: 10.1111/j.1440-1681.2007.04638.x] [Citation(s) in RCA: 402] [Impact Index Per Article: 23.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
1. Arginase is the focal enzyme of the urea cycle hydrolysing L-arginine to urea and L-ornithine. Emerging studies have identified arginase in the vasculature and have implicated this enzyme in the regulation of nitric oxide (NO) synthesis and the development of vascular disease. 2. Arginase inhibits the production of NO via several potential mechanisms, including competition with NO synthase (NOS) for the substrate L-arginine, uncoupling of NOS resulting in the generation of the NO scavenger, superoxide and peroxynitrite, repression of the translation and stability of inducible NOS protein, inhibition of inducible NOS activity via the generation of urea and by sensitization of NOS to its endogenous inhibitor asymmetric dimethyl-L-arginine. 3. Upregulation of arginase inhibits endothelial NOS-mediated NO synthesis and may contribute to endothelial dysfunction in hypertension, ageing, ischaemia-reperfusion and diabetes. 4. Arginase also redirects the metabolism of L-arginine to L-ornithine and the formation of polyamines and L-proline, which are essential for smooth muscle cell growth and collagen synthesis. Therefore, the induction of arginase may also promote aberrant vessel wall remodelling and neointima formation. 5. Arginase represents a promising novel therapeutic target that may reverse endothelial and smooth muscle cell dysfunction and prevent vascular disease.
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Affiliation(s)
- William Durante
- Department of Medical Pharmacology and Physiology, University of Missouri-Columbia, Columbia, Missouri 65212, USA.
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99
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Santhanam L, Lim HK, Lim HK, Miriel V, Brown T, Patel M, Balanson S, Ryoo S, Anderson M, Irani K, Khanday F, Di Costanzo L, Nyhan D, Hare JM, Christianson DW, Rivers R, Shoukas A, Berkowitz DE. Inducible NO synthase dependent S-nitrosylation and activation of arginase1 contribute to age-related endothelial dysfunction. Circ Res 2007; 101:692-702. [PMID: 17704205 DOI: 10.1161/circresaha.107.157727] [Citation(s) in RCA: 156] [Impact Index Per Article: 9.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
Endothelial function is impaired in aging because of a decrease in NO bioavailability. This may be, in part, attributable to increased arginase activity, which reciprocally regulates NO synthase (NOS) by competing for the common substrate, L-arginine. However, the high Km of arginase (>1 mmol/L) compared with NOS (2 to 20 micromol/L) seemingly makes direct competition for substrate unlikely. One of the mechanisms by which NO exerts its effects is by posttranslational modification through S-nitrosylation of protein cysteines. We tested the hypothesis that arginase1 activity is modulated by this mechanism, which serves to alter its substrate affinity, allowing competition with NOS for L-arginine. We demonstrate that arginase1 activity is altered by S-nitrosylation, both in vitro and ex vivo. Furthermore, using site-directed mutagenesis we demonstrate that 2 cysteine residues (C168 and C303) are able to undergo nitrosylation. S-Nitrosylation of C303 stabilizes the arginase1 trimer and reduces its Km value 6-fold. Finally, arginase1 nitrosylation is increased (and thus its Km decreased) in blood vessels from aging rats, likely contributing to impaired NO bioavailability and endothelial dysfunction. This is mediated by inducible NOS, which is expressed in the aging endothelium. These findings suggest that S-nitrosylated arginase1 can compete with NOS for L-arginine and contribute to endothelial dysfunction in the aging cardiovascular system.
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Affiliation(s)
- Lakshmi Santhanam
- Johns Hopkins University School of Medicine, 720 Rutland Ave, Traylor 621, Baltimore MD 21209, USA
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100
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Abstract
L-arginine is a precursor for nitric oxide (NO) synthesis. NO is a ubiquitous mediator that is formed by a family of enzymes named NO synthases. In the brain, NO acts as a neurotransmitter; in the immune system, NO acts as a mediator of host defense; and in the cardiovascular system, NO mediates the protective effects of the intact endothelium, acting as a vasodilator and endogenous antiatherogenic molecule. About 5 g of L-arginine is ingested each day in a normal Western diet. L-arginine plasma levels are not significantly reduced in most disease conditions, except end-stage renal failure during hemodialysis treatment. Nonetheless, intravenous or dietary (oral) administration of relatively large doses of L-arginine has been shown to result in enhanced NO formation in subjects with impaired endothelial function at baseline. In several controlled clinical trials, long-term administration of L-arginine has been shown to improve the symptoms of cardiovascular disease. However, in other trials L-arginine was not beneficial, and in a recent study, the authors reported higher mortality of subjects receiving L-arginine than those receiving placebo. Recently it became clear that endogenous levels of asymmetric dimethylarginine (ADMA), a competitive inhibitor of L-arginine metabolism by NO synthase, may determine a subject's response to L-arginine supplementation. L-arginine appears to exert no effect in subjects with low ADMA levels, whereas in subjects with high ADMA levels, L-arginine restores the L-arginine/ADMA ratio to normal levels and thereby normalizes endothelial function. In conclusion, the effects of L-arginine supplementation on human physiology appear to be multicausal and dose-related. Doses of 3-8 g/d appear to be safe and not to cause acute pharmacologic effects in humans.
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Affiliation(s)
- Rainer H Böger
- Clinical Pharmacology Unit, Institute of Experimental and Clinical Pharmacology, University Hospital Hamburg-Eppendorf, Germany.
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