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Soares JPM, Gonçalves DA, de Sousa RX, Mouro MG, Higa EMS, Sperandio LP, Vitoriano CM, Rosa EBS, dos Santos FO, de Queiroz GN, Yamaguchi RSS, Pereira G, Icimoto MY, de Melo FHM. Disruption of Redox Homeostasis by Alterations in Nitric Oxide Synthase Activity and Tetrahydrobiopterin along with Melanoma Progression. Int J Mol Sci 2022; 23:5979. [PMID: 35682659 PMCID: PMC9181279 DOI: 10.3390/ijms23115979] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/23/2022] [Revised: 05/16/2022] [Accepted: 05/20/2022] [Indexed: 12/12/2022] Open
Abstract
Cutaneous melanoma emerges from the malignant transformation of melanocytes and is the most aggressive type of skin cancer. The progression can occur in different stages: radial growth phase (RGP), vertical growth phase (VGP), and metastasis. Reactive oxygen species contribute to all phases of melanomagenesis through the modulation of oncogenic signaling pathways. Tetrahydrobiopterin (BH4) is an important cofactor for NOS coupling, and an uncoupled enzyme is a source of superoxide anion (O2•-) rather than nitric oxide (NO), altering the redox homeostasis and contributing to melanoma progression. In the present work, we showed that the BH4 amount varies between different cell lines corresponding to distinct stages of melanoma progression; however, they all presented higher O2•- levels and lower NO levels compared to melanocytes. Our results showed increased NOS expression in melanoma cells, contributing to NOS uncoupling. BH4 supplementation of RGP cells, and the DAHP treatment of metastatic melanoma cells reduced cell growth. Finally, Western blot analysis indicated that both treatments act on the PI3K/AKT and MAPK pathways of these melanoma cells in different ways. Disruption of cellular redox homeostasis by the altered BH4 concentration can be explored as a therapeutic strategy according to the stage of melanoma.
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Affiliation(s)
- Jaqueline Pereira Moura Soares
- Department of Physiological Sciences, Santa Casa de São Paulo School of Medical Sciences, São Paulo 01224-001, Brazil; (J.P.M.S.); (R.X.d.S.); (R.S.S.Y.)
| | - Diego Assis Gonçalves
- Department of Parasitology, Microbiology and Immunology, Juiz de Fora Federal University, Juiz de Fora 36036-900, Brazil;
- Micro-Imuno-Parasitology Department, Federal University of Sao Paulo, São Paulo 05508-090, Brazil
| | - Ricardo Xisto de Sousa
- Department of Physiological Sciences, Santa Casa de São Paulo School of Medical Sciences, São Paulo 01224-001, Brazil; (J.P.M.S.); (R.X.d.S.); (R.S.S.Y.)
| | - Margareth Gori Mouro
- Nefrology Discipline, Federal University of Sao Paulo, São Paulo 05508-090, Brazil; (M.G.M.); (E.M.S.H.)
| | - Elisa M. S. Higa
- Nefrology Discipline, Federal University of Sao Paulo, São Paulo 05508-090, Brazil; (M.G.M.); (E.M.S.H.)
| | - Letícia Paulino Sperandio
- Department of Pharmacology, Federal University of Sao Paulo, São Paulo 05508-090, Brazil; (L.P.S.); (G.P.)
| | - Carolina Moraes Vitoriano
- Department of Pharmacology, Institute of Biomedical Science, Universidade de São Paulo, São Paulo 05505-000, Brazil; (C.M.V.); (E.B.S.R.); (F.O.d.S.); (G.N.d.Q.)
| | - Elisa Bachir Santa Rosa
- Department of Pharmacology, Institute of Biomedical Science, Universidade de São Paulo, São Paulo 05505-000, Brazil; (C.M.V.); (E.B.S.R.); (F.O.d.S.); (G.N.d.Q.)
| | - Fernanda Oliveira dos Santos
- Department of Pharmacology, Institute of Biomedical Science, Universidade de São Paulo, São Paulo 05505-000, Brazil; (C.M.V.); (E.B.S.R.); (F.O.d.S.); (G.N.d.Q.)
| | - Gustavo Nery de Queiroz
- Department of Pharmacology, Institute of Biomedical Science, Universidade de São Paulo, São Paulo 05505-000, Brazil; (C.M.V.); (E.B.S.R.); (F.O.d.S.); (G.N.d.Q.)
| | - Roberta Sessa Stilhano Yamaguchi
- Department of Physiological Sciences, Santa Casa de São Paulo School of Medical Sciences, São Paulo 01224-001, Brazil; (J.P.M.S.); (R.X.d.S.); (R.S.S.Y.)
| | - Gustavo Pereira
- Department of Pharmacology, Federal University of Sao Paulo, São Paulo 05508-090, Brazil; (L.P.S.); (G.P.)
| | - Marcelo Yudi Icimoto
- Biophysics Department, Federal University of Sao Paulo, São Paulo 05508-090, Brazil;
| | - Fabiana Henriques Machado de Melo
- Department of Pharmacology, Institute of Biomedical Science, Universidade de São Paulo, São Paulo 05505-000, Brazil; (C.M.V.); (E.B.S.R.); (F.O.d.S.); (G.N.d.Q.)
- Institute of Medical Assistance to Public Servants of the State (IAMSPE), São Paulo 04039-000, Brazil
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de Melo FHM, Gonçalves DA, de Sousa RX, Icimoto MY, Fernandes DDC, Laurindo FRM, Jasiulionis MG. Metastatic Melanoma Progression Is Associated with Endothelial Nitric Oxide Synthase Uncoupling Induced by Loss of eNOS:BH4 Stoichiometry. Int J Mol Sci 2021; 22:9556. [PMID: 34502464 PMCID: PMC8430733 DOI: 10.3390/ijms22179556] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/28/2021] [Revised: 08/13/2021] [Accepted: 08/17/2021] [Indexed: 12/26/2022] Open
Abstract
Melanoma is the most aggressive type of skin cancer due to its high capability of developing metastasis and acquiring chemoresistance. Altered redox homeostasis induced by increased reactive oxygen species is associated with melanomagenesis through modulation of redox signaling pathways. Dysfunctional endothelial nitric oxide synthase (eNOS) produces superoxide anion (O2-•) and contributes to the establishment of a pro-oxidant environment in melanoma. Although decreased tetrahydrobiopterin (BH4) bioavailability is associated with eNOS uncoupling in endothelial and human melanoma cells, in the present work we show that eNOS uncoupling in metastatic melanoma cells expressing the genes from de novo biopterin synthesis pathway Gch1, Pts, and Spr, and high BH4 concentration and BH4:BH2 ratio. Western blot analysis showed increased expression of Nos3, altering the stoichiometry balance between eNOS and BH4, contributing to NOS uncoupling. Both treatment with L-sepiapterin and eNOS downregulation induced increased nitric oxide (NO) and decreased O2• levels, triggering NOS coupling and reducing cell growth and resistance to anoikis and dacarbazine chemotherapy. Moreover, restoration of eNOS activity impaired tumor growth in vivo. Finally, NOS3 expression was found to be increased in human metastatic melanoma samples compared with the primary site. eNOS dysfunction may be an important mechanism supporting metastatic melanoma growth and hence a potential target for therapy.
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Affiliation(s)
- Fabiana Henriques Machado de Melo
- Pharmacology Department, Universidade Federal de São Paulo, São Paulo 05508-090, Brazil
- Department of Pharmacology, Institute of Biomedical Science, University of São Paulo, São Paulo 05508-060, Brazil
| | - Diego Assis Gonçalves
- Micro-Imuno-Parasitology Department, Universidade Federal de São Paulo, São Paulo 05508-090, Brazil;
- Parasitology Department, Microbiology and Immunology, Federal University of Juiz de Fora, Juiz de Fora 36036-900, Brazil
| | - Ricardo Xisto de Sousa
- Department of Physiological Sciences, Santa Casa de São Paulo School of Medical Sciences, São Paulo 01221-020, Brazil;
| | - Marcelo Yudi Icimoto
- Biophysics Department, Universidade Federal de São Paulo, São Paulo 05508-090, Brazil;
| | - Denise de Castro Fernandes
- Vascular Biology Laboratory, Heart Institute (InCor), University of São Paulo School of Medicine, São Paulo 05508-060, Brazil; (D.d.C.F.); (F.R.M.L.)
| | - Francisco R. M. Laurindo
- Vascular Biology Laboratory, Heart Institute (InCor), University of São Paulo School of Medicine, São Paulo 05508-060, Brazil; (D.d.C.F.); (F.R.M.L.)
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Gonçalves DA, Jasiulionis MG, de Melo FHM. The Role of the BH4 Cofactor in Nitric Oxide Synthase Activity and Cancer Progression: Two Sides of the Same Coin. Int J Mol Sci 2021; 22:9546. [PMID: 34502450 PMCID: PMC8431490 DOI: 10.3390/ijms22179546] [Citation(s) in RCA: 16] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/01/2021] [Revised: 08/22/2021] [Accepted: 08/23/2021] [Indexed: 12/14/2022] Open
Abstract
Cancer development is associated with abnormal proliferation, genetic instability, cell death resistance, metabolic reprogramming, immunity evasion, and metastasis. These alterations are triggered by genetic and epigenetic alterations in genes that control cell homeostasis. Increased reactive oxygen and nitrogen species (ROS, RNS) induced by different enzymes and reactions with distinct molecules contribute to malignant transformation and tumor progression by modifying DNA, proteins, and lipids, altering their activities. Nitric oxide synthase plays a central role in oncogenic signaling modulation and redox landscape. Overexpression of the three NOS isoforms has been found in innumerous types of cancer contributing to tumor growth and development. Although the main function of NOS is the production of nitric oxide (NO), it can be a source of ROS in some pathological conditions. Decreased tetrahydrobiopterin (BH4) cofactor availability is involved in NOS dysfunction, leading to ROS production and reduced levels of NO. The regulation of NOSs by BH4 in cancer is controversial since BH4 has been reported as a pro-tumoral or an antitumoral molecule. Therefore, in this review, the role of BH4 in the control of NOS activity and its involvement in the capabilities acquired along tumor progression of different cancers was described.
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Affiliation(s)
- Diego Assis Gonçalves
- Micro-Imuno-Parasitology Department, Universidade Federal de São Paulo, São Paulo 04023-062, Brazil;
- Department of Parasitology, Microbiology and Immunology, Federal University of Juiz de Fora, Juiz de Fora 36036-900, Brazil
| | | | - Fabiana Henriques Machado de Melo
- Department of Pharmacology, Institute of Biomedical Science, University of São Paulo, São Paulo 05508-000, Brazil
- Institute of Medical Assistance to Public Servants of the State (IAMSPE), São Paulo 04039-000, Brazil
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Pontes VCB, Tavares JPTDM, Rosenstock TR, Rodrigues DS, Yudi MI, Soares JPM, Ribeiro SC, Sutti R, Torres LMB, de Melo FHM, Gamberini MT. Increased acute blood flow induced by the aqueous extract of Euterpe oleracea Mart. fruit pulp in rats in vivo is not related to the direct activation of endothelial cells. JOURNAL OF ETHNOPHARMACOLOGY 2021; 271:113885. [PMID: 33539952 DOI: 10.1016/j.jep.2021.113885] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/16/2020] [Revised: 01/21/2021] [Accepted: 01/25/2021] [Indexed: 06/12/2023]
Abstract
ETHNOPHARMACOLOGICAL RELEVANCE Scientific evidence supports the antioxidant, anti-inflammatory and anti-lipidemic properties of Euterpe oleracea Mart. (açaí), which all converge to reduce cardiovascular risks. Macerating the pulp of açaí fruit produces a viscous aqueous extract (AE) rich in flavonoids that is commonly used in food production. In addition to nutritional aspects, cardiovascular benefits are attributed to AE by traditional medicine. AIM OF THE STUDY Evaluation of AE impact on blood flow in vivo in rats and investigation of the mechanism underlying this response in vitro in rat endothelial cells (RECs). MATERIALS AND METHODS For the measurement of acute blood flow, a perivascular ultrasound probe was used in Wistar rats. The in vitro assays employed REC to evaluate: concentration (1-1000 μg/mL) and time response (2-180 min) of AE in MTT cell viability assays; nitric oxide (NO) levels measurement and intracellular calcium handling using DAF-2DA and Fluo-4-AM, respectively; cellular biopterin content by HPLC; activation of Akt pathway using western blot analysis. For the chemical analyses of AE, stock solutions of the standards (+)catechin and quercetin were used for obtaining linear calibration curves. Identification and quantification of flavonoids in AE were based on comparisons with the retention times, increase in peak area determine by co-injection of AE with standards, UV-Vis scan and standard curves of known spectra. Results were expressed as mean ± standard deviation and data were analyzed using ANOVA followed by Tukey's post-test (p < 0.05). RESULTS Although in vivo data have revealed the participation of NO in increasing of acute blood flow on abdominal aorta, in vitro analysis demonstrated that vasodilatation AE-induced is not related to its direct action on endothelial cells inducing eNOS activation. Besides, we demonstrated in isolated endothelial cells that highest concentrations of AE caused a reduction in NO levels, effect that could be partly justified by inhibition of Akt phosphorylation which, in turn, could decrease NOS activation. The involvement of cell transduction pathways involving variations in intracellular calcium and biopterins concentration were discarded. The participation of catechin and quercetin, identified in AE, was postulated to induce the responses of AE in REC. CONCLUSIONS Despite the responses in vitro, vasodilation prevailed in vivo, probably by activating intermediate pathways, validating a potential beneficial effect of AE in reducing cardiovascular risks.
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Affiliation(s)
- Victória Caroline Bottino Pontes
- Department of Physiological Sciences Santa Casa de Sao Paulo School of Medical Sciences - School of Medicine, São Paulo, SP, Brazil.
| | | | | | - Domingos Sávio Rodrigues
- Instituto de Botânica de São Paulo, Centro de Pesquisa Jardim Botânico e Reservas, São Paulo, SP, Brazil.
| | - Marcelo Icimoto Yudi
- Department of Biophysics, Federal University São Paulo (UNIFESP), São Paulo, SP, Brazil.
| | - Jaqueline Pereira Moura Soares
- Department of Physiological Sciences Santa Casa de Sao Paulo School of Medical Sciences - School of Medicine, São Paulo, SP, Brazil.
| | - Suzana Costa Ribeiro
- Department of Physiological Sciences Santa Casa de Sao Paulo School of Medical Sciences - School of Medicine, São Paulo, SP, Brazil.
| | - Rafael Sutti
- Department of Physiological Sciences Santa Casa de Sao Paulo School of Medical Sciences - School of Medicine, São Paulo, SP, Brazil.
| | - Luce Maria Brandão Torres
- Instituto de Botânica de São Paulo, Centro de Pesquisa Jardim Botânico e Reservas, São Paulo, SP, Brazil.
| | | | - Maria Thereza Gamberini
- Department of Physiological Sciences Santa Casa de Sao Paulo School of Medical Sciences - School of Medicine, São Paulo, SP, Brazil.
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Lindsay A, Kemp B, Larson AA, Baumann CW, McCourt PM, Holm J, Karachunski P, Lowe DA, Ervasti JM. Tetrahydrobiopterin synthesis and metabolism is impaired in dystrophin-deficient mdx mice and humans. Acta Physiol (Oxf) 2021; 231:e13627. [PMID: 33580591 DOI: 10.1111/apha.13627] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/29/2020] [Revised: 02/08/2021] [Accepted: 02/10/2021] [Indexed: 12/20/2022]
Abstract
AIM Loss of dystrophin causes oxidative stress and affects nitric oxide synthase-mediated vascular function in striated muscle. Because tetrahydrobiopterin is an antioxidant and co-factor for nitric oxide synthase, we tested the hypothesis that tetrahydrobiopterin would be low in mdx mice and humans deficient for dystrophin. METHODS Tetrahydrobiopterin and its metabolites were measured at rest and in response to exercise in Duchenne and Becker muscular dystrophy patients, age-matched male controls as well as wild-type, mdx and mdx mice transgenically overexpressing skeletal muscle-specific dystrophins. Mdx mice were also supplemented with tetrahydrobiopterin and pathophysiology was assessed. RESULTS Duchenne muscular dystrophy patients had lower urinary dihydrobiopterin + tetrahydrobiopterin/specific gravity1.020 compared to unaffected age-matched males and Becker muscular dystrophy patients. Mdx mice had low urinary and skeletal muscle dihydrobiopterin + tetrahydrobiopterin compared to wild-type mice. Overexpression of dystrophins that localize neuronal nitric oxide synthase restored dihydrobiopterin + tetrahydrobiopterin in mdx mice to wild-type levels while utrophin overexpression did not. Mdx mice and Duchenne muscular dystrophy patients did not increase tetrahydrobiopterin during exercise and in mdx mice tetrahydrobiopterin deficiency was likely because of lower levels of sepiapterin reductase in skeletal muscle. Tetrahydrobiopterin supplementation improved skeletal muscle strength, resistance to fatiguing and injurious contractions in vivo, increased utrophin and capillary density of skeletal muscle and lowered cardiac muscle fibrosis and left ventricular wall thickness in mdx mice. CONCLUSION These data demonstrate that impaired tetrahydrobiopterin synthesis is associated with dystrophin loss and treatment with tetrahydrobiopterin improves striated muscle histopathology and skeletal muscle function in mdx mice.
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Affiliation(s)
- Angus Lindsay
- Division of Rehabilitation Science and Division of Physical Therapy, Department of Rehabilitation Medicine, University of Minnesota, Minneapolis, MN, USA
- Department of Biochemistry, Molecular Biology and Biophysics, University of Minnesota, Minneapolis, MN, USA
- Institute for Physical Activity and Nutrition, School of Exercise and Nutrition Sciences, Deakin University, Geelong, Australia
| | - Bailey Kemp
- Lillehei Heart Institute, Cancer and Cardiovascular Research Center, University of Minnesota, Minneapolis, MN, USA
| | - Alexie A Larson
- Department of Integrative Biology and Physiology, University of Minnesota, Minneapolis, MN, USA
| | - Cory W Baumann
- Division of Rehabilitation Science and Division of Physical Therapy, Department of Rehabilitation Medicine, University of Minnesota, Minneapolis, MN, USA
| | - Preston M McCourt
- Department of Biochemistry, Molecular Biology and Biophysics, University of Minnesota, Minneapolis, MN, USA
| | - John Holm
- Lillehei Heart Institute, Cancer and Cardiovascular Research Center, University of Minnesota, Minneapolis, MN, USA
| | - Peter Karachunski
- Department of Pediatrics, University of Minnesota, Minneapolis, MN, USA
- Department of Neurology, University of Minnesota, Minneapolis, MN, USA
| | - Dawn A Lowe
- Division of Rehabilitation Science and Division of Physical Therapy, Department of Rehabilitation Medicine, University of Minnesota, Minneapolis, MN, USA
| | - James M Ervasti
- Department of Biochemistry, Molecular Biology and Biophysics, University of Minnesota, Minneapolis, MN, USA
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Watanabe T. Neopterin derivatives - a novel therapeutic target rather than biomarker for atherosclerosis and related diseases. VASA 2020; 50:165-173. [PMID: 32924886 DOI: 10.1024/0301-1526/a000903] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/07/2023]
Abstract
This review provides an updated overview of the emerging roles of neopterin derivatives in atherosclerosis. Neopterin, a metabolite of guanosine triphosphate, is produced by interferon-γ-activated macrophages and is expressed at high levels in atheromatous plaques within the human carotid and coronary arteries as well as in the aorta. Plasma concentrations of neopterin are higher in patients with carotid, cerebral, and coronary artery diseases as well as aortic aneurysm. The concentration of neopterin is positively correlated with the severity of coronary artery disease. However, a prospective cohort study showed that neopterin contributes to protection against plaque formation in carotid arteries in patients with atherosclerosis. Moreover, using both in vitro and in vivo experiments, a recent study has shown the atheroprotective effects of neopterin. Neopterin suppresses the expression of monocyte chemotactic protein-1, vascular cell adhesion molecule-1, and intercellular adhesion molecule-1 in endothelial cells, and thereby suppresses the adhesion of monocytes to endothelial cells. It also suppresses the inflammatory phenotype of monocyte-derived macrophages. In addition, neopterin suppresses oxidized low-density lipoprotein-induced foam cell formation in macrophages and the migration and proliferation of vascular smooth muscle cells. Neopterin injection into apolipoprotein E-deficient (Apoe-/-) mice suppresses the development of atherosclerotic lesions. A neopterin derivative tetrahydroneopterin (BH4), also known as a cofactor for nitric oxide (NO) synthases, suppresses atherosclerosis and vascular injury-induced neointimal hyperplasia in Apoe-/- mice. BH4 administration improves endothelial dysfunction in patients with coronary artery disease. These findings suggest that neopterin production may increase to counteract the progression of atherosclerosis, as neopterin contributes to atheroprotection. Otherwise, the increased neopterin levels in atherosclerosis may reflect a compensatory mechanism associated with inducible NO synthase upregulation in macrophages to supply BH4 for high output NO production caused by decreased endothelial NO synthase in atherosclerosis. Therefore, neopterin derivatives are a novel therapeutic target for atherosclerosis and related diseases.
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Affiliation(s)
- Takuya Watanabe
- Department of Internal Medicine, Ushioda General Hospital/Clinic, Yokohama, Japan
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The Nitric Oxide System in Peripheral Artery Disease: Connection with Oxidative Stress and Biopterins. Antioxidants (Basel) 2020; 9:antiox9070590. [PMID: 32640613 PMCID: PMC7402092 DOI: 10.3390/antiox9070590] [Citation(s) in RCA: 20] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/27/2020] [Revised: 06/15/2020] [Accepted: 07/01/2020] [Indexed: 02/06/2023] Open
Abstract
Peripheral artery disease (PAD) pathophysiology extends beyond hemodynamics to include other operating mechanisms, including endothelial dysfunction. Oxidative stress may be linked to endothelial dysfunction by reducing nitric oxide (NO) bioavailability. We aimed to investigate whether the NO system and its regulators are altered in the setting of PAD and to assess the relationship between NO bioavailability and oxidative stress. Sera from 35 patients with intermittent claudication (IC), 26 patients with critical limb ischemia (CLI), and 35 non-PAD controls were analyzed to determine levels of tetrahydrobiopterin (BH4), dihydrobiopterin (BH2), nitrate/nitrite (nitric oxides, or NOx), arginine, citrulline, asymmetric dimethylarginine (ADMA), symmetric dimethylarginine (SDMA), and the oxidative stress markers 8-Oxo-2′-deoxyguanosine (8-OHdG), 4-hydroxynonenal (4-HNE), advanced glycation end products (AGEs), and protein carbonyls. NOx was significantly lower in IC and CLI patients compared to controls in association with elevated oxidative stress, with the greatest NOx reductions observed in CLI. Compared with controls, IC and CLI patients had reduced BH4, elevated BH2, and a reduced BH4/BH2 ratio. SDMA, the arginine/SDMA ratio, and the arginine/ADMA ratio were significantly higher in CLI patients. The NO system and its regulators are significantly compromised in PAD. This dysregulation appears to be driven by increased oxidative stress and worsens as the disease progresses from claudication to CLI.
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Gonçalves DA, Xisto R, Gonçalves JD, da Silva DB, Moura Soares JP, Icimoto MY, Sant’Anna C, Gimenez M, de Angelis K, Llesuy S, Fernandes DC, Laurindo F, Jasiulionis MG, Melo FHMD. Imbalance between nitric oxide and superoxide anion induced by uncoupled nitric oxide synthase contributes to human melanoma development. Int J Biochem Cell Biol 2019; 115:105592. [DOI: 10.1016/j.biocel.2019.105592] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/17/2019] [Revised: 07/20/2019] [Accepted: 08/19/2019] [Indexed: 12/28/2022]
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Rodriguez-Miguelez P, Gregg J, Seigler N, Bass L, Thomas J, Pollock JS, Sullivan JC, Dillard TA, Harris RA. Acute Tetrahydrobiopterin Improves Endothelial Function in Patients With COPD. Chest 2018; 154:597-606. [PMID: 29705218 DOI: 10.1016/j.chest.2018.04.028] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/30/2018] [Revised: 02/27/2018] [Accepted: 04/02/2018] [Indexed: 01/07/2023] Open
Abstract
BACKGROUND Cardiovascular diseases represent a hallmark characteristic in COPD, and endothelial dysfunction has been observed in these patients. Tetrahydrobiopterin (BH4) is an essential cofactor for nitric oxide (NO) synthesis and a regulator of endothelial function. The goal of this study was to test the hypothesis that a single dose of BH4 would improve endothelial function in patients with COPD via an increase in NO bioavailability. METHODS Seventeen patients with COPD completed a randomized, double-blind, placebo (PLC)-controlled, crossover trial with an acute dose of either BH4 (Kuvan; BioMarin Pharmaceutical Inc) or PLC. Flow-mediated dilation (FMD), a bioassay of endothelial function, was completed prior to and 3 h following each treatment. Phospho- and total endothelial NO synthase (NOS3) protein was evaluated after incubating endothelial cells with plasma from the patients prior to and following treatment. Fifteen demographically matched control subjects were tested at baseline for case control comparisons. RESULTS Treatment with BH4 significantly (P ≤ .004) increased FMD, improving endothelial function in patients compared to control values (P ≥ .327). BH4 increased (P = .013) the ratio of phospho-NOS3 to total NOS3 protein. No changes in FMD (P ≥ .776) or the protein ratio (P = .536) were observed following PLC. CONCLUSIONS An acute dose of BH4 was able to improve endothelial function in patients with COPD to values similar to control subjects. The improvement in endothelial function was accompanied by an increase in NOS3 phosphorylation. BH4 may represent a potential novel therapy to improve endothelial function and reduce cardiovascular disease risk in patients with COPD. TRIAL REGISTRY ClinicalTrials.gov; No.: NCT01398943; URL: www.clinicaltrials.gov.
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Affiliation(s)
| | - Justin Gregg
- Pulmonary and Critical Care Medicine Department, Greenville Memorial Hospital, Greenville, SC
| | - Nichole Seigler
- Georgia Prevention Institute, Department of Pediatrics, Augusta University, Augusta, GA
| | - Leon Bass
- Pulmonology Department, Holston Medical Group, Kingsport, TN
| | - Jeffrey Thomas
- Georgia Prevention Institute, Department of Pediatrics, Augusta University, Augusta, GA
| | - Jennifer S Pollock
- Cardio-Renal Physiology & Medicine, University of Alabama at Birmingham, Birmingham, AL
| | | | - Thomas A Dillard
- Pulmonary and Critical Care, Department of Medicine, Augusta University, Augusta, GA
| | - Ryan A Harris
- Georgia Prevention Institute, Department of Pediatrics, Augusta University, Augusta, GA; Sport and Exercise Science Research Institute, Ulster University, Jordanstown, Northern Ireland.
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Lucena SV, Moura GEDD, Rodrigues T, Watashi CM, Melo FH, Icimoto MY, Viana GM, Nader HB, Monteiro HP, Tersariol ILS, Ogata FT. Heparan sulfate proteoglycan deficiency up-regulates the intracellular production of nitric oxide in Chinese hamster ovary cell lines. J Cell Physiol 2017; 233:3176-3194. [DOI: 10.1002/jcp.26160] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/16/2017] [Accepted: 08/17/2017] [Indexed: 01/01/2023]
Affiliation(s)
| | | | - Tiago Rodrigues
- Centro de Ciências Naturais e Humanas (CCNH)-UFABC; Santo André São Paulo Brazil
| | - Carolina M. Watashi
- Centro de Ciências Naturais e Humanas (CCNH)-UFABC; Santo André São Paulo Brazil
| | - Fabiana H. Melo
- Faculdade de Ciências Médicas da Santa Casa de São Paulo; São Paulo São Paulo Brazil
| | | | | | - Helena B. Nader
- Departamento de Bioquímica-UNIFESP; São Paulo São Paulo Brazil
| | | | - Ivarne L. S. Tersariol
- Departamento de Bioquímica-UNIFESP; São Paulo São Paulo Brazil
- Centro Interdisciplinar de Investigação Bioquímica UMC; Mogi das Cruzes São PauloSão Paulo Brazil
| | - Fernando T. Ogata
- Departamento de Bioquímica-UNIFESP; São Paulo São Paulo Brazil
- Division of Biochemistry, Medical Biochemistry & Biophysics, Karolinska Institutet; Stockholm Sweden
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Edgar KS, Galvin OM, Collins A, Katusic ZS, McDonald DM. BH4-Mediated Enhancement of Endothelial Nitric Oxide Synthase Activity Reduces Hyperoxia-Induced Endothelial Damage and Preserves Vascular Integrity in the Neonate. Invest Ophthalmol Vis Sci 2017; 58:230-241. [PMID: 28114584 PMCID: PMC6039076 DOI: 10.1167/iovs.16-20523] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/14/2016] [Accepted: 11/06/2016] [Indexed: 01/11/2023] Open
Abstract
Purpose Endothelial nitric oxide synthase (eNOS)-derived nitric oxide (NO) has important vasoprotective functions that are compromised in the vasodegenerative phase of retinopathy of prematurity, owing to hyperoxia-induced depletion of the essential NOS cofactor BH4. Because modulating eNOS function can be beneficial or detrimental, our aim was to investigate the effect of BH4 supplementation on eNOS function and vascular regression in hyperoxia. Methods Endothelial-specific eNOS-green fluorescent protein (GFP) overexpressing mice at postnatal day 7 (P7) were exposed to hyperoxia for 48 hours in the presence or absence of supplemental BH4, achieved by administration of sepiapterin, a stable BH4 precursor. Tissue was collected either for retinal flat mounts that were stained with lectin to determine the extent of vessel coverage or for analysis of BH4 by high-performance liquid chromatography, nitrotyrosine (NT) marker by Western blotting, VEGF expression by ELISA, and NOS activity by arginine-to-citrulline conversion. Primary retinal microvascular endothelial cells (RMEC) were similarly treated, and hyperoxia-induced damage was determined. Results Sepiapterin effectively enhanced BH4 levels in hyperoxia-exposed retinas and brains, elevated NOS activity, and reduced NT-modified protein, leading to reversal of the exacerbated vasoregression observed in the presence of eNOS overexpression. In RMECs, hyperoxia-mediated depletion of BH4 dysregulated the redox balance by reducing nitrite and elevating superoxide and impaired proliferative ability. BH4 supplementation restored normal RMEC proliferation in vitro and also in vivo, providing a mechanistic link with the enhanced vascular coverage in eNOS-GFP retinas. Conclusions These results demonstrate that BH4 supplementation corrects hyperoxia-induced RMEC dysfunction and preserves vascular integrity by enhancing eNOS function.
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Affiliation(s)
- Kevin S. Edgar
- Centre for Experimental Medicine, Queen's University Belfast, United Kingdom
| | - Orla M. Galvin
- Centre for Experimental Medicine, Queen's University Belfast, United Kingdom
| | - Anthony Collins
- Centre for Experimental Medicine, Queen's University Belfast, United Kingdom
| | - Zvonimir S. Katusic
- Department of Anesthesiology and Pharmacology, Mayo Clinic, Minnesota, United States
| | - Denise M. McDonald
- Centre for Experimental Medicine, Queen's University Belfast, United Kingdom
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Dai Y, Cui J, Gan P, Li W. Downregulation of tetrahydrobiopterin inhibits tumor angiogenesis in BALB/c-nu mice with hepatocellular carcinoma. Oncol Rep 2016; 36:669-75. [PMID: 27279530 PMCID: PMC4933545 DOI: 10.3892/or.2016.4850] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/25/2015] [Accepted: 12/04/2015] [Indexed: 02/06/2023] Open
Abstract
Hepatocellular carcinoma (HCC) is a highly vascular tumor, and treatment options for patients of advanced-stage are limited. Nitric oxide (NO), which is derived from endothelial nitric oxide synthase (eNOS), provides crucial signals for angiogenesis in the tumor microenvironment. Tetrahydrobiopterin (BH4) is an essential cofactor eNOS and represents a critical determinant of NO production. To examine whether treatment of 2,4-diamino-6-hydroxypyrimidine (DAHP) inhibits angiogenesis of HCC, BALB/c-nu mice were injected with HepG-2 cells with DAHP. Supplemental DAHP treatment decreased K-ras mRNA transcripts, inhibition of phosphorylation of eNOS and Akt, inhibition of guanosine triphosphate cyclohydrolase (GTPCH), and decreased significantly NO synthesis, and then inhibited angiogenesis, compared with the results observed in the saline group. Histopathology demonstrated angiogenesis and tumor formation were significantly inhibited in HCC. DAHP downregulates GTPCH protein expression, corresponding to decreased levels of BH4 and the contents of NO. In addition, DAHP downregulates eNOS and Akt protein expression, corresponding to decreased eNOS phosphorylation at Ser1177 and Akt phosphorylation, compared with the saline control. We suggest that DAHP, recognized as a specific competitive inhibitor of GTPCH, can decrease tumor BH4 and NO by the inhibition of the wild-type Ras-PI3K/Akt pathway, and then inhibiting angiogenesis, and may provide a novel and promising way to target BH4 synthetic pathways to inhibit angiogenesis and to control potential progression of HCC. Whether DAHP has a therapeutic potential will require more direct testing in humans.
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Affiliation(s)
- Youguo Dai
- Department of Abdominal Surgery, Third Affiliated Hospital of Kunming Medical University, Kunming, Yunnan 650118
| | | | - Ping Gan
- Department of Abdominal Surgery, Third Affiliated Hospital of Kunming Medical University, Kunming, Yunnan 650118
| | - Weiming Li
- Department of General Surgery, Second Affiliated Hospital of Kunming Medical University, Kunming, Yunnan 650101, P.R. China
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Santhanam AVR, d'Uscio LV, Katusic ZS. Characterization of cerebral microvasculature in transgenic mice with endothelium targeted over-expression of GTP-cyclohydrolase I. Brain Res 2015; 1625:198-205. [PMID: 26343845 PMCID: PMC4637228 DOI: 10.1016/j.brainres.2015.08.034] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/22/2015] [Revised: 08/14/2015] [Accepted: 08/26/2015] [Indexed: 01/05/2023]
Abstract
Tetrahydrobiopterin (BH4) is a critical determinant of nitric oxide (NO) production by nitric oxide synthase (NOS) in the vascular endothelium and its biosynthesis is regulated by the enzymatic activity of GTP-cyclohydrolase I (GTPCH I). The present study was designed to determine the effects of endothelium-targeted overexpression of GTPCH I (eGCH-Tg) on murine cerebral vascular function. Endothelium targeted over-expression of GTPCH I was associated with a significant increase in levels of BH4, as well as its oxidized product, 7,8-dihydrobiopterin (7,8-BH2) in cerebral microvessels. Importantly, ratio of BH4 to 7,8-BH2, indicative of BH4 available for eNOS activation, was significantly increased in eGCH-Tg mice. However, expression of endothelial NOS, levels of nitrate/nitrite--indicative of NO production--remained unchanged between cerebral microvessels of wild-type and eGCH-Tg mice. Furthermore, increased BH4 biosynthesis neither affected production of superoxide anion nor expression of antioxidant proteins. Moreover, endothelium-specific GTPCH I overexpression did not alter intracellular levels of cGMP, reflective of NO signaling in cerebral microvessels. The obtained results suggest that, despite a significant increase in BH4 bioavailability, generation of endothelial NO in cerebral microvessels remained unchanged in eGCH-Tg mice. We conclude that under physiological conditions the levels of BH4 in the cerebral microvessels are optimal for activation of endothelial NOS and NO/cGMP signaling.
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Affiliation(s)
- Anantha Vijay R Santhanam
- Departments of Anesthesiology and Molecular Pharmacology & Experimental Therapeutics, Mayo Clinic College of Medicine, 200 First Street SW, Rochester, MN 55905, USA
| | - Livius V d'Uscio
- Departments of Anesthesiology and Molecular Pharmacology & Experimental Therapeutics, Mayo Clinic College of Medicine, 200 First Street SW, Rochester, MN 55905, USA
| | - Zvonimir S Katusic
- Departments of Anesthesiology and Molecular Pharmacology & Experimental Therapeutics, Mayo Clinic College of Medicine, 200 First Street SW, Rochester, MN 55905, USA.
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Bendall JK, Douglas G, McNeill E, Channon KM, Crabtree MJ. Tetrahydrobiopterin in cardiovascular health and disease. Antioxid Redox Signal 2014; 20:3040-77. [PMID: 24294830 PMCID: PMC4038990 DOI: 10.1089/ars.2013.5566] [Citation(s) in RCA: 163] [Impact Index Per Article: 16.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/15/2013] [Revised: 11/01/2013] [Accepted: 12/02/2013] [Indexed: 01/03/2023]
Abstract
Tetrahydrobiopterin (BH4) functions as a cofactor for several important enzyme systems, and considerable evidence implicates BH4 as a key regulator of endothelial nitric oxide synthase (eNOS) in the setting of cardiovascular health and disease. BH4 bioavailability is determined by a balance of enzymatic de novo synthesis and recycling, versus degradation in the setting of oxidative stress. Augmenting vascular BH4 levels by pharmacological supplementation has been shown in experimental studies to enhance NO bioavailability. However, it has become more apparent that the role of BH4 in other enzymatic pathways, including other NOS isoforms and the aromatic amino acid hydroxylases, may have a bearing on important aspects of vascular homeostasis, inflammation, and cardiac function. This article reviews the role of BH4 in cardiovascular development and homeostasis, as well as in pathophysiological processes such as endothelial and vascular dysfunction, atherosclerosis, inflammation, and cardiac hypertrophy. We discuss the therapeutic potential of BH4 in cardiovascular disease states and attempt to address how this modulator of intracellular NO-redox balance may ultimately provide a powerful new treatment for many cardiovascular diseases.
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Affiliation(s)
- Jennifer K Bendall
- Division of Cardiovascular Medicine, British Heart Foundation Centre of Research Excellence, University of Oxford , John Radcliffe Hospital, Oxford, United Kingdom
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15
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Zhang S, Liu L, Wang R, Tuo H, Guo Y, Yi L, Wang J, Wang D. MiR-199a-5p promotes migration and tube formation of human cytomegalovirus-infected endothelial cells through downregulation of SIRT1 and eNOS. Arch Virol 2013; 158:2443-52. [PMID: 23760629 DOI: 10.1007/s00705-013-1744-1] [Citation(s) in RCA: 28] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/06/2013] [Accepted: 04/22/2013] [Indexed: 01/10/2023]
Abstract
Human cytomegalovirus (HCMV) infection has been shown to contribute to vascular disease through the induction of angiogenesis. However, the role of microRNA in angiogenesis induced by HCMV infection remains unclear. The present study was thus designed to explore the potential effect of miR-199a-5p on angiogenesis and to investigate the underlying mechanism in endothelial cells. We found that HCMV infection of endothelial cells (ECs) enhanced expression of miR-199a-5p and reduced the SIRT1 protein level at 24 h postinfection (hpi). Transfection with miR-199a-5p mimics significantly suppressed SIRT1 protein expression and promoted cellular migration and tube formation induced by HCMV infection, which could be reversed by transfection with an miR-199a-5p inhibitor. Furthermore, pretreatment with resveratrol depressed motility and tube formation of HCMV-infected ECs, which could be reversed by SIRT1 siRNA. Finally, overexpression of miR-199a-5p decreased the level of eNOS modulated by SIRT1, an effect repressed by transfection with an miR-199a-5p inhibitor. In summary, HCMV infection of endothelial cells upregulates miR-199a-5p expression and enhances cell migration and tube formation through downregulation of SIRT1/eNOS by miR-199a-5p.
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Affiliation(s)
- Shanchao Zhang
- Department of Neurology, Beijing Friendship Hospital, Capital Medical University, NO.95 YongAn Road, Xuanwu District, Beijing, 100050, China
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Pickert G, Lim HY, Weigert A, Häussler A, Myrczek T, Waldner M, Labocha S, Ferreirós N, Geisslinger G, Lötsch J, Becker C, Brüne B, Tegeder I. Inhibition of GTP cyclohydrolase attenuates tumor growth by reducing angiogenesis and M2-like polarization of tumor associated macrophages. Int J Cancer 2013; 132:591-604. [PMID: 22753274 DOI: 10.1002/ijc.27706] [Citation(s) in RCA: 42] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/19/2011] [Accepted: 04/23/2012] [Indexed: 01/09/2023]
Abstract
GTP cyclohydrolase (GCH1) is the key-enzyme to produce the essential enzyme cofactor, tetrahydrobiopterin. The byproduct, neopterin is increased in advanced human cancer and used as cancer-biomarker, suggesting that pathologically increased GCH1 activity may promote tumor growth. We found that inhibition or silencing of GCH1 reduced tumor cell proliferation and survival and the tube formation of human umbilical vein endothelial cells, which upon hypoxia increased GCH1 and endothelial NOS expression, the latter prevented by inhibition of GCH1. In nude mice xenografted with HT29-Luc colon cancer cells GCH1 inhibition reduced tumor growth and angiogenesis, determined by in vivo luciferase and near-infrared imaging of newly formed blood vessels. The treatment with the GCH1 inhibitor shifted the phenotype of tumor associated macrophages from the proangiogenic M2 towards M1, accompanied with a shift of plasma chemokine profiles towards tumor-attacking chemokines including CXCL10 and RANTES. GCH1 expression was increased in mouse AOM/DSS-induced colon tumors and in high grade human colon and skin cancer and oppositely, the growth of GCH1-deficient HT29-Luc tumor cells in mice was strongly reduced. The data suggest that GCH1 inhibition reduces tumor growth by (i) direct killing of tumor cells, (ii) by inhibiting angiogenesis, and (iii) by enhancing the antitumoral immune response.
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Affiliation(s)
- Geethanjali Pickert
- Pharmazentrum frankfurt/ZAFES, Institut für Klinische Pharmakologie, Goethe-Universität, Frankfurt, Germany
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Abstract
PURPOSE OF REVIEW The endothelial isoform of nitric oxide synthase (eNOS) is constitutively expressed but dynamically regulated by a number of factors. Building our knowledge of this regulation is necessary to understand and modulate the bioavailability of nitric oxide, central to the cardiovascular complications of diabetes and other diseases. This review will focus on the eNOS substrate (L-arginine), its cofactor (tetrahydrobiopterin), and mechanisms related to the uncoupling of eNOS activity. RECENT FINDINGS The global arginine bioavailability ratio has been proposed as a biomarker reflective of L-arginine availability, arginase activity, and citrulline cycling, as all of these processes impact eNOS activity. The failure of oral supplementation of tetrahydrobiopterin to recouple eNOS has emphasized the importance of the tetrahydrobiopterin to dihydrobiopterin ratio. Identification of transporters for biopterin species as well as signals that regulate endogenous arginine production have provided insight for alternative strategies to raise endothelial tetrahydrobiopterin levels while reducing dihydrobiopterin and alter eNOS activity. Finally, new information about redox regulation of eNOS itself may point to ways of controlling oxidative stress in the vasculature. SUMMARY Restoring proper eNOS activity is key to ameliorating or preventing cardiovascular complications of diabetes. Continued investigation is needed to uncover new means for maintaining endothelial nitric oxide bioavailability.
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Affiliation(s)
- Hai H Hoang
- Department of Systems Biology and Translational Medicine, Texas A&M Health Science Center, Temple, Texas 76504, USA
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18
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Teng RJ, Du J, Xu H, Bakhutashvili I, Eis A, Shi Y, Pritchard KA, Konduri GG. Sepiapterin improves angiogenesis of pulmonary artery endothelial cells with in utero pulmonary hypertension by recoupling endothelial nitric oxide synthase. Am J Physiol Lung Cell Mol Physiol 2011; 301:L334-45. [PMID: 21622842 PMCID: PMC3174740 DOI: 10.1152/ajplung.00316.2010] [Citation(s) in RCA: 31] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/10/2010] [Accepted: 05/23/2011] [Indexed: 02/07/2023] Open
Abstract
Persistent pulmonary hypertension of the newborn (PPHN) is associated with decreased blood vessel density that contributes to increased pulmonary vascular resistance. Previous studies showed that uncoupled endothelial nitric oxide (NO) synthase (eNOS) activity and increased NADPH oxidase activity resulted in marked decreases in NO bioavailability and impaired angiogenesis in PPHN. In the present study, we hypothesize that loss of tetrahydrobiopterin (BH4), a critical cofactor for eNOS, induces uncoupled eNOS activity and impairs angiogenesis in PPHN. Pulmonary artery endothelial cells (PAEC) isolated from fetal lambs with PPHN (HTFL-PAEC) or control lambs (NFL-PAEC) were used to investigate the cellular mechanisms impairing angiogenesis in PPHN. Cellular mechanisms were examined with respect to BH4 levels, GTP-cyclohydrolase-1 (GCH-1) expression, eNOS dimer formation, and eNOS-heat shock protein 90 (hsp90) interactions under basal conditions and after sepiapterin (Sep) supplementation. Cellular levels of BH4, GCH-1 expression, and eNOS dimer formation were decreased in HTFL-PAEC compared with NFL-PAEC. Sep supplementation decreased apoptosis and increased in vitro angiogenesis in HTFL-PAEC and ex vivo pulmonary artery sprouting angiogenesis. Sep also increased cellular BH4 content, NO production, eNOS dimer formation, and eNOS-hsp90 association and decreased the superoxide formation in HTFL-PAEC. These data demonstrate that Sep improves NO production and angiogenic potential of HTFL-PAEC by recoupling eNOS activity. Increasing BH4 levels via Sep supplementation may be an important therapy for improving eNOS function and restoring angiogenesis in PPHN.
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Affiliation(s)
- Ru-Jeng Teng
- Division of Neonatology, Dept. of Pediatrics, Medical College of Wisconsin, Suite C410, Children Corporate Center, 999N 92nd St., Wauwatosa, WI 53226, USA.
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19
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He T, Smith LA, Lu T, Joyner MJ, Katusic ZS. Activation of peroxisome proliferator-activated receptor-{delta} enhances regenerative capacity of human endothelial progenitor cells by stimulating biosynthesis of tetrahydrobiopterin. Hypertension 2011; 58:287-94. [PMID: 21709207 PMCID: PMC3143017 DOI: 10.1161/hypertensionaha.111.172189] [Citation(s) in RCA: 30] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/05/2023]
Abstract
The mechanisms underlying the regenerative capacity of endothelial progenitor cells (EPCs) are not fully understood. We hypothesized that biosynthesis of tetrahydrobiopterin is an important mechanism responsible for the stimulatory effects of peroxisome proliferator-activated receptor-δ (PPARδ) activation on regenerative function of human EPCs. Treatment of human EPCs with a selective PPARδ agonist GW501516 for 24 hours increased the levels of mRNA, protein, and enzymatic activity of GTP cyclohydrolase I (GTPCH I), as well as the production of tetrahydrobiopterin. The effects of GW501516 were mediated by suppression of PTEN expression, thereby increasing phosphorylation of AKT. The AKT signaling also mediated GW501516-induced phosphorylation of endothelial NO synthase. In addition, activation of PPARδ significantly enhanced proliferation of EPCs. This effect was abolished by the GTPCH I inhibitor, 2,4-diamino-6-hydroxypyrimidine, or genetic inactivation of GTPCH I with small interfering RNA but not by inhibition of endothelial NO synthase with N(G)-nitro-l-arginine methyl ester. Supplementation of NO did not reverse 2,4-diamino-6-hydroxypyrimidine-inhibited 5-bromodeoxyuridine incorporation. Furthermore, transplantation of human EPCs stimulated re-endothelialization in a mouse model of carotid artery injury. Pretreatment of EPCs with GW501516 significantly enhanced the ability of transplanted EPCs to repair denuded endothelium. GTPCH I-small interfering RNA transfection significantly inhibited in vivo regenerative capacity of EPCs stimulated with GW501516. Thus, in human EPCs, activation of PPARδ stimulates expression and activity of GTPCH I and biosynthesis of tetrahydrobiopterin via PTEN-AKT signaling pathway. This effect enhances the regenerative function of EPCs.
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Affiliation(s)
- Tongrong He
- Department of Anesthesiology and Molecular Pharmacology and Experimental Therapeutics, Rochester, Minnesota
| | - Leslie A. Smith
- Department of Anesthesiology and Molecular Pharmacology and Experimental Therapeutics, Rochester, Minnesota
| | - Tong Lu
- Department of Internal Medicine, Mayo Clinic College of Medicine, Rochester, Minnesota
| | - Michael J. Joyner
- Department of Anesthesiology and Molecular Pharmacology and Experimental Therapeutics, Rochester, Minnesota
| | - Zvonimir S. Katusic
- Department of Anesthesiology and Molecular Pharmacology and Experimental Therapeutics, Rochester, Minnesota
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20
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Meininger CJ, Wu G. Tetrahydrobiopterin: important endothelial mediator independent of endothelial nitric oxide synthase. Hypertension 2011; 58:145-7. [PMID: 21709208 PMCID: PMC3160747 DOI: 10.1161/hypertensionaha.111.174003] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Affiliation(s)
- Cynthia J. Meininger
- Department of Systems Biology and Translational Medicine, Texas A&M Health Science Center, Temple, TX
| | - Guoyao Wu
- Department of Systems Biology and Translational Medicine, Texas A&M Health Science Center, Temple, TX
- Department of Animal Science, Texas A&M University, College Station, TX
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Inhibition of vascular endothelial growth factor-induced angiogenesis by scopoletin through interrupting the autophosphorylation of VEGF receptor 2 and its downstream signaling pathways. Vascul Pharmacol 2011; 54:18-28. [DOI: 10.1016/j.vph.2010.11.001] [Citation(s) in RCA: 40] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/31/2010] [Revised: 10/25/2010] [Accepted: 11/08/2010] [Indexed: 12/27/2022]
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Chen L, Zeng X, Wang J, Briggs SS, O'Neill E, Li J, Leek R, Kerr DJ, Harris AL, Cai S. Roles of tetrahydrobiopterin in promoting tumor angiogenesis. THE AMERICAN JOURNAL OF PATHOLOGY 2010; 177:2671-80. [PMID: 20847284 PMCID: PMC2966821 DOI: 10.2353/ajpath.2010.100025] [Citation(s) in RCA: 23] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Accepted: 07/21/2010] [Indexed: 01/09/2023]
Abstract
Nitric oxide (NO), which is derived from endothelial NO synthase (eNOS), provides crucial signals for angiogenesis in the tumor microenvironment. Tetrahydrobiopterin (BH4) is an absolute requirement for eNOS activity. In this study, we investigated whether this activation is both maintained by a wild-type Ras/phosphatidylinositol 3-kinase (PI3K)/Akt-positive feedback loop in endothelial cells and affects tumor angiogenesis. We found that supplementation of BH4 (via the pterin salvage pathway with Sep) increased Akt/eNOS phosphorylation in both human eNOS-transfected COS-7 cells and endothelial cells concomitant with increases in NO production, cell proliferation, migration, and tube formation. This augmentation was abrogated by a PI3K inhibitor. Sepiapterin (Sep) also increased GTP-bound wild-type Ras and PI3K/Akt/eNOS activation, which was prevented by the eNOS inhibitor, Nω-Nitro-L-arginine methyl ester (L-NAME). Furthermore, expression of GTP cyclohydrolase I (the rate-limiting enzyme in de novo BH4 synthesis) under doxycycline control potentiated in vivo tumorigenesis, tumor cell proliferation, as well as angiogenesis. Conversely, both switching off GTP cyclohydrolase I expression as well as inhibiting its enzymatic activity significantly decreased eNOS expression and tumor vascularization. This study demonstrates an important role for BH4 synthesis in angiogenesis by the activation of eNOS for NO production, which is maintained by a PI3K/Akt-positive feedback loop through effects on wild-type Ras in endothelial cells. Our findings suggest that BH4 synthesis may be a rational target for antiangiogenesis therapy for tumors.
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Affiliation(s)
- Liye Chen
- Department of Clinical Pharmacology, University of Oxford, John Radcliffe Hospital, Old Road Campus Research Building, Roosevelt Drive, Headington, Oxford OX3 7DQ, UK
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Caposio P, Orloff SL, Streblow DN. The role of cytomegalovirus in angiogenesis. Virus Res 2010; 157:204-11. [PMID: 20869406 DOI: 10.1016/j.virusres.2010.09.011] [Citation(s) in RCA: 54] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/24/2010] [Revised: 09/17/2010] [Accepted: 09/17/2010] [Indexed: 01/02/2023]
Abstract
Human cytomegalovirus (HCMV) infection has been associated with the acceleration of vascular disease including atherosclerosis and transplant associated vasculopathy in solid organ transplants. HCMV promotes vascular disease at many of the different stages of the disease development. These include the initial injury phase, enhancing the response to injury and inflammation, as well as by increasing SMC hyperplasia and foamy macrophage cell formation. Angiogenesis is a critical process involved in the development of vascular diseases. Recently, HCMV has been shown to induce angiogenesis and this process is thought to contribute to HCMV-accelerated vascular disease and may also be important for HCMV-enhanced tumor formation. This review will highlight the role of HCMV in promoting angiogenesis.
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Affiliation(s)
- Patrizia Caposio
- Department of Molecular Microbiology & Immunology and The Vaccine & Gene Therapy Institute, Oregon Health & Science University, Portland, OR 97239, USA
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Kim JW, Lee JH, Lee SH. Role of Nitric Oxide in the Proliferative and Migratory Effect of Triamcinolone in RPE Cells. JOURNAL OF THE KOREAN OPHTHALMOLOGICAL SOCIETY 2010. [DOI: 10.3341/jkos.2010.51.1.120] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/23/2022]
Affiliation(s)
- Jae Woo Kim
- Department of Ophthalmology, Catholic University of Daegu College of Medicine, Daegu, Korea
| | - Jae Hyung Lee
- Department of Ophthalmology, Catholic University of Daegu College of Medicine, Daegu, Korea
| | - Seung Hee Lee
- Department of Ophthalmology, Catholic University of Daegu College of Medicine, Daegu, Korea
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25
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Ionova IA, Vásquez-Vivar J, Whitsett J, Herrnreiter A, Medhora M, Cooley BC, Pieper GM. Deficient BH4 production via de novo and salvage pathways regulates NO responses to cytokines in adult cardiac myocytes. Am J Physiol Heart Circ Physiol 2008; 295:H2178-87. [PMID: 18835915 PMCID: PMC2614582 DOI: 10.1152/ajpheart.00748.2008] [Citation(s) in RCA: 30] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/17/2008] [Accepted: 09/25/2008] [Indexed: 12/25/2022]
Abstract
Adult rat cardiac myocytes typically display a phenotypic response to cytokines manifested by low or no increases in nitric oxide (NO) production via inducible NO synthase (iNOS) that distinguishes them from other cell types. To better characterize this response, we examined the expression of tetrahydrobiopterin (BH4)-synthesizing and arginine-utilizing genes in cytokine-stimulated adult cardiac myocytes. Intracellular BH4 and 7,8-dihydrobiopterin (BH2) and NO production were quantified. Cytokines induced GTP cyclohydrolase and its feedback regulatory protein but with deficient levels of BH4 synthesis. Despite the induction of iNOS protein, cytokine-stimulated adult cardiac myocytes produced little or no increase in NO versus unstimulated cells. Western blot analysis under nonreducing conditions revealed the presence of iNOS monomers. Supplementation with sepiapterin (a precursor of BH4) increased BH4 as well as BH2, but this did not enhance NO levels or eliminate iNOS monomers. Similar findings were confirmed in vivo after treatment of rat cardiac allograft recipients with sepiapterin. It was found that expression of dihydrofolate reductase, required for full activity of the salvage pathway, was not detected in adult cardiac myocytes. Thus, adult cardiac myocytes have a limited capacity to synthesize BH4 after cytokine stimulation. The mechanisms involve posttranslational factors impairing de novo and salvage pathways. These conditions are unable to support active iNOS protein dimers necessary for NO production. These findings raise significant new questions about the prevailing understanding of how cytokines, via iNOS, cause cardiac dysfunction and injury in vivo during cardiac inflammatory disease states since cardiac myocytes are not a major source of high NO production.
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Affiliation(s)
- Irina A Ionova
- Department of Surgery (Transplant Surgery), Medical College of Wisconsin, 8701 Watertown Plank Rd., Milwaukee, WI 53226, USA
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Disruption of the Nitric Oxide Signaling System in Diabetes. Cardiovasc Endocrinol 2008. [DOI: 10.1007/978-1-59745-141-3_3] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/21/2022] Open
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Kaur C, Sivakumar V, Lu J, Tang FR, Ling EA. Melatonin attenuates hypoxia-induced ultrastructural changes and increased vascular permeability in the developing hippocampus. Brain Pathol 2008; 18:533-47. [PMID: 18422758 DOI: 10.1111/j.1750-3639.2008.00156.x] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022] Open
Abstract
Hypoxic injury in the perinatal period may be involved in damaging the developing hippocampus. The damage may be mediated by excess production of vascular endothelial growth factor (VEGF) and nitric oxide (NO). We examined the hippocampus of neonatal Wistar rats subjected to hypoxia for VEGF and NO production. The mRNA and protein expression of hypoxia inducible factor-1alpha, endothelial, neuronal, inducible nitric oxide synthase and VEGF was found to be up-regulated significantly after the hypoxic exposure. Tissue VEGF concentration and NO production were also increased. By electron microscopy, swollen dendrites, vacuolated axons and hypertrophic astrocyte end feet associated with blood vessels were observed in hypoxic animals. In hypoxic rats, the passage of rhodamine isothiocyanate (RhIC) and horseradish peroxidase, administered intraperitoneally or intravenously, was observed through vascular walls. Furthermore, immunoglobulin G was localized in the neuropil and neurons. We suggest that increased VEGF and NO production in hypoxia had resulted in increased vascular permeability, leading to structural alteration of the dendrites and axons. Melatonin administration reduced VEGF and NO levels as well as leakage of RhIC, suggesting that it has a therapeutic potential in reducing hypoxia-associated damage in the developing hippocampus.
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Affiliation(s)
- Charanjit Kaur
- Department of Anatomy, Yong Loo Lin School of Medicine, Blk MD10, 4 Medical Drive, National University of Singapore, Singapore.
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Ridnour LA, Isenberg JS, Espey MG, Thomas DD, Roberts DD, Wink DA. Nitric oxide regulates angiogenesis through a functional switch involving thrombospondin-1. Proc Natl Acad Sci U S A 2005; 102:13147-52. [PMID: 16141331 PMCID: PMC1201580 DOI: 10.1073/pnas.0502979102] [Citation(s) in RCA: 227] [Impact Index Per Article: 11.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/26/2022] Open
Abstract
Nitric oxide (NO) donors have been shown to stimulate and inhibit the proliferation, migration, and differentiation of endothelial cells in vitro and angiogenesis in vivo. Recently, we have shown distinct thresholds for NO to regulate p53-Ser-15P, phosphorylated extracellular signal-regulated kinase (pERK), and hypoxia inducible factor 1alpha in tumor cells. Because these signaling pathways also promote the growth and survival of endothelial cells, we examined their roles in angiogenic responses of venous endothelial cells and vascular outgrowth of muscle explants elicited by NO. An additional protein involved in the regulation of angiogenesis is thrombospondin-1 (TSP1), a matricellular glycoprotein known to influence adhesion, migration, and proliferation of endothelial cells. Here we demonstrate a triphasic regulation of TSP1 mediated by a slow and prolonged release of NO that depends on ERK phosphorylation. Under conditions of 5% serum, a 24-h exposure of NO donor (0.1-1,000 microM) mediated a triphasic response in the expression of TSP1 protein: decreasing at 0.1 microM, rebounding at 100 microM, and decreasing again at 1,000 microM. Under the same conditions, we observed a dose-dependent increase in P53 phosphorylation and inverse biphasic responses of pERK and mitogen-activated protein kinase phosphatase-1. Both the growth-stimulating activity of low-dose NO for endothelial cells and suppression of TSP1 expression were ERK-dependent. Conversely, exogenous TSP1 suppressed NO-mediated pERK. These results suggest that dose-dependent positive- and negative-feedback loops exist between NO and TSP1. Limiting TSP1 expression by positive feedback through the ERK mitogen-activated protein kinase pathway may facilitate switching to a proangiogenic state at low doses of NO.
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Affiliation(s)
- Lisa A Ridnour
- Radiation Biology Branch and Laboratory of Pathology, National Cancer Institute, National Institutes of Health, Bethesda, MD 20892, USA.
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Meininger CJ, Cai S, Parker JL, Channon KM, Kelly KA, Becker EJ, Wood MK, Wade LA, Wu G. GTP cyclohydrolase I gene transfer reverses tetrahydrobiopterin deficiency and increases nitric oxide synthesis in endothelial cells and isolated vessels from diabetic rats. FASEB J 2004; 18:1900-2. [PMID: 15467010 DOI: 10.1096/fj.04-1702fje] [Citation(s) in RCA: 68] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
Abstract
Nitric oxide (NO) synthesis in endothelial cells is impaired in diabetes. We previously showed that impaired NO synthesis in the spontaneously diabetic BB (BBd) rat is due to decreased levels of tetrahydrobiopterin (BH4), secondary to decreased expression of GTP cyclohydrolase I (GTPCH). The aim of this study was to utilize adenoviral GTPCH gene transfer to reverse BH4 deficiency and repair the ability of endothelial cells to produce NO. GTPCH gene transfer increased BH4 levels in BBd endothelial cells from 0.17 +/- 0.02 (mean +/-SE) to 73.37 +/- 14.42 pmol/million cells and NO production from 0.77 +/- 0.07 to 18.74 +/- 5.52 nmol/24 h/million cells. To demonstrate a functional effect of increasing BH4 concentrations in tissues, we transferred GTPCH into aortic rings from BBd and Zucker diabetic fatty (ZDF) rats, models of human type I and type II diabetes, respectively. GTPCH gene transfer led to a dose-dependent increase in acetylcholine-induced vasorelaxation, preventable by inhibiting NO synthase. Maximal relaxation of virus-treated rings (10(10) virus particles/ml) to acetylcholine was significantly higher than sham-treated rings (BBd 64% vs. 37%, P<0.005; ZDF 80% vs. 44%, P<0.05). This study demonstrates that GTPCH gene transfer can reverse BH4 deficiency in both type I and type II diabetes and provides an experimental basis for using gene therapy to treat cardiovascular complications in diabetic patients.
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Affiliation(s)
- Cynthia J Meininger
- Cardiovascular Research Institute, Department of Medical Physiology, Texas A&M University System Health Science Center, Temple, Texas 76504, USA.
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Emanueli C, Graiani G, Salis MB, Gadau S, Desortes E, Madeddu P. Prophylactic gene therapy with human tissue kallikrein ameliorates limb ischemia recovery in type 1 diabetic mice. Diabetes 2004; 53:1096-103. [PMID: 15047627 DOI: 10.2337/diabetes.53.4.1096] [Citation(s) in RCA: 38] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/13/2022]
Abstract
Diabetes macro- and microvascular disease causes tissue hypoperfusion. This deficit, together with a failure to mount an adequate angiogenic response, might explain why vascular occlusion evolves more severely among diabetic patients. The present study investigated whether prophylactic gene therapy with human tissue kallikrein (hTK) may protect diabetic limbs from the consequences of supervening ischemia. Vehicle (saline) or an adenovirus carrying the gene for either hTK (Ad.hTK) or luciferase (Ad.Luc) was injected into left adductor muscles of streptozotocin-induced type 1 diabetic mice 2 weeks before operative occlusion of the ipsilateral femoral artery. Saline-injected nondiabetic mice served as controls. Hindlimb blood flow recovery was analyzed sequentially over the 2 weeks after ischemia induction. At necroscopy, microvessel density and endothelial cell proliferation and apoptosis were quantified in skeletal muscles. We found that limb perfusion recovery of saline-injected type 1 diabetic mice is delayed because of insufficient reparative neovascularization and excessive activation of endothelial cell apoptosis. By contrast, prophylactic Ad.hTK renewed the ability to mount an appropriate neovascularization response to ischemia, suppressed apoptosis, and upregulated endothelial nitric oxide synthase expression. Ultimately, correction of diabetic endotheliopathy by Ad.hTK allowed proper perfusion recovery as seen in nondiabetic mice. These discoveries disclose new therapeutic options for the treatment of diabetic complications.
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Affiliation(s)
- Costanza Emanueli
- Experimental Medicine and Gene Therapy Section, Istituto Nazionale Biostrutture e Biosistemi, Alghero and Osilo, Italy.
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Kohli R, Meininger CJ, Haynes TE, Yan W, Self JT, Wu G. Dietary L-arginine supplementation enhances endothelial nitric oxide synthesis in streptozotocin-induced diabetic rats. J Nutr 2004; 134:600-8. [PMID: 14988454 DOI: 10.1093/jn/134.3.600] [Citation(s) in RCA: 99] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022] Open
Abstract
This study tested the hypothesis that dietary arginine supplementation increases endothelial tetrahydrobiopterin (BH(4)) availability for nitric oxide (NO) synthesis in diabetic rats. Streptozotocin-induced diabetic rats either were given unrestricted access to a casein-based diet (Expt. 1) or were pair-fed the diet on the basis of the food intake per kg of body weight of nondiabetic rats (Expt. 2). Beginning 1 d after vehicle or streptozotocin injection, arginine-HCl (1.51%) or alanine (isonitrogenous control, 2.55%) was added daily to the drinking water for nondiabetic rats, whereas concentrations were adjusted (0.43% arginine-HCl and 0.73% alanine) in the drinking water for diabetic rats (which consumed more water) to ensure isonitrogenous provision. At 2 wk after the initiation of arginine supplementation, coronary endothelial cells and plasma were obtained for the measurement of NO synthesis and metabolites. In both experiments, plasma and endothelial concentrations of N(G)-monomethylarginine, asymmetric dimethylarginine, and symmetric dimethylarginine increased, but those of arginine as well as endothelial BH(4) availability and NO synthesis decreased in diabetic rats, compared with nondiabetic rats. In both diabetic and nondiabetic rats, arginine supplementation increased plasma concentrations of arginine and insulin, endothelial concentrations of arginine and BH(4), and endothelial NO synthesis, but did not affect plasma and endothelial concentrations of methylarginines or plasma concentrations of homocysteine. Dietary arginine supplementation or provision of a BH(4) precursor normalized endothelial NO synthesis in diabetic rats. Arginine supplementation did not affect plasma glucose levels in nondiabetic rats, but reduced body weight loss and plasma glucose levels in diabetic rats. Thus, dietary L-arginine supplementation stimulates endothelial NO synthesis by increasing BH(4) provision, which is beneficial for vascular function and glucose homeostasis in diabetic subjects.
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Affiliation(s)
- Ripla Kohli
- Faculty of Nutrition and Department of Animal Science, Texas A&M University, College Station, TX 77843, USA
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Karagiannis J, Reid JJ, Darby I, Roche P, Rand MJ, Li CG. Impaired Nitric Oxide Function in the Basilar Artery of the Obese Zucker Rat. J Cardiovasc Pharmacol 2003; 42:497-505. [PMID: 14508235 DOI: 10.1097/00005344-200310000-00007] [Citation(s) in RCA: 31] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/08/2023]
Abstract
The effect of insulin-resistance syndrome on vascular function has been examined in isolated basilar arteries using the obese Zucker rat (OZR) and age-matched lean littermate controls (lean Zucker rat; LZR) at 36 weeks of age. The OZR showed significantly reduced oral glucose tolerance and increased body weight, blood pressure, proteinuria, plasma levels of triglycerides, cholesterol, and insulin compared with the LZR. The contractile response to serotonin was significantly increased in the OZR. Furthermore, contractions to serotonin in LZR but not OZR were enhanced in the presence of the nitric oxide synthase inhibitor Nomega-nitro-L-arginine methyl ester (NAME). Relaxations to acetylcholine (ACh), histamine, and A23187 were significantly reduced in precontracted arteries from the OZR. In the presence of NAME, histamine responses were significantly reduced whereas ACh and A23187 responses were almost abolished. Relaxations to free-radical nitric oxide (NO) and papaverine were not different in arteries from the OZR, even though responses to sodium nitroprusside were reduced in the OZR. Western blot and immunofluorescent quantitative analyses of eNOS content in cerebral microvessel fractions and basilar artery preparations, respectively, were not significantly different between OZR and LZR. The results suggest impairment in endothelial function resulting in reduced NO function in the basilar artery from the OZR.
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Affiliation(s)
- J Karagiannis
- Division of Biosciences, School of Medical Sciences, RMIT University, Victoria, Australia
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Abstract
OBJECTIVES The possible link between folic acid or folate and tetrahydrobiopterin (H(4)B), vitamin C, polyunsaturated fatty acids (PUFAs), and nitric oxide (NO), which may explain the beneficial actions of these nutrients in various vascular conditions, was investigated. METHODS The literature pertaining to the actions of folic acid/folate, H(4)B, vitamin C, PUFAs, and NO was reviewed. RESULTS Impaired endothelial NO (eNO) activity is an early marker for cardiovascular disease. Most risk factors for atherosclerosis are associated with impaired endothelium-dependent vasodilatation due to reduced NO production. Folate not only reduces plasma homocysteine levels but also enhances eNO synthesis and shows anti-inflammatory actions. It stimulates endogenous H(4)B regeneration, a cofactor necessary for eNO synthesis, inhibits intracellular superoxide generation, and thus enhances the half-life of NO. H(4)B in turn enhances NO generation and augments arginine transport into the cells. Folic acid increases the concentration of omega-3 PUFAs, which also enhance eNO synthesis. Vitamin C augments eNO synthesis by increasing intracellular H(4)B and stabilization of H(4)B. Insulin stimulates H(4)B synthesis and PUFA metabolism, suppresses the production of proinflammatory cytokine tumor necrosis factor-alpha and superoxide anion, and enhances NO generation. The ability of folate to augment eNO generation is independent of its capacity to lower plasma homocysteine levels. CONCLUSIONS The common mechanism by which folic acid, H(4)B, vitamin C, omega-3 fatty acids, and L-arginine bring about their beneficial actions in various vascular diseases is by enhancing eNO production. Hence, it remains to be determined whether a judicious combination of folic acid, vitamins B12, B6, and C, H(4)B, L-arginine, and omega-3 fatty acids in appropriate amounts may form a novel approach in the prevention and management of various conditions such as hyperlipidemias, coronary heart disease, atherosclerosis, peripheral vascular disease, and some neurodegenerative conditions.
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Pannirselvam M, Anderson TJ, Triggle CR. Endothelial cell dysfunction in type I and II diabetes: The cellular basis for dysfunction. Drug Dev Res 2003. [DOI: 10.1002/ddr.10127] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/10/2022]
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Abstract
Chronic wounds mainly affect elderly individuals and persons with comorbid diseases due to a compromised immune status. An age-related decline in immune function deters proper healing of wounds in an orderly and timely manner. Thus, older adults with 1 or more concomitant illnesses are more likely to experience and sufferfrom a nonhealing wound, which may drastically decrease their quality of life and financial resources. Novel therapies in wound care management rely heavily on our current knowledge of wound healing physiology. It is well established that normal wound healing occurs sequentially and is strictly regulated by pro-inflammatory cytokines and growth factors. A multitude of commercial products such as growth factors are available; however, their effectiveness in healing chronic wounds has yet to be proven. Recently, investigators have implicated nitric oxide (NO) in the exertion of regulatoryforces on various cellular activities of the inflammatory and proliferative phases of wound healing. Gene therapy in animal studies has shown promising results and is furthering our understanding of impaired wound healing. The purpose of this article is to review the literature on NO and its role in wound healing. A discussion of the physiology of normal healing and the pathophysiology of chronic wounds is provided.
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Li H, Meininger CJ, Kelly KA, Hawker JR, Morris SM, Wu G. Activities of arginase I and II are limiting for endothelial cell proliferation. Am J Physiol Regul Integr Comp Physiol 2002; 282:R64-9. [PMID: 11742824 DOI: 10.1152/ajpregu.2002.282.1.r64] [Citation(s) in RCA: 77] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
Polyamines are essential for cell proliferation; therefore, we hypothesized that arginase I or arginase II activities, via production of ornithine for polyamine synthesis, may be limiting for proliferation of endothelial cells (EC). Bovine coronary venular EC stably transfected with a lacZ gene (lacZ-EC, control), rat arginase I cDNA (AI-EC), or mouse arginase II cDNA (AII-EC) were utilized to test this hypothesis. Cell-proliferation assays showed that EC proliferation was markedly increased in AI-EC and AII-EC compared with lacZ-EC. Expression of proliferating cell nuclear antigen was also enhanced in AI-EC and AII-EC. DL-alpha-difluoromethylornithine (DFMO), an irreversible inhibitor of ornithine decarboxylase, was used to establish that increased polyamine synthesis was involved in mediating the enhanced growth of AI-EC and AII-EC. Addition of 5 mM DFMO to the culture medium completely abolished the differences in cellular putrescine concentrations and reduced the differences in spermidine concentrations among AI-EC, AII-EC, and lacZ-EC. The DFMO treatment also prevented an increase in AI-EC and AII-EC proliferation compared with lacZ-EC. Addition of 10 and 50 microM putrescine dose-dependently increased AI-EC, AII-EC, and lacZ-EC growth to the same extent. These results demonstrate that either arginase isoform can potentially play a role in modulating EC proliferation by regulating polyamine synthesis.
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Affiliation(s)
- Hui Li
- Department of Animal Science and Faculty of Nutrition, Texas A&M University, College Station, Texas 77843-2471, USA
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