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Li H, Hardy CD, Reidl CT, Jing Q, Xue F, Cinelli M, Silverman RB, Poulos TL. Crystallographic and Computational Insights into Isoform-Selective Dynamics in Nitric Oxide Synthase. Biochemistry 2024; 63:788-796. [PMID: 38417024 PMCID: PMC10956423 DOI: 10.1021/acs.biochem.3c00601] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/31/2023] [Revised: 01/19/2024] [Accepted: 01/22/2024] [Indexed: 03/01/2024]
Abstract
In our efforts to develop inhibitors selective for neuronal nitric oxide synthase (nNOS) over endothelial nitric oxide synthase (eNOS), we found that nNOS can undergo conformational changes in response to inhibitor binding that does not readily occur in eNOS. One change involves movement of a conserved tyrosine, which hydrogen bonds to one of the heme propionates, but in the presence of an inhibitor, changes conformation, enabling part of the inhibitor to hydrogen bond with the heme propionate. This movement does not occur as readily in eNOS and may account for the reason why these inhibitors bind more tightly to nNOS. A second structural change occurs upon the binding of a second inhibitor molecule to nNOS, displacing the pterin cofactor. Binding of this second site inhibitor requires structural changes at the dimer interface, which also occurs more readily in nNOS than in eNOS. Here, we used a combination of crystallography, mutagenesis, and computational methods to better understand the structural basis for these differences in NOS inhibitor binding. Computational results show that a conserved tyrosine near the primary inhibitor binding site is anchored more tightly in eNOS than in nNOS, allowing for less flexibility of this residue. We also find that the inefficiency of eNOS to bind a second inhibitor molecule is likely due to the tighter dimer interface in eNOS compared with nNOS. This study provides a better understanding of how subtle structural differences in NOS isoforms can result in substantial dynamic differences that can be exploited in the development of isoform-selective inhibitors.
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Affiliation(s)
- Huiying Li
- Departments
of Molecular Biology and Biochemistry, Pharmaceutical Sciences, and
Chemistry, University of California, Irvine, California 92697-3900, United
States
| | - Christine D. Hardy
- Departments
of Molecular Biology and Biochemistry, Pharmaceutical Sciences, and
Chemistry, University of California, Irvine, California 92697-3900, United
States
| | - Cory T. Reidl
- Department
of Chemistry, Department of Molecular Biosciences, Chemistry of Life
Processes Institute, Center for Developmental Therapeutics, Northwestern University, 2145 Sheridan Road, Evanston, Illinois 60208-3113, United States
| | - Qing Jing
- Department
of Chemistry, Department of Molecular Biosciences, Chemistry of Life
Processes Institute, Center for Developmental Therapeutics, Northwestern University, 2145 Sheridan Road, Evanston, Illinois 60208-3113, United States
| | - Fengtian Xue
- Department
of Chemistry, Department of Molecular Biosciences, Chemistry of Life
Processes Institute, Center for Developmental Therapeutics, Northwestern University, 2145 Sheridan Road, Evanston, Illinois 60208-3113, United States
| | - Maris Cinelli
- Department
of Chemistry, Department of Molecular Biosciences, Chemistry of Life
Processes Institute, Center for Developmental Therapeutics, Northwestern University, 2145 Sheridan Road, Evanston, Illinois 60208-3113, United States
| | - Richard B. Silverman
- Department
of Chemistry, Department of Molecular Biosciences, Chemistry of Life
Processes Institute, Center for Developmental Therapeutics, Northwestern University, 2145 Sheridan Road, Evanston, Illinois 60208-3113, United States
- Department
of Pharmacology, Feinberg School of Medicine, Northwestern University, Chicago, Illinois 60611, United States
| | - Thomas L. Poulos
- Departments
of Molecular Biology and Biochemistry, Pharmaceutical Sciences, and
Chemistry, University of California, Irvine, California 92697-3900, United
States
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Zhang Y, Rózsa M, Liang Y, Bushey D, Wei Z, Zheng J, Reep D, Broussard GJ, Tsang A, Tsegaye G, Narayan S, Obara CJ, Lim JX, Patel R, Zhang R, Ahrens MB, Turner GC, Wang SSH, Korff WL, Schreiter ER, Svoboda K, Hasseman JP, Kolb I, Looger LL. Fast and sensitive GCaMP calcium indicators for imaging neural populations. Nature 2023; 615:884-891. [PMID: 36922596 PMCID: PMC10060165 DOI: 10.1038/s41586-023-05828-9] [Citation(s) in RCA: 117] [Impact Index Per Article: 117.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/08/2021] [Accepted: 02/10/2023] [Indexed: 03/17/2023]
Abstract
Calcium imaging with protein-based indicators1,2 is widely used to follow neural activity in intact nervous systems, but current protein sensors report neural activity at timescales much slower than electrical signalling and are limited by trade-offs between sensitivity and kinetics. Here we used large-scale screening and structure-guided mutagenesis to develop and optimize several fast and sensitive GCaMP-type indicators3-8. The resulting 'jGCaMP8' sensors, based on the calcium-binding protein calmodulin and a fragment of endothelial nitric oxide synthase, have ultra-fast kinetics (half-rise times of 2 ms) and the highest sensitivity for neural activity reported for a protein-based calcium sensor. jGCaMP8 sensors will allow tracking of large populations of neurons on timescales relevant to neural computation.
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Affiliation(s)
- Yan Zhang
- Janelia Research Campus, Howard Hughes Medical Institute, Ashburn, VA, USA
| | - Márton Rózsa
- Janelia Research Campus, Howard Hughes Medical Institute, Ashburn, VA, USA
- Allen Institute for Neural Dynamics, Seattle, WA, USA
| | - Yajie Liang
- Janelia Research Campus, Howard Hughes Medical Institute, Ashburn, VA, USA
- Genetically Encoded Neural Indicator and Effector (GENIE) Project, Janelia Research Campus, Howard Hughes Medical Institute, Ashburn, VA, USA
- Department of Diagnostic Radiology and Nuclear Medicine, University of Maryland School of Medicine, Baltimore, MD, USA
| | - Daniel Bushey
- Janelia Research Campus, Howard Hughes Medical Institute, Ashburn, VA, USA
| | - Ziqiang Wei
- Janelia Research Campus, Howard Hughes Medical Institute, Ashburn, VA, USA
| | - Jihong Zheng
- Janelia Research Campus, Howard Hughes Medical Institute, Ashburn, VA, USA
- Genetically Encoded Neural Indicator and Effector (GENIE) Project, Janelia Research Campus, Howard Hughes Medical Institute, Ashburn, VA, USA
| | - Daniel Reep
- Janelia Research Campus, Howard Hughes Medical Institute, Ashburn, VA, USA
- Genetically Encoded Neural Indicator and Effector (GENIE) Project, Janelia Research Campus, Howard Hughes Medical Institute, Ashburn, VA, USA
| | | | - Arthur Tsang
- Janelia Research Campus, Howard Hughes Medical Institute, Ashburn, VA, USA
- Genetically Encoded Neural Indicator and Effector (GENIE) Project, Janelia Research Campus, Howard Hughes Medical Institute, Ashburn, VA, USA
| | - Getahun Tsegaye
- Janelia Research Campus, Howard Hughes Medical Institute, Ashburn, VA, USA
- Genetically Encoded Neural Indicator and Effector (GENIE) Project, Janelia Research Campus, Howard Hughes Medical Institute, Ashburn, VA, USA
| | - Sujatha Narayan
- Janelia Research Campus, Howard Hughes Medical Institute, Ashburn, VA, USA
- Allen Institute for Neural Dynamics, Seattle, WA, USA
| | | | - Jing-Xuan Lim
- Janelia Research Campus, Howard Hughes Medical Institute, Ashburn, VA, USA
| | - Ronak Patel
- Janelia Research Campus, Howard Hughes Medical Institute, Ashburn, VA, USA
| | - Rongwei Zhang
- Janelia Research Campus, Howard Hughes Medical Institute, Ashburn, VA, USA
| | - Misha B Ahrens
- Janelia Research Campus, Howard Hughes Medical Institute, Ashburn, VA, USA
| | - Glenn C Turner
- Janelia Research Campus, Howard Hughes Medical Institute, Ashburn, VA, USA.
- Genetically Encoded Neural Indicator and Effector (GENIE) Project, Janelia Research Campus, Howard Hughes Medical Institute, Ashburn, VA, USA.
| | - Samuel S-H Wang
- Neuroscience Institute, Princeton University, Princeton, NJ, USA.
| | - Wyatt L Korff
- Janelia Research Campus, Howard Hughes Medical Institute, Ashburn, VA, USA
- Genetically Encoded Neural Indicator and Effector (GENIE) Project, Janelia Research Campus, Howard Hughes Medical Institute, Ashburn, VA, USA
| | - Eric R Schreiter
- Janelia Research Campus, Howard Hughes Medical Institute, Ashburn, VA, USA
- Genetically Encoded Neural Indicator and Effector (GENIE) Project, Janelia Research Campus, Howard Hughes Medical Institute, Ashburn, VA, USA
| | - Karel Svoboda
- Janelia Research Campus, Howard Hughes Medical Institute, Ashburn, VA, USA.
- Allen Institute for Neural Dynamics, Seattle, WA, USA.
- Genetically Encoded Neural Indicator and Effector (GENIE) Project, Janelia Research Campus, Howard Hughes Medical Institute, Ashburn, VA, USA.
| | - Jeremy P Hasseman
- Janelia Research Campus, Howard Hughes Medical Institute, Ashburn, VA, USA.
- Genetically Encoded Neural Indicator and Effector (GENIE) Project, Janelia Research Campus, Howard Hughes Medical Institute, Ashburn, VA, USA.
| | - Ilya Kolb
- Janelia Research Campus, Howard Hughes Medical Institute, Ashburn, VA, USA
- Genetically Encoded Neural Indicator and Effector (GENIE) Project, Janelia Research Campus, Howard Hughes Medical Institute, Ashburn, VA, USA
| | - Loren L Looger
- Janelia Research Campus, Howard Hughes Medical Institute, Ashburn, VA, USA.
- Genetically Encoded Neural Indicator and Effector (GENIE) Project, Janelia Research Campus, Howard Hughes Medical Institute, Ashburn, VA, USA.
- Department of Neurosciences, University of California, San Diego, La Jolla, CA, USA.
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Arias-Durán L, Estrada-Soto S, Hernández-Morales M, Millán-Pacheco C, Navarrete-Vázquez G, Villalobos-Molina R, Ibarra-Barajas M, Almanza-Pérez JC. Antihypertensive and vasorelaxant effect of leucodin and achillin isolated from Achillea millefolium through calcium channel blockade and NO production: In vivo, functional ex vivo and in silico studies. J Ethnopharmacol 2021; 273:113948. [PMID: 33610712 DOI: 10.1016/j.jep.2021.113948] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/09/2020] [Revised: 01/31/2021] [Accepted: 02/16/2021] [Indexed: 06/12/2023]
Abstract
ETHNOPHARMACOLOGICAL RELEVANCE Achillea millefolium L. (Asteraceae), known as yarrow (milenrama), is a plant used in Mexican traditional medicine for the treatment of hypertension, diabetes, and related diseases. AIM To determine the vasorelaxant and antihypertensive effect of A. millefollium and to isolate the main bioactive antihypertensive agents. MATERIALS AND METHODS Organic (hexane, dichloromethane and methanol) and hydro-alcohol (Ethanol-H2O: 70:30) extracts obtained from flowers, leaves and stems were evaluated on isolated aorta rat rings with and without endothelium to determine their vasorelaxant effect. Hexane extract from flowers (HEAmF) was studied to evaluate its antihypertensive effect on spontaneously hypertensive rats (SHR). From HEAmF, bioactive compounds were obtained by bio-guided phytochemical separation through chromatography. RESULTS Organic extracts showed the best vasorelaxant activity. Hexane extract from flowers was the most potent and efficient ex vivo vasorelaxant agent, showing significant decrease of systolic and diastolic blood pressure in SHR (p < 0.05). Phytochemical separation of HEAmF yielded two epimeric sesquiterpene lactones: leucodin (1) and achillin (2), the major components of the extract. Both 1 and 2 showed similar vasorelaxant action ex vivo (p < 0.05), and their effects where modified by L-NAME (10 μM, nitric oxide synthase inhibitor), by ODQ (1 μM, soluble guanylyl cyclase inhibitor), and also relaxed the contraction induced by KCl (80 mM). Finally, 1 and 2 intragastric administration (50 mg/kg) decreased systolic and diastolic blood pressure in SHR. CONCLUSIONS Achillea millefolium showed antihypertensive and vasorelaxant effects, due mainly to leucodin and achillin (epimers). Both compounds showed antihypertensive activity by vasorelaxation putatively by endothelium-dependent NO release and cGMP increase, as well as by calcium channels blockade.
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Affiliation(s)
- Luis Arias-Durán
- Facultad de Farmacia, Universidad Autónoma Del Estado de Morelos, Cuernavaca, Morelos, 62209, Mexico
| | - Samuel Estrada-Soto
- Facultad de Farmacia, Universidad Autónoma Del Estado de Morelos, Cuernavaca, Morelos, 62209, Mexico.
| | | | - César Millán-Pacheco
- Facultad de Farmacia, Universidad Autónoma Del Estado de Morelos, Cuernavaca, Morelos, 62209, Mexico
| | - Gabriel Navarrete-Vázquez
- Facultad de Farmacia, Universidad Autónoma Del Estado de Morelos, Cuernavaca, Morelos, 62209, Mexico
| | - Rafael Villalobos-Molina
- Unidad de Biomedicina, Facultad de Estudios Superiores Iztacala, Universidad Nacional Autónoma de México, Tlalnepantla, Estado de México, 54090, Mexico
| | - Maximiliano Ibarra-Barajas
- Unidad de Biomedicina, Facultad de Estudios Superiores Iztacala, Universidad Nacional Autónoma de México, Tlalnepantla, Estado de México, 54090, Mexico
| | - Julio C Almanza-Pérez
- Laboratorio de Farmacología, Depto. Ciencias de La Salud, D.C.B.S, Universidad Autónoma Metropolitana- Iztapalapa, Ciudad de México, 09340, Mexico
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4
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de Freitas MAG, Amaral NO, Álvares ADCM, de Oliveira SA, Mehdad A, Honda DE, Bessa ASM, Ramada MHS, Naves LM, Pontes CNR, Castro CH, Pedrino GR, de Freitas SM. Blood pressure-lowering effects of a Bowman-Birk inhibitor and its derived peptides in normotensive and hypertensive rats. Sci Rep 2020; 10:11680. [PMID: 32669617 PMCID: PMC7363796 DOI: 10.1038/s41598-020-66624-3] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/17/2019] [Accepted: 05/12/2020] [Indexed: 12/14/2022] Open
Abstract
Bioactive plant peptides have received considerable interest as potential antihypertensive agents with potentially fewer side effects than antihypertensive drugs. Here, the blood pressure-lowering effects of the Bowman-Birk protease inhibitor, BTCI, and its derived peptides, PepChy and PepTry, were investigated using normotensive (Wistar-WR) and spontaneously hypertensive rats (SHR). BTCI inhibited the proteases trypsin and chymotrypsin, respectively, at 6 µM and 40 µM, a 10-fold greater inhibition than observed with PepTry (60 µM) and PepChy (400 µM). These molecules also inhibited angiotensin converting enzyme (ACE) with IC50 values of 54.6 ± 2.9; 24.7 ± 1.1; and 24.4 ± 1.1 µM, respectively, occluding its catalytic site, as indicated by molecular docking simulation, mainly for PepChy and PepTry. Gavage administration of BTCI and the peptides promoted a decrease of systolic and diastolic blood pressure and an increase of renal and aortic vascular conductance. These effects were more expressive in SHR than in WR. Additionally, BTCI, PepChy and PepTry promoted coronary vasodilation and negative inotropic effects in isolated perfused hearts. The nitric oxide synthase inhibitor blunted the BTCI and PepChy, with no cardiac effects on PepTry. The findings of this study indicate a therapeutic potential of BTCI and its related peptides in the treatment of hypertension.
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Affiliation(s)
- Maria Alzira Garcia de Freitas
- Biology Institute, Department of Cell Biology, Laboratory of Biophysics, University of Brasília (UnB), Quadra 604, Asa Norte, Bloco J 1° andar, Brasília, DF, 70910-900, Brazil
| | - Nathalia Oda Amaral
- Center of Neuroscience and Cardiovascular Physiology; Department of Physiological Sciences, Biological Sciences Institute, Federal University of Goiás, Goiânia, GO, 74690-900, Brazil
| | - Alice da Cunha Morales Álvares
- Biology Institute, Department of Cell Biology, Laboratory of Biophysics, University of Brasília (UnB), Quadra 604, Asa Norte, Bloco J 1° andar, Brasília, DF, 70910-900, Brazil
| | - Sandriele Aires de Oliveira
- Biology Institute, Department of Cell Biology, Laboratory of Biophysics, University of Brasília (UnB), Quadra 604, Asa Norte, Bloco J 1° andar, Brasília, DF, 70910-900, Brazil
| | - Azadeh Mehdad
- Biology Institute, Department of Cell Biology, Laboratory of Biophysics, University of Brasília (UnB), Quadra 604, Asa Norte, Bloco J 1° andar, Brasília, DF, 70910-900, Brazil
| | - Diego Elias Honda
- Biology Institute, Department of Cell Biology, Laboratory of Biophysics, University of Brasília (UnB), Quadra 604, Asa Norte, Bloco J 1° andar, Brasília, DF, 70910-900, Brazil
| | - Amanda Sá Martins Bessa
- Integrative Laboratory of Cardiovascular and Neurological Pathophysiology; Department of Physiological Sciences, Biological Sciences Institute, Federal University of Goiás, Goiânia, GO, 74690-900, Brazil
| | - Marcelo Henrique Soller Ramada
- Graduate Program in Genomic Science and Biotechnology, and Graduate Program in Gerontology, Catholic University of Brasília, Brasília, DF, 70790-160, Brazil
| | - Lara Marques Naves
- Center of Neuroscience and Cardiovascular Physiology; Department of Physiological Sciences, Biological Sciences Institute, Federal University of Goiás, Goiânia, GO, 74690-900, Brazil
| | - Carolina Nobre Ribeiro Pontes
- Integrative Laboratory of Cardiovascular and Neurological Pathophysiology; Department of Physiological Sciences, Biological Sciences Institute, Federal University of Goiás, Goiânia, GO, 74690-900, Brazil
| | - Carlos Henrique Castro
- Integrative Laboratory of Cardiovascular and Neurological Pathophysiology; Department of Physiological Sciences, Biological Sciences Institute, Federal University of Goiás, Goiânia, GO, 74690-900, Brazil
| | - Gustavo Rodrigues Pedrino
- Center of Neuroscience and Cardiovascular Physiology; Department of Physiological Sciences, Biological Sciences Institute, Federal University of Goiás, Goiânia, GO, 74690-900, Brazil.
| | - Sonia Maria de Freitas
- Biology Institute, Department of Cell Biology, Laboratory of Biophysics, University of Brasília (UnB), Quadra 604, Asa Norte, Bloco J 1° andar, Brasília, DF, 70910-900, Brazil.
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5
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Cho DH. Telmisartan Inhibits Nitric Oxide Production and Vessel Relaxation via Protein Phosphatase 2A-mediated Endothelial NO Synthase-Ser 1179 Dephosphorylation. J Korean Med Sci 2019; 34:e266. [PMID: 31674157 PMCID: PMC6823522 DOI: 10.3346/jkms.2019.34.e266] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/30/2019] [Accepted: 09/03/2019] [Indexed: 12/11/2022] Open
Abstract
BACKGROUND Apart from its blood pressure-lowering effect by blocking the renin-angiotensin-aldosterone system, telmisartan, an angiotensin II type 1 receptor blocker (ARB), exhibits various ancillary effects including cardiovascular protective effects in vitro. Nonetheless, the protective effects of telmisartan in cerebrocardiovascular diseases are somewhat variable in large-scale clinical trials. Dysregulation of endothelial nitric oxide (NO) synthase (eNOS)-derived NO contributes to the developments of various vascular diseases. Nevertheless, the direct effects of telmisartan on endothelial functions including NO production and vessel relaxation, and its action mechanism have not been fully elucidated. Here, we investigated the mechanism by which telmisartan regulates NO production and vessel relaxation in vitro and in vivo. METHODS We measured nitrite levels in culture medium and mouse serum, and performed inhibitor studies and western blot analyses using bovine aortic endothelial cells (BAECs) and a hyperglycemic mouse model. To assess vessel reactivity, we performed acetylcholine (ACh)-induced vessel relaxation assay on isolated rat aortas. RESULTS Telmisartan decreased NO production in normoglycemic and hyperglycemic BAECs, which was accompanied by reduced phosphorylation of eNOS at Ser1179 (p-eNOS-Ser1179). Telmisartan increased the expression of protein phosphatase 2A catalytic subunit (PP2Ac) and co-treatment with okadaic acid completely restored telmisartan-inhibited NO production and p-eNOS-Ser1179 levels. Of the ARBs tested (including losartan and fimasartan), only telmisartan decreased NO production and p-eNOS-Ser1179 levels, and enhanced PP2Ac expression. Co-treatment with GW9662 had no effect on telmisartan-induced changes. In line with in vitro observations, telmisartan reduced serum nitrite and p-eNOS-Ser1179 levels, and increased PP2Ac expression in high fat diet-fed mice. Furthermore, telmisartan attenuated ACh-induced rat aorta relaxation. CONCLUSION We demonstrated that telmisartan inhibited NO production and vessel relaxation at least in part by PP2A-mediated eNOS-Ser1179 dephosphorylation in a peroxisome proliferator-activated receptor γ-independent manner. These results may provide a mechanism that explains the inconsistent cerebrocardiovascular protective effects of telmisartan.
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Affiliation(s)
- Du Hyong Cho
- Department of Pharmacology, Yeungnam University College of Medicine, Daegu, Korea.
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Fernandez Diaz-Rullo F, Zamberlan F, Mewis RE, Fekete M, Broche L, Cheyne LA, Dall'Angelo S, Duckett SB, Dawson D, Zanda M. Synthesis and hyperpolarisation of eNOS substrates for quantification of NO production by 1H NMR spectroscopy. Bioorg Med Chem 2017; 25:2730-2742. [PMID: 28365086 PMCID: PMC5399308 DOI: 10.1016/j.bmc.2017.03.041] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/14/2016] [Revised: 03/13/2017] [Accepted: 03/18/2017] [Indexed: 01/05/2023]
Abstract
Hyperpolarization enhances the intensity of the NMR signals of a molecule, whose in vivo metabolic fate can be monitored by MRI with higher sensitivity. SABRE is a hyperpolarization technique that could potentially be used to image nitric oxide (NO) production in vivo. This would be very important, because NO dysregulation is involved in several pathologies, including cardiovascular ones. The nitric oxide synthase (NOS) pathway leads to NO production via conversion of l-arginine into l-citrulline. NO is a free radical gas with a short half-life in vivo (≈5s), therefore direct NO quantification is challenging. An indirect method - based on quantifying conversion of an l-Arg- to l-Cit-derivative by 1H NMR spectroscopy - is herein proposed. A small library of pyridyl containing l-Arg derivatives was designed and synthesised. In vitro tests showed that compounds 4a-j and 11a-c were better or equivalent substrates for the eNOS enzyme (NO2- production=19-46μM) than native l-Arg (NO2- production=25μM). Enzymatic conversion of l-Arg to l-Cit derivatives could be monitored by 1H NMR. The maximum hyperpolarization achieved by SABRE reached 870-fold NMR signal enhancement, which opens up exciting future perspectives of using these molecules as hyperpolarized MRI tracers in vivo.
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Affiliation(s)
- Fernando Fernandez Diaz-Rullo
- Centre for Therapeutics and School of Medicine, Medical Sciences and Nutrition, University of Aberdeen, Foresterhill, Aberdeen, Scotland AB25 2ZD, United Kingdom
| | - Francesco Zamberlan
- Centre for Therapeutics and School of Medicine, Medical Sciences and Nutrition, University of Aberdeen, Foresterhill, Aberdeen, Scotland AB25 2ZD, United Kingdom
| | - Ryan E. Mewis
- Centre for Hyperpolarisation in Magnetic Resonance, University of York, Heslington, York YO10 5NY, United Kingdom
| | - Marianna Fekete
- Centre for Hyperpolarisation in Magnetic Resonance, University of York, Heslington, York YO10 5NY, United Kingdom
| | - Lionel Broche
- Centre for Therapeutics and School of Medicine, Medical Sciences and Nutrition, University of Aberdeen, Foresterhill, Aberdeen, Scotland AB25 2ZD, United Kingdom
| | - Lesley A. Cheyne
- Centre for Therapeutics and School of Medicine, Medical Sciences and Nutrition, University of Aberdeen, Foresterhill, Aberdeen, Scotland AB25 2ZD, United Kingdom
| | - Sergio Dall'Angelo
- Centre for Therapeutics and School of Medicine, Medical Sciences and Nutrition, University of Aberdeen, Foresterhill, Aberdeen, Scotland AB25 2ZD, United Kingdom
| | - Simon B. Duckett
- Centre for Hyperpolarisation in Magnetic Resonance, University of York, Heslington, York YO10 5NY, United Kingdom
| | - Dana Dawson
- Centre for Therapeutics and School of Medicine, Medical Sciences and Nutrition, University of Aberdeen, Foresterhill, Aberdeen, Scotland AB25 2ZD, United Kingdom
| | - Matteo Zanda
- Centre for Therapeutics and School of Medicine, Medical Sciences and Nutrition, University of Aberdeen, Foresterhill, Aberdeen, Scotland AB25 2ZD, United Kingdom
- C.N.R.- I.C.R.M., via Mancinelli 7, 20131 Milan, Italy
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7
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Wu HE, Baumgardt SL, Fang J, Paterson M, Liu Y, Du J, Shi Y, Qiao S, Bosnjak ZJ, Warltier DC, Kersten JR, Ge ZD. Cardiomyocyte GTP Cyclohydrolase 1 Protects the Heart Against Diabetic Cardiomyopathy. Sci Rep 2016; 6:27925. [PMID: 27295516 PMCID: PMC4904741 DOI: 10.1038/srep27925] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/11/2016] [Accepted: 05/26/2016] [Indexed: 02/06/2023] Open
Abstract
Diabetic cardiomyopathy increases the risk of heart failure and death. At present, there are no effective approaches to preventing its development in the clinic. Here we report that reduction of cardiac GTP cyclohydrolase 1 (GCH1) degradation by genetic and pharmacological approaches protects the heart against diabetic cardiomyopathy. Diabetic cardiomyopathy was induced in C57BL/6 wild-type mice and transgenic mice with cardiomyocyte-specific overexpression of GCH1 with streptozotocin, and control animals were given citrate buffer. We found that diabetes-induced degradation of cardiac GCH1 proteins contributed to adverse cardiac remodeling and dysfunction in C57BL/6 mice, concomitant with decreases in tetrahydrobiopterin, dimeric and phosphorylated neuronal nitric oxide synthase, sarcoplasmic reticulum Ca(2+) handling proteins, intracellular [Ca(2+)]i, and sarcoplasmic reticulum Ca(2+) content and increases in phosphorylated p-38 mitogen-activated protein kinase and superoxide production. Interestingly, GCH-1 overexpression abrogated these detrimental effects of diabetes. Furthermore, we found that MG 132, an inhibitor for 26S proteasome, preserved cardiac GCH1 proteins and ameliorated cardiac remodeling and dysfunction during diabetes. This study deepens our understanding of impaired cardiac function in diabetes, identifies GCH1 as a modulator of cardiac remodeling and function, and reveals a new therapeutic target for diabetic cardiomyopathy.
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Affiliation(s)
- Hsiang-En Wu
- Department of Anesthesiology, Medical College of Wisconsin, 8701 Watertown Plank Road, Milwaukee, WI 53226, USA
- National Institute on Drug Abuse, National Institutes of Health, 251 Bayview Boulevard, Baltimore, MA 21224, USA
| | - Shelley L. Baumgardt
- Department of Anesthesiology, Medical College of Wisconsin, 8701 Watertown Plank Road, Milwaukee, WI 53226, USA
| | - Juan Fang
- Department of Pediatrics, Medical College of Wisconsin, 8701 Watertown Plank Road, Milwaukee, WI 53226, USA
| | - Mark Paterson
- Department of Anesthesiology, Medical College of Wisconsin, 8701 Watertown Plank Road, Milwaukee, WI 53226, USA
| | - Yanan Liu
- Department of Medicine, Columbia University, 630 W. 168th Street, New York, NY 10032, USA
| | - Jianhai Du
- Department of Biochemistry, University of Washington, 1705 NE Pacific Street, Seattle, WA 98195, USA
| | - Yang Shi
- Aurora Research Institute, Aurora Health Care, 750 W. Virginia Street, Milwaukee, WI 53234, USA
| | - Shigang Qiao
- Department of Anesthesiology, Medical College of Wisconsin, 8701 Watertown Plank Road, Milwaukee, WI 53226, USA
| | - Zeljko J. Bosnjak
- Department of Anesthesiology, Medical College of Wisconsin, 8701 Watertown Plank Road, Milwaukee, WI 53226, USA
- Department of Physiology, Medical College of Wisconsin, 8701 Watertown Plank Road, Milwaukee, WI 53226, USA
| | - David C. Warltier
- Department of Anesthesiology, Medical College of Wisconsin, 8701 Watertown Plank Road, Milwaukee, WI 53226, USA
- Department of Pharmacology and Toxicology, Medical College of Wisconsin, 8701 Watertown Plank Road, Milwaukee, WI 53226, USA
| | - Judy R. Kersten
- Department of Anesthesiology, Medical College of Wisconsin, 8701 Watertown Plank Road, Milwaukee, WI 53226, USA
- Department of Pharmacology and Toxicology, Medical College of Wisconsin, 8701 Watertown Plank Road, Milwaukee, WI 53226, USA
| | - Zhi-Dong Ge
- Department of Anesthesiology, Medical College of Wisconsin, 8701 Watertown Plank Road, Milwaukee, WI 53226, USA
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Serizawa K, Yogo K, Tashiro Y, Takeda S, Kawasaki R, Aizawa K, Endo K. Eldecalcitol prevents endothelial dysfunction in postmenopausal osteoporosis model rats. J Endocrinol 2016; 228:75-84. [PMID: 26537128 DOI: 10.1530/joe-15-0332] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Accepted: 11/03/2015] [Indexed: 01/07/2023]
Abstract
Postmenopausal women have high incidence of cardiovascular events as estrogen deficiency can cause endothelial dysfunction. Vitamin D is reported to be beneficial on endothelial function, but it remains controversial whether vitamin D is effective for endothelial dysfunction under the treatment for osteoporosis in postmenopausal women. The aim of this study was to evaluate the endothelial protective effect of eldecalcitol (ELD) in ovariectomized (OVX) rats. ELD (20 ng/kg) was orally administrated five times a week for 4 weeks from 1 day after surgery. After that, flow-mediated dilation (FMD) as an indicator of endothelial function was measured by high-resolution ultrasound in the femoral artery of living rats. ELD ameliorated the reduction of FMD in OVX rats. ELD inhibited the increase in NOX4, nitrotyrosine, and p65 and the decrease in dimer/monomer ratio of nitric oxide synthase in OVX rat femoral arteries. ELD also prevented the decrease in peroxisome proliferator-activated receptor gamma (PPARγ) in femoral arteries and cultured endothelial cells. Although PPARγ is known to inhibit osteoblastogenesis, ELD understandably increased bone mineral density of OVX rats without increase in PPARγ in bone marrow. These results suggest that ELD prevented the deterioration of endothelial function under condition of preventing bone loss in OVX rats. This endothelial protective effect of ELD might be exerted through improvement of endothelial nitric oxide synthase uncoupling, which is mediated by an antioxidative effect through normalization of vascular PPARγ/NF-κB signaling.
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Affiliation(s)
- Kenichi Serizawa
- Product Research DepartmentChugai Pharmaceutical Co., Ltd, 1-135 Komakado, Gotemba, Shizuoka 412-8513, JapanProduct Research DepartmentChugai Pharmaceutical Co., Ltd, 200 Kajiwara, Kamakura, Kanagawa 247-8530, JapanMedical Science DepartmentChugai Pharmaceutical Co., Ltd, 2-1-1 Nihonbashi-Muromachi, Chuo-ku, Tokyo 103-8324, Japan
| | - Kenji Yogo
- Product Research DepartmentChugai Pharmaceutical Co., Ltd, 1-135 Komakado, Gotemba, Shizuoka 412-8513, JapanProduct Research DepartmentChugai Pharmaceutical Co., Ltd, 200 Kajiwara, Kamakura, Kanagawa 247-8530, JapanMedical Science DepartmentChugai Pharmaceutical Co., Ltd, 2-1-1 Nihonbashi-Muromachi, Chuo-ku, Tokyo 103-8324, Japan
| | - Yoshihito Tashiro
- Product Research DepartmentChugai Pharmaceutical Co., Ltd, 1-135 Komakado, Gotemba, Shizuoka 412-8513, JapanProduct Research DepartmentChugai Pharmaceutical Co., Ltd, 200 Kajiwara, Kamakura, Kanagawa 247-8530, JapanMedical Science DepartmentChugai Pharmaceutical Co., Ltd, 2-1-1 Nihonbashi-Muromachi, Chuo-ku, Tokyo 103-8324, Japan
| | - Satoshi Takeda
- Product Research DepartmentChugai Pharmaceutical Co., Ltd, 1-135 Komakado, Gotemba, Shizuoka 412-8513, JapanProduct Research DepartmentChugai Pharmaceutical Co., Ltd, 200 Kajiwara, Kamakura, Kanagawa 247-8530, JapanMedical Science DepartmentChugai Pharmaceutical Co., Ltd, 2-1-1 Nihonbashi-Muromachi, Chuo-ku, Tokyo 103-8324, Japan
| | - Ryohei Kawasaki
- Product Research DepartmentChugai Pharmaceutical Co., Ltd, 1-135 Komakado, Gotemba, Shizuoka 412-8513, JapanProduct Research DepartmentChugai Pharmaceutical Co., Ltd, 200 Kajiwara, Kamakura, Kanagawa 247-8530, JapanMedical Science DepartmentChugai Pharmaceutical Co., Ltd, 2-1-1 Nihonbashi-Muromachi, Chuo-ku, Tokyo 103-8324, Japan
| | - Ken Aizawa
- Product Research DepartmentChugai Pharmaceutical Co., Ltd, 1-135 Komakado, Gotemba, Shizuoka 412-8513, JapanProduct Research DepartmentChugai Pharmaceutical Co., Ltd, 200 Kajiwara, Kamakura, Kanagawa 247-8530, JapanMedical Science DepartmentChugai Pharmaceutical Co., Ltd, 2-1-1 Nihonbashi-Muromachi, Chuo-ku, Tokyo 103-8324, Japan
| | - Koichi Endo
- Product Research DepartmentChugai Pharmaceutical Co., Ltd, 1-135 Komakado, Gotemba, Shizuoka 412-8513, JapanProduct Research DepartmentChugai Pharmaceutical Co., Ltd, 200 Kajiwara, Kamakura, Kanagawa 247-8530, JapanMedical Science DepartmentChugai Pharmaceutical Co., Ltd, 2-1-1 Nihonbashi-Muromachi, Chuo-ku, Tokyo 103-8324, Japan
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9
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Luna-Vázquez FJ, Ibarra-Alvarado C, Rojas-Molina A, Romo-Mancillas A, López-Vallejo FH, Solís-Gutiérrez M, Rojas-Molina JI, Rivero-Cruz F. Role of Nitric Oxide and Hydrogen Sulfide in the Vasodilator Effect of Ursolic Acid and Uvaol from Black Cherry Prunus serotina Fruits. Molecules 2016; 21:78. [PMID: 26771591 PMCID: PMC6273102 DOI: 10.3390/molecules21010078] [Citation(s) in RCA: 24] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/02/2015] [Revised: 01/05/2016] [Accepted: 01/06/2016] [Indexed: 12/27/2022] Open
Abstract
The present research aimed to isolate the non-polar secondary metabolites that produce the vasodilator effects induced by the dichloromethane extract of Prunus serotina (P. serotina) fruits and to determine whether the NO/cGMP and the H2S/KATP channel pathways are involved in their mechanism of action. A bioactivity-directed fractionation of the dichloromethane extract of P. serotina fruits led to the isolation of ursolic acid and uvaol as the main non-polar vasodilator compounds. These compounds showed significant relaxant effect on rat aortic rings in an endothelium- and concentration-dependent manner, which was inhibited by NG-nitro-L-arginine methyl ester (L-NAME), DL-propargylglycine (PAG) and glibenclamide (Gli). Additionally, both triterpenes increased NO and H2S production in aortic tissue. Molecular docking studies showed that ursolic acid and uvaol are able to bind to endothelial NOS and CSE with high affinity for residues that form the oligomeric interface of both enzymes. These results suggest that the vasodilator effect produced by ursolic acid and uvaol contained in P. serotina fruits, involves activation of the NO/cGMP and H2S/KATP channel pathways, possibly through direct activation of NOS and CSE.
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Affiliation(s)
- Francisco J Luna-Vázquez
- Laboratorio de Investigación Química y Farmacológica de Productos Naturales, Facultad de Química, Universidad Autónoma de Querétaro, Centro Universitario, Querétaro 76010, Mexico.
| | - César Ibarra-Alvarado
- Laboratorio de Investigación Química y Farmacológica de Productos Naturales, Facultad de Química, Universidad Autónoma de Querétaro, Centro Universitario, Querétaro 76010, Mexico.
| | - Alejandra Rojas-Molina
- Laboratorio de Investigación Química y Farmacológica de Productos Naturales, Facultad de Química, Universidad Autónoma de Querétaro, Centro Universitario, Querétaro 76010, Mexico.
| | - Antonio Romo-Mancillas
- Laboratorio de Investigación Química y Farmacológica de Productos Naturales, Facultad de Química, Universidad Autónoma de Querétaro, Centro Universitario, Querétaro 76010, Mexico.
| | - Fabián H López-Vallejo
- Laboratorio de Investigación Química y Farmacológica de Productos Naturales, Facultad de Química, Universidad Autónoma de Querétaro, Centro Universitario, Querétaro 76010, Mexico.
| | - Mariana Solís-Gutiérrez
- Laboratorio de Investigación Química y Farmacológica de Productos Naturales, Facultad de Química, Universidad Autónoma de Querétaro, Centro Universitario, Querétaro 76010, Mexico.
| | - Juana I Rojas-Molina
- Laboratorio de Investigación Química y Farmacológica de Productos Naturales, Facultad de Química, Universidad Autónoma de Querétaro, Centro Universitario, Querétaro 76010, Mexico.
| | - Fausto Rivero-Cruz
- Departamento de Farmacia, Facultad de Química, Universidad Nacional Autónoma de México, Ciudad Universitaria s/n, México D.F. 04510, Mexico.
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Peng H, Zhuang Y, Harbeck MC, He D, Xie L, Chen W. Serine 1179 Phosphorylation of Endothelial Nitric Oxide Synthase Increases Superoxide Generation and Alters Cofactor Regulation. PLoS One 2015; 10:e0142854. [PMID: 26560496 PMCID: PMC4641627 DOI: 10.1371/journal.pone.0142854] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/03/2015] [Accepted: 10/26/2015] [Indexed: 02/07/2023] Open
Abstract
Endothelial nitric oxide synthase (eNOS) is responsible for maintaining systemic blood pressure, vascular remodeling and angiogenesis. In addition to producing NO, eNOS can also generate superoxide (O2-.) in the absence of the cofactor tetrahydrobiopterin (BH4). Previous studies have shown that bovine eNOS serine 1179 (Serine 1177/human) phosphorylation critically modulates NO synthesis. However, the effect of serine 1179 phosphorylation on eNOS superoxide generation is unknown. Here, we used the phosphomimetic form of eNOS (S1179D) to determine the effect of S1179 phosphorylation on superoxide generating activity, and its sensitivity to regulation by BH4, Ca2+, and calmodulin (CAM). S1179D eNOS exhibited significantly increased superoxide generating activity and NADPH consumption compared to wild-type eNOS (WT eNOS). The superoxide generating activities of S1179D eNOS and WT eNOS did not differ significantly in their sensitivity to regulation by either Ca2+ or CaM. The sensitivity of the superoxide generating activity of S1179D eNOS to inhibition by BH4 was significantly reduced compared to WT eNOS. In eNOS-overexpressing 293 cells, BH4 depletion with 10mM DAHP for 48 hours followed by 50ng/ml VEGF for 30 min to phosphorylate eNOS S1179 increased ROS accumulation compared to DAHP-only treated cells. Meanwhile, MTT assay indicated that overexpression of eNOS in HEK293 cells decreased cellular viability compared to control cells at BH4 depletion condition (P<0.01). VEGF-mediated Serine 1179 phosphorylation further decreased the cellular viability in eNOS-overexpressing 293 cells (P<0.01). Our data demonstrate that eNOS serine 1179 phosphorylation, in addition to enhancing NO production, also profoundly affects superoxide generation: S1179 phosphorylation increases superoxide production while decreasing sensitivity to the inhibitory effect of BH4 on this activity.
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Affiliation(s)
- Hu Peng
- Department of Emergency Medicine, Shanghai Tenth People’s Hospital, Tongji University, Shanghai, China
- Division of Pulmonary, Critical Care, Sleep and Allergy, Department of Medicine, University of Illinois College of Medicine, Chicago, Illinois, United States
| | - Yugang Zhuang
- Department of Emergency Medicine, Shanghai Tenth People’s Hospital, Tongji University, Shanghai, China
- Division of Pulmonary, Critical Care, Sleep and Allergy, Department of Medicine, University of Illinois College of Medicine, Chicago, Illinois, United States
| | - Mark C. Harbeck
- Division of Pulmonary, Critical Care, Sleep and Allergy, Department of Medicine, University of Illinois College of Medicine, Chicago, Illinois, United States
| | - Donghong He
- Division of Pulmonary, Critical Care, Sleep and Allergy, Department of Medicine, University of Illinois College of Medicine, Chicago, Illinois, United States
| | - Lishi Xie
- Division of Pulmonary, Critical Care, Sleep and Allergy, Department of Medicine, University of Illinois College of Medicine, Chicago, Illinois, United States
| | - Weiguo Chen
- Department of Emergency Medicine, Shanghai Tenth People’s Hospital, Tongji University, Shanghai, China
- Division of Pulmonary, Critical Care, Sleep and Allergy, Department of Medicine, University of Illinois College of Medicine, Chicago, Illinois, United States
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11
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Peng H, Zhuang Y, Chen Y, Rizzo AN, Chen W. The Characteristics and Regulatory Mechanisms of Superoxide Generation from eNOS Reductase Domain. PLoS One 2015; 10:e0140365. [PMID: 26465144 PMCID: PMC4605588 DOI: 10.1371/journal.pone.0140365] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/24/2015] [Accepted: 09/24/2015] [Indexed: 11/21/2022] Open
Abstract
In addition to superoxide (O2.-) generation from nitric oxide synthase (NOS) oxygenase domain, a new O2.- generation site has been identified in the reductase domain of inducible NOS (iNOS) and neuronal NOS (nNOS). Cysteine S-glutathionylation in eNOS reductase domain also induces O2.- generation from eNOS reductase domain. However, the characteristics and regulatory mechanism of the O2.- generation from NOS reductase domain remain unclear. We cloned and purified the wild type bovine eNOS (WT eNOS), a mutant of Serine 1179 replaced with aspartic acid eNOS (S1179D eNOS), which mimics the negative charge caused by phosphorylationand truncated eNOS reductase domain (eNOS RD). Both WT eNOS and S1179D eNOS generated significant amount of O2.- in the absence of BH4 and L-arginine. The capacity of O2.- generation from S1179D eNOS was significantly higher than that of WT eNOS (1.74:1). O2.- generation from both WT eNOS and S1179D eNOS were not completely inhibited by 100nM tetrahydrobiopterin(BH4). This BH4 un-inhibited O2.- generation from eNOS was blocked by 10mM flavoprotein inhibitor, diphenyleneiodonium (DPI). Purified eNOS reductase domain protein confirmed that this BH4 un-inhibited O2.- generation originates at the FMN or FAD/NADPH binding site of eNOS reductase domain. DEPMPO-OOH adduct EPR signals and NADPH consumptions analyses showed that O2.- generation from eNOS reductase domain was regulated by Serine 1179 phosphorylation and DPI, but not by L-arginine, BH4 or calmodulin (CaM). In addition to the heme center of eNOS oxygenase domain, we confirmed another O2.- generation site in the eNOS reductase domain and characterized its regulatory properties.
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Affiliation(s)
- Hu Peng
- Department of Emergency Medicine, Shanghai Tenth People’s Hospital, Tongji University, Shanghai, China
- Division of Pulmonary, Critical Care, Sleep and Allergy, Department of Medicine, University of Illinois College of Medicine, Chicago, Illinois, United States of America
| | - Yugang Zhuang
- Department of Emergency Medicine, Shanghai Tenth People’s Hospital, Tongji University, Shanghai, China
- Division of Pulmonary, Critical Care, Sleep and Allergy, Department of Medicine, University of Illinois College of Medicine, Chicago, Illinois, United States of America
| | - Yuanzhuo Chen
- Department of Emergency Medicine, Shanghai Tenth People’s Hospital, Tongji University, Shanghai, China
| | - Alicia N. Rizzo
- Division of Pulmonary, Critical Care, Sleep and Allergy, Department of Medicine, University of Illinois College of Medicine, Chicago, Illinois, United States of America
| | - Weiguo Chen
- Department of Emergency Medicine, Shanghai Tenth People’s Hospital, Tongji University, Shanghai, China
- Division of Pulmonary, Critical Care, Sleep and Allergy, Department of Medicine, University of Illinois College of Medicine, Chicago, Illinois, United States of America
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12
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Shu X, Keller TCS, Begandt D, Butcher JT, Biwer L, Keller AS, Columbus L, Isakson BE. Endothelial nitric oxide synthase in the microcirculation. Cell Mol Life Sci 2015; 72:4561-75. [PMID: 26390975 DOI: 10.1007/s00018-015-2021-0] [Citation(s) in RCA: 75] [Impact Index Per Article: 8.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/02/2015] [Revised: 07/21/2015] [Accepted: 08/11/2015] [Indexed: 02/07/2023]
Abstract
Endothelial nitric oxide synthase (eNOS, NOS3) is responsible for producing nitric oxide (NO)--a key molecule that can directly (or indirectly) act as a vasodilator and anti-inflammatory mediator. In this review, we examine the structural effects of regulation of the eNOS enzyme, including post-translational modifications and subcellular localization. After production, NO diffuses to surrounding cells with a variety of effects. We focus on the physiological role of NO and NO-derived molecules, including microvascular effects on vessel tone and immune response. Regulation of eNOS and NO action is complicated; we address endogenous and exogenous mechanisms of NO regulation with a discussion of pharmacological agents used in clinical and laboratory settings and a proposed role for eNOS in circulating red blood cells.
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Affiliation(s)
- Xiaohong Shu
- College of Pharmacy, Dalian Medical University, Dalian, 116044, China
- Robert M. Berne Cardiovascular Research Center, University of Virginia School of Medicine, P.O. Box 801394, Charlottesville, VA, 22908, USA
| | - T C Stevenson Keller
- Robert M. Berne Cardiovascular Research Center, University of Virginia School of Medicine, P.O. Box 801394, Charlottesville, VA, 22908, USA
- Department of Molecular Physiology and Biophysics, University of Virginia School of Medicine, Charlottesville, USA
| | - Daniela Begandt
- Robert M. Berne Cardiovascular Research Center, University of Virginia School of Medicine, P.O. Box 801394, Charlottesville, VA, 22908, USA
| | - Joshua T Butcher
- Robert M. Berne Cardiovascular Research Center, University of Virginia School of Medicine, P.O. Box 801394, Charlottesville, VA, 22908, USA
| | - Lauren Biwer
- Robert M. Berne Cardiovascular Research Center, University of Virginia School of Medicine, P.O. Box 801394, Charlottesville, VA, 22908, USA
- Department of Molecular Physiology and Biophysics, University of Virginia School of Medicine, Charlottesville, USA
| | - Alexander S Keller
- Robert M. Berne Cardiovascular Research Center, University of Virginia School of Medicine, P.O. Box 801394, Charlottesville, VA, 22908, USA
- Department of Pharmacology, University of Virginia School of Medicine, Charlottesville, USA
| | - Linda Columbus
- Department of Chemistry, University of Virginia, Charlottesville, USA
| | - Brant E Isakson
- Robert M. Berne Cardiovascular Research Center, University of Virginia School of Medicine, P.O. Box 801394, Charlottesville, VA, 22908, USA.
- Department of Molecular Physiology and Biophysics, University of Virginia School of Medicine, Charlottesville, USA.
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Abstract
Endothelial dysfunction underlies the development of many cardiovascular diseases. Thus endothelium becomes an independent therapeutic target, and the search of new substances with endothelial-protective action to date is one of the promising tasks for pharmacotherapy and medicinal chemistry. Molecular modeling is an effective tool for solving this problem. Computer chemistry methods use is only possible in combination with detailed information on three dimensional structure and functions of molecular targets: receptors and enzymes, involved in signal transduction inside and outside of endothelial cells. Information on structure and function of various macromolecules involved in vascular tone regulation is collected in the review. The structure of endothelial NO-synthase (EC 1.14.13.39) (eNOS)--enzyme, responsible for the nitric oxide synthesis and involved in vascular tone regulation process is reviewed. The importance of eNOS substrate--L-arginine is underlined in the review in terms of this enzyme activity, regulation, the information on structure and functions of L-arginine transport system is provided. Also different ways of eNOS activity regulation are reviewed, among which are enzyme activation and concurrent inhibition by substances interaction with active center of enzyme, inhibition by caveoline binding with oxigenase domain, and also regulation by phosphorylation of certain amino acids of eNOS by proteinkinase and dephoshphorylation of them by phosphatases. The importance of membrane receptors of endothelial cells as targets for endothelial-protective substances is underlined. Among them are receptors of endothelin, platelet activation factor, prostanoids, bradykinin, histamine, serotonin and protease activated receptors. The important role of potassium and calcium ion channels of vascular cells in endothelial-protective activity is underlined. Macromolecules presented in the review finally are considered as targets for searching for medicinal substances with endothelial-protective activity using proposed ways and methods of molecular modeling.
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14
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Chen F, Kumar S, Yu Y, Aggarwal S, Gross C, Wang Y, Chakraborty T, Verin AD, Catravas JD, Lucas R, Black SM, Fulton DJR. PKC-dependent phosphorylation of eNOS at T495 regulates eNOS coupling and endothelial barrier function in response to G+ -toxins. PLoS One 2014; 9:e99823. [PMID: 25020117 PMCID: PMC4096401 DOI: 10.1371/journal.pone.0099823] [Citation(s) in RCA: 45] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/27/2014] [Accepted: 05/19/2014] [Indexed: 11/30/2022] Open
Abstract
Gram positive (G+) infections make up ∼50% of all acute lung injury cases which are characterized by extensive permeability edema secondary to disruption of endothelial cell (EC) barrier integrity. A primary cause of increased permeability are cholesterol-dependent cytolysins (CDCs) of G+-bacteria, such as pneumolysin (PLY) and listeriolysin-O (LLO) which create plasma membrane pores, promoting Ca2+-influx and activation of PKCα. In human lung microvascular endothelial cells (HLMVEC), pretreatment with the nitric oxide synthase (NOS) inhibitor, ETU reduced the ability of LLO to increase microvascular cell permeability suggesting an endothelial nitric oxide synthase (eNOS)-dependent mechanism. LLO stimulated superoxide production from HLMVEC and this was prevented by silencing PKCα or NOS inhibition suggesting a link between these pathways. Both LLO and PLY stimulated eNOS T495 phosphorylation in a PKC-dependent manner. Expression of a phosphomimetic T495D eNOS (human isoform) resulted in increased superoxide and diminished nitric oxide (NO) production. Transduction of HLMVEC with an active form of PKCα resulted in the robust phosphorylation of T495 and increased peroxynitrite production, indicative of eNOS uncoupling. To determine the mechanisms underlying eNOS uncoupling, HLMVEC were stimulated with LLO and the amount of hsp90 and caveolin-1 bound to eNOS determined. LLO stimulated the dissociation of hsp90, and in particular, caveolin-1 from eNOS. Both hsp90 and caveolin-1 have been shown to influence eNOS uncoupling and a peptide mimicking the scaffolding domain of caveolin-1 blocked the ability of PKCα to stimulate eNOS-derived superoxide. Collectively, these results suggest that the G+ pore-forming toxins promote increased EC permeability via activation of PKCα, phosphorylation of eNOS-T495, loss of hsp90 and caveolin-1 binding which collectively promote eNOS uncoupling and the production of barrier disruptive superoxide.
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Affiliation(s)
- Feng Chen
- Department of Forensic Medicine, Nanjing Medical University, Nanjing, Jiangsu, China
- Vascular Biology Center Medical College of Georgia at Georgia Regents University, Augusta, Georgia, United States of America
| | - Sanjiv Kumar
- Vascular Biology Center Medical College of Georgia at Georgia Regents University, Augusta, Georgia, United States of America
| | - Yanfang Yu
- Vascular Biology Center Medical College of Georgia at Georgia Regents University, Augusta, Georgia, United States of America
| | - Saurabh Aggarwal
- Vascular Biology Center Medical College of Georgia at Georgia Regents University, Augusta, Georgia, United States of America
| | - Christine Gross
- Vascular Biology Center Medical College of Georgia at Georgia Regents University, Augusta, Georgia, United States of America
| | - Yusi Wang
- Vascular Biology Center Medical College of Georgia at Georgia Regents University, Augusta, Georgia, United States of America
| | - Trinad Chakraborty
- Institute for Medical Microbiology, Justus Liebig University, Giessen, Germany
| | - Alexander D. Verin
- Vascular Biology Center Medical College of Georgia at Georgia Regents University, Augusta, Georgia, United States of America
| | - John D. Catravas
- Old Dominion University, Norfolk, Virginia, United States of America
| | - Rudolf Lucas
- Vascular Biology Center Medical College of Georgia at Georgia Regents University, Augusta, Georgia, United States of America
- Department of Pharmacology, Medical College of Georgia at Georgia Regents University, Augusta, Georgia, United States of America
| | - Stephen M. Black
- Vascular Biology Center Medical College of Georgia at Georgia Regents University, Augusta, Georgia, United States of America
| | - David J. R. Fulton
- Vascular Biology Center Medical College of Georgia at Georgia Regents University, Augusta, Georgia, United States of America
- Department of Pharmacology, Medical College of Georgia at Georgia Regents University, Augusta, Georgia, United States of America
- * E-mail:
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15
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Tam JCW, Ko CH, Lau KM, To MH, Kwok HF, Chan YW, Siu WS, Etienne-Selloum N, Lau CP, Chan WY, Leung PC, Fung KP, Schini-Kerth VB, Lau CBS. A Chinese 2-herb formula (NF3) promotes hindlimb ischemia-induced neovascularization and wound healing of diabetic rats. J Diabetes Complications 2014; 28:436-47. [PMID: 24731763 DOI: 10.1016/j.jdiacomp.2014.03.004] [Citation(s) in RCA: 21] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/15/2014] [Revised: 02/18/2014] [Accepted: 03/04/2014] [Indexed: 02/07/2023]
Abstract
Diabetic foot ulcer is closely associated with peripheral vascular disease. Enhancement of tissue oxidative stress, reduction of nitric oxide (NO) and angiogenic growth factors, and abnormal matrix metalloproteinase (MMP) activity are pathophysiological factors in post-ischemic neovascularization and diabetic wound healing. Our previous study demonstrated that the Chinese 2-herb formula, NF3, showed significant wound healing effects on diabetic foot ulcer rats. A novel rat diabetic foot ulcer with hindlimb ischemia model was established in order to strengthen our claims on the diabetic wound healing and post-ischemic neovascularization effects of NF3. Our results demonstrate that NF3 can significantly reduce the wound area of the diabetic foot ulcer rat with hindlimb ischemia by 21.6% (p<0.05) compared with the control group. In addition, flow cytometric analysis revealed that NF3 could boost circulating EPC levels for local wound vessel incorporation. Immunohistochemical analysis showed that NF3 could significantly augment blood vessel density, VEGF and eNOS expression, and attenuate tissue oxidative stress of ischemic muscles (p<0.001). NF3 significantly stimulated MMP activity involved in angiogenesis. Our study shows, for the first time, the beneficial effects of NF3 in wound healing and post-ischemic neovascularization in diabetes.
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Affiliation(s)
- Jacqueline Chor-Wing Tam
- Institute of Chinese Medicine, The Chinese University of Hong Kong, Shatin, New Territories, Hong Kong; State Key Laboratory of Phytochemistry and Plant Resources in West China, The Chinese University of Hong Kong, Shatin, New Territories, Hong Kong
| | - Chun-Hay Ko
- Institute of Chinese Medicine, The Chinese University of Hong Kong, Shatin, New Territories, Hong Kong; State Key Laboratory of Phytochemistry and Plant Resources in West China, The Chinese University of Hong Kong, Shatin, New Territories, Hong Kong
| | - Kit-Man Lau
- Institute of Chinese Medicine, The Chinese University of Hong Kong, Shatin, New Territories, Hong Kong; State Key Laboratory of Phytochemistry and Plant Resources in West China, The Chinese University of Hong Kong, Shatin, New Territories, Hong Kong
| | - Ming-Ho To
- Institute of Chinese Medicine, The Chinese University of Hong Kong, Shatin, New Territories, Hong Kong; State Key Laboratory of Phytochemistry and Plant Resources in West China, The Chinese University of Hong Kong, Shatin, New Territories, Hong Kong
| | - Hin-Fai Kwok
- Institute of Chinese Medicine, The Chinese University of Hong Kong, Shatin, New Territories, Hong Kong; State Key Laboratory of Phytochemistry and Plant Resources in West China, The Chinese University of Hong Kong, Shatin, New Territories, Hong Kong
| | - Yuet-Wa Chan
- Institute of Chinese Medicine, The Chinese University of Hong Kong, Shatin, New Territories, Hong Kong; State Key Laboratory of Phytochemistry and Plant Resources in West China, The Chinese University of Hong Kong, Shatin, New Territories, Hong Kong
| | - Wing-Sum Siu
- Institute of Chinese Medicine, The Chinese University of Hong Kong, Shatin, New Territories, Hong Kong; State Key Laboratory of Phytochemistry and Plant Resources in West China, The Chinese University of Hong Kong, Shatin, New Territories, Hong Kong
| | | | - Ching-Po Lau
- Institute of Chinese Medicine, The Chinese University of Hong Kong, Shatin, New Territories, Hong Kong; State Key Laboratory of Phytochemistry and Plant Resources in West China, The Chinese University of Hong Kong, Shatin, New Territories, Hong Kong
| | - Wai-Yee Chan
- School of Biomedical Sciences, The Chinese University of Hong Kong, Shatin, New Territories, Hong Kong
| | - Ping-Chung Leung
- Institute of Chinese Medicine, The Chinese University of Hong Kong, Shatin, New Territories, Hong Kong; State Key Laboratory of Phytochemistry and Plant Resources in West China, The Chinese University of Hong Kong, Shatin, New Territories, Hong Kong
| | - Kwok-Pui Fung
- Institute of Chinese Medicine, The Chinese University of Hong Kong, Shatin, New Territories, Hong Kong; State Key Laboratory of Phytochemistry and Plant Resources in West China, The Chinese University of Hong Kong, Shatin, New Territories, Hong Kong; School of Biomedical Sciences, The Chinese University of Hong Kong, Shatin, New Territories, Hong Kong
| | | | - Clara Bik-San Lau
- Institute of Chinese Medicine, The Chinese University of Hong Kong, Shatin, New Territories, Hong Kong; State Key Laboratory of Phytochemistry and Plant Resources in West China, The Chinese University of Hong Kong, Shatin, New Territories, Hong Kong.
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16
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Chreifi G, Li H, McInnes C, Gibson CL, Suckling CJ, Poulos TL. Communication between the zinc and tetrahydrobiopterin binding sites in nitric oxide synthase. Biochemistry 2014; 53:4216-23. [PMID: 24819538 PMCID: PMC4082377 DOI: 10.1021/bi5003986] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/02/2014] [Revised: 05/10/2014] [Indexed: 01/02/2023]
Abstract
The nitric oxide synthase (NOS) dimer is stabilized by a Zn(2+) ion coordinated to four symmetry-related Cys residues exactly along the dimer 2-fold axis. Each of the two essential tetrahydrobiopterin (H4B) molecules in the dimer interacts directly with the heme, and each H4B molecule is ~15 Å from the Zn(2+). We have determined the crystal structures of the bovine endothelial NOS dimer oxygenase domain bound to three different pterin analogues, which reveal an intimate structural communication between the H4B and Zn(2+) sites. The binding of one of these compounds, 6-acetyl-2-amino-7,7-dimethyl-7,8-dihydro-4(3H)-pteridinone (1), to the pterin site and Zn(2+) binding are mutually exclusive. Compound 1 both directly and indirectly disrupts hydrogen bonding between key residues in the Zn(2+) binding motif, resulting in destabilization of the dimer and a complete disruption of the Zn(2+) site. Addition of excess Zn(2+) stabilizes the Zn(2+) site at the expense of weakened binding of 1. The unique structural features of 1 that disrupt the dimer interface are extra methyl groups that extend into the dimer interface and force a slight opening of the dimer, thus resulting in disruption of the Zn(2+) site. These results illustrate a very delicate balance of forces and structure at the dimer interface that must be maintained to properly form the Zn(2+), pterin, and substrate binding sites.
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Affiliation(s)
- Georges Chreifi
- Departments of Molecular Biology and Biochemistry, Chemistry, and Pharmaceutical
Sciences, University of California, Irvine, California 92697-3900, United States
| | - Huiying Li
- Departments of Molecular Biology and Biochemistry, Chemistry, and Pharmaceutical
Sciences, University of California, Irvine, California 92697-3900, United States
| | - Craig
R. McInnes
- WestCHEM,
Department of Pure and Applied Chemistry, University of Strathclyde, 295 Cathedral Street, Glasgow G1 1XL, Scotland, U.K.
| | - Colin L. Gibson
- WestCHEM,
Department of Pure and Applied Chemistry, University of Strathclyde, 295 Cathedral Street, Glasgow G1 1XL, Scotland, U.K.
| | - Colin J. Suckling
- WestCHEM,
Department of Pure and Applied Chemistry, University of Strathclyde, 295 Cathedral Street, Glasgow G1 1XL, Scotland, U.K.
| | - Thomas L. Poulos
- Departments of Molecular Biology and Biochemistry, Chemistry, and Pharmaceutical
Sciences, University of California, Irvine, California 92697-3900, United States
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17
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Berka V, Liu W, Wu G, Tsai AL. Comparison of oxygen-induced radical intermediates in iNOS oxygenase domain with those from nNOS and eNOS. J Inorg Biochem 2014; 139:93-105. [PMID: 25016313 DOI: 10.1016/j.jinorgbio.2014.06.011] [Citation(s) in RCA: 21] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/02/2014] [Revised: 06/17/2014] [Accepted: 06/17/2014] [Indexed: 12/31/2022]
Abstract
Inducible nitric-oxide synthase (iNOS) produces the reactive oxygen and nitrogen species (ROS/RNS) involved in bacteria killing and is crucial in the host defense mechanism. However, high level ROS/RNS can also be detrimental to normal cells and thus their production has to be tightly controlled. Availability or deficiency of tetrahydrobiopterin (BH4) cofactor and l-arginine substrate controls coupling or uncoupling of NOS catalysis. Fully coupled reaction, with abundant BH4 and l-arginine, produces NO whereas the uncoupled NOS (in the absence of BH4 and/or l-arginine) generates ROS/RNS. In the current work we focus on direct rapid freeze EPR to characterize the structure and kinetics of oxygen-induced radical intermediates produced by ferrous inducible NOS oxygenase domain (iNOSox) in the presence or absence of BH4 and/or l-arginine. Fully reconstituted iNOSox (+BH4, +L-Arg) forms a dimer and yields a typical BH4 radical that indicates coupled reaction. iNOSox (-BH4) remains mainly monomeric and produces exclusively superoxide, that is only marginally affected by the presence of l-arginine. iNOSox (+BH4, -L-Arg) exists as a monomer/dimer mixture and yields both BH4 radical and superoxide. Present study is a natural extension of our previous work on the ferrous endothelial NOSox (eNOSox) [V. Berka, G. Wu, H.C. Yeh, G. Palmer, A.L. Tsai, J. Biol. Chem. 279 (2004) 32243-32251] and ferrous neuronal NOSox (nNOSox) [V. Berka, L.H. Wang, A.L. Tsai, Biochemistry 47 (2008) 405-420]. Overall, our data suggests different regulatory roles of l-arginine and BH4 in the production of oxygen-induced radical intermediates in NOS isoforms which nicely serve individual functional role.
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Affiliation(s)
- Vladimír Berka
- Division of Hematology, Department of Internal Medicine, University of Texas Health Science Center at Houston, Houston, TX 77030, United States.
| | - Wen Liu
- Division of Hematology, Department of Internal Medicine, University of Texas Health Science Center at Houston, Houston, TX 77030, United States
| | - Gang Wu
- Division of Hematology, Department of Internal Medicine, University of Texas Health Science Center at Houston, Houston, TX 77030, United States
| | - Ah-Lim Tsai
- Division of Hematology, Department of Internal Medicine, University of Texas Health Science Center at Houston, Houston, TX 77030, United States.
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18
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Davel AP, Brum PC, Rossoni LV. Isoproterenol induces vascular oxidative stress and endothelial dysfunction via a Giα-coupled β2-adrenoceptor signaling pathway. PLoS One 2014; 9:e91877. [PMID: 24622771 PMCID: PMC3951496 DOI: 10.1371/journal.pone.0091877] [Citation(s) in RCA: 43] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/14/2013] [Accepted: 02/17/2014] [Indexed: 01/18/2023] Open
Abstract
OBJECTIVE Sustained β-adrenergic stimulation is a hallmark of sympathetic hyperactivity in cardiovascular diseases. It is associated with oxidative stress and altered vasoconstrictor tone. This study investigated the β-adrenoceptor subtype and the signaling pathways implicated in the vascular effects of β-adrenoceptor overactivation. METHODS AND RESULTS Mice lacking the β1- or β2-adrenoceptor subtype (β1KO, β2KO) and wild-type (WT) were treated with isoproterenol (ISO, 15 μg.g(-1) x day(-1), 7 days). ISO significantly enhanced the maximal vasoconstrictor response (Emax) of the aorta to phenylephrine in WT (+34%) and β1KO mice (+35%) but not in β2KO mice. The nitric oxide synthase (NOS) inhibitor L-NAME abolished the differences in phenylephrine response between the groups, suggesting that ISO impaired basal NO availability in the aorta of WT and β1KO mice. Superoxide dismutase (SOD), pertussis toxin (PTx) or PD 98,059 (p-ERK 1/2 inhibitor) incubation reversed the hypercontractility of aortic rings from ISO-treated WT mice; aortic contraction of ISO-treated β2KO mice was not altered. Immunoblotting revealed increased aortic expression of Giα-3 protein (+50%) and phosphorylated ERK1/2 (+90%) and decreased eNOS dimer/monomer ratio in ISO-treated WT mice. ISO enhanced the fluorescence response to dihydroethidium (+100%) in aortas from WT mice, indicating oxidative stress that was normalized by SOD, PTx and L-NAME. The ISO effects were abolished in β2KO mice. CONCLUSIONS The β2-adrenoceptor/Giα signaling pathway is implicated in the enhanced vasoconstrictor response and eNOS uncoupling-mediated oxidative stress due to ISO treatment. Thus, long-term β2-AR activation might results in endothelial dysfunction.
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MESH Headings
- Animals
- Aorta/drug effects
- Aorta/metabolism
- Aorta/physiology
- Endothelium, Vascular/cytology
- Endothelium, Vascular/drug effects
- Endothelium, Vascular/metabolism
- GTP-Binding Protein alpha Subunits, Gi-Go/metabolism
- Gene Expression Regulation/drug effects
- Gene Knockout Techniques
- Isoproterenol/pharmacology
- Male
- Mice
- Mitogen-Activated Protein Kinase 1/metabolism
- Mitogen-Activated Protein Kinase 3/metabolism
- Nitric Oxide/metabolism
- Nitric Oxide Synthase Type III/chemistry
- Oxidative Stress/drug effects
- Phenylephrine/pharmacology
- Phosphorylation/drug effects
- Protein Multimerization/drug effects
- Protein Structure, Quaternary
- Receptors, Adrenergic, beta-2/deficiency
- Receptors, Adrenergic, beta-2/genetics
- Receptors, Adrenergic, beta-2/metabolism
- Signal Transduction/drug effects
- Vasoconstriction/drug effects
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Affiliation(s)
- Ana P. Davel
- Department of Structural and Functional Biology, Institute of Biology, State University of Campinas-UNICAMP, Campinas, SP, Brazil
- Department of Physiology and Biophysics, Institute of Biomedical Sciences, University of São Paulo, São Paulo, SP, Brazil
| | - Patricia C. Brum
- School of Physical Education and Sport, University of São Paulo, São Paulo, SP, Brazil
| | - Luciana V. Rossoni
- Department of Physiology and Biophysics, Institute of Biomedical Sciences, University of São Paulo, São Paulo, SP, Brazil
- * E-mail:
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19
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Farb MG, Tiwari S, Karki S, Ngo DTM, Carmine B, Hess DT, Zuriaga MA, Walsh K, Fetterman JL, Hamburg NM, Vita JA, Apovian CM, Gokce N. Cyclooxygenase inhibition improves endothelial vasomotor dysfunction of visceral adipose arterioles in human obesity. Obesity (Silver Spring) 2014; 22:349-55. [PMID: 23640904 PMCID: PMC3766380 DOI: 10.1002/oby.20505] [Citation(s) in RCA: 30] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/21/2012] [Accepted: 04/24/2013] [Indexed: 11/07/2022]
Abstract
OBJECTIVE The purpose of this study was to determine whether cyclooxygenase inhibition improves vascular dysfunction of adipose microvessels from obese humans. DESIGN AND METHODS In 20 obese subjects (age 37 ± 12 years, BMI 47 ± 8 kg/m²), subcutaneous and visceral fat were collected during bariatric surgery and characterized for adipose depot-specific gene expression, endothelial cell phenotype, and microvascular function. Vasomotor function was assessed in response to endothelium-dependent agonists using videomicroscopy of small arterioles from fat. RESULTS Arterioles from visceral fat exhibited impaired endothelium-dependent, acetylcholine-mediated vasodilation, compared to the subcutaneous depot (P < 0.001). Expression of mRNA transcripts relevant to the cyclooxygenase pathway was upregulated in visceral compared to subcutaneous fat. Pharmacological inhibition of cyclooxygenase with indomethacin improved endothelium-dependent vasodilator function of arterioles from visceral fat by twofold (P = 0.01), whereas indomethacin had no effect in the subcutaneous depot. Indomethacin increased activation via serine-1177 phosphorylation of endothelial nitric oxide synthase in response to acetylcholine in endothelial cells from visceral fat. Inhibition of endothelial nitric oxide synthase with N(ω)-nitro-L-arginine methyl ester abrogated the effects of cyclooxygenase-inhibition suggesting that vascular actions of indomethacin were related to increased nitric oxide bioavailability. CONCLUSIONS Our findings suggest that cyclooxygenase-mediated vasoconstrictor prostanoids partly contribute to endothelial dysfunction of visceral adipose arterioles in human obesity.
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MESH Headings
- Adult
- Arterioles/drug effects
- Arterioles/metabolism
- Arterioles/pathology
- Arterioles/physiopathology
- Body Mass Index
- Cells, Cultured
- Cyclooxygenase Inhibitors/pharmacology
- Endothelium, Vascular/drug effects
- Endothelium, Vascular/metabolism
- Endothelium, Vascular/pathology
- Endothelium, Vascular/physiopathology
- Enzyme Activation/drug effects
- Enzyme Inhibitors/pharmacology
- Female
- Gene Expression Regulation/drug effects
- Humans
- Intra-Abdominal Fat/blood supply
- Intra-Abdominal Fat/drug effects
- Intra-Abdominal Fat/metabolism
- Intra-Abdominal Fat/pathology
- Male
- Microscopy, Video
- Nitric Oxide Synthase Type III/antagonists & inhibitors
- Nitric Oxide Synthase Type III/chemistry
- Nitric Oxide Synthase Type III/genetics
- Nitric Oxide Synthase Type III/metabolism
- Obesity/drug therapy
- Obesity/metabolism
- Obesity/pathology
- Obesity/physiopathology
- Phosphorylation/drug effects
- Protein Processing, Post-Translational/drug effects
- Subcutaneous Fat, Abdominal/blood supply
- Subcutaneous Fat, Abdominal/drug effects
- Subcutaneous Fat, Abdominal/metabolism
- Subcutaneous Fat, Abdominal/pathology
- Tissue Culture Techniques
- Vasoconstriction/drug effects
- Vasomotor System/drug effects
- Vasomotor System/metabolism
- Vasomotor System/pathology
- Vasomotor System/physiopathology
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Affiliation(s)
- Melissa G. Farb
- Department of Medicine and Whitaker Cardiovascular Institute, Boston University School of Medicine, Boston, MA
| | - Stephanie Tiwari
- Department of Medicine and Whitaker Cardiovascular Institute, Boston University School of Medicine, Boston, MA
| | - Shakun Karki
- Department of Medicine and Whitaker Cardiovascular Institute, Boston University School of Medicine, Boston, MA
| | - Doan TM Ngo
- Department of Medicine and Whitaker Cardiovascular Institute, Boston University School of Medicine, Boston, MA
| | - Brian Carmine
- Department of General Surgery, Boston University School of Medicine, Boston, MA
| | - Donald T. Hess
- Department of General Surgery, Boston University School of Medicine, Boston, MA
| | - Maria A. Zuriaga
- Department of Medicine and Whitaker Cardiovascular Institute, Boston University School of Medicine, Boston, MA
| | - Kenneth Walsh
- Department of Medicine and Whitaker Cardiovascular Institute, Boston University School of Medicine, Boston, MA
| | - Jessica L. Fetterman
- Department of Medicine and Whitaker Cardiovascular Institute, Boston University School of Medicine, Boston, MA
| | - Naomi M. Hamburg
- Department of Medicine and Whitaker Cardiovascular Institute, Boston University School of Medicine, Boston, MA
| | - Joseph A. Vita
- Department of Medicine and Whitaker Cardiovascular Institute, Boston University School of Medicine, Boston, MA
| | - Caroline M. Apovian
- Department of Medicine, Section of Endocrinology, Diabetes and Nutrition, Boston University School of Medicine, Boston, MA
| | - Noyan Gokce
- Department of Medicine and Whitaker Cardiovascular Institute, Boston University School of Medicine, Boston, MA
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20
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Rafikov R, Kumar S, Aggarwal S, Pardo D, Fonseca FV, Ransom J, Rafikova O, Chen Q, Springer ML, Black SM. Protein engineering to develop a redox insensitive endothelial nitric oxide synthase. Redox Biol 2014; 2:156-64. [PMID: 25460726 PMCID: PMC4297941 DOI: 10.1016/j.redox.2013.12.015] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/18/2013] [Accepted: 12/19/2013] [Indexed: 11/25/2022] Open
Abstract
The zinc tetrathiolate (ZnS4) cluster is an important structural feature of endothelial nitric oxide synthase (eNOS). The cluster is located on the dimeric interface and four cysteine residues (C94 and C99 from two adjacent subunits) form a cluster with a Zn ion in the center of a tetrahedral configuration. Due to its high sensitivity to oxidants this cluster is responsible for eNOS dimer destabilization during periods of redox stress. In this work we utilized site directed mutagenesis to replace the redox sensitive cysteine residues in the ZnS4 cluster with redox stable tetra-arginines. Our data indicate that this C94R/C99R eNOS mutant is active. In addition, this mutant protein is insensitive to dimer disruption and inhibition when challenged with hydrogen peroxide (H2O2). Further, the overexpression of the C94R/C99R mutant preserved the angiogenic response in endothelial cells challenged with H2O2. The over-expression of the C94R/C99R mutant preserved the ability of endothelial cells to migrate towards vascular endothelial growth factor (VEGF) and preserved the endothelial monolayer in a scratch wound assay. We propose that this dimer stable eNOS mutant could be utilized in the treatment of diseases in which there is eNOS dysfunction due to high levels of oxidative stress. The ZnS4 cluster is an important structural feature of eNOS. This cluster is responsible for eNOS dimer destabilization during redox stress. Site directed mutagenesis replaced ZnS4 clusters with redox stable tetra-arginines. This eNOS mutant is insensitive to dimer disruption during redox stress. This eNOS mutant continues to produce NO during redox stress.
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Affiliation(s)
- Ruslan Rafikov
- Pulmonary Vascular Disease, Vascular Biology Center, Georgia Regents University, Augusta, GA, USA
| | - Sanjiv Kumar
- Pulmonary Vascular Disease, Vascular Biology Center, Georgia Regents University, Augusta, GA, USA
| | - Saurabh Aggarwal
- Pulmonary Vascular Disease, Vascular Biology Center, Georgia Regents University, Augusta, GA, USA
| | - Daniel Pardo
- Pulmonary Vascular Disease, Vascular Biology Center, Georgia Regents University, Augusta, GA, USA
| | - Fabio V Fonseca
- Pulmonary Vascular Disease, Vascular Biology Center, Georgia Regents University, Augusta, GA, USA
| | - Jessica Ransom
- Pulmonary Vascular Disease, Vascular Biology Center, Georgia Regents University, Augusta, GA, USA
| | - Olga Rafikova
- Pulmonary Vascular Disease, Vascular Biology Center, Georgia Regents University, Augusta, GA, USA
| | - Qiumei Chen
- The Cardiovascular Research Institute, University of California, San Francisco, San Francisco, CA, USA
| | - Matthew L Springer
- The Division of Cardiology, University of California, San Francisco, San Francisco, CA, USA
| | - Stephen M Black
- Pulmonary Vascular Disease, Vascular Biology Center, Georgia Regents University, Augusta, GA, USA.
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21
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Yuan L, Lu CL, Wang Y, Li Y, Li XY. Ang (1-7) protects islet endothelial cells from palmitate-induced apoptosis by AKT, eNOS, p38 MAPK, and JNK pathways. J Diabetes Res 2014; 2014:391476. [PMID: 24804268 PMCID: PMC3996957 DOI: 10.1155/2014/391476] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/17/2013] [Revised: 02/06/2014] [Accepted: 02/06/2014] [Indexed: 11/28/2022] Open
Abstract
This study aimed to explore the effect of angiotensin (1-7) (Ang (1-7)) on palmitate-induced apoptosis in islet endothelial cells and the mechanism of action. MS-1 cells were treated with palmitate in the presence or absence of Ang (1-7). The percentage of apoptotic cells was determined by DNA fragmentation and flow cytometry. Reactive oxygen species (ROS) production was measured using a Reactive Oxygen Species Assay Kit. Expression of AKT, eNOS, C-Jun N-terminal kinase (JNK), and p38 was detected by western blotting. Compared with palmitate treated group, palmitate-induced apoptosis was decreased in MS-1 cells which were preincubated with Ang (1-7) (P < 0.05). Palmitate decreased the phosphorylation of AKT and eNOS, and Ang (1-7) increased the phosphorylation of these kinases (P < 0.05), with a concomitant reduction in MS-1 cells apoptosis. Ang (1-7) also inhibited the palmitate-induced ROS production and attenuated the apoptosis-related signaling molecule JNK and p38 activation (all P < 0.05). PI3K/AKT, eNOS, p38 MAPK, and JNK inhibitors blocked the antilipoapoptosis of Ang (1-7) (all P < 0.05). Our findings suggest that Ang (1-7) reduces palmitate-induced islet endothelial cells apoptosis. AKT/eNOS/NO signaling and JNK and p38 pathway are involved in the Ang (1-7)-mediated modulation of islet endothelial cells lipoapoptosis.
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Affiliation(s)
- Li Yuan
- Department of Endocrinology, Union Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan 430022, China
- *Li Yuan:
| | - Chun-Li Lu
- Department of Endocrinology, Union Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan 430022, China
| | - Ying Wang
- Department of Endocrinology, Union Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan 430022, China
| | - Yang Li
- Department of Endocrinology, Union Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan 430022, China
| | - Xiao-Ya Li
- Department of Endocrinology, Union Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan 430022, China
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22
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Abstract
Endothelial nitric oxide synthase (eNOS) is expressed in vascular endothelial cells and plays an important role in the regulation of vascular tone, platelet aggregation and angiogenesis. Protein-protein interactions represent an important posttranslational mechanism for eNOS regulation. eNOS has been shown to interact with a variety of regulatory and structural proteins which provide fine tuneup of eNOS activity and eNOS protein trafficking between plasma membrane and intracellular membranes in a number of physiological and pathophysiological processes. eNOS interacts with calmodulin, heat shock protein 90 (Hsp90), dynamin-2, β-actin, tubulin, porin, high-density lipoprotein (HDL) and apolipoprotein AI (ApoAI), resulting in increases in eNOS activity. The negative eNOS interacting proteins include caveolin, G protein-coupled receptors (GPCR), nitric oxide synthase-interacting protein (NOSIP), and nitric oxide synthase trafficking inducer (NOSTRIN). Dynamin-2, NOSIP, NOSTRIN, and cytoskeleton are also involved in eNOS trafficking in endothelial cells. In addition, eNOS associations with cationic amino acid transporter-1 (CAT-1), argininosuccinate synthase (ASS), argininosuccinate lyase (ASL), and soluble guanylate cyclase (sGC) facilitate directed delivery of substrate (L-arginine) to eNOS and optimizing NO production and NO action on its target. Regulation of eNOS by protein-protein interactions would provide potential targets for pharmacological interventions in NO-compromised cardiovascular diseases.
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Affiliation(s)
- Yunchao Su
- Department of Pharmacology and Toxicology, Medical College of Georgia, Georgia Regents University, 1120 15th Street, Augusta, GA 30912.
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23
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Benson MA, Batchelor H, Chuaiphichai S, Bailey J, Zhu H, Stuehr DJ, Bhattacharya S, Channon KM, Crabtree MJ. A pivotal role for tryptophan 447 in enzymatic coupling of human endothelial nitric oxide synthase (eNOS): effects on tetrahydrobiopterin-dependent catalysis and eNOS dimerization. J Biol Chem 2013; 288:29836-45. [PMID: 23965989 PMCID: PMC3795282 DOI: 10.1074/jbc.m113.493023] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/12/2013] [Revised: 08/12/2013] [Indexed: 11/06/2022] Open
Abstract
Tetrahydrobiopterin (BH4) is a required cofactor for the synthesis of NO by NOS. Bioavailability of BH4 is a critical factor in regulating the balance between NO and superoxide production by endothelial NOS (eNOS coupling). Crystal structures of the mouse inducible NOS oxygenase domain reveal a homologous BH4-binding site located in the dimer interface and a conserved tryptophan residue that engages in hydrogen bonding or aromatic stacking interactions with the BH4 ring. The role of this residue in eNOS coupling remains unexplored. We overexpressed human eNOS W447A and W447F mutants in novel cell lines with tetracycline-regulated expression of human GTP cyclohydrolase I, the rate-limiting enzyme in BH4 synthesis, to determine the importance of BH4 and Trp-447 in eNOS uncoupling. NO production was abolished in eNOS-W447A cells and diminished in cells expressing W447F, despite high BH4 levels. eNOS-derived superoxide production was significantly elevated in W447A and W447F versus wild-type eNOS, and this was sufficient to oxidize BH4 to 7,8-dihydrobiopterin. In uncoupled, BH4-deficient cells, the deleterious effects of W447A mutation were greatly exacerbated, resulting in further attenuation of NO and greatly increased superoxide production. eNOS dimerization was attenuated in W447A eNOS cells and further reduced in BH4-deficient cells, as demonstrated using a novel split Renilla luciferase biosensor. Reduction of cellular BH4 levels resulted in a switch from an eNOS dimer to an eNOS monomer. These data reveal a key role for Trp-447 in determining NO versus superoxide production by eNOS, by effects on BH4-dependent catalysis, and by modulating eNOS dimer formation.
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Affiliation(s)
- Matthew A. Benson
- the Nuffield Department of Clinical Medicine, Target Discovery Institute, The Wellcome Trust Centre for Human Genetics, Roosevelt Drive, Oxford OX3 7BN, United Kingdom, and
| | - Helen Batchelor
- From the British Heart Foundation Centre of Research Excellence, Division of Cardiovascular Medicine, University of Oxford, John Radcliffe Hospital, Oxford OX3 9DU, United Kingdom
| | - Surawee Chuaiphichai
- From the British Heart Foundation Centre of Research Excellence, Division of Cardiovascular Medicine, University of Oxford, John Radcliffe Hospital, Oxford OX3 9DU, United Kingdom
| | - Jade Bailey
- From the British Heart Foundation Centre of Research Excellence, Division of Cardiovascular Medicine, University of Oxford, John Radcliffe Hospital, Oxford OX3 9DU, United Kingdom
| | - Hanneng Zhu
- the Nuffield Department of Clinical Medicine, Target Discovery Institute, The Wellcome Trust Centre for Human Genetics, Roosevelt Drive, Oxford OX3 7BN, United Kingdom, and
| | - Dennis J. Stuehr
- the Department of Pathobiology, Lerner Research Institute, Cleveland Clinic Foundation, Cleveland, Ohio 44195
| | - Shoumo Bhattacharya
- From the British Heart Foundation Centre of Research Excellence, Division of Cardiovascular Medicine, University of Oxford, John Radcliffe Hospital, Oxford OX3 9DU, United Kingdom
| | - Keith M. Channon
- From the British Heart Foundation Centre of Research Excellence, Division of Cardiovascular Medicine, University of Oxford, John Radcliffe Hospital, Oxford OX3 9DU, United Kingdom
| | - Mark J. Crabtree
- From the British Heart Foundation Centre of Research Excellence, Division of Cardiovascular Medicine, University of Oxford, John Radcliffe Hospital, Oxford OX3 9DU, United Kingdom
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24
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Cao X, Li H, Tao H, Wu N, Yu L, Zhang D, Lu X, Zhu J, Lu Z, Zhu Q. Metformin inhibits vascular calcification in female rat aortic smooth muscle cells via the AMPK-eNOS-NO pathway. Endocrinology 2013; 154:3680-9. [PMID: 24025223 DOI: 10.1210/en.2013-1002] [Citation(s) in RCA: 62] [Impact Index Per Article: 5.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/25/2022]
Abstract
Metformin exhibits diverse protective effects against diabetic complications, such as bone loss. Here, we investigated the effect of metformin on vascular calcification, another type 2 diabetes complication. In female rat aortic smooth muscle cells (RASMCs), we observed that metformin significantly alleviated β-glycerophosphate-induced Ca deposition and alkaline phosphatase activity, corresponding with reduced expression of some specific genes in osteoblast-like cells, including Runx2 and bone morphogenetic protein-2, and positive effects on α-actin expression, a specific marker of smooth muscle cells. Mechanistic analysis showed that phosphorylation levels of both AMP-activated protein kinase (AMPK) and endothelial nitric oxide synthase (eNOS) were increased with NO overproduction. After inhibition of either AMPK or eNOS with the pharmacologic inhibitors, compound C or Nω-Nitro-L-arginine methyl ester, NO production was lowered and metformin-meditated vascular protection against β-glycerophosphate-induced Ca deposition was removed. Our results support that metformin prevents vascular calcification via AMPK-eNOS-NO pathway.
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MESH Headings
- AMP-Activated Protein Kinases/antagonists & inhibitors
- AMP-Activated Protein Kinases/chemistry
- AMP-Activated Protein Kinases/metabolism
- Animals
- Aorta/cytology
- Aorta/drug effects
- Aorta/metabolism
- Aorta/pathology
- Cell Transdifferentiation/drug effects
- Cells, Cultured
- Diabetic Angiopathies/chemically induced
- Diabetic Angiopathies/metabolism
- Diabetic Angiopathies/pathology
- Diabetic Angiopathies/prevention & control
- Enzyme Activation/drug effects
- Enzyme Inhibitors/adverse effects
- Female
- Glycerophosphates/adverse effects
- Glycerophosphates/antagonists & inhibitors
- Hypoglycemic Agents/antagonists & inhibitors
- Hypoglycemic Agents/pharmacology
- Metformin/antagonists & inhibitors
- Metformin/pharmacology
- Muscle, Smooth, Vascular/cytology
- Muscle, Smooth, Vascular/drug effects
- Muscle, Smooth, Vascular/metabolism
- Muscle, Smooth, Vascular/pathology
- Nitric Oxide/metabolism
- Nitric Oxide Synthase Type III/antagonists & inhibitors
- Nitric Oxide Synthase Type III/chemistry
- Nitric Oxide Synthase Type III/metabolism
- Phosphorylation/drug effects
- Protein Kinase Inhibitors/adverse effects
- Protein Processing, Post-Translational/drug effects
- Rats
- Rats, Sprague-Dawley
- Signal Transduction/drug effects
- Vascular Calcification/chemically induced
- Vascular Calcification/metabolism
- Vascular Calcification/pathology
- Vascular Calcification/prevention & control
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Affiliation(s)
- Xiaorui Cao
- PhD, State Key Laboratory of Cancer Biology, Department of Biochemistry and Molecular Biology, Fourth Military Medical University, 710032 Xi'an, China, ; or Qingshen Zhu, MD, PhD, Department of Orthopedics, Xijing Hospital, Fourth Military Medical University, 710032 Xi'an, China, E-mail:
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25
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Leucker TM, Ge ZD, Procknow J, Liu Y, Shi Y, Bienengraeber M, Warltier DC, Kersten JR. Impairment of endothelial-myocardial interaction increases the susceptibility of cardiomyocytes to ischemia/reperfusion injury. PLoS One 2013; 8:e70088. [PMID: 23894596 PMCID: PMC3718730 DOI: 10.1371/journal.pone.0070088] [Citation(s) in RCA: 35] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/06/2013] [Accepted: 06/14/2013] [Indexed: 12/22/2022] Open
Abstract
Endothelial-myocardial interactions may be critically important for ischemia/reperfusion injury. Tetrahydrobiopterin (BH4) is a required cofactor for nitric oxide (NO) production by endothelial NO synthase (eNOS). Hyperglycemia (HG) leads to significant increases in oxidative stress, oxidizing BH4 to enzymatically incompetent dihydrobiopterin. How alterations in endothelial BH4 content impact myocardial ischemia/reperfusion injury remains elusive. The aim of this study was to examine the effect of endothelial-myocardial interaction on ischemia/reperfusion injury, with an emphasis on the role of endothelial BH4 content. Langendorff-perfused mouse hearts were treated by triton X-100 to produce endothelial dysfunction and subsequently subjected to 30 min of ischemia followed by 2 h of reperfusion. The recovery of left ventricular systolic and diastolic function during reperfusion was impaired in triton X-100 treated hearts compared with vehicle-treated hearts. Cardiomyocytes (CMs) were co-cultured with endothelial cells (ECs) and subsequently subjected to 2 h of hypoxia followed by 2 h of reoxygenation. Addition of ECs to CMs at a ratio of 1∶3 significantly increased NO production and decreased lactate dehydrogenase activity compared with CMs alone. This EC-derived protection was abolished by HG. The addition of 100 µM sepiapterin (a BH4 precursor) or overexpression of GTP cyclohydrolase 1 (the rate-limiting enzyme for BH4 biosynthesis) in ECs by gene trasfer enhanced endothelial BH4 levels, the ratio of eNOS dimer/monomer, eNOS phosphorylation, and NO production and decreased lactate dehydrogenase activity in the presence of HG. These results demonstrate that increased BH4 content in ECs by either pharmacological or genetic approaches reduces myocardial damage during hypoxia/reoxygenation in the presence of HG. Maintaining sufficient endothelial BH4 is crucial for cardioprotection against hypoxia/reoxygenation injury.
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Affiliation(s)
- Thorsten M. Leucker
- Department of Anesthesiology, Medical College of Wisconsin, Milwaukee, Wisconsin, United States of America
| | - Zhi-Dong Ge
- Department of Anesthesiology, Medical College of Wisconsin, Milwaukee, Wisconsin, United States of America
| | - Jesse Procknow
- Department of Anesthesiology, Medical College of Wisconsin, Milwaukee, Wisconsin, United States of America
| | - Yanan Liu
- Department of Anesthesiology, Medical College of Wisconsin, Milwaukee, Wisconsin, United States of America
| | - Yang Shi
- Department of Surgery, Medical College of Wisconsin, Milwaukee, Wisconsin, United States of America
| | - Martin Bienengraeber
- Department of Anesthesiology, Medical College of Wisconsin, Milwaukee, Wisconsin, United States of America
- Deparment of Pharmacology and Toxicology, Medical College of Wisconsin, Milwaukee, Wisconsin, United States of America
| | - David C. Warltier
- Department of Anesthesiology, Medical College of Wisconsin, Milwaukee, Wisconsin, United States of America
- Deparment of Pharmacology and Toxicology, Medical College of Wisconsin, Milwaukee, Wisconsin, United States of America
| | - Judy R. Kersten
- Department of Anesthesiology, Medical College of Wisconsin, Milwaukee, Wisconsin, United States of America
- Deparment of Pharmacology and Toxicology, Medical College of Wisconsin, Milwaukee, Wisconsin, United States of America
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26
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Cheng CP, Tsai SW, Chiu CP, Pan TM, Tsai TY. The effect of probiotic-fermented soy milk on enhancing the NO-mediated vascular relaxation factors. J Sci Food Agric 2013; 93:1219-1225. [PMID: 22996620 DOI: 10.1002/jsfa.5880] [Citation(s) in RCA: 23] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/06/2012] [Revised: 07/19/2012] [Accepted: 08/21/2012] [Indexed: 06/01/2023]
Abstract
BACKGROUND Soy milk is one of the common soy-based foods in Asia. In this study the effects of soy milk fermented with selected probiotics on nitric oxide (NO)-mediated vascular relaxation factors in cell model systems were investigated. RESULTS Soy milk fermented with Lactobacillus plantarum TWK10 or Streptococcus thermophilus BCRC 14085 for 48 h showed a greater transformation of glucoside isoflavones to aglycone isoflavones (P < 0.05). An increase in aglycone isoflavones in ethanol extracts from fermented soy milk stimulated NO production and endothelial NO synthase (eNOS) activity in human umbilical vein endothelial cells. It also had a stimulating effect on superoxide anion scavenging and prostaglandin E₂ production. In addition, it enhanced mRNA expression of the E-prostanoid 4 receptor in rat thoracic aorta smooth muscle cells. Moreover, a small amount of O₂⁻ induced by water extracts from fermented soy milk at low concentration (1 mg mL⁻¹) increased the content of calcium ions and activated eNOS, thereby promoting NO production and the coupling state of eNOS. CONCLUSION Soy milk fermented with selected probiotics promotes the relaxation factors of vascular endothelial cells and can be applied in the development of functional foods.
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MESH Headings
- Animals
- Cell Line
- Cells, Cultured
- Dinoprostone/metabolism
- Endothelium, Vascular/cytology
- Endothelium, Vascular/enzymology
- Endothelium, Vascular/metabolism
- Fermentation
- Glucosides/metabolism
- Human Umbilical Vein Endothelial Cells/cytology
- Human Umbilical Vein Endothelial Cells/enzymology
- Human Umbilical Vein Endothelial Cells/metabolism
- Humans
- Isoflavones/metabolism
- Lactobacillus plantarum/metabolism
- Muscle, Smooth, Vascular/cytology
- Muscle, Smooth, Vascular/enzymology
- Muscle, Smooth, Vascular/metabolism
- Nitric Oxide/metabolism
- Nitric Oxide Synthase Type III/chemistry
- Nitric Oxide Synthase Type III/metabolism
- Probiotics/metabolism
- Rats
- Receptors, Prostaglandin E, EP4 Subtype/biosynthesis
- Receptors, Prostaglandin E, EP4 Subtype/genetics
- Receptors, Prostaglandin E, EP4 Subtype/metabolism
- Soy Milk/metabolism
- Streptococcus thermophilus/metabolism
- Taiwan
- Up-Regulation
- Vasodilation
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Affiliation(s)
- Chein-Pang Cheng
- Department of Food Science, Fu Jen Catholic University, Taipei, Taiwan
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Novella S, Laguna-Fernández A, Lázaro-Franco M, Sobrino A, Bueno-Betí C, Tarín JJ, Monsalve E, Sanchís J, Hermenegildo C. Estradiol, acting through estrogen receptor alpha, restores dimethylarginine dimethylaminohydrolase activity and nitric oxide production in oxLDL-treated human arterial endothelial cells. Mol Cell Endocrinol 2013; 365:11-6. [PMID: 22982060 DOI: 10.1016/j.mce.2012.08.020] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/29/2011] [Revised: 08/28/2012] [Accepted: 08/29/2012] [Indexed: 10/27/2022]
Abstract
Asymmetric dimethylarginine (ADMA) is an endogenous inhibitor of nitric oxide (NO) synthase. ADMA accumulation, mainly due to a decreased dimethylarginine dimethylaminohydrolase (DDAH) activity, has been related to the development of cardiovascular diseases. We investigate whether estradiol prevents the changes induced by oxidized low density lipoprotein (oxLDL) on the DDAH/ADMA/NO pathway in human umbilical artery endothelial cells (HUAEC). HUAEC were exposed to estradiol, native LDL (nLDL), oxLDL and their combinations for 24 h. In some experiments, cells were also exposed to the unspecific estrogen receptor (ER) antagonist ICI 182780, the specific ERα antagonist MPP or specific agonists for ERα, ERβ and GPER. ADMA concentration was measured by HPLC and concentration of NO by amperometry. Protein expression and DDAH activity were measured by immunoblotting and an enzymatic method, respectively. oxLDL, but not nLDL, increased ADMA concentration with a concomitant decrease on DDAH activity. oxLDL reduced eNOS protein and NO production. Estradiol alone had no effects on DDAH/ADMA/NO pathway, but increased the attenuated endothelial NO production induced by oxLDL by reduction in ADMA and preventing loss of eNOS protein levels. ICI 182780 and MPP completely abolished these effects of estradiol on oxLDL-exposed cells. ERα agonist, but not ERβ and GPER agonists, mirrored estradiol effects on NO production. In conclusion, estradiol restores (1) DDAH activity, and therefore ADMA levels, and (2) NO production impaired by oxLDL in HUAEC acting through ERα.
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MESH Headings
- Amidohydrolases/antagonists & inhibitors
- Amidohydrolases/chemistry
- Amidohydrolases/metabolism
- Arginine/adverse effects
- Arginine/analogs & derivatives
- Arginine/antagonists & inhibitors
- Arginine/metabolism
- Blotting, Western
- Cells, Cultured
- Endothelium, Vascular/cytology
- Endothelium, Vascular/drug effects
- Endothelium, Vascular/metabolism
- Estradiol/agonists
- Estradiol/chemistry
- Estradiol/metabolism
- Estrogen Antagonists/pharmacology
- Estrogen Receptor alpha/agonists
- Estrogen Receptor alpha/antagonists & inhibitors
- Estrogen Receptor alpha/metabolism
- Estrogen Receptor beta/agonists
- Estrogen Receptor beta/antagonists & inhibitors
- Estrogen Receptor beta/metabolism
- Estrogens, Non-Steroidal/pharmacology
- Humans
- Isoenzymes/antagonists & inhibitors
- Isoenzymes/chemistry
- Isoenzymes/metabolism
- Lipoproteins, LDL/adverse effects
- Lipoproteins, LDL/antagonists & inhibitors
- Nitric Oxide/agonists
- Nitric Oxide/antagonists & inhibitors
- Nitric Oxide/metabolism
- Nitric Oxide Synthase Type III/antagonists & inhibitors
- Nitric Oxide Synthase Type III/chemistry
- Nitric Oxide Synthase Type III/metabolism
- Protein Stability
- Protein-Arginine N-Methyltransferases/metabolism
- Receptors, Estrogen/agonists
- Receptors, Estrogen/antagonists & inhibitors
- Receptors, Estrogen/metabolism
- Receptors, G-Protein-Coupled/agonists
- Receptors, G-Protein-Coupled/antagonists & inhibitors
- Receptors, G-Protein-Coupled/metabolism
- Repressor Proteins/metabolism
- Umbilical Arteries/cytology
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Affiliation(s)
- Susana Novella
- Research Foundation, Hospital Clínico of Valencia - INCLIVA, Valencia, Spain.
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28
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Kietadisorn R, Juni RP, Moens AL. Tackling endothelial dysfunction by modulating NOS uncoupling: new insights into its pathogenesis and therapeutic possibilities. Am J Physiol Endocrinol Metab 2012; 302:E481-95. [PMID: 22167522 DOI: 10.1152/ajpendo.00540.2011] [Citation(s) in RCA: 154] [Impact Index Per Article: 12.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/17/2022]
Abstract
Endothelial nitric oxide synthase (eNOS) serves as a critical enzyme in maintaining vascular pressure by producing nitric oxide (NO); hence, it has a crucial role in the regulation of endothelial function. The bioavailability of eNOS-derived NO is crucial for this function and might be affected at multiple levels. Uncoupling of eNOS, with subsequently less NO and more superoxide generation, is one of the major underlying causes of endothelial dysfunction found in atherosclerosis, diabetes, hypertension, cigarette smoking, hyperhomocysteinemia, and ischemia/reperfusion injury. Therefore, modulating eNOS uncoupling by stabilizing eNOS activity, enhancing its substrate, cofactors, and transcription, and reversing uncoupled eNOS are attractive therapeutic approaches to improve endothelial function. This review provides an extensive overview of the important role of eNOS uncoupling in the pathogenesis of endothelial dysfunction and the potential therapeutic interventions to modulate eNOS for tackling endothelial dysfunction.
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Affiliation(s)
- Rinrada Kietadisorn
- Maastricht Univ. Medical Centre, Cardiovascular Research Institute Maastricht, Maastricht, The Netherlands
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29
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Aquila S, Giordano F, Guido C, Rago V, Carpino A. Nitric oxide involvement in the acrosome reaction triggered by leptin in pig sperm. Reprod Biol Endocrinol 2011; 9:133. [PMID: 21970701 PMCID: PMC3200170 DOI: 10.1186/1477-7827-9-133] [Citation(s) in RCA: 23] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/15/2011] [Accepted: 10/04/2011] [Indexed: 01/10/2023] Open
Abstract
BACKGROUND Nitric oxide (NO) is a signaling molecule produced by intracellular nitric oxide synthase (NOS) enzymes. This free radical appears to affect sperm capacitation, a maturation step preceding acrosome reaction. Recent studies have reported leptin ability to promote capacitation and acrosome reaction in pig male gametes. METHODS This study has investigated nitric oxide production in leptin-treated pig spermatozoa by fluorescence-activated cell sorting, while the intracellular NOS isoforms were assessed by Western blot analysis. In addition, acrosome status of treated-spermatozoa was evaluated by FITC-PNA staining. RESULTS Significant increases of nitric oxide levels and acrosome reaction extent were detected in leptin-treated spermatozoa, but both the effects were reversed in presence of L-NAME. Furthermore, the immunoblots of sperm extracts have evidenced three bands of ~160 Kd(bNOS), ~130 Kd (iNOS) and ~135 Kd (eNOS). CONCLUSIONS The identification of the three intracellular NOS isoforms suggests that pig spermatozoa could produce NO, while the augmented nitric oxide levels in leptin-treated male gametes indicates the capacity of the hormone to induce nitric oxide production. Furthermore, the inhibitory effect of L-NAME and of Ab-ObR on the promotion of acrosome reaction triggered by leptin suggests a possible involvement of NO in the hormone action.
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Affiliation(s)
- Saveria Aquila
- Department of Pharmaco-Biology, University of Calabria 87036 Arcavacata di Rende (Cosenza), Italy
- Centro Sanitario. University of Calabria 87036 Arcavacata di Rende (Cosenza) Italy
| | - Francesca Giordano
- Department of Cell Biology, Faculty of Pharmacy, University of Calabria 87036 Arcavacata di Rende (Cosenza), Italy
| | - Carmela Guido
- Department of Pharmaco-Biology, University of Calabria 87036 Arcavacata di Rende (Cosenza), Italy
- Centro Sanitario. University of Calabria 87036 Arcavacata di Rende (Cosenza) Italy
| | - Vittoria Rago
- Department of Cell Biology, Faculty of Pharmacy, University of Calabria 87036 Arcavacata di Rende (Cosenza), Italy
| | - Amalia Carpino
- Department of Cell Biology, Faculty of Pharmacy, University of Calabria 87036 Arcavacata di Rende (Cosenza), Italy
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30
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Xue F, Kraus JM, Labby KJ, Ji H, Mataka J, Xia G, Li H, Delker SL, Roman LJ, Martásek P, Poulos TL, Silverman RB. Improved synthesis of chiral pyrrolidine inhibitors and their binding properties to neuronal nitric oxide synthase. J Med Chem 2011; 54:6399-403. [PMID: 21809851 PMCID: PMC3174355 DOI: 10.1021/jm200411j] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/01/2023]
Abstract
We report an efficient synthetic route to chiral pyrrolidine inhibitors of neuronal nitric oxide synthase (nNOS) and crystal structures of the inhibitors bound to nNOS and to endothelial NOS. The new route enables versatile structure-activity relationship studies on the pyrrolidine-based scaffold, which can be beneficial for further development of nNOS inhibitors. The X-ray crystal structures of five new fluorine-containing inhibitors bound to nNOS provide insights into the effect of the fluorine atoms on binding.
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Affiliation(s)
- Fengtian Xue
- Department of Chemistry, Department of Molecular Biosciences, Chemistry of Life Processes Institute, Center for Molecular Innovation and Drug Discovery, Northwestern University, 2145 Sheridan Road, Evanston, Illinois 60208-3113, USA
| | - James M. Kraus
- Department of Chemistry, Department of Molecular Biosciences, Chemistry of Life Processes Institute, Center for Molecular Innovation and Drug Discovery, Northwestern University, 2145 Sheridan Road, Evanston, Illinois 60208-3113, USA
| | - Kristin Jansen Labby
- Department of Chemistry, Department of Molecular Biosciences, Chemistry of Life Processes Institute, Center for Molecular Innovation and Drug Discovery, Northwestern University, 2145 Sheridan Road, Evanston, Illinois 60208-3113, USA
| | - Haitao Ji
- Department of Chemistry, Department of Molecular Biosciences, Chemistry of Life Processes Institute, Center for Molecular Innovation and Drug Discovery, Northwestern University, 2145 Sheridan Road, Evanston, Illinois 60208-3113, USA
| | - Jan Mataka
- Department of Chemistry, Department of Molecular Biosciences, Chemistry of Life Processes Institute, Center for Molecular Innovation and Drug Discovery, Northwestern University, 2145 Sheridan Road, Evanston, Illinois 60208-3113, USA
| | - Guoyao Xia
- Department of Chemistry, Department of Molecular Biosciences, Chemistry of Life Processes Institute, Center for Molecular Innovation and Drug Discovery, Northwestern University, 2145 Sheridan Road, Evanston, Illinois 60208-3113, USA
| | - Huiying Li
- Departments of Molecular Biology and Biochemistry, Pharmaceutical Chemistry, and Chemistry, University of California, Irvine, California 92697-3900
| | - Silvia L. Delker
- Departments of Molecular Biology and Biochemistry, Pharmaceutical Chemistry, and Chemistry, University of California, Irvine, California 92697-3900
| | - Linda J. Roman
- Department of Biochemistry, The University of Texas Health Science Center, San Antonio, Texas 78384-7760
| | - Pavel Martásek
- Department of Biochemistry, The University of Texas Health Science Center, San Antonio, Texas 78384-7760
- Department of Pediatrics and Center for Applied Genomics, 1st School of Medicine, Charles University, Prague, Czech Republic
| | - Thomas L. Poulos
- Departments of Molecular Biology and Biochemistry, Pharmaceutical Chemistry, and Chemistry, University of California, Irvine, California 92697-3900
| | - Richard B. Silverman
- Department of Chemistry, Department of Molecular Biosciences, Chemistry of Life Processes Institute, Center for Molecular Innovation and Drug Discovery, Northwestern University, 2145 Sheridan Road, Evanston, Illinois 60208-3113, USA
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31
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Rafikov R, Fonseca FV, Kumar S, Pardo D, Darragh C, Elms S, Fulton D, Black SM. eNOS activation and NO function: structural motifs responsible for the posttranslational control of endothelial nitric oxide synthase activity. J Endocrinol 2011; 210:271-84. [PMID: 21642378 PMCID: PMC3326601 DOI: 10.1530/joe-11-0083] [Citation(s) in RCA: 166] [Impact Index Per Article: 12.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 02/06/2023]
Abstract
Rather than being a constitutive enzyme as was first suggested, endothelial nitric oxide synthase (eNOS) is dynamically regulated at the transcriptional, posttranscriptional, and posttranslational levels. This review will focus on how changes in eNOS function are conferred by various posttranslational modifications. The latest knowledge regarding eNOS targeting to the plasma membrane will be discussed as the role of protein phosphorylation as a modulator of catalytic activity. Furthermore, new data are presented that provide novel insights into how disruption of the eNOS dimer prevents eNOS uncoupling and the production of superoxide under conditions of elevated oxidative stress and identifies a novel regulatory region we have termed the 'flexible arm'.
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Affiliation(s)
- Ruslan Rafikov
- Pulmonary Vascular Disease Program, Vascular Biology Center: CB-3211B, Georgia Health Sciences University, 1459 Laney Walker Boulevard, Augusta, GA 30912, USA
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32
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Trajanovska S, Donald JA. Endothelial nitric oxide synthase in the amphibian, Xenopus tropicalis. Comp Biochem Physiol B Biochem Mol Biol 2011; 158:274-81. [PMID: 21199680 DOI: 10.1016/j.cbpb.2010.12.008] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/24/2010] [Revised: 12/19/2010] [Accepted: 12/22/2010] [Indexed: 11/19/2022]
Abstract
Nitric oxide (NO) is generated by NO synthase (NOS) of which there are three isoforms: neuronal NOS (nNOS, nos1), inducible NOS (iNOS, nos2), and endothelial NOS (eNOS, nos3). This study utilised the genome of Xenopus tropicalis to sequence a nos3 cDNA and determine if eNOS protein is expressed in blood vessels. A nos3 cDNA was sequenced that encoded a 1177 amino acid protein called XteNOS, which showed closest sequence identity to mammalian eNOS protein. The X. tropicalis nos3 gene and eNOS protein were determined to be an orthologue of mammalian nos3 and eNOS using gene synteny and phylogenetic analyses, respectively. In X. tropicalis, nos3 mRNA expression was highest in lung and skeletal muscle and lower in the liver, gut, kidney, heart and brain. Western analysis of kidney protein using an affinity-purified anti-XteNOS produced a single band at 140kDa. Immunohistochemistry showed XteNOS immunoreactivity in the proximal tubule of the kidney and endocardium of the heart, but not in the endothelium of blood vessels. Thus, X. tropicalis has a nos3 gene that appears not to be expressed in the vascular endothelium.
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Affiliation(s)
- Sofie Trajanovska
- School of Life and Environmental Sciences, Deakin University, Geelong, 3217, Australia.
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33
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Chen W, Druhan LJ, Chen CA, Hemann C, Chen YR, Berka V, Tsai AL, Zweier JL. Peroxynitrite induces destruction of the tetrahydrobiopterin and heme in endothelial nitric oxide synthase: transition from reversible to irreversible enzyme inhibition. Biochemistry 2010; 49:3129-37. [PMID: 20184376 PMCID: PMC2851177 DOI: 10.1021/bi9016632] [Citation(s) in RCA: 84] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/07/2023]
Abstract
Endothelial nitric oxide synthase (eNOS) is an important regulator of vascular and cardiac function. Peroxynitrite (ONOO(-)) inactivates eNOS, but questions remain regarding the mechanisms of this process. It has been reported that inactivation is due to oxidation of the eNOS zinc-thiolate cluster, rather than the cofactor tetrahydrobiopterin (BH(4)); however, this remains highly controversial. Therefore, we investigated the mechanisms of ONOO(-)-induced eNOS dysfunction and their dose dependence. Exposure of human eNOS to ONOO(-) resulted in a dose-dependent loss of activity with a marked destabilization of the eNOS dimer. HPLC analysis indicated that both free and eNOS-bound BH(4) were oxidized during exposure to ONOO(-); however, full oxidation of protein-bound biopterin required higher ONOO(-) levels. Additionally, ONOO(-) triggered changes in the UV/visible spectrum and heme content of the enzyme. Preincubation of eNOS with BH(4) decreased dimer destabilization and heme alteration. Addition of BH(4) to the ONOO(-)-destabilized eNOS dimer only partially rescued enzyme function. In contrast to ONOO(-) treatment, incubation with the zinc chelator TPEN with removal of enzyme-bound zinc did not change the eNOS activity or stability of the SDS-resistant eNOS dimer, demonstrating that the dimer stabilization induced by BH(4) does not require zinc occupancy of the zinc-thiolate cluster. While ONOO(-) treatment was observed to induce loss of Zn binding, this cannot account for the loss of enzyme activity. Therefore, ONOO(-)-induced eNOS inactivation is primarily due to oxidation of BH(4) and irreversible destruction of the heme/heme center.
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Affiliation(s)
- Weiguo Chen
- Davis Heart & Lung Research Institute, Division of Cardiovascular Medicine, Department of Internal Medicine, College of Medicine, The Ohio State University, Columbus, Ohio 43210
| | - Lawrence J. Druhan
- Davis Heart & Lung Research Institute, Division of Cardiovascular Medicine, Department of Internal Medicine, College of Medicine, The Ohio State University, Columbus, Ohio 43210
| | - Chun-An Chen
- Davis Heart & Lung Research Institute, Division of Cardiovascular Medicine, Department of Internal Medicine, College of Medicine, The Ohio State University, Columbus, Ohio 43210
| | - Craig Hemann
- Davis Heart & Lung Research Institute, Division of Cardiovascular Medicine, Department of Internal Medicine, College of Medicine, The Ohio State University, Columbus, Ohio 43210
| | - Yeong-Renn Chen
- Davis Heart & Lung Research Institute, Division of Cardiovascular Medicine, Department of Internal Medicine, College of Medicine, The Ohio State University, Columbus, Ohio 43210
| | - Vladimir Berka
- Division of Hematology, Department of Internal Medicine, University of Texas Health Science Center at Houston, Houston, Texas 77030
| | - Ah-Lim Tsai
- Division of Hematology, Department of Internal Medicine, University of Texas Health Science Center at Houston, Houston, Texas 77030
| | - Jay L. Zweier
- Davis Heart & Lung Research Institute, Division of Cardiovascular Medicine, Department of Internal Medicine, College of Medicine, The Ohio State University, Columbus, Ohio 43210
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34
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Fonseca FV, Ravi K, Wiseman D, Tummala M, Harmon C, Ryzhov V, Fineman JR, Black SM. Mass spectroscopy and molecular modeling predict endothelial nitric oxide synthase dimer collapse by hydrogen peroxide through zinc tetrathiolate metal-binding site disruption. DNA Cell Biol 2010; 29:149-60. [PMID: 20184449 PMCID: PMC2883531 DOI: 10.1089/dna.2009.0858] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/14/2009] [Revised: 10/17/2009] [Accepted: 10/19/2009] [Indexed: 01/24/2023] Open
Abstract
Endothelial nitric oxide synthase (eNOS) is inhibited by hydrogen peroxide (H(2)O(2)), but the mechanism has not been determined. Thus, the purpose of this study was to delineate the mechanism by which H(2)O(2) inhibits eNOS activity. Using mass spectroscopy, we found that the tetrathiolate cysteine residues 94 and 99 were susceptible to oxidation by H(2)O(2). Molecular modeling predicted that these cysteic acid modifications would disrupt the van der Waals interactions and the hydrogen bonding network mediated by the tetrathiolate cysteines 94 and 99 resulting in changes in quaternary structure, zinc release, and dimer collapse. Using recombinant human eNOS (heNOS) to test the predictions of the molecular modeling we found that H(2)O(2) caused disruption of the heNOS dimer and this was accompanied by zinc release and decreased NO generation. We also found that H(2)O(2) increased the oxidation of tetrahydrobiopterin (BH(4)) to dihydrobiopterin (BH(2)), whereas preincubation of heNOS with excess BH(4) prevented the destruction of zinc tetrathiolate and dimer collapse and preserved activity. Interestingly, we found that the dimmer-stabilizing effect of BH(4) is due to its ability to act as a catalase mimetic. Further, we confirmed that, in ovine aortic endothelial cells, H(2)O(2) could also induce dimer collapse and that increasing cellular BH(4) levels could maintain eNOS in its dimeric form and NO signaling when cells were challenged with H(2)O(2). This study links the inhibitory action of H(2)O(2) on heNOS through the destruction of zinc tetrathiolate metal-binding site and dimer collapse both in vitro and in vivo.
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Affiliation(s)
- Fabio V. Fonseca
- Vascular Biology Center, Medical College of Georgia, Augusta, Georgia
| | - Kandasamy Ravi
- Cold Spring Harbor Laboratories, Cold Spring Harbor, New York
| | - Dean Wiseman
- Vascular Biology Center, Medical College of Georgia, Augusta, Georgia
| | - Monorama Tummala
- Department of Chemistry and Biochemistry, Northern Illinois University, DeKalb, Illinois
| | - Cynthia Harmon
- Department of Pediatrics, University of California, San Francisco, California
| | - Victor Ryzhov
- Department of Chemistry and Biochemistry, Northern Illinois University, DeKalb, Illinois
| | - Jeffrey R. Fineman
- Department of Pediatrics, University of California, San Francisco, California
- Department of Cardiovascular Research Institute, University of California, San Francisco, California
| | - Stephen M. Black
- Vascular Biology Center, Medical College of Georgia, Augusta, Georgia
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Kondrikov D, Fonseca FV, Elms S, Fulton D, Black SM, Block ER, Su Y. Beta-actin association with endothelial nitric-oxide synthase modulates nitric oxide and superoxide generation from the enzyme. J Biol Chem 2010; 285:4319-27. [PMID: 19946124 PMCID: PMC2836036 DOI: 10.1074/jbc.m109.063172] [Citation(s) in RCA: 35] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/04/2009] [Revised: 11/20/2009] [Indexed: 11/06/2022] Open
Abstract
Protein-protein interactions represent an important post-translational mechanism for endothelial nitric-oxide synthase (eNOS) regulation. We have previously reported that beta-actin is associated with eNOS oxygenase domain and that association of eNOS with beta-actin increases eNOS activity and nitric oxide (NO) production. In the present study, we found that beta-actin-induced increase in NO production was accompanied by decrease in superoxide formation. A synthetic actin-binding sequence (ABS) peptide 326 with amino acid sequence corresponding to residues 326-333 of human eNOS, one of the putative ABSs, specifically bound to beta-actin and prevented eNOS association with beta-actin in vitro. Peptide 326 also prevented beta-actin-induced decrease in superoxide formation and increase in NO and L-citrulline production. A modified peptide 326 replacing hydrophobic amino acids leucine and tryptophan with neutral alanine was unable to interfere with eNOS-beta-actin binding and to prevent beta-actin-induced changes in NO and superoxide formation. Site-directed mutagenesis of the actin-binding domain of eNOS replacing leucine and tryptophan with alanine yielded an eNOS mutant that exhibited reduced eNOS-beta-actin association, decreased NO production, and increased superoxide formation in COS-7 cells. Disruption of eNOS-beta-actin interaction in endothelial cells using ABS peptide 326 resulted in decreased NO production, increased superoxide formation, and decreased endothelial monolayer wound repair, which was prevented by PEG-SOD and NO donor NOC-18. Taken together, this novel finding indicates that beta-actin binding to eNOS through residues 326-333 in the eNOS protein results in shifting the enzymatic activity from superoxide formation toward NO production. Modulation of NO and superoxide formation from eNOS by beta-actin plays an important role in endothelial function.
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Affiliation(s)
| | | | | | - David Fulton
- From the Department of Pharmacology and Toxicology
- Vascular Biology Center, and
| | | | - Edward R. Block
- the Department of Medicine, University of Florida College of Medicine, Gainesville, Florida 32610
| | - Yunchao Su
- From the Department of Pharmacology and Toxicology
- Department of Medicine
- Vascular Biology Center, and
- Center for Biotechnology and Genomic Medicine, Medical College of Georgia, Augusta, Georgia 30912 and
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36
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Chen PF, Wu KK. Two synthetic peptides corresponding to the proximal heme-binding domain and CD1 domain of human endothelial nitric-oxide synthase inhibit the oxygenase activity by interacting with CaM. Arch Biochem Biophys 2009; 486:132-40. [PMID: 19358819 PMCID: PMC2702655 DOI: 10.1016/j.abb.2009.03.015] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/30/2009] [Revised: 03/23/2009] [Accepted: 03/31/2009] [Indexed: 11/29/2022]
Abstract
Human endothelial nitric-oxide synthase (eNOS) is a complex enzyme, requiring binding of calmodulin (CaM) for electron transfer. The prevailing view is that calcium-activated CaM binds eNOS at the canonical binding site located at residues 493-510, which induces a conformational change to facilitate electron transfer. Here we demonstrated that the CaM enhances the rate of electron transfer from NADPH to FAD on a truncated eNOS FAD subdomain (residues 682-1204) purified from baculovirus-infected Sf9 cells, suggesting more complicated regulatory mechanism of CaM on eNOS. Metabolically (35)S-labeled CaM overlay on fusion proteins spanning the entire linear sequence of eNOS revealed three positive (35)S-CaM binding fragments: sequence 66-205, sequence 460-592, and sequence 505-759. Synthetic peptides derived from these fragments are tested for their effects on CaM binding and eNOS catalytic activities. Peptides corresponding to the proximal heme-binding site (E1, residues 174-193) and the CD1 linker connecting FAD/FMN subdomains (E4, residues 729-757) bind CaM at both high Ca(2+) (Ca(2+)CaM) and low Ca(2+) (apoCaM) concentrations, whereas peptide of the canonical CaM-binding helix (E2, residues 493-510) binds only Ca(2+)CaM. All three peptides E1, E2 and E4 significantly inhibit oxygenase activity in a concentration-dependent manner, but only E2 effectively inhibits reductase activity. Concurrent experiments with human iNOS showed major differences in the CaM binding properties between eNOS and iNOS. The results suggest that multiple regions of eNOS might interact with CaM with differential Ca(2+) sensitivity in vivo. A possible mechanism in regulating eNOS activation and deactivation is proposed.
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Affiliation(s)
- Pei-Feng Chen
- Vascular Biology Research Center, Department of Internal Medicine, The University of Texas Health Science Center at Houston, TX, USA.
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37
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Abstract
S-nitrosylation, or the replacement of the hydrogen atom in the thiol group of cysteine residues by a -NO moiety, is a physiologically important posttranslational modification. In our previous work we have shown that S-nitrosylation is involved in the disruption of the endothelial nitric oxide synthase (eNOS) dimer and that this involves the disruption of the zinc (Zn) tetrathiolate cluster due to the S-nitrosylation of Cysteine 98. However, human eNOS contains 28 other cysteine residues whose potential to undergo S-nitrosylation has not been determined. Thus, the goal of this study was to identify the cysteine residues within eNOS that are susceptible to S-nitrosylation in vitro. To accomplish this, we utilized a modified biotin switch assay. Our modification included the tryptic digestion of the S-nitrosylated eNOS protein to allow the isolation of S-nitrosylated peptides for further identification by mass spectrometry. Our data indicate that multiple cysteine residues are capable of undergoing S-nitrosylation in the presence of an excess of a nitrosylating agent. All these cysteine residues identified were found to be located on the surface of the protein according to the available X-ray structure of the oxygenase domain of eNOS. Among those identified were Cys 93 and 98, the residues involved in the formation of the eNOS dimer through a Zn tetrathiolate cluster. In addition, cysteine residues within the reductase domain were identified as undergoing S-nitrosylation. We identified cysteines 660, 801, and 1113 as capable of undergoing S-nitrosylation. These cysteines are located within regions known to bind flavin mononucleotide (FMN), flavin adenine dinucleotide (FAD), and nicotinamide adenine dinucleotide (NADPH) although from our studies their functional significance is unclear. Finally we identified cysteines 852, 975/990, and 1047/1049 as being susceptible to S-nitrosylation. These cysteines are located in regions of eNOS that have not been implicated in any known biochemical functions and the significance of their S-nitrosylation is not clear from this study. Thus, our data indicate that the eNOS protein can be S-nitrosylated at multiple sites other than within the Zn tetrathiolate cluster, suggesting that S-nitrosylation may regulate eNOS function in ways other than simply by inducing dimer collapse.
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Affiliation(s)
- Monorama Tummala
- Department of Chemistry and Biochemistry, Northern Illinois University, DeKalb, Illinois, USA
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38
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Zickus MA, Fonseca FV, Tummala M, Black SM, Ryzhov V. Identification of the tyrosine nitration sites in human endothelial nitric oxide synthase by liquid chromatography-mass spectrometry. Eur J Mass Spectrom (Chichester) 2008; 14:239-247. [PMID: 18756022 PMCID: PMC2668158 DOI: 10.1255/ejms.927] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/26/2023]
Abstract
The formation of nitric oxide (NO) in biological systems has led to the discovery of a number of post- translational protein modifications that can affect biological conditions such as vasodilation. Studies both from our laboratory and others have shown that beside its effect on cGMP generation from soluble guanylate cylcase, NO can produce protein modifications through both S-nitrosylation of cysteine residues. Previously, we have identified the potential S-nitrosylation sites on endothelial NO synthase (eNOS). Thus, the goal of this study was to further increase our understanding of reactive nitrogen protein modifications of eNOS by identifing tyrosine residues within eNOS that are susceptible to nitration in vitro. To accomplish this, nitration was carried out using tetranitromethane followed by tryptic digest of the protein. The resulting tryptic peptides were analyzed by liquid chromatography/mass spectrometry (LC/MS) and the position of nitrated tyrosines in eNOS were identified. The eNOS sequence contains 30 tyrosine residues and our data indicate that multiple tyrosine residues are capable of being nitrated. We could identify 25 of the 30 residues in our tryptic digests and 19 of these were susceptible to nitration. Interstingly, our data identified four tyrosine residues that can be modified by nitration that are located in the region of eNOS responsible for the binding to heat shock protein 90 (Hsp90), which is responsible for ensuring efficient coupling of eNOS.
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Affiliation(s)
- Michael A Zickus
- Department of Chemistry and Biochemistry, Northern Illinois University, DeKalb, IL 60115, USA
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Abstract
Nitric-oxide synthase (NOS) catalyzes both coupled and uncoupled reactions that generate nitric oxide and reactive oxygen species. Oxygen is often the overlooked substrate, and the oxygen metabolism catalyzed by NOS has been poorly defined. In this paper we focus on the oxygen stoichiometry and effects of substrate/cofactor binding on the endothelial NOS isoform (eNOS). In the presence of both L-arginine and tetrahydrobiopterin, eNOS is highly coupled (>90%), and the measured stoichiometry of O(2)/NADPH is very close to the theoretical value. We report for the first time that the presence of L-arginine stimulates oxygen uptake by eNOS. The fact that nonhydrolyzable L-arginine analogs are not stimulatory indicates that the occurrence of the coupled reaction, rather than the accelerated uncoupled reaction, is responsible for the L-arginine-dependent stimulation. The presence of 5,6,7,8-tetrahydrobiopterin quenched the uncoupled reactions and resulted in much less reactive oxygen species formation, whereas the presence of redox-incompetent 7,8-dihydrobiopterin demonstrates little quenching effect. These results reveal different mechanisms for oxygen metabolism for eNOS as opposed to nNOS and, perhaps, partially explain their functional differences.
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Affiliation(s)
- Ying Tong Gao
- Department of Biochemistry, The University of Texas Health Science Center at San Antonio, San Antonio, Texas 78229-3900
| | - Linda J Roman
- Department of Biochemistry, The University of Texas Health Science Center at San Antonio, San Antonio, Texas 78229-3900
| | - Pavel Martásek
- Department of Pediatrics, Charles University School of Medicine I, 128 08 Prague, Czech Republic
| | - Satya Prakash Panda
- Department of Biochemistry, The University of Texas Health Science Center at San Antonio, San Antonio, Texas 78229-3900
| | - Yuzuru Ishimura
- Department of Biochemistry and Integrated Biology, School of Medicine, Keio University, Tokyo 160-8582, Japan
| | - Bettie Sue S Masters
- Department of Biochemistry, The University of Texas Health Science Center at San Antonio, San Antonio, Texas 78229-3900.
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Abstract
Beta-actin is traditionally considered a structural protein that organizes and maintains the shape of nonmuscle cells, although data now indicate that beta-actin is also a signaling molecule. beta-actin is directly associated with nitric oxide synthase type 3 (NOS-3) in endothelial cells and platelets, and this interaction increases NOS-3 activity and the affinity of NOS-3 for heat shock protein 90 kD (Hsp90). The beta-actin-induced increase in NOS-3 activity may be caused directly by beta-actin, the binding of Hsp90 to NOS-3, or both. Alterations in the interaction between beta-actin and NOS-3 could be caused by changes either in the availability of beta-actin or in the affinity of NOS-3 for beta-actin, and these alterations probably contribute to vascular complications and platelet aggregation. Studies examining the interactions between NOS-3, beta-actin, and Hsp90 could potentially lead to the discovery of effective peptides for the treatment of diseases associated with impaired NOS-3 activity and nitric oxide release, such as systemic and pulmonary hypertension, atherosclerosis, and thrombotic diseases.
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Affiliation(s)
- Yunchao Su
- Department of Medicine, University of Florida College of Medicine, Gainesville, FL 32610, USA.
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41
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Aparna V, Desiraju GR, Gopalakrishnan B. Insights into ligand selectivity in nitric oxide synthase isoforms: A molecular dynamics study. J Mol Graph Model 2007; 26:457-70. [PMID: 17350298 DOI: 10.1016/j.jmgm.2007.02.003] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/25/2006] [Revised: 02/12/2007] [Accepted: 02/12/2007] [Indexed: 11/20/2022]
Abstract
Molecular dynamics (MD) simulations were carried out for inducible nitric oxide synthase (iNOS) and endothelial nitric oxide synthase (eNOS) isoforms complexed with substrate (L-arginine) and the iNOS specific inhibitor GW 273629, 2 for a time period of 1.2ns. The simulations were compared both within and across the isoforms. iNOS specificity of inhibitor 2 is attributed to water mediated interactions and cooperative hydrogen bond networks. Juxtaposition of the carboxylic and ammonium groups in the substrate and inhibitor serve as a modulating key in binding to the isoforms. Based on these investigations, molecules 3 and 4 were rationally designed to attain specificity among the isoforms. The capability of the designed ligands was theoretically tested through MD simulations to envisage binding patterns with both isoforms. A detailed analysis of the molecular recognition pattern shows molecule 4 to be more selective to iNOS when compared to eNOS.
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Affiliation(s)
- V Aparna
- School of Chemistry, University of Hyderabad, Hyderabad 500046, India
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42
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Spratt DE, Taiakina V, Palmer M, Guillemette JG. Differential binding of calmodulin domains to constitutive and inducible nitric oxide synthase enzymes. Biochemistry 2007; 46:8288-300. [PMID: 17580957 DOI: 10.1021/bi062130b] [Citation(s) in RCA: 40] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
Calmodulin (CaM) is a Ca2+ signal transducing protein that binds and activates many cellular enzymes with physiological relevance, including the mammalian nitric oxide synthase (NOS) isozymes: endothelial NOS (eNOS), neuronal NOS (nNOS), and inducible NOS (iNOS). The mechanism of CaM binding and activation to the iNOS enzyme is poorly understood in part due to the strength of the bound complex and the difficulty of assessing the role played by regions outside of the CaM-binding domain. To further elucidate these processes, we have developed the methodology to investigate CaM binding to the iNOS holoenzyme and generate CaM mutant proteins selectively labeled with fluorescent dyes at specific residues in the N-terminal lobe, C-terminal lobe, or linker region of the protein. In the present study, an iNOS CaM coexpression system allowed for the investigation of CaM binding to the holoenzyme; three different mutant CaM proteins with cysteine substitutions at residues T34 (N-domain), K75 (central linker), and T110 (C-domain) were fluorescently labeled with acrylodan or Alexa Fluor 546 C5-maleimide. These proteins were used to investigate the differential association of each region of CaM with the three NOS isoforms. We have also N-terminally labeled an iNOS CaM-binding domain peptide with dabsyl chloride in order to perform FRET studies between Alexa-labeled residues in the N- and C-terminal domains of CaM to determine CaM's orientation when associated to iNOS. Our FRET results show that CaM binds to the iNOS CaM-binding domain in an antiparallel orientation. Our steady-state fluorescence and circular dichroism studies show that both the N- and C-terminal EF hand pairs of CaM bind to the CaM-binding domain peptide of iNOS in a Ca2+-independent manner; however, only the C-terminal domain showed large Ca2+-dependent conformational changes when associated with the target sequence. Steady-state fluorescence showed that Alexa-labeled CaM proteins are capable of binding to holo-iNOS coexpressed with nCaM, but this complex is a transient species and can be displaced with the addition of excess CaM. Our results show that CaM does not bind to iNOS in a sequential manner as previously proposed for the nNOS enzyme. This investigation provides additional insight into why iNOS remains active even under basal levels of Ca2+ in the cell.
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Affiliation(s)
- Donald E Spratt
- Department of Chemistry, University of Waterloo, Waterloo, Ontario N2L 3G1, Canada
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43
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Nishino Y, Yamamoto K, Kimura S, Kikuchi A, Shiro Y, Iyanagi T. Mechanistic studies on the intramolecular one-electron transfer between the two flavins in the human endothelial NOS reductase domain. Arch Biochem Biophys 2007; 465:254-65. [PMID: 17610838 DOI: 10.1016/j.abb.2007.05.021] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/02/2007] [Revised: 05/27/2007] [Accepted: 05/30/2007] [Indexed: 10/23/2022]
Abstract
The object of this study was to clarify the mechanism of electron transfer in the human endothelial nitric oxide synthase (eNOS) reductase domain using recombinant eNOS reductase domains; the FAD/NADPH domain containing FAD- and NADPH-binding sites and the FAD/FMN domain containing FAD/NADPH-, FMN-, and a calmodulin-binding sites. In the presence of molecular oxygen or menadione, the reduced FAD/NADPH domain is oxidized via the neutral (blue) semiquinone (FADH(*)), which has a characteristic absorption peak at 520 nm. The FAD/NADPH and FAD/FMN domains have high activity for ferricyanide, but the FAD/FMN domain has low activity for cytochrome c. In the presence or absence of calcium/calmodulin (Ca(2+)/CaM), reduction of the oxidized flavins (FAD-FMN) and air-stable semiquinone (FAD-FMNH(*)) with NADPH occurred in at least two phases in the absorbance change at 457nm. In the presence of Ca(2+)/CaM, the reduction rate of both phases was significantly increased. In contrast, an absorbance change at 596nm gradually increased in two phases, but the rate of the fast phase was decreased by approximately 50% of that in the presence of Ca(2+)/CaM. The air-stable semiquinone form was rapidly reduced by NADPH, but a significant absorbance change at 520 nm was not observed. These findings indicate that the conversion of FADH(2)-FMNH(*) to FADH(*)-FMNH(2) is unfavorable. Reduction of the FAD moiety is activated by CaM, but the formation rate of the active intermediate, FADH(*)-FMNH(2) is extremely low. These events could cause a lowering of enzyme activity in the catalytic cycle.
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Affiliation(s)
- Yoshitaka Nishino
- Graduate School of Life Science, Himeji Institute of Technology, University of Hyogo, Kouto 3-2-1, Kamigori, Hyogo 678-1297, Japan
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Haque MM, Panda K, Tejero J, Aulak KS, Fadlalla MA, Mustovich AT, Stuehr DJ. A connecting hinge represses the activity of endothelial nitric oxide synthase. Proc Natl Acad Sci U S A 2007; 104:9254-9. [PMID: 17517617 PMCID: PMC1890481 DOI: 10.1073/pnas.0700332104] [Citation(s) in RCA: 54] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/30/2023] Open
Abstract
In mammals, endothelial nitric oxide synthase (eNOS) has the weakest activity, being one-tenth and one-sixth as active as the inducible NOS (iNOS) and the neuronal NOS (nNOS), respectively. The basis for this weak activity is unclear. We hypothesized that a hinge element that connects the FMN module in the reductase domain but is shorter and of unique composition in eNOS may be involved. To test this hypothesis, we generated an eNOS chimera that contained the nNOS hinge and two mutants that either eliminated (P728IeNOS) or incorporated (I958PnNOS) a proline residue unique to the eNOS hinge. Incorporating the nNOS hinge into eNOS increased NO synthesis activity 4-fold, to an activity two-thirds that of nNOS. It also decreased uncoupled NADPH oxidation, increased the apparent K(m)O(2) for NO synthesis, and caused a faster heme reduction. Eliminating the hinge proline had similar, but lesser, effects. Our findings reveal that the hinge is an important regulator and show that differences in its composition restrict the activity of eNOS relative to other NOS enzymes.
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Affiliation(s)
- Mohammad Mahfuzul Haque
- Department of Pathobiology, Lerner Research Institute, Cleveland Clinic, 9500 Euclid Avenue, Cleveland, OH 44195
| | - Koustubh Panda
- Department of Pathobiology, Lerner Research Institute, Cleveland Clinic, 9500 Euclid Avenue, Cleveland, OH 44195
| | - Jesús Tejero
- Department of Pathobiology, Lerner Research Institute, Cleveland Clinic, 9500 Euclid Avenue, Cleveland, OH 44195
| | - Kulwant S. Aulak
- Department of Pathobiology, Lerner Research Institute, Cleveland Clinic, 9500 Euclid Avenue, Cleveland, OH 44195
| | - Mohammed Adam Fadlalla
- Department of Pathobiology, Lerner Research Institute, Cleveland Clinic, 9500 Euclid Avenue, Cleveland, OH 44195
| | - Anthony T. Mustovich
- Department of Pathobiology, Lerner Research Institute, Cleveland Clinic, 9500 Euclid Avenue, Cleveland, OH 44195
| | - Dennis J. Stuehr
- Department of Pathobiology, Lerner Research Institute, Cleveland Clinic, 9500 Euclid Avenue, Cleveland, OH 44195
- To whom correspondence should be addressed. E-mail:
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Beaumont E, Lambry JC, Gautier C, Robin AC, Gmouh S, Berka V, Tsai AL, Blanchard-Desce M, Slama-Schwok A. Synchronous photoinitiation of endothelial NO synthase activity by a nanotrigger targeted at its NADPH site. J Am Chem Soc 2007; 129:2178-86. [PMID: 17263536 DOI: 10.1021/ja067543e] [Citation(s) in RCA: 22] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
We designed a new nanotrigger to synchronize and monitor an enzymatic activity interacting specifically with the conserved NADPH binding site. The nanotrigger (NT) combines a docking moiety targeting the NADPH site and a chromophore moiety responsive to light excitation for efficient electron transfer to the protein. Specific binding of the nanotrigger to the reductase domain of the endothelial nitric oxide synthase (eNOSred) was demonstrated by competition between NADPH and the nanotrigger on the reduction of eNOSred flavin. A micromolar Ki was estimated. We had monitored initiation of eNOSred activity by ultrafast transient spectroscopy. The transient absorption spectrum recorded at 250 ps fits the expected sum of the reduced and oxidized species, independently obtained by other chemical methods, in agreement with a photoinduced electron transfer from the excited nanotrigger to the flavin moiety of eNOSred. The rate of electron transfer from the excited state of the nanotrigger (NT*) to the protein is estimated to be k(ET) = (7 +/- 2) x 10(9) s(-1) using the decay of oxidized eNOSred-bound nanotrigger compared against prereduced eNOSred or glucose 6-P dehydrogenase as controls. This fast electron transfer bypasses the slow hydride transfer to initiate NOS catalysis as shown by ultrafast kinetics using the eNOSred mutated in the regulatory F1160 residue. The selective targeting of the nanotrigger to NADPH sites should allow controlled initiation of the enzymatic activity of numerous proteins containing an NADPH site.
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Al-Ani B, Hewett PW, Ahmed S, Cudmore M, Fujisawa T, Ahmad S, Ahmed A. The release of nitric oxide from S-nitrosothiols promotes angiogenesis. PLoS One 2006; 1:e25. [PMID: 17183652 PMCID: PMC1762402 DOI: 10.1371/journal.pone.0000025] [Citation(s) in RCA: 23] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/24/2006] [Accepted: 09/25/2006] [Indexed: 02/07/2023] Open
Abstract
Background Free nitric oxide (NO) reacts with sulphydryl residues to form S-nitrosothiols, which act as NO reservoirs. We sought to determine whether thiol-preserving agents and antioxidants, such as dithiothreitol (DTT) and vitamin C, induce NO release from S-nitrosylated proteins in endothelial cell cultures to promote angiogenesis. Methodology/Principal Findings NO release was measured directly in cell supernatants using a Sievers NO Analyser, and in vitro angiogenesis was assessed by quantifying capillary-like tube network formation of porcine aortic endothelial cells (PAEC) on growth factor-reduced Matrigel. Incubation of PAEC with DTT or vitamin C significantly increased NO release in a concentration-dependent manner. However, the nitric oxide synthase (NOS) inhibitors, L-NNA and L-NIO, had no effect on DTT- or vitamin C-induced NO release, and there was no concomitant increase in the phosphorylation of endothelial NOS at serine-1177 following DTT or vitamin C treatment. DTT and vitamin C increased capillary-like tube network formation by nine- and two-fold, respectively, and the addition of copper ions doubled the effect of vitamin C. Surprisingly, DTT maintained endothelial tube networks for up to one month under serum-free conditions, and selective inhibitors of guanylyl cyclase (ODQ) and PKG (KT-5823) blocked this, demonstrating the requirement of cyclic GMP and PKG in this process. Conclusions/Significance Both DTT and vitamin C are capable of releasing sufficient NO from S-nitrosothiols to induce capillary morphogenesis. This study provides the first evidence that increased denitrosylation leads to increased bioavailability of NO, independent of NOS activity, to promote sustained angiogenesis.
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Affiliation(s)
- Bahjat Al-Ani
- Department of Reproductive and Vascular Biology, Centre for Cardiovascular Sciences, Institute of Biomedical Research, Medical School, University of BirminghamBirmingham, United Kingdom
| | - Peter W. Hewett
- Department of Reproductive and Vascular Biology, Centre for Cardiovascular Sciences, Institute of Biomedical Research, Medical School, University of BirminghamBirmingham, United Kingdom
| | - Suborna Ahmed
- Department of Reproductive and Vascular Biology, Centre for Cardiovascular Sciences, Institute of Biomedical Research, Medical School, University of BirminghamBirmingham, United Kingdom
| | - Melissa Cudmore
- Department of Reproductive and Vascular Biology, Centre for Cardiovascular Sciences, Institute of Biomedical Research, Medical School, University of BirminghamBirmingham, United Kingdom
| | - Takeshi Fujisawa
- Department of Reproductive and Vascular Biology, Centre for Cardiovascular Sciences, Institute of Biomedical Research, Medical School, University of BirminghamBirmingham, United Kingdom
| | - Shakil Ahmad
- Department of Reproductive and Vascular Biology, Centre for Cardiovascular Sciences, Institute of Biomedical Research, Medical School, University of BirminghamBirmingham, United Kingdom
| | - Asif Ahmed
- Department of Reproductive and Vascular Biology, Centre for Cardiovascular Sciences, Institute of Biomedical Research, Medical School, University of BirminghamBirmingham, United Kingdom
- Birmingham Women's Hospital NHS TrustBirmingham, United Kingdom
- * To whom correspondence should be addressed. E-mail:
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47
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Ji H, Gómez-Vidal JA, Martásek P, Roman LJ, Silverman RB. Conformationally restricted dipeptide amides as potent and selective neuronal nitric oxide synthase inhibitors. J Med Chem 2006; 49:6254-63. [PMID: 17034131 PMCID: PMC2517862 DOI: 10.1021/jm0604124] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
Four new conformationally restricted analogues of a potent and selective neuronal nitric oxide synthase inhibitor, l-nitroargininyl-l-2,4-diaminobutyramide (1), have been synthesized. N(alpha)-Methyl and N(alpha)-benzyl derivatives (3 and 4, respectively) of 4-N-(l-Arg(NO(2))-trans-4-amino-l-prolineamide (2) are also selective inhibitors, but the potency and selectivity of 3 are weak. Analogue 4 has only one-third the potency and one-half to one-third the selectivity of 2 against iNOS (inducible nitric oxide synthase) and eNOS (endothelial nitric oxide synthase), respectively. 3-N-(l-Arg(NO)(2))-trans-3-amino-l-prolineamide (6) is as potent an inhibitor of nNOS (neuronal nitric oxide synthase) as 2; selectivity for nNOS over iNOS is half of that for 2, but the selectivity for nNOS over eNOS is almost double that for 2. The corresponding cis-isomer (5) is a weak inhibitor of nNOS. These results are supported by computer modeling.
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Affiliation(s)
| | | | | | | | - Richard B. Silverman
- Address correspondence to this author at the Department of Chemistry Phone: 1−847−491−5653
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48
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Omoni AO, Aluko RE. Effect of cationic flaxseed protein hydrolysate fractions on the in vitro structure and activity of calmodulin-dependent endothelial nitric oxide synthase. Mol Nutr Food Res 2006; 50:958-66. [PMID: 16967519 DOI: 10.1002/mnfr.200600041] [Citation(s) in RCA: 39] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/10/2022]
Abstract
The objective of this study was to determine the in vitro effects of cationic flaxseed protein hydrolysate fractions on calmodulin (CaM) structure as well as the activity of CaM-dependent endothelial nitric oxide synthase (eNOS). Flaxseed protein isolate was hydrolyzed with alcalase, and two peptide fractions were isolated by cation-exchange chromatography. Fraction I, eluted first from the column, and fraction II contained 42% and 51% contents of basic amino acids, respectively. Fractions I and II reduced the activity of CaM-dependent eNOS through a mostly mixed-type inhibition mode. Fraction II was at least ten times more effective as an eNOS inhibitor when compared to fraction I, as evident from the IC(50) (concentration of protein hydrolysate that reduced eNOS activity by 50%) values. Fluorescence spectroscopy showed that the tyrosine residues in CaM were increasingly exposed upon addition of fraction I, while the opposite was the case when fraction II was added. Circular dichroism studies showed that fractions I and II reduced the alpha-helix content but increased the rigidity of the active calcium/CaM complex. We concluded that ability of the protein hydrolysate fractions to change the secondary and tertiary structures of CaM may explain their ability to reduce activity of CaM-dependent eNOS.
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Affiliation(s)
- Adetayo O Omoni
- Department of Human Nutritional Sciences, University of Manitoba, Winnipeg, Manitoba, Canada
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Komers R, Schutzer WE, Reed JF, Lindsley JN, Oyama TT, Buck DC, Mader SL, Anderson S. Altered endothelial nitric oxide synthase targeting and conformation and caveolin-1 expression in the diabetic kidney. Diabetes 2006; 55:1651-9. [PMID: 16731827 DOI: 10.2337/db05-1595] [Citation(s) in RCA: 67] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/31/2022]
Abstract
Experimental diabetes is associated with complex changes in renal nitric oxide (NO) bioavailability. We explored the effect of diabetes on renal cortical protein expression of endothelial NO synthase (eNOS) with respect to several determinants of its enzymatic function, such as eNOS expression, membrane localization, phosphorylation, and dimerization, in moderately hyperglycemic streptozotocin-induced diabetic rats compared with nondiabetic control rats and diabetic rats with intensive insulin treatment to achieve near-normal metabolic control. We studied renal cortical expression and localization of caveolin-1 (CAV-1), an endogenous modulator of eNOS function. Despite similar whole-cell eNOS expression in all groups, eNOS monomer and dimer in membrane fractions were reduced in moderately hyperglycemic diabetic rats compared with control rats; the opposite trend was apparent in the cytosol. Stimulatory phosphorylation of eNOS (Ser1177) was also reduced in moderately hyperglycemic diabetic rats. eNOS colocalized and interacted with CAV-1 in endothelial cells throughout the renal vascular tree both in control and moderately hyperglycemic diabetic rats. However, the abundance of membrane-localized CAV-1 was decreased in diabetic kidneys. Intensive insulin treatment reversed the effects of diabetes on each of these parameters. In summary, we observed diabetes-mediated alterations in eNOS and CAV-1 expression that are consistent with the view of decreased bioavailability of renal eNOS-derived NO.
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Affiliation(s)
- Radko Komers
- Division of NephrologyHypertension PP262, Oregon Health and Science University, 3314 SW US Veterans Hospital Rd., Portland, OR 97239, USA.
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Whitsett J, Martásek P, Zhao H, Schauer DW, Hatakeyama K, Kalyanaraman B, Vásquez-Vivar J. Endothelial cell superoxide anion radical generation is not dependent on endothelial nitric oxide synthase-serine 1179 phosphorylation and endothelial nitric oxide synthase dimer/monomer distribution. Free Radic Biol Med 2006; 40:2056-68. [PMID: 16716906 DOI: 10.1016/j.freeradbiomed.2006.02.001] [Citation(s) in RCA: 32] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/10/2005] [Revised: 01/29/2006] [Accepted: 02/01/2006] [Indexed: 11/29/2022]
Abstract
Tetrahydrobiopterin (BH4) and heat shock protein 90 (hsp90) have been anticipated to regulate endothelial nitric oxide synthase (eNOS)-dependent superoxide anion radical (O2*-) generation in endothelial cells. It is not known, however, whether hsp90 and BH4 increase O2*- in a synergistic manner, or whether this increase is a consequence of downstream changes in eNOS phosphorylation on serine 1179 (eNOS-S1179) and changes in dimer/monomer distribution. Here O2*- production from purified BH4 -free eNOS and eNOS:hsp90 complexes determined by spin-trapping methodology showed that hsp90 neither inhibits O2*- nor alters the requirement of BH4 to inhibit radical release from eNOS. In endothelial cells, O2*- detection with the novel high-performance liquid chromatography assay of 2-hydroxyethidium showed that inhibition of hsp90 did not increase O2*-, while a significant increase in O2*- was detected in BH4 -depleted cells. Radicicol, a hsp90 inhibitor, disrupted eNOS:hsp90 association, decreased eNOS-S1179, but increased biopterin production in a dose-dependent fashion. These changes were followed by an increase in eNOS activity, demonstrating that high biopterin levels offset inhibition of eNOS phosphorylation and diminished interaction with hsp90. In contrast, depletion of biopterin did not affect hsp90 levels or interaction with eNOS or eNOS dimer/monomer ratio in bovine aorta endothelial cells (BAECs). We conclude that low BH4 but not inhibition of hsp90 increases O2*- in BAECs by mechanism(s) that unlikely involve phosphorylation to eNOS-S1179 or eNOS monomerization.
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Affiliation(s)
- Jennifer Whitsett
- Department of Biophysics, Medical College of Wisconsin, Milwaukee, WI 53226, USA
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