Publication Date:
2010-12-24
Description:
Endothelial nitric oxide synthase (eNOS) is critical in the regulation of vascular function, and can generate both nitric oxide (NO) and superoxide (O(2)(*-)), which are key mediators of cellular signalling. In the presence of Ca(2+)/calmodulin, eNOS produces NO, endothelial-derived relaxing factor, from l-arginine (l-Arg) by means of electron transfer from NADPH through a flavin containing reductase domain to oxygen bound at the haem of an oxygenase domain, which also contains binding sites for tetrahydrobiopterin (BH(4)) and l-Arg. In the absence of BH(4), NO synthesis is abrogated and instead O(2)(*-) is generated. While NOS dysfunction occurs in diseases with redox stress, BH(4) repletion only partly restores NOS activity and NOS-dependent vasodilation. This suggests that there is an as yet unidentified redox-regulated mechanism controlling NOS function. Protein thiols can undergo S-glutathionylation, a reversible protein modification involved in cellular signalling and adaptation. Under oxidative stress, S-glutathionylation occurs through thiol-disulphide exchange with oxidized glutathione or reaction of oxidant-induced protein thiyl radicals with reduced glutathione. Cysteine residues are critical for the maintenance of eNOS function; we therefore speculated that oxidative stress could alter eNOS activity through S-glutathionylation. Here we show that S-glutathionylation of eNOS reversibly decreases NOS activity with an increase in O(2)(*-) generation primarily from the reductase, in which two highly conserved cysteine residues are identified as sites of S-glutathionylation and found to be critical for redox-regulation of eNOS function. We show that eNOS S-glutathionylation in endothelial cells, with loss of NO and gain of O(2)(*-) generation, is associated with impaired endothelium-dependent vasodilation. In hypertensive vessels, eNOS S-glutathionylation is increased with impaired endothelium-dependent vasodilation that is restored by thiol-specific reducing agents, which reverse this S-glutathionylation. Thus, S-glutathionylation of eNOS is a pivotal switch providing redox regulation of cellular signalling, endothelial function and vascular tone.〈br /〉〈br /〉〈a href="https://www.ncbi.nlm.nih.gov/pmc/articles/PMC3370391/" target="_blank"〉〈img src="https://static.pubmed.gov/portal/portal3rc.fcgi/4089621/img/3977009" border="0"〉〈/a〉 〈a href="https://www.ncbi.nlm.nih.gov/pmc/articles/PMC3370391/" target="_blank"〉This paper as free author manuscript - peer-reviewed and accepted for publication〈/a〉〈br /〉〈br /〉〈span class="detail_caption"〉Notes: 〈/span〉Chen, Chun-An -- Wang, Tse-Yao -- Varadharaj, Saradhadevi -- Reyes, Levy A -- Hemann, Craig -- Talukder, M A Hassan -- Chen, Yeong-Renn -- Druhan, Lawrence J -- Zweier, Jay L -- K99 HL103846/HL/NHLBI NIH HHS/ -- K99 HL103846-02/HL/NHLBI NIH HHS/ -- R01 HL038324/HL/NHLBI NIH HHS/ -- R01 HL038324-20/HL/NHLBI NIH HHS/ -- R01 HL063744/HL/NHLBI NIH HHS/ -- R01 HL063744-09/HL/NHLBI NIH HHS/ -- R01HL103846/HL/NHLBI NIH HHS/ -- R01HL38324/HL/NHLBI NIH HHS/ -- R01HL63744/HL/NHLBI NIH HHS/ -- R01HL65608/HL/NHLBI NIH HHS/ -- R01HL83237/HL/NHLBI NIH HHS/ -- England -- Nature. 2010 Dec 23;468(7327):1115-8. doi: 10.1038/nature09599.〈br /〉〈span class="detail_caption"〉Author address: 〈/span〉Davis Heart and Lung Research Institute and Division of Cardiovascular Medicine, Department of Internal Medicine, College of Medicine, Ohio State University, Columbus, Ohio 43210, USA.〈br /〉〈span class="detail_caption"〉Record origin:〈/span〉 〈a href="http://www.ncbi.nlm.nih.gov/pubmed/21179168" target="_blank"〉PubMed〈/a〉
Keywords:
Animals
;
Cattle
;
Cells, Cultured
;
Dithiothreitol/pharmacology
;
Endothelial Cells/metabolism
;
Endothelium, Vascular/*metabolism
;
Glutathione/*metabolism
;
Humans
;
Male
;
Mercaptoethanol/pharmacology
;
Mutation
;
Nitric Oxide Synthase Type III/genetics/*metabolism
;
Oxidation-Reduction
;
Rats
;
Rats, Inbred SHR
;
Rats, Inbred WKY
;
Rats, Sprague-Dawley
;
Reducing Agents/pharmacology
;
Signal Transduction
;
Vasodilation/physiology
Print ISSN:
0028-0836
Electronic ISSN:
1476-4687
Topics:
Biology
,
Chemistry and Pharmacology
,
Medicine
,
Natural Sciences in General
,
Physics
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