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Liu CC, Karimi Galougahi K, Weisbrod RM, Hansen T, Ravaie R, Nunez A, Liu YB, Fry N, Garcia A, Hamilton EJ, Sweadner KJ, Cohen RA, Figtree GA. Oxidative inhibition of the vascular Na+-K+ pump via NADPH oxidase-dependent β1-subunit glutathionylation: implications for angiotensin II-induced vascular dysfunction. Free Radic Biol Med 2013; 65:563-572. [PMID: 23816524 PMCID: PMC4474148 DOI: 10.1016/j.freeradbiomed.2013.06.040] [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] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/31/2013] [Revised: 06/21/2013] [Accepted: 06/21/2013] [Indexed: 02/07/2023]
Abstract
Glutathionylation of the Na(+)-K(+) pump's β1-subunit is a key molecular mechanism of physiological and pathophysiological pump inhibition in cardiac myocytes. Its contribution to Na(+)-K(+) pump regulation in other tissues is unknown, and cannot be assumed given the dependence on specific β-subunit isoform expression and receptor-coupled pathways. As Na(+)-K(+) pump activity is an important determinant of vascular tone through effects on [Ca(2+)]i, we have examined the role of oxidative regulation of the Na(+)-K(+) pump in mediating angiotensin II (Ang II)-induced increases in vascular reactivity. β1-subunit glutathione adducts were present at baseline and increased by exposure to Ang II in rabbit aortic rings, primary rabbit aortic vascular smooth muscle cells (VSMCs), and human arterial segments. In VSMCs, Ang II-induced glutathionylation was associated with marked reduction in Na(+)-K(+)ATPase activity, an effect that was abolished by the NADPH oxidase inhibitory peptide, tat-gp91ds. In aortic segments, Ang II-induced glutathionylation was associated with decreased K(+)-induced vasorelaxation, a validated index of pump activity. Ang II-induced oxidative inhibition of Na(+)-K(+) ATPase and decrease in K(+)-induced relaxation were reversed by preincubation of VSMCs and rings with recombinant FXYD3 protein that is known to facilitate deglutathionylation of β1-subunit. Knock-out of FXYD1 dramatically decreased K(+)-induced relaxation in a mouse model. Attenuation of Ang II signaling in vivo by captopril (8 mg/kg/day for 7 days) decreased superoxide-sensitive DHE levels in the media of rabbit aorta, decreased β1-subunit glutathionylation, and enhanced K(+)-induced vasorelaxation. Ang II inhibits the Na(+)-K(+) pump in VSMCs via NADPH oxidase-dependent glutathionylation of the pump's β1-subunit, and this newly identified signaling pathway may contribute to altered vascular tone. FXYD proteins reduce oxidative inhibition of the Na(+)-K(+) pump and may have an important protective role in the vasculature under conditions of oxidative stress.
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Affiliation(s)
- Chia-Chi Liu
- North Shore Heart Research Group, Kolling Institute of Medical Research, University of Sydney, Australia
| | - Keyvan Karimi Galougahi
- North Shore Heart Research Group, Kolling Institute of Medical Research, University of Sydney, Australia; Department of Cardiology, Royal North Shore Hospital, Sydney, Australia
| | - Robert M Weisbrod
- Vascular Biology Section, Department of Medicine, Whitaker Cardiovascular Institute, Boston University School of Medicine, Boston, MA, USA
| | - Thomas Hansen
- North Shore Heart Research Group, Kolling Institute of Medical Research, University of Sydney, Australia
| | - Ramtin Ravaie
- North Shore Heart Research Group, Kolling Institute of Medical Research, University of Sydney, Australia
| | - Andrea Nunez
- North Shore Heart Research Group, Kolling Institute of Medical Research, University of Sydney, Australia
| | - Yi B Liu
- Laboratory Membrane Biology, Massachusetts General Hospital, Boston, MA, USA
| | - Natasha Fry
- North Shore Heart Research Group, Kolling Institute of Medical Research, University of Sydney, Australia
| | - Alvaro Garcia
- North Shore Heart Research Group, Kolling Institute of Medical Research, University of Sydney, Australia
| | - Elisha J Hamilton
- North Shore Heart Research Group, Kolling Institute of Medical Research, University of Sydney, Australia
| | - Kathleen J Sweadner
- Laboratory Membrane Biology, Massachusetts General Hospital, Boston, MA, USA
| | - Richard A Cohen
- Vascular Biology Section, Department of Medicine, Whitaker Cardiovascular Institute, Boston University School of Medicine, Boston, MA, USA
| | - Gemma A Figtree
- North Shore Heart Research Group, Kolling Institute of Medical Research, University of Sydney, Australia; Department of Cardiology, Royal North Shore Hospital, Sydney, Australia.
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