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Sowers JR, Habibi J, Aroor AR, Yang Y, Lastra G, Hill MA, Whaley-Connell A, Jaisser F, Jia G. Epithelial sodium channels in endothelial cells mediate diet-induced endothelium stiffness and impaired vascular relaxation in obese female mice. Metabolism 2019; 99:57-66. [PMID: 31302199 PMCID: PMC6901094 DOI: 10.1016/j.metabol.2019.153946] [Citation(s) in RCA: 36] [Impact Index Per Article: 7.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/08/2019] [Accepted: 07/10/2019] [Indexed: 12/15/2022]
Abstract
OBJECTIVE Mineralocorticoid receptor activation of the epithelial sodium channel in endothelial cells (ECs) (EnNaC) is accompanied by aldosterone induced endothelial stiffening and impaired nitric oxide (NO)-mediated arterial relaxation. Recent data support enhanced activity of the alpha subunit of EnNaC (αEnNaC) mediates this aldosterone induced endothelial stiffening and associated endothelial NO synthase (eNOS) activation. There is mounting evidence that diet induced obesity diminishes expression and activation of AMP-activated protein kinase α (AMPKα), sirtuin 1 (Sirt1), which would be expected to lead to impaired downstream eNOS activation. Thereby, we posited that enhanced EnNaC activation contributes to diet induced obesity related increases in stiffness of the endothelium and diminished NO mediated vascular relaxation by increasing oxidative stress and related inhibition of AMPKα, Sirt1, and associated eNOS inactivation. MATERIALS/METHODS Sixteen to twenty week-old αEnNaC knockout (αEnNaC-/-) and wild type littermate (EnNaC+/+) female mice were fed a mouse chow or an obesogenic western diet (WD) containing excess fat (46%) and fructose (17.5%) for 16 weeks. Sodium currents of ECs, endothelial stiffness and NO mediated aortic relaxation were examined along with indices of aortic oxidative stress, vascular remodeling and fibrosis. RESULTS Enhanced EnNaC activation-mediated WD-induced increases in sodium currents in isolated lung ECs, increased endothelial stiffness and impaired aortic endothelium-dependent relaxation to acetylcholine (10-9-10-4 mol/L). These abnormalities occurred in conjunction with WD-mediated aortic tissue oxidative stress, inflammation, and decreased activation of AMPKα, Sirt1, and downstream eNOS were substantially mitigated in αEnNaC-/- mice. Importantly, αEnNaC-/- prevented WD induced increases in endothelial stiffness and related impairment of endothelium-dependent relaxation as well as aortic fibrosis and remodeling. However, EnNaC signaling was not involved in diet-induced abnormal expression of adipokines and CYP11b2 in abdominal aortic perivascular adipose tissue. CONCLUSION These data suggest that endothelial specific EnNaC activation mediates WD-induced endothelial stiffness, impaired eNOS activation, aortic fibrosis and remodeling through increased aortic oxidative stress and increased inflammation related to a reduction of AMPKα and Sirt 1 mediated eNOS phosphorylation/activation and NO production.
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Affiliation(s)
- James R Sowers
- Diabetes and Cardiovascular Center, University of Missouri School of Medicine, Columbia, MO 65212, USA; Research Service, Harry S Truman Memorial Veterans Hospital, 800 Hospital Dr, Columbia, MO 65201, USA; Dalton Cardiovascular Research Center, University of Missouri, Columbia, MO 65212, USA; Department of Medical Pharmacology and Physiology, University of Missouri School of Medicine, Columbia, MO 65212, USA
| | - Javad Habibi
- Diabetes and Cardiovascular Center, University of Missouri School of Medicine, Columbia, MO 65212, USA; Research Service, Harry S Truman Memorial Veterans Hospital, 800 Hospital Dr, Columbia, MO 65201, USA
| | - Annayya R Aroor
- Diabetes and Cardiovascular Center, University of Missouri School of Medicine, Columbia, MO 65212, USA; Research Service, Harry S Truman Memorial Veterans Hospital, 800 Hospital Dr, Columbia, MO 65201, USA
| | - Yan Yang
- Dalton Cardiovascular Research Center, University of Missouri, Columbia, MO 65212, USA
| | - Guido Lastra
- Diabetes and Cardiovascular Center, University of Missouri School of Medicine, Columbia, MO 65212, USA; Research Service, Harry S Truman Memorial Veterans Hospital, 800 Hospital Dr, Columbia, MO 65201, USA
| | - Michael A Hill
- Dalton Cardiovascular Research Center, University of Missouri, Columbia, MO 65212, USA; Department of Medical Pharmacology and Physiology, University of Missouri School of Medicine, Columbia, MO 65212, USA
| | - Adam Whaley-Connell
- Diabetes and Cardiovascular Center, University of Missouri School of Medicine, Columbia, MO 65212, USA; Research Service, Harry S Truman Memorial Veterans Hospital, 800 Hospital Dr, Columbia, MO 65201, USA; Department of Medicine, University of Missouri School of Medicine, Columbia, MO 65212, USA
| | - Frederic Jaisser
- INSERM, UMRS 1138, Cordeliers Research Center, Sorbonne University, USPC, Université Paris Descartes, Université Paris Diderot, F-75006 Paris, France
| | - Guanghong Jia
- Diabetes and Cardiovascular Center, University of Missouri School of Medicine, Columbia, MO 65212, USA; Research Service, Harry S Truman Memorial Veterans Hospital, 800 Hospital Dr, Columbia, MO 65201, USA; Dalton Cardiovascular Research Center, University of Missouri, Columbia, MO 65212, USA; Department of Medicine, University of Missouri School of Medicine, Columbia, MO 65212, USA.
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